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Chronic toxicity and carcinogenicity of a food additive, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) was examined by its oral administration to Wistar rats for 18 months. Male rats given 0.4% AF-2 diet developed ataxia of the hind foot around 4 months of feeding, and severe atrophy of skeletal muscles of the whole body was seen in 31 of 43 rats after 12 months. In female rats, mammary tumors developed in 78% of the animals given 0.4% AF-2 diet. Multiple papillomas were observed in the forestomach.  相似文献   

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The reductive metabolism of 4-(5-nitro-2-furyl)thiazole (NFT), a rat mammary gland and forestomach carcinogen, was examined in vitro using rat liver tissues. NFT was reduced by rat liver cytosol or microsomes on anaerobic incubation with NADPH. The stoichiometry of microsomal reduction revealed that about 3 moles of NADPH were used per mole of NFT. Gas chromatographic analysis of the reaction mixture showed a major peak with a retention time of about 4.0 min in contrast to NFT with a retention time of about 6.5 min. Catalytic hydrogenation of NFT with palladium and activated carbon yielded a product with a retention time of 4.0 min. The component corresponding with the above metabolite was isolated from chemically reduced NFT and identified as 1-(4-thiazolyl)-3-cyano-l-propanone. The metabolite derived from enzymatic reduction had chromatographic and spectral properties and a mass spectral fragmentation pattern similar to those obtained chemically. These data establish that the enzymatically derived product is identical to that obtained by chemical reduction and that it corresponds to 1(4thiazolyl)3cyano1propanone.  相似文献   

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N-Acyl-2-aminothiazoles with nonaromatic acyl side chains containing a basic amine were found to be potent, selective inhibitors of CDK2/cycE which exhibit antitumor activity in mice. In particular, compound 21 [N-[5-[[[5-(1,1-dimethylethyl)-2-oxazolyl]methyl]thio]-2-thiazolyl]-4-piperidinecarboxamide, BMS-387032], has been identified as an ATP-competitive and CDK2-selective inhibitor which has been selected to enter Phase 1 human clinical trials as an antitumor agent. In a cell-free enzyme assay, 21 showed a CDK2/cycE IC(50) = 48 nM and was 10- and 20-fold selective over CDK1/cycB and CDK4/cycD, respectively. It was also highly selective over a panel of 12 unrelated kinases. Antiproliferative activity was established in an A2780 cellular cytotoxicity assay in which 21 showed an IC(50) = 95 nM. Metabolism and pharmacokinetic studies showed that 21 exhibited a plasma half-life of 5-7 h in three species and moderately low protein binding in both mouse (69%) and human (63%) serum. Dosed orally to mouse, rat, and dog, 21 showed 100%, 31%, and 28% bioavailability, respectively. As an antitumor agent in mice, 21 administered at its maximum-tolerated dose exhibited a clearly superior efficacy profile when compared to flavopiridol in both an ip/ip P388 murine tumor model and in a s.c./i.p. A2780 human ovarian carcinoma xenograft model.  相似文献   

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1 The ability of sodium p-benzyl-4-[1-oxo-2-(4-chlorobenzyl)-3-phenylpropyl]phenyl phosphonate (N-0164) to antagonize contractions produced by prostaglandins E2 and F2a on isolated preparations of gerbil, rat and guinea-pig gastrointestinal muscle has been studied. 2 N-0164 was found to be a potent, partially selective prostaglandin antagonist in these isolated smooth muscle preparations. The blockade produced by N-0164 in the isolated stomach strip of the rat had some, but not all, the characteristics of a competitive antagonism. 3 N-0164 produced a dose-dependent decrease in tone in the rat stomach strip that was abolished by pretreatment of the preparation with indomethacin. 4 N-0164 prevented diarrhoea induced by prostaglandin E2 in mice when given by intraperitoneal injection but was less effective when given orally. 5 N-0164 inhibited oedema induced with croton-oil and pyridine-ether in the mouse ear. 6 N-0164 delayed the onset of erythema following ultraviolet irradiation of guinea-pig skin only when an equimolar amount of pralidoxime chloride was added to the vehicle. 7 It is concluded that N-0164 is a potent, partially selective prostaglandin antagonist on several isolated smooth msucle preparations. N-0164 exhibits activity in vivo particularly following local application when problems associated with penetration and distribution are minimized.  相似文献   

