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Found 2 structures.
Displayed structures from 1 to 2
| -2)-b-D-Rhap-(1-3)-a-D-Rhap-(1-3)-a-D-Rhap-(1-2)-a-D-Rhap-(1-2)-a-D-Rhap-(1- | Show graphically |
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Structure type: polymer chemical repeating unit
Trivial name: D-rhamnan
Compound class: CPS, O-polysaccharide
Contained glycoepitopes: IEDB_1394181,IEDB_145006,IEDB_145010
An O-specific polysaccharide was isolated from the lipopolysaccharide of a plant-growth-promoting bacterium Azospirillum brasilense Sp245 and studied by sugar analyses along with one- and two-dimensional 1H and 13C NMR spectroscopy, including NOESY. The polysaccharide was found to be a new rhamnan with a pentasaccharide repeating unit having the following structure: →2)-β-D-Rhap-(1→3)-α-D-Rhap-(1→3)-α-D-Rhap-(1→2)-α-D-Rhap-(1→2)-α-D-Rhap-(1→
Lipopolysaccharide, O-antigen, Bacterial polysaccharide, Asymbiotic diazotroph, Azospirillum brasilense
NCBI PubMed ID: 11996841The structural identity of the repeated unit in O-specific polysaccharides (OPSs) present in the outer membrane of strain SR75 of the bacterium Azospirillum brasilense, isolated from wheat rhizosphere in Saratov oblast, and the OPSs of previously studied A. brasilense strain Sp245, isolated from surface-sterilized wheat roots in Brazil, has been demonstrated. Plasmid profiles, DNA restriction, and hybridization assays suggested that A. brasilense strains SR75 and Sp245 have different genomic structures. It was shown that homologous lps loci of both strains was localized in their plasmid DNA. This fact allows us to state that, despite their different origin, the development of the strains studied was convergent. Presumably, the habitation of these bacteria in similar ecological niches influenced this process in many respects
LPS, structure, DNA, strain, structural, polysaccharide, determination, bacteria, O-specific, O-specific polysaccharide, Azospirillum brasilense, polysaccharides, plasmid, O-specific polysaccharides, homology, membrane, outer membrane, root, assay, origin, Plasmids, homologous, development, Azospirillum, P, profile, restriction, ecological, rhizosphere, wheat
NCBI PubMed ID: 16315981Gram-negative bacterial lipopolysaccharides (LPSs) have multiple roles in plant-microbe interactions. LPSs contribute to the low permeabilities of bacterial outer membranes, which act as barriers to protect bacteria from plant-derived antimicrobial substances. Conversely, perception of LPSs by plant cells can lead to the triggering of defence responses or to the priming of the plant to respond more rapidly and/or to a greater degree to subsequent pathogen challenge. LPSs are thus key molecules in the interactions between bacteria and plants, either in symbiosis or pathogenesis. Since LPSs are glycoconjugates genetically and chemically consisting of three different molecular regions, their detailed structure elucidation is a very topical and major scientific task for chemists, and is achieved by a combination of state-of-art chemical and spectroscopic techniques. Knowledge of LPSs' chemical structures is an important prerequisite for any further understanding of the biological processes in plant-microbe interactions. Moreover, the LPSs from Gram-negative bacteria - especially those originating from plant-associated bacteria - are a great source of novel monosaccharides with unusual and occasionally astounding chemical structures, never found in the eukaryotic world. This review presents the structures of LPSs from plant-associated bacteria isolated and identified from 2001 onwards.
lipopolysaccharides, structure elucidation, glycolipids, innate immunity, immunochemistry, plant-associated bacteria
Publication DOI: 10.1002/ejoc.200900682Lipopolysaccharides (LPS) and O-specific polysaccharides (OPS) were obtained from the outermembrane of four Azospirillum strains previously assigned to serogroup I based on the serological affinityrevealed by the antibodies (AB) to the LPS of A. brasilense Sp245. Investigation, including determination ofmonosaccharide composition, methylation analysis, and one- and two-dimensional NMR spectroscopy, wascarried out to determine the OPS structure. The OPSs of A. brasilense Sp107 and S27 and of A. lipoferumRG20a were found to have an identical structure of repeating units represented by a linear penta-D-rhamnan,as was previously described for the OPSs of A. brasilense Sp245 and SR75. The OPS of A. brasilense SR15was found to consist of tetrasaccharide repeating units of the following structure: frame0 2)--D-Rhap-(1 frame1 2)--D-Rhap-(1 frame2 3)--D-Rhap-(1 frame3 2)--D-Rhap-(1 frame4. An opine compound, N-(1-carboxyethyl)-orni-thine, closely associated with the LPS of A. brasilense SR15, was identified in azospirilla for the first time. Thepresence of a 6-deoxisugar (D-rhamnose) in the OPS structure was shown to be the chemical basis of the sero-logical similarity and the reason for classification of these strains within the serogroup I.
Lipopolysaccharide, serological characterization, Azospirillum, structure of O-specific polysaccharides
Publication DOI: 10.1134/S0026261710020116The rhizobacteria Azospirillum brasilense Sp245 produce immunochemically different lipopolysaccharides LPSI and LPSII, both containing identical pentasaccharides built from Drhamnose residues as the repeating units of Ospecific polysaccharides (OPS). In this study, we report the structure of the OPS from A. brasilense LPSI-LPSII- mutant Sp245.5, which spontaneously lost the p85 and p120 plasmids upon the formation of a new 300MDa megaplasmid after the longterm storage of the bacteria in a rich medium. The repeating unit of the OPS of A. brasilense Sp245.5 appeared to be a disaccharide consisting of residues of Nacetyl-D-galactosamine and Nacetyl-D-mannosaminuronic acid: (formula, see text).
Azospirillum brasilense, O-Specific polysaccharide structure, plasmid rearrangements
NCBI PubMed ID: 20531482The lipopolysaccharide (LPS) is the major constituent of the outer leaflet of the outer membrane of Gram-negative bacteria. Its lipid A moiety is embedded in the membrane and serves as an anchor for the rest of the LPS molecule. The outermost repetitive glycan region of the LPS is linked to the lipid A through a core oligosaccharide (OS), and is designated as the O-specific polysaccharide (O-polysaccharide, OPS) or O-antigen. The O-antigen is the most variable portion of the LPS and provides serological specificity, which is used for bacterial serotyping. The OPS also provides protection to the microorganisms from host defenses such as complement mediated killing and phagocytosis, and is involved in interactions of bacteria with plants and bacteriophages. Studies of the OPSs ranging from the elucidation of their chemical structures and conformations to their biological and physico-chemical properties help improving classification schemes of Gram-negative bacteria. Furthermore, these studies contributed to a better understanding of the mechanisms of pathogenesis of infectious diseases, as well as provided information to develop novel vaccines and diagnostic reagents.
