Formation of a new mutagenic DiMeIQx compound in a model system by heating creatinine, alanine and fructose.

A mixture of creatinine, D-fructose and DL-alanine was heated in diethylene glycol containing 14% water for 2 h at ca. 128 degrees C. The mutagens formed were extracted with 1-butanol, and purified by cation-exchange column chromatography, C18 reversed-phase Sep-Pak treatment and reversed-phase HPLC. According to its UV absorption, mass and 1H NMR spectra, one isolated fraction was tentatively assigned the chemical name, 3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxalin-2-amine (4,8-DiMeIQx). This finding is in agreement with the suggestion that sugars, amino acids and creatinine present in meat may be the precursors of the mutagenic imidazoquinolin- and imidazoquinoxalin-2-amines (IQ compounds).