STRUCTURE OF THE O-SPECIFIC POLYSACCHARIDE OF THE BACTERIUM PROTEUS-MIRABILIS O-13 CONTAINING A NOVEL COMPONENT - AN AMIDE OF D-GALACTURONIC ACID WITH N-EPSILON-(1-CARBOXYETHYL)LYSINE

An acidic O-specific polysaccharide was obtained by mild acid degradat ion of the lipopolysaccharide of the bacterium Proteus mirabilis O13 a nd found to contain D-galactose, 2-acetamido-2-deoxy-D-glucose, and N- epsilon-(1 -carboxyethyl)-N-alpha-(D-galacturonoyl)lysine. On the basi s of full acid hydrolysis and H-1- and C-13-NMR spectroscopy, includin g two-dimensional correlation spectroscopy (COSY), H-detected heteronu clear H-1, C-13 multi-quantum coherence (HMQC), and rotating-frame nuc lear Overhauser effect spectroscopy (ROESY), the following structure o f the branched trisaccharide repeating unit of the polysaccharide was established: [GRAPHICS]