Cytotoxic activities and structure-cytotoxic relationships of steroidal saponins.

We have systematically examined the cytotoxic activities of the steroidal saponins mainly isolated from the Liliaceae plants against HL-60 human promyelocytic leukemia cells and found several structure-activity relationships. Some steroidal saponins evaluated in the assay system showed considerable cytotoxic activities, which were almost as potent as that of etoposide used as a positive control. The activities were found to be sensitive to the monosaccharides constituting the sugar moieties and their sequences, as well as to the structures of the aglycons.