首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Anomeric methyl 3-O-(D-mannopyranosyl- and L-rhamnopyranosyl)-beta-D-talopyranosides were synthesised by the stereoselective 1,2-cis- and 1,2-trans manno- and rhamnosylation of methyl 2,4,6-tri-O-acetyl-beta-D-talopyranoside, which has been prepared from methyl beta-D-galactopyranoside by a synthetic scheme including conversion of the C2 configuration. From 13C-NMR spectra of the disaccharides obtained the spectral alpha- and beta-effects of O3-glycosylation of talopyranose were determined.  相似文献   

2.
The Pseudomonas holci 8300 lipopolysaccharide has an O-specific polysaccharide chain, containing L-rhamnose and 3-acetamido-3-deoxy-D-fucose residues in the ratio 4:1. On the basis of methylation, Smith degradation, and 1H- and 13C-NMR spectroscopy data, it was concluded that the polysaccharide is built up of pentasaccharide units of A and B types in the ratio approximately 2.5:1. In some stretches of the polysaccharide, minor B units form rather long chains, and in the others they alternate with predominant A units. (formula; see text)  相似文献   

3.
Water extract and salt-EDTA extract of Pseudomonas syringae, pv. atrofaciens cells were fractionated by ultracentrifugation with following salting out of ultracentrifugal supernatant by ammonium sulphate at 55% saturation (pH 4.5). The composition and distribution of LPS molecular forms were studied in the obtained fractions by means of electrophoresis in 10% polyacrylamide gel with 1% sodium dodecylsulphate when staining gels by silver nitrate and cumassi. It is shown that ultracentrifugal supernatant and a sediment as well as sulphate sediment contain S-LPS and R-LPS. SR-LPS is not differentiated. Sulphate supernatant does not contain the determinable amount of S-LPS but it is enriched by the proteins with molecular weights of 65-15 kDalton. S-LPS is localized in the gel area which corresponds to mobilities of polypeptides with molecular weights 130-45 KDalton and the number of monomeric links in O-specific chains of its molecules reaches 25-30. R-LPS migrates under electrophoresis in gel to the mobility zone of polypeptides with molecular weights 14.5-16 kDalton.  相似文献   

4.
Lipopolysaccharides from Pseudomonas syringae pvs atrofaciens 2399. phaseolicola 120a and Pseudomonas holci 8299, belonging to serogroup VI. possess an identical polysaccharide chain composed of D-rhamnose and D-fucose. On the hasis of methylation, partial acid hydrolysis, 1H- and 13C-NMR data, it was concluded that the backbone of the polysaccharide represents D-rhamnan built up of tetrasaccharide repeating units and alpha-D-fucofuranose residues are attached to the backbone as the monosaccharide branches. The following structure of the repeating unit is established: (Formula: see text).  相似文献   

5.
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.  相似文献   

6.
On mild acid degradation of a lipopolysaccharide from Pseudomonas cepacia strain IMV 4137, a serologically active O-specific polysaccharide was obtained and shown to contain L-rhamnose and D-galactose. According to 1H- and 13C-NMR data as well as methylation analysis, the polysaccharide is made up of disaccharide repeating units of the following structure:----2)-alpha-L-Rhap-(1----4)-alpha-D-Galp-(1----.  相似文献   

7.
The O-specific polysaccharide of Salmonella arizonae O59 (Arizona 19) is composed of D-galactose, N-acetyl-D-glucosamine, and N-acetyl-L-fucosamine (FucNAc, 2-acetamido-2,6-dideoxy-L-galactose) in the ratio 1:1:1. The computerized calculation of the 13C NMR spectrum of the polysaccharide, based on the monosaccharide composition, spectra of the free monosaccharides and glycosydation effects, together with the chemical analysis (methylation and Smith degradation) showed that the polysaccharide is built up of trisaccharide repeating units of the following structure: ----3)-alpha-L-FucNAcp(1----3)-beta-D-GlcNAcp-(1----2)-beta- D-Galp-1(----. The molecular basis of serological interrelations between S. arizonae O59 and Pseudomonas aeruginosa O7 (Lányi) is discussed.  相似文献   

8.
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----.  相似文献   

9.
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.  相似文献   

10.
The O-specific polysaccharide chain of the Salmonella arizonae O63 lipopolysaccharide is composed of D-glucose, D-galactose, N-acetyl-D-galactosamine, and 3-acetamido-3,6-dideoxy-D-galactose (Fuc3NAc) residues in the ratio 1:1:2:1. On the basis of methylation analysis and calculations of 13C-NMR-spectra of the polysaccharide and of the product of its selective cleavage with anhydrous hydrogen fluoride, the linear polymer lacking 3-acetamido-3,6-dideoxygalactose, it was concluded that the polysaccharide has the following structure: (Formula: see text).  相似文献   

11.
The lipopolysaccharide from Pseudomonas aeruginosa O12 (Lányi classification) gave on mild acid hydrolysis an O-specific polysaccharide built of D-ribose and N-acetyl-D-galactosamine. The disaccharide structure----4)-alpha-GalNAcp-(1----2)-beta-Ribf-(1----for the repeating unit of the polysaccharide was established by nondestructive way involving full interpretation of its 1H- and 13C-NMR-spectra, using homonuclear and selective heteronuclear 13C[1H] double resonances.  相似文献   

