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Found 172 structures.
Displayed structures from 1 to 15
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Structure type: oligomer
Trivial name: 1-kestose, inulin
Compound class: fructan, fructo-oligosaccharide
Contained glycoepitopes: IEDB_142488,IEDB_144998,IEDB_146664,IEDB_983931,SB_192
Major fructo-oligosaccharides (FOS) produced by levansucrase (EC 2.4.1.10) from Acetobacter diazotrophicus SRT4 were characterised as 1-kestose and nystose by acid hydrolysis and 13C NMR spectroscopy. The highest yields of 1-kestose (481 mM; 241 g/l) and nystose (81 mM; 54 g/l) were achieved at initial sucrose concentration of 1754 mM (600 g/l), pH 5.5 and 40 C. The synthesized FOS reached 50% (w/w) of total sugars in the reaction mixture, with a conversion efficiency over 70% (w/w) based on the amount of sucrose converted to 1-kestose.
oligosaccharide, structural, analysis, Oligosaccharides, structural analysis, production, 1-kestose, Acetobacter, Acetobacter diazotrophicus, fructo-oligosaccharides, levansucrase, LsdA
Journal NLM ID: 8008051Worldwide interest in oligosaccharides has been increasing ever since they were accorded the prebiotic status. The oligosaccharides of various origin like, bacteria, algae, fungi and higher plants have been used extensively both as food ingredients and pharmacological supplements. The non-digestible oligosaccharides have been implicated as dietary fibre, sweetener, weight controlling agent and humectant in confectioneries, bakeries and breweries. Functional oligosaccharides have been found effective in gastrointestinal normal flora proliferation and pathogen suppression, dental caries prevention, enhancement of immunity, facilitation of mineral absorption, source of antioxidant, antibiotic alternative, regulators of blood glucose in diabetics and serum lipids in hyperlipidemics. Apart from the pharmacological applications, oligosaccharides have found use in drug delivery, cosmetics, animal and fishery feed, agriculture, etc. Keeping in view the importance of the functional oligosaccharides, we present an overview of their natural sources, types, structures, physiological properties. Conventional as well as novel synthesis, purification and analysis methods are summarized. Recent promising developments in this area are presented to facilitate their further exploitation.
Oligosaccharides, microbiota, probiotics, Functional food, Prebiotics
Publication DOI: 10.1007/s11274-010-0558-5Aspergillus phoenicis biofilms on polyethylene as inert support were used to produce fructooligosaccharides (FOS) in media containing 25 % (m/V) of sucrose as a carbon source. The maximum production of total FOS (122 mg/mL), with 68 % of 1-kestose and 32 % of nystose, was obtained in Khanna medium maintained at 30 °C for 48 h under orbital agitation (100 rpm). At high concentrations of sucrose (30 %, m/V), the recovery of FOS was higher than that observed at a low concentration (5 %, m/V). High levels of FOS (242 mg/mL) were also recovered when using the biofilm in sodium acetate buffer with high sucrose concentration (50 %, m/V) for 10 h. When the dried biofilm was reused in a fresh culture medium, there was a recovery of approx. 13.7 % of total FOS after 72 h of cultivation at 30 °C, and 10 % corresponded to 1-kestose. The biofilm morphology, analyzed by scanning electron microscope, revealed a noncompact mycelium structure, with unfilled spaces and channels present among the hyphae. The results obtained in this study show that A. phoenicis biofilms may find application for FOS production in a single-step fermentation process, which is cost-effective in terms of reusability, downstream processing and efficiency.
Biofilm, fructooligosaccharides, Aspergillus sp., kestose, nystose
Journal NLM ID: 9703690In this study, the kinetic for the bioconversion of sucrose to fructooligosaccharides (FOS) by free cells of Aspergillus oryzae N74 was modeled. In addition, the effect of immobilized glucose isomerase (IGI) on FOS production yield was evaluated and considered in the kinetic model. The selected kinetic models were based on a proposed reaction mechanism described by elementary rate equations and modified Michaelis-Menten kinetic equations. The use of IGI allowed to increase the FOS production yield (FOS Yield) and to decrease the glucose/fructose (G/F) ratio. At shake flask scale, the FOS Yield was increased in 4.7 % (final yield 58.3 %), while the G/F ratio was reduced 6.2-fold. At bench scale, the FOS Yield was increased in 2.2 % (final yield 57.3 %), while the G/F ratio was reduced 4.5-fold. The elementary rate equation model was the one that best adjusted experimental data for FOS production using either the fungus biomass or the mixture fungus biomass-IGI, with an overall average percentage error of 7.2. Despite that FOS production yield was not highly improved by the presence of IGI in the reaction mixture, it favored the reduction of residual glucose in the mixture, avoiding the loss of material owe to glucose transformation to fructose that can be used in situ for FOS production by the fructosyltransferase.
fructooligosaccharides, Aspergillus oryzae, fructosyltransferase, immobilized glucose isomerase
NCBI PubMed ID: 22528647Fructooligosaccharides are prebiotics with numerous health benefits within which the improvement of gut microbiota balance can be highlighted, playing a key role in individual health. In this study, an integrated one-stage method for FOS production via sucrose fermentation by Aureobasidium pullulans was developed and optimized using experimental design tools. Optimization of temperature and agitation speed for maximizing the FOS production was performed using response surface methodology. Temperature was found to be the most significant parameter. The optimum fermentation conditions were found to be 32°C and 385 rpm. Under these conditions, the model predicted a total FOS production yield of 64.7 g FOS/g sucrose. The model was validated at optimal conditions in order to check its adequacy and accuracy and an experimental yield of 64.1 (±0.0) g FOS/g sucrose was obtained. A significant improvement of the total FOS production yields by A. pullulans using a one-stage process was obtained.
response surface methodology, Aureobasidium pullulans, fructooligosaccharides, transfructosylation, one-stage fermentation process, product yield
NCBI PubMed ID: 24750929A great demand for prebiotics is driving the search for new sources of fructo-oligosaccharides (FOS) producers and for FOS with differentiated functionalities. In the present work, FOS production by a new isolated strain of Aspergillus ibericus was evaluated. The temperature of fermentation and initial pH were optimized in shaken flask to yield a maximal FOS production, through a central composite experimental design. FOS were produced in a one-step bioprocess using the whole cells of the microorganism. The model (R2 = 0.918) predicted a yield of 0.56, experimentally 0.53 ± 0.03 gFOS.ginitial sucrose −1 was obtained (37.0 °C and a pH of 6.2). A yield of 0.64 ± 0.02 gFOS.ginitial sucrose−1 was obtained in the bioreactor, at 38 h, with a content of 118 ± 4 g.L−1 in FOS and a purity of 56 ± 3%. The chemical structure of the FOS produced by A. ibericus was determined by HPLC and NMR. FOS were identified as 1-kestose, nystose, and 1F-fructofuranosylnystose. In conclusion, A. ibericus was found to be a good alternative FOS producer.
chemical structure, fructo-oligosaccharides, experimental design, Aspergillus ibericus, production yield optimization
Publication DOI: 10.1016/j.lwt.2017.10.015The bifidogenic potential of fructo-oligosaccharides (FOS) produced by a newly isolated strain Aspergillus ibericus was studied. Their activity was compared to FOS produced by Aureobasidium pullulans and to a non microbial commercial FOS sample (Raftilose(center dot) P95). FOS fermentability by a number of probiotic bacteria and their hydrolytic resistance to the simulated harsh conditions of the digestive system was evaluated. Aspergillus ibericus FOS sample effectively promoted probiotic bacteria growth. Overall, microbial-derived FOS promoted greater cellular growth compared to the commercial sample. FOS fermentation was both substrate and strain specific. The FOS structural differences identified may explain their distinct assimilation by the probiotics. [Fru(2→6)Glc] (possibly blastose) and a reducing trisaccharide (possibly [Fru(β2→6)Glc(α1<->β2)Fru], neokestose) were only found in microbial-derived FOS samples, while Raftilosee(center dot) P95 was richer in inulobiose/inulotriose. 1-Kestose and nystose were only slightly hydrolyzed in the presence of gastric and intestinal fluid. FOS synthesized by Aspergillus exhibited great potential as food ingredients with likely prebiotic features.
fructo-oligosaccharides, probiotic, Prebiotics, Aspergillus, glycosidic linkage analysis, neoFOS
Publication DOI: 10.1016/j.jff.2018.05.004Studies on endo-inulinases from yeast are scarce, compared to those from other microbial sources. In this study, a novel endo-inulinase from Lipomyces starkeyi NRRL Y-11557 was identified, expressed in its soluble form, and characterized its physicochemically properties, together with its enzymatic activity and production of fructooligosaccharides (FOSs). A putative endo-inulinase gene inu3 was identified through rational genome mining. Through enzymatic activity and SDS-PAGE analysis, the endo-inulinase putative function of the protein encoded by inu3B gene (INU3B) was confirmed, and its soluble expression was achieved with pET22b (+) in Escherichia coli. INU3B showed effective catalytic activity and high thermostability. To our knowledge, the specific activity of INU3B against inulin reported in this study, 2262.8 ± 82.3 U/mg, at 70 °C and pH 5.0-6.0, is the highest reported to date. When the enzyme catalyzed FOSs production, the main products were DP3, DP4 and DP5. Overall, this report describes a novel yeast-derived endo-inulinase with optimal enzymatic properties, and thus, the reported enzyme has great potential for industrial production of FOSs.
fructooligosaccharides, endo-inulinase, Lipomyces starkeyi, rational genome mining, soluble expression
NCBI PubMed ID: 31233793An efficient system for biotransformation of sucrose to fructooligosaccharides (FOS) was obtained using Aspergillus tamarii NKRC 1229 mycelial fructosyltransferase (m-FTase). Zymographic analysis confirmed mycelial localization of the FTase (36 U/g) and lyophilized fungal pellets were used for bioconversion. m-FTase had molecular weight ~75 kDa with optimum activity at pH 7.0 and 20 °C. FOS production after parametric optimization (sucrose - 50% w/v, m-FTase dose - 4.5% w/v, inoculum age - 48 h and incubation time - 24 h) reached 325 g/L (55% yield) with 14% residual sucrose, 25% glucose and 6% fructose. FTase activity was enhanced after pre-treatment with organic solvents and SDS. FOS was purified in a single step using gel filtration matrix, Bio-Gel P2. FOS was characterized using Diffusion ordered spectroscopy-Nuclear Magnetic Resonance (1H DOSY-NMR) and Fourier-transform infrared spectroscopy (FTIR). Continuous generation of FOS was achieved using recyclable mycelia upto 10 consecutive cycles.
Prebiotics, Aspergillus, fructooligosaccharides (FOS), fructosyltransferase (FTase), zymography, Bio-Gel P2
NCBI PubMed ID: 30827630Starting from a relatively detailed model of a bioprocess producing fructo-oligosaccharides, a set of experimental data collected in batch and fed-batch experiments is exploited to estimate the unknown model parameters. The original model includes the growth of the fungus Aureobasidium pullulans which produces the enzymes responsible for the hydrolysis and transfructosylation reactions, and as such contains 25 kinetic parameters and 16 pseudo-stoichiometric coefficients, which are not uniquely identifiable with the data at hand. The aim of this study is, therefore, to show how sensitivity analysis and quantitative indicators based on the Fisher information matrix can be used to reduce the detailed model to a practically identifiable model. Parametric sensitivity analysis can indeed be used to progressively simplify the model to a representation involving 15 kinetic parameters and 8 pseudo-stoichiometric coefficients. The reduced model provides satisfactory prediction and can be convincingly cross validated.
biotechnology, mathematical modeling, Fisher information matrix, parameter identification
NCBI PubMed ID: 31375963Fructooligosaccharides (FOS) are important ingredients in the functional food industry because they have different biological properties such as decrease level of triglycerides, cholesterol and phospholipids and stimulate growth of probiotics for enhancement of microflora in large intestine. However, current strategies for the FOS production through simple and economical bioprocess has been necessary. The aim of this work was evaluated the capacity of three fungal strains (Aspergillus niger GH1, Aspergillus niger PSH and Aspergillus oryzae DIA-MF) to produce fructooligosaccharides (FOS) using aguamiel from Agave salmiana as an economical substrate. In addition, Czapek Dox medium supplemented with sucrose as carbon source was used as a control medium for the FOS production. A. oryzae DIA-MF was a fungi producer of FOS using aguamiel or Czapek Dox medium as substrate at 24 h of fermentation. However, the yield of FOS was increased two folds (20.30 g/L), with a productivity of 0.84 g FOS/l/h when aguamiel was used as substrate. On the other hand, A. niger GH1 and A. niger PSH showing only hydrolytic activity on sucrose under the studied conditions. In conclusion, this study shown excellent compatibility of A. oryzae DIA-MF using aguamiel as an economical substrate for the FOS production under a simple bioprocess.
Aspergillus, submerged fermentation, fructooligosaccharides (FOS), aguamiel
Publication DOI: 10.1016/j.lwt.2018.12.020The β-fructofuranosidase Ffase from the yeast Schwanniomyces occidentalis produces potential prebiotic fructooligosaccharides with health-promoting properties, making it of biotechnological interest. Ffase is one of the highest and more selective known producers of 6-kestose by transfructosylation of sucrose. In this work, production of 6-kestose was simplified by directly using cultures of S. occidentalis and Saccharomyces cerevisiae expressing both the wild-type enzyme and a mutated Ffase variant including the Ser196Leu substitution (Ffase-Leu196). Best results were obtained using yeast cultures supplemented with sucrose and expressing the Ffase-Leu196, which after only 4 h produced ~ 116 g/L of 6-kestose, twice the amount obtained with the corresponding purified enzyme. 6-Kestose represented ~ 70% of the products synthesized. In addition, a small amount of 1-kestose and the neofructoligosaccharides neokestose and blastose were also produced. The Ser196Leu substitution skewed production of 6-kestose and neofructooligosaccharides resulting in an increase of ~ 2.2- and 1.5-fold, respectively, without affecting production of 1-kestose. Supplementing yeast cultures with glucose clearly showed that blastose originates from direct fructosylation of glucose, a property that has not been described for other similar proteins from yeasts. Modeling neokestose and blastose into the Ffase-active site revealed the molecular basis explaining the peculiar specificity of this enzyme.
β-fructofuranosidase, 6-kestose, blastose, prebiotic sugars, Schwanniomyces occidentalis, yeast cultures
NCBI PubMed ID: 30357454Aspergillus thermomutatus produces an extracellular β-D-fructofuranosidase when cultured in Khanna medium with sucrose as additional carbon source at 30°C under agitation for 72 hr. Addition of glucose and fructose in the culture medium affected the production of the enzyme negatively. The optimum hydrolytic activity was achieved at 60°C and pH 5.0, with half-life (T50) of 30 hr at 50°C and 62% of its activity maintained at pH 5.0 for 48 hr. The extracellular extract containing β-D-fructofuranosidase was effective in producing fructooligosaccharides (FOS), mainly 1-kestose. The highest concentration of FOS was obtained at 30°C and 60°C, indicating the existence of at least two enzymes with transfructosylating activity. At 30°C, the maximal FOS concentration was obtained from 48 to 72 hr, while at 60°C, it was achieved only at 72 hr. The best production of FOS (86.7 g/L) was obtained using 500 g/L sucrose as substrate.
Aspergillus, fructooligosaccharide, transfructosylating, β-D-fructofuranosidase
NCBI PubMed ID: 31368547Fructooligosaccharides (FOS) are fructose-based oligosaccharides employed as additives to improve the nutritional and technological properties of foods. The rhizosphere of inulin-accumulating plants from the Cerrado (Brazilian savanna) harbor fungi capable of synthesizing FOS from sucrose through the transfructosylating activity of β-fructosyltransferases and/or β-fructofuranosidases. Here, we investigated the ability of Penicillium janczewskii Zaleski CCIBt 3352, a fungus isolated from the rhizosphere of Chrysolaena obovata (Asteraceae), to produce FOS in a medium supplemented with sucrose concentrations of 30, 100, or 150 g/L . Hydrolytic activity on sucrose was observed in culture filtrates; however, at 150 g/L sucrose, the accumulation of 8 g/L 1-kestose (inulin-type FOS) and 7.3 g/L neokestose (neolevan-type FOS) was observed, the latter being a type of FOS not commonly produced by filamentous fungi. In addition, minor amounts of four unidentified oligosaccharides, with a high degree of polymerization, were detected. The production of FOS was also observed in enzymatic assays, indicating the presence of extracellular enzymes with transfructosylating activity in the culture filtrates. Our findings demonstrate the feasibility of isolating promising microorganisms, for the production of FOS-synthesizing enzymes, from the rhizosphere of fructan-producing plants of the Brazilian Cerrado.
inulin, prebiotic, invertase, transfructosylation, fructans, soluble fiber
NCBI PubMed ID: 30758071Fructooligosaccharides (FOS) are commonly regarded as prebiotics and used as components of functional foods. Currently, the industrial sucrose-to-FOS biotransformation is mainly carried out using the microbial-derived β-fructofuranosidases with transglycosylation activity as catalysts. Evaluation of the ability of a microorganism to produce β-fructofuranosidase is commonly conducted by measuring enzyme activity. However, the traditional method requires several steps to identify strains with high β-fructofuranosidase activity, which is not suitable for high-throughput screening. To facilitate screening of a large number of microbial cultures, this study developed a plate chromogenic assay method based on the glucose oxidase (GOD) - peroxidase (POD) bienzymatic system for screening of β-fructofuranosidase-producing fungal strains and predicting their potential to produce FOS. This method used the amount of glucose released from sucrose as indicator to form clear pink halos around the microbial colonies with β-fructofuranosidase activity. Cultivation conditions for the plate assay were optimized as cultivation time 5 h and spore inoculum concentration 100000000 1/ml. Moreover, the method was applied to screening of an Aspergillus niger ATCC 20611 mutant library. The mutant A11 displaying the largest pink halo was screened out and its β-fructofuranosidase activity was determined to be 1.65 fold than that of the parental strain. Thin layer chromatography (TLC) assay further indicated that A11 with the largest halo possessed the highest FOS synthesis ability. These results demonstrated the potential of this plate chromogyenic assay method in the rapid and effective identification of excellent FOS producers from a large number of strain samples.
β-fructofuranosidase, fructooligosaccharides (FOS), plate chromogenic assay, GOD-POD bienzymatic system, Aspergillus niger ATCC 20611
NCBI PubMed ID: 31614171Fructooligosaccharides (FOSs) are excellent food ingredients or feed additives by stimulating probiotics. In this paper, a CREA gene encoding a glucose repressor in the β-fructofuranosidase producer Aureobasidium melanogenum 33 with high-level FOS biosynthesis was disrupted, and glucose repression in disruptant D28 was relieved. The disruptant D28 produced up to 2100 U/mL of β-fructofuranosidase activity, whereas the enzyme activities produced by parent strain 33 and complemented strain C11 were below 600 U/mL. The whole cells of the disruptant D28 was used to convert cane molasses into FOSs, and 0.58 g of FOSs/g of molasses sugar was synthesized from 350 g/L cane molasses sugar within 4 h. Results demonstrated that the industrial waste cane molasses can be efficiently converted into FOSs by the glucose derepression mutant D28 with high β-fructofuranosidase activity. This low-cost and environmentally friendly bioprocess has great potential applications in bioengineering and biotechnology for FOS production.
Aureobasidium melanogenum, cane molasses, glucose derepression, high-level FOS biosynthesis
NCBI PubMed ID: 31686508Eight strains of Aspergillus spp. were evaluated for their ability to produce intracellular and extracellular fructosyltransferase and fructooligosaccharides from sucrose. To the best of our knowledge, this is the first time that a study evaluates the production of intracellular and extracellular fructosyltransferase simultaneously with its chemometric characterization. High values of intracellular FTase were exhibited by A. oryzae and A. carbonarius and extracellular FTase by A. japonicus and A. ochraceus. The highest concentrations of intracellular FOS were generated by A. carbonarius and A. ochraceus and extracellular FOS by A. carbonarius and A. japonicus. The variations detected between the behavior of intra- and extra-cellular enzymes can be explained by activation of disulfide bridges and N-terminal signal peptides that occur distinctly between these biological structures. 1-kestose and 1-fructofuranosylnystose were the major oligosaccharides detected by HPLC-RID. Thus, transfructosylation activity is the main contributor to the positive correlation of 1-kestose.
fructooligosaccharides, fructosyltransferase, intracellular enzymes, chemometric characterization, extracellular enzymes
Publication DOI: 10.1016/j.biteb.2020.100546Short chain fructo-oligosaccharides (SC-FOS) are the potential prebiotics possessing diverse applications in both food and feed industries. The present study was aimed to extract inulin from chicory roots followed by its conversion into SC-FOS applying endoinulinase from Aspergillus fumigatus. The inulin was extracted from chicory roots through boiling in hot water, followed by precipitation with ethanol at room temperature or freezing condition. Maximum yield (42%) of inulin was obtained with three volumes of chilled absolute ethanol at room temperature. HPLC analysis of enzymatic hydrolysate detected kestose (GF2), nystose (GF3), and other FOS having higher degree of polymerization (DP). Maximum GF2 (5.79 mg/ml) was detected at temperature 50 °C, pH 5.5 with 2 U of enzyme dose after 6 h of hydrolysis; while maximum GF3 (4.33 mg/ml) was recorded at 60 °C, 5.5 pH with 0.5 U enzyme dose after 2 h of hydrolysis. Nevertheless, complete hydrolysis of inulin was noticed with 99% total oligosaccharide yield at 55 °C, 5.5 pH with 0.5 U enzyme dose after 4 h of hydrolysis with negligible amount of mono- and di-saccharides. The present finding demonstrated the process for higher yield of inulin from chicory roots followed by its conversion into SC-FOS applying fungal endoinulinase.
inulin, fungi, prebiotic, endoinulinase, short chain fructo-oligosaccharides
NCBI PubMed ID: 31845198The aim of the study was the fungal production of fructooligosaccharides from solid-state fermentation of different agro-industrial wastes (sugar cane bagasse, coffee husk, pineapple peel, prickle pear peel and banana peel) enriched with maguey sap. An exploratory statistical design with a factorial arrangement (23) was used to identify some parameters that are directly related to the production of FOS. The production was optimized and evaluated through fermentation kinetics in order to determine the time of maximum FOS production. Among the evaluated materials, sugar cane bagasse was the most promising substrate suited for the FOS production reaching a concentration of 7.64 g of FOS per liter of culture medium based on the initial sucrose concentration (21 g/L), a high Yp/s = 0.45 based on sucrose consumed was observed. The results showed that use of sugar cane bagasse enriched with aguamiel is the most economical and excellent alternative source for the FOS production by Aspergillus oryzae DIA-MF.
Prebiotics, fructooligosaccharides, solid-state fermentation, agricultural by-products
Publication DOI: 10.1016/j.bcab.2020.101704Pectinex Ultra SP-L, a commercial enzyme preparation with fructosyltransferase activity, was successfully immobilized by covalent binding to Fe3O4-chitosan-magnetic nanoparticles. Immobilization carried out according to a 2^3-full factorial design where glutaraldehyde concentration, activation time and time of contact between enzyme and support were selected as the independent variables and immobilization yield as the response. The highest immobilization yield (94.84%) was obtained using 3.0% (v/v) glutaraldehyde and activation and contact times of 180 and 30 min, respectively. The immobilized biocatalyst, which showed for both hydrolytic and transfructosylating activities optimum pH and temperature of 7.0 and 60 °C, respectively, retained 70 and 86% of them after 6 cycles of reuse. A kinetic/thermodynamic study focused on thermal inactivation of the immobilized construct indicated high thermostability at temperatures commonly used for fructo-oligosaccharides (FOS) production. Maximum FOS concentration obtained in lab-scale experiments was 101.56 g/L, with predominant presence of 1-kestose in the reaction mixture. The results obtained in this study suggest that the immobilized-enzyme preparation may be effectively exploited for FOS production and easily recovered from the reaction mixture by action of a magnetic field.
fructo-oligosaccharides, fructosyltransferase, magnetic nanoparticles
NCBI PubMed ID: 32070737Fructooligosaccharides (FOS) have widely used for the manufacture of low-calorie and functional foods, because they can inhibit intestinal pathogenic microorganism growth and increase the absorption of Ca2+ and Mg2+. In this study, the novel fructosyltransferase (FTase) from Aspergillus oryzae strain S719 was successfully purified and characterized. The specific activity of the final purified material was 4200 1/mg with purification ratio of 66 times and yield of 26%. The molecular weight of FTase of A. oryzae S719 was around 95 kDa by SDS-PAGE, which was identified as a type of FTase by Mass Spectrometry (MS). The purified FTase had optimum temperature and pH of 55 °C and 6.0, respectively. The FTase showed to be stable with more than 80% of its original activity at room temperature after 12 h and maintaining activity above 90% at pH 4.0-11.0. The Km and kcat values of the FTase were 310 mmol/L and 2000 1/min, respectively. The FTase was activated by 5 mmol/L Mg2+ and 10 mmol/L Na+ (relative activity of 116 and 114%, respectively), indicating that the enzyme was Mg2+ and Na+ dependent. About 64% of FOS was obtained by the purified FTase under 500 g/L sucrose within 4 h of reaction time, which was the shortest reaction time to be reported regarding the purified enzyme production of FOS. Together, these results indicated that the FTase of A. oryzae S719 is an excellent candidate for the industrial production of FOS.
Aspergillus oryzae, fructosyltransferase, enzyme purification, fructooligosaccharides production
NCBI PubMed ID: 31805395The use of whole-cell biocatalyst for production of fructo-oligosaccharide (FOS) eliminates the need for costly enzyme recovery and purification. In this study, a novel Aureobasidium pullulans strain (FRR 5284) was identified from seven A. pulllulans strains as an efficient whole-cell biocatalyst for FOS production. The strain had a specific intracellular transfructosylating activity of 4.44 ± 0.18 U/mg dry cells, one of the highest transfructosylating activities thus far reported for whole-cell biocatalyst. Under optimal conditions (pH 5.5 and 55 °C), only 5 g/L of dry cells and 3 h reaction time were required to achieve a FOS yield of 61 % from 50 % (w/v) sucrose. Incubation of sugarcane molasses with an invertase-free Saccharomyces cerevisiae prior to addition of A. pullulans whole-cell biocatalyst eliminated glucose inhibition and increased FOS yield from 44 % to 56 % in 1 h. This study has demonstrated that the novel A. pullulans FRR 5284 was an efficient source of whole-cell biocatalyst for FOS production and a promising strategy for transformation of sucrose and sugarcane molasses into a higher-value prebiotic.
Prebiotics, Aureobasidium pullulans, molasses, fructo-oligosaccharide, transfructosylating activity, invertase-free
Publication DOI: 10.1016/j.bej.2020.107747An extracellular fructosyltransferase (Ftase) enzyme with a molar mass of ≈70 kDa from a newly isolated indigenous coprophilous fungus Aspergillus niger sp. XOBP48 is purified to homogeneity and characterized in this study. The enzyme was purified to 4.66-fold with a total yield of 15.53% and specific activity of 1219.17 U/mg of protein after a three-step procedure involving (NH4)2SO4 fractionation, dialysis and anion exchange chromatography. Ftase showed optimum activity at pH 6.0 and temperature 50 °C. Ftase exhibited over 80% residual activity at pH range of 4.0-10.0 and ≈90% residual activity at temperature range of 40-60 °C for 6 h. Metal ion inhibitors Hg2+ and Ag+ significantly inhibited Ftase activity at 1 mmol concentration. Ftase showed Km, vmax and kcat values of 79.51 mmol, 45.04 µmol/min and 31.5 1/min, respectively, with a catalytic efficiency (kcat/Km) of 396 1/µmol/min for the substrate sucrose. HPLC-RI experiments identified the end products of fructosyltransferase activity as monomeric glucose, 1-kestose (GF2), and 1,1-kestotetraose (GF3). This study evaluates the feasibility of using this purified extracellular Ftase for the enzymatic synthesis of biofunctional fructooligosaccharides.
1-kestose, 1, fructooligosaccharides, Aspergillus niger, fructosyltransferase, zymography, 1-kestotetraose
NCBI PubMed ID: 33088656There is a great interest in prebiotics consumptions eminence by their health promoting properties and economic market value. Filamentous fungi have been implicated as the key producers of fructosyltransferase (Ftase) and inulinase for synthesis of fructooligosaccharides (FOSs), which is used as a bioactive ingredient in functional foods. In this study, sixty-one indigenous coprophilous fungal strains were isolated, purified to monoculture and investigated for their potential use in biotransformation of sucrose and inulin into fructooligosaccharides (FOSs) and inulooligosaccharides (IOSs) by producing Ftase and inulinase enzymes, respectively. The molecular identification by 18S rDNA sequencing and morpho-taxonomic keys revealed that axenic fungal strains belonged to the genera Aspergillus, Neocosmospora, Trichoderma, Mucor and Fusarium. The crude enzyme extract from the isolates showed hydrolysis zones of 15–30 mm on the 2,3,5-triphenyltetrazolium chloride (TTC) and Lugol's iodine solution assay plates confirming the Ftase and inulinase activities, respectively. The submerged culture filtrates of eight fungal isolates showed high Ftase activity while six different fungal isolates exhibited high inulinase activity. The reaction products analysed with thin-layer chromatography and high-performance liquid chromatography coupled with refractive index detection indicated the presence of FOSs and IOSs. The strains isolated in this study have potential biotechnological implications to produce FOSs and IOSs.
fructooligosaccharides, fructosyltransferase, coprophilous fungi, inulinase, inulooligosaccharides
Publication DOI: 10.1016/j.bcab.2020.101867Short-chain fructooligosaccharides (ScFOS) are a group of linear fructose oligomers that include 1-kestose, 1-nystose and 1-β-fructofuranosylnystose. ScFOS, which naturally occur at low levels in different plant products, are of high interest as food ingredients because of their prebiotic character, organoleptic characteristics and technological properties. Two different industrial processes are used to achieve large-scale ScFOS production: inulin hydrolysis (enzymatic or chemical hydrolysis) or sucrose biotransformation by transfructosylation (enzymatic synthesis) using specific enzymes like fructosyltransferases and fructofuranosidases. Enzymatic ScFOS synthesis seems to be more advantageous than inulin hydrolysis since it is less expensive, and leads to lower molecular weight FOS. The biotechnological process described to carry out this catalysis includes the production of transfructosylation enzymes, separation, enzyme immobilisation and finally the ScFOS production and purification. Such ScFOS production processes may be conducted under submerged or solid-state fermentation under discontinuous or continuous conditions. Several methodologies with different economic/environmental costs and production yields have been described to carry out these ScFOS production stages, although industrial scale-up needs to be optimised. This review tries to address a revision about enzymatic ScFOS production methods and its scale-up to industrial levels.
submerged fermentation, short-chain fructooligosaccharides, fungal fructosyltransferase, industrial scale-up
Publication DOI: 10.1007/s12393-020-09209-0In present study, statistical optimization of medium composition for endoinulinase production from raw inulin using Aspergillus tritici was performed in shake-flask fermentations. The concentration of four independent variables viz. raw inulin (1.5–3.5%), peptone (0.2–1.8%), (NH4)H2PO4 (0.2–1.8%) and pH (4.5–6.5) was explored to optimize the composition of fermentation medium for maximum endoinulinase production. Fermentation medium containing 2.5% raw inulin, 1% peptone, 1% (NH4)H2PO4 and medium pH adjusted to 5.5 supported maximum (25.39 IU/mL) endoinulinase production. Adequate precision value >4, closeness of coefficient of determination (R2) value to 1, good co-relation between the predicted and experimental values, percentage error <5%, high F-value 164.52 and low Lack of fit F-value 0.19 authenticates the fitness of quadratic model. TLC fingerprints studies confirmed fructooligosaccharides synthesis from inulin by crude fungal endoinulinase. Fructooligosaccharides yield (19.40%) containing 3.70% ketose (GF2), 2.71% nystose (GF3) and 1.42% fructofuranosyl nystose (GF4) were obtained from inulin (10%).
response surface methodology, fructooligosaccharides, endoinulinase, Aspergillus tritici, raw-inulin
Publication DOI: 10.1016/j.biteb.2020.100417Three-step purification technique (isopropanol precipitation, ion-exchange and size-exclusion chromatography) was used for the purification of an endoinulinase from the culture broth of Aspergillus tritici BGPUP6. The molecular mass of purified endoinulinase was found to be 53.45 kDa and 53.70 kDa by denatured protein gel (SDS-PAGE) and size-exclusion (Sephadex G-100) chromatographic analysis, respectively. Higher Km (0.90 mM), Vmax (19.60 mM/min·mg), Kcat (0.0013 1/min) and Vmax/Km ratio (21.77 1/min·mg) of purified endoinulinase for inulin than stachyose depicts its higher affinity towards inulin. Purified enzyme was found stable in a pH range 4.0-7.0 with an optimal pH 5.5. The optimal temperature of purified biocatalyst was 55 °C with thermostability in the range of 50-70 °C. D-value and Z-value for endoinulinase at 55 °C was found to be 100.08 h and 11.62 °C, respectively. Thermodynamics inactivation parameters (ΔG, ΔH and ΔS) of endoinulinase shows its wide range thermal stability. Endoinulinase activity was enhanced by CaCl2 and MnSO4, while CuSO4, CoCl2, AgNO3, CdCl2, NiCl2, ZnSO4, BaCl2, HgCl2 and EDTA inhibited the activity of enzyme. Purified endoinulinase was successfully used for the production of fructooligosaccharides from inulin.
fructooligosaccharides, endoinulinase, Aspergillus tritici, kinetics characterization
NCBI PubMed ID: 32890562A previous study (KL Forsythe, MS Feather [1989] Carbohydr Res 185: 315-319) showed that (13)C nuclear magnetic resonance spectroscopy can be used to detect and identify mixtures of 1-kestose and neokestose after conversion to the acetate derivatives. In this study, unequivocal assignments are made for the anomeric carbon and proton signals for the above two trisaccharide acetates as well as for 6-kestose hendecaacetate and for nystose tetradecaacetate (a 1-kestose-derived tetrasaccharide). A number of oligosaccharide fractions were isolated from several plant species, converted to the acetates, and nuclear magnetic resonance spectra obtained. Using the above reference data, the following information was obtained. The trisaccharide fraction from Dactylis glomerata L. stem tissue and Asparagus officinalis L. roots contain both 1-kestose and neokestose, and the tetrasaccharide fractions contain three components, one of which is nystose. Penta- and hexasaccharide acetates were also isolated from A. officinalis L. roots and were found to contain, respectively, four and at least five components. All components of both of the above species appear to contain a kestose residue and to be produced by the sequential addition of fructofuranosyl units to these. The trisaccharide fraction from Festuca arundinacea is complex, and contains at least five different components, two of which appear to be 1-kestose and neokestose.
