Monitoring of intermediates of clioquinol electro-oxidation by thin-layer spectral and electrophoretic electrochemistry

作者：Zhang, Wen Wen; He, Xiao Lin; Deng, Ning; Wang, Yan; He, Jian Bo^*

来源：Electrochimica Acta, 2014, 127: 403-409.

DOI：10.1016/j.electacta.2014.02.069

• Clioquinol
• Spectroelectrochemistry
• Cyclic voltabsorptometry
• Capillary electrophoresis
• Oxidation pathway

Monitoring of unstable intermediates is very important for clarifying complex electrochemical reaction pathways. A combination of thin-layer spectral and electrophoretic electrochemistry, both based on fast thin-layer electrolysis, has been developed to monitor the intermediates of electro-oxidation of clioquinol in acidic, physiological and alkaline buffer media. Two thin-layer electrochemical cells were fabricated and coupled with a UV-vis spectrometer and an electrophoresis apparatus, respectively. Double-potential thin-layer UV-vis spectroelectrochemistry, double-wavelength thin-layer cyclic voltabsorptometry and thin-layer electrophoretic electrochemistry provided mutually-supporting information on the redox pathway of clioquinol. Two intermediates, a disproportionatable semiquinone anion radical and a labile quinone derivative, were detected. The chemical activity of the semiquinone anion radical is highly pH-dependent. The final soluble products of clioquinol are pH-dependent but irrelevant to whether the oxidation reaction is electrochemical or chemical in nature. A complex reaction pathway is proposed for the oxidation of clioquinol, which may help to better understand the metabolism mechanism and chemical toxicity of this anti-neurodegeneration drug.

• 出版日期2014-5-1
• 单位合肥工业大学