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Found 2 structures.
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Structure type: homopolymer
Trivial name: pustulan, β-1,6-glucan, β-1,6-D-glucan, β(1-6)-D-glucan, β-(1,6)-glucan, lasiodiplodan, pustulan, β-(1,6)-glucan, lasiodiplodan, β-(1,6)-glucan, β-(1,6)-glucan, lasiodiplodan, pustulan, β-1,6-glucan, β-(1,6)-glucan, pustulan, β-(1→6)-glucan PCPS, water-soluble glucan (PS-I)
Compound class: EPS, O-polysaccharide, cell wall polysaccharide, glycoprotein, glucan, polysaccharide, cell wall glucoprotein
Contained glycoepitopes: IEDB_135614,IEDB_141806,IEDB_142488,IEDB_146664,IEDB_241101,IEDB_983931,SB_192
The four recombinant glucosyltransferases (GTFs), GtfJ, GtfK, GtfL and GtfM, that had previously been cloned from Streptococcus salivarius ATCC 25975, were individually expressed in Escherichia coli and their glucan products and kinetic properties were analysed. GtfJ was a primer-dependent GTF which synthesized an insoluble glucan composed mainly of α-(1→3)-linked glucosyl residues in the presence of dextran T-10. GtfK was primer-stimulated, and produced a linear soluble dextran without any detectable branch points both in the absence and in the presence of dextran T-10. GtfL was primer-independent and produced a mixed-linkage insoluble glucan composed of approximately equal proportions of α-(1→3)- and α-(1→6)-linked glucosyl residues. GtfL was inhibited by dextran T-10. GtfM was primer-independent and produced a soluble dextran with approximately 5% α-(1→3)-linked glucosyl residues. GtfM was essentially unaffected by the presence of dextran T-10. The results confirmed that each enzyme represented one of the four possible combinations of primer-dependency and product solubility and that each possessed unique biosynthetic properties. The soluble dextrans formed by GtfK and GtfM, as well as the mixed-linkage insoluble glucan formed by GtfL, were also capable of acting as primers for the primer-dependent GtfJ and the primer-stimulated GtfK. Unexpectedly, the linear dextran produced by GtfK was by far the least effective either at priming itself or at activating and priming the primer-dependent GtfJ.
13C-NMR, Streptococcus salivarius, Glucosyltransferases, kinetics, Glucans
NCBI PubMed ID: 7545511Fungal cell walls are predominantly composed of glucans, mannans, and chitin. Recognition of these glycans by the innate immune system is a critical component of host defenses against the mycoses. Complement, an important arm of innate immunity, plays a significant role in fungal pathogenesis, especially the alternative pathway (AP). Here we determine that the glycan monosaccharide composition and glycosidic linkages affect AP activation and C3 deposition. Furthermore, properdin, a positive regulator of the AP, contributes to these functions. AP activation by glycan particles that varied in composition and linkage was measured by C3a generation in serum treated with 10 mM EGTA and 10 mM Mg(2+) (Mg-EGTA-treated serum) (AP specific; properdin functional) or Mg-EGTA-treated serum that lacked functional properdin. Particles that contained either β1→3 or β1→6 glucans or both generated large and similar amounts of C3a when the AP was intact. Blocking properdin function resulted in 5- to 10-fold-less C3a production by particulate β1→3 glucans. However, particulate β1→6 glucans generated C3a via the AP only in the presence of intact properdin. Interestingly, zymosan and glucan-mannan particles (GMP), which contain both β-glucans and mannans, also required properdin to generate C3a. The β1→4 glycans chitin and chitosan minimally activated C3 even when properdin was functional. Finally, properdin binding to glucan particles (GP) and zymosan in serum required active C3. Properdin colocalized with bound C3, suggesting that in the presence of serum, properdin bound indirectly to glycans through C3 convertases. These findings provide a better understanding of how properdin facilitates AP activation by fungi through interaction with the cell wall components.
properdin
NCBI PubMed ID: 21878570This study examined the response of various forms and sources of glucans toward two different Limulus amebocyte lysate (LAL) methods, the modified LAL, and Glucatell. The glucans studied were curdlan, laminarin, yeast glucan, barley glucan, paramylon, pullulan, pustulan, mannan, and pachyman (as part of the Glucatell kit). Both methods provided largely similar results for each of the glucans; however, the Glucatell method yielded slightly higher responses to certain structures that may not necessarily be of fungal origin, leading to falsely greater positive results. The performance of each method to measure fungal glucan concentration specifically was then assessed.
glucan, Curdlan, dectin receptor, glucatell, LAL, Limulus amebocyte lysate
NCBI PubMed ID: 21830869Recent atomic force microscopy stretching measurements of single polysaccharide molecules suggest that their elasticity is governed by force-induced conformational transitions of the pyranose ring. However, the mechanism of these transitions and the mechanics of the pyranose ring are not fully understood. Here we use steered molecular dynamics simulations of the stretching process to unravel the mechanism of forced conformational transitions in 1,6 linked polysaccharides. In contrast to most sugars, 1,6 linked polysaccharides have an extra bond in their inter-residue linkage, C5-C6, around which restricted rotations occur and this additional degree of freedom increases the mechanical complexity of these polymers. By comparing the computational results with the atomic force microscopy data we determine that forced rotations around the C5-C6 bond have a significant and different impact on the elasticity of α- and β-linked polysaccharides. β-linkages of a polysaccharide pustulan force the rotation around the C5-C6 bonds and produce a Hookean-like elasticity but do not affect the conformation of the pyranose rings. However, α-linkages of dextran induce compound conformational transitions that include simultaneous rotations around the C5-C6 bonds and chair-boat transitions of the pyranose rings. These previously not-recognized transitions are responsible for the characteristic plateau in the force-extension relationship of dextran
molecular dynamics, Glucans, atomic force microscopy, Dextran
NCBI PubMed ID: 15345528ZG16p is a soluble mammalian lectin that interacts with mannose and heparan sulfate. Here we describe detailed analysis of the interaction of human ZG16p with mycobacterial phosphatidylinositol mannosides (PIMs) by glycan microarray and NMR. Pathogen-related glycan microarray analysis identified phosphatidylinositol mono- and di-mannosides (PIM1 and PIM2) as novel ligand candidates of ZG16p. Saturation transfer difference (STD) NMR and transferred NOE experiments with chemically synthesized PIM glycans indicate that PIMs preferentially interact with ZG16p by using the mannose residues. The binding site of PIM was identified by chemical-shift perturbation experiments with uniformly 15N-labeled ZG16p. NMR results with docking simulations suggest a binding mode of ZG16p and PIM glycan; this will help to elucidate the physiological role of ZG16p
NMR spectroscopy, chemical synthesis, lectins, carbohydrate microarrays, microarrays, phosphatidyl inositol mannoside
NCBI PubMed ID: 25919894β-glucans are the dietary nutrients present in oats, barley, algae, and mushrooms. The macromolecules are well known for their immune-modulatory activity; however, how the human gut bacteria digest them is vaguely understood. In this study, Bacteroides uniformis JCM 13288 T was found to grow on laminarin, pustulan, and porphyran. We sequenced the genome of the strain, which was about 5.05 megabase pairs and contained 4868 protein-coding genes. On the basis of growth patterns of the bacterium, two putative polysaccharide utilization loci for β-glucans were identified from the genome, and associated four putative genes were cloned, expressed, purified, and characterized. Three glycoside hydrolases (GHs) that were endo-acting enzymes (BuGH16, BuGH30, and BuGH158), and one which was an exo-acting (BuGH3) enzyme. The BuGH3, BuGH16, and BuGH158 can cleave linear exo/endo-β-1-3 linkages while BuGH30 can digest endo-β-1-6 linkages. BuGH30 and BuGH158 were further explored for their roles in digesting β-glucans and generation of oligosaccharides, respectively. The BuGH30 predominately found to cleave long chain β-1-6-linked glucans, and obtained final product was gentiobiose. The BuGH158 used for producing oligosaccharides varying from degree of polymerization 2 to 7 from soluble curdlan. We demonstrated that these oligosaccharides can be utilized by gut bacteria, which either did not grow or poorly grew on laminarin. Thus, B. uniformis JCM 13288 T is not only capable of utilizing β-glucans but also shares these glycans with human gut bacteria for potentially maintaining the gut microbial homeostasis.