NCBI PubMed ID: 16667365The conformational studies of inulin oligomers from G-F_2 to G-F_9, which isolated from Platycodon grandiflorum, suggested a plausible conformational change between G-F_7 and G-F_8 from the trends in their chemical shift patterns and molecular rotation; the oligomers higher than G-F_8 would form some secondary conformations more rigid than shorter oligomers. On the other hand, spin-latice relaxation (T_1) studies of the protons proposed through-space interactions of 2- and 4-H's of glucose moiety in G-F_5,presumably with some atom(s) of the terminal fructose moiety. This would reflect that the inulin molecule adopts a 5/1 helix.
NMR, conformation, inulin, inulin oligomer, molecular rotation, spin-lattice relaxation time (T1)
Journal NLM ID: 0377775Individual fructan tri-, tetra- and pentasaccharide isomers in neutral, water-soluble extracts from Lolium temulentum were purified and the linkages present in these isomeric oligosaccharides were analysed by combined GC-mass spectrometry of partially methylated alditol acetates. 1-Kestose and neokestose were the most abundant trisaccharides with 6-kestose present in much lower amounts. Analysis of isomers of DP 4 and 5 showed that multiple linkage types were present with structures based on all three trisaccharides. Oligosaccharides based on neokestose but with 2,6 linkages between adjacent fructose residues have not been previously detected in higher plants.
Oligosaccharides, 1-kestose, fructan, sucrose, neokestose, Gramineae, Lolium temulentum
Publication DOI: 10.1016/0031-9422(92)83432-XChembiotech Ltd. Institute of Research and Development, University of Birmingham Research Park, Edgbaston, Birmingham, UK; Birmingham Carbohydrate and Protein Technology Group, Research Laboratory for the Chemistry of Bioactive Carbohydrates and Proteins, School of Chemistry, The University of Birmingham, Edgbaston, Birmingham, UK; School of Chemical Engineering, The University of Birmingham, Edgbaston, Birmingham, UK
Publication DOI: 10.1016/0144-8617(94)90143-0Gomphrena macrocephala St.-Hil. (Amaranthaceae) is a perennial herb that grows spontaneously in the cerrado and is characterized by well-defined phenological phases throughout the year. Soluble carbohydrates are the main reserve compounds of the tuberous root and constitute approximately 50% of the dry weight. These sugars were partially characterized as fructans forming a single homologous series, different from inulin, the most common fructan of dicotyledons. The mean molecular weight of polysaccharides was high and reached 37 kDa in the dormant phase. Fructan spherocrystals were detected in the tuberous root after treatment with ethanol, being associated with the parenchyma of secondary xylem. The content, composition and mean molecular weight of fructans were related to phenology. In late dormancy, there was a marked increase in monosaccharides, particularly fructose, and a concomitant decline of polysaccharides, probably as a result of fructan breakdown. During sprouting and in the vegetative phase, the contents of oligosaccharides and low molecular weight polysaccharides increased. A gradual rise in the molecular weight of polysaccharides occurred during the reproductive phase and at early dormancy, concurrently with decreasing levels of oligosaccharides. The capacity of G. macrocephala to accumulate readily accessible sugars, such as fructans, instead of starch, in response to environmental changes, may be of considerable advantage, since the cerrado is often subjected to seasonal drought and burnings.
fructans, Gomphrena macrocephala St.-Hil., Amaranthaceae, storage carbohydrates, phenology
Publication DOI: 10.1111/j.1365-3040.1993.tb00515.xFructooligosaccharides (FOS) are short-chain sugars that occur naturally and have dietary benefits for humans. They are widely distributed in nature and are a natural part of the human diet. The objective of this study was to determine the concentrations of 1-kestose (GF(2)), nystose (GF(3)), and 1(F)-beta-fructofuranosylnystose (GF(4)) in a variety of common processed and prepared foods. An ion chromatographic method was developed for this purpose in which the sugar concentrations were measured using integrated amperometry. The samples were simply prepared by blending with water and filtering the suspensions through a 10000 Da cutoff centrifugal filter. These samples were then injected into the ion chromatograph, which had been programmed for gradient elution, and the areas of the sugar peaks obtained compared to those of standard sugars on a calibration curve. Selected samples were prepared both with and without standard spikes in order to assess the efficiency of the determination. Of the vegetables investigated, artichokes contained by far the most FOS, followed by onions; bananas contained more FOS than other fruits investigated. The method was shown to be simple, convenient, and relatively fast for the quantitation of FOS in processed and prepared food products.
fructooligosaccharides, food composition, ion exchange chromatography
NCBI PubMed ID: 11087481| b-D-Fruf-(2-1)-b-D-Fruf-(2-1)-b-D-Fruf-(2-1)-a-D-Glcp | Show graphically |
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Show legend Show as text |
Structure type: oligomer
Trivial name: nystose, inulin, 1,1-kestotetraose
Compound class: fructan
Contained glycoepitopes: IEDB_142488,IEDB_144998,IEDB_146664,IEDB_923067,IEDB_983931,SB_192
Major fructo-oligosaccharides (FOS) produced by levansucrase (EC 2.4.1.10) from Acetobacter diazotrophicus SRT4 were characterised as 1-kestose and nystose by acid hydrolysis and 13C NMR spectroscopy. The highest yields of 1-kestose (481 mM; 241 g/l) and nystose (81 mM; 54 g/l) were achieved at initial sucrose concentration of 1754 mM (600 g/l), pH 5.5 and 40 C. The synthesized FOS reached 50% (w/w) of total sugars in the reaction mixture, with a conversion efficiency over 70% (w/w) based on the amount of sucrose converted to 1-kestose.
oligosaccharide, structural, analysis, Oligosaccharides, structural analysis, production, 1-kestose, Acetobacter, Acetobacter diazotrophicus, fructo-oligosaccharides, levansucrase, LsdA
Journal NLM ID: 8008051Worldwide interest in oligosaccharides has been increasing ever since they were accorded the prebiotic status. The oligosaccharides of various origin like, bacteria, algae, fungi and higher plants have been used extensively both as food ingredients and pharmacological supplements. The non-digestible oligosaccharides have been implicated as dietary fibre, sweetener, weight controlling agent and humectant in confectioneries, bakeries and breweries. Functional oligosaccharides have been found effective in gastrointestinal normal flora proliferation and pathogen suppression, dental caries prevention, enhancement of immunity, facilitation of mineral absorption, source of antioxidant, antibiotic alternative, regulators of blood glucose in diabetics and serum lipids in hyperlipidemics. Apart from the pharmacological applications, oligosaccharides have found use in drug delivery, cosmetics, animal and fishery feed, agriculture, etc. Keeping in view the importance of the functional oligosaccharides, we present an overview of their natural sources, types, structures, physiological properties. Conventional as well as novel synthesis, purification and analysis methods are summarized. Recent promising developments in this area are presented to facilitate their further exploitation.
Oligosaccharides, microbiota, probiotics, Functional food, Prebiotics
Publication DOI: 10.1007/s11274-010-0558-5Aspergillus phoenicis biofilms on polyethylene as inert support were used to produce fructooligosaccharides (FOS) in media containing 25 % (m/V) of sucrose as a carbon source. The maximum production of total FOS (122 mg/mL), with 68 % of 1-kestose and 32 % of nystose, was obtained in Khanna medium maintained at 30 °C for 48 h under orbital agitation (100 rpm). At high concentrations of sucrose (30 %, m/V), the recovery of FOS was higher than that observed at a low concentration (5 %, m/V). High levels of FOS (242 mg/mL) were also recovered when using the biofilm in sodium acetate buffer with high sucrose concentration (50 %, m/V) for 10 h. When the dried biofilm was reused in a fresh culture medium, there was a recovery of approx. 13.7 % of total FOS after 72 h of cultivation at 30 °C, and 10 % corresponded to 1-kestose. The biofilm morphology, analyzed by scanning electron microscope, revealed a noncompact mycelium structure, with unfilled spaces and channels present among the hyphae. The results obtained in this study show that A. phoenicis biofilms may find application for FOS production in a single-step fermentation process, which is cost-effective in terms of reusability, downstream processing and efficiency.
Biofilm, fructooligosaccharides, Aspergillus sp., kestose, nystose
Journal NLM ID: 9703690In this study, the kinetic for the bioconversion of sucrose to fructooligosaccharides (FOS) by free cells of Aspergillus oryzae N74 was modeled. In addition, the effect of immobilized glucose isomerase (IGI) on FOS production yield was evaluated and considered in the kinetic model. The selected kinetic models were based on a proposed reaction mechanism described by elementary rate equations and modified Michaelis-Menten kinetic equations. The use of IGI allowed to increase the FOS production yield (FOS Yield) and to decrease the glucose/fructose (G/F) ratio. At shake flask scale, the FOS Yield was increased in 4.7 % (final yield 58.3 %), while the G/F ratio was reduced 6.2-fold. At bench scale, the FOS Yield was increased in 2.2 % (final yield 57.3 %), while the G/F ratio was reduced 4.5-fold. The elementary rate equation model was the one that best adjusted experimental data for FOS production using either the fungus biomass or the mixture fungus biomass-IGI, with an overall average percentage error of 7.2. Despite that FOS production yield was not highly improved by the presence of IGI in the reaction mixture, it favored the reduction of residual glucose in the mixture, avoiding the loss of material owe to glucose transformation to fructose that can be used in situ for FOS production by the fructosyltransferase.
fructooligosaccharides, Aspergillus oryzae, fructosyltransferase, immobilized glucose isomerase
NCBI PubMed ID: 22528647Fructooligosaccharides are prebiotics with numerous health benefits within which the improvement of gut microbiota balance can be highlighted, playing a key role in individual health. In this study, an integrated one-stage method for FOS production via sucrose fermentation by Aureobasidium pullulans was developed and optimized using experimental design tools. Optimization of temperature and agitation speed for maximizing the FOS production was performed using response surface methodology. Temperature was found to be the most significant parameter. The optimum fermentation conditions were found to be 32°C and 385 rpm. Under these conditions, the model predicted a total FOS production yield of 64.7 g FOS/g sucrose. The model was validated at optimal conditions in order to check its adequacy and accuracy and an experimental yield of 64.1 (±0.0) g FOS/g sucrose was obtained. A significant improvement of the total FOS production yields by A. pullulans using a one-stage process was obtained.
response surface methodology, Aureobasidium pullulans, fructooligosaccharides, transfructosylation, one-stage fermentation process, product yield
NCBI PubMed ID: 24750929Studies on endo-inulinases from yeast are scarce, compared to those from other microbial sources. In this study, a novel endo-inulinase from Lipomyces starkeyi NRRL Y-11557 was identified, expressed in its soluble form, and characterized its physicochemically properties, together with its enzymatic activity and production of fructooligosaccharides (FOSs). A putative endo-inulinase gene inu3 was identified through rational genome mining. Through enzymatic activity and SDS-PAGE analysis, the endo-inulinase putative function of the protein encoded by inu3B gene (INU3B) was confirmed, and its soluble expression was achieved with pET22b (+) in Escherichia coli. INU3B showed effective catalytic activity and high thermostability. To our knowledge, the specific activity of INU3B against inulin reported in this study, 2262.8 ± 82.3 U/mg, at 70 °C and pH 5.0-6.0, is the highest reported to date. When the enzyme catalyzed FOSs production, the main products were DP3, DP4 and DP5. Overall, this report describes a novel yeast-derived endo-inulinase with optimal enzymatic properties, and thus, the reported enzyme has great potential for industrial production of FOSs.
fructooligosaccharides, endo-inulinase, Lipomyces starkeyi, rational genome mining, soluble expression
NCBI PubMed ID: 31233793An efficient system for biotransformation of sucrose to fructooligosaccharides (FOS) was obtained using Aspergillus tamarii NKRC 1229 mycelial fructosyltransferase (m-FTase). Zymographic analysis confirmed mycelial localization of the FTase (36 U/g) and lyophilized fungal pellets were used for bioconversion. m-FTase had molecular weight ~75 kDa with optimum activity at pH 7.0 and 20 °C. FOS production after parametric optimization (sucrose - 50% w/v, m-FTase dose - 4.5% w/v, inoculum age - 48 h and incubation time - 24 h) reached 325 g/L (55% yield) with 14% residual sucrose, 25% glucose and 6% fructose. FTase activity was enhanced after pre-treatment with organic solvents and SDS. FOS was purified in a single step using gel filtration matrix, Bio-Gel P2. FOS was characterized using Diffusion ordered spectroscopy-Nuclear Magnetic Resonance (1H DOSY-NMR) and Fourier-transform infrared spectroscopy (FTIR). Continuous generation of FOS was achieved using recyclable mycelia upto 10 consecutive cycles.
Prebiotics, Aspergillus, fructooligosaccharides (FOS), fructosyltransferase (FTase), zymography, Bio-Gel P2
NCBI PubMed ID: 30827630Starting from a relatively detailed model of a bioprocess producing fructo-oligosaccharides, a set of experimental data collected in batch and fed-batch experiments is exploited to estimate the unknown model parameters. The original model includes the growth of the fungus Aureobasidium pullulans which produces the enzymes responsible for the hydrolysis and transfructosylation reactions, and as such contains 25 kinetic parameters and 16 pseudo-stoichiometric coefficients, which are not uniquely identifiable with the data at hand. The aim of this study is, therefore, to show how sensitivity analysis and quantitative indicators based on the Fisher information matrix can be used to reduce the detailed model to a practically identifiable model. Parametric sensitivity analysis can indeed be used to progressively simplify the model to a representation involving 15 kinetic parameters and 8 pseudo-stoichiometric coefficients. The reduced model provides satisfactory prediction and can be convincingly cross validated.
biotechnology, mathematical modeling, Fisher information matrix, parameter identification
NCBI PubMed ID: 31375963Fructooligosaccharides (FOS) are important ingredients in the functional food industry because they have different biological properties such as decrease level of triglycerides, cholesterol and phospholipids and stimulate growth of probiotics for enhancement of microflora in large intestine. However, current strategies for the FOS production through simple and economical bioprocess has been necessary. The aim of this work was evaluated the capacity of three fungal strains (Aspergillus niger GH1, Aspergillus niger PSH and Aspergillus oryzae DIA-MF) to produce fructooligosaccharides (FOS) using aguamiel from Agave salmiana as an economical substrate. In addition, Czapek Dox medium supplemented with sucrose as carbon source was used as a control medium for the FOS production. A. oryzae DIA-MF was a fungi producer of FOS using aguamiel or Czapek Dox medium as substrate at 24 h of fermentation. However, the yield of FOS was increased two folds (20.30 g/L), with a productivity of 0.84 g FOS/l/h when aguamiel was used as substrate. On the other hand, A. niger GH1 and A. niger PSH showing only hydrolytic activity on sucrose under the studied conditions. In conclusion, this study shown excellent compatibility of A. oryzae DIA-MF using aguamiel as an economical substrate for the FOS production under a simple bioprocess.
Aspergillus, submerged fermentation, fructooligosaccharides (FOS), aguamiel
Publication DOI: 10.1016/j.lwt.2018.12.020Aspergillus thermomutatus produces an extracellular β-D-fructofuranosidase when cultured in Khanna medium with sucrose as additional carbon source at 30°C under agitation for 72 hr. Addition of glucose and fructose in the culture medium affected the production of the enzyme negatively. The optimum hydrolytic activity was achieved at 60°C and pH 5.0, with half-life (T50) of 30 hr at 50°C and 62% of its activity maintained at pH 5.0 for 48 hr. The extracellular extract containing β-D-fructofuranosidase was effective in producing fructooligosaccharides (FOS), mainly 1-kestose. The highest concentration of FOS was obtained at 30°C and 60°C, indicating the existence of at least two enzymes with transfructosylating activity. At 30°C, the maximal FOS concentration was obtained from 48 to 72 hr, while at 60°C, it was achieved only at 72 hr. The best production of FOS (86.7 g/L) was obtained using 500 g/L sucrose as substrate.
Aspergillus, fructooligosaccharide, transfructosylating, β-D-fructofuranosidase
NCBI PubMed ID: 31368547Fructooligosaccharides (FOS) are commonly regarded as prebiotics and used as components of functional foods. Currently, the industrial sucrose-to-FOS biotransformation is mainly carried out using the microbial-derived β-fructofuranosidases with transglycosylation activity as catalysts. Evaluation of the ability of a microorganism to produce β-fructofuranosidase is commonly conducted by measuring enzyme activity. However, the traditional method requires several steps to identify strains with high β-fructofuranosidase activity, which is not suitable for high-throughput screening. To facilitate screening of a large number of microbial cultures, this study developed a plate chromogenic assay method based on the glucose oxidase (GOD) - peroxidase (POD) bienzymatic system for screening of β-fructofuranosidase-producing fungal strains and predicting their potential to produce FOS. This method used the amount of glucose released from sucrose as indicator to form clear pink halos around the microbial colonies with β-fructofuranosidase activity. Cultivation conditions for the plate assay were optimized as cultivation time 5 h and spore inoculum concentration 100000000 1/ml. Moreover, the method was applied to screening of an Aspergillus niger ATCC 20611 mutant library. The mutant A11 displaying the largest pink halo was screened out and its β-fructofuranosidase activity was determined to be 1.65 fold than that of the parental strain. Thin layer chromatography (TLC) assay further indicated that A11 with the largest halo possessed the highest FOS synthesis ability. These results demonstrated the potential of this plate chromogyenic assay method in the rapid and effective identification of excellent FOS producers from a large number of strain samples.
β-fructofuranosidase, fructooligosaccharides (FOS), plate chromogenic assay, GOD-POD bienzymatic system, Aspergillus niger ATCC 20611
NCBI PubMed ID: 31614171Fructooligosaccharides (FOSs) are excellent food ingredients or feed additives by stimulating probiotics. In this paper, a CREA gene encoding a glucose repressor in the β-fructofuranosidase producer Aureobasidium melanogenum 33 with high-level FOS biosynthesis was disrupted, and glucose repression in disruptant D28 was relieved. The disruptant D28 produced up to 2100 U/mL of β-fructofuranosidase activity, whereas the enzyme activities produced by parent strain 33 and complemented strain C11 were below 600 U/mL. The whole cells of the disruptant D28 was used to convert cane molasses into FOSs, and 0.58 g of FOSs/g of molasses sugar was synthesized from 350 g/L cane molasses sugar within 4 h. Results demonstrated that the industrial waste cane molasses can be efficiently converted into FOSs by the glucose derepression mutant D28 with high β-fructofuranosidase activity. This low-cost and environmentally friendly bioprocess has great potential applications in bioengineering and biotechnology for FOS production.
Aureobasidium melanogenum, cane molasses, glucose derepression, high-level FOS biosynthesis
NCBI PubMed ID: 31686508Eight strains of Aspergillus spp. were evaluated for their ability to produce intracellular and extracellular fructosyltransferase and fructooligosaccharides from sucrose. To the best of our knowledge, this is the first time that a study evaluates the production of intracellular and extracellular fructosyltransferase simultaneously with its chemometric characterization. High values of intracellular FTase were exhibited by A. oryzae and A. carbonarius and extracellular FTase by A. japonicus and A. ochraceus. The highest concentrations of intracellular FOS were generated by A. carbonarius and A. ochraceus and extracellular FOS by A. carbonarius and A. japonicus. The variations detected between the behavior of intra- and extra-cellular enzymes can be explained by activation of disulfide bridges and N-terminal signal peptides that occur distinctly between these biological structures. 1-kestose and 1-fructofuranosylnystose were the major oligosaccharides detected by HPLC-RID. Thus, transfructosylation activity is the main contributor to the positive correlation of 1-kestose.
fructooligosaccharides, fructosyltransferase, intracellular enzymes, chemometric characterization, extracellular enzymes
Publication DOI: 10.1016/j.biteb.2020.100546Short chain fructo-oligosaccharides (SC-FOS) are the potential prebiotics possessing diverse applications in both food and feed industries. The present study was aimed to extract inulin from chicory roots followed by its conversion into SC-FOS applying endoinulinase from Aspergillus fumigatus. The inulin was extracted from chicory roots through boiling in hot water, followed by precipitation with ethanol at room temperature or freezing condition. Maximum yield (42%) of inulin was obtained with three volumes of chilled absolute ethanol at room temperature. HPLC analysis of enzymatic hydrolysate detected kestose (GF2), nystose (GF3), and other FOS having higher degree of polymerization (DP). Maximum GF2 (5.79 mg/ml) was detected at temperature 50 °C, pH 5.5 with 2 U of enzyme dose after 6 h of hydrolysis; while maximum GF3 (4.33 mg/ml) was recorded at 60 °C, 5.5 pH with 0.5 U enzyme dose after 2 h of hydrolysis. Nevertheless, complete hydrolysis of inulin was noticed with 99% total oligosaccharide yield at 55 °C, 5.5 pH with 0.5 U enzyme dose after 4 h of hydrolysis with negligible amount of mono- and di-saccharides. The present finding demonstrated the process for higher yield of inulin from chicory roots followed by its conversion into SC-FOS applying fungal endoinulinase.
inulin, fungi, prebiotic, endoinulinase, short chain fructo-oligosaccharides
NCBI PubMed ID: 31845198The aim of the study was the fungal production of fructooligosaccharides from solid-state fermentation of different agro-industrial wastes (sugar cane bagasse, coffee husk, pineapple peel, prickle pear peel and banana peel) enriched with maguey sap. An exploratory statistical design with a factorial arrangement (23) was used to identify some parameters that are directly related to the production of FOS. The production was optimized and evaluated through fermentation kinetics in order to determine the time of maximum FOS production. Among the evaluated materials, sugar cane bagasse was the most promising substrate suited for the FOS production reaching a concentration of 7.64 g of FOS per liter of culture medium based on the initial sucrose concentration (21 g/L), a high Yp/s = 0.45 based on sucrose consumed was observed. The results showed that use of sugar cane bagasse enriched with aguamiel is the most economical and excellent alternative source for the FOS production by Aspergillus oryzae DIA-MF.
Prebiotics, fructooligosaccharides, solid-state fermentation, agricultural by-products
Publication DOI: 10.1016/j.bcab.2020.101704Pectinex Ultra SP-L, a commercial enzyme preparation with fructosyltransferase activity, was successfully immobilized by covalent binding to Fe3O4-chitosan-magnetic nanoparticles. Immobilization carried out according to a 2^3-full factorial design where glutaraldehyde concentration, activation time and time of contact between enzyme and support were selected as the independent variables and immobilization yield as the response. The highest immobilization yield (94.84%) was obtained using 3.0% (v/v) glutaraldehyde and activation and contact times of 180 and 30 min, respectively. The immobilized biocatalyst, which showed for both hydrolytic and transfructosylating activities optimum pH and temperature of 7.0 and 60 °C, respectively, retained 70 and 86% of them after 6 cycles of reuse. A kinetic/thermodynamic study focused on thermal inactivation of the immobilized construct indicated high thermostability at temperatures commonly used for fructo-oligosaccharides (FOS) production. Maximum FOS concentration obtained in lab-scale experiments was 101.56 g/L, with predominant presence of 1-kestose in the reaction mixture. The results obtained in this study suggest that the immobilized-enzyme preparation may be effectively exploited for FOS production and easily recovered from the reaction mixture by action of a magnetic field.
fructo-oligosaccharides, fructosyltransferase, magnetic nanoparticles
NCBI PubMed ID: 32070737Fructooligosaccharides (FOS) have widely used for the manufacture of low-calorie and functional foods, because they can inhibit intestinal pathogenic microorganism growth and increase the absorption of Ca2+ and Mg2+. In this study, the novel fructosyltransferase (FTase) from Aspergillus oryzae strain S719 was successfully purified and characterized. The specific activity of the final purified material was 4200 1/mg with purification ratio of 66 times and yield of 26%. The molecular weight of FTase of A. oryzae S719 was around 95 kDa by SDS-PAGE, which was identified as a type of FTase by Mass Spectrometry (MS). The purified FTase had optimum temperature and pH of 55 °C and 6.0, respectively. The FTase showed to be stable with more than 80% of its original activity at room temperature after 12 h and maintaining activity above 90% at pH 4.0-11.0. The Km and kcat values of the FTase were 310 mmol/L and 2000 1/min, respectively. The FTase was activated by 5 mmol/L Mg2+ and 10 mmol/L Na+ (relative activity of 116 and 114%, respectively), indicating that the enzyme was Mg2+ and Na+ dependent. About 64% of FOS was obtained by the purified FTase under 500 g/L sucrose within 4 h of reaction time, which was the shortest reaction time to be reported regarding the purified enzyme production of FOS. Together, these results indicated that the FTase of A. oryzae S719 is an excellent candidate for the industrial production of FOS.
Aspergillus oryzae, fructosyltransferase, enzyme purification, fructooligosaccharides production
NCBI PubMed ID: 31805395The use of whole-cell biocatalyst for production of fructo-oligosaccharide (FOS) eliminates the need for costly enzyme recovery and purification. In this study, a novel Aureobasidium pullulans strain (FRR 5284) was identified from seven A. pulllulans strains as an efficient whole-cell biocatalyst for FOS production. The strain had a specific intracellular transfructosylating activity of 4.44 ± 0.18 U/mg dry cells, one of the highest transfructosylating activities thus far reported for whole-cell biocatalyst. Under optimal conditions (pH 5.5 and 55 °C), only 5 g/L of dry cells and 3 h reaction time were required to achieve a FOS yield of 61 % from 50 % (w/v) sucrose. Incubation of sugarcane molasses with an invertase-free Saccharomyces cerevisiae prior to addition of A. pullulans whole-cell biocatalyst eliminated glucose inhibition and increased FOS yield from 44 % to 56 % in 1 h. This study has demonstrated that the novel A. pullulans FRR 5284 was an efficient source of whole-cell biocatalyst for FOS production and a promising strategy for transformation of sucrose and sugarcane molasses into a higher-value prebiotic.
Prebiotics, Aureobasidium pullulans, molasses, fructo-oligosaccharide, transfructosylating activity, invertase-free
Publication DOI: 10.1016/j.bej.2020.107747An extracellular fructosyltransferase (Ftase) enzyme with a molar mass of ≈70 kDa from a newly isolated indigenous coprophilous fungus Aspergillus niger sp. XOBP48 is purified to homogeneity and characterized in this study. The enzyme was purified to 4.66-fold with a total yield of 15.53% and specific activity of 1219.17 U/mg of protein after a three-step procedure involving (NH4)2SO4 fractionation, dialysis and anion exchange chromatography. Ftase showed optimum activity at pH 6.0 and temperature 50 °C. Ftase exhibited over 80% residual activity at pH range of 4.0-10.0 and ≈90% residual activity at temperature range of 40-60 °C for 6 h. Metal ion inhibitors Hg2+ and Ag+ significantly inhibited Ftase activity at 1 mmol concentration. Ftase showed Km, vmax and kcat values of 79.51 mmol, 45.04 µmol/min and 31.5 1/min, respectively, with a catalytic efficiency (kcat/Km) of 396 1/µmol/min for the substrate sucrose. HPLC-RI experiments identified the end products of fructosyltransferase activity as monomeric glucose, 1-kestose (GF2), and 1,1-kestotetraose (GF3). This study evaluates the feasibility of using this purified extracellular Ftase for the enzymatic synthesis of biofunctional fructooligosaccharides.
1-kestose, 1, fructooligosaccharides, Aspergillus niger, fructosyltransferase, zymography, 1-kestotetraose
NCBI PubMed ID: 33088656There is a great interest in prebiotics consumptions eminence by their health promoting properties and economic market value. Filamentous fungi have been implicated as the key producers of fructosyltransferase (Ftase) and inulinase for synthesis of fructooligosaccharides (FOSs), which is used as a bioactive ingredient in functional foods. In this study, sixty-one indigenous coprophilous fungal strains were isolated, purified to monoculture and investigated for their potential use in biotransformation of sucrose and inulin into fructooligosaccharides (FOSs) and inulooligosaccharides (IOSs) by producing Ftase and inulinase enzymes, respectively. The molecular identification by 18S rDNA sequencing and morpho-taxonomic keys revealed that axenic fungal strains belonged to the genera Aspergillus, Neocosmospora, Trichoderma, Mucor and Fusarium. The crude enzyme extract from the isolates showed hydrolysis zones of 15–30 mm on the 2,3,5-triphenyltetrazolium chloride (TTC) and Lugol's iodine solution assay plates confirming the Ftase and inulinase activities, respectively. The submerged culture filtrates of eight fungal isolates showed high Ftase activity while six different fungal isolates exhibited high inulinase activity. The reaction products analysed with thin-layer chromatography and high-performance liquid chromatography coupled with refractive index detection indicated the presence of FOSs and IOSs. The strains isolated in this study have potential biotechnological implications to produce FOSs and IOSs.
fructooligosaccharides, fructosyltransferase, coprophilous fungi, inulinase, inulooligosaccharides
Publication DOI: 10.1016/j.bcab.2020.101867Short-chain fructooligosaccharides (ScFOS) are a group of linear fructose oligomers that include 1-kestose, 1-nystose and 1-β-fructofuranosylnystose. ScFOS, which naturally occur at low levels in different plant products, are of high interest as food ingredients because of their prebiotic character, organoleptic characteristics and technological properties. Two different industrial processes are used to achieve large-scale ScFOS production: inulin hydrolysis (enzymatic or chemical hydrolysis) or sucrose biotransformation by transfructosylation (enzymatic synthesis) using specific enzymes like fructosyltransferases and fructofuranosidases. Enzymatic ScFOS synthesis seems to be more advantageous than inulin hydrolysis since it is less expensive, and leads to lower molecular weight FOS. The biotechnological process described to carry out this catalysis includes the production of transfructosylation enzymes, separation, enzyme immobilisation and finally the ScFOS production and purification. Such ScFOS production processes may be conducted under submerged or solid-state fermentation under discontinuous or continuous conditions. Several methodologies with different economic/environmental costs and production yields have been described to carry out these ScFOS production stages, although industrial scale-up needs to be optimised. This review tries to address a revision about enzymatic ScFOS production methods and its scale-up to industrial levels.
submerged fermentation, short-chain fructooligosaccharides, fungal fructosyltransferase, industrial scale-up
Publication DOI: 10.1007/s12393-020-09209-0In present study, statistical optimization of medium composition for endoinulinase production from raw inulin using Aspergillus tritici was performed in shake-flask fermentations. The concentration of four independent variables viz. raw inulin (1.5–3.5%), peptone (0.2–1.8%), (NH4)H2PO4 (0.2–1.8%) and pH (4.5–6.5) was explored to optimize the composition of fermentation medium for maximum endoinulinase production. Fermentation medium containing 2.5% raw inulin, 1% peptone, 1% (NH4)H2PO4 and medium pH adjusted to 5.5 supported maximum (25.39 IU/mL) endoinulinase production. Adequate precision value >4, closeness of coefficient of determination (R2) value to 1, good co-relation between the predicted and experimental values, percentage error <5%, high F-value 164.52 and low Lack of fit F-value 0.19 authenticates the fitness of quadratic model. TLC fingerprints studies confirmed fructooligosaccharides synthesis from inulin by crude fungal endoinulinase. Fructooligosaccharides yield (19.40%) containing 3.70% ketose (GF2), 2.71% nystose (GF3) and 1.42% fructofuranosyl nystose (GF4) were obtained from inulin (10%).
response surface methodology, fructooligosaccharides, endoinulinase, Aspergillus tritici, raw-inulin
Publication DOI: 10.1016/j.biteb.2020.100417Three-step purification technique (isopropanol precipitation, ion-exchange and size-exclusion chromatography) was used for the purification of an endoinulinase from the culture broth of Aspergillus tritici BGPUP6. The molecular mass of purified endoinulinase was found to be 53.45 kDa and 53.70 kDa by denatured protein gel (SDS-PAGE) and size-exclusion (Sephadex G-100) chromatographic analysis, respectively. Higher Km (0.90 mM), Vmax (19.60 mM/min·mg), Kcat (0.0013 1/min) and Vmax/Km ratio (21.77 1/min·mg) of purified endoinulinase for inulin than stachyose depicts its higher affinity towards inulin. Purified enzyme was found stable in a pH range 4.0-7.0 with an optimal pH 5.5. The optimal temperature of purified biocatalyst was 55 °C with thermostability in the range of 50-70 °C. D-value and Z-value for endoinulinase at 55 °C was found to be 100.08 h and 11.62 °C, respectively. Thermodynamics inactivation parameters (ΔG, ΔH and ΔS) of endoinulinase shows its wide range thermal stability. Endoinulinase activity was enhanced by CaCl2 and MnSO4, while CuSO4, CoCl2, AgNO3, CdCl2, NiCl2, ZnSO4, BaCl2, HgCl2 and EDTA inhibited the activity of enzyme. Purified endoinulinase was successfully used for the production of fructooligosaccharides from inulin.
fructooligosaccharides, endoinulinase, Aspergillus tritici, kinetics characterization
NCBI PubMed ID: 32890562A previous study (KL Forsythe, MS Feather [1989] Carbohydr Res 185: 315-319) showed that (13)C nuclear magnetic resonance spectroscopy can be used to detect and identify mixtures of 1-kestose and neokestose after conversion to the acetate derivatives. In this study, unequivocal assignments are made for the anomeric carbon and proton signals for the above two trisaccharide acetates as well as for 6-kestose hendecaacetate and for nystose tetradecaacetate (a 1-kestose-derived tetrasaccharide). A number of oligosaccharide fractions were isolated from several plant species, converted to the acetates, and nuclear magnetic resonance spectra obtained. Using the above reference data, the following information was obtained. The trisaccharide fraction from Dactylis glomerata L. stem tissue and Asparagus officinalis L. roots contain both 1-kestose and neokestose, and the tetrasaccharide fractions contain three components, one of which is nystose. Penta- and hexasaccharide acetates were also isolated from A. officinalis L. roots and were found to contain, respectively, four and at least five components. All components of both of the above species appear to contain a kestose residue and to be produced by the sequential addition of fructofuranosyl units to these. The trisaccharide fraction from Festuca arundinacea is complex, and contains at least five different components, two of which appear to be 1-kestose and neokestose.
NCBI PubMed ID: 16667365The conformational studies of inulin oligomers from G-F_2 to G-F_9, which isolated from Platycodon grandiflorum, suggested a plausible conformational change between G-F_7 and G-F_8 from the trends in their chemical shift patterns and molecular rotation; the oligomers higher than G-F_8 would form some secondary conformations more rigid than shorter oligomers. On the other hand, spin-latice relaxation (T_1) studies of the protons proposed through-space interactions of 2- and 4-H's of glucose moiety in G-F_5,presumably with some atom(s) of the terminal fructose moiety. This would reflect that the inulin molecule adopts a 5/1 helix.
NMR, conformation, inulin, inulin oligomer, molecular rotation, spin-lattice relaxation time (T1)
Journal NLM ID: 0377775Individual fructan tri-, tetra- and pentasaccharide isomers in neutral, water-soluble extracts from Lolium temulentum were purified and the linkages present in these isomeric oligosaccharides were analysed by combined GC-mass spectrometry of partially methylated alditol acetates. 1-Kestose and neokestose were the most abundant trisaccharides with 6-kestose present in much lower amounts. Analysis of isomers of DP 4 and 5 showed that multiple linkage types were present with structures based on all three trisaccharides. Oligosaccharides based on neokestose but with 2,6 linkages between adjacent fructose residues have not been previously detected in higher plants.
