Structural determination of a new mutagenic heterocyclic amine, 2-amino-1,7,9-trimethylimidazo[4,5-g]quinoxaline (7,9-DiMeIgQx), present in beef extract.
We previously found two new mutagens, compounds I and II, in bacteriological-grade beef extract by monitoring the mutagenicity to a new Salmonella strain, YG1024; compound I was identified as 2-amino-4-hydroxymethyl-3,8-dimethylimidazo[4,5-f]quinoxaline (4-CH2OH-8-MeIQx). In the present study, we isolated compound II from the beef extract, which accounted for 2% of the total mutagenicity of materials adsorbed on blue cotton. Further, we found that a large quantity of compound II was produced by heating a mixture of creatine, threonine and glucose (1:1:0.5) at 200 degrees C for 5 h, the level being 860-fold of that in the beef extract. The structure of this compound was determined to be 2-amino-1,7,9-trimethylimidazo[4,5-g]quinoxaline (7,9-DiMeIgQx) by X-ray crystallography. The amount of 7,9-DiMeIgQx in bacteriological-grade beef extract was estimated to be 53 ng/g. This compound induced 13 800 and 670 revertants of S. typhimurium YG1024 and TA98 respectively, per micrograms in the presence of S9 mix.
School of Pharmaceutical Science, University of Shizuoka, Japan.
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Nukaya
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Koyota
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Jinno
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Ishida
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Wakabayashi
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Kurosaka
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Kim
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Yamaizumi
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Ushiyama
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Sugimura
D000818:Animals; D002417:Cattle; D008297:Male; D008460:Meat / Q000032:analysis*; D009153:Mutagens / Q000032:analysis*; D011810:Quinoxalines / Q000032:analysis* / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley
C086687:2-amino-1,7,9-trimethylimidazo(4,5-g)quinoxaline; D009153:Mutagens; D011810:Quinoxalines