Synthesis and proaggregatory activity of 1- O-(2-methyloctadecyl)-2- O-acetyl- rac-glycero-3-phosphocholine

Racemic 1- O-(2-methyloctadecyl)-2- O-acetyl-glycero-3-phosphocholine, a branched chain PAF species, was prepared by chemical synthesis and investigated for biological activity on human blood platelets in vitro. The synthesis started from 2- O-benzylglycerol and 2-methyloctadecyl-1-methyl sulfonate and was accomplished in five reaction steps. A comparison with ‘octadecyl-rich’ PAF showed that the PAF species described here exerts a 22-fold weaker proaggregatory activity. Based on [ 3H]PAF-binding studies, an obstruction of PAF-binding or the signal transduction by the branched alkyl chain in C-1 position of the glycerol backbone is suggested.