A new withanolide glycoside (1), two new ergostanol glycosides (2 and 3), and a new furostanol glycoside (4), along with nine known steroidal derivatives (5-12) were isolated from the seeds of Withania somnifera. The structures of the new compounds were determined using spectroscopic analysis and hydrolysis. The cytotoxic activities of the isolated compounds were evaluated against Ca9-22 human gingival carcinoma cells, HSC-2 human mouth carcinoma cells, and HL-60 human promyelocytic leukemia cells. Only 12 exhibited cytotoxic activity against these cell lines with IC50 values of 0.38, 0.54, and 1.5 μM, respectively.
Keywords: Solanaceae; Withania somnifera; cytotoxic activity; ergostanol glycoside; furostanol glycoside; seed; withanolide glycoside.