Lipopolysaccharide, synthesis, lipopolysaccharides, structure, Bacterial, host, O-antigen, O antigen, cell, O antigens, O-antigens, chemical, interaction, cells, PDF, chemical synthesis, biogenesis
Publication DOI: 10.1007/978-3-7091-0733-1_3Lipopolysaccharides of six Azospirillum brasilense strains (SR50, SR80, SR88, SR109, SR111, SR115) and A. lipoferum SR 42 isolated from the rhizosphere of cereal plants of Saratov oblast, Russia and referred to serogroup II by serological analysis were studied. In the lipid A fatty acid composition, the lipopolysaccharides under study were similar to those of other Azospirillum strains and were characterized by a predominance of 3-hydroxytetradecanoic, 3-hydroxyhexadecanoic, and octadecenoic acids. Monosaccharide analysis of the O-specific polysaccharides (including determination of the absolute configurations, methylation analysis, and one- and two-dimensional NMR spectroscopy) revealed the presence of two types of repeating units in varying ratios. A high degree of serological similarity between the strains under study was shown to result from the presence of repeating units with identical structure of their O antigens.
lipopolysaccharides, Azospirillum, structure of the Ospecific polysaccharide, serological investigation
Publication DOI: 10.1134/S0026261714040158The review presents a discussion of the published data of 2002 to 2014 dealing with structural studies of O-specific polysaccharides, representatives of the Azospirillum diazotrophic rhizobacteria, summarizing the results of a series of authors? studies. Some general structures incorporated in O-specific polysaccharides responsible for classification of bacterial cultures into serogroups on the basis of immunochemical studies were characterized. The structures of O-specific polysaccharides of seven azospirillum strains identical to those of previously studied strains are presented in this review for the first time.
lipopolysaccharides, O-specific polysaccharides, Structures, Azospirillum, O-antigenic determinants
Publication DOI: 10.1007/s11172-015-0971-xEffect of the carbon source in the culture medium and of the growth phase on the composition and structure of the capsular polysaccharides (CPSs) and lipopolysaccharides (LPSs) of the bacterium Azospirillum brasilense Sp245 was studied. Growth with fructose resulted in an increased carbohydrate content in the CPSs, while long-term cultivation resulted in an increased content of phosphorus in both CPSs and LPSs. The LPSs produced on the medium with fructose (regardless of the cultivation duration) and the LPSs of the bacteria grown with sodium malate until the stationary phase were characterized by higher levels of unsaturated fatty acids than the LPSs of the bacteria grown with sodium malate to the late exponential phase. The structures of the polysaccharides from the isolated glycopolymers were established using monosaccharide analysis, including determination of the absolute configurations and 1D and 2D NMR spectroscopy. This study is the first to report that the CPS of A. brasilense Sp245 grown with sodium malate to the end of the exponential phase is structurally identical to the O-polysaccharide from the LPS of this bacterium and that the LPS and CPS of A. brasilense Sp245 grown with fructose contain an additional homoglucan of the following structure: [→3)-α-D-Glcp-(1→]n.
Lipopolysaccharide, capsular polysaccharide, Azospirillum brasilense, Azospirillum, cultivation conditions
Publication DOI: 10.1134/S0026261716060096Bacterial extracellular polysaccharides are known as a cell-bound capsule, a sheath, or a slime, which is excreted into the environment. They play an important role in virulence of medical bacteria and plant-to-symbiont interaction and are used for serotyping of bacteria and production of vaccines. Some exopolysaccharides have commercial applications in industry, and claims of health benefits have been documented for an increasing number of them. Exopolysaccharides have diverse composition and structure, and some contain sugar and non-sugar components that are found in bacterial carbohydrates only. The present article provides an updated collection of the data on exopolysaccharides of various classes of gram-negative and gram-positive bacteria reported until the end of 2019. When known, biosynthesis pathways of exopolysaccharides are treated in a summary manner. References are made to structure and biosynthesis relatedness between exopolysaccharides of different bacterial taxa as well as between bacterial polysaccharides and mammalian glycosaminoglycans.
polysaccharide structure, Gram-negative bacteria, capsule, Biofilm, polysaccharide biosynthesis, gram-positive bacteria, Monosaccharide composition, Bacterial exopolysaccharide, non-sugar component
Publication DOI: 10.1016/B978-0-12-819475-1.00005-5| -3)-a-D-Glcp-(1- | Show graphically |
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Structure type: homopolymer
Trivial name: D-rhamnan, α-1,3-D-glucan, α-1,3-glucan, (1-3)-α-Glucan, 1-3-α-glucan, α-(1,3)-glucan, α-(1,3)glucan, (1-3)-α-glucan, pseudonigeran, α-(1,3)-glucan, pseudonigeran, water-insoluble α-D-glucan (TM-I)
Compound class: EPS, O-polysaccharide, cell wall polysaccharide, glucan, polysaccharide, D-glucan
Contained glycoepitopes: IEDB_142488,IEDB_144998,IEDB_146664,IEDB_983931,SB_192
The structure of an alkali-soluble D-glucan (AG-AL) from the fruit body of Agrocybe cylindracea was investigated by a combination of chemical and spectroscopic methods indicating that it was a linear (1→3)-α-D-glucan (molecular weight, ~560,000), [α]D2O +195° (c 0.5, m sodium hydroxide). Both water-soluble and gelatinous products obtained by O-(carboxymethyl)ation of AG-AL showed potent antitumor activity against the solid form of Sarcoma 180 in mice, although the native D-glucan had little effect on the tumor.
mice, glucan, sarcoma 180, Agrocybe cylindracea, carboxymethylated derivative
NCBI PubMed ID: 2550128Effect of the carbon source in the culture medium and of the growth phase on the composition and structure of the capsular polysaccharides (CPSs) and lipopolysaccharides (LPSs) of the bacterium Azospirillum brasilense Sp245 was studied. Growth with fructose resulted in an increased carbohydrate content in the CPSs, while long-term cultivation resulted in an increased content of phosphorus in both CPSs and LPSs. The LPSs produced on the medium with fructose (regardless of the cultivation duration) and the LPSs of the bacteria grown with sodium malate until the stationary phase were characterized by higher levels of unsaturated fatty acids than the LPSs of the bacteria grown with sodium malate to the late exponential phase. The structures of the polysaccharides from the isolated glycopolymers were established using monosaccharide analysis, including determination of the absolute configurations and 1D and 2D NMR spectroscopy. This study is the first to report that the CPS of A. brasilense Sp245 grown with sodium malate to the end of the exponential phase is structurally identical to the O-polysaccharide from the LPS of this bacterium and that the LPS and CPS of A. brasilense Sp245 grown with fructose contain an additional homoglucan of the following structure: [→3)-α-D-Glcp-(1→]n.
Lipopolysaccharide, capsular polysaccharide, Azospirillum brasilense, Azospirillum, cultivation conditions
Publication DOI: 10.1134/S0026261716060096Immunomodulating activities of three carboxymethylated derivatives (AG-AL-CMS, AG-AL-CMI, and AM-APP-CM) of linear (1→3)-α-D-glucans from Agrocybe cylindracea and Amanita muscaria were evaluated with murine peritoneal macrophages playing an important role in tumor immunity. The ratio of macrophages in peritoneal exudate cells increased more than 50% after the administration of three carboxymethylated (1→3)-α-D-glucans. These carboxymethylated (1→3)-α-D-glucans exhibited higher potentiating activities for macrophages than carboxymethylated linear (1→3)-β-D-glucan (CMPS) in the potency of reduction of nitro blue tetrazolium, products of nitric oxide and the soluble cytotoxic factor, the amount of glucose consumption, and the activation of acid phosphatase. AG-AL-CMS, AG-AL-CMI, and AM-APP-CM were found to induce the tumor regressing factor in mouse serum, although the ability of the induction of this factor was weaker than that of CMPS. The reticuloendothelial system-potentiating activation of three carboxymethylated α-D-glucans was similar to that of the carboxymethylated β-D-glucan. AG-AL-CMS and AG-AL-CMI, but not AM-APP-CM, were suggested to possess a higher-order structure, resulting from the formation of a fluorescent complex with aniline blue
polysaccharide, immunomodulator, macrophage, carboxymethylation, (1→3)-α-D-glucan, tumor regressing activity
NCBI PubMed ID: 8820922The preparation of pharmaceutical grade (1→3)-β-D-glucans from Saccharomyces cerevisiae requires that the microparticulate glucans which are employed as the starting material for drug production be of the highest purity. Potential contaminants of the (1→3)-β-D-glucan isolation process are yeast cell wall lipids, which are frequently found in association with glucans. The lipid content of yeast-derived (1→3)-β-D-glucan during various stages of the isolation process by methyl esterification and total ion gas chromatography and mass spectrometry (GC-MS) was examined. Following sequential alkaline and acid hydrolyses, the total lipid content of (1→3)-β-D-glucan was 100.4 nmol/mg with 9-cis-C 18:1 fatty acid accounting for 45.3 nmol/mg glucan (45%). Following ethanol extraction of the (1→3)-β-D-glucan, lipid was not detected. Indeed, fatty acid methyl esters were not detectable by total ion GC-MS in all twelve samples investigated. These data demonstrate that the isolation process for yeast-derived (1→3)-β-D-glucan effectively reduces contamination by yeast cell wall lipids.
