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1.
Helmut Bartsch Benedetto Terracini Christian Malaveille Lorenzo Tomatis Jürgen Wahrendorf Gisle Brun Betty Dodet 《Mutation research》1983,110(2)
The quantitative relationship between carcinogenicity in rodents and mutagenicity in Salmonella typhimurium was examined, by using 10 monofunctional alkylating agents, including N-nitrosamides, alkyl methanesulfonates, epoxides, β-propiolactone and 1,3-propane sultone. The compounds were assayed for mutagenicity in two S. typhimurium strains (TA1535 and TA100) and in plate and liquid assays. The mutagenic activity of the agents was compared with their alkylating activity towards 4-(4′-nitrobenzyl)pyridine and with their half-lives (solvolysis constants) in an aqueous medium. No correlations between these variables were found, nor was mutagenic activity correlated with estimates of carcinogenicity in rodents.There was a positive relationship between carcinogenicity and the initial ratios of 7-: O6-alkylguanine formed or expected after their reaction with double-stranded DNA in vitro. The results suggest that alkylation of guanine at position O6 (or at other O atoms of DNA bases) may be a critical DNA-base modification that determines the overall carcinogenicity of these alkylating agents in rodents. 相似文献
2.
I. Kumashiro A. Yamazaki T. Meguro T. Takenishi T. Tsunoda 《Biotechnology and bioengineering》1968,10(3):303-320
A novel and convenient method for the synthesis of guanosine is described. The reaction of AICA-riboside with sodium methylxanthate gave 2-mercaptoinosine in almost quantitative yield. The latter was oxidized with hydrogen peroxide to afford inosine-2-sulfonic acids, which was readily animated to give guanosine in excellent yield. Similarly, the preparation of N2-methylguanosine and N2,N2-dimethylguanosine, minor constituents of transfer RNA, was also accomplished. Furthermore, this procedure was extended to the synthesis of 2′,3′-O-isopropylideneguanosine and the isopropylidene derivatives of various N2-substituted guanosines from 2′,3′-O-isopropylidene-AICA-riboside. Guanosine via 2′,3′-O-isopropylideneguanosine was successfully phosphorylated to give 5′-guanylic acid. 相似文献
3.
The frequency ofhis
+ revertants induced by N-methyl-N-nitrosourea (MNU) and N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) in the strain TA100 ofSalmonella typhimurium was decreased by gallic and tannic acid. In weak buffer solutions, the inhibition effects of gallic acid towards MNU and
MNNG mutagenicity was caused primarily by a decrease of pH in the incubation mixtures. At adjusted pH (pH 5.0 and 6.5), the
antimutagenic effects are largely the result of an interaction between MNU or MNNG with phenolic acids outside the cells. 相似文献
4.
Takafumi Ohta Takashi Inoue Shoji Takitani 《Bioscience, biotechnology, and biochemistry》2013,77(10):2559-2564
Various Japanese foods were treated with 22 mm nitrite at pH 3 for 1 hr at 37°C. Ethyl acetate extracts of the nitrosation mixtures were examined for their total NC content and mutagenicity to Salmonella typhimurium TA 100 to search for foods which formed a considerable amount of N-nitroso compounds (NCs) but showed no mutagenicity.Most of the foods (32/35) formed NCs at levels in the range of 22–4758 μmol N-NO/kg after the nitrite treatment. Among these foods, fermented products had a high level of NCs (mean = 952 μmol N-NO/kg), vegetables, cereals and fruits had a moderate level of NCs (mean = 225 μmol N-NO/kg), and meat and fish had a low level of NCs (mean = 99 μmol N-NO/kg). Only five kinds of food, i.e., soy sauce, salted Chinese cabbage, cabbage, Japanese radish and sausage, showed mutagenicity to Salmonella typhimurium TA 100. These results imply that considerably large amounts of various precursors of non-mutagenic NCs are present in foods, especially in some fermented products and citrus fruits. 相似文献
5.
