Reactivity of plasmalogens: kinetics of acid-catalyzed hydrolysis.

The acid-catalyzed hydrolysis of the alpha,-unsaturated ether group of two plasmalogens, lysophosphatidal choline and lysophosphatidal ethanolamine, and several model compounds (isobutyl vinyl ether, 1-butenyl ethyl ether, and dihydropyran) was studied by determining the true second-order rate constants. The results indicate that the chemical reactivity of the substituted vinyl ether group in plasmalogens is not appreciably affected by the presence of a bulky substituent on the -carbon. Activation energies, enthalpies, and entropies were also determined (from measurements of the rate constants at different temperatures).