[Structure of the oligosaccharide region (core) of the lipopolysaccharides of Shigella flexneri types 2a and 5b].

The full structure of the lipopolysaccharide core of bacteria Shigella flexneri types 2a and 5b, the causative agents of bacillary dysentery (shigellosis), was established by chemical methods, high-resolution electrospray ionization mass spectrometry, and two-dimensional NMR spectroscopy. The structure of the O-antigen repeating unit and the configuration and position of the linkage between the O-antigen and the core were determined in the lipopolysaccharide of S. flexneri type 2a.

[The structure of the O-specific polysaccharide from a mutant of nitrogen-fixing rhizobacterium Azospirillum brasilense Sp245 with an altered plasmid content].

The rhizobacteria Azospirillum brasilense Sp245 produce antigenically different lipopolysaccharides LPSI and LPSII, both containing identical pentasaccharides built from D-rhamnose residues as the repeated chains of O-specific oligosaccharides (OPS). In this study, we report the structure of the OPS from A. brasilense LPSI(-)LPSII(-)-mutant Sp245.5, which spontaneously lost the p85 and p120 plasmids upon the formation of a new 300-MDa megaplasmid after the long-term storage of the bacteria in a rich medium. The repeating unit of the A. brasilense mutant Sp245.5 appeared to be a disaccharide consisting of residues of N-acetyl-D-galactosamine and N-acetyl-D-mannosaminuronic acid: [Formula: see text].

[Complete structure of the O-polysaccharide from Shigella dysenteriae type 10].

The structure of the O-specific polysaccharide from Shigella dysenteriae type 10, which has been reported previously in Bioorg. Khim. (1977, vol. 3, pp. 1219-1225), was refined: [Formula: see text].

[Bacterial antigen polysaccharides. 43. Structure of O-specific polysaccharide of Providencia alcalifaciens O46].

Acid O-specific polysaccharide containing D-glucose, D-glucuronic acid, L-fucose, and 2-acetamido-2-deoxy-D-glucose was obtained by mild acid degradation of lipopolysaccharide from Providencia alcalifaciens O46. Consideration of the data revealed the following structure of the hexasaccharide repeating unit of O-specific polysaccharide under methylation analyses along with (1)H and (13)C NMR spectroscopy, including 2D (1)H, (1)H-COSY, TOCSY-, ROESY-,(1)H, (13)C-HSQC-, and HMQC-TOCSY experiments: [Formula: see text].

[Antigenic polysaccharides of bacteria: 41. Structures of the O-specific polysaccharides of Shigella dysenteriae types 4 and 5 revised by NMR spectroscopy].

The earlier established structures of the acidic O-specific polysaccharides from two typical strains of the Shigella dysenteriae bacterium were revised using modern NMR spectroscopy techniques. In particular, the configurations of the glycosidic linkages of GlcNAc (S. dysenteriae type 4) and mannose (S. dysenteriae type 5) residues were corrected. In addition, the location of the sites of nonstoichiometric O-acetylation in S. dysenteriae type 4 was determined: the lateral fucose residue was shown to be occasionally O-acetylated; also, the position of the O-acetyl group present at the stoichiometric quantity in S. dysenteriae type 5 was corrected. The revised structures of the polysaccharides studied are shown below. The known identity of the O-specific polysaccharide structures of S. dysenteriae type 5 and Escherichia coli O58 was confirmed by 13C NMR spectroscopy and, hence, the structure of the E. coli O58 polysaccharide should be revised in the same manner. [Formula: see text].

[Structures of O-polysaccharides from two Shigella dysenteriae type 8 strains].

The structure of the O-polysaccharide (O-antigen) from Shigella dysenteriae type 8 bacteria (strain 599) was corrected using modern NMR techniques (structure 1). The revisions concerned the position of the Glc residue (in the main, but not the side, chain), the site of its substitution, and the configuration of the O-glycoside linkage of the GlcNAc residue. The S. dysenteriae type 8 bacterium (strain G1221), the second investigated representative, was found to produce another structural variant of the O-polysaccharide. It contains GlcNAc instead of the Glc residue in the main chain (structure 2). This data may lead to approval of division of S. dysenteriae type 8 into two subtypes: [Formula: see text].

[Antigenic polysaccharides of bacteria: 40. The structures of O-specific polysaccharides from Shigella dysenteriae types 3 and 9 and S. boydii type 4 revised by NMR spectroscopy].

The reported structures of O-specific polysaccharides from three standard strains of Shigella bacteria were corrected by modern NMR techniques. The revisions concerned the configuration of the O-glycoside linkage (S. dysenteriae type 3, structure 1), the positions of monosaccharide residue glycosylation and acetylation by pyruvic acid (S. dysenteriae type 9, structure 2), and the attachment position of the side monosaccharide chain (S. boydii type 4, structure 3) [struxture in text].

