Reactions of the α-tocopheroxyl radical in micellar solutions studied by nanosecond laser flash photolysis

AbstractLaser flash photolysis of α-tocopherol in methanol and in aqueous micellar solutions has been shown to produce the α-tocopheroxyl radical. The reaction between the α-tocopheroxyl radical and ascorbate in positively charged hexadecyltrimethylammonium chloride (HTAC) micelles occurred with a second order rate constant of 7.2 × 107 M−1·s−1, whereas in negatively charged sodium dodecyl sulphate (SDS) micelles the rats constant was only 3.8 × 104 M−1·s−1. The α-tocopheroxyl radical was found to be relatively long-lived in HTAC micelles (t12 ⩾ 5 min), allowing the slow disappearance of the α-tocopheroxyl radical by reaction with glutathione to be observed