Purification of protected cyclohexyl phospho carbobenzyloxy-L-serine benzyl ester and the synthesis and purification of deprotected cyclohexyl phospho-L-serine which is a potential analog of phosphatidylserine

Nicholas Jay Amato, The College of Wooster

Abstract

The purpose of this project is to develop a scheme to purify protected cyclohexyl phospho carbobenzyloxy-L-serine benzyl ester (PcycPS), allowing for the final reaction of a multi-step synthesis of a proposed phospholipid analog (PLA) to be performed, yielding the deprotected cyclohexyl phospho-L-serine (cycPS) PLA. The PLA is important because it will allow us to study the structure and function of the naturally occurring phospholipid, phosphatidylserine (PS). Additionally, the PLA will permit us to study the structural interactions characteristic of the lipid bilayer and associating proteins, in the presence of calcium (Ca2+), by mimicking the structure and function of PS. Purification methods investigated consist of acid and base washing, as well as chromatographic methods using silica gel and cation exchange resins. Following the purification of PcycPS and cycPS respectively, the products were characterized by using proton (1H) and phosphorus (31P) nuclear magnetic resonance (NMR) and thin layer chromatography (TLC) utilizing molybdenum and ninhydrin reagents for visualization. PcycPS was purified to a point of which the final synthesis reaction (hydrogenolysis) was able to be performed. Following the hydrogenolysis reaction, cycPS was purified to 95% pure.