Peroxidase activity and stability of surfactant-heme complex in nonaqueous media

A surfactant-heme complex was prepared from hemin using a water-in-oil emulsion with a synthetic nonionic surfactant. The heme complex was soluble in anhydrous benzene with peroxidase activity for the oxidation of o-phenylene-diamine using tert-butyl hydroperoxide as an oxidant. An absorption spectrum of the heme complex in benzene was distinct from that of free heme in an aqueous buffer solution owing to the different aggregation states in the respec-tive solution. Moreover, the heme complex could not be decomposed in benzene even in excess of the hydroper-oxide due to enhanced stability.