Solvent effects are important in elucidating radical-scavenging mechanisms of antioxidants. A case study on genistein.
In two recent researches on antioxidant mechanisms of flavonoids and isoflavonoids, quantum chemical method was employed to calculate the proton dissociation energies, the bond dissociation energies and the ionization potentials for the phenols and derived radicals to help determine the radical-scavenging mechanisms. As the solvent effect was left out of consideration, the conclusion drawn from the calculation incurred some controversies. In the current study, we re-calculated the parameters for genistein and its anion by employing a B3LYP/6-311+G(d,p)//6-31G(d,p) method with solvent effect. Accordingly, a more reasonable explanation on the experimentally observed behavior of genistein as a radical scavenger was obtained. Therefore, solvent effect should be considered in the investigation of radical-scavenging mechanisms of antioxidants in polar solvents.
Zhang
Hong-Yu
HY
Laboratory for Computational Biology, Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Shandong University of Technology, Zibo 255049, P. R. China. zhanghy@sdut.edu.cn
Wang
Lan-Fen
LF
D000838:Anions; D016588:Anticarcinogenic Agents / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology*; D019833:Genistein / Q000737:chemistry / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000737:chemistry; D007529:Isoflavones / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D011522:Protons; D012997:Solvents; D013816:Thermodynamics
D000838:Anions; D016588:Anticarcinogenic Agents; D000975:Antioxidants; D016166:Free Radical Scavengers; D007529:Isoflavones; D011522:Protons; D012997:Solvents; D017665:Hydroxyl Radical; D019833:Genistein