Enzymes, cross-feeding, glycan utilization, gut bacteria, macroalgae
NCBI PubMed ID: 33043794In this study, we purified and characterized exopolysaccharide (EPS) produced by a high-EPS-producing dairy starter bacterium, Streptococcus thermophilus ASCC 1275. Crude EPS was extracted from S. thermophilus ASCC 1275 and partially purified using dialysis. Further purification and fractionation of exopolysaccharide was conducted using HPLC on a Superose 6 column (Cytiva/Global Life Sciences Solutions, Marlborough, MA). Glycosyl composition analysis, linkage analysis along with 1-dimensional and 2-dimensional nuclear magnetic resonance spectroscopy were performed to deduce the structure of EPS. Three fractions (F) obtained from gel permeation chromatography were termed F1 (2.6%), F2 (45.8%), and F3 (51.6%) with average molecular weights of approximately 511, 40, and 5 kDa, respectively. Monosaccharide composition analysis revealed the dominance of glucose, galactose, and mannose in all 3 fractions. Major linkages observed in F3 were terminal galactopyranosyl (t-Gal), 3-linked glucopyranosyl (3-Glc), 3-linked galactofuranosyl (3-Galf), and 3,6-linked glucopyranosyl (3,6-Glc) and major linkages present in F2 were 4-Glc (48 mol%), followed by terminal mannopyranosyl (t-Man), 2- + 3-linked mannopyranosyl (2-Man+3-Man), and 2,6-linked mannopyranosyl (2,6-Man; total ~28 mol%). The 1-dimensional and 2-dimensional nuclear magnetic resonance spectroscopy revealed that F2 comprised mannans linked by (1→2) linkages and F3 consisted of linear chains of α-d-glucopyranosyl (α-d-Glcp), β-d-glucopyranosyl (β-d-Glcp), and β-d-galactofuranosyl (β-d-Galf) connected by (1→3) linkages; branching was through (1→6) linkage in F3. A possible structure of EPS in F2 and F3 was proposed.
structure, exopolysaccharide, nuclear magnetic resonance (NMR), glycosyl linkage
NCBI PubMed ID: 32475665Several cell wall proteins released from yeast and hyphal cells of Candida albicans by laminarinase reacted with an affinity-purified antiserum raised against β-1,6-glucan. Binding of the antiserum was competitively inhibited by β-1,6-glucan, but not by β-1,3-glucan or isolated N-chains. Immunodetection was completely abolished when the proteins were treated with periodate. These results demonstrate that the laminarinase-released wall proteins of C. albicans possess an epitope consisting of β-1,6-linked glucose residues. The yeast form of C. albicans contained four β-1,6-glucosylated wall proteins, an Endo H-resistant protein of 125 kDa and three glycoproteins which became only detectable after Endo H digestion and had a molecular mass of 320, 170 and 44 kDa, respectively. As for the hyphal form, a different set of β-1,6-glucosylated wall proteins was found consisting of two Endo H-resistant glycoproteins of 125 and 80 kDa, respectively, and two glycoproteins that after Endo H digestion had a molecular mass of 320 and 38 kDa, respectively. Sodium dodecyl sulfate-extractable wall proteins and medium proteins did not react with the β-1,6-glucan antiserum. The β-1,6-glucan epitope could be removed by aqueous hydrofluoric acid indicating that the epitope is phosphodiester-linked to the cell wall proteins. It is speculated that the epitope forms part of a GPI-anchor and might be involved in the anchoring of mannoproteins into the cell wall.
NCBI PubMed ID: 7536675The use of a novel monoclonal antibody (mAb) that reacts with (1,6)-β-glucan has permitted the study of the different covalent linkages between glucan and mannoproteins in the cell wall of Candida albicans. The mAb JRR1 was originally raised by immunization with Zymolyase extracts from C. albicans cell walls, but it soon became apparent that it reacted with a (1,6)-β-glucan epitope. By using this antibody, we show the existence of glucan-mannoprotein complexes between the (1,6)-β-glucan epitope recognized by the antibody and cell wall mannoproteins. The topology of the (1,6)-β-glucan in the cell wall of C. albicans has also been studied.
NCBI PubMed ID: 7551022The cell adhesion protein α-agglutinin is bound to the outer surface of the Saccharomyces cerevisiae cell wall and mediates cell-cell contact in mating. α-Agglutinin is modified by addition of a glycosyl phosphatidylinositol (GPI) anchor as it traverses the secretory pathway. The presence of a GPI anchor is essential for cross-linking into the wall, but the fatty acid and inositol components of the anchor are lost before cell wall association (Lu, C.-F., J. Kurjan, and P. N. Lipke, 1994. A pathway for cell wall anchorage of Saccharomyces cerevisiae α-agglutinin. Mol. Cell. Biol. 14:4825-4833). Cell wall association of α-agglutinin was accompanied by an increase in size and a gain in reactivity to antibodies directed against β-1,6-glucan. Several kre mutants, which have defects in synthesis of cell wall β-1,6-glucan, had reduced molecular size of cell wall α-agglutinin. These findings demonstrate that the cell wall form of α-agglutinin is covalently associated with β-1,6-glucan. The α-agglutinin biosynthetic precursors did not react with antibody to β-1,6-glucan, and the sizes of these forms were unaffected in kre mutants. A COOH-terminal truncated form of α-agglutinin, which is not GPI anchored and is secreted into the medium, did not react with the anti-β-1,6-glucan. We propose that extracellular cross-linkage to β-1,6-glucan mediates covalent association of α-agglutinin with the cell wall in a manner that is dependent on prior addition of a GPI anchor to α-agglutinin.
