The structures of oligosaccharides isolated from the lipopolysaccharide of Moraxella catarrhalis serotype B, strain CCUG 3292.

The oligosaccharides from the lipopolysaccharides of Moraxella catarrhalis serotype B, strain CCUG 3292, were isolated after mild acid hydrolysis and separated by high-performance anion-exchange chromatography. The structures of the oligosaccharides were established by fast atom bombardment mass spectrometry and nuclear magnetic resonance spectroscopy. It is concluded that the oligosaccharides comprise a mixture of mainly a nona- and a deca-saccharide. [formula: see text] Smaller amounts of undeca-saccharides and of truncated forms, namely, hexa-, hepta-, and octa-saccharides, were also detected.

Structural studies of the Vibrio salmonicida lipopolysaccharide.

The oligosaccharide part of the Vibrio salmonicida (strain NCMB 2262) lipopolysaccharide was isolated by mild acid hydrolysis followed by gel-permeation chromatography. The structure was established mainly by methylation analysis, mass spectrometry, and NMR spectroscopy. It is concluded that the oligosaccharide has the following structure, in which L-alpha-D-Hep p is L-glycero-alpha-D-manno-heptopyranose, D-alpha-D-Hepp is D-glycero-alpha-D-manno-heptopyranose, alpha-D-Fuc p4N is 4-amino-4,6-dideoxy-alpha-D-galactopyranose, alpha-NonA is 5-acetamidino-7-acetamido-3,5,7, 9-tetradeoxy-L-glycero-alpha-D-galacto-nonulosonic acid, BA is (R)-3-hydroxybutanoyl, and PEA is phosphoethanolamine. The substitution pattern of the branching heptosyl residue was deduced from 1H NMR chemical shifts and conformations of the branching region, obtained by molecular modelling. The absolute configuration for NonA was determined by NMR spectroscopy from NOE correlations to the neighbouring sugar and 13C NMR chemical shift data. It could also be shown that assignments of nonulosonic acids with the D-glycero-L-galacto configuration, reported by previous investigators, are erroneous and should be changed to L-glycero-D-galacto. The oligosaccharide is assumed to be linked to the 5-position of a Kdo residue, phosphorylated in the 4-position as observed for other lipopolysaccharides from Vibrionaceae. [formula: see text]

Structural studies of the O-antigen oligosaccharides from two strains of Moraxella catarrhalis serotype C.

The oligosaccharide parts from Moraxella (Branhamella) catarrhalis serotype C lipooligosaccharides were isolated by mild acid hydrolysis followed by gel permeation chromatography. Four different oligosaccharides could be identified from strain RS26 and two from strain RS10. The structures of the O-oligosaccharides were established by methylation analyses, mass spectrometry, and NMR spectroscopy. It is concluded that the oligosaccharide O-antigens from RS26 are a mixture of octa-, deca-, and undeca-saccharides, and most likely a heptasaccharide. Strain RS10 contains the deca- and the undeca-saccharide only. The structures for the oligosaccharides are shown below. [formula: see text] OS(7) [formula: see text] OS(8) [formula: see text] OS(10) [formula: see text] OS(11) Methylation analysis of the intact lipooligosaccharides showed that two Kdo residues were present, one terminal and one 4,5-substituted residue. It also showed that they consisted of a lipid A portion with 6-substituted glucosamine residues.

Structural studies of the O-polysaccharide from the lipopolysaccharide of Moraxella (Branhamella) catarrhalis serotype A (strain ATCC 25238).

The polysaccharide of the Moraxella (Branhamella) catarrhalis serotype A lipopolysaccharide was prepared by mild acid hydrolysis followed by gel permeation chromatography. The structure was established by methylation analysis, mass spectrometry, and NMR spectroscopy. It is concluded that the O-antigenic polysaccharide has the following structure. [formula see text] Methylation analysis of the intact lipopolysaccharide showed that the lipid A portion consisted of 6-substituted glucosamine residues. Methylation followed by methanolysis showed that two Kdo residues were present, one terminal and one 4,5-substituted residue. A terminal Kdo thus substitutes the branch-point Kdo in the 4-position.

The structure of the capsular polysaccharide from Klebsiella K43.

The structure of the capsular polysaccharide from Klebsiella type K43 has been investigated using sugar and methylation analysis, uronic acid degradation, and NMR spectroscopy on the native and the O-deacetylated polysaccharide. It is concluded that the polysaccharide is composed of pentasaccharide repeating units with the structure [formula: see text] The polysaccharide contains approximately 0.4 equiv of O-acetyl group per repeating unit, located at a primary position.

Structural studies of the capsular polysaccharide (S-21) from Klebsiella pneumoniae ATCC 31314.

The structure of the polysaccharide (S-21) elaborated by Klebsiella pneumoniae ATCC 31314 has been investigated. NMR spectroscopy, sugar and methylation analysis, uronic acid degradation, and partial hydrolysis to oligosaccharides were the main methods used. In order to obtain good NMR spectra, the polymer was subjected to non-specific degradation by treatment with fuming hydrochoric acid. It is concluded that S-21 is composed of pentasaccharide repeating units with the following structure. [formula: see text] Approximately 0.7 equivalent of O-acetyl group, distributed over at least three positions, was also present but not located. The carbohydrate backbone in S-21 is identical to that of Klebsiella K30 and K33 capsular polysaccharides.