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Found 1 structure.
Displayed structure 1
| -6)-a-D-Glcp-(1- | Show graphically |
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Structure type: homopolymer
Trivial name: glucan, α-D-glucan, dextran, α-1,6-glucan, α-(1,6)-glucan, dextran, α-(1,6)-glucan, α-1,6 dextran, β-1,3-D-glucan, polysaccharide IOP
Compound class: EPS, O-polysaccharide, cell wall polysaccharide, glucan, polysaccharide
Contained glycoepitopes: IEDB_142488,IEDB_144998,IEDB_146664,IEDB_158538,IEDB_983931,SB_192
Helicobacter pylori NCTC11637 expresses a lipopolysaccharide (LPS) that comprises an O antigen side-chain with structural homology to the human blood group antigen Lewis X (Le(x)). The role of this molecule in adhesion of H. pylori to gastric epithelial cells was investigated. Mutants expressing truncated LPS structures were generated through insertional mutagenesis of rfbM and galE; genes encode GDP mannose pyrophosphorylase and galactose epimerase respectively. Compositional and structural analysis revealed that the galE mutant expressed a rough LPS that lacked an O antigen side-chain. In contrast, an O antigen side-chain was still synthesized by the rfbM mutant, but it lacked fucose and no longer reacted with anti-Le(x) monoclonal antibodies (Mabs). The ability of these mutants to bind to paraffin-embedded sections from the antrum region of a human stomach was assessed. Adhesion of the wild type was characterized by tropic binding to the apical surface of mucosal epithelial cells and cells lining gastric pits. In contrast, both the rfbM and galE mutants failed to demonstrate tropic binding and adhered to the tissue surface in a haphazard manner. These results indicate that LPS and, more specifically, Le(x) structures in the O antigen side-chain play an important role in targeting H. pylori to specific cell lineages within the gastric mucosa. The role of Le(x) in this interaction was confirmed by the tropic binding of synthetic Le(x), conjugated to latex beads, to gastric tissue. The observed pattern of adhesion was indistinguishable from that of wild-type H. pylori
NCBI PubMed ID: 10760152The roles of the three ORFs HP0208, HP0159 and HP1416 in the biosynthesis of Helicobacter pylori 26695 LPS were investigated in this study. These ORFs represent a paralogous family of genes with homology to the Salmonella enterica serovar Typhimurium (hereafter referred to as S. typhimurium) waaJ gene, which encodes an α-1,2-glycosyltransferase required for core LPS biosynthesis. HP0208 contains multiple tandem repeats of the dimer 5'GA at its 5' end and its expression is predicted to be subject to phase variation. The number of 5'GA repeats present in this ORF was found to be non-permissive for the expression of HP0208 in the majority of H. pylori strains examined. To determine a role for this ORF in LPS biosynthesis a non-phase-variable, constitutively expressed variant of HP0208 was constructed and introduced into the genome of H. pylori 26695. Analysis of the LPS profile of this strain by Tricine-SDS-PAGE and immunoblotting with anti-Lewis Y antigen (Le(y)) mAbs confirmed a role for HP0208 in the biosynthesis of core LPS. A role for HP0159 and HP1416 in the biosynthesis of core LPS was also established. Although homologous to waaJ, H. pylori HP0208, HP0159 and HP1416 failed to complement an S. typhimurium waaJ mutant, suggesting that these ORFs encode functionally different enzymes
Lipopolysaccharide, biosynthesis, antigen, LPS, core, Phase variation, expression, gene, phase, role, strain, variation, analysis, MAb, mutant, Salmonella, families, Salmonella enterica, Helicobacter pylori, enzyme, variant, Enzymes, homology, genome, Helicobacter, Typhimurium, tandem, homologous, complement, multiple, anti-Lewis, immunoblotting, profile
NCBI PubMed ID: 16014421Two polysaccharide preparations (OPSI and OPSII) were obtained by mild acid degradation of the lipopolysaccharide of Rahnella aquatilis 3-95. Studies by chemical methods and 1H and 13C NMR spectroscopy showed that OPSI has a linear trisaccharide repeat of -d-mannose and OPSII is a mixture of the same mannan and an -(16)-linked d-glucan.
