CASP3 and leukemia: In addition, the cytotoxic activities of compounds 1–7 against five human cancer cell lines were evaluated, of which 3, 4, and 6 exhibited significant cytotoxic activities, with IC50 values ranging from 0.56 to 3.00 μM. The apoptosis-inducing potential of compound 3 and the mechanism of action were further studied by FACS and western blotting, and the results showed that it induced apoptosis in leukemia cells, mediated by activation of caspase-3, degradation of PARP, upregulation of Bax, and downregulation of Bcl-2 and Bcl-xl.