WorldWideScience

Sample records for pyridinyl imidazole compounds

  1. Coordination compounds of metals with imidazoles and benzimidazoles

    International Nuclear Information System (INIS)

    Novikova, G.A.; Molodkin, A.K.; Kukalenko, S.S.

    1988-01-01

    Methods of preparation, composition and structure of UO 2 2+ , Th 4+ , Mo 3+ , Cd 2+ , Ln 3+ metal ion complexes with imidazoles and benzimidazoles are considered in reviews of native and foreign literature of up to 1985. Complexes are customarily prepared by direct interaction of ligands with inorganic salts in different organic solvents. Complex composition is defined by the nature of complexing metal and inorganic salt anion, ligand volume and basicity, as well as solvent characteristics. Effect of R substituent in imidazole and benzimidazole side chain on composition of coordination compounds is considered

  2. Coordination compounds of metals with imidazoles and benzimidazoles. [Metals: V, Th, Mo, Cd, rare earths, etc

    Energy Technology Data Exchange (ETDEWEB)

    Novikova, G A; Molodkin, A K; Kukalenko, S S

    1988-12-01

    Methods of preparation, composition and structure of UO/sub 2//sup 2+/, Th/sup 4+/, Mo/sup 3+/, Cd/sup 2+/, Ln/sup 3+/ metal ion complexes with imidazoles and benzimidazoles are considered in reviews of native and foreign literature of up to 1985. Complexes are customarily prepared by direct interaction of ligands with inorganic salts in different organic solvents. Complex composition is defined by the nature of complexing metal and inorganic salt anion, ligand volume and basicity, as well as solvent characteristics. Effect of R substituent in imidazole and benzimidazole side chain on composition of coordination compounds is considered.

  3. High-Pressure Chemistry of a Zeolitic Imidazolate Framework Compound in the Presence of Different Fluids.

    Science.gov (United States)

    Im, Junhyuck; Yim, Narae; Kim, Jaheon; Vogt, Thomas; Lee, Yongjae

    2016-09-14

    Pressure-dependent structural and chemical changes of the zeolitic imidazolate framework compound ZIF-8 have been investigated using different pressure transmitting media (PTM) up to 4 GPa. The unit cell of ZIF-8 expands and contracts under hydrostatic pressure depending on the solvent molecules used as PTM. When pressurized in water up to 2.2(1) GPa, the unit cell of ZIF-8 reveals a gradual contraction. In contrast, when alcohols are used as PTM, the ZIF-8 unit cell volume initially expands by 1.2% up to 0.3(1) GPa in methanol, and by 1.7% up to 0.6(1) GPa in ethanol. Further pressure increase then leads to a discontinuous second volume expansion by 1.9% at 1.4(1) GPa in methanol and by 0.3% at 2.3(1) GPa in ethanol. The continuous uptake of molecules under pressure, modeled by the residual electron density derived from Rietveld refinements of X-ray powder diffraction, reveals a saturation pressure near 2 GPa. In non-penetrating PTM (silicone oil), ZIF-8 becomes amorphous at 0.9(1) GPa. The structural changes observed in the ZIF-8-PTM system under pressure point to distinct molecular interactions within the pores.

  4. Rapid, convenient method for screening imidazole-containing compounds for heme oxygenase inhibition.

    Science.gov (United States)

    Vlahakis, Jason Z; Rahman, Mona N; Roman, Gheorghe; Jia, Zongchao; Nakatsu, Kanji; Szarek, Walter A

    2011-01-01

    Sensitive assays for measuring heme oxygenase activity have been based on the gas-chromatographic detection of carbon monoxide using elaborate, expensive equipment. The present study describes a rapid and convenient method for screening imidazole-containing candidates for inhibitory activity against heme oxygenase using a plate reader, based on the spectroscopic evaluation of heme degradation. A PowerWave XS plate reader was used to monitor the absorbance (as a function of time) of heme bound to purified truncated human heme oxygenase-1 (hHO-1) in the individual wells of a standard 96-well plate (with or without the addition of a test compound). The degradation of heme by heme oxygenase-1 was initiated using l-ascorbic acid, and the collected relevant absorbance data were analyzed by three different methods to calculate the percent control activity occurring in wells containing test compounds relative to that occurring in control wells with no test compound present. In the cases of wells containing inhibitory compounds, significant shifts in λ(max) from 404 to near 412 nm were observed as well as a decrease in the rate of heme degradation relative to that of the control. Each of the three methods of data processing (overall percent drop in absorbance over 1.5h, initial rate of reaction determined over the first 5 min, and estimated pseudo first-order reaction rate constant determined over 1.5h) gave similar and reproducible results for percent control activity. The fastest and easiest method of data analysis was determined to be that using initial rates, involving data acquisition for only 5 min once reactions have been initiated using l-ascorbic acid. The results of the study demonstrate that this simple assay based on the spectroscopic detection of heme represents a rapid, convenient method to determine the relative inhibitory activity of candidate compounds, and is useful in quickly screening a series or library of compounds for heme oxygenase inhibition

  5. Synthesis and Biological Evaluation of Indolyl-Pyridinyl-Propenones Having Either Methuosis or Microtubule Disruption Activity

    OpenAIRE

    Trabbic, Christopher J.; Overmeyer, Jean H.; Alexander, Evan M.; Crissman, Emily J.; Kvale, Heather M.; Smith, Marcie A.; Erhardt, Paul W.; Maltese, William A.

    2015-01-01

    Methuosis is a form of nonapoptotic cell death characterized by an accumulation of macropinosome-derived vacuoles with eventual loss of membrane integrity. Small molecules inducing methuosis could offer significant advantages compared to more traditional anticancer drug therapies that typically rely on apoptosis. Herein we further define the effects of chemical substitutions at the 2- and 5-indolyl positions on our lead compound 3-(5-methoxy-2-methyl-1H-indol-3-yl)-1-(4-pyridinyl)-2-propene-1...

  6. Increased urinary imidazolepropionic acid, n-acetylhistamine and other imidazole compounds in patients with intestinal disorders

    NARCIS (Netherlands)

    Heiden, C. van der; Wadman, S.K.; Bree, P.K. de; Wauters, E.A.K.

    In 26 out of a large group of patients with gastrointestinal disorders abnormal urinary imidazole excretion patterns were found. Most frequently excessive or increased amounts of imidazolepropionic acid (ImPA) occurred, and as next N-acetylhistamine was excreted in excess. In a number of cases the

  7. INHIBITORY ACTIVITY OF AN IMIDAZOLE COMPOUND ON ECDYSIOSYNTHETIC ORGANS IN MEALWORMS UNDER IN VIVO AND IN VITRO CONDITIONS

    Directory of Open Access Journals (Sweden)

    N SOLTANI-MAZOUNI

    2000-12-01

    Full Text Available KK-42, an imidazole derivative was tested on adult females of Tenebrio molitor L. (Insecta: Coleoptera. The compound was applied topically (1, 5, 10 mg/insect on 0- or 2-day old adult females or added to the culture medium (1 and 10 mM of abdominal sternites explanted from newly ecdysed pupae or ovaries removed from 2- and 4-day old adult females. Ecdysteroid measurements using an enzymo-immunoassay demonstrated that this compound applied on newly emerged adult females reduced the hormonal amounts in ovaries. However, when applied later, i.e. on 2-day old females corresponding to the beginning of the vitellogenesis, it had no significant effect on the amount of ovarian ecdysteroids with the lowest dose. Finally, the compound was also tested on the in vitro production of ecdysteroids. The amount of ecdysteroid released into the culture medium by ovaries or integumental explants were significantly reduced by KK-42.

  8. 2-(2-Hydroxyphenyl)imidazole-based four-coordinate organoboron compounds with efficient deep blue photoluminescence and electroluminescence.

    Science.gov (United States)

    Zhang, Zhenyu; Zhang, Zuolun; Zhang, Hongyu; Wang, Yue

    2017-12-19

    Two new four-coordinate organoboron compounds with 2-(2-hydroxyphenyl)imidazole derivatives as the chelating ligands have been synthesized. They possess high thermal stability and are able to form an amorphous glass state. Crystallographic analyses indicate that the differences in ligand structure cause the change of ππ stacking character. The CH 2 Cl 2 solutions and thin films of these compounds display bright blue emission, and these compounds have appropriate HOMO and LUMO energy levels for carrier injection in OLEDs. By utilizing the good thermal and luminescent properties, as well as the proper frontier orbital energy levels, bright non-doped OLEDs with a simple structure have been realized. Notably, these simple devices show deep blue electroluminescence with the Commission Internationale de l'Éclairage (CIE) coordinate of ca. (0.16, 0.08), which is close to the CIE coordinate of (0.14, 0.08) for standard blue defined by the National Television System Committee. In addition, one of the devices exhibits good performance, showing brightness, current efficiency, power efficiency and external quantum efficiency up to 2692 cd m -2 , 2.50 cd A -1 , 1.81 lm W -1 and 3.63%, respectively. This study not only provides good deep-blue emitting OLED materials that are rarely achieved by using four-coordinate organoboron compounds, but also allows a deeper understanding of the structure-property relationship of 2-(2-hydroxyphenyl)imidazole-based boron complexes, which benefits the further structural design of this type of material.

  9. Preparation of an aminopropyl imidazole-modified silica gel as a sorbent for solid-phase extraction of carboxylic acid compounds and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Wang, Na; Guo, Yong; Wang, Licheng; Liang, Xiaojing; Liu, Shujuan; Jiang, Shengxiang

    2014-05-21

    In this paper, a kind of aminopropyl imidazole-modified silica sorbent was synthesized and used as a solid-phase extraction (SPE) sorbent for the determination of carboxylic acid compounds and polycyclic aromatic hydrocarbons (PAHs). The resultant aminopropyl imidazole-modified silica sorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and elemental analysis (EA) to ensure the successful binding of aminopropyl imidazole on the surface of silica gel. Then the aminopropyl imidazole-modified silica sorbent served as a SPE sorbent for the enrichment of carboxylic acid compounds and PAHs. The new sorbent exhibited high extraction efficiency towards the tested compounds and the results show that such a sorbent can offer multiple intermolecular interactions: electrostatic, π-π, and hydrophobic interactions. Several parameters affecting the extraction recovery, such as the pH of sample solution, the pH of eluent, the solubility of eluent, the volume of eluent, and sample loading, were also investigated. Under the optimized conditions, the proposed method was applied to the analysis of four carboxylic acid compounds and four PAHs in environmental water samples. Good linearities were obtained for all the tested compounds with R(2) larger than 0.9903. The limits of detection were found to be in the range of 0.0065-0.5 μg L(-1). The recovery values of spiked river water samples were from 63.2% to 112.3% with relative standard deviations (RSDs) less than 10.1% (n = 4).

  10. New Approaches for the Synthesis, Cytotoxicity and Toxicity of Heterocyclic Compounds Derived from 2-Cyanomethylbenzo[c]imidazole.

    Science.gov (United States)

    Mohareb, Rafat M; Mohamed, Abeer A; Abdallah, Amira E M

    2016-01-01

    The reaction of ethyl cyanoacetate with o-phenylenediamine gave the 2-cyanomethylbenzo[c]imidazole (1). The latter compound was used as the key starting material to synthesise biologically active heterocyclic derivatives. Thus, the reaction of 1 with cyclohexanone and either of benzaldehyde, 4-methoxybenzaldehyde or 4-chlorobenzaldehyde gave the annulated derivatives 2a-c, respectively. The antitumor evaluations of the newly synthesized products against the three cancer cell lines MCF-7 (breast adeno-carcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer) showed that compounds 2b, 6, 11b, 11c, 12b, 16a, 16b and 18a exhibited optimal cytotoxic effect against cancer cell lines, with IC50 values in the nM range. Bioactive compounds are often toxic to shrimp larvae. Thus, in order to monitor these chemicals in vivo lethality to shrimp larvae (Artemia salina), Brine-Shrimp Lethality Assay was used. Compounds 11b, 12b and 16b showed no toxicity against the tested organisms.

  11. Imidazole: Having Versatile Biological Activities

    Directory of Open Access Journals (Sweden)

    Amita Verma

    2013-01-01

    Full Text Available Imidazoles have occupied a unique position in heterocyclic chemistry, and its derivatives have attracted considerable interests in recent years for their versatile properties in chemistry and pharmacology. Imidazole is nitrogen-containing heterocyclic ring which possesses biological and pharmaceutical importance. Thus, imidazole compounds have been an interesting source for researchers for more than a century. The imidazole ring is a constituent of several important natural products, including purine, histamine, histidine, and nucleic acid. Being a polar and ionisable aromatic compound, it improves pharmacokinetic characteristics of lead molecules and thus is used as a remedy to optimize solubility and bioavailability parameters of proposed poorly soluble lead molecules. There are several methods used for the synthesis of imidazole-containing compounds, and also their various structure reactions offer enormous scope in the field of medicinal chemistry. The imidazole derivatives possess extensive spectrum of biological activities such as antibacterial, anticancer, antitubercular, antifungal, analgesic, and anti-HIV activities. This paper aims to review the biological activities of imidazole during the past years.

  12. Adsorbed States of phosphonate derivatives of N-heterocyclic aromatic compounds, imidazole, thiazole, and pyridine on colloidal silver: comparison with a silver electrode.

    Science.gov (United States)

    Podstawka, Edyta; Olszewski, Tomasz K; Boduszek, Bogdan; Proniewicz, Leonard M

    2009-09-03

    Here, we report a systematic surface-enhanced Raman spectroscopy (SERS) study of the structures of phosphonate derivatives of the N-heterocyclic aromatic compounds imidazole (ImMeP ([hydroxy(1H-imidazol-5-yl)methyl]phosphonic acid) and (ImMe)(2)P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]phosphinic acid)), thiazole (BAThMeP (butylaminothiazol-2-yl-methyl)phosphonic acid) and BzAThMeP (benzylaminothiazol-2-yl-methyl)phosphonic acid)), and pyridine ((PyMe)(2)P (bis[(hydroxypyridin-3-yl-methyl)]phosphinic acid)) adsorbed on nanometer-sized colloidal particles. We compared these structures to those on a roughened silver electrode surface to determine the relationship between the adsorption strength and the geometry. For example, we showed that all of these biomolecules interact with the colloidal surface through aromatic rings. However, for BzAThMeP, a preferential interaction between the benzene ring and the colloidal silver surface is observed more so than that between the thiazole ring and this substrate. The PC(OH)C fragment does not take part in the adsorption process, and the phosphonate moiety of ImMeP and (ImMe)(2)P, being removed from the surface, only assists in this process.

  13. Unusual Conformational Aspects of Some Novel Chiral Non-Racemic Pyridinyl-2-phosphonates

    NARCIS (Netherlands)

    Dros, A.C.; Zijlstra, R.W.J.; Duijnen, P.Th. van; Spek, A.L.; Kooijman, H.; Kellogg, R.M.

    1998-01-01

    Reaction of pyridinyl-2-phosphonyl dichloride (6) with 1-phenyl-2,2-dimethylpropane-1,3-diol (9) leads to the two epimeric 2-oxo-2-(2-pyridinyl)-4-phenyl-5,5-dimethyl-1,3,2-dioxaphosphorinanes (10a,b). These can be separated and the stereochemistry assigned on the basis of 31P NMR spectroscopy. For

  14. Synthesis and biological evaluation of indolyl-pyridinyl-propenones having either methuosis or microtubule disruption activity.

    Science.gov (United States)

    Trabbic, Christopher J; Overmeyer, Jean H; Alexander, Evan M; Crissman, Emily J; Kvale, Heather M; Smith, Marcie A; Erhardt, Paul W; Maltese, William A

    2015-03-12

    Methuosis is a form of nonapoptotic cell death characterized by an accumulation of macropinosome-derived vacuoles with eventual loss of membrane integrity. Small molecules inducing methuosis could offer significant advantages compared to more traditional anticancer drug therapies that typically rely on apoptosis. Herein we further define the effects of chemical substitutions at the 2- and 5-indolyl positions on our lead compound 3-(5-methoxy-2-methyl-1H-indol-3-yl)-1-(4-pyridinyl)-2-propene-1-one (MOMIPP). We have identified a number of compounds that induce methuosis at similar potencies, including an interesting analogue having a hydroxypropyl substituent at the 2-position. In addition, we have discovered that certain substitutions on the 2-indolyl position redirect the mode of cytotoxicity from methuosis to microtubule disruption. This switch in activity is associated with an increase in potency as large as 2 orders of magnitude. These compounds appear to represent a new class of potent microtubule-active anticancer agents.

  15. Inhibition of glycolysis and growth of colon cancer cells by 3-(3-pyridinyl-1-(4-pyridinyl-2-propen-1-one (3PO in combination with butyrate, 2-deoxy glucose, 3-bromopyruvate or biguanides

    Directory of Open Access Journals (Sweden)

    Lea MA

    2015-09-01

    Full Text Available Introduction: Glycolysis shows a positive correlation with growth of human colon cancer cells. PFKFB3 is an important enzyme regulating glycolysis in many tumor cells and presents a target for cancer chemotherapy. We studied the action of an inhibitor of PFKFB3, 3-(3-pyridinyl-1-(4-pyridinyl-2-propen-1-one (3PO, as a single agent and in combination with other molecules that affect glycolysis. Materials and methods: Effects on growth were studied in four human colon cancer cell lines. Glucose metabolism was monitored by uptake from the incubation medium and lactic acid production was judged by acidification of the medium. Induction of alkaline phosphatase served as a marker of differentiation. Results: Growth of colon cancer cells was inhibited by 3PO and butyrate but only butyrate induced activation of alkaline phosphatase. Although metformin and phenformin can increase glucose metabolism, they inhibit colon cancer cell growth and can exert additive inhibitory effects in combination with 3PO. Additive growth inhibitory effects with 3PO were also observed with two compounds that inhibit glycolysis: 2-deoxyglucose and 3-bromopyruvate. Conclusion: 3PO was an inhibitor of growth of colon cancer cells and may be a useful agent in combination with other drugs that inhibit colon cancer cell proliferation.

  16. Synthesis, biological evaluation and structure-activity correlation study of a series of imidazol-based compounds as Candida albicans inhibitors.

    Science.gov (United States)

    Moraca, Francesca; De Vita, Daniela; Pandolfi, Fabiana; Di Santo, Roberto; Costi, Roberta; Cirilli, Roberto; D'Auria, Felicia Diodata; Panella, Simona; Palamara, Anna Teresa; Simonetti, Giovanna; Botta, Maurizio; Scipione, Luigi

    2014-08-18

    A new series of 2-(1H-imidazol-1-yl)-1-phenylethanol derivatives was synthesized. The antifungal activity was evaluated in vitro against different fungal species. The biological results show that the most active compounds possess an antifungal activity comparable or higher than Fluconazole against Candida albicans, non-albicans Candida species, Cryptococcus neoformans and dermathophytes. Because of their racemic nature, the most active compounds 5f and 6c were tested as pure enantiomers. For 6c the (R)-enantiomer resulted more active than the (S)-one, otherwise for 5f the (S)-enantiomer resulted the most active. To rationalize the experimental data, a ligand-based computational study was carried out; the results of the modelling study show that (S)-5f and (R)-6c perfectly align to the ligand-based model, showing the same relative configuration. Preliminary studies on the human lung adenocarcinoma epithelial cells (A549) have shown that 6c, 5e and 5f possess a low cytotoxicity. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. Benzimidazole and imidazole hexachlorocerates

    Energy Technology Data Exchange (ETDEWEB)

    Bayanov, A P; Burylev, B P; Temerdashev, Z A; Gusev, V I [Kubanskij Gosudarstvennyj Univ., Krasnodar (USSR)

    1983-02-01

    The process of hexachlorocerium acid with benzimidazole and imidazole interaction and the reaction products are investigated. The values of thermodynamic characteristics of the hexachlorocerium acid reaction with benzimidazole are equal: ..delta..Gsub(298K)=-16.5+-0.2 kJ/mol, ..delta..Hsub(298K)=-63.6+-0.8 kJ/mol, ..delta..Ssub(298K)=-157+-5 J/mol degrees. By the IR spectroscopy and radiography method the individuality of separated compounds has been found. The thermal stability of compounds is determined. The temperature dependence of splitting off chlorine atom from benzimidazole hexachlorocerate on pressure is investigated. Thermodynamic characteristics and activation energies of the process are calculated.

  18. Benzimidazole and imidazole hexachlorocerates

    International Nuclear Information System (INIS)

    Bayanov, A.P.; Burylev, B.P.; Temerdashev, Z.A.; Gusev, V.I.

    1983-01-01

    The process of hexachlorocerium acid with benzimidazole and imidazole interaction and the reaction products are investigated. The values of thermodynamic characteristics of the hexachlorocerium acid reaction with benzimidazole are equal: ΔGsub(298K)=-16.5+-0.2 kJ/mol, ΔHsub(298K)=-63.6+-0.8 kJ/mol, ΔSsub(298K)=-157+-5 J/mol degrees. By the IR spectroscopy and radiography method the individuality of separated compounds has been found. The thermal stability of compounds is determined. The temperature de-- pendence of splitting off chlorine atom from benzimidazole hexachlorocerate on pressure is investigated. Thermodynamic characteristics and activation energies of the process are calculated

  19. Experimental and quantum chemical studies of a new organic proton transfer compound, 1H-imidazole-3-ium-3-hydroxy-2,4,6-trinitrophenolate

    Science.gov (United States)

    Dhamodharan, P.; Sathya, K.; Dhandapani, M.

    2018-02-01

    A new proton transfer compound, 1H-imidazole-3-ium-3-hydroxy-2,4,6-trinitrophenolate (IMHTP), was crystallized by slow evaporation-solution growth technique. 1H and 13C NMR spectral studies confirm the molecular structure of the grown crystal. Single crystal X-ray diffraction study confirms that IMHTP crystallizes in monoclinic system with space group P21/c. Thermal curves (TG/DTA) show that the material is thermally stable up to 198 °C. The crystal emits fluorescence at 510 nm, proving its utility in making green light emitting materials in optical applications. The stable molecular structure was optimized by Gaussian 09 program with B3LYP/6-311++G(d,p) level of basis set. The frontier molecular orbital study shows that the charge transfer interaction occurs within the complex. The calculated first-order hyperpolarizability value of IMHTP is 44 times higher than that the reference material, urea. The electrostatic potential map was used to probe into electrophilic and nucleophilic reactive sites present in the molecule.

  20. Group 11 Metal Compounds with Tripodal Bis(imidazole Thioether Ligands. Applications as Catalysts in the Oxidation of Alkenes and as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Armando Varela-Ramírez

    2011-08-01

    Full Text Available New group 11 metal complexes have been prepared using the previously described tripodal bis(imidazole thioether ligand (N-methyl-4,5-diphenyl-2-imidazolyl2C(OMeC(CH32S(tert-Bu ({BITOMe,StBu}, 2. The pincer ligand offers a N2S donor atom set that can be used to coordinate the group 11 metals in different oxidation states [AuI, AuIII, AgI, CuI and CuII]. Thus the new compounds [Au{BITOMe,StBu}Cl][AuCl4]2 (3, [Au{BITOMe,StBu}Cl] (4, [Ag{BITOMe,StBu}X] (X = OSO2CF3- 5, PF6- 6 and [Cu{BITOMe,StBu}Cl2] (7 have been synthesized from reaction of 2 with the appropriate metal precursors, and characterized in solution. While attempting characterization in the solid state of 3, single crystals of the neutral dinuclear mixed AuIII-AuI species [Au2{BITOMe,S}Cl3] (8 were obtained and its crystal structure was determined by X-ray diffraction studies. The structure shows a AuIII center coordinated to the pincer ligand through one N and the S atom. The soft AuI center coordinates to the ligand through the same S atom that has lost the tert-butyl group, thus becoming a thiolate ligand. The short distance between the AuI-AuIII atoms (3.383 Å may indicate a weak metal-metal interaction. Complexes 2-7 and the previously described CuI compound [Cu{BITOMe,StBu}]PF6 (9 have been evaluated in the oxidation of biphenyl ethylene with tert-butyl hydrogen peroxide (TBHP as the oxidant. Results have shown that the AuI and AgI complexes 4 and 6 (at 10 mol % loading are the more active catalysts in this oxidative cleavage. The antimicrobial activity of compounds 2-5, 7 and 9 against Gram-positive and Gram-negative bacteria and yeast has also been evaluated. The new gold and silver compounds display moderate to high antibacterial activity, while the copper derivatives are mostly inactive. The gold and silver complexes were also potent against fungi. Their cytotoxic properties have been analyzed in vitro utilizing HeLa human cervical carcinoma cells. The compounds displayed a

  1. Biologic activities of molecular chaperones and pharmacologic chaperone imidazole-containing dipeptide-based compounds: natural skin care help and the ultimate challenge: implication for adaptive responses in the skin.

    Science.gov (United States)

    Babizhayev, Mark A; Nikolayev, Gennady M; Nikolayeva, Juliana G; Yegorov, Yegor E

    2012-03-01

    Accumulation of molecular damage and increased molecular heterogeneity are hallmarks of photoaged skin and pathogenesis of human cutaneous disease. Growing evidence demonstrates the ability of molecular chaperone proteins and of pharmacologic chaperones to decrease the environmental stress and ameliorate the oxidation stress-related and glycation disease phenotypes, suggesting that the field of chaperone therapy might hold novel treatments for skin diseases and aging. In this review, we examine the evidence suggesting a role for molecular chaperone proteins in the skin and their inducer and protecting agents: pharmacologic chaperone imidazole dipeptide-based agents (carcinine and related compounds) in cosmetics and dermatology. Furthermore, we discuss the use of chaperone therapy for the treatment of skin photoaging diseases and other skin pathologies that have a component of increased glycation and/or free radical-induced oxidation in their genesis. We examine biologic activities of molecular and pharmacologic chaperones, including strategies for identifying potential chaperone compounds and for experimentally demonstrating chaperone activity in in vitro and in vivo models of human skin disease. This allows the protein to function and traffic to the appropriate location in the skin, thereby increasing protein activity and cellular function and reducing stress on skin cells. The benefits of imidazole dipeptide antioxidants with transglycating activity (such as carcinine) in skin care are that they help protect and repair cell membrane damage and help retain youthful, younger-looking skin. All skin types will benefit from daily, topical application of pharmacologic chaperone antioxidants, anti-irritants, in combination with water-binding protein agents that work to mimic the structure and function of healthy skin. General strategies are presented addressing ground techniques to improve absorption of usually active chaperone proteins and dipeptide compounds, include

  2. Effects of ionizing radiation in cocrystals of DNA model compounds: ESR-ENDOR studies of X-irradiated imidazole:barbital and adenosine:5-bromouracil

    International Nuclear Information System (INIS)

    Kar, L.

    1982-01-01

    Electron spin resonance (ESR) and electron nuclear double resonance (ENDOR) techniques have been used to study radiation induced damage in cocrystalline complexes X-irradiated at 12 K. The study addresses the following questions: (1) whether radiation induced damage is stabilized preferentially on one of the components of the cocrystalline system; and (2) whether charge transfer occurs between purine and pyrimidine bases in hydrogen bonded or stacked configurations. The cocrystals used in this study are imidazole:5,5-diethylbarbituric acid (barbital) and adenosine:5-bromouracil (AR:BU). Results indicate that (1) preferential stability of radiation damage may be observed in a cocrystal even in the absence of stacking interactions; (2) in the presence of purine:pyrimidine stacking electron transfer may occur, but hole transfer is not likely to be the mechanism of redistribution of radiation damage in cocrystalline systems. The radiation chemistry of AR:BU is used as a model to predict the effects of ionizing radiation on DNA

  3. Evolution of glycaemia in the blood of mice in the presence or absence of imidazole

    International Nuclear Information System (INIS)

    Polverelli, M.; Teoule, R.

    1969-01-01

    With respect to the radioprotective properties of the heterocyclic compound, imidazole, the authors followed the action of this product on blood sugar levels of mice X irradiated with a lethal dose. The main results of this work are: probably a hypo-glycemic action of the imidazole; an abolishment of the post-irradiation hyperglycemia by imidazole; an appreciably difference between male and female towards irradiation. (author) [fr

  4. Quantum Chemical Benchmarking, Validation, and Prediction of Acidity Constants for Substituted Pyridinium Ions and Pyridinyl Radicals.

    Science.gov (United States)

    Keith, John A; Carter, Emily A

    2012-09-11

    Sensibly modeling (photo)electrocatalytic reactions involving proton and electron transfer with computational quantum chemistry requires accurate descriptions of protonated, deprotonated, and radical species in solution. Procedures to do this are generally nontrivial, especially in cases that involve radical anions that are unstable in the gas phase. Recently, pyridinium and the corresponding reduced neutral radical have been postulated as key catalysts in the reduction of CO2 to methanol. To assess practical methodologies to describe the acid/base chemistry of these species, we employed density functional theory (DFT) in tandem with implicit solvation models to calculate acidity constants for 22 substituted pyridinium cations and their corresponding pyridinyl radicals in water solvent. We first benchmarked our calculations against experimental pyridinium deprotonation energies in both gas and aqueous phases. DFT with hybrid exchange-correlation functionals provide chemical accuracy for gas-phase data and allow absolute prediction of experimental pKas with unsigned errors under 1 pKa unit. The accuracy of this economical pKa calculation approach was further verified by benchmarking against highly accurate (but very expensive) CCSD(T)-F12 calculations. We compare the relative importance and sensitivity of these energies to selection of solvation model, solvation energy definitions, implicit solvation cavity definition, basis sets, electron densities, model geometries, and mixed implicit/explicit models. After determining the most accurate model to reproduce experimentally-known pKas from first principles, we apply the same approach to predict pKas for radical pyridinyl species that have been proposed relevant under electrochemical conditions. This work provides considerable insight into the pitfalls using continuum solvation models, particularly when used for radical species.

  5. Synthesis and Antibacterial Activities of New Metronidazole and Imidazole Derivatives

    Directory of Open Access Journals (Sweden)

    Abdul Jabar Kh. Atia

    2009-07-01

    Full Text Available New imidazole ring derivatives comprising 1,3-oxazoline, Schiff's bases, thiadiazole, oxadiazole and 1,2,4-triazole moieties are reported. 3-Aminobiimidazol-4-one compounds 7a-c were synthesized by the reaction of compounds 6a-c with hydrazine hydrate. Biimidazole esters 9a-c were converted into biimidazole hydrazide esters 10a-c. Compounds 7a-c and 10a-c were converted into a variety of derivatives.

  6. Comprehensive review in current developments of imidazole-based medicinal chemistry.

    Science.gov (United States)

    Zhang, Ling; Peng, Xin-Mei; Damu, Guri L V; Geng, Rong-Xia; Zhou, Cheng-He

    2014-03-01

    Imidazole ring is an important five-membered aromatic heterocycle widely present in natural products and synthetic molecules. The unique structural feature of imidazole ring with desirable electron-rich characteristic is beneficial for imidazole derivatives to readily bind with a variety of enzymes and receptors in biological systems through diverse weak interactions, thereby exhibiting broad bioactivities. The related research and developments of imidazole-based medicinal chemistry have become a rapidly developing and increasingly active topic. Particularly, numerous imidazole-based compounds as clinical drugs have been extensively used in the clinic to treat various types of diseases with high therapeutic potency, which have shown the enormous development value. This work systematically gives a comprehensive review in current developments of imidazole-based compounds in the whole range of medicinal chemistry as anticancer, antifungal, antibacterial, antitubercular, anti-inflammatory, antineuropathic, antihypertensive, antihistaminic, antiparasitic, antiobesity, antiviral, and other medicinal agents, together with their potential applications in diagnostics and pathology. It is hoped that this review will be helpful for new thoughts in the quest for rational designs of more active and less toxic imidazole-based medicinal drugs, as well as more effective diagnostic agents and pathologic probes. © 2013 Wiley Periodicals, Inc.

  7. The lattice dynamics of imidazole

    International Nuclear Information System (INIS)

    Link, K.H.

    1983-05-01

    The lattice dynamics of imidazole have been investigated. To this end dispersion curves have been determined at 10 K by inelastic coherent neutron scattering. RAMAN measurements have been done to investigate identical gamma - point modes. The combination of extinction rules for RAMAN - and neutron scattering leads to the symmetry assignment of identical gamma - point modes. The experiment yields a force constant of the streching vibration of the hydrogen bond of 0.33 mdyn/A. A force model has been developed to describe the intermolecular atom - atom Interactions in imidazole. (orig./BHO)

  8. Characterization and Solubilization of Pyrrole–Imidazole Polyamide Aggregates

    OpenAIRE

    Hargrove, Amanda E.; Raskatov, Jevgenij A.; Meier, Jordan L.; Montgomery, David C.; Dervan, Peter B.

    2012-01-01

    To optimize the biological activity of pyrrole–imidazole polyamide DNA-binding molecules, we characterized the aggregation propensity of these compounds through dynamic light scattering and fractional solubility analysis. Nearly all studied polyamides were found to form measurable particles 50–500 nm in size under biologically relevant conditions, while HPLC-based analyses revealed solubility trends in both core sequences and peripheral substituents that did not correlate with overall ionic c...

  9. Thermodynamic study of phase transitions of imidazoles and 1-methylimidazoles

    International Nuclear Information System (INIS)

    Almeida, Ana R.R.P.; Monte, Manuel J.S.

    2012-01-01

    Highlights: → Sublimation vapor pressures of imidazole, N-methylimidazole and four derivatives were measured. → Liquid vapor pressures were also measured for four of the compounds studied. → Vapor pressure results enabled determination of sublimation, vaporization, and fusion enthalpy. → From enthalpies of sublimation, enthalpies of intermolecular N-H...N bonds were estimated. - Abstract: The vapor pressures of imidazole, N-methylimidazole and of their dichloro and dicyano substituted compounds were measured at different temperatures, in the crystalline phase for two of them, and in crystalline and liquid phases for the other four. From these measurements, enthalpies and standard entropies of sublimation and vaporization were derived. The results allowed the determination of the triple points (p, T) coordinates of the four compounds studied in both condensed phases as well as the calculation of their enthalpy of fusion. Enthalpies and temperatures of fusion were also determined using d.s.c. The experimental results enabled the estimation of the enthalpy of the intermolecular N-H...N bonds in the imidazoles studied.

  10. Thermodynamic study of phase transitions of imidazoles and 1-methylimidazoles

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Ana R.R.P., E-mail: ana.figueira@fc.up.pt [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Monte, Manuel J.S., E-mail: mjmonte@fc.up.pt [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

    2012-01-15

    Highlights: > Sublimation vapor pressures of imidazole, N-methylimidazole and four derivatives were measured. > Liquid vapor pressures were also measured for four of the compounds studied. > Vapor pressure results enabled determination of sublimation, vaporization, and fusion enthalpy. > From enthalpies of sublimation, enthalpies of intermolecular N-H...N bonds were estimated. - Abstract: The vapor pressures of imidazole, N-methylimidazole and of their dichloro and dicyano substituted compounds were measured at different temperatures, in the crystalline phase for two of them, and in crystalline and liquid phases for the other four. From these measurements, enthalpies and standard entropies of sublimation and vaporization were derived. The results allowed the determination of the triple points (p, T) coordinates of the four compounds studied in both condensed phases as well as the calculation of their enthalpy of fusion. Enthalpies and temperatures of fusion were also determined using d.s.c. The experimental results enabled the estimation of the enthalpy of the intermolecular N-H...N bonds in the imidazoles studied.

  11. Evolution of glycaemia in the blood of mice in the presence or absence of imidazole; Evolution de la glycemie sanguine chez la souris protegee ou non par l'imidazole

    Energy Technology Data Exchange (ETDEWEB)

    Polverelli, M; Teoule, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    With respect to the radioprotective properties of the heterocyclic compound, imidazole, the authors followed the action of this product on blood sugar levels of mice X irradiated with a lethal dose. The main results of this work are: probably a hypo-glycemic action of the imidazole; an abolishment of the post-irradiation hyperglycemia by imidazole; an appreciably difference between male and female towards irradiation. (author) [French] Dans le cadre de l'etude des proprietes radioprotectrices de l'imidazole, nous nous sommes attaches a suivre l'action de ce produit sur le taux de glucose sanguin de souris irradiees a dose letale. Les principaux resultats de ce travail sont les suivants: l'action probablement hypoglycemiante de l'imidazole; en tant que radioprotecteur, cet heterocycle azote supprime l'hyperglycemie consecutive a l'irradiation; une difference assez sensible entre males et femelles vis-a-vis de l'irradiation. (auteur)

  12. Imidazole and Triazole Coordination Chemistry for Antifouling Coatings

    Directory of Open Access Journals (Sweden)

    Markus Andersson Trojer

    2013-01-01

    Full Text Available Fouling of marine organisms on the hulls of ships is a severe problem for the shipping industry. Many antifouling agents are based on five-membered nitrogen heterocyclic compounds, in particular imidazoles and triazoles. Moreover, imidazole and triazoles are strong ligands for Cu2+ and Cu+, which are both potent antifouling agents. In this review, we summarize a decade of work within our groups concerning imidazole and triazole coordination chemistry for antifouling applications with a particular focus on the very potent antifouling agent medetomidine. The entry starts by providing a detailed theoretical description of the azole-metal coordination chemistry. Some attention will be given to ways to functionalize polymers with azole ligands. Then, the effect of metal coordination in azole-containing polymers with respect to material properties will be discussed. Our work concerning the controlled release of antifouling agents, in particular medetomidine, using azole coordination chemistry will be reviewed. Finally, an outlook will be given describing the potential for tailoring the azole ligand chemistry in polymers with respect to Cu2+ adsorption and Cu2+→Cu+ reduction for antifouling coatings without added biocides.

  13. Studies on the π-π stacking features of imidazole units present in a series of 5-amino-1-alkylimidazole-4-carboxamides

    Science.gov (United States)

    Ray, Sibdas; Das, Aniruddha

    2015-06-01

    Reaction of 2-ethoxymethyleneamino-2-cyanoacetamide with primary alkyl amines in acetonitrile solvent affords 1-substituted-5-aminoimidazole-4-carboxamides. Single crystal X-ray diffraction studies of these imidazole compounds show that there are both anti-parallel and syn-parallel π-π stackings between two imidazole units in parallel-displaced (PD) conformations and the distance between two π-π stacked imidazole units depends mainly on the anti/ syn-parallel nature and to some extent on the alkyl group attached to N-1 of imidazole; molecules with anti-parallel PD-stacking arrangements of the imidazole units have got vertical π-π stacking distance short enough to impart stabilization whereas the imidazole unit having syn-parallel stacking arrangement have got much larger π-π stacking distances. DFT studies on a pair of anti-parallel imidazole units of such an AICA lead to curves for 'π-π stacking stabilization energy vs. π-π stacking distance' which have got similarity with the 'Morse potential energy diagram for a diatomic molecule' and this affords to find out a minimum π-π stacking distance corresponding to the maximum stacking stabilization energy between the pair of imidazole units. On the other hand, a DFT calculation based curve for 'π-π stacking stabilization energy vs. π-π stacking distance' of a pair of syn-parallel imidazole units is shown to have an exponential nature.

  14. Synthesis and Biological Evaluation of Isomeric Methoxy Substitutions on Anti-Cancer Indolyl-Pyridinyl-Propenones: Effects on Potency and Mode of Activity

    OpenAIRE

    Trabbic, Christopher J.; George, Sage M.; Alexander, Evan M.; Du, Shengnan; Offenbacher, Jennifer M.; Crissman, Emily J.; Overmeyer, Jean H.; Maltese, William A.; Erhardt, Paul W.

    2016-01-01

    Certain indolyl-pyridinyl-propenone analogues kill glioblastoma cells that have become resistant to conventional therapeutic drugs. Some of these analogues induce a novel form of non-apoptotic cell death called methuosis, while others primarily cause microtubule disruption. Ready access to 5-indole substitution has allowed characterization of this position to be important for both types of mechanisms when a simple methoxy group is present. We now report the syntheses and biological effects of...

  15. Synthesis and potential cytotoxic activity of some new benzoxazoles, imidazoles, benzimidazoles and tetrazoles.

    Science.gov (United States)

    Arulmurugan, Subramaniyan; Kavitha, Helen P

    2013-06-01

    2 The present work deals with the synthesis of some novel heterocyclic compounds such as benzoxazoles , 7, 13 and 19, imidazoles 3, 8, 14 and 20, benzimidazoles 4, 9, 15 and 21, and tetrazoles 10, 16, and 22. The synthesized compounds were characterized by IR, 1H NMR, mass spectrometry and elemental analysis. The compounds were evaluated for cytotoxicity against human cancer cell lines such as MCF-7 (breast cancer) and HT-29 (colon cancer) by the MTT assay method. Among the tested compounds, 4,4'-sulfonylbis(N-(2-(1H-benzo[d]imidazol- -2-yl)ethyl)aniline (9), N-bis(2-(benzo[d]oxazol-2-yl)-ethyl)- 6-phenyl-1,3,5-triazine-2,4-diamine (13), N-bis(2-(1H-benzo[ d]imidazol-2-yl)ethyl)-6-phenyl-1,3,5-triazine-2,4-diamine (15) and N-tris(2-1H-benzo[d]imidazol-2-yl)ethyl)- 1,3,5-triazine-2,4,6-triamine (21) showed potent cytotoxicity.

  16. Ab initio study of the EFG at the N sites in imidazole

    Energy Technology Data Exchange (ETDEWEB)

    Brown Goncalves, Marcos, E-mail: browngon@if.usp.br [Universidade de Sao Paulo, Instituto de Fisica (Brazil); Di Felice, R. [National Center on Nanostructures and Biosystems at Surfaces (S3) of INFM-CNR (Italy); Poleshchuk, O. Kh. [Tomsk State Pedagogical University (Russian Federation); Petrilli, H. M. [Universidade de Sao Paulo, Instituto de Fisica (Brazil)

    2008-01-15

    We study the nuclear quadrupole interaction at the nitrogen sites in the molecular and crystalline phases of the imidazole compound. We use PAW which is a state-of-the-art method to calculate the electronic structure and electric field gradient at the nucleus in the framework of the density functional theory. The quadrupole frequencies at both imino and amino N sites are in excellent agreement with measurements. This is the first time that the electric field gradient at crystalline imidazole is correctly treated by an ab initio theoretical approach.

  17. Building blocks for ionic liquids: Vapor pressures and vaporization enthalpies of 1-(n-alkyl)-imidazoles

    International Nuclear Information System (INIS)

    Emel'yanenko, Vladimir N.; Portnova, Svetlana V.; Verevkin, Sergey P.; Skrzypczak, Andrzej; Schubert, Thomas

    2011-01-01

    Highlights: → We measured vapor pressures of the 1-(n-alkyl)-imidazoles by transpiration method. → Variations on the alkyl chain length n were C 3 , C 5 -C 7 , and C 9 -C 10 . → Enthalpies of vaporization were derived from (p, T) dependencies. → Enthalpies of vaporization at 298.15 K were linear dependent on the chain length. - Abstract: Vapor pressures of the linear 1-(n-alkyl)-imidazoles with the alkyl chain C 3 , C 5 -C 7 , and C 9 -C 10 have been measured by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. A linear correlation of enthalpies of vaporization Δ l g H m (298.15 K) of the 1-(n-alkyl)-imidazoles with the chain length has been found.

  18. Structural, photophysical, and theoretical studies of imidazole-based excited-state intramolecular proton transfer molecules

    Science.gov (United States)

    Somasundaram, Sivaraman; Kamaraj, Eswaran; Hwang, Su Jin; Park, Sanghyuk

    2018-02-01

    Imidazole-based excited state intramolecular proton transfer (ESIPT) blue fluorescent molecules, 2-(1-(4-chlorophenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenol (BHPI-Cl) and 2-(1-(4-bromophenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenol (BHPI-Br) were designed and synthesized by Debus-Radziszewski method through a one-pot multicomponent reaction in high yield. The synthesized compounds were fully characterized by 1H NMR, 13C NMR, FT-IR, FT-Raman, GC-Mass, and elemental analysis. The molecular structures in single crystal lattice were studied by X-ray crystallographic analysis. Because of the intramolecular hydrogen bonding, hydroxyphenyl group is planar to the central imidazole ring, while the other phenyl rings gave distorted conformations to the central heterocyclic ring. BHPI-Cl and BHPI-Br molecules showed intense ESIPT fluorescence at 480 nm, because the two twisted phenyl rings on 4- and 5-positions have reduced intermolecular interaction between adjacent molecules in each crystal through a head-to-tail packing manner. Quantum chemical calculations of energies were carried out by (TD-)DFT using B3LYP/6-31G(d, p) basis set to predict the electronic absorption spectra of the compounds, and they showed good agreement between the computational and the experimental values. The thermal analyses of the synthesized molecules were also carried out by TGA/DSC method.

  19. A Novel Tetrasubstituted Imidazole as a Prototype for the Development of Anti-inflammatory Drugs.

    Science.gov (United States)

    Nascimento, Marcus Vinicius P S; Munhoz, Antonio C M; Theindl, Lais C; Mohr, Eduarda Talita B; Saleh, Najla; Parisotto, Eduardo B; Rossa, Thaís A; Zamoner, Ariane; Creczynski-Pasa, Tania B; Filippin-Monteiro, Fabíola B; Sá, Marcus M; Dalmarco, Eduardo Monguilhott

    2018-04-14

    Although inflammation is a biological phenomenon that exists to protect the host against infections and/or related problems, its unceasing activation results in the aggravation of several medical conditions. Imidazoles, whether natural or synthetic, are molecules related to a broad spectrum of biological effects, including anti-inflammatory properties. In this study, we screened eight novel small molecules of the imidazole class synthesized by our research group for their in vitro anti-inflammatory activity. The effect of the selected molecules was confirmed in an in vivo inflammatory model. We also analyzed whether the effects were caused by inhibition of nuclear factor kappa B (NF-κB) transcription factor transmigration. Of the eight imidazoles tested, methyl 1-allyl-2-(4-fluorophenyl)-5-phenyl-1H-imidazole-4-acetate (8) inhibited nitric oxide metabolites and pro-inflammatory cytokine (TNF-α, IL-6, and IL-1β) secretion in J774 macrophages stimulated with LPS. It also attenuated leukocyte migration and exudate formation in the pleural cavity of mice challenged with carrageenan. Furthermore, imidazole 8 reverted the oxidative stress pattern triggered by carrageenan in the pleural cavity by diminishing myeloperoxidase, superoxide dismutase, catalase, and glutathione S-transferase activities and reducing the production of nitric oxide metabolites and thiobarbituric acid-reactive substances. Finally, these effects can be attributed, at least in part, to the ability of this compound to prevent NF-κB transmigration. In this context, our results demonstrate that imidazole 8 has promising potential as a prototype for the development of a new anti-inflammatory drug to treat inflammatory conditions in which NF-κB and oxidative stress play a prominent role. Graphical Abstract ᅟ.

  20. Epoxy Nanocomposites Containing Zeolitic Imidazolate Framework-8.

    Science.gov (United States)

    Liu, Cong; Mullins, Michael; Hawkins, Spencer; Kotaki, Masaya; Sue, Hung-Jue

    2018-01-10

    Zeolitic imidazole framework-8 (ZIF-8) is utilized as a functional filler and a curing agent in the preparation of epoxy nanocomposites. The imidazole group on the surface of the ZIF-8 initiates epoxy curing, resulting in covalent bonding between the ZIF-8 crystals and epoxy matrix. A substantial reduction in dielectric constant and increase in tensile modulus were observed. The implication of the present study for utilization of metal-organic framework to improve physical and mechanical properties of polymeric matrixes is discussed.

  1. Parallel Synthesis of a Library of Symmetrically- and Dissymmetrically-disubstituted Imidazole-4,5-dicarboxamides Bearing Amino Acid Esters

    Directory of Open Access Journals (Sweden)

    Rosanna Solinas

    2009-01-01

    Full Text Available The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters to afford symmetrically- and dissymmetrically-disubstituted imidazole-4,5-dicarboxamides with intramolecularly hydrogen bonded conformations that predispose the presentation of amino acid pharmacophores. In this work, a total of 45 imidazole-4,5-dicarboxamides bearing amino acid esters were prepared by parallel synthesis. The library members were purified by column chromatography on silica gel and the purified compounds characterized by LC-MS with LC detection at 214 nm. A selection of the final compounds was also analyzed by 1H-NMR spectroscopy. The analytically pure final products have been submitted to the Molecular Library Small Molecule Repository (MLSMR for screening in the Molecular Library Screening Center Network (MLSCN as part of the NIH Roadmap.

  2. Synthesis and biological evaluation of isomeric methoxy substitutions on anti-cancer indolyl-pyridinyl-propenones: Effects on potency and mode of activity.

    Science.gov (United States)

    Trabbic, Christopher J; George, Sage M; Alexander, Evan M; Du, Shengnan; Offenbacher, Jennifer M; Crissman, Emily J; Overmeyer, Jean H; Maltese, William A; Erhardt, Paul W

    2016-10-21

    Certain indolyl-pyridinyl-propenone analogues kill glioblastoma cells that have become resistant to conventional therapeutic drugs. Some of these analogues induce a novel form of non-apoptotic cell death called methuosis, while others primarily cause microtubule disruption. Ready access to 5-indole substitution has allowed characterization of this position to be important for both types of mechanisms when a simple methoxy group is present. We now report the syntheses and biological effects of isomeric methoxy substitutions on the indole ring. Additionally, analogues containing a trimethoxyphenyl group in place of the pyridinyl moiety were evaluated for anticancer activity. The results demonstrate that the location of the methoxy group can alter both the potency and the mechanism of cell death. Remarkably, changing the methoxy from the 5-position to the 6-position switched the biological activity from induction of methuosis to disruption of microtubules. The latter may represent a prototype for a new class of mitotic inhibitors with potential therapeutic utility. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. cobaloxime by imidazoles and amino acids

    Indian Academy of Sciences (India)

    Unknown

    to replicate them in experimental model systems with ... Axial ligation kinetics was monitored .... A trans influence study in propyl (aquo)cobaloxime by imidazoles and amino acids. 307 .... unfilled π* anti-bonding orbitals through dπ–pπ back-.

  4. Extreme Flexibility in a Zeolitic Imidazolate Framework

    DEFF Research Database (Denmark)

    Wharmby, M.T.; Henke, S.; Bennett, T.D.

    2015-01-01

    Desolvated zeolitic imidazolate framework ZIF-4(Zn) undergoes a discontinuous porous to dense phase transition on cooling through 140 K, with a 23% contraction in unit cell volume. The structure of the non-porous, low temperature phase was determined from synchrotron X-ray powder diffraction data...

  5. A Study of the Radioprotective Activity of the Imidazole Nucleus and Some of Its Derivatives; Etude de l'activite radioprotectrice du noyau imidazole et de quelquesuns de ses derives

    Energy Technology Data Exchange (ETDEWEB)

    Rinaldi, R; Bernard, Y [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires, 38 - Grenoble (France)

    1962-07-01

    A study was made of the radioprotective properties of 8 compounds derived from imidazole. The effectiveness of the compounds was tested in mice exposed to a lethal dose of x radiation. Results showed that imidazole afforded protection to about 85% of the animals. Little protection was afforded by imidazoline and thione-imidazoline compounds in spite of the existence of a free sulfhydryl group in these compounds. (authors) [French] Cette etude a ete consacree a la determination des proprietes radioprotectrices eventuelles de huit composes derives de l'imidazole. Ces substances ont ete, soit synthetisees, soit obtenues dans le commerce. Leur efficacite a ete mise en evidence par le pourcentage de survie obtenu chez des souris soumises a une dose mortelle de rayons X. Les resultats ont fait apparaitre: - l'activite remarquable de l'imidazole qui protege environ 85 pour cent des animaux; - la protection faible ou nulle obtenue avec les imidazolinones et les thione-imidazolines, malgre la presence dans la molecule de ces dernieres d'un groupement sulfhydrile libre. (auteurs)

  6. Crystal structure of 2-diazo-imidazole-4,5-dicarbo-nitrile.

    Science.gov (United States)

    Parrish, Damon A; Kramer, Stephanie; Windler, G Kenneth; Chavez, David E; Leonard, Philip W

    2015-07-01

    In the title compound, C5N6, all the atoms are approximately coplanar. In the crystal, mol-ecules are packed with short contact distances of 2.885 (2) (between the diazo N atom connected to the ring and a cyano N atom on a neighboring mol-ecule) and 3.012 (2) Å (between the terminal diazo N atom and an N atom of a neighboring imidazole ring).

  7. Tioconazole, a new imidazole-antifungal agent for the treatment of dermatomycoses. Antifungal and pharmacologic properties.

    Science.gov (United States)

    Marriott, M S; Baird, J R; Brammer, K W; Faulkner, J K; Halliwell, G; Jevons, S; Tarbit, M H

    1983-01-01

    Tioconazole is a new imidazole antifungal agent with broad-spectrum activity. Its in vitro activity against common dermal pathogens is generally better than miconazole by a factor of 2-8. This activity is paralleled by good topical efficacy in a guinea pig dermatomycosis model. Pharmacokinetic studies in animals have demonstrated minimal systemic exposure following dermal application. Acute general pharmacology studies have shown that the compound is well tolerated in animals and unlikely to produce side-effects in man.

  8. Synthesis of pyrido[1,2-a]benzimidazoles and other fused imidazole derivatives with a bridgehead nitrogen atom

    Science.gov (United States)

    Begunov, Roman S.; Ryzvanovich, Galina A.

    2013-01-01

    Main methods for the synthesis of fused imidazole derivatives with a bridgehead nitrogen atom are systematically considered and summarized. The reaction mechanisms that underlie the methods for the synthesis of pyrido[1,2-a]benzimidazoles and related compounds are described. Biological properties and mechanisms of the biological activity of fused azaheterocycles are discussed. The bibliography includes 152 references.

  9. Evolution of glycaemia in the blood of mice in the presence or absence of imidazole; Evolution de la glycemie sanguine chez la souris protegee ou non par l'imidazole

    Energy Technology Data Exchange (ETDEWEB)

    Polverelli, M.; Teoule, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    With respect to the radioprotective properties of the heterocyclic compound, imidazole, the authors followed the action of this product on blood sugar levels of mice X irradiated with a lethal dose. The main results of this work are: probably a hypo-glycemic action of the imidazole; an abolishment of the post-irradiation hyperglycemia by imidazole; an appreciably difference between male and female towards irradiation. (author) [French] Dans le cadre de l'etude des proprietes radioprotectrices de l'imidazole, nous nous sommes attaches a suivre l'action de ce produit sur le taux de glucose sanguin de souris irradiees a dose letale. Les principaux resultats de ce travail sont les suivants: l'action probablement hypoglycemiante de l'imidazole; en tant que radioprotecteur, cet heterocycle azote supprime l'hyperglycemie consecutive a l'irradiation; une difference assez sensible entre males et femelles vis-a-vis de l'irradiation. (auteur)

  10. Synthesis and radiolabelling of a new fluoro anolog of WAY100635: 4-fluoro-(2'-methoxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p-benzamido]ethyl] piperazine(18F-MPPF)

    International Nuclear Information System (INIS)

    Wu, C.Y.; Lu, C.X.; Lin, X.T.

    2002-01-01

    Aim: The serotonin system in the brain plays an important role and regulates various physiological functions and behavior including depression, anxiety and a lot of kinds of psychotropic syndrome. Among many serotonin receptors , 5HT 1A has been fully investigated because of the availability of the best highly selectively 5HT 1A agonist 8-OH-DPAT. In order to quantitatively measure the 5HT 1A in brain, we reported the synthesis and radiolabelling of fluoro analog of WAY100635 MPPF. Material and Method: MPPF was synthesized using the starting precursor 4-nitro-(2'-methoxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p-benzamido]ethyl] piperazine. It was obtained by the reaction of an acyl chloride with amino compound. No carrier-added 18 F-MPPF can be easily achieved by the nucleophilic method using the starting nitro-precursor in the presence of Kryptofix 222, K 2 CO 3 and DMF. Radiochemical purity(RPC) of 18 F-MPPF was determined by HPLC. Results: The physical properties of MPPF and each key intermediate are characterized by IR, 1 HNMR, elementary analysis and MS. The radiochemical yield was 10% in 90min using classical heating technique, and was 34% in about 60min using microwave technique. Both the RPC are higher than 98% after being purified on the Sep-Pak isolation. Conclusion: Microwave labelling can enhance the radiochemical yield and shorten the reaction time. Both nitro-precursor and 18 F-MPPF have high chemical purities and can be put into preclincal and clinical trials

  11. 1-[(3-Aryloxy-3-aryl)propyl]-1H-imidazoles, new imidazoles with potent activity against Candida albicans and dermatophytes. Synthesis, structure-activity relationship, and molecular modeling studies.

    Science.gov (United States)

    La Regina, Giuseppe; D'Auria, Felicia Diodata; Tafi, Andrea; Piscitelli, Francesco; Olla, Stefania; Caporuscio, Fabiana; Nencioni, Lucia; Cirilli, Roberto; La Torre, Francesco; De Melo, Nadja Rodrigues; Kelly, Steven L; Lamb, David C; Artico, Marino; Botta, Maurizio; Palamara, Anna Teresa; Silvestri, Romano

    2008-07-10

    New 1-[(3-aryloxy-3-aryl)propyl]-1 H-imidazoles were synthesized and evaluated against Candida albicans and dermatophytes in order to develop structure-activity relationships (SARs). Against C. albicans the new imidazoles showed minimal inhibitory concentrations (MICs) comparable to those of ketoconazole, miconazole, and econazole, and were more potent than fluconazole. Several derivatives ( 10, 12, 14, 18- 20, 24, 28, 29, 30, and 34) turned out to be potent inhibitors of C. albicans strains resistant to fluconazole, with MIC values less than 10 microg/mL. Against dermatophytes strains, compounds 20, 25, and 33 (MIC imidazoles 10- 44 were rationalized with reasonable accuracy by a previously developed quantitative pharmacophore for antifungal agents.

  12. Imidazoles and benzimidazoles as tubulin-modulators for anti-cancer therapy.

    Science.gov (United States)

    Torres, Fernando C; García-Rubiño, M Eugenia; Lozano-López, César; Kawano, Daniel F; Eifler-Lima, Vera L; von Poser, Gilsane L; Campos, Joaquín M

    2015-01-01

    Imidazoles and benzimidazoles are privileged heterocyclic bioactive compounds used with success in the clinical practice of innumerous diseases. Although there are many advancements in cancer therapy, microtubules remain as one of the few macromolecular targets validated for planning active anti-cancer compounds, and the design of drugs that modulate microtubule dynamics in unknown sites of tubulin is one of the goals of the medicinal chemistry. The discussion of the role of new and commercially available imidazole and benzimidazole derivatives as tubulin modulators is scattered throughout scientific literature, and indicates that these compounds have a tubulin modulation mechanism different from that of tubulin modulators clinically available, such as paclitaxel, docetaxel, vincristine and vinblastine. In fact, recent literature indicates that these derivatives inhibit microtubule formation binding to the colchicine site, present good pharmacokinetic properties and are capable of overcoming multidrug resistance in many cell lines. The understanding of the mechanisms involved in the imidazoles/benzimidazoles modulation of microtubule dynamics is very important to develop new strategies to overcome the resistance to anti-cancer drugs and to discover new biomarkers and targets for cancer chemotherapy.

  13. Imidazole incorporated semicarbazone derivatives as a new class of anticonvulsants: design, synthesis and in-vivo screening.

    Science.gov (United States)

    Amir, Mohammad; Ali, Israr; Hassan, Mohd Zaheen

    2013-06-01

    A series of novel imidazole incorporated semicarbazones was synthesized using an appropriate synthetic route and characterized by spectral analysis (IR, 1H NMR, 13C NMR and Mass). The anticonvulsant activity of the synthesized compounds was determined using doses of 30, 100, and 300 mg kg-1 against maximal electroshock seizure (MES), subcutaneous pentylenetetrazole (scPTZ) induced seizure and minimal neurotoxicity test. Six compounds exhibited protection in both models and 2-(1-(4-chlorophenyl)-2-(1H-imidazol-1-yl)ethylidene)-N-p-tolylsemicarbazone emerged as the most active compound of the series without any neurotoxicity and significant CNS depressant effect. Liver enzyme estimations (SGOT, SGPT, Alkaline phosphatase) of the compound also showed no significant change in the enzymes levels. Moreover, it caused 80% elevation of γ-amino butyric acid (GABA) levels in the whole mice brain, thus indicating that it could be a promising candidate in designing of a potent anticonvulsant drug.

  14. Synthesis, characterization and toxicity of azanonaborane-containing imidazoles for boron neutron capture therapy

    International Nuclear Information System (INIS)

    El-Zaria, Mohamed E.; Genady, Afaf R.; Gabel, Detlef

    2006-01-01

    The exo-NH 2 R group of the azanonaborane of the type [(RH 2 N)B 8 H 11 NHR] can be exchanged by one hetero-nitrogen atom of the imidazole ring. In the case of histamine, the exchange takes place on the aliphatic amino group, the hetero-nitrogen atom of the imidazole ring or both of them. In vitro experiments using B16 melanoma cells showed that incorporation of B 8 N cluster unit into primary amino group of the histamine increases the compound's toxicity. In contrast, this specificity for cytotoxicity effect was not observed in the case of histamine containing two B 8 N clusters which was relatively nontoxic and did not inhibit colony formation up to 2 mM. (author)

  15. Synthesis, chemical and biological properties of the new mono- and bis-derivatives of imidazoles

    Directory of Open Access Journals (Sweden)

    E. V. Welchinska

    2014-12-01

    Full Text Available The aim of research. The problem of finding effective antitumour medical preparation with low toxicity is an important issue of medical and pharmaceutical chemistry. Knowledge of cancer cell features and its metabolism enables to predict the direction of chemical and biological research, to conduct a targeted synthesis of potential drugs, and to assess their applicability in oncological practice as antitumor agents. The purpose of work is to explain preformed heterocycles as purines, its synthesis and investigation of chemical and biological properties. After construction of the potential active structures we proposed the new method of original derivatives synthesis which are received on the base of imidazole, from one side, and fluorocontaining common anesthetic halothane (2-bromo-1,1,1-trifluoro-2-chloroethane from other side. Molecular complex of more perspective biologically active bis-imidazole with antitumour bacterial lectine has been received. With the purpose to synthesize potential antitumour compounds on the base of halothane and imidazole, new convenient methods for the preparation of original heterocyclic derivatives of imidazole have been described. The structure and composition of synthesized compound has been confirmed by the methods of elemental analysis, IR- and NMRІН-spectra. Materials and methods. The majority of the absolute organic solvents (benzene, dimethylformamide, ethyl ester employed in the present studies were distilled before their use. Organic solvents were dried over anhydrous magnesium sulfate or metallic sodium. Gas-liquid chromatography was carried out by Perkin Elmer chromatograph with UV-detector ("Perkin", Germany. IR spectra were recorded in a UR-20 spectrometer ("Charles Ceise Hena", Germany. The 1HNMR spectra were recorded in DMSO-d6 on a 200 MHz BrakerWP-200 ("Braker", Switzerland or Varian T-60 spectrometer ("Varian", USA. Investigation of critical toxicity of new compounds was carried out at

  16. Alkylation of imidazole under ultrasound irradiation over alkaline carbons

    International Nuclear Information System (INIS)

    Costarrosa, L.; Calvino-Casilda, V.; Ferrera-Escudero, S.; Duran-Valle, C.J.; Martin-Aranda, R.M.

    2006-01-01

    N-Alkyl-imidazole has been synthesized by sonochemical irradiation of imidazole and 1-bromobutane using alkaline-promoted carbons (exchanged with the binary combinations of Na, K and Cs). The catalysts were characterized by X-ray photoelectron spectroscopy, thermal analysis and N 2 adsorption isotherms. Under the experimental conditions, N-alkyl-imidazoles can be prepared with a high activity and selectivity. It is observed that imidazole conversion increases in parallel with increasing the basicity of the catalyst. The influence of the alkaline promoter, the reaction temperature, and the amount of catalyst on the catalytic activity has been studied. For comparison, the alkylation of imidazole has also been performed in a batch reactor system under thermal activation

  17. Synthesis and characterization of some complexes with imidazole and pyrazole from saccharinate transition ions in oxidation state (II)

    International Nuclear Information System (INIS)

    Pineda Cedeno, Leslie William

    2001-01-01

    The synthesis and characterization of metal ions saccharinate of the first serie of transition with the imidazole and pyrazole molecules in water and absolute ethanol were studied. In general, it found that in this series of saccharinate of coordinated water molecules are replaced by imidazole and pyrazole molecules with different substitution patterns, generating neutral complex of molecular formula [M(Sac) 2 (L) n (H 2 O) n-4 ] and cationic complex of molecular formula [M(L) n (H 2 O) 2 ]x2Sac, [M(L) n (H 2 O) 3 ]x2Sac, [M(L) n ]x2Sac, where M = V(II), Cr(II), Mc(II), Fe(II), Co(II), Ni(II) y Zn(II); Sac = saccharinate ion; L = imidazole (imd) and pyrazole (pir) and n = 6,4,3 and 2. These compounds are soluble in DMF and insoluble in all other common solvents. In turn, synthesized compounds in water were characterized by X ray crystallography, where preliminary data of refinement cycles, generate formulas of isostructural type [M(imd) 4 (H 2 O) 2 ]x2Sac and [M(Sac) 2 (pir) 2 (H 2 O) 2 ] where M = Co(II), Ni(II). The imidazole complex crystallize in the triclinic crystal system and space group P-1, while the pyrazole complexes crystallize in the monoclinic crystal system and space group P2 (1)/n. Gradual diminution was observed in the bond distances of M-N (saccharinate ion), M-N (imidazole) and M-N (pyrazole). The complex was characterized by spectroscopic methods, magnetic and electrochemical. (author) [es

  18. Green synthesis of novel quinoline based imidazole derivatives and evaluation of their antimicrobial activity

    Directory of Open Access Journals (Sweden)

    N.C. Desai

    2014-12-01

    Full Text Available We have described the conventional and microwave method for the synthesis of N-(4-((2-chloroquinolin-3-ylmethylene-5-oxo-2-phenyl-4,5-dihydro-1H-imidazol-1-yl(arylamides 3a–l. It is observed that the solvent-free microwave thermolysis is a convenient, rapid, high-yielding, and environmental friendly protocol for the synthesis of quinoline based imidazole derivatives when compared with conventional reaction in a solution phase. Antimicrobial activity of the newly synthesized compounds is screened in vitro on the following microbial cultures: Escherichia coli (MTCC 443, Pseudomonas aeruginosa (MTCC 1688, Staphylococcus aureus (MTCC 96, Streptococcus pyogenes (MTCC 442, Candida albicans (MTCC 227, Aspergillus niger (MTCC 282, Aspergillus clavatus (MTCC 1323. All the synthesized bio-active molecules are tested for their in vitro antimicrobial activity by bioassay namely serial broth dilution. Among these compounds 3c, 3d, 3f, 3h and 3j show significant potency against different microbial strains. All the compounds have been characterized by IR, 1H NMR, 13C NMR and mass spectral data. On the basis of statistical analysis, it is observed that these compounds give significant co-relation.

  19. 1-[(1-Methyl-1H-imidazol-5-ylmethyl]-1H-indole-5-carbonitrile

    Directory of Open Access Journals (Sweden)

    Josephus Jacobus de Jager

    2012-12-01

    Full Text Available In the title compound, C14H12N4, the dihedral angle between the indole ring system (r.m.s. deviation = 0.010 Å and the imidazole ring is 77.70 (6°. In the crystal, molecules are linked by C—H...N hydrogen bonds. One set of hydrogen bonds forms an undulating chain running parallel to the b-axis direction, while the other undulating chain is parallel to the c-axis direction. In combination, (100 sheets result.

  20. Bis(1H-imidazole-κN3bis(1-naphthaleneacetato-κ2O,O′cadmium(II

    Directory of Open Access Journals (Sweden)

    Hong-Mian Wu

    2008-05-01

    Full Text Available In the mononuclear title compound, [Cd(C12H9O22(C3H4N22], the CdII centre has a distorted octahedral coordination geometry defined by four O atoms from two naphthaleneacetate ligands and two N atoms from two imidazole ligands. The molecules are linked by N—H...O hydrogen bonds, forming a layer network.

  1. Complex-forming capacity of some biologically active imidazoles

    Energy Technology Data Exchange (ETDEWEB)

    Lenarcik, B; Wisniewski, M

    1983-01-01

    By using the potentiometric and spectrophotometric methods, formation of Co(2), Cu(2), Zn(2), Ni(2) and Cd(2) complexes of (3S-cis)-3-ethyl-dihydro-4-((1-methyl-1H-imidazol-5-yl)-methyl)-2(3H)-furanone (pilocarpine, PLC), 4,5-dihydro-2-(phenylmethyl)-1H-imidazole (tolazoline, TLZ), 2-methyl-5-nitro-1H-imidazole-1-ethanol (metronidazole, MET) and 1H-imidazole-4-ethanamine (histamine, HIST) was investigated. The stability constants, ..beta../sub n/, of these complexes were determined. It was shown that the electron-donor strength of the ligands was controlled by the heterocyclic nitrogen atom, and that the formation of the Zn(2)-PLC complex was accompanied by the change in the structure of the coordination sphere of the metal. With Cu(2), the PLC and TLZ ligands were shown to enhance the Jahn-Teller deformation.

