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1.
Investigations concerned Escherichia coli nitroreductase in creation of mutagens from non-mutagenic pesticides-derivatives of urea. Three new compounds were studied: N-phenyl-N'-methylurea (IPO 4328), N-methyl,N-(2-hydroxyethyl)-N'phenylurea (IPO 2363), N-(2-hydroxyethyl), N-methyl-N'-(3,4 dichloroethyl) urea, and diurone-3-(3,4 dichlorophenyl)-1,1 dimethylurea. These compounds were incubated in anaerobic conditions with cells of E. coli K-12 (KF) strain and nitrate or nitrite. Using Ames test, mutagenicity of resulting metabolites was investigated. It was found that during incubation of herbicide IPO 4328 with cells of E. coli K-12 (KF) and nitrate, mutagenic product for strain of S. typhimurium TA 1537 is created. Very weak mutagenic metabolite for the same strain was appearing during incubation of herbicide IPO 2363 with cells of E. coli K-12 (KF) in presence of nitrite. Incubation of investigated compounds with E. coli K-12 (KF) cells alone did not result in appearance of mutagenic substances. Thus, role of Escherichia coli in creation of mutagenic compounds from non-mutagenic derivatives of urea consisted of nitrite from nitrate production with participation of nitroreductase, which afterwards in absence of bacteria or action of their enzymes reacted with investigated pesticides.  相似文献   

2.
New 3(2H)-pyridazinone derivatives containing a N'-benzyliden-acetohydrazide moiety at position 2 were synthesized. The structures of these newly synthesized compounds were confirmed by IR, 1H NMR, and MS data. These compounds were tested for their antibacterial, antifungal, antimycobacterial, and cytotoxic activities. The compounds 2-[4-(4-chlorophenyl)-6-(morpholin-4-yl)-3-oxo-(2H)-pyridazin-2-yl]-N'-(4-tert-butylbenzyliden)acetohydrazide and 2-[4-(4-chlorophenyl)-6-(morpholin-4-yl)-3-oxo-(2H)-pyridazin-2-yl]-N'-(4-chlorobenzyliden) acetohydrazide exhibited activity against both Gram-positive and Gram-negative bacteria. Most of the compounds were active against E. coli ATCC 35218. The preliminary results of this study revealed that some target compounds exhibited promising antimicrobial activities.  相似文献   

3.
Mast cell derived leukotrienes (LT's) play a vital role in pathophysiology of allergy and asthma. We synthesized various analogues of indolyl, naphthyl and phenylethyl substituted halopyridyl, thiazolyl and benzothiazolyl thioureas and examined their in vitro effects on the high affinity IgE receptor/FcERI-mediated mast cell leukotriene release. Of the 22 naphthylethyl thiourea compounds tested, there were seven active compounds and N-[1-(1-naphthyl)ethyl]-N'-[2-(ethyl-4-acetylthiazolyl)]thiourea (17 and 16) (IC(50)=0.002 microM) and N-[1-(1R)-naphthylethyl]-N'-[2-(5-methylpyridyl)]thiourea (5) (IC(50)=0.005 microM) were identified as the lead compounds. Among the 11 indolylethyl thiourea compounds tested, there were seven active compounds and the halopyridyl compounds N-[2-(3-indolylethyl)]-N'-[2-(5-chloropyridyl)]thiourea and N-[2-(3-indolylethyl)]-N'-[2-(5-bromopyridyl)]thiourea were the most active agents and inhibited the LTC(4) release with low micromolar IC(50) values of 4.9 microM and 6.1 microM, respectively. The hydroxylphenyl substituted compounds N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(5-chloropyridyl)]thiourea (IC(50)=12.6 microM), N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(5-bromopyridyl)]thiourea (IC(50)=16.8 microM) and N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(pyridyl)]thiourea (IC(50)=8.5 microM) were the most active pyridyl thiourea agents. Notably, the introduction of electron withdrawing or donating groups had a marked impact on the biological activity of these thiourea derivatives and the Hammett sigma values of their substituents were identified as predictors of their potency. In contrast, experimentally determined partition coefficient values did not correlate with the biological activity of the thiourea compounds which demonstrates that their liphophilicity is not an important factor controlling their mast cell inhibitory effects.  相似文献   

