title: Kinetics of ozone reaction with uric acid, ascorbic acid, and glutathione at physiologically relevant conditions.
abstract: This study quantified the reaction kinetics of O3 with three low molecular weight antioxidants-uric acid (UA), ascorbic acid (AH2), and glutathione (GSH)-found in respiratory mucous. Using a semi-batch reactor in which a 500 ml/min flow of air containing 1-5 parts per million of O3 contacted 3 ml of well-stirred physiological saline solution containing 100-200 microM antioxidant, we found that: (1) mass transfer resistances in the gas and liquid phases were successfully eliminated by the reactor design; (2) the reaction of O3 with UA, AH2 and GSH had stoichiometries of 1:1, 1:1, and 1:2.5, respectively; (3) the reactivity between O3 and antioxidants was in the order UA approximately AH2>GSH. Simulating the measured amounts of O3 absorbed and antioxidant consumed with a mathematical model, reaction rate constants of O(3) with UA, AH2, and GSH were found to be 5.83 x 10(4) M(-1) s(-1), 5.5 x 10(4) M(-1) s(-1), and 57.5 M(-0.75) s(-1), respectively.
authors.affiliation: Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA. szk109@psu.edu
authors.forename: Sanaz
authors.initials: S
authors.lastname: Kermani
authors.forename: Abdellaziz
authors.initials: A
authors.lastname: Ben-Jebria
authors.forename: James S
authors.initials: JS
authors.lastname: Ultman
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D007700:Kinetics; D008956:Models, Chemical; D018384:Oxidative Stress / Q000502:physiology; D010126:Ozone / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000473:pathology; D012965:Sodium Chloride; D014527:Uric Acid / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D014527:Uric Acid; D012965:Sodium Chloride; D010126:Ozone; D005978:Glutathione; D001205:Ascorbic Acid