  2. Multifunctional switches based on bis-imidazole derivative

    Indian Academy of Sciences (India)

    Administrator

    photonic, chemical, electrochemical, or magnetic stimuli and generate ... that upon oxidation with potassium ferricyanide in ethanolic ... cooled to room temperature and filtered to remove ... Recrystaliztion from ethanol afforded the imidazole 3.

  3. Synthesis, spectroscopic, computational (DFT/B3LYP), AChE inhibition and antioxidant studies of imidazole derivative

    Science.gov (United States)

    Ahmad, Faheem; Alam, Mohammad Jane; Alam, Mahboob; Azaz, Shaista; Parveen, Mehtab; Park, Soonheum; Ahmad, Shabbir

    2018-01-01

    The present study reports the synthesis and evaluation of biological properties of 3a,8a-dihydroxy-8-oxo-1,3,3a,8a-tetrahydroindeno[1,2-d]imidazol-2(1H)-iminium chloride (3). The structure was confirmed by the FTIR, NMR, MS, CHN microanalysis and X-ray crystallographic analysis. Quantum chemical calculations have been performed at B3LYP-D3/6-311++G(d,p) level of theory to study the molecular geometry, IR, (1H and 13C) NMR, UV/Vis spectra and other molecular parameters of the asymmetric unit of crystal of imidazole compound (3). An empirical dispersion correction to hybrid functional (B3LYP-D3) has been incorporated in the present calculations due to presence of non-covalent interaction, Cl⋯H-O, in the present compound. The remarkable agreement has been observed between theoretical data and those measured experimentally. Moreover, the Hirshfeld analysis was carried out to ascertain the secondary interactions and associated 2D fingerprint plots. The synthesized imidazole derivative showed promising antioxidant property and inhibitory activity against acetylcholinesterase (AChE). Molecular docking was also performed in order to explain in silico antioxidant studies and to ascertain the probable binding mode of compound with the amino acid residues of protein.

  4. Synthesis of Trisubstituted Imidazoles Using Lewis and Bronsted Acid Catalysts

    OpenAIRE

    Hekmatshoar, Rahim; HEKMATSHOAR, Rahim; JAHANBAKHSHI, Hajar; MOUSAVIZADEH, Farnoosh; RAHNAMAFAR, Reyhane

    2010-01-01

    An efficient and one-pot method for the preparation of trisubstituted imidazoles by condensation of benzil, different aldehydes and ammonium acetate in the presence of  a catalytic amount of NiSO4.7H2O or H3BO3 under different conditions is reported.                    Key Words: Trisubstituted imidazoles, Multi-component &a...

  5. Synthesis of the zeolitic imidazolate framework ZIF-4 from the ionic liquid 1-butyl-3-methylimidazolium imidazolate

    Science.gov (United States)

    Hovestadt, Maximilian; Schwegler, Johannes; Schulz, Peter S.; Hartmann, Martin

    2018-05-01

    A new synthesis route for the zeolitic imidazolate framework ZIF-4 using imidazolium imidazolate is reported. Additionally, the ionic liquid-derived material is compared to conventional ZIF-4 with respect to the powder X-ray diffraction pattern pattern, nitrogen uptake, particle size, and separation potential for olefin/paraffin gas mixtures. Higher synthesis yields were obtained, and the different particle size affected the performance in the separation of ethane and ethylene.

  6. Structure of eight molecular salts assembled from noncovalent bonding between carboxylic acids, imidazole, and benzimidazole

    Science.gov (United States)

    Jin, Shouwen; Zhang, Huan; Liu, Hui; Wen, Xianhong; Li, Minghui; Wang, Daqi

    2015-09-01

    Eight organic salts of imidazole/benzimidazole have been prepared with carboxylic acids as 2-methyl-2-phenoxypropanoic acid, α-ketoglutaric acid, 5-nitrosalicylic acid, isophthalic acid, 4-nitro-phthalic acid, and 3,5-dinitrosalicylic acid. The eight crystalline forms reported are proton-transfer compounds of which the crystals and compounds were characterized by X-ray diffraction analysis, IR, mp, and elemental analysis. These structures adopted hetero supramolecular synthons, with the most common R22(7) motif observed at salts 2, 3, 5, 6 and 8. Analysis of the crystal packing of 1-8 suggests that there are extensive strong Nsbnd H⋯O, and Osbnd H⋯O hydrogen bonds (charge assisted or neutral) between acid and imidazolyl components in all of the salts. Except the classical hydrogen bonding interactions, the secondary propagating interactions also play important roles in structure extension. This variety, coupled with the varying geometries and number of acidic groups of the acids utilized, has led to the creation of eight supramolecular arrays with 1D-3D structure. The role of weak and strong noncovalent interactions in the crystal packing is analyzed. The results presented herein indicate that the strength and directionality of the Nsbnd H⋯O, and Osbnd H⋯O hydrogen bonds between acids and imidazole/benzimidazole are sufficient to bring about the formation of organic salts.

  7. Mutagenicity of 1-Ethyl-2,4,5-triphenyl-1H-imidazole and Six Derivatives in Salmonella typhimurium

    OpenAIRE

    KORKMAZ, Ferhan; Korkmaz, Ferhan; MERCANGOZ, Ayse

    2010-01-01

     Newly synthesized 1-Ethyl-2,4,5-triphenyl-1H-imidazole and its six derivatives were tested by Ames assay. In order to reveal the mutagenic activities of the compounds, two different mutant strains of Salmonella typhimurium (TA98 and TA100) were used in an Ames assay with/without S9 microsomal fraction from rat liver. It was found that the compounds have no mutagenic activities.          &nb...

  8. Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

    Directory of Open Access Journals (Sweden)

    Jiří Kulhánek

    2012-01-01

    Full Text Available Research activities in the field of imidazole-derived push–pull systems featuring intramolecular charge transfer (ICT are reviewed. Design, synthetic pathways, linear and nonlinear optical properties, electrochemistry, structure–property relationships, and the prospective application of such D-π-A organic materials are described. This review focuses on Y-shaped imidazoles, bi- and diimidazoles, benzimidazoles, bis(benzimidazoles, imidazole-4,5-dicarbonitriles, and imidazole-derived chromophores chemically bound to a polymer chain.

  9. Cu(II) coordination polymers constructed by tetrafluoroterephthalic acid and varied imidazole-containing ligands: Syntheses, structures and properties

    Science.gov (United States)

    Liu, Kang; Sun, Yayong; Deng, Liming; Cao, Fan; Han, Jishu; Wang, Lei

    2018-02-01

    Six new copper(II) coordination polymers combining 2,3,5,6-tetrafluoroterephthalatic acid (H2tfBDC) and diverse imidazole-containing ligands, {[Cu(tfBDC)(1,2-bix)2]·2(H2O)}n (1), {Cu(tfBDC)(Im)2}n (2), {[Cu(1,4-bmimb)2(H2O)]·(tfBDC)·2(H2O)}n (3), {Cu(1,4-bimb)2(H2O)2·(tfBDC)}n (4), {[Cu(1,3-bix)2(H2O)2]·(tfBDC)·6(H2O)}n (5) and {[Cu(1,4-bix)2(H2O)2]·(tfBDC)·(1,4-bix)·4(H2O)}n (6) (1,2-bix = 1,2-bis(imidazole-1-ylmethyl)-benzene, Im = imidazole, 1,4-bmimb = 1,4-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene, 1,4-bimb = 1,4-bis(imidazol-1-yl)-butane, 1,3-bix = 1,3-bis(imidazole-1-ylmethyl)-benzene, 1,4-bix = 1,4-bis(imidazole-1-ylmethyl)-benzene), have been obtained and structurally verified by single-crystal X-ray diffraction analyses and further characterized by powder X-ray diffraction (PXRD), elemental analyses and infrared spectroscopy (IR). Single crystal X-ray diffraction analysis revealed that 1 is 2D 4-connected sql topology (point symbol: {44·62}) based on a single metal ion node. Compound 2 is characterized as an infinite 1D chain structure, which is further extended into a 2D layer through N-H···O hydrogen bonds and then a 3D supramolecular architecture via π···π stacking interactions. Note that 2 was prepared through an in situ ligand reaction in which N,N'-carbonyldiimidazole (cdi) broke up into imidazole ligand. Compound 3 possesses a 3D 4-fold interpenetrated architecture with 4-connected dia topology (Schläfli symbol: {66}) in which tfBDC2- is stabilized in the channel by hydrogen bonds. Compounds 4-6 are all linear 1D coordination polymers. In 4, the free tfBDC2- ligand acts as a μ4-bridge to link four coordinated water molecules from the chain to construct a 2D structure via hydrogen bonds. While in 5 and 6, the uncoordinated tfBDC2- ligands and multimeric water clusters is responsible for the conversion of these 1D coordination polymers into 3D supramolecular assemblies through O-H⋯O hydrogen bonding interactions. Moreover

  10. Imidazole and beta-carotene photoprotection against photodynamic therapy evaluated by synchrotron infrared microscopy

    Science.gov (United States)

    Bosio, Gabriela N.; Parisi, Julieta; García Einschlag, Fernando S.; Mártire, Daniel O.

    2018-04-01

    In order to better understand the role of β-carotene and imidazole on the Photodynamic Therapy (PDT) mechanism, synchrotron infrared microscopy was used to detect the associated intracellular biochemical modifications following the visible light irradiation of HeLa cells incubated with these compounds as typical hydrophobic and hydrophilic singlet oxygen quenchers, respectively. For this purpose, PDT was performed employing the hydrophilic sensitizer 5,10,15,20-Tetrakis (1-methyl-4-pyridinio) porphyrin tetra (p-toluenesulfonate), TMPyP, and the hydrophobic sensitizer 5-(4-Methoxycarboxyphenyl)-10,15,20-triphenyl-21H,23H-porphyrin. The single cell IR spectra of PDT-treated, PDT plus quencher-treated and control HeLa cells were recorded at the SOLEIL Synchrotron Infrared SMIS beamline targeting specifically the cell nucleus. Principal Component Analysis (PCA) was used to assess the IR spectral changes. PCA revealed that there is a frequency shift of the protein Amide I vibrational band for the assays with the TMPyP sensitizer, indicating changes in the protein secondary structures of the PDT-treated cancer cells compared to the controls. In addition, the scores in those cells treated with both quenchers appear to be similar to the controls indicating a photoprotective effect. Comparative experiments carried out with SKMEL-28 and HaCat cells showed non- significant photoprotective effects of β-carotene and imidazole.

  11. Spectroscopic analysis and molecular docking of imidazole derivatives and investigation of its reactive properties by DFT and molecular dynamics simulations

    Science.gov (United States)

    Thomas, Renjith; Hossain, Mossaraf; Mary, Y. Sheena; Resmi, K. S.; Armaković, Stevan; Armaković, Sanja J.; Nanda, Ashis Kumar; Ranjan, Vivek Kumar; Vijayakumar, G.; Van Alsenoy, C.

    2018-04-01

    Solvent-free synthesis pathway for obtaining two imidazole derivatives (2-chloro-1-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole (CLMPDI) and 1-(4-bromophenyl)-2-chloro-4,5-dimethyl-1H-imidazole (BPCLDI) has been reported in this work, followed by detailed experimental and computational spectroscopic characterization and reactivity study. Spectroscopic methods encompassed IR, FT-Raman and NMR techniques, with the mutual comparison of experimentally and computationally obtained results at DFT/B3LYP level of theory. Reactivity study based on DFT calculations encompassed molecular orbitals analysis, followed by calculations of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) values, Fukui functions and bond dissociation energies (BDE). Additionally, the stability of title molecules in water has been investigated via molecular dynamics (MD) simulations, while interactivity with aspulvinonedimethylallyl transferase protein has been evaluated by molecular docking procedure. CLMPDI compound showed antimicrobial activity against all four bacterial strain in both gram positive and gram negative bacteria while, BPCLDI showed only in gram positive bacteria, Staphylococcus Aureus (MTCC1144). The first order hyperpolarizability of CLMPDI and BPCLDI are 20.15 and 6.10 times that of the standard NLO material urea.

  12. Non-covalent interactions between {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol at T = (298.15, 308.15 and 318.15) K

    International Nuclear Information System (INIS)

    Brahman, Dhiraj; Sinha, Biswajit

    2014-01-01

    Highlights: • Methanolic solution of pyridoxine hydrochloride used as solvent. • {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) used as solute. • Partial molar volumes and viscosity B-coefficients of the solute were determined. • Weak 1:1 association between the complex and pyridoxine hydrochloride found. • Non-covalent interactions and Cu(II) complex acts as a net structure maker in the ternary solutions. - Abstract: Non-covalent interactions between of {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol were investigated by a combination of physico-chemical and spectrophotometric methods at T = (298.15, 308.15 and 318.15) K under ambient pressure. From measured density and viscosity data the apparent molar volume (ϕ V ), the slope (S V ∗ ), standard partial molar volume (ϕ V 0 ), standard transfer volume (Δ t ϕ V 0 ), isobaric apparent molar expansibility (ϕ E ), standard isobaric partial molar expansibility (ϕ E 0 ), the viscosity B-coefficient, its temperature derivative (∂B/∂T), solvation number (S n ) were calculated and discussed on the basis of specific or non-specific (solute + cosolute) and (solute + solvent) interactions. Thermodynamics of viscous flow were discussed on the basis of the transition state theory. Spectrophotometric results indicated 1:1 (solute + cosolute) interaction between the complex and pyridoxine hydrochloride

  13. Spectroscopic investigation of Bovine Liver Catalase interactions with a novel phen-imidazole derivative of platinum.

    Science.gov (United States)

    Ghobadi, Roohollah; Divsalar, Adeleh; Harifi-Mood, Ali Reza; Saboury, Ali Akbar

    2018-02-01

    Successful clinical experience of using cisplatin and its derivatives in cancer therapy has encouraged scientists to synthesize new metal complexes with the aim of interacting with special targets such as proteins In this regard, biological effects of [Pt(FIP)(Phen)](NO 3 ) 2 compound which contains a novel phen-imidazole ligand, FIP, was investigated on bovine liver catalase (BLC) structure and function. Various spectroscopic methods such as UV-visible, fluorescence, and circular dichroism (CD) were applied at two temperatures 25 and 37°C for kinetics and structural studies. As a consequence, the enzymatic activity decreased slightly with increasing the platinum compound's concentration up to 30 μM and then remained constant at near 80% after this concentration. On the other hand, the fluorescence quenching measurements revealed that despite slight changes in activity, catalase experiences notable alterations in three-dimensional environment around the chromophores of the enzyme structure with increasing platinum complex concentration. Moreover, quenching data showed that BLC has two binding sites for Pt complex and hydrogen bonding interactions play a major role in the binding process. Furthermore, CD spectroscopy data showed that Pt(II) complex induces significant decrease in α-helix content of the secondary structure of BLC, but notable increase in random coil proportion accompanying a slight decrease in β-sheet content. All in all, hydrogen bonding interactions which are mainly involved in the binding process of the novel phen-imidazole compound to BLC significantly alter the protein structure but slightly change its function. This might be a promising outcome for chemotherapists and medicinal chemists to investigate in vivo properties of this novel metal complex with significant binding tendency to a macromolecule in the low concentrations without decreasing its intrinsic function.

  14. Synthesis and characterization of new N-heterocyclic carbene ligands: 1,3-Bis(acetamide)imidazol-3-ium bromide and 3-(acetamide)-1-(3-aminopropyl)-1H-imidazol-3-ium bromide

    Science.gov (United States)

    Turkyilmaz, Murat; Uluçam, Gühergül; Aktaş, Şaban; Okan, S. Erol

    2017-05-01

    Two new pincer type N-heterocyclic carbene ligands were synthesized. The compounds were characterized by FTIR, NMR (1H, 13C) GC-MS and elemental analyses. They were also both modelled by DFT calculations as the crystal structure of 1,3-bis(acetamide)imidazol-3-ium bromide was determined by XRD which is an orthorhombic system with space group P21212. The structural analyses in gas phase were realized by comparing the experimental NMR and IR spectra with those of the theoretical calculations. In vitro biological activities of the molecules were determined and found that one of them exhibits significant cytotoxic activity.

  15. β–Cyclodextrin–Propyl Sulfonic Acid Catalysed One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles as Local Anesthetic Agents

    Directory of Open Access Journals (Sweden)

    Yan Ran

    2015-11-01

    Full Text Available Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. The local anesthetic effect of these derivatives was assessed in comparison to lidocaine as a standard using a rabbit corneal and mouse tail anesthesia model. The three most potent promising compounds were subjected to a rat sciatic nerve block assay where they showed considerable local anesthetic activity, along with minimal toxicity. Among the tested analogues, 4-(1-benzyl-4,5-diphenyl-1H-imidazol-2-yl-N,N-dimethylaniline (5g was identified as most potent analogue with minimal toxicity. It was further characterized by a more favourable therapeutic index than the standard.

  16. Novel fluorescent pH sensor based on coumarin with piperazine and imidazole substituents.

    Science.gov (United States)

    Saleh, Na'il; Al-Soud, Yaseen A; Nau, Werner M

    2008-12-01

    A new coumarin derivative containing piperazine and imidazole moieties is reported as a fluorophore for hydrogen ions sensing. The fluorescence enhancement of the studied sensor with an increase in hydrogen ions concentration is based on the hindering of photoinduced electron transfer from the piperazinyl amine and the imidazolyl amine to the coumarin fluorophore by protonation. The presented sensor has a novel design of fluorophore-spacer-receptor(1)-receptor(2) format, which is proposed to sense two ranges of pH (from 2.5 to 5.5) and (from 10 to 12) instead of sensing one pH range. A model compound, in which the piperazinyl ring is absent, was synthesized as well to confirm the novel pH sensing of the proposed sensor.

  17. Bromidotetra?kis?(1H-2-ethyl-5-methyl?imidazole-?N 3)copper(II) bromide

    OpenAIRE

    Godlewska, Sylwia; Baranowska, Katarzyna; Socha, Joanna; Do??ga, Anna

    2011-01-01

    The CuII ion in the title compound, [CuBr(C6H10N2)4]Br, is coordinated in a square-based-pyramidal geometry by the N atoms of four imidazole ligands and a bromide anion in the apical site. Both the CuII and Br− atoms lie on a crystallographic fourfold axis. In the crystal, the [CuBr(C6H10N2)4]+ complex cations are linked to the uncoordinated Br− anions (site symmetry overline{4}) by N—H...Br hydrogen bonds, generating a three-dimensional network. The ethyl group ...

  18. Novel decavanadate cluster complexes [H2V10O28][LH]4·nH2O (L = Imidazole, n = 2 or 2-methylimidazole, n = 0): Preparation, characterization and genotoxic studies

    Science.gov (United States)

    Siddiqi, Zafar A.; Anjuli; Sharma, Prashant K.; Shahid, M.; Khalid, Mohd.; Siddique, Armeen; Kumar, Sarvendra

    2012-12-01

    The title complexes were obtained from the reaction of VOSO4 with imidazole or 2-methyl imidazole in presence of adipic acid/iminodiacetic acid. X-ray crystallographic investigations on [H2V10O28](2-MeImzH)4 (2) revealed a strong interaction between decavanadate anion and the protonated ligand moieties as counter cations to stabilize the crystal motif resulting in a high symmetry 2D sheet network. The cyclic voltammetry of (2) suggested formation of a quasi-reversible redox (VV/IV) couple in the solution. The genotoxic studies employing single cell gel electrophoresis (comet assay) confirmed the non-toxic nature of the compounds.

  19. IMIDAZOLE DERIVATIVES AS PRODRUGS OF DICLOFENAC

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a compound of formula (I): wherein R1is R3-IPU and R2 is the acyloxy residue of diclofenac, and specified by the following structures: (II), (III) wherein OH-R3-IPU is selected from (IV) and R4 and R5 may be the same or different selected from H and CH3 and salts,...

  20. Synthesis and spectroscopic characterization of Y-shaped fluorophores with an imidazole core containing crown ether moieties

    International Nuclear Information System (INIS)

    Doğru, Ümit; Öztürk Ürüt, Gülsiye; Bayramin, Dilek

    2015-01-01

    In this study three new Y-shaped fluorophores, 4,5-(2,2'-diphenyl)vinyl-{2-[(1,4,7,10-tetraoxa-13-azacyclopentadecyl) phenyl]}-1H-imidazole (1a), 4,5-{[2,2'-bis(4-methoxyphenyl)vinyl]-[2-(1,4,7,10-tetraoxa-13- azacyclopentadecyl)-phenyl]}-1H-imidazole (1b) and 4,5-(2,2'-diphenyl)vinyl-{2-(1,4,7,10,13-benzopentaoxacyclopentadecyl)} -1H-imidazole (1c) were synthesized. 1,6-Diphenylhexa-1,5-diene-3,4-dione (2a) and 1,6-bis(4-methoxyphenyl)hexa-1,5-diene-3,4-dione (2b) were synthesized as preliminary fluorophores and then reacted with 4-formylbenzo-aza-15-crown-5 (3a) and 4-formylbenzo-15-crown-5 (3b) to obtain the three Y-shaped fluorophores 1a, 1b and 1c. 4-formylbenzo-aza-15-crown-5 and 4-formylbenzo-15-crown-5 intermediates were synthesized with Vilsmeier–Haack reaction. The photophysical properties such as maximum absorption wavelengths, maximum emission wavelengths, Stokes' shifts, singlet energies, fluorescence quantum yields and photostabilities of the compounds were investigated by measuring absorption and emission spectra in a series of solvents of varying polarities of toluene (TOL), dichloromethane (DCM), tetrahydrofuran (THF), ethyl acetate (EA), acetonitrile (ACN), and N,N-dimethylformamide (DMF). The three compounds 1a, 1b and 1c exhibited emission maxima in the 412–677 nm range. All the derivatives synthesized exhibited excellent photostability in all the solvents tested. - Highlights: • Three new Y-shaped fluorophores were synthesized for the first time. • Their absorption and emission properties were investigated. • All the derivatives synthesized exhibited excellent photostability

  1. Synthesis and spectroscopic characterization of Y-shaped fluorophores with an imidazole core containing crown ether moieties

    Energy Technology Data Exchange (ETDEWEB)

    Doğru, Ümit; Öztürk Ürüt, Gülsiye, E-mail: gulsiye.ozturk@deu.edu.tr; Bayramin, Dilek

    2015-07-15

    In this study three new Y-shaped fluorophores, 4,5-(2,2'-diphenyl)vinyl-{2-[(1,4,7,10-tetraoxa-13-azacyclopentadecyl) phenyl]}-1H-imidazole (1a), 4,5-{[2,2'-bis(4-methoxyphenyl)vinyl]-[2-(1,4,7,10-tetraoxa-13- azacyclopentadecyl)-phenyl]}-1H-imidazole (1b) and 4,5-(2,2'-diphenyl)vinyl-{2-(1,4,7,10,13-benzopentaoxacyclopentadecyl)} -1H-imidazole (1c) were synthesized. 1,6-Diphenylhexa-1,5-diene-3,4-dione (2a) and 1,6-bis(4-methoxyphenyl)hexa-1,5-diene-3,4-dione (2b) were synthesized as preliminary fluorophores and then reacted with 4-formylbenzo-aza-15-crown-5 (3a) and 4-formylbenzo-15-crown-5 (3b) to obtain the three Y-shaped fluorophores 1a, 1b and 1c. 4-formylbenzo-aza-15-crown-5 and 4-formylbenzo-15-crown-5 intermediates were synthesized with Vilsmeier–Haack reaction. The photophysical properties such as maximum absorption wavelengths, maximum emission wavelengths, Stokes' shifts, singlet energies, fluorescence quantum yields and photostabilities of the compounds were investigated by measuring absorption and emission spectra in a series of solvents of varying polarities of toluene (TOL), dichloromethane (DCM), tetrahydrofuran (THF), ethyl acetate (EA), acetonitrile (ACN), and N,N-dimethylformamide (DMF). The three compounds 1a, 1b and 1c exhibited emission maxima in the 412–677 nm range. All the derivatives synthesized exhibited excellent photostability in all the solvents tested. - Highlights: • Three new Y-shaped fluorophores were synthesized for the first time. • Their absorption and emission properties were investigated. • All the derivatives synthesized exhibited excellent photostability.

  2. Photoinduced Processes in Hydrogen Bonded System: Photodissociation of Imidazole Clusters

    Czech Academy of Sciences Publication Activity Database

    Poterya, Viktoriya; Profant, V.; Fárník, Michal; Šištík, L.; Slavíček, P.; Buck, U.

    2009-01-01

    Roč. 113, č. 52 (2009), s. 14583-14590 ISSN 1089-5639 R&D Projects: GA AV ČR KAN400400651; GA AV ČR KJB400400902; GA ČR GA203/09/0422 Institutional research plan: CEZ:AV0Z40400503 Keywords : scattering analysis * molecules * imidazole clusters Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.899, year: 2009

  3. Alcohol and water adsorption in zeolitic imidazolate frameworks

    KAUST Repository

    Zhang, Ke; Lively, Ryan P.; Dose, Michelle E.; Brown, Andrew J.; Zhang, Chen; Chung, Jaeyub; Nair, Sankar; Koros, William J.; Chance, Ronald R.

    2013-01-01

    Alcohol (methanol, ethanol, 1-propanol, 2-propanol and 1-butanol) and water vapor adsorption in zeolitic imidazolate frameworks (ZIF-8, ZIF-71 and ZIF-90) with similar crystal sizes was systematically studied. The feasibility of applying these ZIF materials to the recovery of bio-alcohols is evaluated by estimating the vapor-phase alcohol-water sorption selectivity. © 2013 The Royal Society of Chemistry.

  4. On the mechanism of action of ribonucleases: dinucleotide cleavage catalyzed by imidazole and Zn2+.

    OpenAIRE

    Breslow, R; Huang, D L; Anslyn, E

    1989-01-01

    Cyclization/cleavage of the 2-(p-nitrophenyl) phosphate ester of propylene glycol is catalyzed by imidazole and, much more effectively, by Zn2+ with imidazole. In the latter case, the mechanism involves simultaneous Lewis acid/base catalysis. Similar Zn2+ and imidazole catalysis of cyclization/cleavage is seen with the dinucleotide 3',5'-UpU (uridylyluridine). Again, the zinc system is much more effective than is catalysis by imidazole alone, and in this case simultaneous Lewis acid/base cata...

  5. Imidazole, a New Tunable Reagent for Producing Nanocellulose, Part I: Xylan-Coated CNCs and CNFs

    Directory of Open Access Journals (Sweden)

    Jia Mao

    2017-09-01

    Full Text Available Imidazole is reported to be an effective reactant for the production of nanocellulose from hardwood pulp. The morphologies and surface properties of the nanocellulose can be simply tailored according to the water content in the imidazole system: with pure imidazole, cellulose nanofibrils (CNFs in a yield of 10 wt % can be produced. With 25 wt % of water in imidazole, cellulose nanocrystals (CNCs are obtained in 20 wt % yield. Both nanocelluloses exhibit crystallinity indices in the order of 70%. Interestingly, they retain the original xylan from the pulp with ca. 9–10 wt % of residual xylan content.

  6. DFT study on the standard electrode potentials of imidazole, tetrathiafulvalene, and tetrathiafulvalene-imidazole.

    Science.gov (United States)

    Tugsuz, Tugba

    2010-12-30

    Extensive DFT calculations on the standard electrode potentials of imidazole (Im), tetrathiafulvalene (TTF), and 2-, 4-, and 5-TTF-Im were carried out. Geometries and Gibbs free energies of H-bonded dimer, anion, protonated cation, and neutral structures of Im, mono- and dication, and neutral structures of TTF in gas and acetonitrile solvent were computed by using 10 hybrid density functionals (B3LYP, TPSSH, PBEH1PBE, M06, M062X, X3LYP, BMK, B1B95, M05, M052X) combined with the TZVP basis set. CPCM and SMD solvation models were applied to predict the Gibbs free energies of molecules in acetonitrile solvent. Frequency calculations were carried out for all structures, and none of them has been found to exhibit any imaginary frequency. Finally, the BMK hybrid functional was selected for computation of the standard electrode potential of TTF-Im, because it gives the most accurate values in both Im and TTF, differing by 0.05 V from the experimental ones. Moreover, frequencies from the BMK functional are reasonably close to the experimental ones. The standard electrode potentials of 2-, 4-, and 5-TTF-Im predicted for two-electron oxidation are 0.946, 0.870, and 0.839 V in CPCM and 0.927, 0.866, and 0.824 V in SMD. For one-electron oxidation these are 0.491, 0.421, and 0.400 V in CPCM and 0.476, 0.377, and 0.360 V in SMD, respectively.

  7. Synthesis of Heteroaromatic Compounds by Oxidative Aromatization Using an Activated Carbon/Molecular Oxygen System

    Directory of Open Access Journals (Sweden)

    Masahiko Hayashi

    2009-08-01

    Full Text Available A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. In the final section, we will disclose the efficient synthesis of substituted 9,10-anthracenes via oxidative aromatization.

  8. SYNTHESIS AND STUDY OF ANTIOXIDANT ACTIVITY OF [(1-ARYL-5-FORMYL-1H-IMIDAZOLE-4-ILTHIO]PROPIONIC ACIDS

    Directory of Open Access Journals (Sweden)

    A. O. Palamar

    2014-12-01

    Full Text Available Introduction. Derivatives of imidazole belong to the promising group of compounds for antioxidant activity study, due to the series of recent publications. This is defined by special features of their structure, specific reactivity and significant potential of pharmacological action. Earlier during process of looking for new antioxidants we studied significant amount of imidazole derivatives, among which the [(1-aryl-5-formylimidazole-4-ilthio]acetic acids structurally modified by the formyl group and thioacetic acid fragment, are especially worth noting. The purpose of the study. Synthesis of [(1-aryl-5-formylimidazole-4-ilthio]propionic acids and comparison of their antioxidant effect with [(1-aryl-5-formylimidazole-4-ilthio]acetic acids with to identify prospects of in-depth study of the most active compounds as antioxidants. Materials and methods. The method based on interaction of available 4-chloro-5-formylimidazoles with thiopropionic acid was proposed for the synthesis of [(1-aryl-5-formylimidazole-4-ilthio]propionic acids. The reaction takes place in ethanol in presence of potassium hydroxide and leads to the target compounds with yields of 81-86%. The study of antioxidant activity of synthesized compounds was conducted in vitro by speed inhibition value of rats’ liver endogenous lipids ascorbate-dependent peroxide oxidation. It was determined by concentration of one of the final products of free radical oxidation of lipids (FROL – maleic aldehyde (MA in the investigated sample. Concentrations of synthesized compounds were chosen within concentrations which were studied for thiotriazolin (manufactured by corporation “Arterium”, Ukraine, solution for injection, 25 mg/ml. The results of the study and their discussion. Preparative method for the synthesis of [(1-aryl-5-formylimidazole-4-ilthio]propionic acids has been designed. Imidazolylthiopropionic acids have been synthesized; they are crystalline compounds, of light

  9. A study of the vaporization enthalpies of some 1-substituted imidazoles and pyrazoles by correlation-gas chromatography.

    Science.gov (United States)

    Lipkind, Dmitry; Plienrasri, Chatchawat; Chickos, James S

    2010-12-23

    The vaporization enthalpies of 1-methyl-, 1-ethyl-, 1-phenyl-, and 1-benzylimidazole, 1-methyl- and 1-phenylpyrazole, and trans-azobenzene are evaluated by correlation-gas chromatography (C-GC) using a variety of azines and diazines as standards. The vaporization enthalpies obtained by C-GC when compared to literature values are approximately 14 kJ·mol(-1) smaller for the imidazoles and 6 kJ·mol(-1) smaller for the pyrazoles. The literature vaporization enthalpies of 1-methylpyrrole and 1-methylindole, two closely related compounds with one less nitrogen, are reproduced by C-GC. These results suggest that the magnitude of the intermolecular interactions present in 1-substituted imidazoles and pyrazoles are significantly larger than the those present in the reference compounds and greater than or equal in magnitude to the enhanced intermolecular interactions observed previously in aromatic 1,2-diazines. The vaporization enthalpy and vapor pressure of a trans-1,2-diazine, trans-azobenzene, measured by C-GC using similar standards reproduced the literature values within experimental error.

  10. Synthesis and DNA-binding study of imidazole linked thiazolidinone derivatives.

    Science.gov (United States)

    War, Javeed Ahmad; Srivastava, Santosh Kumar; Srivastava, Savitri Devi

    2017-02-01

    A novel series of imidazole-linked thiazolidinone hybrid molecules were designed and synthesized through a feasible synthetic protocol. The molecules were characterized with Fourier transform infrared (FT-IR), 1 H nuclear magnetic resonance (NMR), 13 C NMR and high-resolution mass spectrometry (HRMS) techniques. In vitro susceptibility tests against Gram-positive (S. aureus and B. subtilis) and Gram-negative bacteria (E. coli and P. aeruginosa) gave highly promising results. The most active molecule (3e) gave a minimal inhibitory concentration (MIC) value of 3.125 μg/mL which is on par with the reference drug streptomycin. Structure-activity relationships revealed activity enhancement by nitro and chloro groups when they occupied meta position of the arylidene ring in 2-((3-(imidazol-1-yl)propyl)amino)-5-benzylidenethiazolidin-4-ones. DNA-binding study of the most potent molecule 3e with salmon milt DNA (sm-DNA) under simulated physiological pH was probed with UV-visible absorption, fluorescence quenching, gel electrophoresis and molecular docking techniques. These studies established that compound 3e has a strong affinity towards DNA and binds at DNA minor groove with a binding constant (K b ) 0.18 × 10 2  L mol -1 . Molecular docking simulations predicted strong affinity of 3e towards DNA with a binding affinity (ΔG) -8.5 kcal/mol. Van der Waals forces, hydrogen bonding and hydrophobic interactions were predicted as the main forces of interaction. The molecule 3e exhibited specific affinity towards adenine-thiamine base pairs. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Imidazole Alkaloids from the South China Sea Sponge Pericharax heteroraphis and Their Cytotoxic and Antiviral Activities

    Directory of Open Access Journals (Sweden)

    Kai-Kai Gong

    2016-01-01

    Full Text Available Marine sponges continue to serve as a rich source of alkaloids possessing interesting biological activities and often exhibiting unique structural frameworks. In the current study, chemical investigation on the marine sponge Pericharax heteroraphis collected from the South China Sea yielded one new imidazole alkaloid named naamidine J (1 along with four known ones (2–5. Their structures were established by extensive spectroscopic methods and comparison of their data with those of the related known compounds. All the isolates possessed a central 2-aminoimidazole ring, substituted by one or two functionalized benzyl groups in some combination of the C4 and C5 positions. The cytotoxicities against selected HL-60, HeLa, A549 and K562 tumor cell lines and anti-H1N1 (Influenza a virus (IAV activity for the isolates were evaluated. Compounds 1 and 2 exhibited cytotoxicities against the K562 cell line with IC50 values of 11.3 and 9.4 μM, respectively. Compound 5 exhibited weak anti-H1N1 (influenza a virus, IAV activity with an inhibition ratio of 33%.

  12. Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

    Directory of Open Access Journals (Sweden)

    Monika Mazik

    2010-02-01

    Full Text Available Compounds 4 and 5, including both 4(5-substituted imidazole or 3-substituted indole units as the entities used in nature, and 2-aminopyridine group as a heterocyclic analogue of the asparagine/glutamine primary amide side chain, were prepared and their binding properties towards carbohydrates were studied. The design of these receptors was inspired by the binding motifs observed in the crystal structures of protein–carbohydrate complexes. 1H NMR spectroscopic titrations in competitive and non-competitive media as well as binding studies in two-phase systems, such as dissolution of solid carbohydrates in apolar media, revealed both highly effective recognition of neutral carbohydrates and interesting binding preferences of these acyclic compounds. Compared to the previously described acyclic receptors, compounds 4 and 5 showed significantly increased binding affinity towards β-galactoside. Both receptors display high β- vs. α-anomer binding preferences in the recognition of glycosides. It has been shown that both hydrogen bonding and interactions of the carbohydrate CH units with the aromatic rings of the receptors contribute to the stabilization of the receptor–carbohydrate complexes. The molecular modeling calculations, synthesis and binding properties of 4 and 5 towards selected carbohydrates are described and compared with those of the previously described receptors.

  13. A NEW COPPER (II)-IMIDAZOLE DERIVATIVE EFFECTIVELY INHIBITS REPLICATION OF DENV-2 IN VERO CELL

    Science.gov (United States)

    Sucipto, Teguh Hari; Churrotin, Siti; Setyawati, Harsasi; Martak, Fahimah; Mulyatno, Kris Cahyo; Amarullah, Ilham Harlan; Kotaki, Tomohiro; Kameoka, Masanori; Yotopranoto, Subagyo; Soegijanto, and Soegeng

    2018-01-01

    Background: Dengue is a kind of infectious disease that was distributed in the tropical and sub-tropical areas. To date, there is no clinically approved dengue vaccine or antiviral for humans, even though there have been great efforts towards this end. Therefore, finding the effective compound against dengue virus (DENV) replication is very important. Among the complex compounds, copper(II)-imidazole derivatives are of interest because of their biological and medicinal benefits. Materials and Methods: In the present study, antiviral activity of [Cu(2,4,5-triphenylimidazole)2]n, was evaluated against different stages of dengue virus type 2 (DENV-2) replication in Vero cell using focus forming unit reduction assay and quantitative ELISA. Results: [Cu(2,4,5-triphenylimidazole)2]n inhibited DENV-2 replication in Vero cells with IC50 = 2.3 μg/ml and SI= 19.42 when cells were treated 2 days after virus infection, whereas its CC50 for cytotoxicity to Vero cells was 44.174 μg/ml. Conclusion: The compound has high anti-DENV2 activity, less toxicity, and a high possibility to be considered a drug candidate. PMID:29619441

  14. The marine sponge Agelas citrina as a source of the new pyrrole–imidazole alkaloids citrinamines A–D and N-methylagelongine

    Directory of Open Access Journals (Sweden)

    Christine Cychon

    2015-10-01

    Full Text Available The chemical investigation of the Caribbean sponge Agelas citrina revealed four new pyrrole–imidazole alkaloids (PIAs, the citrinamines A–D (1–4 and the bromopyrrole alkaloid N-methylagelongine (5. All citrinamines are dimers of hymenidin (6 which was also isolated from this sponge as the major metabolite. Citrinamines A (1 and B (2 are derivatives of the PIA dimer mauritiamine (7, whereas citrinamine C (3 is derived from the PIA dimer nagelamide B (8. Citrinamine D (4 shows an uncommon linkage between the imidazole rings of both monomeric units as it is only observed in the benzocyclobutane ring moiety of benzosceptrins A–C (9–11. Compound 5 is the N-methyl derivative of agelongine (12 which consist of a pyridinium ring and an ester linkage instead of the aminoimidazole moiety and the common amide bond in PIAs.

  15. Crystal structure of 1-[2-(4-chlorophenyl-4,5-diphenyl-1H-imidazol-1-yl]propan-2-ol

    Directory of Open Access Journals (Sweden)

    Shaaban K. Mohamed

    2017-01-01

    Full Text Available The title compound, C24H21ClN2O, crystallizes with two unique molecules in the asymmetric unit. In each molecule, the central imidazole ring is substituted at the 2-, 4- and 5-positions by benzene rings. The 2-substituted ring carries a Cl atom at the 4-position. One of the imidazole N atoms in each molecule has a propan-2-ol substituent. In the crystal, a series of O—H...N, C—H...O and C—H...Cl hydrogen bonds, augmented by several C—H...π(ring interactions, generate a three-dimensional network of molecules stacked along the a-axis direction.

  16. Formation and structure of inhibitive molecular film of imidazole on iron surface

    International Nuclear Information System (INIS)

    Kokalj, Anton

    2013-01-01

    Highlights: ► Atomic scale details of interaction between imidazole and Fe(1 0 0) elucidated by DFT calculations. ► Imidazole dehydrogenates upon adsorption with the C2-H bond cleaved. ► Stablest identified structure consists of high coverage C2 dehydrogenated imidazoles. ► Passivation of Fe(1 0 0) due to strong adsorbate-surface bond and high adsorbate coverage. ► Previously suggested polymerization of imidazole molecules at high coverage is found improbable. - Abstract: Adsorption of imidazole on clean Fe(1 0 0) was addressed by DFT calculations. It is shown that even though the imidazole in protonated form binds stronger to the surface than the neutral form, it is prone to deprotonation (dehydrogenation) resulting in neutral form, which further dehydrogenates due to the breaking of the C2–H bond. Thermodynamically the stablest identified structures thus consist of strongly bound and densely packed C2 dehydrogenated imidazole molecules, which may act as a thin protective film. On the other hand, the polymerization of imidazole molecules upon adsorption has been found improbable.

  17. Phosphoric acid doped polysulfone membranes with aminopyridine pendant groups and imidazole cross-links

    DEFF Research Database (Denmark)

    Hink, Steffen; Elsøe, Katrine; Cleemann, Lars Nilausen

    2015-01-01

    Udel polysulfone based membranes with 4-aminopyridine pendant groups and cross-linking imidazole units are synthesized in a simple two step reaction. The ratio of 4-aminopyridine and imidazole is varied and the materials are extensively characterized. The average phosphoric acid uptake (in 85 wt%...

  18. Novel synthesis of 4(5)-monosubstituted imidazoles via cycloaddition of tosylmethyl isocyanide to aldimines

    NARCIS (Netherlands)

    ten Have, Ronald; Huisman, M; Meetsma, A; van Leusen, A.M.

    1997-01-01

    4(5)-Monosubstituted imidazoles (9) have been prepared via base-induced cycloaddition of tosylmethyl isocyanide (TosMIC) to N-(dimethylsulfamoyl)aldimines (2) or N-tosylaldimines (3). In the first case, N-(dimethylsulfamoyl)imidazoles 8 are the initial reaction products, from which the

  19. Some thiocyanato complexes of cadmium(II) with substituted pyridines and imidazoles

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, B P; Ramana Rao, D V [Regional Engineering Coll., Rourkela (India). Dept. of Chemistry

    1979-05-01

    The complexes formed by cadmium(II) thiocyanate with 3-acetyl-, 3-bromo-, 3-methyl-, 4-acetyl-, 4-cyano-, 4-benzoyl pyridines, isoquinoline, 3,5-lutidine and imidazole, 2-methyl imidazole, 2-methyl benzimidazoles have been characterised through elemental analysis and molar conductance data. On the basis of infra-red spectroscopic studies, probable structures are discussed.

  20. Design, Synthesis, Antibacterial and Antifungal Activity of Novel 2-[(E-2-aryl-1-ethenyl]-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl-3,4- dihydro-4-quinolinones

    Directory of Open Access Journals (Sweden)

    Anisetti Ravinder Nath

    2012-01-01

    Full Text Available The novel 2-[(E-2-aryl-1-ethenyl]-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl-3,4- dihydro-4-quinolinones (4a-j analogs were synthesized by Knoevenagel condensation of a solution of 2-methyl-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl-3,4-dihydro-4-quinazolinone (3 with aromatic aldehyde in presence of catalytic amount of piperidine. Compounds (4a-j showed significant biological activity against all the standard strains. All the synthesized compounds were characterized on the basis of their IR, 1H NMR, MASS spectroscopic data and elemental analyses. All the compounds have been tested for antimicrobial and antifungal activity by the cup-plate method.

  1. DNA-Directed alkylating agents. 7. Synthesis, DNA interaction, and antitumor activity of bis(hydroxymethyl)- and bis(carbamate)-substituted pyrrolizines and imidazoles.

    Science.gov (United States)

    Atwell, G J; Fan, J Y; Tan, K; Denny, W A

    1998-11-19

    A series of bis(hydroxymethyl)-substituted imidazoles, thioimidazoles, and pyrrolizines and related bis(carbamates), linked to either 9-anilinoacridine (intercalating) or 4-(4-quinolinylamino)benzamide (minor groove binding) carriers, were synthesized and evaluated for sequence-specific DNA alkylation and cytotoxicity. The imidazole and thioimidazole analogues were prepared by initial synthesis of [(4-aminophenyl)alkyl]imidazole-, thioimidazole-, or pyrrolizine dicarboxylates, coupling of these with the desired carrier, and reduction to give the required bis(hydroxymethyl) alkylating moiety. The pyrrolizines were the most reactive alkylators, followed by the thioimidazoles, while the imidazoles were unreactive. The pyrrolizines and some of the thioimidazoles cross-linked DNA, as measured by agarose gel electrophoresis. Strand cleavage assays showed that none of the compounds reacted at purine N7 or N3 sites in the gpt region of the plasmid gpt2Eco, but the polymerase stop assay showed patterns of G-alkylation in C-rich regions. The corresponding thioimidazole bis(carbamates) were more selective than the bis(hydroxymethyl) pyrrolizines, with high-intensity bands at 5'-NCCN, 5'-NGCN and 5'-NCGN sequences in the PCR stopping assay ( indicates block sites). The data suggest that these targeted compounds, like the known thioimidazole bis(carbamate) carmethizole, alkylate exclusively at guanine residues via the 2-amino group, with little or no alkylation at N3 and N7 guanine or adenine sites. The cytotoxicities of the compounds correlated broadly with their reactivities, with the bis(hydroxymethyl)imidazoles being the least cytotoxic (IC50s >1 microM; P388 leukemia) and with the intercalator-linked analogues being more cytotoxic than the corresponding minor-groove-targeted ones. This was true also for the more reactive thioimidazole bis(carbamates) (IC50s 0.8 and 11 microM, respectively), but both were more active than the analogous "untargeted" carmethizole (IC50 20

  2. A new class of analogues of the bifunctional radiosensitizer alpha-(1-aziridinylmethyl)-2-nitro-1H-imidazole-1-ethanol (RSU 1069): The cycloalkylaziridines

    International Nuclear Information System (INIS)

    Suto, M.J.; Stier, M.A.; Werbel, L.M.; Arundel-Suto, C.M.; Leopold, W.R.; Elliott, W.E.; Sebolt-Leopold, J.S.

    1991-01-01

    A series of compounds related to alpha-(1-aziridinylmethyl)-2-nitro-1H-imidazole-1-ethanol (RSU 1069, 1) were synthesized and evaluated as selective hypoxic cell cytotoxic agents and as radiosensitizers. The aziridine moiety was replaced with a number of other potential alkylating groups including cycloalkylaziridines and azetidines. The data indicated that modification of the aziridine of 1 resulted in a substantial decrease in the ability of the compounds to selectively kill hypoxic cells. However, these modifications did not affect the compounds' in vitro radiosensitizing activity since many of the derivatives were as potent as 1. All of the compounds that were evaluated in vivo were less toxic than 1, and several members of this series had significant activity. The best compound was trans-alpha-[[(4-bromotetrahydro-2H-pyran-3-yl) amino]methyl]-2-nitro-1H-imidazole-1-ethanol (18), which, due to its activity and log P value, is a candidate for additional in vivo studies

  3. Spectroscopic investigations and molecular docking study of 3-(1H-imidazol-1-yl)-1-phenylpropan-1-one, a potential precursor to bioactive agents

    Science.gov (United States)

    Al-Alshaikh, Monirah A.; Mary Y, Sheena; Panicker, C. Yohannan; Attia, Mohamed I.; El-Emam, Ali A.; Alsenoy, C. Van

    2016-04-01

    The optimized molecular structure, vibrational wavenumbers, corresponding vibrational assignments of 3-(1H-imidazol-1-yl)-1-phenylpropan-1-one have been investigated theoretically and experimentally. The calculated geometrical parameters of the title compound are in agreement with the reported XRD data. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. Molecular electrostatic potential was performed by the DFT method and from the MEP plot, it is evident that the negative charge covers the carbonyl group and the nitrogen atom N3 of the imidazole ring and the positive region is over the remaining portions of the molecule. The first and second hyperpolarizabilities are calculated and the first hyperpolarizability of the title compound is 16.99 times that of standard NLO material urea and the title compound and its derivatives are good object for further studies in nonlinear optics. The docked ligand title compound forms a stable complex with plasmodium falciparum and gives a binding affinity value of -5.5 kcal/mol and the preliminary results suggest that the compound might exhibit antimalarial activity against plasmodium falciparum.

  4. Etude structurale et vibrationnelle d'un nouveau composé complexe de cobalt: [Co(imidazole)4Cl]Cl.

    Science.gov (United States)

    Derbel, Amira; Mhiri, Tahar; Graia, Mohsen

    2015-10-01

    In the title complex, chlorido-tetra-kis-(1H-imidazole-κN (3))cobalt(II) chloride, [CoCl(C3H4N2)4]Cl, the Co(II) cation has a distorted square-pyramidal coordination environment. It is coordinated by four N atoms of four imidazole (Im) groups in the basal plane, and by a Cl atom in the apical position. It is isostructural with [Cu(Im)4Cl]Cl [Morzyk-Ociepa et al. (2012 ▸). J. Mol. Struct. 1028, 49-56] and [Cu(Im)4Br]Br [Hossaini Sadr et al. (2004 ▸). Acta Cryst. E60, m1324-m1326]. In the crystal, the [CoCl(C3H4N2)4](+) cations and Cl(-) anions are linked via N-H⋯Cl hydrogen bonds, forming layers parallel to (010). These layers are linked via C-H⋯Cl hydrogen bonds and C-H⋯π and π-π [inter-centroid distance = 3.794 (2) Å] inter-actions, forming a three-dimensional framework. The IR spectrum shows vibrational bands typical for imidazol groups. The monoclinic unit cell of the title compound emulates an ortho-rhom-bic cell as its β angle is close to 90°. The crystal is twinned, with the refined ratio of twin components being 0.569 (1):0.431 (1).

  5. Synthesis and antimicrobial properties of 3-aryl-1-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-yl)propanes as 'carba-analogues' of the N-arylmethyl-N-[(1,1'-biphenyl)-4-ylmethyl])-1H-imidazol-1-amines, a new class of antifungal agents.

    Science.gov (United States)

    Castellano, Sabrina; Stefancich, Giorgio; Chillotti, Annalisa; Poni, Graziella

    2003-08-01

    A new series of 3-phenyl-1-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-yl)propane derivatives 2a-l (related to the antifungal bifonazole) was synthesized and tested for antimicrobial activity. A number of substituents on the phenyl ring were chosen to compare the relative biological properties with those of corresponding aza-analogues, previously described by us. The in vitro antifungal activities of the newly synthesized azoles were tested against several pathogenic fungi responsible for human disease. Test pathogens included representatives of yeasts (Candida albicans, Candida parapsilosis, Criptococcus neoformans), dermathophytes (Tricophyton verrucosum, Tricophyton rubrum, Microsporum gypseum) and moulds (Aspergillus fumigatus). Bifonazole and miconazole were used as reference drugs. Title compounds were prepared by alkylation of 1-biphenyl-4-yl-2-imidazol-1-yl-ethanone with the proper arylmethyl halide and subsequent reduction of corresponding ketones applying the Huang-Minlon modification of the Wolff-Kishner reaction.

  6. Antitumor activity of sequence-specific alkylating agents: pyrolle-imidazole CBI conjugates with indole linker.

    Science.gov (United States)

    Shinohara, Ken-ichi; Bando, Toshikazu; Sasaki, Shunta; Sakakibara, Yogo; Minoshima, Masafumi; Sugiyama, Hiroshi

    2006-03-01

    DNA-targeting agents, including cisplatin, bleomycin and mitomycin C, are used routinely in cancer treatments. However, these drugs are extremely toxic, attacking normal cells and causing severe side effects. One important question to consider in designing anticancer agents is whether the introduction of sequence selectivity to DNA-targeting agents can improve their efficacy as anticancer agents. In the present study, the growth inhibition activities of an indole-seco 1,2,9,9a-tetrahydrocyclopropa[1,2-c]benz[1,2-e]indol-4-one (CBI) (1) and five conjugates with hairpin pyrrole-imidazole polyamides (2-6), which have different sequence specificities for DNA alkylation, were compared using 10 different cell lines. The average values of -log GI50 (50% growth inhibition concentration) for compounds 1-6 against the 10 cell lines were 8.33, 8.56, 8.29, 8.04, 8.23 and 8.83, showing that all of these compounds strongly inhibit cell growth. Interestingly, each alkylating agent caused significantly different growth inhibition patterns with each cell line. In particular, the correlation coefficients between the -log GI50 of compound 1 and its conjugates 2-6 showed extremely low values (Ralkylation lead to marked differences in biological activity. Comparison of the correlation coefficients between compounds 6 and 7, with the same sequence specificity as 6, and MS-247, with sequence specificity different from 6, when used against a panel of 37 human cancer cell lines further confirmed the above hypothesis.

  7. Photoinduced electron-transfer from imidazole derivative to nano-semiconductors.

    Science.gov (United States)

    Karunakaran, C; Jayabharathi, J; Jayamoorthy, K; Devi, K Brindha

    2012-04-01

    Bioactive imidazole derivative absorbs in the UV region at 305 nm. The interaction of imidazole derivative with nanoparticulate WO3, Fe2O3, Fe3O4, CuO, ZrO2 and Al2O3 has been studied by UV-visible absorption, FT-IR and fluorescence spectroscopies. The imidazole derivative adsorbs strongly on the surfaces of nanosemiconductor, the apparent binding constants for the association between nanomaterials and imidazole derivative have been determined from the fluorescence quenching. In the case of nanocrystalline insulator, fluorescence quenching through electron transfer from the excited state of the imidazole derivative to alumina is not possible. However, a possible mechanism for the quenching of fluorescence by the insulator is energy transfer, that is, energy transferred from the organic molecule to the alumina lattice. Based on Forster's non-radiation energy transfer theory, the distance between the imidazole derivative and nanoparticles (r0∼2.00 nm) as well as the critical energy transfer distance (R0∼1.70 nm) has been calculated. The interaction between the imidazole derivative and nanosurfaces occurs through static quenching mechanism. The free energy change (ΔGet) for electron transfer process has been calculated by applying Rehm-Weller equation. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Pyrrolo-dC Metal-Mediated Base Pairs in the Reverse Watson-Crick Double Helix: Enhanced Stability of Parallel DNA and Impact of 6-Pyridinyl Residues on Fluorescence and Silver-Ion Binding.

    Science.gov (United States)

    Yang, Haozhe; Mei, Hui; Seela, Frank

    2015-07-06

    Reverse Watson-Crick DNA with parallel-strand orientation (ps DNA) has been constructed. Pyrrolo-dC (PyrdC) nucleosides with phenyl and pyridinyl residues linked to the 6 position of the pyrrolo[2,3-d]pyrimidine base have been incorporated in 12- and 25-mer oligonucleotide duplexes and utilized as silver-ion binding sites. Thermal-stability studies on the parallel DNA strands demonstrated extremely strong silver-ion binding and strongly enhanced duplex stability. Stoichiometric UV and fluorescence titration experiments verified that a single (2py) PyrdC-(2py) PyrdC pair captures two silver ions in ps DNA. A structure for the PyrdC silver-ion base pair that aligns 7-deazapurine bases head-to-tail instead of head-to-head, as suggested for canonical DNA, is proposed. The silver DNA double helix represents the first example of a ps DNA structure built up of bidentate and tridentate reverse Watson-Crick base pairs stabilized by a dinuclear silver-mediated PyrdC pair. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Inhibiting effects of imidazole on copper corrosion in 1 M HNO3 solution

    International Nuclear Information System (INIS)

    Lee, Woo-Jin

    2003-01-01

    The present work deals with the inhibiting effects of imidazole on the pure copper (Cu) corrosion in 1 M HNO 3 solution analysing potentiodynamic polarisation curves, potentiostatic anodic current transient, AC impedance spectra and X-ray photoelectron spectra (XPS). By adding imidazole to HNO 3 solution, the polarisation curves showed decrease in the corrosion current and the cathodic current, suggesting that imidazole acts as an effective cathodic inhibitor to Cu corrosion. From the measured anodic current transients, it is inferred that the protective Cu-imidazole complex film is simultaneously formed with the Cu oxide in the presence of imidazole during the early stage of the anodic polarisation. Analysis of the AC impedance spectra revealed that the values of the charge transfer resistance R ct obtained in imidazole-containing HNO 3 solution were greater than that value in imidazole-free one and at the same time steadily increased with immersion time to the constant value. Contrarily, the capacitance value was abruptly lowered from the double layer capacitance C dl to the complex film capacitance C cf in the progress of immersion time. Furthermore, the Warburg coefficient σ value for the ion diffusion through the complex film was observed to increase with immersion time. This means that the Cu(N-OH) complex film becomes thicker during immersion in the HNO 3 solution with imidazole through the inward growth of the N-rich outer layer to the O-rich inner layer, as well validated by XPS. Based upon the experimental results, it is suggested that the Cu corrosion in 1 M HNO 3 solution is efficiently inhibited with the addition of imidazole by retarding both the charge transfer on cathodic sites of the Cu surface in the early stage of immersion time and the subsequent ion diffusion through the steadily growing complex film

  10. Characterization for coating processes of imidazole powders using an ultrasonic atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Sik; Kim, Jun Ki [Korea Institute of Industrial Technology, Incheon (Korea, Republic of); Kim, Mok Soon [Inha University, Incheon (Korea, Republic of); Lee, Jong Hyun [Seoul National University, Seoul (Korea, Republic of)

    2010-01-15

    Imidazole-curing accelerator powders were coated with stearic acid to increase the pot life of anisotropic conductive adhesive (ACA) formulations. To accomplish an efficient coating process, the coating was tested using an ultrasonic atomizer after mixing imidazole powders with a molten coating agent. Design of experiments analysis was organized to elucidate the effect of process parameters and to determine the most crucial parameter. The final formulation incorporating well-processed imidazole loaded powders indicated longer pot life, higher shear strength, and excellent highly accelerated stress test (HAST) reliability. Results show that the coating process using an ultrasonic atomizer is effective in increasing the pot life of ACA formulations

  11. Synthesis and biological evaluation of 2-(phenyl-3H-benzo[d]imidazole-5-carboxylic acids and its methyl esters as potent anti-breast cancer agents

    Directory of Open Access Journals (Sweden)

    Chandrabose Karthikeyan

    2017-05-01

    Full Text Available A series of novel substituted 2-(phenyl-3H-benzo[d]imidazole-5-carboxylic acids (1a–1j and its methyl esters (2a–2f were synthesized and examined for their antiproliferative effects against three breast cancer cell lines (MDA-MB231, MDA-MB468 and MCF7 in vitro. Most of the compounds exhibited comparable or greater antiproliferative effects than the reference compound cisplatin. Compound 2e bearing 5-fluoro-2-hydroxyphenyl substituent was found to be the most active derivative of the series with GI50 values of 6.23, 4.09 and 0.18 μM against MDA-MB468, MDA-MB231 and MCF7 breast cancer cell lines, respectively. Our findings described here exemplify the usefulness of the title compounds as a lead for the development of more effective cancer therapeutics for the treatment of breast cancer.

  12. Racemic cobalt phosphonates incorporating flexible bis(imidazole) co-ligands.

    Science.gov (United States)

    Feng, Jian-Shen; Cai, Zhong-Sheng; Ren, Min; Bao, Song-Song; Zheng, Li-Min

    2015-11-07

    By incorporating flexible bis(imidazol-1-ylmethyl)benzene (bix) co-ligands, four new racemic cobalt phosphonates with formulae Co3(3-ppap)2(1,4-bix)2(H2O)4·4H2O (1), Co3(3-ppap)2(1,3-bix)2(H2O)4·5H2O (2), Co3(3-ppap)2(1,2-bix)2(H2O)4·4H2O (3) and Co3(ppa)2(1,2-bix)2·4H2O (4) are isolated, where 3-ppapH3 represents 3-phenyl-3-((phosphonomethyl)amino)propanoic acid and ppaH3 is 2-phenyl-2-(phosphonomethylamino)acetic acid. Compounds 1-3 crystallize in the monoclinic space group P21/c and show two-dimensional structures in which the Co3(3-ppap)2 chains are bridged by 1,4-bix, 1,3-bix and 1,2-bix ligands in trans-modes, respectively. Within the chain, a racemic dimer of Co2(3-ppap)2(2-) is found, where the Co atoms are doubly bridged by O-P-O units from the (S)- and (R)-3-ppap(3-) ligands. The dimers are connected by another crystallographically independent Co atom through O-P-O linkages to form an infinite racemic chain. The packing modes of the layers in 1-3 are quite different, however, which are ABAB in the cases of 1 and 3 while ABCDABCD in the case of 2, attributed to the positional isomerism of the bix co-ligands. Compound 4 displays a chain structure in which the 1,2-bix bridges the Co atoms in cis-mode within the chain. Magnetic properties are investigated for all compounds.

  13. Polyacrylonitrile nanofibers with added zeolitic imidazolate frameworks (ZIF-7) to enhance mechanical and thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Wook [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor St., Chicago, Illinois 60607-7022 (United States); An, Seongpil; Song, Kyo Yong; Joshi, Bhavana N.; Jo, Hong Seok; Yoon, Sam S., E-mail: skyoon@korea.ac.kr, E-mail: ayarin@uic.edu [School of Mechanical Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Al-Deyab, Salem S. [Department of Chemistry, King Saud University, Riyadh 11451 (Saudi Arabia); Yarin, Alexander L., E-mail: skyoon@korea.ac.kr, E-mail: ayarin@uic.edu [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor St., Chicago, Illinois 60607-7022 (United States); School of Mechanical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2015-12-28

    Zeolitic imidazolate framework 7/polyacrylonitrile (ZIF-7/PAN) nanofiber mat of high porosity and surface area can be used as a flexible fibrous filtration membrane that is subjected to various modes of mechanical loading resulting in stresses and strains. Therefore, the stress-strain relation of ZIF-7/PAN nanofiber mats in the elastic and plastic regimes of deformation is of significant importance for numerous practical applications, including hydrogen storage, carbon dioxide capture, and molecular sensing. Here, we demonstrated the fabrication of ZIF-7/PAN nanofiber mats via electrospinning and report their mechanical properties measured in tensile tests covering the elastic and plastic domains. The effect of the mat fabrication temperature on the mechanical properties is elucidated. We showed the superior mechanical strength and thermal stability of the compound ZIF-7/PAN nanofiber mats in comparison with that of pure PAN nanofiber mats. Material characterization including scanning electron microscope, energy-dispersive X-ray spectroscopy, tensile tests, differential scanning calorimetry, and Fourier transform infrared spectroscopy revealed the enhanced chemical bonds of the ZIF-7/PAN complex.

  14. Imidazole-containing farnesyltransferase inhibitors: 3D quantitative structure-activity relationships and molecular docking

    Science.gov (United States)

    Xie, Aihua; Odde, Srinivas; Prasanna, Sivaprakasam; Doerksen, Robert J.

    2009-07-01

    One of the most promising anticancer and recent antimalarial targets is the heterodimeric zinc-containing protein farnesyltransferase (FT). In this work, we studied a highly diverse series of 192 Abbott-initiated imidazole-containing compounds and their FT inhibitory activities using 3D-QSAR and docking, in order to gain understanding of the interaction of these inhibitors with FT to aid development of a rational strategy for further lead optimization. We report several highly significant and predictive CoMFA and CoMSIA models. The best model, composed of CoMFA steric and electrostatic fields combined with CoMSIA hydrophobic and H-bond acceptor fields, had r 2 = 0.878, q 2 = 0.630, and r pred 2 = 0.614. Docking studies on the statistical outliers revealed that some of them had a different binding mode in the FT active site based on steric bulk and available active site space, explaining why the predicted activities differed from the experimental activities.

  15. 2-(1H-Imidazol-1-yl)-3-isopropyl-1-benzothieno[3,2-d]pyrimidin-4(3H)-one

    OpenAIRE

    Xu, Sheng-Zhen

    2007-01-01

    In the title compound, C16H14N4OS, the three fused rings of the benzothieno[3,2-d]pyrimidinone unit are essentially coplanar, the maximum deviation from the mean plane being 0.067 (3) Å. The dihedral angle between the mean plane of the fused rings and the imidazole ring is 72.00 (3)°. Offset π–π stacking interactions involving the fused rings are effective in the stabilization of the crystal structure. The centroid–centroid distances between t...

  16. Synthesis and XRD, FT-IR vibrational, UV-vis, and nonlinear optical exploration of novel tetra substituted imidazole derivatives: A synergistic experimental-computational analysis

    Science.gov (United States)

    Ahmad, Muhammad Saeed; Khalid, Muhammad; Shaheen, Muhammad Ashraf; Tahir, Muhammad Nawaz; Khan, Muhammad Usman; Braga, Ataualpa Albert Carmo; Shad, Hazoor Ahmad

    2018-04-01

    Heterocyclic compounds have potential applications in many fields of life. We synthesized novel tetra substituted imidazoles by four-component condensation of benzil, substituted aldehydes, substituted anilines and ammonium acetate as a source of ammonia and acetic acid as the solvent. Their chemical structures were resolved through X-ray crystallographic and spectroscopic (Fourier transform IR and UV-vis) techniques. In addition to experimental analysis, density functional theory (DFT) calculations at the B3LYP/6-311 + G(d,p) level were performed on 4-bromo-2-(1-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazole-2-yl)phenol (1), 4-bromo-2-(1-(1-naphthalen-yl)-4,5-diphenyl-1H-imidazole-2-yl)phenol (2), and 2-(1-(2-chlorophenyl)-4,5-diphenyl-1-H-imidazole-2-yl)-6-methoxyphenol (3) to obtain the optimized geometry and spectroscopic (Fourier transform IR and UV-vis) and non-linear optical properties. Frontier molecular orbital analysis was performed at the Hartee-Fock/6-311+g(d,p) and DFT/B3LYP/6-311+G(d,p) levels of theory. Natural bond orbital (NBO) and UV-vis spectral analyses were performed at the M06-2X/6-31+G(d,p) and time-dependent DFT/B3LYP/6-311+G(d,p) levels, respectively. Overall, the DFT findings show good agreement with the experimental data. The hyper conjugative interaction network, which is responsible for the stability of compounds 1, 2 and 3 was explored by the NBO approach. The global reactivity parameters were explored with use of the energy of the frontier molecular orbitals. DFT calculations predict the first-order hyperpolarizabilities of compounds 1, 2 and 3 are 294.89 × 10-30, 219.45 × 10-30 and 146.77 × 10-30 esu, respectively. A two-state model was used to describe the non-linear optical properties of the compounds investigated.

  17. A Submarine Journey: The Pyrrole-Imidazole Alkaloids

    Directory of Open Access Journals (Sweden)

    Alessandra Scolaro

    2009-11-01

    Full Text Available In his most celebrated tale “The Picture of Dorian Gray”, Oscar Wilde stated that “those who go beneath the surface do so at their peril”. This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity − from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products.

  18. Thermal and mechanical stability of zeolitic imidazolate frameworks polymorphs

    Directory of Open Access Journals (Sweden)

    Lila Bouëssel du Bourg

    2014-12-01

    Full Text Available Theoretical studies on the experimental feasibility of hypothetical Zeolitic Imidazolate Frameworks (ZIFs have focused so far on relative energy of various polymorphs by energy minimization at the quantum chemical level. We present here a systematic study of stability of 18 ZIFs as a function of temperature and pressure by molecular dynamics simulations. This approach allows us to better understand the limited stability of some experimental structures upon solvent or guest removal. We also find that many of the hypothetical ZIFs proposed in the literature are not stable at room temperature. Mechanical and thermal stability criteria thus need to be considered for the prediction of new MOF structures. Finally, we predict a variety of thermal expansion behavior for ZIFs as a function of framework topology, with some materials showing large negative volume thermal expansion.

  19. Pore closure in zeolitic imidazolate frameworks under mechanical pressure.

    Science.gov (United States)

    Henke, Sebastian; Wharmby, Michael T; Kieslich, Gregor; Hante, Inke; Schneemann, Andreas; Wu, Yue; Daisenberger, Dominik; Cheetham, Anthony K

    2018-02-14

    We investigate the pressure-dependent mechanical behaviour of the zeolitic imidazolate framework ZIF-4 (M(im) 2 ; M 2+ = Co 2+ or Zn 2+ , im - = imidazolate) with high pressure, synchrotron powder X-ray diffraction and mercury intrusion measurements. A displacive phase transition from a highly compressible open pore ( op ) phase with continuous porosity (space group Pbca , bulk modulus ∼1.4 GPa) to a closed pore ( cp ) phase with inaccessible porosity (space group P 2 1 / c , bulk modulus ∼3.3-4.9 GPa) is triggered by the application of mechanical pressure. Over the course of the transitions, both ZIF-4 materials contract by about 20% in volume. However, the threshold pressure, the reversibility and the immediate repeatability of the phase transition depend on the metal cation. ZIF-4(Zn) undergoes the op-cp phase transition at a hydrostatic mechanical pressure of only 28 MPa, while ZIF-4(Co) requires about 50 MPa to initiate the transition. Interestingly, ZIF-4(Co) fully returns to the op phase after decompression, whereas ZIF-4(Zn) remains in the cp phase after pressure release and requires subsequent heating to switch back to the op phase. These variations in high pressure behaviour can be rationalised on the basis of the different electron configurations of the respective M 2+ ions (3d 10 for Zn 2+ and 3d 7 for Co 2+ ). Our results present the first examples of op-cp phase transitions ( i.e. breathing transitions) of ZIFs driven by mechanical pressure and suggest potential applications of these functional materials as shock absorbers, nanodampers, or in mechanocalorics.

