A new quantitative method for the analysis of monoacylglycerol isomers using 13C nuclear magnetic resonance spectroscopy.

Current methods for determining the regiochemistry of monoacylglycerols are lengthy, tedious and aggravated by the ready isomerization of 2-acyl-sn-glycerols. A new method employs a very rapid adsorption chromatography step in which isomerization is kept to a minimum, followed by formation of the isopropylidene derivatives using mild procedures. These cyclic derivatives of 1- and 3-acyl-sn-glycerols and 2-acyl-sn-glycerols are stable thermally and display certain characteristic 13C NMR resonances. Integration of these resonances yields directly the proportion of monoacylglycerol isomers in the mixture. The method was applied to the analysis of monoacylglycerols produced by enzymatic hydrolysis of synthetic and naturally occurring triacylglycerols.