The structure of the O-specific polysaccharide from the lipopolysaccharide of Aeromonas bestiarum strain 207

The O-specific polysaccharide obtained by mild-acid degradation of Aeromonas bestiarum 207 lipopolysaccharide was studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy. The sequence of the sugar residues was determined by ROESY and HMBC experiments. It is concluded that the O-polysaccharide is composed of branched pentasaccharide repeating units of the following structure: