3-Oxobetulin acetate is a derivative of the cholesterol biosynthesis inhibitor betulin. It inhibits the growth of P388 murine lymphocytic leukemia cells (EC50 = 0.12 µg/ml), as well as human MCF-7 breast, SF-268 CNS, H460 lung, and KM20L2 colon cancer cells (GI50s = 8, 10.6, 5.2, and 12.7 µg/ml, respectively), but not BxPC-3 pancreas or DU145 prostate cancer cells (GI50s = >10 µg/ml for both). 3-Oxobetulin acetate inhibits replication of X4 tropic recombinant HIV (NL4.3-Ren) in MT-2 lymphoblastoid cells (IC50 = 13.4 µM). It is also active against L. donovani amastigotes when used at a concentration of 50 µM.