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Anodic behavior of clioquinol at a glassy carbon electrode

Ghalkhani, M ; Sharif University of Technology | 2011

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  1. Type of Document: Article
  2. DOI: 10.1016/j.bioelechem.2010.10.001
  3. Publisher: 2011
  4. Abstract:
  5. Clioquinol is an antifungal, antiprotozoal and an Alzheimer's disease drug with cytotoxic activity toward human cancer cells. The electrochemical behavior of clioquinol and its oxidation product was studied using cyclic, differential pulse and square-wave voltammetry over a wide pH range on a glassy carbon electrode. The results revealed that the oxidation of clioquinol is an irreversible pH-dependent process that proceeds with the transfer of one electron and one proton in an adsorption-controlled mechanism and results in the formation of a main oxidation product, which adsorbs very strongly on the glassy carbon surface. The charge transfer coefficient was calculated as 0.64. The adsorbed oxidation product presented reversible redox behavior, with two electron and two proton transfer. The electrochemical oxidation of clioquinol as a phenolic compound involves the formation of a phenoxy radical which reacts in at least two ways: in one pathway the radical initiates polymerization, the products remaining at the electrode surface, and in the other the radical is oxidized to a quinone-like structure. A mechanism for the oxidation of clioquinol is proposed
  6. Keywords:
  7. Adsorption process ; Clioquinol ; Oxidation mechanism ; Phenoxy radical ; Alzheimer's disease ; Anodic behavior ; Anti-fungal ; Charge transfer coefficient ; Cytotoxic activities ; Differential pulse ; Electrochemical behaviors ; Electrode surfaces ; Glassy carbon electrodes ; Glassy carbon surfaces ; Human cancer cells ; Oxidation products ; PH-dependent ; Phenolic compounds ; Phenoxy radicals ; Redox behavior ; Square wave voltammetry ; Wide pH range ; Adsorption ; Charge transfer ; Drug products ; Electrochemical oxidation ; Electrodes ; Glass membrane electrodes ; Ion exchange ; Phenols ; Phenoxy resins ; Protons ; Voltammetry ; Glassy carbon ; Quinone derivative ; Chemical structure ; Differential pulse voltammetry ; Drug oxidation ; Electrode ; Electron transport ; Oxidation reduction reaction ; pH ; Polymerization ; Potentiometry ; Proton transport ; Surface property ; Adsorption ; Anti-Infective Agents ; Carbon ; Electrochemistry ; Glass ; Humans ; Hydrogen-Ion Concentration ; Oxidation-Reduction
  8. Source: Bioelectrochemistry ; Volume 80, Issue 2 , 2011 , Pages 175-181 ; 15675394 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S1567539410001556