Oligosaccharides, 1-kestose, fructan, sucrose, neokestose, Gramineae, Lolium temulentum
Publication DOI: 10.1016/0031-9422(92)83432-XLeaves of field-grown cheatgrass (Bromus tectorum L.) plants were sampled during early spring when day- and night-time temperatures were relatively cool. Fructan oligomers with a degree of polymerization (DP) 3–6 were extracted and purified using gel and anion-exchange chromatography. The structures of 13 cheatgrass fructans were established. They included two trisaccharides [1-kestotriose (1-kestose) and 6-kestotriose (6-kestose)], four tetrasaccharides [(1.1)-kestotetraose (nystose), (1&6)-kestotetraose (bifurcose), (6,1)-kestotetraose and (6,6)-kestotetraose], three pentasaccharides [(1,1&6)-kestopentaose, (1&6,6)-kestopentaose and (6;1&6)-kestopentaose] plus four hexasaccharides [(1,1,1&6)-kestohexaose (1&6,6,6)-kestohexaose, (6;1&6,6)-kestohexaose and (6;1,6&6)-kestohexaose]. All fructans larger then DP 4 contained a branch point. Each member of the dominant series(1&6)-kestotetraose, (1&6,6)-kestopentaose and (1&6,6,6)-kestohexaose, is a branched fructan in which two fructose moieties are linked to the fructose subunit of each sucrose molecule. Thus the dominant series is built upon (1&6)-kestotetraose. Fructans larger than DP 3 with exclusively 2→1- or 2→6-linkages were absent except for a very small amount of (6,6)-kestotetraose. The unique fructan structures synthesized in cheatgrass, wheat and oats illustrate diversity in the enzymology of fructan biosynthesis among grass species.
synthesis, Structures, fructan, degree of polymerization, Bromus
Publication DOI: 10.1111/j.1469-8137.1993.tb03829.xFructooligosaccharides (FOS) are short-chain sugars that occur naturally and have dietary benefits for humans. They are widely distributed in nature and are a natural part of the human diet. The objective of this study was to determine the concentrations of 1-kestose (GF(2)), nystose (GF(3)), and 1(F)-beta-fructofuranosylnystose (GF(4)) in a variety of common processed and prepared foods. An ion chromatographic method was developed for this purpose in which the sugar concentrations were measured using integrated amperometry. The samples were simply prepared by blending with water and filtering the suspensions through a 10000 Da cutoff centrifugal filter. These samples were then injected into the ion chromatograph, which had been programmed for gradient elution, and the areas of the sugar peaks obtained compared to those of standard sugars on a calibration curve. Selected samples were prepared both with and without standard spikes in order to assess the efficiency of the determination. Of the vegetables investigated, artichokes contained by far the most FOS, followed by onions; bananas contained more FOS than other fruits investigated. The method was shown to be simple, convenient, and relatively fast for the quantitation of FOS in processed and prepared food products.
fructooligosaccharides, food composition, ion exchange chromatography
NCBI PubMed ID: 11087481| -4)-a-D-Glcp-(1- | Show graphically |
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Show legend Show as text |
Structure type: homopolymer
Trivial name: methyl glucose lipopolysaccharide, glucan, maltosaccharide, α-1,4-D-glucan, amylose, α-glucan, glycogen backbone, α-(1,4)-glucan, starch, α-(1-4)-glucan, starch, glycogen
Compound class: CPS, EPS, O-polysaccharide, cell wall polysaccharide, glucan, polysaccharide, methyl glucose lipopolysaccharide
Contained glycoepitopes: IEDB_140629,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_420417,IEDB_420418,IEDB_420421,IEDB_857742,IEDB_983931,SB_192
Methyl glucose lipopolysaccharides (MGLP)were first isolated in 1964 from a fast growing, nonpathogenic mycobacterial strain, Mycobacterium smegmatis. Their complete structure was achieved in 1982 by Forsberg et al.2 It was established that the M. smegmatis MGLP heterogeneity arises from the acyl appendages borne by the polysaccharidic core. In the present study, we report the occurrence of MGLP from a slow growing strain M. xenopi and the structure of the deacylated derivatives (MGP). A new analytical strategy, based on the use of High h]pH Anion Exchange liquid Chromatography (HPAEC) and Liquid Secondary Ion Mass Spectrometry (LSIMS) was successfully develiped. Thanks to HPAEC, the MGP mixture was fractionated and from LSIMS data, it was clearly established that the heterogeneity of the MGP polysaccharidic core arises from the number of glycosyl and methoxyl units.
analysis, mass spectrometry, purification, Mycobacterium smegmatis, methyl glucose lipopolysaccharides
Publication DOI: 10.1080/07328309508005364Three kinds of capsular polysaccharide (CP) were found to be produced by Burkholderia pseudomallei. When the bacterium was grown with the medium without glycerol, CP-1a and CP-1b were produced. CP-1a was mainly 1.4-linked glucan and CP-1b was identified as a polymer composed of galactose and 3-deoxy-D-manno-octulosonic acid, whose chemical structure was recently reported by other laboratories. When the bacterium was grown with the medium containing 5" glycerol. CP-2 was synthesized. CP-2 contained galactose, rhamnose, mannose, glucose and a uronic acid in a ratio of approximately 3:1:0.3:1:1. Methylation analysis of the purified polysaccharides demonstrated that the two acidic polysaccharides. CP-1b and CP-2 shared no common structure, indicating that CP-2 was an acidic capsular polysaccharide whose chemical characters were not reported previously.
capsular, characterization, polysaccharide, Burkholderia, capsular polysaccharides, capsular polysaccharide, Burkholderia pseudomallei, melioidosis
NCBI PubMed ID: 10744478Campylobacter jejuni infection is a main source of severe gastroenteritis-related illnesses in humans and there is also evidence that it may be linked to neurological disorders. C. jejuni 81-176 is a virulent strain that has become the global model in the study of mechanisms and pathogenesis of C. jejuni infection. For this reason, we were engaged in studying the fine structures of cell-surface carbohydrate antigens of C. jejuni 81-176, namely, the capsule polysaccharide (CPS) and lipooligosaccharide (LOS). Serologically, C. jejuni 81-176 has been classified as belonging to serogroups HS23 and HS36, and indeed previous studies have shown that the LOS and CPS structures possess components similar to those expressed by serostrains HS23 and HS36. Here, we describe that in addition to the LOS and CPS, this strain also produced an independent cell-surface (1→4)-α-glucan capsule
Campylobacter jejuni, capsule, glucan
NCBI PubMed ID: 16055105The cell envelope which surrounds pathogenic mycobacteria is postulated to be a defence barrier against phagocytic cells and its outermost constituents have a tendency to accumulate in the culture medium. The present work demonstrates that the exocellular material of Mycobacterium tuberculosis contains large amounts of polysaccharides with only traces, if any at all, of lipids. Three types of polysaccharides were purified by anion-exchange and gel-filtration chromatography; all were found to be neutral compounds devoid of acyl substituents. They consisted of D-glucan, D-arabino-D-mannan and D-mannan, which were eluted from gel-filtration columns in positions corresponding to molecular masses of 123, 13 and 4 kDa respectively. Their predominant structural features were determined by the characterization of the per-O-methyl derivatives of enzymic, acetolysis and Smith-degradation products and by 1H- and 13C-n.m.r. spectroscopy of the purified polysaccharides, using mono- and two-dimensional homonuclear chemical-shift correlated spectroscopy and two-dimensional heteronuclear (1H/13C) spectroscopy. The glucan which represented up to 90% of the polysaccharides was composed of repeating units of five or six →4-α-D-Glcp-1→ residues and a →4-α-D-Glcp substituted at position 6 with an α-D-Glcp, indicating a glycogen-like highly branched structure not related to the so-called polysaccharide-II previously identified in tuberculin. The arabinomannan consisted of a mannan segment composed of a →6-α-D-Man-1→ core substituted at some positions 2 with an α-D-Manp. The arabinan termini of the arabinomannan were found to be extensively capped with mannosyl residues. The possibility that these polysaccharides contribute to the persistence of the tubercle bacillus in the macrophage by molecular mimicry is discussed.
NCBI PubMed ID: 8297342Mycobacterium tuberculosis and other pathogenic mycobacterial species produce large amounts of a glycogen-like α-glucan that represents the major polysaccharide of their outermost capsular layer. To determine the role of the surface-exposed glucan in the physiology and virulence of these bacteria, orthologues of the glg genes involved in the biosynthesis of glycogen in Escherichia coli were identified in M. tuberculosis H37Rv and inactivated by allelic replacement. Biochemical analyses of the mutants and complemented strains indicated that the synthesis of glucan and glycogen involves the α-1,4-glucosyltransferases Rv3032 and GlgA (Rv1212c), the ADP-glucose pyrophosphorylase GlgC (Rv1213) and the branching enzyme GlgB (Rv1326c). Disruption of glgC reduced by half the glucan and glycogen contents of M. tuberculosis, whereas the inactivation of glgA and Rv3032 affected the production of capsular glucan and glycogen, respectively. Attempts to disrupt Rv3032 in the glgA mutant were unsuccessful, suggesting that a functional copy of at least one of the two α-1,4-glucosyltransferases is required for growth. Importantly, the glgA mutant was impaired in its ability to persist in mice, suggesting a role for the capsular glucan in the persistence phase of infection. Unexpectedly, GlgB was found to be an essential enzyme
biosynthesis, gene, Mycobacterium tuberculosis, tuberculosis, a-glucan, glgA mutant
NCBI PubMed ID: 18808383The results of in vitro studies of the immunomodulatory action of the lipopolysaccharides (LPS) of the Pseudomonas bacteria— P. fluorescens biovar I strains IMV 4125 = ATCC 13525, IMV 7769, and IMV 1152; P. fluorescens biovar IV strain IMV 2111; P. syringae pv. syringae IMV 281 = CPPB 281 = ATCC 19310 and IMV 467; and P. wieringae IMV 7923—on the mouse spleenocytes and human peripheral blood mononuclear cells (PBMC), B lymphocytes, and T lymphocytes are described. The proliferative activity of mouse spleenocytes correlated with the degree of LPS toxicity. The PBMC mitogenic activity induced by the P. fluorescens IMV 7769 LPS preparation exceeded the activity of E. coli 026: B6 LPS. The immunomodulatory effect of LPS on T cells was strain and dose dependent. The LPS of P. syringae pv. syringae INV 467 displayed a comparatively pronounced immunomodulatory effect on human blood B lymphocytes.
lipopolysaccharides, structural, Pseudomonas, specific, immunomodulatory
NCBI PubMed ID: 19145969BACKGROUND: Helicobacter pylori cell surface is composed of lipopolysaccharides (LPSs) yielding structures homologous to mammalian Lewis O-chains blood group antigens. These structures are key mediators in the definition of host-microbial interactions and known to change their expression pattern in response to environmental pressure. AIMS: The present work is focused on the identification of new H. pylori cell-surface glycosides. Special attention is further devoted to provide insights on the impact of in vitro subcultivation on H. pylori cell-surface phenotypes. METHODS: Cell-surface glycans from H. pylori NCTC 11637 and two clinical isolates were recovered from the aqueous phase resulting from phenol:water extraction of intact bacteria. They were evaluated in relation to their sugars and glycosidic-linkages composition by CG-MS, size-exclusion chromatography, NMR, and Mass Spectrometry. H. pylori glycan profile was also monitored during subcultivation in vitro in agar and F12 liquid medium. RESULTS: All three studied strains produce LPS expressing Lewis epitopes and express bioaccumulate amylose-like glycans. Bioaccumulation of amylose was found to be enhanced with the subcultivation of the bacterium on agar medium and accompanied by a decrease in the expression of LPS O-chains. In contrast, during exponential growth in F12 liquid medium, an opposite behavior is observed, that is, there is an increase in the overall amount of LPS and decrease in amylose content. CONCLUSIONS: This work shows that under specific environmental conditions, H. pylori expresses a phase-variable cell-surface α-(1→4)-glucose moiety
Helicobacter pylori, glucan, cell-surface polysaccharide, environmental pressure
NCBI PubMed ID: 19889074Two specific polysaccharides, together with an →4)-α-d-Glcp-(1→ glucan (bacterial glycogen), were obtained from a lipopolysaccharide preparation isolated from the bacterium Pseudomonas putida BIM B-1100 by phenol/water extraction. The following structures of the polysaccharides were established by composition analysis, Smith degradation, ESI-MS, and 1D and 2D NMR spectroscopy.
Lipopolysaccharide, O-polysaccharide, bacterial polysaccharide structure, Pseudomonas putida
NCBI PubMed ID: 29304442Although the ability to secrete exopolysaccharides (EPS) is widespread among microorganisms, only a few bacterial (e.g. xanthan, levan, dextran) and fungal (e.g. pullulan) EPS have reached full commercialization. During the last years, other microbial EPS producers have been the subject of extensive research, including endophytes, extremophiles, microalgae and Cyanobacteria, as well as mixed microbial consortia. Those studies have demonstrated the great potential of such microbial systems to generate biopolymers with novel chemical structures and distinctive functional properties. In this work, an overview of the bioprocesses developed for EPS production by the wide diversity of reported microbial producers is presented, including their development and scale-up. Bottlenecks that currently hinder microbial EPS development are identified, along with future prospects for further advancement.
bacteria, Extremophiles, exopolysaccharide (EPS), fungi, mixed microbial consortia
NCBI PubMed ID: 28554522Glucans are the most abundant natural polysaccharides across the living kingdom with tremendous biological activities. Now a days, α-D-glucans are gaining importance as a prebiotics, nutraceuticals, immunostimulants, antiproliferative agents and biodegradable polymers in pharmaceutical and cosmetic sectors. A wide variety of bioresources including bacteria, fungi, lichens, algae, plants and animals produce α-D-glucans either as an exopolysaccharide (EPS) or a cell wall component or an energy storage polymer. The α-D-glucans exhibit great structural and functional diversity as the type of linkage and percentage of branching dictate the functional properties of glucans. Among the different linkages, bioactivities are greatly confined to the α-D-(1 → 3) linkages whereas starch and other polymers consisting of α-D-(1 → 4) (1 → 6) linkages are specific for food and pharmaceutical applications. However, the bioactivities of the α-D-(1 → 3) glucans in native form is limited mainly due to their hydrophobic nature. Hence several derivatization techniques have been developed to improve the bioavailability as well as bioactive features such as antiviral, antimicrobial, anti-inflammatory, antioxidant, immunomodulatory and antitumor properties. Though, several reports have presented about α-D-glucans, still there is an ambiguity in terms of their structure among different natural sources and moreover no comprehensive information was available on their derivatization techniques and application potential. Therefore, the present review summarizes distinct description on diverse sources, type of linkages, derivatization techniques as well as the application potential of the native and modified α-D-glucans.
exopolysaccharides, derivatization, Prebiotics, α-D-Glucans, bioavailability, biodegradable polymer, immunomodulating agent
NCBI PubMed ID: 33813321This study identified a rhamnose-containing cell wall polysaccharide (RhaCWP) in an alkaline extract prepared to analyze intracellular polysaccharides (IPS) from Streptococcus mutans biofilm. IPS was an 1,4-α-D-glucan with branchpoints introduced by 1,6-α-glucan while RhaCWP presented 1,2-α-L-and 1,3-α-L rhamnose backbone and side chains connected by 1,2-α-D-glucans, as identified by nuclear magnetic resonance (NMR) spectroscopy and methylation analyses. The MW of IPS and RhaCWP was 11,298 Da, as determined by diffusion-ordered NMR spectroscopy. Therefore, this study analyzed the chemical structure of RhaCWP and IPS from biofilm in a single fraction prepared via a convenient hot-alkali extraction method. This method could be a feasible approach to obtain such molecules and improve the comprehension of the structure-function relationships in polymers from S. mutans in future studies
Biofilm, rhamnoglucan, dental caries, intracellular polysaccharide
NCBI PubMed ID: 38350588Crude membrane preparations of fungi contain the enzyme glucan synthase (EC 2.4.1.34) which produces a polymer of glucose linked through 1,3-β-glycosidic bonds. This polymer is a major structural element of the fungal cell wall. Preparations of glucan synthase are contaminated with the enzyme glycogen synthase (EC 2.4.1.11). Glycogen synthase forms the storage carbohydrate glycogen, a polymer of glucose consisting of mainly 1,4-α-glycosidic linkage. Both enzymes utilize uridine diphosphoglucose as substrate. Discrimination of glucan synthase from glycogen synthase activity has relied upon the inclusion of glycogen-degrading enzymes in the crude reactions. The polysaccharide reaction products of glucan synthase assays have been characterized by their susceptibility to enzymatic degradation by various glucanohydrolases. These degradative enzymes are impure and inclusion of appropriate control polysaccharides often leads to ambiguous results. A method for comparative qualitative analysis of polysaccharides formed in fungal glucan synthase reactions has been developed using high-performance anion-exchange chromatography. Using this method, polymers of glucose with 1,3-β-glycosidic linkage and 1,4-α linkage can be readily distinguished. This method has been applied to map oligosaccharides derived by partial acid hydrolysis from fungal glucan synthase reaction products from Candida albicans protoplasts prepared by two different methods.
NCBI PubMed ID: 8297006A study was made of polysaccharides and glycosphingolipids isolated from Aspergillus fumigatus grown in media supplemented with human serum from healthy donors. Fractionation of Cetavlon-precipitated polysaccharides on Sephacryl S-400 gave rise to an excluded fraction (Fraction I) with molecular weight of >400 kDa and an included peak (Fraction II) with an averagemolecular weight of 30-80 kDa. Fraction I comprises about 5% of total polysaccharide and was identified as a glycogen-like molecule. Its structure was deduced from methylation data, treatment with amyloglucosidase, a red-browncoloration produced with an iodine solution and by 1Hand 13C NMR spectroscopy. It was previously suggested that higher amounts of glycogen-like polysaccharide (20%) were present in A. fumigatus grown in serum-free medium. Fraction II was identified as a galactomannan and was the main polysaccharide of A. fumigatus grown in serum-supplemented medium. Its structure was elucidated mainly by 13C NMR spectroscopy combined with partial acetolysis and methylation analysis. The 13C NMR spectrum of the galactomannan showed a much greater complexity in the b-D-galf and a-D-manp C-1 regions, than was evident for galactomannan from serum-free cultures previously described, reflecting differences in the glycosylation pattern, stimulated in serum-supplemented medium. No differences in A. fumigatus glycosphingolipid could be detected between serum-containing and serum-free growth conditions. Our results demonstrate that the change in polysaccharide structure is a more specific response to the altered growth conditions and not merely a symptom of more general changes.
structure, human, polysaccharide, polysaccharides, glycolipid, serum, glycolipids, human serum, Galactomannan, glucan, Aspergillus fumigatus
NCBI PubMed ID: 9299754The production of pigment-free pullulan by Aureobasidium pullulans in batch and fed-batch culture was investigated. Batch culture proved to be a better fermentation system for the production of pullulan than the fed-batch culture system. A maximum polysaccharide concentration (31.3 g l−1), polysaccharide productivity (4.5 g l−1 per day), and sugar utilization (100%) were obtained in batch culture. In fed-batch culture, feed medium composition influenced the kinetics of fermentation. For fed-batch culture, the highest values of pullulan concentration (24.5 g l−1) and pullulan productivity (3.5 g l−1 per day) were obtained in culture grown with feeding substrate containing 50 g l−1 sucrose and all nutrients. The molecular size of pullulan showed a decline as fermentation progressed for both fermentation systems. At the end of fermentation, the polysaccharide isolated from the fed-batch culture had a slightly higher molecular weight than that of batch culture. Structural characterization of pullulan samples (methylation and enzymic hydrolysis with pullulanase) revealed the presence of mainly α-(1→4) (~66%) and α-(1→6) (~31%) glucosidic linkages; however, a small amount (<3%) of triply linked (1,3,4-, 1,3,6-, 1,2,4- and 1,4,6-Glc p) residues were detected. The molecular homogeneity of the alcohol-precipitated polysaccharides from the fermentation broths as well as the structural features of pullulan were confirmed by 13C-NMR and pullulanase treatments followed by gel filtration chromatography of the debranched digests.
pullulan, Aureobasidium pullulans, batch culture, fed-batch culture
Publication DOI: 10.1016/S0032-9592(98)00106-XYCP, a mitogenic polysaccharide with its molecular weight (MW) of 2.4 x 10^3 kDa, was isolated from the mycelium of the marine filamentous fungus Phoma herbarum YS4108 by a combination of ion-exchange chromatography on DEAE-32 and gel permeation over Sephacryl S-400. The detailed compositional, spectroscopic and methylation analyses of the polysaccharide demonstrated that its backbone possessed most likely a linear α-(1-4) bonded glucopyranoside main chain co-bearing through side α-(1-6)-linkage. The α-(1-4) bondage of the glucopyranoside building blocks in YCP was confirmed by the observation that it could be hydrolyzed by the α-amylase produced by Bacillus licheniformis. A reliable concentration monitoring experimentation highlighted that the reducing sugars released continuously from YCP during its incubation with the enzyme, and the MW of the main resulting fragment weighed 0.8 x 10^4 Da with approximately 10% of YCP converted to maltose, maltotriose and glucose after a 120-min enzymatic degradation. Finally, YCP was found to be able to increase phagocytic activity of mice in vitro and in vivo, indicating that it may be looked up as a potent immunomodulator that could activate macrophages.
Phoma herbarum, a-amylase, YCP, enzymatic modification, mitogenic activity
NCBI PubMed ID: 15885873Several structurally different glucans were characterized as components of Ramalina celastri. Aqueous KOH extraction of the lichen at 100°C, followed by dialysis provided amylose (0.02%), identified and quantified by its blue coloration with iodine. The extract was frozen and thawed and the resulting precipitate (2% yield) shown to be a mixture of two insoluble D-glucans, with (1→3)- and (1→3),(1→4)-linkages, respectively, as shown by 13C NMR spectroscopy. On treatment with 0.5% aqueous NaOH at 50°C, the material which remained insoluble was a linear β-glucan with regularly distributed (1→3)- and (1→4)-linkages in a 1:1 molar ratio (nigeran, 1.2% yield), whereas that which solubilised was a linear β-glucan with (1→3)-linkages (laminaran, 0.8% yield). The mother liquor of the KOH extraction was treated with Fehling solution to give a precipitate and the supernatant contained an α-D-glucan (28% yield) with (1→3)- and (1→4)- linkages in a molar ratio of 3:1, and which were distributed irregularly. The structures of these two (1→3),(1→4)-linked β-glucans were characterized by methylation, controlled Smith degradation and 13C and 1H NMR spectroscopic analyses.
β-D-glucan, α-D-Glucans, amylose, Ramalina celastri
Publication DOI: 10.1016/S0144-8617(99)00048-XFungal glucans represent various structurally different d-glucose polymers with a large diversity of molecular mass and configuration. According to glucose anomeric structure, it is possible to distinguish α-D-glucans, β-D-glucans and mixed α,β-D-glucans. Further discrimination could be made on the basis of glycosidic bond position in a pyranoid ring, distribution of specific glycosidic bonds along a chain, branching and molecular mass. Fungal glucans can be chemically modified to obtain various derivatives of potential industrial or medicinal importance. NMR spectroscopy is a powerful tool in structural analysis of fungal glucans. Together with chemolytic methods like methylation analysis and periodate oxidation, NMR is able to determine exact structure of these polysaccharides. Fungal glucans or their derivatives exert various biological activities, which are usually linked to structure, molecular mass and substitution degree.
nuclear magnetic resonance, chemical modification, fungal glucans, structural diversity, structure–activity relationship
NCBI PubMed ID: 23218369Biological activities of medicinal mushrooms have been attributed to β-(1→3),(1→6)-glucans that are present in the cell wall of fungi and some plants. Antitumor, immunomodulatory, antimicrobial, antinociception, antiinflammatory, prebiotic, antioxidant, and antidiabetic are some of different properties already described for β-(1→3),(1→6)-glucans. Immune activation systems, including specific β-glucan receptors like Dectin-1, complement (CR3), and Toll (TLR), have been identified to clarify these biological effects. The β-(1→3)-glucans are synthesized by β-(1→3)-glucan synthase (GLS), an enzyme belonging to the glucosyltransferase group, which has a catalytic unit (FKS) and another regulatory (RHO). The mechanisms for adding β-(1→6) branches to the non-reducing ends of the β-(1→3)-glucan chains are unclear until now. Due to the biological importance of β-(1→3),(1→6)-glucan, it is necessary to understand the biochemical and molecular mechanisms of its synthesis, both to optimize the production of bioactive compounds and to develop antifungal drugs that interrupt this process. Therefore, the aim of this review is to gather information about the potential of β-(1→3),(1→6)-glucans, their methods of isolation, purification, and chemical characterization, as well as how these biomolecules are synthesized by fungi and what studies involving biotechnology or molecular biology have contributed to this subject.
characterization, biotechnology, molecular biology, β-(1→3), (1→6)-glucans, β-(1→3)-glucan synthase, medicinal activities
NCBI PubMed ID: 26252967D-Glucans have triggered increasing interest in commercial applications in the chemical and pharmaceutical sectors because of their technological properties and biological activities. The glucans are foremost among the polysaccharide groups produced by microorganisms with demonstrated activity in stimulating the immune system, and have potential in treating human disease conditions. Chemical alterations in the structure of D-glucans through derivatization (sulfonylation, carboxymethylation, phosphorylation, acetylation) contributes to their increased solubility that, in turn, can alter their biological activities such as antioxidation and anticoagulation. This review surveys and cites the latest advances on the biological and technological potential of D-glucans following chemical modifications through sulfonylation, carboxymethylation, phosphorylation or acetylation, and discusses the findings of their activities. Several studies suggest that chemically modified D-glucans have potentiated biological activity as anticoagulants, antitumors, antioxidants, and antivirals. This review shows that indepth future studies on chemically modified glucans with amplified biological effects will be relevant in the biotechnological field because of their potential to prevent and treat numerous human disease conditions and their clinical complications
exopolysaccharides, α- and β-Glucans, biomolecules
NCBI PubMed ID: 25239192Mushroom polysaccharides (MPs) act as a functional food and perform diverse biological activities. Significance of MPs in various health promoting products have been extensively reported by scientific community mainly on structural features, biological activities, potential uses and advances in their extraction, cultivation and biomolecular techniques which need to be reviewed for their better understanding and utilization. From the perspective of how MPs were utilized in various nutraceuticals, pharmaceuticals and cosmeceuticals (NPC) products as health promoting agents, this review aims to comprehensively discuss MPs phyto-pharmacology, structural features, advances and trends of utilization. Moreover, this review also highlights the challenges and future consideration for its holistic utilization in different NPC formulations. MPs were found to be effective against various disease conditions mainly through modulating cell surface receptors. Overall from the last ten years, the research on MPs has increased tremendously and countries like China ranked first. Among various biological activities, MPs are a better choice for antioxidant followed by immunomodulatory, anticancer and anti-inflammatory activity and its use been increased as functional food. Various advanced techniques for MPs extraction, biomolecular characterization and artificial synthesis for NPC formulations are currently in use, however, the study on its complex structure, better culture and extraction conditions need further research. Moreover, a holistic approach needs to be adopted for mushroom utilization for the production of MPs as functional food. This review presents a comprehensive discussion on MPs research as functional compounds utilized in food and medicine and could be beneficial for various NPC formulations.
immunomodulatory, Antioxidant, bioactivity, Anticancer, mushroom polysaccharides, nutraceuticals
Publication DOI: 10.1016/j.tifs.2019.08.009A common edible mushroom Lentinula edodes, is an important source of numerous biologically active substances, including polysaccharides, with immunomodulatory and antitumor properties. In the present work, the biological activity of the crude, homogenous (Se)-enriched fraction (named Se-Le-30), which has been isolated from L. edodes mycelium by a modified Chihara method towards human peripheral blood mononuclear cells (PBMCs) and peripheral granulocytes, was investigated. The Se-Le-30 fraction, an analog of lentinan, significantly inhibited the proliferation of human PBMCs stimulated with anti-CD3 antibodies or allostimulated, and down-regulated the production of tumor necrosis factor (TNF)-? by CD3+ T cells. Moreover, it was found that Se-Le-30 significantly reduced the cytotoxic activity of human natural killer (NK) cells. The results suggested the selective immunosuppressive activity of this fraction, which is non-typical for mushroom derived polysaccharides.
polysaccharides, Lentinula edodes, selenium, immunosuppressant
NCBI PubMed ID: 34944419We previously described the biosynthesis, isolation, and immunosuppressive activity of the selenium-containing polysaccharide fraction isolated from the mycelial culture of Lentinula edodes. Structural studies have shown that the fraction was a protein-containing mixture of high molar mass polysaccharides α- and β-glucans. However, which of the components of the complex fraction is responsible for the immunosuppressive activity non-typical for polysaccharides of fungal origin has not been explained. In the current study, we defined four-polysaccharide components of the Se-containing polysaccharide fraction determined their primary structure and examined the effect on T- and B-cell proliferation. The isolated Se-polysaccharides, α-1,4-glucan (Mw 2250000 g/mol), unbranched β-1,6-D-glucan, unbranched β-1,3-D-glucan and β-1,3-branched β-1,6-D-glucan (Mw 110000 g/mol), are not typical as components of the cell wall of L. edodes. All are biologically active, but the inhibitory effect of the isolated polysaccharides on lymphocyte proliferation was weaker, though more selective than that of the crude fraction.
polysaccharides, T lymphocyte, Lentinula edodes, immunosuppressant, Se-containing polysaccharide
NCBI PubMed ID: 34500837Scedosporium and Lomentospora are a group of filamentous fungi with some clinically relevant species causing either localized, invasive, or disseminated infections. Understanding how the host immune response is activated and how fungi interact with the host is crucial for a better management of the infection. In this context, an α-glucan has already been described in S. boydii, which plays a role in the inflammatory response. In the present study, an α-glucan has been characterized in L. prolificans and was shown to be exposed on the fungal surface. The α-glucan is recognized by peritoneal macrophages and induces oxidative burst in activated phagocytes. Its recognition by macrophages is mediated by receptors that include Dectin-1 and Mincle, but not TLR2 and TLR4. These results contribute to the understanding of how Scedosporium's and Lomentospora's physiopathologies are developed in patients suffering with scedosporiosis and lomentosporiosis.
toll-like receptors, α-glucan, C-type lectin receptors, Lomentospora prolificans, Scedosporium boydii
NCBI PubMed ID: 36983458Mushroom polysaccharides are recognized as "biological response modifiers". Besides several bioactivities, a growing interest in their prebiotic potential has been raised due to the gut microbiota modulation potential. This review comprehensively summarizes mushroom polysaccharides' biological properties, structure-function relationship, and underlying mechanisms. It provides a recent overview of the key findings in the field (2018-2024). Key findings and limitations on structure-function correlation are discussed. Although most studies focus on β-glucans or extracts, α-glucans and chitin have gained interest. Prebiotic capacity has been associated with α-glucans and chitin, while antimicrobial and wound healing potential is attributed to chitin. However, further research is of utmost importance. Human fecal fermentation is the most reported approach to assess prebiotic potential, indicating impacts on intestinal biological, mechanical, chemical and immunological barriers. Gut microbiota dysbiosis has been directly connected with intestinal, cardiovascular, metabolic, and neurological diseases. Concerning gut microbiota modulation, animal experiments have suggested proinflammatory cytokines reduction and redox balance re-establishment. Most literature focused on the anticancer and immunomodulatory potential. However, anti-inflammatory, antimicrobial, antiviral, antidiabetic, hypocholesterolemic, antilipidemic, antioxidant, and neuroprotective properties are discussed. A significant overview of the gaps and research directions in synergistic effects, underlying mechanisms, structure-function correlation, clinical trials and scientific data is also given
mushroom polysaccharides, health benefits, 2018–2024 data overview, gut microbiota modulation, structure-function correlation, underlying mechanisms
NCBI PubMed ID: 38494231Pleurotus ostreatus, also known as the oyster mushroom, is a popular edible mushroom cultivated worldwide. This review aims to survey recent progress in the molecular genetics of this fungus and demonstrate its potential as a model mushroom for future research. The development of modern molecular genetic techniques and genome sequencing technologies has resulted in breakthroughs in mushroom science. With efficient transformation protocols and multiple selection markers, a powerful toolbox, including techniques such as gene knockout and genome editing, has been developed, and numerous new findings are accumulating in P. ostreatus. These include molecular mechanisms of wood component degradation, sexual development, protein secretion systems, and cell wall structure. Furthermore, these techniques enable the identification of new horizons in enzymology, biochemistry, cell biology, and material science through protein engineering, fluorescence microscopy, and molecular breeding
cell wall, genome editing, agaricomycete, breeding, mycelial materials, wood degradation
NCBI PubMed ID: 38372792Disproportionating enzyme (d-enzyme) is a plastidial α-1,4-glucanotransferase but its role in starch metabolism is unclear. Using a reverse genetics approach we have isolated a mutant of Arabidopsis thaliana in which the gene encoding this enzyme (DPE1) is disrupted by a T-DNA insertion. While d-enzyme activity is eliminated in the homozygous dpe1-1 mutant, changes in activities of other enzymes of starch metabolism are relatively small. During the diurnal cycle, the amount of leaf starch is higher in dpe1-1 than in wild type and the amylose to amylopectin ratio is increased, but amylopectin structure is unaltered. The amounts of starch synthesised and degraded are lower in dpe1-1 than in wild type. However, the lower amount of starch synthesised and the higher proportion of amylose are both eliminated when plants are completely de-starched by a period of prolonged darkness prior to the light period. During starch degradation, a large accumulation of malto-oligosaccharides occurs in dpe1-1 but not in wild type. These data show that d-enzyme is required for malto-oligosaccharide metabolism during starch degradation. The slower rate of starch degradation in dpe1-1 suggests that malto-oligosaccharides affect an enzyme that attacks the starch granule, or that d-enzyme itself can act directly on starch. The effects on starch synthesis and composition in dpe1-1 under normal diurnal conditions are probably a consequence of metabolism at the start of the light period, of the high levels of malto-oligosaccharides generated during the dark period. We conclude that the primary function of d-enzyme is in starch degradation.
