Formation of three-carbon sugar fragment at an early stage of the browning reaction of sugar with amines or amino acids.

Abstract

Formation of a product easily converted to methylglyoxal on TLC with silica gel was observed in an early stage of the reaction mixture of sugar with an alkylamine or amino acid. NMR spectra of the ether extract of reaction mixtures indicated that methylglyoxal dialkylimme was produced mainly at an early stage of the reaction of glucose with alkylamine, and was assumed to change to methylglyoxal on the TLC. The C3 imine production in the t-butylamine system was apparently little and slow compared to that in the normal alkylamine system. A large, rapid production of C3 imine was also observed in the system of the Amadori product and n-butylamine. These results suggested that the C3 formation in the system with normal alkylamine may occur mainly via a newly proposed mechanism, though the ?-butylamine system may possibly produce it according to the scheme proposed by Hodge.