Structure of the O-polysaccharide of Vibriocholerae O43 containing a new monosaccharide derivative, 4-(N-acetyl-l-allothreonyl)amino-4,6-dideoxy-D-glucose

Abstract

The O-polysaccharide of Vibrio cholerae O43 was studied using chemical analyses, triflic acid solvolysis and 2D NMR spectroscopy, including (1)H/(1)H COSY, TOCSY, NOESY and (1)H/(13)C gradient-selected HSQC experiments. The following structure of the tetrasaccharide repeating unit of the polysaccharide was established: →3)-β-D-Quip4NAcyl-(1→3)-α-D-GalpNAcA-(1→4)-α-D-GalpNAc-(1→3)-α-D-QuipNAc-(1→ where D-QuiNAc stands for 2-acetamido-2,6-dideoxy-D-glucose, D-Qui4NAcyl for 4-(N-acetyl-L-allothreonyl)amino-4,6-dideoxy-D-glucose and D-GalNAcA for 2-acetamido-2-deoxy-D-galacturonic acid.