TY - JOUR
T1 - Redox and ligand exchange reactions of potential gold(I) and gold(III)-cyanide metabolites under biomimetic conditions
AU - Canumalla, Annapurna J.
AU - Al-Zamil, Norah
AU - Phillips, Matthew
AU - Isab, Anvarhusein A.
AU - Shaw, C. Frank
PY - 2001
Y1 - 2001
N2 - 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)2X2]-, 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)2Cl2]. Reaction of trans-[Au(CN)2X2]- (X-=Cl- and Br-) or [AuCl4]- with HCN in aqueous solution at pH 7.4 leads directly to [Au(CN)4]- without detection of the anticipated [Au(CN)xX4-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.
AB - 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)2X2]-, 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)2Cl2]. Reaction of trans-[Au(CN)2X2]- (X-=Cl- and Br-) or [AuCl4]- with HCN in aqueous solution at pH 7.4 leads directly to [Au(CN)4]- without detection of the anticipated [Au(CN)xX4-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.
KW - Auricyanide
KW - Aurocyanide
KW - Biological redox reactions
KW - Cis effects
KW - Gold
KW - Hypochlorite
KW - Trans effects
UR - https://www.scopus.com/pages/publications/0034983253
U2 - 10.1016/S0162-0134(00)00224-5
DO - 10.1016/S0162-0134(00)00224-5
M3 - Article
C2 - 11377697
AN - SCOPUS:0034983253
SN - 0162-0134
VL - 85
SP - 67
EP - 76
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
IS - 1
ER -