[The structure of the glycerophosphate-containing O-specific polysaccharide from Escherichia coli 0130].

A phosphorylated O-specific polysaccharide was obtained by mild acidic degradation of the lipopolysaccharide from the intestinal bacterium Escherichia coli 0130 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.

[Generation of vaccine strains of gram-negative bacteria with reduced adverse reactions].

The main shortcoming of the modem live and killed vaccines based on gram-negative bacterial strains is their ability to cause adverse reactions. The majority of the adverse reactions are associated with the effect of biological activity of lipopolysaccharide. The report covers the problems concerned with biogenesis of the lipid A, lipopolysaccharide structural component, responsible for its endotoxic activity, as well as with genes determining lipid A synthesis. The special attention is paid to gene-engineering technique for reduction of adverse reactions of vaccine strains that are based on the knock-out mutagenesis of genes waaM and/or waaN responsible for addition of lauroyl and myristoyl residues to the distal glucosamine unit lipid A, generating acyloxyacyl moieties.

[Experimental and theoretical conformation analysis of the O-antigenic polysaccharide from Pseudomonas cepacia strain 3181. I. Disaccharide links]. / Eksperimental'nyi i teoreticheskii konformatsionnyi analiz O-antigennogo polisakharida Pseudomonas cepacia shtamma 3181. I. Disakharidnye zven'ia.

Nuclear Overhauser effects, with preirradiation of glycoside bond anomeric protons, coupling constants 3J C3, H1' and 3J C1', H4 and linkage optical rotations A were measured for L-Rha beta 1-3-L-Rha alpha 1-OMe and L-Rha alpha 1-3-L-Rha alpha 1-OMe which are the models of the disaccharide units of the Pseudomonas cepacia polysaccharide. Theoretical conformational analysis was carried out in terms of a mechanical molecular model approximation. The spatial structures of these disaccharides as well as of D-Rha alpha 1-2-D-Rha beta 1-OMe in aqueous solutions were discussed basing on the obtained results.

[Experimental and theoretical conformation analysis of the O-antigenic polysaccharide from Pseudomonas cepacia strain 3181. II. The polysaccharide]. / Eksperimental'nyi i teoreticheskii konformatsionnyi analiz O-antigennogo polisakharida Pseudomonas cepacia shtamma 3181. II. Polisakharid.

The spatial structure of Pseudomonas cepacia 3181 polysaccharide in aqueous solution is discussed basing on the data of nuclear Overhauser effect, observed with preirradiation of anomeric protons of all 3 D-rhamnose residues in the repeat unit, and theoretical conformational analysis. It is shown that conformational states of the free disaccharides and corresponding disaccharide units of the polysaccharide are similar. All conformations of the polysaccharide may be described by one shape representing an extended structure with characteristic turns in the D-Rha alpha 1-2-D-Rha beta 1-3-D-Rha units.

[The structure of O-specific polysaccharide from Pseudomonas aeruginosa 013 containing 5,7-diacetoamido-3,5,7,9-tetradeoxy-D- glycero-L-galacto-nonulosonic acid and 2-acetamidino-2,6-dideoxy-L-galactose]. / Stroenie O-spetsificheskogo polisakharida Pseudomonas aeruginosa 013, soderzhashchego 5,7-diatsetoamido-3,5,7,9-tetradezoksi-D- glitsero-L-galakto-nonulozonovuiu kislotu i 2-atsetamidino-2,6-didezoksi-L-galaktozu.

O-Specific polysaccharide chain of P. aeruginosa 013 (Lányi) lipopolysaccharide is composed of N-acetyl-D-quinovosamine (QuiNAc), acetamidino derivative of L-fucosamine (FucNAm), and 5,7-diacetamido-3,5,7,9-tetradeoxy-D-glycero-L-galacto-nonuloso nic acid (Sug). On solvolysis with HF in methanol, the polysaccharide afforded methylglycosides of a disaccharide and a trisaccharide both containing fucosamine and ulosonic acid derivatives. Chemical transformations (alkaline hydrolysis, reductive deamination, acetylation accompanied by intramolecular acylation of acetamidino group by ulosonic acid), 1H and 13C NMR analysis and mass spectral data proved the following structure of the trisaccharide unit of the polysaccharide: -8)-beta-Sug-(1-3)-alpha-L-FucNAm-(1-3)-alpha-D-QuiNAc -(1-

[Antigenic polysaccharides of bacteria. 16. The structure of O-specific polysaccharide chain of Pseudomonas aeruginosa 025 (Wokatsch) lipopolysaccharide]. / Antigennye polisakharidy bakterii. 16. Struktura O-spetsificheskoi polisakharidnoi tsepi lipopolisakharida Pseudomonas aeruginosa 025 (Wokatsch).

