Peroxidase-mediated oxidation, a possible pathway for metabolic activation of diethylstilbestrol

$\text{In vitro}$ oxidation of diethylstilbestrol (DES) by peroxidase preparations from horse radish or mouse uterus in the presence of hydrogen peroxide yields β-dienestrol, which is also a major $\text{in vivo}$ metabolite of DES in several mammalian species. The oxidation reaction appears to involve reactive intermediates, presumably the semiquinone and quinone of DES, since nonextractable binding to salmon sperm deoxyribonucleic acid and bovine serum albumin was found. The peroxidase-catalyzed oxidation of DES to reactive metabolites in estrogen target organs may be related to the organ toxicity of this synthetic estrogen.