Mechanisms of interference of p-diphenols with the Trinder reaction
| Autor: | Damian Tarasek, Hubert Wojtasek, Beata Gąsowska-Bajger |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Radical
Substituent Electrons Photochemistry 01 natural sciences Biochemistry Redox Horseradish peroxidase Homogentisic acid chemistry.chemical_compound Gentisic acid Phenols Drug Discovery Benzoquinones Enzymatic assay interference Hydrogen peroxide Molecular Biology Horseradish Peroxidase Calcium dobesilate biology 010405 organic chemistry Organic Chemistry Hydrogen Peroxide Chromophore Etamsylate 0104 chemical sciences Ampyrone 010404 medicinal & biomolecular chemistry chemistry Spectrophotometry biology.protein Oxidation-Reduction Trinder reaction |
| Zdroj: | Bioorganic Chemistry. 97:1-8 |
| ISSN: | 0045-2068 |
| Popis: | p-Diphenols, such as homogentisic acid, gentisic acid, etamsylate, and calcium dobesilate, interfere with diagnostic tests utilizing the Trinder reaction but the mechanisms of these effects are not fully understood. We observed substantial differences both in oxidation of p-diphenols by horseradish peroxidase and their influence on oxidation of 4-aminoantipyrine and various phenolic substrates. Homogentisic acid was rapidly oxidized by the enzyme and completely blocked chromophore formation. Enzymatic oxidation of the remaining p-diphenols was slow and they only moderately inhibited chromophore formation. However, in the presence of standard substrates all tested p-diphenols were rapidly converted to p-quinones. Hydrogen peroxide consumption was significantly accelerated by homogentisic acid but not much affected by the other p-diphenols. The magnitude and mechanisms of interference caused by p-diphenols therefore depend on their structure which determines their electrochemical properties - while for homogentisic acid with an electron-donating substituent and a lower reduction potential both enzymatic oxidation and reduction of the peroxidase-generated radicals occur, for p-diphenols with electron-withdrawing substituents and higher reduction potentials only the second mechanism is significant. Correlation of the effects on the Trinder reaction with reduction potentials of interfering compounds allows prediction of such properties for a wide range of other reducing compounds based on this parameter. It also explains why compounds with very different structures but strong reducing properties show such effects. |
| Databáze: | OpenAIRE |
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