Use of 31PNMR spectroscopy to follow the time course of phosphatidylcholine chemical synthesis.

Abstract

31PNMR spectroscopy is shown to be useful for studying the chemical synthesis of phosphatidylcholine from phosphatidic acid and choline. Sharp, well-resolved resonances were obtained by chelating multivalent cations, thereby enabling quantitation of reactants, products, and intermediates. The syntheses of several types of phosphatidylcholines were monitored by 31PNMR spectroscopy, including perdeuterated and headgroup spin-labeled molecules. For perdeuterated phosphatidylcholines, this analysis led to reaction conditions giving much better conversion to product than conditions previously observed. In addition, a polyphosphate side-product was identified in reactions which do not produce phosphatidylcholine, implying either a polyphosphate intermediate in the reaction mechanism, or else a competing side reaction.