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1.
2.
利用微量肉汤稀释法测定3-对烯-1-胺(1)及其席夫碱衍生物(2a~2l)对革兰氏阳性菌金黄色葡萄球菌、革兰氏阴性菌肺炎克雷伯氏菌及真菌白色念珠菌的抑菌活性,并讨论了构效关系。结果表明:3-对烯-1-胺及其部分席夫碱衍生物对这3种菌具有一定的抑菌活性,其中化合物1对金黄色葡萄球菌的抑菌活性最强,最小抑菌浓度(MIC)值为56.25 mg/L;化合物2h和2i对肺炎克雷伯氏菌的抑菌活性最强,MIC值均为112.5 mg/L;化合物2l对白色念珠菌的抑菌活性最强,MIC值为28.125 mg/L。构效关系分析结果表明:向3-对烯-1-胺席夫碱衍生物中引入Br、Cl等卤素后,能显著增强抑菌活性;含有吡啶环的3-对烯-1-胺席夫碱衍生物对真菌白色念珠菌的抑菌活性明显要高于含呋喃环、吡咯环或噻吩环的3-对烯-1-胺席夫碱衍生物。  相似文献   

3.
This study describes the adsorption behavior of three arylthiophene derivatives namely: 2-(4-amidino-3-fluorophenyl)-5-[4-methoxy phenyl] thiophene dihydrochloride salt (MA-1217), 2-(4-amidinophenyl)-5-[4-chlorophenyl] thiophene dihydrochloride salt (MA-1316) and 2-(4-amidino-3-fluorophenyl)-5-[4-chlorophenyl]thiophene dihydrochloride salt (MA-1312) at C-steel in 1.0 mol·L-1 HCl interface using experimental and theoretical studies. Electrochemical and mass loss measurements showed that the inhibition efficiency (IE) of the arylthiophene derivatives increases with increasing concentrations and exhibited maximum efficiency 89% at 21×10-6 mol·L-1 (MA-1217) by mass loss method. The investigated arylthiophene derivatives obey the Langmuir adsorption isotherm. From polarization studies the arylthiophene derivatives act as mixed-type inhibitors. Surface analysis were carried out and discussed. The mode of orientation and adsorption of inhibitor molecules on C-steel surface was studied using molecular dynamics (MD) simulations. Quantum chemical parameters as well as the radial distribution function indices and binding energies confirm the experimental results.  相似文献   

4.
5.
以取代基苯乙酮为原料,经溴代、羟醛缩合、Paal—Knott反应制得6个2,5-二苯基呋喃、噻吩、吡咯衍生物,总收率为20.9%-29.1%,产物结构经红外和核磁确定。  相似文献   

6.
汽油微生物固定化细胞脱硫技术   总被引:3,自引:0,他引:3  
探索用一株古地分支杆菌(Mycobacterium goodii)X7B菌株在固定化细胞体系中对汽油组分进行脱硫,通过生物脱硫实验,对于直馏汽油的脱除率达69.1%以上,进一步使用气相色谱-原子发射仪(GC-AED)对汽油脱硫前后的硫分布进行检测,发现X7B菌能有效地脱除汽油组分中的硫醇、硫醚等有机硫化合物,但对于噻吩类衍生物的处理能力有限,仅为36%。  相似文献   

7.
The synthesis and physiological activity of thiophenes and furans with methoxyacetophenone derivatives were examined. 3-Methoxyacetophenone (1) and 4-methoxyacetophenone (2) were converted, respectively, to the oximes (3) and (4) by oximation with hydroxylamine hydrochloride, and to the primary amines (5) and (6) by reduction with LiAlH(4). The primary amine derivatives were further converted into the thiophene and furan compounds (5a) approximately (5h) and (6a) approximately (6h), respectively. Bioassay of these compounds (5a) approximately (5h) and (6a) approximately (6h) on the germination of lettuce(Lactuca satiba) seeds showed that compound (5b) exhibits growthpromoting activity.  相似文献   

8.
The electrochemical copolymerization of furan and thiophene was performed at a constant electrode potential in a binary solvent system consisting of boron trifluoride/ethyl ether and an additional amount of ethyl ether (molar ratio = 1 : 2). The obtained homopolymers and copolymers were characterized with cyclic voltammetry and infrared spectroscopy. The influence of the applied electropolymerization potential and the monomer feed ratio of furan and thiophene on the copolymers was investigated. The furan–thiophene copolymers showed good stability of the redox activity in an acetonitrile‐based electrolyte solution. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008  相似文献   

