ABSTRACT
Two different polysaccharides were obtained by mild acid degradation of the lipopolysaccharide of Rahnella aquatilis 33071(T). These were studied by sugar and methylation analyses along with 1D and 2D (1)H and (13)C NMR spectroscopy. The following structures were established for the polysaccharides: -->4)-alpha-D-Rhap-(1-->3)-alpha-D-Rhap-(1-->3)beta-D-Galp-(1-->3)-alpha-D-Manp-(1-->2)-alpha-D-Manp-(1--> beta-D-Glcp-(1-->3)-alpha-D-galp-(1-->4)-alpha-D-GlcpA-(1-->2). The former structure is new, whereas the latter has been reported earlier as the structure of the O-specific polysaccharide of R. aquatilis 95 U003 (Zdorovenko, E. L.; Varbanets, L. D.; Zatonsky, G. V.; Kachala, V. V.; Zdorovenko, G. M.; Shashkov, A. S.; Knirel, Y. A. Carbohydr. Res.2008, 343, 2494-2497).
Subject(s)
Lipopolysaccharides/chemistry , Polysaccharides/chemistry , Polysaccharides/isolation & purification , Rahnella/chemistry , Carbohydrate Sequence , Magnetic Resonance Spectroscopy , Molecular Sequence DataABSTRACT
The O-polysaccharide of Rahnella aquatilis 95 U003 was obtained by mild acid degradation of the lipopolysaccharide and studied by sugar and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy, including 2D (1)H,(1)H COSY, TOCSY, ROESY, H-detected (1)H,(13)C HSQC and HMQC-TOCSY experiments. The O-polysaccharide was found to have a branched hexasaccharide repeating unit of the following structure: [carbohydrate structure: see text]
Subject(s)
Lipopolysaccharides/chemistry , O Antigens/chemistry , Rahnella/chemistry , Carbohydrate Sequence , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Rahnella/classificationABSTRACT
The core structure of the lipopolysaccharide (LPS) isolated from a rough strain of the phytopathogenic bacterium Pseudomonas syringae pv. phaseolicola, GSPB 711, was investigated by sugar and methylation analyses, Fourier transform ion-cyclotron resonance ESI MS, and one- and two-dimensional 1H-, 13C- and 31P-NMR spectroscopy. Strong alkaline deacylation of the LPS resulted in two core-lipid A backbone undecasaccharide pentakisphosphates in the ratio approximately 2.5 : 1, which corresponded to outer core glycoforms 1 and 2 terminated with either L-rhamnose or 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo), respectively. Mild acid degradation of the LPS gave the major glycoform 1 core octasaccharide and a minor truncated glycoform 2 core heptasaccharide, which resulted from the cleavage of the terminal Kdo residues. The inner core of P. syringae is distinguished by a high degree of phosphorylation of L-glycero-D-manno-heptose residues with phosphate, diphosphate and ethanolamine diphosphate groups. The glycoform 1 core is structurally similar but not identical to one of the core glycoforms of the human pathogenic bacterium Pseudomonas aeruginosa. The outer core composition and structure may be useful as a chemotaxonomic marker for the P. syringae group of bacteria, whereas a more conserved inner core structure appears to be representative for the whole genus Pseudomonas.
Subject(s)
Lipopolysaccharides/chemistry , Pseudomonas syringae/chemistry , Carbohydrate Sequence , Molecular Sequence Data , Nuclear Magnetic Resonance, Biomolecular , Spectrometry, Mass, Electrospray IonizationABSTRACT
The O-specific polysaccharide of P. fluorescens IMV 2366 was studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D gsCOSY, TOCSY, gsNOESY, H-detected 1H,(13)C gsHSQC, HMQC-TOCSY, and gsHMBC experiments. The polysaccharide contains L-rhamnose, 2-acetamido-2,6-dideoxy-D-galactose (D-FucNAc) and 3-acylamido-3,6-dideoxy-D-glucose (D-Qui3NAcyl, where Acyl is 3-hydroxy-2,3-dimethyl-5-oxoprolyl). The structure 1 of the polysaccharide was found to be similar to the structure 2 of a 6-deoxy-L-talose (L-6dTal)-containing O-specific polysaccharide of a non-classified P. fluorescens strain, 361, studied earlier [Khomenko, V. A.; Naberezhnykh, G. A.; Isakov, V. V.; Solov'eva, T. F.; Ovodov, Y. S.; Knirel, Y. A.; Vinogradov, E. V. Bioorg. Khim. 1986, 12, 1641-1648; Naberezhnykh, G. A.; Khomenko, V. A.; Isakov, V. V., El'kin, Y. N.; Solov'eva, T. F.; Ovodov, Y. S. Bioorg. Khim. 1987, 13, 1428-1429]. --> 2)-beta-D-Quip3NAcyl-(1 --> 3)-alpha-L-Rhap-(1 --> 3)-alpha-D-FucpNAc-(1 --> 1. --> 4)-beta-D-Quip3NAcyl-(1 --> 3)-alpha-L-6dTalp4Ac-(1 --> 3)-alpha-D-FucpNAc-(1 -->2.
