ABSTRACT
The enantiomeric resolution of a series of chiral fatty acid epoxide and alpha-substituted palmitic acid analogues was examined by high-performance liquid chromatography on chiral stationary phases. The compounds were chromatographed as ester or amide derivatives on commercially available stationary phases that consisted of (R)-N-(3,5-dinitrobenzoyl)phenylglycine either covalently or ionically bonded to aminopropylsilica gel. Factors affecting separation included hydrocarbon chain length of the fatty acid, the type of substituents attached to the chiral center, the type of derivative, and column temperature. Effects of sample size, mobile phase composition, column type, and flow-rate on the resolution and separation factor values were also explored.
Subject(s)
Fatty Acids/analysis , Amides/analysis , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Esters/analysis , Solvents , Spectrophotometry, Ultraviolet , StereoisomerismABSTRACT
The enantiomeric composition of an enzymatically synthesized sample of the coenzyme A ester of 2-tetradecylglycidic acid (TDGA-CoA) was determined by the use of high-performance liquid chromatography with a chiral stationary phase. The stationary phase was commercially available and consisted of (R)-N-(3,5-dinitrobenzoyl)phenylglycine covalently bonded to aminopropyl silica gel. Analysis was performed using the phenacyl derivative of 2-tetradecylglycidic acid (TDGA), obtained by mild hydrolysis of the TDGA-CoA followed by reaction of the extracted TDGA with phenacyl chloride. Chromatography showed the enantiomeric purity of TDGA-CoA, synthesized in a rat liver microsomal enzyme mixture over a 2-h period, to be a 15.6:1 ratio of the R:S enantiomers (88% ee). The result demonstrates the stereoselectivity of the long-chain fatty acid-coenzyme A synthetase for chiral fatty acid epoxide, TDGA.
