An acidic O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Escherichia coli O112ab and studied by sugar analysis along with (1)H and (13)C NMR spectroscopy. The O-polysaccharide was found to contain a rarely occurring sugar component, l-iduronic acid (l-IdoA), and the following structure of the branched pentasaccharide repeating unit was established:
Structure of the O-polysaccharide of Escherichia coli O112ab containing l-iduronic acid. Publishing Authors By Initials