Resolution of enantiomers of hydroxyeicosatetraenoate derivatives by chiral phase high-pressure liquid chromatography

A new method was developed for analyzing the steric configuration of hydroxyeicosatetraenoates (HETEs) and other hydroxy fatty acids. Racemic HETE methyl esters were reacted with either benzoyl or naphthoyl chloride in pyridine and the resulting aromatic ester derivatives purified by reversed phase HPLC and subsequently chromatographed on a chiral stationary phase HPLC column (R)-(-)-N-3,5-dinitrobenzoyl-alpha-phenylglycine)]. In contrast to the enantiomers of the underivatized HETE methyl esters which were only partially resolved, the enantiomers of their aromatic ester derivatives were completely separable on this chiral phase. Chiral HETEs can be retrieved from the aromatic derivatives by alkaline hydrolysis. Thus, this method has both analytical and preparative applications.