Reactions of copper macrocycles with antioxidants and HOCl: potential for biological redox sensing

Rebecca J. Sowden, Katherine D. Trotter, Lynsey Dunbar, Gemma Craig, Omer Erdemli, Corinne M. Spickett, John Reglinski

Research output: Contribution to journalArticle

Abstract

A series of simple copper N(2)S(2) macrocycles were examined for their potential as biological redox sensors, following previous characterization of their redox potentials and crystal structures. The divalent species were reduced by glutathione or ascorbate at a biologically relevant pH in aqueous buffer. A less efficient reduction was also achieved by vitamin E in DMSO. Oxidation of the corresponding univalent copper species by sodium hypochlorite resulted in only partial (~65 %) recovery of the divalent form. This was concluded to be due to competition between metal oxidation and ligand oxidation, which is believed to contribute to macrocycle demetallation. Electrospray mass spectrometry confirmed that ligand oxidation had occurred. Moreover, the macrocyclic complexes could be demetallated by incubation with EDTA and bovine serum albumin, demonstrating that they would be inappropriate for use in biological systems. The susceptibility to oxidation and demetallation was hypothesized to be due to oxidation of the secondary amines. Consequently these were modified to incorporate additional oxygen donor atoms. This modification led to greater resistance to demetallation and ligand oxidation, providing a better platform for further development of copper macrocycles as redox sensors for use in biological systems.
LanguageEnglish
Pages85-96
Number of pages12
JournalBioMetals
Volume26
Issue number1
Early online date18 Nov 2012
DOIs
Publication statusPublished - Feb 2013

Fingerprint

Antioxidants
Oxidation-Reduction
Copper
copper
oxidation
Ligands
antioxidants
Oxidation
Sodium Hypochlorite
Bovine Serum Albumin
Dimethyl Sulfoxide
Vitamin E
Edetic Acid
Biological systems
Amines
Glutathione
Mass Spectrometry
Buffers
Metals
Oxygen

Bibliographical note

Strathclyde University; WestChem; BBSRC [BBS/B/01553]

Keywords

  • copper macrocycles
  • oxidation–reduction
  • glutathione
  • ascorbate
  • vitamin E
  • oxidative stress

Cite this

Sowden, Rebecca J. ; Trotter, Katherine D. ; Dunbar, Lynsey ; Craig, Gemma ; Erdemli, Omer ; Spickett, Corinne M. ; Reglinski, John. / Reactions of copper macrocycles with antioxidants and HOCl : potential for biological redox sensing. In: BioMetals. 2013 ; Vol. 26, No. 1. pp. 85-96.
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Sowden, RJ, Trotter, KD, Dunbar, L, Craig, G, Erdemli, O, Spickett, CM & Reglinski, J 2013, 'Reactions of copper macrocycles with antioxidants and HOCl: potential for biological redox sensing' BioMetals, vol. 26, no. 1, pp. 85-96. https://doi.org/10.1007/s10534-012-9596-9

Reactions of copper macrocycles with antioxidants and HOCl : potential for biological redox sensing. / Sowden, Rebecca J.; Trotter, Katherine D.; Dunbar, Lynsey; Craig, Gemma; Erdemli, Omer; Spickett, Corinne M.; Reglinski, John.

In: BioMetals, Vol. 26, No. 1, 02.2013, p. 85-96.

Research output: Contribution to journalArticle

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