mutant, Arabidopsis thaliana, starch metabolism, disproportionating enzyme, malto-oligosaccharides
Publication DOI: 10.1046/j.1365-313x.2001.01012.xThe concentrations of water-soluble carbohydrate (WSC) and its components, starch, total nitrogen, and dry matter of phalaris (Phalaris aquatica L. cv. Australian) pasture were varied by shading for periods ranging from 38.5 to 46.5 h. In unshaded pasture, WSC concentrations were lowest at sunrise [103 mg/g dry matter (DM)] and increased until early afternoon (to 160 mg/g DM). Sucrose and starch increased in concentration during daylight, whilst the concentrations of glucose, fructose, fructan, and a component of WSC considered to be mainly the carbohydrate moiety of glycoside(s) were relatively constant. The concentrations of starch, and all components of WSC except sucrose, were reduced by shading, but increased to the concentrations observed in the unshaded pasture within 2–4 h after removal of the cover. The fructans present in phalaris were determined to be oligosaccharides of degree of polymerisation (DP) 3 and DP 4 and high molecular mass fructans with DP >10. Nitrogen concentration of shaded pasture was initially higher (4.7% DM) than in unshaded pasture (3.9% DM), but decreased after removal of the shade cover. Dry matter content was reduced in shaded pasture, partly due to increased retention of water on the exterior of plants. The experiment was a precursor for a grazing trial in which the WSC content of pasture was to be altered by shading. It indicated that shading would potentially alter WSC and N concentrations, and DM content, but would have only a relatively small impact on the digestibility of the pasture.
glycosides, nitrogen, digestibility, nutritive value
Publication DOI: 10.1071/AR99150The ability to synthesize high molecular weight inulin was transferred to potato plants via constitutive expression of the 1-SST (sucrose:sucrose 1-fructosyltransferase) and the 1-FFT (fructan: fructan 1-fructosyltransferase) genes of globe artichoke (Cynara scolymus). The fructan pattern of tubers from transgenic potato plants represents the full spectrum of inulin molecules present in artichoke roots as shown by high-performance anion exchange chromatography, as well as size exclusion chromatography. These results demonstrate in planta that the enzymes sucrose:sucrose 1-fructosyltransferase and fructan:fructan 1-fructosyltransferase are sufficient to synthesize inulin molecules of all chain lengths naturally occurring in a given plant species. Inulin made up 5% of the dry weight of transgenic tubers, and a low level of fructan production also was observed in fully expanded leaves. Although inulin accumulation did not influence the sucrose concentration in leaves or tubers, a reduction in starch content occurred in transgenic tubers, indicating that inulin synthesis did not increase the storage capacity of the tubers.
gene expression, inulin, fructans, potato, artichoke
NCBI PubMed ID: 10890908Over the years numerous studies have lauded the benefits of a high fiber diet. In fact, fiber along with β-carotene and co-3 polyunsaturated fatty acids may be viewed as the emissaries of the modern day nutraceutical and functional foods field. In accordance, the United States Food and Drug Administration (FDA) have approved the use of several health claims related to either the specific or general fiber content of a food. Fiberous molecules include the complex carbohydrates cellulose, hemicelluloses, pectin, algal polysaccharides and mucilages along with the polyphenolic structural molecule lignin. While by strict definition fiber is not considered dietary essential, the health promoting benefits of higher fiber diet has made this class of nutrients very recognizable in the rapidly developing nutraceutical field. Fiber consumption has been linked in decreased incidence of heart disease, various types of cancer, and diverticulosis. While still controversial, it has also been proposed that fiber might be beneficial to individuals with diabetes mellitus in controlling their blood glucose response to a given meal. Fiber structure, physical properties and their role in health promotion will be discussed in this review.
diabetes, cancer, fiber, nutraceuticals, functional foods, heart disease
Publication DOI: 10.1300/J133v02n04_03| -4)-b-D-Xylp-(1- | Show graphically |
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Structure type: homopolymer
Trivial name: β-(1,4)-xylan
Compound class: EPS, polysaccharide, xylan
Contained glycoepitopes: IEDB_114701,IEDB_167188,IEDB_174332
No abstract available
NCBI PubMed ID: 1596931Barley straw and a preparation of perennial ryegrass were sequentially extracted with oxalic acid, dimethyl sulphoxide (DMSO) and a “cellulolytic” enzyme preparation Driselase and the fractions studied by methylation analysis, 13C NMR and other methods. Oxalic acid, as expected, solubilised the bulk of the arabinose and ferulic acid in both samples, although appreciable amounts of xylose were also solubilised. DMSO yielded polymeric lignin-carbohydrate complexes (LCC), both of which consisted predominantly of a β(1→4) xylan. From the results of methylation analysis, sensitivity to oxalic acid hydrolysis and size-exclusion chromatography after alkaline hydrolysis, it was evident that lignin polymers were attached to arabinosyl and xylosyl residues by both ester and aryl-ether linkages. After cellulolytic hydrolysis of the residues, thioacidolysis analysis of the lignin component in the DMSO-soluble and Driselase-insoluble fractions from ryegrass revealed differences in every measurable aspect. The DMSO-soluble lignin was found to be more highly condensed, have a higher S/G ratio and have a higher terminal G/internal G ratio.
lignin, hemicellulose, p-coumaric acid, ferulic acid
Publication DOI: 10.1016/0008-6215(95)00036-SThe cell-wall polysaccharides of Arabidopsis thaliana leaves have been isolated, purified, and characterized. The primary cell walls of all higher plants that have been studied contain cellulose, the three pectic polysaccharides homogalacturonan, rhamnogalacturonan I and rhamnogalacturonan II, the two hemicelluloses xyloglucan and glucuronoarabinoxylan, and structural glycoproteins. The cell walls of Arabidopsis leaves contain each of these components and no others that we could detect, and these cell walls are remarkable in that they are particularly rich in phosphate buffer-soluble polysaccharides (34% of the wall). The pectic polysaccharides of the purified cell walls consist of rhamnogalacturonan I (11%), rhamnogalacturonon II (8%), and homogalacturonan (23%). Xyloglucan (XG) accounts for 20% of the wall, and the oligosaccharide fragments generated from XG by endoglucanase consist of the typical subunits of other higher plant XGs. Glucuronoarabinoxylan (4%), cellulose (14%) and protein (14%) account for the remainder of the wall. Except for the phosphate buffer-soluble pectic polysaccharides, the polysaccharides of Arabidopsis leaf cell walls occur in proportions similar to those of other plants. The structure of the Arabidopsis cell-wall polysaccharides are typical of those of many other plants.
NCBI PubMed ID: 7770522Understanding of the biosynthesis of plant cell wall polysaccharides is lacking at present. More attention has been paid to the synthesis of other carbohydrate sink-materials such as starch and sucrose and progress in the study of wall polysaccharides has been more directed towards understanding turnover up to the present time. The main reasons for this deficiency are the potential number and complexity of enzymes required for wall polysaccharide synthesis, difficulty in their purification and the consequent lack of identified genes. This review illustrates the progress in the light of work in the author's laboratory which has been directed towards improving identification of the enzymes involved. Wider progress in the field is reviewed that has led to identification of the first set of polysaccharide synthase genes. Some aspects of regulation of cell wall polysaccharide synthesis during growth, differentiation and biotic stress are also highlighted. Progress in engineering the polysaccharide content of walls is also reviewed.
cell wall, nucleotide sugars, gene cloning, enzyme purification, polysaccharide synthases
Publication DOI: 10.4052/tigg.12.143| -4)-b-D-Glcp-(1- | Show graphically |
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Structure type: homopolymer
Trivial name: cellulose, β-(1,4)-glucan, cellulose, β-(1,4)-glucan
Compound class: EPS, O-polysaccharide, cell wall polysaccharide, glucan, polysaccharide
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Endo-β-1,4-glucanase A (CenA), a cellulase from the bacterium Cellulomonas fimi, is composed of two domains: a catalytic domain and a cellulose-binding domain. Adsorption of CenA and its isolated cellulose-binding domain (CBD.PTCenA) to Valonia cellulose microcrystals was examined by transmission electron microscopy using an antibody sandwich technique (CenA/CBD.PTCenA-α CenA IgG-protein A-gold conjugate). Adsorption of both CenA and CBD.PTCenA occurred along the lengths of the microcrystals, with an apparent preference for certain crystal faces or edges. CenA or CBD.PTCenA, but not the isolated catalytic domain, were shown to prevent the flocculation of microcrystalline bacterial cellulose. The cellulose-binding domain may assist crystalline cellulose hydrolysis in vitro by promoting substrate dispersion.
NCBI PubMed ID: 8110656In order to elucidate the biosynthetic process of cellulose and curdlan, 13Clabeled polysaccharides were biosynthesized by Acetobacter xylinum (IFO 13693) and Agrobacterium sp. (ATCC 317491, from culture media containing D-(1-13C)glucose, D-(2-13C)glucose, D-(4-13C)glucose, or D-(6-13C)glucose as the carbon source, and their structures were determined by 13C NMR spectroscopy. The labeling was mainly found in the original position, indicating direct polymerization of introduced glucoses. In addition, the transfer of labeling from C-2 to C-I, C-3 and C-5, from C-4 to C-l, C-2 and C-3, and from C-6 to C-1 was found in celluloses. In curdlan, the transfer of labeling from C-1 to C-3, from C-2 to C-I and C-3, from C-4 to C-I, C-2 and C-3, and from C-6 to C-I and C-3 was observed. From analysis of this labeling, the biosynthetic process of cellulose and curdlan was explained as involving six routes. The percentages of each route via which cellulose or curdlan is biosynthesized were estimated for upper (C-t to C-3) and lower portions (C-4 to C-6) of glucosidic units in the polysaccharides. It is noted that very few polysaccharides are formed via the Embden-Meyerhof pathway. The lower half (C-4 to C-6) structure of introduced glucoses is well preserved in the polysaccharides.
Publication DOI: 10.1016/0144-8617(94)90184-8Bacterial glucans have aroused increasing interest in commercial applications in the food and pharmaceutical sectors. A number of bacterial glucans have been reported over recent decades, and their structure, production, and functional properties have been extensively studied. In this paper, we review recent researches on bacterial glucans, with emphasis on the production, physical and chemical properties, and the new developments in food, biomedical, pharmaceutical, and other industrial applications.
food, property, production, pharmaceutical, Bacterial glucans, Biomedical
NCBI PubMed ID: 27678120Bacteria produce a wide range of exopolysaccharides which are synthesized via different biosynthesis pathways. The genes responsible for synthesis are often clustered within the genome of the respective production organism. A better understanding of the fundamental processes involved in exopolysaccharide biosynthesis and the regulation of these processes is critical toward genetic, metabolic and protein-engineering approaches to produce tailor-made polymers. These designer polymers will exhibit superior material properties targeting medical and industrial applications. Exploiting the natural design space for production of a variety of biopolymer will open up a range of new applications. Here, we summarize the key aspects of microbial exopolysaccharide biosynthesis and highlight the latest engineering approaches toward the production of tailor-made variants with the potential to be used as valuable renewable and high-performance products for medical and industrial applications.
biosynthesis, gene clusters, Bacterial exopolysaccharides, polysaccharide engineering, tailor-made exopolysaccharides
NCBI PubMed ID: 26074894Cervical cancer is the fourth-ranked cancer in the world and is associated with a large number of deaths annually. Chemotherapy and radiotherapy are known as the common therapeutic approaches in the treatment of cervical cancer, but because of their side effects and toxicity, researchers are trying to discovery alternative therapies. β-glucans, a group of glucose polymers that are derived from the cell wall of fungi, bacteria, and etc. it has been showed that β-glucans have some anti-cancer properties which due to their impacts on adaptive and innate immunity. Along to these impacts, these molecules could be used as drug carriers. In this regard, the application of β-glucans is a promising therapeutic option for the cancer prevention and treatment especially for cervical cancer. Herein, we have summarized the therapeutic potential of β-glucans alone or as adjuvant therapy in the treatment of cervical cancer. Moreover, we highlighted β-glucans as drug carriers for preventive and therapeutic purposes.
bacteria, β-Glucans, fungi, cervical cancer
NCBI PubMed ID: 32138756The cell-wall components of the interface compartment in functioning mycorrhizal roots of maize (Zea mays L. cv. W64A) have been investigated with the use of immunocytochemistry and enzyme/lectin-gold techniques. The distribution of specific cell-wall probes was determined in the apical and differentiated regions of maize roots in the presence and in the absence of the mycorrhizal fungus, Glomus versiforme. Labelling experiments showed that a maize hydroxyproline-rich glycoprotein (HRGP), identified with a specific antibody, was particularly abundant in the apical dividing cells of the root meristem. Cellulose, located with a cellobiohydrolase-gold complex, showed a similar labelling pattern in the walls of both meristematic and differentiated parts of the roots. When the cortex was colonized by the mycorrhizal fungus, the HRGP and cellulose were expressed in two sites: the wall and the interface area created by invagination of the host membrane around the developing fungus. In contrast, in uninfected roots of the same age, they were only present in the inner part of the wall. A specific antibody against β-1,3-glucans demonstrated that these glucans were not laid down at the interface between the plant and fungus, while they appeared to be a skeletal component of the fungal wall, together with chitin.
cell wall, cellulose, β-1, arbuscular mycorrhizae, 3-glucans, hydroxyproline-rich glycoprotein, zea root meristem
Publication DOI: 10.1007/BF00199680For centuries, macrofungi have been used as food and medicine in different parts of the world. This is mainly attributed to their nutritional value as a potential source of carbohydrates, proteins, amino acids, and minerals. In addition, they also include many bioactive metabolites which make mushrooms and truffles common components in folk medicine, especially in Africa, the Middle East, China, and Japan. The reported medicinal effects of mushrooms include anti-inflammatory effects, with anti-inflammatory compounds of mushrooms comprising a highly diversified group in terms of their chemical structure. They include polysaccharides, terpenoids, phenolic compounds, and many other low molecular weight molecules. The aims of this review are to report the different types of bioactive metabolites and their relevant producers, as well as the different mechanisms of action of mushroom compounds as potent anti-inflammatory agents.
reishi, Ganoderma, ganoderic acid
NCBI PubMed ID: 25505823Brewers spent yeast insoluble residue (BSYIR) is the insoluble material that remains after the exhaustive extraction with strong alkali solutions of brewers spent yeast (BSY). BSYIR contains 57% polysaccharides, composed mainly of glucose residues (98%) and minor amount of mannose residues (1%). The glucans were mainly (1→4)-linked (56.6%); with lower amounts of (1→3)-, (1→4,6)-, terminal-, (1→6)-, and (1→3,6)-linked glucose residues, together with terminal- and (1→6)-linked mannose residues. Scanning electron microscopy (SEM) showed that in BSYIR the spherical shape of BSY was preserved. However, when the BSYIR was treated with chlorite solutions, either under alkali or acidic conditions, followed by an extraction with aqueous KOH (0.1 M) solution, it promoted the destruction of the cell wall three-dimensional structure. The treatments with chlorite solutions allowed the solubilisation of yeast non carbohydrate material in BSYIR and the recovered residues were enriched in carbohydrates. The residue left after treatment with chlorite under alkaline solutions was composed of 92% of carbohydrates and the residue left with chlorite/acetic acid treatment contained 89% carbohydrate. Both residues were composed of only glucose. Comparing the BSYIR with the residue obtained after treatment with chlorite under alkaline solutions, it was observed an enrichment in linear glucans, (1→4)-Glc (61%) and (1→3)-Glc (from 17% to 20%), and the decrease in branched glucans, namely (1→4,6)-Glc, from 10% to 4%. The results obtained show that the three-dimensional spherical structure of the yeast cell wall is preserved by a network of glucans and mannoproteins. The oxidation of this network promotes its disruption by formation of an unbranched compact structure of glucans.
glycoproteins, Glucans, Saccharomyces pastorianus, scanning electronmicroscopy(SEM)
Journal NLM ID: 101634698Grass culms are known to differ in breaking strength, but there is little physicochemical data to explain the response. The fourth internode of four brittle and two nonbrittle barley (Hordeum vulgare L.) strains were used for physical and chemical studies of culm strength. Inner and outer culm diameters of brittle strains (3.6 +/- 0.2 and 5.0 +/- 0.1 millimeters) were not significantly different from those of nonbrittle strains (3.9 +/- 0.2 and 5.2 +/- 0.2 millimeters). Maximum bending stress, at which the culm was broken, was 192 +/- 34 g/mm(2) for brittle and 490 +/- 38 g/mm(2) for nonbrittle strains. Wall thickness and cell dimensions of epidermal, sclerenchyma, and parenchyma cells were measured in culm cross sections. The area of cell wall per unit cell area for each tissue was significantly correlated with the maximum bending stress (r = 0.93 for epidermis, 0.90 for sclerenchyma, and 0.84 for parenchyma). Cell walls of brittle culms had 6 to 64% as much cellulose content as those of nonbrittle culms. Maximum bending stress correlated significantly with cellulose content of the cell walls (r = 0.93), but not with the contents of noncellulosic compounds. The lower cellulose content of the brittle culm was significantly correlated with brittleness.
NCBI PubMed ID: 16667151The elongation growth of stem segments is determined by the outer cell layers (epidermis and collenchyma). We measured the sugar composition and molecular weight distribution of pectin and hemicellulose fractions obtained from inner and outer tissues of squash (Cucurbita maxima Duch.) hypocotyls. In addition, we studied the changes in these parameters after a 9 hour period of incubation of the segments. The results show that outer tissues have higher molecular weight pectin and hemicellulose compared to inner tissues (2-3 times higher). Incubation results in a 13 to 25% decrease in the amount of pectin and hemicellulose in inner tissues and an increase of 11 to 32% in the outer tissues. This increase in the outer tissues is accompanied by a decrease in the molecular weight of some of the components. These results clearly show that cell wall metabolism during elongation growth differs markedly in inner and outer tissues, and that future studies on the effect of auxin need to take these differences into account.
NCBI PubMed ID: 16667612Effects of indole-3-acetic acid (IAA) on the mechanical properties of cell walls and structures of cell wall polysaccharides in outer and inner tissues of segments of dark grown squash (Cucurbita maxima Duch.) hypocotyls were investigated. IAA induced the elongation of unpeeled, intact segments, but had no effect on the elongation of peeled segments. IAA induced the cell wall loosening in outer tissues as studied by the stress-relaxation analysis but not in inner tissues. IAA-induced changes in the net sugar content of cell wall fractions in outer and inner tissues were very small. Extracted hemicellulosic xyloglucans derived from outer tissues had a molecular weight about two times as large as in inner tissues, and the molecular weight of xyloglucans in both outer and inner tissues decreased during incubation. IAA substantially accelerated the depolymerization of xyloglucans in outer tissues, while it prevented that in inner tissues. These results suggest that IAA-induced growth in intact segments is due to the cell wall loosening in outer tissues, and that IAA-accelerated depolymerization of hemicellulosic xyloglucans in outer tissues is involved in the cell wall loosening processes.
NCBI PubMed ID: 16668092The physicochemical nature of the cell wall was determined in the fourth internode of three isogenic brittle mutants of barley (Hordeum vulgare L.) and corresponding nonbrittle strains. Cellulose contents of the brittle culms were 17.5 to 20.3% of those of corresponding nonbrittle strains. No major difference was found in lignin and noncellulose components (except glucose) between brittle and nonbrittle strains. Maximum bending stresses of brittle culms were 38.0 to 54.2% of those of corresponding nonbrittle strains. The degree of polymerization of cellulose, measured by viscometry, was similar between the brittle and the nonbrittle strains. Mole number of cellulose molecules in a unit length of brittle culms, calculated by dividing cellulose mass by molecular weight, was 7.7 to 17.3% of those of the nonbrittle strains. These results indicate that brittleness of mutant culms is due to fewer numbers of cellulose molecules in the cell walls.
NCBI PubMed ID: 16668428Growth of squash (Cucurbita maxima Duch.) roots was significantly inhibited by 1 mM AlCl3 as early as 1 h after the treatment. The growth inhibition was confined to the elongating zone (1-6 mm from the root tip). Chemical analysis of cell-wall polysaccharides from roots revealed that aluminum increased pectin, hemi-cellulose, and cellulose contents after 3 h of treatment. The effect of aluminum on pectin content was found in the elongating zone including the root tip, whereas change in cellulose content was confined to only nonelongating zones. Hemicellulose content increased in all of the regions along the root axis. The increase in the pectin fraction was due to the increases in uronic acids, galactose, and arabinose constituents, whereas hemicellulose content changed due to increases in glucose, xylose, galactose, and arabinose. The results clearly indicate that aluminum rapidly reduced squash root growth by inhibiting cell elongation and altering metabolism of cell-wall polysaccharides in the nonelongating zone as well as in the elongating zone.
NCBI PubMed ID: 12232377The biochemical mechanisms underlying cell wall expansion in plants have long been a matter of conjecture. Previous work in our laboratory identified two proteins (named "expansins") that catalyze the acid-induced extension of isolated cucumber cell walls. Here we examine the mechanism of expansin action with three approaches. First, we report that expansins did not alter the molecular mass distribution or the viscosity of solutions of matrix polysaccharides. We conclude that expansins do not hydrolyze the major pectins or hemicelluloses of the cucumber wall. Second, we investigated the effects of expansins on stress relaxation of isolated walls. These studies show that expansins account for the pH-sensitive and heat-labile components of wall stress relaxation. In addition, these experiments show that expansins do not cause a progressive weakening of the walls, as might be expected from the action of a hydrolase. Third, we studied the binding of expansins to the cell wall and its components. The binding characteristics are consistent with this being the site of expansin action. We found that expansins bind weakly to crystalline cellulose but that this binding is greatly increased upon coating the cellulose with various hemicelluloses. Xyloglucan, either solubilized or as a coating on cellulose microfibrils, was not very effective as a binding substrate. Expansins were present in growing cell walls in low quantities (approximately 1 part in 5000 on a dry weight basis), suggesting that they function catalytically. We conclude that expansins bind at the interface between cellulose microfibrils and matrix polysaccharides in the wall and induce extension by reversibly disrupting noncovalent bonds within this polymeric network. Our results suggest that a minor structural component of the matrix, other than pectin and xyloglucan, plays an important role in expansin binding to the wall and, presumably, in expansin action.
NCBI PubMed ID: 11536663The cell-wall polysaccharides of Arabidopsis thaliana leaves have been isolated, purified, and characterized. The primary cell walls of all higher plants that have been studied contain cellulose, the three pectic polysaccharides homogalacturonan, rhamnogalacturonan I and rhamnogalacturonan II, the two hemicelluloses xyloglucan and glucuronoarabinoxylan, and structural glycoproteins. The cell walls of Arabidopsis leaves contain each of these components and no others that we could detect, and these cell walls are remarkable in that they are particularly rich in phosphate buffer-soluble polysaccharides (34% of the wall). The pectic polysaccharides of the purified cell walls consist of rhamnogalacturonan I (11%), rhamnogalacturonon II (8%), and homogalacturonan (23%). Xyloglucan (XG) accounts for 20% of the wall, and the oligosaccharide fragments generated from XG by endoglucanase consist of the typical subunits of other higher plant XGs. Glucuronoarabinoxylan (4%), cellulose (14%) and protein (14%) account for the remainder of the wall. Except for the phosphate buffer-soluble pectic polysaccharides, the polysaccharides of Arabidopsis leaf cell walls occur in proportions similar to those of other plants. The structure of the Arabidopsis cell-wall polysaccharides are typical of those of many other plants.
NCBI PubMed ID: 7770522The cell walls of styles of Nicotiana alata Link et Otto (ornamental tobacco; Solanaceae) were analysed chemically and examined histochemically. Cell-wall preparations were obtained from whole styles and from isolated transmitting-tissue cells. The style epidermal cells were shown histochemically to have thick, lignified secondary walls. These walls probably constituted a large proportion of the cell-wall preparation from whole styles as analysis of whole-style walls indicated that the major polysaccharides were xylans and cellulose, which are typical of lignified secondary walls of Magnoliopsida (dicotyledons). Lignification of the style epidermal walls was also demonstrated histochemically in 10 other species (5 genera including Nicotiana) of the sub-family Cestroideae of the Solanaceae, but not in 15 species (9 genera) of the sub-family Solanoideae of the Solanaceae, nor in 3 other species of dicotyledons and 2 species of Liliopsida (monocotyledons). Analysis of the cell-wall preparation from isolated transmitting-tissue cells of N. alata indicated that these contained cellulose, xyloglucans, and pectic polysaccharides, which is typical of primary cell walls of dicotyledons. However, the analysis indicated that the walls also contained an unusually high proportion of Type II arabinogalactans. Staining of the transmitting-tissue cell-wall preparation with β-glucosyl Yariv reagent, a histochemical reagent specific for arabinogalactan proteins, confirmed their presence, which may be related to the role of these cells in secreting the stylar extracellular matrix.
polysaccharide, cell wall, lignin, Nicotiana, arabinogalactan protein, style
Publication DOI: 10.1007/BF00199682Susceptible and resistant cotton lines were cytologically and histochemically investigated for their defense reactions to a highly aggressive and defoliating strain of Verticillium dahliae, a fungus responsible for vascular wilt. Cytochemistry showed that early responses consisted of reinforcement in structural barriers with polysaccharides, including callose and cellulose. Ultrastructural modifications of parenchyma cells of the vascular tissues were associated with strong production of terpenoids and phenolics. These defense reactions were detected early in roots of the resistant line, one to four days after inoculation, while they were seen later in roots of the susceptible line.
ultrastructure, terpenoids, phenolics, callose, cytochemistry, vascular wilt
Publication DOI: 10.1023/A:1018558225454In plants, cell walls are one of the first lines of defence for protecting cells from successful invasion by fungal pathogens and are a major factor in basal host resistance. For the plant cell to block penetration attempts, it must adapt its cell wall to withstand the physical and chemical forces applied by the fungus. Papillae that have been effective in preventing penetration by pathogens are traditionally believed to contain callose as the main polysaccharide component. Here, we have re-examined the composition of papillae of barley (Hordeum vulgare) attacked by the powdery mildew fungus Blumeria graminis f. sp. hordei (Bgh) using a range of antibodies and carbohydrate-binding modules that are targeted to cell wall polysaccharides. The data show that barley papillae induced during infection with Bgh contain, in addition to callose, significant concentrations of cellulose and arabinoxylan. Higher concentrations of callose, arabinoxylan and cellulose are found in effective papillae, compared with ineffective papillae. The papillae have a layered structure, with the inner core consisting of callose and arabinoxylan and the outer layer containing arabinoxylan and cellulose. The association of arabinoxylan and cellulose with penetration resistance suggests new targets for the improvement of papilla composition and enhanced disease resistance.
cellulose, callose, Blumeria graminis, arabinoxylan, papillae, penetration, powdery mildew
NCBI PubMed ID: 25138067In addition to morphological factors (height of the plant, proportion of stems), alfalfa quality is related to several biochemical factors, especially the content and monomeric composition of the cell wall components. This work was aimed at studying internode development in relation to the chemical composition and fractionation of cell walls. Analyses were performed on the fourth apical internodes (elongating), the two following ones (onset of cambial activity), and bottom internodes (mature). Deposition of guaiacyl type lignin occurred in the pectin rich cell walls of apical internodes. The onset of cambial activity corresponded to cell wall accumulation of syringyl-guaiacyl lignin, xylans and/or glucuronoxylans, and cellulose. Such events were related to the thickening of secondary cell walls which proportion increased in mature internodes. Chemical fractionation of the cell walls allowed the release of a high content of water soluble pectins from apical internodes, whereas alkalis were more efficient in extracting heteroxylans from bottom internodes. A partial release of lignin from the cell walls also occurred during the extraction steps. Lignin solubilization was enhanced by the cleavage of labile-ether lignin structures and appeared closely related to the extent of internode differentiation along the stem. Data gained from chemical fractionations evidenced that lignin-xylan-pectic complexes accumulated progressively in secondary wall rich tissues.
cell wall, growth, lignin, Medicago sativa, structural polysaccharides, length, internode
Publication DOI: 10.1021/jf9709818Cell walls harbor proteins and polysaccharides able to condition the development of a plant. In the past year, genes and enzymes modulating the composition and physical properties of walls have been characterized, and wall composition has been linked to the way a cell interacts with another cell, and to the way in which it differentiates. The sum of the signaling and physical activities of a cell wall may explain much about the control of development.
mutants, polysaccharides, deep-water rice, xyloglucan endotransglycosylase, arabinogalactan-proteins, developmental regulation, arabidopsis-thaliana, root-meristem, expansion, localization
NCBI PubMed ID: 10066626A scheme is presented for the fractionation of plant cell walls and treated plant cell walls (fibres) after suspending/dissolving in >99% trifluoroacetic acid (TFA), with oat straw and crystalline cellulose being given as examples. While cleavage of covalent bonds occurs, particularly in the non-cellulosic polysaccharides, many bonds are not hydrolysed and fragments have been identified in which covalent bonds remain between carbohydrates and phenolic components. Cellulose chains do not undergo extensive hydrolysis, even after being dissolved in TFA for at least 8 days. However, CP/MAS NMR and DRIFT IR spectroscopy both confirm that the secondary and tertiary structures of regenerated cellulose are severely modified. By analogy with the crystalline cellulose sample, all the cellulose from the oat straw should be present in the material which is soluble in TFA but is precipitated on addition of water (fraction II). The DRIFT spectrum of oat straw fraction II confirms the presence of non-cellulosic components as well. Most of the lignin from the straw is present in the fraction not soluble in TFA.
cellulose, trifluoroacetic acid, phenolics, Gramineae, Avena sativa, oat straw, non-cellulosic polysaccharides, DRIFT spectroscopy, CP/MAS NMR spectroscopy
NCBI PubMed ID: 11711064The plant cell wall is essential to almost every aspect of plant life. The cell wall is a dynamic and highly ordered complex of polysaccharides, structural proteins and phenolics. The introduction of new techniques in the study of cell-wall architecture, namely the availability of antibodies to cell wall components, new methods in electron microscopy, application of physico-chemical techniques like FTIR and NMR as well as refined biochemical analyses have substantially changed our conception of the cell wall. The extracellular matrix is no longer understood as a static, mainly covalently cross-linked macromolecular structure but as a flexible, developmentally regulated network that is largely based on non-covalent interactions. Three principally independent but interacting networks that form local microdomains can be distinguished: The cellulose-microfibril-xyloglucan network, the network of pectins and the network of structural cell wall proteins. This review summarizes the current ideas about the architecture and biochemical composition of primary cell walls.
polysaccharides, nuclear magnetic resonance, Arabidopsis thaliana, arabinogalactan proteins, plant extracellular matrix, auxin mediated growth, maize coleoptiles, suspension cultures, cross linking, carrot cells
Publication DOI: 10.1002/jpln.1998.3581610503It has been controversial for many years whether in the cellulose of higher plants, the microfibrils are aggregates of 'elementary fibrils', which have been suggested to be about 3.5 nm in diameter. Solid-state NMR spectroscopy was used to examine two celluloses whose fibril diameters had been established by electron microscopy: onion (810 nm, but containing 40% of xyloglucan as well as cellulose) and quince (2 nm cellulose core). Both of these forms of cellulose contained crystalline units of similar size, as estimated from the ratio of surface to interior chains, and the time required for proton magnetisation to diffuse from the surface to the interior. It is suggested that the onion microfibrils must therefore be constructed from a number of cellulose subunits 2 nm in diameter, smaller than the 'elementary fibrils' envisaged previously. The size of these subunits would permit a hexagonal arrangement resembling the cellulose synthase complex.
cellulose, electron microscopy, fiber, xyloglucan, cellulose synthase, onion, quince
NCBI PubMed ID: 22507135The cell wall of higher plants has been studied in numerous species using methods of carbohydrate chemistry, biochemistry and cell biology portraying the wall as a dynamic structure composed of highly complex polysaccharides and structural proteins encoded by multi-gene families. The recent discovery of proteins involved in cell wall loosening has provided opportunities to elucidate the mechanism of extension growth. Genetic tools have rarely been used to analyze the function of these proteins in vivo, or to identify genes involved in the synthesis of cell wall polysaccharides. It has recently been demonstrated that mutants with changes in cell wall composition can be isolated in Arabidopsis thaliana opening possibilities to clone genes involved in the synthesis or modification of cell wall material via map-based approaches. The number of Arabidopsis mutants in cell wall synthesis is very limited, suggesting that novel screening procedures are required to come closer to the goal of saturating cell wall biosynthetic pathways. The availability of large numbers of expressed sequence tags in combination with collections of T-DNA and transposon-tagged Arabidopsis lines offers a considerable potential for the genetic characterization of cell wall-related genes which can be identified via database searches. The recent identification of Arabidopsis genes involved in the synthesis of cell wall precursors, and the discovery of plant homologs to bacterial cellulose synthases offer numerous and exciting possibilities for the genetic dissection of cell wall synthesis in higher plants using Arabidopsis thaliana as a model system.
polysaccharide, Arabidopsis, nucleotide sugar, xyloglucan, cellulose synthase, cell wall mutant, expansin
Publication DOI: 10.1016/S0981-9428(98)80101-0Over the years numerous studies have lauded the benefits of a high fiber diet. In fact, fiber along with β-carotene and co-3 polyunsaturated fatty acids may be viewed as the emissaries of the modern day nutraceutical and functional foods field. In accordance, the United States Food and Drug Administration (FDA) have approved the use of several health claims related to either the specific or general fiber content of a food. Fiberous molecules include the complex carbohydrates cellulose, hemicelluloses, pectin, algal polysaccharides and mucilages along with the polyphenolic structural molecule lignin. While by strict definition fiber is not considered dietary essential, the health promoting benefits of higher fiber diet has made this class of nutrients very recognizable in the rapidly developing nutraceutical field. Fiber consumption has been linked in decreased incidence of heart disease, various types of cancer, and diverticulosis. While still controversial, it has also been proposed that fiber might be beneficial to individuals with diabetes mellitus in controlling their blood glucose response to a given meal. Fiber structure, physical properties and their role in health promotion will be discussed in this review.
diabetes, cancer, fiber, nutraceuticals, functional foods, heart disease
Publication DOI: 10.1300/J133v02n04_03| -4)-b-D-GlcpNAc-(1- | Show graphically |
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Show legend Show as text |
Structure type: homopolymer
Trivial name: chitin
Compound class: O-polysaccharide, cell wall polysaccharide, glucan, polysaccharide, chitin
Contained glycoepitopes: IEDB_135813,IEDB_137340,IEDB_141807,IEDB_151531,IEDB_153212,IEDB_241099,IEDB_423114,IEDB_423150,SB_74,SB_85
This chapter describes the range of glycan structures and pathways that are found in different parasitic protozoa. All parasitic protists express a range of glycoconjugates that form protective protein-rich or carbohydrate-rich surface coats. Protein-rich coats are typically found on developmental stages that inhabit nonhydrolytic niches, such as the bloodstream and nonacidified intracellular vacuoles. These coats are commonly dominated by a limited repertoire of antigenically diverse proteins that are commonly, but not always, glycosylphosphatidylinositol- (GPI-) anchored and modified with N- or O-glycans. Carbohydrate-rich coats are commonly found on developmental stages that dwell within hydrolytic environments, such as vertebrate and arthropod digestive tracts and lysosomal vacuoles. These coats are dominated by GPI-anchored glycoproteins that are heavily modified with N-glycans, O-glycans, or phosphoglycans. Free GPI glycolipids (not attached to protein) can also be abundant or dominant components of these coats. Some parasitic protists can also form highly resistant cyst stages encased within polysaccharide-rich cell walls. Considerable progress has been made in defining the structures of the surface and intracellular glycans of the parasitic protists, their biosynthesis and the role that individual components play in parasite infectivity.
