Bacterial antigenic polysaccharides. 12. Structure and 13C NMR spectrum of the polysaccharide chain of Shigella boydii type 8 lipopolysaccharide

A specific acidic polysaccharide was isolated from Sh. boydii type 8 antigenic lipopolysaccharide after mild hydrolysis followed by chromatography on Sephadex G-50. The polysaccharide consists of D-glucuronic acid, D-galacturonic acid, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose and 2-amino-1,3-propanediol residues in 1:1:1:1:1 ratio. From the results of methylation analysis, partial acid hydrolysis and Smith degradation, the structure of the repeating unit of the specific polysaccharide was deduced as: (Formula: see text). The 13C NMR spectra of native, O-deacetylated and carboxyl-reduced polysaccharides, as well as the spectrum of oligosaccharide produced by Smith degradation were interpreted. The 13C NMR data fully confirmed the structure of the polysaccharide repeating unit.     

Antigenic bacterial polysaccharides. 36. A study of the structure of the O-specific polysaccharide chain of the lipopolysaccharide of Pseudomonas fluorescens IMV 2763 (biostrain G)

Chemical and serological characterization of the Pseudomonas fluorescens IMV 2763 (biovar G) lipopolysaccharide was carried out. The O-specific polysaccharide chain of the lipopolysaccharide is composed of D-mannose, 6-deoxy-L-talose, N-acetyl-D-galactosamine and O-acetyl groups in the ratio of approximately 2:1:1:1. The polysaccharide is branched and a half of residues of 6-deoxytalose and monosubstituted mannose carry O-acetyl groups. On the basis of methylation, partial acid hydrolysis and 13C NMR analysis it was concluded that the repeating unit of the polysaccharide has the following structure: (formula; see text)     

Structural determination and biosynthetic studies of the O-antigenic polysaccharide from the enterohemorrhagic Escherichia coli O91 using 13C-enrichment and NMR spectroscopy.

The structure of the O-antigenic polysaccharide from the enterohemorrhagic Escherichia coli O91 has been determined using primarily NMR spectroscopy on the (13)C-enriched polysaccharide. The O-antigen is composed of pentasaccharide repeating units with the following structure: -->4)-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->4)-beta-D-GlcpA-6-N- Gly -(1-->3)-beta-D-GlcpNAc-(1-->4)-alpha-D-Quip-3-N-[(R)-3-hydroxy butyra mido]-(1-->. The bacterium was grown with D-[UL-(13)C]glucose in the medium which resulted in an overall degree of labeling of approximately 65% in the sugar residues and approximately 50% in the N-acyl substituents, indicating some metabolic dilution in the latter. The (13)C-enrichment of the polysaccharide proved valuable since NMR assignments could be made on the basis of (13)C, (13)C-connectivity in uniformly labeled residues. The biosynthesis of the (R)-3-hydroxybutyramido substituent via C(2) fragments was identified by NMR spectroscopy. The (R)-configuration at C3 is in accord with fatty acid biosynthesis. Additional cultures with specifically labeled D-[1-(13)C]glucose or D-[6-(13)C]glucose corroborated the direct incorporation of glucose as the building block for the hexose skeletons in the polysaccharide and the biosynthesis of acyl substituents occurring via the triose pool followed by decarboxylation to give acetyl building blocks labeled with (13)C at the methyl group.     

Structure and immunochemistry of an oligosaccharide repeating unit of the capsular polysaccharide of type III group B Streptococcus. A revised structure for the type III group B streptococcal polysaccharide antigen

