Tânia Petta
University of São Paulo, Brazil
Title: Target and untargeted identification of oxylipids in biological samples by tandem mass spectrometry
Biography
Biography: Tânia Petta
Abstract
Polyunsaturated fatty acids (PUFA) such as arachidonic acid (AA-C20:4), eicosapentaenoic acid (EPA-C20:5) and docosahexahenoic acid (DHA-C22:6) are precursors in the biosynthesis of bioactive oxylipids known as eicosanoids and docosanoids, which are involved in many immunological and physiological processes (1). The position at which an oxygen is inserted into the PUFA chain is highly controlled by regio- and stereoselective enzymes, such as LOX, COX and cytocrome-P450 (2). In biological systems, they are minor components present as isomeric and isobaric species. In this sense, Mass Spectrometry (MS) have shown great potential for quantification and identification of these lipid species (3). In this work, we present the versatility of tandem mass spectrometry for target and untargeted analysis of oxylipids. The developed methods were applied to analyze a hypothalamus rat extract. Using the target LC-MS/MS approach, 10 pre-selected eicosanoids were identified in the crude extract. The untargeted LC-MS/MS approach enabled the detection of several mono- and poly-oxygenated AA products, which were not identified when using the targeted method. Their structures were proposed according to individual product-ion mass spectra achieved via collision induced dissociation. In conjunction, these MS methods represent powerful strategies to accelerate the identification of oxylipids, and can strongly contribute to the discovery of novel lipid mediators in biological samples.