Nitric oxide production inhibitory eudesmane-type sesquiterpenoids from Artemisia argyi.

Six new eudesmane-type sesquiterpene derivatives, artemargyinins A-F were isolated from the leaves ofArtemisia 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 IC(50)values ranging from 7.66 +/- 0.53 to 61.19 +/- 2.54 mu M than the positive control quercetin (IC50=74.34 +/- 1.39 mu M). Among them, artemargyinins C and D exhibited strong inhibitory activity with IC(50)values of 8.08 +/- 0.21 and 7.66 +/- 0.53 mu M, respectively.