Formation of new heterocyclic amine mutagens by heating creatinine, alanine, threonine and glucose.
A mixture of alanine, threonine, creatinine and glucose was heated in diethylene glycol and water (5:1, v/v) for 15 min at 200 degrees C. The mutagens formed were purified by high-performance liquid chromatography using the Ames/Salmonella mutagenic activity to guide the purification. The structures of the purified mutagens were determined using UV absorption, mass and NMR spectrometry. A new mutagenic compound with a mass number of 217 was found and its mass spectrum did not correspond to any known mutagen derived from food. This new compound accounted for 4% of the total mutagenic activity. Other mutagenic compounds were identified as MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline), and a new mutagen 4,7,8-TriMeIQx (2-amino-3,4,7,8-tetramethylimidazo[4,5-f]quinoxaline) with a mutagenic activity of 73,000 TA98 revertants per microgram. The percentage of the mutagenic activity attributable to MeIQx, 4,8-DiMeIQx and 4,7,8-TriMeIQx was 10%, 70% and 3%, respectively. The yield of MeIQx, 4,8-DiMeIQx and 4,7,8-TriMeIQx was 10, 36 and 6 nmole/mmole creatinine. The formation of TriMeIQx from natural meat components suggests that this new quinoxaline mutagen may be present in cooked foods.
Skog
K
K
Department of Food Chemistry, University of Lund, Sweden.
Knize
M G
MG
Felton
J S
JS
Jägerstad
M
M
D000409:Alanine / Q000737:chemistry; D000588:Amines / Q000138:chemical synthesis* / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003296:Cooking; D003404:Creatinine / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D015416:Maillard Reaction; D013058:Mass Spectrometry; D008460:Meat; D009152:Mutagenicity Tests; D009153:Mutagens / Q000138:chemical synthesis* / Q000737:chemistry; D011810:Quinoxalines / Q000138:chemical synthesis; D012486:Salmonella typhimurium; D013912:Threonine / Q000737:chemistry
D000588:Amines; D000596:Amino Acids; D006571:Heterocyclic Compounds; D009153:Mutagens; D011810:Quinoxalines; D013912:Threonine; D003404:Creatinine; D005947:Glucose; D000409:Alanine