Analysis of diacylglycerol molecular species in cellular lipid extracts by normal-phase LC-electrospray mass spectrometry

The quantitative determination of 48 molecular species of regioisomeric diacylglycerols has been made in a single analysis of an extract of bone marrow derived macrophages. The analytical procedure involves solvent extraction of neutral lipids, including diacylglycerols, derivatization of free hydroxyl moieties as 2,4-difluorophenyl urethane, and analysis by normal phase liquid chromatography–tandem mass spectrometry. The derivatization step not only prevents fatty acyl group migration, thus allowing determination of both 1,2- and 1,3-diacylglycerols, but also yields species that are sensitively and uniquely determined by constant neutral loss mass spectrometry. The method also detected monoacylglycerols, which were characterized by unique retention time and collisional spectra, and were present in mouse bone marrow derived macrophage extracts.

Derivatization of diacylglycerols (DAGs) by 2,4-difluorophenyl isocyanate followed by LC/MS/MS analysis of difluorophenylurethane-DAG derivatives permits the quantitation of 1,3- and 1,2-DAG molecular species in cells.Figure optionsDownload high-quality image (93 K)Download as PowerPoint slideResearch highlights▶ Diacylglycerols 2,4-difluorophenyl urethane derivatives. ▶ Normal phase LC/MS analysis of 1,3- and 1,2-DAG DFPU derivatives ▶ Monoacylglycerols as DFPU derivatives. ▶ Quantitative analysis in bone marrow derived macrophages. ▶ Neutral loss scanning of 190 u.