Lipopolysaccharide, O-antigen, bacterial polysaccharide structure, Rahnella aquatilis
NCBI PubMed ID: 16313891The 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_3Bifidobacterium bifidum 791 (commercially available as B. bifidum BIM B-733D) cell-surface biopolymers (BPs) interact selectively with human serum thyroid peroxidase (TPO) and thyroglobulin (Tg) autoantibodies (anti TPO and anti Tg, respectively). BPanti-TPO and BPanti-Tg were isolated from the soluble fraction of B. bifidum BIM B-733D by affinity chromatography with anti-TPO or anti-Tg, respectively. Homogeneity of affinity eluates (AEanti-TPO and AEanti-Tg) was tested by size exclusion chromatography. For each AE, the elution profiles generated on the basis of absorbance at 280 nm do not conform to ELISA data for functional activity characteristic of BPs. Moreover, high functional activity was detected in chromatographic fractions that had significantly different molecular weights and no absorbance at 280 nm, which suggests a non-protein (carbohydrate) nature of BPanti-TPO and BPanti-Tg. The semi-preparative size exclusion chromatography of AEanti-TPO and AEanti-Tg with detection by refractometer gave 5,000-7,000 Da fractions containing substances that interact selectively with either anti TPO (BPanti-TPO) or anti-Tg (BPanti-Tg) according to ELISA data. Analysis by two-dimensional NMR spectroscopy including a 1H, 13C-heteronuclear single-quantum coherence experiment indicated that both substances are linear α-1,6-glucans. For the first time, an immunological similarity (molecular mimicry) of glycopolymers of B. bifidum BIM B-733D and human thyroid proteins, TPO and Tg, was shown. On the whole, our data point to a possible role of bifidobacteria in the pathogenesis of autoimmune thyroid diseases (ATD). The main requirements for triggering/acceleration or prevention/abrogation of ATD by bifidobacteria through molecular mimicry mechanism are hypothesised to be (1) genetic predisposition to ATD and (2) intestinal epithelium penetration by α-1,6-glucan.
Autoantibodies, molecular mimicry, Bifidobacterium, α-1, 6-glucan
NCBI PubMed ID: 24311320We have recently demonstrated that synthetic glycoconjugates based on delipidated lipopolysaccharide (LPS) of Helicobacter pylori and containing an α(1-6)-glucan chain induced broadly cross-reactive functional antibodies in immunized animals. To investigate the candidacy of α(1-6)-glucan as an alternative vaccine strategy we prepared glycoconjugates based on dextrans produced by lactic acid bacteria Leuconostoc mesenteroides B512F and consisting of linear α(1-6)-glucan chains with limited branching. Three dextrans with averaged molecular masses of 5,000 Da, 3,500 Da and 1,500 Da, respectively, were modified with a diamino group-containing linker and conjugated to a carrier protein, tetanus toxoid (TT) or diphtheria toxoid (DT), and their immunological properties investigated. The conjugates were immunogenic in both rabbits and mice and induced specific IgG responses against α(1-6)-glucan-expressing H. pylori LPS. Studies performed with post-immune sera of mice and rabbits immunized with dextran-based conjugates demonstrated cross-reactivity with LPS from typeable and non-typeable strains of H. pylori and selected mutants. The post-immune sera from rabbits that received the conjugates exhibited functional activity against α(1-6)-glucan-positive strains of H. pylori. These data provide evidence that dextran-based conjugates may offer a simplified approach to the development of carbohydrate-based vaccines against H. pylori.
Helicobacter pylori, Helicobacter, conjugate vaccine, glycoconjugate, Dextran, Bactericidal assay
NCBI PubMed ID: 23990317Burkholderia multivorans C1576 is a Gram negative opportunistic pathogen causing serious lung infection in cystic fibrosis patients. Considering that bacteria naturally form biofilms, and exopolysaccharides are recognized as important factors for biofilm architecture set-up, B. multivorans was grown both in biofilm and in non-biofilm mode on two different media in order to compare the exopolysaccharides biosynthesized in these different experimental conditions. The exopolysaccharides produced were purified and their structure was determined resorting mainly to NMR spectroscopy, ESI mass spectrometry and gas chromatography coupled to mass spectrometry. The experimental data showed that both in biofilm and non-biofilm mode B. multivorans C1576 produced a novel exopolysaccharide having the following structure: [Formula: see text]. About 50% of the 2-linked rhamnose residues are substituted on C-3 with a methyl ether group. The high percentage of deoxysugar Rha units, coupled with OMe substitutions, suggest a possible role for polymer domains with marked hydrophobic characteristics able to create exopolysaccharide junction zones favouring the stability of the biofilm matrix.