We have derived oligosaccharides from the capsular polysaccharide of type III group B Streptococcus by enzymatic hydrolysis of a specific backbone glycosidic bond utilizing an endo-beta-galactosidase from Flavobacterium keratolyticus. Enzymatic digestion of the polysaccharide produced oligosaccharide fragments of one or more pentasaccharide repeating units. On the basis of 13C NMR, 1H NMR, and methylation analyses, it was established that the smallest digestion fragment was alpha-D-NeupNAc-(2----3)-beta-D-Galp-(1----4)-[beta-D-Glcp-(1----6 )]- beta-D-GlcpNAc-(1----3)-beta-D-Gal. The isolation of this oligosaccharide is consistent with the susceptibility of the beta-D-Galp-(1----4)-beta-D-Glcp linkage in the backbone of the type III group B streptococcal polysaccharide and confirms that the polysaccharide is composed of a pentasaccharide repeating unit. High resolution 13C NMR spectroscopic studies indicated that, as in the case of the pentasaccharide, the terminal sialic acid residues of the type III group B streptococcal polysaccharide were linked to O-3 and not to O-6 of its branch beta-D-galactopyranosyl residues as had been previously reported (Jennings, H. J., Rosell, K.-G., and Kasper, D. L. (1980) Can. J. Chem. 58, 112-120). This linkage was confirmed in an independent methylation analysis of the type III group B streptococcal polysaccharide. Thin layer chromatogram binding assay and radioactive antigen binding assays with radiolabeled oligosaccharides demonstrated the single repeating unit pentasaccharide oligosaccharide to be poorly antigenic. Increasing oligosaccharide size to a decasaccharide consisting of two repeating units resulted in an 8-fold increase in antigen binding in the direct radioactive antigen binding assay. The results suggest that a region of the immunodeterminant site critical for antibody binding is located in the backbone of the polysaccharide and involves the beta-D-galactopyranose-(1----4) beta-D-glucopyranose bond.     

Antigenic polysaccharides of bacteria. 17. The structure of O-specific polysaccharide chain of Pseudomonas aeruginosa X (Meitert) lipopolysaccharide

O-Specific polysaccharide composed of L-rhamnose and 2-acetamido-2-deoxy-D-mannose was obtained on mild acid degradation of P. aeruginosa X (Meitert classification) lipopolysaccharide. On the basis of non-destructive analis using 1H, 13C NMR spectroscopy and Klyne's rule calculation, as well as chemical methods (acid hydrolysis, methylation, Smith degradation), it was established that the polysaccharide is built up of disaccharide repeating units of the following structure: ----4)-alpha-L-Rha-(1----3)-beta-D-ManNAc-(1----.     

Structure of an acidic polysaccharide from the marine bacterium Pseudoalteromonas aliena type strain KMM 3562T containing two residues of L-serine in the repeating unit

The structure of an acidic polysaccharide from Pseudoalteromonas aliena type strain KMM 3562(T) has been elucidated. The polysaccharide was studied by component analysis, (1)H and (13)C NMR spectroscopy, including 2D NMR experiments. A (1)H, (13)C band-selective constant-time heteronuclear multiple-bond connectivity experiment was used to determine amide linkages, between serine and uronic acid (UA) residues, via (3)J(H,C) correlations between Ser-alphaH and UA-C-6. It was found that the polysaccharide consists of pentasaccharide repeating units with the following structure: [carbohydrate structure]; see text.     

Antigenic determinants of bacteria. The structure of the repeating unit of a specific polysaccharide from Shigella boydii type 7

Acid hydrolysis of the antigenic lipopolysaccharide from Shigella boydii type 7 afforded a specific polysaccharide composed of 2-acetamido-2-deoxy-D-glucose, D-glucose, D-galactose, 5-acetamido-3,5,7,9-tetradeoxy-7-[(3R)-3-hydroxybutyramido]-L- glycero-L-manno-nonulosonic acid (NonN2A) and acetic acid residues in the 1:1:2:1:1 ratio. From the results of methylation analysis, hydrogen fluoride solvolysis and Smith degradation, the structure of the repeating unit of the specific polysaccharide was dedused as: -2) Galf (beta 1-3)GlcNAcp (alpha 1-8)NonN2A (beta 2-6) Galp (alpha 1-6) Glcp (alpha 1-4 increases Ac. The 13C NMR spectrum of the polysaccharide was interpreted, and the spectral data fully confirmed the structure of the polysaccharide repeating unit.     

Structure of the O-specific polysaccharide of the Yersinia enterocolitica serovar O:4.32 lipopolysaccharide. Serologic relations of lipopolysaccharides of Y. enterocolitica O:4.32 and Y. intermedia O:4.33

O-Specific polysaccharide has been isolated on mild acid hydrolysis of the lipopolysaccharide from Yersinia enterocolitica O: 4.32 (strain 96) and shown to consist of yersiniose B (3,6-dideoxy-4-C-(1-hydroxyethyl)-D-xylo-hexose, YerB) acetylated at C1' and 2-acetamido-2-deoxy-D-galactose residues in a molar ratio 1:2. Acid hydrolysis, methylation and 13C NMR studies indicated the polysaccharide to be composed of trisaccharide repeating units of the following structure: (sequence; see text) The data obtained revealed structural and serological interrelation between O-antigens of Y. enterocolitica O:4.32 and Y. intermedia O:4.33.     

