The structure of the carbohydrate backbone of the lipopolysaccharide from Acinetobacter baumannii strain ATCC 19606

The chemical structure of the phosphorylated carbohydrate backbone of the lipopolysaccharide (LPS) from Acinetobacter baumannii strain ATCC 19606 was investigated by chemical analysis and NMR spectroscopy of oligosaccharides obtained after deacylation or mild acid hydrolysis. From the combined information the following carbohydrate backbones can be deduced: [GRAPHICS] where R-1 = H and R-2 = alpha-Glcp-(1 --> 2)-beta-Glcp-(1 --> 4)-beta-Glcp-(1 --> 4)-beta-Glcp-(1 as major and R-1 = Ac and R-2 = H as minor products. All monosaccharides are D-configured. Also, smaller oligosaccharide phosphates were identified that are thought to represent degradation products of the above structures.