4.
Mast cell derived leukotrienes (LT's) play a vital role in pathophysiology of allergy and asthma. We synthesized various analogues of indolyl, naphthyl and phenylethyl substituted halopyridyl, thiazolyl and benzothiazolyl thioureas and examined their in vitro effects on the high affinity IgE receptor/Fc epsilon RI-mediated mast cell leukotriene release. Of the 22 naphthylethyl thiourea compounds tested, there were 7 active compounds and N-[1-(1-naphthyl)ethyl]-N'-[2-(ethyl-4-acetylthiazolyl)]thiourea (17 and 16) (IC(50)=0.002 microM) and N-[1-(1R)-naphthylethyl]-N'-[2-(5-methylpyridyl)]thiourea (compound 5) (IC(50)=0.005 microM) were identified as the lead compounds. Among the 11 indolylethyl thiourea compounds tested, there were seven active compounds and the halopyridyl compounds N-[2-(3-indolylethyl)]-N'-[2-(5-chloropyridyl)]thiourea (24) and N-[2-(3-indolylethyl)]-N'-[2-(5-bromopyridyl)]thiourea (25) were the most active agents and inhibited the LTC(4) release with low micromolar IC(50) values of 4.9 and 6.1 microM, respectively. The hydroxylphenyl substituted compounds N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(5-chloropyridyl)]thiourea (37; IC(50)=12.6 microM), N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(5-bromopyridyl)]thiourea (50; IC(50)=16.8 microM) and N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(pyridyl)]thiourea (35; IC(50)=8.5 microM) were the most active pyridyl thiourea agents. Notably, the introduction of electron withdrawing or donating groups had a marked impact on the biological activity of these thiourea derivatives and the Hammett sigma values of their substituents were identified as predictors of their potency. In contrast, experimentally determined partition coefficient values did not correlate with the biological activity of the thiourea compounds which demonstrates that their liphophilicity is not an important factor controlling their mast cell inhibitory effects. These results establish the substituted halopyridyl, indolyl and naphthyl thiourea compounds as a new chemical class of anti-allergic agents inhibiting IgE receptor/Fc epsilon RI-mediated mast cell LTC(4) release. Further lead optimization efforts may provide the basis for new and effective treatment as well as prevention programs for allergic asthma in clinical settings.  相似文献   

5.
DL-p-chlorophenylalanine (PCPA) and its derivatives were evaluated for genotoxic effects using Escherichia coli and Bacillus subtilis strains lacking various DNA-repair mechanisms in spottest and in suspension test. The mutagenic activity of studied compounds was determined by the Ames test. Reverse mutation test was performed with Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 without S9 mix. 0.02 M nitrosomethylurea (NMU) standard mutagen was used as a positive control. The results showed that the parent nonessential amino acid PCPA had no detectable genotoxic and mutagenic activities in bacteria. The methyl ester of this amino acid and its N-phenylacetyl derivative possessed weak genotoxicity. Meanwhile N-sec-butyloxycarbonyl, N-benzyloxycarbonyl, N-(p-nitrophenylacetyl) and N-(p-nitrophenoxyacetyl) derivatives of DL-p-chlorophenylalanine exhibited appreciable genotoxicity. Among the seven tested compounds only N-benzyloxycarbonyl and N-(p-nitrophenoxyacetyl) derivatives of DL-p-chlorophenylalanine have been found to be mutagenic. Only parent PCPA possessed antimutagenic properties in respect of nitrosomethylurea. The structural modification, which strongly affects genotoxicity and mutagenicity perhaps may be due to steric hydrance of the substituents, causing interference with enzyme and DNA interactions.  相似文献   

6.
An insect grwoth regulator (IGR), Thompson-Hayward TH 6040 (N-(4-chlorophenyl)-N'-(2,6-difluorobenzoyl)urea), incorporated in the feed of rhinoceroses at rates of 1 and 0.1 mg/kg inhibited development of Musca domestica L. and Stomoxys calcitrans (L.) in the feces.  相似文献   

7.
1,2-Bis-[2-(5-H/Me/Cl/NO2)-1H-benzimidazolyl]-1,2-ethanediols (L1-L4), 1,4-bis-[2-(5-H/Me/Cl)-1H-benzimidazolyl]-1,2,3,4-butanetetraols (L5-L7) and their complexes with ZnCl2, CdCl2 and HgCl2 were synthesized and antibacterial activity of the compounds was tested toward Staphylococcus aureus, S. epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Proteus mirabilis and antifungal activity against Candida albicans. HgII complexes have a considerably higher antimicrobial activity against all microorganisms. Some HgII complexes show higher antifungal activity than clotrimazole toward C. albicans. Zn2(L3)Cl4, Zn2(L4)Cl4, and Cd(L3)Cl2 were moderately effective against S. aureus and S. epidermidis; Cd(L4)Cl2 exhibited a weak activity only against S. epidermidis.  相似文献   

