Exploratory laser flash photolysis study of free radical reactions and magnetic field effects in melatonin chemistry.
Melatonin is an excellent free radical scavenger, reacting with tert-butoxyl and cumyloxyl radicals with rate constants of 3.4 x 10(7) and 6.7 x 10(7) M-1s-1, respectively. Reaction with benzophenone triplet occurs with a near-diffusion-controlled rate constant of 7.6 x 10(9) M-1s-1 in acetonitrile and probably involves charge transfer. When the radical pair formed by reaction of benzophenone triplet and melatonin is sequestered in a micelle, it is subject to extensive magnetic field effects that can be readily interpreted by the radical pair model.
Scaiano
J C
JC
Department of Chemistry, University of Ottawa, Ontario, Canada.
D001577:Benzophenones / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000528:radiation effects; D005609:Free Radicals / Q000737:chemistry / Q000528:radiation effects; D066298:In Vitro Techniques; D007834:Lasers; D008280:Magnetics; D008550:Melatonin / Q000737:chemistry* / Q000528:radiation effects*; D008823:Micelles; D010777:Photochemistry; D010782:Photolysis; D017319:Photosensitizing Agents / Q000737:chemistry; D013053:Spectrophotometry
D001577:Benzophenones; D016166:Free Radical Scavengers; D005609:Free Radicals; D008823:Micelles; D017319:Photosensitizing Agents; C047723:benzophenone; D008550:Melatonin