Synthesis of new lathyrane diterpenoid derivatives from Euphorbia lathyris and evaluation of their anti-inflammatory activities.

Euphorbia factor L3, a lathyrane diterpenoid extracted from Euphorbia lathyris, was found to display good anti-inflammatory activity with very low cytotoxicity. To find more potent anti-inflammatory drugs, two series of Euphorbia factor L3 derivatives with fatty and aromatic acids were designed and synthesized. Among them, compound 5n exhibited most potent inhibition on LPS-induced NO production in RAW264.7 cells with no obvious cytotoxicity. To determine the key characteristics of Euphorbia factor L3 derivatives that contribute to anti-inflammatory activity, we conducted a structure-activity relationship study of these compounds.