  20. Hybrid Zeolitic Imidazolate Frameworks: Controlling Framework Porosity and Functionality by Mixed-Linker Synthesis

    KAUST Repository

    Thompson, Joshua A.; Blad, Catherine R.; Brunelli, Nicholas A.; Lydon, Megan E.; Lively, Ryan P.; Jones, Christopher W.; Nair, Sankar

    2012-01-01

    Zeolitic imidazolate frameworks (ZIFs) are a subclass of nanoporous metal-organic frameworks (MOFs) that exhibit zeolite-like structural topologies and have interesting molecular recognition properties, such as molecular sieving and gate

  1. Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

    Data.gov (United States)

    U.S. Environmental Protection Agency — A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology has been synthesized and its application as a recyclable...

  2. An Imidazole based probe for relay recognition of Cu and OH ions ...

    Indian Academy of Sciences (India)

    biological activities.1 Biological activity of imidazole derivatives is the main motive for ... These systems use physical or chemical inputs to gen- erate outputs based on a set ... exhibit α-glucosidase inhibition to treat diabetes.21. 2. Experimental.

  3. {Tris[2-(imidazol-2-ylmethyliminoethyl]methylammonium}iron(II tris(perchlorate dihydrate

    Directory of Open Access Journals (Sweden)

    Greg A. Brewer

    2008-01-01

    Full Text Available The title complex, [Fe(C19H27N10](ClO43·2H2O, is a new polymorph of an iron(II Schiff base complex of tris(2-aminoethylmethylammonium with imidazole-2-carboxaldehyde. The octahedral FeII atom is bound to three facial imidazole N atoms with average Fe—Nimidazole and Fe—Nimine bond distances of 1.963 (5 and 1.951 (5 Å, respectively. The central N atom of the tripodal ligand is outside the bonding distance at 3.92 Å. The crystal packing is stabilized by the hydrogen-bonding interactions between the two water molecules (acceptor and two of the three imidazole NH groups (donor. The third imidazole NH group (donor forms a hydrogen bond to one of the three perchlorate counter-ions (acceptor.

  4. Investigation of the Linker Swing Motion in the Zeolitic Imidazolate Framework ZIF-90

    KAUST Repository

    Zheng, Bin; Fu, Fang; Wang, Lian Li; Yang, Limin; Zhu, Yihan; Du, Huiling

    2018-01-01

    The linker swing motion in the zeolitic imidazolate framework ZIF-90 is investigated by density functional theory (DFT) calculation, molecular dynamics (MD) and grand-canonical Monte Carlo (GCMC) simulations. The relation between the terminal

  5. Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

    Science.gov (United States)

    A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology was synthesized and itsefficacy was demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide.

  6. Imidazole as a pH Probe: An NMR Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Hagan, William J., Jr.; Edie, Dennis L.; Cooley, Linda B.

    2007-01-01

    The analysis describes an NMR experiment for the general chemistry laboratory, which employs an unknown imidazole solution to measure the pH values. The described mechanism can also be used for measuring the acidity within the isolated cells.

  7. Synthesis, single crystal X-ray, spectroscopic (FT-IR, UV-vis, fluorescence, 1H &13C NMR), computational (DFT/B3LYP) studies of some imidazole based picrates

    Science.gov (United States)

    Arockia doss, M.; Rajarajan, G.; Thanikachalam, V.; Selvanayagam, S.; Sridhar, B.

    2018-04-01

    2,4,5-triphenyl-1H-imidazol-3-ium picrate (1), 2-(4-fluorophenyl)-4,5-diphenyl-1H-imidazol-3-ium picrate (2), 2-(4-methylphenyl)-4,5-diphenyl-1H-imidazol-3-ium picrate (3) were synthesised. These compounds 1-3 were characterized by elemental, FT-IR, 1H NMR and 13C NMR analyses. The structure of compound 3 was further confirmed by single crystal X-ray diffraction. The studies reveal that the molecule is associated with weak Nsbnd H⋯O and Csbnd H⋯N and van der Waals interactions which are responsible for the formation and strengthening of supramolecular assembly. The nature of the interactions and their importance are explored using the Hirshfeld surface method. The physicochemical properties of the compounds 1-3 were evaluated by UV-vis spectroscopy, fluorescence spectroscopy, and thermogravimetric analysis. According to thermal data the salts possess excellent thermal stabilities with decomposition temperatures ranging from 220 to 280 °C. Second-harmonic generation (SHG) results exposed that the picrates 1-3 were about 1.13-1.50 times greater than potassium dihydrogen phosphate (KDP). Here we also used Density functional theory (DFT) calculations in order to investigate the opto-electronic properties. The obtained theoretical results validate with available experimental data.

  8. Protection by imidazol(ine) drugs and agmatine of glutamate-induced neurotoxicity in cultured cerebellar granule cells through blockade of NMDA receptor.

    Science.gov (United States)

    Olmos, G; DeGregorio-Rocasolano, N; Paz Regalado, M; Gasull, T; Assumpció Boronat, M; Trullas, R; Villarroel, A; Lerma, J; García-Sevilla, J A

    1999-07-01

    This study was designed to assess the potential neuroprotective effect of several imidazol(ine) drugs and agmatine on glutamate-induced necrosis and on apoptosis induced by low extracellular K+ in cultured cerebellar granule cells. Exposure (30 min) of energy deprived cells to L-glutamate (1-100 microM) caused a concentration-dependent neurotoxicity, as determined 24 h later by a decrease in the ability of the cells to metabolize 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) into a reduced formazan product. L-glutamate-induced neurotoxicity (EC50=5 microM) was blocked by the specific NMDA receptor antagonist MK-801 (dizocilpine). Imidazol(ine) drugs and agmatine fully prevented neurotoxicity induced by 20 microM (EC100) L-glutamate with the rank order (EC50 in microM): antazoline (13)>cirazoline (44)>LSL 61122 [2-styryl-2-imidazoline] (54)>LSL 60101 [2-(2-benzofuranyl) imidazole] (75)>idazoxan (90)>LSL 60129 [2-(1,4-benzodioxan-6-yl)-4,5-dihydroimidazole](101)>RX82 1002 (2-methoxy idazoxan) (106)>agmatine (196). No neuroprotective effect of these drugs was observed in a model of apoptotic neuronal cell death (reduction of extracellular K+) which does not involve stimulation of NMDA receptors. Imidazol(ine) drugs and agmatine fully inhibited [3H]-(+)-MK-801 binding to the phencyclidine site of NMDA receptors in rat brain. The profile of drug potency protecting against L-glutamate neurotoxicity correlated well (r=0.90) with the potency of the same compounds competing against [3H]-(+)-MK-801 binding. In HEK-293 cells transfected to express the NR1-1a and NR2C subunits of the NMDA receptor, antazoline and agmatine produced a voltage- and concentration-dependent block of glutamate-induced currents. Analysis of the voltage dependence of the block was consistent with the presence of a binding site for antazoline located within the NMDA channel pore with an IC50 of 10-12 microM at 0 mV. It is concluded that imidazol(ine) drugs and agmatine are

  9. Synthesis and evaluation of alpha-[[(2-haloethyl)amino]methyl]-2- nitro-1H-imidazole-1-ethanols as prodrugs of alpha-[(1-aziridinyl)methyl]-2- nitro-1H-imidazole-1-ethanol (RSU-1069) and its analogues which are radiosensitizers and bioreductively activated cytotoxins

    International Nuclear Information System (INIS)

    Jenkins, T.C.; Naylor, M.A.; O'Neill, P.; Threadgill, M.D.; Cole, S.; Stratford, I.J.; Adams, G.E.; Fielden, E.M.; Suto, M.J.; Stier, M.A.

    1990-01-01

    alpha-[(1-Aziridinyl)methyl]-2-nitro-1H-imidazole-1-ethanols, of general formula ImCH2CH(OH)CH2NCR1R2CR3R4, where Im = 2-nitroimidazole and R1, R2, R3, R4 = H, Me, are radiosensitizers and selective bioreductively activated cytotoxins toward hypoxic tumor cells in vitro and in vivo. Treatment of the aziridines with hydrogen halide in acetone or aqueous acetone gave the corresponding 2-haloethylamines of general formula ImCH2CH(OH)CH2(+)-NH2CR1R2CR3R4X X-, where R1, R2, R3, R4 = H, Me, and X = F, Cl, Br, I. These 2-haloethylamines were evaluated as prodrugs of the parent aziridines. The rates of ring closure in aqueous solution at pH approximately 6 were found to increase with increasing methyl substitution and to depend on the nature of the leaving group (I approximately Br greater than Cl much greater than F). A competing reaction of ImCH2CH(OH)CH2+NH2CH2CH2X X- (X = Cl, Br) with aqueous HCO3- ions gives 3-[2-hyroxy-3-(2-nitro-1H-imidazol-1-yl)propyl]-2-oxazolidinone. The activities of these prodrugs as radiosensitizers or as bioreductively activated cytotoxins were consistent with the proportion converted to the parent aziridine during the course of the experiment. alpha-[[(2-Bromoethyl)amino]methyl]-2-nitro-1H-imidazole-1- ethanol (RB 6145, 10), the prodrug of alpha-[(1-aziridinyl)methyl]-2-nitro-1H-imidazole-1-ethanol (RSU-1069, 3), is identified as the most useful compound in terms of biological activity and rate of ring closure under physiological conditions

  10. Dual role of imidazole as activator/inhibitor of sweet almond (Prunus dulcis β-glucosidase

    Directory of Open Access Journals (Sweden)

    Sara Caramia

    2017-07-01

    Full Text Available The activity of Prunus dulcis (sweet almond β-glucosidase at the expense of p-nitrophenyl-β-d-glucopyranoside at pH 6 was determined, both under steady-state and pre-steady-state conditions. Using crude enzyme preparations, competitive inhibition by 1–5 mM imidazole was observed under both kinetic conditions tested. However, when imidazole was added to reaction mixtures at 0.125–0.250 mM, we detected a significant enzyme activation. To further inspect this effect exerted by imidazole, β-glucosidase was purified to homogeneity. Two enzyme isoforms were isolated, i.e. a full-length monomer, and a dimer containing a full-length and a truncated subunit. Dimeric β-glucosidase was found to perform much better than the monomeric enzyme, independently of the kinetic conditions used to assay enzyme activity. In addition, the sensitivity towards imidazole was found to differ between the two isoforms. While monomeric enzyme was indeed found to be relatively insensitive to imidazole, dimeric β-glucosidase was observed to be significantly activated by 0.125–0.250 mM imidazole under pre-steady-state conditions. Further, steady-state assays revealed that the addition of 0.125 mM imidazole to reaction mixtures increases the Km of dimeric enzyme from 2.3 to 6.7 mM. The activation of β-glucosidase dimer by imidazole is proposed to be exerted via a conformational transition poising the enzyme towards proficient catalysis.

  11. Electronic structure tautomerism, and mechanism of H-D exchange in imidazole aqueous solutions

    International Nuclear Information System (INIS)

    Borisov, Yu.A.; Vorob'eva, N.P.; Abronin, I.A.; Kolomiets, A.F.

    1988-01-01

    The imidazole electronic structure in a gaseous phase is studied taking into account the influence of solvation effects in aqueous solutions. Possible mechanisms of tautomeric transformations and H-D exchange reactions with water molecules are discussed. Using the quantum chemistry methods, it is shown that the intramolecular mechanism of imidazole isomerization in the gaseous phase and the aqueous solution is unprofitable, and the intermolecular mechanism can proceed through the stage of protonated and carbene form formation

  12. Dual role of imidazole as activator/inhibitor of sweet almond (Prunus dulcis) β-glucosidase.

    Science.gov (United States)

    Caramia, Sara; Gatius, Angela Gala Morena; Dal Piaz, Fabrizio; Gaja, Denis; Hochkoeppler, Alejandro

    2017-07-01

    The activity of Prunus dulcis (sweet almond) β-glucosidase at the expense of p -nitrophenyl-β-d-glucopyranoside at pH 6 was determined, both under steady-state and pre-steady-state conditions. Using crude enzyme preparations, competitive inhibition by 1-5 mM imidazole was observed under both kinetic conditions tested. However, when imidazole was added to reaction mixtures at 0.125-0.250 mM, we detected a significant enzyme activation. To further inspect this effect exerted by imidazole, β-glucosidase was purified to homogeneity. Two enzyme isoforms were isolated, i.e. a full-length monomer, and a dimer containing a full-length and a truncated subunit. Dimeric β-glucosidase was found to perform much better than the monomeric enzyme, independently of the kinetic conditions used to assay enzyme activity. In addition, the sensitivity towards imidazole was found to differ between the two isoforms. While monomeric enzyme was indeed found to be relatively insensitive to imidazole, dimeric β-glucosidase was observed to be significantly activated by 0.125-0.250 mM imidazole under pre-steady-state conditions. Further, steady-state assays revealed that the addition of 0.125 mM imidazole to reaction mixtures increases the K m of dimeric enzyme from 2.3 to 6.7 mM. The activation of β-glucosidase dimer by imidazole is proposed to be exerted via a conformational transition poising the enzyme towards proficient catalysis.

  13. High-Resolution Infrared Spectroscopy of Imidazole Clusters in Helium Droplets Using Quantum Cascade Lasers

    Science.gov (United States)

    Mani, Devendra; Can, Cihad; Pal, Nitish; Schwaab, Gerhard; Havenith, Martina

    2017-06-01

    Imidazole ring is a part of many biologically important molecules and drugs. Imidazole monomer, dimer and its complexes with water have earlier been studied using infrared spectroscopy in helium droplets^{1,2} and molecular beams^{3}. These studies were focussed on the N-H and O-H stretch regions, covering the spectral region of 3200-3800 \\wn. We have extended the studies on imidazole clusters into the ring vibration region. The imidazole clusters were isolated in helium droplets and were probed using a combination of infrared spectroscopy and mass spectrometry. The spectra in the region of 1000-1100 \\wn and 1300-1460 \\wn were recorded using quantum cascade lasers. Some of the observed bands could be assigned to imidazole monomer and higher order imidazole clusters, using pickup curve analysis and ab initio calculations. Work is still in progress. The results will be discussed in detail in the talk. References: 1) M.Y. Choi and R.E. Miller, J. Phys. Chem. A, 110, 9344 (2006). 2) M.Y. Choi and R.E. Miller, Chem. Phys. Lett., 477, 276 (2009). 3) J. Zischang, J. J. Lee and M. Suhm, J. Chem. Phys., 135, 061102 (2011). Note: This work was supported by the Cluster of Excellence RESOLV (Ruhr-Universitat EXC1069) funded by the Deutsche Forschungsgemeinschaft.

  14. Homology modeling and virtual screening to discover potent inhibitors targeting the imidazole glycerophosphate dehydratase protein in Staphylococcus xylosus

    Science.gov (United States)

    Chen, Xing-Ru; Wang, Xiao-Ting; Hao, Mei-Qi; Zhou, Yong-Hui; Cui, Wen-Qiang; Xing, Xiao-Xu; Xu, Chang-Geng; Bai, Jing-Wen; Li, Yan-Hua

    2017-11-01

    The imidazole glycerophosphate dehydratase (IGPD) protein is a therapeutic target for herbicide discovery. It is also regarded as a possible target in Staphylococcus xylosus (S. xylosus) for solving mastitis in the dairy cow. The 3D structure of IGPD protein is essential for discovering novel inhibitors during high-throughput virtual screening. However, to date, the 3D structure of IGPD protein of S. xylosus has not been solved. In this study, a series of computational techniques including homology modeling, Ramachandran Plots, and Verify 3D were performed in order to construct an appropriate 3D model of IGPD protein of S. xylosus. Nine hits were identified from 2500 compounds by docking studies. Then, these 9 compounds were first tested in vitro in S. xylosus biofilm formation using crystal violet staining. One of the potential compounds, baicalin was shown to significantly inhibit S. xylosus biofilm formation. Finally, the baicalin was further evaluated, which showed better inhibition of biofilm formation capability in S. xylosus by scanning electron microscopy. Hence, we have predicted the structure of IGPD protein of S. xylosus using computational techniques. We further discovered the IGPD protein was targeted by baicalin compound which inhibited the biofilm formation in S. xylosus. Our findings here would provide implications for the further development of novel IGPD inhibitors for the treatment of dairy mastitis.

  15. Transition-metal-free synthesis of N-(1-alkenyl)imidazoles by potassium phosphate-promoted addition reaction of alkynes to imidazoles.

    Science.gov (United States)

    Lu, Linhua; Yan, Hong; Liu, Defu; Rong, Guangwei; Mao, Jincheng

    2014-01-01

    The addition reaction of alkynes to N-heterocycles by simply heating in DMSO with potassium phosphate is reported. Good yields with high stereoselectivity could be achieved for a range of substrates. The scope is quite general for both amines and phenylacetylenes. In addition, internal alkynes and α-bromostyrene were also examined in this reaction. This process is efficient and useful for the synthesis of (Z)-N-(1-alkenyl)imidazoles and related Z products. Thus, the reaction is useful because of the importance of the imidazole scaffold. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Evolutionary convergence in the biosyntheses of the imidazole moieties of histidine and purines.

    Directory of Open Access Journals (Sweden)

    Alberto Vázquez-Salazar

    Full Text Available The imidazole group is an ubiquitous chemical motif present in several key types of biomolecules. It is a structural moiety of purines, and plays a central role in biological catalysis as part of the side-chain of histidine, the amino acid most frequently found in the catalytic site of enzymes. Histidine biosynthesis starts with both ATP and the pentose phosphoribosyl pyrophosphate (PRPP, which is also the precursor for the de novo synthesis of purines. These two anabolic pathways are also connected by the imidazole intermediate 5-aminoimidazole-4-carboxamide ribotide (AICAR, which is synthesized in both routes but used only in purine biosynthesis. Rather surprisingly, the imidazole moieties of histidine and purines are synthesized by different, non-homologous enzymes. As discussed here, this phenomenon can be understood as a case of functional molecular convergence.In this work, we analyze these polyphyletic processes and argue that the independent origin of the corresponding enzymes is best explained by the differences in the function of each of the molecules to which the imidazole moiety is attached. Since the imidazole present in histidine is a catalytic moiety, its chemical arrangement allows it to act as an acid or a base. On the contrary, the de novo biosynthesis of purines starts with an activated ribose and all the successive intermediates are ribotides, with the key β-glycosidic bondage joining the ribose and the imidazole moiety. This prevents purine ribonucleotides to exhibit any imidazole-dependent catalytic activity, and may have been the critical trait for the evolution of two separate imidazole-synthesizing-enzymes. We also suggest that, in evolutionary terms, the biosynthesis of purines predated that of histidine.As reviewed here, other biosynthetic routes for imidazole molecules are also found in extant metabolism, including the autocatalytic cyclization that occurs during the formation of creatinine from creatine phosphate

  17. Study of the improvement of the radioprotective power of imidazole; Etude de l'amelioration du pouvoir radioprotecteur de l'imidazole

    Energy Technology Data Exchange (ETDEWEB)

    Mourret, A; Rinaldi, R [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    In studies made on the Imidazole radioprotective power, the authors have attempted to neutralize its convulsive properties by the Depamide so as to decrease drug toxicity. Then, having studied in what manner the two products simultaneous action could carry one increase of radioprotective activity, they have established that if the Depamide permits to decrease very much the Imidazole toxicity, the variation of radioprotection power which is subject to animal sex, generally increases for females and decreases for males. (authors) [French] Dans le cadre de l'etude du pouvoir radioprotecteur de l'Imidazole, les auteurs ont essaye de neutraliser les proprietes convulsivantes de cette substance par le Depamide afin d'en dimunuer la toxicite. Ayant ensuite etudie dans quelle mesure l'action simultanee de ces deux produits pouvait apporter une amelioration de l'activite radioprotectrice, ils ont constate que si le Depamide permet de diminuer tres sensiblement la toxicite de l'Imidazole, la variation du pouvoir radioprotecteur, qui depend du sexe de l'animal, augmente en general pour les femelles et diminue pour les males. (auteurs)

  18. Unexpected Molecular Sieving Properties of Zeolitic Imidazolate Framework-8

    KAUST Repository

    Zhang, Chen

    2012-08-16

    We studied molecular sieving properties of zeolitic imidazolate framework-8 (ZIF-8) by estimating the thermodynamically corrected diffusivities of probe molecules at 35 °C. From helium (2.6 Å) to iso-C 4H 10 (5.0 Å), the corrected diffusivity drops 14 orders of magnitude. Our results further suggest that the effective aperture size of ZIF-8 for molecular sieving is in the range of 4.0 to 4.2 Å, which is significantly larger than the XRD-derived value (3.4 Å) and between the well-known aperture size of zeolite 4A (3.8 Å) and 5A (4.3 Å). Interestingly, because of aperture flexibility, the studied C 4 hydrocarbon molecules that are larger than this effective aperture size still adsorb in the micropores of ZIF-8 with kinetic selectivities for iso-C 4H 8/iso-C 4H 10 of 180 and n-C 4H 10/iso-C 4H 10 of 2.5 × 10 6. These unexpected molecular sieving properties open up new opportunities for ZIF materials for separations that cannot be economically achieved by traditional microporous adsorbents such as synthetic zeolites. © 2012 American Chemical Society.

  19. Unexpected Molecular Sieving Properties of Zeolitic Imidazolate Framework-8

    KAUST Repository

    Zhang, Chen; Lively, Ryan P.; Zhang, Ke; Johnson, Justin R.; Karvan, Oguz; Koros, William J.

    2012-01-01

    We studied molecular sieving properties of zeolitic imidazolate framework-8 (ZIF-8) by estimating the thermodynamically corrected diffusivities of probe molecules at 35 °C. From helium (2.6 Å) to iso-C 4H 10 (5.0 Å), the corrected diffusivity drops 14 orders of magnitude. Our results further suggest that the effective aperture size of ZIF-8 for molecular sieving is in the range of 4.0 to 4.2 Å, which is significantly larger than the XRD-derived value (3.4 Å) and between the well-known aperture size of zeolite 4A (3.8 Å) and 5A (4.3 Å). Interestingly, because of aperture flexibility, the studied C 4 hydrocarbon molecules that are larger than this effective aperture size still adsorb in the micropores of ZIF-8 with kinetic selectivities for iso-C 4H 8/iso-C 4H 10 of 180 and n-C 4H 10/iso-C 4H 10 of 2.5 × 10 6. These unexpected molecular sieving properties open up new opportunities for ZIF materials for separations that cannot be economically achieved by traditional microporous adsorbents such as synthetic zeolites. © 2012 American Chemical Society.

  20. Biological applications of zinc imidazole framework through protein encapsulation

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    2015-12-01

    Full Text Available Abstract The robustness of biomolecules is always a significant challenge in the application of biostorage in biotechnology or pharmaceutical research. To learn more about biostorage in porous materials, we investigated the feasibility of using zeolite imidazolate framework (ZIF-8 with respect to protein encapsulation. Here, bovine serum albumin (BSA was selected as a model protein for encapsulation with the synthesis of ZIF-8 using water as a media. ZIF-8 exhibited excellent protein adsorption capacity through successive adsorption of free BSA with the formation of hollow crystals. The loading of protein in ZIF-8 crystals is affected by the molecular weight due to diffusion-limited permeation inside the crystals and also by the affinity of the protein to the pendent group on the ZIF-8 surface. The polar nature of BSA not only supported adsorption on the solid surface, but also enhanced the affinity of crystal spheres through weak coordination interactions with the ZIF-8 framework. The novel approach tested in this study was therefore successful in achieving protein encapsulation with porous, biocompatible, and decomposable microcrystalline ZIF-8. The presence of both BSA and FITC–BSA in ZIF-8 was confirmed consistently by spectroscopy as well as optical and electron microscopy.

  1. Zeolitic imidazolate framework-8 for selective extraction of a highly active anti-oxidant flavonoid from Caragana Jubata.

    Science.gov (United States)

    Cui, Yuan-Yuan; Yang, Cheng-Xiong; Yang, Xue-Dong; Yan, Xiu-Ping

    2018-04-06

    The medicinal compositions or active components in medicinal plants are the major sources to find new drugs or lead compounds. Exploring novel sorbents with good selectivity for extraction and separation of medicinal compositions or active components from complex medicinal plants are interesting and challenging. Metal-organic frameworks (MOFs) show great potential in adsorption and extraction recently. Herein, we report our primary attempt of zeolitic imidazolate framework-8 (ZIF-8) as a model MOF for selective extraction of a flavonoid named 3,4-dihydroxy-8,9-methylenedioxypterocarpan (compound 1) from a traditional medicinal plant Caragana Jubata. The enrichment factor of ZIF-8 for compound 1 is 57.7. The recoveries of compound 1 at three spiked levels (50, 100, 150 mg L -1 ) in Caragana Jubata dichloromethane extract are 62.1%, 66.4%, and 75.4%, respectively, with the relative standard deviations of less than 2.9%. The compound 1 also gave good linearity (R 2 of 0.999) in the concentration range of 5-1000 mg L -1 . The obtained compound 1 gave highly antioxidant activity (DPPH radical scavenging rate of 79.03%, inhibitory rate on lipid peroxidation of 75.30%, which were higher than the positive controls Vitamin C and BHT) and low IC 50 values (5.438 ± 0.068, 20.970 ± 0.083 μg mL -1 for DPPH radical scavenging activities and inhibitory effects on lipid peroxidation, respectively). These results demonstrated the feasibility of MOFs in selective extraction of medicinal compositions or active components from complex medicinal plants. The current work may open a new way of MOFs in selective extraction of pharmacological active components from medicinal plants. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. First catalytic hetero-Diels-Alder reaction of imidazole-2-thiones and in silico biological evaluation of the cycloadducts

    NARCIS (Netherlands)

    Eleftheriadis, Nikolaos; Samatidou, Evanthia; Neochoritis, Constantinos G.

    The Lewis acid-catalyzed Diels-Alder reactions of suitably substituted imidazole-2-thiones with dienes were studied. It was found that the electron density of the imidazole core influenced the reaction, since electron withdrawing groups led to the novel spiro-derivatives 2 whereas electron donating

  3. Absorption tuning of the green fluorescent protein chromophore: synthesis and studies of model compounds

    DEFF Research Database (Denmark)

    Brøndsted Nielsen, Mogens; Andersen, Lars Henrik; Rinza, Tomás Rocha

    2011-01-01

    The green fluorescent protein (GFP) chromophore is a heterocyclic compound containing a p-hydroxybenzylidine attached to an imidazol-5(4H)-one ring. This review covers the synthesis of a variety of model systems for elucidating the intrinsic optical properties of the chromophore in the gas phase ...

  4. Comparative study between phenol and imidazole derivatives in radiolabeling of some steroid hormones

    International Nuclear Information System (INIS)

    Sallam, Kh.M.

    2010-01-01

    A phenol or imidazole ring is rarely present in steroid hormones, So, the molecule of steroid hormone requires chemical modification by addition of an iodinable residue like phenol or imedazole. So that the comparative study between phenol derivatives, include tyrosine methyl ester (TME) and tyramine, and imidazole derivatives, like histamine and histedine methyl ester (HME), for radiolabeling of some steroid hormones include estradiol and testosterone is the aim of the present study. The conjugation step was carried using mixed anhydride method and followed by radioiodination using iodogen as an oxidizing agent. Purification step was carried out using high performance liquid chromatography (HPLC). Optimization and validation of the tracer were carried out. Immunoreactivity of the all obtained tracers was check by using specific polyclonal antibodies. The results indicated that imidazols derivatives are more suitable from immunoreactivity view and storage period.

  5. 15N Hyperpolarization of Imidazole-15N2 for Magnetic Resonance pH Sensing via SABRE-SHEATH.

    Science.gov (United States)

    Shchepin, Roman V; Barskiy, Danila A; Coffey, Aaron M; Theis, Thomas; Shi, Fan; Warren, Warren S; Goodson, Boyd M; Chekmenev, Eduard Y

    2016-06-24

    15 N nuclear spins of imidazole- 15 N 2 were hyperpolarized using NMR signal amplification by reversible exchange in shield enables alignment transfer to heteronuclei (SABRE-SHEATH). A 15 N NMR signal enhancement of ∼2000-fold at 9.4 T is reported using parahydrogen gas (∼50% para-) and ∼0.1 M imidazole- 15 N 2 in methanol:aqueous buffer (∼1:1). Proton binding to a 15 N site of imidazole occurs at physiological pH (p K a ∼ 7.0), and the binding event changes the 15 N isotropic chemical shift by ∼30 ppm. These properties are ideal for in vivo pH sensing. Additionally, imidazoles have low toxicity and are readily incorporated into a wide range of biomolecules. 15 N-Imidazole SABRE-SHEATH hyperpolarization potentially enables pH sensing on scales ranging from peptide and protein molecules to living organisms.

  6. Structural insight into activity enhancement and inhibition of H64A carbonic anhydrase II by imidazoles

    Directory of Open Access Journals (Sweden)

    Mayank Aggarwal

    2014-03-01

    Full Text Available Human carbonic anhydrases (CAs are zinc metalloenzymes that catalyze the hydration and dehydration of CO2 and HCO3−, respectively. The reaction follows a ping-pong mechanism, in which the rate-limiting step is the transfer of a proton from the zinc-bound solvent (OH−/H2O in/out of the active site via His64, which is widely believed to be the proton-shuttling residue. The decreased catalytic activity (∼20-fold lower with respect to the wild type of a variant of CA II in which His64 is replaced with Ala (H64A CA II can be enhanced by exogenous proton donors/acceptors, usually derivatives of imidazoles and pyridines, to almost the wild-type level. X-ray crystal structures of H64A CA II in complex with four imidazole derivatives (imidazole, 1-methylimidazole, 2-methylimidazole and 4-methylimidazole have been determined and reveal multiple binding sites. Two of these imidazole binding sites have been identified that mimic the positions of the `in' and `out' rotamers of His64 in wild-type CA II, while another directly inhibits catalysis by displacing the zinc-bound solvent. The data presented here not only corroborate the importance of the imidazole side chain of His64 in proton transfer during CA catalysis, but also provide a complete structural understanding of the mechanism by which imidazoles enhance (and inhibit when used at higher concentrations the activity of H64A CA II.

  7. CONVERSION OF VERNONIA GALAMENSIS OIL TO PYRIDINYL ...

    African Journals Online (AJOL)

    a

    Incorporation of vernonia oil in the production of high solid coatings would lead to reduction in ... Applications includes its transformation to fatty amides, which are important chemical ... temperatures of 50-60 °C. These reaction temperatures are approximately 100 °C lower than the ... The anti-microbial properties of these.

  8. Spectroscopic study of 2-, 4- and 5-substituents on p Ka values of imidazole heterocycles prone to intramolecular proton-electrons transfer

    Science.gov (United States)

    Eseola, Abiodun O.; Obi-Egbedi, Nelson O.

    2010-02-01

    New 2-(1H-imidazol-2-yl)phenols ( L1Et- L8tBuPt) bearing a phenolic proton in the vicinity of the imidazole base were prepared and characterized. Experimental studies of the dependence of their protonation/deprotonation equilibrium on substituent identities and intramolecular hydrogen bonding tendencies were carried out using electronic absorption spectroscopy at varying pH values. In order to make comparison, 2-(anthracen-10-yl)-4,5-diphenyl-1H-imidazole ( L9Anthr) bearing no phenolic proton and 4,5-diphenyl-2-(4,5-diphenyl-1H-imidazol-2-yl)-1H-imidazole ( L10BisIm) bearing two symmetrical imidazole base fragments were also prepared and experimentally investigated. DFT calculations were carried out to study frontier orbitals of the investigated molecules. While electron-releasing substituents produced increase in protonation-deprotonation p Kas for the hydroxyl group, values for the imidazole base were mainly affected by polarization of the imidazole ring aromaticity across the 2-imidazole carbon and the 4,5-imidazole carbons axis of the imidazole ring. It was concluded that electron-releasing substituents on the phenol ring and/or electron-withdrawing substituents on 4,5-imidazole carbons negatively affects donor strengths/coordination chemistries of 2-(1H-imidazol-2-yl)phenols, and vice versa. Change of substituents on the phenol ring significantly altered the donor strength of the imidazole base. The understanding of p Ka variation on account of electronic effects of substituents in this work should aid the understanding of biochemical properties and substituent environments of imidazole-containing biomacromolecules.

  9. Crystal structure of tetraaqua[2-(pyridin-2-yl-1H-imidazole-κ2N2,N3]iron(II sulfate

    Directory of Open Access Journals (Sweden)

    Zouaoui Setifi

    2015-04-01

    Full Text Available In the title compound, [Fe(C8H7N3(H2O4]SO4, the central FeII ion is octahedrally coordinated by two N atoms from the bidentate 2-(pyridin-2-yl-1H-imidazole ligand and by four O atoms of the aqua ligands. The largest deviation from the ideal octahedral geometry is reflected by the small N—Fe—N bite angle of 76.0 (1°. The Fe—N coordination bonds have markedly different lengths [2.1361 (17 and 2.243 (2 Å], with the shorter one to the pyrimidine N atom. The four Fe—O coordination bond lengths vary from 2.1191 (18 to 2.1340 (17 Å. In the crystal, the cations and anions are arranged by means of medium-strength O—H...O hydrogen bonds into layers parallel to the ab plane. Neighbouring layers further interconnect by N—H...O hydrogen bonds involving the imidazole fragment as donor group to one sulfate O atom as an acceptor. The resulting three-dimensional network is consolidated by C—H...O, C—H...π and π–π interactions.

  10. Syntheses and structures of three supramolecular complexes based on 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid

    Science.gov (United States)

    Yu, Xiao-Yang; Zhang, Xiao; Liu, Zhi-Gang; Cui, Xiao-Bing; Xu, Jia-Ning; Luo, Yu-Hui

    2017-11-01

    Three new supramolecular compounds, [Cu(o-HPIDC)(bpy)(H2O)]·2H2O 1, [Cu(o-H2PIDC)(phen)Cl]·[Cu(phen)2Cl]·10H2O·Cl 2 and {[Cd(o-H2PIDC)(H2O)2Cl]·H2O}23 (o-H3PIDC = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline), were hydrothermally synthesized and characterized. In compound 1, the adjacent two supramolecular layers are constructed from different types of helical chains with the same pitch. In compound 2, the adjacent 2D water-chloride layers, {[(H2O)10Cl]-}n, are pillared by [Cu(o-H2PIDC)(phen)Cl] units to form the overall 3D supramolecular network with 1D channels through Osbnd H⋯O hydrogen bond interactions. In compound 3, two Cd(II) are linked into a binuclear [Cd2(o-H2PIDC)2(H2O)4Cl2] with a ten-membered ring by two o-H2PIDC- ligands. The three compounds self-assemble into 3D supramolecular structures via hydrogen bond and π-π stacking interactions. The fluorescence properties of compound 3 was also investigated.

  11. Efficient library synthesis of imidazoles using a multicomponent reaction and microwave irradiation

    NARCIS (Netherlands)

    Gelens, E.; De Kanter, F.J.J.; Schmitz, R.F.; Sliedregt, L.A.; Van Steen, B.J.; Kruse, C.G.; Leurs, R.; Groen, M.B.; Orru, R.V.A.

    2006-01-01

    Optimization of Radziszewski's four-component reaction employing a microwave-assisted protocol, led to a small library of 48 imidazoles with a success rate of 65% (conversion >45%). All three diversity points of the four-component reaction were varied. Aromatic and aliphatic inputs were successfully

  12. Tannic acid Catalyzed an Efficient Synthesis of 2,4,5-Triaryl-1H-Imidazole

    Directory of Open Access Journals (Sweden)

    Shitole Nana Vikram

    2013-05-01

    Full Text Available Tannic acid (C76H52O46 has been found to be an efficient catalyst for one-pot synthesis of 2,4,5-triaryl substituted imidazoles by the reaction of an arylaldehyde, benzyl/benzoin and an ammonium acetate. The short reaction time and excellent yields making this protocol practical and economically attractive.

  13. Synthesis and properties of imidazole-grafted hybrid inorganic-organic polymer membranes

    International Nuclear Information System (INIS)

    Li Siwen; Zhou Zhen; Liu Meilin; Li Wen; Ukai, Junzo; Hase, Kohei; Nakanishi, Masatsugu

    2006-01-01

    Imidazole rings were grafted on alkoxysilane with a simple nucleophilic substitute reaction to form hybrid inorganic-organic polymers with imidazole rings. Proton exchange membranes (PEM) based on these hybrid inorganic-organic polymers and H 3 PO 4 exhibit high proton conductivity and high thermal stability in an atmosphere of low relative humidity. The grafted imidazole rings improved the proton conductivity of the membranes in the high temperature range. It is found that the proton conductivities increase with H 3 PO 4 content and temperature, reaching 3.2 x 10 -3 S/cm at 110 deg. C in a dry atmosphere for a membrane with 1 mole of imidazole ring and 7 moles of H 3 PO 4 . The proton conductivity increases with relative humidity (RH) as well, reaching 4.3 x 10 -2 S/cm at 110 deg. C when the RH is increased to about 20%. Thermogravimetric analysis (TGA) indicates that these membranes are thermally stable up to 250 deg. C in dry air, implying that they have a good potential to be used as the membranes for high-temperature PEM fuel cells

  14. Changes in the hydration structure of imidazole upon protonation: Neutron scattering and molecular simulations

    Czech Academy of Sciences Publication Activity Database

    Duboué-Dijon, Elise; Mason, Philip E.; Fischer, H. E.; Jungwirth, Pavel

    2017-01-01

    Roč. 146, č. 18 (2017), č. článku 185102. ISSN 0021-9606 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388963 Keywords : imidazole protonation * molecular dynamics * neutron scattering Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.965, year: 2016

  15. Controlled synthesis of phase-pure zeolitic imidazolate framework Co-ZIF-9

    NARCIS (Netherlands)

    Öztürk, Z.; Hofmann, J.P.; Lutz, M.; Mazaj, M.; Zabukovec Logar, N.; Weckhuysen, B.M.

    2015-01-01

    The synthesis of phase-pure Co-ZIF-9, an important cobalt-based zeolitic imidazolate framework, could be achieved by modification of the reported synthesis procedure through pH adjustment of the starting synthesis mixture. The phase-pure Co-ZIF-9 material obtained has been characterized by a

  16. Metal-containing Complexes of Lactams, Imidazoles, and Benzimidazoles and Their Biological Activity

    Science.gov (United States)

    Kukalenko, S. S.; Bovykin, B. A.; Shestakova, S. I.; Omel'chenko, A. M.

    1985-07-01

    The results of the latest investigations of the problem of the synthesis of metal-containing complexes of lactams, imidazoles, and benzimidazoles, their structure, and their stability in solutions are surveyed. Some data on their biological activity (pesticide and pharmacological) and the mechanism of their physiological action are presented. The bibliography includes 190 references.

  17. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin; Xue, Ming; Song, Qingshan; Chen, Siru; Pan, Ying; Qiu, Shilun

    2014-01-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, b

  18. Topoisomerase II poisoning by indazole and imidazole complexes ...

    Indian Academy of Sciences (India)

    Unknown

    These molecules constitute two of the few most effective anticancer ruthenium compounds. ... however was hindered due to toxic side effects on the human body. Our ... cells. The catalytic cycle of topoisomerase II (topo II) typically involves ...

  19. Recognition/removal of phloretic acid on molecularly imprinted poly(n-vinyl imidazole) based polymers grafted onto nonwoven fabrics

    International Nuclear Information System (INIS)

    Ranada, Ma. Llorina; Abad, Lucille; Akbulut, Meshude; Guven, Olgun

    2013-01-01

    Molecular imprinting is the process of developing polymeric matrices for recognizing a target molecule in the presence of chemically similar structures. These matrices can be tailored using one or more functional monomers with a cross linker in the presence of a molecule behaving as the template. Phloretic acid is one of the members of dietary phenolic group which may have physiological antioxidant properties, potentially modifying pathological mechanisms relevant to some health problems such as cardiovascular diseases and cancer. The content of these compounds is generally very low in plants to be detected by traditional instruments. Thus, the development of an easy, cheap and reliable method is an important issue. In this study, a solution of n-vinyl imidazole was grafted onto polypropylene/polyethylene (PP/PE) films through gamma irradiation to create a film-based polymer matrix for phloretic acid. These films are assessed in terms of structural and binding capacity. The maximum free-volume ratio was obtained at 5 kGy using positron annihilation lifetime spectroscopy (PALS). The imprinting capacity of the matrix system is 2.41 between the molecularly-imprinted and the non-imprinted films. Scanning electron microscopy and Fourier-Transform Infrared Spectroscopy complemented the PALS data in elucidating the structure of the grafted films. (author)

  20. Aqua[bis(2-ethyl-5-methyl-1H-imidazol-4-yl-κN3methane]oxalatocopper(II dihydrate

    Directory of Open Access Journals (Sweden)

    Yang-Hui Luo

    2011-02-01

    Full Text Available In the title compound, [Cu(C2O4(C13H20N4(H2O]·2H2O, the CuII atom exhibits a distorted square-pyramidal geometry with the two N atoms of the imidazole ligand and the two O atoms of the oxalate ligand forming the basal plane, while the O atom of the coordinated water molecule is in an apical position. The CuII atom is shifted 0.232 (2 Å out of the basal plane toward the water molecule. The asymmetric unit is completed by two solvent water molecules. These water molecules participate in the formation of an intricate three-dimensionnal network of hydrogen bonds involving the coordinated water molecule and the NH groups.

  1. N-{4-[4-(4-Fluorophenyl-1-(2-methoxyethyl-2-methylsulfanyl-1H-imidazol-5-yl]-2-pyridyl}-2-methyl-3-phenylpropionamide

    Directory of Open Access Journals (Sweden)

    Stefan Laufer

    2009-12-01

    Full Text Available In the crystal structure of the title compound, C28H29FN4O2S, the imidazole ring makes dihedral angles of 11.85 (7, 73.33 (7 and 22.83 (8° with the 4-fluorophenyl, pyridine and phenyl rings, respectively. The 4-fluorophenyl ring makes dihedral angles of 77.91 (7 and 26.93 (8° with the pyridine and phenyl rings, respectively. The phenyl and pyridine rings are nearly perpendicular, making a dihedral angle of 86.47 (9°. The crystal packing shows an intermolecular N—H...O hydrogen-bonding interaction between the N—H and carbonyl groups of the amide functions.

  2. A series of novel metal–organic coordination polymers constructed from the new 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole spacer and aromatic carboxylates: Synthesis, crystal structures, and luminescence properties

    International Nuclear Information System (INIS)

    Sun, Jiayin; Zhang, Daojun; Wang, Li; Zhang, Renchun; Wang, Junjie; Zeng, Ying; Zhan, Jinling; Xu, Jianing; Fan, Yong

    2013-01-01

    Using bifunctional organic ligand 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole (HL) and different aromatic carboxylates as secondary ligands, four novel metal-organic coordination polymers, [Zn(L)(1,4-bdc) 0.5 ] (1), [Zn 1.5 (L)(2,5-pydc)] (2), [Zn(HL)(1,2,4,5-btec) 0.5 ] (3), and [Cd(HL)(1,2,4,5-btec) 0.5 ] (4) (1,4-bdc, 1,4-benzenedicarboxylate; 2,5-pydc, 2,5-pyridinedicarboxylate; 1,2,4,5-btec, 1,2,4,5-benzenetetracarboxylate) have been successfully synthesized and analyzed. Compound 1 features the 2D [Zn(L)] n layers built by μ 3 -L bridging ligands and Zn(II) ions, which are further linked by pillared 1,4-bdc 2− ligands to form a 2-fold interpenetrating dmc framework. The 3D network of compound 2 can be simplified as a rare 2-nodal (3,6)-connected rtl (rutile) topology. Compound 3 possesses a 2D layer structure which is accomplished by connecting ladder-chains to L ligands. Compound 4 exhibits 2D [Cd(1,2,4,5-btec)] layers with infinite Cd–O–Cd rods and the adjacent 2D networks are further pillared by L with terminal bidentate coordination mode to generate the final 3D structure. The solid-state luminescent studies show that compounds 1–4 display intense fluorescent emissions. - Graphical abstract: Using bifunctional organic ligand 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole (HL) and different aromatic carboxylates as secondary ligands, four novel metal-organic coordination polymers have been obtained. All compounds show good luminescence properties at room temperature. Display Omitted - Highlights: • Four Zn(II)/Cd(II)-MOCPs have been successfully prepared with the rigid bifunctional ligand 5-(4-imidazol -1-yl-phenyl) -2H-tetrazole and different aromatic carboxylates mixed ligands. • Compound 2 is a 2-nodal rtl (rutile) net and compound 4 is a binodal (5, 6)-connected net with yav topology. • Compounds 1-4 display intense fluorescent emissions at room temperature

  3. Discovery of α-Substituted Imidazole-4-acetic Acid Analogues as a Novel Class of ρ1 γ-Aminobutyric Acid Type A Receptor Antagonists with Effect on Retinal Vascular Tone

    DEFF Research Database (Denmark)

    Krall, Jacob; Brygger, Benjamin M.; Sigurðardóttir, Sara B.

    2016-01-01

    The ρ-containing γ-aminobutyric acid type A receptors (GABAA Rs) play an important role in controlling visual signaling. Therefore, ligands that selectively target these GABAA Rs are of interest. In this study, we demonstrate that the partial GABAA R agonist imidazole-4-acetic acid (IAA) is able...... to penetrate the blood-brain barrier in vivo; we prepared a series of α- and N-alkylated, as well as bicyclic analogues of IAA to explore the structure-activity relationship of this scaffold focusing on the acetic acid side chain of IAA. The compounds were prepared via IAA from l-histidine by an efficient...

  4. Synthesis of 1-(2,3-dihydroxypropyl)-2-nitro-1H-imidazole-2-14C and N-(2-hydroxyethyl)-2-(2-nitro-1H-imidazol-1-YL-2-14C)acetamide

    International Nuclear Information System (INIS)

    Fong, M.T.; Leaffer, M.A.

    1986-01-01

    We have prepared the 14 C-labeled analogs of NSC 261036, 1-(2,3-dihydroxypropyl)-2-nitro-1H-imidazole-2- 14 C, and NSC 301467, N-(2-hydroxyethyl)-2-(2-nitro-1H-imidazol-1-yl-2- 14 C) acetamide, for pharmacological, drug distribution, and mechanisms of action studies. The latter is an analog designed for lower toxicity and improved properties. The former is a metabolite of, and appears to be less toxic than, misonidazole. (author)

  5. On the radioprotective properties of heterocyclic nitrogenous compounds

    International Nuclear Information System (INIS)

    Rinaldi, R.; Bernard, Y.

    1964-01-01

    Continuing their study of the possible radioprotective properties of heterocyclic nitrogenous compounds, the authors study certain derivatives of imidazole and other compounds of similar structure. The results obtained showed: 1 - that the derivatives resulting from the presence in the imidazole ring of the mercapto, methyl, carbonyl, or benzyl groups are inactive: these substitutions appear to destroy the significant radioprotective activity of the imidazole, 2 - that benzimidazole, on the contrary, seems to possess highly interesting properties. The percentage of survivals obtained with mice treated with benzimidazole and exposed to lethal irradiation has encouraged the authors to undertake careful study of this substance, with a view to define optimum activity conditions, and to determine the mechanism responsible for its radioprotective action. Further on and so as to of clarify certain points that might give useful data concerning the mechanisms of action of radioprotective chemicals, in respect of each of the products the authors have studied: a - the action of these bodies on the internal temperature of mice, b - their radioprotective activity in vitro, in a solution of irradiated hemin. (authors) [fr

  6. Mixed-linker zeolitic imidazolate framework mixed-matrix membranes for aggressive CO2 separation from natural gas

    KAUST Repository

    Thompson, Joshua A.; Vaughn, Justin T.; Brunelli, Nicholas A.; Koros, William J.; Jones, Christopher W.; Nair, Sankar

    2014-01-01

    Zeolitic imidazolate framework (ZIF) materials are a promising subclass of metal-organic frameworks (MOF) for gas separations. However, due to the deleterious effects of gate-opening phenomena associated with organic linker rotation near

  7. Synthesis and characterization of new chiral ketopinic acid-derived catalysts immobilized on polystyrene-bound imidazole

    Directory of Open Access Journals (Sweden)

    Hassan Yusuf

    2017-02-01

    Full Text Available Four new chiral ketopinic acid-derived catalysts were anchored on a polystyrene-bound imidazole via non-covalent bond. The resulting heterogeneous catalysts were successfully characterized using IR, SEM, and TGA analyses.

  8. High-performance polyamide thin-film-nanocomposite reverse osmosis membranes containing hydrophobic zeolitic imidazolate framework-8

    KAUST Repository

    Duan, Jintang; Pan, Yichang; Pacheco Oreamuno, Federico; Litwiller, Eric; Lai, Zhiping; Pinnau, Ingo

    2015-01-01

    A hydrophobic, hydrothermally stable metal-organic framework (MOF) - zeolitic imidazolate framework-8 (ZIF-8) was successfully incorporated into the selective polyamide (PA) layer of thin-film nanocomposite (TFN) membranes for water desalination

  9. Phase transition behavior of novel pH-sensitive polyaspartamide derivatives grafted with 1-(3-aminopropyl)imidazole.

    Science.gov (United States)

    Seo, Kwangwon; Kim, Dukjoon

    2006-09-15

    New pH-sensitive polyaspartamide derivatives were synthesized by grafting 1-(3-aminopropyl)imidazole and/or O-(2-aminoethyl)-O'-methylpoly(ethylene glycol) 5000 on polysuccinimide for application in intracellular drug delivery systems. The DS of 1-(3-aminopropyl)imidazole was adjusted by the feed molar ratio, and the structure of the prepared polymer was confirmed using FT-IR and 1H NMR spectroscopy. Their pH-sensitive properties were characterized by light transmittance measurements, and the particle size and its distribution were investigated by dynamic light scattering measurements at varying pH values. The pH-sensitive phase transition was clearly observed in polymer solutions with a high substitution of 1-(3-aminopropyl)imidazole. The prepared polymers showed a high buffering capacity between pH 5 and 7, and this increased with the DS of 1-(3-aminopropyl)imidazole. The pH dependence of the aggregation and de-aggregation behavior was examined using a fluorescence spectrometer. For MPEG/imidazole-g-polyaspartamides with a DS of 1-(3-aminopropyl)imidazole over 82%, self aggregates associated with the hydrophobic interactions of the unprotonated imidazole groups were observed at pH values above 7, and their mean size was over 200 nm, while the aggregates of polymers were dissociated at pH values below 7 by the protonation of imidazole groups. These pH-sensitive polyaspartamide derivatives are potential basic candidates for intracellular drug delivery carriers triggered by small pH changes.

  10. New copper (II)-imidazole derivative effectively inhibits replication of ...

    African Journals Online (AJOL)

    Background: Dengue is a kind of infectious disease that was distributed in the tropical and sub-tropical areas. To date, there is no clinically approved dengue vaccine or antiviral for humans, even though there have been great efforts towards this end. Therefore, finding the effective compound against dengue virus (DENV) ...

  11. Investigation of cobalt porphyrin doped polymer membrane films for the optical sensing of imidazole and its derivatives

    Directory of Open Access Journals (Sweden)

    Yueyang Tan

    2015-03-01

    Full Text Available A cobalt(II porphyrin was successfully incorporated into polymer membranes for the optical sensing of imidazole and its derivatives. This research has led to a better understanding of the behavior of Co(II porphyrin in solution and in polymeric membranes. In aprotic dichloromethane (DCM, the Co(II tetraphenylporphyrin (CoTPP and Co(II octaethylporphyrin (CoOEP show a sensitive response to imidazole due to the strong ligation of the N-3 on the imidazole ring to the Co(II center, which induces an absorbance change to the Soret band. However, when doped in polymeric films, only the CoTPP exhibits moderate sensitivity towards aqueous imidazole, histamine and histidine. This weakened coordination ability of CoTPP towards imidazole in the polymer films may be due to the coordination of the plasticizer, the impurities from the THF and polymer matrix at the Co(II center. The selectivity of the polymer films towards imidazole over common anions is high. Lifetime of the cobalt(II porphyrin incorporated polymer film was relatively short.

  12. synthesis and labelling of some nitrogenous heterocyclic compounds

    International Nuclear Information System (INIS)

    Mahmoud, A.A.L.

    2002-01-01

    the imidazole nucleus has wide range of pharmaceutical activities . also , radioiodinated compounds are used in nuclear medicine. this thesis deals with the synthesis of 2-(iodophenyl)-4-oxazoline-5-ons e, which are used as starting materials in the synthesis of the corresponding imidazolinone derivatives. also, it deals with radioiodination f the synthesized compounds to evaluate their application in nuclear medicine. interaction of o- iodo hippuric acid (I) with aromatic aldehydes (i.e., benzaldehyde, p- methoxybenzaldehyde and p- nitrobenzaldehyde) in acetic anhydride and in the presence of fused sodium acetate effected cyclization to afford the corresponding 2-(2-iodophenyl)-4-arylidene- 2-oxazoline-5-ones(l l a-c )

  13. Mitochondria Targeted Nanoscale Zeolitic Imidazole Framework-90 for ATP Imaging in Live Cells.

    Science.gov (United States)

    Deng, Jingjing; Wang, Kai; Wang, Ming; Yu, Ping; Mao, Lanqun

    2017-04-26

    Zeolitic imidazole frameworks (ZIFs) are an emerging class of functional porous materials with promising biomedical applications such as molecular sensing and intracellular drug delivery. We report herein the first example of using nanoscale ZIFs (i.e., ZIF-90), self-assembled from Zn 2+ and imidazole-2-carboxyaldehyde, to target subcellular mitochondria and image dynamics of mitochondrial ATP in live cells. Encapsulation of fluorescent Rhodamine B (RhB) into ZIF-90 suppresses the emission of RhB, while the competitive coordination between ATP and the metal node of ZIF-90 dissembles ZIFs, resulting in the release of RhB for ATP sensing. With this method, we are able to image mitochondrial ATP in live cells and study the ATP level fluctuation in cellular glycolysis and apoptosis processes. The strategy reported here could be further extended to tune nanoscale ZIFs inside live cells for targeted delivery of therapeutics to subcellular organelles for advanced biomedical applications.

  14. Chemical structure, network topology, and porosity effects on the mechanical properties of Zeolitic Imidazolate Frameworks

    OpenAIRE

    Tan, J. C.; Bennett, T. D.; Cheetham, A. K.

    2010-01-01

    The mechanical properties of seven zeolitic imidazolate frameworks (ZIFs) based on five unique network topologies have been systematically characterized by single-crystal nanoindentation studies. We demonstrate that the elastic properties of ZIF crystal structures are strongly correlated to the framework density and the underlying porosity. For the systems considered here, the elastic modulus was found to range from 3 to 10 GPa, whereas the hardness property lies between 300 MPa and 1.1 GPa. ...

  15. Bromidotetra?kis?(2-isopropyl-1H-imidazole-?N 3)copper(II) bromide

    OpenAIRE

    Godlewska, Sylwia; Socha, Joanna; Baranowska, Katarzyna; Do??ga, Anna

    2011-01-01

    The CuII atom in the title salt, [CuBr(C6H10N2)4]Br, is coordinated in a square-pyramidal geometry by four imidazole N atoms and one bromide anion that is located at the apex of the pyramid. The cations and the anions form a two-dimensional network parallel to (001) through N—H...Br hydrogen bonds.

  16. CNTs grown on nanoporous carbon from zeolitic imidazolate frameworks for supercapacitors.

    Science.gov (United States)

    Kim, Jeonghun; Young, Christine; Lee, Jaewoo; Park, Min-Sik; Shahabuddin, Mohammed; Yamauchi, Yusuke; Kim, Jung Ho

    2016-10-27

    Carbon nanotubes (CNT) grown on nanoporous carbon (NPC), which yields coexisting amorphous and graphitic nanoarchitectures, have been prepared on a large scale from zeolitic imidazolate framework (ZIF) by introducing bimetallic ions (Co 2+ and Zn 2+ ). Interestingly, the hybrid Co/Zn-ZIF-derived NPC showed rich graphitic CNTs on the surface. This NPC was utilized for a coin-type supercapacitor cell with an aqueous electrolyte, which showed enhanced retention at high current density and good stability over 10 000 cycles.

  17. Antibacterial activity of synthesized 2,4,5-trisubstituted imidazole derivatives

    Digital Repository Service at National Institute of Oceanography (India)

    Khan, M.S.; Siddiqui, S.A.; Siddiqui, M.S.R.A.; Goswami, U.; Srinivasan, K.V.; Khan, M.I.

    release or inhibiting the p38 MAP kinase (1), anti-allergic activity (2) and analgesic activity (3). They are also sensitizers of multidrug-resistant cancer cells (4), pesticides (5), antibiotics (6) or sodium-channel mod- ulators (7). Some imidazole... (ATCC 25922), Klebsiella pneumoniae (ATCC 13883), Pseudomonas aeruginosa (ATCC 27853) and Serratia morganii (ATCC 31665), obtained from Goa Medical college, Goa, India, grown to mid-logarithmic phase were harvested by centrifu- gation, washed with 10 m...

  18. Toward Anhydrous Proton Conductivity Based on Imidazole Functionalized Mesoporous Silica/Nafion Composite Membranes

    International Nuclear Information System (INIS)

    Amiinu, Ibrahim Saana; Li, Wei; Wang, Guangjin; Tu, Zhengkai; Tang, Haolin; Pan, Mu; Zhang, Haining

    2015-01-01

    Highlights: • Imidazole-functionalized mesoporous silica/Nafion composite is formed. • Electrostatic interaction between ionic clusters leads to enhanced molecular rigidity and T g . • Charge transfer resistance decreases with increase in temperature up to 130 °C. • The composite membrane exhibited considerable stability over 70 h at 130 °C. - Abstract: Although Nafion is regarded as the most preferred electrolyte membrane and often used as a benchmark for comparative evaluation of other electrolyte membranes, its wide spread for commercial PEM fuel cells is limited by the poor electrochemical properties at elevated temperatures and low relative humidity conditions. Herein, sol–gel synthesized mesoporous silica functionalized with a protogenic molecule (imidazole) is introduced into the Nafion matrix via a colloid mediated process. The formation of a stable colloid enables homogeneous dispersion of the silica-imidazole nanoparticles without aggregation. Under non-humidified conditions, the amphoteric and self-dissociative character of the tethered imidazole within the matrix functions as a transporting medium to facilitate proton conductivity. The structural and chemical phases are characterized, and qualitatively evaluated by XRD, TEM, FT-IR, TGA, and DMA. The results show that the average proton conductivity of the composite membrane with the optimal amount of functionalized nanoparticles increases progressively to 1.06 × 10 −2 S cm −1 at 130 °C, corresponding to an activation energy of 6.95 kJ mol −1 under non-humidified conditions. The mechanism governing the dynamics of proton conductivity and structural limitations as a function of temperature is discussed

  19. Tuning the crystal morphology and size of zeolitic imidazolate framework-8 in aqueous solution by surfactants

    KAUST Repository

    Pan, Yichang

    2011-01-01

    Herein we report a facile synthesis method using surfactant cetyltrimethylammonium bromide (CTAB) as a capping agent for controlling the crystal size and morphology of zeolitic imidazolate framework-8 (ZIF-8) crystals in aqueous systems. The particle sizes can be precisely adjusted from ca. 100 nm to 4 μm, and the morphology can be changed from truncated cubic to rhombic dodecahedron. This journal is © The Royal Society of Chemistry.

  20. Non-specific vaginitis: diagnostic features and response to imidazole therapy (metronidazole, ornidazole).

    Science.gov (United States)

    Meech, R J; Loutit, J

    1985-05-22

    Detailed quantitative aerobic, anaerobic, fungal and mycoplasma flora was obtained for 43 women presenting with complaints of vaginal discharge and malodour. Clinical response was associated with eradication of the abnormal anaerobic flora, despite persistence of G vaginalis in nine (26%). Topical imidazole therapy appeared to have some advantage over oral therapy. Gram stains of vaginal swabs were found to be the most useful laboratory investigation.

  1. γ-Alumina Nanoparticle Catalyzed Efficient Synthesis of Highly Substituted Imidazoles

    Directory of Open Access Journals (Sweden)

    Bandapalli Palakshi Reddy

    2015-10-01

    Full Text Available γ-Alumina nano particle catalyzed multi component reaction of benzil, arylaldehyde and aryl amines afforded the highly substituted 1,2,4,5-tetraaryl imidazoles with good to excellent yield in less reaction time under the sonication as well as the conventional methods. Convenient operational simplicity, mild conditions and the reusability of catalyst were the other advantages of this developed protocol.

  2. cis-Tetra­chloridobis(1H-imidazole-κN 3)platinum(IV)

    Science.gov (United States)

    Bokach, Nadezhda A.; Kukushkin, Vadim Yu.; Izotova, Yulia A.; Usenko, Natalia I.; Haukka, Matti

    2012-01-01

    In the title complex, cis-[PtCl4(C3H4N2)2], the PtIV ion lies on a twofold rotation axis and is coordinated in a slightly distorted octa­hedral geometry. The dihedral angle between the imidazole rings is 69.9 (2)°. In the crystal, mol­ecules are linked by N—H⋯Cl hydrogen bonds, forming a three-dimensional network. PMID:22590070

  3. cis-Tetrachloridobis(1H-imidazole-κN3platinum(IV

    Directory of Open Access Journals (Sweden)

    Vadim Yu. Kukushkin

    2012-05-01

    Full Text Available In the title complex, cis-[PtCl4(C3H4N22], the PtIV ion lies on a twofold rotation axis and is coordinated in a slightly distorted octahedral geometry. The dihedral angle between the imidazole rings is 69.9 (2°. In the crystal, molecules are linked by N—H...Cl hydrogen bonds, forming a three-dimensional network.

  4. Spectral, biological screening of metal chelates of chalcone based Schiff bases of N-(3-aminopropyl) imidazole.

    Science.gov (United States)

    Kalanithi, M; Rajarajan, M; Tharmaraj, P; Sheela, C D

    2012-02-15

    Tridentate chelate complexes of Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized from the chalcone based ligands 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol(HL(1)), 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-p-tolylallyl]phenol(HL(2)), 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol(HL(3)). Microanalytical data, UV-vis spectrophotometric method, magnetic susceptibility measurements, IR, 1H NMR, Mass, and EPR techniques were used to characterize the structure of chelates. The electronic absorption spectra and magnetic susceptibility measurements suggest a distorted square planar geometry for the copper(II) ion. The other metal complexes show distorted tetrahedral geometry. The coordination of the ligands with metal(II) ions was further confirmed by solution fluorescence spectrum. The antimicrobial activity of the ligands and metal(II) complexes against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger has been carried out and compared. The electrochemical behavior of copper(II) complex is studied by cyclic voltammetry. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Study of Antibacterial Effect of Novel Thiazole, Imidazole and Tetrahydropyridine Derivatives against Escherichia coli

    Directory of Open Access Journals (Sweden)

    Behzad Ghasemi

    2016-01-01

    Full Text Available > Introduction: Escherichia coli is one of the important pathogens in human with globalimportance. Because of the necessity for identification and the use of novel antibacterialcompounds against E. coli, in this present study we focused on the antibacterial effects ofsynthesized thiazole, imidazole and tetrahydropyridine derivatives on E. coli.Methods: For evaluation of antibacterial effect, the disk diffusion method was applied to measurethe growth inhibition zone diameter and broth micro-dilution was performed to determine theminimum inhibitory concentration (MIC.Results: Assessing the antibacterial effect showed that only 6d derivative of thiazole hadinhibitory effect on E. coli and the other thiazole, imidazole and tetrahydropyridine derivativeslacked any inhibitory result on this organism. The inhibitory effect of 6d derivative of thiazolewas MIC=125 and growth inhibition zone diameter of 16±0.1.Discussion: The antibacterial effect of thiazole, imidazole and tetrahydropyridine derivativesdiffers from each other and chemical linkages such as oxygen to thiazole ring in 6d derivative,could have reinforced this effect. The next step is determination of the toxicity and therapeuticeffects in the laboratory animals.

  6. Trapped in imidazole: how to accumulate multiple photoelectrons on a black-absorbing ruthenium complex.

    Science.gov (United States)

    Zedler, Linda; Kupfer, Stephan; de Moraes, Inês Rabelo; Wächtler, Maria; Beckert, Rainer; Schmitt, Michael; Popp, Jürgen; Rau, Sven; Dietzek, Benjamin

    2014-03-24

    Ruthenium dyes incorporating a 4H-imidazole chromophore as a ligand exhibit a spectrally broad absorption in the UV/Vis region. Furthermore, they show the ability to store two electrons within the 4H-imidazole ligand. These features render them promising molecular systems, for example, as inter- or intramolecular electron relays. To optimize the structures with respect to their electron-storage capability, it is crucial to understand the impact of structural changes accompanying photoinduced charge transfer in the electronic intermediates of multistep electron-transfer processes. The photophysical properties of these (reactive) intermediates might impact the function of the molecular systems quite substantially. However, the spectroscopic study of short-lived intermediates in stepwise multielectron-transfer processes is experimentally challenging. To this end, this contribution reports on the electrochemical generation of anions identical to intermediate structures and their spectroscopic characterization by in situ resonance Raman and UV/Vis spectroelectrochemistry and computational methods. Thereby, an efficient two-electron pathway to the 4H-imidazole electron-accepting ligand is identified. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Theoretical prediction of the mechanical properties of zeolitic imidazolate frameworks (ZIFs)

    KAUST Repository

    Zheng, Bin

    2017-08-25

    A good resistance against mechanical stress is essential for the utilization of metal-organic frameworks (MOFs) in practical applications such as gas sorption, separation, catalysis or energy conversion. Here, we report on the successful modification of the mechanical properties of zeolitic imidazolate frameworks (ZIFs) achieved through a substitution of the terminal group. The mechanical modulus of SALEM-2 was found to significantly improve when the -H groups at position 2 of the imidazole linkers were replaced with electron withdrawing groups (-CHO, -Cl, or -Br). The charge distribution and electron density were analyzed to reveal the mechanism behind the observed variation of the elastic stiffness. Furthermore, ZIF-I with a -I group at position 2 of the imidazole linkers was predicted to exhibit an excellent mechanical strength in our study and then prepared experimentally. The results indicate that an inconspicuous change of the structure of ZIFs, i.e., additional groups strengthening the ZnN4 tetrahedron, will lead to a stiffer framework.

  8. Theoretical prediction of the mechanical properties of zeolitic imidazolate frameworks (ZIFs)

    KAUST Repository

    Zheng, Bin; Zhu, Yihan; Fu, Fang; Wang, Lian Li; Wang, Jinlei; Du, Huiling

    2017-01-01

    A good resistance against mechanical stress is essential for the utilization of metal-organic frameworks (MOFs) in practical applications such as gas sorption, separation, catalysis or energy conversion. Here, we report on the successful modification of the mechanical properties of zeolitic imidazolate frameworks (ZIFs) achieved through a substitution of the terminal group. The mechanical modulus of SALEM-2 was found to significantly improve when the -H groups at position 2 of the imidazole linkers were replaced with electron withdrawing groups (-CHO, -Cl, or -Br). The charge distribution and electron density were analyzed to reveal the mechanism behind the observed variation of the elastic stiffness. Furthermore, ZIF-I with a -I group at position 2 of the imidazole linkers was predicted to exhibit an excellent mechanical strength in our study and then prepared experimentally. The results indicate that an inconspicuous change of the structure of ZIFs, i.e., additional groups strengthening the ZnN4 tetrahedron, will lead to a stiffer framework.

  9. Hydrogen-deuterium exchange in imidazole as a tool for studying histidine phosphorylation.

    Science.gov (United States)

    Cebo, Małgorzata; Kielmas, Martyna; Adamczyk, Justyna; Cebrat, Marek; Szewczuk, Zbigniew; Stefanowicz, Piotr

    2014-12-01

    Isotope exchange at the histidine C2 atom of imidazole in D2O solution is well known to occur at a significantly slower rate than the exchange of amide protons. Analysis of the kinetics of this isotope-exchange reaction is proposed herein as a method of detecting histidine phosphorylation. This modification of His-containing peptides is challenging to pinpoint because of its instability under acidic conditions as well as during CID-MS analysis. In this work, we investigated the effect of phosphorylation of the histidine side chain in peptides on deuterium-hydrogen exchange (DHX) in the imidazole. The results demonstrate that phosphorylation dramatically slows the rate of the DHX reaction. This phenomenon can be applied to detect phosphorylation of peptides at the histidine residue (e.g., in enzymatic digests). We also found that the influence of the peptide sequence on the exchange kinetics is relatively small. A CID fragmentation experiment revealed that there was no detectable hydrogen scrambling in peptides deuterated at C2 of the imidazole ring. Therefore, MS/MS can be used to directly identify the locations of deuterium ions incorporated into peptides containing multiple histidine moieties.

  10. Understanding reactivity of two newly synthetized imidazole derivatives by spectroscopic characterization and computational study

    Science.gov (United States)

    Hossain, Mossaraf; Thomas, Renjith; Mary, Y. Sheena; Resmi, K. S.; Armaković, Stevan; Armaković, Sanja J.; Nanda, Ashis Kumar; Vijayakumar, G.; Van Alsenoy, C.

