All compounds were tested against 22Rv1 and PC3 prostate cancer cells. Among them, compounds 4a, 4b, and 4c displayed antiproliferative activity. Estrane derivative 4a inhibited the growth of PC3 and 22Rv1 prostate cancer cells with IC50 of 13.5 and 11.7 μM, respectively, while androstene derivative 4b displayed cytotoxicity comparable to that of cisplatin in hormone-dependent 22Rv1 prostate cancer cells. Androstene derivative 4c was less active against prostate cancer cells than compounds 4a and 4b, and revealed the IC50 value about 20 μM (Table 1).