STRUCTURES AND REACTIVITIES OF SEVERAL IRON(III) COMPLEXES IN THE PRESENCE OF HYDROGEN-PEROXIDE - RELEVANCE TO INDUCTION OF TISSUE-DAMAGE CAUSED BY IRON(III) CHELATES IN RATS

Although the structural features of iron(III) complexes with nitrilotriacetic acid (nta), ethylenediamine-N,N'-diacetic acid (edda) and 2-aminomethyl-pyridine-N,N-diacetic acid (pac) are very similar, the reactivity of the iron(III) chelate in the presence of hydrogen peroxide is quite different in each case; the Fe-III-nta/H2O2 system is highly active for the degradation of deoxyribose, and the Fe-III-edda/H2O2 system is active for the hydroxylation reaction of 2'-deoxyguanosine, but Fe-III-pac/H2O2 is completely inactive for both reactions. The above facts have been elucidated in terms of the structural characteristics of the peroxide adducts, and the origin of the severe tissue damage caused by the iron(III)-nta complex in rats is discussed based on the present results.