Uncatalysed Intramolecular Acyl Transfer in a Lipid Hydrolysis Product Mixture

The speciation of short-chain mixed acylglycerols in the product mix from enzymatic hydrolysis has been examined by 13C n.m.r. spectroscopy. Under conditions similar to those of the enzymatic reaction, but in the absence of any enzyme, sample mixtures were allowed to stand in buffered emulsions of known pH and temperature. There is clear evidence of uncatalysed conversion of rac-1,2-diacylglycerol into the 1,3-isomer to form an equilibrium mixture. Conversion kinetics to reach equilibrium are first order and do not depend on the state of the emulsion.