Raisa P. Gorshkova

Structure of a phosphorylated polysaccharide from Shewanella putrefaciens strain S29

A phosphorylated polysaccharide was isolated from the aqueous layer of the phenol-water extract of a non-halophilic bacterium Shewanella putrefaciens strain S29. The glycosyl phosphate linkage in the polysaccharide was split under mild acid conditions to give, after borohydride reduction, a phosphorylated oligosaccharide-alditol. On the basis of sugar analysis and 1H, 13C and 31P NMR spectroscopy, including 2D COSY, relayed COSY, rotating-frame NOE spectroscopy (ROESY), heteronuclear 13C,1H COSY, and H-detected heteronuclear 1H,31P multiple-quantum coherence (HMQC), it was concluded that the polysaccharide is built up of tetrasaccharide-phosphate repeating units having the following structure: [sequence: see text] where QuiNAc and Qui4NAc are 2-acetamido-2,6-dideoxyglucose and 4-acetamido-4,6-dideoxyglucose, respectively.

Structure of the capsular polysaccharide from Alteromonas sp. CMM 155

Capsular polysaccharide (CPS) was obtained by water-saline extraction of the Alteromonas sp. CMM 155. On the basis of solvolysis with anhydrous HF and 1H- and 13C-NMR spectral data, including NOE experiments, it was concluded that the capsular polysaccharide had the following structure containing novel N-acyl-amino sugar and bacillosamine residues: --> 3)-alpha-D-GalpNAc-(1 --> 4)-alpha-L-GalApNAc(1 --> 3)- alpha-D-QuipNAc4NAc-(1 --> 3)-beta-D-Quip4NAlaAc-(1 -->

Structure of an acidic polysaccharide from the marine bacterium Pseudoalteromonas flavipulchra NCIMB 2033T

An acidic polysaccharide was isolated from Pseudoalteromonas flavipulchra type strain NCIMB 2033(T) and found to consist of 6-deoxy-L-talose (L-6dTal), D-galactose and 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo). The identities of the monosaccharides were ascertained by sugar analysis and 1D 1H and 13C NMR spectroscopy in conjunction with 2D COSY, TOCSY, ROESY and 1H, 13C HMQC experiments, which enabled determination of the following structure of the trisaccharide repeating unit of the polysaccharide:-->3)-alpha-L-6dTalp4Ac-(1-->3)-beta-D-Galp-(1-->7)-alpha-Kdop-(2-->.

Structure of the acidic polysaccharide chain of the lipopolysaccharide of Shewanella alga 48055

A lipopolysaccharide (LPS) with an acidic polysaccharide chain was isolated from the bacterium Shewanella alga strain 48055 and cleaved selectively at the glycosidic linkage of N-acetylneuraminic acid to give a tetrasaccharide. Studies of the tetrasaccharide and the O-deacylated LPS by 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, rotating-frame NOE spectroscopy (ROESY), and H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC) experiments, revealed the following structure of the polysaccharide repeating unit: -->3)-beta-D-GalpA6GroN-(1-->3)-beta-D-GlcpNAc-(1-->3)-alpha-D- GalpA6GroN- (1-->4)-alpha-Neup5Ac-(2--> where GroN is an amidically linked residue of 2-amino-1,3-propanediol (2-amino-2-deoxyglycerol). A similar structure, but with 2-acetamido-2,6-dideoxy-D-glucose instead of 2-acetamido-2-deoxy-D-glucose, has been reported previously for the polysaccharide chain of a non-O1 Vibrio cholerae H11 LPS [E. V. Vinogradov, O. Holst, J.E. Thomas-Oates, K.W. Broady, and H. Brade, Eur. J. Biochem., 210 (1992) 491-498].

Structure of the capsular polysaccharide from Alteromonas nigrifaciens IAM 13010T containing 2-acetamido-2,6-dideoxy-L-talose and 3-deoxy-D-manno-octulosonic acid.

