ChemInform Abstract: The Composition of Reducing Sugars in Solution: Current Aspects

Publisher Summary This chapter analyzes the composition of reducing sugars in solution. It elaborates the concepts of relative stabilities of various forms of sugars and elaborates the composition of aldoses, ketoses, and substituted and derived sugars in aqueous solution. Neuclear Magnetic Resonance (NMR) spectrometers have considerably improved over the past few years, and important advances now allow the detection and measurement of components that occur in the range of 0.01 -0.1%. Gas-liquid chromatography (GLC) of trimethylsilyl derivatives has been used to determine the composition of some dozen sugars in water and in pyridine. In the latter solvent, the results agree well with previous determinations; in aqueous solution, however, some of the values for furanoses prove to be too high and the values for idose (presumably mutarotating) rapidly differ considerably from those obtained by NMR spectroscopy. GLC of the trimethylsilyl derivatives is also used for studying the mutarotation of D-fructose. The composition data obtained for the major components agree well with those given by NMR spectroscopy.