IDENTIFICATION OF O-PHENYLENEDIAMINE POLYMERIZATION PRODUCT CATALYZEDBY CYTOCHROME-C

The hydrogen peroxide (H2O2) and cytochrome c-dependent oxidation of o -phenylenediamine (o-PD) was investigated by spectrophotometry and ele ctrochemistry. The results indicated that o-PD underwent facile cataly tic oxidation in the presence of cytochrome c, and that the degradatio n of cytochrome c by hydrogen peroxide can also be partly prevented in the presence of o-PD. The hydroxyl radical scavengers (mannitol and s odium benzoate) and oxo-heme species scavenger (uric acid) do not inhi bit the oxidation, which implies that the hydroxylation of o-PD may no t be involved in its oxidation. Combining with the results of the mass spectrum, elemental analysis, nuclear magnetic resonance and Fourier transform infrared spectrum of the isolated product, a conceivable str ucture of the product was suggested. (C) 1998 Elsevier Science B.V.