Steroidal saponins from the bark of Dracaena draco and their cytotoxic activities

From the stem bark of Dracaena draco, three new compounds, namely, draconins A-C (1-3), were isolated, along with 17 known compounds. The structures of the new compounds isolated were elucidated on the basis of spectroscopic data interpretation. Several of the isolated compounds showed potent cytotoxic activities measured on the human leukemia cell line HL-60 (IC(50)'s from 2.0 to 9.7 microM at 72 h). The mechanism by which compounds 1 and 2 display their cytostatic properties is through induction of cell death by apoptosis, as evaluated by fluorescence microscopy and DNA fragmentation.