41] Microdetermination of stereoisomers of 2-hydroxy and 3-hydroxy fatty acids

Abstract

Publisher Summary This chapter discusses the microdetermination of stereoisomers of 2-hydroxy and 3-hydroxy fatty acids. 2-Hydroxy acids and 3-hydroxy acids are intermediates in animal and plant degradation of fatty acids. 3-Hydroxy acids are also intermediates in the biosynthesis of fatty acids and 2-hydroxy acids are constituents of brain cerebrosides and of certain waxes. It is possible to determine the enantiomeric composition of microgram amounts of these acids by gas-liquid chromatography of diastereoisomeric derivatives. 2-Hydroxy acid methyl esters are analyzed as O (–)-menthyloxycarbonyl derivatives. About 100 μg of hydroxy acid is methylated with diazomethane and subsequently treated with (–)-menthyl chloroformate. 3-Hydroxy acid methyl esters are converted to 2-D-phenylpropionate derivatives. About 100 μg of hydroxy acid is methylated with diazomethane and then treated with 2-D-phenylpropionyl chloride.