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Micronutrient Information Center

Potential Interactions Between Coenzyme Q and Alpha-Tocopherol


When alpha-tocopherol (α-TOH) neutralizes a free radical, such as a lipid peroxyl radical (LOO), it becomes oxidized itself, forming the alpha-tocopheroxyl radical (α-TO), which can promote the oxidation of lipoprotein lipids under certain conditions in the test tube (Reaction 1). When the reduced form of coenzyme Q (CoQH2) reacts with α-TO, α-TOH is regenerated and the semiquinone radical (CoQH) is formed (Reaction 2). It is possible for CoQH to react with oxygen (O2) to produce superoxide (O2-), which is a much less oxidizing radical than LOO (Reaction 3a). Alternatively, CoQH can also reduce α-TO back to α-TOH, resulting in the formation of fully oxidized coenzyme Q (CoQ), which does not react with O2 to form O2- (Reaction 3b).