Triterpenoid Constituents from the Roots of <i>Paeonia rockii</i> ssp. <i>rockii</i>

Abstract

An investigation of a chloroform-soluble extract from the roots of Paeonia rockii ssp. rockii yielded three new noroleanane triterpenoids (1–3) together with 19 known compounds. Their structures were established by analysis of the spectroscopic data. The effects of this chloroform-soluble extract and its major constituents on cell proliferation and apoptosis of a panel of human cancer cell lines (melanoma M-14, colon cancer HT-29, breast cancer MCF-7) were evaluated by the MTT bioassay and propidium iodide staining, respectively, in comparison with normal human embryonic kidney cells (HEK-293). Two of the triterpenoids, betulinic acid (4) and oleanolic acid (5), and the crude extract were cytotoxic and induced apoptosis selectively in the M-14 melanoma cell line. This effect was reversed by the caspase-inhibitor z-VAD-fmk, suggesting that such action is mediated by caspase-3 activation