SYNTHESIS OF 1,2-DIACYL-SN-GLYCEROPHOSPHATIDYLSERINE FROM EGG PHOSPHATIDYLCHOLINE BY PHOSPHORAMIDITE METHODOLOGY

A simple chemical method for the synthesis of 1,2-diacyl-sn-glyceropho sphatidylserine (PS), with the same fatty acid composition in the sn-1 and sn-2 glycerol positions as egg phosphatidylcholine (PC), is descr ibed. PS synthesis was carried out by a phosphite-triester approach, u sing anoethyl-N,N,N,N'-tetraisopropylphosphorodiamidite (phosphoramidi tate) as the phosphorylating agent, for the formation of phosphate lin kage between serine and diacylglycerol. 1,2-Diacylglycerol, obtained f rom PC hydrolysis by phospholipase C, was coupled with N-t-BOC-L-serin ebenzhydryl ester phosphoramidite with tetrazole as catalyst. Phosphit e-triester was oxidized to the corresponding phosphate-triester with 3 0% H2O2 in CH2Cl2. The cyanoethyl group was removed by addition of an Et(3)N/CH3CN/pyridine mixture, and trifluoroacetic acid was used to el iminate the protecting groups of -diacylglycero-3-phospho)-N-t-BOC-ser inebenzhydril ester. Purified PS was identified by thin-layer chromato graphy, infrared, and H-1 nuclear magnetic resonance.