Reaction of carbohydrates with ammonia as studied by paper chromatography

The reaction on paper between reducing sugars and ammonia has been studied. The reaction products were separated by developing the paper chromatogram with an ammonia-containing solvent. In all cases there were obtained three ninhydrin-, as well as p-anisidine-, reactive spots, the relative intensities of which depended on the reaction time, on the concentration of ammonia, and on the presence or absence of catalysts. These spots are provisionally identified as hexose-ammonia, hexose-1-amine, and dihexosamine. The value of paper chromatography in study reactions involving labile intermediates is discussed.