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.