Shizuko Yamaguchi Tomoko Yoshikawa Shingo Ikeda Tsunehiko Ninomiya 《Bioscience, biotechnology, and biochemistry》2013,77(7):797-802
Taste effects of six newly synthesized ribonucleotide derivatives, i.e., disodium salts of 2-methyl-5′-inosinic acid · 6H2O, 2-ethyl-5′-inosinic acid · 1.5H2O, 2-N-methyl-5′-guanylic acid · 5.5H2O, 2-N-dimethyl-5′-guanylic acid · 2.5H2O, 2-methylthio-5′-inosinic acid · 6H2O and 2-ethylthio-5′-inosinic acid · 2H2O, were studied. Stimulus thresholds (detection thresholds) of these derivatives ranged from about 0.02 to 0.006 g/100ml. Flavor-enhancing activities of them were 2.3 to 8.0 times larger than that of disodium 5′-inosinate · 7.5H2O IMP) in the synergistic effect with monosodium glutamate. Furthermore, the quality of taste of all the derivatives was recognized to be the same kind to that of IMP. 相似文献
6.
《Mutation Research Letters》1995,346(2):99-105
Mutagenicity of 6-aminoquinoxaline derivatives was tested with Salmonella typhimurium strains Ta98 and TA100 in the presence and absence of S9 mix from the viewpoint that the 6-aminoquinoxaline skeleton is a common unit of mutagenic imidazoquinoxalines. We tested nine compounds: 5-methyl-6-methylaminoquinoxaline (1), 3,5-dimethyl-6-methylaminoquinoxaline (2), 2,5-dimethyl-6-metnylaminoquinoxaline (3), 6-methylamino-2,3,5-trimethylquinoxaline (4), 2,3-diethyl-5-methyl-6-methylaminoquinoxaline (5), 5-methyl-6-methylamino 3-phenylquinoxaline (6), 6-amino-2,3,5-trimethylquinoxaline (7), 6-dimethylamino-2,3-5-trimethylaminoquinoxaline (8), 6-amino-2,3-dimethylquinoxaline (9). These compounds showed the mutagenic activity for both TA98 and TA100 in the presence of S9 mix, where they were more sensitive for TA100 strain. Methyl groups at the 2, 3 and/or 5 positions increased the potency of mutagenicity (1 < 2 < 3 ⪡ 4, 9 < 7). However, ethyl groups at the 2 and 3 positions lowered the mutagenicity of the methyl substitute but elevated it of the parental compound (1 < 5 < 4). A methyl group at the N6 position decreased the mutagenicity (7 > 4 > 8). 相似文献
7.
The mutagenicity of N-methyl-N′-nitro-N-nitrosoguanidine to Salmonella typhimurium hisG46 was enhanced by pre-incubating the chemical with bacteria in sodium phosphate buffer. Addition of glucose (to 15 mM) to the pre-incubation mixture further enhanced the mutagenicity. Pre-incubation with glucose also increased the mutagenicity of N-methyl-N-nitrosourea. Fructose, galactose, pyruvate and succinate also enhanced the mutagenicity of N-methyl-N′-nitro-N-nitrosoguanidine. The effect of glucose was observed with S. typhimurium strains hisG46, TA1975, TA1950, TA1535 and TA100. 相似文献
8.
Yoshinari Kobayashi Ryukichi Matsuo 《Bioscience, biotechnology, and biochemistry》2013,77(6):1369-1370
The effect was examined of aqueous dialyzates from 16 kinds of vegetables and fruits on the mutagenicity of some mutagens toward Salmonella typhimurium TA 100. Each dialyzate inhibited the mutagenicity of Trp-P-2, and the antimutagenicity was retained even after heating at 100°C for 20 min. Dialyzates of burdock, eggplant, spinach and apple also inhibited the mutagenicity of Trp-P-l, benzo[a]pyrene, sterigmatocystin, aflatoxin Bl, 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and N-methyl-N′-nitroso-N-nitrosoguanidine. The dialyzates of apple reacted with S9 mix and Trp-P-2. A Sepharose CL 6B gel filtration study of the dialyzates of apple indicated that the antimutagenic activity of these dialyzates on Trp-P-2 and AF-2 was mainly detectable in the polyphenol-rich fractions. 相似文献
9.
