Structural characterization of the O-antigenic polysaccharide from the lipopolysaccharide of Vibrio cholerae O37

The chemical structure of the O-antigenic polysaccharide isolated from the lipopolysaccharide of Vibrio cholerae 037 by mild acid hydrolysis was elucidated. The O-antigenic polysaccharidc is found to consist of D-glucose, N-acctyl-D-Quinovosamine and small amount of 4-O-methyl-N-acetyl-D-quinovasamine. The structure of the O-antigcn is established by using sugar and methylation analyses, Smith degradation studies and by using GLC, GC-MS, FAB-MS, one dimensional 1 H and 13 C NMR spectroscopy and two dimensional NMR spectroscopy including COSY, TOCSY, HSQC, experiments.