Redox and ligand exchange reactions of potential gold(I) and gold(III)-cyanide metabolites under biomimetic conditions.
A J Canumalla, N Al-Zamil, M Phillips, A A Isab, C F Shaw
Index: J. Inorg. Biochem. 85(1) , 67-76, (2001)
Full Text: HTML
Abstract
Biomimetic pathways for the oxidation of [Au(CN)(2)](-), a gold metabolite, and further cyanation of the gold(III) products to form Au(CN)(4)(-) were investigated using 13C NMR and UV-Visible spectroscopic methods. Hypochlorite ion, an oxidant released during the oxidative burst of immune cells, was employed. The reaction generates mixed dicyanoaurate(III) complexes, trans-[Au(CN)(2)X(2)](-), where X(-) represents equilibrating hydroxide and chloride ligands, and establishes the chemical feasibility of dicyanoaurate oxidation by OCl(-) to gold(III) species. This oxidation reaction suggests a new procedure for synthesis of H[Au(CN)(2)Cl(2)]. Reaction of trans-[Au(CN)(2)X(2)](-) (X(-)=Cl(-) and Br(-)) or [AuCl(4)](-) with HCN in aqueous solution at pH 7.4 leads directly to [Au(CN)(4)](-) without detection of the anticipated [Au(CN)(x)X(4-x)](-)intermediates, which is attributed to the cis- and trans-accelerating effects of the cyanides. The reduction of [Au(CN)(4)](-) by glutathione and other thiols is a complex, pH-dependent process that proceeds through two intermediates and ultimately generates [Au(CN)(2)](-). These studies provide further insight into the possible mechanisms of an immunogenically generated gold(I)/gold(III) redox cycle in vivo.
Related Compounds
Related Articles:
2007-02-15
[Biophys. J. 92(4) , 1241-53, (2007)]
Cholestatic hepatitis caused by acute gold potassium cyanide poisoning.
2001-01-01
[J. Toxicol. Clin. Toxicol. 39(7) , 739-43, (2001)]
Contact allergy to gold sodium thiosulfate. A comparative study.
1997-08-01
[Contact Dermatitis 37(2) , 78-81, (1997)]
2009-09-28
[Anal. Chim. Acta 651(1) , 81-4, (2009)]
2008-03-01
[J. Inorg. Biochem. 102(3) , 584-93, (2008)]