title: Free radical scavenging activity of morin 2'-O(-) phenoxide anion.
abstract: Due to intramolecular H-atom transfer, deprotonation of the most acidic 3-OH group of morin yields 2'-O(-) phenoxide anion. The reaction enthalpies related to mechanisms of free radical scavenging activity of this dominant species at a physiological pH of 7.4 were calculated by PM6 and DFT methods in gas-phase, water, benzene and DMSO. Results indicate the 4'-OH group of 2'-O(-) phenoxide anion is the active site for radical inactivation. The thermodynamically favoured mechanism depends on the polarity of the reaction media: in polar solvents (water and DMSO), the sequential proton loss electron transfer (SPLET) mechanism is preferred while in non-polar benzene (and in gas-phase), the hydrogen atom transfer (HAT) mechanism is responsible for the free radical scavenging activity of the morin phenoxide anion. Results show that the fast, semiempirical PM6 method fairly mimics more accurate, though time-consuming DFT methodologies.
authors.affiliation: Department of Chemical-Technological Sciences, State University of Novi Pazar, Vuka Karadžića bb, 36300 Novi Pazar, Serbia. zmarkovic@np.ac.rs
authors.forename: Zoran
authors.initials: Z
authors.lastname: Marković
authors.forename: Dejan
authors.initials: D
authors.lastname: Milenković
authors.forename: Jelena
authors.initials: J
authors.lastname: Dorović
authors.forename: Jasmina M
authors.initials: JM
authors.lastname: Dimitrić Marković
authors.forename: Višnja
authors.initials: V
authors.lastname: Stepanić
authors.forename: Bono
authors.initials: B
authors.lastname: Lučić
authors.forename: Dragan
authors.initials: D
authors.lastname: Amić
mesh_terms: D000838:Anions / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D047309:Flavones
chemical_list: D000838:Anions; D005419:Flavonoids; D016166:Free Radical Scavengers; C008548:morin; D047309:Flavones