Close relation of the O-polysaccharide structure of Escherichia coli O168 and revised structure of the O-polysaccharide of Shigella dysenteriae type 4

摘要

The O-polysaccharide was isolated from the lipopolysaccharide of Escherichia coli 0168 and studied by chemical analyses and Smith degradation along with ~1H and ~(13)C NMR spectroscopies.The following structure of the branched pentasaccharide repeating unit of the O-polysaccharide was established:where 6-O-acetylation of GlcNAc is partial.Reinvestigation of the O-polysaccharide of Shigella dysenteriae type 4 established earlier showed it to have the same structure except for that the lateral Fuc residue is nonstoichiometrically O-acetylated at each position.