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.