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Mutagenicity of soy sauce treated with nitrite in the presence of ethanol or alcoholic beverages
233 mutagenicity of 1,3,5-trinitronaphthalene. Other quinones, such as anthraquinone, coumarin and phylloquinone (2-methyl-3-phytyl-l,4-naphthoquinone, vitamin K~) hardly affected the results for 1,3,5-trinitronaphthalene and 1,3-dinitropyrene in TA98. Similar effects of quinones on the mutagenicity of 1,3,5-trinitronaphthalene were observed in TAI00. Further study is in progress to clarify the interacting effects of nitroarenes and quinones with regard to mutagenesis.
96 Higashimoto, M. a, T. Yamamoto a, T. Kinouchi h, H. Matsumot&, Y. Ohnishi b, aFaculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima 770, Japan, bSchool of Medicine, The University of Tokushima, Tokushima 770, Japan
Mutagenicity of soy sauce treated with nitrite in the presence of ethanol or alcoholic beverages Mutagenicity induced by soy sauce after reaction with 50 mM nitrite at pH 3, 37°C, for 60 rain in the presence of 1.25-10% ethanol, was reduced in proportion to the ethanol concentration. The mutagenicity of soy sauce treated with nitrite was also reduced, in proportion to the concentration, in the presence of commercial alcoholic beverages - Japanese sake, wine, shochu, whisky and brandy - but not beer. It was found that the production of mutagenic 3-diazotyramine from tyramine, which is a major precursor of a mutagen in soy sauce treated with nitrite, was strongly reduced in the presence of ethanol. On the other hand, the mutagenicity of nitrite-treated l-methyl- 1,2,3,4-tetrahydro-/3-carboline-3-carboxylic acid (MTCCA), another mutagen precursor in soy sauce, was highly increased in the presence of ethanol. The mutagenicity of the nitrite-treated soy sauce was reduced in the presence of ethanol. This was because the decrease in the mutagen formation from tyramine was stronger than the increase in that from MTCCA by ethanol.
97 Iwasaki, K., A. Matsumoto, T. Yagi, M. Furugouri, K. Shimoi, N. Kinae, School of Food and Nutritional Sciences, University of Shizuoka, 52-1, Yada, Shizuoka 422, Japan
Degradation efficiency of MX, a potent mutagen, in drinking water 3-Chloro-4-dichloromethyl-5-hydroxy-2(5H)-furanone (MX) has been isolated from drinking water and pulp mill effluents. Recently, we reported that MX also exists in swimming pool water and comes from several organic compounds, as well as fumic acid and tyrosine. MX shows extremely high mutagenic activity (TA100, - $9 mix: 13 000 revs/nmol) in the Ames test. The carcinogenic potency and metabolic pathway are obscure. In this experiment, we tried to determine the effects of temperature, ultraviolet (UV) light, human serum and saliva, and beverages on the mutagenic activity of Mx. When an aqueous solution (0.1-500 ppm) of MX was heated at 100°C on a dry bath, or exposed to UV light (3.5 J / m 2 / s ) , the mutagenic activity of both test systems decreased with reaction time. The mutagenic activity also decreased after incubation at 37°C with serum, but not with saliva. In the reaction mixture of MX exposed to UV light, a new peak appeared on a chromatogram in HPLC equipped with a reverse phase column. In an LC-MS study, it was found that the decomposition product contains carbonyl groups in the molecule.
98Yamada, M. a, B. Sedgwick h, K. Matsui ~, T. Nohmi ~, T. Sofuni ~, ~Division of Genetics and Mutagenesis, National Institute of Health Sciences, 118-1, Kamiyoga, Setagaya-ku, Tokyo 158, Japan, bClare Hall Laboratories, ICRF, UK
Biochemical characterization and spontaneous reverse mutation in alkylating-agent hypersensitive strain of S. typhimurium We have constructed the strains lacking O6-meth ylguanine DNA methyl-transferase (MT) and have verified that the ogtsv mutant is more sensitive than the parent strain or adasT mutant to the mutagenicity of methylating agents, such as N-methyl-N'-nitroN-nitroso-guanidine (MNNG), methyl methanesulfonate or dimethylnitrosamine, and ethylating derivative of those chemicals. Since these strains does not exhibit higher mutagenicity against non-alkylating mutagens like AF-2 than wild-type, the hypersensi-
96 Higashimoto, M. a, T. Yamamoto a, T. Kinouchi h, H. Matsumot&, Y. Ohnishi b, aFaculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima 770, Japan, bSchool of Medicine, The University of Tokushima, Tokushima 770, Japan
Mutagenicity of soy sauce treated with nitrite in the presence of ethanol or alcoholic beverages Mutagenicity induced by soy sauce after reaction with 50 mM nitrite at pH 3, 37°C, for 60 rain in the presence of 1.25-10% ethanol, was reduced in proportion to the ethanol concentration. The mutagenicity of soy sauce treated with nitrite was also reduced, in proportion to the concentration, in the presence of commercial alcoholic beverages - Japanese sake, wine, shochu, whisky and brandy - but not beer. It was found that the production of mutagenic 3-diazotyramine from tyramine, which is a major precursor of a mutagen in soy sauce treated with nitrite, was strongly reduced in the presence of ethanol. On the other hand, the mutagenicity of nitrite-treated l-methyl- 1,2,3,4-tetrahydro-/3-carboline-3-carboxylic acid (MTCCA), another mutagen precursor in soy sauce, was highly increased in the presence of ethanol. The mutagenicity of the nitrite-treated soy sauce was reduced in the presence of ethanol. This was because the decrease in the mutagen formation from tyramine was stronger than the increase in that from MTCCA by ethanol.
97 Iwasaki, K., A. Matsumoto, T. Yagi, M. Furugouri, K. Shimoi, N. Kinae, School of Food and Nutritional Sciences, University of Shizuoka, 52-1, Yada, Shizuoka 422, Japan
Degradation efficiency of MX, a potent mutagen, in drinking water 3-Chloro-4-dichloromethyl-5-hydroxy-2(5H)-furanone (MX) has been isolated from drinking water and pulp mill effluents. Recently, we reported that MX also exists in swimming pool water and comes from several organic compounds, as well as fumic acid and tyrosine. MX shows extremely high mutagenic activity (TA100, - $9 mix: 13 000 revs/nmol) in the Ames test. The carcinogenic potency and metabolic pathway are obscure. In this experiment, we tried to determine the effects of temperature, ultraviolet (UV) light, human serum and saliva, and beverages on the mutagenic activity of Mx. When an aqueous solution (0.1-500 ppm) of MX was heated at 100°C on a dry bath, or exposed to UV light (3.5 J / m 2 / s ) , the mutagenic activity of both test systems decreased with reaction time. The mutagenic activity also decreased after incubation at 37°C with serum, but not with saliva. In the reaction mixture of MX exposed to UV light, a new peak appeared on a chromatogram in HPLC equipped with a reverse phase column. In an LC-MS study, it was found that the decomposition product contains carbonyl groups in the molecule.
98Yamada, M. a, B. Sedgwick h, K. Matsui ~, T. Nohmi ~, T. Sofuni ~, ~Division of Genetics and Mutagenesis, National Institute of Health Sciences, 118-1, Kamiyoga, Setagaya-ku, Tokyo 158, Japan, bClare Hall Laboratories, ICRF, UK
Biochemical characterization and spontaneous reverse mutation in alkylating-agent hypersensitive strain of S. typhimurium We have constructed the strains lacking O6-meth ylguanine DNA methyl-transferase (MT) and have verified that the ogtsv mutant is more sensitive than the parent strain or adasT mutant to the mutagenicity of methylating agents, such as N-methyl-N'-nitroN-nitroso-guanidine (MNNG), methyl methanesulfonate or dimethylnitrosamine, and ethylating derivative of those chemicals. Since these strains does not exhibit higher mutagenicity against non-alkylating mutagens like AF-2 than wild-type, the hypersensi-