NCBI PubMed ID: 7837997A linear (1→3)-α-d-glucan was isolated from the spores of Ganoderma lucidum (Fr.) Karst. Six different functionalized derivatives of the (1→3)-α-d-glucan—aminopropylated, hydroxyethylated, sulfated, carboxymethylated, carboxymethylated and sulfated, and benzylamidated–carboxymethylated—with varying degrees of substitution were synthesized. The structural features and physicochemical properties of all derivatives were investigated by means of chemical and spectral analyses, and their effects on lymphocyte proliferation and antibody production were tested in vitro and in vivo. In general, the structural and physicochemical properties, and lymphocyte proliferation activity of all samples varied with the functionalized groups and the degree of substitution. The results of immunological assays indicated that some modified derivatives had potent stimulating effects on lymphocyte proliferation and antibody production and the introduction of carboxymethyl group with low degree of substitution (DS<0.28) was the best choice on the improvement of the immunostimulating activity.
chemical modification, immunological activity, (1→3)-α-D-glucan, Ganoderma lucidum
Journal NLM ID: 0043535A water-insoluble α-(1→3)-D-glucan (A) from Lentinus edodes was fractionated into 13 fractions in dimethyl sulfoxide containing 0.25 M lithium chloride (0.25 M LiCl-Me(2)SO). Five fractions were treated with sulfur trioxide-pyridine complex at 25 degrees C to synthesize water-soluble sulfated derivatives (S-A). The weight-average molecular weights, M(w), and intrinsic viscosities [eta], of the samples A and S-A were determined by multi-angler laser light scattering (MALLS), and viscosity. The M(w) dependence of [eta] and of the radius of gyration
conformation, solution properties, molecular weight, intrinsic viscosity, Lentinus edodes, α-(1→3)-d-glucan, sulfated derivatives
Publication DOI: 10.1016/S0008-6215(01)00289-0Mycelia of a wild strain Poria cocos were cultured in two media differing in one constituent: bran extract or corn steep liquor, and are designated as wb and wc, respectively. Six polysaccharide fractions were isolated sequentially from the two mycelia by 0.9% NaCl (PCM1), hot water (PCM2), 0.5 M NaOH (PCM3-I and -II) and 88% formic acid (PCM4-I and -II). Their chemical and physical characteristics were determined by infrared spectroscopy (IR), gas chromatography (GC), 13C NMR, light scattering (LS) and viscometry. The results indicated that wb-, wc-PCM1, and PCM2 were heteropolysaccharides mainly composed of α-d-glucose, mannose, and galactose, whereas wb-PCM3-I and wc-PCM3-I were mainly (1→3)-α-d-glucans, and wb- and wc-PCM3-II, PCM4-I and PCM4-II were (1→3)-β-D-glucans. Interestingly, (1→3) α- and (1→3)-β-D-glucans co-existed in the 0.5 M NaOH fraction and were separated individually into the two fractions (PCM3-I and PCM3-II) after neutralizing with acetic acid. The polysaccharides from wc-PCM cultured in media containing corn steep liquor contained relatively more protein. The polysaccharide fractions also existed in conformations including random coil (as in PCM0 and PCM1) and expanded chain (as in PCM3), and differed molecular mass. In addition, two exo-polysaccharides isolated from the two culture media by methanol precipitation (wb- and wc-PCM0) also differed in their monosaccharide composition.
conformation, polysaccharide, light scattering, composition, molecular mass, Poria cocos
NCBI PubMed ID: 12829396Alkali extraction and methylation analyses in the 1970s revealed that the cell walls of the yeast Schizosaccharomyces pombe contain a (1→3)-α-d-glucan, a (1→3)-β-D-glucan, a (1→6)-β-D-glucan, and a α-galactomannan. To refine the structures of these polysaccharides, cell-wall glucans of S. pombe were extracted, fractionated, and analyzed by NMR spectroscopy. S. pombe cells were treated with 3% NaOH, and alkali-soluble and insoluble fractions were prepared. The alkali-insoluble fraction was treated with 0.5 M acetic acid or Zymolyase 100 T to yield an alkali-insoluble, acetic acid-insoluble fraction, an alkali-insoluble, Zymolyase-insoluble fraction, and an alkali-insoluble, Zymolyase-soluble fraction. 13C NMR and 2D-NMR spectra disclosed that the cell wall of S. pombe is composed of three types of glucans, specifically, a (1→3)-α-d-glucan, a (1→3)-β-D-glucan, which may either be linear or slightly branched, and a highly branched (1→6)-β-D-glucan, in addition to α-galactomannan. The highly branched (1→6)-β-D-glucan was identified by selective periodate degradation of side-chain glucose as a highly (1→3)-β-branched (1→6)-β-D-glucan with more branches than that of Saccharomyces cerevisiae. Flexibility of these polysaccharides in the cell wall was analyzed by 13C NMR spectra in D2O. The data collectively indicate that (1→3)-α- and (1→3)-β-D-glucans are rigid and contribute to the cell shape, while the highly branched (1→6)-β-D-glucan and α-galactomannan are flexible.
NMR, cell-wall glucan, Schizosaccharomyces pombe
NCBI PubMed ID: 15337454The cell wall of Aspergillus fumigatus is composed of a branched PI,3 glucan covalently bound to chitin, β-1,3, β-1,4 glucans, and galactomannan, that is embedded in an amorphous cement composed of α-1,3 glucan, galactomannan and polygalactosamin. The mycelial cell wall of A. fumigatus is very different from the yeast Saccharomyces cerevisiae cell wall, and in particular lacks 01,6 glucans and proteins covalently bound to cell wall polysaccharides. The differences in cell wall composition between the mould A. fumigatus and the yeast S. cerevisiae are also reflected at the genomic level where unique features have been identified in A. fumigatus. A single gene codes for the glucan synthase catalytic subumit; this finding has lead to the development of a RNAi methodology for the disruption of essential genes in A. fumigatus. In contrast to the glucan synthase, multiple genes have been found in the chitin synthase and the α-glucan synthase families; in spite of homologous sequences, each gene in each family have very different function. Similarly homologous mannosyltransferase genes are found in yeast and moulds but they lead to the synthesis of very different N-mannan structures. This chemo-genomic comparative analysis has also suggested that GPI-anchored proteins do not have a role of linker in the three dimensional organization of the fungal cell wall.
cell wall, mannan, glucan, GPI, chitin
Publication DOI: 10.1080/13693780400029155Two polysaccharides were isolated from submergedly cultured mycelium of the basidiomycete Ganoderma lucidum by extraction with alkali followed by fractionation with Fehling reagent. The polysaccharides were shown to be a linear (1→3)-α-D-glucan and a highly branched xylomannan containing a backbone built up of (1→3)-linked α-D-mannopyranose residues, the majority of which are substituted at O-4 by single β-D-xylopyranose residues or by disaccharide fragments β-D-Manp-(1→3)-β-D-Xylp-(1→. Polysaccharide structures were elucidated by NMR spectroscopy in combination with methylation analysis and periodate oxidation. An interesting feature of the xylomannan is the simultaneous presence of α-D-mannopyranose and β-D-mannopyranose residues, the first forming the backbone, and the second being the non-reducing terminal units of disaccharide side chains.
