Chemistry of Non-enzymic Browning. VII. Crystalline Di-D-fructose-glycine and some related compounds

Abstract

Glycine and D-glucose react to give N-(carboxymethyl)-1-amino-1-deoxy-D-fructose. The further reaction with D-glucose or D-mannose to yield di-D-fructose-glycine [NN-di-(D-arabino-3,4,5,6-tetrahydroxy-2-oxohexyl)glycine] is now reported. Di-D-fructose- glycine was isolated as the crystalline dihydrate, m.p. 112 °C, [α]_D²⁵ -78°, and its structure was deduced from its formation, its decomposition, and from the products formed on periodate oxidation. Infra-red spectra showed that both the above compounds occurred in a ring form, probably the β-D-fructopyranose form. Di-D-fructose-glycine was a labile compound which decomposed to give a quantitative yield of N-(carboxy-methyl)-1-amino-1-deoxy-D-fructose and unknown carbonyl compounds. The rate of this decomposition has been studied at various pH values and temperatures.    Other primary aliphatic amines and aldoses gave the corresponding diketose-amines which have similar properties. These compounds possibly have an important role in non-enzymic browning reactions.