Structure and anticancer activity of sulfated O-polysaccharide from marine bacterium Cobetia litoralis KMM 3880T

• Structure of polysaccharide moiety of LPS from C. litoralis was established.
• O-polysaccharide contains sulfated 3-deoxy-D-manno-oct-2-ulosonic acid.
• LPS and DPS inhibited a colony formation of human cancer cell lines.

We presented the structure of the polysaccharide moiety and anticancer activity in vitro of the sulfated lipopolysaccharide isolated from the marine bacterium Cobetia litoralis KMM 3880T. The structure of O-polysaccharide was investigated by chemical methods along with 1H and 13C NMR spectroscopy. The O-polysaccharide was built up of branched trisaccharide repeating units consist of D-glucose (D-Glcр), D-mannose (D-Manр) and sulfated 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo5S): →7-β-Kdoр4Ac5S-(2→4)-[β-d-Glcp-(1→2)-]-β-d-Manр6Ac-1→. We demonstrated that the lipopolysaccharide and О-deacetylated O-polysaccharide from Cobetia litoralis KMM 3880T inhibited a colony formation of human melanoma SK-MEL-28 and colorectal carcinoma HTC-116 cells.