NMR spectroscopy, polysaccharides, (1→3)-α-D-glucan, Basidiomycetes, Ganoderma lucidum, white rot fungi, branched xylomannan
NCBI PubMed ID: 19538127The glucans of basidiomycetes are an important class of polysaccharides with potential biological activities. In this work, the β-glucans were isolated from the fruiting bodies of edible mushrooms, Pleurotus eryngii and Pleurotus ostreatoroseus, via extraction with hot water, and then fractionation by freeze-thawing. The insoluble glucans gave similar 13C NMR spectra, monosaccharide composition and methylation analyses, and P. eryngii was selected for further controlled Smith degradation, and DEPT and 1H (obs.), 13C HMQC spectroscopy. It was a branched β-glucan, with a main chain of (1→3)-linked-Glcp residues, substituted at O-6 by single-unit β-Glcp side-chains, on average to every third residue of the backbone, as in scleroglucan.
polysaccharides, Pleurotus florida, Edible mushrooms, αβ-glucan
Publication DOI: 10.1016/j.carbpol.2007.11.030Mushrooms have been valued as edible and medicinal resources, and antitumor substances have been identified in many mushroom species. Polysaccharides are the best known and most potent mushroom-derived substances with antitumor and immunomodulating properties. Although the isolation process, structural characterization and antitumor activity of mushroom polysaccharides have been extensively investigated in the past three decades, the relationship between the antitumor activity and the chemical composition as well as the high order structure of their active components is still not well established. These studies are still in progress in many laboratories, and the role of polysaccharides as antitumor agent is especially under intense debate. The purpose of the present review is to summarize the available information, and to reflect the current status of this research area with a view for future direction.
structure, biological activity, mushrooms, antitumor polysaccharides
Publication DOI: 10.1016/j.tifs.2006.07.013Preliminary data on the polysaccharide composition of mycelium and cell walls of the submergedly grown fungus Penicillium roqueforti were obtained. Mild acid hydrolysis of mycelium and cell walls led to formation of glucose, mannose and galactose, whereas acid treatment under drastic conditions afforded glucosamine as the hydrolysis product of chitin, which content in the cell walls was estimated as 19%. Sequential treatment of the mycelium with hot water and 1 M NaOH at room temperature gave rise to several polysaccharide fractions, which were characterized by their monosaccharide composition. The main fraction obtained by the action of alkali, according to NMR spectroscopy, mass spectrometry and chemical methods of structural analysis data, is a linear α-D-glucopyranan containing blocks of (1→3)-linked glucose residues interconnected by (1→4)-linkages. Water-soluble polysaccharides contained linear blocks of (1→5)-linked β-galactofuranose residues, probably connected with a mannan core. The data obtained may be important for chemotaxonomy of the genus Penicillium.
polysaccharides, Penicillium roqueforti, (1→3, 1→4)-α-D-glucopyranan, (1→5)-β-galactofuranan.
NCBI PubMed ID: 21899056Polysaccharides from Phaffia rhodozyma SDS-treated cell walls were successively obtained via cold water, hot water, and dimethylsulfoxide extractions. For this, processed yeast cells were grown under a physiological condition of active production of astaxanthin, its characteristic carotenoid metabolite. Afterwards, the extracted fractions were fractionated via freeze-thawing and precipitation with either Fehling reagent or Cetavlon. An α-D-glucan and a heteropolysaccharide were isolated and structurally investigated using monosaccharide composition determination, methylation analysis, and COSY, TOCSY and HMQC techniques of 13C- and 1H-NMR. The DMSO-extracted and Fehling-purified α-D-glucan was determined to be a linear chain of α-D-(1→3)-glucopyranosyl units. The hot water-extracted and Cetavlon-precipitated heteropolysaccharide showed a complex structure containing α-D-(1→4)-mannopyranosyl units-based main chain with side chains containing β-D-(1→4)-xylopyranosyl units along with D-mannose, D-galactose, and D-glucose units. In addition, these monosaccharides are found to be non-reducing ends of the heteropolysaccharide as well. The cell wall extraction schedule also yielded several minor glucan fractions displaying a positive iodophilic reaction which was abolished after pretreatment with crystalline Bacillus subtilis α-amylase. The knowledge of these cell wall features is of importance for the application of whole P. rhodozyma cells as single cell protein, improved digestibility, and astaxanthin release.
polysaccharide, yeast cell wall, Phaffia rhodozyma
Publisher: Nova Science Publishers, Inc., New York, USATo show biological activity of carboxymethylated α-(1→3)-D-glucans isolated from the selected macromycetes fungi on human tumor and normal cells. Water-insoluble, alkali-soluble polysaccharides (WIP) were isolated from fruiting bodies of four macromycetes fungi: Lentinus edodes, Pleurotus ostreatus, Piptoporus betulinus and Laetiporus sulphureus. The structure of the polysaccharides was determined using composition analysis, methylation analysis, fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The chemical and spectroscopic investigations indicated that the polysaccharides were an α-(1→3)-D-glucans. A biological activity analysis of the carboxymethylated (CM) α-(1→3)-D-glucans was based on an assessment of their cytotoxic, mitochondrial metabolism-modulating, and free radical scavenging effects. The cytotoxic activity of the CM-glucans was concentration- and cell-type-dependent. The tested CM-glucans, generally, did not have a free radical scavenging effect. The CM-α-(1→3)-D-glucans isolated from the selected macromycetes fungi are biologically active and may therefore be used as diet or therapy supplements.
cytotoxicity, carboxymethylation, α-(1→3)-d-glucan, human cell cultures, macromycetes fungi
NCBI PubMed ID: 21188616Preliminary data on the polysaccharide composition of mycelium of the fungus Cunninghamella japonica (synonymous with C. echinulata) grown by the method of submerged cultivation were obtained. Mild acidic hydrolysis of mycelium resulted in the formation of glucose, mannose, and galactose; while the treatment with acid under drastic conditions afforded glucosamine as a product of hydrolysis of chitin and chitosan, their total content was about 35%. Several polysaccharide fractions were isolated from mycelium by successive extraction with hot water, 2% aqueous NaOH, and 10% AcOH; their monosaccharide composition was characterized. The yield of chitosan extracted with AcOH was insignificant. Additional purification of the fraction obtained after extraction with alkali afforded polysaccharide which was a linear (1→3)-α-D-glucopyranan according to the data of NMR spectroscopy and the chemical methods of structural analysis. The presence of this polysaccharide, as well as a low content of chitosan and polyuronides, distinguishes the studied strain C. japonica from most of the known Mucorales.
polysaccharides, Cunninghamella japonica, (1→3)-α-D-glucopyranan
NCBI PubMed ID: 22792730Cultivated oyster mushrooms (genus Pleurotus) are interesting as a source of biologically active glucans. Partially, β-glucan from Pleurotus sp. (pleuran) has been used as food supplements due to its immunosuppressive activity. Like other dietary fibre components, oyster mushroom polysaccharides can stimulate the growth of colon microorganisms (probiotics), i.e. act as prebiotics. Specific glucans were isolated from stems of Pleurotus ostreatus and Pleurotus eryngii by subsequent boiling water and alkali extraction. Obtained water soluble (L1), alkali soluble (L2) and insoluble (S) fractions were characterised by various analytical methods. Spectroscopic analysis detected glucans in all the fractions: branched 1,3-1,6-β-D-glucan predominated in L1 and S, while linear 1,3-α-d-glucan in L2. Fractions L1 also contained marked amount of proteins partially in complex with glucans; protein content in L2 was insignificant. Effective deproteinisation of L1 and separation of α- and β-glucans in L2 was achieved by the treatment with phenolic reagent. Small amount of chitin was found in S as a component of cell wall chitin-glucan complex. Potential prebiotic activity of extracts L1 and L2 was testing using nine probiotic strains of Lactobacillus, Bifidobacterium and Enterococcus. These probiotics showed different growth characteristics dependently on used extract and strain specificity due to the presence of structurally diverse compounds. The extracts L1 and L2 can be applied to synbiotic construction only for carefully selected probiotic strains. This exploitation of fruit body extracts extends the use of mushrooms P. ostreatus and P. eryngii for human health.