Dhrubajyoti Datta 《Nucleosides, nucleotides & nucleic acids》2020,39(4):530-541
AbstractSynthesis of exclusive N2-(isobutyryl)-9-(carboxymethyl)guanine, an important moiety for peptide nucleic acid synthesis has been reported through a high-yielding reaction scheme starting from 6-chloro-2-amino purine. Crystal structures of two intermediates confirmed the formation of N9-regioisomer. This new synthetic route can potentially replace the conventional tedious method with moderate overall yield. 相似文献
10.
Sinem Helvacıoğlu Mohammad Charehsaz Etil Güzelmeriç Mehmet Ali Oçkun İrem Ayran Hasan Kırmızıbekmez Yüksel Kan Ahmet Aydın Erdem Yeşilada 《化学与生物多样性》2021,18(10):e2000936
The antioxidant and mutagenic/antimutagenic activities of the fixed oils from Nigella sativa (NSO) and Nigella damascena (NDO) seeds, obtained by cold press-extraction from the cultivar samples, were comparatively investigated for the first time. The antimutagenicity test was carried out using classical and modified Ames tests. The fatty acid composition of the fixed oils was characterized by gas chromatography–mass spectrometry (GC-MS) while the quantification of thymoquinone in the fixed oils was determined by UPC2. The main components of the NSO and NDO were found to be linoleic acid, oleic acid, and palmitic acid. The results of the Ames test confirmed the safety of NSO and NDO from the viewpoint of mutagenicity. The results of the three antioxidant test methods were correlated with each other, indicating NDO as having a superior antioxidant activity, when compared to the NSO. Both NSO and NDO exhibited a significant protective effect against the mutagenicity induced by aflatoxin B1 in Salmonella typhimurium TA98 and TA100 strains. When microsomal metabolism was terminated after metabolic activation of the mycotoxin, a significant increase in antimutagenic activity was observed, suggesting that the degradation of aflatoxin B1 epoxides by these oils may be a possible antimutagenic mechanism. It is worthy to note that this is the first study to assess the mutagenicity of NSO and NDO according to the OECD 471 guideline and to investigate antimutagenicity of NDO in comparison to NSO against aflatoxin. 相似文献
11.
《Mutation Research/DNA Repair Reports》1984,131(3-4):89-95
The mutagenicity of N-acetoxy-N-2-acetylaminofluorene-(N-acetoxy-2AAF) for Salmonella typhimuricum TA98 is greatly reduced when compared to that of N-hydroxy-2-aminofluorene. This decrease in mutagenic response is accompanied by the formation of a deoxyguanosine-2-acetylaminofluorene adduct. The deoxyguanosine-2-aminofluorene adduct, characteristic of cells exposed to N-hydroxy-2-aminofluorene, was not detected in N-acetoxy-2AAF-treated cells. Enzymic deacetylation of N-acetoxy-2AAF results in restoration of potent mutagenicity. N-Acetoxy-2-acetylamino-7-iodofluorene is also more mutagenic than N-acetoxy-2AAF. Because the acetylated and unacetylated guanine induce greatly different configurational changes, the results may be indicative that the introduction of the syn configuration and a possible shift to the Z-conformation at the mutational hot spot of Salmonella typhimurium TA98 [(dG-dC)8] results in reduced mutagenic potency. 相似文献
12.
The fried food mutagens IQ, MeIQ, Glu-P-1 and Trp-P-2 were treated with nitrite at pH 3.0 for 1 h at 37 degrees C. The resulting reaction mixtures were tested for mutagenicity towards Salmonella typhimurium TA97, TA98, TA100 and TA1535. Glu-P-1 and Trp-P-2 were readily converted to weak or non-mutagenic deaminated compounds, whereas IQ and MeIQ were converted to extremely strong mutagenic derivatives in both the presence and the absence of rat liver S9 mix. The mutagenicity of MeIQ in TA98 was enhanced by nitrite up to 3-fold, while that of nitrosated MeIQ was further enhanced by S9 mix up to 15-fold. The nitrosation products of MeIQ were resolved into 7 bands by TLC on silica gel plate. Bands I, III, V and VI were highly mutagenic to both TA98 and TA100. The experimental results suggest that the non-enzymatic formation of direct-acting mutagens from indirect-acting mutagens such as IQ or MeIQ might be physiologically important, especially with regard to the etiology of human gastrointestinal tract tumors. 相似文献
13.
