^{18}O-Labeled lipid hydroperoxides and HPLC coupled to mass spectrometry as valuable tools for studying the generation of singlet oxygen in biological system

Issue title: The Proceedings of the 3rd International Conference on Food Factors (ICoFF 03)

Article type: Research Article

Authors: Miyamoto, Sayuri | Martinez, Glaucia R. | Martins, Ana Paula B. | Medeiros, Marisa H.G. | Di Mascio, Paolo

Affiliations: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP26077, CEP 05513-970, São Paulo, SP, Brazil

Note: [] Corresponding author. Tel.: +55 11 3091 3815 (ext. 224); Fax: +55 11 38155579; E-mail: pdmascio@iq.usp.br

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 (^1O_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 ^1O_2 (^{18}[^1O_2]) by chemical trapping of ^1O_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 ^1O_2by the Russell mechanism. Similarly the reaction of LA^{18}O^{18}OH with peroxynitrite also generated^{18}[^1O_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.

Keywords: linoleic acid hydroperoxide, singlet oxygen, HPLC-MS/MS, [TeX:] ^{18}O-labeled hydroperoxide

Journal: BioFactors, vol. 22, no. 1-4, pp. 333-339, 2004