isolation, Glucans, prebiotic activity, oyster mushroom Pleurotus
Publication DOI: 10.1016/j.carbpol.2008.11.021The carbon-13 nmr spectra of two cyclodextrins and several linear glucans have been completely assigned. These assignments were made by comparison with the spectra of glucose, some of its specifically O-methylated derivatives, and a number of differently linked glucobioses and glucotrioses. This technique enables the composition, structure, and major sequence of a number of glucans to be determined. Conformational effects are also apparent in some of the spectra. The 1→4, 1→4, and 1→6 linkage sequence of the glucans from T. mesenterica and P. pullulans give, in addition to an anomeric signal for the 1→6 linkage, two separate anomeric signals for each of the 1→4 linkages. This multiplicity, apparent also in other carbon signals of the spectra, is due to the sensitivity of these carbons to the type of linkage on the neighboring glucose units. Some evidence that conformational effects are involved in this multiplicity is provided by a comparison of the spectra of the 1→4-linked cyclodextrins and linear glucans, where appreciable chemical shift differences are apparent for C1 and C4. These effects are influenced by pH modification and are attributed to differences in rotational isomers at the linked carbons.
NMR, oligosaccharide, Bacterial polysaccharide, amylose
NCBI PubMed ID: 4464319More than 90% of the cell wall of the filamentous fungus Aspergillus fumigatus comprises polysaccharides. Biosynthesis of the cell wall polysaccharides is under the control of three types of enzymes: transmembrane synthases, which are anchored to the plasma membrane and use nucleotide sugars as substrates, and cell wall-associated transglycosidases and glycosyl hydrolases, which are responsible for remodeling the de novo synthesized polysaccharides and establishing the three-dimensional structure of the cell wall. For years, the cell wall was considered an inert exoskeleton of the fungal cell. The cell wall is now recognized as a living organelle, since the composition and cellular localization of the different constitutive cell wall components (especially of the outer layers) vary when the fungus senses changes in the external environment. The cell wall plays a major role during infection. The recognition of the fungal cell wall by the host is essential in the initiation of the immune response. The interactions between the different pattern-recognition receptors (PRRs) and cell wall pathogen-associated molecular patterns (PAMPs) orientate the host response toward either fungal death or growth, which would then lead to disease development. Understanding the molecular determinants of the interplay between the cell wall and host immunity is fundamental to combatting Aspergillus diseases.
polysaccharide, infection, interaction, fungi, mycelium, Conidia
NCBI PubMed ID: 28701066The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
NCBI PubMed ID: 28513415Water-insoluble, alkali-soluble polysaccharide (marked as ASP) was extracted from the vegetative mycelium and fruiting body of Cerrena unicolor strain. Monosaccharide examination of ASP demonstrated that the isolated biopolymer was composed mainly of glucose, xylose, and mannose monomers. The methylation investigation of studied polymers indicated that (1→3)-linked α-D-Glcp is the major chain constituent (92.2% for glucans isolated from fruiting body and 90.1% from mycelium). 1H NMR, FT-IR, and immunofluorescent labelling determinations confirmed that the polysaccharides isolated from both fruiting body and mycelium of C. unicolor are (1→3)-α-D-glucans. The obtained (1→3)-α-D-glucans showed differences in viscosity and similar characteristics in optical rotations. (1→3)-α-D-Glucans extracted from mycelium and fruiting body of C. unicolor were also used as potential and specific inducers of mutanase synthesis by Trichoderma harzianum. The highest mutanase activity (0.38 U/mL) was obtained after induction of enzyme by (1→3)-α-D-glucan isolated from the mycelium of C. unicolor, and this biopolymer has been suggested as a new alternative to streptococcal mutan for the mutanase induction in T. harzianum. (1→3)-α-D-Glucan-induced mutanase showed high hydrolysis potential in reaction with dextranase-pretreated mutan, where maximal degree of saccharification and solubilization of this bacterial homoglucan (83.1% and 78.4%, resp.) was reached in 3 h at 45°C.
Publication DOI: 10.1155/2017/1249134Two glucans, one α-glucan (TM-I) and one β-glucan (TM-II) were isolated from an edible mushroom, Termitomyces microcarpus by extraction with 5% NaOH/0.05% NaBH4, followed by a precipitation with 1 M acetic acid. The repeating units of two polysaccharides have been identified by means of NMR studies (1H, 13C, DEPT-135 and HSQC) and chemical investigations. The structures of repeating units of two polymers were established.
polysaccharide, mushroom, glucan, HSQC, Termitomyces microcarpus
Publication DOI: 10.1177/1934578X1701201226Mutanase (α-(1→3)-glucanase) is a little-known inductive enzyme that is potentially useful in dentistry. Here, it was shown that the cell wall preparation (CWP) obtained from the fruiting body or vegetative mycelium of polypore fungus Laetiporus sulphureus is rich in α-(1→3)-glucan and can be successfully used for mutanase induction in Trichoderma harzianum. The content of this biopolymer in the CWP depended on the age of fruiting bodies and increased along with their maturation. In the case of CWP prepared from vegetative mycelia, the amount of α-(1→3)-glucan depended on the mycelium age and also on the kind of medium used for its cultivation. All CWPs prepared from the individually harvested fruiting body specimens induced high mutanase activity (0.53-0.82 U/mL) in T. harzianum after 3 days of cultivation. As for the CWPs obtained from the hyphal mycelia of L. sulpureus, the maximal enzyme productivity (0.34 U/mL after 3 days of incubation) was recorded for CWP prepared from the 3 week-old mycelium cultivated in Sabouraud medium. Statistically, a high positive correlation was found between the total percentage content of α-(1→3)-glucan in the CWP and the mutanase activity.
Laetiporus sulphureus, fruiting body, Trichoderma harzianum, mutanase, polypore fungus, α-(1→3)-glucan
NCBI PubMed ID: 22949817α-(1,3)-Glucan is a major component of the cell wall of Aspergillus fumigatus, an opportunistic human fungal pathogen. There are three genes (AGS1, AGS2 and AGS3) controlling the biosynthesis of α-(1,3)-glucan in this fungal species. Deletion of all the three AGS genes resulted in a triple mutant that was devoid of α-(1,3)-glucan in its cell wall; however, its growth and germination was identical to that of the parental strain in vitro. In the experimental murine aspergillosis model, this mutant was less pathogenic than the parental strain. The AGS deletion resulted in an extensive structural modification of the conidial cell wall, especially conidial surface where the rodlet layer was covered by an amorphous glycoprotein matrix. This surface modification was responsible for viability reduction of conidia in vivo, which explains decrease in the virulence of triple agsΔ mutant.
NCBI PubMed ID: 24244155Although α-1,3-glucan is one of the major cell wall polysaccharides in filamentous fungi, the physiological roles of α-1,3-glucan remain unclear. The model fungus Aspergillus nidulans possesses two α-1,3-glucan synthase (AGS) genes, agsA and agsB. For functional analysis of these genes, we constructed several mutant strains in A. nidulans: agsA disruption, agsB disruption, and double-disruption strains. We also constructed several CagsB strains in which agsB expression was controlled by the inducible alcA promoter, with or without the agsA-disrupting mutation. The agsA disruption strains did not show markedly different phenotypes from those of the wild-type strain. The agsB disruption strains formed dispersed hyphal cells under liquid culture conditions, regardless of the agsA genetic background. Dispersed hyphal cells were also observed in liquid culture of the CagsB strains when agsB expression was repressed, whereas these strains grew normally in plate culture even under the agsB-repressed conditions. Fractionation of the cell wall based on the alkali solubility of its components, quantification of sugars, and (13)C-NMR spectroscopic analysis revealed that α-1,3-glucan was the main component of the alkali-soluble fraction in the wild-type and agsA disruption strains, but almost no α-1,3-glucan was found in the alkali-soluble fraction derived from either the agsB disruption strain or the CagsB strain under the agsB-repressed conditions, regardless of the agsA genetic background. Taken together, our data demonstrate that the two AGS genes are dispensable in A. nidulans, but that AgsB is required for normal growth characteristics under liquid culture conditions and is the major AGS in this species.
