共查询到20条相似文献,搜索用时 31 毫秒
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Kamil Jatczak Mariusz Gruza Katarzyna Filip Piotr Cmoch Grzegorz Grynkiewicz 《Central European Journal of Chemistry》2014,12(12):1222-1231
Protoescigenin, the main aglycone of horse chestnut saponin mixture known as escin, was selected as substrate for exploratory chemistry towards selective protection, followed by propargyl ether formation and subsequent condensation with azido-monosaccharides, to obtain novel triazole linked conjugates of the triterpene. 相似文献
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Iryna O. Lebedyeva Sean M. Sileno Kunal Patel Ion Ghiviriga Peter J. Steel Alan R. Katritzky 《Central European Journal of Chemistry》2013,11(6):1019-1022
Amination by organic azides has been carried out to provide aminobarbiturates by fusion of a triazole ring to the 5,6-positions of barbituric acid followed by cleavage and thermal elimination of nitrogen, whereas aza-Wittig reaction gave phosphoranylidene barbituric acid salts. 相似文献
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Attila Sipos Antal Udvardy Attila C. Bényei Sándor Berényi 《Central European Journal of Chemistry》2013,11(8):1278-1285
The synthesis of 3-deoxyoripavine (7) was realized as a novel and promising intermediate towards the synthesis of the important class of dopaminergic and/or serotonergic 10-deoxyaporphines and the special pharmacological tool µ opioid antagonist cyprodime. Generally, the preparation of these valuable biologically active compounds was achieved in remarkable yields. 相似文献
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Pawel Mierczynski Tomasz P. Maniecki Joanna Kaluzna-Czaplinska Ma?gorzata I. Szynkowska Waldemar Maniukiewicz Magdalena Lason-Rydel Wojciech K. Jozwiak 《Central European Journal of Chemistry》2013,11(2):304-312
Nickel catalysts supported on Na-mordenite were used for paraffin LTP56-H hydroconversion into liquid material as a possible component for engine fuels. The effects of none-catalytic thermal treatment and catalytic conditions-zeolite type and reaction conditions (solvent) on the process of liquefaction of LTP56-H paraffin and physicochemical properties of catalysts were studied. The physicochemical properties of catalytic systems were investigated using XRD, TPR, TPD-NH3 and SEM-EDS methods. 相似文献
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Rǎdiţa Aparaschivei Valeriu Şunel Mihaela Holban Marcel Popa Jacques Desbrieres 《Central European Journal of Chemistry》2013,11(11):1808-1815
New potentially biologically active compounds derived from 2-mercapto-benzoxazole were synthesized and coupled on polymeric support of poly (maleic anhydride-alt-vinyl acetate) for the preparation of polymer-drug conjugates with controlled drug release. All compounds were characterized by elemental and spectroscopy (FT-IR, 1H-NMR) analysis. The toxicological tests recommend the products for further laboratory screening. 相似文献
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Enantioselective organocatalytic Michael additions affords useful building blocks for many biologically and medicinally relevant compounds. Ionically-tagged diphenylprolinol silyl ether efficiently catalyzes several Michael additions of aldehydes to nitroalkenes in ionic liquids. The Michael additions work well in ionic liquids; yields up to 95% and enantioselectivities up to 95% ee were achieved. Furthermore, in some cases, the catalytic system was reusable. 相似文献
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Rui Liu Tonglai Zhang Li Yang Zunning Zhou 《Central European Journal of Chemistry》2014,12(6):672-677
The thermal decomposition of five double-base propellants modified with RDX was studied by dynamic pressure thermal analysis to determine the effect of RDX content (20–60 wt.%) on performance. All have good stability. Both stability and activation energy increase as RDX increases from 20% to 50% then decrease; 50% RDX performs best. The decomposition mechanism is affected by RDX content and temperature. Increasing temperature induces autocatalysis and accelerates decomposition. 相似文献
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Formation of stable complexes between xenon and podand polyoxyethylene ligands was ascertained. The complexation process was studied by 129Xe NMR titration, NMR diffusiometry and heteronuclear NOE measurements. The ligands studied form a 1:1 complexes with Xe(0). Their stability constants depend on the ligand structure, i.e., polyoxyethylene chain length, number of complexating polyether units and the topology of the anchoring centre. 相似文献
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Radomir Jasiński Magda Ziółkowska Oleh M. Demchuk Agata Maziarka 《Central European Journal of Chemistry》2014,12(5):586-593
[2+3] Cycloaddition reactions of the highly reactive (Z)-C-(3,4,5-trimethoxyphenyl)-N-methylnitrone with (E)-2-R-nitroethenes proceed under mild conditions and yield mixtures of stereoisomeric 2-methyl-3-(3,4,5-trimethoxyphenyl)-4-nitro-5-R-isoxazolidines. The effect of regiospecificity of the cycloadditions may be accounted for by the theory of electrophilicity indexes. Stereoselectivity, however, is determined by a compilation of steric and secondary orbital effects. 相似文献
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Iryna Pohrelyuk Oleh Tkachuk Roman Proskurnyak 《Central European Journal of Chemistry》2014,12(2):260-265
The corrosion properties of Ti-6Al-4V alloy with oxidized thermodiffusion nitride coatings were investigated in isotonic 0.9% solution of NaCl at temperature of 40°C. It was shown that modification of nitride coatings by oxygen leads to a deterioration of the protective properties of nitrided surface of Ti-6Al-4V alloy. The protective properties of the alloy with nitride coatings modified by oxygen are determined by the composition of formed surface oxynitride film. 相似文献
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Konstantin P. Arefyev Victor I. Grafutin Evgeny P. Prokopyev Andrey M. Lider Roman S. Laptev Yury S. Bordulev 《Central European Journal of Chemistry》2014,12(12):1280-1284