9.
在四(三苯基膦)钯(Pd(PPh3)4催化作用下,通过催化偶合法可合成5,8-二噻基-萘基喹喔啉(DThQx(ace))和3,6-二噻基-哒嗪(DThPD)两种新型噻吩衍生物,同时也可合成了4,7-二噻基-2,1,3-苯并噻二唑(DThB)和1,4-二噻基-苯(DThPh),上述化合物产率分别为75%,78%,82%和67%。用红外光谱、核磁共振谱、元素分析等方法进行了表征,并对噻吩与不同芳香环构成的衍生物的紫外-可见吸收光谱和荧光光谱进行了对比研究。这四种化合物的紫外-可见吸收光谱中分别在435,336,446,325 nm处有最大吸收波长。其中DThQx(ace)、DThB和DThPh的荧光光谱中分别在564,568 nm和384 nm处观察到荧光,而DThPD无荧光。  相似文献   

10.
考察了微波炉加热强度及加热时间对于维生素C降解的影响,采用气质联机分析中火加热维生素C 5分钟的挥发性产物,鉴定出18种可能对于维生素C微波“加热香气”具有重要贡献的呋喃环或吡喃环结构类型挥发性成分。  相似文献   

11.
杨荣强  邵建华  张胜建  赵迎宪 《广东化工》2011,38(10):45+53-45,53
以磷酸为催化剂,研究不同离子液体对呋喃、噻吩与乙酸酐的乙酰化反应影响。还考察了原料比例、反应温度和时间对反应的影响。结果表明:[Bmim]PF6、[Bmim]BF4与磷酸存在协同催化作用。离子液体中的阳离子[Bmim]+可能对呋喃等杂环起稳定作用且减少缩合,阴离子可促进反应。50℃,反应8 h,n(呋喃):n(乙酸酐)=1:1.5,m(呋喃):m(磷酸):m([Bmim]PF6)=13.6:1:1,转化率94.8%,收率88.5%。噻吩乙酰化时,m(呋喃):m(磷酸):m([Bmim]PF6)=16.8:1:1,其他条件同呋喃一样,收率95.4%。  相似文献   

12.
噻吩及其衍生物裂化脱硫反应比较   总被引:3,自引:1,他引:2  
采用半经验的AM1量子化学计算方法和静态理论,分别考察了噻吩、3-甲基噻吩和2,5-二甲基噻吩分子结构特性的不同,从偶极矩、各自垂直于芳香环平面的二维电势能分布曲线和整个分子周围三维电势能分布情况等方面分析了它们在分子筛催化剂表面吸附速度的快慢和生成正碳离子稳定性的高低,进一步比较了噻吩及其衍生物所生成的正碳离子进一步反应的能量变化,从而可判断噻吩及其衍生物裂化脱硫速度的快慢,噻吩及其衍生物裂化脱硫的速度由大到小分别为:2,5-二甲基噻吩、3-甲基噻吩、噻吩。这与在实验室固定床微反装置上以噻吩、3-甲基噻吩和2,5-二甲基噻吩为模型化合物进行实验所得到的结果是一致的。  相似文献   

13.
Molecular‐imprinted poly(methacrylic acid) was synthesized with a template of retinoic acid to separate retinoid derivatives. The suspension polymerization technique was used to prepare round microparticles for high‐performance liquid chromatography (HPLC) packing column materials. The effects of the types and amounts of the dispersing agents and surfactants on the structure and size of the prepared molecular‐imprinted‐polymer particles were investigated. The separation of retinoic acid from its derivatives was more efficient when the perfluorocarbon dispersing agent was used instead of water, as the latter reduced the binding force between the objective molecules and monomers. HPLC separation features were also affected by the size and distribution of particles loaded in the column. A higher retention volume was obtained for smaller particles with a broader size distribution. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 200–212, 2005  相似文献   

14.
The efficiency of three furan derivatives (2-methylfuran, furfuryl alcohol and furfurylamine), as corrosion inhibitors for carbon steel in 1 M HCl, has been determined by gravimetric and electrochemical measurements. These compounds inhibit corrosion even at very low concentrations, and furfuryl alcohol is the best inhibitor. Polarization curves indicate that all compounds are mixed inhibitors, affecting both cathodic and anodic corrosion currents. Adsorption of furan derivatives on the carbon steel surface is in agreement with the Langmuir adsorption isotherm model, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. The structural and electronic properties of these inhibitors, obtained using AM1, PM3, MNDO and MINDO/3 semi-empirical self-consistence field methods, are correlated with their experimental efficiencies.  相似文献   

