Phenylpropanoids from Daphne feddei and Their Inhibitory Activities against NO Production

Chemical examination of the methanolic extract from the stem bark of Daphne feddei led to the isolation of five new phenylpropanoids, 4,4'-dihydroxy-3,3'-dimethoxy-9-butoxy-9,9'-epoxylignan (1), 4,4'-dihydroxy-3,3'-dimethoxy-9-ethoxy9,9'-epoxylignan (2), daphneresinol (3), armaosigenin (4), and isocubebin (5), together with 33 known phenylpropanoids. All 38 compounds were isolated for the first time from D. feddei. All compounds were tested for inhibitory activity against LPS-induced NO production in RAW 264.7 macrophages. Compounds 2, 8, 9, 12, 13, and 15 showed potent inhibitory activities against the production of NO with IC50 values of 0.091, 0.047, 0.005, 0.088, 0.004, and 0.074 mu M/mL, respectively.