Copper(II)/H2O2-mediated DNA cleavage: involvement of a copper(III) species in H-atom abstraction of deoxyribose units

A new bis-amido–copper(II) complex 2 has been prepared. In the presence of reducing agents (ascorbate or DTT) under air atmosphere or hydrogen peroxide, complex 2 exhibited interesting nuclease activities in the 1–10 μM concentration range. For explaining the activity observed with hydrogen peroxide, we propose the occurrence of a bis-amido–copper(III) intermediate and an oxidation mechanism involving a H-atom abstraction of deoxyribose moieties of DNA.