Structure of an acidic polysaccharide from a marine bacterium Pseudoalteromonas distincta KMM 638 containing 5-acetamido-3,5,7,9-tetradeoxy-7-formamido-l-glycero-l-manno-nonulosonic acid Original Research Article

An acidic polysaccharide was obtained from the lipopolysaccharide of Pseudoalteromonas distincta strain KMM 638, isolated from a marine sponge, and found to contain d-GlcA, d-GalNAc, 2-acetamido-2,6-dideoxy-d-glucose (d-QuiNAc) and two unusual acidic amino sugars: 2-acetamido-2-deoxy-d-galacturonic acid (d-GalNAcA) and 5-acetamido-3,5,7,9-tetradeoxy-7-formamido-l-glycero-l-manno-nonulosonic acid (Pse5Ac7Fo, a derivative of pseudaminic acid). Oligosaccharides were derived from the polysaccharide by partial acid hydrolysis and mild alkaline degradation and characterised by electrospray ionisati