摘要 : The structure of the repeating unit of the O-antigenic polysaccharide from Plesiomonas shigelloides strain AM36565 has been determined. Component analysis and ~1H and ~(13)C NMR spectroscopy experiments were employed to elucidate ... 展开 The structure of the repeating unit of the O-antigenic polysaccharide from Plesiomonas shigelloides strain AM36565 has been determined. Component analysis and ~1H and ~(13)C NMR spectroscopy experiments were employed to elucidate the structure. Inter-residue correlations were determined by ~1H, ~(13)C heteronuclear multiple-bond correlation, ~1H, ~1H-NOESY, and ~1H, ~(13)C-HSQC- ~1H, ~1H-NOESY experiments. The O-antigen polysaccharide is composed of repeating units with the following structure: →3)-α-l- Rhap-(1→2)-α-l-Rhap-(1→4)[β-d-GalpNAc-(1→3)] -α-d-GlcpNAc-(1→, in which the monosaccharide side-chain substitutes the backbone in half of the repeating units. A matrix-assisted laser desorption/ionization mass spectrometry experiment suggested that the polysaccharide consists of two regions, one with tetrasaccharide repeating units and one with trisaccharide repeating units. 收起