title: The inactivation of lipid peroxide radical by quercetin. A theoretical insight.
abstract: The effectiveness of naturally occurring antioxidant quercetin in the inactivation of the damaging lipid peroxide radical was investigated by means of hybrid density functional based approach, using the direct dynamics method, where the thermal rate constants were calculated using variational transition-state theory with multidimensional tunneling. H-atom abstraction in quercetin by CH(3)OO peroxide occurs preferentially at the 4'OH phenolic site, from both kinetic and thermodynamic points of view. In principle, the narrowness of the obtained adiabatic potential-energy profile makes the occurrence of a significant tunnelling contribution possible. In fact, this contribution enhances the value of the computed rate constant at 300 K from 1.94 x 10(1) to 9.63 x 10(3) M(-1) s(-1) indicating that quercetin is a potent natural antioxidant in trapping and scavenging free radicals.
authors.affiliation: Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d'Eccellenza MIUR, Università della Calabria, I-87030 Arcavacata di Rende (CS), Italy.
authors.forename: Sandro G
authors.initials: SG
authors.lastname: Chiodo
authors.forename: Monica
authors.initials: M
authors.lastname: Leopoldini
authors.forename: Nino
authors.initials: N
authors.lastname: Russo
authors.forename: Marirosa
authors.initials: M
authors.lastname: Toscano
mesh_terms: D000465:Algorithms; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology; D006859:Hydrogen / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects; D008054:Lipid Peroxides / Q000737:chemistry*; D008956:Models, Chemical; D010636:Phenols / Q000737:chemistry; D011794:Quercetin / Q000737:chemistry* / Q000494:pharmacology; D013816:Thermodynamics
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D008054:Lipid Peroxides; D010636:Phenols; D017665:Hydroxyl Radical; D006859:Hydrogen; D011794:Quercetin