    2018-04-01

    Two newly synthetized imidazole derivatives (1-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (MPDIA) and 1-(4-bromophenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (BPDIA)) have been prepared by solvent-free synthesis pathway and their specific spectroscopic and reactive properties have been discussed based on combined experimental and computational approaches. Aside of synthesis, experimental part of this work included measurements of IR, FT-Raman and NMR spectra. All of the aforementioned spectra were also obtained computationally, within the framework of density functional theory (DFT) approach. Additionally, DFT calculations have been used in order to investigate local reactivity properties based on molecular orbital theory, molecular electrostatic potential (MEP), average local ionization energy (ALIE), Fukui functions and bond dissociation energy (BDE). Molecular dynamics (MD) simulations have been used in order to obtain radial distribution functions (RDF), which were used for identification of the atoms with pronounced interactions with water molecules. MEP showed negative regions are mainly localized over N28, O29, O35 atoms, it is represent with red colour in rainbow color scheme for MPDIA and BPDIA (which are most reactive sites for electrophilic attack). The first order hyperpolarizabilities of MPDIA and BPDIA are 20.15 and 6.10 times that of the standard NLO material urea. Potential interaction with antihypertensive protein hydrolase.

  11. Imidazole derivatives as angiotensin II AT1 receptor blockers: Benchmarks, drug-like calculations and quantitative structure-activity relationships modeling

    Science.gov (United States)

    Alloui, Mebarka; Belaidi, Salah; Othmani, Hasna; Jaidane, Nejm-Eddine; Hochlaf, Majdi

    2018-03-01

    We performed benchmark studies on the molecular geometry, electron properties and vibrational analysis of imidazole using semi-empirical, density functional theory and post Hartree-Fock methods. These studies validated the use of AM1 for the treatment of larger systems. Then, we treated the structural, physical and chemical relationships for a series of imidazole derivatives acting as angiotensin II AT1 receptor blockers using AM1. QSAR studies were done for these imidazole derivatives using a combination of various physicochemical descriptors. A multiple linear regression procedure was used to design the relationships between molecular descriptor and the activity of imidazole derivatives. Results validate the derived QSAR model.

  12. Biological activities of the natural imidazole-containing peptidomimetics n-acetylcarnosine, carcinine and L-carnosine in ophthalmic and skin care products.

    Science.gov (United States)

    Babizhayev, Mark A

    2006-04-11

    Apart from genetically programmed cell aging, different external aggressors related to oxidative stress and lipid peroxidation (LPO) can accelerate the skin aging phenomenon. Oxidative stress associated with the formation of lipid peroxides is suggested to contribute to pathological processes in aging and systemic diseases known as the risk factors for cataract. Despite the fact that L-carnosine-related peptidomimetics N-acetylcarnosine (N-acetyl-beta-alanyl-L-histidine) (NAC) and carcinine (beta-alanylhistamine) are metabolically related to L-carnosine and have been demonstrated to occur in tissues of many vertebrates, including humans, these compounds were shown resistant toward enzymatic hydrolysis. A series of related biocompatible imidazole-containing peptidomimetics were synthesized in order to confer resistance to enzymatic hydrolysis and ex vivo improvement of protective antioxidative properties related to L-carnosine. The included findings revealed a greater role of N-acetylcarnosine (NAC) and carcinine ex vivo in the prolongation and potentiation of physiological responses to the therapeutical and cosmetics treatments with L-carnosine as antioxidant. 3-D molecular conformation studies proposed the antioxidant activity of peptidomimetics (carcinine, L-prolylhistamine, N-acetylcarnosine, L-carnosine) for metal ion binding, quenching of a number free radicals, and binding of hydroperoxide or aldehyde (including dialdehyde LPO products) in an imidazole-peroxide adducts. NAC can act as a time release (carrier) stable version of L-carnosine during application in ophthalmic pharmaceutical and cosmetics formulations which include lubricants. Carcinine, L-prolylhistamine show efficient deactivation of lipid hydroperoxides monitored by HPLC and protection of membrane phospholipids and water soluble proteins from the lipid peroxides-induced damages. This activity is superior over the lipophilic antioxidant vitamin E. The biologically significant applications of

  13. Three PbII coordination polymers based on 2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylic acid: Syntheses, crystal structures, and fluorescent properties

    International Nuclear Information System (INIS)

    Yu, Xiao-Yang; Xin, Rui; Gao, Wei-Ping; Wang, Na; Zhang, Xiao; Yang, Yan-Yan; Qu, Xiao-Shu

    2013-01-01

    Three lead coordination polymers, [PbCl(C 10 H 6 N 3 O 4 )(H 2 O)·H 2 O] n (1), [Pb(C 10 H 6 N 3 O 4 ) 2 (H 2 O)] n (2) and [Pb 3 (C 10 H 5 N 3 O 4 ) 3 ] n (3) (C 10 H 7 N 3 O 4 =2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylic acid), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. In 1, Cl anions connected neighboring wave-like 2D layers, which are constructed with left- and right-handed helical chains, into a 3D network structure with a (6 3 )(6 5 ·8) topology. In 2, Pb cations are linked into a 3D 6 6 network with left- and right-handed helixes by μ 2 -bridging C 10 H 6 N 3 O 4 − ligands. In 3, C 10 H 5 N 3 O 4 2− ligands link Pb 6 O 12 clusters into a 3D (4 12 ·6 3 ) network. Their fluorescent properties were also investigated. - Graphical abstract: Three 3D lead compounds based on 2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylic acid have been hydrothermally synthesized. Four new coordination modes of the organic ligand are first reported. Display Omitted - Highlights: • Three new Pb(II) complexes have been synthesized and characterized. • Left- and right-handed helical chains can be found in the 3D networks of 1 and 2. • Pb 6 O 12 clusters are connected into (4 12 ·6 3 ) network in 3

  14. Structure–activity relationships of imidazole-derived 2-[N-carbamoylmethyl-alkylamino]acetic acids, dual binders of human insulin-degrading enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Charton, Julie; Gauriot, Marion; Totobenazara, Jane; Hennuyer, Nathalie; Dumont, Julie; Bosc, Damien; Marechal, Xavier; Elbakali, Jamal; Herledan, Adrien; Wen, Xiaoan; Ronco, Cyril; Gras-Masse, Helene; Heninot, Antoine; Pottiez, Virginie; Landry, Valerie; Staels, Bart; Liang, Wenguang G.; Leroux, Florence; Tang, Wei-Jen; Deprez, Benoit (INSRM-France); (UC); (IP-France)

    2015-10-30

    Insulin degrading enzyme (IDE) is a zinc metalloprotease that degrades small amyloid peptides such as amyloid-â and insulin. So far the dearth of IDE-specific pharmacological inhibitors impacts the understanding of its role in the physiopathology of Alzheimer's disease, amyloid-â clearance, and its validation as a potential therapeutic target. Hit 1 was previously discovered by high-throughput screening. Here we describe the structure-activity study, that required the synthesis of 48 analogues. We found that while the carboxylic acid, the imidazole and the tertiary amine were critical for activity, the methyl ester was successfully optimized to an amide or a 1,2,4-oxadiazole. Along with improving their activity, compounds were optimized for solubility, lipophilicity and stability in plasma and microsomes. The docking or co-crystallization of some compounds at the exosite or the catalytic site of IDE provided the structural basis for IDE inhibition. The pharmacokinetic properties of best compounds 44 and 46 were measured in vivo. As a result, 44 (BDM43079) and its methyl ester precursor 48 (BDM43124) are useful chemical probes for the exploration of IDE's role.

  15. Poly[[sesqui[mu2-1,4-bis(imidazol-1-ylmethyl)benzene-kappa(2)N:N'](carbonato-kappa(2)O,O')copper(II)] 1,4-bis(imidazol-1-ylmethyl)benzene hemisolvate pentahydrate].

    Science.gov (United States)

    Dai, Yu-Mei; Tang, En; Huang, Jin-Feng; Yang, Qiu-Yan

    2008-10-01

    The asymmetric unit of the title compound, {[Cu(CO(3))(C(14)H(14)N(4))(1.5)] x 0.5 C(14)H(14)N(4) x 5 H(2)O}(n), contains one Cu(II) cation in a slightly distorted square-pyramidal coordination environment, one CO(3)(2-) anion, one full and two half 1,4-bis(imidazol-1-ylmethyl)benzene (bix) ligands, one half-molecule of which is uncoordinated, and five uncoordinated water molecules. One of the coordinated bix ligands and the uncoordinated bix molecule are situated about centers of symmetry, located at the centers of the benzene rings. The coordinated bix ligands link the copper(II) ions into a [Cu(bix)(1.5)](n) molecular ladder. These molecular ladders do not form interpenetrated ladders but are arranged in an ABAB parallel terrace, i.e. with the ladders arranged one above another, with sequence A translated with respect to B by 8 A. To best of our knowledge, this arrangement has not been observed in any of the molecular ladder frameworks synthesized to date. The coordination environment of the Cu(II) atom is completed by two O atoms of the CO(3)(2-) anion. The framework is further strengthened by extensive O-H...O and O-H...N hydrogen bonds involving the water molecules, the O atoms of the CO(3)(2-) anion and the N atoms of the bix ligands. This study describes the first example of a molecular ladder coordination polymer based on bix and therefore demonstrates further the usefulness of bix as a versatile multidentate ligand for constructing coordination polymers with interesting architectures.

  16. Screening for Methylated Poly(⌊-histidine with Various Dimethylimidazolium/Methylimidazole/Imidazole Contents as DNA Carrier

    Directory of Open Access Journals (Sweden)

    Shoichiro Asayama

    2015-08-01

    Full Text Available Methylated poly(l-histidine (PLH-Me, our original polypeptide, has controlled the contents of dimethylimidazolium, τ/π-methylimidazole and imidazole groups for efficient gene delivery. The screening for the PLH-Me as DNA carrier has been carried out by use of the PLH with 25 mol% (τ-methyl, 16 mol%; π-methyl, 17 mol%; deprotonated imidazole, 41 mol%, 68 mol% (τ-methyl, 16 mol%; π-methyl, 8 mol%; deprotonated imidazole, 8 mol% and 87 mol% (τ-methyl, 7 mol%; π-methyl, 4 mol%; deprotonated imidazole, 2 mol% dimethylimidazolium groups, that is, PLH-Me(25, PLH-Me(68 and PLH-Me(87, respectively. The screening of the chemical structure of PLH-Me has been carried out for DNA carrier properties, which are the stability of its DNA polyion complexes and gene expression. The DNA complexes with the 25 mol% and 68 mol% dimethylated PLH-Me possessed almost same ability to retain DNA, as compared with the 87 mol% dimethylated PLH-Me, which was examined by competitive exchange with dextran sulfate. From the gene transfection experiment against HepG2 cells, human hepatoma cell line, the PLH-Me(25/DNA complex was revealed to mediate highest gene expression. These results suggest that the dimethyl-imidazolium/methylimidazole/imidazole balance of the PLH-Me is important for DNA carrier design.

  17. Regio- and Enantioselective N-Allylations of Imidazole, Benzimidazole, and Purine Heterocycles Catalyzed by Single-Component Metallacyclic Iridium Complexes

    Science.gov (United States)

    Stanley, Levi M.

    2010-01-01

    Highly regio- and enantioselective iridium-catalyzed N-allylations of benzimidazoles, imidazoles, and purines have been developed. N-Allylated benzimidazoles and imidazoles were isolated in high yields (up to 97%) with high branched-to-linear selectivity (up to 99:1) and enantioselectivity (up to 98% ee) from the reactions of benzimidazole and imidazole nucleophiles with unsymmetrical allylic carbonates in the presence of single component, ethylene-bound, metallacyclic iridium catalysts. N-Allylated purines were also obtained in high yields (up to 91%) with high N9:N7 selectivity (up to 96:4), high branched-to-linear selectivity (98:2), and high enantioselectivity (up to 98% ee) under similar conditions. The reactions encompass a range of benzimidazole, imidazole, and purine nucleophiles, as well as a variety of unsymmetrical aryl, heteroaryl, and aliphatic allylic carbonates. Competition experiments between common amine nucleophiles and the heterocyclic nitrogen nucleophiles studied in this work illustrate the effect of nucleophile pKa on the rate of iridium-catalyzed N-allylation reactions. Kinetic studies on the allylation of benzimidazole catalyzed by metallacyclic iridium-phosphoramidite complexes, in combination with studies on the deactivation of these catalysts in the presence of heterocyclic nucleophiles, provide insight into the effects of the structure of the phosphoramidite ligands on the stability of the metallacyclic catalysts. The data obtained from these studies has led to the development of N-allylations of benzimidazoles and imidazoles in the absence of an exogenous base. PMID:19480431

  18. [4-t-butylphenyl]-N-(4-imidazol-1-yl phenyl)sulfonamide (ISCK03) inhibits SCF/c-kit signaling in 501mel human melanoma cells and abolishes melanin production in mice and brownish guinea pigs.

    Science.gov (United States)

    Na, Yong Joo; Baek, Heung Su; Ahn, Soo Mi; Shin, Hyun Jung; Chang, Ih-Seop; Hwang, Jae Sung

    2007-09-01

    It is well known that c-kit is related to pigmentation as well as to the oncology target protein. The objective of this study was to discover a skin-whitening agent that regulates c-kit activity. We have developed a high-throughput screening system using recombinant human c-kit protein. Approximately 10,000 synthetic compounds were screened for their effect on c-kit activity. Phenyl-imidazole sulfonamide derivatives showed inhibitory activity on c-kit phosphorylation in vitro. The effects of one derivative, [4-t-butylphenyl]-N-(4-imidazol-1-yl phenyl)sulfonamide (ISCK03), on stem-cell factor (SCF)/c-kit cellular signaling in 501mel human melanoma cells were examined further. Pretreatment of 501mel cells with ISCK03 inhibited SCF-induced c-kit phosphorylation dose dependently. ISCK03 also inhibited p44/42 ERK mitogen-activated protein kinase (MAPK) phosphorylation, which is known to be involved in SCF/c-kit downstream signaling. However ISCK03 did not inhibit hepatocyte growth factor (HGF)-induced phosphorylation of p44/42 ERK proteins. To determine the in vivo potency of ISCK03, it was orally administered to depilated C57BL/6 mice. Interestingly, oral administration of ISCK03 induced the dose-dependent depigmentation of newly regrown hair, and this was reversed with cessation of ISCK03 treatment. Finally, to investigate whether the inhibitory effect of ISCK03 on SCF/c-kit signaling abolished UV-induced pigmentation, ISCK03 was applied to UV-induced pigmented spots on brownish guinea pig skin. The topical application of ISCK03 promoted the depigmentation of UV-induced hyperpigmented spots. Fontana-Masson staining analysis showed epidermal melanin was diminished in spots treated with ISCK03. These results indicate that phenyl-imidazole sulfonamide derivatives are potent c-kit inhibitors and might be used as skin-whitening agents.

  19. Non-imidazole-based histamine H3 receptor antagonists with anticonvulsant activity in different seizure models in male adult rats

    Directory of Open Access Journals (Sweden)

    Sadek B

    2016-11-01

    Full Text Available Bassem Sadek,1 Ali Saad,1 Gniewomir Latacz,2 Kamil Kuder,2 Agnieszka Olejarz,2 Tadeusz Karcz,2 Holger Stark,3 Katarzyna Kieć-Kononowicz2 1Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates; 2Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy, Jagiellonian University Medical College, Kraków, Poland; 3Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany Abstract: A series of twelve novel non-imidazole-based ligands (3–14 was developed and evaluated for its in vitro binding properties at the human histamine H3 receptor (hH3R. The novel ligands were investigated for their in vivo protective effects in different seizure models in male adult rats. Among the H3R ligands (3–14 tested, ligand 14 showed significant and dose-dependent reduction in the duration of tonic hind limb extension in maximal electroshock (MES-induced seizure model subsequent to acute systemic administration (5, 10, and 20 mg/kg, intraperitoneally, whereas ligands 4, 6, and 7 without appreciable protection in MES model were most promising in pentylenetetrazole (PTZ model. Moreover, the protective effect observed for ligand 14 in MES model was lower than that observed for the reference drug phenytoin and was entirely abrogated when rats were co-administered with the brain-penetrant H1R antagonist pyrilamine (PYR but not the brain-penetrant H2R antagonist zolantidine (ZOL, demonstrating that histaminergic neurotransmission by activation of postsynaptically located H1Rs seems to be involved in the protective action. On the contrary, PYR and ZOL failed to abrogate the full protection provided by 4 in PTZ model and the moderate protective effect by 14 in strychnine (STR model. Moreover, the experimental and in silico estimation of properties such as metabolism was

  20. Thermodynamics of organic mixtures containing amines. X. Phase equilibria for binary systems formed by imidazoles and hydrocarbons: Experimental data and modelling using DISQUAC

    Energy Technology Data Exchange (ETDEWEB)

    Domanska, Urszula; Zawadzki, Maciej [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw (Poland); Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.e [G.E.T.E.F., Grupo Especializado en Termodinamica de Equilibrio entre Fases, Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E-47071, Valladolid (Spain)

    2010-04-15

    (Solid + liquid) equilibrium (SLE) temperatures have been determined using a dynamic method for the systems (1H-imidazole, + benzene, + toluene, + hexane, or + cyclohexane; 1-methylimidazole + benzene, or + toluene, 2-methyl-1H-imidazole + benzene, + toluene, or + cyclohexane, and benzimidazole + benzene). In addition (liquid + liquid) equilibrium (LLE) temperatures have been obtained using a cloud point method for (1H-imidazole, + hexane, or + cyclohexane; 1-methylimidazole + toluene, and 2-methyl-1H-imidazole + cyclohexane). The measured systems show positive deviations from the Raoult's law, due to strong dipolar interactions between amine molecules related to the high dipole moment of imidazoles. On the other hand, DISQUAC interaction parameters for the contacts present in these solutions and for the amine/hydroxyl contacts in (1H-imidazole + 1-alkanol) mixtures have been determined. The model correctly represents the available data for the examined systems. Deviations between experimental and calculated SLE temperatures are similar to those obtained using the Wilson or NRTL equations, or the UNIQUAC association solution model. The quasichemical interaction parameters are the same for mixtures containing 1H-imidazole, 1-methylimidazole, or 2-methyl-1H-imidazole and hydrocarbons. This may be interpreted assuming that they are members of a homologous series. Benzimidazole behaves differently.

  1. Thermodynamics of organic mixtures containing amines. X. Phase equilibria for binary systems formed by imidazoles and hydrocarbons: Experimental data and modelling using DISQUAC

    International Nuclear Information System (INIS)

    Domanska, Urszula; Zawadzki, Maciej; Gonzalez, Juan Antonio

    2010-01-01

    (Solid + liquid) equilibrium (SLE) temperatures have been determined using a dynamic method for the systems (1H-imidazole, + benzene, + toluene, + hexane, or + cyclohexane; 1-methylimidazole + benzene, or + toluene, 2-methyl-1H-imidazole + benzene, + toluene, or + cyclohexane, and benzimidazole + benzene). In addition (liquid + liquid) equilibrium (LLE) temperatures have been obtained using a cloud point method for (1H-imidazole, + hexane, or + cyclohexane; 1-methylimidazole + toluene, and 2-methyl-1H-imidazole + cyclohexane). The measured systems show positive deviations from the Raoult's law, due to strong dipolar interactions between amine molecules related to the high dipole moment of imidazoles. On the other hand, DISQUAC interaction parameters for the contacts present in these solutions and for the amine/hydroxyl contacts in (1H-imidazole + 1-alkanol) mixtures have been determined. The model correctly represents the available data for the examined systems. Deviations between experimental and calculated SLE temperatures are similar to those obtained using the Wilson or NRTL equations, or the UNIQUAC association solution model. The quasichemical interaction parameters are the same for mixtures containing 1H-imidazole, 1-methylimidazole, or 2-methyl-1H-imidazole and hydrocarbons. This may be interpreted assuming that they are members of a homologous series. Benzimidazole behaves differently.

  2. Investigation into organic boron compounds complexing. 25. Triaryl borane complexes with benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Belonovich, M I; Lapkin, I I; Morozova, T L; Okatysheva, L Yu; Rybakova, M N; Yuzhakova, G A [Permskij Gosudarstvennyj Univ. (USSR)

    1984-02-01

    Coordination of organic boron compounds with heterocyclic ligands is studied. Substances containing one molecule of ligand per one molecule of triarylborane are extracted when mixing ether solution of triarylborane and alcohol solution of benzimidazole. Based on IR spectra it is stated that coordination with boron is realized at the expense of pyridine nitrogen atom of imidazole cycle. Dipole momenta are determined for synthesized complexes using Debye method.

  3. Synthesis and characterization of novel polyamide-ethers based on bis-imidazole containing bulky aryl pendant groups

    Directory of Open Access Journals (Sweden)

    Seyed Mahdi Saadati

    2013-01-01

    Full Text Available A series of novel polyamide-ethers (PAEs based on bis-imidazole containing bulky aryl pendant groups was prepared by direct polycondensation of a diamine, 4-(1-(4-(4-(2-(4-aminophenyl-4,5-diphenyl-1H-imidazol-1-ylphenoxyphenyl-4,5-diphenyl-1H-imidazol-2-ylbenzenamine (DABI, and various dicarboxylic acids. All the resulting polyamide-ethers were amorphous with inherent viscosities ranged from 0.52 to 0.61 dL/g and were readily soluble in many organic solvents which could be solution-cast into transparent and tough films. The glass transition temperatures (Tg of these polymers were affected considerably by their chemical structure and ranged from 230 to 310 ºC. They had useful levels of thermal stability associated with relatively high temperatures of 10% weight loss (T10 in the range of 329-399 ºC in air atmosphere.

  4. Silylation of leached-vermiculites following reaction with imidazole and copper sorption behavior

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Saloana S.G.; Pereira, Mariana B.B. [Chemistry Department of Paraíba Federal University, João Pessoa, Paraíba (Brazil); Almeida, Ramon K.S. [Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, 13083-970 Campinas, São Paulo (Brazil); Souza, Antônio G. [Chemistry Department of Paraíba Federal University, João Pessoa, Paraíba (Brazil); Fonseca, Maria G., E-mail: mgardennia@quimica.ufpb.br [Chemistry Department of Paraíba Federal University, João Pessoa, Paraíba (Brazil); Jaber, M. [Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8220, Laboratoire d' archéologie moléculaire et structurale (LAMS), Boîte courrier 225, 4 place Jussieu, 75005 Paris (France)

    2016-04-05

    Highlights: • Silylated vermiculites reacted covalently with imidazole. • Modified vermiculites adsorbed copper from aqueous solution. • Copper retention in all solids occurred at rapid time of 80 min. • Higher organic content on the solid improved the copper adsorption. - Abstract: Organically modified vermiculites were synthesized by previous silylation of three leached vermiculites, V0.3Cl, V0.5Cl and V0.8Cl, under anhydrous conditions following reaction with imidazole (Im), which acted as chelating agent for copper retention. Elemental analysis, X-ray diffraction, infrared spectroscopy, scanning electronic microscopy, transmission electron microscopy, {sup 29}Si and {sup 13}C NMR and nitrogen adsorption/desorption measurements were used to characterize pristine, leached and organofunctionalized solids. X-ray photoelectron spectroscopy (XPS) was used to evaluate the surface after copper sorption. Parameters such as contact time, pH and initial cation concentration for the adsorption of Cu(II) ions were investigated. The adsorption equilibrium data were fitted using the Langmuir isotherm model and the monolayer adsorption capacities were 2.38, 2.52 and 2.69 mmol g{sup −1} for V0.5Cl-Im, V0.3Cl-Im and V0.8Cl-Im, respectively, at pH 6.0 and 298 K for a time reaction of 80 min. The sorption rates were described by pseudo-second-order kinetics. The chloropropyl imidazole vermiculites are promising adsorbents for the rapid removal of Cu(II) ions from aqueous solution.

  5. Synthesis of backbone P-functionalized imidazol-2-ylidene complexes: en route to novel functional ionic liquids.

    Science.gov (United States)

    Majhi, Paresh Kumar; Sauerbrey, Susanne; Schnakenburg, Gregor; Arduengo, Anthony J; Streubel, Rainer

    2012-10-01

    1-Alkyl-3-methyl-4-diphenylphosphoryl-imidazolium hydrogensulfate (4a,b) (a: R(1) = R(2) = Me; b: R(1) = (i)Pr, R(2) = Me) and 1-alkyl-3-methyl-4,5-bis(diphenylphosphoryl)imidazolium hydrogensulfate (6a,c) (c: R(1) = (n)Bu, R(2) = Me) were obtained selectively and in good yields by oxidative desulfurization of 1-alkyl-3-methyl-4-diphenylphosphino-imidazole-2-thiones (2a,b) and 1-n-butyl-3-methyl-4,5-bis(diphenylphosphoryl)imidazole-2-thione (3c) or 1,3-dimethyl-4-diphenylthiophosphoryl-5-diphenylphosphino-imidazole-2-thione (5a), respectively, with hydrogen peroxide. Synthesis of phosphoryl functionalized imidazol-2-ylidene complexes of group VI metal pentacarbonyls (7a-9a) and (10b-12b) and bis(phosphoryl) functionalized imidazol-2-ylidene complexes of group VI metal pentacarbonyls (13c-15c) and (16a) with low steric demand (methyl, isopropyl, n-butyl) at both N-centers was achieved through deprotonation of imidazolium salts (4a,b) and (6a,c), respectively,-having HSO(4)(-) as a counterion-with potassium tert-butoxide followed by rapid addition of metal pentacarbonyl acetonitrile complexes [M(CO)(5)(CH(3)CN)] (M = Cr, Mo, W). The products were unambiguously characterized by elemental analyses, spectroscopic and spectrometric methods, and in addition, by single-crystal X-ray structure studies in the cases of 4b, 8a, 15c, and 16a; the latter two reveal imidazole ring bond distance alternation in contrast to 8a.

  6. Tumor Repression of VCaP Xenografts by a Pyrrole-Imidazole Polyamide

    OpenAIRE

    Hargrove, Amanda E.; Martinez, Thomas F.; Hare, Alissa A.; Kurmis, Alexis A.; Phillips, John W.; Sud, Sudha; Pienta, Kenneth J; Dervan, Peter B.

    2015-01-01

    Pyrrole-imidazole (Py-Im) polyamides are high affinity DNA-binding small molecules that can inhibit protein-DNA interactions. In VCaP cells, a human prostate cancer cell line overexpressing both AR and the TMPRSS2-ERG gene fusion, an androgen response element (ARE)-targeted Py-Im polyamide significantly downregulates AR driven gene expression. Polyamide exposure to VCaP cells reduced proliferation without causing DNA damage. Py-Im polyamide treatment also reduced tumor growth in a VCaP mouse ...

  7. Microwave-Assisted Solvent-Free Synthesis of Zeolitic Imidazolate Framework-67

    Directory of Open Access Journals (Sweden)

    Heng Zhang

    2016-01-01

    Full Text Available A microporous metal-organic framework (MOF, cobalt-based zeolitic imidazolate framework-67 (ZIF-67, was synthesized by the combination of solvent-free hand-mill and microwave irradiation, without any organic solvent and within 30 minutes. The hand-milling process can mix the reactants well by the virtue of high moisture/water absorption capacity of reactants. In addition, the outstanding electromagnetic wave absorption capability of cobalt leads to efficient conversion to MOF structures before carbonization. The obtained ZIF-67 possesses high surface area and micropore volume.

  8. Crystal structure of 2-methyl-1H-imidazol-3-ium hydrogen oxalate dihydrate

    Directory of Open Access Journals (Sweden)

    Mouhamadou Birame Diop

    2016-08-01

    Full Text Available Single crystals of the title molecular salt, C4H7N2+·HC2O4−·2H2O, were isolated from the reaction of 2-methyl-1H-imidazole and oxalic acid in a 1:1 molar ratio in water. In the crystal, the cations and anions are positioned alternately along an infinite [010] ribbon and linked together through bifurcated N—H...(O,O hydrogen bonds. The water molecules of crystallization link the chains into (10-1 bilayers, with the methyl groups of the cations organized in an isotactic manner.

  9. Cytokinin oxidase from Phaseolus vulgaris callus tissues. Enhanced in vitro activity of the enzyme in the presence of copper-imidazole complexes

    International Nuclear Information System (INIS)

    Chatfield, J.M.; Armstrong, D.J.

    1987-01-01

    The effects of metal ions on cytokinin oxidase activity extracted from callus tissues of Phaseolus vulgaris L. cv Great Northern have been examined using an assay based on the oxidation of N 6 -(Δ 2 -isopentenyl)-adenine-2,8- 3 H (i 6 Ade) to adenine (Ade). The addition of cupric ions to reaction mixtures containing imidazole buffer markedly enhanced cytokinin oxidase activity. In the presence of optimal concentrations of copper and imidazole, cytokinin oxidase activity was stimulated more than 20-fold. The effect was enzyme dependent, specific for copper, and observed only in the presence of imidazole. The substrate specificity of the copper-imidazole enhanced reaction, as judged by substrate competition tests, was the same as that observed in the absence of copper and imidazole. Similarly, in tests involving DEAE-cellulose chromatography, elution profiles of cytokinin oxidase activity determined using a copper-imidazole enhanced assay were identical to those obtained using an assay without copper and imidazole. On the basis of these results, the addition of copper and imidazole to reaction mixtures used to assay for cytokinin oxidase activity is judged to provide a reliable and specific assay of greatly enhanced sensitivity for the enzyme. The mechanism by which copper and imidazole enhance cytokinin oxidase activity is not certain, but the reaction catalyzed by the enzyme was not inhibited by anaerobic conditions when these reagents were present. This observation suggests that copper-imidazole complexes are substituting for oxygen in the reaction mechanism by which cytokinin oxidase effects cleavage of the N 6 -side chain of i 6 Ade

  10. Imidazole-containing phthalazine derivatives inhibit Fe-SOD performance in Leishmania species and are active in vitro against visceral and mucosal leishmaniasis.

    Science.gov (United States)

    Sánchez-Moreno, M; Gómez-Contreras, F; Navarro, P; Marín, C; Ramírez-Macías, I; Rosales, M J; Campayo, L; Cano, C; Sanz, A M; Yunta, M J R

    2015-07-01

    The in vitro leishmanicidal activity of a series of imidazole-containing phthalazine derivatives 1-4 was tested on Leishmania infantum, Leishmania braziliensis and Leishmania donovani parasites, and their cytotoxicity on J774·2 macrophage cells was also measured. All compounds tested showed selectivity indexes higher than that of the reference drug glucantime for the three Leishmania species, and the less bulky monoalkylamino substituted derivatives 2 and 4 were clearly more effective than their bisalkylamino substituted counterparts 1 and 3. Both infection rate measures and ultrastructural alterations studies confirmed that 2 and 4 were highly leishmanicidal and induced extensive parasite cell damage. Modifications to the excretion products of parasites treated with 2 and 4 were also consistent with substantial cytoplasmic alterations. On the other hand, the most active compounds 2 and 4 were potent inhibitors of iron superoxide dismutase enzyme (Fe-SOD) in the three species considered, whereas their impact on human CuZn-SOD was low. Molecular modelling suggests that 2 and 4 could deactivate Fe-SOD due to a sterically favoured enhanced ability to interact with the H-bonding net that supports the antioxidant features of the enzyme.

  11. Activity of Ingavirin (6-[2-(1H-Imidazol-4-ylethylamino]-5-oxo-hexanoic Acid Against Human Respiratory Viruses in in Vivo Experiments

    Directory of Open Access Journals (Sweden)

    Oleg I. Kiselev

    2011-11-01

    Full Text Available Respiratory viral infections constitute the most frequent reason for medical consultations in the World. They can be associated with a wide range of clinical manifestations ranging from self-limited upper respiratory tract infections to more devastating conditions such as pneumonia. In particular, in serious cases influenza A leads to pneumonia, which is particularly fatal in patients with cardiopulmonary diseases, obesity, young children and the elderly. In the present study, we show a protective effect of the low-molecular weight compound Ingavirin (6-[2-(1H-imidazol-4-ylethylamino]-5-oxohexanoic acid against influenza A (H1N1 virus, human parainfluenza virus and human adenovirus infections in animals. Mortality, weight loss, infectious titer of the virus in tissues and tissue morphology were monitored in the experimental groups of animals. The protective action of Ingavirin was observed as a reduction of infectious titer of the virus in the lung tissue, prolongation of the life of the infected animals, normalization of weight dynamics throughout the course of the disease, lowering of mortality of treated animals compared to a placebo control and normalization of tissue structure. In case of influenza virus infection, the protective activity of Ingavirin was similar to that of the reference compound Tamiflu. Based on the results obtained, Ingavirin should be considered as an important part of anti-viral prophylaxis and therapy.

  12. Ultrasound-promoted synthesis of (4 or 5-aryl-2-aryloyl-(1H-imidazoles in water

    Directory of Open Access Journals (Sweden)

    Behzad Khalili

    2014-01-01

    Full Text Available A green and efficient method for the synthesis of (4 or 5-aryl-2-aryloyl-(1H-imidazoles via self-condensation reaction of arylglyoxal hydrates in the presence of ammonium acetate using water as solvent under ultrasonic irradiation was reported. The reactions proceeded in high yields and very short reaction time. Introduced procedure is completely ecofriendly and don’t need any toxic organic solvent in all performing steps. In addition we use computational chemistry for acquiring some information about the thermochemistry and geometrical structure of these imidazole derivatives.

  13. Dichloridobis[1-(2,4,6-trimethylphenyl-1H-imidazole-κN3]copper(II

    Directory of Open Access Journals (Sweden)

    Yantao Zhang

    2013-11-01

    Full Text Available In the title complex, [CuCl2(C12H14N22], the Cu2+ cation is situated on an inversion centre and is coordinated by two N atoms from symmetry-related 1-mesityl-1H-imidazole ligands and by two chloride anions in a slightly distorted square-planar geometry. In the organic ligand, the dihedral angle between the benzene ring of the mesityl moiety and the imidazole ring is 76.99 (18°. Weak intramolecular C—H...Cl hydrogen-bonding interactions consolidate the molecular conformation.

  14. Bis[μ-1,2-bis(1H-imidazol-1-ylmethylbenzene-κ2N3:N3′]disilver(I 3-carboxylato-4-hydroxybenzenesulfonate methanol solvate trihydrate

    Directory of Open Access Journals (Sweden)

    Hong-Mei Sun

    2009-09-01

    Full Text Available In the title compound, [Ag2(C14H14N42](C7H4O6S·CH3OH·3H2O, the complex dication has a binuclear structure in which each AgI ion is two-coordinated in a slightly distorted linear coordination geometry. The two AgI atoms are bridged by two 1,2-bis[(1H-imidazol-1-ylmethyl]benzene (IBI ligands, forming a 22-membered ring. In the dication, π–π interactions are observed between the imidazole rings with centroid–centroid distances of 3.472 (3 and 3.636 (3 Å. In the crystal, the uncoordinated water molecules, anions and methanol solvent molecules are linked into chains along the b axis by O—H...O hydrogen bonds. In addition, π–π interactions are observed between the benzene rings of the IBI ligands, with a centroid–centroid distance of 3.776 (2 Å. The sulfonate group is disordered over two orientations with occupancies of 0.676 (12 and 0.324 (12.

  15. Non-Imidazole Histamine H₃ Ligands. Part VII. Synthesis, In Vitro and In Vivo Characterization of 5-Substituted-2-thiazol-4-n-propylpiperazines.

    Science.gov (United States)

    Guryn, Roman; Staszewski, Marek; Stasiak, Anna; McNaught Flores, Daniel; Fogel, Wiesława Agnieszka; Leurs, Rob; Walczyński, Krzysztof

    2018-02-03

    H₃ receptors present on histaminergic and non-histaminergic neurons, act as autoreceptors or heteroreceptors controlling neurotransmitter release and synthesis. Previous, studies have found that the compound N -methyl- N -3-phenylalkyl-2-[2-(4-n-propylpiperazin-1-yl)-1,3-thiazol-5-yl]ethan-1-amine ( ADS-531, 2c ) exhibits high in vitro potency toward H₃ guinea pig jejunal receptors, with pA₂ = 8.27. To optimize the structure of the lead compound ADS-531 , a series of 5-substituted-2-thiazol-4- n -propylpiperazines 3 were synthesized and subjected to in vitro pharmacological characterization; the alkyl chain between position 2 of the thiazole ring and the terminal secondary N -methylamino function was elongated from three to four methylene groups and the N -methylamino functionality was substituted by benzyl-, 2-phenylethyl-, and 3-phenyl-propyl- moieties. SAR studies on novel non-imidazole, 5-substituted-2-thiazol-4- n -propyl-piperazines 3 showed that the most active compound 3a (pA₂ = 8.38), additionally possessed a weak competitive H₁-antagonistic activity. Therefore, compound ADS-531 , which did not exhibit any H₁-antagonistic activity, was chosen for further evaluation for its affinity to the recombinant rat and human histamine H₃ receptors (rH₃R and hH₃R, respectively). ADS-531 exhibited nanomolar affinity for both rH₃R and hH₃R receptors. It was also shown that, ADS-531 given subchronically to rats (s.c. 3 mg/kg, 5 days) penetrated the brain, where it affected dopamine, noradrenaline and serotonin concentration; however, it did not affect histamine concentration nor feeding behavior.

  16. Reaction of Nα-acetyl-L-histidine with diazomethane: A model esterification reaction of carboxylic groups in the presence of imidazole rings

    Directory of Open Access Journals (Sweden)

    Zamora, R.

    1996-10-01

    Full Text Available The reaction of Nα-acetyl-L-histidine with diazomethane was studied in order to analyze the esterification reaction of a carboxylic group in the presence of an imidazole ring. The reaction produced the expected Nα-acetyl-L-histidine methyl ester (1 as a major product. However, important amounts of [S]-acetyl-1-methylimidazole-4-alanine methyl ester (2 and [S]-acetyl-1-methylimidazole-5-alanine methyl ester (3 were also produced. These compounds, which could be detected by capillary electrophoresis (HPCE and thin layer chromatography, were fractionated by column chromatography and identified by gas chromatography coupled with mass spectrometry (GC-MS, and 1H and 13C nuclear magnetic resonance spectroscopy. Structures for compounds 1-3 were confirmed by HPCE after acid hydrolysis. These results indicated that the use of diazomethane produces the methyl derivative of the heterocyclic ring in addition to the methyl ester. This reaction should be considered when preparing derivatives for GC-MS analysis.

    La reacción de la Nα-acetil-L-histidina con diazometano fue estudiada con objeto de conocer el comportamiento de la reacción de esterificación de un grupo carboxílico en presencia de un anillo de imidazol. La reacción produjo el esperado éster metílico de la Nα-acetil-L-histidina (1 como producto mayoritario. Sin embargo, también se observó la formación de cantidades importantes de los esteres metílicos de la [S]-acetil-1-metilimidazol- 4-alanina (2 y la [S]-acetil-1-metilimidazol-5-alanina (3. Estos compuestos que pudieron ser detectados por electroforesis capilar y cromatografía en capa fina, fueron separados por cromatografía en columna e identificados por cromatografía de gases acoplada a espectrometría de masas, y por espectroscopia de resonancia magnética nuclear de 1H y 13C. Las estructuras de los compuestos

  17. Nonenzymatic electrochemical sensor based on imidazole-functionalized graphene oxide for progesterone detection.

    Science.gov (United States)

    Gevaerd, Ava; Blaskievicz, Sirlon F; Zarbin, Aldo J G; Orth, Elisa S; Bergamini, Márcio F; Marcolino-Junior, Luiz H

    2018-07-30

    The modification of electrode surfaces has been the target of study for many researchers in order to improve the analytical performance of electrochemical sensors. Herein, the use of an imidazole-functionalized graphene oxide (GO-IMZ) as an artificial enzymatic active site for voltammetric determination of progesterone (P4) is described for the first time. The morphology and electrochemical performance of electrode modified with GO-IMZ were characterized by scanning electron microscopy and cyclic voltammetry, respectively. Under optimized conditions, the proposed sensor showed a synergistic effect of the GO sheets and the imidazole groups anchored on its backbone, which promoted a significant enhancement on electrochemical reduction of P4. Figures of merits such as linear dynamic response for P4 concentration ranging from 0.22 to 14.0 μmol L -1 , limit of detection of 68 nmol L -1 and limit of quantification and 210 nmol L -1 were found. In addition, presented a higher sensitivity, 426 nA L µmol -1 , when compared to the unmodified electrode. Overall, the proposed device showed to be a promising platform for a simple, rapid, and direct analysis of progesterone. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Effect of phenols and carboxylic acids on photochromism of 1-alkyl-2-(arylazo)imidazoles

    Energy Technology Data Exchange (ETDEWEB)

    Gayen, Pallab [Inorganic Chemistry Section, Department of Chemistry, Jadavpur University, Kolkata 700032 (India); Sinha, Chittaranjan, E-mail: c_r_sinha@yahoo.com [Inorganic Chemistry Section, Department of Chemistry, Jadavpur University, Kolkata 700032 (India)

    2012-09-15

    Light irradiated trans-to-cis isomerization of 1-alkyl-2-(arylazo)imidazole in the presence of phenol, catechol, benzoic acid and salicylic acid (called co-factors) has been studied in this work. The rate of trans{yields}cis photoisomerization is decreased in the presence of co-factor in the medium and is dependent on the concentration of active quotient about photochrome. The decrease in rate follows catechol>benzoic acid>phenol>salicylic acid. This trend is due to the effects of dissociation ability of -O-H/-COOH, intermolecular association of the molecules etc. The reverse change, cis-to-trans, is very slow in light irradiation and has been carried out by a thermal process in the dark. The quantum yield of isomerization follows the same sequence of effects of co-factors. - Highlights: Black-Right-Pointing-Pointer Photoisomerisation of 1-alkyl-2-(arylazo)imidazoles, trans-to-cis, is described in this work. Black-Right-Pointing-Pointer The process is sensitive to the environment of the photochrome and the solution. Black-Right-Pointing-Pointer The rate of photoisomerization decreases as catechol>benzoic acid>phenol>salicylic acid. Black-Right-Pointing-Pointer The reverse isomerization, cis-to-trans is very slow with light and has been carried out with heat. Black-Right-Pointing-Pointer The activation energy is less than these values when carried out in fresh solution only.

  19. Effect of phenols and carboxylic acids on photochromism of 1-alkyl-2-(arylazo)imidazoles

    International Nuclear Information System (INIS)

    Gayen, Pallab; Sinha, Chittaranjan

    2012-01-01

    Light irradiated trans-to-cis isomerization of 1-alkyl-2-(arylazo)imidazole in the presence of phenol, catechol, benzoic acid and salicylic acid (called co-factors) has been studied in this work. The rate of trans→cis photoisomerization is decreased in the presence of co-factor in the medium and is dependent on the concentration of active quotient about photochrome. The decrease in rate follows catechol>benzoic acid>phenol>salicylic acid. This trend is due to the effects of dissociation ability of –O–H/–COOH, intermolecular association of the molecules etc. The reverse change, cis-to-trans, is very slow in light irradiation and has been carried out by a thermal process in the dark. The quantum yield of isomerization follows the same sequence of effects of co-factors. - Highlights: ► Photoisomerisation of 1-alkyl-2-(arylazo)imidazoles, trans-to-cis, is described in this work. ► The process is sensitive to the environment of the photochrome and the solution. ► The rate of photoisomerization decreases as catechol>benzoic acid>phenol>salicylic acid. ► The reverse isomerization, cis-to-trans is very slow with light and has been carried out with heat. ► The activation energy is less than these values when carried out in fresh solution only.

  20. A study on superoxide dismutase activity of some model compounds.

    Science.gov (United States)

    Liao, Z; Liu, W; Liu, J; Jiang, Y; Shi, J; Liu, C

    1994-08-15

    The synthesis and characteristics of a binuclear ligand N,N,N',N'-tetrakis (2'-benzimidazolyl methyl)-1,4-diethylene amino glycol ether (EGTB) and its series of coordination compounds containing copper(II), iron(III), and manganese(II) with and without exogenous bridging ligand which was imidazolate ion (Im-), bipyridine (bpy), or 1,10-phenanthroline (phen) are reported. Depending on the redox potentials by cyclic voltammetry, the coordination compounds can act as catalysts for the dismutation of superoxide radicals (O2-). The detection of the rate constant of the reaction of superoxide ion with nitroblue tetrazolium (NBT) which is inhibited by superoxide dismutase (SOD) and its model compounds of the EGTB system has been performed by a modified illumination method. The rate constants kQ of the catalytic dismutation have been obtained.

  1. Anoxic degradation of nitrogenous heterocyclic compounds by activated sludge and their active sites.

    Science.gov (United States)

    Xu, Peng; Han, Hongjun; Zhuang, Haifeng; Hou, Baolin; Jia, Shengyong; Wang, Dexin; Li, Kun; Zhao, Qian

    2015-05-01

    The potential for degradation of five nitrogenous heterocyclic compounds (NHCs), i.e., imidazole, pyridine, indole, quinoline, and carbazole, was investigated under anoxic conditions with acclimated activated sludge. Results showed that NHCs with initial concentration of 50 mg/L could be completely degraded within 60 hr. The degradation of five NHCs was dependent upon the chemical structures with the following sequence: imidazole>pyridine>indole>quinoline>carbazole in terms of their degradation rates. Quantitative structure-biodegradability relationship studies of the five NHCs showed that the anoxic degradation rates were correlated well with highest occupied molecular orbital. Additionally, the active sites of NHCs identified by calculation were confirmed by analysis of intermediates using gas chromatography and mass spectrometry. Copyright © 2015. Published by Elsevier B.V.

  2. Synthetic polyspermine imidazole-4, 5-amide as an efficient and cytotoxicity-free gene delivery system

    Directory of Open Access Journals (Sweden)

    Duan S

    2012-07-01

    Full Text Available Shi-Yue Duan, Xue-Mei Ge, Nan Lu, Fei Wu, Weien Yuan, Tuo JinSchool of Pharmacy, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of ChinaAbstract: A chemically dynamic spermine-based polymer: polyspermine imidazole-4, 5-amide (PSIA, Mw > 7 kDa was designed, synthesized, and evaluated in terms of its ability to deliver nucleic acids. This polymer was made from an endogenous monomer professionally condensing genes in sperms, spermine, and a known safety drug metabolite, imidazole-4, 5-dicarboxylic acid, through a bis-amide bond conjugated with the imidazole ring. This polymer can condense pDNA at a W/W ratio above 10 to form polyplexes (100–200 nm in diameter, which is consistent with the observation by transmission electron microscopy (TEM, and the zeta potential was in the range of 10–20 mV. The pDNA packaged polymer was stable in phosphate buffer solution (PBS at pH 7.4 (simulated body fluid while the polyplexes were releasing pDNA into the solution at pH 5.8 (simulated endo-lysosomes due to the degradation of the bis-amide linkages in response to changes in pH values. PSIA-polyplexes were able to achieve efficient cellular uptake and luciferase gene silencing by co-transfection of pDNA and siRNA in COS-7 cells and HepG2 cells with negligible cytotoxicity. Biodistribution of Rhodamine B-labeled PSIA-polyplexes after being systemically injected in BALB/c nude-mice showed that the polyplexes circulated throughout the body, accumulated mainly in the kidney at 4 hours of sample administration, and moved to the liver and spleen after 24 hours. All the results suggested that PSIA offered a promising example to balance the transfection efficiency and toxicity of a synthetic carrier system for the delivery of therapeutic nucleic acids.Keywords: gene delivery, polyspermine, cytotoxicity, transfection efficiency, biodistribution

  3. Spectroscopic (FT-IR, FT-Raman, UV, 1H and 13C NMR insights, electronic profiling and DFT computations on ({(E-[3-(1H-imidazol-1-yl-1-phenylpropylidene] amino}oxy(4-nitrophenylmethanone, an imidazole-bearing anti-Candida agent

    Directory of Open Access Journals (Sweden)

    Al-Wahaibi Lamya H.

    2018-02-01

    Full Text Available The anti-Candida agent, ({(E-[3-(1H-imidazol-1-yl-1-phenylpropylidene]amnio}oxy(4-nitropheny methanone (IPAONM, was subjected to comprehensive spectroscopic (FT-IR, FT-Raman, UV–Vis 1H and 13C NMR characterization as well as Hartree Fock and density functional theory computation studies. The selected optimized geometric bond lengths and bond angles of the IPAONM molecule were compared with the experimental values. The calculated wavenumbers have been scaled and compared with the experimental spectra. Mulliken charges and natural bond orbital analysis of the title molecule were calculated and interpreted. The energy and oscillator strengths of the IPAONM molecule were calculated by time-dependent density functional theory (TD-DFT. In addition, frontier molecular orbitals and molecular electrostatic potential diagram of the title compound were computed and analyzed. A study on the electronic properties, such as HOMO, HOMO-1, LUMO and LUMO+1 energies was carried out using TD-DFT approach. The 1H and 13C NMR chemical shift values of the title compound were calculated by the gauge independent atomic orbital method and compared with the experimental results.

  4. Three d10 coordination polymers assembled from 3,5-bis(imidazole-1-yl)pyridine and different polycarboxylates: Syntheses, structures and luminescence properties

    Science.gov (United States)

    Pan, Jie; Zhang, Di; Xue, Zhen-Zhen; Wei, Li; Han, Song-De; Wang, Guo-Ming

    2017-11-01

    Three novel Zn(II)/Cd(II) coordination polymers, [Cd2(bip)2(m-bdc)2(H2O)2·3H2O]n (1), [Zn2(bip)2(p-bdc)2·2.5H2O]n (2) and [Zn(bip) (p-bdc)·3H2O]n (3), where bip = 3,5-bis(imidazole-1-yl)pyridine, m-H2bdc = 1,3-benzenedicarboxylic acid, p-H2bdc = 1,4-benzenedicarboxylic acid, have been successfully synthesized under solvothermal conditions. The linkage of different ligands with Cd(II) ions in compound 1 affords a (3,5)-connected layer. Furthermore, 2D→3D parallel polycatenation occurs wherein the layers are polycatenated with the adjacent two parallel layers to form a 3D framework. In 2 and 3, the polycarboxylates act as pillars to combine the metal-bip chains, yielding the layered structures. These 2D networks are extended to the final 3D supramolecular architectures by π-π stacking interactions. The results show that bip can act as a versatile building block for the construction of various coordination polymers. Moreover, the fluorescent properties of 1-3 in the solid state at room temperature have been investigated.

  5. Imidazole-4-acetic acid, a new lead structure for interaction with the taurine transporter in outer blood-retinal barrier cells

    DEFF Research Database (Denmark)

    Valembois, Sophie Annick N; Krall, Jacob; Frølund, Bente

    2017-01-01

    therapeutic approach. The taurine transporter (TAUT) plays a key role in the retinal transport of GABA and has been previously suggested to display a higher functional activity in the retina compared to the brain. TAUT would therefore stand as a suitable target for the selective delivery of ρ GABAAR ligands...... by testing their ability to inhibit the TAUT-mediated influx of taurine in ARPE-19 cells. Results showed that taurine influx was seven-fold higher when the ARPE-19 cells were cultured under hyperosmotic conditions and was demonstrated to display saturable kinetics (Km = 27.7 ± 2.2 μM and Jmax = 24.2 ± 0.......6 pmol/cm2·min). Furthermore, the taurine influx was significantly inhibited in a concentration-dependent manner by GABA and imidazole-4-acetic acid (IAA), which is a naturally occurring metabolite of histamine. These compounds display similar Ki values of 644.2 μM and 658.6 μM, respectively. Moreover...

  6. catena-Poly[[[aquasilver(I]-μ-1,1′-(butane-1,4-diyldi-1H-imidazole-κ2N3:N3′] hemi(biphenyl-4,4′-dicarboxylate dihydrate

    Directory of Open Access Journals (Sweden)

    Zheyu Zhang

    2009-12-01

    Full Text Available In the title compound, {[Ag(C10H14N4(H2O](C14H8O40.5·2H2O}n, the AgI ion is three-coordinated by two N atoms from two independent 1,1′-(butane-1,4-diyldi-1H-imidazole (BBI ligands and one water O atom in a distorted T-shaped coordination geometry. The biphenyl-4,4′-dicarboxylate (BPDC dianions do not coordinate to AgI ions but act as counter-ions. The AgI ions are linked by BBI ligands, forming a zigzag chain. These chains are linked into a two-dimensional supramolecular architecture by O—H...O hydrogen-bonding interactions between water molecules and carboxylate O atoms of the BPDC dianions.

  7. Tumor Repression of VCaP Xenografts by a Pyrrole-Imidazole Polyamide.

    Directory of Open Access Journals (Sweden)

    Amanda E Hargrove

    Full Text Available Pyrrole-imidazole (Py-Im polyamides are high affinity DNA-binding small molecules that can inhibit protein-DNA interactions. In VCaP cells, a human prostate cancer cell line overexpressing both AR and the TMPRSS2-ERG gene fusion, an androgen response element (ARE-targeted Py-Im polyamide significantly downregulates AR driven gene expression. Polyamide exposure to VCaP cells reduced proliferation without causing DNA damage. Py-Im polyamide treatment also reduced tumor growth in a VCaP mouse xenograft model. In addition to the effects on AR regulated transcription, RNA-seq analysis revealed inhibition of topoisomerase-DNA binding as a potential mechanism that contributes to the antitumor effects of polyamides in cell culture and in xenografts. These studies support the therapeutic potential of Py-Im polyamides to target multiple aspects of transcriptional regulation in prostate cancers without genotoxic stress.

  8. High-Flux Zeolitic Imidazolate Framework Membranes for Propylene/Propane Separation by Postsynthetic Linker Exchange.

    Science.gov (United States)

    Lee, Moon Joo; Kwon, Hyuk Taek; Jeong, Hae-Kwon

    2018-01-02

    While zeolitic imidazolate framework, ZIF-8, membranes show impressive propylene/propane separation, their throughput needs to be greatly improved for practical applications. A method is described that drastically reduces the effective thickness of ZIF-8 membranes, thereby substantially improving their propylene permeance (that is, flux). The new strategy is based on a controlled single-crystal to single-crystal linker exchange of 2-methylimidazole in ZIF-8 membrane grains with 2-imidazolecarboxaldehyde (ZIF-90 linker), thereby enlarging the effective aperture size of ZIF-8. The linker-exchanged ZIF-8 membranes showed a drastic increase in propylene permeance by about four times, with a negligible loss in propylene/propane separation factor when compared to as-prepared membranes. The linker-exchange effect depends on the membrane synthesis method. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Characterization and application of zeolitic imidazolate framework-8@polyvinyl alcohol nanofibers mats prepared by electrospinning

    Science.gov (United States)

    Fan, Xiaoxiao; Yu, Linling; Li, Lianghao; Yang, Cao; Wen, Junjie; Ye, Xiaokun; Cheng, Jianhua; Hu, Yongyou

    2017-02-01

    In this study, Zeolitic imidazolate framework-8@polyvinyl alcohol (ZIF-8@PVA) nanofibers were creatively fabricated by electrospinning technique, and the nanofibers membranes were characterized by SEM, TEM, XRD, FTIR, TG, DSC, DTA, BET. Its thermal stability, mechanical property, water stability and adsorption nature were also performed. The optimized fabrication parameter of the ZIF-8@PVA was 10 wt% and the uniform diameters of the nanofibers has been obtained. In addition, the ZIF-8@PVA nanofibers displayed unique properties such as a water stable and flexible structure. The adsorption test for Congo red treatment revealed that the nanofibers had a great adsorption performance. The results indicated that the nonwoven fiber mats had a great potential as a new type of membrane adsorbents in wastewater purification. The possible mechanism of CR adsorption onto ZIF-8@PVA was researched.

  10. Use of imidazole 4,5-dicarboxylic acid in vanadium speciation

    International Nuclear Information System (INIS)

    Banerjee, D.; Mondal, B.C.; Das, D.; Das, A.K.

    2003-01-01

    A new resin has been synthesized by fictionalization of polystyrene-divinylbenzene (8 %) with imidazole 4,5-dicarboxylic acid through -N=N- bonding. The resulting resin has been characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, hydrogen ion capacity and metal ion capacity. The speciation study of vanadium has been studied by using this resin and the maximum exchange capacity was found to be 0.45 mmol g -1 for V 4+ and that for V 5+ was 1.57 mmol g -1 at pH 3 for both. The eluents malonic acid and sodium hydroxide have been used for the selective separation of vanadium(IV) and vanadium(V) species respectively. The effects of diverse ions on the sorption and recovery of each species have been studied. Finally, the developed method has been applied for the speciation and determination of these two species in natural water samples. (author)

  11. Electric properties and fabrication of IMI-O LB films containing the imidazole group

    CERN Document Server

    Yoo, S Y; Kwon, Y S; Park, J C

    1999-01-01

    We fabricated an IMI-O polymer containing an imidazole group that could form a complex structure between the monolayer and the metal ions at the air-water interface. Also, the monolayer behavior at the air-water interface and the electrical properties of metal-complexed Langmuir-Blodgett (LB) films were investigated by using Brewster angle microscopy (BAM) and current-voltage(I-V) measurements. The difference in the BAM images between the pure water and the aqueous metal ions is attributed to the interactions of the copolymers with the metal ions at the interface and the consequent change of the monolayer organization. In the I-V characteristics, the current for LB films with different metal ion depended on the quantity of the metal-ion complexed with the LB film due to the interaction between the metal ion and the IMI-O polymer.

  12. Investigation of the Linker Swing Motion in the Zeolitic Imidazolate Framework ZIF-90

    KAUST Repository

    Zheng, Bin

    2018-03-13

    The linker swing motion in the zeolitic imidazolate framework ZIF-90 is investigated by density functional theory (DFT) calculation, molecular dynamics (MD) and grand-canonical Monte Carlo (GCMC) simulations. The relation between the terminal aldehyde group rotation and the linker swing motion is revealed. The extremely high activation energy of the linker swing motion in ZIF-90 can be attributed to the asymmetric geometry and electron distribution of aldehyde groups. The change in the gate structure resulting from the linker rotation is used to understand the guest adsorption in ZIF-90. This study shows that it is possible to tune the linker swing motion and then the properties of ZIF-90 by manipulating the terminal group rotation. The results highlight the importance of considering the internal freedom effects to correctly describe the linker swing motion and the flexibility of metal-organic frameworks (MOFs).

  13. Zeolitic Imidazolate Framework-8 (ZIF-8) Membranes for Kr/Xe Separation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ting; Feng, Xuhui; Elsaidi, Sameh K.; Thallapally, Praveen K.; Carreon, Moises A.

    2017-01-30

    Herein, we demonstrate that a prototypical type of metal organic framework, zeolitic imidazolate framework-8 (ZIF-8), in membrane form, can effectively separate Kr/Xe gas mixtures at industrially relevant compositions. The best membranes separated Kr/Xe mixtures with average Kr permeances as high as 1.5 × 10-8 ± 0.2 mol/m2 s Pa and average separation selectivities of 14.2 ± 1.9 for molar feed compositions corresponding to Kr/Xe ratio encountered typically in air. Molecular sieving, competitive adsorption, and differences in diffusivities were identified as the prevailing separation mechanisms. These membranes potentially represent a less-energy-intensive alternative to cryogenic distillation, which is the benchmark technology used to separate this challenging gas mixture. To our best knowledge, this is the first example of any metal organic membrane composition displaying separation ability for Kr/Xe gas mixtures.

  14. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin

    2014-08-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, bIm and 2-mbIm in DMF solution at 180 °C. Topological analysis indicated that JUC-160 has a zeolite GIS (gismondine) topology. Study of the gas adsorption and thermal and chemical stability of JUC-160 demonstrated its selective adsorption property for carbon dioxide, high thermal stability, and remarkable chemical resistance to boiling alkaline water and organic solvent for up to one week. © 2014 Elsevier B.V.

  15. Gas-Phase Thermal Tautomerization of Imidazole-Acetic Acid: Theoretical and Computational Investigations

    Directory of Open Access Journals (Sweden)

    Saadullah G. Aziz

    2015-11-01

    Full Text Available The gas-phase thermal tautomerization reaction between imidazole-4-acetic (I and imidazole-5-acetic (II acids was monitored using the traditional hybrid functional (B3LYP and the long-range corrected functionals (CAM-B3LYP and ωB97XD with 6-311++G** and aug-cc-pvdz basis sets. The roles of the long-range and dispersion corrections on their geometrical parameters, thermodynamic functions, kinetics, dipole moments, Highest Occupied Molecular Orbital–Lowest Unoccupied Molecular Orbital (HOMO–LUMO energy gaps and total hyperpolarizability were investigated. All tested levels of theory predicted the preference of I over II by 0.750–0.877 kcal/mol. The origin of predilection of I is assigned to the H-bonding interaction (nN8→σ*O14–H15. This interaction stabilized I by 15.07 kcal/mol. The gas-phase interconversion between the two tautomers assumed a 1,2-proton shift mechanism, with two transition states (TS, TS1 and TS2, having energy barriers of 47.67–49.92 and 49.55–52.69 kcal/mol, respectively, and an sp3-type intermediate. A water-assisted 1,3-proton shift route brought the barrier height down to less than 20 kcal/mol in gas-phase and less than 12 kcal/mol in solution. The relatively high values of total hyperpolarizability of I compared to II were interpreted and discussed.

  16. Zeolitic imidazolate framework membranes and methods of making and using same for separation of c2- and c3+ hydrocarbons and separation of propylene and propane mixtures

    KAUST Repository

    Lai, Zhiping

    2012-12-06

    Certain embodiments are directed to processes for fabrication of zeolitic imidazolate framework (ZIF) membranes. These ZIF membranes can be used in separating C2-hydrocarbons from C3+ hydrocarbons and propylene/propane mixtures.

  17. Zeolitic imidazolate framework membranes and methods of making and using same for separation of c2- and c3+ hydrocarbons and separation of propylene and propane mixtures

    KAUST Repository

    Lai, Zhiping; Pan, Yichang

    2012-01-01

    Certain embodiments are directed to processes for fabrication of zeolitic imidazolate framework (ZIF) membranes. These ZIF membranes can be used in separating C2-hydrocarbons from C3+ hydrocarbons and propylene/propane mixtures.

  18. Radioprotective properties of some heterocyclic nitrogenous compounds against changes in hemoglobin concentration and hematocrit value in x-irradiated mice

    International Nuclear Information System (INIS)

    Rousdhy, H.; Pierotti, T.; Polverelli, M.

    1969-01-01

    Radioprotective properties of imidazole and benzimidazole have been proved in previous works. In this study, authors try to demonstrate radioprotective action of these compounds in comparison with cysteamine upon the hematopoietic system after lethal X-irradiation. Results show: no drastic variations of hematologic constants (hemoglobin concentration and hematocrit value) after intraperitoneal injection of radioprotective compounds apart certain apparent reactions with the heterocyclic compounds; the better radioprotective action of benzimidazole. Twenty five days after irradiation, hemoglobin concentration and hematocrit of radio protected mice return to normal values. (author) [fr

  19. Synthesis, anti-microbial activity, cytotoxicity of some novel substituted (5-(3-(1H-benzo[d]imidazol-2-yl)-4-hydroxybenzyl)benzofuran-2-yl)(phenyl)methanone analogs.

    Science.gov (United States)

    Shankar, Bhookya; Jalapathi, Pochampally; Saikrishna, Balabadra; Perugu, Shaym; Manga, Vijjulatha

    2018-01-09

    There is a dire need for the discovery and development of new antimicrobial agents after several experiments for a better resistance of microorganisms towards antimicrobial agents become a serious health problem for a few years in the past. As benzimidazole possess various types of biological activities, it has been synthesized, in the present study, a new series of (5-(3-(1H-benzo[d]imidazol-2-yl)-4-hydroxybenzyl)benzofuran-2-yl)(phenyl)methanone analogs by using the condensation and screened for its in vitro antimicrobial activity and cytotoxicity. The synthesized (5-(3-(1H-benzo[d]imidazol-2-yl)-4-hydroxybenzyl) benzofuran-2-yl)(phenyl)methanone analogs were confirmed by IR, 1 H and 13 C-NMR, MS spectra and HRMS spectral data. The synthesized compounds were evaluated for their in vitro antimicrobial potential against Gram-positive (Bacillus subtilis, Bacillus megaterium, Staph aureus and Streptococcus pyogenes), Gram-negative (Escherichia coli, Proteus vulgaris, Proteus mirabilis and Enterobacter aerogenes) bacterial and fungal (Aspergillus niger, Candida albicans, Fusarium oxysporum, Fusarium solani) strains by disc diffusion method and the minimum inhibitory concentration (MIC) in which it has been recorded in microgram per milliliter in comparison to the reference drugs, ciprofloxacin (antibacterial) and nystatin (antifungal). Further, the cytotoxicity (IC 50 value) has also been assessed on human cervical (HeLa), Supt1 cancer cell lines by using MTT assay. The following screened compounds (4d), (4f), (4g), (4k), (4l), (4o) and (4u) were found to be the best active against all the tested bacterial and fungal strains among all the demonstrated compounds of biological study. The MIC determination was also carried out against bacteria and fungi, the compounds (4f) and (4u) are found to be exhibited excellent potent against bacteria and fungi respectively. The compounds (4f) and (4u) were shown non-toxic in nature after screened for cytotoxicity against the

  20. Zinc (II) [tetra(4-methylphenyl)] Porphyrin: a Novel and Reusable Catalyst for Efficient Synthesis of 2,4,5-trisubstituted Imidazoles Under Ultrasound Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Safari, Javad; Khalili, Shiva Dehghan; Banitaba, Sayed Hossein; Dehghani, Hossein [Univ. of Kashan, Kashan (Iran, Islamic Republic of)

    2011-10-15

    An efficient three-component one-step synthesis of 2,4,5-trisubstituted imidazoles by condensation reaction of 1,2-diketones or α-hydroxyketones with aromatic aldehydes and ammonium acetate using Zinc (II) [tetra (4-methylphenyl)] porphyrin as a novel and reusable catalyst under ultrasound irradiation at ambient temperature is described. In this method, α-hydroxyketones as well as 1,2-diketones were converted to their corresponding 2,4,5-trisubstituted imidazoles in excellent yields.

  1. Crystal structure of di-μ-chlorido-bis[chloridobis(1,2-dimethyl-5-nitro-1H-imidazole-κN3copper(II] acetonitrile disolvate

    Directory of Open Access Journals (Sweden)

    Patrick J. Quinlivan

    2016-11-01

    Full Text Available 1,2-Dimethyl-5-nitroimidazole (dimetridazole, dimet is a compound that belongs to a class of nitroimidazole drugs that are effective at inhibiting the activity of certain parasites and bacteria. However, there are few reports that describe structures of compounds that feature metals complexed by dimet. Therefore, we report here that dimet reacts with CuCl2·H2O to yield a chloride-bridged copper(II dimer, [Cu2Cl4(C5H7N3O24] or [Cu(μ-ClCl(dimet2]2. In this molecule, the CuII ions are coordinated in an approximately trigonal–bipyramidal manner, and the molecule lies across an inversion center. The dihedral angle between the imidazole rings in the asymmetric unit is 4.28 (7°. Compared to metronidazole, dimetridazole lacks the hydroxyethyl group, and thus cannot form intermolecular O...H hydrogen-bonding interactions. Instead, [Cu(μ-ClCl(dimet2]2 exhibits weak intermolecular interactions between the hydrogen atoms of C—H groups and (i oxygen in the nitro groups, and (ii the terminal and bridging chloride ligands. The unit cell contains four disordered acetonitrile molecules. These were modeled as providing a diffuse contribution to the overall scattering by SQUEEZE [Spek (2015. Acta Cryst. C71, 9–18], which identified two voids, each with a volume of 163 Å3 and a count of 46 electrons, indicative of a total of four acetonitrile molecules. These acetonitrile molecules are included in the chemical formula to give the expected calculated density and F(000.

  2. Endosomal Escape and Delivery of CRISPR/Cas9 Genome Editing Machinery Enabled by Nanoscale Zeolitic Imidazolate Framework

    KAUST Repository

    Alsaiari, Shahad K.

    2017-12-22

    CRISPR/Cas9 is a combined protein (Cas9) and an engineered single guide RNA (sgRNA) genome editing platform that offers revolutionary solutions to genetic diseases. It has, however, a double delivery problem owning to the large protein size and the highly charged RNA component. In this work, we report the first example of CRISPR/Cas9 encapsulated by nanoscale zeolitic imidazole frameworks (ZIFs) with a loading efficiency of 17% and enhanced endosomal escape promoted by the protonated imidazole moieties. The gene editing potential of CRISPR/Cas9 encapsulated by ZIF-8 (CC-ZIFs) is further verified by knocking down the gene expression of green fluorescent protein by 37% over 4 days employing CRISPR/Cas9 machinery. The nanoscale CC-ZIFs are biocompatible and easily scaled-up offering excellent loading capacity and controlled co-delivery of intact Cas9 protein and sgRNA.

  3. Endosomal Escape and Delivery of CRISPR/Cas9 Genome Editing Machinery Enabled by Nanoscale Zeolitic Imidazolate Framework

    KAUST Repository

    Alsaiari, Shahad K.; Patil, Sachin; Alyami, Mram Z.; Alamoudi, Kholod; Aleisa, Fajr A; Merzaban, Jasmeen; Li, Mo; Khashab, Niveen M.

    2017-01-01

    CRISPR/Cas9 is a combined protein (Cas9) and an engineered single guide RNA (sgRNA) genome editing platform that offers revolutionary solutions to genetic diseases. It has, however, a double delivery problem owning to the large protein size and the highly charged RNA component. In this work, we report the first example of CRISPR/Cas9 encapsulated by nanoscale zeolitic imidazole frameworks (ZIFs) with a loading efficiency of 17% and enhanced endosomal escape promoted by the protonated imidazole moieties. The gene editing potential of CRISPR/Cas9 encapsulated by ZIF-8 (CC-ZIFs) is further verified by knocking down the gene expression of green fluorescent protein by 37% over 4 days employing CRISPR/Cas9 machinery. The nanoscale CC-ZIFs are biocompatible and easily scaled-up offering excellent loading capacity and controlled co-delivery of intact Cas9 protein and sgRNA.