NCBI PubMed ID: 7844147We 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: 7992508The BGL2 gene encodes a unique 1,3-β-glucosyltransferase (Bgl2p) present in the cell wall of Candida albicans and other fungi. Although believed to be involved in cell wall assembly, disruption of the gene in Saccharomyces cerevisiae showed no apparent phenotype. We performed sequential disruptions of the BGL2 loci in a homozygous ura3 clinical isolate of C. albicans using the URA3 blaster method, in order to investigate the role of Bgl2p in this dimorphic, pathogenic fungus. Strain CACW-1 contained disruptions of both homologues of the BGL2 gene and lacked Bgl2p, as assessed by protein extraction, SDS-PACE and Western blot analysis, and enzyme assay; however, residual non-Bgl2p transferase activity was detected. CACW-1 was attenuated in virulence for mice when compared to an isogenic parent strain, and fewer organisms were recovered from the kidneys of infected animals. Additional phenotypic changes included: (1) a dramatic increase in the sensitivity to the chitin synthesis inhibitor nikkomycin Z when CACW-1 cells were incubated at 37 or 42 degrees C; (2) an 8.7 +/- 1.6% slower growth rate at 37 degrees C for CACW-1 when compared to its isogenic parent; and (3) aggregation of CACW-1 cells during stationary phase and/or incubation of stationary phase cells in phosphate buffer. Characterization of SDS-extracted cell walls did not reveal any significant differences in the levels of 1,3-β- or 1,6-β-glucan. These data reveal that loss of Bgl2p does have a phenotype in C. albicans, and indicate that (1) loss of Bgl2p function renders cells more dependent on chitin for wall integrity, and attenuates virulence (probably due to subtle changes in walt structure), and (2) that additional 1,3-β-glucosyltransferases are present in the C. albicans BGL2 disruptant.
Candida albicans, BGL2, transglycosylation
NCBI PubMed ID: 9043114Four exopolysaccharides (EPS) obtained from Botryosphaeria rhodina strains isolated from rotting tropical fruit (graviola, mango, pinha, and orange) grown on sucrose were purified on Sepharose CL-4B. Total acid hydrolysis of each EPS yielded only glucose. Data from methylation analysis and (13)C NMR spectroscopy indicated that the EPS from the graviola isolate consisted of a main chain of glucopyranosyl (1→3) linkages substituted at O-6 as shown in the putative structure below: [carbohydrate structure: see text]. The EPS of the other fungal isolates consisted of a linear chain of (1→6)-linked glucopyranosyl residues of the following structure: [carbohydrate structure: see text]. FTIR spectra showed one band at 891 cm(-1), and (13)C NMR spectroscopy showed that all glucosidic linkages were of the β-configuration. Dye-inclusion studies with Congo Red indicated that each EPS existed in a triple-helix conformational state. β-(1→6)-d-Glucans produced as exocellular polysaccharides by fungi are uncommon.
exopolysaccharides, Botryosphaeria rhodina isolates, β(1-6)-d-Glucans, β(1-3;1-6)-d-Glucans, Triple-helix conformation
NCBI PubMed ID: 18639868Three D-glucans were isolated from the mycelium of the fungus Botryosphaeria rhodina MAMB-05 by sequential extraction with hot-water and hot aqueous KOH (2% w/v) followed by ethanol precipitation. Following their purification by gel permeation chromatography on Sepharose CL-4B, the structural characteristics of the D-glucans were determined by FT-IR and 13C NMR spectroscopy and, after methylation, by GC-MS. The hot-water extract produced a fraction designated Q1A that was a β-(1→6)-D-glucan with the following structure: [Formula: see text] The alkaline extract, when subjected to repeated freeze-thawing, yielded two fractions: K1P (insoluble) that comprised a β-(1→3)-D-glucan with β-D-glucose branches at C-6 with the structure: [Formula: see text] and K1SA (soluble) consisting of a backbone chain of α-(1→4)-linked D-glucopyranosyl residues substituted at O-6 with α-D-glucopyranosyl residues: [Formula: see text]
Botryosphaeria rhodina MAMB-05, Fungal cell wall polysaccharides, d-Glucans
NCBI PubMed ID: 18237722Mushrooms 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.2006.07.013The milk yeast Kluyveromyces lactis is an alternative model yeast to the well established Saccharomyces cerevisiae. The cell wall of these fungi consists of polysaccharides (i.e. long chains of β-1,3- and β-1,6-linked sugar chains and some chitin) and mannoproteins, both of which are continually adapted to environmental conditions in terms of their abundance and organization. This implies the need to perceive signals at the cell surface and to transform them into a proper cellular response. The signal transduction cascade involved in this process is generally referred to as the cell wall integrity (CWI) pathway. CWI signaling and cell wall composition have been extensively studied in the Baker's yeast S. cerevisiae and are also of interest in other yeast species with commercial potential, such as K. lactis. We here summarize the results obtained in the past years on CWI signaling in K. lactis and use a comparative approach to the findings obtained in S. cerevisiae to highlight special adaptations to their natural environments.
cell wall proteome, MAP kinase cascade, protein kinase C, transmission electron microscopy
NCBI PubMed ID: 21628080Three polysaccharide fractions (PS-I, PS-II, and PS-III) were isolated from the aqueous extract of a hybrid mushroom obtained through backcross mating of a somatic hybrid mushroom PfloVv12 (Sterile line) with Volvariella volvacea. PfloVv12 was obtained through protoplast fusion of Pleurotus florida and V. volvacea. PS-I was identified as 1,6-β glucan. PS-II and PS-III were identified as mannoglucogalactan but differing in molecular weights only. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation, and NMR experiment ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC) the structures of these polysaccharides were established as: PS-I is -6)bDGlcp(1-, PS-II and PS-III is -6)[bDManp(1-2)]aDGlcp(1-6)aDGalp(1-.
structure, polysaccharide, NMR spectroscopy, Hybrid mushroom
NCBI PubMed ID: 21924407The 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: 28513415Studies evaluating the toxicity caused by fungal exopolysaccharides of the β-(1→6)-D-glucan type are rare. In this study, the toxicological effects of sub-chronic treatments with lasiodiplodan (β-(1→6)-D-glucan from Lasiodiplodia theobromae MMPI) were evaluated in mice through the assessment of biochemical, hematological, and histopathological alterations. Thirty-two mice (16 male, 16 female) were used in this study divided in two groups; one group received lasiodiplodan (50 mg/kg body weight) daily for 28 days via gavage, and another (control group) received saline during the same period. Blood samples were collected via cardiac puncture for hematological and biochemical analyses. Liver, heart, kidney, and spleen were collected for histopathological analysis. Statistical analysis was performed through one-way analysis of variance and only p < 0.05 F-values were presented. Significant reduction in blood glucose in the male group (35%; p < 0.01), transaminases activity in both sexes (AST and ALT; ~35%; p < 0.05), and urea (20%; p < 0.01) in the female group was observed with the lasiodiplodan treatment. The results showed that sub-chronic treatments with lasiodiplodan did not generate hematological and histopathological alterations leading to signs of toxicity in healthy mice, independent of gender.
