1,3-Diacylglycero-2-phosphocholines--synthesis, aggregation behaviour and properties as inhibitors of phospholipase D.

A series of 1,3-diacylglycero-2-phosphocholines (1,3-PCs) with acyl chain lengths of C8-C18 were synthesised by chemical introduction of the phosphocholine moiety into the regioisomerically pure 1,3-diacylglycerols, which were obtained from glycerol and the vinyl esters of fatty acid by means of lipase from Rhizomucor mihei. The 1,3-PCs being regioisomers of the natural glycerophospholipids were studied with respect to their aggregation behaviour in the absence and in the presence of sodium dodecylsulfate (SDS) as well as their properties as substrates and inhibitors of phospholipase D (PLD) from cabbage. While the main structures of the pure 1,3-PCs were micelles (C8), liposomes (C10, C12) or planar bilayers (C14, C16, C18), the addition of SDS resulted in the formation of mixed micelles (C8, C10) and mixed liposomes (C12, C14, C16, C18). None of the 1,3-PCs was found to be hydrolysed by PLD, whereas all of them showed inhibitory properties in the standard assay for PLD. The inhibitory power was strongest with 1,3-didecanoylglycero-2-phosphocholine (IC50 = 43 microM).