Spectroscopic, kinetic and mechanistic studies of the influence of ligand and substrate concentration on the activation by peroxides of Cu-I-thiolate and other Cu-I complexes

B C Gilbert, S Silvester, P H Walton

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Abstract

Both free-radical and non-radical routes for peroxide oxidation of Cu-I can be identified for copper complexes obtained by the reduction of Cu-II by thiols, including glutathione. Copper(I)-thiolate complexes are obtained, except in the presence of e.g. 1,10-phenanthroline, and these undergo ready reaction with H2O2 and (BuOOH)-Bu-t. EPR spin-trapping studies establish a free-radical reaction mechanism (to give (BuO.)-Bu-t) with the latter, and the formation of HO. from the former occurs only at low concentrations of copper. Kinetic studies (using UV-vis and EPR spectroscopies), together with NMR analysis, lead to the proposal that Cu-I aggregates react via non-radical pathways in contrast to monomeric Cu-I.

Original languageEnglish
Pages (from-to)1115-1121
Number of pages7
JournalJOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
Issue number6
Publication statusPublished - Jun 1999

Keywords

  • HYDROGEN-PEROXIDE
  • DNA-DAMAGE
  • COPPER
  • ION
  • CLEAVAGE
  • H2O2

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