15.
The catalysts were prepared from pseudo-boehmite mixed with dilute nitric acid and calcined at different temperatures. The vapour-phase reaction of furan and hydrogen sulfide was performed in a fixed-bed flow in the presence of catalyst. The catalysts were characterized by XRD, N2 adsorption, FT-IR techniques. The Al2O3 calcined at 550 °C has large surface areas which resulted in high yield of thiophene under the conditions: at atmosphere, reaction temperature 500 °C, the ratio of H2S to Furan about 10 (mol) and LHSV 0.2 h−1. The reaction mechanism was proposed for the synthesis of thiophene from furan and hydrogen sulfide over Al2O3.  相似文献   

16.
A comprehensive and facile method for the synthesis of new functionalized bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif is described. The hitherto unknown bis-pyrazolothieno[2,3-b]thiophene derivatives 2a-c, bis-pyridazin othieno[2,3-b]thiophene derivatives 4, bis-pyridinothieno[2,3-b]thiophene derivatives 6a,b, and to an analogous bis-pyridinothieno[2,3-b]thiophene nitrile derivatives 7 are obtained. Additionally, the novel bis-pyradazinonothieno[2,3-b]thiophene derivatives 9, and nicotinic acid derivatives 10, 11 are obtained via bis-dienamide 8. The structures of all newly synthesized compounds have been elucidated by (1)H, (13)C NMR, GCMS, and IR spectrometry. These compounds represent a new class of sulfur and Nitrogen containing heterocycles that should also be of interest as new materials.  相似文献   

17.
In this work, the synthesis and characterization of highly aromatic bisoxazoline (BOX) monomers containing diphenyl ether, furan, and thiophene backbones are presented. Preliminary investigations of the cure and reaction kinetics are performed to understand the impact of these moieties on polymerization and their glass transition temperatures. To do this, two catalysts are used, methyl triflate (MT) and dodecyl benzene sulfonic acid (DBS) to explore their role in controlling the cationic ring-opening polymerization (CROP) mechanism. Polymerization was monitored using non-isothermal differential scanning calorimetry and characterized according to the Kissinger and Ozawa models. Kinetic modeling using the Malek and Sestak-Berggren methods showed excellent agreement with experimental values and was used to determine reaction rate constants. The polymerization of BOX monomers in the presence of both MT and DBS is shown to be highly latent, being stable until the melting point is reached, after which reaction occurs rapidly.  相似文献   

18.
高选择性地制备单溴代噻吩衍生物   总被引:1,自引:0,他引:1  
用N-溴代丁二亚酰胺溴化噻吩、2-甲基噻吩、3-甲基噻吩、2,5-二甲基噻吩、苯并噻吩、2-甲基苯并噻吩时,高产率、高区域选择性地得到2-溴噻吩、5-甲基-2-溴噻吩、3-甲基-2-溴噻吩、2,5-二甲基-3-溴噻吩、3-溴苯并噻吩、2-甲基-3-溴苯并噻吩,反应只生成单溴代噻吩衍生物.产物分离方便,同时发现噻吩衍生物的甲基对溴代反应的速度有较大的影响.  相似文献   

19.
The interactions between chemosensors, 3-amino-5-(4,5,6,7-tetrahydro-1H-indol-2-yl)isoxazole-4-carboxamide (AIC) derivatives, and different anions (F Cl, Br, AcO, and H2PO4) have been theoretically investigated using DFT approaches. It turned out that the unique selectivity of AIC derivatives for F is ascribed to their ability of deprotonating the host sensors. Frontier molecular orbital (FMO) analyses have shown that the vertical electronic transitions of absorption and emission for the sensing signals are characterized as intramolecular charge transfer (ICT). The study of substituent effects suggests that all the substituted derivatives are expected to be promising candidates for fluoride chemosensors both in UV-vis and fluorescence spectra except for derivative with benzo[d]thieno[3,2-b]thiophene fragment that can serve as ratiometric fluorescent fluoride chemosensor only.  相似文献   

20.
以顺丁烯二酸酐和呋喃为起始原料,经Diels-Alder、取代和缩合反应,合成了7个去甲去氢斑蝥素酰亚胺衍生物,其结构经NMR和元素分析证实。通过滤纸片法分别测定合成物对大肠杆菌、金黄色葡萄球菌的抑菌活性。结果表明,中间体N-氨基去甲去氢斑蝥素酰亚胺和部分产物对两种细菌都有较好的抑菌活性。其中,N-(氨基缩对甲氧基苯甲醛)-去甲去氢斑蝥素酰亚胺对大肠杆菌的抑菌活性最强,抑菌圈直径为28 mm。  相似文献   

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