The structure of the O-polysaccharide of the Pseudoalteromonas rubra ATCC 29570T lipopolysaccharide containing a keto sugar Original Research Article

The structure of the phenol-soluble polysaccharide from Pseudoalteromonas rubra type strain ATCC 29570T has been elucidated using 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, gNOESY, ROESY, 1H,13C gHMQC and gHMBC experiments. It is concluded that the trisaccharide repeating unit of the polysaccharide has the following structure: where Sug is 2-acetamido-2,6-dideoxy-d-xylo-hexos-4-ulose, Am is acetimidoyl and Acyl is a malic acid residue, which is O-acetylated in ∼70% of the units.