Maillard reaction of D-glucose: identification of a colored product with conjugated pyrrole and furanone rings.

Formation of colored compounds during the Maillard reaction of D-glucose with butylammonium acetate in aqueous solution has been investigated. Butylamine was used as a model compound analogous to the lysine side chains of proteins. The previously unknown, yellow product, 4-hydroxy-5-methyl-2-(N-butyl-3-hydroxy-5-(2-hydroxyethyl)pyrrolyl-2-methylidene)-2H-furan-3-one (1a), was isolated from the reaction mixtures and identified by spectroscopic data.