O-glycosylation, Glycosylphosphatidylinositol, N-glycosylation, protozoan parasites, Phosphoglycosylation
Publication DOI: 10.1016/B978-0-12-374546-0.00012-2The impact of fungal infections on humans is a serious public health issue that has received much less attention than bacterial infection and treatment, despite ever-increasing incidence exacerbated by an increased incidence of immunocompromised individuals in the population. Candida species, in particular, cause some of the most prevalent hospital-related fungal infections. Fungal infections are also detrimental to the well-being of grazing livestock, with milk production in dairy cows, and body and coat condition adversely affected by fungal infections. Fungal cell walls are essential for viability, morphogenesis and pathogenesis: numerous anti-fungal drugs rely on targeting either the cell wall or cell membrane, but the pipeline of available bioactives is limited. There is a clear and unmet need to identify novel targets and develop new classes of anti-fungal agents. This mini review focuses on fungal cell wall structure, composition and biosynthesis in Candida spp., including C. auris. In addition, an overview of current advances in the development of cell wall targeted therapies is considered.
vaccines, glycoproteins, inhibitors, chitin, fungal cell wall
NCBI PubMed ID: 34746525The cell wall of Trichosporon cutaneum consists of 11% protein, 63% neutral carbohydrate, 9% glucosamine and 13% glucuronic acid. The sugars include glucose (32%), mannose (6%) and traces of xylose and galactose. The cell wall was fractionated with alkali to yield a mixture of alkali-soluble matrix components, and an alkali-insoluble glucan associated with chitin. The alkali-insoluble glucan contained a mixture of (1-3) and (1-6) glycosidic linkages. It was only partly susceptible to digestion by the β(1-3) glucanase, Zymolyase. The alkali-soluble fraction contained glucan, mannan and acidic polymers. The glucan was (1-3)-linked with no (1-6) linkages and only trace amounts of (1-3-6)-linked glucose. It was resistant to digestion by Zymolyase. Extensive hydrolysis of this fraction with trifluoroacetic acid released a high-molecular-mass glucuronan which had 1H- and 13C-NMR profiles matching those of the β(1-4) glucuronan, mucoric acid. Xylomannan was purified from isolated cell walls and from whole cells. It contained glucose, mannose, xylose, and D-glucuronic acid. It was very similar in composition and structure to the capsular polysaccharides of Cryptococcus neoformans, and to an extracellular polysaccharide produced by another yeast described as T. cutaneum. Electron microscopy showed that the cell wall of T. cutaneum has a lamellar structure characteristic of a basidiomycetous yeast rather than the electron-dense 'fuzzy coat' seen in Candida albicans.
NCBI PubMed ID: 8245838Deproteinated A. niger biomass contains several covalently bound amino acids. The most abundant are arginine, serine, and proline in molar ratio of 3: 2: 2. One order of magnitude less is the amount of valine, phenylalanine, leucine and glycine. On deacetylation and separation of chitosan from glucan, the main three amino acids remain bound predominantly to chitosan, whereas the hydrophobic amino acids accompany mainly glucan. The presence of arginine could be the cause of stronger basicity of fungal chitosan compared to polyglucosamine.
Publication DOI: 10.1007/BF00805812During the past few years, cyto- and immunocytochemical techniques have been developed and widely used for locating and identifying various molecules in plant cell compartments. The last decade has witnessed tremendous improvements in molecular cytology, thus allowing an accurate in situ detection of various components thought to play important biological functions in the plant metabolism. The use of immunocytochemistry to investigate resistance mechanisms of plants upon pathogen attack has provided key information on the defense strategy that plants elaborate during a host-pathogen interaction. Of the various proteins induced in response to infection, chitinases and β-1,3-glucanases have been the focus of particular attention due to their believed antimicrobial activity through the hydrolysis of the main fungal wall components, chitin and β-1,3-glucans. Attention has also been paid to β-fructosidase, the enzyme that hydrolyzes sucrose into glucose and fructoside. The marked accumulation of this enzyme upon pathogen infection has led to the consideration that infection may greatly influence the metabolic activity of colonized tissues by creating alterations of source-sink relationships. Another facet of the plant's defense strategy that has been the focus of considerable interest is related to the accumulation of structural compounds, such as hydroxyproline-rich glycoproteins and callose, to reinforce the wall architecture, thus decreasing vulnerability to microbial enzymes. A number of alternatives designed to improve plant protection towards pathogen invasion have been suggested. Among these, the production of transgenic plants expressing constitutively a foreign resistance gene and the pretreatment of plants with elicitors of defense reactions have been the subject of intensive studies at the molecular, biochemical, and cytological levels. Results of such studies clearly demonstrate the important contribution that cyto- and immunocytochemical approaches can make to our knowledge of how plants defend themselves and how plant disease resistance can be directly enhanced. These approaches will undoubtedly be active areas for future research in the development of biological control alternatives in which the mode of action of the product used is of key importance.
NCBI PubMed ID: 7626800The cell-wall components of the interface compartment in functioning mycorrhizal roots of maize (Zea mays L. cv. W64A) have been investigated with the use of immunocytochemistry and enzyme/lectin-gold techniques. The distribution of specific cell-wall probes was determined in the apical and differentiated regions of maize roots in the presence and in the absence of the mycorrhizal fungus, Glomus versiforme. Labelling experiments showed that a maize hydroxyproline-rich glycoprotein (HRGP), identified with a specific antibody, was particularly abundant in the apical dividing cells of the root meristem. Cellulose, located with a cellobiohydrolase-gold complex, showed a similar labelling pattern in the walls of both meristematic and differentiated parts of the roots. When the cortex was colonized by the mycorrhizal fungus, the HRGP and cellulose were expressed in two sites: the wall and the interface area created by invagination of the host membrane around the developing fungus. In contrast, in uninfected roots of the same age, they were only present in the inner part of the wall. A specific antibody against β-1,3-glucans demonstrated that these glucans were not laid down at the interface between the plant and fungus, while they appeared to be a skeletal component of the fungal wall, together with chitin.
cell wall, cellulose, β-1, arbuscular mycorrhizae, 3-glucans, hydroxyproline-rich glycoprotein, zea root meristem
Publication DOI: 10.1007/BF00199680Glycosylphosphatidylinositol (GPI) membrane anchors are essential for the integration of yeast cell adhesion proteins into the cell wall, but mature cell-wall proteins are unlikely to be attached directly to the membrane. We thus propose that GPI-anchored glycoprotein forms are intermediates in a process that crosslinks the major components of the cell wall by transglycosylation. This mechanism may be critical for both the biosynthesis and overall architecture of the cell wall.
NCBI PubMed ID: 14731865We have previously shown that mutations in the yeast KNR4 gene resulted in pleiotropic cell wall defects, including resistance to killer 9 toxin, elevated osmotic sensitivity to SDS and increased resistance to zymolyase, a (1→3)-β-glucanase. In this report, we further demonstrated that knr4 mutant cells were more permeable to a chromogenic substrate, X-GAL, suggesting that the mutant cell walls were leakier to certain non-permeable molecules. To determine if these defects resulted from structural changes in the cell walls, we analysed the alkali-insoluble cell wall components using HPLC assays developed for this purpose. Comparative analysis using four isogenic strains from a 'knr4 disrupted' tetrad demonstrated that mutant cell walls contained much less (1→3)-β-glucan and (1→6)-β-glucan; however, the level of chitin, a minor cell wall component, was found to be five times higher in the mutant strains compared to the wild-type strains. The data suggested that the knr4 mutant cell walls were dramatically weakened, which may explain the pleiotropic cell wall defects.
NCBI PubMed ID: 7992508In recent years it has become evident that the structural polysaccharide chitin is synthesized from a family of enzymes encoded by multiple CHS chitin synthase genes, and regulated by an array of ancillary gene products that influence CHS activation and localization. Considerable attention has therefore been given to elucidating the function of specific CHS gene products in individual fungi. In those fungi in which individual CHS genes have been deleted systematically, there is little evidence for redundancy of function in family members. Chs enzymes are now known that participate in lateral wall biosynthesis, septum synthesis and spore formation but the phenotype of some CHS gene mutations is subtle, and so the role of the corresponding isoenzymes remains obscure. Nonetheless, it has become clear that certain members of the CHS gene families of fungi are more important for growth, integrity and viability than others, and this knowledge has already led to the design of new classes of antifungal agents that are targeted against key enzyme activities. Future work in this area will help define how individual Chs enzymes are targeted to specific regions of the cell wall and at specific times of the cell cycle, and should facilitate the rational development of novel and highly specific antifungal agents.
cell wall, mutagenesis, morphogenesis, antifungal drugs, chitin synthesis
Publication DOI: 10.1080/mmy.39.1.41.53N-Acetylchitooligosaccharides (oligochitin, chitin oligosaccharides) of a specific size can act as potent elicitor signals for suspension-cultured rice cells as well as various plant cells which include many monocots and some dicots. We recently isolated and characterized a highly elicitor-active glucopentaose from the cell wall P-Glucan from rice blast disease fungus. The results indicated that rice and soybean cells recognize different structural units of fugal glucans as elicitor signals. Because this elicitor treatment can induce many defense reactions, it has been serving as an excellent model system for the study of the signal transduction cascade leading to the activation of defense-related genes. It is critically important to identify and characterize the receptor molecules which perceive the elicitor signal to clarify the whole signal transduction cascade. A 75 kDa chitin oligosaccharide binding protein in the plasma membrane of suspension-cultured rice cells was identified as a putative receptor for the elicitor and purified. Recent studies on the structure and function of the binding proteins for these oligosaccharide elicitors will provide a clue to understanding how these elicitors are perceived and transduced in rice and other plant cells and also how such recognition systems have evolved.
receptor, signal transduction, elicitor
Publication DOI: 10.4052/tigg.12.113Background: To explore chitin synthesis initiation, the effect of addition of exogenous oligosaccharides on in vitro chitin synthesis was studied. Oligosaccharides of various natures and lengths were added to a chitin synthase assay performed on a Saccharomyces cerevisiae membrane fraction. Findings. N-acetylchito-tetra, -penta and -octaoses resulted in 11 to 25% [14C]-GlcNAc incorporation into [14C]-chitin, corresponding to an increase in the initial velocity. The activation appeared specific to N-acetylchitooses as it was not observed with oligosaccharides in other series, such as β-(1,4), β-(1,3) or α-(1,6) glucooligosaccharides. Conclusions: The effect induced by the N-acetylchitooses was a saturable phenomenon and did not interfere with free GlcNAc and trypsin which are two known activators of yeast chitin synthase activity in vitro. The magnitude of the activation was dependent on both oligosaccharide concentration and oligosaccharide size.
Oligosaccharides, glycosyltransferase, chitin synthase, polymerization activation, polysaccharide synthase
NCBI PubMed ID: 22032207Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. Chitin occurs in nature as ordered macrofibrils. It is the major structural component in the exoskeleton of crab and shrimp shells and the cell wall of fungi and yeast. As chitin is not readily dissolved in common solvents, it is often converted to its more deacetylated derivative, chitosan. Chitin, chitosan, and its derivatives are widely used in tissue engineering, wound healing, and as functional foods. Recently, easy methods for the preparation of chitin and chitosan nanofibers have been developed, and studies on biomedical applications of chitin and chitosan nanofibers are ongoing. Chitin and chitosan nanofibers are considered to have great potential for various biomedical applications, because they have several useful properties such as high specific surface area and high porosity. This review summarizes methods for the preparation of chitin and chitosan nanofibers. Further, biomedical applications of chitin and chitosan nanofibers in (i) tissue engineering, (ii) wound dressing, (iii) cosmetic and skin health, (iv) stem cell technology, (v) anti-cancer treatments and drug delivery, (vi) anti-inflammatory treatments, and (vii) obesity treatment are summarized. Many studies indicate that chitin and chitosan nanofibers are suitable materials for various biomedical applications.
drug delivery, cosmetics, chitosan, chitin, obesity, nanofibers, biomedical applications, tissue engineering, stem cells
NCBI PubMed ID: 25992423Chitin synthases (CHS) produce chitin, an essential component of the fungal cell wall. The molecular mechanism of processive chitin synthesis is not understood, limiting the discovery of new inhibitors of this enzyme class. We identified the bacterial glycosyltransferase NodC as an appropriate model system to study the general structure and reaction mechanism of CHS. A high throughput screening-compatible novel assay demonstrates that a known inhibitor of fungal CHS also inhibit NodC. A structural model of NodC, on the basis of the recently published BcsA cellulose synthase structure, enabled probing of the catalytic mechanism by mutagenesis, demonstrating the essential roles of the DD and QXXRW catalytic motifs. The NodC membrane topology was mapped, validating the structural model. Together, these approaches give insight into the CHS structure and mechanism and provide a platform for the discovery of inhibitors for this antifungal target.
cell wall, chitin, chitin synthase
NCBI PubMed ID: 24942743Chitin and β-glucan are conserved throughout evolution in the fungal cell wall and are the most common polysaccharides in fungal species. Together, these two polysaccharides form a structural scaffold that is essential for the survival of the fungus. In the present study, we demonstrated that Aspergillus fumigatus alkali-insoluble cell wall fragments (AIF), composed of chitin linked covalently to β-glucan, induced enhanced immune responses when compared with individual cell wall polysaccharides. Intranasal administration of AIF induced eosinophil and neutrophil recruitment, chitinase activity, TNF-α and TSLP production in mice lungs. Selective destruction of chitin or β-glucan from AIF significantly reduced eosinophil and neutrophil recruitment as well as chitinase activity and cytokine expression by macrophages, indicating the synergistic effect of the cell wall polysaccharides when presented together as a composite PAMP. We also showed that these cell wall polysaccharides induced chitin-specific IgM in mouse serum. Our in vivo and in vitro data indicate that chitin and β-glucan play important roles in activating innate immunity when presented as composite cell wall PAMPs.
inflammation, glucan, innate immunity, lung, chitin, Fungal cell wall polysaccharides
NCBI PubMed ID: 24286790Polysaccharides such as α- and β-glucans, chitin, and glycoproteins extensively modified with both N- and O-linked carbohydrates are the major components of fungal surfaces. The fungal cell wall is an excellent target for the action of antifungal agents, since most of its components are absent from mammalian cells. Recognition of these carbohydrate-containing molecules by the innate immune system triggers inflammatory responses and activation of microbicidal mechanisms by leukocytes. This review will discuss the structure of surface fungal glycoconjugates and polysaccharides and their recognition by innate immune receptors.
glycoconjugates, polysaccharides, innate immunity, fungal pathogens, pattern recognition receptors
NCBI PubMed ID: 25353009Candida albicans is a major life-threatening human fungal pathogen in the immunocompromised host. Host defense against systemic Candida infection relies heavily on the capacity of professional phagocytes of the innate immune system to ingest and destroy fungal cells. A number of pathogens, including C. albicans, have evolved mechanisms that attenuate the efficiency of phagosome-mediated inactivation, promoting their survival and replication within the host. Here we visualize host-pathogen interactions using live-cell imaging and show that viable, but not heat- or UV-killed C. albicans cells profoundly delay phagosome maturation in macrophage cell lines and primary macrophages. The ability of C. albicans to delay phagosome maturation is dependent on cell wall composition and fungal morphology. Loss of cell wall O-mannan is associated with enhanced acquisition of phagosome maturation markers, distinct changes in Rab GTPase acquisition by the maturing phagosome, impaired hyphal growth within macrophage phagosomes, profound changes in macrophage actin dynamics, and ultimately a reduced ability of fungal cells to escape from macrophage phagosomes. The loss of cell wall O-mannan leads to exposure of β-glucan in the inner cell wall, facilitating recognition by Dectin-1, which is associated with enhanced phagosome maturation.
cell wall, β-glucan, Candida albicans, b-glucan
NCBI PubMed ID: 25467440GPI-anchoring is a universal and critical post-translational protein modification in eukaryotes. In fungi, many cell wall proteins are GPI-anchored, and disruption of GPI-anchored proteins impairs cell wall integrity. After being synthesized and attached to target proteins, GPI anchors undergo modification on lipid moieties. In spite of its importance for GPI-anchored protein functions, our current knowledge of GPI lipid remodelling in pathogenic fungi is limited. In this study, we characterized the role of a putative GPI lipid remodelling protein, designated PerA, in the human pathogenic fungus Aspergillus fumigatus. PerA localizes to the endoplasmic reticulum and loss of PerA leads to striking defects in cell wall integrity. A perA null mutant has decreased conidia production, increased susceptibility to triazole antifungal drugs, and is avirulent in a murine model of invasive pulmonary aspergillosis. Interestingly, loss of PerA increases exposure of β-glucan and chitin content on the hyphal cell surface, but diminished TNF production by bone marrow-derived macrophages relative to wild type. Given the structural specificity of fungal GPI-anchors, which is different from humans, understanding GPI lipid remodelling and PerA function in A. fumigatus is a promising research direction to uncover a new fungal specific antifungal drug target.
Aspergillus fumigatus, GPI
NCBI PubMed ID: 24779420The cell wall structure of mushroom sclerotium was investigated by a fractionation of its soluble cell wall polysaccharides followed by chemical, physico-chemical and microscopic analyses. The present results suggest that cell wall structure of Pleurotus tuber regium sclerotium contains three main layers: an outer layer of glycoproteins, a middle layer of hyper-branched glucans and an inner layer of complex between hyper-branched glucan and chitin. The structure of the hyper-branched glucans were elucidated by the methylation analysis to be composed of →1)-Glcp-(4→ linkages as the backbone with some →1)-Glcp(6→ linkages existed in the side chains, while some →1)-Glcp-(3→ linkages might exist in the backbone or side chains. SEC-MALLS analysis revealed that hyper-branched β-glucans had a M-w ranging from 1400000 to 5200000 g/mol and R.M.S. radius ranging from 26 nm to 38.5 nm. SEM and AFM further showed that hyper-branched β-glucans were spherical in shape when dispersed in water.
Publication DOI: 10.1016/j.foodhyd.2013.09.023Within the domain of Eukarya, the fungi form a seperate kingdom. The typical formation of branched mycelia from single hyphae is based on cell wall production at the growing hyphal tip. There, excretory vesicle fuse with the membrane releasing cell wall synthesis enzymes like chitin synthase forming the polymer of N-acetyl glucosamin, the backbone of fungal cell walls. In addition, glucan synthases form the structural component β-1,3-glucan. Via β-1,6-glucan, cell wall proteins can be linked to the maturing cell wall, and α-1,3-glucan can form a matrix within the cell wall, but also a slimy matrix secreted into the medium. A layer of hydrophobins allows for growth into the air, but also facilitates formation of macroscopic structures like mushrooms.
cell wall, glucan, fungi, chitin
Publication DOI: 10.1002/biuz.201610599This study was devoted to polysaccharides extraction (chitin and chitosan) from Penicillium camembertii cell wall. A culture on solid medium was adopted under carefully selected conditions, appropriate to mycelium growth: duration 6 days, medium YPGA and pH 5. The temperature was adjusted (20 °C to 28 °C) in order to study the effect of temperature on chitin/chitosan production. Biomass decreased with increasing temperatures: 13 g/L at 20 °C and 11.6 g/L at 28 °C. For all tested temperatures, the yields of insoluble alkaline fractions (AIM) were almost identical (200 mg/g). The solubility of fractions in 2% acetic acid allowed obtaining two fractions: an insoluble fraction (AcIM) with 18% of maximum yield and soluble fraction (AcSM) with 1% yield. The SEM micrographs of AcIM fractions were similar to AIM fractions. These showed a compact structure different from commercial chitin. The presence of chitin in P. Camembertii cultured in YPGA medium was also confirmed by ATR spectroscopy.
chitin, Biomass, free chitosan, Penicillium camembertii, YPGA
NCBI PubMed ID: 31004649In 1799, Hatchett decalcified shells of crabs, lobsters, prawns and crayfish with mineral acids, observing that they produced a moderate effervescence and in a short time were found to be soft and plastic of a yellowish color and like a cartilage, which retained the original figure. Although this is the first mention of calcified chitin in invertebrates, the discovery of chitin is usually attributed both to Braconnot in 1811 who discovered chitin from fungi, and to Odier in 1823 who obtained a hornlike material after treatment of cockchafer elytra with potassium hydroxide. Chitin was first named fongine by Braconnot and then chitine by Odier. Children revealed the nitrogenous nature of chitin in 1824. The history of chitosan, the main derivative of chitin, dates back to 1859 with the work of Rouget. The name of chitosan was, however, introduced in 1894 by Hoppe-Seyler. In 1876, Ledderhose hydrolyzed arthropod chitin and discovered glykosamin, the first derivative of chitin. This review describes the 220 years of the development of chitin. I have roughly divided the story into five periods: discovery from 1799 to 1894, a period of confusion and controversy from 1894 to 1930, exploration in 1930–1950, a period of doubt from 1950 to 1970, and finally the period of application from 1970. The different periods are illustrated by examples of published studies, in particular from outstanding scholars who have left their mark on the history of this polysaccharide. Although this historic review is not exhaustive, it highlights the work of researchers who have contributed to the development of our knowledge of chitin throughout the 220 years of its history.
History, chitosan, chitin, discovery, Braconnot, controversy, exploration, period of doubt, period of application
Publication DOI: 10.1007/s10311-019-00901-0Chitin is a linear polysaccharide of the amino sugar N-acetyl glucosamine. It is present in the extracellular matrix of a variety of invertebrates including sponges, molluscs, nematodes and arthropods and fungi. Generally, it is an important component of protective or supportive extracellular matrices that cover the tissue that produces it or the whole body of the organism. Chitin fibres associate with each other adopting one of three possible crystalline organisations, i.e. α-, β- or γ-chitin. Usually, chitin fibre bundles interact with chitin-binding proteins forming higher order structures. Chitin laminae, which are two-dimensional sheets of α-chitin crystals with antiparallel running chitin fibres in association with β-folded proteins, are primary constituents of the arthropod cuticle and the fibrous extracellular matrix in sponges. A tri-dimensional composite material of proteins coacervates and β-chitin constitute hard biomaterials such as the squid beak. The molecular composition of γ-chitin-based structures that contribute to the physical barrier found in insect cocoons is less well studied. In principle, chitin is a versatile extracellular polysaccharide that in association with proteins defines the mechanical properties of tissues and organisms.
evolution, Extracellular matrix, barrier, Cuticle, body shape
NCBI PubMed ID: 31102240Chitin is an important structural polysaccharide, which supports and organizes extracellular matrices in a variety of taxonomic groups including bacteria, fungi, protists, and animals. Additionally, chitin has been recognized as a molecule that is required for Rhizobia-legume symbiosis and involved in arbuscular mycorrhizal signaling in the symbiotic interaction between terrestrial plants and fungi. Moreover, it serves as a unique molecular pattern in the plant defense system against pathogenic fungi and parasites, and in the innate and adaptive immune response of mammals and humans. In this review, we will focus on the prevalence and structural function of chitin in bacteria, fungi, and protists, with a particular focus on the evolution of chitin synthases and the function of chitin oligosaccharides as a signaling molecule in symbiosis and immunity.
Rhizobia, cell wall, fungi, protists, skeleton
NCBI PubMed ID: 31102241Chitin is one of the most important carbohydrates of the fungal cell wall, and is synthesized by chitin synthases. Chitin can be degraded by chitinases, which are important virulence factors in pathogenic fungi. Knowledge about the biosynthesis and degradation of chitin, and the enzymes responsible, has accumulated in recent years. In this review, we analyze the amino acid sequences of chitin synthases from several typical fungi. These enzymes can be divided into seven groups. While the different chitin synthases from a single fungus share a low degree of similarity, the same type of chitin synthase from different fungi shows high similarity. The number of chitinase genes in fungi display wide variation, from a single gene in Schizosaccharomyces pombe, to 36 genes in Trichoderma virens. Chitinases from different fungi can be divided into four groups. The functions of chitin synthases and chitinases in several typical fungi are summarized, and the crystal structures of chitinases and chitinase modification are also discussed.
crystal structure, modification, chitin, chitin synthase, chitinase
NCBI PubMed ID: 31102246The traditional yeast Saccharomyces cerevisiae has been widely used as a host for the production of recombinant proteins and metabolites with industrial potential. However, its thick and rigid cell wall presents problems for the effective recovery of products. In this study, we modulated the expression of ScOCH1, encoding the α-1,6-mannosyltransferase responsible for outer chain biosynthesis of N-glycans, and ScCHS3, encoding the chitin synthase III required for synthesis of the majority of cell wall chitin, by exploiting the repressible ScMET3 promoter. The conditional single mutants PMET3-OCH1 and PMET3-CHS3 and the double mutant PMET3-OCH1/PMET3-CHS3 showed comparable growth to the wild-type strain under normal conditions but exhibited increased sensitivity to temperature and cell wall-disturbing agents in the presence of methionine. Such conditional growth defects were fully recovered by supplementation with 1 M sorbitol. The osmotic lysis of the conditional mutants cultivated with methionine was sufficient to release the intracellularly expressed recombinant protein, nodavirus capsid protein, with up to 60% efficiency, compared to lysis by glass bead breakage. These mutant strains also showed approximately three-fold-enhanced secretion of a recombinant extracellular glycoprotein, Saccharomycopsis fibuligera β-glucosidase, with markedly reduced hypermannosylation, particularly in the PMET3-OCH1 mutants. Furthermore, a substantial increase of extracellular glutathione production, up to four-fold, was achieved with the conditional mutant yeast cells. Together, our data support that the conditional cell wall lysis mutants constructed based on the modulation of ScOCH1 and ScCHS3 expression would likely be useful hosts for the improved recovery of proteins and metabolites with industrial application.
α-1, conditional mutant, Saccharomyces cerevisiae, 6-mannosyltransferase, chitin synthase III, MET3 promoter
NCBI PubMed ID: 30706115This review discusses the wealth of information available for the N. crassa cell wall. The basic organization and structure of the cell wall is presented and how the wall changes during the N. crassa life cycle is discussed. Over forty cell wall glycoproteins have been identified by proteomic analyses. Genetic and biochemical studies have identified many of the key enzymes needed for cell wall biogenesis, and the roles these enzymes play in cell wall biogenesis are discussed. The review includes a discussion of how the major cell wall components (chitin, β-1,3-glucan, mixed β-1,3-/β-1,4- glucans, glycoproteins, and melanin) are synthesized and incorporated into the cell wall. We present a four-step model for how cell wall glycoproteins are covalently incorporated into the cell wall. In N. crassa, the covalent incorporation of cell wall glycoproteins into the wall occurs through a glycosidic linkage between lichenin (a mixed β-1,3-/β-1,4- glucan) and a "processed" galactomannan that has been attached to the glycoprotein N-linked oligosaccharides. The first step is the addition of the galactomannan to the N-linked oligosaccharide. Mutants affected in galactomannan formation are unable to incorporate glycoproteins into their cell walls. The second step is carried out by the enzymes from the GH76 family of α-1,6-mannanases, which cleave the galactomannan to generate a processed galactomannan. The model suggests that the third and fourth steps are carried out by members of the GH72 family of glucanosyltransferases. In the third step the glucanosyltransferases cleave lichenin and generate enzyme/substrate intermediates in which the lichenin is covalently attached to the active site of the glucanosyltransferases. In the final step, the glucanosyltransferases attach the lichenin onto the processed galactomannans, which creates new glycosidic bonds and effectively incorporates the glycoproteins into the cross-linked cell wall glucan/chitin matrix.
cell wall, Galactomannan, glucan, filamentous fungi, melanin, Neurospora, glucanosyltransferase, mannanase
NCBI PubMed ID: 31649638Invasive fungal infections are some of the most life-threatening infectious diseases in the hospital setting. In industrialized countries, the most common fungal species isolated from immunocompromised patients are Candida and Aspergillus spp. However, the number of infections due to Mucorales spp. is constantly increasing and little is known about the virulence factors of these fungi. The fungal cell wall is an important structure protecting fungi from the environment. A better knowledge of its composition should improve our understanding of host-pathogen interactions. Cell wall molecules are involved in tissue adherence, immune escape strategies, and stimulation of host defenses including phagocytosis and mediators of humoral immunity. The fungal cell wall is also a target of choice for the development of diagnostic or therapeutic tools. The present review discusses our current knowledge on the cell wall structure of Mucorales in terms of the polysaccharides and glyco-enzymes involved in its biosynthesis and degradation, with an emphasis on the missing gaps in our knowledge.
cell wall, polysaccharides, glucuronic acid, Mucorales, glyco-enzymes
NCBI PubMed ID: 30941108Chitin, chitosan and their complexes with β-glucan (chitin–glucan complex, CGC, and chitosan–glucan complex, ChGC) are value-added polysaccharides extracted from the cell-walls of many fungi. Commercial chitin and its deacetylated form, chitosan, are currently obtained from marine waste material, mostly animal sources (crustaceans and marine invertebrates), through harsh chemical procedures that have low reproducibility due to the variability of the composition of the sources and their seasonal character. These disadvantages are overcome by using fungi as sources of chitinous polymers. The extraction of chitin/chitosan from fungi cell-walls has the great advantage of yielding products with stable composition and properties, using simpler procedures, with the added benefit of also generating CGC and ChGC, two copolymers that combine the proven properties of chitin/chitosan with those of β-glucans. Over the last decades, fungal chitinous polymers have been the focus of extensive research that included optimization of the cultivation conditions of a wide range of species and the development of optimized extraction, purification and characterization techniques, as well as the demonstration of the biopolymers' biological properties, which include immunomodulatory, anticancer, antioxidant and antimicrobial activity. Given these properties, several attempts were made to develop applications for them in areas ranging from biomedicine and pharmaceuticals to food and agriculture. Despite their wide range of proven functional properties that include the ability to form different polymeric structures, as well as biological activity, fungal chitinous biopolymers are still underexplored. Nevertheless, these biopolymers hold great potential for development into valuable products or applications that are surely worth further investigation.
fungi, chitosan, chitin, cell-wall polysaccharides, chitin–glucan complex (CGC), chitosan–glucan complex (ChGC)
Publication DOI: 10.1002/jctb.6325Chitin is a unique structural exopolysaccharide abundantly found in nature. This exopolysaccharide has a unique chemical structure that acts as a protective outermost covering for most of the crustaceans in aquatic ecosystem. This fortification is because of the insoluble nature of this exopolysaccharide which consist of a linear chain of β-(1→4)-linked-N-acetylglucosamine units. Chitin is hydrolyzed with the help of a hydrolase known as chitinase. Variety of microbial species have been explored for chitinase production. Chitinolytic microbial species can be alternatively used for degradation of chitin instead of chemical treatment in agricultural sector. This biological approach has lesser environmental impact because of its apparently safe nature. In the current study, bioprospecting of chitinase producing species was conducted and different chitinolytic bacterial strains were screened for chitinase production which could have anti-fungal potential. Bacterial isolates were identified based on polyphasic approach and the enzyme production was optimized using one-variable-at-a-time technique. Hyphal extension method was used for determination of anti-fungal potential of chitinase.Glutamicibacter uratoxydans was indigenously isolated and identified for chitinase production. G. uratoxydans is a novel bacterial species which has not been previously explored to produce chitinase or other hydrolases. G. uratoxydans biosynthesized chitinase utilizing colloidal chitin as a sole source of carbon. The chitinase biosynthesized by G. uratoxydans is effectively potent against Aspergillus fumigatus thus, suggesting that this extracellular enzyme could be used for the treatment of fungal infection caused by filamentous fungi.
cell wall, antifungal activity, chitin, chitinase, Glutamicibacter uratoxydans
Publication DOI: 10.1007/s12649-019-00746-2Chitin and chitosan are two related polysaccharides that provide important structural stability to fungal cell walls. Often embedded deeply within the cell wall structure, these molecules anchor other components at the cell surface. Chitin-directed organization of the cell wall layers allows the fungal cell to effectively monitor and interact with the external environment. For fungal pathogens, this interaction includes maintaining cellular strategies to avoid excessive detection by the host innate immune system. In turn, mammalian and plant hosts have developed their own strategies to process fungal chitin, resulting in chitin fragments of varying molecular size. The size-dependent differences in the immune activation behaviors of variably sized chitin molecules help to explain how chitin and related chitooligomers can both inhibit and activate host immunity. Moreover, chitin and chitosan have recently been exploited for many biomedical applications, including targeted drug delivery and vaccine development.
NCBI PubMed ID: 31807896The fungal cell wall serves as the interface between the cell and the environment. Fungal cell walls are composed largely of polysaccharides, primarily glucans and chitin, though in many fungi stress-resistant cell types elaborate additional cell wall structures. Here, we use solid-state nuclear magnetic resonance spectroscopy to compare the architecture of cell wall fractions isolated from Saccharomyces cerevisiae spores and Cryptococcus neoformans melanized cells. The specialized cell walls of these two divergent fungi are highly similar in composition. Both use chitosan, the deacetylated derivative of chitin, as a scaffold on which a polyaromatic polymer, dityrosine and melanin, respectively, is assembled. Additionally, we demonstrate that a previously identified but uncharacterized component of the S. cerevisiae spore wall is composed of triglycerides, which are also present in the C. neoformans melanized cell wall. Moreover, we identify a tyrosine-derived constituent in the C. neoformans wall that, although it is not dityrosine, is a non-pigment constituent of the cell wall. The similar composition of the walls of these two phylogenetically distant species suggests that triglycerides, polyaromatics, and chitosan are basic building blocks used to assemble highly stress-resistant cell walls and the use of these constituents may be broadly conserved in other fungal species.
chitosan, Saccharomyces cerevisiae, chitin, fungal cell wall, solid-state NMR, Cryptococcus neoformans, melanin, macromolecular assembly, dityrosine, triglycerides
NCBI PubMed ID: 33271921Cryptococcus neoformans and Cryptococcus gattii are two species complexes in the large fungal genus Cryptococcus and are responsible for potentially lethal disseminated infections. These two complexes share several phenotypic traits, such as production of the protective compound melanin. In C. neoformans, the pigment associates with key cellular constituents that are essential for melanin deposition within the cell wall. Consequently, melanization is modulated by changes in cell-wall composition or ultrastructure. However, whether similar factors influence melanization in C. gattii is unknown. Herein, we used transmission EM, biochemical assays, and solid-state NMR spectroscopy of representative isolates and "leaky melanin" mutant strains from each species complex to examine the compositional and structural factors governing cell-wall pigment deposition in C. neoformans and C. gattii. The principal findings were the following. 1) C. gattii R265 had an exceptionally high chitosan content compared with C. neoformans H99; a rich chitosan composition promoted homogeneous melanin distribution throughout the cell wall but did not increase the propensity of pigment deposition. 2) Strains from both species manifesting the leaky melanin phenotype had reduced chitosan content, which was compensated for by the production of lipids and other nonpolysaccharide constituents that depended on the species or mutation. 3) Changes in the relative rigidity of cell-wall chitin were associated with aberrant pigment retention, implicating cell-wall flexibility as an independent variable in cryptococcal melanin assembly. Overall, our results indicate that cell-wall composition and molecular architecture are critical factors for the anchoring and arrangement of melanin pigments in both C. neoformans and C. gattii species complexes.