Antigenic polysaccharides of bacteria of the genus Shigella. The structure of the polysaccharide chain of Shigella boydii type 14

A specific acidic polysaccharide has been isolated from the Shigella boydii type 14 antigenic lipopolysaccharide after mild hydrolysis followed by chromatography on Sephadex G-50. The polysaccharide consists of the D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose and D-galactose residues in the ratio 1:1:3. From the results of methylation analysis and partial acid hydrolysis, the structure of the repeating unit of the specific polysaccharide was deduced as follows: (-6DGalp alpha 1-4DGlcAp beta 1-6DGalp beta 1-4DGalp beta 1-4DGlcNAcp beta 1-)n. The 13C NMR spectra of native and carboxyl-reduced polysaccharides, as well as of oligosaccharides produced by partial acid hydrolysis fully confirmed the proposed structure. The approach was suggested to determine the type of substitution of uronic acid moieties in polysaccharide chain by use of chromato-mass-spectrometry of acetylated methyl esters of partially methylated aldonic acids. Serological characteristics of Sh. boydii LPS type 14 and its modified derivatives are discussed.     

Study of galactoglucomannans from the seed of Cercis canadensis L

Galactoglucomannans were isolated by selective precipitation from aqueous and alkaline extracts of endosperm and hulls of Cercis canadensis, a member of the family Fabaceae. Their monosaccharide composition (Man: Gal: Glu) was as follows: 10.4: 0.9: 1 (polysaccharide from the endosperm) and 4.5: 0.9: 1 (polysaccharide from the hulls). The identity of IR spectra was indicative of the commonness of their structure. Analysis of the structure of the galactoglucomannan from endosperm by 13C NMR spectroscopy showed that its main chain consisted of 1,4-beta-D-manno- and 1,4-beta-D-glucopyranose. Part of mannose residues in the chain were substituted at C6 with single residues of alpha-D-galactopyranose. Galactoglucomannans are located in different part of the seed and implement different functions.     

A study of fucoidan from the brown seaweed Chorda filum.

Fucoidan fractions from the brown seaweed Chorda filum were studied using solvolytic desulfation. Methylation analysis and NMR spectroscopy were applied for native and desulfated polysaccharides. Homofucan sulfate from C. filum was shown to contain poly-alpha-(1-->3)-fucopyranoside backbone with a high degree of branching, mainly of alpha-(1-->2)-linked single units. Some fucopyranose residues are sulfated at O-4 (mainly) and O-2 positions. Some alpha-(1-->3)-linked fucose residues were shown by NMR to be 2-O-acetylated. The 1H and 13C NMR spectra of desulfated, deacetylated fucan were completely assigned. The spectral data obtained correspond to a quasiregular polysaccharide structure with a branched hexasaccharide repeating unit. Other fucoidan fractions from C. filum have more complex carbohydrate composition and give rather complex methylation patterns. [formula: see text]     

Structure of the O-specific polysaccharide chain of the Yersinia pseudotuberculosis lipopolysaccharide (serovar II C)]

An O-specific polysaccharide has been isolated on mild acid hydrolysis of lipopolysaccharide from Yersinia pseudotuberculosis serovar IIc and shown to consist of abequose, D-mannose and 2-acetamido-2-deoxy-D-galactose residues in the ratio 0.8:3:1. From the results of acid hydrolysis, 13C NMR, methylation and periodate oxidation studies the structure of the repeating unit of the O-specific polysaccharide is deduced as follows: (formula; see text)     

Structural investigation of a heteropolysaccharide isolated from the pods (fruits) of Moringa oleifera (Sajina)

A water-soluble polysaccharide was isolated from the aqueous extract of pods of Moringa oleifera. The polysaccharide contains d-galactose, 6-O-Me-D-galactose, D-galacturonic acid, l-arabinose, and l-rhamnose in a molar ratio of 1:1:1:1:1. On the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR ((1)H, (13)C, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC) studies, the repeating unit of the polysaccharide is established as [structure: see text].     