Derivatives of 2-aryl-substitute (o-hydroxy-, m-bromo-, o-methoxy-, o-nitro-phenyl or 4-pyridyl) benzothiazole were synthesized and tested for their mutagenicity in in vitro assays: (i) in the Ames test with Salmonella typhimurium TA98 and TA100 strains; and (ii) in the sister chromatid exchange (SCE) in cultured human lymphocytes. The four of compounds
(BT-11, B-12, BT-14 and BT-15) caused statistically significant increase in revertant colonies of TA98 and TA100. Treatment
of lymphocytes with compounds also caused a significant increase in SCE/cell in association with high levels and long exposure
(300 μg/mL and 48 h) of the four compounds. It can be concluded that benzothiazole derivatives showed mutagenic activity and
were also able to exert a genotoxic effect reducing both the replication index and mitotic index. 相似文献
14.
Ten imidazole derivatives were tested for mutagenicity in Salmonella typhimurium strains TA98 and TA100 both in the absence and presence of metabolic activation by the microsomal fraction S9 mix. In a general
manner, derivatives tested exhibited a greater mutagenic activity in the TA100 strain comparing to the responses in TA 98.
In the standard plate incorporation assay, 8 of these substances (80%) were found to be mutagenic for at least one of the
two strains in the presence or absence of metabolic activation. Two compounds showed positive results in TA98 and 6 compounds
were also mutagenic in TA100 without S9. In the presence of S9 mix, all of the 10 substances were non-mutagenic in TA98, whereas
4 compounds were positive in TA100. The results suggested the mutagenic potentials of the imidazole derivatives particularly
inducing the reversion of base-pair substitutions. According to the structure-activity relationships phenyl groups in position
2 with different substituents can confer the mutagenic activity of the tested compounds. Methyl groups in different positions
of these phenyl substituents can cause different types of mutations. This mutagenic effect is observed more clearly when the
phenyl group is inhibited with a nitro group. 相似文献
15.
Haruhiko Kawasaki Hitoshi Yahara Kenzo Tonomura 《Bioscience, biotechnology, and biochemistry》2013,77(7):1639-1641
Inhibitory effects of lactic acid bacteria for dairy use on the mutagenicities of some volatile nitrosamines were investigated in vitro using a Salmonella typhimurium TA 98 streptomycin-dependent strain (SD 510) as an indicator bacterium. Among 40 strains examined, Leuconostoc paramesenteroides R-62, R-8, Streptococcus lactis subsp. diacetylactis R-63, and St. cremoris R-48 strongly inhibited the mutagenicity of N-nitroso-diethylamine (NDEA) and moderately N-nitroso-dimethylamine (NDMA), but not N-nitroso-piperidine (NPIP) or N-nitroso-pyrrolidine (NPYR). In addition, the filtrates obtained from cell suspensions of the lactic acid bacteria examined inhibited the mutagenicity of NDEA. 相似文献
16.
Despoina Lazarou Raphael Grougnet Athanasios Papadopoulos 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2007,634(1-2):163-171
A polyphenolic mixture derived from sesame-seed perisperm (SSP) strongly reduced the mutagenicity of hydrogen peroxide (H2O2), sodium azide (NaN3), and benzo[a]pyrene (BaP) in strains TA100 and/or TA98 of Salmonella typhimurium. It exhibited desmutagenic activity against H2O2, BaP in TA98 and/or TA100 and biomutagenic activity (apparently by affecting the DNA-repair system) against NaN3 in strain TA100. According to in vitro experiments the polyphenolic mixture inhibited the activity of the CYP1A1 (EROD) enzyme responsible for the activation of BaP in the Ames’ test, as well as that of the cytosolic enzyme GST.A cytosolic fraction from liver of male Wistar rats treated with either 20% SSP in the food, or 3 mg or 6 mg of polyphenolic mixture/20 g food/day for a time period of 8 weeks reduced the mutagenic potential of BaP in strains TA100 and TA98, with the cytosolic fraction from rats treated with SSP causing the strongest reduction. Furthermore, a microsomal fraction from the 20% SSP-treated rats inhibited the mutagenicity of BaP in strains TA100 (26.3%) and TA98 (23%). In contrast, a microsomal fraction from rats treated with 3 mg of polyphenolic mixture stimulated the mutagenicity of BaP in TA100 but reduced it in TA98, while for the microsomal fraction from rats treated with 6 mg of polyphenolic mixture, these effects on TA100 and TA98 were reversed. 相似文献
17.