Lasiodiplodia theobromae MMPI, fungal β-glucan, toxicity evaluation, Swiss albino mice
NCBI PubMed ID: 23208465Lasiodiplodan, an exopolysaccharide of the (1→6)-β-D-glucan type, is produced by Lasiodiplodia theobromae MMPI when grown under submerged culture on glucose. The objective of this study was to evaluate lasiodiplodan production by examining the effects of carbon (glucose, fructose, maltose, sucrose) and nitrogen sources (KNO3, (NH4)2SO4, urea, yeast extract, peptone), its production in shake flasks compared to a stirred-tank bioreactor, and to study the rheology of lasiodiplodan, and lasiodiplodan's anti-proliferative effect on breast cancer MCF-7 cells. Although glucose (2.05 ± 0.05 g/L), maltose (2.08 ± 0.04 g/L) and yeast extract (2.46 ± 0.06 g/L) produced the highest amounts of lasiodiplodan, urea as N source resulted in more lasiodiplodan per unit biomass than yeast extract (0.74 ± 0.006 vs. 0.22 ± 0.008 g/g). A comparison of the fermentative parameters of L. theobromae MMPI in shake flasks and a stirred-tank bioreactor at 120 h on glucose as carbon source showed maximum lasiodiplodan production in agitated flasks (7.01 ± 0.07 g/L) with a specific yield of 0.25 ± 0.57 g/g and a volumetric productivity of 0.06 ± 0.001 g/(L·h). A factorial 2^2 statistical design developed to evaluate the effect of glucose concentration (20-60 g/L) and impeller speed (100-200 rpm) on lasiodiplodan production in the bioreactor showed the highest production (6.32 g/L) at 72 h. Lasiodiplodan presented pseudoplastic behaviour, and the apparent viscosity increased at 60°C in the presence of CaCl2. Anti-proliferative activity of lasiodiplodan was demonstrated in MCF-7 cells, which was time- and dose-dependent with an IC(50) of 100 μg lasiodiplodan/mL.
Lasiodiplodia theobromae, lasiodiplodan, (1→6)-β-D-glucan, carbon and nitrogen nutrients, anti-proliferative activity, breast cancer cells (MCF-7)
NCBI PubMed ID: 22399240A 13C-NMR study of 56 species of Umbilicariaceae shows that pustulan-type polysaccharides, previously known from only 11 species, are apparently constant in the family. For most species analyzed, the high concentration of this single linear homoglucan enables its detection in very small samples, in this case primarily the same ones used earlier to identify secondary products by HPLC and TLC. For chemical analysis, pustulan is extracted with boiling water. Using sections prepared for SEM, however, even cold water extracted some pustulan from two species containing only trace amounts of secondary products, but not from two others having them in high concentrations. The thallus structure, observed with SEM, was altered in the first pair, but scarcely changed in the second. Pustulan is less readily extracted from thalli with high concentrations of secondary products.
glucan, lichens, Pustulan, Umbilicariaceae
Publication DOI: 10.2307/3244464Despite a great deal of effort made by many researchers throughout the world, chemotherapeutic agents that attack cancer cells directly do not seem to have the expected effects except on some leukaemias. Besides, these agents show strong toxicity to the host, and reduce the host defense against infections, especially destroying lymphocytes and bone marrow cells. To find a new cancer drug that can activate or restore host defense mechanisms, we examined fungi, which had traditionally been said to be effective against cancer in Japan and other Asian countries, such as Ganoderma applanatum (Pers.) Pat. and Coriolus versicolor (Fr.) Quél., and several kinds of Japanese edible mushrooms. Test substances were administered intraperitoneally and screened for their ability to inhibit the growth of sarcoma 180 cells subcutaneously transplanted into swiss or ICR mice. This method, reported by Nakahara et al. [1], has been proven to be simple and suitable for screening of host-mediated anticancer drugs. Table 1 shows various antitumoral polysaccharides including lentinan that were isolated from fungi, basidiomysetes and yeast. Lentinan, a (1→3)-β-D-glucan with (1→6)-β-D-glucopyranoside branches isolated from an edible mushroom, Lentinus edodes (Berk.) Sing., exhibits a marked antitumor effect against sarcoma 180 cells transplanted subcutaneously at a dose of 1 mg/kg/day for ten days (Fig. 1) [2–4]. Its chemical and physical characteristics are listed in Table 2.
Francisella tularensis, Edible mushroom, delay type hypersensitivity, Lewis lung carcinoma, recurrent gastric cancer
Publication DOI: 10.1007/978-3-0348-8763-2_8Non-prescriptional use of medicinal herbs among cancer patients is common around the world. The alleged anti-cancer effects of most herbal extracts are mainly based on studies derived from in vitro or in vivo animal experiments. The current information suggests that these herbal extracts exert their biological effect either through cytotoxic or immunomodulatory mechanisms. One of the active compounds responsible for the immune effects of herbal products is in the form of complex polysaccharides known as β-glucans. β-glucans are ubiquitously found in both bacterial or fungal cell walls and have been implicated in the initiation of anti-microbial immune response. Based on in vitro studies, β-glucans act on several immune receptors including Dectin-1, complement receptor (CR3) and TLR-2/6 and trigger a group of immune cells including macrophages, neutrophils, monocytes, natural killer cells and dendritic cells. As a consequence, both innate and adaptive response can be modulated by β-glucans and they can also enhance opsonic and non-opsonic phagocytosis. In animal studies, after oral administration, the specific backbone 1→3 linear β-glycosidic chain of β-glucans cannot be digested. Most β-glucans enter the proximal small intestine and some are captured by the macrophages. They are internalized and fragmented within the cells, then transported by the macrophages to the marrow and endothelial reticular system. The small β-glucans fragments are eventually released by the macrophages and taken up by other immune cells leading to various immune responses. However, β-glucans of different sizes and branching patterns may have significantly variable immune potency. Careful selection of appropriate β-glucans is essential if we wish to investigate the effects of β-glucans clinically. So far, no good quality clinical trial data is available on assessing the effectiveness of purified β-glucans among cancer patients. Future effort should direct at performing well-designed clinical trials to verify the actual clinical efficacy of β-glucans or β-glucans containing compounds.
