Structure of acidic o-specific polysaccharide from the marine bacterium <Emphasis Type="Italic">Cellulophaga baltica</Emphasis>

The structure of an acidic O-specific polysaccharide from the marine bacterium Cellulophaga baltica was established by chemical methods and NMR spectroscopy. The polysaccharide was shown to consist of repeating tetrasaccharide units containing two mannose residues, one N-acetyl-D-glucosamine residue, and one D-glucuronic acid residue. An O-acetyl group was also found in the polysaccharide in nonstoichiometric amount. The polysaccharide had the following structure:

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Structural studies of the capsular polysaccharide of Klebsiella type 37

The structure of the Klebsiella type 37 capsular polysaccharide has been investigated. Methylation analysis, various specific degradations, and n.m.r. spectroscopy were the principal methods used. It is concluded that the polysaccharide is composed of tetrasaccharide repeating-units having the structure 4-O-Lac-d-GlcA  4-O-[(S)-1-carboxyethyl]-d-glucuronic acid:

     

The structure of the glycerophosphate-containing O-specific polysaccharide from <Emphasis Type="Italic">Escherichia coli</Emphasis> O130

A phosphorylated O-specific polysaccharide was obtained by mild acidic degradation of the lipopolysaccharide from the enteric bacterium Escherichia coli O130 and characterized by the methods of chemical analysis, including dephosphorylation and ¹H and ¹³C NMR spectroscopy. The polysaccharide was shown to be composed of branched tetrasaccharide repeating units containing two N-acetyl-D-galactosamine residues, D-galactose, D-glucose, and glycerophosphate residues (one of each). The polysaccharide has the following structure, which is unique among the known bacterial polysaccharides:

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Structural studies of the haemophilus influenzae type f capsular polysaccharide

The structure of the Haemophilus influenzae type f capsular polysaccharide was studied by chemical and nuclear magnetic resonance spectroscopic techniques. The repeating unit of the polysaccharide was found to be

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Structural studies of the Rhizobium trifolii extracellular polysaccharide

The structure of the extracellular polysaccharide of Rhizobium trifolii has been investigated. Methylation analysis, sequential degradations by oxidation and elimination of oxidized residues, uronic acid degradation, and degradation by oxidation of the acetylated polysaccharide with chromium trioxide in acetic acid were the main methods used. It is proposed that the polysaccharide is composed of heptasaccharide repeating-units having the following structure:

An unusual feature is that some of the repeating units are incomplete and lack the terminal β-d-galactopyranosyl group. The polysaccharide contains O-acetyl groups (somewhat more than 1 mol. per unit), linked to O-2 and O-3 of 4-O-substituted d-glucopyranosyl chain-residues. A previous finding that the polysaccharide contains 2-deoxy-d-arabino-hexose (2-deoxy-d-glucose) residues is erroneous.     

Structure of the extracellular polysaccharide from xanthomonas campestris

Xanthan gum, the extracellular polysaccharide from Xanthomonas campestris, has been reinvestigated by methylation analysis, and by uronic acid degradation followed by oxidation and elimination of the oxidized residue. The polysaccharide is composed of pentasaccharide repeating-units with the following structure:

     

Structural determination of the capsular polysaccharide of Streptococcus pneumoniae type 19A (57)

The structure of the Pneumococcus type 19A (57) capsular polysaccharide has been reinvestigated by using methylation analysis and n.m.r. spectroscopy. It is composed of residues of 2-acetamido-2-deoxy-d-mannose, d-glucose, l-rhamnose, and phosphate in the molar ratios of 1:1:1:1. The polysaccharide is linear, and is composed of these components in a repeating unit of the following structure.

The type 19A polysaccharide (Na⁺ salt) was depolymerized by heating it in water at 100°, conditions that also hydrolyzed the newly formed phosphoric monoesters.     

