Characterization of the antigenic O-polysaccharide produced by Escherichia coli serotype O:70

The structure of the antigenic O-polysaccharide (O-PS) produced by Escherichia coli serotype O:70 was determined by analysis of the chromatographically purified O-PS polymer prepared by mild hydrolysis of its aqueous phenol-extracted smooth-type somatic lipopolysaccharide. The O-PS is composed of d-glucose, d-galactose, d-fucose, 2-acetamido-2-deoxy-d-galactose, and 3-acetamido-3-deoxy-d-quinovose in a ratio of 1:1:1:1:1. From the use of DOC–PAGE, methylation, Smith-type periodate oxidation, and 1H and 13C NMR spectroscopy, including 2D experiments, the O-PS was shown to be a polymer of a branched repeating pentasaccharide unit having the structure:Figure optionsDownload full-size imageDownload as PowerPoint slide

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