AQUOPENTACYANOFERRATE(II) - EFFECTIVE PROBING ELECTRON-DONOR IN THE CONVERSION OF OXYHEMOGLOBIN TO METHEMOGLOBIN AND PEROXIDE

HbA O2 reacts readily with FeII(CN)5H2O3- to form aquometHb and peroxide via a second order process: rate=k[HbO2][FeII(CN)5H2O3-]. A slight enchancement in the rate of metHb formation due to the H2O2 produced can be prevented by addition of catalase. The reaction is free from complications exhibited by other reductants. The hexacyanide, ferrocyanide, reacts with HbA O2 but at only ca. 0.02% the rate and with formation of cyanometHb. Reductants such as phenols and sulfa drugs may produce radicals that can enter into side reactions. FeII(CN)5H2O3- shows promise as an effective probing reagent for the characterization of H2O2 production from oxygenated heme and other proteins. © 1979.