Structural studies of the O-specific polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense type strain Sp7

摘要

Lipopolysaccharide was obtained by phenol-water extraction from dried bacterial cells of Azospirillum brasilense type strain Sp7. Mild acid hydrolysis of the lipopolysaccharide followed by GPC on Sephadex G-50 resulted in a polysaccharide mixture, which was studied by composition and methylation analyses, Smith degradation and ~1H and ~(13)C NMR spectroscopy. The following polysaccharide structures were established, where italics indicate a non-stoichiometric (～40%) 2-O-methylation of l-rhamnose.