Molecular Structure, cell wall, polysaccharides, virulence factor, opportunistic pathogen, nuclear magnetic resonance (NMR), fungi, Cryptococcus, solid-state NMR, melanin
NCBI PubMed ID: 31896575The human gut microbiota has been revealed in recent years as a factor that plays a decisive role in the maintenance of human health, as well as in the development of many non-communicable diseases. This microbiota can be modulated by various dietary factors, among which complex carbohydrates have a great influence. Although most complex carbohydrates included in the human diet come from vegetables, there are also options to include complex carbohydrates from non-vegetable sources, such as chitin and its derivatives. Chitin, and its derivatives such as chitosan can be obtained from non-vegetable sources, the best being insects, crustacean exoskeletons and fungi. The present review offers a broad perspective of the current knowledge surrounding the impacts of chitin and its derived polysaccharides on the human gut microbiota and the profound need for more in-depth investigations into this topic. Overall, the effects of whole insects or meal on the gut microbiota have contradictory results, possibly due to their high protein content. Better results are obtained for the case of chitin derivatives, regarding both metabolic effects and effects on the gut microbiota composition.
polysaccharides, insect, gut microbiota, prebiotic, chitosan, chitin, crustacean
NCBI PubMed ID: 32545663Two chitosan extracts were prepared by chemical and enzymatic treatment of Ganoderma lucidum mushroom, as an alternative source to crustacean shells. The molecular weight of the enzymatic extract was lower than that of the chemical one and of shrimp chitosan, as determined by viscosity measurements. Characteristic signals were identified in the 1 H-NMR spectra and high deacetylation degree indicated good physico-chemical properties for both mushroom chitosan extracts. The scavenging capacity of mushroom chitosan extracts was moderate against the synthetic radicals of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH), but higher values were observed for the enzymatic extract, compared to the chemical extract and shrimp chitosan. In vitro cytotoxicity was evaluated in L929 mouse fibroblast cell lines and the results of MTT assay showed good cytocompatibility in the tested range of concentrations. The growth of Gram-positive bacteria was inhibited more than Gram-negative bacteria in the presence of mushroom chitosan extracts, in particular by the chemical one, indicating their efficiency as antimicrobial agents. All these results strengthen the evidence of mushroom polysaccharide preparations availability for biomedical applications.
extraction, deacetylation, fungi, radical scavenging activity, α-amylase
NCBI PubMed ID: 32333466To develop more ecologically sustainable agricultural practices requires that we reduce our reliance on synthetic chemical pesticides for crop protection. This will likely involve optimized biocontrol approaches - the use of beneficial soil microbes to attack potential plant pathogens to protect plants from diseases. Many bacterial species, including strains of Bacillus subtilis, have been explored for their biocontrol properties, as they can control the growth of harmful fungi, often by disrupting the fungal cell wall. A strain that is not often considered for this particular application is Bacillus subtilis natto, primarily known for fermenting soybeans via cell wall degradation in the Japanese probiotic dish "natto." Because deconstruction of the fungal cell wall is considered an important biocontrol trait, we were motivated to explore the possible anti-fungal properties of the B. subtilis natto strain. We show that B. subtilis natto can use complex fungal material as a carbon source for growth, and can effectively deconstruct fungal cell walls. We found degradation of fungal cell wall proteins, and showed that growth on a mix of peptides was very strong. We also found that intact fungal cell walls can induce the secretion of chitinases and proteases. Surprisingly, we could show that chitin, the bulk component of the fungal cell wall, does not permit successful growth of the natto strain or induce the secretion of chitinolytic enzymes, although these were produced during exposure to proteins or to complex fungal material. We have further shown that protease secretion is likely a constitutively enabled mechanism for nutrient scavenging by B. subtilis natto, as well as a potent tool for the degradation of fungal cell walls. Overall, our data highlight B. subtilis natto as a promising candidate for biocontrol products, with relevant behaviors that can be optimized by altering growth conditions. Whereas it is common for bacterial biocontrol products to be supplied with chitin or chitosan as a priming polysaccharide, our data indicate that this is not a useful approach with this particular bacterium, which should instead be supplied with either glucose or attenuated fungal material.
protease, secretome, fungal cell wall, chitinase, biocontrol, Bacillus subtilis natto
NCBI PubMed ID: 32296406Vast efforts have been devoted to the development of antifungal drugs targeting the cell wall, but the supramolecular architecture of this carbohydrate-rich composite remains insufficiently understood. Here we compare the cell wall structure of a fungal pathogen Aspergillus fumigatus and four mutants depleted of major structural polysaccharides. High-resolution solid-state NMR spectroscopy of intact cells reveals a rigid core formed by chitin, β-1,3-glucan, and α-1,3-glucan, with galactosaminogalactan and galactomannan present in the mobile phase. Gene deletion reshuffles the composition and spatial organization of polysaccharides, with significant changes in their dynamics and water accessibility. The distribution of α-1,3-glucan in chemically isolated and dynamically distinct domains supports its functional diversity. Identification of valines in the alkali-insoluble carbohydrate core suggests a putative function in stabilizing macromolecular complexes. We propose a revised model of cell wall architecture which will improve our understanding of the structural response of fungal pathogens to stresses.
polysaccharides, Aspergillus fumigatus, chitin, fungal cell wall, solid-state NMR
NCBI PubMed ID: 34732740Background: During the last three decades systemic fungal infections associated to immunosuppressive therapies have become a serious healthcare problem. Clinical development of new antifungals is an urgent requirement. Since fungal but not mammalian cells are encased in a carbohydrate-containing cell wall, which is required for the growth and viability of fungi, the inhibition of cell wall synthesizing machinery, such as β(1,3)-D-glucan synthases (GS) and chitin synthases (CS) that catalyze the synthesis of β(1-3)-D-glucan and chitin, respectively, represent an ideal mode of action of antifungal agents. Although the echinocandins anidulafungin, caspofungin and micafungin are clinically well-established GS inhibitors for the treatment of invasive fungal infections, much effort must still be made to identify inhibitors of other enzymes and processes involved in the synthesis of the fungal cell wall. Purpose: Since natural products (NPs) have been the source of several antifungals in clinical use and also have provided important scaffolds for the development of semisynthetic analogues, this review was devoted to investigate the advances made to date in the discovery of NPs from plants that showed capacity of inhibiting cell wall synthesis targets. The chemical characterization, specific target, discovery process, along with the stage of development are provided here. Methods: An extensive systematic search for NPs against the cell wall was performed considering all the articles published until the end of 2020 through the following scientific databases: NCBI PubMed, Scopus and Google Scholar and using the combination of the terms 'natural antifungals' and 'plant extracts' with 'fungal cell wall'. Results: The first part of this review introduces the state of the art of the structure and biosynthesis of the fungal cell wall and considers exclusively those naturally produced GS antifungals that have given rise to both existing semisynthetic approved drugs and those derivatives currently in clinical trials. According to their chemical structure, natural GS inhibitors can be classified as 1) cyclic lipopeptides, 2) glycolipids and 3) acidic terpenoids. We also included nikkomycins and polyoxins, NPs that inhibit the CS, which have traditionally been considered good candidates for antifungal drug development but have finally been discarded after enduring unsuccessful clinical trials. Finally, the review focuses in the most recent findings about the growing field of plant-derived molecules and extracts that exhibit activity against the fungal cell wall. Thus, this search yielded sixteen articles, nine of which deal with pure compounds and seven with plant extracts or fractions with proven activity against the fungal cell wall. Regarding the mechanism of action, seven (44%) produced GS inhibition while five (31%) inhibited CS. Some of them (56%) interfered with other components of the cell wall. Most of the analyzed articles refer to tests carried out in vitro and therefore are in early stages of development. Conclusion: This report delivers an overview about both existing natural antifungals targeting GS and CS activities and their mechanisms of action. It also presents recent discoveries on natural products that may be used as starting points for the development of potential selective and non-toxic antifungal drugs.
Plant Extracts, chitin, fungal cell wall, antifungal drugs, bioactive natural products, cell wall synthases, systemic fungal infection
NCBI PubMed ID: 33958276Extracellular matrixes (ECMs), such as the cell walls and biofilms, are important for supporting cell integrity and function and regulating intercellular communication. These biomaterials are also of significant interest to the production of biofuels and the development of antimicrobial treatment. Solid-state nuclear magnetic resonance (ssNMR) and magic-angle spinning-dynamic nuclear polarization (MAS-DNP) are uniquely powerful for understanding the conformational structure, dynamical characteristics, and supramolecular assemblies of carbohydrates and other biomolecules in ECMs. This review highlights the recent high-resolution investigations of intact ECMs and native cells in many organisms spanning across plants, bacteria, fungi, and algae. We spotlight the structural principles identified in ECMs, discuss the current technical limitation and underexplored biochemical topics, and point out the promising opportunities enabled by the recent advances of the rapidly evolving ssNMR technology.
bacteria, algae, Plants, fungi, ssNMR
NCBI PubMed ID: 34878762Halophilic fungi thrive in hypersaline habitats and face a range of extreme conditions. These fungal species have gained considerable attention due to their potential applications in harsh industrial processes, such as bioremediation and fermentation under unfavorable conditions of hypersalinity, low water activity, and extreme pH. However, the role of the cell wall in surviving these environmental conditions remains unclear. Here we employ solid-state NMR spectroscopy to compare the cell wall architecture of Aspergillus sydowii across salinity gradients. Analyses of intact cells reveal that A. sydowii cell walls contain a rigid core comprising chitin, β-glucan, and chitosan, shielded by a surface shell composed of galactomannan and galactosaminogalactan. When exposed to hypersaline conditions, A. sydowii enhances chitin biosynthesis and incorporates α-glucan to create thick, stiff, and hydrophobic cell walls. Such structural rearrangements enable the fungus to adapt to both hypersaline and salt-deprived conditions, providing a robust mechanism for withstanding external stress. These molecular principles can aid in the optimization of halophilic strains for biotechnology applications.
cell wall, solid-state NMR, Aspergillus sydowii, halophilic fungi
NCBI PubMed ID: 37925437Solid-state NMR (ssNMR) spectroscopy facilitates the non-destructive characterization of structurally heterogeneous biomolecules in their native setting, for example, comprising proteins, lipids and polysaccharides. Here we demonstrate the utility of high and ultra-high field 1 H-detected fast MAS ssNMR spectroscopy, which exhibits increased sensitivity and spectral resolution, to further elucidate the atomic-level composition and structural arrangement of the cell wall of Schizophyllum commune, a mushroom-forming fungus from the Basidiomycota phylum. These advancements allowed us to reveal that Cu(II) ions and the antifungal peptide Cathelicidin-2 mainly bind to cell wall proteins at low concentrations while glucans are targeted at high metal ion concentrations. In addition, our data suggest the presence of polysaccharides containing N-acetyl galactosamine (GalNAc) and proteins, including the hydrophobin proteins SC3, shedding more light on the molecular make-up of cells wall as well as the positioning of the polypeptide layer. Obtaining such information may be of critical relevance for future research into fungi in material science and biomedical contexts.
NMR, NMR spectroscopy, cell wall, peptide, Schizophyllum commune, proton detection
NCBI PubMed ID: 36181715Pleurotus ostreatus, also known as the oyster mushroom, is a popular edible mushroom cultivated worldwide. This review aims to survey recent progress in the molecular genetics of this fungus and demonstrate its potential as a model mushroom for future research. The development of modern molecular genetic techniques and genome sequencing technologies has resulted in breakthroughs in mushroom science. With efficient transformation protocols and multiple selection markers, a powerful toolbox, including techniques such as gene knockout and genome editing, has been developed, and numerous new findings are accumulating in P. ostreatus. These include molecular mechanisms of wood component degradation, sexual development, protein secretion systems, and cell wall structure. Furthermore, these techniques enable the identification of new horizons in enzymology, biochemistry, cell biology, and material science through protein engineering, fluorescence microscopy, and molecular breeding
cell wall, genome editing, agaricomycete, breeding, mycelial materials, wood degradation
NCBI PubMed ID: 38372792Integral and membrane-associated proteins extracted from neuron-enriched perirhopalial tissue of the jellyfish Cyanea capillata were probed with a panel of lectins that recognize sugar epitopes of varying complexity. Of the 13 lectins tested, only concanavalin A, jacalin lectin and tomato lectin stained distinct bands on Western blots, indicating the presence of repeating α-1,6-mannoses, terminal Gal-α-1,6-GalNAc and repeating β-1,4-linked GlcNAc, respectively. In whole-mounted perirhopalial tissue, jacalin lectin stained several cell types, including neurons, muscle, cilia and mucus strands. Tomato lectin stained secretory cells intensely, and neurons in a punctate fashion. Concanavalin A stained cytoplasmic epitopes in both ecto-and endodermal cells, and ectodermal secretory cells and the mucus strands emanating from them. With the exception of tomato lectin's sugar epitope, the other sugar epitopes identified in this study are “non-complex.” This study suggests that while glycosylation of integral and membrane-associated proteins occurs in Cyanea, the sugars post-translationally linked to these proteins tend to be simple.
carbohydrate, linkage, sugar, Scyphozoa, nerve, Cyanea capillata (Cnidaria)
Publication DOI: 10.1007/BF00318487| a-D-Glcp-(1-6)-a-D-Glcp | Show graphically |
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Structure type: oligomer
Trivial name: isomaltose
Contained glycoepitopes: IEDB_142488,IEDB_144998,IEDB_146664,IEDB_983931,SB_192
Theoretical calculations reveal that oligosaccharides are second to no other class of biochemical oligomery in terms of coding capacity. As integral part of cellular glycoconjugates they can serve as recognitive units for receptors (lectins). Having first been detected in plants, lectins are present ubiquitously. Remarkably for this field, they serve as bacterial and viral adhesins. Following a description of these branches of lectinology to illustrate history, current status and potential for medicinal chemistry, we document that lectins are involved in a wide variety of biochemical processes including intra- and intercellular glycoconjugate trafficking, initiation of signal transduction affecting e. g. growth regulation and cell adhesion in animals. It is thus justified to compare crucial carbohydrate epitopes with the postal code ensuring correct mail routing and delivery. In view of the functional relevance of lectins the design of high-affinity reagents to occupy their carbohydrate recognition domains offers the perspective for an attractive source of new drugs. Their applications can be supposed to encompass the use as cell-type-selective determinant for targeted drug delivery and as blocking devices in anti-adhesion therapy during infections and inflammatory disease. To master the task of devising custom-made glycans/glycomimetics for this purpose, the individual enthalpic and entropic contributions in the molecular rendezvous between the sugar receptor under scrutiny and its ligand in the presence of solvent molecules undergoing positional rearrangements need to be understood and rationally exploited. As remunerative means to this end, cleverly orchestrated deployment of a panel of methods is essential. Concerning the carbohydrate ligand, its topological parameters and flexibility are assessed by the combination of computer-assisted molecular-mechanics and molecular-dynamics calculations and NMR-spectroscopic measurements. In the presence of the receptor, the latter technique will provide insights into conformational aspects of the bound ligand and into spatial vicinity of the ligand to distinct side chains of amino acids establishing the binding site in solution. Also in solution, the hydrogen-bonding pattern in the complex can be mapped with monodeoxy and monofluoro derivatives of the oligosaccharide. Together with X-ray crystallographic and microcalorimetric studies the limits of a feasible affinity enhancement can be systematically probed. With galactoside-binding lectins as instructive mo del, recent progress in this area of drug design will be documented, emphasizing the general applicability of the outlined interdisciplinary approach.
Molecular mechanics, Rhizobium meliloti, lectinology, lectins as targets, computer assisted, NMR spectoscopic, crystallographic elucidation, sugar code, chemioal tailoring, phosphodiester backbone, microheterogeneity of glycan, monomer variability, N acetylneuramicinic, transgenic pollen, nitrogen enriched nutrients, non agglutinating ricin, hydrophobic molecules, phytopathogenic fungus, phosphomannose mutase, B bearing individuals, anti adhesion therapy, NMR spectrum, parenchymal host cells
NCBI PubMed ID: 10702616Several lactic acid bacteria are able to produce water-soluble and water-insoluble homoexopolysaccharides (HoEPS) from sucrose. In this study, structures of all HoEPS which were fermentatively produced by Leuconostoc mesenteroides subsp. dextranicum NRRL B-1121 and B-1144, Leuconostoc mesenteroides subsp. mesenteroides NRRL B-1149, B-1438 and B-1118, Leuconostoc suionicum DSM 20241, and Liquorilactobacillus satsumensis DSM 16230 were systematically analyzed. Monosaccharide analysis, methylation analysis, NMR spectroscopy, size-exclusion chromatography, and different enzymatic fingerprinting methods were used to obtain detailed structural information. All strains produced water-soluble dextrans and/or levans as well as water-insoluble glucans. Levans showed different degrees of branching and high molecular weights, whereas dextrans had comparable structures and broader size distributions. Fine structures of water-soluble HoEPS were analyzed after endo-dextranase and endo-levanase hydrolysis. Water-insoluble glucans were composed of different portions of 1,3-linkages (5 to 40 %). Hydrolysis with endo-dextranase and endo-mutanase yielded further information on block sizes and varying fine structures. Overall, clear differences between HoEPS yields and structures were observed
enzymatic hydrolysis, Dextran, levan, mutan, HPAEC-PAD/MS, HPSEC-RI
NCBI PubMed ID: 37940249Koji amazake, prepared from rice koji, is a traditional Japanese sweet beverage. The main source of sweetness is glucose derived from rice starch following digestion by enzymes of Aspergillus oryzae during saccharification. The temperature of this process was empirically determined as 45°C–60°C, but no studies have systematically investigated the effect of temperature on saccharification efficiency. We addressed this in the present study by evaluating saccharification efficiency at various temperatures. We found that glucose content was the highest at 50°C (100%) and was reduced at temperatures of 40°C (66.4%), 60°C (91.9%), and 70°C (76.6%). We previously reported that 12 types of oligosaccharides are present in koji amazake; the levels of eight of these, namely nigerose, kojibiose, trehalose, isomaltose, gentiobiose, raffinose, panose, and isomaltotriose, were the highest at 50°C–60°C, whereas sophorose production was maximal at 70°C. Based on these findings, we initially performed saccharification at 50°C and then switched the temperature to 70°C. The maximum amount of each saccharide including sophorose that was produced was close to the values obtained at these two temperatures. Thus, oligosaccharide composition of koji amazake is dependent on saccharification temperature. These findings provide useful information for improving the consumer appeal of koji amazake by enhancing oligosaccharide content.
oligosaccharide, sophorose, koji, amazake, saccharification
NCBI PubMed ID: 30414826| b-D-Galp-(1-1)-CER | Show graphically |
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Structure type: monomer
Compound class: glycolipid, glycosphingolipid, glycosylceramide, ceramide
Contained glycoepitopes: IEDB_136044,IEDB_137472,IEDB_141794,IEDB_190606,SB_1,SB_165,SB_166,SB_187,SB_195,SB_7,SB_88
The first work reporting synthesis of glucosylceramide (cerebrin, GlcCer) by yeasts was published in 1930. During approximately 70-years members of this class of glycosphingolipids (GSL) were considered merely structural components of plasma membrane in fungi. However, in the last decade GlcCer was reported to be involved with fungal growth, differentiation, virulence, immunogenicity, and lipid raft architecture in at least two human pathogens. Fungal GlcCer are structurally distinct from their mammalian counterparts and enriched at the cell wall, which makes this molecule an effective target for antifungal activity of specific ligands (peptides and antibodies to GlcCer). Therefore, GSL are promising targets for new drugs to combat fungal diseases. This review discusses the most recent information on biosynthesis and role of GlcCer in fungal pathogens.
glucosylceramide, antifungal targets, fungal pathogens
NCBI PubMed ID: 22025918Glucosylceramide and galactosylceramide were detected in three Aspergillus species: Aspergillus oryzae, Aspergillus sojae and Aspergillus. awamori, using borate-coated TLC. The cerebrosides from A. oryzae were further purified by ion exchange and iatrobeads column chromatographies with or without borate, and determined the composition of sugar, fatty acid and sphingoid base by GC/MS, MALDI-TOF/MS and 1H-NMR. We identified them as β-glucosylceramide and β-galactosylceramide. The ceramide moiety of both cerebrosides consisted mainly of 2-hydroxystearic acid and either 9-methyl-octadeca-4, 8-sphingadienine or octadeca-4, 8-sphingadienine. To our knowledge, this is the first study to provide evidence for the presence of β-galactosylceramide in A. oryzae.
glycosphingolipid, galactosylceramide, cerebroside, Aspergillus oryzae, filamentous fungus
NCBI PubMed ID: 25129050glycolipids, HPLC, TLC, HPTLC, phosphoinositides, biotinylation
NCBI PubMed ID: 10820743| b-D-Glcp-(1-6)-b-D-Glcp | Show graphically |
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Show legend Show as text |
Structure type: oligomer
Trivial name: gentiobiose, bruceacanthinoside
Compound class: glycoside, Apotirucallane triterpe glycoside
Contained glycoepitopes: IEDB_141806,IEDB_142488,IEDB_146664,IEDB_241101,IEDB_983931,SB_192
Theoretical calculations reveal that oligosaccharides are second to no other class of biochemical oligomery in terms of coding capacity. As integral part of cellular glycoconjugates they can serve as recognitive units for receptors (lectins). Having first been detected in plants, lectins are present ubiquitously. Remarkably for this field, they serve as bacterial and viral adhesins. Following a description of these branches of lectinology to illustrate history, current status and potential for medicinal chemistry, we document that lectins are involved in a wide variety of biochemical processes including intra- and intercellular glycoconjugate trafficking, initiation of signal transduction affecting e. g. growth regulation and cell adhesion in animals. It is thus justified to compare crucial carbohydrate epitopes with the postal code ensuring correct mail routing and delivery. In view of the functional relevance of lectins the design of high-affinity reagents to occupy their carbohydrate recognition domains offers the perspective for an attractive source of new drugs. Their applications can be supposed to encompass the use as cell-type-selective determinant for targeted drug delivery and as blocking devices in anti-adhesion therapy during infections and inflammatory disease. To master the task of devising custom-made glycans/glycomimetics for this purpose, the individual enthalpic and entropic contributions in the molecular rendezvous between the sugar receptor under scrutiny and its ligand in the presence of solvent molecules undergoing positional rearrangements need to be understood and rationally exploited. As remunerative means to this end, cleverly orchestrated deployment of a panel of methods is essential. Concerning the carbohydrate ligand, its topological parameters and flexibility are assessed by the combination of computer-assisted molecular-mechanics and molecular-dynamics calculations and NMR-spectroscopic measurements. In the presence of the receptor, the latter technique will provide insights into conformational aspects of the bound ligand and into spatial vicinity of the ligand to distinct side chains of amino acids establishing the binding site in solution. Also in solution, the hydrogen-bonding pattern in the complex can be mapped with monodeoxy and monofluoro derivatives of the oligosaccharide. Together with X-ray crystallographic and microcalorimetric studies the limits of a feasible affinity enhancement can be systematically probed. With galactoside-binding lectins as instructive mo del, recent progress in this area of drug design will be documented, emphasizing the general applicability of the outlined interdisciplinary approach.
Molecular mechanics, Rhizobium meliloti, lectinology, lectins as targets, computer assisted, NMR spectoscopic, crystallographic elucidation, sugar code, chemioal tailoring, phosphodiester backbone, microheterogeneity of glycan, monomer variability, N acetylneuramicinic, transgenic pollen, nitrogen enriched nutrients, non agglutinating ricin, hydrophobic molecules, phytopathogenic fungus, phosphomannose mutase, B bearing individuals, anti adhesion therapy, NMR spectrum, parenchymal host cells
NCBI PubMed ID: 10702616Despite its essential role in the yeast cell wall, the exact composition of the β-(1,6)-glucan component is not well characterized. While solubilizing the cell wall alkali-insoluble fraction from a wild type strain of Saccharomyces cerevisiae using a recombinant β-(1,3)-glucanase followed by chromatographic characterization of the digest on an anion exchange column, we observed a soluble polymer that eluted at the end of the solvent gradient run. Further characterization indicated this soluble polymer to have a molecular mass of ~38 kDa and could be hydrolyzed only by β-(1,6)-glucanase. Gas chromatography, mass spectrometry and NMR(1H and 13C) analyses confirmed it to be a β-(1,6)-glucan polymer with, on average, branching at every fifth residue with one or two β-(1,3)-linked glucose units in the side chain. This polymer peak was significantly reduced in the corresponding digests from mutants of the kre genes (kre9 and kre5) that are known to play a crucial role in the β-(1,6)-glucan biosynthesis. In the current study, we have developed a biochemical assay wherein incubation of UDP-[14C]glucose with permeabilized S. cerevisiae yeasts resulted in the synthesis of a polymer chemically identical to the branched β-(1,6)-glucan isolated from the cell wall. Using this assay, parameters essential for β-(1,6)-glucan synthetic activity were defined.
mutants, cell wall, β-glucan, Saccharomyces cerevisiae, biochemical assay, carbon isotope
NCBI PubMed ID: 19279004Koji amazake, prepared from rice koji, is a traditional Japanese sweet beverage. The main source of sweetness is glucose derived from rice starch following digestion by enzymes of Aspergillus oryzae during saccharification. The temperature of this process was empirically determined as 45°C–60°C, but no studies have systematically investigated the effect of temperature on saccharification efficiency. We addressed this in the present study by evaluating saccharification efficiency at various temperatures. We found that glucose content was the highest at 50°C (100%) and was reduced at temperatures of 40°C (66.4%), 60°C (91.9%), and 70°C (76.6%). We previously reported that 12 types of oligosaccharides are present in koji amazake; the levels of eight of these, namely nigerose, kojibiose, trehalose, isomaltose, gentiobiose, raffinose, panose, and isomaltotriose, were the highest at 50°C–60°C, whereas sophorose production was maximal at 70°C. Based on these findings, we initially performed saccharification at 50°C and then switched the temperature to 70°C. The maximum amount of each saccharide including sophorose that was produced was close to the values obtained at these two temperatures. Thus, oligosaccharide composition of koji amazake is dependent on saccharification temperature. These findings provide useful information for improving the consumer appeal of koji amazake by enhancing oligosaccharide content.
oligosaccharide, sophorose, koji, amazake, saccharification
NCBI PubMed ID: 30414826Three new apotirucallane-type triterpenoids named bruceajavanin A (1) dihydrobruceajavanin A (2), and bruceajavanin B (3), and a novel β-carboline alkaloidal glycoside named bruceacanthinoside (4) were isolated from the stems of Brucea javanica (Simaroubaceae), a traditional medicine used to treat malaria in the Bengkulu area, Sumatra, Indonesia. Their chemical structures have been elucidated on the bases of their chemical and physicochemical properties. Bruceajavanin A (1), dihydrobruceajavanin A (2) and bruceacanthinoside (4) were shown to inhibit growth of the cultured malarial parasite Plasmodium falciparum K1 of a chloroquine-resistant strain.
Journal NLM ID: 0377775| b-D-Fruf-(2-1)-b-D-Fruf-(2-1)-b-D-Fruf-(2-1)-b-D-Fruf-(2-1)-a-D-Glcp | Show graphically |
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Show legend Show as text |
Structure type: oligomer
Trivial name: inulin, fructosylnystose
Compound class: fructan
Contained glycoepitopes: IEDB_142488,IEDB_144998,IEDB_146664,IEDB_923067,IEDB_983931,SB_192
Aspergillus phoenicis biofilms on polyethylene as inert support were used to produce fructooligosaccharides (FOS) in media containing 25 % (m/V) of sucrose as a carbon source. The maximum production of total FOS (122 mg/mL), with 68 % of 1-kestose and 32 % of nystose, was obtained in Khanna medium maintained at 30 °C for 48 h under orbital agitation (100 rpm). At high concentrations of sucrose (30 %, m/V), the recovery of FOS was higher than that observed at a low concentration (5 %, m/V). High levels of FOS (242 mg/mL) were also recovered when using the biofilm in sodium acetate buffer with high sucrose concentration (50 %, m/V) for 10 h. When the dried biofilm was reused in a fresh culture medium, there was a recovery of approx. 13.7 % of total FOS after 72 h of cultivation at 30 °C, and 10 % corresponded to 1-kestose. The biofilm morphology, analyzed by scanning electron microscope, revealed a noncompact mycelium structure, with unfilled spaces and channels present among the hyphae. The results obtained in this study show that A. phoenicis biofilms may find application for FOS production in a single-step fermentation process, which is cost-effective in terms of reusability, downstream processing and efficiency.
Biofilm, fructooligosaccharides, Aspergillus sp., kestose, nystose
Journal NLM ID: 9703690In this study, the kinetic for the bioconversion of sucrose to fructooligosaccharides (FOS) by free cells of Aspergillus oryzae N74 was modeled. In addition, the effect of immobilized glucose isomerase (IGI) on FOS production yield was evaluated and considered in the kinetic model. The selected kinetic models were based on a proposed reaction mechanism described by elementary rate equations and modified Michaelis-Menten kinetic equations. The use of IGI allowed to increase the FOS production yield (FOS Yield) and to decrease the glucose/fructose (G/F) ratio. At shake flask scale, the FOS Yield was increased in 4.7 % (final yield 58.3 %), while the G/F ratio was reduced 6.2-fold. At bench scale, the FOS Yield was increased in 2.2 % (final yield 57.3 %), while the G/F ratio was reduced 4.5-fold. The elementary rate equation model was the one that best adjusted experimental data for FOS production using either the fungus biomass or the mixture fungus biomass-IGI, with an overall average percentage error of 7.2. Despite that FOS production yield was not highly improved by the presence of IGI in the reaction mixture, it favored the reduction of residual glucose in the mixture, avoiding the loss of material owe to glucose transformation to fructose that can be used in situ for FOS production by the fructosyltransferase.
fructooligosaccharides, Aspergillus oryzae, fructosyltransferase, immobilized glucose isomerase
NCBI PubMed ID: 22528647The conformational studies of inulin oligomers from G-F_2 to G-F_9, which isolated from Platycodon grandiflorum, suggested a plausible conformational change between G-F_7 and G-F_8 from the trends in their chemical shift patterns and molecular rotation; the oligomers higher than G-F_8 would form some secondary conformations more rigid than shorter oligomers. On the other hand, spin-latice relaxation (T_1) studies of the protons proposed through-space interactions of 2- and 4-H's of glucose moiety in G-F_5,presumably with some atom(s) of the terminal fructose moiety. This would reflect that the inulin molecule adopts a 5/1 helix.
NMR, conformation, inulin, inulin oligomer, molecular rotation, spin-lattice relaxation time (T1)
Journal NLM ID: 0377775Individual fructan tri-, tetra- and pentasaccharide isomers in neutral, water-soluble extracts from Lolium temulentum were purified and the linkages present in these isomeric oligosaccharides were analysed by combined GC-mass spectrometry of partially methylated alditol acetates. 1-Kestose and neokestose were the most abundant trisaccharides with 6-kestose present in much lower amounts. Analysis of isomers of DP 4 and 5 showed that multiple linkage types were present with structures based on all three trisaccharides. Oligosaccharides based on neokestose but with 2,6 linkages between adjacent fructose residues have not been previously detected in higher plants.
Oligosaccharides, 1-kestose, fructan, sucrose, neokestose, Gramineae, Lolium temulentum
Publication DOI: 10.1016/0031-9422(92)83432-XFructooligosaccharides (FOS) are short-chain sugars that occur naturally and have dietary benefits for humans. They are widely distributed in nature and are a natural part of the human diet. The objective of this study was to determine the concentrations of 1-kestose (GF(2)), nystose (GF(3)), and 1(F)-beta-fructofuranosylnystose (GF(4)) in a variety of common processed and prepared foods. An ion chromatographic method was developed for this purpose in which the sugar concentrations were measured using integrated amperometry. The samples were simply prepared by blending with water and filtering the suspensions through a 10000 Da cutoff centrifugal filter. These samples were then injected into the ion chromatograph, which had been programmed for gradient elution, and the areas of the sugar peaks obtained compared to those of standard sugars on a calibration curve. Selected samples were prepared both with and without standard spikes in order to assess the efficiency of the determination. Of the vegetables investigated, artichokes contained by far the most FOS, followed by onions; bananas contained more FOS than other fruits investigated. The method was shown to be simple, convenient, and relatively fast for the quantitation of FOS in processed and prepared food products.
fructooligosaccharides, food composition, ion exchange chromatography
NCBI PubMed ID: 11087481| a-D-Manp-(1-2)-a-D-Manp-(1-6)-+ | a-D-Manp-(1-2)-a-D-Manp-(1-3)-a-D-Manp-(1-6)-+ | a-Glcp-(1-2)-a-Glcp-(1-3)-a-Glcp-(1-3)-a-D-Manp-(1-2)-a-D-Manp-(1-2)-a-D-Man-(1-3)-a-D-Man-(1-4)-b-D-GlcpNAc-(1-4)-b-D-GlcpNAc-(1--/(->4) Asn-X-Ser/Thr (protein)/ | Show graphically |
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Structure type: oligomer
Aglycon: (->4) Asn-X-Ser/Thr (protein)
Compound class: N-glycan
Contained glycoepitopes: IEDB_130701,IEDB_1309329,IEDB_135813,IEDB_136104,IEDB_137340,IEDB_140116,IEDB_141793,IEDB_141807,IEDB_141828,IEDB_141829,IEDB_141830,IEDB_141831,IEDB_142488,IEDB_143632,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_151079,IEDB_151531,IEDB_152206,IEDB_153212,IEDB_153220,IEDB_164174,IEDB_232584,IEDB_241100,IEDB_76933,IEDB_857734,IEDB_983930,IEDB_983931,SB_136,SB_191,SB_192,SB_196,SB_197,SB_198,SB_44,SB_53,SB_55,SB_67,SB_72,SB_73,SB_74,SB_77,SB_85
The composition and organization of the cell walls from Saccharomyces cerevisiae, Candida albicans, Aspergillus fumigatus, Schizosaccharomyces pombe, Neurospora crassa, and Cryptococcus neoformans are compared and contrasted. These cell walls contain chitin, chitosan, β-1,3-glucan, β-1,6-glucan, mixed β-1,3-/β-1,4-glucan, α-1,3-glucan, melanin, and glycoproteins as major constituents. A comparison of these cell walls shows that there is a great deal of variability in fungal cell wall composition and organization. However, in all cases, the cell wall components are cross-linked together to generate a cell wall matrix. The biosynthesis and properties of each of the major cell wall components are discussed. The chitin and glucans are synthesized and extruded into the cell wall space by plasma membrane-associated chitin synthases and glucan synthases. The glycoproteins are synthesized by ER-associated ribosomes and pass through the canonical secretory pathway. Over half of the major cell wall proteins are modified by the addition of a glycosylphosphatidylinositol anchor. The cell wall glycoproteins are also modified by the addition of O-linked oligosaccharides, and their N-linked oligosaccharides are extensively modified during their passage through the secretory pathway. These cell wall glycoprotein posttranslational modifications are essential for cross-linking the proteins into the cell wall matrix. Cross-linking the cell wall components together is essential for cell wall integrity. The activities of four groups of cross-linking enzymes are discussed. Cell wall proteins function as cross-linking enzymes, structural elements, adhesins, and environmental stress sensors and protect the cell from environmental changes.
