Bioorganic mechanisms of the formation of free radicals catalyzed by glucose oxidase.

In this communication, we have described the activation of several xenobiotics by glucose oxidase from Aspergillus niger. The following compounds are readily reduced by d-glucose, in the presence of glucose oxidase: p-nitroso-N,N-dimethylaniline, methyl-1,4-benzoquinone, and 7,7,8,8-tetracyano-quinodimethane. In each case, the products of enzymatic reduction undergo a dismutation reaction with the parent compound and thus afford the formation of free radicals. In some cases, and at an appropriate pH value, the transformation of a parent compound into free radicals is almost quantitative. Under optimal conditions, free radicals are stable for several minutes in aqueous solutions under physiological conditions.