Determination of antioxidant capacity of thiol-containing compounds by electron spin resonance spectroscopy based on Cu2+ ion reduction
| Autor: | Dan Li, Shuang Zang, Ziwei Zhang, Kun Wang, Jia Jiang, Aimin Yu, Sizhu Tian |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
medicine.diagnostic_test 010405 organic chemistry 010401 analytical chemistry Trolox equivalent antioxidant capacity Captopril Glutathione 01 natural sciences 0104 chemical sciences Analytical Chemistry Ion law.invention chemistry.chemical_compound chemistry law Spectrophotometry Tiopronin medicine Thiol Electron paramagnetic resonance Nuclear chemistry medicine.drug |
| Zdroj: | Talanta. 184:23-28 |
| ISSN: | 0039-9140 |
| DOI: | 10.1016/j.talanta.2018.02.098 |
| Popis: | Electron spin resonance spectroscopy was applied to determining the antioxidant capacity of eight thiol-containing compounds, including reduced glutathione, N-acetyl-L-cycsteine, methimazole, captopril, and tiopronin with one thiol group, 1,4-dithioerythritol and 2,3-dimercapto-1-propanol with two thiol groups, as well as L-cystine with no free thiol group. Cu2+ ion gives an electron spin resonance signal and is reduced to Cu+ ion with no electron spin resonance signal by the free thiol group in the compounds. Trolox equivalent antioxidant capacity (TEAC) was used to evaluate the reducing ability of the thiol-containing compounds and the TEAC values were found to be relevant to the number of thiol groups contained in the compounds. For the purpose of comparison, the UV-vis spectrophotometry, cupric reducing antioxidant capacity (CUPRAC) method, and Ellman assay were applied to the determination of the antioxidant capacity of the thiol-containing compounds. The TEAC values obtained by the present method were very close to those obtained by UV-vis method. However, compared with CUPRAC method, for methimazole the present method gave a more reasonable TEAC value. The present method was also applied to the quantification of N-acetyl-L-cycsteine, methimazole, captopril, and tiopronin in their pharmaceutical formulations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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