An intermediate in the synthesis of ubiquinones that has anticancer activity; inhibits the growth of SKOV-3, A2780, and A2870/CP70 human ovarian carcinoma cells (IC50s = 26.6, 27.3, and 28.4 μM, respectively); halts the cell cycle at the G2/M phase, increases ROS production, and induces autophagy and apoptosis in SKOV-3 human ovarian carcinoma cells; downregulates the protooncogene HER-2 in vitro; decreases the incidence of tumors and tumor burden in a SKOV-3 mouse xenograft model at 2.5 mg/kg every four days