On the action of ozone on the haemoglobin prosthetic group, haemin and haematoporphyrin: a comparison with the synthetic copper phthalocyanines

Abstract

The action of O 3 on haeme, the prosthetic groups of haemoglobin and other haemoproteins, has been studied by electronic absorption spectroscopy in aqueous solution and in concentrated sulphuric acid. Haeme molecules are the active sites of haemoglobin and belong to the porphin class of molecules: cyclic tetrameric derivatives of pyrrole. Two haeme derivatives were studied: haemin and haematoporphyrin. The action of ozone on these two substrates was studied under different reaction conditions and compared with the behaviour of copper phthalocyanine, an azaporphin. The pseudo first-order reaction rate constant was determined. It has been found that the central metal atom in haemin and copper phthalocyanine catalyzed the decomposition of O 3. In any case ozone is able to cause porphin and azaporphin ring breakdown as evidenced by electronic spectroscopy and also by FT-IR spectroscopy. The medical implications of these results, in particular in relation to the so-called auto-haemotherapy, which involves blood ozonization and reinfusion into the patient, are discussed.