8.
AIMS: To determine the effect of a composition comprising ovotransferrin (OT), protamine sulfate (PS) and ethylenediaminetetraacetic acid (EDTA) on biofilm formation by catheter-associated bacteria. METHODS AND RESULTS: The in vitro activity of OT, PS and EDTA alone and in combinations against biofilm formation by Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Enterococcus faecalis and Staphylococcus epidermidis was investigated. All the three compounds either alone or in combinations failed to inhibit the growth completely at the concentrations tested. However, the subinhibitory concentrations of three compounds in a composition showed synergistic inhibitory effect on biofilm formation by K. pneumoniae, Ps. aeruginosa and S. epidermidis. Furthermore, 79-95% reduction in Ps. aeruginosa and S. epidermidis biofilm formation was observed in a clear vinyl urinary catheter treated with the composition. CONCLUSION: The subinhibitory concentrations of OT, PS and EDTA in a composition were effective in reducing biofilm formation by catheter-associated bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that a synergistic composition-comprising non-antibiotic generally regarded as safe (GRAS) compounds such as OT, PS and EDTA may be used in the prevention of catheter-related infections.  相似文献   

9.
2-(2-Pyridinyl)- (LI), 2-(6-methyl-2-pyridinyl)- (LII), 2-(6-methyl-2-pyridinyl)-5-methyl-(LIII), 2-(3-pyridinyl)- (LIV), 2-(3-pyridinyl)-5-methyl-1H-benzimidazoles (LV) and their complexes with Fe(NO3)3, Cu(NO3)2, Zn(NO3)2, and AgNO3 were synthesized and antibacterial activity of the compounds was tested toward Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Proteus mirabilis and antifungal activity against Candida albicans. The methyl groups of LIII increase the antimicrobial activity. The AgI complexes have considerable activity toward the microorganisms. Some ZnII complexes show an antimicrobial effect against S. aureus and S. flexneri, although the ligands themselves have no effect. CuII complexes have a considerable antibacterial effect to S. aureus and S. epidermidis.  相似文献   

10.
The mutagenic activity of N,N-dimethyl-, N,N-diethyl-, N,N-dibutyl-, N,N-diisobutyl-, N,N-di(p-tolyl)-, N-ethyl-N-phenyl-, N,N-dibenzyl-, N,N-diphenyl- and N,N-diisopropylhydrazine was examined in the Salmonella/mammalian microsome assay using the strains TA1535, TA1537, TA97, TA98, TA100, TA102 and TA1530. All nine hydrazines were mutagenic in at least one tester strain, although of borderline significance for some of the compounds. The mutagenic potencies of the hydrazines varied 2-3 orders of magnitude, from very weak to moderate mutagenic activity. In general, the addition of S9 resulted in a lowering of the mutagenic activity and a lowering of the toxic properties of the hydrazines. The test results were relatively difficult to evaluate due to toxic effects of many of the test compounds on the test bacteria which may have resulted in an underestimation of the mutagenic potencies of some of the compounds. The pattern of mutagenic activity of the hydrazines in the different tester strains indicates that more than one mechanism of action may be involved in the mutagenicity.  相似文献   

11.
12.
In a systematic search for novel dual function antioxidants with potent anti-HIV activity, we evaluated 9 rationally designed non-nucleoside inhibitors (NNI) of HIV-1 RT for antioxidant and anti-HIV activities. Our lead phenethyl-5-bromopyridyl thiourea (PEPT) compounds, N-[2-(2-methoxyphenylethyl)]-N'-[2-(5-bromopyridyl)]-thioure a (2) and N-[2-(2-chlorophenylethyl)]-N'-[2-(5-bromopyridyl)]-thiourea (9), inhibited the oxidation of ABTS to ABTS*+ by metmyoglobin in the presence of hydrogen peroxide with EC50 values of 79 and 75 microM, respectively. Both compounds effectively inhibited the oxidation-induced green fluorescence emission from the free radical-sensitive indicator dye 2',7'-dichlorodihydrofluorescein diacetate in CEM human T-cells and Nalm-6 human B-cells exposed to hydrogen peroxide. To our knowledge, compounds 2 and 9 are the first NNI of HIV-1 RT with potent anti-oxidant activity. Furthermore, the activity center was defined as the sulfhydryl group since alkylated PEPT derivatives were inactive. The presence of a free thiourea group was also essential for the anti-HIV activity of the PEPT compounds.  相似文献   

