Canumalla A J, Al-Zamil N, Phillips M, Isab A A, Shaw C F
Department of Chemistry, The University of Wisconsin-Milwaukee, Milwaukee, WI 43201-0413, USA.
J Inorg Biochem. 2001 May;85(1):67-76. doi: 10.1016/s0162-0134(00)00224-5.
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.
利用13C核磁共振和紫外可见光谱方法，研究了金代谢物[Au(CN)₂]⁻的氧化以及金(III)产物进一步氰化形成Au(CN)₄⁻的仿生途径。使用了次氯酸根离子，它是免疫细胞氧化爆发过程中释放的一种氧化剂。该反应生成了混合的二氰合金(III)配合物反式-[Au(CN)₂X₂]⁻，其中X⁻代表平衡的氢氧根和氯配体，并确定了OCl⁻将二氰合金酸盐氧化为金(III)物种的化学可行性。这种氧化反应为合成H[Au(CN)₂Cl₂]提出了一种新方法。反式-[Au(CN)₂X₂]⁻（X⁻ = Cl⁻和Br⁻）或[AuCl₄]⁻与HCN在pH 7.4的水溶液中反应直接生成[Au(CN)₄]⁻，未检测到预期的[Au(CN)ₓX₄₋ₓ]⁻中间体，这归因于氰化物的顺式和反式加速效应。谷胱甘肽和其他硫醇对[Au(CN)₄]⁻的还原是一个复杂的、依赖pH的过程，该过程通过两个中间体进行，最终生成[Au(CN)₂]⁻。这些研究进一步深入了解了体内免疫原性产生的金(I)/金(III)氧化还原循环的可能机制。
