Triterpene Derivatives from and Their Anti-Cancer Activity.

Phytochemical investigations of leaves and twigs from Merr. resulted in the isolation of five undescribed triterpene derivatives (-) and six known analogs (-). Their structures were determined based on extensive spectroscopic data and high-resolution mass spectra analyses. Compounds - were tested for their in vitro cytotoxicity against three human cancer cell lines (HeLa, HepG-2, and MCF-7). Compounds , , and exhibited broad and significant cytotoxicity against the tested cell lines with IC values ranging from 5.04 to 21.55 μM. Compounds and showed cytotoxicity against HeLa and MCF-7 with IC values ranging from 13.22 to 19.62 μM. The preliminary structure-activity relationship for the 11 isolated compounds is also discussed.