Cytotoxic and anti-oxidative constituents from Garcinia subelliptica

Garcinia subelliptica Merr. (Guttiferae) is a tree which has been served as a dye source in tropical and subtropical Asia area. In our continuing search for antitumor agents from Taiwanese plants, we found that the acetone extract afforded of the fruits of G. subelliptica exhibited cytotoxicity against several human tumor cell lines. Bioassay-directed fractionation from the acetone extract, three new polyisoprenyl benzophenonoids, tentatively namely garcinielliptone FC (1), garcinielliptone FD (2) and garcinielliptone FE (3), along with four known compounds, including xanthochymol (4), 1,3,6,7-tetrahydroxy xanthone (5), isoxanthochymol (6) and cycloxanthochymol (7). Structural elucidation of 1–3 was based on spectroscopic analysis, mainly 1D and 2D NMR techniques. Biological evaluation showed that 1–7 had significant anti-oxidative effect, and 4 exhibited moderate cytotoxicity against MCF-7, Hep2, Hela and KB tumor cells. Moreover, low concentrations of 4 may induce early apoptosis in KB cells when added before 12 hours.