O-Specific polysaccharide built up of trisaccharide repeating units containing 3-acetamidino-2-acetamido-2,3-dideoxy-D-mannuronic acid (ManNAcAmA), 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid (Man(NAc)2A), N-acetyl-D-fucosamine (FucNAc), and O-acetyl group was obtained on mild acid hydrolysis of P. aeruginosa O25 (Wokatsch classification) lipopolysaccharide. Basing on de-O-acetylation of polysaccharide with aqueous triethylamine accompanied by hydrolysis of acetamidino group to acetamido group, as well as on the 1H and 13C NMR data, the following structure of the repeating unit of the polysaccharide was established: (Formula: see text) P. aeruginosa O25 polysaccharide has the same carbohydrate skeleton as that of P. aeruginosa O3a,b (Lányi classification) and differs from the latter only by the presence of the O-acetyl group at position 4 of N-acetylfucosamine.

[Identification of 3-acetamidino-2-acetamido-2,3-dideoxy-L-guluronic acid in lipopolysaccharide from Pseudomonas aeruginosa immunotype 7]. / Identifikatsiia 3-atsetamidino-2-atsetamido-2, 3-didezoksi-L-guluronovoi kisloty v sostave lipopolisakharida Pseudomonas aeruginosa, immunotip 7.

O-Specific polysaccharide chain of Pseudomonas aeruginosa immunotype 7 lipopolysaccharide is composed of 3-acetamidino-2-acetamido-2,3-dideoxy-L-guluronic acid (GulNAcAmA), 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid (ManN2Ac2A), and N-acetyl-D-fucosamine (FucNAc). On solvolysis with anhydrous hydrogen fluoride, the polysaccharide afforded a trisaccharide containing all its components. Borohydride reduction of the trisaccharide in boric acid solution resulted in conversion of reducing fucosamine into fucosaminitol, whereas in water the reduction was accompanied by reductive deamination of acetamidino function into ethylamino group. On hydrolysis with aqueous triethylamine, acetamidino group gave acetamido group. Analysis of the trisaccharides thus obtained by 1H NMR spectroscopy (including nuclear Overhauser effect), 13C NMR spectroscopy, and fast-atom bombardment mass spectrometry allowed the determination of the structure of the unusual uronic acid derivative and the following structure of the polysaccharide repeating unit: -4)-alpha-L-GulNAcAmA-(1-4)-beta-D-ManN2Ac2A-(1-3)-alpha-D-+ ++FucNAc-(1-.

[The structure of O-specific polysaccharide of Pseudomonas aeruginosa immunotype 3; revision of the structure of acetoamidine derivative of 2,3-diamino-2,3-dideoxy-D-mannuronic acid]. / Stroenie O-spetsificheskogo polisakharida Pseudomonas aeruginosa, immunotip 3; peresmotr struktury atsetamidinovogo proizvodnogo 2,3-diamino-2,3-didezoksi-D-mannuronovoi kisloty.

O-Specific side chain of P. aeruginosa immunotype 3 lipopolysaccharide is composed of N-acetyl-D-fucosamine (FucNAc), 2,3-diacetamido-2,3-dideoxy-L-guluronic acid (GulN2Ac2A) and 3-acetamidino = 2-acetamido = 2,3 = dideoxy = D-mannuronic acid (ManNAcAmA). The latter sugar is identified on the basis of solvolysis with anhydrous hydrogen fluoride, 13C NMR spectroscopy and fast-atom bombardment mass spectrometry analysis, as well as of reactions of acetamidino function (alkaline hydrolysis to acetamido group and reductive deamination to ethylamino group). Earlier, in the course of investigation of P. aeruginosa O3 lipopolysaccharides, the structure of 1-methyl-2-imidazoline was erroneously ascribed to the acetamidino group. The following structure was established for the repeating unit of immunotype 3 polysaccharide which is identical to P. aeruginosa O3(a),3c polysaccharide: ----4)-beta-D-ManNAcAmA-(1----4)-alpha-L-GulN2Ac2A-(1----3)- beta-D-FucNac-(1----.

[Antigenic polysaccharides of bacteria. 19. The structure of the O-specific polysaccharide chain of Alcaligenes faecalis lipopolysaccharide]. / Antigennye polisakharidy bakterii. 19. Stroenie O-spetsificheskoi polisakharidnoi tsepi lipopolisakharida Alcaligenes faecalis.

On mild acid hydrolysis of Alcaligenes faecalis lipopolysaccharide, the O-specific polysaccharide containing D-rhamnose and D-xylose in the 3:2 ratio was obtained. Solvolysis of the polysaccharide with hydrogen fluoride in methanol resulted in methyl glycoside of a branched tetrasaccharide including three rhamnose and one xylose residues. Smith degradation of the polysaccharide led to the glycoside of disaccharide composed of two rhamnose residues and glycerol. On the basis of identification of the oligosaccharide fragments, methylation, 1H and 13C NMR analysis (including nuclear Overhauser effect data), it was established that the polysaccharide linear chain is a rhamnan, both xylose residues being attached to one of the rhamnose residues as two branches. The repeating unit of the polysaccharide has the following structure: (Formula: see text).

