Isolation, identification, and structure of a potent alkyl-peroxyl radical scavenger in crude canola oil, canolol

Abstract

Alkylhydroperoxides in oxidized oil are undesirable components because they become alkylperoxyl radicals (ROO•) in the presence of heme, hemoglobin, or myoglobin in red meat. ROO• are biochemically reactive and damage nucleic acids and proteins, thereby harming living cells. We isolated a component, a highly potent ROO• scavenger, from crude canola oil (rapeseed), which we designated canolol, and identified its chemical structure, 4-vinyl-2,6-dimethoxyphenol. The canolol content of crude canola oil greatly increased after the seed was roasted as compared with that from unroasted seed, but it decreased in highly purified oil. This anti-ROO• activity was highest in crude oil, deceased after each refining step, and was lowest in highly purified refined oil. Canolol was thus generated during roasting. As shown previously, canolol is one of the most potent anti-ROO• components in crude canola oil and its potency is much greater than that of well-known antioxidants, including α-tocopherol, vitamin C, β-carotene, rutin, and quercetin.