|Byrdwell, W Craig|
Submitted to: Journal of Chromatography A
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2006
Publication Date: 8/30/2006
Citation: Byrdwell, W.C., Perry, R.H. 2006. Liquid chromatography with dual parallel mass spectrometry and 31p nuclear magnetic resonance spectroscopy for analysis of sphingomyelin and dihydrosphingomyelin: I. bovine brain and chicken egg yolk. Journal of Chromatography A. 1133:149-171. Interpretive Summary: Sphingolipids are molecules that make up the walls, or membranes, of cells. Sphingolipids have been mis-characterized in numerous literature reports in the past. This study definitively shows the presence of a class of sphingolipids that has been overlooked in most previous reports. It uses mass spectrometry to identify each of the individual molecules within the class of sphingolipids. It will force people to re-examine what is currently known about sphingolipids
Technical Abstract: Liquid chromatography coupled to atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) mass spectrometry (MS), in parallel, was used for detection of bovine brain and chicken egg sphingolipids (SL). APCI-MS mass spectra exhibited mostly ceramide-like fragment ions, [Cer-H2O+H]+ and [Cer-2H2O+H]+, whereas ESI-MS produced mostly intact protonated molecules, [M+H]+. APCI-MS/MS and MS3 were used to differentiate between isobaric SL. APCI-MS/MS mass spectra exhibited long-chain base related fragments, [LCB]+ and [LCB-H2O]+, that allowed the sphinganine backbone to be differentiated from the sphingenine backbone. Fragments formed from the fatty amide chain, [FA(long)]+ and [FA(short)]+ allowed an overall fatty acid composition to be determined. The presence of both dihydrosphingomyelin (DSM) and sphingomyelin (SM) sphingolipid classes was confirmed using 31P NMR spectroscopy.