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.
Nukaya
H
H
School of Pharmaceutical Science, University of Shizuoka, Japan.
Koyota
S
S
Jinno
F
F
Ishida
H
H
Wakabayashi
K
K
Kurosaka
R
R
Kim
I S
IS
Yamaizumi
Z
Z
Ushiyama
H
H
Sugimura
T
T
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