α-1, 3-glucan synthase
NCBI PubMed ID: 23365684For 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: 25505823The Neurospora crassa cps-1 gene encodes a polysaccharide synthase with homology to the Cryptococcus neoformans hyaluronic acid synthase Cps1p. Homologs of the cps-1 gene are found in the genomes of many fungi. Loss of CPS-1 results in a cell wall defect that affects all stages of the N. crassa life cycle, including vegetative growth, protoperithecia (female mating structure) development, and conidia (asexual spore) development. The cell wall of cps-1 deletion mutants is sensitive to cell wall perturbation reagents. Our results demonstrate that CPS-1 is required for the incorporation of cell wall proteins into the cell wall and plays a critical role in cell wall biogenesis. We found that the N. crassa cell wall is devoid of hyaluronic acid, and conclude that the polysaccharide produced by the CPS-1 is not hyaluronic acid.
cell wall polysaccharide, fungal cell wall, polysaccharide synthase, Neurospora crassa, cell wall biogenesis, cell wall glucan
NCBI PubMed ID: 24953997The cell wall of mushroom fruiting body is constituted of nondigestible macromolecules that are a rich source of dietary fiber with biological functions that are beneficial to human health. The cell wall components of an edible mushroom fruiting body from Pleurotus tuber-regium (PTR) were fractionated, and their chemical structures were investigated by chemical, physicochemical, and microscopic analyses. The present results suggest that the cell wall of the PTR mushroom fruiting body contains four main fractions: an outer fraction of polysaccharide and protein complex, which can be extracted using boiling water; a cold alkali-soluble fraction of heteropolysaccharides associated with a small amount of proteins; a hot alkali-soluble fraction of hyper-branched glucans; and an alkali-insoluble fraction of glucan-chitin complex with a normalized relative percentage of 3.6:21.9:55.7:18.8. The anomeric linkage of all the glucans was revealed by infrared spectroscopy to be β type. The structure of the major mushroom fruiting body cell wall polysaccharide (the hot alkali-soluble one, FHA-I) was elucidated by the methylation analysis to be composed of →1)-Glcp-(4→ linkages as the backbone with a 52% degree of branching consisting of →1)-Glcp-(6→ linkages in the side chains, whereas some →1)-Glcp-(3→ linkages might exist in the backbone or side chains. Size exclusion chromatography coupled with multiangle laser light scattering analysis revealed that FHA-I had a molecular weight of 4224000 g/mol and a root-mean-square radius of 30.4 nm. Both scanning electron and atomic force microscopy further showed the highly branched microstructure of FHA-I when dispersed in an aqueous sodium dodecyl sulfate solution.
cell wall polysaccharides, Pleurotus tuber-regium, dietary fiber, mushroom fruiting body
NCBI PubMed ID: 24625260Fungal 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: 23218369In this study, we aim to investigate the physiochemical and biological properties of water-soluble phosphorylated polysaccharides (P-DIP) obtained from a water-insoluble polysaccharide (DIP) extracted from Dictyophora indusiata. A series of physiochemical properties were determined, including morphology, water-solubility, molecular weight, and degree of substitution (DS). To investigate the antioxidant activity of P-DIP, we determined the scavenging activity of hydroxyl radicals and DPPH, as well as the reducing power. MTT assay was performed to determine the cytotoxic effects of DIP and P-DIP on the cellular proliferation of MCF-7 and B16 cells. Compared with DIP, P-DIP showed a satisfactory water-solubility and significant increase in the antioxidant properties. Moreover, P-DIP also showed more significant inhibitory effects on the growth of MCF-7 and B16 tumor cells than the water-insoluble DIP. These results indicated that phosphorylation might contribute to the improvement of water solubility, as well as antioxidant and anti-tumor activities of natural DIP.
phosphorylation, Dictyophora indusiata, anti-oxidant and anti-tumor activity, dialyisis, centrifugation
NCBI PubMed ID: 25316421Biological 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: 26252967Consumption of edible mushrooms has been practiced since ages to promote human health and as traditional remedies for multiple human ailments. The excellent nutritional quality of these organisms collectively called as filamentous fungi for their filament like hyphal extension, owes to a high protein, low fat and cholesterol free profile. Over the last decade, a diverse repertoire of protein-glycan conjugates isolated from these organisms has been attributed with immunomodulatory, anticancer, and other therapeutic activities. An integrated use of conventional chemical analyses, improved separation technologies, and new generation high-throughput proteomic approaches has revealed features in these complex biomolecules unknown elsewhere amongst the eukaryotes. However, due to some serious technological bottlenecks, a comprehensive structure-function delineation of the fungal glycoproteome has eluded the scientists. If we can prevail over these constraints and dig deep into this unique niche of the fungal kingdom, the quest for new generation nutraceuticals and therapeutics will get headway.
glycoproteins, mushrooms, Glycoproteomics, filamentous fungi, polysaccharopeptide complexes, nutraceuticals, therapeutic enzymes
Publication DOI: 10.1002/9781118930458.ch20Mushrooms were considered as a special delicacy by early civilizations and valued as a credible source of nutrients including considerable amounts of dietary fiber, minerals, and vitamins (in particularly, vitamin D). Mushrooms are also recognized as functional foods for their bioactive compounds offer huge beneficial impacts on human health. One of those potent bioactives is b-glucan, comprising a backbone of glucose residues linked by β-(1-3)-glycosidic bonds with attached β-(1-6) branch points, which exhibits antitumor and immunostimulating properties. The commercial pharmaceutical products from this polysaccharide source, such as schizophyllan, lentinan, grifolan, PSP (polysaccharide-peptide complex) and PSK (polysaccharide-protein complex), have shown evident clinical results. The immunomodulating action of mushroom polysaccharides is to stimulate natural killer cells, T-cells, B-cells, neutrophils, and macrophage dependent immune system responses via differing receptors involving Dectin-1, the toll-like receptor-2 (a class of proteins that play a role in the immune system), scavengers and lactosylceramides. b-Glucans with various structures present distinct affinities toward these receptors to trigger different host responses. Basically, their antitumor abilities are influenced by the molecular mass, branching configuration, conformation, and chemical modification of the polysaccharides. This review aims to integrate the information regarding nutritional, chemical and biological aspects of polysaccharides in mushrooms, which will possibly be employed to elucidate the correlation between their structural features and biological functions
polysaccharides, mushroom, immune system, TLR, Dectin-1
Publication DOI: 10.1039/c2fo10279jThe β-glucans are the glucose polymers present in the cells walls of yeast, fungi and cereals. β-Glucans are the major compositions of various nutritional diets such as oats, barley, seaweeds and mushrooms. Various biological activities of β-glucans have been reported such as anticancer, antidiabetic, anti-inflammatory and immune-modulating effects. The importance of β-glucans in food processing industries such as bread preparation, yogurt and pasta have been well elucidated. In recent findings on food science research gut microbiota plays a significant role and vastly studied for its intermediate role in regulating health. Several reports have suggested that β-glucans should have a significant impact on the gut microbiota changes and in turn on human health. The review was aimed to accumulate the evidence on types of β-glucans, their functional properties and the mechanism by how the β-glucans regulate the gut microbiota and human health. The various in vitro, in vivo and clinical studies, have been summarized, in particular, the changes happening upon the β-glucans supplementation on the gut microbiota. Overall, this review updates the recent studies on β-glucans and gut microbiota and also inputs the demanding questions to be addressed in β-glucans-microbiota research in the future.
