Synthesis of Carboxymethyl GLA-60 Ether Derivatives Containing an Olefin in Their Chains and Their LPS-Antagonistic Activities

Anomeric carboxymethyl GLA-60 olefine derivatives having ether chains instead of ester chains in their side chains were synthesized and their biological activities toward both human U937 cells and mouse PEC-macrophage cells were measured. The species-specific behavior of these compounds in humans (LPS-antagonistic) and mice (very weak LPS-antagonistic, but almost inactive) found this time was different from that in humans (LPS-antagonistic) and mice (endotoxic) found in the biosynthetic precursor of lipid A, such as lipid IVa. However, this fact also shows, interestingly enough, that a difference exists in the molecular recognition between human and mouse LPS receptors.