Characterization of epoxides of polyunsaturated fatty acids by mass spectrometry via 3-pyridinylmethyl esters.
The isomeric epoxides of linoleic, arachidonic and docosahexaenoic acids were prepared by reaction with m-chloroperoxybenzoic acid and, after separation by normal-phase high-performance liquid chromatography, were esterified with 3-pyridylcarbinol via the unstable imidazolide generated by the reaction with 1,1'-carbonyldiimidazole. The electron impact mass spectra of these derivatives showed a molecular ion and a sequence of peaks with two characteristic abundant ions that resulted from formal cleavage of the carbon-carbon bonds at the oxirane ring. Both these ions retained the ester group. This fragmentation pattern allowed the unequivocal identification of the separate epoxide isomers.
Balazy
M
M
University of Colorado Health Sciences Center, Division of Clinical Pharmacology, Denver 80262.
Nies
A S
AS
D001095:Arachidonic Acids / Q000032:analysis; D002723:Chlorobenzoates / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D004852:Epoxy Compounds / Q000032:analysis*; D004988:Ethers, Cyclic / Q000032:analysis*; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D011725:Pyridines / Q000032:analysis*
D001095:Arachidonic Acids; D002723:Chlorobenzoates; D004852:Epoxy Compounds; D004988:Ethers, Cyclic; D005231:Fatty Acids, Unsaturated; D007202:Indicators and Reagents; D011725:Pyridines; C000433:3-chloroperbenzoic acid