β-Glucans, immunomodulation, microbiota, Antidiabetic, Anticancer, SCFA
NCBI PubMed ID: 30196242Within 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.201610599Aspergillus species are among the most important filamentous fungi from the viewpoints of industry, pathogenesis, and mycotoxin production. Fungal cells are exposed to a variety of environmental stimuli, including changes in osmolality, temperature, and pH, which create stresses that primarily act on fungal cell walls. In addition, fungal cell walls are the first interactions with host cells in either human or plants. Thus, understanding cell wall structure and the mechanism of their biogenesis is important for the industrial, medical, and agricultural fields. Here, we provide a systematic review of fungal cell wall structure and recent findings regarding the cell wall integrity signaling pathways in aspergilli. This accumulated knowledge will be useful for understanding and improving the use of industrial aspergilli fermentation processes as well as treatments for some fungal infections.
cell wall, polysaccharides, Glucans, signal transduction, Aspergillus species
NCBI PubMed ID: 27140698Over the past several decades, research on the synthesis and organization of the cell wall polysaccharides of Aspergillus fumigatus has expanded our knowledge of this important fungal structure. Besides protecting the fungus from environmental stresses and maintaining structural integrity of the organism, the cell wall is also the primary site for interaction with host tissues during infection. Cell wall polysaccharides are important ligands for the recognition of fungi by the innate immune system and they can mediate potent immunomodulatory effects. The synthesis of cell wall polysaccharides is a complicated process that requires coordinated regulation of many biosynthetic and metabolic pathways. Continuous synthesis and remodeling of the polysaccharides of the cell wall is essential for the survival of the fungus during development, reproduction, colonization and invasion. As these polysaccharides are absent from the human host, these biosynthetic pathways are attractive targets for antifungal development. In this review, we present recent advances in our understanding of Aspergillus fumigatus cell wall polysaccharides, including the emerging role of cell wall polysaccharides in the host-pathogen interaction.
polysaccharide, cell wall, Biofilm, glycobiology, Aspergillus fumigatus
NCBI PubMed ID: 26920883Exopolysaccharides play an important structural and functional role in the development and maintenance of microbial biofilms. Although the majority of research to date has focused on the exopolysaccharide systems of biofilm-forming bacteria, recent studies have demonstrated that medically relevant fungi such as Candida albicans and Aspergillus fumigatus also form biofilms during infection. These fungal biofilms share many similarities with those of bacteria, including the presence of secreted exopolysaccharides as core components of the extracellular matrix. This review will highlight our current understanding of fungal biofilm exopolysaccharides, as well as the parallels that can be drawn with those of their bacterial counterparts.
polysaccharide, exopolysaccharide, Bacterial Adhesion, Biofilm, Extracellular matrix, carbohydrate biosynthesis
NCBI PubMed ID: 27129222Oyster mushrooms are an interesting source of biologically active glucans and other polysaccharides. This work is devoted to the isolation and structural characterization of polysaccharides from basidiocarps of the cultivated oyster mushroom, Pleurotus ostreatus. Five polysaccharidic fractions were obtained by subsequent extraction with cold water, hot water and two subsequent extractions with 1 m sodium hydroxide. Branched partially methoxylated mannogalactan and slightly branched (1→6)-β-D-glucan predominated in cold- and hot-water-soluble fractions, respectively. Alternatively, these polysaccharides were obtained by only hot water extraction and subsequent two-stage chromatographic separation. The alkali-soluble parts originating from the first alkali extraction were then fractionated by dissolution in dimethyl sulfoxide (DMSO). The polysaccharide insoluble in DMSO was identified as linear (1→3)-α-D-glucan, while branched (1→3)(1→6)-β-D-glucans were found to be soluble in DMSO. The second alkaline extract contained the mentioned branched β-D-glucan together with some proteins. Finally, the alkali insoluble part was a cell wall complex of chitin and β-D-glucans.
polysaccharides, Glucans, Fractionation, mannogalactan, basidiocarps, oyster mushrooms
NCBI PubMed ID: 31357717Novel α-(1→3)-glucooligosaccharides (α-(1→3)-GOS) were prepared by acid hydrolysis of α-(1→3)-glucan isolated from Fomitopsis betulina fruiting bodies and characterized. Their anti-cancer potential was evaluated in in vitro assays in a colon cancer cell model. The tested α-(1→3)-GOS showed antiproliferative (MTT assay) and pro-apoptotic (Annexin V-FITC and PI technique) features against colon cancer but not against normal epithelial colon cells. Additionally, we did not observe cytotoxic activity (neutral red and lactate dehydrogenase assays) of α-(1→3)-GOS against several types of normal cell lines. In the present study, we demonstrated the anticancer potential of α-(1→3)-GOS in a colon carcinoma model. The anti-tumour effect of α-(1→3)-GOS is related with induction of apoptosis. Based on these results, we conclude that α-(1→3)-GOS may be considered as a dietary or therapeutic agent with an ability to inhibit the growth of cancer cells.
Colon cancer, α-(1→3)-glucan, Fomitopsis betulina, α-(1→3)-glucooligosaccharides
NCBI PubMed ID: 31440877The cell walls of fungi are composed of glycoproteins, chitin, and α- and β-glucans. Although there are many reports on β-glucans, α-glucan polysaccharides are not yet fully understood. This review characterizes the physicochemical properties and functions of (1→3)-α-D-glucans. Particular attention has been paid to practical application and the effect of glucans in various respects, taking into account unfavourable effects and potential use. The role of α-glucans in plant infection has been proven, and collected facts have confirmed the characteristics of Aspergillus fumigatus infection associated with the presence of glucan in fungal cell wall. Like β-glucans, there are now evidence that α-glucans can also stimulate the immune system. Moreover, α-d-glucans have the ability to induce mutanases and can thus decompose plaque.
polysaccharides, cell walls, fungi, (1→3)-α-D-glucans
NCBI PubMed ID: 31684030During infection, many fungal pathogens form biofilms within tissues or on biomedical devices. The growth of fungi within biofilms increases dramatically their resistance to both immune defences and antifungal therapies. In the last twenty years, studies have begun to shed light on many of the steps involved in biofilm synthesis and composition, revealing new antifungal strategies. This chapter will focus on the biofilm exopolysaccharides produced by A. fumigatus and C. albicans, the two main causes of human fungal infections. We will review the current state of our understanding of the structure, biosynthesis, and role of exopolysaccharides in biofilm development and function with a view to identifying future strategies for prophylaxis and treatment of these devastating infections.
exopolysaccharides, biofilms, Candida albicans, Aspergillus fumigatus, fungal pathogens
NCBI PubMed ID: 32072265A polysaccharide-enriched extract obtained from Lentinula edodes was submitted to several purification steps to separate three different D-glucans with β-(1→6), β-(1→3),(1→6) and α-(1→3) linkages, being characterized through GC-MS, FT-IR, NMR, SEC and colorimetric/fluorimetric determinations. Moreover, in vitro hypocholesterolemic, antitumoral, anti-inflammatory and antioxidant activities were also tested. Isolated glucans exerted HMGCR inhibitory activity, but only β-(1→6) and β-(1→3),(1→6) fractions showed DPPH scavenging capacity. Glucans were also able to lower IL-1β and IL-6 secretion by LPS-activated THP-1/M cells and showed cytotoxic effect on a breast cancer cell line that was not observed on normal breast cells. These in vitro results pointed important directions for further in vivo studies, showing different effects of each chemical structure of the isolated glucans from shiitake mushrooms.
