The cytochrome P 450 and other peroxidases which contain an Fe-porphyrin active center play a key role in H2O2 removal from biol. systems. The mechanistic studies on this reaction catalyzed by model iron porphyrins have been discussed. In the active intermediate (Fe-oxene porphyrin) forming step, a general base catalyzed heterolytic-type cleavage of O-O bond scheme is consistent with most experiment results from direct observations of reactions in solution and the comparisons with thermolysis studies of peroxides, which is a well known homolytic. A direct, rapid reaction of peroxides with the Fe-oxene intermediate can take place. Peroxides react as substrates as well as oxidants. Those systems could provide convenient models to study the enzyme catalysis.

Key words: ENZYME, OXIDATION, REACTION MECHANISM, IRON COMPLEX, CYTOCHROME, PEROXIDE, FRACTURE MECHANISM, ACTIVE SITE, PORPHINE