New diterpene lactone derivatives from leaves inhibit nitric oxide production in RAW 264.7 cells.

Phytochemical studies on plants have attracted considerable attention over the past few decades due to the structural diversities and significant biological activities of terpenoids produced by these plants. In the present study, five new acyclic diterpene lactone derivatives, aphanamixionolides A-E (1-5), and three known tirucallane-type triterpenes, namely, piscidinol A (6), hispidone (7), and bourjotinolone A (8), were isolated from the leaves of . Their structures were elucidated by comprehensive analyses of HR-ESI-MS and NMR spectroscopic data and by comparison with those reported in the literature. Absolute configurations of the new compounds were determined by experimental and TD-DFT calculated ECD spectra. Compounds 1-8 inhibited NO production with IC values of 10.2-37.7 μM, which are comparable to positive control l-NMMA (IC: 31.5 μM).