[Antigenic polysaccharides of bacteria. 18. Structure of O-specific polysaccharide chains of Pseudomonas aeruginosa 05 (Lányi) lipopolysaccharide]. / Antigennye polisakharidy bakterii. 18. Struktura O-spetsificheskikh polisakharidnykh tsepei lipopolisakharidov Pseudomonas aeruginosa 05 (Lani).

Polysaccharide chains of P. aeruginosa O5a, b, c, O5a, b, d and O5a, d (Lányi classification) lipopolysaccharides contain D-xylose, N-acetyl-D-fucosamine (FucNAc) and a derivative of 5,7-diamino-3,5,7,9-tetradeoxy-L-glycero-L-manno-nonulosonic acid (pseudaminic acid, PseN2) carrying acetyl or (R)-3-hydroxybutyryl (Hb) and formyl (Fm) groups as N-acyl substituents. Degradation of the lipopolysaccharides with dilute acetic acid caused depolymerisation of the polysaccharide chains as a result of cleavage of glycosidic linkage of pseudaminic acid to give trisaccharides representing chemical repeating units of the polysaccharides. Basing on analysis of the trisaccharides using 1H and 13C NMR spectroscopy and mass-spectrometry, the following structures of the polysaccharide chains were established: (Formula: see text). O5a, d polysaccharide is identical to P. aeruginosa immunotype 6 O-specific polysaccharide.

[Structure of O-specific polysaccharide chains of Pseudomonas aeruginosa II (Sandwick) and V (Verder-Evans) lipopolysaccharides containing N-acetyl-D-galactosaminuronic acid]. / Struktura O-spetsificheskikh polisakharidnykh tsepei lipopolisakharidov Pseudomonas aeruginosa II (Séndvik) i V (Verder-Evans), soderzhashchikh N-atsetil-D-galaktozaminuronovuiu kislotu.

Acidic polysaccharides were isolated from the Pseudomonas aeruginosa II (Sandvik) and V (Verder-Evans) lipopolysaccharides on mild acid hydrolysis followed by gel filtration on Sephadex G-50. The Sandvik II polysaccharide consists of 2-acetamido-2-deoxy-D-galacturonic acid, 2-acetamido-2,6-dideoxy-D-glucose, and L-rhamnose in the ratio 1:1:2. The Verder-Evans V polysaccharide contained the same monosaccharides and, in addition, a D-glucose residue. On the basis of 13C NMR data, methylation analysis, Smith degradation and solvolysis with hydrogen fluoride, the following structures were determined for the repeating units of the polysaccharides: (Formula: see text).

[Bacterial antigenic polysaccharides. 20. The structure of the O-specific polysaccharide chain of Pseudomonas aeruginosa O(3a),3d,3f (Lányi) lipopolysaccharide]. / Antigennye polisakharidy bakterii. 20. Struktura O-spetsificheskoi polisakharidnoi tsepi lipopolisakharida Pseudomonas aeruginosa O(3a),3d,3f (Lani).

Mild acid degradation of lipopolysaccharide from Pseudomonas aeruginosa O(3a), 3d, 3f (Lányi classification) afforded O-specific polysaccharide containing N-acetyl-D-fucosamine, 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid, 3-acetamidino-2-acetamido-2,3-dideoxy-L-guluronic and D-mannuronic acid as well as O-acetyl groups. On the basis of O-deacetylation, selective cleavage with anhydrous fluoride, chemical transformation of the oligosaccharides obtained (hydrolysis or reductive deamination of the acetamidino group into acetamido or ethylamino group, respectively) and analysis by 13C NMR spectroscopy, it was concluded that the polysaccharide is built up mainly by trisaccharide repeating units of types A and B in the ratio approximately 2:1: (Formula: see text). The units of both types most probably enter the same polymeric chain. If so, such a hybrid structure can be accounted for by incompleteness of epimerization at C5 of the acetamidino derivative of mannuronic acid at the polymer level in the course of biosynthesis of this polysaccharide.

[Antigenic polysaccharides of bacteria. 22. Structure of the O-specific polysaccharide chain of Proteus hauseri lipopolysaccharide]. / Antigennye polisakharidy bakterii. 22. Struktura O-spetsificheskoi polisakharidnoi tsepi lipopolisakharida Proteus hauseri.

The following structure of the repeating unit of the Proteus hauseri O-specific polysaccharide was established on the basis of monosaccharide composition and 13C NMR data of the polysaccharide and products of its Smith degradation and partial cleavage with hydrogen fluoride: (Formula: see text).