The present disclosure relates to inhibitors of mitochondrial function. Methods of screening compounds for mitochondrial inhibition are disclosed. Also described are methods of using mitochondrial inhibitors called mitoriboscins—;mitochondrial-based therapeutic compounds having anti-cancer and antibiotic properties—;to prevent or treat cancer, bacterial infections, and pathogenic yeast, as well as methods of using mitochondrial inhibitors to provide anti-aging benefits. Specific mitoriboscin compounds and groups of mitoriboscins are also disclosed.