title: Recent Advances on Mass Spectrometry Analysis of Nitrated Phospholipids.
abstract: In recent years, there has been an increasing interest in nitro fatty acids (NO2-FA) as signaling molecules formed under nitroxidative stress. NO2-FA were detected in vivo in a free form, although it is assumed that they may also be esterified to phospholipids (PL). Nevertheless, insufficient discussion about the nature, origin, or role of nitro phospholipids (NO2-PL) was reported up to now. The aim of this study was to develop a mass spectrometry (MS) based approach which allows identifying nitroalkenes derivatives of three major PL classes found in living systems: phosphatidylcholines (PCs), phosphatidylethanolamine (PEs), and phosphatidylserines (PSs). NO2-PLs were generated by NO2BF4 in hydrophobic environment, mimicking biological systems. The NO2-PLs were then detected by electrospray ionization (ESI-MS) and ESI-MS coupled to hydrophilic interaction liquid chromatography (HILIC). Identified NO2-PLs were further analyzed by tandem MS in positive (as [M + H](+) ions for all PL classes) and negative-ion mode (as [M - H](-) ions for PEs and PSs and [M + OAc](-) ions for PCs). Typical MS/MS fragmentation pattern of all NO2-PL included a neutral loss of HNO2, product ions arising from the combined loss of polar headgroup and HNO2, [NO2-FA + H](+) and [NO2-FA - H](-) product ions, and cleavages on the fatty acid backbone near the nitro group, allowing its localization within the FA akyl chain. Developed MS method was used to identify NO2-PL in cardiac mitochondria from a well-characterized animal model of type 1 diabetes mellitus. We identified nine NO2-PCs and one NO2-PE species. The physiological relevance of these findings is still unknown.
authors.affiliation: Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago , 3810-193 Aveiro, Portugal.
authors.forename: Tânia
authors.initials: T
authors.lastname: Melo
authors.affiliation: Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago , 3810-193 Aveiro, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Domingues
authors.affiliation: Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago , 3810-193 Aveiro, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Ferreira
authors.affiliation: Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig , 04109 Leipzig, Germany.|Center for Biotechnology and Biomedicine, Universität Leipzig , 04109 Leipzig, Germany.
authors.forename: Ivana
authors.initials: I
authors.lastname: Milic
authors.affiliation: Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig , 04109 Leipzig, Germany.|Center for Biotechnology and Biomedicine, Universität Leipzig , 04109 Leipzig, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Fedorova
authors.affiliation: Department of Chemistry and CICECO, University of Aveiro , 3810-193 Aveiro, Portugal.
authors.forename: Sérgio M
authors.initials: SM
authors.lastname: Santos
authors.affiliation: UCIBIO, REQUIMTE, Department of Chemistry, Faculty of Pharmacy, University of Porto , 4099-002 Porto, Portugal.
authors.forename: Marcela A
authors.initials: MA
authors.lastname: Segundo
authors.affiliation: Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago , 3810-193 Aveiro, Portugal.
authors.forename: M Rosário M
authors.initials: MR
authors.lastname: Domingues
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism; D008297:Male; D008929:Mitochondria, Heart / Q000737:chemistry; D009574:Nitro Compounds / Q000032:analysis*; D010713:Phosphatidylcholines / Q000032:analysis*; D010714:Phosphatidylethanolamines / Q000032:analysis*; D010718:Phosphatidylserines / Q000032:analysis*; D017208:Rats, Wistar; D053719:Tandem Mass Spectrometry
chemical_list: D009574:Nitro Compounds; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines