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A S Shashkov

Publications and source records attributed to A S Shashkov.

At least 235 records · Page 13Linked to original sources
PubMed1991

Structural features of cell wall teichoic acid and peptidoglycan of Actinomadura cremea INA 292.

The teichoic acid from the cell wall of Actinomadura cremea INA 292 has an unusual structure, being a poly(galactosylglycerol phosphate) chain with glycerol phosphate groups. Monomeric units of 1-O, beta-D-galactopyranosylglycerol monophosphate are joined in the polymer by phosphodiester links involving the glycerol C3 and the galactose C6 atoms. Approximately every second galactosyl substituent has a glycerol phosphate residue at its C3 atom. The teichoic acid structure was established by chemical analysis and 13C-NMR spectroscopy. There also is a peptidoglycan belonging to the A1 gamma type: as well as meso-2,6-diaminopimelic acid it contains small amounts of the LL form and glycine.

Actinomycetales↗
PubMed1991

1,3-poly(glycerol phosphate) chains in the cell wall of Streptomyces rutgersensis var. castelarense VKM Ac-238.

The cell wall of Streptomyces rutgersensis var. castelarense contains structurally different chains of 1,3-type glycerol teichoic acid. Part of the molecules consisting of 20-25 monomers, carry on every third glycerol phosphate unit (at C-2) alpha-glucosamine residues, only half of which are N-acetylated. There are chains with O-lysine groups, and free nonsubstituted ones. The chain structure has been ascertained by chemical analysis and 13C- and 1H-NMR spectroscopy.

Carbohydrate Sequence↗
PubMed1991

The structure of the O-specific polysaccharide chain of Proteus penneri strain 16 lipopolysaccharide.

O-Specific polysaccharide was obtained by mild acid degradation of Proteus penneri strain 16 lipopolysaccharide and found to contain D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and 3,6-dideoxy-3-[(R)-3-hydroxybutyramido]- D-galactose in the ratio of 2:1:1:1 as well as a small proportion of O-acetyl groups. On the basis of one-dimensional 1H-NMR13C-NMR and NOE spectroscopy, two-dimensional homonuclear-shift-correlated spectroscopy with one-step and two-step relayed coherence transfer and heteronuclear 1H/13C NMR shift-correlated spectroscopy, it was concluded that the O-specific polysaccharide of P. penneri strain 16 has the following structure: (formula; see text) This structure was confirmed by methylation analysis and structural analysis of a linear tetrasaccharide fragment prepared by cleavage of the polysaccharide with anhydrous hydrogen fluoride followed by conversion of the alpha-tetrosyl fluoride obtained in to the corresponding free oligosaccharide and alditol. O-Acetyl groups were tentatively located at position 3 of the glucuronic acid residue and at position 4 of the 6-substituted glucose residue, the degree of acetylation being less than 20% of the total. Cross-reactions of P. penneri strain 16 anti-(O-specific polysaccharide) antiserum with lipopolysaccharides from several other Proteus strains and the role of 3,6-dideoxy-3-(R)-3-hydroxybutyramido-D-galactose in the serological specificity of P. penneri strain 16 are discussed.

Carbohydrate Conformation↗
PubMed1991

Lysodektose--a new trisaccharide from Micrococcus lysodeikticus which is transformed into an aminoxyl free radical with the loss of an electron.

A new trisaccharide 6-0-(2-deoxy-2-(N-methyl)-hydroxylamino-beta-D- glucopyranosyl)-alpha,alpha-trehalose named lysodektose has been isolated from Micrococcus lysodeikticus. In oxygenated solutions or in the presence of K3 Fe (CN)6 lysodektose is transformed into a long lived free radical. Spin trapping data are presented and functions are suggested for the substance.

Carbohydrate Sequence↗
PubMed1991

[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.

Antigens, Bacterial↗
PubMed1991

[Structure of the O-specific polysaccharide chain of Yersinia aldovae lipopolysaccharide].

O-specific polysaccharide has been isolated on mild hydrolysis of lipopolysaccharide from Yersinia aldovae and shown to consist of 2-acetamido-2-deoxy-D-glucose, D-glucose, 2-acetamido-2-deoxy-D-galactose, and 3,6-dideoxy-3- [(R)-3-hydroxybutyramido]-D-galactose in molar ratio 2:2:1:1. Acid hydrolysis, methylation, solvolysis with anhydrous hydrogen fluoride, 1H and 13C NMR studies indicated the polysaccharide to be composed of hexasaccharide repeating units of the following structure: [formula see text].