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Epidemiological studies indicate an association between exposure to chlorinated drinking water and risk of intestinal cancer. In order to study this experimentally, we have examined the effects of 3,4-dichloro-5-hydroxy-2[5H]-furanone (mucochloric acid, MCA) and 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX), mutagenic and genotoxic compounds in drinking water, on aberrant crypt foci and tumours in the intestines of male F344 rats and Balb/cA mice, and C57BL/6J-Min (multiple intestinal neoplasia)/+ mice of both sexes, in six independent experiments. In some experiments the effects of MCA and MX on aberrant crypt foci induced by the colon carcinogens 1,2-dimethylhydrazine or its metabolite azoxymethane were also studied. Neither MCA nor MX alone induced aberrant crypt foci or intestinal tumours when given in drinking water. With this route of exposure neither MCA nor MX, when given in combination with 1,2-dimethylhydrazine or azoxymethane, had any effect on the induction or growth of the aberrant crypt foci. Drinking water exposure of MX did not affect the number or growth of aberrant crypt foci or intestinal tumours in the Minl+ mice. When administered intrarectally MCA had a weak inducing effect on aberrant crypt foci in the colons of Balb/cA mice. Exposure to MCA and MX intrarectally apparently promoted the growth of aberrant crypt foci both in rats and mice, increasing the crypt multiplicity, aberrant crypts/aberrant crypt foci. Based on an overall evaluation of these experiments, the intestinal tract, at least in rats and mice, seems not to be a main target organ for effects of MCA or MX on preneoplastic or neoplastic development.  相似文献   

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Some 3- and 4-bromophenyl and dimethylsulfonium analogues of the muscarinic agent [4-[[N-(3-chlorophenyl)-carbamoyl]oxy]-2-butynyl] trimethylammonium chloride (McN-A-343) (1) were synthesized. The new compounds were assayed for effects on arterial blood pressure in the pithed rat (ganglionic muscarinic activity). The dimethylsulfonium salts (13a-d) appeared to be partial agonists in relation to 1. The 4-bromophenyl-substituted trimethylammonium iodide 10d exceeded 1 in potency by 3-fold. The compounds retained the selectivity for ganglionic muscarinic receptors shown by 1 since they had only weak effects on the guinea pig ileum in vitro.  相似文献   

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4-Chloro-2-(4-pyridinyl)pyrimidines were treated with alkylamines to afford the corresponding N-substituted amino derivatives. 4-Amino-2-(4-pyridinyl)pyrimidines and their N-substituted analogues were converted to amides, carbamates, aminomethylenemalonates, and ureas. Many of these compounds were found to have potential antiallergic activity as indicated by the rat passive cutaneous anaphylaxis screen. The most compounds were found in the last two series.  相似文献   

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In this study, a series of twelve novel 5-[2-(morpholin-4-yl)acetamido] and/or 5-[2-(4-substituted pip-erazine-1-yl)acetamido]-2-(p-substituted phenyl]benzoxazole derivatives have been synthesized and their structures were confirmed by IR, (1)H NMR, and mass spectral data. These compounds were prepared by reacting 5-(2-chloroacetamido)-2-(4-p-substituted-phenyl)benzoxazoles, which were obtained by using 5-amino-2-[p-substituted-phenyl]benzoxazoles with chloroacetyl chloride, in the presence of morpholine or 1-substituted piperazines. All synthesized compounds 3-14 were tested by using the method of twofold serial dilution technique for in vitro activities against certain strains of Gram-positive, Gram-negative bacteria as well as the yeasts Candida albicans, Candida krusei, and Candida glabrata in comparison with standard drugs. Microbiological results showed that the newly synthesized compounds possessed a broad spectrum of activity, showing MIC values of 3.12-50 mug/mL against the Candida species.  相似文献   

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The synthesis of N-[5-(2-phenoxyphenyl)-1, 3, 4-oxadiazole-2-yl]-N'-phenylurea derivatives is reported. The structures of these compounds are supported by their IR, (1)H-NMR and mass spectra. Conformational analysis and superimposition of energy minima conformers of these compounds on L-365, 260, a known 3-ureido-1, 4-benzodiazepine CCK-B antagonist, showed that the aromatic rings fell in the same contour. Morphine analgesia enhancement evaluation of the synthesized compounds in comparison with a control group showed that compounds 8a, 8c, 8h-8j, 8l, 8o have significant effects.  相似文献   

