Copper(II) ethylenediaminetetraacetate complex does activate hydrogen peroxide in the presence of biological reductants.

The reaction of CuII (edta) (edta: ethylenediaminetetraacetic acid) with hydrogen peroxide (H2O2) was studied in the pH range of 6.0 to 8.0. CuII (edta) did not react with H2O2 in the all pH range examined in the absence of biological reductants. CuII (edta), however, could react with H2O2 in the presence of biological reductants such as ascorbic acid, cysteine and NADH to give thibarbituric acid (TBA) reactive substance, regardless of the pH. From these results, it is concluded that CuII (edta) cannot be bound to H2O2 and that the change of the redox potential of Cu2+ ion on ligating with edta may cause CuII (edta) to be unable to oxidize H2O2.