title: One-electron oxidation of antioxidants: a kinetic-thermodynamic correlation.
abstract: The values of the bimolecular rate constants for the reactions of 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) radical cation with epicatechin (((2.4 ± 0.2)) s(-1) M(-1)), and epigallocatechingallate ((29 ± 5) s(-1) M(-1)) were obtained by spectrophotometric measurements. We propose a correlation between the Gibbs energy ΔG(o) for the one-electron charge-transfer reactions from several antioxidants to radical species and the rate constants of the corresponding bimolecular reactions. This correlation can be used to predict rate constants of reactions of known ΔG(o) values.
authors.affiliation: Universidad Nacional de La Plata, Diag 113 y 64, La Plata, Argentina.
authors.forename: Laura S
authors.initials: LS
authors.lastname: Villata
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Berkovic
authors.forename: Mónica C
authors.initials: MC
authors.lastname: Gonzalez
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Mártire
mesh_terms: D052160:Benzothiazoles / Q000737:chemistry; D002392:Catechin / Q000737:chemistry; D004583:Electrons; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D007700:Kinetics; D010084:Oxidation-Reduction; D013451:Sulfonic Acids / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D052160:Benzothiazoles; D013451:Sulfonic Acids; C491764:epigallocatecol gallate; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D005707:Gallic Acid; D002392:Catechin
references.citation: Arch Biochem Biophys. 2001 Apr 15;388(2):261-6
references.pmid: 11368163
references.citation: Food Chem Toxicol. 1999 Sep-Oct;37(9-10):937-42
references.pmid: 10541448
references.citation: Clin Biochem. 2004 Apr;37(4):277-85
references.pmid: 15003729
references.citation: Free Radic Biol Med. 1999 May;26(9-10):1231-7
references.pmid: 10381194
references.citation: Methods Enzymol. 1999;299:50-62
references.pmid: 9916196
references.citation: Methods Enzymol. 1999;299:15-27
references.pmid: 9916193
references.citation: Free Radic Biol Med. 1999 Feb;26(3-4):285-94
references.pmid: 9895218
references.citation: Biochem Biophys Res Commun. 2001 Apr 20;282(5):1161-8
references.pmid: 11302737