Steroidal saponins from Solanum nigrum.

Six new steroidal saponins, solanigrosides C-H (2-7), and one known saponin, degalactotigonin (1), were isolated from the whole plant of Solanum nigrum. Their chemical structures were elucidated using spectroscopic analysis, chemical degradation, and derivatization. All seven compounds were tested for their cytotoxicity using four human tumor cell lines (HepG2, NCI-H460, MCF-7, SF-268). Only compound 1 was cytotoxic, with IC50 values of 0.25-4.49 microM.