12.
Lipopolysaccharides (LPS) of the representatives of strains of serogroup VI Pseudomonas syringae (P. syringae pv. atrofaciens 2399, pv. phaseolicola 120a, 7842 and P. holci 8299) possessing virulence and confinement to the host-plant are characterized by high serological activity in direct and cross reactions of the binary diffusion in agar, immunoelectrophoresis, passive hemagglutination and inhibition of passive hemagglutination. A supernatant and a sediment obtained after ultracentrifugation of LPS preparations possessed O-antigenic activity. O-specific polysaccharide (PS) is serologically less active than the LPS preparations. Problems of the intergroup and intragroup serological affinity in connection with the structure of O-specific PS. It is proved that the basic chain of O-specific polysaccharide (D-rhamnane) plays definite (but not a single) part in displaying antigenic properties of the whole LPS macromolecule.  相似文献   

13.
It was shown by the method of electron microscopy that cells of virulent strain Pseudomonas syringae rv. atrofaciens 4394 have extracellular, probably, polysaccharide glycocalix. It consists of acid components giving positive cytochemical reaction with ruthenium red, a specific reagent to polyanions.  相似文献   

14.
The O-specific polysaccharide chain of the Pseudomonas aurantiaca IMV 31 lipopolysaccharide contains N-acetyl-L-fucosamine (FucNAc) and di-N-acetyl-D-bacillosamine (2,4-diacetamido-2,4,6-trideoxyglucose, Bac(NAc)2) in the ratio 2:1. On the basis of methylation, solvolysis with anhydrous hydrogen fluoride, and computer-assisted analysis of 13C-NMR spectrum, it was concluded that the trisaccharide repeating unit of the polysaccharide possesses the following structure: structure: ----3)-beta-D-Bac(NAc)2-(1----3)-alpha-L-FucNAc-(1----3)-alpha-L- FucNAc-(1----.  相似文献   

15.
On mild acid degradation of the Pseudomonas cepacia serotype 6 lipopolysaccharide, the O-specific polysaccharide was obtained, which contains D-mannose and D-galactose residues in the ratio approximately 1:1, as well as O-acetyl groups. On the basis of 1H and 13C NMR analysis, calculation of specific optical rotation, and methylation, it was concluded that the polysaccharide possesses the following structure: (formula; see text) Regularities in glycosidation effects in 13C NMR spectra of 1,3-linked disaccharides containing furanoside residues are discussed.  相似文献   

16.
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)  相似文献   

17.
Serologically active O-specific polysaccharides were obtained on mild acid hydrolysis of lipopolysaccharides from Pseudomonas cerasi 467 and Pseudomonas syringae pv. syringae strains 218 and P-55. On the basis of 1H- and 13C-NMR analysis, it was concluded that the P. cerasi polysaccharide has the following structure: ----3)-alpha-D-Rhap-(1----3)-alpha-D-Rhap-(1----2)-alpha-D-+ ++Rhap-(1---- which is identical to that of O-specific polysaccharide from P. syringae pv. morsprunorum C28 (Smith A. R. W. et al. Eur. J. Biochem., 1985, V. 149, No 1, p. 73-78). The polysaccharides from P. syringae pv. syringae strains possess the same backbone but differ by the presence of D-fucose as monosaccharide branches. Methylation and 1H- and 13C-NMR analysis revealed the following structure of these polysaccharides: (Formula: see text). The degree of substitution of the backbone trisaccharide units by the fucofuranose residues is about 35% for the strain 218 and about 85% for the strain P-55.  相似文献   

18.
An O-specific polysaccharide, containing 6-deoxy-L-talose (6dTal), N-acetyl-D-fucosamine (FucNAc), 3-amino-3,6-dideoxy-D-glucose with an unidentified N-acyl substituent (Qui3NR), and O-acetyl groups, was obtained on mild acid degradation of a Pseudomonas fluorescens strain 361 lipopolysaccharide. On the basis of O-deacetylation, acid hydrolysis, methylation, selective solvolysis with anhydrous hydrogen fluoride, and 13C NMR analysis, the polysaccharide is built up of trisaccharide repeating units of the following structure: (Formula: see text).  相似文献   

19.
The sidechain of the lipopolysaccharide from the phytopathogen Pseudomonas syringae pv. morsprunorum C28 was shown to be composed of D-rhamnose. Using 1H and 13C-NMR spectroscopy, methylation analysis, Smith degradation and optical rotation data, the repeat unit was found to have the structure: ----3)-D-Rhap-(alpha 1----3)-D-Rhap-(alpha 1----2)-D-Rhap-(alpha 1---- and a degree of polymerization of approximately 70. Attention is drawn to the possible prevalence of D-6-deoxyhexoses in the lipopolysaccharides of plant pathogenic bacteria.  相似文献   

20.
The paper deals with a comparative analysis of the serological and ecological properties of Pseudomonas syringae pv. atrofaciens strains from the collections of microbial cultures at the Malkov Institute for Plant Genetic Resources and Zabolotny Institute of Microbiology and Virology. All of the strains from the Bulgarian collection, except for one, fall into five serogroups (II through VI) of the classification system of Pastushenko and Simonovich. The P. syringae pv. atrofaciens strains isolated from Bulgarian and Ukrainian wheats belong mainly to serogroups II and IV, respectively. The strains that were isolated from rye plants belong to serogroup I. The strains isolated from sorghum and Sudan grass belong to serogroups II, IV, and VI. Serogroup III includes the P. syringae pv. atrofaciens strains that were isolated from cereals in the United Kingdom but not in Ukraine.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号