Biological activities of chemically synthesized analogues of the nonreducing sugar moiety of lipid A

Abstract

Biological activities of five synthetic lipid A analogues (D‐glucosamine derivatives) were examined to elucidate the structure required for expression of the biological activities of endotoxin. Proclotting enzyme of horseshoe crab activation, interferon‐inducing and tumor necrosis factor‐inducing activities were significantly expressed by an analogue which possesses 4‐O‐phosphoryl, 3‐O‐tetradecanoyl and N‐tetradecanoyloxytetradecanoyl groups. The results obtained with different analogues show that the 4‐O‐phosphoryl and N‐tetradecanoyloxytetradecanoyl groups are important for expression of the above activities. The effect of 6‐O‐acylation in preventing the expression of these biological activities is also suggested. Pyrogenic activity was not detected in any of the compounds tested.