Candida albicans, Aspergillus fumigatus, Saccharomyces cerevisiae, fungal cell wall, Schizosaccharomyces pombe, Neurospora crassa, cell wall biogenesis, glucan; chitin, Cryptococcus neoformas
NCBI PubMed ID: 23419716The synthesis of many of the proteins that are translocated into the endoplasmic reticulum is accompanied by the co-translational attachment of preformed oligosaccharide chains to certain Asn residues. These glycans can play a variety of roles in the mature proteins, including the one of stabilizing the protein and protecting the polypeptide backbone from the action of proteases. In addition, they can have a crucial function during the process of polypeptide folding, when aggregation with other proteins would hamper the acquisition of the native conformation. Their influence on protein folding can be direct, or mediated by interactions with endoplasmic reticulum-located molecular chaperones. The elucidation of the mechanisms that govern glycoprotein folding in the plant endoplasmic reticulum should contribute to the understanding of how much plant cells rely on glycan chains to achieve the efficient folding of many proteins under diverse environmental conditions. In addition, a better knowledge of the level of conservation of the in vivo folding mechanisms will be important for the exploitation of plant cells in the production of heterologous glycoproteins.
endoplasmic reticulum, calnexin, calreticulin, glucose trimming, glycoprotein stability
Publication DOI: 10.1093/jxb/49.324.1091| a-D-Manp-(1-6)-+ | a-D-Manp-(1-3)-b-D-Manp-(1-4)-b-D-GlcpNAc-(1-4)-b-D-GlcpNAc-(1--/(->4) Asn-X-Ser/Thr (protein)/ | Show graphically |
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Structure type: oligomer
Aglycon: (->4) Asn-X-Ser/Thr (protein)
Compound class: N-glycan
Contained glycoepitopes: IEDB_123886,IEDB_130701,IEDB_135813,IEDB_137340,IEDB_137485,IEDB_141793,IEDB_141807,IEDB_144983,IEDB_151531,IEDB_152206,IEDB_153212,IEDB_548907,IEDB_983930,SB_197,SB_198,SB_33,SB_44,SB_67,SB_72,SB_73,SB_74,SB_85
Dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl α-1,3-mannosyltransferase (also known as "asparagine-linked glycosylation 3", or ALG3) is involved in early N-linked glycan synthesis and thus is essential for formation of N-linked protein glycosylation. In this study, we examined the effects of alg3 gene deletion (alg3Δ) on growth, development, pigment production, protein secretion and recombinant Trichoderma reesei cellobiohydrolase (rCel7A) expressed in Aspergillus niger. The alg3Δ delayed spore germination in liquid cultures of complete medium (CM), potato dextrose (PD), minimal medium (MM) and CM with addition of cAMP (CM+cAMP), and resulted in significant reduction of hyphal growth on CM, potato dextrose agar (PDA), and CM+cAMP and spore production on CM. The alg3Δ also led to a significant accumulation of red pigment on both liquid and solid CM cultures. The relative abundances of 54 of the total 215 proteins identified in the secretome were significantly altered as a result of alg3Δ, 63% of which were secreted at higher levels in alg3Δ strain than the parent. The rCel7A expressed in the alg3Δ mutant was smaller in size than that expressed in both wild-type and parental strains, but still larger than T. reesei Cel7A. The circular dichroism (CD)-melt scans indicated that change in glycosylation of rCel7A does not appear to impact the secondary structure or folding. Enzyme assays of Cel7A and rCel7A on nanocrystalline cellulose and bleached kraft pulp demonstrated that the rCel7As have improved activities on hydrolyzing the nanocrystalline cellulose. Overall, the results suggest that alg3 is critical for growth, sporulation, pigment production, and protein secretion in A. niger, and demonstrate the feasibility of this alternative approach to evaluate the roles of N-linked glycosylation in glycoprotein secretion and function.
N-linked glycosylation, filamentous fungi, Aspergillus niger, asparagine-linked glycosylation 3 (ALG3), Trichoderma reesei cellobiohydrolase (Cel7A), protein secretion and expression
NCBI PubMed ID: 24076077Yeasts are valuable hosts for recombinant protein production, as these unicellular eukaryotes are easy to handle, grow rapidly to a high cell density on cost-effective defined media, often offer a high space-time yield, and are able to perform posttranslational modifications. However, a key difference between yeasts and mammalian cells involves the type of glycosylation structures, which hampers the use of yeasts for the production of many biopharmaceuticals. Glycosylation is not only important for the folding process of most recombinant proteins; it has a large impact on pharmacokinetics and pharmacodynamics of the therapeutic proteins as well. Yeasts' hypermannosylated glycosyl structures in some cases can evoke immune responses and lead to rapid clearance of the therapeutic protein from the blood. This chapter highlights the efforts made so far regarding the glyco-engineering of N- and O-type glycosylation, removing or reducing yeast-specific glycans. In some cases, this is combined with the introduction of humanized glycosylation pathways. After many years of patient development to overcome remaining challenges, these efforts have now culminated in effective solutions that should allow yeasts to reclaim the primary position in biopharmaceutical manufacturing that they enjoyed in the early days of biotechnology.
Recombinant Protein Expression, fungi, Saccharomyces cerevisiae, yeast, Pichia pastoris, N-glycosylation engineering, O-glycosylation engineering
NCBI PubMed ID: 30397726Peptide mapping of lupin acid phosphatase clearly demonstrated the homology between its two subunits. Sequenced tryptic peptides also showed 78% identity (92% similarity) to the red bean acid phosphatase. Peptides exclusive for the 50-kDa subunit are homologous to N-terminally located sequences in red bean acid phosphatase, leading to the assumption that the shorter subunit of lupin acid phosphatase is generated by the deletion of the N-terminal part of the longer subunit. Carbohydrate moiety was found to be identical in both subunits. Oligosaccharide chains released by hydrazinolysis from the both subunits were fluorescently labeled and separated by HPLC. The structure of oligosaccharides was elucidated by exoglycosidase sequencing. Seventeen percent of isolated glycans were found to be of the high-mannose type, while the rest belonged to plant complex-type structures. Most of the complex glycans were fucosylated and xylosylated; some were fucosylated or xylosylated only.
glycoprotein, acid phosphatase, Lupinus luteus, subunits, exoglycosidase sequencing
NCBI PubMed ID: 9826432In plants, most proteins of the extracellular compartment and the endomembrane system are glycosylated by N-linked oligosaccharides. The N-glycosylation of proteins has a great impact both on their physicochemical properties and on their biological functions. Over the last ten years, a number of laboratories have contributed considerably to the understanding of the structure, the biosynthesis and the function of plant N-linked glycans. In this review, data on this domain will be summarized and the recent results on the N-glycosylation of a vacuolar lectin, the bean phytohaemagglutinin (PHA) will also be included. This PHA, used as a model glycoprotein, was expressed in different plant systems and the N-glycosylation patterns of different recombinant PHA were compared. In addition to this study on plant-specific glycosylation, the same model glycoprotein was used to investigate whether or not N-glycosylation and N-glycan maturation is organ-specific in plants.
N-Linked oligosaccharide, biosynthesis and function, phytohaemagglutinin
Publication DOI: 10.1093/jxb/49.326.1463| b-D-Glcp-(1-3)-Subst Subst = β-sitosterol = SMILES O{3}[C@H](C1)CC[C@@]2(C)C1=CC[C@]3([H])[C@@]2([H])CC[C@@]4(C)[C@]3([H])CC[C@]4([C@@H](C)CC[C@@H](CC)C(C)C)[H] | Show graphically |
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Structure type: monomer
Trivial name: daucosterol, β-daucosterol, β-sitosterol, β-sitosterol-β-D-glucoside, androsine, saxifragifolin B, β-sitosterol 3-O-β-D-glucopyranoside
Compound class: saponin glycoside, glycoside, steroid glycoside, triterpenoid glycoside
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
An endophytic fungus Aspergillus terreus, var. boedijnii (Blochwitz) was isolated from red marine alga Laurencia ceylanica, J. Agardh, cultured in large scale and extracted with EtOAc. The above-mentioned extract yielded a new butyrolactone, 3-hydroxy-4-(4-hydroxyphenyl)-5-methoxycarbonyl-5-(4-hydroxy-3-formylbenzyl)-2,5-dihydro-2-furanone (1), along with the previously reported nine compounds, butyrolactone-1 (2), 6-hydroxymellin (3), (3R, 4R)-6,7-dimethoxy-4-hydroxymellin (4), (+)-territonin (5), (+)-territonin-A (6), (+)-asterrelenin (7), (+)-terrein (8), oleic acid (9) and glucopyranosyl-β-sitosterol (10), on column and preparative thin-layer chromatography. Compounds 1-8 were subjected to β-glucuronidase inhibitory activity test, and 1 showed a remarkable activity, while 2 and 7 showed moderate activity.
β-glucuronidase, Aspergillus terreus, Laurencia ceylanica, butyrolactone, 3-hydroxy-4-(4-hydroxyphenyl)-5-methoxycarbonyl-5-(4-hydroxy-3-formylbenzyl)-2, 5-dihydro-2-furanone
NCBI PubMed ID: 22913423The isolation and characterization of rat lens aldose reductase (RLAR) inhibitors from the fruiting bodies of Ganoderma applanatum were conducted. Among the extracts and fractions from G. applanatum tested, the MeOH extract and EtOAc fraction were found to exhibit potent RLAR inhibition in vitro, their IC50 being 1.7 and 0.8 μg/ml, respectively. From the active EtOAc fraction, seven compounds with diverse structural moieties were isolated and identified as D-mannitol (1), 2-methoxyfatty acids (2), cerebrosides (3), daucosterol (4), 2,5-dihydroxyacetophenone (5), 2,5-dihydroxybenzoic acid (6), and protocatechualdehyde (7). Among them, protocatechualdehyde (7) was found to be the most potent RLAR inhibitor (IC50=0.7 μg/ml), and may be useful for the prevention and/or treatment of diabetic complications
Polyporaceae, Ganoderma applanatum, protocatechualdehyde, aldose reductase activity, diabetic complication
NCBI PubMed ID: 15930755Cultivation of the endophytic fungus Penicillium commune, which was isolated from the semi-mangrove plant Hibiscus tiliaceus, afforded one new compound 1-O-(2,4-dihydroxy-6-methylbenzoyl)-glycerol (1) along with thirteen known products, including 1-O-acetylglycerol (2), N-acetyltryptophan (3), 3-indolylacetic acid methyl ester (4), 1-(2,4-dihydroxy-3,5-dimethylphenyl)ethanone (5), 2-(2,5-dihydroxyphenyl)acetic acid (6), (4R,5S)-5-hydroxyhexan-4-olide (7), thymidine (8), uracil (9), thymine (10), ergosterol (11), β-sitosterol (12), β-daucosterol (13), and ergosta-7,22-dien-3β,5α,6β-triol (14). The structures of these compounds were established by detailed NMR spectroscopic analysis, as well as by comparison with literature data or with authentic samples
ergosterol, Hibiscus tiliaceus, endophytic fungus, nucleosides, Penicillium commune G2M
NCBI PubMed ID: 20657476The endophytic fungus Fusarium equiseti was isolated from the brown alga Padina pavonica, collected from the Red Sea. The fungus was identified by its morphology and 18S rDNA. Cultivation of this fungal strain in biomalt-peptone medium led to isolation of 12 known metabolites of diketopeprazines and anthraquinones. The organic extract and isolated compounds were screened for their inhibition of hepatitis C virus NS3/4A protease (HCV PR). As a result, the fungal metabolites showed inhibition of HCV protease (IC50 from 19 to 77 μM), and the fungus was subjected to culture on Czapek's (Cz) media, with a yield of nine metabolites with potent HCV protease inhibition ranging from IC50 10 to 37 μM. The Cz culture extract exhibited high-level inhibition of HCV protease (IC50 27.6 μg/mL) compared to the biomalt culture extract (IC50 56 μg/mL), and the most potent HCV PR isolated compound (Griseoxanthone C, IC50 19.8 μM) from the bio-malt culture extract showed less of an inhibitory effect compared to isolated ω-hydroxyemodin (IC50 10.7 μM) from the optimized Cz culture extract. Both HCV PR active inhibitors ω-hydroxyemodin and griseoxanthone C were considered as the lowest selective safe constituents against Trypsin inhibitory effect with IC50 48.5 and 51.3 μM, respectively.
Fusarium equiseti, HCV protease, Padina pavonica, Red Sea, brown alga
NCBI PubMed ID: 27775589A soft coral-derived fungus Penicillium sp. among other isolates e high antibacterial, anti-yeast and cytotoxic activities. The fungus, Penicillium sp. MMA, isolated from Sarcphyton glaucoma, afforded nine diverse compounds (1-9). Their structures were identified by 1D and 2 D NMR and ESI-MS spectroscopic data as two alkaloids: veridicatol (1), aurantiomide C (2); one sesquiterpene, aspterric acid (3); two carboxylic acids, 3,4-dihydroxy-benzoic acid; (4) and linoleic acid (5); three steroids, ergosterol (6), β-Sitosterol (7), β-Sitosterol glucoside (8) along with the sphingolipid, cerebroside A (9). Biologically, the antimicrobial, antioxidant, in vitro cytotoxicity and antibiofilm activities were studied in comparison with the fungal extract. The in silico computational studies were implemented to predict drug and lead likeness properties for 1-4. The fungus was taxonomically characterized by morphological and molecular biology (18srRNA) approaches.
cytotoxicity, antibiofilm, marine-derived fungus, alkaloids, sesquiterpene, Penicillium sp. MMA
NCBI PubMed ID: 32476047From a methanolic extract of fresh leaves of Ficus pumila LINN (Moraceae), a new tocopherol-related compound has been isolated together,vith alpha-tocopherol, and its structure determined by spectral methods. Along with these compounds, two known sterols, fifteen known triterpenoids and five known flavonoid glycosides were identified as constituents.
triterpenoid, flavonoid glycoside, Ficus pumila leaf, Moraceae, alpha-tocopherol-related compound
Publication DOI: 10.1248/cpb.46.1647A novel glycoside (4S*,5R*)-4-[(9Z)-2,13-di-(O-2b-D-glucopyranosyl)- 5,9,10-trimethyl-8-oxo-9-tetradecene-5-yl]-3,3,5-trimethylcyclohexanone, namely stenopaluside, and a new cerebroside, 1-O-β-D-glucopyranosyl- (2S*,3R*,4E,8Z)-2-N-[(2R)-hydroxytetracosanoyl]octadecasphinga-4,8-dienine, were isolated from the leaves of Stenochlaena palustris, along with four known natural products, 3-oxo-4,5-dihydro-α-ionyl β-D-glucopyranoside, 3- formylindole, lutein, and β-sitosterol-3-O-β-D-glucopyranoside. The structures of the isolates were elucidated by spectroscopic and chemical methods.
glycoside, cerebroside, leaves, Pteridaceae, Stenochlaena palustris, stenopaluside, 3-oxo-4, 5-dihydro-a-ionyl b-D-glucopyranoside, 3-formylindole
Publication DOI: 10.1016/S0031-9422(98)00352-5A denitro-aristolochic acid derivative, aristofolin-A, together with ten known compounds, were isolated from the fresh flowers of Aristolochia kaempferi. The structures of these compounds were determined by spectral analysis.
amino acid, flavonoid, flowers, A. liukiunesis, Aristolochia kaempferi, Aristolochiaceae, denitro aristolochic acid
Publication DOI: 10.1016/S0031-9422(98)00223-4A new triterpene glycoside, 2α,3β,19α-trihydroxyurs-12-ene-23,28- dioic acid-28-O-(6'-O-methyl-β-D-glucopyranosyl) ester and a new triterpene derivative, 24-O-butyl-2α,3β,19α,24-tetrahydroxyurs-12-en-28-oic acid, together with six known compounds, have been isolated from the aerial parts of Rubus pungens Camb. var oldhamii. The structures of these compounds were established mainly by spectroscopic methods.
rosaceae, pentacyclic triterpene, ursane glycosyl esters, methylglucoside, Rubus pungens
Publication DOI: 10.1016/S0031-9422(97)01057-1Androsin, β-sitosteryl glucoside and a new lignan glycoside named schizandriside were isolated from the woody part of Schizandra nigra MAX., in addition to schizandronic acid, schizandrolic acid, schizandronol, oplodiol and (+)-catechin-7-β-D-glucopyranoside. Schizandriside (I) was shown to be (+)-isolariciresinol-2α-β-D-xylopyranoside on the basis of spectral and chemical data.
13C NMR, lignan glycoside, (+)-isolariciresinol xyloside, Schizandra nigra Max., Magnoliaceae, schizandriside
Publication DOI: 10.1248/cpb.27.1422Saxifragifolins A and B, two new triterpenoid tetrasaccharides isolated from the aerial part of Androsace saxifragifolia, were respectively shown to be androsacenol-3-O-{β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranoside}(1) and cyclamiretin A 3-O-{β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranoside}(2). The structural details were elucidated by a combination of fast-atom-bombardment mass spectrometry, chemical degradation, and one- and two-dimensional n.m.r. spectroscopy.
tetrasaccharide, triterpenoid, Androsace saxifragifolia
Publication DOI: 10.1039/P19860001527The methanolic extract from sweetclover, Melilotus messanensis, afforded the new coumestan melimessanol A, the 3-arylcoumarin melimessanol B and the 2-arylbenzofuran melimessanol C, which where identified on the basis of spectroscopic methods. The known isoflavones formononetin and cyclosin, the isoflavanone vestitone, the flavanone liquiritigenin, the pterocarpans (3R,4R)-medicarpin, 3-hydroxymedicarpin and melilotocarpane B, the coumestans coumestrol, 4'-O-methylcoumestrol and 7-hydroxy-4',5'-dimethoxycoumestan, the 3-arylcoumarin 3-(4'-methoxy-2'-hydroxyphenyl)-7-hydroxycoumarin, the lignan pinoresinol, 3-hydroxycoumarin and the simple phenolics p-coumaric acid, vanillic acid, p-hydroxybenzoic acid, a diterpene, two loliolides, a cyclitol and two saponins have been also isolated and spectroscopically identified. Cyclosin, vestitone, 4'-O-methylcoumestrol, 7-hydroxy-4',5'-dimethoxycoumestan,3-(4'-methoxy-2'-hydroxyphenyl)-7-hydroxycoumarin and 3-hydroxycoumarin are first reported in the genus Melilotus. The effects of a series of aqueous solutions from 10-4-10-9 M of twelve phenolics, two loliolides, a diterpene and a cyclitol on germination and growth of the dicotyledons Lactuca sativa cvs. Roman and Nigra and Lycopersicum esculentum and the monocotyledons Allium cepa and Hordeum vulgare, have been studied. The isoflavones formononetin and cyclosin and the pterocarpan medicarpin have been found to inhibit principally A. cepa germination.
phenolics, coumarins, flavonoids, Leguminosae, lignan, allelopathy, Melilotus messanensis, sweetclover, melimessanols A-C, diterpenesaponinscyclitolloliolides
Publication DOI: 10.1016/S0031-9422(98)00453-1In addition to the plant sterols β-sitosterol and daucosterol, a new bisabolane-typed sesquiterpene glycoside and three bioactive compounds (artemetin, geniposide and 6β-hydroxygeniposide) were characterized from the whole plant of Biebersteinia heterostemon endemic to the Tibetan area. The structure determination of the novel glycoside and identification of the known phytochemicals were accomplished by a combination of modern spectroscopic methods. Tests of all isolates for the antimicrobial activity indicated that the new sesquiterpene glycoside exhibited pronounced antibacterial activities against Bacillus subtilis, Staphylococcus aureus and Pseudomonas sp. with MICs at 50, 50 and 70 μg/ml, respectively.
antibacterial activity, Geraniaceae, Iridoids, Biebersteinia heterostemon, monoterpenes, (-)-anymol glycoside
Publication DOI: 10.1080/00387019909350045In addition to the known soyasaponin I, 3-O-[α-L-rhamnopyranosyl(1→2)-β-D-galactopyranosyl(1→2-β-D-glucuronopyranosyl]-22-O-[β-D-glucuronopyranosyl(1→2)-β-D-glucopyranosyl]soyasapogenol B, soyasaponin II, 3-O-β-D-glucopyranosyl sitosterol, 3-O-β-D-glucopyranosyl stigmasterol and 3-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosyl]oct-1-ene-3-ol, the new saponin, 3-O-α-L-rhamnopyranosyl(1→2)-β-D-galactopyranosyl(1→2)-β-D-glucuronopyranosyl]-22-O-β-D-glucopyranosyl soyasapogenol B (2) was isolated and characterised from the seed saponins fraction of Trifolium resupinatum. The structural determination is based on spectroscopic methods (including DQF-COSY, HETCOR, TOCSY, ROESY and NOEs experiments).
glycosides, saponins, Leguminosae, clover seeds, Persian clover, Trifolium resupinatum
Publication DOI: 10.1016/S0031-9422(99)00192-2From the leaves of Lafoensia glyptocarpa Koehne (Lytraceae) was isolated a triterpenoid saponin, 3β-O-β-L-arabnopyranosylolean-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester, along with the known compound 3β-O-β-D-glucopyranosylsitosterol. The structures of both compounds were elucidated with spectral data of the natural products and their acetyl derivatives, including 2D NMR spectroscopic experiments.
triterpene saponin, spectral data, Lafoensia glyptocarpa, Lytraceae
Publication DOI: 10.1016/S0031-9422(99)00311-8Xanthine oxidase is a key enzyme associated with the incidence of hyperuricemia-related disorders. Repeated chromatography of the enzyme inhibitory part of the water extract of the twigs and leaves of Brandisia hancei (Scrophulariaceae) gave a flavone luteolin, an iridoid glycoside mussaenoside, two β-sitosterol glycosides daucosterol and β-sitosterol gentiobioside, and five phenylethanoids arenarioside, brandioside, acteoside, 2'-O-acetylacteoside and isoacteoside. Luteolin and isoacteoside inhibited the xanthine oxidase (XO, EC 1.2.3.2) with the IC50 values at 7.83 and 45.48 μM, respectively. Isoacteoside was found to be the first phenylethanoid that decreased substantially the formation of uric acid by inhibiting competitively xanthine oxidase (K(i) value: 10.08 μM). Furthermore, the study suggested that the caffeoylation of the 6'-hydroxyl group of the phenylethanoids was essential for the enzyme inhibitory action.
inhibitor, Brandisia hancei, xanthine oxidase
NCBI PubMed ID: 10630118From the aerial parts of Zygophyllum simplex a new glycoside was isolated and identified as 6"-(2-E-butenoyl) isorhamnetin-3-O-glucoside in addition to the known compounds: isorhamnetin, isorhamnetin 3-O-glucoside, kaempferol 3-O-rutinoside, sitosterol glucoside and quinovic acid 3-α-L-rhamnoside. The structures of the isolated compounds were elucidated by spectral analysis.
flavonoids, flavonol glycosides, Zygophyllaceae, aerial parts, Zygophyllum simplex, isorhamnetin 3-glucoside, 2-butenoate ester
Publication DOI: 10.1016/0031-9422(92)83503-QBioassay-directed chromatographic separation of the ethyl acetate extract of the whole plant of Psittacanthus cucullaris afforded a new phenolic xyloside, ellagic acid-4-O-β-xyloside-3,3',4'-trimethyl ether (1) together with four known compounds, ellagic acid-4-O-β-xyloside-3,3'-dimethyl ether (2), gallic acid, β-sitosterol, and β-sitosterol β-D-glucoside. The structure of the new compound was determined by spectroscopic methods. Like other β-D-xylosides, compounds 1 and 2 stimulated the formation of glycosaminoglycan chains when fed to the cultured Chinese hamster ovary cells.
Psittacanthus cucullaris, phenolic xyloside, glycoside primer
NCBI PubMed ID: 10425137Yew trees, taxonomically classified under the genus Taxus, are sources of a number of physiologically active compounds of different classes. Taxane derivatives with various carbon skeletons, lignans, flavonoids, steroids and sugar derivatives have been isolated from different Taxus species. Compounds isolated from the genus Taxus between 1908 and December 1997 have been comprehensively reviewed.
steroids, yew, flavonoids, lignans, Taxus, Taxaceae, taxanes, abeotaxanes, taxoids, nontaxoidic isoprenoids, sugar derivatives, T. baccata, T. brevifolia, T. caradensis, T. chinensis, T. cuspidata, T. floridana, T. mairei, T. media, T. wallichiana, T. yunnanensis
NCBI PubMed ID: 10326254The structure, properties, distribution in nature, and biological activity of sterol glycosides and acylgylcosides are reviewed.
biological activity, sterol glycoside, acylgylcoside
Publication DOI: 10.1007/BF02323277The ethanolic extract from the stem bark of Dimocarpus fumatus, showed in vitro cytotoxic activity against KB cells. Fractionation of the extract gave compounds belonging to different classes. The two major components have been identified as a benzoquinone, sargaquinone, and a chromene, sargaol. One sphingolipid, soyacerebroside I, two glycosides of sitosterol, and fatty acids were also identified. Besides these known compounds, two new glycosides of long-chain fatty alcohols have been identified as 1-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl]hexadecanol and 1-O-[[α-L-arabinopyranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl] hexadecanol, and a mixture of three new diacylglycerylglucosides has been isolated. These structures were elucidated by analysis of 2D-NMR and mass spectra.
cytotoxicity, stem bark, Sapindaceae, Dimocarpus fumatus, hexadecanol glycosides, diacylglycerylglucoside, benzoquinone, chromene
NCBI PubMed ID: 9891934Hepatoprotective effect of MeOH, MeOH-H2O (1:1) and H2O extracts of Combretum quadrangulare seeds were examined on D-galactosamine (D-GalN)/tumor necrosis factor-α(TNF-α)-induced cell death in primary cultured mouse hepatocytes. The MeOH extract showed the strongest inhibitory effect on D-GalN/TNF-α-induced cell death (IC50, 56.4 μg/ml). Moreover, the MeOH extract also significantly lowered the serum glutamic pyruvic transaminase (sGPT) level on D-GalN/lipopolysaccharide (LPS)-induced liver injury in mice. Bioguided separation of the MeOH extract led to the isolation of 38 compounds of various classes including triterpene glucosides, lignans and catechin derivatives. Among the isolated triterpene glucosides, lupane-type (1-3; IC50, 63.1, 59.8 and 76.2 μM, respectively) and ursane-type (11, mixture of 12 and 14; IC50, 30.2 and 34.6 μM, respectively) compounds exhibited strong hepatoprotective activity. 1-O-Galloyl-6-O-(4-hydroxy-3,5-dimethoxy)benzoyl-β-D-glucose (26; IC50, 7.2 μM), methyl gallate (28; IC50, 19.9 μM), and (-)-epicatechin (31; IC50, 71.2 μM) also had a potent hepatoprotective effect on D-GalN/TNF-α-induced cell death in primary cultured mouse hepatocytes.
hepatoprotective effect, catechin, Combretum quadrangulare, triterpene glucoside, Vietnamese medicinal plant, 1-O-Galloyl-6-O-(4-hydroxy-3, 5-dimethoxy)benzoyl-β-D-glucose
NCBI PubMed ID: 11085361Five new triterpene glucosides, quadranosides I-V (1-5), have been isolated from a MeOH extract of the seeds of Combretum quadrangulare, together with 13 known compounds. The structures of compounds 1-5 were elucidated on the basis of spectroscopic analysis. Among the new triterpene glucosides, three compounds (1, 2, 5) showed significant hepatoprotective effects against D-galactosamine (D-GalN)/tumor necrosis factor-α (TNF-α)-induced cell death in primary cultured mouse hepatocytes.
hepatoprotective effect, Combretaceae, Combretum quadrangulare, triterpene glucoside, quadranoside, Vietnamese medicinal plant
NCBI PubMed ID: 10785422The MeOH extract of leaves of Combretum quadrangulare showed significant hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced experimental liver injury in mice and on D-GalN/tumor necrosis factor-α (TNF-α)-induced cell death in primary cultured mouse hepatocytes. Phytochemical investigation led to the isolation of thirty cycloartane-type triterpenes together with betulinic acid, beta-sitosterol, beta-sitosterol glucoside, 4 flavones (34-37), and 3 flavone C-glucosides (38-40). These compounds showed various potencies of hepatoprotective effect on D-GalN/TNF-α-induced cell death in primary cultured mouse hepatocytes. Quadrangularol B (29), methyl quadrangularate I (33), kamatakenin (34), 5,7,4'-trihydroxy-3,3'-dimethoxyflavone (35), 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (36) and isokaempferide (37) showed strong inhibitory effect on TNF-α-induced cell death with IC50 values of 34.3, 33.7, 13.3, 22.4, 13.4 and 22.8 μM, respectively, whereas clinically-used silibinin had an IC50 value of 39.6 microM and glycyrrhizin showed very weak inhibitory effect. Methyl quadrangularates A (30) and N (32), norquadrangularic acid B (31) and vitexin (40) also showed potent inhibition on TNF-α-induced cell death with IC50 values of 45.7, 89.3, 67.6 and 40.1 μM, respectively. The flavonoids and some of the cycloartane-type triterpenes appeared to be the hepatoprotective principles of the leaves of C. quadrangulare.
flavone, flavone C-glycoside, hepatoprotective effect, Combretum quadrangulare, cycloartane-type triterpene
NCBI PubMed ID: 10784427Phytochemical studies on the leaves of Eucalyptus camaldulensis var. obtusa have resulted in the isolation of a new triterpenoid camaldulin (3β-formyloxyurs-11-en-28,13β-olide) (1) along with ursolic acid lactone acetate (2), ursolic acid lactone (3), betulinic acid (4), and β-sitosterol 3-O-β-D-glucopyranoside (5). The structures were assigned on the basis of 1D and 2D NMR studies. Compounds 1-3 were tested for spasmolytic activity and were found to possess calcium antagonist activity.
Eucalyptus, terpenoids, spasmolytic activity
NCBI PubMed ID: 11000033Twenty compounds including a dioxoaporphine, annobraine (1); two oxoaporphines, liriodenine (2) and lysicamine (3); five aporphines, (-)-nornuciferine (4), (-)-anonaine (5), (-)-N-formylanonaine (6), (-)-asimilobine (7) and (+)-nordomesticine (8); one proaporphine, (+)-stepharine (9); two protoberberines, (-)-kikemanine (10) and dehydrocorydalmine (11); one azaanthraquinone, 1-aza-4-methyl-2-oxo-1,2-dihydro-9,10-anthracenedione (12); two amides, N-trans-feruloyltyramine (13) and N-p-coumaroyltyramine (14); one ionone, blumenol A (15); and five steroids, β-sitosterol (16), stigmasterol (17), β-sitosteryl-D-glucoside (18), stigmasteryl-D-glucoside (19) and 6-O-palmitoyl-β-sitosteryl-D-glucoside (20), were isolated from the fruits and stems of Annona glabra. Among them, 1 is a novel dioxoaporphine alkaloid and 12 was obtained for the first time from natural sources. These compounds were characterized and identified by physical and spectral evidence.
Annona glabra
Publication DOI: 10.1002/jccs.200000124Twenty-eight compounds including seven alkaloids, (+)-3-chloro-N-formylnornantenine (1), (+)-N-formylnornantenine (2), (+)-boldine (3), (+)-norboldine (4), (-)-norboldine (5), lycicamine (6), and tetrahydroberberine (7); four flavonoids, kaempferol (8), kaempferol-3-O-arabinoside (9), quercetin (10), and quercetin-3-O-rhamnoside (11); one butanolide, akolactone A (12); one p-quinone, 2,6-dimethoxy-p-quinone (13); one cyclohex-2-en-1-one, blumenol A (14); six benzenoids, methylparaben (15), p-hydroxybenzoic acid (16), vanillic acid (17), syringic acid (18), 3,4,5-trimethoxybenzoic acid (19), and 3-(3,4-dihydroxyphenyl) propionic acid (20); one diterpene, phytol (21); one triterpene, squalene (22); six steroids, (3-sitosterol (23), β-sitostenone (24), stigmasta-4,22-dien-3-one (25), 6β-hydroxy-β-sitostenone (26), 6β-hydroxystigmasterone (27), and β-sitosteryl-D-glucoside (28) were isolated from the aerial part of Lindera glauca. These compounds were characterized and identified by physical and spectral method. All compounds were isolated for the first time from this plant. Among them, (+)-3-chloro-N-formylnornantenine (1) is a new one.
