Revision of the O-polysaccharide structure of Yersinia pseudotuberculosis O:1b

The O-polysaccharide of Yersinia pseudotuberculosis O:1b was reinvestigated using (1)H and (13)C NMR spectroscopy, and the anomeric configuration of the mannose residue at the branching point was revised. The following is the revised structure of the O-polysaccharide: [structure: see the text] where Par stands for 3,6-dideoxy-D-ribo-hexose (paratose). The revised structure of the main chain is shared by the O-polysaccharide of Y. pseudotuberculosis O:11, which differs in the presence of a lateral alpha-L-6-deoxyaltrofuranose residue in place of the beta-paratofuranose residue [Cunneen, M. M.; de Castro, C.; Kenyon, J.; Parrilli, M.; Reeves, P. R.; Molinaro, A.; Holst, O.; Skurnik, M. Carbohydr. Res.2009, 344, 1533-1540].