Structural studies of the O-polysaccharide from the Escherichia coli O77 lipopolysaccharide

The structure of the O-antigen polysaccharide (PS) from Escherichia coli O77 has been determined. Sugar and methylation analysis together with 1H and 13C NMR spectroscopy were the main methods used. The PS is composed of tetrasaccharide repeating units with the following structure:→2)-α-d-Manp-(1→2)-β-d-Manp-(1→3)-α-d-GlcpNAc-(1→6)-α-d-Manp-(1→