Utility of nicotinoyl derivatives in structural studies of mono- and diacylglycerols by gas chromatography/mass spectrometry. Part 3 - Application to acylglycerols with methyl branchings and epoxy and cyclopropyl rings

Article abstract of DOI:10.1002/(SICI)1096-9888(199604)31:4<411::AID-JMS314>3.0.CO;2-2

Mono- and diacylglycerols with methyl branches and epoxy and cyclopropyl rings were synthesized and, subsequently converted into their nicotinoyl derivatives by reaction with nicotinic acid and N,N'-dicyclohexylcarbodiimide in the presence of N,N-dimethyl-4-aminopyridine. The resulting nicotinoyl derivatives were examined by gas chromatography/mass spectrometry (GC/MS). Their electron impact mass spectra reveal the structures of mono- and diacylglycerols in greater detail than the mass spectra of other acylglycerol derivatives. The positions of methyl branches and epoxy and cyclopropyl rings in mono- and diacylglycerols can be determined from characteristic features in the fragmentation patterns, which are caused by radical-induced cleavage of the alkyl chains following random hydrogen abstraction by the pyridine nucleus. These results offer a promising; approach to the structural analysis of glycerophospholipids by means of GC/MS.