Journal of Lipid Research, Vol 31, 2119-2126, Copyright © 1990 by Lipid Research, Inc.
Determination of molecular species of enantiomeric diacylglycerols by chiral phase high performance liquid chromatography and polar capillary gas-liquid chromatography
Y Itabashi, A Kuksis and JJ Myher
Banting and Best Department of Medical Research, University of Toronto, Canada.
A simple method is described for the determination of molecular species of
enantiomeric sn-1,2- and sn-2,3-diacylglycerols derived from natural
triacylglycerols by Grignard degradation. The method is based on a
preparative separation of the enantiomeric diacylglycerols as 3,5-
dinitrophenylurethane (DNPU) derivatives by high performance liquid
chromatography (HPLC) on a chiral column (25 cm x 4.6 mm ID) containing
R-(+)-1-(1-naphthyl)ethylamine as a stationary phase. This is followed by
polar capillary gas-liquid chromatography (GLC) of the trimethylsilyl (TMS)
ether derivatives of the enantiomeric diacylglycerols derived from the DNPU
derivatives using trichlorosilane, which does not cause acyl migration and
racemization during the reaction. The cleavage is better than 94% complete.
The method was standardized with synthetic sn-1,2- and sn-2,3-dipalmitoyl-
and rac-1,2-dioleoylglycerols and was applied to the identification and
quantitation of individual molecular species of enantiomeric
diacylglycerols generated by Grignard degradation of the triacylglycerols
from corn oil, cocoa butter, and lard.