Free Radical Intermediate in the N-Demethylation of Aminopyrine by Catalase-Cumene Hydroperoxide System

抄録

Cumene hydroperoxide-supported N-demethylation of aminopyrine catalyzed by catalase has been investigated. The transient free radical of aminopyrine was detected by electron spin resonance at room temperature. When cumene hydroperoxide was previously added to the catalase solution, the rate of the reaction and the concentration of the radical were very low. On the other hand, cumene hydroperoxide did not inhibit the catalase-catalyzed decomposition of hydrogen peroxide. On the contrary, sodium azide significantly inhibited the latter reaction and only slightly inhibited the former reaction. Methanol was not oxidized in the catalase-cumene hydroperoxide system. These results suggest that the active site of catalase for the cumene hydroperoxide-supported N-demethylation of aminopyrine is different from that for the decomposition of hydrogen peroxide.