NMR, Exopolysaccharide structure, cystic fibrosis, Biofilm, Burkholderia multivorans C1576
NCBI PubMed ID: 25974852Capsular polysaccharide (CPS) was isolated from a nosocomial pathogen Acinetobacter baumannii (A. baumannii) NIPH67 and studied by sugar analysis, Smith degradation, and 1H and 13C NMR spectroscopy. The CPS was found to contain 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Pse5Ac7Ac), and the structure of the linear trisaccharide repeating unit of the CPS was established as →4)-α-Psep5Ac7Ac-(2→6)-β-D-Galp-(1→3)-α-D-GalpNAc-(1→. The genetic content of the capsule biosynthesis cluster of A. baumannii NIPH67, designated KL33, is consistent with the established CPS structure, and thus the capsule of the investigated strain was assigned to K33 group. Functions of proteins including two glycosyltransferases encoded by the genes of the K33 locus were assigned based on the structure of CPS and by the comparison with related proteins of other capsular types of A. baumannii.
capsular polysaccharide, Acinetobacter baumannii, pseudaminic acid, glycosyltransferase, biotechnology, K locus, KL33 gene cluster, structure of capsular polysaccharide
Publication DOI: 10.1007/s11172-016-1342-yKlebsiella pneumoniae is a major health threat. Vaccination and passive immunization are considered as alternative therapeutic strategies for managing Klebsiella infections. Lipopolysaccharide O antigens are attractive candidates because of the relatively small range of known O-antigen polysaccharide structures, but immunotherapeutic applications require a complete understanding of the structures found in clinical settings. Currently, the precise number of Klebsiella O antigens is unknown because available serological tests have limited resolution, and their association with defined chemical structures is sometimes uncertain. Molecular serotyping methods can evaluate clinical prevalence of O serotypes but require a full understanding of the genetic determinants for each O-antigen structure. This is problematic with Klebsiella pneumoniae because genes outside the main rfb (O-antigen biosynthesis) locus can have profound effects on the final structure. Here, we report two new loci encoding enzymes that modify a conserved polysaccharide backbone comprising disaccharide repeat units [→3)-α-d-Galp-(1→3)-β-d-Galf-(1→] (O2a antigen). We identified in serotype O2aeh a three-component system that modifies completed O2a glycan in the periplasm by adding 1,2-linked α-Galp side-group residues. In serotype O2ac, a polysaccharide comprising disaccharide repeat units [→5)-β-d-Galf-(1→3)-β-d-GlcpNAc-(1→] (O2c antigen) is attached to the non-reducing termini of O2a-antigen chains. O2c-polysaccharide synthesis is dependent on a locus encoding three glycosyltransferase enzymes. The authentic O2aeh and O2c antigens were recapitulated in recombinant Escherichia coli hosts to establish the essential gene set for their synthesis. These findings now provide a complete understanding of the molecular genetic basis for the known variations in Klebsiella O-antigen carbohydrate structures based on the O2a backbone.
polysaccharide, O antigen, polysaccharide structure, Gram-negative bacteria, glycosyltransferase, serotyping, lipopolysaccharide (LPS), carbohydrate structure, nuclear magnetic resonance (NMR), Klebsiella pneumonia
NCBI PubMed ID: 29602878Fungal 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: 21878570Cyanothece sp. 113, a unicellular, aerobic, diazotrophic and photosynthetic marine cyanobacterium, produced 22.34 g/l of exopolysaccharide in 11 days at 29 °C, aeration rate of 7.0 l/min and continuous illumination with 4300 lux. After purification, the spectra of UV, IR, 1H NMR, 13C NMR and GC-MS analysis showed that the purified exopolysaccharide was α-D-1,6-homoglucan. This is first report describing linear α-D-1,6-homoglucan exopolysaccharide produced by marine cyanobacteria.
