5,7,3′,4′-Hydroxy substituted flavonoids reduce the heme of cytochrome c with a range of rate constants
| Autor: | Imani R. Williams, Evan D. Kindl, Veronica R. Moorman, Montserrat Rabago Smith |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Heme Biochemistry Medicinal chemistry Antioxidants Structure-Activity Relationship 03 medical and health sciences chemistry.chemical_compound Animals Taxifolin heterocyclic compounds Flavonoids 030102 biochemistry & molecular biology biology Cytochrome c fungi Cytochromes c food and beverages Catechin Flavanonol General Medicine Plants Eriodictyol 030104 developmental biology chemistry biology.protein Quercetin Oxidation-Reduction Flavanone Luteolin |
| Zdroj: | Biochimie. 162:167-175 |
| ISSN: | 0300-9084 |
| Popis: | Flavonoids are antioxidants known to be abundant in edible plants. Seven 5,7,3',4'-tetrahydroxy substituted flavonoids representing each major flavonoid class were used as cytochrome c reductants to systematically investigate the redox role of their C-rings. Additional examples of flavonoids and benzenediols were investigated to better understand the role of the B-ring. Pseudo-first order rate constants (kobs) and apparent bimolecular rate constants (kapp) values were calculated from spectroscopic measurements. Of the seven flavonoids tested, five yielded measurable observed reduction rate constants. Butein (a chalcone) had the highest apparent bimolecular rate constant (kapp), followed by taxifolin (a flavanonol), catechin (a flavanol), eriodictyol (a flavanone), and luteolin (a flavone). Quercetin (a flavonol) and cyanidin (an anthocyanidin), however, reduced cytochrome c but kapp rate constants were unable to be calculated. Neither this trend nor trends in observed rate constants correlated with flavonoid pKa, solvent accessible surface area, polar surface area, reduction potential, antioxidant ability, resonance, or radical scavenging efficiency. Weak correlation, however, was found with degrees of freedom and the number of redox involved electrons. While some cytochrome c reduction rates have been reported, this study is the first to systematically investigate the role of the structure of the flavonoid C-ring across a full set of flavonoids with identical B-rings. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect