Isolation and identification of a new mutagen, 2-amino-4-hydroxy-methyl-3, 8-dimethylimidazo[4,5-f] quinoxaline (4-CH2OH-8-MeIQx), from beef extract

By monitoring the miutagenicity to a new Salmonella tester strain, YG1024, which has a much higher level of O-acetyltransferase activity than S. typhimurium TA98, we found two new mutagenic compounds in bacteriological-grade beef extract. One of them (compound I), which had a similar UV spectrum to that of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), was isolated and shown to account for ∼2% of the total miutagenicity of the materials absorbedc to blue cotton, and its concentration was estimated to be 6.0 ng/g beef extract