  4. Synthesis, Crystal Structure and Luminescent Property of A Novel Cd(II) Coordination Polymer with Bis-imidazole Ligand

    International Nuclear Information System (INIS)

    Zhou, Yong Hong

    2013-01-01

    The key to the successful design of metal-organic coordination polymers is the judicious selection of organic ligand. Recently, polydentate aromatic nitrogen heterocyclic ligands with five-membered rings have been well-studied in the construction of supramolecular structure for their N-coordinated sites apt to coordinating to transition metals. Similar to six-membered N-heterocyclic ligands, the azole-based five-membered N-heterocyclic ligands, such as imidazoles, triazoles and tetrazoles have been extensively employed in the construction of various coordination polymers with diverse topologies and interesting properties. The bis(azole) ligands in which N-donor azole rings (imidazole, triazole, or tetrazole) are separated by alkyl, (CH 2 ) n , spacers are good choices for flexible bridging ligands. The conformational flexibility of the spacers makes the ligands adaptable to various coordination networks with one-, two-, and three dimensional structures

  5. Synthesis and Characterization of New Silver (I N-Heterocyclic Ccarbene Ccomplex Dderived from Imidazol-2-ylidene salt

    Directory of Open Access Journals (Sweden)

    Mohammedl Mujbe Hasson

    2018-04-01

    Full Text Available A new N, N'-imidazolium salt 1-(2,6-diisopropylphenyl-3- (4,6-dimorpholino -1,3,5-traizine-2-yl-1H-imidazol-3-ium chloride as a precursor of N - heterocyclic carbene ligand was prepared via the reaction of 1 - (2, 6 - diisopropyl phenyl - 1H - imidazole with 1, 3, 5 - triazine derivative bearing morpholine substituent (2, 6 -dimorpholine - 6- chloro-1, 3, 5-triaziazine. Linear coordi-nated Ag (І NHC complex was synthesised via deprotonation of the imidazolium salt and reac-tion with Ag2O in darkness at room temperature by in situ method. The complex was synthesised for using as transfer agent to prepare another transition metals complexes by transmetallation method in the future. The imidazolium salt and their silver complex have been characterized by 1 H and 13C NMR spectroscopy as well as mass spectrometry.

  6. Solidification of liquid electrolyte with imidazole polymers for quasi-solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang Miao; Lin Yuan; Zhou Xiaowen; Xiao Xurui; Yang Lei; Feng Shujing; Li Xueping

    2008-01-01

    Quasi-solid-state electrolytes were prepared by employing the imidazole polymers to solidify the liquid electrolyte containing lithium iodide, iodine and ethylene carbonate (EC)/propylene carbonate (PC) mixed solvent. The ionic conductivity and diffusion behavior of triiodide in the quasi-solid-state electrolytes were examined in terms of the polymer content. Application of the quasi-solid-state electrolytes to the dye-sensitized solar cells, the maximum energy conversion efficiency of 7.6% (AM 1.5, 100 mW cm -2 ) was achieved. The dependence of the photovoltaic performance on the polymer content and on the different anions of the imidazole polymers was studied by electrochemical impedance spectroscopy and cyclic voltammetry. The results indicate the charge transfer behaviors occurred at nanocrystalline TiO 2 /electrolyte and Pt/electrolyte interface play an important role in influencing the photovoltaic performance of quasi-solid-state dye-sensitized solar cells

  7. Preparation of kinase-biased compounds in the search for lead inhibitors of kinase targets.

    Science.gov (United States)

    Lai, Justine Y Q; Langston, Steven; Adams, Ruth; Beevers, Rebekah E; Boyce, Richard; Burckhardt, Svenja; Cobb, James; Ferguson, Yvonne; Figueroa, Eva; Grimster, Neil; Henry, Andrew H; Khan, Nawaz; Jenkins, Kerry; Jones, Mark W; Judkins, Robert; Major, Jeremy; Masood, Abid; Nally, James; Payne, Helen; Payne, Lloyd; Raphy, Gilles; Raynham, Tony; Reader, John; Reader, Valérie; Reid, Alison; Ruprah, Parminder; Shaw, Michael; Sore, Hannah; Stirling, Matthew; Talbot, Adam; Taylor, Jess; Thompson, Stephen; Wada, Hiroki; Walker, David

    2005-05-01

    This work describes the preparation of approximately 13,000 compounds for rapid identification of hits in high-throughput screening (HTS). These compounds were designed as potential serine/threonine or tyrosine kinase inhibitors. The library consists of various scaffolds, e.g., purines, oxindoles, and imidazoles, whereby each core scaffold generally includes the hydrogen bond acceptor/donor properties known to be important for kinase binding. Several of these are based upon literature kinase templates, or adaptations of them to provide novelty. The routes to their preparation are outlined. A variety of automation techniques were used to prepare >500 compounds per scaffold. Where applicable, scavenger resins were employed to remove excess reagents and when necessary, preparative high performance liquid chromatography (HPLC) was used for purification. These compounds were screened against an 'in-house' kinase panel. The success rate in HTS was significantly higher than the corporate compound collection. Copyright (c) 2004 Wiley Periodicals, Inc.

  8. A convenient method for 14C-labeling of 2-methylthio-1-[4-N-α-ethoxycarbonylbenzyl)-amino-benzyl] -5-hydroxymethyl-2-[14C]-1H-imidazole and 1-[4-N-α-ethoxy-carbonylbenzyl)-aminobenzyl]-5-hydroxymethyl-2-[14C] -1H-imidazole as potential antihypertensives

    International Nuclear Information System (INIS)

    Nader Saemian; Gholamhossein Shirvani; Mohsen Javaheri; Sayed Sajad Oliyaee

    2012-01-01

    The key synthetic intermediate, (2-mercapto-1-(4-nitrobenzyl)-1H-imidazol-5-yl)methanol-[2- 14 C], has been synthesized by using one pot procedure from potassium[ 14 C]-thiocyanate. It was converted to two nonpeptide angiotensin II receptor antagonists, 2-methylthio-1-[4-N-α-ethoxycarbonyl benzyl)-aminobenzyl]-5-hydroxymethyl-1H-imidazole-[2- 14 C] and 1-[4-N-α-ethoxy-carbonylbenzyl)-aminobenzyl] -5-hydroxymethyl-1H-imidazole-[2- 14 C] via a 3-step sequence synthetic pathway. (author)

  9. Construction, Structural Diversity and Properties of Five Coordination Polymers Based on 5-Nitroisophthalate and Bis(imidazole) Linkers

    Science.gov (United States)

    Arıcı, Mürsel

    2018-06-01

    Five coordination polymers, namely, [Cd(μ3-5-nip)(μ-obix)]n (1), [Co(μ3-5-nip)(μ-obix)]n (2), [Zn(μ-5-nip)(μ-obix)]n (3 and 4) and [Cd(μ-5-nip)(μ-bisobix)]n (5) (5-nip: 5-nitroisophthalate, obix: 1,2-bis(imidazol-1ylmethyl)benzene, bisobix: 1,2-bis(2-isopropylimidazol-1ylmethyl)benzene) were hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, single crystal and powder X-ray diffraction and thermal analysis (TG/DTA). X-ray results showed that the complexes displayed structural diversity depending on metal ions and conformations of bis(imidazole) linkers. Complexes 1 and 2 were 1D structures and obix ligand displayed cis-conformation. Complexes 3 and 4 exhibited 2D and 3D structures with same components depending on obix conformation. In complex 5, 3D+3D→3D interpenetrated structure was obtained with dia topology when bisobix having sterically hindered groups on imidazole rings was used. Moreover, thermal, photoluminescence and optical properties of the complexes were also investigated.

  10. Synthesis, crystal structure, DFT studies, acid dissociation constant, and antimicrobial activity of methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate

    Science.gov (United States)

    Nural, Yahya; Gemili, Muge; Seferoglu, Nurgul; Sahin, Ertan; Ulger, Mahmut; Sari, Hayati

    2018-05-01

    A novel bicyclic thiohydantoin fused to pyrrolidine compound, methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate, was synthesized by the cyclization reaction of dimethyl 5,5-diphenylpyrrolidine-2,4-dicarboxylate and 4-chlorophenyl isothiocyanate in the presence of 4-(dimethylamino)pyridine to form methyl 2-(4-chlorophenyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate with concomitant addition reaction of the 4-chlorophenyl isothiocyanate in 79% yield. The structural characterization was performed by NMR, FT-IR, MS and HRMS techniques, and the stereochemistry of the compound was determined by single crystal X-ray diffraction study. In addition, the molecular structure and 1H and 13C NMR chemical shifts of the compound were obtained with the density functional theory and Hartree-Fock calculations. Acid dissociation constants of the compound were determined using potentiometric titration method in 25% (v/v) dimethyl sulfoxide-water hydroorganic solvent at 25 ± 0.1 °C, at an ionic background of 0.1 mol/L of NaCl using the HYPERQUAD computer program. Four acid dissociation constants were obtained for the compound, and we suggest that these acid dissociation constants are related to the NH, for two groups of enthiols and enol groups. Antimicrobial activity study was performed against S. aureus, B. subtilis, A. hydrophila, E. coli and A. baumannii as bacterial standard strains, and against M. tuberculosis H37Rv as mycobacterial strain. The compound exhibited antibacterial activity in the range of 31.25-62.5 μg/mL, and antimycobacterial activity with a MIC value of 40 μg/mL against the indicated strains.

  11. Organolanthanoid compounds

    International Nuclear Information System (INIS)

    Schumann, H.

    1984-01-01

    Up to little more than a decade ago organolanthanoid compounds were still a curiosity. Apart from the description of an isolated number of cyclopentadienyl and indenyl derivatives, very few significant contributions had been made to this interesting sector of organometallic chemistry. However, subsequent systematic studies using modern preparative and analytical techniques, together with X-ray single crystal structure determinations, enabled the isolation and characterization of a large number of very interesting homoleptic and heteroleptic compounds in which the lanthanoid is bound to hydrogen, to substituted or unsubstituted cyclopentadienyl groups, to allyl or alkynyl groups, or even to phosphorus ylides, trimethylsilyl, and carbonylmetal groups. These compounds, which are all extremely sensitive to oxygen and water, open up new possibilities in the field of catalysis and have great potential in organic synthesis - as recent studies with pentamethylcyclopentadienyl derivatives, organolanthanoid(II) compounds, and hexamethyllanthanoid complexes have already shown. (orig.) [de

  12. In vitro anti-Candida activity and single crystal X-ray structure of ({(1E-[3-(1H-imidazol-1-yl-1-phenylpropylidene]amino}oxy(4-nitrophenylmethanone

    Directory of Open Access Journals (Sweden)

    Mohamed I. Attia

    2014-03-01

    Full Text Available Synthesis, characterization, and anti-Candida activity of ({(E-[3-(1H-imidazol-1-yl-1-phenylpropylidene]amino}oxy(4-nitrophenylmethanone (4 are repor-ted. Compound 4 showed anti-Candida albicans activity (MIC = 0.6862 µmol/mL being nearly 5-fold more potent than the gold standard antifungal drug, fluconazole (MIC ˃ 3.265 µmol/mL, on the clinical isolates of Candida albicans. Single crystal X-ray structure of the title compound 4 confirmed its assigned (E-configuration. The compound crystallizes in the triclinic, P-1 (no. 2, a = 6.4633 (1 Å, b = 11.1063 (2 Å, c = 12.9872 (2 Å, α = 67.650 (1°, β = 86.415 (1°, γ = 86.776 (1°, V = 860.01 (3Å3, Z = 2, R(F = 0.046, wR(F2 = 0.139, T = 296 K. The crystal structure is stabilized by weak intermolecular C—H•••O hydrogen interactions.

  13. On the radioprotective properties of heterocyclic nitrogenous compounds; Etude des proprietes radioprotectrices de composes heterocycliques azotes

    Energy Technology Data Exchange (ETDEWEB)

    Rinaldi, R; Bernard, Y [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    Continuing their study of the possible radioprotective properties of heterocyclic nitrogenous compounds, the authors study certain derivatives of imidazole and other compounds of similar structure. The results obtained showed: 1 - that the derivatives resulting from the presence in the imidazole ring of the mercapto, methyl, carbonyl, or benzyl groups are inactive: these substitutions appear to destroy the significant radioprotective activity of the imidazole, 2 - that benzimidazole, on the contrary, seems to possess highly interesting properties. The percentage of survivals obtained with mice treated with benzimidazole and exposed to lethal irradiation has encouraged the authors to undertake careful study of this substance, with a view to define optimum activity conditions, and to determine the mechanism responsible for its radioprotective action. Further on and so as to of clarify certain points that might give useful data concerning the mechanisms of action of radioprotective chemicals, in respect of each of the products the authors have studied: a - the action of these bodies on the internal temperature of mice, b - their radioprotective activity in vitro, in a solution of irradiated hemin. (authors) [French] Les proprietes radioprotectrices de l'imidazole ayant ete mises en evidence dans un precedent travail, les auteurs poursuivent leur experimentation sur certains derives de ce noyau ainsi que des composes de structure voisine. Leurs resultats montrent: 1 - que les composes obtenus par substitution d'un groupement mercapto, methyle, carbonyle ou benzyle, a un hydrogene du noyau imidazole sont inactifs, 2 - que le benzimidazole presente par contre des proprietes interessantes. Pour ce dernier compose le pourcentage de survie pouvant atteindre 90 pour cent les auteurs ont determine les conditions optimales de son activite radioprotectrice; de plus, dans le but d'obtenir des renseignements susceptibles de preciser le mecanisme d'action de la radioprotection

  14. Formation and ecotoxicity of N-heterocyclic compounds on ammoxidation of mono- and polysaccharides.

    Science.gov (United States)

    Klinger, Karl Michael; Liebner, Falk; Fritz, Ines; Potthast, Antje; Rosenau, Thomas

    2013-09-25

    Ammoxidation of technical lignins under mild conditions is a suitable approach to artificial humic substances. However, carbohydrates as common minor constituents of technical lignins have been demonstrated to be a potential source of N-heterocyclic ecotoxic compounds. Ethyl acetate extracts of ammoxidation mixtures of the monosaccharides glucose and xylose exhibited considerable growth inhibiting activity in the OECD 201 test, with 4-methyl-1H-imidazole, 4-(hydroxymethyl)-1H-imidazole, and 3-hydroxypyridine being the most active compounds. The amount of N-heterocyclic compounds formed at moderate ammoxidation conditions (70 °C, 0.2 MPa O2, 3 h) was significantly lower for the polysaccharides cellulose and xylan (16-30 μg/g of educt) compared to glucose (15.4 mg). Ammoxidation at higher temperature is not recommendable for carbohydrate-rich materials as much higher amounts of N-heterocyclic compounds were formed from both monosaccharides (100 °C: 122.4-160.5 mg/g of educt) and polysaccharides (140 °C: 5.52-16.03 mg/g of educt).

  15. Zeolitic imidazolate frameworks with optimized pore structure for olefin/paraffin-separation

    Energy Technology Data Exchange (ETDEWEB)

    Paula, C.; Boehme, U.; Hartmann, M. [Erlangen-Nuernberg Univ. (Germany). Erlangen Catalysis Resource Center

    2013-11-01

    In the chemical industry, the largest part of energy is spent on separation processes such as the separation of olefin/paraffin mixtures from steam cracker effluents by low-temperature rectification. A suitable alternative to this energy and cost intensive process is separation by selective adsorption with suitable microporous adsorbent. In this work, different ZIFs (Zeolitic Imidazolate Frameworks) have been explored with respect to their separation of olefins and paraffins. The studied materials (e.g. ZIF-8 (SOD-Topology), ZIF-71 (RHO-Topology)) were selected because of their low diameter of the largest pore entrance (0.29 to 4.2 nm) which is close to the kinetic diameter of the C{sub 2} to C{sub 4} olefins and paraffins under study. In contrast to other MOF- or zeolite-based adsorbents, in ZIF-8 and ZIF-71, the paraffin is preferentially adsorbed, which is evident from the single-component adsorption isotherms at different temperature. In the corresponding mixture breakthrough curves, the olefin breaks through first and the alkane even displaces the olefin from the pores. Thus, ZIF-8 and ZIF-71 are interesting candidates for the envisaged paraffin/olefin separation. Whether the observed separation behavior is due to the structural properties of the studied ZIFs or a consequence of peculiar chemical properties is subject to further studies. (orig.) (Published in summary form only)

  16. Hybrid Zeolitic Imidazolate Frameworks: Controlling Framework Porosity and Functionality by Mixed-Linker Synthesis

    KAUST Repository

    Thompson, Joshua A.

    2012-05-22

    Zeolitic imidazolate frameworks (ZIFs) are a subclass of nanoporous metal-organic frameworks (MOFs) that exhibit zeolite-like structural topologies and have interesting molecular recognition properties, such as molecular sieving and gate-opening effects associated with their pore apertures. The synthesis and characterization of hybrid ZIFs with mixed linkers in the framework are described in this work, producing materials with properties distinctly different from the parent frameworks (ZIF-8, ZIF-90, and ZIF-7). NMR spectroscopy is used to assess the relative amounts of the different linkers included in the frameworks, whereas nitrogen physisorption shows the evolution of the effective pore size distribution in materials resulting from the framework hybridization. X-ray diffraction shows these hybrid materials to be crystalline. In the case of ZIF-8-90 hybrids, the cubic space group of the parent frameworks is continuously maintained, whereas in the case of the ZIF-7-8 hybrids there is a transition from a cubic to a rhombohedral space group. Nitrogen physisorption data reveal that the hybrid materials exhibit substantial changes in gate-opening phenomena, either occurring at continuously tunable partial pressures of nitrogen (ZIF-8-90 hybrids) or loss of gate-opening effects to yield more rigid frameworks (ZIF-7-8 hybrids). With this synthetic approach, significant alterations in MOF properties may be realized to suit a desired separation or catalytic process. © 2012 American Chemical Society.

  17. Hydrothermal Synthesis of Zeolitic Imidazolate Frameworks-8 (ZIF-8) Crystals with Controllable Size and Morphology

    KAUST Repository

    Lestari, Gabriella

    2012-05-01

    Zeolitic imidazolate frameworks (ZIFs) is a new class of metal-organic frameworks (MOFs) with zeolite-like properties such as permanent porosity, uniform pore size, and exceptional thermal and chemical stability. Until recently, ZIF materials have been mostly synthesized by solvothermal method. In this thesis, further analysis to tune the size and morphology of ZIF-8 is done upon our group’s recent success in preparing ZIF-8 crystals in pure aqueous solutions. Compositional parameters (molar ratio of 2-methylimidazole/Zn2+, type of zinc salt reagents, reagent concentrations, addition of surfactants) as well as process parameters (temperature and time) were systematically investigated. Upon characterizations of as-synthesized samples by X-ray powder diffraction, thermal gravimetric analysis, N2 adsorption, and field-emission scanning electron microscope, the results show that the particle size and morphology of ZIF-8 crystals are extremely sensitive to the compotional parameters of reagent concentration and addition of surfactants. The particle size and morphology of hydrothermally synthesized ZIF-8 crystals can be finely tuned; with the size ranging from 90 nm to 4 μm and the shape from truncated cubic to rhombic dodecahedron.

  18. Adsorptive removal of 1-naphthol from water with Zeolitic imidazolate framework-67

    Science.gov (United States)

    Yan, Xinlong; Hu, Xiaoyan; Chen, Tao; Zhang, Shiyu; Zhou, Min

    2017-08-01

    1-Naphthol is widely used as an intermediate in the plastics, dyes, fibers and rubbers production areas, leading to the increasing detection of 1-naphthol in the soil and water environment, which is of particular concern due to its acute toxicity and negative environmental impacts. Considering the high surface area and good stability of ZIFs (zeolitic imidazole frameworks) material, ZIF-67 (a representative cobalt-based ZIFs material) was synthesized and applied as an adsorbent for removal of 1-naphthol from aqueous solution. The obtained ZIF-67 was characterized by XRD, TEM, XPS, N2 physisorption and TG, and the adsorption isotherm, kinetics, and regeneration of the adsorbent were studied in detail. The adsorption of 1-naphthol on ZIF-67 followed a pseudo-second-order equation kinetics and fitted Langmuir adsorption model with a maximum adsorption capacity of 339 mg/g at 313 K, which is much higher than that of the common adsorbents reported such as activated carbon and carbon nanotubes et al. The solution pH was found to be an important factor influencing the adsorption process, which could be explained by the predominant mechanism controlling the process, i.e. electrostatic attraction. In addition, the ZIF-67 showed desirable reusability toward 1-naphthol removal from alkaline aqueous solution.

  19. Caseoperoxidase, mixed β-casein-SDS-hemin-imidazole complex: a nano artificial enzyme.

    Science.gov (United States)

    Moosavi-Movahedi, Zainab; Gharibi, Hussein; Hadi-Alijanvand, Hamid; Akbarzadeh, Mohammad; Esmaili, Mansoore; Atri, Maliheh S; Sefidbakht, Yahya; Bohlooli, Mousa; Nazari, Khodadad; Javadian, Soheila; Hong, Jun; Saboury, Ali A; Sheibani, Nader; Moosavi-Movahedi, Ali A

    2015-01-01

    A novel peroxidase-like artificial enzyme, named "caseoperoxidase", was biomimetically designed using a nano artificial amino acid apo-protein hydrophobic pocket. This four-component nano artificial enzyme containing heme-imidazole-β-casein-SDS exhibited high activity growth and k(cat) performance toward the native horseradish peroxidase demonstrated by the steady state kinetics using UV-vis spectrophotometry. The hydrophobicity and secondary structure of the caseoperoxidase were studied by ANS fluorescence and circular dichroism spectroscopy. Camel β-casein (Cβ-casein) was selected as an appropriate apo-protein for the heme active site because of its innate flexibility and exalted hydrophobicity. This selection was confirmed by homology modeling method. Heme docking into the newly obtained Cβ-casein structure indicated one heme was mainly incorporated with Cβ-casein. The presence of a main electrostatic site for the active site in the Cβ-casein was also confirmed by experimental methods through Wyman binding potential and isothermal titration calorimetry. The existence of Cβ-casein protein in this biocatalyst lowered the suicide inactivation and provided a suitable protective role for the heme active-site. Additional experiments confirmed the retention of caseoperoxidase structure and function as an artificial enzyme.

  20. Comparing gas separation performance between all known zeolites and their zeolitic imidazolate framework counterparts.

    Science.gov (United States)

    Gómez-Álvarez, Paula; Hamad, Said; Haranczyk, Maciej; Ruiz-Salvador, A Rabdel; Calero, Sofia

    2016-01-07

    To find optimal porous materials for adsorption-based separations is a challenging task due to the extremely large number of possible pore topologies and compositions. New porous material classes such as Metal Organic Frameworks (MOFs) are emerging, and hope to replace traditionally used materials such as zeolites. Computational screening offers relatively fast searching for candidate structures as well as side-by-side comparisons between material families. This work is pioneering at examining the families comprised by the experimentally known zeolites and their respective Zeolitic Imidazolate Framework (ZIF) counterparts in the context of a number of environmental and industrial separations involving carbon dioxide, nitrogen, methane, oxygen, and argon. Additionally, unlike related published work, here all the targeted structures have been previously relaxed through energy minimization. On the first level of characterization, we considered a detailed pore characterization, identifying 24 zeolites as promising candidates for gas separation based on adsorbate sizes. The second level involved interatomic potential-based calculations to assess the adsorption performance of the materials. We found no correlation in the values of heat of adsorption between zeolites and ZIFs sharing the same topology. A number of structures were identified as potential experimental targets for CO2/N2, and CO2/CH4 affinity-based separations.

  1. Effect of imidazole and indomethacin on hemodynamics of the obstructed canine kidney

    International Nuclear Information System (INIS)

    Balint, P.; Laszlo, K.

    1985-01-01

    In the anesthetized dog renal blood flow (RBF) and its intrarenal distribution were investigated by the radioactive microsphere technique 24 hr after bilateral (BUL) and unilateral (UUL) ureteral ligation. In the control series indomethacin (IM) led to a decrease in RBF with outward shifting of zonal perfusions; imidazole (IA) did not cause significant changes in renal hemodynamics. In the BUL series there was a sharp drop in RBF with a proportional decrease in outer (OC) and inner (IC) cortical perfusion; IM treatment resulted in a further decrease in overall and zonal perfusions. IA, a selective inhibitor of thromboxane synthetase, relieved IC vasoconstriction. In the ligated kidney of the UUL preparations decrease in RBF was due to OC vasoconstriction, while IC perfusion equalled controls. IM led to an overall vasoconstriction in all cortical layers; IA did not influence either total RBF or its distribution. It was concluded that BUL ''unmasked'' TXA2 production in the IC layers, while IM treatment, by inhibiting the production of PGE2, PGI2, and TXA2, resulted in an overall vasoconstriction both in controls and the BUL and UUL preparations

  2. Novel catalytic micromotor of porous zeolitic imidazolate framework-67 for precise drug delivery.

    Science.gov (United States)

    Wang, Linlin; Zhu, Hongli; Shi, Ying; Ge, You; Feng, Xiaomiao; Liu, Ruiqing; Li, Yi; Ma, Yanwen; Wang, Lianhui

    2018-06-07

    Micromotors hold promise as drug carriers for targeted drug delivery owing to the characteristics of self-propulsion and directional navigation. However, several defects still exist, including high cost, short movement life, low drug loading and slow release rate. Herein, a novel catalytic micromotor based on porous zeolitic imidazolate framework-67 (ZIF-67) synthesized by a greatly simplified wet chemical method assisted with ultrasonication is described as an efficient anticancer drug carrier. These porous micromotors display effective autonomous motion in hydrogen peroxide and long durable movement life of up to 90 min. Moreover, the multifunctional micromotor ZIF-67/Fe3O4/DOX exhibits excellent performance in precise drug delivery under external magnetic field with high drug loading capacity of fluorescent anticancer drug DOX up to 682 μg mg-1 owing to its porous nature, high surface area and rapid drug release based on dual stimulus of catalytic reaction and solvent effects. Therefore, these porous ZIF-67-based catalytic micromotors combine the domains of metal-organic frameworks (MOFs) and micomotors, thus developing potential resources for micromotors and holding great potential as label-free and precisely controlled high-quality candidates of drug delivery systems for biomedical applications.

  3. Efficient adsorptive removal of Congo red from aqueous solution by synthesized zeolitic imidazolate framework-8

    Directory of Open Access Journals (Sweden)

    Canlan Jiang

    2016-10-01

    Full Text Available Dyes exposure in aquatic environment creates risks to human health and biota due to their intrinsic toxic mutagenic and carcinogenic characteristics. In this work, a metal-organic frameworks materials, zeolitic imidazolate framework-8 (ZIF-8, was synthesized through hydrothermal reaction for the adsorptive removal of harmful Congo red (CR from aqueous solution. Results showed that the maximum adsorption capacity of CR onto ZIF-8 was ultrahigh as 1250 mg g−1. Adsorption behaviors can be successfully fitted by the pseudo-second order kinetic model and the Langmuir isotherm equation. Solution conditions (pH condition and the co-exist anions may influent the adsorption behaviors. The adsorption performance at various temperatures indicated the process was a spontaneous and endothermic adsorption reaction. The enhanced adsorption capacity was determined due to large surface area of ZIF-8 and the strong interactions between surface groups of ZIF-8 and CR molecules including the electrostatic interaction between external active sites Zn−OH on ZIF-8 -and −SO3 or –N=N– sites in CR molecule, and the π–π interaction.

  4. Synthesis of triazole-based and imidazole-based zinc catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, Carlos A.; Satcher, Jr., Joe H.; Aines, Roger D.; Baker, Sarah E.

    2013-03-12

    Various methods and structures of complexes and molecules are described herein related to a zinc-centered catalyst for removing carbon dioxide from atmospheric or aqueous environments. According to one embodiment, a method for creating a tris(triazolyl)pentaerythritol molecule includes contacting a pentaerythritol molecule with a propargyl halide molecule to create a trialkyne molecule, and contacting the trialkyne molecule with an azide molecule to create the tris(triazolyl)pentaerythritol molecule. In another embodiment, a method for creating a tris(imidazolyl)pentaerythritol molecule includes alkylating an imidazole 2-carbaldehyde molecule to create a monoalkylated aldehyde molecule, reducing the monoalkylated aldehyde molecule to create an alcohol molecule, converting the alcohol molecule to create an alkyl halide molecule using thionyl halide, and reacting the alkyl halide molecule with a pentaerythritol molecule to create a tris(imidazolyl)pentaerythritol molecule. In another embodiment, zinc is bound to the tris(triazolyl)pentaerythritol molecule to create a zinc-centered tris(triazolyl)pentaerythritol catalyst for removing carbon dioxide from atmospheric or aqueous environments.

  5. Tunable CO 2 Adsorbents by Mixed-Linker Synthesis and Postsynthetic Modification of Zeolitic Imidazolate Frameworks

    KAUST Repository

    Thompson, Joshua A.

    2013-04-25

    The incorporation of accessible amine functionality in zeolitic imidazolate frameworks (ZIFs) is used to improve the adsorption selectivity for CO 2/CH4 gas separation applications. Two synthetic approaches are described in this work to introduce functionality into the ZIF: (i) mixed-linker ZIF synthesis with 2-aminobenzimidazole as a substitution linker and (ii) postsynthetic modification of a mixed-linker ZIF with ethylenediamine. Using 2-aminobenzimidazole, a linker with a primary amine functional group, substitution of the ZIF-8 linker during synthesis allows for control over the adsorption properties while maintaining the ZIF-8 structure with up to nearly 50% substitution in the mixed-linker ZIF framework, producing a material with tunable pore size and amine functionality. Alternatively, postsynthetic modification of a mixed-linker ZIF containing an aldehyde functional group produces a ZIF material with a primary amine without detrimental loss of micropore volume by controlling the amount of functional group sites for modification. Both approaches using mixed-linker ZIFs yield new materials that show improvement in adsorption selectivity for the CO 2/CH4 gas pair over ZIF-8 and commercially available adsorbents as well as an increase in the heat of adsorption for CO2 without significant changes to the crystal structure. These results indicate that tuning the surface properties of ZIFs by either mixed-linker synthesis and/or postsynthetic modification may generate new materials with improved gas separation properties, thereby providing a new method for tailoring metal-organic frameworks. © 2013 American Chemical Society.

  6. Tunable CO 2 Adsorbents by Mixed-Linker Synthesis and Postsynthetic Modification of Zeolitic Imidazolate Frameworks

    KAUST Repository

    Thompson, Joshua A.; Brunelli, Nicholas A.; Lively, Ryan P.; Johnson, J. R.; Jones, Christopher W.; Nair, Sankar

    2013-01-01

    The incorporation of accessible amine functionality in zeolitic imidazolate frameworks (ZIFs) is used to improve the adsorption selectivity for CO 2/CH4 gas separation applications. Two synthetic approaches are described in this work to introduce functionality into the ZIF: (i) mixed-linker ZIF synthesis with 2-aminobenzimidazole as a substitution linker and (ii) postsynthetic modification of a mixed-linker ZIF with ethylenediamine. Using 2-aminobenzimidazole, a linker with a primary amine functional group, substitution of the ZIF-8 linker during synthesis allows for control over the adsorption properties while maintaining the ZIF-8 structure with up to nearly 50% substitution in the mixed-linker ZIF framework, producing a material with tunable pore size and amine functionality. Alternatively, postsynthetic modification of a mixed-linker ZIF containing an aldehyde functional group produces a ZIF material with a primary amine without detrimental loss of micropore volume by controlling the amount of functional group sites for modification. Both approaches using mixed-linker ZIFs yield new materials that show improvement in adsorption selectivity for the CO 2/CH4 gas pair over ZIF-8 and commercially available adsorbents as well as an increase in the heat of adsorption for CO2 without significant changes to the crystal structure. These results indicate that tuning the surface properties of ZIFs by either mixed-linker synthesis and/or postsynthetic modification may generate new materials with improved gas separation properties, thereby providing a new method for tailoring metal-organic frameworks. © 2013 American Chemical Society.

  7. Novel Zeolitic Imidazolate Framework/Polymer Membranes for Hydrogen Separations in Coal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Musselman, Inga H.

    2013-01-31

    Nanoparticles of zeolitic imidazolate frameworks and other related hybrid materials were prepared by modifying published synthesis procedures by introducing bases, changing stoichiometric ratios, or adjusting reaction conditions. These materials were stable at temperatures >300 °C and were compatible with the polymer matrices used to prepare mixed-matrix membranes (MMMs). MMMs tested at 300 °C exhibited a >30 fold increase in permeability, compared to those measured at 35 °C, while maintaining H{sub 2}/CO{sub 2} selectivity. Measurements at high pressure (up to 30 atm) and high temperature (up to 300 °C) resulted in an increase in gas flux across the membrane with retention of selectivity. No variations in permeability were observed at high pressures at either 35 or 300 °C. CO{sub 2}-induced plasticization was not observed for Matrimid®, VTEC, and PBI polymers or their MMMs at 30 atm and 300 °C. Membrane surface modification by cross-linking with ethylenediamine resulted in an increase in H{sub 2}/CO{sub 2} selectivity at 35 °C. Spectrometric analysis showed that the cross-linking was effective to temperatures <150 °C. At higher temperatures, the cross-linked membranes exhibit a H2/CO2 selectivity similar to the uncrosslinked polymer.

  8. Antifungal activity of tioconazole (UK-20,349), a new imidazole derivative.

    Science.gov (United States)

    Jevons, S; Gymer, G E; Brammer, K W; Cox, D A; Leeming, M R

    1979-04-01

    Tioconazole (UK-20,349), a new antifungal imidazole derivative, was compared with miconazole for activity in vitro against Candida spp., Torulopsis glabrata, Cryptococcus neoformans, Aspergillus spp., and dermatophyte fungi (Trichophyton spp. and Microsporum spp.). Tioconazole was more active than miconazole against all the fungal species examined except Aspergillus, against which both agents showed similar activity. Both tioconazole and miconazole inhibited the growth of all fungi examined at concentrations well below their quoted minimum inhibitory concentrations. Their activity against fungi in vivo was investigated in mice infected systemically with Candida albicans. Both agents significantly reduced the numbers of viable Candida cells recoverable from the kidneys of infected animals, with tioconazole producing a generally more marked reduction. After administration of a single oral dose (25 mg/kg) to beagle dogs or white mice, higher and more sustained circulating levels of bioactive drug were detectable of tioconazole than of miconazole. These observations suggest that tioconazole may have potential in the treatment of both superficial and systemic mycoses in humans.

  9. Fine-scale tribological performance of zeolitic imidazolate framework (ZIF-8 based polymer nanocomposite membranes

    Directory of Open Access Journals (Sweden)

    Nay Win Khun

    2014-12-01

    Full Text Available We combined zeolitic imidazolate framework nanoparticles (ZIF-8: ˜150 nm diameter with Matrimid® 5218 polymer to form permeable mixed matrix membranes, featuring different weight fractions of nanoparticles (up to 30 wt. % loading. We used ball-on-disc micro-tribological method to measure the frictional coefficient of the nanocomposite membranes, as a function of nanoparticle loading and annealing heat treatment. The tribological results reveal that the friction and wear of the unannealed samples rise steadily with greater nanoparticle loading because ZIF-8 is relatively harder than the matrix, thus promoting abrasive wear mechanism. After annealing, however, we discover that the nanocomposites display an appreciably lower friction and wear damage compared with the unannealed counterparts. Evidence shows that the major improvement in tribological performance is associated with the greater amounts of wear debris derived from the annealed nanocomposite membranes. We propose that detached Matrimid-encapsulated ZIF-8 nanoparticles could function as “spacers,” which are capable of not only reducing direct contact between two rubbing surfaces but also enhancing free-rolling under the action of lateral forces.

  10. Multipurpose Compound

    Science.gov (United States)

    1983-01-01

    Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

  11. Anticonvulsant and reproductive toxicological studies of the imidazole-based histamine H3R antagonist 2-18 in mice

    Directory of Open Access Journals (Sweden)

    Bastaki SM

    2018-01-01

    Full Text Available Salim M Bastaki,1 Yousef M Abdulrazzaq,2 Mohamed Shafiullah,1 Małgorzata Więcek,3 Katarzyna Kieć-Kononowicz,3 Bassem Sadek1 1Department of Pharmacology and Therapeutics, College of Medicine and Health Science, United Arab Emirates University, Al Ain, 2Department of Medical Education, Dubai Health Authority, Dubai, UAE; 3Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna, Kraków, Poland Abstract: The imidazole-based H3R antagonist 2-18 with high in vitro H3R antagonist affinity, excellent in vitro selectivity profile, and high in vivo H3R antagonist potency was tested for its anticonvulsant effect in maximal electroshock (MES-induced convulsions in mice having valproic acid (VPA as a reference antiepileptic drug (AED. Additionally, H3R antagonist 2-18 was evaluated for its reproductive toxicity in the same animal species. The results show that acute systemic administration (intraperitoneal; i.p. of H3R antagonist 2-18 (7.5, 15, 30, and 60 mg/kg, i.p. significantly and dose dependently protected male as well as female mice against MES-induced convulsion. The protective action observed for H3R antagonist 2-18 in both mice sexes was comparable to that of VPA and was reversed when mice were pretreated with the selective H3R agonist (R-alpha-methylhistamine (RAMH, 10 mg/kg, i.p.. Moreover, the results show that acute systemic administration of single (7.5, 15, 30, or 60 mg/kg, i.p. or multiple doses (15×3 mg/kg, i.p. of H3R antagonist 2-18 on gestation day (GD 8 or 13 did not affect the maternal body weight of mice when compared with the control group. Furthermore, no significant differences were observed in the average number of implantations and resorptions between the control and H3R antagonist 2-18-treated group at the early stages of gestation and the organogenesis period. However, oral treatment with H3R antagonist 2-18 (15 mg/kg on GD 8 induced a reduced number of

  12. Polymer compound

    NARCIS (Netherlands)

    1995-01-01

    A Polymer compound comprising a polymer (a) that contains cyclic imidesgroups and a polymer (b) that contains monomer groups with a 2,4-diamino-1,3,5-triazine side group. According to the formula (see formula) whereby themole percentage ratio of the cyclic imides groups in the polymer compoundwith

  13. Mesoionic Compounds

    Indian Academy of Sciences (India)

    Organic Chemistry. Kamatak University,. Dharwad. Her research interests are synthesis, reactions and synthetic utility of sydnones. She is currently working on electrochemical and insecticidal/antifungal activities for some of these compounds. Keywords. Aromaticity, mesoionic hetero- cycles, sydnones, tandem re- actions.

  14. Comparative pharmacodynamic analysis of imidazoline compounds using rat model of ocular mydriasis with a test of quantitative structure-activity relationships.

    Science.gov (United States)

    Raczak-Gutknecht, Joanna; Nasal, Antoni; Frąckowiak, Teresa; Kornicka, Anita; Sączewski, Franciszek; Wawrzyniak, Renata; Kubik, Łukasz; Kaliszan, Roman

    2017-09-10

    Imidazol(in)e derivatives, having the chemical structure similar to clonidine, exert diverse pharmacological activities connected with their interactions with alpha2-adrenergic receptors, e.g. hypotension, bradycardia, sedation as well as antinociceptive, anxiolytic, antiarrhythmic, muscle relaxant and mydriatic effects. The mechanism of pupillary dilation observed after systemic administration of imidazol(in)es to rats, mice and cats depends on the stimulation of postsynaptic alpha2-adrenoceptors within the brain. It was proved that the central nervous system (CNS)-localized I1-imidazoline receptors are not engaged in those effects. It appeared interesting to analyze the CNS-mediated pharmacodynamics of imidazole(in)e agents in terms of their chromatographic and calculation chemistry-derived parameters. In the present study a systematic determination and comparative pharmacometric analysis of mydriatic effects in rats were performed on a series of 20 imidazol(in)e agents, composed of the well-known drugs and of the substances used in experimental pharmacology. The eye pupil dilatory activities of the compounds were assessed in anesthetized Wistar rats according to the established Koss method. Among twenty imidazol(in)e derivatives studied, 18 produced diverse dose-dependent mydriatic effects. In the quantitative structure-activity relationships (QSAR) analysis, the pharmacological data (half maximum mydriatic effect - ED 50 in μmol/kg) were considered along with the structural parameters of the agents from molecular modeling. The theoretically calculated lipophilicity parameters, CLOGP, of imidazol(in)es, as well as their lipophilicity parameters from HPLC, logk w , were also considered. The attempts to derive statistically significant QSAR equations for a full series of the agents under study were unsuccessful. However, for a subgroup of eight apparently structurally related imidazol(in)es a significant relationship between log(1/ED 50 ) and logk w values was

  15. Crystal structures of eight 3D molecular adducts derived from bis-imidazole, bis(benzimidazole), and organic acids

    Science.gov (United States)

    Ding, Aihua; Jin, Shouwen; Jin, Shide; Hu, KaiKai; Lin, Zhihao; Liu, Hui; Wang, Daqi

    2018-01-01

    Cocrystallization of the bis(imidazole)/bis(benzimidazole) with a series of organic acids gave a total of eight molecular adducts with the compositions: (3,6-bis(imidazole-1-yl)pyridazine): (trichloroacetic acid)2(1) [(H2L1)2+ · (tca-)2, L1 = 3,6-bis(imidazole-1-yl)pyridazine, tca- = trichloroacetate], (bis(N-imidazolyl)methane): (suberic acid) (2) [(L2) · (H2suba), L2 = bis(N-imidazolyl)methane, H2suba = suberic acid], bis(N-imidazolyl)methane: (3-nitrophthalic acid): 3H2O (3) [(H2L2)2+ · (3-Hnpa-)2 · 3H2O, 3-Hnpa- = 3-nitro hydrogenphthalate], (bis(N-imidazolyl)butane)0.5: (4-nitrophthalic acid): H2O (4) [(H2L3)0.5+ · (4-Hnpa-)- · H2O, L3 = bis(N-imidazolyl)butane, 4-Hnpa- = 4-nitro hydrogenphthalate], (1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole): (3,5-dinitrosalicylic acid) (5) [(HL4) · (3,5-dns-), L4 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole, 3,5-dns- = 3,5-dinitrosalicylate], (1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole): (3-nitrophthalic acid) (6) [(H2L4) · (3-npa2-), L4 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole, 3-npa2-=3-nitrogenphthalate], (bis(N-imidazolyl)butane): (pamoic acid) (7) [(H2L3) · (pam), pam = pamoate], and (3,6-bis(imidazole-1-yl)pyridazine): (1,5-naphthalenedisulfonic acid) [(H2L1)2+ · (npda)2- = 1,5-naphthalenedisulfonate] (8). The eight adducts have been characterized by X-ray diffraction technique, infrared spectrum, and elemental analysis, and the melting points of all adducts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the eight investigated crystals both the end ring N in the bis(imidazole) moieties are protonated when the organic acids are deprotonated except 2, and 5, and the crystal packing is interpreted in terms of the strong ionic Nsbnd H⋯O H-bond between the imidazolium and the deprotonated acidic groups. Except the Nsbnd H⋯O H-bond, the Osbnd H⋯O H-bonds were also found at the salts 3, 4

  16. Structural Contraction of Zeolitic Imidazolate Frameworks: Membrane Application on Porous Metallic Hollow Fibers for Gas Separation.

    Science.gov (United States)

    Cacho-Bailo, Fernando; Etxeberría-Benavides, Miren; David, Oana; Téllez, Carlos; Coronas, Joaquín

    2017-06-21

    Positive thermal expansion coefficients (TECs) of 52 × 10 -6 and 35 × 10 -6 K -1 were experimentally calculated in the -116 to 250 °C range for the III-phases of zeolitic imidazolate frameworks (ZIF) ZIF-9(Co) and ZIF-7(Zn), respectively, by means of the unit cell dimensions and volume of the materials in the monoclinic crystal system calculated from the XRD patterns. The unit cell dimensions and volume showed a significant expansion phenomenon as the temperature increased, by as much as 5.5% for ZIF-9-III in the studied range. To exploit the advantages of such thermal behavior, a new approach to the fabrication of ZIF-9-III membranes on thin, flexible, and highly porous nickel hollow fiber (Ni HF) supports by a versatile and easy-controllable microfluidic setup is herein reported. These Ni HF supports result from the sintering of 25-μm Ni particles and display very positive mechanical properties and bending resistance. As compared to the traditional polymer-based HF membranes, the ZIF metal-supported membrane exhibited good durability and robustness throughout its operation in a wide temperature range and after heating and cooling cycles. These benefits derive from (1) the pore-plugging membrane configuration resulting from the high porosity of the support and (2) the similarity between the TECs of the ZIF and the metallic support, both positive, which enhances their mutual compatibility. An increase in the H 2 /CO 2 separation selectivity at low temperatures (as high as 22.2 at -10 °C, along with 102 GPU permeance of H 2 ) was achieved, in agreement with the structural variations observed in the ZIF material.

  17. Compound odontoma

    Directory of Open Access Journals (Sweden)

    Monica Yadav

    2012-01-01

    Full Text Available Odontomas have been extensively reported in the dental literature, and the term refers to tumors of odontogenic origin. Though the exact etiology is still unknown, the postulated causes include: local trauma, infection, inheritance and genetic mutation. The majority of the lesions are asymptomatic; however, may be accompanied with pain and swelling as secondary complaints in some cases. Here, we report a case of a compound odontome in a 14 year old patient.

  18. Preparation of poly(vinyl alcohol) membranes grafted with N-vinyl imidazole/acrylic acid binary monomers

    International Nuclear Information System (INIS)

    Ajji, Zaki; Ali, Ali

    2006-01-01

    Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl imidazole. The influence of different parameters on the grafting yield was investigated as: type of solvent and solvent composition, comonomer concentration and composition, addition of mineral acids, and irradiation dose. Water uptake in respect to the grafting yield was also evaluated. The ability of the grafted films to adsorb copper ions was elaborated and discussed for different grafting yields and ph values of the solution. (authors)

  19. Stacking Faults and Mechanical Behavior beyond the Elastic Limit of an Imidazole-Based Metal Organic Framework: ZIF-8.

    Science.gov (United States)

    Hegde, Vinay I; Tan, Jin-Chong; Waghmare, Umesh V; Cheetham, Anthony K

    2013-10-17

    We determine the nonlinear mechanical behavior of a prototypical zeolitic imidazolate framework (ZIF-8) along two modes of mechanical failure in response to tensile and shear forces using first-principles simulations. Our generalized stacking fault energy surface reveals an intrinsic stacking fault of surprisingly low energy comparable to that in copper, though the energy barrier associated with its formation is much higher. The lack of vibrational spectroscopic evidence for such faults in experiments can be explained with the structural instability of the barrier state to form a denser and disordered state of ZIF-8 seen in our analysis, that is, large shear leads to its amorphization rather than formation of faults.

  20. Biology-oriented drug synthesis (BIODS) of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl ether derivatives, in vitro α-amylase inhibitory activity and in silico studies.

    Science.gov (United States)

    Taha, Muhammad; Imran, Syahrul; Ismail, Nor Hadiani; Selvaraj, Manikandan; Rahim, Fazal; Chigurupati, Sridevi; Ullah, Hayat; Khan, Fahad; Salar, Uzma; Javid, Muhammad Tariq; Vijayabalan, Shantini; Zaman, Khalid; Khan, Khalid Mohammed

    2017-10-01

    A new library of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl ether derivatives (1-23) were synthesized and characterized by EI-MS and 1 H NMR, and screened for their α-amylase inhibitory activity. Out of twenty-three derivatives, two molecules 19 (IC 50 =0.38±0.82µM) and 23 (IC 50 =1.66±0.14µM), showed excellent activity whereas the remaining compounds, except 10 and 17, showed good to moderate inhibition in the range of IC 50 =1.77-2.98µM when compared with the standard acarbose (IC 50 =1.66±0.1µM). A plausible structure-activity relationship has also been presented. In addition, in silico studies was carried out in order to rationalize the binding interaction of compounds with the active site of enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Sequential one-pot synthesis of imidazoles and 2H-imidazolones from β-ketoamines, acylating agents and ammonium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Jalani, Hitesh B.; Venkateswararao, Edda; Manickam, Manoj; Jung, Sang Hun [College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon (Korea, Republic of)

    2016-12-15

    An efficient, practical, straight forward, and transition metal-free three-component synthesis of diversely substituted imidazoles and 2H-imidazolones from β-ketoamines, acylating agents, and ammonium acetate has been described herein. This approach involves [3+1+1] cyclization through consecutive formation of three C–N bonds as a sequence of initial amidation of β-ketoamines with acylating agent, β-iminoketoamide formation with ammonia, and acid catalyzed concomitant cyclodehydration to afford the imidazoles and 2H-imidazolones. This methodology has advantages such as single flask operation, readily available starting materials, mild conditions, broad functional groups tolerance, and simple work-up procedure.

  2. Model Studies of the Histidine-Tyrosine Cross-Link in Cytochrome c Oxidase Reveal the Flexible Substituent Effect of the Imidazole Moiety

    Science.gov (United States)

    Pratt, Derek A.; Pesavento, Russell P.; van der Donk, Wilfred A.

    2010-01-01

    Experimental and theoretical studies were carried out to interrogate the effect of an imidazole substituent in each of the ortho, meta, and para positions on the pKa, E°, and O–H BDE of phenol. The results reveal that imidazole substitution lowers the pKa of phenol and increases the E° of phenoxide due to its σ-electron withdrawing ability (σp− = +0.21, σm− = +0.45) but decreases the O–H BDE and E° of phenol due to its σ-electron-donating ability (σp+ = −0.45). PMID:15957934

  3. Synthesis, spectroscopic and DNA binding ability of CoII, NiII, CuII and ZnII complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex.

    Science.gov (United States)

    Yarkandi, Naeema H; El-Ghamry, Hoda A; Gaber, Mohamed

    2017-06-01

    A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L) 2 ]·l2H 2 O, [Ni(L)Cl·(H 2 O) 2 ].5H 2 O, [Cu(L)Cl] and [Zn(L)(CH 3 COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, 1 H & 13 C NMR, mass spectral analysis, molar conductivity measurement, UV-Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV-Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (K b ). Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Imidazole-4-acetic acid, a new lead structure for interaction with the taurine transporter in outer blood-retinal barrier cells.

    Science.gov (United States)

    Valembois, Sophie; Krall, Jacob; Frølund, Bente; Steffansen, Bente

    2017-05-30

    Retinal diseases leading to impaired vision and ultimately blindness are mainly characterized by ischemic and hypoxic stress. Targeting the retinal ρ-containing γ-aminobutyric acid type A receptors (ρ GABA A Rs) and thereby decreasing the retinal neuronal activity has been proposed as a novel therapeutic approach. The taurine transporter (TAUT) plays a key role in the retinal transport of GABA and has been previously suggested to display a higher functional activity in the retina compared to the brain. TAUT would therefore stand as a suitable target for the selective delivery of ρ GABA A R ligands into the retina. Consequently, an in vitro model of TAUT at the outer blood-retinal barrier (BRB) was developed and characterized using the ARPE-19 cell line. Furthermore, the structural requirements of GABA A R ligands for interacting with TAUT at the BRB were investigated for a series of standard GABA A R ligands by testing their ability to inhibit the TAUT-mediated influx of taurine in ARPE-19 cells. Results showed that taurine influx was seven-fold higher when the ARPE-19 cells were cultured under hyperosmotic conditions and was demonstrated to display saturable kinetics (K m =27.7±2.2μM and J max =24.2±0.6pmol/cm 2 ·min). Furthermore, the taurine influx was significantly inhibited in a concentration-dependent manner by GABA and imidazole-4-acetic acid (IAA), which is a naturally occurring metabolite of histamine. These compounds display similar K i values of 644.2μM and 658.6μM, respectively. Moreover, IAA demonstrated higher inhibitory properties than the other tested GABA analogs: 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP), 4,5,6,7-tetrahydropyrazolo[5,4-c]pyridin-3-ol (Aza-THIP), muscimol, and thiomuscimol. These studies demonstrated that IAA interacts with TAUT, which makes IAA a new lead structure in the development of new compounds, which are not only interacting with TAUT but also potent ρ GABA A R ligands. Copyright © 2017 Elsevier B

  5. Highly efficient removal of Malachite green from water by a magnetic reduced graphene oxide/zeolitic imidazolate framework self-assembled nanocomposite

    International Nuclear Information System (INIS)

    Lin, Kun-Yi Andrew; Lee, Wei-Der

    2016-01-01

    Graphical abstract: - Highlights: • MRGO/ZIF nanocomposite was prepared via self-assembly and used for MG adsorption. • MRGO/ZIF can exhibit an ultra-high adsorption capacity for MG of ∼3000 mg g −1 . • Adsorption isotherm was properly fitted to the Langmuir–Freundlich isotherm model. • Effects of temperature, pH and co-existing compounds were investigated. • Recyclability of MRGO/ZIF for MG adsorption was highly efficient and stable. - Abstract: Compared to the relatively low adsorption capacities of conventional adsorbents for Malachite Green (MG) (i.e., ∼500 mg g −1 ), zeolitic imidazolate framework (ZIF) appears to be a promising adsorbent considering its significantly high adsorption capacity (i.e., >2000 mg g −1 ). Nevertheless, using such a nano-scale ZIF material for adsorption may lead to secondary contamination from the release of nanomaterials to the environment. Thus, ZIF has to be recovered conveniently to prevent the secondary contamination and facilitate the separation of adsorbent from water after adsorption. To this end, in this study ZIF nanocrystals were loaded on the sheet-like magnetic reduced graphene oxide (MRGO) to form a self-assembled MRGO/ZIF. The self-assembly of MRGO/ZIF was achieved possibly via the electrostatic attraction and the π–π stacking interaction between MRGO and ZIF. The resultant MRGO/ZIF exhibited an ultra-high adsorption capacity for MG (∼3000 mg g −1 ). The adsorption kinetics, isotherm, activation and thermodynamics were also determined. Other factors affecting the adsorption were examined including temperature, pH and co-existing ions/compound. To demonstrate that MRGO/ZIF can be recovered and reused, a multiple-cycle of MG adsorption using the regenerated MRGO/ZIF was revealed and the recyclability remained highly efficient and stable. The highly-effective, recoverable and re-usable features enable MRGO/ZIF a promising adsorbent to remove MG from water.

  6. Reversible uptake of molecular oxygen by heteroligand Co(II)-L-α-amino acid-imidazole systems: equilibrium models at full mass balance.

    Science.gov (United States)

    Pająk, Marek; Woźniczka, Magdalena; Vogt, Andrzej; Kufelnicki, Aleksander

    2017-09-19

    The paper examines Co(II)-amino acid-imidazole systems (where amino acid = L-α-amino acid: alanine, asparagine, histidine) which, when in aqueous solutions, activate and reversibly take up dioxygen, while maintaining the structural scheme of the heme group (imidazole as axial ligand and O 2 uptake at the sixth, trans position) thus imitating natural respiratory pigments such as myoglobin and hemoglobin. The oxygenated reaction shows higher reversibility than for Co(II)-amac systems with analogous amino acids without imidazole. Unlike previous investigations of the heteroligand Co(II)-amino acid-imidazole systems, the present study accurately calculates all equilibrium forms present in solution and determines the [Formula: see text]equilibrium constants without using any simplified approximations. The equilibrium concentrations of Co(II), amino acid, imidazole and the formed complex species were calculated using constant data obtained for analogous systems under oxygen-free conditions. Pehametric and volumetric (oxygenation) studies allowed the stoichiometry of O 2 uptake reaction and coordination mode of the central ion in the forming oxygen adduct to be determined. The values of dioxygen uptake equilibrium constants [Formula: see text] were evaluated by applying the full mass balance equations. Investigations of oxygenation of the Co(II)-amino acid-imidazole systems indicated that dioxygen uptake proceeds along with a rise in pH to 9-10. The percentage of reversibility noted after acidification of the solution to the initial pH ranged within ca 30-60% for alanine, 40-70% for asparagine and 50-90% for histidine, with a rising tendency along with the increasing share of amino acid in the Co(II): amino acid: imidazole ratio. Calculations of the share of the free Co(II) ion as well as of the particular complex species existing in solution beside the oxygen adduct (regarding dioxygen bound both reversibly and irreversibly) indicated quite significant values for the

  7. Magnesium compounds

    Science.gov (United States)

    Kramer, D.A.

    2007-01-01

    Seawater and natural brines accounted for about 52 percent of U.S. magnesium compounds production in 2006. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from sea-water by Premier Chemicals in Florida; from well brines in Michigan by Martin Marietta and Rohm and Haas; and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from brucite by Applied Chemical Magnesias in Texas, from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta and Rohm and Haas from their operations mentioned above. About 59 percent of the magnesium compounds consumed in the United States was used for refractories that are used mainly to line steelmaking furnaces. The remaining 41 percent was consumed in agricultural, chemical, construction, environmental and industrial applications.

  8. Synthesis of Iron Doped Zeolite Imidazolate Framework-8 and Its Remazol Deep Black RGB Dye Adsorption Ability

    Directory of Open Access Journals (Sweden)

    Mai Thi Thanh

    2017-01-01

    Full Text Available Zeolite imidazole framework-8 (ZIF-8 and the iron doped ZIF-8 (Fe-ZIF-8 were synthesized by the hydrothermal process. The obtained materials were characteristic of X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, scanning electron microscope (SEM, nitrogen adsorption/desorption isotherms, and atomic absorption spectroscopy (AAS. The results showed that the obtained Fe-ZIF-8 possessed the ZIF-8 structure with a large specific area. ZIF-8 and Fe-ZIF-8 were used for the removal of Remazol Deep Black (RDB RGB dye from aqueous solutions. The various factors affecting adsorption such as pH, initial concentration, contact time, and temperature were investigated. The results showed that the introduction of iron into ZIF-8 provided a much larger adsorption capacity and faster adsorption kinetics than ZIF-8 without iron. The electrostatic interaction and π-π interaction between the aromatic rings of the RDB dye and the aromatic imidazolate rings of the adsorbent were responsible for the RDB adsorption. Moreover, the coordination of the nitrogen atoms and oxygen in carboxyl group in RDB molecules with the Fe2+ ions in the ZIF-8 framework played a vital role for the effective removal of RDB from aqueous solution.

  9. Luminescent pH sensor of a novel imidazole-containing hexanuclear Ru(II) polypyridyl complex

    Science.gov (United States)

    Cheng, Feixiang; Tang, Ning; Chen, Jishu; Chen, Guang

    2013-10-01

    Hexapodal ligand H6L containing imidazole rings has been prepared by the reaction of 1,10-phenanthroline-5,6-dione with 1,2,3,4,5,6-hexakis[(3-formylphenoxy)methyl]benzene. The Ru(II) polypyridyl complex [{Ru(bpy)2}6(μ6-H6L)](PF6)12 (bpy = 2,2'-bipyridine) has been synthesized by the reaction of Ru(bpy)2Cl2·2H2O with ligand H6L. The pH effects on the UV-vis absorption and emission spectra of the complex have been studied. The ground- and excited-state ionization constants of the acid-base equilibria have been calculated according to the absorbance and emission data. The complex acts as an off-on-off luminescent pH sensor through two successive deprotonation processes of imidazole rings, with a maximum on-off ratio of 5 in buffer solution.

  10. Faradaic impedance titration and control of electron transfer of 1-(12-mercaptododecyl)imidazole monolayer on a gold electrode

    International Nuclear Information System (INIS)

    Hwang, Seongpil; Lee, Bang Sook; Chi, Young Shik; Kwak, Juhyoun; Choi, Insung S.; Lee, Sang-gi

    2008-01-01

    In this work, we studied interfacial proton transfer of the self-assembled monolayer (SAM) of 1-(12-mercaptododecyl)imidazole on a gold electrode by faradaic impedance titration method with Fe(CN) 6 3- as an anionic redox probe molecule. The surface pK 1/2 was found to be 7.3, which was nearly the same as that of 1-alkylimidazole in solution. We also investigated the electrochemical properties of the SAM-modified electrode by cyclic voltammetry. Cyclic voltammetry was performed (1) in the solution containing Fe(CN) 6 3- with repeated alternation of pH values to investigate the electrostatic interaction of the protonated or deprotonated imidazole with Fe(CN) 6 3- and (2) in the acidic or basic electrolyte containing Ru(NH 3 ) 6 3+ as a cationic redox probe to verify the effect of the polarity of a redox probe. We observed the reversible adsorption/desorption of Fe(CN) 6 3- and concluded that the adsorbed Fe(CN) 6 3- catalyzed the electron transfer of both Fe(CN) 6 3- itself and cationic Ru(NH 3 ) 6 3+

  11. Zeolitic imidazolate framework-coated acoustic sensors for room temperature detection of carbon dioxide and methane.

    Science.gov (United States)

    Devkota, Jagannath; Kim, Ki-Joong; Ohodnicki, Paul R; Culp, Jeffrey T; Greve, David W; Lekse, Jonathan W

    2018-05-03

    The integration of nanoporous materials such as metal organic frameworks (MOFs) with sensitive transducers can result in robust sensing platforms for monitoring gases and chemical vapors for a range of applications. Here, we report on an integration of the zeolitic imidazolate framework - 8 (ZIF-8) MOF with surface acoustic wave (SAW) and thickness shear mode quartz crystal microbalance (QCM) devices to monitor carbon dioxide (CO2) and methane (CH4) under ambient conditions. The MOF was directly coated on the Y-Z LiNbO3 SAW delay lines (operating frequency, f0 = 436 MHz) and AT-cut quartz TSM resonators (resonant frequency, f0 = 9 MHz) and the devices were tested for various gases in N2 under ambient conditions. The devices were able to detect the changes in CO2 or CH4 concentrations with relatively higher sensitivity to CO2, which was due to its higher adsorption potential and heavier molecular weight. The sensors showed full reversibility and repeatability which were attributed to the physisorption of the gases into the MOF and high stability of the devices. Both types of sensors showed linear responses relative to changes in the binary gas compositions thereby allowing to construct calibration curves which correlated well with the expected mass changes in the sorbent layer based on mixed-gas gravimetric adsorption isotherms measured on bulk samples. For 200 nm thick films, the SAW sensitivities to CO2 and CH4 were 1.44 × 10-6/vol% and 8 × 10-8/vol%, respectively, against the QCM sensitivities 0.24 × 10-6/vol% and 1 × 10-8/vol%, respectively, which were evaluated as the fractional change in the signal. The SAW sensors were also evaluated for 100 nm-300 nm thick films, the sensitivities of which were found to increase with the thickness due to the increased number of pores for the adsorption of a larger amount of gases. In addition, the MOF-coated SAW delay lines had a good response in wireless mode, demonstrating their potential to operate remotely for the

  12. Poly(hydroxyethyl methacrylate) nanobeads containing imidazole groups for removal of Cu(II) ions

    Energy Technology Data Exchange (ETDEWEB)

    Tuerkmen, Deniz; Yilmaz, Erkut [Department of Chemistry, Hacettepe University, Ankara (Turkey); Oztuerk, Nevra; Akgoel, Sinan [Department of Chemistry, Adnan Menderes University, Aydin (Turkey); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Department of Chemistry, Hacettepe University, Ankara (Turkey)

    2009-08-01

    Poly(hydroxyethyl methacrylate) (PHEMA) nanobeads with an average size of 300 nm in diameter and with a polydispersity index of 1.156 were produced by a surfactant free emulsion polymerization. Specific surface area of the PHEMA nanobeads was found to be 996 m{sup 2}/g. Imidazole containing 3-(2-imidazoline-1-yl)propyl(triethoxysilane) (IMEO) was used as a metal-chelating ligand. IMEO was covalently attached to the nanobeads. PHEMA-IMEO nanobeads were used for the removal of copper(II) ions from aqueous solutions. To evaluate the degree of IMEO loading, the PHEMA nanobeads were subjected to Si analysis by using flame atomizer atomic absorption spectrometer and it was estimated as 973 {mu}mol IMEO/g of polymer. The PHEMA nanobeads were characterized by transmission electron microscopy and fourier transform infrared spectroscopy. Adsorption equilibrium was achieved in about 8 min. The adsorption of Cu{sup 2+} ions onto the PHEMA nanobeads was negligible (0.2 mg/g). The IMEO attachment into the PHEMA nanobeads significantly increased the Cu{sup 2+} adsorption capacity (58 mg/g). Adsorption capacity of the PHEMA-IMEO nanobeads increased significantly with increasing concentration. The adsorption of Cu{sup 2+} ions increased with increasing pH and reached a plateau value at around pH 5.0. Competitive heavy metal adsorption from aqueous solutions containing Cu{sup +}, Cd{sup 2+}, Pb{sup 2+} and Hg{sup 2+} was also investigated. The adsorption capacities are 61.4 mg/g (966.9 {mu}mol/g) for Cu{sup 2+}; 180.5 mg/g (899.8 {mu}mol/g) for Hg{sup 2+}; 34.9 mg/g (310.5 {mu}mol/g) for Cd{sup 2+} and 14.3 mg/g (69 {mu}mol/g) for Pb{sup 2+}. The affinity order in molar basis is observed as Cu{sup 2+} > Hg{sup 2+} > Cd{sup 2+} > Pb{sup 2+}. These results may be considered as an indication of higher specificity of the PHEMA-IMEO nanobeads for the Cu{sup 2+} comparing to other ions. Consecutive adsorption and elution operations showed the feasibility of repeated use for PHEMA

  13. Heterogeneous photochemistry of imidazole-2-carboxaldehyde: HO2 radical formation and aerosol growth

    Directory of Open Access Journals (Sweden)

    L. González Palacios

    2016-09-01

    Full Text Available The multiphase chemistry of glyoxal is a source of secondary organic aerosol (SOA, including its light-absorbing product imidazole-2-carboxaldehyde (IC. IC is a photosensitizer that can contribute to additional aerosol ageing and growth when its excited triplet state oxidizes hydrocarbons (reactive uptake via H-transfer chemistry. We have conducted a series of photochemical coated-wall flow tube (CWFT experiments using films of IC and citric acid (CA, an organic proxy and H donor in the condensed phase. The formation rate of gas-phase HO2 radicals (PHO2 was measured indirectly by converting gas-phase NO into NO2. We report on experiments that relied on measurements of NO2 formation, NO loss and HONO formation. PHO2 was found to be a linear function of (1 the [IC]  ×  [CA] concentration product and (2 the photon actinic flux. Additionally, (3 a more complex function of relative humidity (25 %  <  RH  <  63 % and of (4 the O2 ∕ N2 ratio (15 %  <  O2 ∕ N2  <  56 % was observed, most likely indicating competing effects of dilution, HO2 mobility and losses in the film. The maximum PHO2 was observed at 25–55 % RH and at ambient O2 ∕ N2. The HO2 radicals form in the condensed phase when excited IC triplet states are reduced by H transfer from a donor, CA in our system, and subsequently react with O2 to regenerate IC, leading to a catalytic cycle. OH does not appear to be formed as a primary product but is produced from the reaction of NO with HO2 in the gas phase. Further, seed aerosols containing IC and ammonium sulfate were exposed to gas-phase limonene and NOx in aerosol flow tube experiments, confirming significant PHO2 from aerosol surfaces. Our results indicate a potentially relevant contribution of triplet state photochemistry for gas-phase HO2 production, aerosol growth and ageing in the atmosphere.

  14. Compound odontoma

    Directory of Open Access Journals (Sweden)

    José Marcelo Vargas Pinto

    2008-01-01

    Full Text Available Odontomas are the most common types of odontogenic tumors, as they are considered more as a developmental anomaly (hamartoma than as a true neoplasia. The aim of the present study is to describe a clinical case of compound odontoma, analyzing its most commonsigns, its region of location, the decade of life and patient’s gender, disorders that may occur as well as the treatment proposed. In order to attain this objective, the method was description of the present clinical case and bibliographic revision, arriving at the result that the treatment for this type of lesion invariably is surgical removal (enucleation and curettage and the prognosis is excellent. The surgical result was followed up in the post-operative period by radiographic exam, and it was possible to conclude that there was complete cicatrization and tissue repair.

  15. Magnesium compounds

    Science.gov (United States)

    Kramer, D.A.

    2012-01-01

    Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

  16. alpha,beta-unsaturated 2-acyl imidazoles as a practical class of dienophiles for the DNA-Based catalytic asymmetric diels-alder reaction in water

    NARCIS (Netherlands)

    Boersma, A.J.; Feringa, B.L.; Roelfes, G.

    2007-01-01

    alpha,beta-Unsaturated 2-acyl imidazoles are a novel and practical class of dienophiles for the DNA-based catalytic asymmetric Diels-Alder reaction in water. The Diels-Alder products are obtained with very high diastereoselectivities and enantioselectivities in the range of 83-98%. The catalytic

  17. Magnetic graphene oxide modified by imidazole-based ionic liquids for the magnetic-based solid-phase extraction of polysaccharides from brown alga.

