The radical cation of N,N-diethyl-para-phenylendiamine: a possible indicator of oxidative stress in biological samples

The alkoxy and peroxy radicals formed in the degradation of hydroperoxides brought about by transition metal ions in acidic media can convert substrates with suitably low oxidation potentials, such as N,N-diethyl-para-phenylendiamine, to the corresponding radical cations. The possibility that these reactions are used in the evaluation of oxidative stress in human beings is discussed.