Structure of the O-Specific polysaccharide from Shewanella japonica KMM 3601 containing 5,7-Diacetamido-3,5,7,9-tetradeoxy-D-glycero-D-talo-non-2-ulosonic acid.

Structure of the O-specific polysaccharide chain of the lipopolysaccharide (LPS) of Shewanella japonica KMM 3601 was elucidated. The initial and O-deacylated LPS as well as a trisaccharide representing the O-deacetylated repeating unit of the O-specific polysaccharide were studied by sugar analysis along with 1H and 13C NMR spectroscopy. The polysaccharide was found to contain a rare higher sugar, 5,7-diacetamido-3,5,7,9-tetradeoxy-D-glycero-D-talo-non-2-ulosonic acid (a derivative of 4-epilegionaminic acid, 4eLeg). The following structure of the trisaccharide repeating unit was established: →4)-α-4eLegp5Ac7Ac-(2→4)-β-D-GlcpA3Ac-(1→3)-β-D-GalpNAc-(1→.