Synthesis of Helicobacter pylori lipid A and its analogue using p-(trifluoromethyl)benzyl protecting group

Synthesis of lipid A 1 isolated from Helicobacter pylori strain 206-1 has b een achieved in 2.2% total yield through 14 steps from D-glucosamine by emp loying a p-(trifluoromethyl)benzyl group for protection of the hydroxy grou p on the 3-hydroxy fatty acid residue. The synthetic specimen was identical with the natural counterpart in chromatographic, spectroscopic, and biolog ical aspects. A structural analogue 2 which lacks the ethanolamine residue of 1 was also synthesized, and 2 was found to exhibit less potent IL-1 beta -inducing activity than 1. (C) 2000 Elsevier Science Ltd. All rights reserv ed.