The total synthesis of dilinoleoylphosphatidylserine and its activity in blood clotting systems

A total synthesis ofdl‐phosphatidyl‐(dilinoleoyl)‐l‐serine was achieved by the acylation of the barium salt of the phthalimidomethyl ester of glycerophosphoryl‐n‐anisyloxycarbonyl‐l‐serine. The dilinoleoyl intermediate was treated with hydrazine to remove the phthalimidomethyl group and with hydrogen chloride to remove the anisyloxycarbonyl protecting group. The resulting phosphatidylserine was purified by Rouser's methods, solubilized, and tested for biological activity in the antithromboplastin, recalcification, and Hicks‐Pitney tests. It was found to have about the same anticoagulant activity as beef brain phosphatidylserine and hence was more active than the less unsaturated phosphatidylserine synthesized earlier.