Sesquiterpenoids and triterpenoids from Secamone lanceolata blume with inhibitory effects on nitric oxide production.

Five previously undescribed sequiterpenoids, including three guaiane sesquiterpenoids secamonol A (2), secamonester (3), secamonether (4), and one elemanolide sequiterpenoid secamonol B (7), and one eudesmane sesquiterpenoid secamonol C (8) along with nine known compounds were isolated from Secamone lanceolata Blume. Their structures and absolute configurations were established by analyzing of NMR, CD, MS spectrum and single-crystal X-ray diffraction, as well as comparing with the literatures. Compounds 1 and 4-8 exhibited potential inhibition activities of NO production with IC50 values in the range of 27.9-57.5 μM with no obvious cytotoxicities even at the high concentration (100 μM). Whereas, compound 3 showed significant cytotoxicity with CC50 value of 5.6 μM against macrophages RAW264.7 Cells.