Steroidal constituents from Solanum nigrum.

Three previously undescribed steroidal constituents including two sterols (1-2) and one pregnane-type steroidal glycoside (6), along with nineteen known ones (3-5, 7-22), were isolated from the 80% alcohol extraction of Solanum nigrum L. Their structures and the absolute configurations were established by analysis of the extensive spectroscopic data (H/ NMR, HH COSY, HSQC, HMBC, and NOESY), and/or by comparisons of the experimental electronic circular dichroism (ECD) spectra with those calculated ones by TDDFT method. Further, a MTT assay was applied to demonstrate that compounds 1-4, 6-12, 18, and 22 exhibited significant cytotoxic activities against SW480 cells, and compounds 1-4, 6-14, and 16-22 showed significant cytotoxic activities against Hep3B cells.