Garlic: Source of the Ultimate Antioxidants—Sulfenic Acids

The medicinal properties of garlic, thought to derive at least in part from the antioxidant activity of its sulfur-containing secondary metabolites, have been recognized for hundreds of years. The ability of garlic to scavenge peroxyl radicals can be accounted for in terms of the action of transient sulfenic acids, which are predicted to react by diffusion-controlled five-center proton-coupled electron transfer (see scheme and transition state).