exopolysaccharide, glucan, aeration rate, Cyanothece, marine cyanobacteria
NCBI PubMed ID: 16782333After isolation from different doughs and sourdoughs, 177 strains of lactic acid bacteria were screened at the phenotypic level for exopolysaccharide production on media containing different carbohydrate sources. Two exopolysaccharide-producing lactic acid bacteria (Lactobacillus curvatus 69B2 and Leuconostoc lactis 95A) were selected through quantitative analysis on solid media containing sucrose and yeast extract. The PCR detection of homopolysaccharide (gtf and lev) and heteropolysaccharide (epsA, epsB, epsD and epsE, and epsEFG) genes showed different distributions within species and strains of the lactic acid bacteria studied. Moreover, in some strains both homopolysaccharide and heteropolysaccharide genes were detected. Proton nuclear magnetic resonance spectra suggest that Lactobacillus curvatus 69B2 and Leuconostoc lactis 95A produced the same exopolysaccharide, which was constituted by a single repeating glucopyranosyl unit linked by an α-(1→6) glycosidic bond in a dextran-type carbohydrate. Microbial growth, acidification, and viscoelastic properties of sourdoughs obtained by exopolysaccharide-producing and nonproducing lactic acid bacterial strains were evaluated. Sourdough obtained after 15 h at 30°C with exopolysaccharide-producing lactic acid bacteria reached higher total titratable acidity as well as elastic and dissipative modulus curves with respect to the starter not producing exopolysaccharide, but they showed similar levels of pH and microbial growth. On increasing the fermentation time, no difference in the viscoelastic properties of exopolysaccharide-producing and nonproducing samples was observed. This study suggests that dextran-producing Leuconostoc lactis 95A and Lactobacillus curvatus 69B2 can be employed to prepare sourdough, and this would be particularly useful to improve the quality of baked goods while avoiding the use of commercially available hydrocolloids as texturizing additives.
exopolysaccharide, Dextran, α-D-glucan, Leuconostoc lactis, Lactobacillus curvatus
NCBI PubMed ID: 22307283Recent 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: 15345528Steel corrosion is a global issue that affects safety and the economy. Currently, the homopolysaccharide (HoPS) structure of a novel lactic acid bacterium (LAB) is under study, as well as its application as a green corrosion inhibitor. Weissella cibaria FMy 2-21-1 is a LAB strain capable of producing HoPS in sucrose enriched media. The isolated and purified HoPS was characterized by different spectroscopic analyses as a linear α-1,6 dextran adopting a random coil conformation, with high molecular weight and extended size in water. The polysaccharide showed a semi-crystalline organization, which is a requirement for film formation. Its biocoating showed a grainy network structure, with a slightly lesser hydrophobic role in the aqueous environment than in the ionic one. The electrochemical measurements of the steel-HoPS coating showed that the biopolymer layer acts as an anodic-type corrosion inhibitor, with high resistance to corrosion by water and with chloride ions which prevent pitting, a corrosion process typical of bare steel. Few reports have cited the application of LAB HoPS as corrosive coating inhibitors. This work is the first to explore the influence of a structurally characterized dextran from Weissella cibaria strain as a potential steel corrosion inhibitor in ionic environments.
Lactic acid bacteria, LAB, biocoating, corrosion inhibitor, HoPS structure, Weissella cibaria
NCBI PubMed ID: 35594939The production of pigment-free pullulan by Aureobasidium pullulans in batch and fed-batch culture was investigated. Batch culture proved to be a better fermentation system for the production of pullulan than the fed-batch culture system. A maximum polysaccharide concentration (31.3 g l−1), polysaccharide productivity (4.5 g l−1 per day), and sugar utilization (100%) were obtained in batch culture. In fed-batch culture, feed medium composition influenced the kinetics of fermentation. For fed-batch culture, the highest values of pullulan concentration (24.5 g l−1) and pullulan productivity (3.5 g l−1 per day) were obtained in culture grown with feeding substrate containing 50 g l−1 sucrose and all nutrients. The molecular size of pullulan showed a decline as fermentation progressed for both fermentation systems. At the end of fermentation, the polysaccharide isolated from the fed-batch culture had a slightly higher molecular weight than that of batch culture. Structural characterization of pullulan samples (methylation and enzymic hydrolysis with pullulanase) revealed the presence of mainly α-(1→4) (~66%) and α-(1→6) (~31%) glucosidic linkages; however, a small amount (<3%) of triply linked (1,3,4-, 1,3,6-, 1,2,4- and 1,4,6-Glc p) residues were detected. The molecular homogeneity of the alcohol-precipitated polysaccharides from the fermentation broths as well as the structural features of pullulan were confirmed by 13C-NMR and pullulanase treatments followed by gel filtration chromatography of the debranched digests.
