Two new compounds, the 6-oxo oleanane-type triterpenoid uncarilic acid, and its 5,6-secotriterpenoid derivative, secouncarilic acid, were isolated from the hooks and stems of Uucaria sessilifructus together with seven known ursane-type triterpenoids. Uncarilic acid is the second 6-oxo oleanane-type triterpenoid ever reported, while secouncarilic acid is the first oleanane-type 5,6-secotriterpenoid. A plausible biosynthetic pathway from uncarilic acid to secouncarilic acid was also postulated. The inhibitory activities of all the nine compounds against LPS-induced nitric oxide production in RAW264.7 macrophages were evaluated.
1.Chinese Acad Sci, Key Lab Trop Plant Resource Sci, Xishuangbanna Trop Bot Garden, Mengla 666303, Yunnan, Peoples R China 2.Yunnan Univ Tradit Chinese Med, Coll Tradit Chinese Med, Kunming 650200, Yunnan, Peoples R China 3.Guiyang Med Coll, Engn Res Ctr Dev & Applicat Ethn Med, Sch Pharm, Guiyang 550004, Guizhou, Peoples R China 4.Guiyang Med Coll, TCM, Sch Pharm, Guiyang 550004, Guizhou, Peoples R China 5.Chinese Acad Sci, State Key Lab Phytochem & Plant Resources West Ch, Kunming Inst Bot, Kunming 650204, Yunnan, Peoples R China 6.Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China