Deprotonation of flavonoids severely alters the thermodynamics of the hydrogen atom transfer
| Autor: | Jozef Lengyel, Erik Klein, Adam Vagánek, Erika Senajová, Ján Rimarčík |
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| Rok vydání: | 2016 |
| Předmět: |
010405 organic chemistry
Chemistry Hydrogen atom 010402 general chemistry Condensed Matter Physics Photochemistry 01 natural sciences Biochemistry Bond-dissociation energy Dissociation (chemistry) 0104 chemical sciences Solvent chemistry.chemical_compound Electron transfer Deprotonation Computational chemistry Molecule Physical and Theoretical Chemistry Benzene |
| Zdroj: | Computational and Theoretical Chemistry. 1085:7-17 |
| ISSN: | 2210-271X |
| DOI: | 10.1016/j.comptc.2016.04.004 |
| Popis: | Deprotonated polyphenolics exhibit different free radical scavenging activity than parent molecules. Therefore, this study is focused on the hydrogen atom transfer (HAT) from mono-deprotonated forms (phenoxide anions) of 16 flavonoids in terms of OH bond dissociation enthalpies, BDE(A), using B3LYP/6-311++G∗∗ approach. Solvent (benzene and water) contribution is computed using integral equation formalism polarized continuum model, IEF-PCM. Obtained BDE(A) values are usually lower than BDEs of the parent species. In general, from the thermodynamic point of view, HAT from a phenoxide anion is favored to the electron transfer, i.e. formation of the phenoxy radical. For the studied environments, preferred radical anions are identified. Obtained results can contribute to the explanation of experimentally observed pH dependent antioxidant effect of polyphenolics. |
| Databáze: | OpenAIRE |
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