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 (1)H and (13)C 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)-alpha-4eLegp5Ac7Ac-(2 -> 4)-beta-D-GlcpA3Ac-(1 -> 3)-beta-D-GalpNAc-(1 ->