title: 18O-Labeled lipid hydroperoxides and HPLC coupled to mass spectrometry as valuable tools for studying the generation of singlet oxygen in biological system.
abstract: Decomposition of lipid hydroperoxides (LOOH) is known to generate toxic products capable to induce tissue injury. We have recently confirmed that decomposition of LOOH into peroxyl radicals is a potential source of singlet oxygen ((1)O(2) in biological system. Using (18)O-labeled linoleic acid hydroperoxide (LA(18)O(18)OH) in the presence of Ce(4+) or Fe(2+), we observed the formation of (18)O-labeled (1)O(2) ((18)[(1)O(2)]) by chemical trapping of (1)O(2) with 9,10-diphenylanthracene (DPA) and detecting the corresponding (18)O-labeled DPA endoperoxide (DPA(18)O(18)O) by HPLC coupled to tandem mass spectrometry (HPLC-MS/MS). (18)O-Labeled alcohol and ketone were also detected providing further evidence for the generation of (1)O(2) by the Russell mechanism. Similarly the reaction of LA(18)O(18)OH with peroxynitrite also generated (18)[(1)O(2)].In conclusion, these results indicates that the use of (18)O-labeled LOOH associated with HPLC-MS/MS can be an useful tool to clarify mechanistic features involved in the reaction of LOOH in biological media.
authors.affiliation: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP26077, CEP 05513-970, São Paulo, SP, Brazil.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Glaucia R
authors.initials: GR
authors.lastname: Martinez
authors.forename: Ana Paula B
authors.initials: AP
authors.lastname: Martins
authors.forename: Marisa H G
authors.initials: MH
authors.lastname: Medeiros
authors.forename: Paolo
authors.initials: P
authors.lastname: Di Mascio
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005609:Free Radicals; D007553:Isotope Labeling / Q000379:methods; D008054:Lipid Peroxides / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D010103:Oxygen Isotopes; D026082:Singlet Oxygen / Q000032:analysis*; D013055:Spectrophotometry, Infrared
chemical_list: D005609:Free Radicals; D008054:Lipid Peroxides; D010103:Oxygen Isotopes; D026082:Singlet Oxygen