Structure of the O-antigen of Yersinia pseudotuberculosis O:4a revised

Abstract The O-specific polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Yersinia pseudotuberculosis O:4a and studied by NMR spectroscopy, including 2D ROESY and 1 H, 13 C HMBC experiments. The following structure of the pentasaccharide repeating unit of the polysaccharide was established, which differs from the structure reported earlier [Gorshkova, R. P. et al., Bioorg. Khim . 1983 , 9 , 1401–1407] in the linkage modes between the monosaccharides: where Tyv stands for 3,6-dideoxy- d -arabino- hexose (tyvelose). The structure of the Y. pseudotuberculosis O:4a antigen resembles that of Y. pseudotuberculosis O:2c, which differs in the presence of abequose (3,6-dideoxy- d - xylo -hexose) in place of tyvelose only .