Kadcoccilactones K–R, triterpenoids from Kadsura coccinea

Phytochemical investigation on the stems of Kadsura coccinea led to the isolation of 8 new triterpenoids, kadcoccilactones K–R (1–8), and 10 known analogues. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compounds 1–3 characterized with an aromatic ring E in their molecules are rarely naturally occurred kadlongilactone derivatives. Moreover, all compounds were evaluated for their inhibitory activity against K562, Bel-7402, and A549 human tumor cells. Compounds 9 and 10 exhibited potent cytotoxicity against K562, Bel-7402, and A549 cell lines with IC50 values less than 0.1, 0.1, and 1.0 μm, respectively.