Derivatives of mDIVI-1 may be used to target and eliminate cancer stem cells. Disruption in the mitochondrial dynamics balance plays a role in cancer. Proteins involved in regulating mitochondrial dynamics represent potential targets for cancer treatment. Mitochondrial fission protein DRP1 is such a target. Derivatives of mDIVI-1 inhibit DRP1, and have demonstrated inhibition of tumorsphere forming capacity, migration and stemness-related signaling in breast cancer cells. These properties result from induction of mitochondrial oxidative stress and reduction of mitochondrial metabolism in the target cancer cells. The potency of an mDIVI-1 derivative may be dramatically increased through addition of at least one membrane-targeting signal and/or a mitochondria-targeting signal.