    Science.gov (United States)

    Wang, Xiaoqin; Li, Guizhen; Row, Kyung Ho

    2017-08-01

    Magnetic graphene oxide was modified by four imidazole-based ionic liquids to synthesize materials for the extraction of polysaccharides by magnetic solid-phase extraction. Fucoidan and laminarin were chosen as the representative polysaccharides owing to their excellent pharmaceutical value and availability. Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and thermogravimetric analysis were applied to characterize the synthesized materials. Single-factor experiments showed that the extraction efficiency of polysaccharides was affected by the amount of ionic liquids for modification, solid-liquid ratio of brown alga and ethanol, the stirring time of brown alga and ionic liquid-modified magnetic graphene oxide materials, and amount of 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide materials added to the brown alga sample solution. The results indicated that 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide possessed better extraction ability than graphene oxide, magnetic graphene oxide, and other three ionic-liquid-modified magnetic graphene oxide materials. The highest extraction recoveries of fucoidan and laminarin extracted by 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide were 93.3 and 87.2%, respectively. In addition, solid materials could be separated and reused easily owing to their magnetic properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Reactivity of Hydroxy and Amino Derivatives of 2-Phenyl-1H-imidazoline and 2-Phenyl-1H-imidazole toward Isocyanates: Synthesis of Appropriate Carbamates and Ureas

    Czech Academy of Sciences Publication Activity Database

    Pařík, P.; Jansa, J.; Holešová, S.; Marek, Aleš; Klimešová, V.

    2013-01-01

    Roč. 50, č. 4 (2013), s. 903-910 ISSN 0022-152X Grant - others:GA ČR(CZ) GA205/08/0869 Institutional support: RVO:61388963 Keywords : elevated-temperature * hydrolysis * imidazoles * alkylation Subject RIV: CC - Organic Chemistry Impact factor: 0.873, year: 2013

  19. A tailored biocatalyst achieved by the rational anchoring of imidazole groups on a natural polymer: furnishing a potential artificial nuclease by sustainable materials engineering.

    Science.gov (United States)

    Ferreira, José G L; Grein-Iankovski, Aline; Oliveira, Marco A S; Simas-Tosin, Fernanda F; Riegel-Vidotti, Izabel C; Orth, Elisa S

    2015-04-11

    Foreseeing the development of artificial enzymes by sustainable materials engineering, we rationally anchored reactive imidazole groups on gum arabic, a natural biocompatible polymer. The tailored biocatalyst GAIMZ demonstrated catalytic activity (>10(5)-fold) in dephosphorylation reactions with recyclable features and was effective in cleaving plasmid DNA, comprising a potential artificial nuclease.

  20. Water swelling, brine soluble imidazole based zwitterionic polymers-synthesis and study of reversible UCST behaviour and gel-sol transitions

    NARCIS (Netherlands)

    Vasantha, Vivek Arjunan; Jana, Satyasankar; Parthiban, Anbanandam; Vancso, Julius G.

    2014-01-01

    New vinylbenzene substituted imidazole based zwitterionic polymers with unique characteristics like swelling in water and solubility in concentrated brine solution in which they exhibited a reversible upper critical solution temperature (UCST) and gel-sol transitions are reported herein. © 2014 The

  1. Directly oxidized chemiluminescence of 2-substituted-4,5-di(2-furyl)-1H -imidazole by acidic potassium permanganate and its analytical application for determination of albumin.

    Science.gov (United States)

    Kang, Jing; Zhang, Yumin; Huang, Zhongxiu; Han, Lu; Tang, Jieli; Wang, Shuaijun; Zhang, Yihua

    2011-07-01

    In the paper, 2,4,5-tri(2-furyl)-1H-imidazole (TFI) and 2-phenyl-4,5-di(2-furyl)-1H-imidazole (PDFI), were chosen to investigate chemiluminescence (CL) properties of 2-substituted-4,5-di(2-furyl)-1H-imidazoles. The directly oxidized CL of analytes by potassium permanganate (KMnO(4)) was in detail studied. The KMnO(4) could directly oxidize TFI/PDFI to produce strong CL emission in acidic solution. The effects of experimental conditions were investigated. Under the optimal conditions, the effect of albumin on the TFI/PDFI-KMnO(4) system was investigated. It was found that the addition of albumin into the system could induce enhancement of CL signal, and the enhanced CL intensity is linearly related to the logarithm of concentration of albumin. Based on this study, a novel CL method has been developed for the determination of albumin with high sensitivity and good selectivity. The method was applied to the determination of albumin in human serum samples, and the results were in agreement with those obtained by the bromcresol green (BCG) method. The relative errors for the analytical results were from -5.8% to 4.2%. These new phenomena would further enable people to exploit more CL analytical application of the heterocyclic imidazole derivatives. © Springer Science+Business Media, LLC 2011

  2. Pure white OLED based on an organic small molecule: 2,6-Di(1H-benzo[d]imidazol-2-yl)pyridine

    Science.gov (United States)

    Liu, Jian

    2015-10-01

    2,6-Di(1H-benzo[d]imidazol-2-yl)pyridine (DBIP) was synthesized. The single-crystal structure of DBIP was resolved. DBIP-based OLED was fabricated. The electroluminescence for the device corresponds to a pure white emission. In addition, thermal stability, UV-vis, photoluminescence and electrochemical behaviors of DBIP were investigated as well.

  3. Synthesis, characterization and metal coordination of a potential β-lactamase inhibitor: 5-Methyl-2-phenoxymethyl-3-H-imidazole-4-carboxylic acid (PIMA

    Directory of Open Access Journals (Sweden)

    Chiara Romagnoli

    2017-12-01

    Full Text Available Among relevant metal ions in biological systems, zinc and iron play a key role as active partners of the catalytic machinery. In particular, the inhibition of metal enzymes that are involved in physiological and pathological processes has been deeply investigated for the rational design of selective and efficient drugs based on chelators. Since imidazole histidine residue is one of the most versatile sites in proteins, especially in enzymes acting in the presence of metal ions as cofactors, in this work the synthesis and characterization of a new imidazole derivative, namely 5-methyl-2-phenoxymethyl-3-H-imidazole-4-carboxylic acid (PIMA is reported. PIMA was designed as metallo-β-lactamase inhibitor thanks to its similarity with penicillin V, a β-lactam antibiotic inactivated by metallo-β-lactamase, for which there are no commercially available inhibitors. The evaluation of PIMA coordinating ability toward iron, zinc, and gallium, these latter selected as a non-paramagnetic probe for iron, is performed by theoretical DFT calculations and in solution by experimental techniques, i.e. potentiometry, UV–vis and NMR spectroscopy. PIMA exhibits an efficient metal chelating ability; the prevailing species in physiological condition are ML3 for Fe3+ and Ga3+ and ML2 for Zn2+, in which chelation is due to deprotonated carboxylic oxygen and imidazole nitrogen in the N,O donor set. The demonstrated ability of PIMA to chelate zinc ion, combined with its structure similarity with penicillin V, supports further exploration of this imidazole-4-carboxylate as metallo-β-lactamase inhibitor.

  4. Model studies of the Cu(B) site of cytochrome c oxidase utilizing a Zn(II) complex containing an imidazole-phenol cross-linked ligand.

    Science.gov (United States)

    Pesavento, Russell P; Pratt, Derek A; Jeffers, Jerry; van der Donk, Wilfred A

    2006-07-21

    Cytochrome c oxidase, the enzyme complex responsible for the four-electron reduction of O2 to H2O, contains an unusual histidine-tyrosine cross-link in its bimetallic heme a3-CuB active site. We have synthesised an unhindered, tripodal chelating ligand, BPAIP, containing the unusual ortho-imidazole-phenol linkage, which mimics the coordination environment of the CuB center. The ligand was used to investigate the physicochemical (pKa, oxidation potential) and coordination properties of the imidazole-phenol linkage when bound to a dication. Zn(II) coordination lowers the pKa of the phenol by 0.6 log units, and increases the potential of the phenolate/phenoxyl radical couple by approximately 50 mV. These results are consistent with inductive withdrawal of electron density from the phenolic ring. Spectroscopic data and theoretical calculations (DFT) were used to establish that the cationic complex [Zn(BPAIP)Br]+ has an axially distorted trigonal bipyramidal structure, with three coordinating nitrogen ligands (two pyridine and one imidazole) occupying the equatorial plane and the bromide and the tertiary amine nitrogen of the tripod in the axial positions. Interestingly, the Zn-Namine bonding interaction is weak or absent in [Zn(BPAIP)Br]+ and the complex gains stability in basic solutions, as indicated by 1H NMR spectroscopy. These observations are supported by theoretical calculations (DFT), which suggest that the electron-donating capacity of the equatorial imidazole ligand can be varied by modulation of the protonation and/or redox state of the cross-linked phenol. Deprotonation of the phenol makes the equatorial imidazole a stronger sigma-donor, resulting in an increased Zn-Nimd interaction and thereby leading to distortion of the axial ligand axis toward a more tetrahedral geometry.

  5. Synthesis of novel 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds and their evaluation for tuberculostatic activity.

    Science.gov (United States)

    Gobis, Katarzyna; Foks, Henryk; Bojanowski, Krzysztof; Augustynowicz-Kopeć, Ewa; Napiórkowska, Agnieszka

    2012-01-01

    A series of novel 3-cyclohexylpropanoic acid derivatives and 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds (1-8) have been synthesized and evaluated for tuberculostatic activity. Compounds 1a, 1c, 1e and 1f bearing benzimidazole or benzimidazole-like systems showed the most potent tuberculostatic activity against Mycobacterium tuberculosis strains with MIC values ranging from 1.5 to 12.5μg/mL. More importantly 1a (6-chloro-2-(2-cyclohexylethyl)-4-nitro-1H-benzo[d]imidazole) and 1f (2-(2-cyclohexylethyl)-1H-imidazo[4,5-b]phenazine) appeared selective for M. tuberculosis as compared with eukaryotic cells (human fibroblasts), and other antimicrobial strains. These compounds may thus represent a novel, selective class of antitubercular agents. Additionally compound 1a stimulated type I collagen output by fibroblasts, in vitro. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Syntheses and structure characterization of ten acid-base hybrid crystals based on imidazole derivatives and mineral acids

    Science.gov (United States)

    Hu, Kaikai; Deng, Bowen; Jin, Shouwen; Ding, Aihua; Jin, Shide; Zhu, Jin; Zhang, Huan; Wang, Daqi

    2018-04-01

    Cocrystallization of the imidazole derivatives with a series of mineral acids gave a total of ten hybrid salts with the compositions: [(H2bzm)(Cl)2·3H2O] (1), [(H2bzm)(ClO4)2] (2), [(H2bze)(Cl)2·2H2O] (3), [(H2bze)(Br)2·2H2O] (4), [(H2bzp)(Cl)2·4H2O] (5), [(H2bzp)(Br)2·4H2O] (6), (2-(imidazol-1-yl)-1-phenylethanone): (phosphoric acid) [(Himpeta)+(H2PO4)-] (7), [(H2impd)(Br)2] (8), [(H2impd)(ClO4)2] (9), and [(Hbzml)(Cl)] (10). The ten salts have been characterised by X-ray diffraction analysis, IR, and elemental analysis, and the melting points of all the salts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the ten investigated crystals the ring N atoms of the imidazole are protonated when the acids are deprotonated, and the crystal packing is interpreted in terms of the strong charge-assisted classical H-bonds between the NH+ and deprotonated acidic groups. Further analysis of the crystal packing of the salts indicated that a different set of additional CHsbnd O, CH2sbnd O, CHsbnd Cl, CH2sbnd Cl, CHsbnd N, CHsbnd Br, CH2sbnd Br, Osbnd O, O-π, Br-π, CH-π, and π-π associations contribute to the stabilization and expansion of the total high-dimensional frameworks. For the coexistence of the various weak nonbonding interactions these structures adopted homo or hetero supramolecular synthons or both. Some classical supramolecular synthons, such as R21(7), R22(7), R22(8), and R42(8), usually observed in the organic solids, were again shown to be involved in constructing some of these H-bonding networks.

  7. Hantzsch reaction and quinoxaline synthesis using 1-methyl-3-(2-(sulfooxyethyl-1H-imidazol-3-ium chloride as a new, efficient and BrØnsted acidic ionic liquid catalyst

    Directory of Open Access Journals (Sweden)

    Sami Sajjadifar

    2013-10-01

    Full Text Available In this work, the efficiency, generality and applicability of new BrØnsted acidic ionic liquid (BAIL 1-methyl-3-(2-(sulfooxyethyl-1H-imidazol-3-ium chloride {[Msei]Cl} as heterogeneous and green catalyst for organic transformations are studied. Herein, the following one-pot multi-component reactions in the presence of [Msei]Cl are investigated: (i the synthesis of quinoxaline derivatives from the reaction of phenylenediamines and 1,2-diketones in EtOH under mild conditions (room temperature, (ii the preparation of 1,4-dihydropyridines from one-pot multi component condensation of 1,3-dicarbonyl compounds, NH4OAcand aldehydes under solvent-free conditions at moderate temperature (90 °C. High yields, relatively short reaction times, efficiency, generality, clean process, simple methodology, low cost, easy work-up, ease of preparation and regeneration of the catalyst and green conditions (in the synthesis of the quinoxaline derivatives are advantages of the application of [Mesi]Cl as catalyst in the above organic reactions.

  8. One-pot synthesis of zeolitic imidazolate framework-8/poly (methyl methacrylate-ethyleneglycol dimethacrylate) monolith coating for stir bar sorptive extraction of phytohormones from fruit samples followed by high performance liquid chromatography-ultraviolet detection.

    Science.gov (United States)

    You, Linna; He, Man; Chen, Beibei; Hu, Bin

    2017-11-17

    In this work, zeolitic imidazolate framework-8 (ZIF-8)/poly (methyl methacrylate-ethyleneglycol dimethacrylate) (MMA-EGDMA) composite monolith was in situ synthesized on stir bar by one-pot polymerization. Compared with the neat monolith, ZIF-8/poly(MMA-EGDMA) composite monolith has larger surface area and pore volume. It also exhibits higher extraction efficiency for target phytohormones than poly(MMA-EGDMA) monolith and commercial polyethylene glycol (PEG) coated stir bar. Based on it, a method of ZIF-8/poly(MMA-EGDMA) monolith coated stir bar sorptive extraction (SBSE)-high performance liquid chromatography-ultraviolet detection (HPLC-UV) was established for the analysis of five phytohormones in apple and pear samples. The developed method exhibited low limits of detection (0.11-0.51μg/L), wide linear range (0.5-500μg/L) and good recoveries (82.7-111%), which demonstrated good application potential of the ZIF-8/monolith coated stir bar in trace analysis of organic compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Spectroscopic investigations (FT-IR & FT-Raman) and molecular docking analysis of 6-[1-methyl-4-nitro-1H-imidazol-5-yl) sulfonyl]-7H-purine

    Science.gov (United States)

    Prasath, M.; Govindammal, M.; Sathya, B.

    2017-10-01

    The Azathioprine is used as anticancer agent. Azathioprine is chemically called 6-[1-methyl-4-nitro-1H-imidazol-5-yl) sulfonyl]-7H-purine (6M4N5P). The vibrational analysis of the 6M4N5P compound was carried out by using FT-IR and FT-Raman spectroscopic techniques and compared with aspects. The optimized geometry, frequency and intensity of the vibrational bands of 6M4N5P were obtained from the HF and DFT methods with 6-31G (d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FT-IR and FT-Raman spectra. The calculated Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies show that charge transfer occur within the molecule. MEP (Molecular Electrostatic Potential) is very useful in the investigation of the charge distributions and molecular structure. The molecule orbital contributions were determined by using the total density of states (TDOS). A molecular docking analysis has been carried out to understand the conformational change and electrostatic properties of 6M4N5P in the active site of Rac1-Receptor.

  10. Isotopically modified compounds

    International Nuclear Information System (INIS)

    Kuruc, J.

    2009-01-01

    In this chapter the nomenclature of isotopically modified compounds in Slovak language is described. This chapter consists of following parts: (1) Isotopically substituted compounds; (2) Specifically isotopically labelled compounds; (3) Selectively isotopically labelled compounds; (4) Non-selectively isotopically labelled compounds; (5) Isotopically deficient compounds.

  11. A novel poly(propylene-co-imidazole) based biofuel cell: System optimization and operation for energy generation

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Muhammet Samet [Department of Chemistry, Bulent Ecevit University, 67100 Zonguldak (Turkey); Korkut, Seyda, E-mail: s.korkut@beun.edu.tr [Department of Environmental Engineering, Bulent Ecevit University, 67100 Zonguldak (Turkey); Hazer, Baki [Department of Chemistry, Bulent Ecevit University, 67100 Zonguldak (Turkey)

    2015-02-01

    This study describes the construction of an enzymatic fuel cell comprised of novel gold nanoparticles embedded poly(propylene-co-imidazole) coated anode and cathode. Working electrode fabrication steps and operational conditions for the fuel cell have been optimized to get enhanced power output. Electrical generation capacity of the optimized cell was tested by using the municipal wastewater sample. The enzymatic fuel cell system reached to maximum power density with 1 μg and 8 μg of polymer quantity and bilirubin oxidase on electrode surface, respectively. The maximum power output was calculated to be 5 μW cm{sup −2} at + 0.56 V (vs. Ag/AgCl) in phosphate buffer (pH 7.4, 100 mM, 20 °C) by the addition of 15 mM of glucose as a fuel source. The optimized enzymatic fuel cell generated a power density of 0.46 μW cm{sup −2} for the municipal wastewater sample. Poly(propylene-co-imidazole) was easily used for a fuel cell system owing to its metallic nanoparticle content. The developed fuel cell will play a significant role for energy conversion by using glucose readily found in wastewater and in vivo mediums. - Highlights: • Gold nanoparticles provided faster electron transfer in the circuit. • The maximum power density of 5 μW cm{sup −2} was generated at + 0.56 V cell potential. • The cell can be easily operated for in vivo mediums.

  12. Probing the hydrogen equilibrium and kinetics in zeolite imidazolate frameworks via molecular dynamics and quasi-elastic neutron scattering experiments.

    Science.gov (United States)

    Pantatosaki, Evangelia; Jobic, Hervé; Kolokolov, Daniil I; Karmakar, Shilpi; Biniwale, Rajesh; Papadopoulos, George K

    2013-01-21

    The problem of simulating processes involving equilibria and dynamics of guest sorbates within zeolitic imidazolate frameworks (ZIF) by means of molecular dynamics (MD) computer experiments is of growing importance because of the promising role of ZIFs as molecular "traps" for clean energy applications. A key issue for validating such an atomistic modeling attempt is the possibility of comparing the MD results, with real experiments being able to capture analogous space and time scales to the ones pertained to the computer experiments. In the present study, this prerequisite is fulfilled through the quasi-elastic neutron scattering technique (QENS) for measuring self-diffusivity, by elaborating the incoherent scattering signal of hydrogen nuclei. QENS and MD experiments were performed in parallel to probe the hydrogen motion, for the first time in ZIF members. The predicted and measured dynamics behaviors show considerable concentration variation of the hydrogen self-diffusion coefficient in the two topologically different ZIF pore networks of this study, the ZIF-3 and ZIF-8. Modeling options such as the flexibility of the entire matrix versus a rigid framework version, the mobility of the imidazolate ligand, and the inclusion of quantum mechanical effects in the potential functions were examined in detail for the sorption thermodynamics and kinetics of hydrogen and also of deuterium, by employing MD combined with Widom averaging towards studying phase equilibria. The latter methodology ensures a rigorous and efficient way for post-processing the dynamics trajectory, thereby avoiding stochastic moves via Monte Carlo simulation, over the large number of configurational degrees of freedom a nonrigid framework encompasses.

  13. Designing inhibitors of cytochrome c/cardiolipin peroxidase complexes: mitochondria-targeted imidazole-substituted fatty acids.

    Science.gov (United States)

    Jiang, Jianfei; Bakan, Ahmet; Kapralov, Alexandr A; Silva, K Ishara; Huang, Zhentai; Amoscato, Andrew A; Peterson, James; Garapati, Venkata Krishna; Saxena, Sunil; Bayir, Hülya; Atkinson, Jeffrey; Bahar, Ivet; Kagan, Valerian E

    2014-06-01

    Mitochondria have emerged as the major regulatory platform responsible for the coordination of numerous metabolic reactions as well as cell death processes, whereby the execution of intrinsic apoptosis includes the production of reactive oxygen species fueling oxidation of cardiolipin (CL) catalyzed by cytochrome (Cyt) c. As this oxidation occurs within the peroxidase complex of Cyt c with CL, the latter represents a promising target for the discovery and design of drugs with antiapoptotic mechanisms of action. In this work, we designed and synthesized a new group of mitochondria-targeted imidazole-substituted analogs of stearic acid TPP-n-ISAs with various positions of the attached imidazole group on the fatty acid (n = 6, 8, 10, 13, and 14). By using a combination of absorption spectroscopy and EPR protocols (continuous wave electron paramagnetic resonance and electron spin echo envelope modulation) we demonstrated that TPP-n-ISAs indeed were able to potently suppress CL-induced structural rearrangements in Cyt c, paving the way to its peroxidase competence. TPP-n-ISA analogs preserved the low-spin hexa-coordinated heme-iron state in Cyt c/CL complexes whereby TPP-6-ISA displayed a significantly more effective preservation pattern than TPP-14-ISA. Elucidation of these intermolecular stabilization mechanisms of Cyt c identified TPP-6-ISA as an effective inhibitor of the peroxidase function of Cyt c/CL complexes with a significant antiapoptotic potential realized in mouse embryonic cells exposed to ionizing irradiation. These experimental findings were detailed and supported by all-atom molecular dynamics simulations. Based on the experimental data and computation predictions, we identified TPP-6-ISA as a candidate drug with optimized antiapoptotic potency. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Cd(II)-coordination polymers based on tetracarboxylic acid and diverse bis(imidazole) ligands: Synthesis, structural diversity and photoluminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Arıcı, Mürsel, E-mail: marici@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Yeşilel, Okan Zafer [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Taş, Murat [Department of Science Education, Education Faculty, Ondokuz Mayıs University, 55139 Samsun (Turkey)

    2017-01-15

    Three new Cd(II)-coordination polymers, namely, ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,5-bipe){sub 2}]·2H{sub 2}O){sub n} (1), ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,4-bix){sub 2}]{sub n}·2DMF) (2) and ([Cd{sub 2}(μ{sub 8}-abtc)(μ-1,4-betix)]·DMF·H{sub 2}O){sub n} (3) (ao{sub 2}btc=di-oxygenated form of 3,3′,5,5′-azobenzenetetracarboxylate, 1,5-bipe: 1,5-bis(imidazol-1yl)pentane, 1,4-bix=1,4-bis(imidazol-1ylmethyl)benzene, 1,4-betix=1,4-bis(2-ethylimidazol-1ylmethyl)benzene) were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi-flexible substituted bis(imidazole) linker was used, 3D framework of complex 3 was obtained with the paddlewheel Cd{sub 2}(CO{sub 2}){sub 4}-type binuclear SBU. Moreover, thermal and photoluminescence properties of the complexes were determined in detailed. - Graphical abstract: In this study, three novel Cd(II)-coordination polymers were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi

  15. Abrupt spin transition with thermal hysteresis of iron(III) complex [Fe(III)(Him)2(hapen)]AsF6 (Him = imidazole, H2hapen = N,N'-bis(2-hydroxyacetophenylidene)ethylenediamine).

    Science.gov (United States)

    Fujinami, Takeshi; Koike, Masataka; Matsumoto, Naohide; Sunatsuki, Yukinari; Okazawa, Atsushi; Kojima, Norimichi

    2014-02-17

    The solvent-free spin crossover iron(III) complex [Fe(III)(Him)2(hapen)]AsF6 (Him = imidazole, H2hapen = N,N'-bis(2-hydroxyacetophenylidene)ethylenediamine), exhibiting thermal hysteresis, was synthesized and characterized. The Fe(III) ion has an octahedral coordination geometry, with N2O2 donor atoms of the planar tetradentate ligand (hapen) and two nitrogen atoms of two imidazoles at the axial positions. One of two imidazoles is hydrogen-bonded to the phenoxo oxygen atom of hapen of the adjacent unit to give a hydrogen-bonded one-dimensional chain, while the other imidazole group is free from hydrogen bonding. The temperature dependencies of the magnetic susceptibilities and Mössbauer spectra revealed an abrupt spin transition between the high-spin (S = 5/2) and low-spin (S = 1/2) states, with thermal hysteresis.

  16. Nitrotriazole- and imidazole-based amides and sulfonamides as antitubercular agents.

    Science.gov (United States)

    Papadopoulou, Maria V; Bloomer, William D; Rosenzweig, Howard S; Arena, Alexander; Arrieta, Francisco; Rebolledo, Joseph C J; Smith, Diane K

    2014-11-01

    Twenty-three 3-nitrotriazole-based and 2-nitroimidazole-based amides and sulfonamides were screened for antitubercular (anti-TB) activity in aerobic Mycobacterium tuberculosis H37Rv by using the BacTiter-Glo (BTG) microbial cell viability assay. In general, 3-nitrotriazole-based sulfonamides demonstrated anti-TB activity, whereas 3-nitrotriazole-based amides and 2-nitroimidazole-based amides and sulfonamides were inactive. Three 3-nitrotriazole-based sulfonamides (compounds 4, 2, and 7) demonstrated 50% inhibitory concentration (IC50), IC90, and MIC values of 0.38, 0.43, and 1.56 μM (compound 4), 0.57, 0.98, and 3.13 μM (compound 2), and 0.79, 0.87, and 3.13 μM (compound 7), respectively. For 3-nitrotriazole-based sulfonamides, anti-TB activity increased with lipophilicity, whereas the one-electron reduction potential (E1/2) did not play a role. 2-Nitroimidazole-based analogs, which were inactive in the BTG assay, were significantly more active in the low-oxygen assay and more active than the 3-nitrotriazoles. All active nitrotriazoles in the BTG assay were similarly active or more potent (lower MIC values) against resistant strains, with the exception of compounds 2, 3, 4, and 8, which demonstrated greater MIC values against isoniazid-resistant strains. Five 3-nitrotriazole-based sulfonamides demonstrated activity in infected murine J774 macrophages, causing log reductions similar to those seen with rifampin. However, some compounds caused toxicity in uninfected macrophages. In conclusion, the classes of 3-nitrotriazole-based amides and sulfonamides merit further investigation as potential antitubercular agents. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  17. Synthesis, X-ray Single Crystal Structure, Molecular Docking and DFT Computations on N-[(1E)-1-(2H-1,3-Benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propylidene]-hydroxylamine: A New Potential Antifungal Agent Precursor.

    Science.gov (United States)

    Al-Wabli, Reem I; Al-Ghamdi, Alwah R; Ghabbour, Hazem A; Al-Agamy, Mohamed H; Monicka, James Clemy; Joe, Issac Hubert; Attia, Mohamed I

    2017-02-28

    Mycoses are serious health problem, especially in immunocompromised individuals. A new imidazole-bearing compound containing an oxime functionality was synthesized and characterized with different spectroscopic techniques to be used for the preparation of new antifungal agents. The stereochemistry of the oxime double bond was unequivocally determined via the single crystal X-ray technique. The title compound 4 , C 13 H 13 N₃O₃·C₃H₈O, crystallizes in the monoclinic space group P 2₁with a = 9.0963(3) Å, b = 14.7244(6) Å, c = 10.7035(4) Å, β = 94.298 (3)°, V = 1429.57(9) ų, Z = 2. The molecules were packed in the crystal structure by eight intermolecular hydrogen bond interactions. A comprehensive spectral analysis of the title molecule 4 has been performed based on the scaled quantum mechanical (SQM) force field obtained by density-functional theory (DFT) calculations. A molecular docking study illustrated the binding mode of the title compound 4 into its target protein. The preliminary antifungal activity of the title compound 4 was determined using a broth microdilution assay.

  18. Evaluation of some organic compounds on bloodstream forms of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    João S. Silva

    1992-09-01

    Full Text Available Accidental transmission of Chagas' disease to man by blood transfusion is a serious problem in Latin-America. This paper describes the testing of several synthetic, semi-synthetic, and natural compounds for their activity against blood trypomastigotes in vitro at 4-C. The compounds embody several types of chemical structures: benzoquinone, naphthoquinone, anthracenequinone, phenanthrenequinone, imidazole, piperazine, quinoline, xanthene, and simple benzenic and naphthalenic derivates. Some of them are for the first time tested against Trypanosoma cruzi. The toxic effect these compounds on this parasite was done by two quite distinct sets of experiments. In one set, the compounds were added to infected blood as ethanolic solution. In this situation the most active one was a furan-1, 2-naphthoquinone, in the same range as gentian violet, a new fact to be considered in the assessment of structure-activity relationships in this class of compounds. In other set, we tentatively evaluated the biological activity of water insoluble compounds by adding them in a pure form without solvent into infected blood. In this way some appear to be very active and it was postulated that the effectiveness of such compounds must result from interactions between them and specific blood components.

  19. Probing vibrational activities, electronic properties, molecular docking and Hirshfeld surfaces analysis of 4-chlorophenyl ({[(1E)-3-(1H-imidazol-1-yl)-1-phenylpropylidene]amino}oxy)methanone: A promising anti-Candida agent

    Science.gov (United States)

    Jayasheela, K.; Al-Wahaibi, Lamya H.; Periandy, S.; Hassan, Hanan M.; Sebastian, S.; Xavier, S.; Daniel, Joseph C.; El-Emam, Ali A.; Attia, Mohamed I.

    2018-05-01

    The promising anti-Candida agent, 4-chlorophenyl ({[1E-3(1H-imidazole-1-yl)-1-phenylpropylidene}oxy)methanone (4-CPIPM) was comprehensively characterized by FT-IR, FT-Raman, UV, as well as 1H and 13C spectroscopic techniques. The theoretical calculations in the current study utilized Gaussian 09 W software with DFT approach of the B3LYP/6-311++G(d,p) method. The experimental X-ray diffraction data of the 4-CPIPM molecule were compared with the optimized structure and showed well agreement. Intermolecular electronic interactions and their stabilization energies have been analyzed by natural bond orbital method. Potential energy distribution confirmed the normal fundamental mode of vibration with the aid of MOLVIB software. The chemical shift values of the 1H and 13C spectra of the title compound were computed using gauge independent atomic orbital and the results were compared with the experimental values. The time-dependent density function theory method was used to predict the electronic, absorption wavelength and frontier molecular orbital energies. The HOMO-LUMO plots proved the charge transfer in the molecular system of the title compound through conjugated paths. The molecular electrostatic potential analysis provided the electrophilic and nucleophilic reactive sites in the title molecule which have been analyzed using Hirshfeld surface and two dimensions fingerprint plots. Non covalent interactions were also studied using reduced density gradient analysis and color filled electron density diagram. Molecular docking studies of the ligand-protein interactions along with their binding energies were carried out aiming to explain the potent anti-Candida activity of the title molecule.

  20. Antifungal agents. 10. New derivatives of 1-[(aryl)[4-aryl-1H-pyrrol-3-yl]methyl]-1H-imidazole, synthesis, anti-candida activity, and quantitative structure-analysis relationship studies.

    Science.gov (United States)

    Tafi, Andrea; Costi, Roberta; Botta, Maurizio; Di Santo, Roberto; Corelli, Federico; Massa, Silvio; Ciacci, Andrea; Manetti, Fabrizio; Artico, Marino

    2002-06-20

    The synthesis, anti-Candida activity, and quantitative structure-activity relationship (QSAR) studies of a series of 2,4-dichlorobenzylimidazole derivatives having a phenylpyrrole moiety (related to the antibiotic pyrrolnitrin) in the alpha-position are reported. A number of substituents on the phenyl ring, ranging from hydrophobic (tert-butyl, phenyl, or 1-pyrrolyl moiety) to basic (NH(2)), polar (CF(3), CN, SCH(3), NO(2)), or hydrogen bond donors and acceptor (OH) groups, were chosen to better understand the interaction of these compounds with cytochrome P450 14-alpha-lanosterol demethylase (P450(14DM)). Finally, the triazole counterpart of one of the imidazole compounds was synthesized and tested to investigate influence of the heterocyclic ring on biological activity. The in vitro antifungal activities of the newly synthesized azoles 10p-v,x-c' were tested against Candida albicans and Candida spp. at pH 7.2 and pH 5.6. A CoMFA model, previously derived for a series of antifungal agents belonging to chemically diverse families related to bifonazole, was applied to the new products. Because the results produced by this approach were not encouraging, Catalyst software was chosen to perform a new 3D-QSAR study. Catalyst was preferred this time because of the possibility of considering each compound as a collection of energetically reasonable conformations and of considering alternative stereoisomers. The pharmacophore model developed by Catalyst, named HYPO1, showed good performances in predicting the biological activity data, although it did not exhibit an unequivocal preference for one enantiomeric series of inhibitors relative to the other. One aromatic nitrogen with a lone pair in the ring plane (mapped by all of the considered compounds) and three aromatic ring features were recognized to have pharmacophoric relevance, whereas neither hydrogen bond acceptor nor hydrophobic features were found. These findings confirmed that the key interaction of azole

  1. Cloud Point Extraction and Determination of Silver Ion in Real Sample using Bis((1H-benzo[d ]imidazol-2ylmethylsulfane

    Directory of Open Access Journals (Sweden)

    Farshid Ahmadi

    2011-01-01

    Full Text Available Bis((1H-benzo[d]imidazol-2ylmethylsulfane (BHIS was used as a complexing agent in cloud point extraction for the first time and applied for selective pre-concentration of trace amounts of silver. The method is based on the extraction of silver at pH 8.0 by using non-ionic surfactant T-X114 and bis((1H-benzo[d]imidazol-2ylmethylsulfane as a chelating agent. The adopted concentrations for BHIS, Triton X-114 and HNO3, bath temperature, centrifuge rate and time were optimized. Detection limits (3SDb/m of 1.7 along with enrichment factor of 39 for silver ion was achieved. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed method was successfully applied to the ultra-trace determination of silver in real samples.

  2. Electron spin resonance and E.N.D.O.R. double resonance study of free radicals produced by gamma irradiation of imidazole single crystals

    International Nuclear Information System (INIS)

    Lamotte, B.

    1970-01-01

    Gamma irradiation of imidazole single crystals at 300 deg. K gives two radicals. Identification and detailed studies of their electronic and geometric structure have been made by ESR and ENDOR techniques. A study of the hydrogen bonded protons hyperfine tensor is made and let us conclude to the inexistence of movement and tunneling of these protons. The principal low temperature radical, produced by gamma irradiation at 77 deg. K has been also studied by ESR and a model has been proposed. (author) [fr

  3. Catalytic constructive deoxygenation of lignin-derived phenols: new C-C bond formation processes from imidazole-sulfonates and ether cleavage reactions.

    Science.gov (United States)

    Leckie, Stuart M; Harkness, Gavin J; Clarke, Matthew L

    2014-10-09

    As part of a programme aimed at exploiting lignin as a chemical feedstock for less oxygenated fine chemicals, several catalytic C-C bond forming reactions utilising guaiacol imidazole sulfonate are demonstrated. These include the cross-coupling of a Grignard, a non-toxic cyanide source, a benzoxazole, and nitromethane. A modified Meyers reaction is used to accomplish a second constructive deoxygenation on a benzoxazole functionalised anisole.

  4. Rubber compounding and processing

    CSIR Research Space (South Africa)

    John, MJ

    2014-06-01

    Full Text Available This chapter presents an overview on the compounding and processing techniques of natural rubber compounds. The introductory portion deals with different types of rubbers and principles of rubber compounding. The primary and secondary fillers used...

  5. Experimental and theoretical investigations on the inhibition of mild steel corrosion in the ground water medium using newly synthesised bipodal and tripodal imidazole derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Gopi, D., E-mail: dhanaraj_gopi@yahoo.com [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Sherif, El-Sayed M. [Center of Excellence for Research in Engineering Materials (CEREM), Advanced Manufacturing Institute, King Saud University, P.O. Box 800, Al-Riyadh 11421 (Saudi Arabia); Electrochemistry and Corrosion Laboratory, Department of Physical Chemistry, National Research Centre (NRC), Dokki, 12622 Cairo (Egypt); Surendiran, M. [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Jothi, M.; Kumaradhas, P. [Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India); Kavitha, L. [Department of Physics, School of Basic and Applied Sciences, Central University of Tamilnadu, Thiruvarur 610 101, Tamilnadu (India)

    2014-10-15

    Two new imidazole derivatives, namely 1,4-bis(N-imidazolylmethyl)-2-5-dimethoxybenzene (BIDM) and 1,3,5-tris(N-imidazolylmethyl)-2,4,6-trimethoxybenzene (TITM), were synthesised and their effects on the inhibition of mild steel corrosion in ground water medium are reported. The study was carried out using gravimetric and electrochemical techniques in order to determine the corrosion inhibition efficiencies of the bipodal and tripodal structured imidazoles. Further, the quantum chemical calculations using density functional theory (DFT) gave a profound insight into the inhibitory action mechanism of BIDM and TITM and their calculation parameters, such as E{sub HOMO}, E{sub LUMO} and ΔE were in good agreement with the results of the experimental studies. BIDM and TITM exhibited lowest corrosion current densities of circa 7.5 μA cm{sup −2} and 4.1 μAcm{sup −2} at the optimum concentrations of 0.67 and 0.49 mM, respectively. All measurements thus confirmed that both BIDM and TITM behaved as good inhibitors for mild steel corrosion in ground water medium. - Highlights: • Synthesis of new imidazole derivatives-BIDM(bipodal) and TITM(tripodal) inhibitors. • Gravimetric analysis to investigate mild steel corrosion inhibition in ground water. • Electrochemical characterizations to substantiate results of weight loss method. • Quantum studies to analyse the chemical behavior, structure and substituent effect.

  6. Experimental and theoretical investigations on the inhibition of mild steel corrosion in the ground water medium using newly synthesised bipodal and tripodal imidazole derivatives

    International Nuclear Information System (INIS)

    Gopi, D.; Sherif, El-Sayed M.; Surendiran, M.; Jothi, M.; Kumaradhas, P.; Kavitha, L.

    2014-01-01

    Two new imidazole derivatives, namely 1,4-bis(N-imidazolylmethyl)-2-5-dimethoxybenzene (BIDM) and 1,3,5-tris(N-imidazolylmethyl)-2,4,6-trimethoxybenzene (TITM), were synthesised and their effects on the inhibition of mild steel corrosion in ground water medium are reported. The study was carried out using gravimetric and electrochemical techniques in order to determine the corrosion inhibition efficiencies of the bipodal and tripodal structured imidazoles. Further, the quantum chemical calculations using density functional theory (DFT) gave a profound insight into the inhibitory action mechanism of BIDM and TITM and their calculation parameters, such as E HOMO , E LUMO and ΔE were in good agreement with the results of the experimental studies. BIDM and TITM exhibited lowest corrosion current densities of circa 7.5 μA cm −2 and 4.1 μAcm −2 at the optimum concentrations of 0.67 and 0.49 mM, respectively. All measurements thus confirmed that both BIDM and TITM behaved as good inhibitors for mild steel corrosion in ground water medium. - Highlights: • Synthesis of new imidazole derivatives-BIDM(bipodal) and TITM(tripodal) inhibitors. • Gravimetric analysis to investigate mild steel corrosion inhibition in ground water. • Electrochemical characterizations to substantiate results of weight loss method. • Quantum studies to analyse the chemical behavior, structure and substituent effect

  7. Radio-prophylactic treatment with imidazole and/or Serotonin for Modulation of Tissue Catecholamines in whole body gamma irradiated Rats

    International Nuclear Information System (INIS)

    Hassan, S.H.M.; Roushdy, H.M.; Maklaad, Y.A.; El-Sayed, M.E.

    1995-01-01

    The present study has been conducted to evaluate the radioprotective effects of imidazole, serotonin and their combination on radiation induced reduction in catecholamine contents of the heart and adrenal glands in albino rat. The contribution of catecholamines in the radioprotective role of these agents has been evaluated. Whole-body gamma-irradiation (6 Gy) induced a significant reduction in heart and adrenal glands contents of catecholamine (epinephrine, norepinephrine and dopamine) one day post irradiation. Such reduction in catecholamine contents was more pronounced on the seventh day post exposure. Administration of imidazole (350 mg kg-1) or serotonin. (15 mg. kg-1) controlled the radiation induced reduction in catecholamine contents of heart as well as adrenal glands. Whereas, combination of imidazole (17 mg kg-1) serotonin (15 mg. kg-1) afforded a better protection than either agent given alone, in view that all the measured parameters could be fully restored to the values pre-irradiation. This study appreciate the usage of such combination as a prophylactic treatment for controlling the stress-state induced by irradiation which is associated with disturbed level of endogenous catecholamine contents in those sensitive patients undergoing radiotherapy. 2 tabs

  8. Characteristics of oxidative homolytic alkylation of imidazoles and organic-inorganic hybrid extended networks from large aromatic building blocks

    Science.gov (United States)

    Li, Kunhao

    The discovery of the dramatic in vitro antimalarial activity of 2-iodo-L-histidine and 2-fluoro-L-histidine, as well as their in vivo limitations, has prompted a systematic search for novel 2-substituted imidazoles and bioimidazoles as agents against human malaria. Previous research has shown that the regioselective alkyl free radical substitution on imidazoles and bioimidazoles could serve as a simple and efficient route to a wide variety of 2-alkylimidazoles. In this research, this methodology was successfully extended to include alkyl radicals substituted with various functional groups such as amide or ester. While this novel methodology should be of some synthetic utility when tertiary radicals are used, poorer yields are usually encountered in the cases of primary radicals. In the second part of this dissertation, a series of novel ligands containing multiple ortho-bis(organothio) groups were synthesized and their coordination and network forming properties were studied in the context of crystalline organic-inorganic hybrid extended networks. For the syntheses of HRTTs [2,3,6,7,10,11-hexakis(alkylthio)triphenylenes], a simpler, safer and higher yielding one-pot process was developed. Quenching the hexa-anions (formed when sodium methylthiolate was refluxed with hexabromotriphenylene) with alkyl halides or acid chlorides afforded HRTTs. This newly developed process was also successfully expanded to the pyrene system. In the syntheses of unsymmetrically substituted triphenlyenes, it was shown for the first time that the oxidative cyclization process is applicable to thioether containing systems, pointing to a novel strategy for the preparation of this type of unsymmetrically substituted triphenlyenes. Treating these novel ligands with various metal salts [i.e. bismuth(III) chloride and bismuth(III) bromide] under carefully controlled conditions resulted in a series of air-stable semiconductive coordination networks. Their single crystal structures were

  9. Hexakis(1-methyl-1H-imidazole-κN3cobalt(II dibromide dihydrate

    Directory of Open Access Journals (Sweden)

    Rufu Yao

    2009-02-01

    Full Text Available The asymmetric unit of the title compound, [Co(C4H6N26]Br2·2H2O, contains one-half of the centrosymmetric cation, one Br atom and one water molecule. The CoII atom, lying on an inversion center, has a distorted octahedral geometry, defined by six N atoms from six 1-methylimidazole ligands. In the crystal structure, intra- and intermolecular O—H...Br hydrogen bonds link pairs of uncoordinated water molecules and bromide anions.

  10. DFT/TDDFT investigation on the electronic structures and photophysical properties of phosphorescent iridium(III) complexes with 2-(pyridin-2-yl)-benzo[d]imidazole ligand

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Xiaohong, E-mail: shangxiaohong58@aliyun.com [College of Chemistry and Life Science, Changchun University of Technology, Changchun 130012 (China); Han, Deming [School of Life Science and Technology, Changchun University of Science and Technology, Changchun 130022 (China); Li, Dongfeng [College of Chemistry and Life Science, Changchun University of Technology, Changchun 130012 (China); Zhang, Gang [State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023 (China)

    2014-03-15

    We have reported a theoretical analysis of a series of heteroleptic iridium(III) complexes (mpmi){sub 2}Ir(pybi) [mpmi=1-(4-tolyl)-3-methyl-imidazole, pybi=2-(pyridin-2-yl)-benzo[d]imidazole] (1a), (fpmi){sub 2}Ir(pybi) [fpmi=1-(4-fluoro-phenyl)-3-methyl-imidazole] (1b), (tfpmi){sub 2}Ir(pybi) [tfpmi=1-methyl-3-(4-trifluoromethyl-phenyl)-imidazole] (1c), (pypmi){sub 2}Ir(pybi) [pypmi=3-(3-methyl-imidazol)-pyrazole] (2a), (phpymi){sub 2}Ir(pybi) [phpymi=3-(3-methyl-imidazol)-5-phenyl-pyrazole] (2b), and (inpymi){sub 2}Ir(pybi) [inpymi=3-(3-methyl-imidazol)-indeno[1,2-c]pyrazole] (2c) by using the density functional theory (DFT) method to investigate their electronic structures and photophysical properties and obtain further insights into the phosphorescent efficiency mechanism. By changing cyclometalated ligands, the conjugation length, and substituents of the cyclometalated ligands, one can tune the emission color from green (λ{sub em}=520 nm) to orange (λ{sub em}=592 nm). Complexes 1a, 1b, 2a, and 2b have the almost identical emission wavelength about 550 nm, while 592 nm for 1c and 520 nm for 2c are red shifted and blue shifted, respectively, relative to 1a. The calculated results indicate that, for 1b and 1c, the substituents of −F and −CF{sub 3} at the phenyl moiety cause a poor hole-injection ability compared with that of 1a. For all these complexes studied, the hole-transporting performances are better than the electron-transporting ones. The difference between reorganization energies for hole transport (λ{sub ih}) and reorganization energies for electron transport (λ{sub ie}) for complex 1c are relatively smaller, indicating that the hole and electron transfer balance could be achieved more easily in the emitting layer. The alteration of cyclometalated ligands with different conjugation lengths and substituents has an impact on the optoelectronic properties of these complexes. It is believed that the larger metal to ligand charge transfer (MLCT

  11. Carbon materials derived from chitosan/cellulose cryogel-supported zeolite imidazole frameworks for potential supercapacitor application.

    Science.gov (United States)

    Li, Zehui; Yang, Lan; Cao, Hongbin; Chang, Yu; Tang, Kexin; Cao, Zhiqin; Chang, Junjun; Cao, Youpeng; Wang, Wenbo; Gao, Meng; Liu, Chenming; Liu, Dagang; Zhao, He; Zhang, Yi; Li, Mingjie

    2017-11-01

    In order to promote sustainable development, green and renewable clean energy technologies continue to be developed to meet the growing demand for energy, such as supercapacitor, fuel cells and lithium-ion battery. It is urgent to develop appropriate nanomaterials for these energy technologies to reduce the volume of the device, improve the efficiency of energy conversion and enlarge the energy storage capacity. Here, chitosan/cellulose carbon cryogel (CCS/CCL) were designed and synthesized. Through the introduction of zeolite imidazole frameworks (ZIFs) into the chitosan/cellulose cryogels, the obtained materials showed a microstructure of ZIF-7 (a kind of ZIFs) coated chitosan/cellulose fibers (CS/CL). After carbonizing, the as-prepared carbonized ZIF-7@cellulose cryogel (NC@CCL, NC is carbonized ZIF-7) and carbonized ZIF-7@chitosan cryogel (NC@CCS) exhibited suitable microspore contents of 34.37% and 30%, respectively, and they both showed an internal resistance lower than 2Ω. Thereby, NC@CCL and NC@CCS exhibited a high specific capacitance of 150.4Fg -1 and 173.1Fg -1 , respectively, which were much higher than those of the original materials. This approach offers a facile method for improving the strength and electronic conductivity of carbon cryogel derived from nature polymers, and also efficiently inhibits the agglomeration of cryogel during carbonization in high temperature, which opens a novel avenue for the development of carbon cryogel materials for application in energy conversion systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Decoding Nucleation and Growth of Zeolitic Imidazolate Framework Thin Films with Atomic Force Microscopy and Vibrational Spectroscopy.

    Science.gov (United States)

    Öztürk, Zafer; Filez, Matthias; Weckhuysen, Bert M

    2017-08-10

    The synthesis of metal-organic framework (MOF) thin films has garnered significant attention during the past decade. By better understanding the parameters governing the nucleation and growth of such thin films, their properties can be rationally tuned, empowering their application as (reactive) membranes. Here, a combined AFM-vibrational spectroscopy research strategy is employed to detail the chemistries governing the nucleation and growth of zeolitic imidazolate framework (ZIF) thin films, in particular isostructural Co-ZIF-67 and Zn-ZIF-8. First, a single step direct synthesis approach is used to investigate the influence of different synthesis parameters -metal/linker ratio, temperature, and metal type- on the thin film nucleation and growth behaviour. While the metal/linker ratio has a pronounced effect on the thin film nucleation rate, the temperature mainly influences the growth kinetics of nuclei forming the thin film. In addition, the nucleation and growth of ZIF thin films is shown to be highly dependent on the electronegativity of the metal type. Thin-film thickness control can be achieved by using a multistep synthesis strategy, implying repetitive applications of single step deposition under identical synthesis conditions, for which a growth mechanism is proposed. This study provides insight into the influence of synthesis parameters on the ZIF thin film properties, using tools at hand to rationally tune MOF thin film properties. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  13. Quantitation of Pyrrole-Imidazole Polyamide in Rat Plasma by High-Performance Liquid Chromatography Coupled with UV Detection

    Directory of Open Access Journals (Sweden)

    Tomonori Kamei

    2012-01-01

    Full Text Available A simple and robust method using high-performance liquid chromatography with UV detection was developed and validated for the determination of six pyrrole-imidazole (PI polyamides (HN.49, TGF-β1f, TGF-β1t, HN.50f, HN.50t, and LOX-1 in rat plasma. After the plasma proteins were precipitated with methanol containing phenacetin as an internal standard, the analytes were separated on a Luna C18 (2 (5 μm, 4.6×150 mm. Calibration curves were linear over the range of 0.5 to 200 μg/mL for HN.49, 0.25 to 200 μg/mL for TGF-β1f, TGF-β1t, HN.50t, and LOX-1, 1 to 200 μg/mL for HN.50f in rat plasma. The inter- and intraday precision were below 15%, and the accuracy was within 15% at the quality controls. The validated method was successfully applied to sample analysis for the pharmacokinetic study.

  14. Rapid One-Pot Microwave Synthesis of Mixed-Linker Hybrid Zeolitic-Imidazolate Framework Membranes for Tunable Gas Separations.

    Science.gov (United States)

    Hillman, Febrian; Brito, Jordan; Jeong, Hae-Kwon

    2018-02-14

    The relatively slow and complex fabrication processes of polycrystalline metal-organic framework (MOF) membranes often times restrict their way to commercialization, despite their potential for molecular separation applications. Herein, we report a rapid one-pot microwave synthesis of mixed-linker hybrid zeolitic-imidazolate framework (ZIF) membranes consisting of 2-methylimidazolate (ZIF-8 linker) and benzimidazolate (ZIF-7 linker) linkers, termed ZIF-7-8 membranes. The fast-volumetric microwave heating in conjunction with a unique counter diffusion of metal and linker solutions enabled unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes in ∼90 s, the fastest MOF membrane preparation up to date. Furthermore, we were able to tune the molecular sieving properties of the ZIF-7-8 membranes by varying the benzimidazole-to-2-methylimidazole (bIm-to-mIm) linker ratio in the hybrid frameworks. The tuning of their molecular sieving properties led to the systematic change in the permeance and selectivity of various small gases. The unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes with tunable molecular sieving properties is an important step forward for the commercial gas separation applications of ZIF membranes.

  15. Synthesis of ceramic hollow fiber supported zeolitic imidazolate framework-8 (ZIF-8) membranes with high hydrogen permeability

    KAUST Repository

    Pan, Yichang; Wang, Bo; Lai, Zhiping

    2012-01-01

    Purification and recovery of hydrogen from hydrocarbons in refinery streams in the petrochemical industry is an emerging research field in the study of membrane gas separation. Hollow fiber membrane modules can be easily implemented into separation processes at the industrial scale. In this report, hollow yttria-stabilized zirconia (YSZ) fiber-supported zeolitic imidazole framework-8 (ZIF-8) membranes were successfully prepared using a mild and environmentally friendly seeded growth method. Our single-component permeation studies demonstrated that the membrane had a very high hydrogen permeance (~15×10 -7mol/m 2sPa) and an ideal selectivity of H 2/C 3H 8 of more than 1000 at room temperature. This high membrane permeability and selectivity caused serious concentration polarization in the separation of H 2/C 3H 8 mixtures, which led to almost 50% drop in both the H 2 permeance and the separation factor. Enhanced mixing on the feed side could reduce the effect of the concentration polarization. Our experimental data also indicated that the membranes had excellent reproducibility and long-term stability, indicating that the hollow fiber-supported ZIF-8 membranes developed in this study have great potential in industry-scale separation of hydrogen. © 2012 Elsevier B.V.

  16. Synthesis of ceramic hollow fiber supported zeolitic imidazolate framework-8 (ZIF-8) membranes with high hydrogen permeability

    KAUST Repository

    Pan, Yichang

    2012-12-01

    Purification and recovery of hydrogen from hydrocarbons in refinery streams in the petrochemical industry is an emerging research field in the study of membrane gas separation. Hollow fiber membrane modules can be easily implemented into separation processes at the industrial scale. In this report, hollow yttria-stabilized zirconia (YSZ) fiber-supported zeolitic imidazole framework-8 (ZIF-8) membranes were successfully prepared using a mild and environmentally friendly seeded growth method. Our single-component permeation studies demonstrated that the membrane had a very high hydrogen permeance (~15×10 -7mol/m 2sPa) and an ideal selectivity of H 2/C 3H 8 of more than 1000 at room temperature. This high membrane permeability and selectivity caused serious concentration polarization in the separation of H 2/C 3H 8 mixtures, which led to almost 50% drop in both the H 2 permeance and the separation factor. Enhanced mixing on the feed side could reduce the effect of the concentration polarization. Our experimental data also indicated that the membranes had excellent reproducibility and long-term stability, indicating that the hollow fiber-supported ZIF-8 membranes developed in this study have great potential in industry-scale separation of hydrogen. © 2012 Elsevier B.V.

  17. Ultra-high adsorption capacity of zeolitic imidazole framework-67 (ZIF-67) for removal of malachite green from water.

    Science.gov (United States)

    Lin, Kun-Yi Andrew; Chang, Hsuan-Ang

    2015-11-01

    Zeolitic imidazole frameworks (ZIFs), a new class of adsorbents, are proposed to adsorb Malachite Green (MG) in water. Particularly, ZIF-67 was selected owing to its stability in water and straightforward synthesis. The as-synthesized ZIF-67 was characterized and used to adsorb MG from water. Factors affecting the adsorption capacity were investigated including mixing time, temperature, the presence of salts and pH. The kinetics, adsorption isotherm and thermodynamics of the MG adsorption to ZIF-67 were also studied. The adsorption capacity of ZIF-67 for MG could be as high as 2430mgg(-1) at 20°C, which could be improved at the higher temperatures. Such an ultra-high adsorption capacity of ZIF-67 was almost 10-times of those of conventional adsorbents, including activated carbons and biopolymers. A mechanism for the high adsorption capacity was proposed and possibly attributed to the π-π stacking interaction between MG and ZIF-67. ZIF-67 also could be conveniently regenerated by washing with ethanol and the regeneration efficiency could remain 95% up to 4 cycles of the regeneration. ZIF-67 was also able to remove MG from the aquaculture wastewater, in which MG can be typically found. These features enable ZIF-67 to be one of the most effective and promising adsorbent to remove MG from water. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Heteropoly acid encapsulated into zeolite imidazolate framework (ZIF-67) cage as an efficient heterogeneous catalyst for Friedel–Crafts acylation

    Energy Technology Data Exchange (ETDEWEB)

    Ammar, Muhammad; Jiang, Sai; Ji, Shengfu, E-mail: jisf@mail.buct.edu.cn

    2016-01-15

    A new strategy has been developed for the encapsulation of the phosphotungstic heteropoly acid (H{sub 3}PW{sub 12}O{sub 40} denoted as PTA) into zeolite imidazolate framework (ZIF-67) cage and the PTA@ZIF-67(ec) catalysts with different PTA content were prepared. The structure of the catalysts was characterized by XRD, BET, SEM, FT-IR, ICP-AES and TG. The catalytic activity and recovery properties of the catalysts for the Friedel-Crafts acylation of anisole with benzoyl chloride were evaluated. The results showed that 14.6–31.7 wt% PTA were encapsulated in the ZIF-67 cage. The PTA@ZIF-67(ec) catalysts had good catalytic activity for Friedel-Crafts acylation. The conversion of anisole can reach ~100% and the selectivity of the production can reach ~94% over 26.5 wt% PTA@ZIF-67(ec) catalyst under the reaction condition of 120 °C and 6 h. After reaction, the catalyst can be easily separated from the reaction mixture by the centrifugation. The recovered catalyst can be reused five times and the selectivity can be kept over 90%. - Graphical abstract: The PTA@ZIF-67 catalysts with different PTA content were prepared by encapsulating the PTA into ZIF-67 cage and the as-synthesized catalysts exhibited good catalytic activity for the Friedel–Craft acylation of anisole with benzoyl chloride.

  19. Facile fabrication of porous ZnO by thermal treatment of zeolitic imidazolate framework-8 and its photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Du, Y. [College of Environment, Jiangsu Key Laboratory of Industrial Water-Conservation and Emission Reduction, Nanjing University of Technology, Nanjing 210009 (China); Chen, R.Z., E-mail: rizhichen@163.com [State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu Key Laboratory of Industrial Water-Conservation and Emission Reduction, Nanjing University of Technology, Nanjing 210009 (China); Yao, J.F. [Department of Chemical Engineering, Monash University, Clayton, Vic 3800 (Australia); Wang, H.T., E-mail: huanting.wang@monash.edu [Department of Chemical Engineering, Monash University, Clayton, Vic 3800 (Australia)

    2013-02-25

    Highlights: Black-Right-Pointing-Pointer Porous ZnO powders can be obtained by thermal decomposition of ZIF-8. Black-Right-Pointing-Pointer The morphology, structure and performance of porous ZnO can be controlled. Black-Right-Pointing-Pointer ZnO-500-5 exhibits efficient photocatalytic activity for the degradation of MB. - Abstract: In this work, porous ZnO photocatalysts were attempted to be prepared by a facile method, i.e. the thermal treatment of zeolitic imidazolate framework-8, and then characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy and nitrogen adsorption-desorption. It was found that the calcination temperature and time significantly influenced the morphology, composition and pore structure of ZnO. The photocatalytic activities of as-prepared ZnO powders were evaluated in the degradation of methylene blue (MB) under UV light in comparison with commercial anatase TiO{sub 2} and Degussa P25 TiO{sub 2}. The surface area and crystallinity of porous ZnO obviously affected the photocatalytic activity of ZnO. The ZnO prepared at 500 Degree-Sign C for 5 h (ZnO-500-5) showed the highest photocatalytic activity, which was higher than that of the commercial anatase TiO{sub 2} and lower than that of Degussa P25 TiO{sub 2}.

  20. High-Performance Thin-Film-Nanocomposite Cation Exchange Membranes Containing Hydrophobic Zeolitic Imidazolate Framework for Monovalent Selectivity

    Directory of Open Access Journals (Sweden)

    Jian Li

    2018-05-01

    Full Text Available Zeolitic imidazolate framework-8 (ZIF-8 offers good hydrothermal, chemical, and thermal stabilities, and is therefore of interest in membrane synthesis. In this work, an interfacial polymerization (IP method was applied by anchoring ZIF-8 to the skin layer of thin-film nanocomposite (TFN membranes in order to obtain monovalent selectivity in electrodialysis. Organic trimesoyl chloride (TMC, 0.1 wt % solutions and aqueous m-phenyl diamine (MPD, 2% w/v solutions were used during the interfacial polymerization process. A range of polyamine (PA/ZIF-8 based membranes was fabricated by varying the concentration of ZIF-8 in the organic solution. The properties of the primary and modified membrane were characterized by scanning electron microscope (SEM, energy dispersive X-ray analysis (EDAX, atomic force microscopy (AFM, water uptake, ion exchange capacity, and contact angle measurements. No significant changes of the surface structure of the PA/ZIF-8 based membranes were observed. Nevertheless, the presence of ZIF-8 under the PA layer plays a key role in the separation process. For single salt solutions that were applied in electrodialysis (ED, faster transport of Na+ and Mg2+ was obtained after introducing the ZIF-8 nanoparticles, however, the desalination efficiency remained constant. When the hybrid membranes were applied to electrodialysis for binary mixtures containing Na+ as well as Mg2+, it was demonstrated that the monovalent selectivity and Na+ flux were enhanced by a higher ZIF-8 loading.

  1. Porous CNTs/Co Composite Derived from Zeolitic Imidazolate Framework: A Lightweight, Ultrathin, and Highly Efficient Electromagnetic Wave Absorber.

    Science.gov (United States)

    Yin, Yichao; Liu, Xiaofang; Wei, Xiaojun; Yu, Ronghai; Shui, Jianglan

    2016-12-21

    Porous carbon nanotubes/cobalt nanoparticles (CNTs/Co) composite with dodecahedron morphology was synthesized by in situ pyrolysis of the Co-based zeolitic imidazolate framework in a reducing atmosphere. The morphology and microstructure of the composite can be well tuned by controlling the pyrolysis conditions. At lower pyrolysis temperature, the CNTs/Co composite is composed of well-dispersed Co nanoparticles and short CNT clusters with low graphitic degree. The increase of pyrolysis temperature/time promotes the growth and graphitization of CNTs and leads to the aggregation of Co nanoparticles. The optimized CNTs/Co composite exhibits strong dielectric and magnetic losses as well as a good impedance matching property. Interestingly, the CNTs/Co composite displays extremely strong electromagnetic wave absorption with a maximum reflection loss of -60.4 dB. More importantly, the matching thickness of the absorber is as thin as 1.81 mm, and the filler loading of composite in the matrix is only 20 wt %. The highly efficient absorption is closely related to the well-designed structure and the synergistic effect between CNTs and Co nanoparticles. The excellent absorbing performance together with lightweight and ultrathin thickness endows the CNTs/Co composite with the potential for application in the electromagnetic wave absorbing field.

  2. Separation of 1,3-substituted imidazoles for quality control of a Lewis acidic ionic liquid for aluminum electroplating.

    Science.gov (United States)

    Kosmus, Patrick; Steiner, Oliver; Goessler, Walter; Gollas, Bernhard

    2014-05-01

    Ionic liquids (ILs) are already used or have great potential in many industrial applications. Knowledge about their unique physicochemical characteristics makes ILs suitable for the electrodeposition of metals with very low negative potentials. Aluminum with its good corrosion protection behavior has great capability to be electroplated from IL electrolytes on steel substrates. The stability of the chosen electrolyte is very important to ensure industrial applicability. In this study, temperature and electrochemical long-term stability from electrolytes based on a Lewis acidic mixture of AlCl3 and 1-ethyl-3-methylimidazolium chloride are investigated. A published method was modified to identify possible degradation products using mass spectrometric detection. The optimized method used an Agilent Zorbax SB-Phenyl column (2.0 × 150 mm, 5 μm particles) with a 20 mmol TFA and 5% ACN mobile phase. This method allowed the quantification of several imidazoles from 0.1 to 100 mg/L. When analyzing the long-term stressed electrolytes, no significant changes in electrolyte composition could be observed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. High-performance polyamide thin-film-nanocomposite reverse osmosis membranes containing hydrophobic zeolitic imidazolate framework-8

    KAUST Repository

    Duan, Jintang

    2015-02-01

    A hydrophobic, hydrothermally stable metal-organic framework (MOF) - zeolitic imidazolate framework-8 (ZIF-8) was successfully incorporated into the selective polyamide (PA) layer of thin-film nanocomposite (TFN) membranes for water desalination. The potential advantages of ZIF-8 over classic hydrophilic zeolite used in TFNs include: i) theoretically faster water transport within the framework and ii) better compatibility with the PA matrix. The TFN membranes were characterized with SEM, TEM, AFM, XPS, water contact angle measurements and reverse osmosis tests under 15.5bar hydraulic pressure with 2000ppm NaCl solution. Lab-made, nano-sized (~200nm) ZIF-8 increased water permeance to 3.35±0.08L/m2·h·bar at 0.4% (w/v) loading, 162% higher than the pristine PA membranes; meanwhile, high NaCl rejection was maintained. The TFN surface was less crosslinked and more hydrophilic than that of the pristine PA. A filler encapsulation mechanism was proposed for the effects of filler on TFN membrane surface morphology and properties. This study experimentally verified the potential use of ZIF-8 in advanced TFN RO membranes.

  4. Sanskrit Compound Processor

    Science.gov (United States)

    Kumar, Anil; Mittal, Vipul; Kulkarni, Amba

    Sanskrit is very rich in compound formation. Typically a compound does not code the relation between its components explicitly. To understand the meaning of a compound, it is necessary to identify its components, discover the relations between them and finally generate a paraphrase of the compound. In this paper, we discuss the automatic segmentation and type identification of a compound using simple statistics that results from the manually annotated data.

  5. Synthesis, Spectral and Anthelmintic Activity Studies on Some Novel Imidazole Derivatives

    Directory of Open Access Journals (Sweden)

    Rajiv Dahiya

    2008-01-01

    Full Text Available Present study describes the synthesis of a novel series of 3,5-diiodo-4-(5-nitro-1H-2-imidazolylbenzoyl amino acids and di/tri/tetrapeptides using diisopropylcarbodiimide/dicyclohexylcarbodiimide (DIPC/DCC as coupling agents and N-methylmorpholine/triethylamine (NMM/TEA as bases. Structure elucidation of all the newly synthesized compounds was done by elemental analysis and IR, 1H NMR, 13C NMR and mass spectral data. Synthesized imidazolopeptides were screened for their anthelmintic activity and found to possess moderate to good bioactivity against earthworms Megascoplex konkanensis, Pontoscotex corethruses and Eudrilus eugeniea when compared to reference drugs - albendazole and mebendazole at dose level of 2 mg mL−1.

  6. Cytoprotection of human endothelial cells against oxidative stress by 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im): application of systems biology to understand the mechanism of action.

    Science.gov (United States)

    Wang, Xinyu; Bynum, James A; Stavchansky, Solomon; Bowman, Phillip D

    2014-07-05

    Cellular damage from oxidative stress, in particular following ischemic injury, occurs during heart attack, stroke, or traumatic injury, and is potentially reducible with appropriate drug treatment. We previously reported that caffeic acid phenethyl ester (CAPE), a plant-derived polyphenolic compound, protected human umbilical vein endothelial cells (HUVEC) from menadione-induced oxidative stress and that this cytoprotective effect was correlated with the capacity to induce heme oxygenase-1 (HMOX1) and its protein product, a phase II cytoprotective enzyme. To further improve this cytoprotective effect, we studied a synthetic triterpenoid, 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), which is known as a potent phase II enzyme inducer with antitumor and anti-inflammatory activities, and compared it to CAPE. CDDO-Im at 200nM provided more protection to HUVEC against oxidative stress than 20μM CAPE. We explored the mechanism of CDDO-Im cytoprotection with gene expression profiling and pathway analysis and compared to that of CAPE. In addition to potent up-regulation of HMOX1, heat shock proteins (HSP) were also found to be highly induced by CDDO-Im in HUVEC. Pathway analysis results showed that transcription factor Nrf2-mediated oxidative stress response was among the top canonical pathways commonly activated by both CDDO-Im and CAPE. Compared to CAPE, CDDO-Im up-regulated more HSP and some of them to a much higher extent. In addition, CDDO-Im treatment affected Nrf2 pathway more significantly. These findings may provide an explanation why CDDO-Im is a more potent cytoprotectant than CAPE against oxidative stress in HUVEC. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Determination of imidazole derivatives by micellar electrokinetic chromatography combined with solid-phase microextraction using activated carbon-polymer monolith as adsorbent.

    Science.gov (United States)

    Shih, Yung-Han; Lirio, Stephen; Li, Chih-Keng; Liu, Wan-Ling; Huang, Hsi-Ya

    2016-01-08

    In this study, an effective method for the separation of imidazole derivatives 2-methylimidazole (2-MEI), 4- methylimidazole (4-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) in caramel colors using cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography (CSEI-sweeping-MEKC) was developed. The limits of detection (LOD) and quantitation (LOQ) for the CSEI-sweeping-MEKC method were in the range of 4.3-80μgL(-1) and 14-270μgL(-1), respectively. Meanwhile, a rapid fabrication activated carbon-polymer (AC-polymer) monolithic column as adsorbent for solid-phase microextraction (SPME) of imidazole colors was developed. Under the optimized SPME condition, the extraction recoveries for intra-day, inter-day and column-to-column were in the range of 84.5-95.1% (<6.3% RSDs), 85.6-96.1% (<4.9% RSDs), and 81.3-96.1% (<7.1% RSDs), respectively. The LODs and LOQs of AC-polymer monolithic column combined with CSEI-sweeping-MEKC method were in the range of 33.4-60.4μgL(-1) and 111.7-201.2μgL(-1), respectively. The use of AC-polymer as SPME adsorbent demonstrated the reduction of matrix effect in food samples such as soft drink and alcoholic beverage thereby benefiting successful determination of trace-level caramel colors residues using CSEI-sweeping-MEKC method. The developed AC-polymer monolithic column can be reused for more than 30 times without any significant loss in the extraction recovery for imidazole derivatives. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Structure and Heme-Independent Peroxidase Activity of a Fully-Coordinated Mononuclear Mn(II) Complex with a Schiff-Base Tripodal Ligand Containing Three Imidazole Groups

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Shuranjan; Lee, Hong In [Kyungpook National University, Daegu (Korea, Republic of); Moon, Do Hyun [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Lah, Myoung Soo [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2010-11-15

    New complex [Mn(II)H{sub 1.5}L]{sub 2}[Mn(II)H{sub 3}L]{sub 2}(ClO{sub 4}){sub 5}·3H{sub 2}O, where H{sub 3}L is tris{2-(4-imidazolyl)methyliminoethyl} amine (imtren), has been prepared by reacting manganese(II) perchlorate hexahydrate with the imtren ligand in methanol. X-ray crystallographic study revealed that the imtren ligand hexadentately binds to Mn(II) ion through the three Schiff-base imine N atoms and three imidazole N atoms with a distorted octahedral geometry, and the apical tertiary amine N atom of the ligand pseudo-coordinates to Mn(II), forming overall a pseudo-seven coordination environment. The hydrogen-bonds between imidazole and imidazolate of [Mn(II)H{sub 1.5}L]{sup 0.5+} complex ions are extended to build a 2D puckered network with trigonal voids. [Mn(II)H{sub 3}L]{sup 2+} complex ions constitutes another extended 2D puckered layer without hydrogen bonds. Two layers are wedged each other to constitute overall stack of the crystal. Peroxidase activity of complex 1 was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)- 6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of complex 1. Generation of ABTS{sup +·} was observed by UV-vis and EPR spectroscopies, indicating that the complex 1, a fully-coordinated mononuclear Mn(II) complex with nitrogen-only ligand, has a heme-independent peroxidase activity.

  9. Sequence-selective single-molecule alkylation with a pyrrole-imidazole polyamide visualized in a DNA nanoscaffold.

    Science.gov (United States)

    Yoshidome, Tomofumi; Endo, Masayuki; Kashiwazaki, Gengo; Hidaka, Kumi; Bando, Toshikazu; Sugiyama, Hiroshi

    2012-03-14

    We demonstrate a novel strategy for visualizing sequence-selective alkylation of target double-stranded DNA (dsDNA) using a synthetic pyrrole-imidazole (PI) polyamide in a designed DNA origami scaffold. Doubly functionalized PI polyamide was designed by introduction of an alkylating agent 1-(chloromethyl)-5-hydroxy-1,2-dihydro-3H-benz[e]indole (seco-CBI) and biotin for sequence-selective alkylation at the target sequence and subsequent streptavidin labeling, respectively. Selective alkylation of the target site in the substrate DNA was observed by analysis using sequencing gel electrophoresis. For the single-molecule observation of the alkylation by functionalized PI polyamide using atomic force microscopy (AFM), the target position in the dsDNA (∼200 base pairs) was alkylated and then visualized by labeling with streptavidin. Newly designed DNA origami scaffold named "five-well DNA frame" carrying five different dsDNA sequences in its cavities was used for the detailed analysis of the sequence-selectivity and alkylation. The 64-mer dsDNAs were introduced to five individual wells, in which target sequence AGTXCCA/TGGYACT (XY = AT, TA, GC, CG) was employed as fully matched (X = G) and one-base mismatched (X = A, T, C) sequences. The fully matched sequence was alkylated with 88% selectivity over other mismatched sequences. In addition, the PI polyamide failed to attach to the target sequence lacking the alkylation site after washing and streptavidin treatment. Therefore, the PI polyamide discriminated the one mismatched nucleotide at the single-molecule level, and alkylation anchored the PI polyamide to the target dsDNA.

  10. Selective toxicity of 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide toward hypoxic mammalian cells

    International Nuclear Information System (INIS)

    Rauth, A.M.; Mohindra, J.K.

    1981-01-01

    The chemotherapeutic agent 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide (DTIC) is used in the treatment of malignant melanoma where response rates of 15 to 30% have been reported. Some current interest exists in combining DTIC chemotherapy with localized high-dose (800 rads)-per-fraction radiotherapy in the treatment of unresectable metastatic melanoma. The present work investigates the radiosensitizing and chemotherapeutic properties of DTIC in an in vitro system using Chinese hamster ovary or HeLa cells and in vivo, using the KHT transplantable murine tumor. No evidence of a radiosensitizing effect of DTIC was found towards hypoxic or aerobic cells either in vitro or in vivo. In vitro, high drug concentrations (1 mg/ml) were approximately 5 times more effective in killing hypoxic Chinese hamster ovary or HeLa cells than in killing aerobic cells over exposure times of 0 to 12 hr. The degree of toxicity was drug dose and temperature dependent but was not highly dependent on cell number or cell type. In vivo plasma levels of DTIC were measured with high-pressure liquid chromatography after i.p. injection of drug into C3H mice. At the highest drug doses tested, near the 50% lethal dose in mice for DTIC (0.5 mg/g), the drug was toxic to both aerobic and hypoxic tumor cells with some evidence of increased toxicity towards hypoxic cells. The present work suggests that DTIC may be more efficiently activated under hypoxic conditions as compared to aerobic conditions. The increased toxicity of DTIC under hypoxic versus aerobic conditions may prove to be a feature of this drug that can be exploited in its clinical use and in the design of new analogs of DTIC

  11. Mixed-linker zeolitic imidazolate framework mixed-matrix membranes for aggressive CO2 separation from natural gas

    KAUST Repository

    Thompson, Joshua A.

    2014-07-01

    Zeolitic imidazolate framework (ZIF) materials are a promising subclass of metal-organic frameworks (MOF) for gas separations. However, due to the deleterious effects of gate-opening phenomena associated with organic linker rotation near the limiting pore apertures of ZIFs, there have been few demonstrations of improved gas separation properties over pure polymer membranes when utilizing ZIF materials in composite membranes for CO2-based gas separations. Here, we report a study of composite ZIF/polymer membranes, containing mixed-linker ZIF materials with ZIF-8 crystal topologies but composed of different organic linker compositions. Characterization of the mixed-linker ZIFs shows that the mixed linker approach offers control over the porosity and pore size distribution of the materials, as determined from nitrogen physisorption and Horváth-Kawazoe analysis. Single gas permeation measurements on mixed-matrix membranes reveal that inclusion of mixed-linker ZIFs yields membranes with better ideal CO2/CH4 selectivity than membranes containing ZIF-8. This improvement is shown to likely occur from enhancement in the diffusion selectivity of the membranes associated with controlling the pore size distribution of the ZIF filler. Mixed-gas permeation experiments show that membranes with mixed-linker ZIFs display an effective plasticization resistance that is not typical of the pure polymeric matrix. Overall, we demonstrate that mixed-linker ZIFs can improve the gas separation properties in composite membranes and may be applicable to aggressive CO2 concentrations in natural gas feeds. © 2013 Elsevier Inc. All rights reserved.

  12. Electron spin resonance and E.N.D.O.R. double resonance study of free radicals produced by gamma irradiation of imidazole single crystals; Etude par resonance paramagnetique electronique et double resonance E.N.D.O.R. des radicaux libres crees par irradiation gamma de monocristaux d'imidazole

    Energy Technology Data Exchange (ETDEWEB)

    Lamotte, B [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    Gamma irradiation of imidazole single crystals at 300 deg. K gives two radicals. Identification and detailed studies of their electronic and geometric structure have been made by ESR and ENDOR techniques. A study of the hydrogen bonded protons hyperfine tensor is made and let us conclude to the inexistence of movement and tunneling of these protons. The principal low temperature radical, produced by gamma irradiation at 77 deg. K has been also studied by ESR and a model has been proposed. (author) [French] L'irradiation gamma de monocristaux d'imidazole a 300 deg. K conduit a deux radicaux dont l'identification et l'etude detaillee des structures electroniques et geometriques ont ete obtenues par la resonance paramagnetique electronique (RPE) et la double resonance ENDOR. En particulier l'examen des protons de la liaison hydrogene permet de conclure, pour ceux-ci, a l'inexistence de tout mouvement par effet tunnel. De plus, l'analyse des spectres de RPE du radical principal cree par irradiation gamma de l'imidazole a 77 deg. K nous a permis de proposer un modele pour ce radical. (auteur)

  13. Si-Imidazole-HSO4 Functionalized Magnetic Fe3O4 Nanoparticles as an Efficient and Reusable Catalyst for the Regioselective Ring Opening of Epoxides in Water

    Directory of Open Access Journals (Sweden)

    Eshagh Rezaee Nezhad

    2016-01-01

    Full Text Available An efficient and simple method for the preparation of Si-Imidazole-HSO4 functionalized magnetic Fe3O4 nanoparticles (Si-Im-HSO4 MNPs and used as an efficient and reusable magnetic catalysts for the regioselective ring opening of epoxides under green conditions in water. This catalyst was used for the ring opening of epoxide corresponding to the thiocyanohydrins and azidohydrines. Compared to the classical ring opening of epoxides, this new method consistently has the advantage of excellent yields, short reaction times, and methodological simplicity.

  14. Structure and thermal behavior of a nickel complex based on a V-shaped bis(4-(1H-imidazol-1-yl)phenyl)amine ligand

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Yan, E-mail: felixjiao@163.com; Wang, Zhe; Qiu, Yu; He, Jing-Man; Chen, Min-dong [Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Innovative Research Laboratory of Energy & Environmental Catalysis, School of Environmental Science and Engineering (China)

    2015-12-15

    A new coordination polymer ([Ni(BIPA)(bpdc)(H{sub 2}O){sub 2}]){sub n} has been prepared based on a new V-shaped bis(4-(1H-imidazol-1-yl)phenyl)amine (BIPA) ligand. Complex was characterized by elemental analysis, IR spectra, X-ray powder diffraction, thermal analysis and single crystal X-ray analysis. Complex exhibits a 1D → 3D structure. Hydrogen bonds play an important role in the formation of supramolecular network structure. Thermal analysis indicates that complex exhibits a high thermal stability.

  15. 2D→3D polycatenated and 3D→3D interpenetrated metal–organic frameworks constructed from thiophene-2,5-dicarboxylate and rigid bis(imidazole) ligands

    Energy Technology Data Exchange (ETDEWEB)

    Erer, Hakan [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Yeşilel, Okan Zafer, E-mail: yesilel@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Arıcı, Mürsel [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Keskin, Seda [Department of Chemical and Biological Engineering, Koç University, İstanbul (Turkey); Büyükgüngör, Orhan [Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, 55139 Samsun (Turkey)

    2014-02-15

    Hydrothermal reactions of rigid 1,4-bis(imidazol-1-yl)benzene (dib) and 1,4-bis(imidazol-1-yl)-2,5-dimethylbenzene (dimb) with deprotonated thiophene-2,5-dicarboxylic acid (H{sub 2}tdc) in the presence of Zn(II) and Cd(II) salts in H{sub 2}O produced three new metal–organic frameworks, namely, [Zn(µ-tdc)(H{sub 2}O)(µ-dib)]{sub n} (1), [Cd(µ-tdc)(H{sub 2}O)(µ-dib)]{sub n} (2), and ([Cd{sub 2}(µ{sub 3}-tdc){sub 2}(µ-dimb){sub 2}]·(H{sub 2}O)){sub n}(3). These MOFs were characterized by FT-IR spectroscopy, elemental, thermal (TG, DTA, DTG and DSC), and single-crystal X-ray diffraction analyses. Isomorphous complexes 1 and 2 reveal polycatenated 2D+2D→3D framework based on an undulated (4,4)-sql layer. Complex 3 exhibits a new 4-fold interpenetrating 3D framework with the point symbol of 6{sup 6}. Molecular simulations were used to assess the potentials of the complexes for H{sub 2} storage application. Moreover, these coordination polymers exhibit blue fluorescent emission bands in the solid state at room temperature. - Graphical abstract: In this study, hydrothermal reactions of rigid 1,4-bis(imidazol-1-yl)benzene (dib) and 1,4-bis(imidazol-1-yl)-2,5-dimethylbenzene (dimb) with deprotonated thiophene-2,5-dicarboxylic acid (H{sub 2}tdc) in the presence of Zn(II) and Cd(II) salts in H{sub 2}O produced three new metal–organic frameworks. Isomorphous complexes 1 and 2 reveal polycatenated 2D+2D→3D framework based on an undulated (4,4)-sql layer. Complex 3 exhibits a new 4-fold interpenetrating 3D framework with the point symbol of 6{sup 6}. Molecular simulations were used to assess the potentials of the complexes for H{sub 2} storage application. These coordination polymers exhibit blue fluorescent emission bands in the solid state at room temperature. Display Omitted - Highlights: • Complexes 1 and 2 display polycatenated 2D+2D→3D framework. • Complex 3 exhibits a new 4-fold interpenetrating 3D framework. • Complex 1 adsorbs the highest amount of

  16. From bis(imidazole-2-thion-4-yl)phosphane to a flexible P-bridged bis(NHC) ligand and its silver complex.

    Science.gov (United States)

    Majhi, Paresh Kumar; Schnakenburg, Gregor; Streubel, Rainer

    2014-11-28

    Synthesis of the first P(V)-bridged bis(NHC) ligand 7 was achieved via deprotonation of P(V)-functionalized bis(imidazolium) salt 6, which was obtained via oxidative desulfurization of bis(imidazole-2-thion-4-yl)phosphane 2. Bis(imidazolium) salt 6 was also employed to synthesize the corresponding silver complex 8. All new products were firmly established by spectroscopic and spectrometric methods as well as elemental analysis and, in addition, X-ray crystal structure analysis in the case of 3.

  17. Synthesis, characterization and catalytic application of silica supported tin oxide nanoparticles for synthesis of 2,4,5-tri and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    Ashok V. Borhade

    2017-02-01

    Full Text Available Highly efficient and eco-friendly, one pot synthesis of 1,2,4,5-tetra substituted imidazoles and 2,4,5-trisubstituted imidazoles was reported under solvent free conditions using nanocrystalline silica supported tin oxide (SiO2:SnO2 as a catalyst with excellent yield. The present methodology offers several advantages such as mild reaction conditions, short reaction time, good yield, high purity of product, recyclable catalyst without a noticeable decrease in catalytic activity and can be used for large scale synthesis. The synthesized SiO2:SnO2 nanocrystalline catalyst was characterized by XRD, BET surface area and TEM techniques.

  18. Self-assembled magnetic nanoparticle supported zeolitic imidazolate framework-8: An efficient adsorbent for the enrichment of triazine herbicides from fruit, vegetables, and water.

    Science.gov (United States)

    Zhou, Lian; Su, Ping; Deng, Yulan; Yang, Yi

    2017-02-01

    Zeolitic imidazolate frameworks have positive surface charges and high adsorption capabilities. In this work, zeolitic imidazolate frameworks-8 and negatively charged magnetic nanoparticles were self-assembled by electrostatic attraction under sonication. The extraction performance of the synthesized hybrid material was evaluated by using it as a magnetic adsorbent for the enrichment of triazine herbicides in various sample matrices prior to analysis using ultrafast liquid chromatography. The main parameters, that is, extraction time, adsorbent dosage, salt concentration, and desorption conditions, were evaluated. Under the optimum conditions, good linear responses from 2.5 to 200 ng/mL for atrazine (simazine) and 1 to 200 ng/mL for prometryn (ametryn), with correlation coefficients (R 2 ) higher than 0.9992 were obtained. The detection limits of the method (S/N = 3) were 0.18-0.72 ng/mL. The proposed method was successfully used to determine triazine herbicides in six samples, namely, apple, pear, strawberry, pakchoi, lettuce, and water. The amounts of simazine in all the fruit and vegetable samples were 10.8-25.2 ng/mL. The recoveries of all the analytes were 88.0-101.9%, with relative standard deviations of less than 8.8%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Theoretical study of the microscopic appearance of the capture and storage of CO2 by zeolites: Studies of Zn-imidazole and triazole clusters with CO2

    International Nuclear Information System (INIS)

    Boulmene, Rida

    2016-01-01

    Several experimental and theoretical studies have shown the ability of zeolitic-imidazole frameworks (ZIFs) materials to capture the CO 2 gas. In this study, we have focused on the interaction of CO 2 with one of the sub-unit of ZIFs i.e. the complex between the imidazole and zinc (Im-Zn+q, q = 0,1, 2) or triazole without zinc. Various adsorption sites are examined for these complexes.The calculations were performed using ab initio methods MP2; CCSD(T)-F12 and density functional theory with PBE PBE0, M1 and M05-2X functionals with different basis set (aug-cc-pVDZ, aug-cc-pVTZ and 6-311++G(d, p), tightly integrated in GAUSSIAN and MOLPRO packages. The Grimme corrections for dispersion forces description (DFT-D3) are also included. Our results shows that the stability of our complex structures is achieved by the presence of strong covalent bonds (chemical bonds of organic ligands) and also by Van der Waals and hydrogen weak bonds. Both types of bonding are in competition. This allowed us to better understand the experimental observations. (author)

  20. DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole

    Science.gov (United States)

    Li, Mei; kong, Lin Lin; Gou, Yi; Yang, Feng; Liang, Hong

    2014-07-01

    A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV-vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV-vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells.

  1. Neutral coordination polymers based on a metal-mono(dithiolene) complex: synthesis, crystal structure and supramolecular chemistry of [Zn(dmit)(4,4'-bpy)]n, [Zn(dmit)(4,4'-bpe)]n and [Zn(dmit)(bix)]n (4,4'-bpy = 4,4'-bipyridine, 4,4'-bpe = trans-1,2-bis(4-pyridyl)ethene, bix = 1,4-bis(imidazole-1-ylmethyl)-benzene.

    Science.gov (United States)

    Madhu, Vedichi; Das, Samar K

    2011-12-28

    This article describes a unique synthetic route that enables a neutral mono(dithiolene)metal unit, {Zn(dmit)}, to link with three different organic molecules, resulting in the isolation of a new class of neutral coordination polymers. The species {Zn(dmit)} coordinates with 4,4'-bipyridine (4,4'-bpy), trans-1,2-bis(4-pyridyl)ethene (4,4'-bpe) and 1,4-bis(imidazole-1-ylmethyl)-benzene (bix) as linkers giving rise to the formation of coordination polymers [Zn(dmit)(4,4'-bpy)](n) (1), [Zn(dmit)(4,4'-bpe)](n) (2) and [Zn(dmit)(bix)](n) (3) respectively. Compounds 1-3 were characterized by elemental analyses, IR, diffuse reflectance and single crystal X-ray diffraction studies. Compounds 1 and 3 crystallize in the monoclinic space group P2(1)/n, whereby compound 2 crystallizes in triclinic space group P1[combining macron]. In the present study, we chose three linkers 4,4'-bpy, 4,4'-bpe and bix (see , respectively, for their structural drawings), that differ in terms of their molecular dimensions. The crystal structures of compounds 1-3 are described here in terms of their supramolecular diversities that include π-π interactions, not only among aromatic stacking (compounds 1 and 3), but also between an aromatic ring and an ethylenic double bond (compound 2). The electronic absorption spectroscopy of compounds 1-3 support these intermolecular π-π interactions. This journal is © The Royal Society of Chemistry 2011

  2. Symmetric and asymmetric zeolitic imidazolate frameworks (ZIFs)/polybenzimidazole (PBI) nanocomposite membranes for hydrogen purification at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tingxu; Shi, Gui Min; Chung, Tai-Shung [Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore (Singapore)

    2012-11-15

    High-performance zeolitic imidazolate frameworks (ZIFs)/polybenzimidazole (PBI) nanocomposites are molecularly designed for hydrogen separation at high temperatures, and demonstrate it in a useful configuration as dual-layer hollow fibers for the first time. By incorporating as-synthesized nanoporous ZIF-8 nanoparticles into the high thermal stability but extremely low permeability polybenzimidazole (PBI), the resultant mixed matrix membranes show an impressive enhancement in H{sub 2} permeability as high as a hundred times without any significant deduction in H{sub 2}/CO{sub 2} selectivity. The 30/70 ZIF-8/PBI dense membrane has a H{sub 2} permeability of 105.4 Barrer and a H{sub 2}/CO{sub 2} selectivity of 12.3. This performance is far superior to ZIF-7/PBI membranes and is the best ever reported data for H{sub 2}-selective polymeric materials in the literature. Meanwhile, defect-free ZIF-8-PBI/Matrimid dual-layer hollow fibers are successfully fabricated, without post-annealing and coating, by optimizing ZIF-8 nanoparticle loadings, spinning conditions, and solvent-exchange procedures. Two types of hollow fibers targeted at either high H{sub 2}/CO{sub 2} selectivity or high H{sub 2} permeance are developed: i) PZM10-I B fibers with a medium H{sub 2} permeance of 64.5 GPU (2.16 x 10{sup -8} mol m{sup -2} s{sup -1} Pa{sup -1}) at 180 C and a high H{sub 2}/CO{sub 2} selectivity of 12.3, and, ii) PZM33-I B fibers with a high H{sub 2} permeance of 202 GPU (6.77 x 10{sup -8} mol m{sup -2} s{sup -1} Pa{sup -1}) at 180 C and a medium H{sub 2}/CO{sub 2} selectivity of 7.7. This work not only molecularly designs novel nanocomposite materials for harsh industrial applications, such as syngas and hydrogen production, but also, for the first time, synergistically combines the strengths of both ZIF-8 and PBI for energy-related applications. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies.

    Science.gov (United States)

    D'Souza, Francis; El-Khouly, Mohamed E; Gadde, Suresh; McCarty, Amy L; Karr, Paul A; Zandler, Melvin E; Araki, Yasuyaki; Ito, Osamu

    2005-05-26

    Spectroscopic, redox, and electron transfer reactions of a self-assembled donor-acceptor dyad formed by axial coordination of magnesium meso-tetraphenylporphyrin (MgTPP) and fulleropyrrolidine appended with an imidazole coordinating ligand (C(60)Im) were investigated. Spectroscopic studies revealed the formation of a 1:1 C(60)Im:MgTPP supramolecular complex, and the anticipated 1:2 complex could not be observed because of the needed large amounts of the axial coordinating ligand. The formation constant, K(1), for the 1:1 complex was found to be (1.5 +/- 0.3) x 10(4) M(-1), suggesting fairly stable complex formation. The geometric and electronic structures of the dyads were probed by ab initio B3LYP/3-21G() methods. The majority of the highest occupied frontier molecular orbital (HOMO) was found to be located on the MgTPP entity, while the lowest unoccupied molecular orbital (LUMO) was on the fullerene entity, suggesting that the charge-separated state of the supramolecular complex is C(60)Im(*-):MgTPP(*+). Redox titrations involving MgTPP and C(60)Im allowed accurate determination of the oxidation and reduction potentials of the donor and acceptor entities in the supramolecular complex. These studies revealed more difficult oxidation, by about 100 mV, for MgTPP in the pentacoordinated C(60)Im:MgTPP compared to pristine MgTPP in o-dichlorobenzene. A total of six one-electron redox processes corresponding to the oxidation and reduction of the zinc porphyrin ring and the reduction of fullerene entities was observed within the accessible potential window of the solvent. The excited state events were monitored by both steady state and time-resolved emission as well as transient absorption techniques. In o-dichlorobenzene, upon coordination of C(60)Im to MgTPP, the main quenching pathway involved electron transfer from the singlet excited MgTPP to the C(60)Im moiety. The rate of forward electron transfer, k(CS), calculated from the picosecond time-resolved emission

  4. Cyclometalated N-heterocyclic carbene iridium(iii) complexes with naphthalimide chromophores: a novel class of phosphorescent heteroleptic compounds.

    Science.gov (United States)

    Lanoë, Pierre-Henri; Chan, Jonny; Groué, Antoine; Gontard, Geoffrey; Jutand, Anny; Rager, Marie-Noelle; Armaroli, Nicola; Monti, Filippo; Barbieri, Andrea; Amouri, Hani

    2018-03-06

    A series of cyclometalated N-heterocyclic carbene complexes of the general formula [Ir(C^N) 2 (C^C:)] has been prepared. Two sets of compounds were designed, those where (C^C:) represents a bidentate naphthalimide-substituted imidazolylidene ligand and (C^N) = ppy (3a), F2ppy (4a), bzq (5a) and those where (C^C:) represents a naphthalimide-substituted benzimidazolylidene ligand and (C^N) = ppy (3b), F2ppy (4b), bzq (5b). The naphthalimide-imidazole and naphthalimide-benzimidazole ligands 1a,b and the related imidazolium and benzimidazolium salts 2a,b were also prepared and fully characterized. The N-heterocyclic carbene Ir(iii) complexes have been characterized by NMR spectroscopy, cyclic voltammetry and elemental analysis. Moreover, the molecular structures of one imidazolium salt and four Ir(iii) complexes were determined by single-crystal X-ray diffraction. The structures provide us with valuable information, most notably the orientation of the naphthalimide chromophore with respect to the N-heterocyclic carbene moiety. All compounds are luminescent at room temperature and in a frozen solvent at 77 K, exhibiting a broad emission band that extends beyond 700 nm. The presence of the naphthalimide moiety changes the character of the lowest excited state from 3 MLCT to 3 LC, as corroborated by DFT and TD-DFT calculations. Remarkably, replacing imidazole with a benzimidazole unit improves the quantum yields of these compounds by decreasing the k nr values which is an important feature for optimized emission performance. These studies provide valuable insights about a novel class of N-heterocyclic carbene-based luminescent complexes containing organic chromophores and affording metal complexes emitting across the red-NIR range.

  5. Two new hydrogen bond-supported supramolecular compounds assembly from polyoxovanadate and organoamines

    International Nuclear Information System (INIS)

    Duan Weijie; Cui Xiaobing; Xu Yan; Xu Jiqing; Yu Haihui; Yi Zhihui; Cui Jiwen; Wang Tiegang

    2007-01-01

    Two novel organic-inorganic hybrid compounds based on organoamines and polyoxovanadates formulated as (H 2 dien) 4 [H 10 V 18 O 42 (PO 4 )](PO 4 ).2H 2 O (1) (dien=diethylenetriamine) and (Him) 8 [HV 18 O 42 (PO 4 )] (2) (im=imidazole) have been prepared under hydrothermal conditions by using different starting materials, and characterized by elemental analyses, IR, ESR, XPS, TGA and single-crystal X-ray diffraction analyses. Crystal data for compound 1: C 16 H 74 N 12 O 52 V 18 P 2 , Monoclinic, space group C2/c, a=23.9593(4) A, b=13.0098(2) A, c=20.1703(4) A, β=105.566(3) o , V=6056.6(19) A 3 , Z=4; for compound 2, C 24 H 41 N 16 O 46 V 18 P, Tetragonal, space group I4/mmm, a=13.5154(8) A, b=13.5154(8) A, c=19.1136 A, β=90 o , V=3491.4(3) A 3 , Z=2. Compound 1 consists of protonated diens together with polyoxovanadates [H 10 V 18 O 42 (PO 4 )] 5- . Compound 2 is composed of protonated ims and polyoxovanadates [HV 18 O 42 (PO 4 )] 8- . There are hydrogen-bonding interactions between polyoxovanadates and different organoamines in 1 and 2. Polyoxovanadates are linked through H 2 dien into a three-dimensional network via hydrogen bonds in 1, while polyoxovanadates are linked by Him into a two-dimensional layer network via hydrogen bonds in 2. The crystal packing patterns of the two compounds reveal various supramolecular frameworks. - Graphical abstract: Two new organic-inorganic hybrid compounds based on [V 18 O 42 (PO 4 )] building blocks have been hydrothermally synthesized. 1 is the first 3-D supramolecular network structure consisting of [V 18 O 42 (PO 4 )] unit, while 2 possesses 2-D layered supramolecular structure

  6. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  7. X-ray Molecular Structure of ({[(1E)-3-(1H-Imidazol-1-yl)-1 ...

    African Journals Online (AJOL)

    1Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud ... Results: The titled compound crystallized in the triclinic space group P-1 with a = 11.0719 (7) Е, b = ..... Jeng MR, Feusner J. Itraconazole-enhanced vincristine.

  8. Characterization of Anti-bacterial Compounds from the Seed Coat of Chinese Windmill Palm Tree (Trachycarpus fortunei

    Directory of Open Access Journals (Sweden)

    Shakeel Ahmed

    2017-10-01

    Full Text Available The increasing of multidrug resistance in bacterial associated infections has impaired the current antimicrobial therapy and it forces the search for other alternatives. In this study, we aimed to find the in vitro antibacterial activity of seed coat of Trachycarpus fortunei against a panel of clinically important bacterial species. Ethanolic extracts of target tissues were fractionated through macro porous resin by column chromatography, using ethanol as an organic solvent with a concentration gradient of 0–100%, each along with 20% concentration increment. The minimum inhibitory (MIC concentrations of all fractions were measured. It is found that 20% ethanolic fraction showed the most significant inhibition against tested bacterial species. All fractions were analyzed by Ultra-Performance Liquid Chromatography/mass spectrometry (UPLC/MS and compounds were identified by comparing mass spectra with standard libraries. By pairing the identified compounds from different fractions with the antibacterial activity of each fraction, it was shown that compounds stearamide (7, 1-(4-Fluorophenyl-2-(methylthio-1H-imidazole-5-carboxylic acid (9 and 2,4,5 triacetoxybiphenyl (10 topped in the list for anti-bacterial activity. Further experiment with pure chemicals verified that compounds 9 and 10 have antibacterial activity against Gram-negative bacteria. Whereas, the lowest MIC value (39.06 μg/mL was obtained by compound 10 against Staphylococcus epidermidis. Hence, the seed coat of T. fortunei with its antimicrobial spectrum could be a good candidate for further bactericidal research.

  9. Characterization of Anti-bacterial Compounds from the Seed Coat of Chinese Windmill Palm Tree (Trachycarpus fortunei).

    Science.gov (United States)

    Ahmed, Shakeel; Liu, Huimin; Ahmad, Aqeel; Akram, Waheed; Abdelrahman, Eman K N; Ran, Fengming; Ou, Wuling; Dong, Shuang; Cai, Qian; Zhang, Qiyun; Li, Xiaohua; Hu, Sheng; Hu, Xuebo

    2017-01-01

    The increasing of multidrug resistance in bacterial associated infections has impaired the current antimicrobial therapy and it forces the search for other alternatives. In this study, we aimed to find the in vitro antibacterial activity of seed coat of Trachycarpus fortunei against a panel of clinically important bacterial species. Ethanolic extracts of target tissues were fractionated through macro porous resin by column chromatography, using ethanol as an organic solvent with a concentration gradient of 0-100%, each along with 20% concentration increment. The minimum inhibitory (MIC) concentrations of all fractions were measured. It is found that 20% ethanolic fraction showed the most significant inhibition against tested bacterial species. All fractions were analyzed by Ultra-Performance Liquid Chromatography/mass spectrometry (UPLC/MS) and compounds were identified by comparing mass spectra with standard libraries. By pairing the identified compounds from different fractions with the antibacterial activity of each fraction, it was shown that compounds stearamide (7), 1-(4-Fluorophenyl)-2-(methylthio)-1H-imidazole-5-carboxylic acid (9) and 2,4,5 triacetoxybiphenyl (10) topped in the list for anti-bacterial activity. Further experiment with pure chemicals verified that compounds 9 and 10 have antibacterial activity against Gram-negative bacteria. Whereas, the lowest MIC value (39.06 μg/mL) was obtained by compound 10 against Staphylococcus epidermidis . Hence, the seed coat of T. fortunei with its antimicrobial spectrum could be a good candidate for further bactericidal research.

  10. Compounding around the world.

    Science.gov (United States)

    Vail, Jane

    2008-01-01

    Pharmaceutical compounding is universal in its prevalence. Variations in disease patterns, culture, and tradition; the role of government in health care; and the availability of essential equipment and required agents shape a compounding profile unique to each country worldwide. In the following reflections, pharmacists form Argentina, Belgium, Colombia, Germany, Puerto Rico, Spain, and the United States describe their experiences in the compounding setting unique to their practice and their nation. The unifying theme in their comments is the dedication of each contributor to enabling recovery and ensuring the good health of his or her clients.

  11. Discovery of a Novel Inhibitor of the Hedgehog Signaling Pathway through Cell-based Compound Discovery and Target Prediction.

    Science.gov (United States)

    Kremer, Lea; Schultz-Fademrecht, Carsten; Baumann, Matthias; Habenberger, Peter; Choidas, Axel; Klebl, Bert; Kordes, Susanne; Schöler, Hans R; Sterneckert, Jared; Ziegler, Slava; Schneider, Gisbert; Waldmann, Herbert

    2017-10-09

    Cell-based assays enable monitoring of small-molecule bioactivity in a target-agnostic manner and help uncover new biological mechanisms. Subsequent identification and validation of the small-molecule targets, typically employing proteomics techniques, is very challenging and limited, in particular if the targets are membrane proteins. Herein, we demonstrate that the combination of cell-based bioactive-compound discovery with cheminformatic target prediction may provide an efficient approach to accelerate the process and render target identification and validation more efficient. Using a cell-based assay, we identified the pyrazolo-imidazole smoothib as a new inhibitor of hedgehog (Hh) signaling and an antagonist of the protein smoothened (SMO) with a novel chemotype. Smoothib targets the heptahelical bundle of SMO, prevents its ciliary localization, reduces the expression of Hh target genes, and suppresses the growth of Ptch +/- medulloblastoma cells. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Dual functions of imidazole-based polymeric ionic liquid (PIL) on the anticorrosive performance of graphene-based waterborne epoxy coatings

    Science.gov (United States)

    Liu, Chengbao; Du, Peng; Nan, Feng; Zhao, Haichao; Wang, Liping

    2018-06-01

    Dispersion of graphene nanosheets in a water and polymer matrix has been rarely achieved due to graphene’s hydrophobicity, which thus impedes its potential anticorrosive application. In this study, stable graphene aqueous dispersion was obtained by using imidazole-based polymeric ionic liquid (PIL) as the dispersant with ultrasonic vibration. Stacked graphene sheets were exfoliated to a few layers via cation-π interaction between PIL and graphene nanosheets. Electrochemical impedance measurements were taken to investigate the anticorrosion performance of epoxy coatings with or without polymeric ionic liquid–graphene (PIL–G) hybrids. Results indicated that the PIL–G hybrid significantly enhanced the long-term protective performance of epoxy coatings, which was attributed to the synergistic effects of the corrosion-inhibitive PIL and impermeable graphene nanosheets.

  13. Crystal structures and luminescence properties of two Cd(II) complexes based on 2-(1H-imidazol-1methyl)-6-methyl-1H-benzimidazole

    International Nuclear Information System (INIS)

    Zhang, Yuhong; Meng, Xiangru; Wen, Yu; Li, Peng; Ma, Lin; Zhang, Qiuju

    2015-01-01

    Two new complexes, {[Cd(immb)I 2 ].DMF} n (1) and {[Cd 3 (immb)(btc) 2 ]. H 2 O} n (2) (immb = 2-(1H-imidazol- 1-methyl)-6-methyl-1H-benzimidazole, btc = 1,2,3-benzenetricarboxylate, DMF = dimethyl formamide), have been synthesized and characterized. Single crystal X-ray diffraction shows that 1 exhibits a chain structure constructed by immb ligands bridging Cd(II) ions. In 2, Cd(II) ions are linked by immb ligands with bridging mode and btc3- anions with the μ 2 -η 2 :η 1 bonding pattern leading to a 2D structure. Luminescent properties have been investigated in the solid state at room temperature.

  14. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  15. Hexavalent Chromium Compounds

    Science.gov (United States)

    Learn about chromium, exposure to which can increase your risk of lung cancer and cancer of the paranasal sinuses and nasal cavity. Hexavalent chromium compounds have been used as corrosion inhibitors in a wide variety of products and processes.

  16. MEA 86 Compound data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data file contains the full raw parameter data for the 86 compounds tested in the developmental MEA assay, as well as Area Under the Curve (AUC) calculations...

  17. Synthesis, spectroscopic and DNA binding ability of Co{sup II}, Ni{sup II}, Cu{sup II} and Zn{sup II} complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex

    Energy Technology Data Exchange (ETDEWEB)

    Yarkandi, Naeema H. [Chemistry Department, Faculty of Applied Science, Umm Al–Qura University, Makkah (Saudi Arabia); El-Ghamry, Hoda A., E-mail: helghamrymo@yahoo.com [Chemistry Department, Faculty of Applied Science, Umm Al–Qura University, Makkah (Saudi Arabia); Chemistry Department, Faculty of Science, Tanta University, Tanta (Egypt); Gaber, Mohamed [Chemistry Department, Faculty of Science, Tanta University, Tanta (Egypt)

    2017-06-01

    A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L){sub 2}]·l2H{sub 2}O, [Ni(L)Cl·(H{sub 2}O){sub 2}].5H{sub 2}O, [Cu(L)Cl] and [Zn(L)(CH{sub 3}COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, {sup 1}H &{sup 13}C NMR, mass spectral analysis, molar conductivity measurement, UV–Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV–Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (K{sub b}). - Highlights: • Synthesis of Co{sup II}, Ni{sup II}, Cu{sup II} and Zn{sup II} complexes of the Schiff base ligand based on 2-(aminomethyl)benzimidazole moiety. • The constitutions and structures of the ligand and complexes were elucidated. • Molecular structure of Co{sup II} complex was confirmed by single crystal X-ray diffraction method. • The ligand and its complexes interact with SS-DNA via intercalation mods.

  18. Unlock your Compound Management

    OpenAIRE

    Steffen Eller

    2016-01-01

    Pharmaceutical industry faces the increased demand for innovative medicines against various diseases. In this regard, the compound library in pharmaceutical industry is the most valuable asset. However, the compound distribution from the library into the screening plates is often still done manually and binds highly qualified resources to very time-consuming, tedious and error-prone tasks. To overcome these challenges, Chemspeed launched the first automated true one-to-one gravimetric "pi...

  19. 4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide – A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation

    Energy Technology Data Exchange (ETDEWEB)

    Mahal, Katharina, E-mail: katharina.mahal@uni-bayreuth.de [Organic Chemistry Laboratory, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth (Germany); Kahlen, Philip, E-mail: philip.kahlen@uni-bayreuth.de [Department of Genetics, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth (Germany); Biersack, Bernhard, E-mail: bernhard.biersack@yahoo.com [Organic Chemistry Laboratory, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth (Germany); Schobert, Rainer, E-mail: rainer.schobert@uni-bayreuth.de [Organic Chemistry Laboratory, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth (Germany)

    2015-08-15

    Histone deacetylases (HDAC) which play a crucial role in cancer cell proliferation are promising drug targets. However, HDAC inhibitors (HDACi) modelled on natural hydroxamic acids such as trichostatin A frequently lead to resistance or even an increased agressiveness of tumours. As a workaround we developed 4-(1-ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide (etacrox), a hydroxamic acid that combines HDAC inhibition with synergistic effects of the 4,5-diarylimidazole residue. Etacrox proved highly cytotoxic against a panel of metastatic and resistant cancer cell lines while showing greater specificity for cancer over non-malignant cells when compared to the approved HDACi vorinostat. Like the latter, etacrox and the closely related imidazoles bimacroxam and animacroxam acted as pan-HDACi yet showed some specificity for HDAC6. Akt signalling and interference with nuclear beta-catenin localisation were elicited by etacrox at lower concentrations when compared to vorinostat. Moreover, etacrox disrupted the microtubule and focal adhesion dynamics of cancer cells and inhibited the proteolytic activity of prometastatic and proangiogenic matrix metalloproteinases. As a consequence, etacrox acted strongly antimigratory and antiinvasive against various cancer cell lines in three-dimensional transwell invasion assays and also antiangiogenic in vivo with respect to blood vessel formation in the chorioallantoic membrane assay. These pleiotropic effects and its water-solubility and tolerance by mice render etacrox a promising new HDACi candidate. - Graphical abstract: A novel histone deacetylase inhibitor with pleiotropic anticancer effects. - Highlights: • Etacrox is a new HDACi with cytotoxic, antiangiogenic and antiinvasive activity. • Etacrox causes aberrant cancer cell signalling and cytoskeletal reorganisation. • Pro-metastatic and angiogenic matrix metalloproteinases are inhibited by etacrox. • Etacrox impairs blood vessel maturation in vivo and cancer cell

  20. 4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide – A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation

    International Nuclear Information System (INIS)

    Mahal, Katharina; Kahlen, Philip; Biersack, Bernhard; Schobert, Rainer

    2015-01-01

    Histone deacetylases (HDAC) which play a crucial role in cancer cell proliferation are promising drug targets. However, HDAC inhibitors (HDACi) modelled on natural hydroxamic acids such as trichostatin A frequently lead to resistance or even an increased agressiveness of tumours. As a workaround we developed 4-(1-ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide (etacrox), a hydroxamic acid that combines HDAC inhibition with synergistic effects of the 4,5-diarylimidazole residue. Etacrox proved highly cytotoxic against a panel of metastatic and resistant cancer cell lines while showing greater specificity for cancer over non-malignant cells when compared to the approved HDACi vorinostat. Like the latter, etacrox and the closely related imidazoles bimacroxam and animacroxam acted as pan-HDACi yet showed some specificity for HDAC6. Akt signalling and interference with nuclear beta-catenin localisation were elicited by etacrox at lower concentrations when compared to vorinostat. Moreover, etacrox disrupted the microtubule and focal adhesion dynamics of cancer cells and inhibited the proteolytic activity of prometastatic and proangiogenic matrix metalloproteinases. As a consequence, etacrox acted strongly antimigratory and antiinvasive against various cancer cell lines in three-dimensional transwell invasion assays and also antiangiogenic in vivo with respect to blood vessel formation in the chorioallantoic membrane assay. These pleiotropic effects and its water-solubility and tolerance by mice render etacrox a promising new HDACi candidate. - Graphical abstract: A novel histone deacetylase inhibitor with pleiotropic anticancer effects. - Highlights: • Etacrox is a new HDACi with cytotoxic, antiangiogenic and antiinvasive activity. • Etacrox causes aberrant cancer cell signalling and cytoskeletal reorganisation. • Pro-metastatic and angiogenic matrix metalloproteinases are inhibited by etacrox. • Etacrox impairs blood vessel maturation in vivo and cancer cell

  1. Phenolic Molding Compounds

    Science.gov (United States)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  2. Synthesis and Spectroscopic Analysis of Novel 1H-Benzo[d]imidazoles Phenyl Sulfonylpiperazines

    Directory of Open Access Journals (Sweden)

    Amjad M. Qandil

    2012-05-01

    Full Text Available A group of benzimidazole analogs of sildenafil, 3-benzimidazolyl-4-methoxy-phenylsulfonylpiperazines 2–4 and 3-benzimidazolyl-4-methoxy-N,N-dimethyl- benzenesulfonamide (5, were efficiently synthesized. Compounds 2–5 were characterized by NMR and MS and contrary to the reported mass spectra of sildenafil, the spectra of the piperazine-containing compounds 2–4 showed a novel fragmentation pattern leading to an m/z = 316. A mechanism for the formation of this fragment was proposed.

  3. Fluorine-18 labelled compounds

    International Nuclear Information System (INIS)

    Kleijn, J.P. de

    1978-01-01

    The work presented in this thesis deals with the problems involved in the adaption of reactor-produced fluorine-18 to the synthesis of 18 F-labelled organic fluorine compounds. Several 18 F-labelling reagents were prepared and successfully applied. The limitations to the synthetic possibilities of reactor-produced fluoride- 18 become manifest in the last part of the thesis. An application to the synthesis of labelled aliphatic fluoro amino acids has appeared to be unsuccessful as yet, although some other synthetic approaches can be indicated. Seven journal articles (for which see the availability note) are used to compose the four chapters and three appendices. The connecting text gives a survey of known 18 F-compounds and methods for preparing such compounds. (Auth.)

  4. Chloric organic compound

    International Nuclear Information System (INIS)

    Moalem, F.

    2000-01-01

    Since many years ago, hazardous and toxic refuses which are results of human activities has been carelessly without any Biological and Engineering facts and knowledge discharged into our land and water. The effects of discharging those materials in environment are different. Some of refuse materials shows short and other has long-time adverse effects in our environment, Among hazardous organic chemical materials, chlorine, consider, to be the main element. Organic materials with chlorine is called chlorine hydrocarbon as a hazardous compound. This paper discuss the hazardous materials especially chloric organic compound and their misuse effects in environment and human being

  5. Medicinal gold compounds

    International Nuclear Information System (INIS)

    Parish, R.V.; Cottrill, S.M.

    1987-01-01

    A major use of gold compounds in the pharmaceutical industry is for anti-arthritic agents. The disease itself is not understood and little is known about the way in which the drugs act, but detailed pictures of the distribution of gold in the body are available, and some of the relevant biochemistry is beginning to emerge. The purpose of this article is to give a survey of the types of compounds presently employed in medicine, of the distribution of gold in the body which results from their use, and of some relevant chemistry. Emphasis is placed on results obtained in the last few years

  6. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  7. Prediction of intermetallic compounds

    International Nuclear Information System (INIS)

    Burkhanov, Gennady S; Kiselyova, N N

    2009-01-01

    The problems of predicting not yet synthesized intermetallic compounds are discussed. It is noted that the use of classical physicochemical analysis in the study of multicomponent metallic systems is faced with the complexity of presenting multidimensional phase diagrams. One way of predicting new intermetallics with specified properties is the use of modern processing technology with application of teaching of image recognition by the computer. The algorithms used most often in these methods are briefly considered and the efficiency of their use for predicting new compounds is demonstrated.

  8. Magnetic Study of the Novel Polynuclear Compound [Cu(II)(6-Mercaptopurinolate 2-)] n

    Science.gov (United States)

    Acevedo-Chávez, Rodolfo; Costas, María. Eugenia; Escudero, Roberto

    1997-08-01

    Chemical reactions between Cu(II) and 6-mercaptopurine, both in aqueous and in methanolic media, yield the novel amorphous polynuclear compound [Cu(II)(6-mercaptopurinolate)2-]n, which is also obtained from diverse Cu(II)-heterocyclic ligand competitive reactions. The kinetic and thermodynamic stabilities associated with the formation of this compound are inferred as remarkable. The spectroscopic data let us suggest the involvement of the exocyclic S(6) donor site and the N atoms in the imidazolic moiety of the deprotonated heterocyclic ligand in the coordination to Cu(II) atoms, forming a distorted bidimensional metallic network. The magnetic studies show the existence of very weak antiferromagnetic coupling in the solid sample. This system represents the first example of a 1 : 1 metal : 6-mercaptopurinolate2-system with ad-type open shell metallic center. The magnetic study carried out also represents the first example of magnetic characterization for this type of polynuclear Cu(II) systems with the dianionic 6-mercaptopurine ligand.

  9. Compound floating pivot micromechanisms

    Science.gov (United States)

    Garcia, Ernest J.

    2001-04-24

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

  10. The Onium Compounds

    Science.gov (United States)

    Tsarevsky, Nicolay V.; Slaveykova, Vera; Manev, Stefan; Lazarov, Dobri

    1997-06-01

    The onium salts are of a big interest for theoretical and structural chemistry, and for organic synthesis. Some representatives of the group (e.g. ammonium salts) were known from the oldest times. Many onium salts are met the nature: ammonium salts (either as inorganic salts, and organic derivatives, e.g. aminoacids, salts of biogenic amines and alkaloids, etc.); oxonium salts (plant pigments as anthocyans are organic oxonium compounds), etc. In 1894 C. Hartmann and V. Meyer prepared the first iodonium salts - 4-iododiphenyliodonium hydrogensulfate and diphenyliodonium salts, and suggested the ending -onium for all compounds with properties similar to those of ammonium salts. Nowadays onium compounds of almost all nonmetals are synthesised and studied. A great variety of physical methods: diffraction (e.g. XRD) and spectral methods (IR-, NMR-, and UV-spectra), as well as the chemical properties and methods of preparation of onium salts have been used in determination of the structure of these compounds. The application of different onium salts is immense. Ammonium, phosphonium and sulfonium salts are used as phase-transfer catalysts; diazonium salts - for the preparation of dyes, metalochromic and pH-indicators. All the onium salts and especially diazonium and iodonium salts are very useful reagents in organic synthesis.

  11. Forecasting of superconducting compounds

    International Nuclear Information System (INIS)

    Savitskii, E.M.; Gribulya, V.G.; Kiseleva, N.N.

    1981-01-01

    In forecasting new superconducting intermetallic compounds of the A15 and Mo 3 Se types most promising from the viewpoint of high critical temperature Tsub(c), high critical magnetic fields Hsub(c), and high critical currents and in estimating their transition temperature it is proposed to apply cybernetic methods of computer learning

  12. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    A. M. Nasukhova

    2014-01-01

    Full Text Available In article the review of the initial stage of researches of natural polyacetylene compounds is resulted. The high reactionary ability leading to fast oxidation and degradation of these compounds, especially at influence of Uf-light, oxygen of air, pH and other factors, has caused the serious difficulties connected with an establishment of structure and studying of their physical and chemical properties. Therefore the greatest quantity of works of this stage is connected with studying of essential oils of plants from families Apiaceae, Araliaceae, Asteraceae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae where have been found out, basically, diacetylene compounds. About development of physical and chemical methods of the analysis of possibility of similar researches have considerably extended. More than 2000 polyacetylenes are known today, from them more than 1100 are found out in plants fam. Asteraceae. Revolution in the field of molecular biology has allowed to study processes of biosynthesis of these compounds intensively.

  13. Aminopropyl thiophene compounds

    International Nuclear Information System (INIS)

    Goodman, M.M.; Knapp, F.F.

    1990-01-01

    This patent describes radiopharmaceuticals useful in brain imaging comprising radiohalogenated thienylethylamine derivatives. The compounds are 5-halo-thiophene-2-isopropyl amines able to cross the blood-brain barrier and be retained for a sufficient length of time to allow the evaluation of regional blood flow by radioimaging of the brain

  14. Aminopropyl thiophene compounds

    Science.gov (United States)

    Goodman, Mark M.; Knapp, Jr., Furn F.

    1990-01-01

    Radiopharmaceuticals useful in brain imaging comprising radiohalogenated thienylethylamine derivatives. The compounds are 5-halo-thiophene-2-isopropyl amines able to cross the blood-brain barrier and be retained for a sufficient length of time to allow the evaluation of regional blood flow by radioimaging of the brain.

  15. Hyperon compound nucleus

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu.

    1987-11-01

    The formation of various hypernuclei from K - absorption at rest is discussed from the viewpoints of compound decay of highly excited hypernuclei in contrast to the direct reaction mechanism. Recent (stopped K - , π) experiments at KEK as well as old data of emulsion and bubble chamber experiments are discussed. Some future direction of hypernuclear spectroscopy is suggested. (author)

  16. Toxicology of perfluorinated compounds

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Thorsten [Hessian State Laboratory, Wiesbaden (Germany); Mattern, Daniela; Brunn, Hubertus [Hessian State Laboratory, Giessen (Germany)

    2011-12-15

    Perfluorinated compounds [PFCs] have found a wide use in industrial products and processes and in a vast array of consumer products. PFCs are molecules made up of carbon chains to which fluorine atoms are bound. Due to the strength of the carbon/fluorine bond, the molecules are chemically very stable and are highly resistant to biological degradation; therefore, they belong to a class of compounds that tend to persist in the environment. These compounds can bioaccumulate and also undergo biomagnification. Within the class of PFC chemicals, perfluorooctanoic acid and perfluorosulphonic acid are generally considered reference substances. Meanwhile, PFCs can be detected almost ubiquitously, e.g., in water, plants, different kinds of foodstuffs, in animals such as fish, birds, in mammals, as well as in human breast milk and blood. PFCs are proposed as a new class of 'persistent organic pollutants'. Numerous publications allude to the negative effects of PFCs on human health. The following review describes both external and internal exposures to PFCs, the toxicokinetics (uptake, distribution, metabolism, excretion), and the toxicodynamics (acute toxicity, subacute and subchronic toxicities, chronic toxicity including carcinogenesis, genotoxicity and epigenetic effects, reproductive and developmental toxicities, neurotoxicity, effects on the endocrine system, immunotoxicity and potential modes of action, combinational effects, and epidemiological studies on perfluorinated compounds). (orig.)

  17. Chemical compounds in teak

    Directory of Open Access Journals (Sweden)

    Fernanda Viana da Silva Leonardo

    2015-09-01

    Full Text Available Quinone compounds are largely generated at extractive fraction of the woods in a complex and variable biological system. The literature has indications for many segments from food industry to pharmaceutical industry. Within the field of industrial use of wood, they are less desirable since they are treated only as incidental substances in production strings of pulp, paper, charcoal, and sawmill. In spite of its small amount, compared to other chemical compounds called essential, these substances have received special attention from researchers revealing a diverse range of offerings to market products textiles, pharmaceuticals, colorants, and other polymers, for which are being tested and employed. Quinones are found in fungi, lichens, and mostly in higher plants. Tectona grandis, usually called teak, is able to biosynthesize anthraquinones, which is a quinone compound, byproduct of secondary metabolism. This species provides wood that is much prized in the furniture sector and can also be exploited for metabolites to supply the market in quinone compounds and commercial development of new technologies, adding value to the plantations of this species within our country.

  18. Comparative and non-comparative studies of the efficacy and tolerance of tioconazole cream 1% versus another imidazole and/or placebo in neonates and infants with candidal diaper rash and/or impetigo.

    Science.gov (United States)

    Gibbs, D L; Kashin, P; Jevons, S

    1987-01-01

    Eleven open multicentre studies were conducted to evaluate the efficacy of tioconazole cream 1% as a treatment for diaper rash with or without fungal (Candida) involvement, or impetigo in neonates and infants. In the dermal candidiasis/diaper rash group, 320 patients had either tioconazole (n = 220), a comparative imidazole (n = 43), or vehicle cream (n = 57) applied to the affected area twice daily. Twenty-one impetigo patients had only tioconazole cream 1% applied three times daily to lesions. The overall cure rate (patients with both clinical and mycological cure) at the end of treatment for tioconazole treated patients was 78%, for the comparative imidazole group it was 76% and for vehicle cream it was 39%. At the long-term follow-up evaluation approximately 6 weeks after treatment for patients with diaper rash, the overall cure rate was about the same in both tioconazole- and comparative imidazole-treated patients (87% and 90%, respectively), and 14% in patients using vehicle cream. Side-effects were coincident with disease symptoms and consisted primarily of erythema localized to the treatment area; they occurred in 5.4% (13/241) of the patients who received tioconazole and in 21% (9/43) of the patients who received comparative imidazole (econazole or miconazole). No side-effects were reported in this open study for the 57 patients who used vehicle cream. The results of these studies show that tioconazole cream 1% is safe and effective for the treatment of neonates and infants with dermal candidiasis, diaper rash and impetigo.

  19. Selenium-75-labelled foliate compounds

    International Nuclear Information System (INIS)

    1974-01-01

    A saturation method to analyze a foliate is presented; it uses competitive reaction of the compound to be measured and of a radioactive-labelled version of this compound with a reagent specific to this compound present in insufficient quantity to combine with the whole of the compound and its labelled version, separation of the bound compound from its non-bound homologue and measurement of the radioactivity concentration in the bound compound, the non-bound compound or both. The radioactive isotope used in the labelled foliate is selenium 75 [fr

  20. Synthesis of O-[2-[18F]fluoro-3-(2-nitro-1H-imidazole-1-yl)propyl]tyrosine ([18F]FNT]) as a new class of tracer for imaging hypoxia

    International Nuclear Information System (INIS)

    Noeen Malik; Xian Lin; Christoph Solbach; Hans-Juergen Machulla; Bin Shen; Gerald Reischl; Wolfgang Voelter

    2012-01-01

    For detection of hypoxic tumor tissue, all radiotracers synthesized until now, are based on the concept that cellular uptake is being controlled by diffusion. As a new approach, we chose the concept to have the tracer hypothetically transported into the cells by well known carrier systems like the amino acid transporters. For this purpose, radiosynthesis of O-[2-[ 18 F]fluoro-3-(2-nitro-1H-imidazole-1yl)propyl]tyrosine ([18F]FNT]) was carried out from methyl 2-(benzyloxycarbonyl)-3-(4-3-(2-nitro-1H-imidazol-1-yl) -2-(tosyloxy)propoxy) phenyl)propanoate via no-carrier-added nucleophilic aliphatic substitution. After labelling, 81 ± 0.9% of labelled intermediate i.e. methyl 2-(benzyloxycarbonyl)-3-(4-(2-[ 18 F]fluoro-3- (2-nitro-1H-imidazole-1-yl)propoxy) phenyl)propanoate was obtained at 140 deg C. At the end of radiosynthesis, [ 18 F]FNT was obtained in an overall radiochemical yield of 40 ± 0.9% (not decay corrected) within 90 min in a radiochemical purity of >98% in a formulation ready for application in the clinical studies for PET imaging of hypoxia. (author)

  1. Seven new Zn(II)/Cd(II) coordination polymers with 2-(hydroxymethyl)-1H-benzo[d]imidazole-5-carboxylic acid: Synthesis, structures and properties

    Science.gov (United States)

    Wang, Xin-Fang; Zhou, Sheng-Bin; Du, Ceng-Ceng; Wang, Duo-Zhi; Jia, Dianzeng

    2017-08-01

    Using a new simi-rigid multitopic ligand 2-(hydroxymethyl)-1H-benzo[d]imidazole-5-carboxylic acid (H2L), seven new coordination polymers [Zn3(L)2(μ2-OH)2]n (1), {[Zn2(HL)2(H2O)2]·SiF6}n (2), [Zn(HL)(SCN)]n (3), {[Zn2(HL)2(SO4)]·(4,4‧-bpy)}n (4) [4,4‧-bpy =4,4‧-bipyridine], {[Zn(HL)2]·2H2O}n (5), {[Cd(HL)2]·2H2O}n (6) and [Cd2(HL)2(H2O)2(SO4)]n (7) have been successfully obtained from H2L ligand under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, powder X-ray diffraction and IR spectroscopy. In addition, UV-vis diffuse-reflectance spectra demonstrate wide band gaps. Complex 1 features a 3D topological net of {412·63} with the stoichiometry (6-c), contains 1D channels with the accessible solvent volume of 42.1%. 3, 4, 5 and 6 have a 1D chain structure, 5 and 6 further assemble to form 2D sheet and 3D supramolecular frameworks by hydrogen-bonding interactions, respectively. Complexes 2 and 7 possess a 2D layered structure, and the 2D supramolecular network of 2 can be rationalized to be four-connected {44·62} topological sql network with the dinuclear units, while 7 shows a 3-nodal 2D net with a point symbol of {63}. Moreover, the fluorescent emission, fluorescence lifetimes of 1-7 have been investigated and discussed. Interesting enough, complex 1 showed high efficiency for catalyzing the Knoevenagel condensation reaction between 4-substituted aromatic aldehydes and malononitrile as selective heterogeneous catalyst. The CPs combining catalytic and fluorescent properties could further meet the requirement as a multifunctional material. Seven new Zn(II)/Cd(II) coordination polymers with simi-rigid multitopic ligand, [(2-(hydroxymethyl)-1H-benzo[d]imidazole-5-carboxylic acid) (H2L)] have been successfully obtained and structurally characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, powder X-ray diffraction and IR

  2. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  3. Tripolar Mesoionic Compounds

    OpenAIRE

    Shuki, Araki; Jiro, Mizuya; Naomitsu, Aoyama; Yasuo, Butsugan

    1995-01-01

    Tripolar mesoionic compounds have been synthesized by the reaction of (1,3-diphenyltetrazol-5-ylio)cyclopentadienide (or -indenide) with the dicationic ether salts derived from mesoionic olates and trifluoromethanesulfonic anhydride. The structures of the newly prepared mesoionic systems are discussed on the basis of spectroscopic analysis; it is shown that the tripolar [tetrazolium-cyclopentadienide (or indenide)-tetrazolium] canonical structure contributes significantly to the ground state ...

  4. Oligosilanylated Antimony Compounds

    OpenAIRE

    Zitz, Rainer; Gatterer, Karl; Reinhold, Crispin R. W.; M?ller, Thomas; Baumgartner, Judith; Marschner, Christoph

    2015-01-01

    By reactions of magnesium oligosilanides with SbCl3, a number of oligosilanylated antimony compounds were obtained. When oligosilanyl dianions were used, either the expected cyclic disilylated halostibine was obtained or alternatively the formation of a distibine was observed. Deliberate formation of the distibine from the disilylated halostibine was achieved by reductive coupling with C8K. Computational studies of Sb?Sb bond energies, barriers of pyramidal inversion at Sb, and the conformati...

  5. Labelled compounds. (Pt. B)

    International Nuclear Information System (INIS)

    Buncel, E.; Jones, J.R.

    1991-01-01

    Since the end of World War II there has been a tremendous increase in the number of compounds that have been synthesized with radioactive or stable isotopes. They have found application in many diverse fields, so much so, that hardly a single area in pure and applied science has not benefited. Not surprisingly it has been reflected in appearance of related publications. The early proceedings of the Symposia on Advances in Trace Methodology were soon followed by various Euratom sponsored meetings in which methods of preparing and storing labelled compounds featured prominently. In due course a resurgence of interest in stable isotopes, brought about by their greater availability (also lower cost) and partly by development of new techniques such as gas chromatography - mass spectrometry (gc-ms), led to the publication of proceedings of several successful conferences. More recently conferences dealing with the synthesis and applications of isotopes and isotopically labelled compounds have been established on a regular basis. In addition to the proceedings of conferences and journal publications individuals left their mark by producing definitive texts, usually on specific nuclides. Only the classic two volume publication of Murray and Williams (Organic syntheses with isotopes, New York 1985), now over 30 years old and out of print, attempted to do justice to several nuclides. With the large amount of work that has been undertaken since then it seems unlikely that an updated edition could be produced. The alternative strategy was to ask scientists currently active to review specific areas and this is the approach adopted in the present series of monographs. In this way it is intended to cover the broad advances that have been made in the synthesis and applications of isotopes and isotopically labelled compounds in the physical and biomedical sciences. (author). refs.; figs.; tabs

  6. Process for compound transformation

    KAUST Repository

    Basset, Jean-Marie

    2016-12-29

    Embodiments of the present disclosure provide for methods of using a catalytic system to chemically transform a compound (e.g., a hydrocarbon). In an embodiment, the method does not employ grafting the catalyst prior to catalysis. In particular, embodiments of the present disclosure provide for a process of hydrocarbon (e.g., C1 to C20 hydrocarbon) metathesis (e.g., alkane, olefin, or alkyne metathesis) transformation, where the process can be conducted without employing grafting prior to catalysis.

  7. Compound Semiconductor Radiation Detector

    International Nuclear Information System (INIS)

    Kim, Y. K.; Park, S. H.; Lee, W. G.; Ha, J. H.

    2005-01-01

    In 1945, Van Heerden measured α, β and γ radiations with the cooled AgCl crystal. It was the first radiation measurement using the compound semiconductor detector. Since then the compound semiconductor has been extensively studied as radiation detector. Generally the radiation detector can be divided into the gas detector, the scintillator and the semiconductor detector. The semiconductor detector has good points comparing to other radiation detectors. Since the density of the semiconductor detector is higher than that of the gas detector, the semiconductor detector can be made with the compact size to measure the high energy radiation. In the scintillator, the radiation is measured with the two-step process. That is, the radiation is converted into the photons, which are changed into electrons by a photo-detector, inside the scintillator. However in the semiconductor radiation detector, the radiation is measured only with the one-step process. The electron-hole pairs are generated from the radiation interaction inside the semiconductor detector, and these electrons and charged ions are directly collected to get the signal. The energy resolution of the semiconductor detector is generally better than that of the scintillator. At present, the commonly used semiconductors as the radiation detector are Si and Ge. However, these semiconductor detectors have weak points. That is, one needs thick material to measure the high energy radiation because of the relatively low atomic number of the composite material. In Ge case, the dark current of the detector is large at room temperature because of the small band-gap energy. Recently the compound semiconductor detectors have been extensively studied to overcome these problems. In this paper, we will briefly summarize the recent research topics about the compound semiconductor detector. We will introduce the research activities of our group, too

  8. Bronzes and relative compounds

    International Nuclear Information System (INIS)

    Uehlls, A.

    1987-01-01

    Preparation and the crystal structure of bronzes based on complex oxides of transition (Ti, V, Nb, Ta, Mo, W, Re, Ru and etc.) and alkali metals, as well as oxides of some other elements (Sr, In, La and etc.) are described. Peculiarities of formation of the structure of tetragonal, tungsten, molybdenum, vanadium bronzes and their analogs depending on the chemical composition of these compounds are considered

  9. Compound Wiretap Channels

    Directory of Open Access Journals (Sweden)

    Shlomo Shamai (Shitz

    2009-01-01

    Full Text Available This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom (s.d.o.f. are derived for the degraded case with one receiver. Schemes to achieve the s.d.o.f. for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable s.d.o.f. is given for the general case.

  10. Antifungal compounds from cyanobacteria.

    Science.gov (United States)

    Shishido, Tânia K; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P; Permi, Perttu; Andreote, Ana P D; Fiore, Marli F; Sivonen, Kaarina

    2015-04-13

    Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.

  11. Toxic compounds in honey.

    Science.gov (United States)

    Islam, Md Nazmul; Khalil, Md Ibrahim; Islam, Md Asiful; Gan, Siew Hua

    2014-07-01

    There is a wealth of information about the nutritional and medicinal properties of honey. However, honey may contain compounds that may lead to toxicity. A compound not naturally present in honey, named 5-hydroxymethylfurfural (HMF), may be formed during the heating or preservation processes of honey. HMF has gained much interest, as it is commonly detected in honey samples, especially samples that have been stored for a long time. HMF is a compound that may be mutagenic, carcinogenic and cytotoxic. It has also been reported that honey can be contaminated with heavy metals such as lead, arsenic, mercury and cadmium. Honey produced from the nectar of Rhododendron ponticum contains alkaloids that can be poisonous to humans, while honey collected from Andromeda flowers contains grayanotoxins, which can cause paralysis of limbs in humans and eventually leads to death. In addition, Melicope ternata and Coriaria arborea from New Zealand produce toxic honey that can be fatal. There are reports that honey is not safe to be consumed when it is collected from Datura plants (from Mexico and Hungary), belladonna flowers and Hyoscamus niger plants (from Hungary), Serjania lethalis (from Brazil), Gelsemium sempervirens (from the American Southwest), Kalmia latifolia, Tripetalia paniculata and Ledum palustre. Although the symptoms of poisoning due to honey consumption may differ depending on the source of toxins, most common symptoms generally include dizziness, nausea, vomiting, convulsions, headache, palpitations or even death. It has been suggested that honey should not be considered a completely safe food. Copyright © 2013 John Wiley & Sons, Ltd.

  12. Antifungal Compounds from Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Tânia K. Shishido

    2015-04-01

    Full Text Available Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.

  13. Compound Wiretap Channels

    Directory of Open Access Journals (Sweden)

    Kramer Gerhard

    2009-01-01

    Full Text Available Abstract This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom ( are derived for the degraded case with one receiver. Schemes to achieve the for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable is given for the general case.

  14. 1D and 2D assembly structures by imidazole···chloride hydrogen bonds of iron(II) complexes [Fe(II)(HL(n-Pr))3]Cl·Y (HL(n-Pr) = 2-methylimidazol-4-yl-methylideneamino-n-propyl; Y = AsF6, BF4) and their spin states.

    Science.gov (United States)

    Fujinami, Takeshi; Nishi, Koshiro; Matsumoto, Naohide; Iijima, Seiichiro; Halcrow, Malcolm A; Sunatsuki, Yukinari; Kojima, Masaaki

    2011-12-07

    Two Fe(II) complexes fac-[Fe(II)(HL(n-Pr))(3)]Cl·Y (Y = AsF(6) (1) and BF(4) (2)) were synthesized, where HL(n-Pr) is 2-methylimidazole-4-yl-methylideneamino-n-propyl. Each complex-cation has the same octahedral N(6) geometry coordinated by three bidentate ligands and assumes facial-isomerism, fac-[Fe(II)(HL(n-Pr))(3)](2+) with Δ- and Λ-enantiomorphs. Three imidazole groups per Δ- or Λ-fac-[Fe(II)(HL(n-Pr))(3)](2+) are hydrogen-bonded to three Cl(-) ions or, from the viewpoint of the Cl(-) ion, one Cl(-) ion is hydrogen-bonded to three neighbouring fac-[Fe(II)(HL(n-Pr))(3)](2+) cations. The 3 : 3 NH···Cl(-) hydrogen bonds between Δ- or Λ-fac-[Fe(II)(HL(n-Pr))(3)](2+) and Cl(-) generate two kinds of assembly structures. The directions of the 3 : 3 NH···Cl(-) hydrogen bonds and hence the resulting assembly structures are determined by the size of the anion Y, though Y is not involved into the network structure and just accommodated in the cavity. Compound 1 has a 1D ladder structure giving a larger cavity, in which the Δ- and Λ-fac-[Fe(II)(HL(n-Pr))(3)](2+) enantiomorphs are bridged by two NH···Cl(-) hydrogen bonds. Compound 2 has a 2D network structure with a net unit of a cyclic trimer of {fac-[Fe(II)(HL(n-Pr))(3)](2+)···Cl(-)}(3) giving a smaller cavity, in which Δ- or Λ-fac-[Fe(II)(HL(n-Pr))(3)](2+) species with the same chirality are linked by NH···Cl(-) hydrogen bonds to give a homochiral 2D network structure. Magnetic susceptibility and Mössbauer spectral measurements demonstrated that compound 1 showed an abrupt one-step spin crossover with 4.0 K thermal hysteresis of T(c↓) = 125.5 K and T(c↑) = 129.5 K and compound 2 showed no spin transition and stayed in the high-spin state over the 5-300 K temperature range.