β-Glucans, α-glucans, anti-inflammatory, cytotoxic, shiitake mushroom, hypocholesterolemic
NCBI PubMed ID: 31826486Increasing knowledge of the role of the intestinal microbiome in human health and well-being has resulted in increased interest in prebiotics, mainly oligosaccharides of various origins. To date, there are no reports in the literature on the prebiotic properties of oligosaccharides produced by the hydrolysis of pure fungal α-(1→3)-glucan. The aim of this study was to prepare α-(1→3)-glucooligosaccharides (α-(1→3)-GOS) and to perform initial evaluation of their prebiotic potential. The oligosaccharides were obtained by acid hydrolysis of α-(1→3)-glucan isolated from the fruiting bodies of Laetiporus sulphureus and then, characterized by HPLC. Fermentation of α-(1→3)-GOS and reference prebiotics was compared in in vitro pure cultures of Lactobacillus, Bifidobacterium, and enteric bacterial strains. A mixture of α-(1→3)-GOS, notably with a degree of polymerization of 2 to 9, was obtained. The hydrolysate was utilized for growth by most of the Lactobacillus strains tested and showed a strong bifidogenic effect, but did not promote the growth of Escherichia coli and Enterococcus faecalis. α-(1→3)-GOS proved to be effective in the selective stimulation of beneficial bacteria and can be further tested to determine their prebiotic functionality.
prebiotic, fruiting bodies, Laetiporus sulphureus, α-(1→3)-glucan, α-(1→3)-glucooligosaccharides
NCBI PubMed ID: 33255915Polysaccharides from P. eryngii mushroom were selectively extracted using low-cost technologies (water at different conditions of temperature and pressure). Mannogalactan was the main polysaccharide in cold-water extracted fraction (CWEF), while a linear (1→6)-β-d-glucan was the main polymer in hot-water extracted fraction (HWEF). Autoclave-extracted fraction (AEF) contained a mixture of at least four different α- and β-glucans. The report of linear (1→6)-β-glucan and linear (1→3)-β-glucan is a new finding for P. eryngii fruiting bodies. The immunostimulatory properties of the fractions on THP-1 macrophages were studied. All fractions at 50, 250 and 500 μg/mL were not cytotoxic and produced different stimulus on NO, IL-1β and IL-10 secretion by the cells. Thus, our results showed that it is possible to concentrate different P. eryngii polysaccharides in selected fractions using a simple and low-cost procedure. Since biological effects depends on the polysaccharide structure, this technique allows the obtainment of fractions with distinct immunomodulatory activities.
polysaccharides, β-glucan, Grifola frondosa, mannogalactan, immunostimulatory properties, Pleurotus eryngii mushroom
NCBI PubMed ID: 33183624Vast 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: 34732740Extracellular 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: 34878762As an endemic species,Wolfiporia cocos (F.A. Wolf) Ryvarden & Gilb. is widely distributed, such as in China, Korea, Japan, and North America, which have had a dual-purpose resource for medicines and food for over 2000 years. The applications of W. cocos were used to treat diseases including edema, insomnia, spleen deficiency, and vomiting. What's more, there have been wide uses of such edible fungi as a function food or dietary supplement recently. Up until now, 166 kinds of chemical components have been isolated and identified from W. cocos including triterpenes, polysaccharides, sterols, diterpenes, and others. Modern pharmacological studies showed that the components hold a wide range of pharmacological activities both in vitro and in vivo, such as antitumor, anti-inflammatory, antibacterial, anti-oxidant, and antidepressant activities. In addition, present results showed that the mechanisms of pharmacological activities were closely related to chemical structures, molecular signaling paths and the expression of relate proteins for polysaccharides and triterpenes. For further in-depth studies on this fungus based on the recent research status, this review provided some perspectives and systematic summaries of W. cocos in traditional uses, chemical components, pharmacological activities, separation and analysis technologies, and structure-activity relationships.
review, chemical components, pharmacological activities, structure-activity relationship (SAR), Wolfiporia cocos
NCBI PubMed ID: 35300566Termitomyces are well-known wild edible and medicinal basidiomycete mushrooms. The frequent consumption of Termitomyces stimulated studies on their health-promoting properties. Numerous health benefits of Termitomyces are associated with the main categories of components in Termitomyces, polysaccharides. Although the homopolysaccharides β-glucans are believed to be the major bioactive polysaccharides of Termitomyces, other heteropolysaccharides also possess biological activities. In this review, the extraction methods, chemical structures, and biological activities of polysaccharides from Termitomyces were thoroughly reviewed. The polysaccharides from different species of Termitomyces differ in molecular weight, monosaccharide composition, and linkages of constituent sugars. The health-promoting effects, including antioxidation, ulcer-healing and analgesic properties, immunomodulation, hypolipidemic and hepatoprotective effects, and antidiabetic properties of Termitomyces polysaccharides were summarized and discussed. Further studies were needed for a better understanding of the relationship between the fine chemical structure and health-promoting properties. This review provides a theoretical overview for future studies and utilization of Termitomyces polysaccharides.
polysaccharides, mushroom, Structures, bioactivities, Termitomyces
NCBI PubMed ID: 34936332Halophilic 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: 36181715Ganoderma lucidum, widely used in traditional medicine, has several biological properties. Polysaccharides, mainly glucans, are known as one of its main bioactive compounds. Consequently, the achievement and chemical investigation of such molecules are of pharmaceutical interest. Herein, we obtained water-insoluble and water-soluble polysaccharides from G. lucidum by alkaline extraction. Fractionation process yielded three fractions (GLC-1, GLC-2, and GLC-3). All samples showed to be composed mainly of glucans. GLC-1 is a linear (1→3)-linked β-glucan; GLC-2 is a mixture of three different linear polysaccharides: (1→3)-β-glucan, (1→3)-α-glucan, and (1→4)-α-mannan; while GLC-3 is a branched β-glucan with a (1→4)-linked main chain, which is branched at O-3 or O-6 by (1→3)- or (1→6)-linked side chains. This research reports the variability of glucans in Ganoderma lucidum fruiting bodies and applicable methodologies to obtain such molecules. These polysaccharides can be further applied in biological studies aiming to investigate how their chemical differences may affect their biological properties
branched, polysaccharides, linear, mannan, Glucans, Ganoderma lucidum
NCBI PubMed ID: 38574411Glucans are the most abundant class of macromolecule polymers in fungi, which are commonly found in Ascomycota and Basidiomycota. Fungal glucans are not only essential for cell integrity and function but also crucial for the immense industrial interest in high value applications. They present a variety of structural characteristics at the nanoscale due to the high regulation of genes and the involvement of stochastic processes in synthesis. However, although recent findings have demonstrated the genes of glucans synthesis are relatively conserved across diverse fungi, the formation and organization of diverse glucan structures is still unclear in fungi. Here, we summarize the structural features of fungal glucans and the recent developments in the mechanisms of glucans biosynthesis. Furthermore, we propose the engineering strategies of targeted glucan synthesis and point out the remaining challenges in the synthetic process. Understanding the synthesis process of diverse glucans is necessary for tailoring high value glucan towards specific applications. This engineering strategy contributes to enable the sustainable and efficient production of glucan diversity
biosynthesis, gene, diversity, glucan, fungi, target glucan
NCBI PubMed ID: 38286552Mushroom 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: 38494231The fungal cell wall plays a critical role in regulating cellular integrity and communication, and serves as a frontline defense against stress. It is also a prime target for the development of antifungal agents. The cell wall is comprised of diverse polysaccharides and proteins and poses a challenging target for high-resolution structural characterization. Recently, the solid-state nuclear magnetic resonance (ssNMR) analysis of intact Aspergillus fumigatus cells has provided atomic-level insights into the structural polymorphism and functional assembly principles of carbohydrate components within the cell wall. This physical perspective, alongside structural information from biochemical assays, offers a renewed understanding of the cell wall as a highly complex and dynamic organelle. Here, we summarize key conceptual advancements in the structural elucidation of A. fumigatus mycelial and conidial cell walls and their responses to stressors. We also highlight underexplored areas and discuss the opportunities facilitated by technical advancements in ssNMR spectroscopy
polysaccharide, carbohydrate, cell wall, glucan, Aspergillus, fungi, antifungal, chitin, solid-state NMR
Publication DOI: 10.3390/jof10030219Pleurotus 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
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