antitumor activity
NCBI PubMed ID: 19515245A laminarin-diphtheria toxoid (CRM197) conjugate vaccine conferred protection against fungal infections in mice. We have now generated novel β-glucan-CRM197 vaccines, with either natural (Curd-CRM197) or synthetic linear (15mer-CRM197), or β-(1,6)-branched (17mer-CRM197) β-(1,3)-oligosaccharides, formulated with the human-acceptable adjuvant MF59. Curd-CRM197 and 15mer-CRM197 conjugates, which induced high titers of anti-β-(1,3)-glucan IgG, but no antibodies against β-(1,6)-glucan, conferred protection to mice lethally challenged with C. albicans. In contrast, the 17mer-CRM197 conjugate, which induced anti-β-(1,6)-glucan antibodies in addition to the anti-β-(1,3)-glucan IgG, was non-protective. These data provide some insights on β-glucan epitope(s) mediating antifungal protection and open the way to develop a synthetic oligosaccharide vaccine against fungal diseases.
adjuvant, β-glucan, antifungal vaccine, antifungal antibody
NCBI PubMed ID: 20096763Lichens have been used for medicinal purposes throughout the ages, and beneficial claims have to some extent been correlated with their polysaccharide content. Of 13,500 lichen species growing worldwide, less than 100 species have been investigated for polysaccharide content. Lichen polysaccharides are mainly of three different structural types: β-glucans, α-glucans, and galactomannans. In addition, a few complex heteroglycans have recently been described, such as thamnolan, a water-soluble, immunologically active heteroglycan with a novel rhamnopyranosylgalactofuranan type of structure. A number of investigations have been carried out on biological effects of lichen polysaccharides, most notably antitumour, immunomodulating, antiviral, and memory-enhancing effects. The current review summarizes present knowledge on the structural characteristics and biological activity of lichen polysaccrides.
polysaccharides, biological activity, immunological activity, lichens, structural characteristics, antitumour activity
NCBI PubMed ID: 11345688Candida 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: 25467440Fungal cell walls contain several types of glycans, which play important roles in the pathogenesis of fungal infection and host immune response. Among them, glycosphingolipids have attracted much attention lately since they contribute actively to the fungi development and fungal-induced pathogenesis. Although glycosphingolipids are present in pathogenic and non-pathogenic fungi, pathogenic strains exhibit distinct glycan structures on their sphingolipids, which contribute to the regulatory processes engaged in inflammatory response. In Candida albicans, phospholipomannan (PLM) represents a prototype of these sphingolipids. Through its glycan and lipid moieties, PLM induces activation of host signaling pathways involved in the initial recognition of fungi, causing immune system disorder and persistent fungal disease. In this review, first we describe the general aspects of C. albicans sphingolipids synthesis with a special emphasize on PLM synthesis and its insertion into the cell wall. Then, we discuss the role of PLM glycosylation in regulating immune system activation and its contribution to the chronic persistent inflammation found in Candida infections and chronic inflammatory diseases.
regulation, glycosphingolipids, yeasts, inflammatory response
NCBI PubMed ID: 25394861Fungal 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: 23218369β-Glucans from fungi exhibit a broad spectrum of biological activities including anti-tumor, immune-modulating and anti-inflammatory properties. The anti-inflammatory effect is mediated through the regulation of various inflammatory cytokines, such as nitric oxide (NO), interleukins (ILs), tumor necrosis factor alpha (TNF-α), interferon gamma (INF)-γ as well as non-cytokine mediator, prostaglandin E2 (PGE2). Up to now, the anti-inflammatory activity of β-glucans has received little attention. It is worthwhile to investigate the anti-inflammatory properties of fungal β-glucans in a separate review, discussing in vitro studies, animal studies and human studies on anti-inflammation effects of fungal β-glucans, as well as the structure-anti-inflammatory activity relationships.
cytokines, macrophages, anti-inflammatory, inflammatory responses
Publication DOI: 10.1016/j.tifs.2014.09.002Many species of higher basidiomycetes have traditionally been used because of their medicinal properties. The positive effects associated to the consumption of those fungi have been mainly attributed to cell wall polysaccharides, which have important structural roles and are present throughout the entire life cycles of fungi. One of the most consumed and studied species native of the Americas is Agaricus subrufescens, a mushroom prescribed in different countries for prophylaxis and noninvasive treatment of numerous health-related disorders. Prior to the process of extraction, purification, and application of these polysaccharides, one needs to be concerned with the preservation of the specimen and production of fungal biomass. Even though basidiomata (syn. fruiting body, mushrooms) generally yield larger volumes of biomass when compared to the mycelium, cultivation of mycelium allows a more efficient control of the process and, therefore, is the method of choice of polysaccharide production. Mycelial biomass can be produced by solid-state fermentation (SSF) or submersed fermentation (SmF). Further separation and concentration of bioactive polysaccharides can be done by means of porous membranes, such as tangential flow nanofiltration.
polysaccharide, biological activity, Agaricus subrufescens, fungal biomass, solid-state fermentation (SSF), submersed fermentation (SmF), nanofiltration
Publication DOI: 10.1007/978-3-319-16298-0_21Biological 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: 26252967Subcutaneous Ehrlich tumor-bearing mice were treated with in situ inoculation of a β-glucan-rich extract of Agaricus brasiliensis (ATF), which reduced tumor growth. Histopathological analysis showed that the tumor masses of control mice (Ehr) presented giant tumor cells and many mitotic figures whereas the tumor tissue obtained from ATF-treated animals (Ehr-ATF) presented a lower frequency of both mitotic and giant cells, associated with a higher frequency of apoptotic cells than Ehr. Analysis of the lymphoproliferative activity of spleen cells showed that the treatment had a suppressive rather than a stimulatory effect. Spleen cells of the Ehr group produced higher in vitro levels of IL-10 than normal controls and this occurrence was partially avoided by treatment with ATF. Analysis of cytokine production by tumor-infiltrating cells (ELISpot) showed that ATF induced a higher number of IFN-gamma-producing cells at 7 and 14days as well as reduction of IL-10-secreting cells at the latter time. Confocal microscopy analysis showed higher intensity of labeling of CD4+ and Mac-3+ cells in ATF-treated mice. Analysis of in situ expression of angiogenic growth factors showed a slight decrease of FGF-2 mRNA in Ehr-ATF animals (7th day) but not of VEGF-A or TGF-β expression. This fraction could not directly lyse either lymphocytes or tumor cells and we speculate that antitumor effect of ATF could be due to induction of a selective migration of immunocompetent cells from the spleen to the tumor site and to the switch of cytokine production.
