Immunological and chemical studies of Salmonella haarlem somatic antigen epitopes. I. Structural studies of O-antigen.
Lipopolysaccharide (LPS) of Salmonella haarlem was hydrolyzed and the products separated. The structure of the O-specific polysaccharide (OPS) was found from sugar and methylation analyses. Rhamnose, mannose, galactose and tyvelose were detected and their linkage modes were established. The structure was confirmed by 1H, homonuclear and heteronuclear correlations and 13C NMR spectra. Anomeric configurations were assigned by chromium trioxide oxidation and proton coupled 13C spectra. Sugar sequence was established from specific carbon shift data and nuclear Overhauser effect spectroscopy. The repeating unit structure of S. haarlem OPS as --> 3)-alpha-D-Galp-(1 --> 6)-[alpha-Tyvp-(1 --> 3)]-beta-D-Manp-(1 --> 4)-alpha-L-Rhap was estimated. No structural heterogeneity of the antigen was found.