Lindera glauca
Publication DOI: 10.1002/jccs.200000050The adaptogen concept is examined from an historical, biological, chemical, pharmacological and medical perspective using a wide variety of primary and secondary literature. The definition of an adaptogen first proposed by Soviet scientists in the late 1950s, namely that an adaptogen is any substance that exerts effects on both sick and healthy individuals by 'correcting' any dysfunction(s) without producing unwanted side effects, was used as a point of departure. We attempted to identify critically what an adaptogen supposedly does and to determine whether the word embodies in and of itself any concept(s) acceptable to western conventional (allopathic) medicine. Special attention was paid to the reported pharmacological effects of the 'adaptogen-containing plant' Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. (Araliaceae), referred to by some as 'Siberian ginseng', and to its secondary chemical composition. We conclude that so far as specific pharmacological activities are concerned there are a number of valid arguments for equating the action of so-called adaptogens with those of medicinal agents that have activities as anti-oxidants, and/or anti-cancerogenic, immunomodulatory and hypocholesteroletic as well as hypoglycemic and choleretic action. However, 'adaptogens' and 'anti-oxidants' etc. also show significant dissimilarities and these are discussed. Significantly, the classical definition of an adaptogen has much in common with views currently being invoked to describe and explain the 'placebo effect'. Nevertheless, the chemistry of the secondary compounds of Eleutherococcus isolated thus far and their pharmacological effects support our hypothesis that the reported beneficial effects of adaptogens derive from their capacity to exert protective and/or inhibitory action against free radicals. An inventory of the secondary substances contained in Eleutherococcus discloses a potential for a wide range of activities reported from work on cultured cell lines, small laboratory animals and human subjects. Much of the cited work (although not all) has been published in peer-reviewed journals. Six compounds show various levels of activity as anti-oxidants, four show anti-cancer action, three show hypocholesterolemic activity, two show immunostimulatory effects, one has choleretic activity and one has the ability to decrease/moderate insulin levels, one has activity as a radioprotectant, one shows anti-inflammatory and anti-pyretic activities and yet another has shown activity as an antibacterial agent. Some of the compounds show more than one pharmacological effect and some show similar effects although they belong to different chemical classes. Clearly, Eleutherococcus contains pharmacologically active compounds but one wishes that the term adaptogen could be dropped from the literature because it is vague and conveys no insights into the mechanism(s) of action. If a precise action can be attributed to it, then the exact term for said action should obviously be used; if not, we strongly urge that generalities be avoided. Also, comparison of Eleutherococcus with the more familiar Panax ginseng C.A. Meyer (Araliaceae), 'true ginseng' has underscored that they differ considerably chemically and pharmacologically and cannot be justifiably considered as mutually interchangeable. Accordingly, we recommend that the designation 'Siberian ginseng' be dropped and be replaced with 'Eleutherococcus'. In the case of both Eleutherococcus and true ginseng, problems inherent in herbal preparation use include inconsistencies not only in terms of indications for use, but in the nomenclature of constituent chemical compounds, standardization, dosage and product labeling. Finally, our re-examination and fresh interpretation of the literature on Eleutherococcus and comparison with true ginseng shows that the potential for a scientifically more complete and defensible exploitation of these plants will be better served by investigating and considering them in a context that consciously ignores the fact that the word ‘adaptogen’ was ever invented.
saponins, Panax ginseng, lignans, adaptogen, adaptogenic activity, Eleutherococcus senticosus, anti-cancer agents, anti-oxidants, placebo effect, true ginseng, ‘Siberian ginseng’
NCBI PubMed ID: 10996277A pentacyclic triterpenoid, ursolic acid (1), two iridoid glucosides, verbenalin (2) and hastatoside (3), and a phenylpropanoid glycoside, verbascoside (4), were isolated from Verbena officinalis Linn. (Verbenaceae), a plant listed in the Chinese Pharmacopoeia and the British Herbal Pharmacopoeia. A procedure for the optimised extraction of these constituents for quantitative estimations has been established. An HPTLC method was employed for the determination of 1 using Liebermann Burchard reagent. A reversed-phase HPLC system with photodiode array detector was used to resolve compounds 2, 3 and 4 in the methanol extracts of different parts of the plant. Tender parts of the plant were rich in all of these constituents (0.24–0.34%, w/w) while the roots, which are not official in the Pharmacopoeias, contained a maximum amount (0.32%, w/w) of the bioactive verbascoside (4). The assay methods described are simple, rapid and accurate, and may form part of future drug authentication protocols.
anti-inflammatory, ursolic acid, Verbenaceae, verbascoside, high pressure liquid chromatography, Verbena officinalis, verbenalin, high performance thin layer chromatography, hastatoside
Publication DOI: 10.1002/1099-1565(200011/12)11:6<351::AID-PCA544>3.0.CO;2-Sn an attempt to locate the biologically active fraction(s) of the plant Verbena officinalis Linn. (Verbenaceae), a preliminary screening of successive petroleum ether, chloroform and methanol extracts of aerial parts for antiinflammatory activity using carrageenan paw oedema model was carried out. All three extracts were found to exhibit antiinflammatory activity with the chloroform extract being the most active. Chemical investigations of petroleum ether and chloroform extracts led to the isolation of β-sitosterol, ursolic acid, oleanolic acid, 3-epiursolic acid, 3-epioleanolic acid, and minor triterpenoids of derivatives of ursolic acid and oleanolic acids. Chromatographic purification of the methanol extract yielded two iridoid glucosides, verbenalin and hastatoside, a phenylpropanoid glycoside, verbascoside and β-sitosterol-D-glucoside.
β-sitosterol, ursolic acid, oleanolic acid, Verbenaceae, verbascoside, Verbena officinalis, verbenalin, hastatoside, antiinflammatory, oedema inhibition, 3-epiursolic acid, 3-epioleanolic acid, β-sitosterol-D-glucoside
NCBI PubMed ID: 10960904A mixture of the title compound-(6′) stearate, margarate, palmitate, linolate, and linolenate (2a-e) was isolated from shredded dried leaves and twigs of Flacourtia indica. The margarate was observed for the first time. 0.5% solutions of the triacetate mixture (1a-e) in methanol or ethanol give “solid" gels stable for months. From these the unchanged triacetates 1a-e can be recovered indicating that this low-molecular material is responsible for the formation of the gel.
Flacourtia indica, gel formation
Publication DOI: 10.1515/znb-2000-3-416Macfadyena unguis-cati (L.) has been widely used in folk medicine as an anti-inflammatory, antimalarial and antivenereal. The purpose of this study was to chemically characterize the main plant components, and to evaluate the biological properties of some of the fractions derived from leaves (MACb) and liana (MACa) of this plant. Chemical characterization allowed the identification of the compounds corymboside, vicenin-2, quercitrin, chlorogenic acid, isochlorogenic acid, lupeol, β-sitosterol, β-sitosterylglucoside, allantoin and lapachol. The biological screening of fractions and/or purified substances derived from fractions revealed antitumoral and antitrypanosomal activities in fractions MACa/lapachol and MACb/MACb21, respectively. The anti-lipoxygenase and anti-cyclooxygenase effect seen in fractions MACa and MACb showed a partial correlation with the anti-inflammatory property attributed to this plant.
anti-inflammatory activity, Macfadyena unguis-cati, corymboside, antitrypanosomal activiity
NCBI PubMed ID: 10757425Two soyasaponins were isolated from the aerial parts of Astragalus tribuloides Del. Their structures were established on the basis of spectroscopic and chemical methods. In addition, ursolic acid, β-sitosterol β-D-glucoside and isorhamnetin 3-O-glucoside were isolated and identified by comparing their mp, spectral and chromatographic data with those of authentic samples. This is the first report of screening and isolation of the chemical constituents of this species of genus Astragalus.
Leguminosae, soyasapogenol B, aerial parts, Astragalus tribuloides, azukisaponins II, V
Journal NLM ID: 9714997The aerial parts from Blutaparon portulacoides yielded a flavonol whose structure was established as 3,5,3'-trihydroxy-4'-methoxy-6,7-methylenedioxyflavone. In addition, the aerial parts yielded the isoflavone irisone B and the steroids stigmasterol, sitosterol and campesterol. The roots of B. portucaloides furnished sitosteryl, stigmast-7-enyl and spinasteryl β-D-glucopyranosides as well as vanillic acid.
Amaranthaceae, Blutaparon portulacoides, capotiragua, methylenedioxyflavonol
NCBI PubMed ID: 10656422The aerial parts of Pergularia tomentosa L. afforded three cardenolides, desglucouzarin, coroglaucigenin and uzarigenin, in addition to β-sitosterol glucoside. The isolated compounds were identified by physical and spectral means, including IR, UV, [α]D, 1D-, 2D-NMR and FAB-MS experiments. The cardenolides, ghalakinoside, calactin and pergularoside previously reported from roots, were also identified in the aerial parts.
NMR, FAB-MS, cardenolides, desglucouzarin, uzarigenin, Pergularia tomentosa, Asclepiadacae, coroglaucigenin, calactin, ghalakinoside, pergularoside, β-sitosterol glucoside
Journal NLM ID: 9714997MeOH extract of Cuscuta chinensis seeds was fractionated with n-hexane, EtOAc and BuOH successively, and antioxidant activities were tested for all fractions using DPPH free radical scavenging method. In the tested fractions, EtOAc fraction showed high antioxidant activity (EC50, 50 μg) From the EtOAc fraction, five compounds have been isolated. On the basis of spectral data, these compounds were identified as β-sitosterol, methyl 4-hydroxy-3,5-dimethoxycinnamate, β-sitosterol-3-O-β-D-glucopyranoside, caffeic acid, quercetin, kaempferol and calycopteretin. Among these compounds, β-sitosterol and β-sitosterol-3-O-β-D-glucopyranoside showed no antioxidant activity. EC50 values of methyl 4-hydroxy-3,5-dimethoxycinnamate, caffeic acid, quercetin, kaempferol and calycopteretin were 0.6, 8, 19, 17 and 12 μg, respectively.
Antioxidants, flavonoids, Convolvulaceae, Cuscuta chinensis, sitosterols, phenyl propanoids, methyl 4-hydroxy-3, 5-dimethoxycinnamate, calycopteretin, DPPH free radical scavenging method
Journal NLM ID: 9714997Diabetes mellitus is a chronic metabolic disorder characterized by a high blood glucose concentration (hyperglycemia) which is due to insulin deficiency and/or insulin resistance. Hyperglycemia occurs because the liver and skeletal muscle cannot store glycogen and the tissues are unable to take up and utilize glucose. Treatment of diabetes is afforded by the following: (i) diet and exercise, (ii) insulin replacement therapy and (iii) the use of oral hypoglycemic agents. In folklore, a variety of plant extracts have been used to treat diabetic patients for centuries. Folklore has given the field of medicine many useful drugs, such pharmacologic prototypes include Digitalis(digitoxin, digoxin), Atropa, Hyoscyamnsand Datura(atropine, scopolamine), Catharanthus(vincristine, vinblastine), Erythroxylon(cocaine), Claviceps(ergonovine, ergotamine), Papaver(morphine, codeine and papaverine), Pilocarpus(pilocarpine) Rauvolfia(reserpine, rescinnamine, deserpidine), and Cinchona(quinine, quinidine); and many others. Obviously evaluation of plants and their active constituents has proven a very useful way of obtaining several useful therapeutic agents. Hence, a logical review of plant constituents having hypoglycemic activity could provide useful clues for obtaining new hypoglycemic agents. Plant constituents reportedly possessing hypoglycemic activity can be classified as follows: 1. Alkaloids; 2. Flavonoids and related compounds; 3. Glycosides/Steroids/Terpenoids; 4. Polysaccharides/ Proteins; and 5. Miscellaneous compounds. Phytoconstituents based upon the above classification are discussed including selected names of plants which are listed alphabetically according to genus. Appropriate data on their pharmacological activity, mechanisms of action (where applicable), and other relevant properties are discussed.
diabetes mellitus, hypoglycemic activity, natural drugs
Publication DOI: 10.1016/S1572-5995(00)80012-5Phytochemical and pharmacological studies of Croton cajucara were oriented by traditional medicine. The stem bark of the mature plant is a rich source of clerodane-type diterpenes: trans-dehydrocrotonin (DCTN), trans-crotonin (CTN), cis-cajucarin B, cajucarin A, cajucarinolide and two novel clerodanes, trans-cajucarin B and sacacarin. In young (18-month-old) plants, the triterpene acetyl aleuritolic acid (AAA) was the major stem bark component and in these the diterpene DCTN was not present. The highest concentration of DCTN (1.4% of dry bark) was detected in 4–6 year-old plants, while 3-year-old plants contained only 0.26% of this diterpene. Three steroids (β-sitosterol, stigmasterol and sitosterol-3-O-β-glucoside), two flavonoids (kaempferol 3,4′,7-trimethyl ether and 3,7-dimethyl ether) and one diterpene (cajucarinolide) were isolated from the leaves of this Croton. The main pharmacological activity was correlated with DCTN. This clerodane produced anti-inflammatory and antinociceptive effects and a significant hypoglycemia in alloxan-induced diabetic rats. The compound also reduced the index of gastric lesions induced by restraint-in-cold. Dose-related DCTN and CTN inhibited in vivo the basal acid secretion in pylorus-ligature rats and oxyntic glands isolated from rabbit gastric mucosa, DCTN, CTN or AAA decreased in vitro uptake basal acid secretion induced by histamine and measured with the 14C-aminopyrine uptake method. Uniquely DCTN inhibited 14C-AP uptake induced by bethanechol. The terpenoids, DCTN and AAA, and the chloroform extract of 6-month-old plants reduced gastrointestinal transit in mice. The effects of DCTN and CTN on the survival of mice bearing Sarcoma 180 and Ehrlich carcinoma ascitic tumors, on the proliferation of cultured cells and TNFα were determined. DCTN was also evaluated for a possible antioestrogenic activity using the immature rat as a model system for bioassay of oestrogen and for an anti-implantation effect in regularly cycling rats. The biological experiments, using the plant extracts and the terpenoids DCTN, CTN and AAA, are herein discussed.
Croton cajucara; clerodane; trans-dehydrocrotonin; trans-crotonin; acetyl aleuritolic acid; pharmacological properties
NCBI PubMed ID: 10720788Constituents of the fruit of Amomum tsao-ko were investigated following a preliminary screening of the antioxidant activity of several extracts of the fruit of this plant that showed that the dichloromethane extract and the ethyl acetatesoluble and water-soluble fractions of the 70% aqueous acetone extract had higher activity than α-tocopherol and butylated hydroxytoluene (BHT). Eleven compounds were isolated from the ethyl acetate-soluble fraction, and their structures were elucidated as (+)-hannokinol (1), meso-hannokinol (2), (+)-epicatechin (3), (−)-catechin (4), β-sitosterol (5), β-sitosterol 3-O-glucoside (6), 2,6-dimethoxyphenol (7), protocatechualdehyde (8), protocatechuic acid (9), vanillic acid (10), and p-hydroxybenzoic acid (11) based on mass and various nuclear magnetic resonance (NMR) spectroscopic techniques. This is the first isolation of epicatechin and catechin from the genus Amomum. The radical scavenging activity of the isolated compounds was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and colorimetric and electron spin resonance (ESR) analyses. The antioxidant activity of the compounds was also determined based on the oxidative stability index (OSI). The catechins and catechol derivatives showed strong activities in both the DPPH radical scavenging activity and antioxidant activity assays.
Antioxidant, radical scavenging, DPPH, catechin, epicatechin, ESR, Amomum tsao-ko, BHT, oxidative stability index (OSI), α-tocopherol
Publication DOI: 10.1007/s11746-000-0107-4Two new isoflavones, pentandrin (1) and pentandrin glucoside (2), were isolated from the stem barks of Ceiba pentandra along with β-sitosterol and its 3-O-β-D-glucopyranoside, which was isolated for the first time from this plant. The structures of these compounds were elucidated with the help of spectroscopic techniques, while the structure of 1 was unambiguously confirmed by single-crystal X-ray diffraction studies.
isoflavones; Ceiba pentandra; pentandrin; pentandrin glucoside; X-ray diffraction
NCBI PubMed ID: 10846755A sterol mixture, 3-O-glucosides of these sterols, 6'-O-fattyacyl ester of these sterol glucosides, kaempferol, quercetin and isoquercitrin were isolated from the whole plants of Hypericum ascyron L. The sterols were found to be a mixture of β-sitosterol, campesterol and stigmasterol by GC-MS. The kinds of fatty acids linked at 6'-OH of sterol glucoside ester mixture were shown to be palmitic acid, stearic acid, oleic acid and linoleic acid by GC- MS. Three flavonoids were identified by spectroscopic methods and comparisons of mixed mp and co-TLC with authentic specimens.
Hypericum ascyron L.; Hypericaceae; flavonoid; steroid
Journal NLM ID: 9713418Two novel diglycosylated steroidal alkaloids of 5-pregnene nucleus, named obtusine-20(R)-O-[β-thevetopyranosyl-(1→4)-β-cymaropyranoside] and obtusolactam-20(R)-O-[β-thevetopyranosyl-(1→4)-β-cymaropyranoside], together with the known β-sitosteryl-3-O-β-glucopyranoside were isolated from the roots of Cryptolepis obtusa N. E. Br.
saponins, Cryptolepis obtusa, Periplocaceae or Asclepiadaceae, 5Δ-pregnene steroidal alkaloids
NCBI PubMed ID: 10703068Two new alkaloids have been isolated from the leaves of Aberia caffra, and characterised as aberiamine N1 pentyl-10-(1,3-dimethylhexahydro-2-pyrimidinyl)-1-dacanamine and aberiamide N-1[{E)-1-butenyl 17-dimethylcarboxamidoheptadecyl)amino}methyl]-N-1-methylacetamide. In addition to α- ,β-amyrin, β-sitosterol and its glucoside, three flavonoids, have also been isolated. Identification of these compounds has been done by spectral analysis and comparison with authentic samples.
alkaloids, β-sitosterol, flavonoids, Aberia caffra
Journal NLM ID: 7613422Four new compounds, the limonoid 24-epi-melianodiol (8), the tirucallane aglaiodiol (9), and the two cyclopentatetrahydrobenzopyran derivatives pyramidaglain A (11) and B (12) were isolated from the leaves of Aglaia andamanica Hiern (Meliaceae), together with the eleven known constituents β-sitosterol, β-sitosterol glucoside, cycloart-23E-ene-3β,25-diol (1), three flavonoids 5-hydroxy-3,4′,7-trimethoxyflavone (2), retusin (3) and pachypodol (4), the tirucallane 24-epi-piscidinol A (5), the lignan yangambin (6), the limonoid melianodiol (7), the bisamide pyramidatine (10) and the amino acid N-methyl-trans-4-hydroxy-L-proline (13). All structures were established by means of detailed spectroscopic analysis.
Meliaceae, Aglaia andamanica, 24-epi-melianodiol, aglaiodiol, pyramidaglain A and B
NCBI PubMed ID: 11199132The free radical scavenging abilities of the structurally related steroids β-sitosterol, β-sitosterol glucoside (plant sterols and sterolins), cholesterol, and dehydroepiandrosterone sulphate (DHEAS) were compared with melatonin (an efficient free radical scavenger) in an in vitro system which measures lipid peroxidation of platelet membranes in the presence of iron (Fe2+). Lipid peroxidation is a process whereby cellular membranes are damaged due to the oxidative deterioration of polyunsaturated lipids, which may lead to cell death and disease in living organisms. Substances such as vitamin E protect cellular membranes against oxidative damage due to their chemical structures. The steroids cholesterol, β-sitosterol, β-sitosterol glucoside and dehydroepiandrosterone (DHEA) are structurally related to each other. During aging, serum concentrations of DHEA, DHEAS and melatonin decrease, while the concentration of cholesterol tends to increase. The aim of the present study was to compare the role these substances play in lipid peroxidation over a wide concentration range. At concentrations lower than the free iron in the reaction mixture, all the steroids investigated decreased lipid peroxidation. At higher concentrations, cholesterol and β-sitosterol increased lipid peroxidation, while DHEAS and melatonin continued to decrease lipid peroxidation.
cholesterol, lipid peroxidation, melatonin, DHEAS, plant sterols, aging
NCBI PubMed ID: 11383550The phytochemical investigation of a methanolic leaf extract of Aglaia rubiginosa furnished 15 isoprenoid constituents, eight of which represented new natural entities. Two androstane derivatives (1 and 2), previously synthesized, and also obtained by microbiological transformations; an extraordinary 17-octanor-cycloartane-ring-A-seco acid (3); four cycloartane-type triterpenes (4−7); and three unusual cholesterol derivatives (8−10) were isolated, along with two known dammaranes (11 and 12), a stigmastandiol (13), and β-sitosterol and its β-d-glucoside. Spectroscopic structure elucidation of the new natural products (1−3, 6, 7, 8−10) is described.
triterpenoids, Aglaia rubiginosa
NCBI PubMed ID: 10843575The anti-inflammatory activity of euphol, twelve other triterpene alcohols and sitosterol-β-D-glucopyranoside, isolated from the dichloromethane extract of the roots of Euphorbia kansui, has been evaluated in mice with inflammation induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA). TPA (1.7 nmol; 1.0 μg/ear) was dissolved in acetone and 10 μL delivered to the inner and outer surfaces of the right ear of ICR mice. A triterpene alcohol, sterol glucoside or vehicle (20 μL; chloroform—methanol 1: 1), was applied topically approximately 30 min before each TPA treatment. The ear thickness was measured before treatment and then oedema was measured 6 h after TPA treatment. For the two-stage carcinogenesis experiment, initiation was accomplished by administration of a single topical application of 7,12-dimethylbenz[a]anthracene (DMBA; 195 nmol; 50 μg/mouse) to the shaved backs of mice. Promotion was with 1.7 nmol (1.0 μg) TPA, applied twice weekly to the same shaved area, begun one week after the initiation. Euphol (2.0 μmol; 853 μg), or its vehicle (acetone-dimethylsulphoxide, 9:1; 100 μL), was applied topically 30 min before each TPA treatment. The number and diameter of skin tumours were measured every other week for 20 weeks. All the compounds were found to possess marked inhibitory activity and their 50% inhibitory dose for TPA-induced inflammation was 0.2–1.0 mg/ear. Topical application of euphol (2.0 μmol; 853 μg/mouse) markedly suppressed the tumour-promoting effect of TPA (1.7 nmol; 1.0 μg/mouse) in mouse skin initiated with DMBA.
antitumour activity, carcinogenesis, Euphorbia kansui, euphol, triterpene alcohols
NCBI PubMed ID: 10716613A novel oleane acid was isolated from the leaves and the fruits of Vochysia ferruginea. The structure of the new triterpenoid was elucidated by NMR spectroscopy as 2α,3β,6β-trihydroxyolean-12-en-28-oic acid (6β-hydroxymaslinic acid, 1). In addition, β-sitosterol-glucoside and three mixtures containing known triterpenoids, uvaol and erythrodiol, ursolic and oleanolic acids, 2α,3β-dihydroxyurs-12-en-28-oic acid and its respective oleanolic isomer (maslinic or crategolic acid), were isolated from the leaves and the fruits of Vochysia ferruginea. In the fruits, bellericagenin A and its (28→1) β-D-glucopyranosyl ester (bellericaside A) were present in high amount.
pentacyclic triterpenes, Vochysia ferruginea, Vochysiaceae, 6β-hydroxymaslinic acid
Publication DOI: 10.1590/S0103-50532000000300007| a-D-Glcp-(1-4)-a-D-Glcp | Show graphically |
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Structure type: oligomer
Trivial name: maltose, maltobiose, maltodextrin
Compound class: glucan
Contained glycoepitopes: IEDB_140629,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_983931,SB_192
Theoretical calculations reveal that oligosaccharides are second to no other class of biochemical oligomery in terms of coding capacity. As integral part of cellular glycoconjugates they can serve as recognitive units for receptors (lectins). Having first been detected in plants, lectins are present ubiquitously. Remarkably for this field, they serve as bacterial and viral adhesins. Following a description of these branches of lectinology to illustrate history, current status and potential for medicinal chemistry, we document that lectins are involved in a wide variety of biochemical processes including intra- and intercellular glycoconjugate trafficking, initiation of signal transduction affecting e. g. growth regulation and cell adhesion in animals. It is thus justified to compare crucial carbohydrate epitopes with the postal code ensuring correct mail routing and delivery. In view of the functional relevance of lectins the design of high-affinity reagents to occupy their carbohydrate recognition domains offers the perspective for an attractive source of new drugs. Their applications can be supposed to encompass the use as cell-type-selective determinant for targeted drug delivery and as blocking devices in anti-adhesion therapy during infections and inflammatory disease. To master the task of devising custom-made glycans/glycomimetics for this purpose, the individual enthalpic and entropic contributions in the molecular rendezvous between the sugar receptor under scrutiny and its ligand in the presence of solvent molecules undergoing positional rearrangements need to be understood and rationally exploited. As remunerative means to this end, cleverly orchestrated deployment of a panel of methods is essential. Concerning the carbohydrate ligand, its topological parameters and flexibility are assessed by the combination of computer-assisted molecular-mechanics and molecular-dynamics calculations and NMR-spectroscopic measurements. In the presence of the receptor, the latter technique will provide insights into conformational aspects of the bound ligand and into spatial vicinity of the ligand to distinct side chains of amino acids establishing the binding site in solution. Also in solution, the hydrogen-bonding pattern in the complex can be mapped with monodeoxy and monofluoro derivatives of the oligosaccharide. Together with X-ray crystallographic and microcalorimetric studies the limits of a feasible affinity enhancement can be systematically probed. With galactoside-binding lectins as instructive mo del, recent progress in this area of drug design will be documented, emphasizing the general applicability of the outlined interdisciplinary approach.
Molecular mechanics, Rhizobium meliloti, lectinology, lectins as targets, computer assisted, NMR spectoscopic, crystallographic elucidation, sugar code, chemioal tailoring, phosphodiester backbone, microheterogeneity of glycan, monomer variability, N acetylneuramicinic, transgenic pollen, nitrogen enriched nutrients, non agglutinating ricin, hydrophobic molecules, phytopathogenic fungus, phosphomannose mutase, B bearing individuals, anti adhesion therapy, NMR spectrum, parenchymal host cells
NCBI PubMed ID: 10702616Three polysaccharides, two heteroglycans (PL-1 and PL-4) and one glucan (PL-3), were solubilized from the fruit bodies of Ganoderma lucidum and isolated by anion-exchange and gel-filtration chromatography. Their structural features were elucidated by glycosyl residue and glycosyl linkage composition analyses, partial acid hydrolysis, acetolysis, periodate oxidation, 1D and 2D NMR spectroscopy, and ESI-MS experiments. The data obtained indicated that PL-1 had a backbone consisting of 1,4-linked α-D-glucopyranosyl residues and 1,6-linked β-D-galactopyranosyl residues with branches at O-6 of glucose residues and O-2 of galactose residues, composed of terminal glucose, 1,6-linked glucosyl residues and terminal rhamnose. PL-3 was a highly branched glucan composed of 1,3-linked β-D-glucopyranosyl residues substituted at O-6 with 1,6-linked glucosyl residues. PL-4 was comprised of 1,3-, 1,4-, 1,6-linked β-D-glucopyranosyl residues and 1,6-linked β-D-mannopyranosyl residues. These polysaccharides enhanced the proliferation of T- and B-lymphocytes in vitro to varying contents and PL-1 exhibited an immune-stimulating activity in mice.
structural elucidation, glucan, immunological activity, Ganoderma lucidum, heteroglycan, Polyparaceae
NCBI PubMed ID: 11809453The non-cellulosic polysaccharides of flax fibre cells were isolated using chemical extraction methods. Extraction of mature retted flax fibre with the calcium chelating agent trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid (CDTA) removed polysaccharides enriched in galacturonic acid. These pectic polysaccharides were fractionated by their solubility in water into two fractions that differed in their neutral sugar content. Extraction of the fibre with aqueous 24% (w/v) potassium hydroxide produced the first hemicellulosic fraction (Hc1), which was enriched in xylose and, to a lesser extent, glucose- and galactose-containing polysaccharides. Digestion of aliquots of this fraction using the fungal carbohydrase mixture, Driselase, yielded xylobiose and isoprimeverose, which are characteristic limit digestion products of xylans and xyloglucans, respectively. Digestion of Hc1 with a crude cellulase preparation from Aspergillus niger yielded oligosaccharide products, one of which was similar to a characteristic nonasaccharide subunit of xyloglucan. Further extraction of the fibre residue with aqueous 18% (w/v) potassium hydroxide supplemented with 4% (w/v) of boric acid removed a second hemicellulosic fraction (Hc2), which was enriched in mannose-containing polysaccharides. Digestion of this fraction with a highly purified endo-(1→4)-β-d-mannanase converted 67% of the total polysaccharide into oligosaccharides within one hour. The β-d-mannanase-derived oligosaccharides had a monosaccharide composition of mannose-glucose of 1.6:1.0. Analysis of the oligosaccharides by TLC and high-performance anion exchange chromatography revealed products characteristic of a glucomannan similar to those found in hardwoods. The presence of β-linked d-glucose residues was confirmed by the removal of glucose from the β-d-mannanase-derived oligosaccharides by a purified β-d-glucosidase. A final extraction of the fibre with aqueous 90% Me2SO containing 4% (w/v) of boric acid removed a further pectic fraction (Hc3) enriched in neutral sugars. Preliminary analyses suggest that this fraction may contain a polysaccharide akin to rhamnogalacturonan I.
Publication DOI: 10.1016/0008-6215(93)80109-RMaltose is exported from the Arabidopsis chloroplast as the main product of starch degradation at night. To investigate its fate in the cytosol, we characterised plants with mutations in a gene encoding a putative glucanotransferase (disproportionating enzyme; DPE2), a protein similar to the maltase Q (MalQ) gene product involved in maltose metabolism in bacteria. Use of a DPE2 antiserum revealed that the DPE2 protein is cytosolic. Four independent mutant lines lacked this protein and displayed a decreased capacity for both starch synthesis and starch degradation in leaves. They contained exceptionally high levels of maltose, and elevated levels of glucose, fructose and other malto-oligosaccharides. Sucrose levels were lower than those in wild-type plants, especially at the start of the dark period. A glucosyltransferase activity, capable of transferring one of the glucosyl units of maltose to glycogen or amylopectin and releasing the other, was identified in leaves of wild-type plants. Its activity was sufficient to account for the rate of starch degradation. This activity was absent from dpe2 mutant plants. Based on these results, we suggest that DPE2 is an essential component of the pathway from starch to sucrose and cellular metabolism in leaves at night. Its role is probably to metabolise maltose exported from the chloroplast. We propose a pathway for the conversion of starch to sucrose in an Arabidopsis leaf.
glucosyltransferase, Arabidopsis, maltose metabolism, maltose transporter, starch degradation, starch mutants
Publication DOI: 10.1111/j.1365-313X.2003.02012.xTwo liquid chromatography methods using an evaporative light scattering detection (ELSD) have been developed to determine the carbohydrate profile of maltodextrins. The first method requires an octadecyl-bonded silica column and a methanol/water mobile phase. With the second method, an amino-bonded polymeric stationary phase and an acetonitrile/water eluent are used. In the two cases, a gradient elution was necessary to desorb the higher molecular weight polysaccharides. This elution mode was perfectly compatible with ELSD since no baseline drift was observed. These two methods were applied to quantify maltodextrins present in plant spray dried-powder of melilot and basil.
HPLC, Plant Extracts, ELSD, maltodextrins
Publication DOI: 10.1081/JLC-100101240| a-D-Glcp-(1-4)-a-D-Glcp-(1-4)-a-D-Glcp | Show graphically |
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Structure type: oligomer
Trivial name: maltotriose, maltodextrin
Compound class: glucan
Contained glycoepitopes: IEDB_140629,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_420421,IEDB_857742,IEDB_983931,SB_192
Three polysaccharides, two heteroglycans (PL-1 and PL-4) and one glucan (PL-3), were solubilized from the fruit bodies of Ganoderma lucidum and isolated by anion-exchange and gel-filtration chromatography. Their structural features were elucidated by glycosyl residue and glycosyl linkage composition analyses, partial acid hydrolysis, acetolysis, periodate oxidation, 1D and 2D NMR spectroscopy, and ESI-MS experiments. The data obtained indicated that PL-1 had a backbone consisting of 1,4-linked α-D-glucopyranosyl residues and 1,6-linked β-D-galactopyranosyl residues with branches at O-6 of glucose residues and O-2 of galactose residues, composed of terminal glucose, 1,6-linked glucosyl residues and terminal rhamnose. PL-3 was a highly branched glucan composed of 1,3-linked β-D-glucopyranosyl residues substituted at O-6 with 1,6-linked glucosyl residues. PL-4 was comprised of 1,3-, 1,4-, 1,6-linked β-D-glucopyranosyl residues and 1,6-linked β-D-mannopyranosyl residues. These polysaccharides enhanced the proliferation of T- and B-lymphocytes in vitro to varying contents and PL-1 exhibited an immune-stimulating activity in mice.
structural elucidation, glucan, immunological activity, Ganoderma lucidum, heteroglycan, Polyparaceae
NCBI PubMed ID: 11809453The non-cellulosic polysaccharides of flax fibre cells were isolated using chemical extraction methods. Extraction of mature retted flax fibre with the calcium chelating agent trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid (CDTA) removed polysaccharides enriched in galacturonic acid. These pectic polysaccharides were fractionated by their solubility in water into two fractions that differed in their neutral sugar content. Extraction of the fibre with aqueous 24% (w/v) potassium hydroxide produced the first hemicellulosic fraction (Hc1), which was enriched in xylose and, to a lesser extent, glucose- and galactose-containing polysaccharides. Digestion of aliquots of this fraction using the fungal carbohydrase mixture, Driselase, yielded xylobiose and isoprimeverose, which are characteristic limit digestion products of xylans and xyloglucans, respectively. Digestion of Hc1 with a crude cellulase preparation from Aspergillus niger yielded oligosaccharide products, one of which was similar to a characteristic nonasaccharide subunit of xyloglucan. Further extraction of the fibre residue with aqueous 18% (w/v) potassium hydroxide supplemented with 4% (w/v) of boric acid removed a second hemicellulosic fraction (Hc2), which was enriched in mannose-containing polysaccharides. Digestion of this fraction with a highly purified endo-(1→4)-β-d-mannanase converted 67% of the total polysaccharide into oligosaccharides within one hour. The β-d-mannanase-derived oligosaccharides had a monosaccharide composition of mannose-glucose of 1.6:1.0. Analysis of the oligosaccharides by TLC and high-performance anion exchange chromatography revealed products characteristic of a glucomannan similar to those found in hardwoods. The presence of β-linked d-glucose residues was confirmed by the removal of glucose from the β-d-mannanase-derived oligosaccharides by a purified β-d-glucosidase. A final extraction of the fibre with aqueous 90% Me2SO containing 4% (w/v) of boric acid removed a further pectic fraction (Hc3) enriched in neutral sugars. Preliminary analyses suggest that this fraction may contain a polysaccharide akin to rhamnogalacturonan I.
Publication DOI: 10.1016/0008-6215(93)80109-RMaltose is exported from the Arabidopsis chloroplast as the main product of starch degradation at night. To investigate its fate in the cytosol, we characterised plants with mutations in a gene encoding a putative glucanotransferase (disproportionating enzyme; DPE2), a protein similar to the maltase Q (MalQ) gene product involved in maltose metabolism in bacteria. Use of a DPE2 antiserum revealed that the DPE2 protein is cytosolic. Four independent mutant lines lacked this protein and displayed a decreased capacity for both starch synthesis and starch degradation in leaves. They contained exceptionally high levels of maltose, and elevated levels of glucose, fructose and other malto-oligosaccharides. Sucrose levels were lower than those in wild-type plants, especially at the start of the dark period. A glucosyltransferase activity, capable of transferring one of the glucosyl units of maltose to glycogen or amylopectin and releasing the other, was identified in leaves of wild-type plants. Its activity was sufficient to account for the rate of starch degradation. This activity was absent from dpe2 mutant plants. Based on these results, we suggest that DPE2 is an essential component of the pathway from starch to sucrose and cellular metabolism in leaves at night. Its role is probably to metabolise maltose exported from the chloroplast. We propose a pathway for the conversion of starch to sucrose in an Arabidopsis leaf.
glucosyltransferase, Arabidopsis, maltose metabolism, maltose transporter, starch degradation, starch mutants
Publication DOI: 10.1111/j.1365-313X.2003.02012.xTwo liquid chromatography methods using an evaporative light scattering detection (ELSD) have been developed to determine the carbohydrate profile of maltodextrins. The first method requires an octadecyl-bonded silica column and a methanol/water mobile phase. With the second method, an amino-bonded polymeric stationary phase and an acetonitrile/water eluent are used. In the two cases, a gradient elution was necessary to desorb the higher molecular weight polysaccharides. This elution mode was perfectly compatible with ELSD since no baseline drift was observed. These two methods were applied to quantify maltodextrins present in plant spray dried-powder of melilot and basil.
HPLC, Plant Extracts, ELSD, maltodextrins
Publication DOI: 10.1081/JLC-100101240| New query | Export IDs | Home | Help |
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