mushroom, β-glucan, Agaricus blazei, angiogenesis, IL-10, Ehrlich tumor
NCBI PubMed ID: 19243740Consumption 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.ch20Polysaccharides of the European strain of A. brasiliensis were obtained by hot water extraction and ethanol precipitation (HWPE I) of fruiting bodies, and further purified by dialysis (HWPE II) and pronase incubation (PPE). These polysaccharides consisted mainly of (1→6)-β-D-glucans. PPE was free of proteins and polyphenols as demonstrated by quantitative assays and NMR profiling. They showed a clear IFN-γ inducing activity in human PBMCs, which suggests these polysaccharides to have proinflammatory effects. Treatment by β-glucosidase caused the polysaccharides to be degraded into smaller fragments and at the same time increased their IFN-γ inducing activity in PBMCs fourfold. In vitro, PPE showed a dose-dependent inhibition of the proliferation of the human leukemia Jurkat cell. At 100μg/mL the cells' viability was decreased by appr. 51% compared to the control. EPR spin trapping demonstrated a high antioxidative activity against •OH and •O2- radicals of HWPE I and PPE. Further, the results of the antioxidant assays indicated that antioxidant activity against •OH radicals in the Fenton system was achieved through scavenging or through chelating iron mechanisms. The good immunomodulating and antioxidative properties of A. brasiliensis polysaccharide extract obtained by hot water extraction and ethanol precipitation make it suitable for everyday use as an inexpensive dietary supplement.
immunomodulation, Antioxidant activity, A. brasiliensis, EPR spin trapping, polysaccharide extracts
NCBI PubMed ID: 30011685Virulence of Candida is linked with its ability to form biofilms. Once established, biofilm infections are nearly impossible to eradicate. Biofilm cells live immersed in a self-produced matrix, a blend of extracellular biopolymers, many of which are uncharacterized. In this study, we provide a comprehensive analysis of the matrix manufactured by Candida albicans both in vitro and in a clinical niche animal model. We further explore the function of matrix components, including the impact on drug resistance. We uncovered components from each of the macromolecular classes (55% protein, 25% carbohydrate, 15% lipid, and 5% nucleic acid) in the C. albicans biofilm matrix. Three individual polysaccharides were identified and were suggested to interact physically. Surprisingly, a previously identified polysaccharide of functional importance, β-1,3-glucan, comprised only a small portion of the total matrix carbohydrate. Newly described, more abundant polysaccharides included α-1,2 branched α-1,6-mannans (87%) associated with unbranched β-1,6-glucans (13%) in an apparent mannan-glucan complex (MGCx). Functional matrix proteomic analysis revealed 458 distinct activities. The matrix lipids consisted of neutral glycerolipids (89.1%), polar glycerolipids (10.4%), and sphingolipids (0.5%). Examination of matrix nucleic acid identified DNA, primarily noncoding sequences. Several of the in vitro matrix components, including proteins and each of the polysaccharides, were also present in the matrix of a clinically relevant in vivo biofilm. Nuclear magnetic resonance (NMR) analysis demonstrated interaction of aggregate matrix with the antifungal fluconazole, consistent with a role in drug impedance and contribution of multiple matrix components. Importance: This report is the first to decipher the complex and unique macromolecular composition of the Candida biofilm matrix, demonstrate the clinical relevance of matrix components, and show that multiple matrix components are needed for protection from antifungal drugs. The availability of these biochemical analyses provides a unique resource for further functional investigation of the biofilm matrix, a defining trait of this lifestyle.
mannan, glucan
NCBI PubMed ID: 25096878Inflammation is a major cause of respiratory impairment during Pneumocystis pneumonia. Studies support a significant role for cell wall β-glucans in stimulating inflammatory responses. Fungal β-glucans are comprised of d-glucose homopolymers containing β-1,3-linked glucose backbones with β-1,6-linked glucose side chains. Prior studies in Pneumocystis carinii have characterized β-1,3 glucan components of the organism. However, recent investigations in other organisms support important roles for β-1,6 glucans, predominantly in mediating host cellular activation. Accordingly, we sought to characterize β-1,6 glucans in the cell wall of Pneumocystis and to establish their activity in lung cell inflammation. Immune staining revealed specific β-1,6 localization in P. carinii cyst walls. Homology-based cloning facilitated characterization of a functional P. carinii kre6 (Pckre6) β-1,6 glucan synthase in Pneumocystis that, when expressed in kre6-deficient Saccharomyces cerevisiae, restored cell wall stability. Recently synthesized β-1,6 glucan synthase inhibitors decreased the ability of isolated P. carinii preparations to generate β-1,6 carbohydrate. In addition, isolated β-1,6 glucan fractions from Pneumocystis elicited vigorous tumor necrosis factor α (TNF-α) responses from macrophages. These inflammatory responses were significantly dampened by inhibition of host cell plasma membrane microdomain function. Together, these studies indicate that β-1,6 glucans are present in the P. carinii cell wall and contribute to lung cell inflammatory activation during infection
cell wall, β-Glucans, Pneumocystis carinii, lung cell inflammation
NCBI PubMed ID: 25916991D-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: 25239192D-Glucans possess immunomodulatory activities and potential for the development of new therapeutic agents. Biological activities can be enhanced in these biopolymers through chemical derivatization, e.g., carboxymethylation. This work presents the carboxymethylation, characterization and the evaluation of antioxidant activities of the exocellular (1→6)-β-D-glucan produced by Lasiodiplodia theobromae MMPI. Thermal analysis indicated that the native and carboxymethylated polysaccharides presented four stages of mass-loss. The first stage occurred at 125°C (loss of water) with two consecutive events of mass loss (200-400°C) attributed to polymer degradation and the fourth stage between 425 and 620°C (final decomposition). Scanning electron microscopy analysis indicated that the gross morphological features of lasiodiplodan were ruptured following carboxymethylation. X-ray diffractometry analysis demonstrated that the native and carboxymethylated polysaccharides presented a non-crystalline structure. Carboxymethylation contributed to improving the polysaccharide's water solubility and antioxidant capacity
exopolysaccharides, β-Glucans, Biopolymers, antioxidant capacity
NCBI PubMed ID: 25965498Fungal β-D-glucans of the (1→3)-type are known to exhibit direct antitumor effects, and can also indirectly decrease tumor proliferation through immunomodulatory responses. The underlying molecular mechanisms involved in decreasing tumor formation, however, are not well understood. In this study, we examined the antiproliferative role and mechanism of action of three different fungal exocellular β-glucans in MCF-7 breast cancer cells. The β-glucans were obtained from Botryosphaeria rhodina MAMB-05 [two botryosphaerans; (1→3)(1→6)-β-D-glucan; one produced on glucose, the other on fructose] and Lasiodiplodia theobromae MMPI [lasiodiplodan; (1→6)-β-D-glucan, produced on glucose]. Using the cell proliferation-MTT assay, we showed that the β-glucans exhibited a time- and concentration-dependent antiproliferative activity (IC50, 100 μg/ml). Markers of cell cycle, apoptosis, necrosis and oxidative stress were analyzed using flow cytometry, RT-PCR and Western blotting. Exposure to β-glucans increased apoptosis, necrosis, oxidative stress, mRNA expression of p53, p27 and Bax; the activity of AMP-activated protein-kinase, Forkhead transcription factor FOXO3a, Bax and caspase-3; and decreased the activity of p70S6K in MCF-7 cells. In the presence of hydrogen peroxide, the fungal β-glucans increased oxidative stress, which was associated with reduced cell viability. We showed that these β-glucans exhibited an antiproliferative effect that was associated with apoptosis, necrosis and oxidative stress. This study demonstrated for the first time that the apoptosis induced by β-glucans was mediated by AMP-activated protein-kinase and Forkhead transcription factor, FOXO3a. Our findings provide novel mechanistic insights into their antiproliferative roles, and compelling evidence that these β-glucans possess a broad range of biomodulatory properties that may prove useful in cancer treatment
apoptosis, oxidative stress, Botryosphaeran, lasiodiplodan, AMPK, FOXO3a
NCBI PubMed ID: 26255117The 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: 30196242β-glucans, a group of polysaccharides exist in many organism species such as mushrooms, yeasts, oats, barley, seaweed, but not mammalians, have a variety of biological activities and applications in drugs and other healthcare products. In recent years, β-glucans have been studied as adjuvants in anti-infection vaccines as well as immunomodulators in anti-cancer immunotherapy. β-glucans can regulate immune responses when administered alone and can connect innate and adaptive immunity to improve immunogenicity of vaccines. When β-glucans act as immunostimulants or adjuvants, a set of receptors have been revealed to recognize β-glucans, including dectin-1, complement receptor 3 (CR3), CD5, lactosylceramide, and so on. Therefore, this review is mainly focused on the application of β-glucans as immune adjuvants, the receptors of β-glucans, as well as their structure and activity relationship which will benefit future research of β-glucans.
