Determination of singlet oxygen quantum yields with 1,3-diphenylisobenzofuran in model membrane systems.
The oxidation of 1,3-diphenylisobenzofuran by singlet oxygen was investigated in methanol and in two different types of liposomes. It was found that at high concentrations of scavenger 1,3-diphenylisobenzofuran, e.g., > 100 microM in methanol, the 1:1 oxidation stoichiometry is lost and more than one scavenger molecule per molecule of singlet oxygen is consumed. In model membrane systems, where local scavenger concentrations are high due to compartmentalization, correct singlet oxygen quantum yields with 1,3-diphenylisobenzofuran are only determined if the increased oxidation is taken into account.
Krieg
M
M
Department of Pediatrics, MACC Fund Research Center, Medical College of Wisconsin, Milwaukee 53226.
D015060:1,2-Dipalmitoylphosphatidylcholine; D001572:Benzofurans / Q000138:chemical synthesis*; D004134:Dimyristoylphosphatidylcholine; D016166:Free Radical Scavengers; D008081:Liposomes / Q000737:chemistry; D008567:Membranes, Artificial; D008954:Models, Biological; D010084:Oxidation-Reduction; D010777:Photochemistry; D011789:Quantum Theory; D017382:Reactive Oxygen Species / Q000737:chemistry*; D012395:Rose Bengal; D012996:Solutions / Q000737:chemistry
D001572:Benzofurans; D016166:Free Radical Scavengers; D008081:Liposomes; D008567:Membranes, Artificial; D017382:Reactive Oxygen Species; D012996:Solutions; D012395:Rose Bengal; D015060:1,2-Dipalmitoylphosphatidylcholine; C011238:1,3-diphenylisobenzofuran; D004134:Dimyristoylphosphatidylcholine