Fatty Acidomics: Global Analysis of Lipid Species Containing a Carboxyl Group with a Charge-Remote Fragmentation-Assisted Approach

Abstract

Charge-remote fragmentation has been well recognized as an effective approach for dissociation of long aliphatic chains. Herein, we exploited this approach for structural identification of all fatty acids including saturated, unsaturated, and modified ones by using electrospray ionization tandem mass spectrometry (ESI-MS/MS) after one-step derivatization of a charge-carried reagent through an amidation reaction. We tested the approach with different charge-carried reagents with respective to the hydrophobicity, charge strength, and distance from the charge to the carboxyl group. We found all the derivatives with these reagents could yield informative charge-remote fragmentation patterns regardless of the different chemical and physical properties of the reagents and these informative fragmentation patterns all could be effectively used for structural elucidation of lipid species containing a carboxyl group. We further found that the distinguished charge-remote fragmentations of fatty acid isomers enabled us to determine the composition of these isomers without any chromatographic separation. Finally, the abundant fragments yielded from individual derivatized moiety enabled us to sensitively quantify the individual species containing a carboxyl group. The described approach was a great extension to the multidimensional mass spectrometry-based shotgun lipidomics for global analysis of fatty acids including isomers and modifications. We believe that this approach could greatly facilitate the identification of the biochemical mechanisms underlying numerous pathological conditions.

Maresin-like Lipid Mediators Are Produced by Leukocytes and Platelets and Rescue Reparative Function of Diabetes-Impaired Macrophages

“…In this study, we identified and characterized two novel ϖ-hydroxy docosahexaenoids, 14 S ,22-diHDHA and 14 R ,22-diHDHA, which are generated from DHA by leukocytes and/or PLT. We performed structural elucidation by aR chiral LC-UV-MS/MS spectroscopy and chromatography including use of deuterium-labeled isotopomers (Wang et al, 2013). The chiralities of the two 14,22-diHDHA stereoisomers were identified.…”

Neuroprotectin/protectin D1: endogenous biosynthesis and actions on diabetic macrophages in promoting wound healing and innervation impaired by diabetes

“…Lipidomics were performed as reported previously (4,47,75). Briefly, wounded skin was extracted three times with cold methanol:butylated hydroxytoluene (1:0.005%).…”

Characterization of phthiocerol and phthiodiolone dimycocerosate esters of M. tuberculosis by multiple-stage linear ion-trap MS

“…6 ) ( 34, 40-43 ), and ions from charge-remote fragmentations can locate the methyl side chains ( 34,43 ) and the functional groups unambiguously ( Fig. 6 , inset).…”

“…By contrast, the traditional GC/MS method for identifi cation of mycocerosic acids is laborious, requiring acid methanolysis to form the methyl ester, separated by TLC, followed by reductive degradation to mycocerosic alcohol and another two-dimensional TLC purifi cation, before formation of the fi nal t-butyldimethylsilyl ether derivatives (23)(24)(25). The superb sensitivity gained for the acid detected as the AMPP derivative (as compared with its underivatized form) also facilitates structural identifi cation and quantitation ( 34,(40)(41)(42)(43). This aspect may deserve further investigation.…”