Spectroscopic studies on the reaction of superoxide ion with tocopherol model compound, 6-hydroxy-2,2,5,7,8-pentamethylchroman

Abstract

The reaction of superoxide ion, O 2 − , with α-tocopherol model compound, 6-hydroxy-2,2,5,7,8-pentamethylchroman ( lb ), was investigated spectrophotometrically in acetonitirle. The transient absorption (λmax=330 nm) observed at the initial stage of the reaction was ascribed to the chromanoxyl-type radical, one-elecron oxidation product of compound lb , on the basis of the spectroscopic [ultraviolet(UV)/visible and electron spin resonance (ESR)] data. Further, the final product observed was ascribable to the tocopherol quinone ( 3 ).