Structure of the O-specific polysaccharide from a marine bacterium Echinicola pacifica КММ 6172Т containing 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid

•The O-polysacchride was isolated from a marine bacterium Echinicola pacifica.•The structure of the polysaccharide was established by NMR and chemical approaches.•The polysaccharide is built up of branched pentasaccharide repeating units.•2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (GlcNAc3NAcA) was found in the O-polysaccharide.

The O-polysaccharide was isolated from the lipopolysaccharide of Echinicola pacifica KMM 6172T and studied by chemical analyses along with 1H and 13C NMR spectroscopy, including 1H, 1H COSY, 1D and 2D TOCSY, ROESY, 1H, 13С HMQC, HMBC and H2BC experiments. It was found that the polysaccharide is built up of branched pentasaccharide repeating units, containing D-galactose (Gal), L-rhamnose (Rha), 2-acetamido-2-deoxy-D-glucose (GlcNAc), two residues of 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (GlcNAc3NAcA) and O-acetyl group in nonstoichiometric amount and has the following structure:Figure optionsDownload full-size imageDownload as PowerPoint slide

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