A gas-liquid chromatographic method for steric analysis of 2-hydroxy, 3-hydroxy, and 2,3-dihydroxy acids

Article abstract of DOI:10.1016/0009-3084(94)90056-6

A method was developed for assignment of the absolute configuration of oxylipin-derived 2-hydroxy acids, 3-hydroxy acids and 2,3-dihydroxy acids.The monohydroxy acids were converted into diastereomeric N-(propionoxyacyl)-L-phenylalanine-methyl ester (PAP) derivatives by coupling to the methyl ester of L-phenylalanine followed by propionylation, whereas 2,3-dihydroxy acids were derivatized by treatment with L-phenylalanine methyl ester followed by acetone and perchloric acid, to afford diastereomeric N-(2,3-isopropylidenedioxyacyl)-L-phenylalanine methyl ester (IAP) derivatives.The PAP and IAP derivatives were readily resolved by capillary gas-liquid chromatography.In addition, the method described allowed steric analysis of 3-hydroxy-3-methylheptanoic acid, a branched chain hydroxy acid derived from the prostaglandin analogue, misoprostol. - Keywords: Hydroxy acid; Phenylalanine; Steric analysis; Gas-liquid chromatography