pullulan, Aureobasidium pullulans, batch culture, fed-batch culture
Publication DOI: 10.1016/S0032-9592(98)00106-XThe water-soluble glucan was obtained from Pleurotus florida fruit bodies by hot water extraction, ethanol precipitation, DEAE cellulose dialysis and Sephadex G-75 gel filtration. The structural information of the glucan was achieved by chemical (hydrolysis, methylation, periodate oxidation) and spectroscopic (H-1 and C-13) analyses, indicated a repeating unit built up of (1 -> 6)-linked D-glucose. The following structure has been determined for the repeating unit: -> 6)-alpha-D-Glc(p)-(1 -> This fraction exhibited significant macrophage activity through the release of nitric oxide.
glucan, fungi, branched (1-3)-beta-D-glucan, antitumor polysaccharides, alkaline extract, chinese mushroom
Publication DOI: 10.1007/s00044-004-0050-6For 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: 25505823Fungal 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: 23218369D-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: 25239192Pectic polysaccharides and hemicelluloses extracted from plants were studied in highly hydrated films on BaF2 discs. Distinctive absorption band maxima in the mid-infrared region at 1200–800 1/cm were shown to be useful for the identification of polysaccharides with different structure and composition. Two series of the hexopyranose and pentopyranose monosaccharides, which are the structural units of the plant cell wall polysaccharides, were also studied by FT-IR spectroscopy in solution (i.e. comparable to the amorphous state of the polymers). Their spectral data showed that the main IR band positions are influenced by the relative position of axial and equatorial (OH) groups on the pyranoid ring.
polysaccharides, cell wall, monosaccharides, FT-IR spectroscopy
Publication DOI: 10.1016/S0144-8617(00)00151-XIntroduction: The macromolecular polysaccharide Inonotus obliquus polysaccharide (IOP) is composed of various monosaccharides, and it could modulate the composition and diversity of intestinal flora. However, its impact on the intestinal flora in rats of different genders remains unclear. Therefore, this study aims to investigate the structural changes of IOP and its effects on the intestinal flora after administration in male and female rats. Methods: In this study, the molecular weight and purity of IOP were analyzed by high-performance gel permeation chromatography (HPGPC) and phenol sulfuric acid method, and NMR was used to confirm the chemical structure of IOP. Sex hormone [testosterone (T) and estradiol (E2)] levels and intestinal microbial changes were detected by enzyme-linked immunosorbent assay (ELISA) and 16S rRNA, respectively, after gavage of IOP (100 mg/kg) in male and female Sprague Dawley (SD) rats. Results: HPGPC analysis showed that the average molecular weight (Mw) of IOP was 4,828 Da, and the total sugar content of the purified IOP was 96.2%, indicating that the polysaccharide is of high purity. NMR revealed that IOP is a linear macromolecule with an α-D-type glucose backbone. The results of ELISA and 16S rRNA showed that the IOP increased the abundance of beneficial bacteria, such as Clostridia_UCG-014 and Prevotellaceae_NK3B31, and reduced that of harmful bacteria, such as Colidextribacter and Desulfobacterota in the intestine of both male and female rats, and IOP changed the levels of sex hormones in male and female rats. Further analyses revealed that the increase in alpha diversity was higher in male than female rats. α diversity and β diversity revealed a significant difference in the composition of cecal microbiota between male and female rats in the control group, but IOP intake reduced this difference. Meanwhile, α analysis revealed a change in the composition of bacterial flora was more stable in male than female rats. Conclusions: This study enhances our comprehension of the IOP structure and elucidates the alterations in intestinal flora following IOP administration in rats of varying genders. Nonetheless, further investigation is warranted to explore the specific underlying reasons for these discrepancies.
rats, gut microbiota, gender differences, Inonotus obliquus polysaccharide, structure of IOP
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