18O-Labeled lipid hydroperoxides and HPLC coupled to mass spectrometry as valuable tools for studying the generation of singlet oxygen in biological system.
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.
Miyamoto
Sayuri
S
Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP26077, CEP 05513-970, São Paulo, SP, Brazil.
Martinez
Glaucia R
GR
Martins
Ana Paula B
AP
Medeiros
Marisa H G
MH
Di Mascio
Paolo
P
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
D005609:Free Radicals; D008054:Lipid Peroxides; D010103:Oxygen Isotopes; D026082:Singlet Oxygen