title: Chlorine dioxide oxidation of dihydronicotinamide adenine dinucleotide (NADH).
abstract: The oxidation of dihydronicotinamide adenine dinucleotide (NADH) by chlorine dioxide in phosphate buffered solutions (pH 6-8) is very rapid with a second-order rate constant of 3.9 x 10(6) M(-1) s(-1) at 24.6 degrees C. The overall reaction stoichiometry is 2ClO2(*) per NADH. In contrast to many oxidants where NADH reacts by hydride transfer, the proposed mechanism is a rate-limiting transfer of an electron from NADH to ClO2(*). Subsequent sequential fast reactions with H(+) transfer to H2O and transfer of an electron to a second ClO2(*) give 2ClO2(-), H3O(+), and NAD(+) as products. The electrode potential of 0.936 V for the ClO2(*)/ClO2(-) couple is so large that even 0.1 M of added ClO2(-) (a 10(3) excess over the initial ClO2(*) concentration) fails to suppress the reaction rate.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA.
authors.forename: Ekaterina V
authors.initials: EV
authors.lastname: Bakhmutova-Albert
authors.forename: Dale W
authors.initials: DW
authors.lastname: Margerum
authors.forename: Jameson G
authors.initials: JG
authors.lastname: Auer
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Applegate
mesh_terms: D017606:Chlorine Compounds / Q000737:chemistry*; D007700:Kinetics; D009243:NAD / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D017606:Chlorine Compounds; D010087:Oxides; D009243:NAD; C025109:chlorine dioxide