Carbohydrate Conformation↗
PubMed1991

[Structure of the antineoplastic antibiotic variamycin].

The results of the structural study of antitumor antibiotic variamycin and its peracetyl derivative by 1H-and 13C-NMR spectroscopy are reported. Structures of carbohydrate chains of the antibiotics molecule are revised. Variamycin is shown to be 2-[beta-cymmarosyl(1-3)-beta-oliosyl (1-3)-beta-olivosyl]-6-[beta-olivosyl (1-3)-beta-olivosyl] chromomycinone.

Antibiotics, Antineoplastic↗
PubMed1990

The structure of the biological repeating unit of the O-antigen of Hafnia alvei O39.

On mild acid-catalysed degradation of the lipopolysaccharide from Hafnia alvei O39 followed by gel filtration of Sephadex G-50, the O-specific polysaccharide and three oligosaccharides were obtained, which represent the core substituted with 0-2 O-antigen repeating-units. On the basis of sugar and methylation analyses, 13C-n.m.r. data, solvolysis of the polysaccharide with anhydrous hydrogen fluoride, and computer-assisted 13C-n.m.r. analysis of the Smith-degraded polysaccharide, it was concluded that the biological repeating unit of the O39 antigen was Formula; see text

Antigens, Bacterial↗
PubMed1990

The structure of Proteus mirabilis O3 O-specific polysaccharide containing N-(2-hydroxyethyl)-D-alanine.

O-Specific polysaccharide was obtained by mild acid degradation of Proteus mirabilis O3 lipopolysaccharide. The polysaccharide was dephosphorylated with 48% HF to give a linear polysaccharide and an amino acid, N-(2-hydroxyethyl)-D-alanine. The structure of the polysaccharide was determined by methylation, Smith degradation and computer-assisted analysis of the 13C-NMR spectra of original and dephosphorylated polymers and oligomers. The structure of the amino acid was investigated by using 1H and 13C-NMR spectroscopy and mass spectrometry (applied to the acetylated methyl ester derivative). Its absolute configuration was established by comparison of the optical rotation value and CD spectrum of the natural and synthetic product. On the basis of the data obtained, it was concluded that the repeating unit of P. mirabilis O3 O-specific polysaccharide has the following structure: (formula; see text) Removal of the amino acid phosphate substituent significantly decreased serological activity of the O-specific polysaccharide, thus showing the immunodominant role of this group. Serological cross-reactions between P. mirabilis O3 and O27 were demonstrated and tentatively substantiated.

Alanine↗
PubMed1990

[Antigenic polysaccharides of bacteria. 37. Structure of the polysaccharide chain of Pseudomonas syringae pv.tabaci (serogroup VII) lipopolysaccharide].

The structure of the O-specific polysaccharide chain of Pseudomonas syringae pv. tabaci strain 223 (serogroup VII) lipopolysaccharide was established on the basis of one- and two-dimensional 1H NMR analysis, 13C NMR analysis and calculation of optical rotation. The structure determined by the non-destructive way was confirmed by acid hydrolysis and methylation. (Sequence: see text). O-Antigen of the strain studied is similar in structure and serological properties to O-antigens of Pseudomonas syringae strains belonging to serogroup I.

Antigens, Bacterial↗
PubMed1990

[The structure of a repetitive unit of the glycerolphosphate- containing O-specific polysaccharide chain from Yersinia kristensenii strain 103 (0:12,26) lipopolysaccharide].

Mild acid hydrolysis of the lipopolysaccharide from Yersinia kristensenii strain 103 (0:12.26) afforded teichoic acid-like polysaccharide. From the results of methylation, dephosphorylation, partial Smyth degradation, and 13C and 31P NMR data the structure of the repeating unit of the polysaccharide was deduced as follows: [formula: see text] The structure was confirmed by complete interpretation of polysaccharide 13C NMR spectrum.

Antigens, Bacterial↗
PubMed1989

Nuclear Overhauser effects and conformations of branched trisaccharide methyl beta-glycosides that contain a 3,4-disubstituted galactose residue.

N.O.e. data after pre-irradiation of the anomeric protons and the 3JC,H values associated with the glycosidic linkages for a series of methyl beta-glycosides of trisaccharides that contain 3,4-disubstituted galactose residues have been measured. On the basis of the experimental results and theoretical calculations, it was shown that one preferred conformer (less than 90%) was present for each trisaccharide derivative.

Carbohydrate Conformation↗