Synthesis and Cytostatic Activity of New Mepregenol 17-Acetate Derivatives with Respect to Hela Cancer Cell Culture

New mepregenol 17-acetate derivatives with potential cytotoxicity were synthesized. Mepregenol 17-acetate 3-acrylate ( III ) was shown to exhibit potent cytotoxicity although the ester of N -benzylpyrrolidine-3-carboxylic acid ( IV ) had weaker activity that was comparable with those of megestrol acetate and progesterone. The IC 50 values for III , IV , progesterone, and megestrol acetate were 30, 200, 480, and 130 μMwith respect to native HeLa culture and 9.1, 180, 5.6, and 115 μm for an estradiol-stimulated culture of HeLa, respectively. The cytotoxicities of steroids III and IV correlated with their DNA-damaging effect in a DNA comet assay. Thus, III was promising for further research as an antitumor compound with respect to estradiol-dependent tumors.