13.
We have previously identified ring-substituted quinolines as a new structural class of anti-tuberculosis agents. In our ongoing efforts at structural optimization of this class, four series of ring-substituted-2/4-quinolinecarbaldehyde derivatives were synthesized. All twenty-four compounds were synthesized using short and convenient one to two high yielding steps. The newly synthesized compounds were tested in vitro against drug-sensitive Mycobacterium tuberculosis H37Hv strain. Several derivatives were found to be promising inhibitors of M. tuberculosis. For example, derivatives 4a-c (Series 2), 7a-d (Series 3), and 8a-b (Series 4) displayed >90% inhibition at 6.25 microg/mL in the primary assay. The most active compounds, N-(2-fluorophenyl)-N'-quinolin-2-ylmethylene-hydrazine (4a), N-(2-adamantan-1-yl-quinolin-4-ylmethylene)-N'-(4-fluorophenyl)hydrazine (7c), and N-(2-cyclohexyl-quinolin-4-ylmethylene)-N'-(2-fluorophenyl)hydrazine (8a), exhibited 99% inhibition at the lowest tested concentration of 3.125 microg/mL against drug-sensitive M. tuberculosis H37Rv strain. The similarity index based on steric and electrostatic features of the molecules was used, in conjunction with principal component analysis and linear discriminant analysis, successively to classify the molecules based on their activity into two classes. This classification method gives us confidence in predicting the activity class of any new unsynthesized molecule belonging to these series.  相似文献   

14.
A rapid and sensitive in vitro assay was developed to quantitatively assess the adherence of Staphylococcus epidermidis to a hydrophobic plastic surface. The assay is based upon the detection of cell-associated urease activity as a marker of bacteria remaining adherent to the polystyrene microwells of flat-bottomed, 96-well tissue culture plates. Using ATCC 35984, a slime-producing strain of S. epidermidis, the assay could detect as few as 3 x 10(3) bacteria and was linear to 3.5 x 10(7) bacteria. The adherence of both slime-positive and slime-negative coagulase-negative staphylococci could be evaluated by using this method. This assay could be used to examine factors which influence the adherence of individual S. epidermidis strains to hydrophobic surfaces and to develop agents or coating materials which suppress the adherence of coagulase-negative staphylococci to biomedical implants.  相似文献   

15.
The following organophosphates were tested for their ability to induce DNA damage in a rec-type repair test with Proteus mirabilis strains PG713 (rec- hcr-) and PG273 (wild-type) and point mutations in the his- strain TA100 of Salmonella typhimurium: O,O-dimethyl-O-(1,2-dibromo-2,2-dichloroethyl)-phosphate (NALED); trichlorfon-O-methyl ether (TCP-O-ME), O,O-dimethyl-(1-methoxy-2,2,2-trichlorethyl)-phosphonate; trichlorfon-O-methyl ether vinyl derivative (TCP-O-MEVD), O,O-dimethyl-(1-methoxy-2,2-dichlorovinyl)-phosphonate. All compounds were negative in the repair test but induced base pair substitutions in S. typhimurium. The mutagenicity of NALED is due to the direct alkylating ability of the parental molecule and to mutagenic metabolites generated by enzymatic splitting of the side chain. Glutathion-dependent enzymes in the S9-mix eliminate the mutagenic activity of NALED completely. Mutation induction by TCP-O-ME and TCP-O-MEVD is predominantly caused by the reactive O-methyl ether configuration of the side chain and is resistant to metabolic inactivation by NADPH- or glutathion-dependent enzymatic pathways in the S9-mix of mice.  相似文献   

16.
Freshly brewed blended coffee, instant coffee and instant caffeine-free coffee induced prophage lambda in lysogenic E. coli K12, strain GY5027. Because coffee prepared from green beans by the same extraction method as used for freshly brewed blended coffee had no prophage-inducing activity, this activity may be attributed to compounds produced in the roasting process. Roasting also produced compounds that were mutagenic in S. typhimurium TA100 and E. coli WP2 uvrA/pKM101.  相似文献   

