Ellipticinequinone, also known as NSC-383230, is a Drp1 inhibitor. rpitor1 and Drpitor1a inhibited the GTPase activity of Drp1 without inhibiting the GTPase of dynamin 1. Ellipticinequinone showed greater potency than the current std. Drp1 GTPase inhibitor, mdivi-1, (IC50 for mitochondrial fragmentation are (0.06, and 10 μM, resp.). Ellipticinequinone suppressed lung cancer tumor growth in a mouse xenograft model. Ellipticinequinone also inhibited mitochondrial ROS prodn., prevented mitochondrial fission, and improved right ventricular diastolic dysfunction during IR injury.