Structure of O-specific polysaccharide isolated from the Yersinia pseudotuberculosis serotype 1A lipopolysaccharide

An O-specific polysaccharide from the lipopolysaccharide Yersinia pseudotuberculosis 1A serovar has been isolated and characterized. This compound was shown to contain residues of paratose, 6-deoxy-D-manno-heptose, D-galactose and 2-amino-2-deoxy-D-glucose in equimolar ratios. Using methylation studies, partial acid hydrolysis and 13C NMR spectroscopy, the following structure was proposed for the repeating unit of the O-specific polysaccharide: (Formula: see text).     

Structural studies of a methyl galacturonosyl-methoxyxylan isolated from the stem of Lagenaria siceraria (Lau)

A water-soluble polysaccharide was isolated from the aqueous extract of the stem of Lagenaria siceraria. The polysaccharide was found to be constituted of methyl d-galacturonate, 2-O-methyl-D-xylose, and d-xylose in a ratio of 1:1:1. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation, NMR studies ((1)H, (13)C, 2D-COSY, TOCSY, NOESY, HSQC, and HMBC), and MALDI-TOF MS analysis, the structure of the repeating unit of the polysaccharide is determined as.     

Antigenic polysaccharides of Shigella bacteria. Structure of the polysaccharide chain of the lipopolysaccharide from Shigella boydii, type 11]

On mild acid degradation of the Shigella boydii, type 11 lipopolysaccharide, the corresponding O-specific polysaccharide composed of D-glucuronic acid, 2-acetylamino-2-deoxy-D-glucose, D-ribose and L-rhamnose residues in the ratio 1:1:1:3 was obtained. Methylation, partial acid hydrolysis and 13C-NMR spectral data for the polysaccharide led to the structure of the oligosaccharide repeating unit as a branched hexasaccharide: [formula: see text]. Numerous O-acetyl groups attached non-stoichiometrically to the residues of D-glucuronic acid, L-rhamnose and 2-acetylamino-2-deoxy-D-glucose were located with the use of 13C-NMR spectroscopy.     

Structural investigation of a heteroglycan isolated from the fruit bodies of an ectomycorrhizal fungus Astraeus hygrometricus

A polysaccharide fraction (AQS-II) has been isolated from the hot aqueous extract of the fruits of an ectomycorrhizal fungus Astraeus hygrometricus. It was found to contain 63% polysaccharide and 35% protein. The polysaccharide part contains glucose, galactose, and fucose in a 2:1:1 molar ratio. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, HMBC, and HSQC) the structure of the repeating unit of the polysaccharide was established as [structure: see text].     

Structure of a viscous exopolysaccharide produced by Lactobacillus helveticus K16

A viscous extracellular polysaccharide produced by Lactobacillus helveticus K16 has been investigated. Sugar and methylation analysis, 1H and 13C NMR spectroscopy revealed that the polysaccharide is composed of a hexasaccharide repeating unit. The sequence of sugar residues was determined by use of two-dimensional nuclear Overhauser effect spectroscopy and heteronuclear multiple bond connectivity experiments. The structure of the repeating unit of the exopolysaccharide from L. helveticus K16 is as follows: carbohydrate sequence [see text].     

Isolation and characterization of a heteroglycan from the fruits of Astraeus hygrometricus

A water-soluble polysaccharide was isolated from an alkaline extract of the fruits of the ectomycorrhizal fungus, Astraeus hygrometricus. It was found to contain D-mannose, D-glucose, and L-fucose in a molar ratio of 1:2:1. On the basis of total hydrolysis, methylation analysis, periodate oxidation, Smith degradation, and NMR studies (1H, 13C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC) the structure of the repeating unit of the polysaccharide was established as [Formula: see text]     

Structural determination and immunochemical characterization of the type V group B Streptococcus capsular polysaccharide

The type V capsular polysaccharide of group B Streptococcus has been isolated and purified, and its repeating unit structure determined. The native type V polysaccharide contains D-glucose, D-galactose, 2-acetamido-2-deoxy-D-glucose, and sialic acid in a molar ratio of 3:2:1:1. Methylation analysis and 1H NMR and 13C NMR analysis of the native type V polysaccharide and of its specifically degraded products permitted the determination of the repeating unit structure of the type V polysaccharide: [formula: see text] The type V polysaccharide has certain structural features in common with other group B streptococcal capsular polysaccharides but is antigenically distinct: no immunologic cross-reactivity was observed between type V and types Ia, Ib, II, III, or IV polysaccharides. Studies of antibody binding to the partially degraded forms of the type V polysaccharide indicated that the native epitope is complex, involving most if not all of the sugar residues of the repeating unit.