Bioactive constituents of the leaves of Phyllanthus polyphyllus var. siamensis.

A dichloromethane extract of the leaves of Phyllanthus polyphyllus var. siamensis afforded two new monoacetylated triterpene arabinosides (1 and 2) and 15 known compounds. The structures of the new compounds were elucidated on the basis of spectroscopic data interpretation. The isolates and some chemical transformation products were evaluated biologically, and the presence of an arabinosyl moiety among the hederagenin glycosides evaluated was found to be important for the modulation of cytotoxic activity against cancer cells.