Table of Contents
Metal-Based Drugs
Volume 8, Issue 1, Pages 47-56

Guanine Oxidation in Double-stranded DNA by MnTMPyP/KHSO5: At Least Three Independent Reaction Pathways

Laboratoire de Chimie de Coordination du CNRS, 205 route de Narbonne, Toulouse Cedex 4 F-31077, France

Copyright © 2001 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In order to better define the mechanism and the products of guanine oxidation within DNA, we investigated the details of the mechanism of guanine oxidation by a metalloporphyrin, Mn-TMPyP, associated to KHSO5 on oligonucleotides. We found that the three major products of guanine oxidation are formed by independent reaction routes. The oxidized guanidinohydantoin (1) and the proposed spiro compound 3 derivatives are not precursors of imidazolone lesion (Iz). These guanine lesions as well as their degradation products, may account for non-detected guanine oxidation products on oxidatively damaged DNA.