vaccine, adjuvant, receptor, β-glucan, anti-tumor, anti-infection, structure and activity relationship
NCBI PubMed ID: 30049632Ascomycete fungi are promising biofactories producing bioactive compounds exhibiting diverse biological activities. In an ongoing search for bioactive potential of microorganisms from different ecological niches, a promising Lasiodiplodia sp. strain B2 (MTCC 6000) was identified as a producer of exopolysaccharide (designated as Lasiosan). The exopolysaccharide was purified and structurally characterized as glucomannan having glucose and mannose residues (ratio 1:1) with average molecular mass of 29.3 kDa. Lasiosan demonstrated promising antimicrobial and anti-biofilm activities by inhibiting the growth of different Gram-negative, Gram-positive, drug-resistant bacteria and different Candida strains. The purified exopolysaccharide exhibited potential antioxidant activity in terms of good reducing power and scavenging of DPPH free radicals, superoxide anions and lipid peroxyl radicals. Further, the in vitro immune responses of Lasiosan were demonstrated in mouse RAW 264.7 macrophages. Lasiosan inhibited the LPS-stimulated reactive oxygen species (ROS) and nitric oxide (NO) generation in RAW 264.7 macrophages without affecting cell proliferation. Furthermore, Lasiosan significantly down-regulated the production of LPS stimulated proinflammatory mediators such as TNF-α and IL-6 from RAW 264.7 macrophages. This is the first report on Lasiosan exhibiting broad spectrum antimicrobial, anti-biofilm, antioxidant and immunomodulatory activities, which could be explored as a promising candidate for application in biotechnological and biomedical fields.
exopolysaccharide, antimicrobial, immunomodulatory, Antioxidant, Lasiodiplodia
Publication DOI: 10.1016/j.procbio.2018.06.014Exopolysaccharides 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: 27129222Exocellular (1→6)-β-D-glucan (lasiodiplodan) produced by the fungus Lasiodiplodia theobromae MMPI was derivatized by carboxymethylation using different concentrations of a derivatizing agent. Lasiodiplodan was derivatized by carboxymethylation in an attempt to increase its solubility and enhance its biological activities. Carboxymethylglucans with degrees of substitution (DS) of 0.32, 0.47, 0.51, 0.58, and 0.68 were produced and characterized. FTIR analysis showed a band of strong intensity at 1600 cm-1 and an absorption band at 1421 cm-1, resulting from asymmetric and symmetrical stretching vibrations, respectively, of the carboxymethyl group COO- in the carboxymethylated samples. Thermal analysis showed that native lasiodiplodan (LN) and carboxymethylated derivatives (LC) exhibited thermal stability up to 200-210 °C. X-ray diffractometry demonstrated that both native and carboxymethylated lasiodiplodan presented predominantly an amorphous nature. Scanning electron microscopy revealed that carboxymethylation promoted morphological changes in the biopolymer and increased porosity, and alveolar structures were observed along the surface. The introduction of carboxymethyl groups in the macromolecule promoted increased solubility and potentiated the hydroxyl radical-scavenging activity, suggesting a correlation between degree of substitution and antioxidant activity.
carbohydrate, exopolysaccharide, biopolymer, lasiodiplodan, bioactive macromolecules
NCBI PubMed ID: 31083511In the recent era, bioactive compounds from plants have received great attention because of their vital health-related activities, such as antimicrobial activity, antioxidant activity, anticoagulant activity, anti-diabetic activity, UV protection, antiviral activity, hypoglycemia, etc. Previous studies have already shown that polysaccharides found in plants are not likely to be toxic. Based on these inspirational comments, most research focused on the isolation, identification, and bioactivities of polysaccharides. A large number of biologically active polysaccharides have been isolated with varying structural and biological activities. In this review, a comprehensive summary is provided of the recent developments in the physical and chemical properties as well as biological activities of polysaccharides from a number of important natural sources, such as wheat bran, orange peel, barely, fungi, algae, lichen, etc. This review also focused on biomedical applications of polysaccharides. The contents presented in this review will be useful as a reference for future research as well as for the extraction and application of these bioactive polysaccharides as a therapeutic agent.
extraction, biomedical applications, bioactive polysaccharides
NCBI PubMed ID: 31374889Infectious bronchitis virus (IBV) is a highly contagious avian coronavirus. IBV causes substantial worldwide economic losses in the poultry industry. Vaccination with live-attenuated viral vaccines, therefore, are of critical importance. Live-attenuated viral vaccines, however, exhibit the potential for reversion to virulence and recombination with virulent field strains. Therefore, alternatives such as subunit vaccines are needed together with the identification of suitable adjuvants, as subunit vaccines are less immunogenic than live-attenuated vaccines. Several glycan-based adjuvants directly targeting mammalian C-type lectin receptors were assessed in vitro using chicken bone marrow-derived dendritic cells (BM-DCs). The β-1-6-glucan, pustulan, induced an up-regulation of MHC class II (MHCII) cell surface expression, potentiated a strong proinflammatory cytokine response, and increased endocytosis in a cation-dependent manner. Ex vivo co-culture of peripheral blood monocytes from IBV-immunised chickens, and BM-DCs pulsed with pustulan-adjuvanted recombinant IBV N protein (rN), induced a strong recall response. Pustulan-adjuvanted rN induced a significantly higher CD4+ blast percentage compared to either rN, pustulan or media. However, the CD8+ and TCRγδ+ blast percentage were significantly lower with pustulan-adjuvanted rN compared to pustulan or media. Thus, pustulan enhanced the efficacy of MHCII antigen presentation, but apparently not the cross-presentation on MHCI. In conclusion, we found an immunopotentiating effect of pustulan in vitro using chicken BM-DCs. Thus, future in vivo studies might show pustulan as a promising glycan-based adjuvant for use in the poultry industry to contain the spread of coronaviridiae as well as of other avian viral pathogens.
