Oxidation Mechanism of 1-Methyl-tryptophan and Tryptophan on Glassy Carbon Electrode: A Comparative Study |
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| Authors: | Nathalia L. Queiroz Carlos H. S. Mendes José A. M. Nascimento Maycom W. F. Silva José Eudes S. Oliveira Severino Carlos B. Oliveira |
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| Affiliation: | Department of Chemistry, Rural Federal University of Pernambuco - UFRPE, 52171-900 Recife-PE, Brazil |
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| Abstract: | The anodic behaviour of 1-methyl-tryptophan (1-mTrp) in aqueous electrolytes was investigated on a glassy carbon electrode (GCE), using voltammetric techniques. The oxidation of 1-mTrp was associated with an electrochemical-chemical (EC) mechanism: one electron and one proton were removed of C2 to form an intermediate radical, 1-mTrp⋅. This was followed by a two-way reaction, producing a 1-mTrp dimer and/or reaction with water to form a final hydroxylated product. The oxidation mechanism of 1-mTrp proposed was also compared with the anodic oxidation Trp on GCE. Differential pulse voltammetry was also explored for quantification of Trp and 1-mTrp in neutral medium with low detection limits, on an anodically pre-treated GCE. |
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| Keywords: | 1-methyl-tryptophan tryptophan glassy carbon electrode amino acids oxidation |
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