Cytotoxic dammarane triterpenoids from the hydrolyzate of Gynostemma pentaphyllum.

[Display omitted] • Three undescribed triterpenoids with rare skeletons (1 - 3) were reported. • One unreported gypenoside (4) was isolated. • The absolute configurations were determined by ECD analysis. • Their antiproliferative effects were evaluated in a variety of cell lines. Three undescribed dammarane-type triterpenoids with rare carbon skeletons (1 - 3), together with one unreported gypenoside (4), were isolated from a acid hydrolysis product of Gynostemma pentaphyllum (Thunb.) Makino. Their molecular structures were elucidated via a combination of spectroscopic and spectrometric data, while the absolute configurations of compounds 1 , 2 and 4 were determined by electronic circular dichroism (ECD) analyse. Notably, compounds 1 - 3 possess a 19(10→1)abeo structural moiety in the A ring. Saponin 4 possesses an unusual cyclopentenone side chain. Compounds 1 , 2 and 4 were screened for their antiproliferative effects against HepG2, MCF-7 and DU145 cell lines. [ABSTRACT FROM AUTHOR]