Abstract: Compounds, preferably 5-pyrimidinol and 3-pyridinol derivatives, that act as effective chain breaking antioxidants of both the lipid and water-soluble variety (analogous to the natural Vitamins E and C), many of which are more reactive toward peroxyl radicals than the most potent form of Vitamin E. These compounds may exhibit many chemopreventive effects associated with conditions in which free radical-mediated cellular damage or disruption is implicated and Vitamins E and C are shown to have protective effects. Additionally, these compounds should be excellent oxidation inhibitors as additives to fuels, lubricants, rubber, polymers, chemicals, solvents and foodstuffs.