THE ANALYSIS OF NEUTRAL GLYCOSES IN BIOLOGICAL MATERIALS BY GAS–LIQUID PARTITION CHROMATOGRAPHY

Abstract

A new method for the determination and characterization of neutral aldoses is presented. The method involves the oxidation of aldoses with hypoiodite or hypobromite to their corresponding aldonic acids which, after conversion to their 1,4-lactones, are treated with pyridine–trimethylchlorosilane–hexamethyl-disilazane mixtures to yield the O-(trimethylsilyl)-aldono-1,4-lactone derivatives. These derivatives are sufficiently stable and volatile to allow their separation and quantitative analysis to be made by gas–liquid partition chromatography (g.l.p.c).The procedure was successfully applied to the analysis of mixtures of aldopentoses, aldohexoses, and aldoheptoses and was found to provide a rapid and accurate method for the quantitative analysis of the glycoses commonly occurring in natural glycans. Preparative g.l.p.c. yielded samples of the individual O-(trimethylsilyl)-aldono-1,4-lactones which had characteristic specific optical rotations, infrared spectra, and g.l.p.c. retention times. Comparison of the properties of the authentic O-(trimethylsilyl)-aldono-1,4-lactones with derivatives prepared from the original glycoses found in the hydrolysates of natural glycans permitted a positive identification of the component glycoses to be made on a microscale.