Lipid A-Type Pyrancarboxylic Acid Derivatives, their Synthesis and their Biological Activities

Synthesis of lipid A-type pyrancarboxylic acid derivatives, which have a carboxylic acid group in the anomeric position of the reducing sugar part of the disaccharide instead of the phosphoric acid group in lipid A, is described. We investigated the influence of the substituents in the 2′- and 6′-position of the molecules synthesized on their activities toward human monoblastic U937 cells. It was revealed that a series of compounds, possessing an acetamido group in the 2′-position showed strong LPS-antagonistic activity.