Two new norsesquiterpenoids with estrogenic activity from the stems and leaves of Dioscorea oppositifolia L

Two new norsesquiterpenoids, dioscopposin A (1) and dioscopposin B (2), as well as 21 known compounds (3–23) were isolated from the stems and leaves of Dioscorea oppositifolia L. Their structures were elucidated by detailed analysis of comprehensive spectroscopic data. The absolute configurations were deduced by the comparison of experimental and calculated electronic circular dichroism spectra. Estrogenic activity of all the isolated compounds were evaluated using MCF-7 cells proliferation assay and compounds 2, 3, 7, 13, 15, 16, 18 and 21 exhibited proliferation activity.