Chemical structure of lipid A from Helicobacter pylori strain 206-1 lipopolysaccharide.

The chemical structure of a novel lipid A, which was obtained as a major component from lipopolysaccharide of Helicobacter pylori strain 206-1, was determined to be a glucosamine beta(1-6) disaccharide 1-(2-aminoethyl)phosphate acylated by (R)-3-hydroxyoctadecanoic acid and (R)-3-(octadecanoyloxy)octadecanoic acid at the 2- and 2'-position, respectively. The absence of a phosphoryl group at the 4'-position and fatty acyl groups at the 3- and 3'-position, and the stoichiometric presence of 2-aminoethyl phosphate at the 1-position are unique features, distinguishing it from the lipid A of enterobacteria.