(20)R-Protopanaxadiol is a sapogenin that has been found in P. ginseng and has anticancer and antibacterial activities. It has a cytotoxic concentration (CC50) value of 6.1 μM in MT-4 human T cell leukemia cells and inhibits the growth of several additional cancer cell lines, including A549 human lung carcinoma, SKOV3 human ovarian adenocarcinoma, SK-Mel-2 human melanoma, P388 and L1210 murine leukemia, and K562 human chronic leukemia cells (ED50s = 11-26 μM). (20)R-protopanaxadiol also inhibits the growth of H. pylori in vitro (MICs = 50-100 μg/ml).