17.
Compounds of various chemical classes were comparatively assayed in the Ames reversion test with his- S. typhimurium strains TA1535, TA157 , TA1538, TA98, TA100, and, in part, TA97 , and in a DNA-repair test with trp- E. coli strains WP2 (repair-proficient), WP67 (uvrA- polA-) and CM871 (uvrA- recA- lexA-). A liquid micromethod procedure for the assessment of the minimal inhibitory concentration (MIC) of test compounds, using the same reagents as the Ames test, was set up and calibrated in its technical details. Other techniques (spot test and treat-and-plate method) were applied to a number of compounds in order to obtain more complete information on their DNA-damaging activity in E. coli. From a qualitative standpoint, the results obtained in the reversion test and in the DNA-repair test (liquid micromethod) were overlapping for 96 (59 positive and 37 negative) out of 135 compounds (71.1%). There was disagreement for 39 compounds (28.9%), 9 of which were positive only in the reversion test (8 requiring metabolic activation and 5 genotoxic in the treat-and-plate method). 30 compounds were positive only in the lethality test, showing a direct DNA-damaging activity, which in half of the cases was completely eliminated by S9 mix. Although the experimental protocol intentionally included several compounds already reported as nonmutagenic carcinogens or as noncarcinogenic mutagens, the overall accuracy was 64.5% for the reversion test and 72.4% for the DNA-repair test, as evaluated for 75 compounds classified according to their carcinogenic activity. Quantitation of results was obtained in the Ames test by relating the net number of revertants to nmoles of compound and in the DNA-repair test by means of a formula relating the difference and ratio of MICs in repair-proficient and -deficient bacteria to nmoles of compound. Following these criteria, the genotoxic potency varied over a 4.5 X 10(7)-fold range among compounds positive in the reversion test and over a 6 X 10(9)-fold range among compounds damaging E. coli DNA. The genotoxic potencies in the two bacterial systems were correlated within the majority of the chemical classes under scrutiny.  相似文献   

18.
1,2-Bis-[2-(5-H/Me/Cl/NO2)-1H-benzimidazolyl]-1,2-ethanediols (L1-L4), 1,4-Bis-[2-(5-H/Me/Cl)-1H-benzimidazolyl]-1,2,3,4-butanetetraols (L5-L7) and their complexes with FeCl3, CuCl2, and AgNO3 were synthesized; antibacterial activity of the compounds was determined toward Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Proteus mirabilis, and antifungal activity against Candida albicans. The AgI complexes have considerable activity toward the microorganisms. Some AgI complexes show higher activity toward S. epidermidis than AgNO3 and cefuroxime. Cu(L3)Cl2 and Fe(L3)Cl3 show an antifungal effect on C. albicans but L3 itself has no activity.  相似文献   

19.
A Nomura  K Negishi    H Hayatsu 《Nucleic acids research》1985,13(24):8893-8899
To investigate the mechanism of N4-aminocytidine-induced mutagenesis, N'-alkyl-N4-aminocytidines and N4-alkyl-N4-aminocytidines were prepared and their mutagenicity on bacteria were assayed. N'-Methyl-N4-aminocytidine, N'-(2-hydroxyethyl)-N4-aminocytidine and N',N'-dimethyl-N4-aminocytidine showed direct-acting mutagenicity on S. typhimurium TA100 and E. coli WP2 uvrA, tester strains that are sensitive to base-pair substitutions. In contrast, N4-methyl-N4-aminocytidine, N4-(2-hydroxyethyl)-N4-aminocytidine and N4,N'-dimethyl-N4-aminocytidine were not mutagenic on these bacteria. Since N'-methyl-N4-aminocytidine does not form hydrazones, the possibility that N4-aminocytidine causes mutation due to its reactivity with carbonyl compounds has been excluded. Furthermore, the fact that only those alkyl N4-aminocytidines having a hydrogen on the nitrogen at position 4 are mutagenic is consistent with the previously proposed mechanism in which the tautomerization between the amino and the imino forms of N4-aminocytosine allowing an ambiguous base pairing is the cause of the mutagenesis.  相似文献   

20.
A number of hitherto undescribed 4-hydroxy-5-formylbenzoic acid derivatives (A), have been prepared and characterized. (formula; see text) Esters (X = CH3) and Schiff's bases (Z = N-aryl) were prepared by conventional methods and were obtained in satisfactory yield and in a good state of purity. The prepared compounds have been tested for "in vitro" activity against Gram+ bacteria (S.epidermidis, B.subtilis, B.anthracis, M.paratuberculosis), Gram- bacteria (P.aeruginosa, S.typhi murium, E.coli Bb, S.typhi O, S.typhi infantis, S.paratyphi A, S.paratyphi B) and fungi (C.albicans, A.niger, S.cerevisiae) by agar-diffusion method (Kirby-Bauer modified). The prepared compounds, generally, showed inhibitory activity against Gram+ bacteria. Esters (A: X = CH3) showed antibacteric and antimycotic activity. The greatest activity was observed in the methyl ester (XV) of 4-hydroxy-5-formylbenzoic acid (I).  相似文献   

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