A capsular polysaccharide was obtained from Alteromonas nigrifaciens IAM 13010T by saline extraction. On the basis of 1H and 13C NMR spectroscopy, including one-dimensional (1D) NOE spectroscopy, 2D rotating-frame NOE spectroscopy (ROESY), and 1H-detected heteronuclear 1H,13C multiple-quantum coherence (HMQC), it was concluded that the polysaccharide contained inter alia an acidic sugar, 3-deoxy-D-manno-octulosonic acid (Kdo), and a rare amino sugar, 2-acetamido-2,6-dideoxy-L-talose (L-6dTalNAc, N-acetylpneumosamine), and has a pentasaccharide repeating unit of the following structure: [equation: see text]

Structural studies of O-specific polysaccharide chains of the lipopolysaccharide from Yersinia enterocolitica serovar O:10

Lipopolysaccharide (LPS) was isolated from Yersinia enterocolitica serovars O:10 and O:10 KL and the structural pattern of O-specific sugar chains elucidated. The rhamnan and L-xylulose (L-threo-pent-2-ulose) as constituents of the O-specific polysaccharide were obtained by autohydrolysis of the LPS. The rhamnan was shown to be a linear, alpha-(1-->3)-linked polysaccharide in the D configuration. L-Xylulose was purified using paper chromatography on a preparative scale and its structure was confirmed by 13C NMR spectroscopy. Using sugar and methylation analysis and 13C NMR spectroscopy of the LPS and the rhamnan, the structural features of the disaccharide repeating unit of the Y. enterocolitica O:10 O-specific polysaccharide were elucidated as: [formula: see text]

Structure of the O-specific polysaccharide of the lipopolysaccharide from Yersinia kristensenii O:25.35

Mild hydrolysis of the lipopolysaccharide (LPS) from Yersinia kristensenii serovar O:25.35 with acid afforded the O-specific polysaccharide (PS) which contained D-glucose, D-galactose, 2-acetamido-2,6-dideoxy-L-galactose, 2-acetamido-2-deoxy-D-glucose, glycerol, and phosphate in the ratios 3:1:1:1:1. On the basis of 31P and 13C NMR spectroscopy, hydrolysis, methylation studies, Smith degradation, and dephosphorylation, the repeating unit of PS was shown to have the following structure. [formula: see text]

Against the rules: A marine bacterium, Loktanella rosea, possesses a unique lipopolysaccharide

Bacteria are an inimitable source of new glyco-structures potentially useful in medicinal and environmental chemistry. Lipopolysaccharides (LPS; endotoxins) are the major components of the outer membrane of Gram-negative bacteria; being exposed toward the external environment they can undergo structural changes and thus, they often possess peculiar chemical features that allow them to thrive in harsh chemical and physical environments. Marine bacteria have evolved and adapted over millions of years in order to succeed in different environments, finding a niche for their survival characterized by severe physical or chemical parameters. The present work focuses on the structural investigation of the LPS from Loktanella rosea, a marine Gram-negative bacterium. Through chemical analysis, 2D nuclear magnetic resonance and matrix-assisted laser desorption ionization mass spectrometry investigations, a unique LPS carbohydrate backbone has been defined. The lipid A skeleton consists of a trisaccharide backbone lacking the typical phosphate groups and is characterized by two beta-glucosamines and an alpha-galacturonic acid. The core region is built up of three ulosonic acids, with two 3-deoxy-d-manno-oct-2-ulopyranosonic acid residues, one of which is carrying a neuraminic acid. This carbohydrate structure is an exceptional variation from the typical architectural skeleton of endotoxins which consequently implies a very different biosynthesis.

Structure of O-Specific Polysaccharide from Pseudoalteromonas nigrifaciens Strain KMM 161

AbstractOn mild acid degradation of the lipopolysaccharide of the marine microorganism Pseudoalteromonas nigrifaciens KMM 161 an O-specific polysaccharide containing D-galactose, 2-acetamido-2-deoxy-D-glucose, 3,6-dideoxy-3-(4-hydroxybutyramido)-D-galactose, and 2-acetamido-2-deoxy-L-guluronic acid residues was obtained. From the results of Smith degradation, O-deacetylation of the polysaccharide, and NMR spectroscopy the following structure of the tetrasaccharide repeating unit of the O-specific polysaccharide was established: