Antioxidant flavanes from Livistona chinensis.

Three new flavanes and eight known flavonoids were isolated from the fruits of Livistona chinensis. The structure of the new flavanes were established as 2S,3S-3,5,7,3',5'-pentahydroxyflavane (1), 2R,3R-3,5,6,7,8,4'-hexahydroxyflavane (2) and 2R,3R-3,5,6,7,8,3',5'-heptahydroxyflavane (3), respectively, on the basis of chemical and spectroscopic data. The antiproliferative activity against four human tumor cell lines (HL-60, Mata, HepG2 and CNE-1) was evaluated. 1 had significantly antiproliferative effects against HL-60 and CNE-1 with the IC(50) of 0.2 ± 0.01 and 1.0 ± 0.1 μM, respectively, overpowering the reference compound in the assay (cisplatin). Most compounds also exhibited potent antioxidant activity.