ESR detection of free radical intermediates during autoxidation of 5-hydroxyprimaquine. Free Radic Res Commun 1990;9(3-6):383-9
Date
01/01/1990Pubmed ID
2167276DOI
10.3109/10715769009145698Scopus ID
2-s2.0-0025013036 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
Autoxidation of 5-hydroxyprimaquine, a putative metabolite of the antimalarial primaquine, was studied by oxygen consumption and ESR spectroscopy. 5-Hydroxyprimaquine underwent fast autoxidation under mild conditions (pH 7.4-8.5, 25 degrees C, and presence of 1 mM diethylenetriamine pentaacetic acid); each mol of the drug consumed 0.75 mol of oxygen and formed 0.5 mol of hydrogen peroxide. Direct-ESR experiments demonstrated that 5-hydroxyprimaquine autoxidation was accompanied by generation of a drug-derived free radical that is oxygen sensitive. Generation of hydroxyl radical was also established by spin-trapping experiments in the presence of 5,5-dimethyl-1-pyrroline N-oxide. The effect of antioxidant enzymes on hydroxyl radical adduct yield and analysis of autoxidation stoichiometry suggest that the main route for hydroxyl radical generation is the iron-catalyzed reaction between the drug-derived free radical and hydrogen peroxide.
Author List
Vasquez-Vivar J, Augusto OAuthor
Jeannette M. Vasquez-Vivar PhD Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Cyclic N-OxidesElectron Spin Resonance Spectroscopy
Free Radicals
Hydroxides
Hydroxyl Radical
Oxidation-Reduction
Oxygen Consumption
Primaquine
Spin Labels
