STRUCTURAL DETERMINATION OF A NEW MUTAGENIC HETEROCYCLIC AMINE, 2-AMINO-1,7,9-TRIMETHYLIMIDAZO[4,5-G]QUIOXALINE (7,9-DIMEIGQX), PRESENT IN BEEF EXTRACT
H. Nukaya et al., STRUCTURAL DETERMINATION OF A NEW MUTAGENIC HETEROCYCLIC AMINE, 2-AMINO-1,7,9-TRIMETHYLIMIDAZO[4,5-G]QUIOXALINE (7,9-DIMEIGQX), PRESENT IN BEEF EXTRACT, Carcinogenesis, 15(6), 1994, pp. 1151-1154
We previously found two new mutagens, compounds I and II, in bacteriol
ogical-grade beef extract by monitoring the mutagenicity to a new Salm
onella strain, YG1024; compound I was identified as 2-amino-4-hydroxym
ethyl-3,8-dimethylimidazo[4,5-f] quinoxaline (4-CH2OH-8-MeIQx). In the
present study, we isolated compound II from the beef extract, which a
ccounted for 2% of the total mutagenicity of materials adsorbed on blu
e cotton. Further, we found that a large quantity of compound II was p
roduced 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-am
ino-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
mu g in the presence of S9 mix.