Dammarane-type saponins from Gynostemma pentaphyllum

Dammarane-type saponins, gypenosides VN1-VN7 (1-7), were isolated from the total saponin extract of Gynostemma pentaphyllum aerial parts, with their structures elucidated on the basis of spectroscopic and chemical methods. These compounds showed moderate cytotoxic activity against four human cancer cell lines, A549 (lung), HT-29 (colon), MCF-7 (breast), and SK-OV-3 (ovary), with IC(50) values ranging from 19.6+/-1.1 to 43.1+/-1.0 microM. Regarding the HL-60 (acute promyelocytic leukemia) cell line, compounds 1, 5, and 6 showed weakly active with IC(50) values of 62.8+/-1.9, 72.6+/-3.6, and 82.4+/-3.2 nM, respectively, while 2, 3, 4, and 7 were less active with IC(50) values>100 microM.