Effects of Oxygen and Antioxidants on the cis-trans-Isomerization of Unsaturated Fatty Acids Caused by Thiyl Radicals

The interaction of unsaturated compounds methyllinoleate and ?-carotene with thiyl radicals occurred in exchange radical reactions with mercaptoethanol. ?-Carotene was shown to be an effective thiyl radical acceptor. In the case of methyllinoleate, thiyl radicals catalyze cis/trans isomerization, which can be reduced by the natural antioxidant ?-tocopherol; the cis/trans isomerization rate decreases in an oxygen atmosphere