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Withdrawal: Jianfeng Liu et al. ‘The radiosynthesis of novel PI3K inhibitor, 8-ethoxy-2-(4-[18F]fluorophenyl)-3-nitro-2H-chromene (18F-EFPNC)’, Journal of Labelled Compounds and Radiopharmaceuticals ( https://doi.org/10.1002/jlcr.3524 ). The above article, published online on 30 May 2017 on Wiley Online Library (wileyonlinelibrary.com), has been withdrawn by agreement between the journal's Editor-in-Chief Committee, and John Wiley & Sons Ltd. The withdrawal has been agreed as it was not possible to complete corrections and finalise the article.  相似文献   

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Novel omega-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl derivatives 1-6 containing 4-, 5- and/or 6-arylsubstituted pyrid-2(1H)-one moiety were synthesized. All the new compounds were examined in vitro to assess their 5-HT1A and 5-HT2A receptor affinities. Compounds 3 and 4 with a 5- or a 6-phenylsubstituted pyridone ring demonstrated high 5-HT1A receptor affinity (Ki = 17 and 38 nM, respectively) and were tested in behavioral functional models. Derivative 3 can be regarded as a weak 5-HT1A postsynaptic antagonist, whereas 4 showed features of a weak partial agonist of 5-HT1A receptors (an agonist of pre- and an antagonist of postsynaptic ones). Binding affinities and in vivo results were discussed in comparison with those for the previously described tetramethylene analogs. The obtained results showed that the shortening of the aliphatic chain to two methylene groups exposed the intrinsic activity of the ligand 4 at 5-HT1A receptor sites.  相似文献   

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Recent studies have demonstrated that selective 5-HT(1F) receptor agonists inhibit neurogenic dural inflammation, a model of migraine headache, indicating that these compounds may be effective therapies for the treatment of migraine pain. This communication describes the synthesis and discovery of a novel compound, N-[3-(2-(dimethylamino)ethyl)-2-methyl-1H-indol-5-yl]-4-fluorobenzamide (4), which possesses high binding affinity and selectivity at the 5-HT(1F) receptor relative to more than 40 other serotonergic and nonserotonergic receptors examined.  相似文献   

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This paper describes the chemical synthesis, mu/kappa opioid receptor selectivity and analgesic activity of 14 novel N-[2-(1-pyrrolidinyl)-4- or -5-substituted-cyclohexyl]arylacetamide derivatives. The prototype kappa-selective agonist, PD117302 (trans-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]benzo[b]thiophene-4- acetamide, 2) has been regio- and stereoselectively substituted in the C-4 and C-5 positions of the cyclohexyl ring with the methyl ether and spiro tetrahydrofuran groups. It is observed that optimal mu/kappa-receptor selectivity is obtained when the oxygen atom of the methyl ether or the tetrahydrofuran ring is joined to the equatorial C-4 position. Hence, (-)-(5 beta,7 beta,8 alpha)-N-methyl-N-[7-(1-pyrrolidinyl)-1- oxaspiro[4.5]dec-8-yl]benzo[b]furan-4-acetamide monohydrochloride (21) has exceptionally high kappa opioid receptor affinity and selectivity in vitro (kappa Ki = 0.83 nM, mu/kappa ratio = 1520) is the most potent kappa-selective analgesic ever reported. Compound 21 is 25 times more potent than morphine and 17 times more potent than U-62066 (spiradoline, 19) when assayed by the rat paw pressure test by intravenous administration (MPE50 = 0.024, 0.6, and 0.4 mg/kg, respectively).  相似文献   

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The discovery of a structurally distinct cannabinoid-1 receptor (CB1R) positron emission tomography tracer is described. Starting from an acyclic amide CB1R inverse agonist (1) as the lead compound, an efficient route to introduce 18F to the molecule was developed. Further optimization focused on reducing the lipophilicity and increasing the CB1R affinity. These efforts led to the identification of [18F]-16 that exhibited good brain uptake and an excellent signal-to-noise ratio in rhesus monkeys.  相似文献   

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