Structural determination of the O-antigenic polysaccharide from Escherichia coli O141.

The structure of the O-antigenic polysaccharide from Escherichia coli O141 has been determined. NMR spectroscopy and sugar and methylation analyses were the principal methods used. The sequence of the sugar residues could be determined by NOESY and heteronuclear multiple-bond connectivity (HMBC-) NMR experiments. The polysaccharide is composed of pentasaccharide repeating units with 1 O-acetyl group/repeating unit. The following structure, where Rha is 6-deoxymannose is concluded: carbohydrate sequence [see text].