adjuvant, chicken, Pustulan, APC-targeting, BM-DC, IBV, subunit vaccination
NCBI PubMed ID: 32429204A 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: 31826486Polysaccharides 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: 33183624In the brewing process, the consumption of resources and the amount of waste generated are high and due to a lot of organic compounds in waste-water, the capacity of natural regeneration of the environment is exceeded. Residual yeast, the second by-product of brewing is considered to have an important chemical composition. An approach with nutritional potential refers to the extraction of bioactive compounds from the yeast cell wall, such as β-glucans. Concerning the potential food applications with better textural characteristics, spent brewer's yeast glucan has high emulsion stability and water-holding capacity fitting best as a fat replacer in different food matrices. Few studies demonstrate the importance and nutritional role of β-glucans from brewer's yeast, and even less for spent brewer's yeast, due to additional steps in the extraction process. This review focuses on describing the process of obtaining insoluble β-glucans (particulate) from spent brewer's yeast and provides an insight into how a by-product from brewing can be converted to potential food applications.
Saccharomyces cerevisiae, yeast, bioactive polysaccharides, particulate β-glucans, spent brewer's yeast
NCBI PubMed ID: 33467670A 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: 34500837This paper reviews the effects of thallophytic glucans on rodent cognitive performance modelled by a combination of behavioural and electrophysiological approaches. Glucans were isolated from thallophytic plants, based on prescriptions used in traditional Chinese and Japanese medicine. In parallel with the already described enhancement of hippocampal synaptic plasticity by disaccharides, polysaccharides isolated from lichens Flavoparmelia caperata and Cetrariella islandica, enhanced hippocampal plasticity and behavioural performance in rats.
isolichenan, PC-2, Cetrariella islandica, senile dementia, learning behaviour, short-term potentiation, long-term potentiation
NCBI PubMed ID: 10815005The mushrooms have contributed to the development of active ingredients of fundamental importance in the field of pharmaceutical chemistry as well as of important tools in human and animal health, nutrition, and functional food. This review considers studies on the beneficial effects of medicinal mushrooms on the nutrition and health of humans and farm animals. An overview of the chemical structure and composition of mycochemicals is presented in this review with particular reference to phenolic compounds, triterpenoids and sterols, fatty acids and lipids, polysaccharides, proteins, peptides, and lectins. The nutritional value and chemical composition of wild and cultivated mushrooms in Italy is also the subject of this review which also deals with mushrooms as nutraceuticals and the use of mushrooms in functional foods. The nutraceutical benefits of UV irradiation of cultivated species of basidiomycetes to generate high amounts of vitamin D2 is also highlighted and the ability of the muhsrooms to inhibit glycation is analyzed. Finally, attention is paid to studies on bioactivities of some Italian wild and cultivated mushrooms with particular reference to species belonging to the genus Pleurotus. The review highlights the potential of medicinal mushrooms in the production of mycochemicals that represent a source of drugs, nutraceutical, and functional food. Graphic abstract: [Figure not available: see fulltext.]
mushroom, chemical structures, cultivation, nutrition, fungal diversity, mycochemicals
Publication DOI: 10.1007/s11101-021-09748-2Extracellular 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: 34878762Termitomyces 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: 34936332Solid-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: 36181715Glucans 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: 38286552Macrofungi, such as edible mushrooms, have been used as a valuable medical resource for millennia as a result of their antibacterial and immuno-modulatory components. Mushrooms contain dietary fibers known as β-glucans, a class of polysaccharides previously linked to the induction of Trained Immunity. However, little is known about the ability of mushroom-derived β-glucans to induce Trained Immunity. Using various powdered forms of the white button mushroom (Agaricus bisporus), we found that mouse macrophages pre-treated with whole mushroom powder (WMP) displayed enhanced responses to restimulation with TLR ligands, being particularly sensitive to Toll-like receptor (TLR)-2 stimulation using synthetic lipopeptides. This trained response was modest compared to training observed with yeast-derived β-glucans and correlated with the amount of available β-glucans in the WMP. Enriching for β-glucans content using either a simulated in-vitro digestion or chemical fractionation retained and boosted the trained response with WMP, respectively. Importantly, both WMP and digested-WMP preparations retained β-glucans as identified by nuclear magnetic resonance analysis and both displayed the capacity to train human monocytes and enhanced responses to restimulation. To determine if dietary incorporation of mushroom products can lead to Trained Immunity in myeloid cells in vivo, mice were given a regimen of WMP by oral gavage prior to sacrifice. Flow cytometric analysis of bone-marrow progenitors indicated alterations in hematopoietic stem and progenitor cells population dynamics, with shift toward myeloid-committed multi-potent progenitor cells. Mature bone marrow-derived macrophages derived from these mice displayed enhanced responses to restimulation, again particularly sensitive to TLR2. Taken together, these data demonstrate that β-glucans from common macrofungi can train innate immune cells and could point to novel ways of delivering bio-available β-glucans for education of the innate immune system
mushroom, β-glucan, trained immunity, digestion, immunometabolism
NCBI PubMed ID: 38425482| -6)-b-D-Glcp-(1- | Show graphically |
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Show legend Show as text |
Structure type: homopolymer
; 29000-45000
Compound class: glucan
Contained glycoepitopes: IEDB_135614,IEDB_141806,IEDB_142488,IEDB_146664,IEDB_241101,IEDB_983931,SB_192
The (1→6)-β-D-glucans from Agaricus bisporus and Agaricus brasiliensis were purified to evaluate their effects on the innate immune system. THP-1 macrophages were used to investigate the induction of the expression of TNF-α, IL1β, and COX-2 by RT-PCR. The purification of the polysaccharides gave rise to fractions containing 96-98% of glucose. The samples were analyzed by GC-MS, HPSEC and (13)C NMR, which confirmed the presence of homogeneous (1→6)-β-D-glucans. The β-glucans were incubated with THP-1 derived macrophages, for 3 h and 6 h to evaluate their effects on the expression of pro-inflammatory genes. Both β-glucans stimulated the expression of such genes as much as the pro-inflammatory control (LPS). When the cells were incubated with LPS+β-glucan, a significant inhibition of the expression of IL-1β and COX-2 was observed for both treatments after 3 h of incubation. By the results, we conclude that the (1→6)-β-D-glucans present an immunostimulatory activity when administered to THP-1 derived macrophages.
Immunostimulatory activity, Agaricus bisporus, (1→6)-β-D-glucan, Agaricus brasiliensis
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