This article considers the possibility of applying the positron annihilation spectroscopy method for investigating the pore space of rocks from oil-gas and methane-coal deposits. The diagnostics of the structure was performed using the method of spectrometry of angular correlation of annihilation rays (ACAR). Using the samples of porous silicon, the authors have shown the applicability of the ACAR method for determination of the average dimensions of spherical and cylindrical nanosized objects and their concentration 相似文献
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Kornela Kasperczyk Beata Orlińska Jan Zawadiak 《Central European Journal of Chemistry》2014,12(11):1176-1182
4-Hexyloxycarbonyl-, 4-dodecyloxycarbonyl- and 4-hexadecyloxycarbonyl-N-hydroxyphthalimides were synthesised using trimellitic anhydride chloride as the starting material. The obtained lipophilic derivatives of N-hydroxyphthalimide were applied as catalysts of the cumene oxidation reaction with oxygen performed in polar acetonitrile, in non-polar tert-butylbenzene and in the absence of a solvent. The courses of reactions catalysed by N-hydroxyphthalimide and its derivatives were compared. 相似文献
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Here we report the transformation of tetracyclic morphinan salutaridine (1) into 2,3,10,11-tetrasubstituted (R)-aporphines. This method serves as another chemical proof of the previously verified biosynthetic connection with pentacyclic morphinan-6,8-diene-type thebaine. In the presence of nucleophiles, this procedure could lead to pharmacologically interesting new tetrasubstituted aporphinoids. The enantioselective synthesis of 7S-salutaridinol (2) has been also achieved in order to investigate the acid-catalyzed reactions of this natural morphinan. 相似文献
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Yurii Slyvka Evgeny Goreshnik Oleksii Pavlyuk Marian Mys’kiv 《Central European Journal of Chemistry》2013,11(12):1875-1901
In this review an exhaustive crystallochemical analysis of copper(I) π-complexes with allyl derivatives of heterocyclic compounds has been performed. Structural genesis of inorganic constituents starting from the simplest units to the most complicated aggregates was considered taking into account the specific role of Cu-(C=C) interaction, the construction of the organic ligands, the basicity and nucleophilic activity of their heteroatoms, as well as olefin Cu(I) π-complex preparation route. 相似文献
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Controlled pesticide release from biodegradable polymers 总被引:2,自引:0,他引:2
Anamika Roy Sunil K. Singh Jaya Bajpai Anil K. Bajpai 《Central European Journal of Chemistry》2014,12(4):453-469
Polymers have been widely used in agriculture for applications including controlled release of pesticides and other active ingredients. The ability to predict their delivery helps avoid environmental hazards. Macromolecular matrices used as carriers in controlled release of agricultural active agents, especially pesticides, are reviewed. The review focuses on the advantages and mechanisms of controlled release. It includes biodegradable polymers in agriculture, their manufacturing methods, and their degradation mechanisms and kinetics. The article also presents a critical account of recent release studies and considers upcoming challenges. 相似文献
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Sasa S. Randjelovic Danijela A. Kostic Gordana S. Stojanovic Snezana S. Mitic Milan N. Mitic Biljana B. Arsic Aleksandra N. Pavlovic 《Central European Journal of Chemistry》2014,12(11):1144-1151
The concentrations of Zn, Mn, Fe, Pb, Ni, Cu and Cd in soil, leaves and edible wild fruit (Crataegus laevigata L., Cornus mas L. and Prunus spinosa L.) from southeast Serbia were determined by atomic absorption spectroscopy. Metal translocations from soil to fruit were calculated as well as their oral intake and health risk indices. Positive correlations were found among metal concentrations in soil, leaves and fruit. 相似文献
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Krzysztof Nieszporek Tomasz Banach Przemywslaw Podkościelny 《Central European Journal of Chemistry》2014,12(2):185-193
The Non-Random Two-Liquid activity coefficient model is applied to describe the kinetics of pure gas adsorption on energetically heterogeneous solid surfaces. The surface energetic heterogeneity has been represented by the Gaussian-like function of the adsorption energy distribution. Two different kinetic isotherms have been presented. One of them, determined by using the statistical rate theory, has been critically discussed. The applicability of the presented approach has been demonstrated by a quantitative analysis of two sets of experimental data previously reported in the literature. 相似文献
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Bogdan Dereka Denis Svechkarev Andrey O. Doroshenko 《Central European Journal of Chemistry》2013,11(4):584-593
Prospects for analytical application of 2,5-diphenyloxazole-substituted 3-hydroxychromone for detection of mercury ions are presented. Sensitivity and selectivity for a number of metal ions both in methanol solution and in the plasticized polymer are outlined. Ultrasensitive and highly selective fluorescent ratiometric response of the polymer film containing the title compound for mercury ions in water media is revealed. Reversibility of ratiometric response to mercury ions and influence of plasticizer’s content in the polymer film on the optical feedback are also discussed. 相似文献
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Nikolay Velinov Kremena Koleva Tanya Tsoncheva Daniela Paneva Elina Manova Krassimir Tenchev Boris Kunev Izabela Genova Ivan Mitov 《Central European Journal of Chemistry》2014,12(2):250-259
Copper-cobalt ferrites with composition Cu1?xCoxFe2O4, where x= 0.2 and 0.8 were prepared by thermal treatment of co-precipitated precursor. The obtained materials were characterized by TG-DSC, XRD, Transmission and Conversion Electron Mössbauer spectroscopy and temperature programmed reduction with hydrogen. The catalytic properties of ferrites were tested in methanol decomposition to CO and hydrogen. 相似文献