Structural studies of gellan gum,an extracellular polysaccharide elaborated by Pseudomonas elodea

The structure of gellan gum, a polysaccharide of potential commercial usefulness elaborated by Pseudomonas elodea, has been investigated. It is concluded that the polysaccharide is composed of tetrasaccharide repeating-units having the following structure.

Of the repeating units, ～25% contain an O-acetyl group linked to C-6 of one of the β-d-glucopyranosyl residues.     

Isolation and characterization of a heteropolysaccharide from the corm of Amorphophallus campanulatus

A water-soluble polysaccharide isolated from the aqueous extract of the corm of Amorphophallus campanulatus was found to contain d-galactose, d-glucose, 4-O-acyl-d-methyl galacturonate, and l-arabinose in a molar ratio 2:1:1:1. Structural investigation of the polysaccharide was carried out using acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies (¹H, ¹³C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of the above-mentioned experiments the structure of the repeating unit of the polysaccharide was established as:This molecule showed splenocyte activation.     

Structural studies of the polysaccharide antigen of Eubacterium saburreum, strain L. 452

The structure of the polysaccharide antigen produced by Eubacterium saburreum, strain L 452, has been investigated. Methylation analysis, graded hydrolysis with acid, and n.m.r. spectroscopy were the principal methods used. The polysaccharide is composed of trisaccharide repeating-units having the following structure:

The assignment of the β configuration to the d-ribofuranosyl residue is tentative.     

Chemical structure of the cell wall-associated polysaccharide of Bifidobacterium animalis subsp. lactis LKM512

We have demonstrated that Bifidobacterium animalis subsp. lactis LKM512 had some probiotic properties in vivo and in vitro. To further understand their mechanisms, the chemical structure of the extracellular polysaccharide that constructs the cell envelope was determined. The strain was anaerobically cultured in MRS broth at 37 °C for 20 h, then the bacterial cells were harvested by centrifugation and washed. The cell wall-associated polysaccharide (CPS) was prepared from the cell wall component digested by lysozyme. The results of anion exchange and gel filtration chromatography showed that the polysaccharide was negatively charged and had a high molecular mass. The CPS was found to compose of galactopyranosyl, galactofuranosyl, glucopyranosyl and rhamnopyranosyl residues in the molar ratio of 1:1:1:3 by using methylation analysis with GC-MS and HPLC profiling. From the results of the structural characterization by 1 dimensional and 2 dimensional NMR spectroscopy, the polysaccharide was established to be a hexasaccharide repeating unit with the following structure:      

The elucidation of the structure of the core part of the LPS from Plesiomonas shigelloides serotype O17 expressing O-polysaccharide chain identical to the Shigella sonnei O-chain

Plesiomonas shigelloides O17 LPS contains the same O-antigenic polysaccharide chain as a causative agent of dysentery, Shigella sonnei. This polysaccharide can be used as a component of a vaccine against dysentery. Core part of the P. shigelloides O17 LPS was studied using NMR and mass spectrometry and the following structure was proposed: Significant similarity of the P. shigelloides O17 LPS core with the structure of the P. shigelloides O54 core was observed.     

Structure of a peptidoglycan-related polysaccharide from <Emphasis Type="Italic">Providencia alcalifaciens</Emphasis> O45

A polysaccharide was isolated from the opportunistic human pathogen Providencia alcalifaciens O45:H26 by extraction with aqueous phenol and studied by sugar and methylation analyses along with ¹H and ¹³C NMR spectroscopy, including two-dimensional ROESY and H-detected ¹H,¹³C HSQC experiments. The polysaccharide contains N-acetylglu-cosamine and N-acetylmuramic acid (D-GlcpNAc3Rlac) amidated with L-alanine and has the following structure:

$\to 4) - \beta - D - GlcpNAc - (1 \to 4) - \beta - D - GlcpNAc3(Rlac - L - Ala) - (1 \to .$

The polysaccharide possesses a remarkable structural similarity to the bacterial cell wall peptidoglycan. It is not unique to the strain studied but is common to strains of at least four P. alcalifaciens O-serogroups (O3, O24, O38, and O45). No evidence was obtained that the polysaccharide is associated with the LPS, and hence it might represent a bacterial capsule component.

