Oxidative DNA Cleavage Mediated by Water-soluble Carboxyl Iron(III) Corrole

A new water-soluble iron corrole, 5,10,15 -tris[4-(carboxy)phenyl] corrolato-iron (III) ((FeTCPC)-T-III), was synthesized and characterized. UV-Vis, fluorescence and CD spectra, as well as relative viscosity were used to study the interaction between (FeTCPC)-T-III and ct-DNA. Agarose gel electrophrosis was also carried out to investigate the oxidative cleavage ability of (FeTCPC)-T-III to pBR322 DNA in the presence of hydrogen peroxide(H2O2) or tert-BuOOH(TBPH). The results suggest that (FeTCPC)-T-III binds to CT-DNA via an outside binding mode with intrinsic binding constant K-b of 1.96x10(5)L.mol(-1). In the presence of H2O2 or TBPH, (FeTCPC)-T-III exhibits good oxidative cleavage activity toward pBR322 DNA, and TBPH shows a higher oxidative efficiency. Inhibitor tests reveal that neither the hydroxyl radicals nor singlet oxygen is involved in (FeTCPC)-T-III mediated DNA oxidative cleavage. It is suggested that (oxo) iron(V) corrole is the possible active intermediate involved in DNA oxidative damage.