TheO-chainpolysaccharide of the lipopolysaccharide (LPS) of a previously nonclassi®ed strain ofProteus mirabilis termed G1 was studied by sugar analysis and 1 Hand13 C NMR spectroscopy, including 2D COSY, TOCSY, rota-ting-frameNOE(ROESY),H-detected 1 H, 13 CHMQC,and heteronuclear multiple-bond correlation (HMBC) experi-ments.