The nitrofurans, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2), N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT), nitrofurantoin, 5-nitro-2-furoic acid, 5-nitro-2-furamidoxime, 5-nitrofurfurylidene diacetate and the urine of rats fed these compounds, were assayed for mutagenic activity in Salmonella typhimurium strains TA100 and TA100FR1. All the nitrofurans were mutagenic in the order: AF-2 and FANFT > nitrofurantoin > 5-nitro-2-furamidoxime > 5-nitrofurfurylidene diacetate > 5-nitro-2-furoic acid. Strain TA100 was more sensitive than TA100FR1 to the mutagenic influence of these nitrofurans. Only the urine of rats fed AF-2, FANFT and nitrofurantoin had mutagenic activity. Again, TA100 was more sensitive than TA100FR1. The mutagenicity of the urine was not increased by treatment with β-glucuronidase. AF-2, 2-amino-4-(5-nitro-2-furyl)thiazole (deformylated product of FANFT) and nitrofurantoin were excreted in the urine of rats fed these compounds; whereas the other nitrofurans were not excreted. 相似文献
18.
Jeremy McCallum Solomon Amare Rebecca Nolan 《Nucleosides, nucleotides & nucleic acids》2013,32(11-12):801-808
The properties of the self-assembly of two lipophilic guanine derivatives, 2′,3′,5′-O-tris(tert-butyldimethylsilyl)-guanosine and N9-(3,5-bis(tert-butyldimethylsilyloxy)-benzyl)-guanine, are described. In the presence of K+, both guanine derivatives self-associate into D 4-symmetric octamers consisting of two G-quartets stacked around a central ion. 相似文献
19.
《Bioscience, biotechnology, and biochemistry》2013,77(7):1450-1454
The structure of the yellow pigment found in salted radish roots was studied. It was found that 1-(2-thioxopyrrolidin-3-yl)-1,2,3,4-tetrahydro-β-carboline-3- carboxylic acid (TPCC) was unstable under neutral pH, and was easily converted into the yellow pigment. The yellow pigment was isolated and identified as 2-[3-(2-thioxopyrrolidin-3-ylidene)methyl]-tryptophan (TPMT) by IR, MS, 1H-, and 13C-NMR spectroscopy. In addition, we proved that this compound was the main yellow pigment in salted radish roots. This compound induced no mutagenicity in Salmonella typhimurium TA98 and TA100, either with or without prior activation. 相似文献
20.
Aya Onoda Masaharu Asanoma Haruo Nukaya 《Bioscience, biotechnology, and biochemistry》2016,80(5):833-839
To identify the major mutagen in pyroligneous acid (PA), 10 wood and 10 bamboo pyroligneous acids were examined using the Ames test in Salmonella typhimurium strains TA100 and TA98. Subsequently, the mutagenic dicarbonyl compounds (DCs), glyoxal, methylglyoxal (MG), and diacetyl in PA were quantified using high-performance liquid chromatography, and the mutagenic contribution ratios for each DC were calculated relative to the mutagenicity of PA. Eighteen samples were positive for mutagens and showed the strongest mutagenicity in TA100 in the absence of S9 mix. MG had the highest mutagenic contribution ratio, and its presence was strongly correlated with the specific mutagenicity of PA. These data indicate that MG is the major mutagen in PA. 相似文献