Nitric Oxide Production Inhibitory Eudesmane-Type Sesquiterpenoids from Artemisia argyi.

Six new eudesmane-type sesquiterpene derivatives, artemargyinins A-F were isolated from the leaves of Artemisia argyi. Their structures were elucidated based on the extensive analysis of spectroscopic data. Artemargyinins A-F feature a lactone ring-opening eudesmane-type sesquiterpene with an isoprenoid group at C(8). All compounds were tested for their inhibitory effects on lipopolysaccharide-induced nitric oxide (NO) production in RAW264.7 macrophages. Artemargyinins A-F showed more potent NO production inhibitory activity with IC50 values ranging from 7.66±0.53 to 61.19±2.54 µM than the positive control quercetin (IC50 =74.34±1.39 µM). Among them, artemargyinins C and D exhibited strong inhibitory activity with IC50 values of 8.08±0.21 and 7.66±0.53 µM, respectively.