Abstract
The chloroperoxidase-catalyzed oxidation of 1, 4-diazabicyclo[2.2.2]octane (DABCO) by H2O2 or ethylhydroperoxide (EHP) in the presence of Cl- was investigated at pH 2.75, 5.0, and 7.0, and the results were compared with those of the chemical oxidation by HOCl. The oxidation of DABCO in the chloroperoxidase-EHP-Cl- system at pH 5.0 gave a fairly well-resolved electron spin resonance spectrum, which was identified as that of the radical cation of DABCO. The detection of the radical cation suggests that the first step of the chloroperoxidase-catalyzed oxidation of DABCO is the formation of the DABCO chloroammonium cation followed by the homolysis of the cation.
