Guaiane Sesquiterpenoids Isolated from the Fruits of Torilis japonica and Their Cytotoxic Activity

Two new guaiane sesquiterpenoids, 11-(acetyloxy)-1,8-dihydroxyguai-4-en-3-one (5) and (1 alpha,6 beta)-1,6-dihydroxytorilin (6), were isolated from the fruits of Thrills japonica (Umbelliferae), along with four known sesquiterpenes, torilin (1), torilolone (2), (1 beta)-1-hydroxytorilin (3), and (1 alpha)-1-hydroxytorilin (4). During the phytochemical investigation, daucosterol, friedelin, and epifriedelanol were also isolated from the plant for the first time. The structures of the new sesquiterpenoids 5 and 6 were determined by comprehensive analyses of MS and NMR spectroscopic data. These isolates were evaluated against human breast cancer cells (MCF-7) and Lewis lung carcinoma (LLC) cells. Compounds 1, 3, and 4 exhibited cytotoxic activity against the LLC cells with IC(50) values of 31.3, 32.5, and 34.0 mu g/ml, respectively. However, no significant cytotoxicity was found against the MCF-7 cells for any of the compounds tested.