     

Structural studies of the capsular polysaccharide from Klebsiella type 1

The structure of the capsular polysaccharide from Klebsiella type 1, which is composed of D-glucose, D-glucuronic acid, L-fucose, and pyruvic acid (1:1:1:1), has been investigated. Methylation analysis, n.m.r. spectroscopy, graded hydrolysis, and periodate-oxidation studies were the principal methods used. These studies demonstrated that the polysaccharide consists of the following trisaccharide repeating-unit:

     

Structure of the O-antigen of Yersinia pseudotuberculosis O:4a revised

The O-specific polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Yersinia pseudotuberculosis O:4a and studied by NMR spectroscopy, including 2D ROESY and ¹H, ¹³C HMBC experiments. The following structure of the pentasaccharide repeating unit of the polysaccharide was established, which differs from the structure reported earlier [Gorshkova, R. P. et al., Bioorg. Khim. 1983, 9, 1401-1407] in the linkage modes between the monosaccharides: where Tyv stands for 3,6-dideoxy-d-arabino-hexose (tyvelose). The structure of the Y. pseudotuberculosis O:4a antigen resembles that of Y. pseudotuberculosis O:2c, which differs in the presence of abequose (3,6-dideoxy-d-xylo-hexose) in place of tyvelose only.     

Structural studies on a polysaccharide from Shigella dysenteriae type 7

The polysaccharide obtained from the O-somatic antigen of Shigella dysenteriae type 7 (strain NCTC 519/66) contains d-glucose, d-galactose, and 2-acetamido-2-deoxy-d-glucose in the mole ratios of 2:1:1. From the results of methylation, periodate oxidation, graded hydrolysis, and deamination studies, the structure assigned to the repeating unit of the polysaccharide is as follows.

Oxidation studies with chromium trioxide revealed the nature of the anomeric linkages of some of the sugar residues in the polysaccharide.     

Structure of a polysaccharide from the lipopolysaccharide of Vibrio vulnificus CECT4602 containing 2-acetamido-2,3,6-trideoxy-3-[(S)- and (R)-3-hydroxybutanoylamino]-l-mannose

A polysaccharide was isolated by GPC after mild acid treatment of the lipopolysaccharide of Vibrio vulnificus CECT4602 and found to contain l-Rha, d-GlcpNAc and 2-acetamido-2,3,6-trideoxy-3-(3-hydroxybutanoylamino)-l-mannose (l-RhaNAc3NHb). GLC analysis of the trifluoroacetylated (S)-2-octyl esters derived by full acid hydrolysis of the polysaccharide showed that ∼80% of the 3-hydroxybutanoic acid has the S configuration and ∼20% the R configuration. The following structure of the polysaccharide was established by ¹H and ¹³C NMR spectroscopies, including 2D ROESY and ¹H/¹³C HMBC experiments:      

Structural studies of an extracellular polysaccharide (S-198) elaborated by Alcaligenes ATCC 31853

The structure of an extracellular polysaccharide, S-198, elaborated by Alcaligenes ATCC 31853 has been investigated; methylation analysis, specific degradations, and ¹H-n.m.r. spectroscopy were the main methods used. It is suggested that the polysaccharide is composed of “repeating units” with the structure

A sugar residue in the chain may be either L-rhamnose or L-mannose and only ≈50% of the residues contain the branching α-L-rhamnopyranosyl group. The polysaccharide further contains O-acryl groups. It belongs to a group of polysaccharides, elaborated by Alcaligenes and Pseudomonas species, which all have the same linear backbone (except that some of them do not contain L-mannose) without branching or with branches that differ in their chemical structures and/or positions.