  15. Radioprotective properties of some heterocyclic nitrogenous compounds against changes in hemoglobin concentration and hematocrit value in x-irradiated mice; Proprietes radioprotectrices de certains composes heterocycliques azotes sur les variations du taux d'hemoglobine et de la valeur hematocrite chez la souris irradiee

    Energy Technology Data Exchange (ETDEWEB)

    Rousdhy, H; Pierotti, T; Polverelli, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Radioprotective properties of imidazole and benzimidazole have been proved in previous works. In this study, authors try to demonstrate radioprotective action of these compounds in comparison with cysteamine upon the hematopoietic system after lethal X-irradiation. Results show: no drastic variations of hematologic constants (hemoglobin concentration and hematocrit value) after intraperitoneal injection of radioprotective compounds apart certain apparent reactions with the heterocyclic compounds; the better radioprotective action of benzimidazole. Twenty five days after irradiation, hemoglobin concentration and hematocrit of radio protected mice return to normal values. (author) [French] Les proprietes radioprotectrices de l'imidazole et du benzimidazole ayant ete demontrees dans de precedents travaux, les auteurs se sont attaches a etudier l'action de ces produits sur le systeme hematopofetique en comparaison avec celle de la cysteamine, apres une irradiation a dose letale. A l'aide des criteres choisis, les resultats demontrent: qu'en dehors de certaines reactions apparentes, succedant a l'injection intraperitoneale des heterocycles azotes, les constantes hematologiques (taux d'hemoglobine et valeur hematocrite) ne sont que legerement modifiees; la superiorite du benzimidazole sur les autres produits utilises. Enfin, le vingt-cinquieme jour apres irradiation, les souris protegees par les heterocycles azotes ont un taux d'hemoglobine et une valeur hematocrite tout a fait normaux. (auteur)

  16. Dipicolinate salt of imidazole: Discovering its structure and properties using different experimental methodologies and quantum chemical investigations

    Science.gov (United States)

    Thirumurugan, R.; Anitha, K.

    2018-03-01

    A novel organic proton transfer complex of imidazolium dipicolinate (ID) has been synthesized and it was grown as single crystals using slow evaporation method. The molecular structure of synthesized compound and vibrational modes of its functional groups were confirmed by (1H and 13C) NMR, FTIR and FT-Raman spectroscopic studies, respectively. Single crystal X-ray diffraction (SCXRD) analysis confirmed the orthorhombic system with noncentrosymmetric (NCS), P212121, space group of grown ID crystal. UV-Vis-NIR spectral study confirmed its high optical transparency within the region of 285-1500 nm. Powder second harmonic generation (SHG) efficiency of ID crystal was confirmed and it was 6.8 times that of KDP crystal. TG-DTA and DSC analysis revealed the higher thermal stability of grown crystal as 249 °C. The dielectric response and mechanical behaviour of grown crystal were studied effectively. Density functional theory calculations were performed to probe the relationship between the structure and its properties including molecular optimization, Mulliken atomic charge distribution, frontier molecular orbital (FMOs) and molecular electrostatic potential map (MEP) analysis and first hyperpolarizability. All these experimental and computational results were discussed in this communication and it endorsed the ID compound as a potential NLO candidate could be employed in optoelectronics device applications in near future.

  17. Nomenclature on an inorganic compound

    International Nuclear Information System (INIS)

    1998-10-01

    This book contains eleven chapters : which mention nomenclature of an inorganic compound with introduction and general principle on nomenclature of compound. It gives the description of grammar for nomenclature such as brackets, diagonal line, asterisk, and affix, element, atom and groups of atom, chemical formula, naming by stoichiometry, solid, neutral molecule compound, ion, a substituent, radical and name of salt, oxo acid and anion on introduction and definition of oxo acid, coordination compound like symbol of stereochemistry , boron and hydrogen compound and related compound.

  18. ZnO Nanorod-Induced Heteroepitaxial Growth of SOD Type Co-Based Zeolitic Imidazolate Framework Membranes for H2 Separation.

    Science.gov (United States)

    Nian, Pei; Li, Yujia; Zhang, Xiang; Cao, Yi; Liu, Haiou; Zhang, Xiongfu

    2018-01-31

    Up to now, the fabrication of well-intergrown Co-based zeolitic imidazolate framework (ZIF) membranes on porous tubular supports is still a major challenge. We report here a heteroepitaxial growth for preparing well-intergrown Co-based ZIFs (ZIF-67 and ZIF-9) tubular membranes with high performance and excellent thermal stability by employing a thin layer of ZnO nanorods acting as both nucleation centers and anchor sites for the growth of metal-organic framework membranes. The results show that well-intergrown Co-ZIF-67 and Co-ZIF-9 membranes are successfully achieved on the ZnO nanorod-modified porous ceramic tubes. This highly active heteroepitaxial growth may be attributed to the fact that the (Zn,Co) hydroxy double salt intermediate produced in situ from ZnO nanorods acts as heteroseeds and enables the uniform growth of Co-based membranes. The H 2 /CO 2 selectivity of the as-prepared Co-ZIF-9 tubular membrane could reach about 23.8 and the H 2 /CH 4 selectivity of Co-ZIF-67 tubular membrane is as high as 45.4. Moreover, the membranes demonstrate excellent stability because of the ZnO nanorods as linkers between the membrane and substrate.

  19. Zeolitic imidazolate framework-8-derived N-doped porous carbon coated olive-shaped FeOx nanoparticles for lithium storage

    Science.gov (United States)

    Gan, Qingmeng; Zhao, Kuangmin; He, Zhen; Liu, Suqin; Li, Aikui

    2018-04-01

    We propose a new strategy to uniformly coat zeolitic imidazolate framework-8 (ZIF-8) on iron oxides containing no Zn to obtain an α-Fe2O3@ZIF-8 composite. After carbonization, the α-Fe2O3@ZIF-8 transforms into iron oxides@N-doped porous carbon (FeOx@NC). The uniform N-doped porous carbon layer gives rise to a superior electrical conductivity, highly-increased specific BET surface area (179.2 m2 g-1), and abundant mesopores for the FeOx@NC composite. When served as the LIB anode, the FeOx@NC shows a high reversible capacity (of 1064 mA h g-1 at 200 mA g-1), excellent rate performance (of 198.1 mA h g-1 at 10000 mA g-1) as well as brilliant long-term cyclability (with a capacity retention of 93.3% after 800 cycles), which are much better than those of the FeOx@C and pristine FeOx anodes. Specifically, the Li-ion intercalation pseudocapacitive behavior of the FeOx@NC anode is improved by this N-doped porous carbon coating, which is beneficial for rapid Li-ion insertion/extraction processes. The excellent electrochemical performance of FeOx@NC should be ascribed to the increased electrolyte penetration areas, improved electrical conductivity, boosted lithium storage kinetics, and shortened Li-ion transport length.

  20. Neuronal NOS inhibitor 1-(2-trifluoromethylphenyl)-imidazole augment the effects of antidepressants acting via serotonergic system in the forced swimming test in rats.

    Science.gov (United States)

    Ulak, Güner; Mutlu, Oguz; Akar, Füruzan Yildiz; Komsuoğlu, F Ipek; Tanyeri, Pelin; Erden, B Faruk

    2008-10-01

    Treatment-resistant depression has necessitated new therapeutic strategies in augmenting the therapeutic actions of currently existing antidepressant drugs. The aim of this study was to investigate the possibility of synergistic interaction between 1-(2-trifluoromethylphenyl)-imidazole (TRIM), a novel neuronal nitric oxide synthase (nNOS) inhibitor and conventional antidepressants of different classes in the forced swimming test (FST) in rats. TRIM decreased the immobility time at 50 mg/kg doses in the FST in rats. Treatment with a behaviourally subeffective dose of TRIM (20 mg/kg) augmented the behavioural effect of tricyclic antidepressant imipramine, selective serotonin re-uptake inhibitor (SSRI) citalopram and fluoxetine or selective serotonin reuptake enhancer tianeptine but failed to augment the antidepressant effect of reboxetine, a noradrenaline re-uptake inhibitor, in this test. Therefore inhibition of NOS augments the effects of antidepressants acting on serotonergic system in the FST. Neither TRIM (10-50 mg/kg) nor other drug treatments affected the locomotor activity of animals. These findings are in agreement with the view that antidepressant effects or augmentation of these effects in the FST may be explained with inhibition of NOS activity and this may be a new approach in offering greater therapeutic efficacy of antidepressants acting via serotonergic system.

  1. Di-μ-chlorido-bis(chlorido{2,2′-[3-(1H-imidazol-4-ylmethyl-3-azapentane-1,5-diyl]diphthalimide}copper(II

    Directory of Open Access Journals (Sweden)

    Xi-Xi Wang

    2009-12-01

    Full Text Available The centrosymmetric dinuclear CuII complex, [Cu2Cl4(C24H21N5O42], was synthesized by the reaction of CuCl2·2H2O with the tripodal ligand 2,2′-[3-(1H-imidazol-4-ylmethyl-3-azapentane-1,5-diyl]diphthalimide (L. Each of the CuII ions is coordinated by two N atoms from the ligand, two bridging Cl atoms and one terminal Cl atom. The CuII coordination can be best be described as a transition state between four- and five-coordination, since one of the bridging Cl atoms has a much longer Cu—Cl bond distance [2.7069 (13 Å] than the other [2.2630 (12 Å]. In addition, the Cu...Cu distance is 3.622 (1 Å. The three-dimensional structrure is generated by N—H...O, C—H...O and C—H...Cl hydrogen bonds and π–π interactions [centroid–centroid distances = 3.658 (4 and 4.020 (4 Å].

  2. Flexible and porous cellulose aerogels/zeolitic imidazolate framework (ZIF-8) hybrids for adsorption removal of Cr(IV) from water

    Science.gov (United States)

    Bo, Shaoguo; Ren, Wenjing; Lei, Chao; Xie, Yuanbo; Cai, Yurong; Wang, Shunli; Gao, Junkuo; Ni, Qingqing; Yao, Juming

    2018-06-01

    The low cost of adsorption treatment of heavy metal ions in water has been extensively studied. In this paper, we have demonstrated a facile method of combining two emerging materials cellulose aerogels (CA) and metal-organic frameworks (MOFs) into one highly functional aerogel to adsorption removal of heavy metal ions from water, by entrapping MOF particles into a flexible and porous CA. The resultant hybrid cellulose aerogels had a highly porous structure with zeolitic imidazolate framework-8 (ZIF-8) loadings can reach 30 wt%. The hybrid cellulose aerogels (named as ZIF-8@CA) show good adsorption capacity for Cr(Ⅵ). The adsorption process of ZIF-8@CA is better described by pseudo-second-order kinetic model and Langmuir isotherm, with maximum monolayer adsorption capacity of 41.8 mg g-1 for Cr(Ⅵ), whose adsorption capacity has greatly improved when compared with a single CA or ZIF-8. Thus, such a flexible and durable hybrid cellulose aerogel is a very prospective material for metal ions cleanup and industrial wastewater purification.

  3. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  4. Toxicology of alkylmercury compounds.

    Science.gov (United States)

    Aschner, Michael; Onishchenko, Natalia; Ceccatelli, Sandra

    2010-01-01

    Methylmercury is a global pollutant and potent neurotoxin whose abundance in the food chain mandates additional studies on the consequences and mechanisms of its toxicity to the central nervous system. Formulation of our new hypotheses was predicated on our appreciation for (a) the remarkable affinity of mercurials for the anionic form of sulfhydryl (-SH) groups, and (b) the essential role of thiols in protein biochemistry. The present chapter addresses pathways to human exposure of various mercury compounds, highlighting their neurotoxicity and potential involvement in neurotoxic injury and neurodegenerative changes, both in the developing and senescent brain. Mechanisms that trigger these effects are discussed in detail.

  5. Compound composite odontoma

    Directory of Open Access Journals (Sweden)

    S Kailasam

    2012-01-01

    Full Text Available Odontomas are the most common type of odontogenic tumors and generally they are asymptomatic. Frequently, it may interfere with the eruption of the teeth. This is a case report of a compound composite odontoma in a 10-year-old girl, which results in failure of eruption of the permanent upper right central incisor while the contralateral tooth had erupted. A calcified mass was seen in the radiograph and was provisionally diagnosed as odontoma following which the odontoma was enucleated. Routine follow-up was done for more than a year and no recurrence was seen. This case report indicates that early diagnosis and management ensures better prognosis.

  6. Flavour Compounds in Fungi

    DEFF Research Database (Denmark)

    Ravasio, Davide Antonio

    . This selection of strains was used in fermentations with the aim of identifying new interesting flavour producers. Fermentation profiles, volatile analyses, off-flavour identification and resistance to osmotic/oxidative stress have been addressed to highlight new candidates to use for industrial applications....... This resulted in the identification of Wickerhamomyces anomalus and Pichia kluyveri as high producers of esters fruity compounds, which contribute to enhance the complexity of wine and beer product. In addition the strain Debaromyces subglobosus showed high yields of aldehydes and fruity ketones, which...

  7. Antifouling Compounds from Marine Invertebrates.

    Science.gov (United States)

    Qi, Shu-Hua; Ma, Xuan

    2017-08-28

    In this review, a comprehensive overview about the antifouling compounds from marine invertebrates is described. In total, more than 198 antifouling compounds have been obtained from marine invertebrates, specifically, sponges, gorgonian and soft corals.

  8. Antifouling Compounds from Marine Invertebrates

    OpenAIRE

    Qi, Shu-Hua; Ma, Xuan

    2017-01-01

    In this review, a comprehensive overview about the antifouling compounds from marine invertebrates is described. In total, more than 198 antifouling compounds have been obtained from marine invertebrates, specifically, sponges, gorgonian and soft corals.

  9. Tricarbonyl[tris(1-methyl-1H-imidazol-2-yl-κN3methanol]manganese(I trifluoromethanesulfonate

    Directory of Open Access Journals (Sweden)

    Guido J. Reiss

    2012-09-01

    Full Text Available In the title compound, [Mn(C13H16N6O(CO3](CF3O3S, the MnI atom has a slightly distorted octahedral geometry. The three CO ligands have C—Mn—C angles in the range 89.44 (10–92.31 (9°, while the three N atoms of the tripodal ligand form significantly smaller N—Mn—N angles of 82.76 (2–85.51 (6°. The three N atoms of the tripodal ligand and the three carbonyl ligands coordinate facially. In the crystal, the trifluoromethanesulfonate counter anion is connected by a medium-strength O—H...O hydrogen bond to the hydroxyl group of the manganese complex.

  10. Catalytic properties of niobium compounds

    International Nuclear Information System (INIS)

    Tanabe, K.; Iizuka, T.

    1983-04-01

    The catalytic activity and selectivity of niobium compounds including oxides, salts, organometallic compounds and others are outlined. The application of these compounds as catalysts to diversified reactions is reported. The nature and action of niobium catalysts are characteristic and sometimes anomalous, suggesting the necessity of basic research and the potential use as catalysts for important processes in the chemical industry. (Author) [pt

  11. Molecular modeling of inorganic compounds

    National Research Council Canada - National Science Library

    Comba, Peter; Hambley, Trevor W; Martin, Bodo

    2009-01-01

    ... mechanics to inorganic and coordination compounds. Initially, simple metal complexes were modeled, but recently the field has been extended to include organometallic compounds, catalysis and the interaction of metal ions with biological macromolecules. The application of molecular mechanics to coordination compounds is complicated by the numbe...

  12. Organometallic compounds in the environment

    National Research Council Canada - National Science Library

    Craig, P. J

    2003-01-01

    ... of Organometallic Species in the Environment 20 1.10 Stability of Organometallic Compounds in Biological Systems 1.11 G eneral Comments on the Toxicities of Organometallic Compounds 22 1.12 General Considerations on Environmental R eactivity of Organometallic Compounds 24 1.13 Microbial Biotransformation of Metals and M etalloids 25 1.13.1 Introduction 25 1...

  13. Goldenphilicity: Luminescent gold compounds

    International Nuclear Information System (INIS)

    Sansores, L.E.

    2002-01-01

    In the solids and molecules different types of bonds are presented depending on the involved atoms, covalent bonds are common among elements of open shell, where more bond orbitals are filled than anti bond orbitals. It is expected that ionic bonds among closed shell atoms which have charges of opposite sign. Bonds type Van der Waals are presented among molecules which have a bipolar moment. It would not be expected bonds among zero charge species, or more generally with the same nominal charge and in any case the attractive forces would be very small. In fact it is expected that two metallic cations to be repelled each other. There recently is evidence that in organic or organometallic compounds could exist attractive interactions between two cations of the d 8 -d 10 -s 2 families. These bonds are weak but stronger than those of Van der Waals. They are compared with the hydrogen bonds. In this work it was reviewed some examples in which the goldenphilicity plays an important role in the luminescence that the gold complexes present. Examples of mono, bi and trinuclear and the structures that these organometallic compounds could take are examined. (Author)

  14. Semiconducting III-V compounds

    CERN Document Server

    Hilsum, C; Henisch, Heinz R

    1961-01-01

    Semiconducting III-V Compounds deals with the properties of III-V compounds as a family of semiconducting crystals and relates these compounds to the monatomic semiconductors silicon and germanium. Emphasis is placed on physical processes that are peculiar to III-V compounds, particularly those that combine boron, aluminum, gallium, and indium with phosphorus, arsenic, and antimony (for example, indium antimonide, indium arsenide, gallium antimonide, and gallium arsenide).Comprised of eight chapters, this book begins with an assessment of the crystal structure and binding of III-V compounds, f

  15. Volatile organic compounds

    International Nuclear Information System (INIS)

    Silseth, May Liss

    1998-01-01

    The goal is: Not more emission of volatile organic compounds (VOCs) than necessary. The items discussed in this presentation are the VOCs, how to calculate emission of VOCs, how to reduce or avoid them, and different recovery processes. The largest source of Norwegian emissions of non methane VOCs (NMVOCs) is offshore loading of raw petroleum. Emissions of VOCs should be reduced mainly for two reasons: (1) on sunny days NMVOCs may react with NOx to form ozon and smog close to the surface, (2) ozone and smog close to the surface may be harmful to plants and animals, and they are hazardous to human health. As for the calculation of VOC emissions, the VOCON project will release the calculation program HCGASS in 1999. This project is a cooperative project headed by SINTEF/Marintek

  16. Synthesis of labeled compounds

    International Nuclear Information System (INIS)

    Whaley, T.W.

    1977-01-01

    Intermediate compounds labeled with 13 C included methane, sodium cyanide, methanol, ethanol, and acetonitrile. A new method for synthesizing 15 N-labeled 4-ethylsulfonyl-1-naphthalene-sulfonamide was developed. Studies were conducted on pathways to oleic-1- 13 C acid and a second pathway investigated was based on carbonation of 8-heptadecynylmagnesium bromide with CO 2 to prepare sterolic acid. Biosynthetic preparations included glucose- 13 C from starch isolated from tobacco leaves following photosynthetic incubation with 13 CO 2 and galactose- 13 C from galactosylglycerol- 13 C from kelp. Research on growth of organisms emphasized photosynthetic growth of algae in which all cellular carbon is labeled. Preliminary experiments were performed to optimize the growth of Escherichia coli on sodium acetate- 13 C

  17. Deposition of acidifying compounds

    International Nuclear Information System (INIS)

    Fowler, D.; Cape, J.N.; Sutton, M.A.; Mourne, R.; Hargreaves, K.J.; Duyzer, J.H.; Gallagher, M.W.

    1992-01-01

    Inputs of acidifying compounds to terrestrial ecosystems include deposition of the gases NO 2 , NO, HNO 2 , HNO 3 , NH 3 and SO 2 and the ions NO 3- , NH 4+ , SO 4 2- and H + in precipitation, cloud droplets and particles. Recent research has identified particular ecosystems and regions in which terrestrial effects are closely linked with specific deposition processes. This review paper identifies areas in which important developments have occurred during the last five years and attempts to show which aspects of the subject are most important for policy makers. Amongst the conclusions drawn, the authors advise that current uncertainties in estimates of S and N inputs by dry deposition should be incorporated in critical load calculations, and that, in regions dominated by wet deposition, spatial resolution of total inputs should be improved to match the current scales of information on landscape sensitivity to acidic inputs. 44 refs., 9 figs

  18. Interaction of 2-aminopyrimidine with dichloro-[1-alkyl-2-(naphthylazo imidazole]palladium(II complexes : Kinetic and mechanistic studies

    Directory of Open Access Journals (Sweden)

    Saha Sushanta

    2007-10-01

    Full Text Available Abstract Background The anticancer properties of cisplatin and palladium(II complexes stem from the ability of the cis-MCl2 fragment to bind to DNA bases. However, cisplatin also interacts with non-cancer cells, mainly through bonding molecules containing -SH groups, resulting in nephrotoxicity. This has aroused interest in the design of palladium(II complexes of improved activity and lower toxicity. The reaction of DNA bases with palladium(II complexes with chelating N,N/donors of the cis-MCl2 configuration constitutes a model system that may help explore the mechanism of cisplatin's anticancer activity. Heterocyclic compounds are found widely in nature and are essential to many biochemical processes. Amongst these naturally occurring compounds, the most thoroughly studied is that of pyrimidine. This was one of the factors that encouraged this study into the kinetics and mechanism of the interaction of 2-aminopyrimidine (2-NH2-Pym with dichloro-{1-alkyl-2-(α-naphthylazoimidazole}palladium(II [Pd(α-NaiRCl2, 1] and dichloro-{1-alkyl-2-(β-naphthylazoimidazole}palladium(II [Pd(β-NaiRCl2, 2] complexes where the alkyl R = Me (a, Et (b, or Bz (c. Results 2-NH2-Pym reacts with 1a, 1b, and 1c to yield [{1-alkyl-2-(α-naphthylazoimidazole}bis(2-aminopyrimidine]palladium(II (3a, 3b, 3c dichloride and with 2a, 2b, and 2c to yield [{1-alkyl-2-(β-naphthylazoimidazole}bis(2-aminopyrimidine]palladium(II (4a, 4b, 4c dichloride in an acetonitrile (MeCN medium. The products were characterized using spectroscopic techniques (FT-IR, UV-Vis, NMR. The ligand substitution reactions follow second order kinetics – first order dependence on the concentration of the Pd(II complex and 2-NH2-Pym. Addition of LiCl to the reaction does not influence its rate. The thermodynamic parameters (standard enthalpy of activation, Δ‡H° and standard entropy of activation, Δ‡S° were determined from variable temperature kinetic studies. The magnitude of the second order

  19. Porous Nano-Si/Carbon Derived from Zeolitic Imidazolate Frameworks@Nano-Si as Anode Materials for Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Song, Yonghai; Zuo, Li; Chen, Shouhui; Wu, Jiafeng; Hou, Haoqing; Wang, Li

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •The porous cage-like carbon/Si nanocomposites were synthesized based on nano-Si@ZIF-8-templatedmethod. •The nano-Si was uniformly embedded in porous amorphous carbon matrices. •The porous dodecahedral carbon framework effectively accommodates the volume variation of Si during the discharge/charge process. •The Si/C nanocomposites exhibit superior reversible capacity of 1168 mA h g −1 after 100 cycles. -- Abstract: Novel porous cage-like carbon (C)/nano-Si nanocomposites as anode materials for lithium-ion batteries (LIBs) was prepared based on nano-Si@zeolitic imidazolate frameworks (ZIF-8)-templated method. In this strategy, p-aminobenzoic acid was initially grafted onto nano-Si to form benzoic acid-functionalized nano-Si, and then nano-Si@ZIF-8 was constructed by alternately growing Zn(NO 3 ) 2 ·6H 2 O and 2-methylimidazolate on benzoic acid-functionalized nano-Si under ultrasound. The novel porous cage-like nano-Si/C nanocomposites were fabricated by pyrolyzing the resulted nano-Si@ZIF-8 and washing with HCl to remove off ZnO. Scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Raman spectra and N 2 adsorption/desorption isotherms were employed to characterize the porous cage-like nano-Si/C nanocomposites. The resulted nano-Si/C nanocomposites as anode materials for LIBs showed a high reversible capacity of ∼1168 mA h g −1 at 100 mA g −1 after 100 cycles, which was higher than many previously reported Si/C nanocomposites. The porous nanostructure, high specific surface area and good electrical conductivity of the cage-like nano-Si/C nanocomposites contributed together to the good performance for LIBs. It might open up a new way for application of silicon materials

  20. Properties of pure 1,1,3,3-tetramethylguanidine imidazole ionic liquid and its binary mixtures with alcohols at T = (293.15 to 313.15) K

    International Nuclear Information System (INIS)

    Chen, Jiayi; Chen, Lingxiao; Xu, Yingjie

    2015-01-01

    Highlights: • Densities and viscosities of [TMG]IM + alcohol mixtures were measured. • Coefficient of thermal expansion, molecular volume, standard entropy, and lattice energy were obtained. • Excess molar volumes and viscosity deviations were calculated and fitted to Redlich–Kister equation. • Other volumetric properties and excess Gibbs free energy of activation for viscous flow were deduced. • The intermolecular interactions between [TMG]IM and alcohols were analyzed. - Abstract: Densities and viscosities of the pure ionic liquid 1,1,3,3-tetramethylguanidine imidazole ([TMG]IM) and its binary mixtures with methanol, ethanol, 1-propanol, and 1-butanol were measured at temperatures from T = (293.15 to 313.15) K. The thermal expansion coefficient, molecular volume, standard entropy, and lattice energy of [TMG]IM were obtained from the experimental density value. The temperature dependence of the viscosity of [TMG]IM was fitted to the fluidity equation. Excess molar volumes V E and viscosity deviations Δη of the binary mixtures were calculated and fitted to the Redlich–Kister equation with satisfactory results. The result shows that the V E values of the binary mixtures are negative over the whole composition range, while Δη values have an S-shape deviation. Temperature has little effect on the V E of the systems, but it has significant effect on the Δη. Furthermore, the absolute values of V E for {[TMG]IM (1) + alcohol (2)} systems at the same temperature decrease with increasing carbon alkyl chain of the primary alcohol. Other derived properties, such as the apparent molar volumes, partial molar volumes, excess partial molar volumes, Gibbs free energy of activation for viscous flow, and excess Gibbs free energy of activation for viscous flow of the above-mentioned systems were also calculated

  1. The novel non-imidazole histamine H3 receptor antagonist DL77 reduces voluntary alcohol intake and ethanol-induced conditioned place preference in mice.

    Science.gov (United States)

    Bahi, Amine; Sadek, Bassem; Nurulain, Syed M; Łażewska, Dorota; Kieć-Kononowicz, Katarzyna

    2015-11-01

    It has become clear that histamine H3 receptors (H3R) have been implicated in modulating ethanol intake and preference in laboratory animals. The novel non-imidazole H3R antagonist DL77 with excellent selectivity profile shows high in-vivo potency as well as in-vitro antagonist affinity with ED50 of 2.1 ± 0.2 mg/kg and pKi=8.08, respectively. In the present study, and applying an unlimited access two-bottle choice procedure, the anti-alcohol effects of the H3R antagonist, DL77 (0, 3, 10 and 30 mg/kg; i.p.), were investigated in adult mice. In this C57BL/6 line, effects of DL77 on voluntary alcohol intake and preference, as well as on total fluid intake were evaluated. Results have shown that DL77, dose-dependently, reduced both ethanol intake and preference. These effects were very selective as both saccharin and quinine, used to control for taste sensitivity, and intakes were not affected following DL77 pre-application. More importantly, systemic administration of DL77 (10 mg/kg) during acquisition inhibited ethanol-induced conditioned-place preference (EtOH-CPP) as measured using an unbiased protocol. The anti-alcohol activity observed for DL77 was abrogated when mice were pretreated with the selective H3R agonist R-(α)-methyl-histamine (RAMH) (10 mg/kg), or with the CNS penetrant H1R antagonist pyrilamine (PYR) (10mg/kg). These results suggest that DL77 has a predominant role in two in vivo effects of ethanol. Therefore, signaling via H3R is essential for ethanol-related consumption and conditioned reward and may represent a novel therapeutic pharmacological target to tackle ethanol abuse and alcoholism. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Steric and electronic parameters of a bulky yet flexible N-heterocyclic carbene: 1,3-bis(2,6-bis(1-ethylpropyl)phenyl)imidazol-2-ylidene (IPent)

    KAUST Repository

    Collado, Alba; Balogh, Já nos; Meiries, Sé bastien; Slawin, Alexandra M. Z.; Falivene, Laura; Cavallo, Luigi; Nolan, Steven P.

    2013-01-01

    The free N-heterocyclic carbene IPent (1; IPent = 1,3-bis(2,6-bis(1- ethylpropyl)phenyl)imidazol-2-ylidene) was prepared from the corresponding imidazolium chloride salt (2). The steric and electronic parameters of 1 were determined by synthesis of the gold(I) chloride complex [Au(IPent)Cl] (3) and the nickel-carbonyl complex [Ni(IPent)(CO)3] (4), respectively. 3 and 4 were fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction studies on single crystals. © 2013 American Chemical Society.

  3. Steric and electronic parameters of a bulky yet flexible N-heterocyclic carbene: 1,3-bis(2,6-bis(1-ethylpropyl)phenyl)imidazol-2-ylidene (IPent)

    KAUST Repository

    Collado, Alba

    2013-06-10

    The free N-heterocyclic carbene IPent (1; IPent = 1,3-bis(2,6-bis(1- ethylpropyl)phenyl)imidazol-2-ylidene) was prepared from the corresponding imidazolium chloride salt (2). The steric and electronic parameters of 1 were determined by synthesis of the gold(I) chloride complex [Au(IPent)Cl] (3) and the nickel-carbonyl complex [Ni(IPent)(CO)3] (4), respectively. 3 and 4 were fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction studies on single crystals. © 2013 American Chemical Society.

  4. TSTA compound cryopump

    International Nuclear Information System (INIS)

    Batzer, T.H.; Patrick, R.E.; Call, W.R.

    1980-01-01

    The Tritium System Test Assembly (TSTA), at the Los Alamos Scientific Laboratory, is intended to demonstrate realistic fuel supply and cleanup scenarios for future fusion reactors. The vacuum pumps must be capable of handling large quantities of reactor exhaust gases consisting largely of mixtures of hydrogen and helium isotopes. Cryocondensing pumps will not pump helium at 4.2 K; while cryosorption pumps using molecular sieves or charcoal have good helium pumping speed, the adsorbent clogs with condensed hydrogen while pumping mixtures of both. A solution to this problem is a compound design whereby the first stage condenses the hydrogen and the second, or sorption, stage pumps the helium. The TSTA pump designed at Lawrence Livermore National Laboratory uses argon gas to cryotrap the helium in the helium-hydrogen mixture. The argon is sprayed directly onto the 4.2 K surface at a rate proportional to the helium flow rate, permitting continuous pumping of the helium-hydrogen mixtures in a single-stage pump. However, the possibility of differential desorption as a first stage in the TSTA gas separation cycle required the inclusion of a first-stage hydrogen isotope condenser. The design, performance, and operating characteristics are discussed

  5. Pluto's Nonvolatile Chemical Compounds

    Science.gov (United States)

    Grundy, William M.; Binzel, Richard; Cook, Jason C.; Cruikshank, Dale P.; Dalle Ore, Cristina M.; Earle, Alissa M.; Ennico, Kimberly; Jennings, Donald; Howett, Carly; Kaiser, Ralf-Ingo; Linscott, Ivan; Lunsford, A. W.; Olkin, Catherine B.; Parker, Alex Harrison; Parker, Joel Wm.; Philippe, Sylvain; Protopapa, Silvia; Quirico, Eric; Reuter, D. C.; Schmitt, Bernard; Singer, Kelsi N.; Spencer, John R.; Stansberry, John A.; Stern, S. Alan; Tsang, Constantine; Verbiscer, Anne J.; Weaver, Harold A.; Weigle, G. E.; Young, Leslie

    2016-10-01

    Despite the migration of Pluto's volatile ices (N2, CO, and CH4) around the surface on seasonal timescales, the planet's non-volatile materials are not completely hidden from view. They occur in a variety of provinces formed over a wide range of timescales, including rugged mountains and chasms, the floors of mid-latitude craters, and an equatorial belt of especially dark and reddish material typified by the informally named Cthulhu Regio. NASA's New Horizons probe observed several of these regions at spatial resolutions as fine as 3 km/pixel with its LEISA imaging spectrometer, covering wavelengths from 1.25 to 2.5 microns. Various compounds that are much lighter than the tholin-like macromolecules responsible for the reddish coloration, but that are not volatile at Pluto surface temperatures such as methanol (CH3OH) and ethane (C2H6) have characteristic absorption bands within LEISA's wavelength range. This presentation will describe their geographic distributions and attempt to constrain their origins. Possibilities include an inheritance from Pluto's primordial composition (the likely source of H2O ice seen on Pluto's surface) or ongoing production from volatile precursors through photochemistry in Pluto's atmosphere or through radiolysis on Pluto's surface. New laboratory data inform the analysis.This work was supported by NASA's New Horizons project.

  6. Affixation and compounding in Hakka

    OpenAIRE

    Ungsitipoonporn, Siriopen

    2014-01-01

    This paper aims to present the internal structures of words in the Hakka language. Similar to other languages, affixation and compounding are outstanding in Hakka. In general, prefixes and suffixes are bound morphemes which do not occur independently, but in Hakka they sometimes appear as independent forms. Apart from single words, identifying compound words is of particular interest. Compound nouns can be made up of two or three words (characters) which ...

  7. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Mariano Fracchiolla

    2007-12-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  8. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Pasquale Montemurro

    2011-02-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  9. Antimicrobial compounds in tears.

    Science.gov (United States)

    McDermott, Alison M

    2013-12-01

    The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Potent Plasmodium falciparum gametocytocidal activity of diaminonaphthoquinones, lead antimalarial chemotypes identified in an antimalarial compound screen.

    Science.gov (United States)

    Tanaka, Takeshi Q; Guiguemde, W Armand; Barnett, David S; Maron, Maxim I; Min, Jaeki; Connelly, Michele C; Suryadevara, Praveen Kumar; Guy, R Kiplin; Williamson, Kim C

    2015-03-01

    Forty percent of the world's population is threatened by malaria, which is caused by Plasmodium parasites and results in an estimated 200 million clinical cases and 650,000 deaths each year. Drug resistance has been reported for all commonly used antimalarials and has prompted screens to identify new drug candidates. However, many of these new candidates have not been evaluated against the parasite stage responsible for transmission, gametocytes. If Plasmodium falciparum gametocytes are not eliminated, patients continue to spread malaria for weeks after asexual parasite clearance. Asymptomatic individuals can also harbor gametocyte burdens sufficient for transmission, and a safe, effective gametocytocidal agent could also be used in community-wide malaria control programs. Here, we identify 15 small molecules with nanomolar activity against late-stage gametocytes. Fourteen are diaminonaphthoquinones (DANQs), and one is a 2-imino-benzo[d]imidazole (IBI). One of the DANQs identified, SJ000030570, is a lead antimalarial candidate. In contrast, 94% of the 650 compounds tested are inactive against late-stage gametocytes. Consistent with the ineffectiveness of most approved antimalarials against gametocytes, of the 19 novel compounds with activity against known anti-asexual-stage targets, only 3 had any strong effect on gametocyte viability. These data demonstrate the distinct biology of the transmission stages and emphasize the importance of screening for gametocytocidal activity. The potent gametocytocidal activity of DANQ and IBI coupled with their efficacy against asexual parasites provides leads for the development of antimalarials with the potential to prevent both the symptoms and the spread of malaria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. II-VI semiconductor compounds

    CERN Document Server

    1993-01-01

    For condensed matter physicists and electronic engineers, this volume deals with aspects of II-VI semiconductor compounds. Areas covered include devices and applications of II-VI compounds; Co-based II-IV semi-magnetic semiconductors; and electronic structure of strained II-VI superlattices.

  12. Compound-heterozygous Marfan syndrome

    NARCIS (Netherlands)

    van Dijk, F. S.; Hamel, B. C.; Hilhorst-Hofstee, Y.; Mulder, B. J. M.; Timmermans, J.; Pals, G.; Cobben, J. M.

    2009-01-01

    We report two families in which the probands have compound-heterozygous Marfan syndrome (MFS). The proband of family I has the R2726W FBN1 mutation associated with isolated skeletal features on one allele and a pathogenic FBN1 mutation on the other allele. The phenotype of the compound-heterozygous

  13. Radioactive decay and labeled compounds

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter on radioactive decay and labeled compounds has numerous intext equations and worked, sample problems. Topics covered include the following: terms and mathematics of radioactive decay; examples of calculations; graphs of decay equations; radioactivity or activity; activity measurements; activity decay; half-life determinations; labeled compounds. A 20 problem set is also included. 1 ref., 4 figs., 1 tab

  14. Radiolysis of other organic compounds

    International Nuclear Information System (INIS)

    Pikaev, A.K.

    1986-01-01

    Peculiarities of radiolysis of organic halogen, phosphorus, sulfur and nitrogen (including amines, amides, nitriles et al.) compounds in liquid phase are discussed. Intermediate and stable finish products of radiolysis of the given compounds, properties and radiochemical yields of these products are considered

  15. 2. Intermetallic compounds with lanthanides

    International Nuclear Information System (INIS)

    Elemans, J.B.A.A.

    1975-01-01

    Theoretical considerations are given concerning the structures of intermetallic compounds of the lanthanides and thorium (R) on the one hand, and with Fe, Co or Ni (M) on the other. They all derive from the parent composition RM 5 with the CaCu 5 hexagonal structure. This consists of alternate layers in which the M atoms are distinguished as M 1 and M 2 . The other compounds whose structures are studied are obtained by systematic replacement of R by M, or vice versa. In the first type, every third R is replaced by two M's yielding R 2 M 17 compounds. The substitution may be truly random or structured in two ways: so that either the hexagonal structure is maintained or that it is converted into a rhombihedral one. In the second type, one M (in a M 1 position) out of every five is replaced by one R, giving rise to RM 2 compounds which form Laves phases. In the third type, the M 1 's are replaced by R's, resulting in compounds RM 3 . In the fourth type, every third M is replaced by R, yielding R 2 M 7 compounds. With M = Co and R a light lanthanide, the compounds are ferromagnets; with R yttrium, thorium, or a heavy lanthanide, they are ferrimagnets. The preparation of the compounds in an arc-melting apparatus under an Ar-atmosphere followed by annealing is described

  16. Xenobiotic organic compounds in wastewater

    DEFF Research Database (Denmark)

    Eriksson, Eva; Baun, Anders; Henze, Mogens

    2002-01-01

    hundred of XOCs, among them mainly originating from hygiene products: chlorophenols, detergents and phthalates. Several compounds not deriving from hygiene products were also identified e.g. flame-retardants and drugs. A environmental hazard identification showed that a large number of compounds with high...

  17. Devices for collecting chemical compounds

    Science.gov (United States)

    Scott, Jill R; Groenewold, Gary S

    2013-12-24

    A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from a fixed surface so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agents, chemical attribution signatures and toxic industrial chemicals.

  18. Highly sensitive analysis of polycyclic aromatic hydrocarbons in environmental water with porous cellulose/zeolitic imidazolate framework-8 composite microspheres as a novel adsorbent coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Liang, Xiaotong; Liu, Shengquan; Zhu, Rong; Xiao, Lixia; Yao, Shouzhuo

    2016-07-01

    In this work, novel cellulose/zeolitic imidazolate frameworks-8 composite microspheres have been successfully fabricated and utilized as sorbent for environmental polycyclic aromatic hydrocarbons efficient extraction and sensitive analysis. The composite microspheres were synthesized through the in situ hydrothermal growth of zeolitic imidazolate frameworks-8 on cellulose matrix, and exhibited favorable hierarchical structure with chemical composition as assumed through scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction patterns, and Brunauer-Emmett-Teller surface areas characterization. A robust and highly efficient method was then successfully developed with as-prepared composite microspheres as novel solid-phase extraction sorbent with optimum extraction conditions, such as sorbent amount, sample volume, extraction time, desorption conditions, volume of organic modifier, and ionic strength. The method exhibited high sensitivity with low limit of detection down to 0.1-1.0 ng/L and satisfactory linearity with correlation coefficients ranging from 0.9988 to 0.9999, as well as good recoveries of 66.7-121.2% with relative standard deviations less than 10% for environmental polycyclic aromatic hydrocarbons analysis. Thus, our method was convenient and efficient for polycyclic aromatic hydrocarbons extraction and detection, potential for future environmental water samples analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Four coordination polymers based on 5-tert-butyl isophthalic acid and rigid bis(imidazol-1yl)benzene linkers: Synthesis, luminescence detection of acetone and optical properties

    Science.gov (United States)

    Arıcı, Mürsel; Zafer Yeşilel, Okan; Büyükgüngör, Orhan

    2017-05-01

    Four coordination polymers including, [Co(μ-Htbip)2(μ-dib)]n (1), [Co(μ-tbip)(μ-dmib)0.5]n (2), [Zn2(μ-tbip)(μ3-tbip)(μ-dmib)1.5]n (3) and [Cd(μ3-tbip)(μ-dib)0.5 (H2O)]n (4) (tbip: 5-tert-butylisophthalate, dib: 1,4-bis(imidazol-1yl)benzene, dmib: 1,4-bis(imidazol-1yl)-2,5-dimethylbenzene), were hydrothermally synthesized and characterized by elemental analysis, IR spectra, single crystal and powder X-ray diffraction and thermal analysis (TG/DTA). The structural diversity is observed depending on ligands and coordination number of metal centers in the synthesized complexes. The tbip ligand displayed five different coordination modes in its complexes. In 1 and 2, complex 1 is 3D framework with the dia topology while complex 2 has 2D structure with the sql topology depending on coordination geometries of Co ions. Complex 3 is 3D framework with the fsh 4,6-conn topology and complex 4 has 2D 4-connected sql topology. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in methanol could be used as a fluorescent sensor for the detection of acetone. Moreover, thermal and optical properties of the complexes were also studied.

  20. Crystal structure of 4-tert-butyl-2-{2-[N-(3,3-dimethyl-2-oxobutyl-N-isopropylcarbamoyl]phenyl}-1-isopropyl-1H-imidazol-3-ium perchlorate

    Directory of Open Access Journals (Sweden)

    Olga V. Hordiyenko

    2015-02-01

    Full Text Available In the title salt, C26H40N3O2+·ClO4−, the positive charge of the organic cation is delocalized between the two N atoms of the imidazole ring. The C...;N bond distances are 1.338 (2 and 1.327 (3 Å. The substituents on the benzene ring are rotated almost orthogonal with respect to this ring due to the presence of the bulky isopropyl substituents. The dihedral angle between the benzene and imidazole rings is 75.15 (12°. Three of the O atoms of the anion are disordered over two sets of sites due to rotation around one of the O—Cl bonds. The ratio of the refined occupancies is 0.591 (14:0.409 (14. In the crystal, the cation and perchlorate anion are bound by an N—H...O hydrogen bond. In addition, the cation–anion pairs are linked into layers parallel to (001 by multiple weak C—H...O hydrogen bonds.

  1. IMIDAZOLE-BASED IONIC LIQUIDS FOR USE IN POLYMER ELECTROLYTE MEMBRANE FUEL CELLS: EFFECT OF ELECTRON-WITHDRAWING AND ELECTRON-DONATING SUBSTITUENTS

    Energy Technology Data Exchange (ETDEWEB)

    Chang, E.; Fu, Y.; Kerr, J.

    2009-01-01

    Current polymer electrolyte membrane fuel cells (PEMFCs) require humidifi cation for acceptable proton conductivity. Development of a novel polymer that is conductive without a water-based proton carrier is desirable for use in automobiles. Imidazole (Im) is a possible replacement for water as a proton solvent; Im can be tethered to the polymer structure by means of covalent bonds, thereby providing a solid state proton conducting membrane where the solvating groups do not leach out of the fuel cell. These covalent bonds can alter the electron availability of the Im molecule. This study investigates the effects of electron-withdrawing and electron-donating substituents on the conductivity of Im complexed with methanesulfonic acid (MSA) in the form of ionic liquids. Due to the changes in the electronegativity of nitrogen, it is expected that 2-phenylimidazole (2-PhIm, electron-withdrawing) will exhibit increased conductivity compared to Im, while 2-methylimidazole (2-MeIm, electron-donating) will exhibit decreased conductivity. Three sets of ionic liquids were prepared at defi ned molar ratios: Im-MSA, 2-PhIm-MSA, and 2-MeIm- MSA. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and 1H-NMR were used to characterize each complex. Impedance analysis was used to determine the conductivity of each complex. Both the 2-PhIm-MSA and 2-MeIm-MSA ionic liquids were found to be less conductive than the Im-MSA complex at base-rich compositions, but more conductive at acid-rich compositions. 1H-NMR data shows a downfi eld shift of the proton on nitrogen in 2-PhIm compared to Im, suggesting that other factors may diminish the electronic effects of the electron withdrawing group at base-rich compositions. Further studies examining these effects may well result in increased conductivity for Im-based complexes. Understanding the conductive properties of Im-derivatives due to electronic effects will help facilitate the development of a new electrolyte

  2. Multi-angle compound imaging

    DEFF Research Database (Denmark)

    Jespersen, Søren Kragh; Wilhjelm, Jens Erik; Sillesen, Henrik

    1998-01-01

    This paper reports on a scanning technique, denoted multi-angle compound imaging (MACI), using spatial compounding. The MACI method also contains elements of frequency compounding, as the transmit frequency is lowered for the highest beam angles in order to reduce grating lobes. Compared to conve......This paper reports on a scanning technique, denoted multi-angle compound imaging (MACI), using spatial compounding. The MACI method also contains elements of frequency compounding, as the transmit frequency is lowered for the highest beam angles in order to reduce grating lobes. Compared...... to conventional B-mode imaging MACI offers better defined tissue boundaries and lower variance of the speckle pattern, resulting in an image with reduced random variations. Design and implementation of a compound imaging system is described, images of rubber tubes and porcine aorta are shown and effects...... on visualization are discussed. The speckle reduction is analyzed numerically and the results are found to be in excellent agreement with existing theory. An investigation of detectability of low-contrast lesions shows significant improvements compared to conventional imaging. Finally, possibilities for improving...

  3. EPR investigations on technetium compounds

    International Nuclear Information System (INIS)

    Abram, U.; Munze, R.; Kirmse, R.; Stach, J.

    1986-01-01

    Stimulated by the widespread use of the isotope /sup 99m/Tc in the field of nuclear medicine, there has been a substantial growth of interest in the chemistry of this man-made element. A particular need emerges for analytical methods allowing solution investigations of coordination compounds of technetium with low substance use. Considering these facts, Electron Paramagnetic Resonance Spectroscopy (EPR) appears to be a very suitable method because only very small amounts of the compounds are needed (lower than 1 mg). The resulting spectra give information regarding the valence state, symmetry and bonding properties of the compounds under study

  4. Industrial uses of boron compounds

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, H [Eurotungstene; Thevenot, F

    1978-06-01

    A review includes a section on the use in the chemical industry of some transition-metal borides as heterogeneous catalysts in the hydrogenation and dehydrogenation of organic compounds and in fuel cells.

  5. The demise of compound houses

    DEFF Research Database (Denmark)

    Andreasen, Jørgen; Eskemose Andersen, Jørgen

    2006-01-01

    of compound housing and analyses the advantages and disadvantages of life within such housing in Kumasi. Issues of privacy, image and communal life are usually cited by occupants dissatiesfied with life in compound houses, and the difficulty of extending them without spoiling the open spaces...... perceptions of what is acceptable urban life to the growing cohort of young African households. In addition, there is a need to explore innovative forms of tenure in order to secure the majority of Kumasi's population access to land for housing.......The compound house has long provided the accomodation required by low income households in West African cities. In Kumasi, Ghana, evidence suggests that no new compounds are being built. Instead, the city is being ringed by relatively affluent villa-style development while neighbourhoods dominated...

  6. Detection of chlorinated aromatic compounds

    Science.gov (United States)

    Ekechukwu, A.A.

    1996-02-06

    A method for making a composition for measuring the concentration of chlorinated aromatic compounds in aqueous fluids, and an optical probe for use with the method are disclosed. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis. 5 figs.

  7. Third Symposium on Macrocyclic Compounds

    International Nuclear Information System (INIS)

    1979-01-01

    At the Third Symposium on Macrocyclic Compounds there were sessions on facilitated transport, analytical applications, organic synthesis and reactions, phase transfer catalysis, and metal complexation. Abstracts of the individual presentations are included

  8. Quality control of labelled compounds

    International Nuclear Information System (INIS)

    Matucha, M.

    1979-01-01

    Some advantages and disadvantages of methods used for quality control of organic labelled compounds (1 31 I, 14 C) are shortly discussed. The methods used are electrophoresis, ultraviolet and infrared spectrometry, radiogas and thin-layer chromatography. (author)

  9. Compound cueing in free recall

    Science.gov (United States)

    Lohnas, Lynn J.; Kahana, Michael J.

    2013-01-01

    According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cueing in free recall. Specifically, the temporal contiguity effect should be greater when the two most recently recalled items were studied in contiguous list positions. A meta-analysis of published free recall experiments demonstrates evidence for compound cueing in both conditional response probabilities and inter-response times. To help rule out a rehearsal-based account of these compound cueing effects, we conducted an experiment with immediate, delayed and continual-distractor free recall conditions. Consistent with retrieved context theory but not with a rehearsal-based account, compound cueing was present in all conditions, and was not significantly influenced by the presence of interitem distractors. PMID:23957364

  10. Compound cuing in free recall.

    Science.gov (United States)

    Lohnas, Lynn J; Kahana, Michael J

    2014-01-01

    According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cuing in free recall. Specifically, the temporal contiguity effect should be greater when the 2 most recently recalled items were studied in contiguous list positions. A meta-analysis of published free recall experiments demonstrates evidence for compound cuing in both conditional response probabilities and interresponse times. To help rule out a rehearsal-based account of these compound cuing effects, we conducted an experiment with immediate, delayed, and continual-distractor free recall conditions. Consistent with retrieved context theory but not with a rehearsal-based account, compound cuing was present in all conditions, and was not significantly influenced by the presence of interitem distractors.

  11. Crystallographic properties of fertilizer compounds

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.

    1991-02-01

    This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA's fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

  12. Polishing compound for plastic surfaces

    Science.gov (United States)

    Stowell, M.S.

    1991-01-01

    This invention is comprised of a polishing compound for plastic materials. The compound includes approximately by approximately by weight 25 to 80 parts at least one petroleum distillate lubricant, 1 to 12 parts mineral spirits, 50 to 155 parts abrasive paste, and 15 to 60 parts water. Preferably, the compound includes approximately 37 to 42 parts at least one petroleum distillate lubricant, up to 8 parts mineral spirits, 95 to 110 parts abrasive paste, and 50 to 55 parts water. The proportions of the ingredients are varied in accordance with the particular application. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC), and similar plastic materials whenever a smooth, clear polished surface is desired.

  13. Phenolic Compounds in Brassica Vegetables

    Directory of Open Access Journals (Sweden)

    Pablo Velasco

    2010-12-01

    Full Text Available Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom. Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. Phenolic compounds have received considerable attention for being potentially protective factors against cancer and heart diseases, in part because of their potent antioxidative properties and their ubiquity in a wide range of commonly consumed foods of plant origin. The Brassicaceae family includes a wide range of horticultural crops, some of them with economic significance and extensively used in the diet throughout the world. The phenolic composition of Brassica vegetables has been recently investigated and, nowadays, the profile of different Brassica species is well established. Here, we review the significance of phenolic compounds as a source of beneficial compounds for human health and the influence of environmental conditions and processing mechanisms on the phenolic composition of Brassica vegetables.

  14. Fourth symposium on macrocyclic compounds

    International Nuclear Information System (INIS)

    Christensen, J.J.; Izatt, R.M.

    1980-01-01

    Both theoretical and experimental aspects of the properties and behavior of synthetic and naturally occurring macrocyclic compounds are covered in this symposium. This document contains abstracts of the papers

  15. Radiation curable hydantoin diacrylate compounds

    International Nuclear Information System (INIS)

    Seltzer, R.; DiPrima, J.F.

    1979-01-01

    The diacrylate compounds are liquid at room temperature, easily processable as adhesives, casting and laminating resins and when cured possess excellent resistance to water. These compositions are easily cured exposure to ionizing radiations

  16. Inorganic, coordination and organometallic compounds

    International Nuclear Information System (INIS)

    Jursik, F.

    1978-01-01

    Separation of cations and anions of inorganic, coordination and metalloorganic compounds by the method of liquid column chromatography is considered. Common scheme of multicomponent cation mixture is suggesteed. Separation conditions, adsrbents, eluents, pH value solution concenstration, elution rate are also suggested. Separation of rare earth elements Cs, Be, Cd, Te, Th, U, Mo, Re, V, Ru, Zr, In compounds is considered as an example of liquid column chromatography application. Data on column chromatography application are summarized in a table

  17. Radioprotective properties of some heterocyclic nitrogenous compounds against spectral modifications in hemoglobin of x-irradiated mice; Proprietes radioprotectrices de certains composes heterocycliques azotes sur les modifications spectrales de l'hemoglobine de souris irradiee

    Energy Technology Data Exchange (ETDEWEB)

    Roushdy, H; Pierotti, T; Polverelli, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Imidazole and benzimidazole are known for their radioprotective action. In this work, authors have studied the radioprotective action of these compounds on visible and ultra-violet hemoglobin absorption spectra obtained from mice after in vivo X-irradiation. Results compared to those obtained with cysteamine show: 1- a possible pharmacological action of the heterocyclic nitrogenous compounds on the {alpha} and {beta} bands (540 and 580 m{mu}). 2 - a significative variation of the ratio of the optical densities (580/540) after irradiation with hemoglobin of non and radio-protected mice. However, following a real drop of absorption maxima, the twenty-fifth day after irradiation, normal optical densities of each band are found again. A physico-chemical study would be necessary to understand the hemoglobin transformation after irradiation and perhaps, its possible radioprotection. (authors) [French] Les proprietes radioprotectrices de l'imidazole et du benzimidazole etant deja connues, les auteurs ont etudie l'action de ces produits sur les spectres d'absorption de l'hemoglobine dans le visible et le proche ultra-violet apres une irradiation in vivo de souris a dose letale. L'action de ces produits comparee a celle de la cysteamine utilisee dans les memes conditions a permis de constater: 1- l'action pharmacologique probable des heterocycles azotes sur les bandes {alpha} et {beta} situees a 540 et 580 m{mu}; 2 - qu'avec et sans radioprotecteurs, les modifications spectrales se traduisaient par des variations du rapport d'intensite d'absorption existant entre les bandes a 540 et 580 m{mu}. Toutefois, apres une chute des maxima d'absorption, ceux-ci retournent aux valeurs normales le vingt-cinquieme jour apres irradiation. Une etude physicochimique complementaire de l'hemoglobine permettrait de definir la nature exacte du changement apres irradiation et peut-etre son eventuelle radioprotection. (auteurs)

  18. Compound Odontoma in young girl

    Directory of Open Access Journals (Sweden)

    Nurwahida Nurwahida

    2017-08-01

    Full Text Available Introduction. Odontomas are the most common type of odontogenic tumors and generally they are asymptomatic. These tumors are formed from enamel and dentin, and can have variable amounts of cement and pulp tissues. According to radiographic, microscopic, and clinical features, two types of odontomas are recognized: Complex and compound odontomas. Complex odontomas occur mostly in the posterior part of the mandible and compound odontomas in the anterior maxilla. Case Report. A young girl patient, 9 years old came to Department of Oral and Maxillofacial Surgery with a slow growing and asymptomatic swelling in her left posterior mandible for 5 years in his history taking. The panoramic radiograph show  a radioopacity and radiolucent lesion at the lower second molar region, with well-corticated limits. An insisional biopsi   confirmed  as compound odontoma. The surgery  performed with simple enucleation and curettage under general anaesthesia. Discussion. Compound odontomas are usually located in the anterior maxilla, over the crowns of unerupted teeth, or between the roots of erupted teeth. In this case report, Compound odontomas are found in the posterior mandible. Conclusion. Compound odontomas in the posterior mandible is a rare. The treatment of odontomas depends on the size of the lesion. The early diagnosis, the treatment of choice is conservative surgical enucleation and curettage and prognosis is excellent.

  19. Animacroxam, a Novel Dual-Mode Compound Targeting Histone Deacetylases and Cytoskeletal Integrity of Testicular Germ Cell Cancer Cells.

    Science.gov (United States)

    Steinemann, Gustav; Dittmer, Alexandra; Kuzyniak, Weronika; Hoffmann, Björn; Schrader, Mark; Schobert, Rainer; Biersack, Bernhard; Nitzsche, Bianca; Höpfner, Michael

    2017-11-01

    Novel approaches for the medical treatment of advanced solid tumors, including testicular germ cell tumors (TGCT), are desperately needed. Especially, TGCT patients not responding to cisplatin-based therapy need therapeutic alternatives, as there is no effective medical treatment available for this particular subgroup. Here, we studied the suitability of the novel dual-mode compound animacroxam for TGCT treatment. Animacroxam consists of an HDAC-inhibitory hydroxamate moiety coupled to a 4,5-diarylimidazole with inherent cytoskeleton disrupting potency. Animacroxam revealed pronounced antiproliferative, cell-cycle arresting, and apoptosis-inducing effects in TGCT cell lines with different cisplatin sensitivities. The IC 50 values of animacroxam ranged from 0.22 to 0.42 μmol/L and were not correlated to the cisplatin sensitivity of the tumor cells. No unspecific cytotoxicity of animacroxam was observed in either cisplatin-sensitive or resistant TGCT cells, even at doses as high as 10 μmol/L. Furthermore, animacroxam induced the formation of actin stress fibers in cancer cells, thereby confirming the cytoskeleton-disrupting and antimigratory properties of its imidazole moiety. When compared with the clinically established HDAC inhibitor vorinostat, the novel dual-mode compound animacroxam exhibited superior antitumoral efficacy in vitro Animacroxam also reduced the tumor size of TGCT tumors in vivo , as evidenced by performing xenograft experiments on tumor bearing chorioallantoic membranes of fertilizes chicken eggs (CAM assay). The in vivo experiments also revealed a very good tolerability of the compound, and hence, animacroxam may be a promising candidate for innovative treatment of TGCT in general and the more so for platinum-insensitive or refractory TGCT. Mol Cancer Ther; 16(11); 2364-74. ©2017 AACR . ©2017 American Association for Cancer Research.

  20. Syntheses, structures, and properties of imidazolate-bridged Cu(II)-Cu(II) and Cu(II)-Zn(II) dinuclear complexes of a single macrocyclic ligand with two hydroxyethyl pendants.

    Science.gov (United States)

    Li, Dongfeng; Li, Shuan; Yang, Dexi; Yu, Jiuhong; Huang, Jin; Li, Yizhi; Tang, Wenxia

    2003-09-22

    The imidazolate-bridged homodinuclear Cu(II)-Cu(II) complex, [(CuimCu)L]ClO(4).0.5H(2)O (1), and heterodinuclear Cu(II)-Zn(II) complex, [(CuimZnL(-)(2H))(CuimZnL(-)(H))](ClO(4))(3) (2), of a single macrocyclic ligand with two hydroxyethyl pendants, L (L = 3,6,9,16,19,22-hexaaza-6,19-bis(2-hydroxyethyl)tricyclo[22,2,2,2(11,14)]triaconta-1,11,13,24,27,29-hexaene), have been synthesized as possible models for copper-zinc superoxide dismutase (Cu(2),Zn(2)-SOD). Their crystal structures analyzed by X-ray diffraction methods have shown that the structures of the two complexes are markedly different. Complex 1 crystallizes in the orthorhombic system, containing an imidazolate-bridged dicopper(II) [Cu-im-Cu](3+) core, in which the two copper(II) ions are pentacoordinated by virtue of an N4O environment with a Cu.Cu distance of 5.999(2) A, adopting the geometry of distorted trigonal bipyramid and tetragonal pyramid, respectively. Complex 2 crystallizes in the triclinic system, containing two similar Cu-im-Zn cores in the asymmetric unit, in which both the Cu(II) and Zn(II) ions are pentacoordinated in a distorted trigonal bipyramid geometry, with the Cu.Zn distance of 5.950(1)/5.939(1) A, respectively. Interestingly, the macrocyclic ligand with two arms possesses a chairlike (anti) conformation in complex 1, but a boatlike (syn) conformation in complex 2. Magnetic measurements and ESR spectroscopy of complex 1 have revealed the presence of an antiferromagnetic exchange interaction between the two Cu(II) ions. The ESR spectrum of the Cu(II)-Zn(II) heterodinuclear complex 2 displayed a typical signal for mononuclear trigonal bipyramidal Cu(II) complexes. From pH-dependent ESR and electronic spectroscopic studies, the imidazolate bridges in the two complexes have been found to be stable over broad pH ranges. The cyclic voltammograms of the two complexes have been investigated. Both of the two complexes can catalyze the dismutation of superoxide and show rather high activity.

  1. Four coordination polymers based on 5-tert-butyl isophthalic acid and rigid bis(imidazol-1yl)benzene linkers: Synthesis, luminescence detection of acetone and optical properties

    International Nuclear Information System (INIS)

    Arıcı, Mürsel; Zafer Yeşilel, Okan; Büyükgüngör, Orhan

    2017-01-01

    Four coordination polymers including, [Co(µ-Htbip) 2 (µ-dib)] n (1), [Co(µ-tbip)(µ-dmib) 0.5 ] n (2), [Zn 2 (µ-tbip)(µ 3 -tbip)(µ-dmib) 1.5 ] n (3) and [Cd(µ 3 -tbip)(µ-dib) 0.5 (H 2 O)] n (4) (tbip: 5-tert-butylisophthalate, dib: 1,4-bis(imidazol-1yl)benzene, dmib: 1,4-bis(imidazol-1yl)-2,5-dimethylbenzene), were hydrothermally synthesized and characterized by elemental analysis, IR spectra, single crystal and powder X-ray diffraction and thermal analysis (TG/DTA). The structural diversity is observed depending on ligands and coordination number of metal centers in the synthesized complexes. The tbip ligand displayed five different coordination modes in its complexes. In 1 and 2, complex 1 is 3D framework with the dia topology while complex 2 has 2D structure with the sql topology depending on coordination geometries of Co ions. Complex 3 is 3D framework with the fsh 4,6-conn topology and complex 4 has 2D 4-connected sql topology. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in methanol could be used as a fluorescent sensor for the detection of acetone. Moreover, thermal and optical properties of the complexes were also studied. - Graphical abstract: Four coordination polymers were hydrothermally synthesized and characterized by various techniques. The complexes showed the structural diversity depending on ligands and coordination number of metal centers. The tbip ligand displayed four different coordination modes in its complexes. In 1 and 2, complexes 1 and 2 are 3D and 2D structures with the dia and sql topologies depending on coordination geometries of Co ions, respectively. Complexes 3 and 4 are 3D and 2D structures with the fsh 4,6-conn and sql topology, respectively. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in methanol could be used as a fluorescent sensor for the

  2. Four coordination polymers based on 5-tert-butyl isophthalic acid and rigid bis(imidazol-1yl)benzene linkers: Synthesis, luminescence detection of acetone and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Arıcı, Mürsel, E-mail: marici@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Zafer Yeşilel, Okan [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Büyükgüngör, Orhan [Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, 55139 Samsun (Turkey)

    2017-05-15

    Four coordination polymers including, [Co(µ-Htbip){sub 2}(µ-dib)]{sub n} (1), [Co(µ-tbip)(µ-dmib){sub 0.5}]{sub n} (2), [Zn{sub 2}(µ-tbip)(µ{sub 3}-tbip)(µ-dmib){sub 1.5}]{sub n} (3) and [Cd(µ{sub 3}-tbip)(µ-dib){sub 0.5} (H{sub 2}O)]{sub n} (4) (tbip: 5-tert-butylisophthalate, dib: 1,4-bis(imidazol-1yl)benzene, dmib: 1,4-bis(imidazol-1yl)-2,5-dimethylbenzene), were hydrothermally synthesized and characterized by elemental analysis, IR spectra, single crystal and powder X-ray diffraction and thermal analysis (TG/DTA). The structural diversity is observed depending on ligands and coordination number of metal centers in the synthesized complexes. The tbip ligand displayed five different coordination modes in its complexes. In 1 and 2, complex 1 is 3D framework with the dia topology while complex 2 has 2D structure with the sql topology depending on coordination geometries of Co ions. Complex 3 is 3D framework with the fsh 4,6-conn topology and complex 4 has 2D 4-connected sql topology. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in methanol could be used as a fluorescent sensor for the detection of acetone. Moreover, thermal and optical properties of the complexes were also studied. - Graphical abstract: Four coordination polymers were hydrothermally synthesized and characterized by various techniques. The complexes showed the structural diversity depending on ligands and coordination number of metal centers. The tbip ligand displayed four different coordination modes in its complexes. In 1 and 2, complexes 1 and 2 are 3D and 2D structures with the dia and sql topologies depending on coordination geometries of Co ions, respectively. Complexes 3 and 4 are 3D and 2D structures with the fsh 4,6-conn and sql topology, respectively. Photoluminescent properties of complex 3 dispersed in various organic solvents were investigated and the results showed that 3 dispersed in

  3. Diazo compounds in the chemistry of fullerenes

    International Nuclear Information System (INIS)

    Tuktarov, Airat R; Dzhemilev, Usein M

    2010-01-01

    Experimental and theoretical data on the reactions of different diazo compounds (diazomethane, its derivatives, cyclic diazo compounds and diazocarbonyl compounds) with fullerenes are summarized. The structures and stereochemistry of cycloadducts formed in these reactions are considered.

  4. Diazo compounds in the chemistry of fullerenes

    Science.gov (United States)

    Tuktarov, Airat R.; Dzhemilev, Usein M.

    2010-09-01

    Experimental and theoretical data on the reactions of different diazo compounds (diazomethane, its derivatives, cyclic diazo compounds and diazocarbonyl compounds) with fullerenes are summarized. The structures and stereochemistry of cycloadducts formed in these reactions are considered.

  5. Diazo compounds in the chemistry of fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Tuktarov, Airat R; Dzhemilev, Usein M [Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, Ufa (Russian Federation)

    2010-09-14

    Experimental and theoretical data on the reactions of different diazo compounds (diazomethane, its derivatives, cyclic diazo compounds and diazocarbonyl compounds) with fullerenes are summarized. The structures and stereochemistry of cycloadducts formed in these reactions are considered.

  6. Method for purifying bidentate organophosphorus compounds

    International Nuclear Information System (INIS)

    Schulz, W.W.

    1977-01-01

    Bidentate organophosphorus compounds useful for extracting actinide elements from acidic nuclear waste solutions are purified of undesirable acidic impurities by contacting the compounds with ethylene glycol which preferentially extracts the impurities found in technical grade bidentate compounds

  7. Extraterrestrial Organic Compounds in Meteorites

    Science.gov (United States)

    Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

    2003-01-01

    Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

  8. Vanadium Compounds as PTP Inhibitors

    Directory of Open Access Journals (Sweden)

    Elsa Irving

    2017-12-01

    Full Text Available Phosphotyrosine signaling is regulated by the opposing actions of protein tyrosine kinases (PTKs and protein tyrosine phosphatases (PTPs. Here we discuss the potential of vanadium derivatives as PTP enzyme inhibitors and metallotherapeutics. We describe how vanadate in the V oxidized state is thought to inhibit PTPs, thus acting as a pan-inhibitor of this enzyme superfamily. We discuss recent developments in the biological and biochemical actions of more complex vanadium derivatives, including decavanadate and in particular the growing number of oxidovanadium compounds with organic ligands. Pre-clinical studies involving these compounds are discussed in the anti-diabetic and anti-cancer contexts. Although in many cases PTP inhibition has been implicated, it is also clear that many such compounds have further biochemical effects in cells. There also remain concerns surrounding off-target toxicities and long-term use of vanadium compounds in vivo in humans, hindering their progress through clinical trials. Despite these current misgivings, interest in these chemicals continues and many believe they could still have therapeutic potential. If so, we argue that this field would benefit from greater focus on improving the delivery and tissue targeting of vanadium compounds in order to minimize off-target toxicities. This may then harness their full therapeutic potential.

  9. PREPARATION AND PROPERTIES OF THREE NEUTRAL COPPER (I COMPLEXES BASED ON BIS[2-(DIPHENYLPHOSPHINOPHENYL]ETHER PHENYL] ETHER AND SUBSTITUTED IMIDAZOLE-2,9-DIMETHYL-1,10-PHENANTHROLINE

    Directory of Open Access Journals (Sweden)

    Xin Fang Liu

    2017-10-01

    Full Text Available With deprotonated 2-(4-nitro phenyl-, 2-(4-methyl phenyl-, and 2-(4-methoxy phenyl imidazoled-2,9-dimethyl-1,10-phenanthroline (NPIP, MPIP and MoPIP as nitrogen ligands, as well as bis[2-(diphenylphosphino phenyl]ether (DPEphos as phosphorus ligand, three Cu(I neutral complex has been synthesized and characterized by infrared spectroscopy (IR, elemental analysis and 1H NMR methods. TG-DTA shows that the complex begins to decompose when the temperature reached about 220 oC, indicating their high thermo-stability. The emission spectrum shows that the complexes exhibit yellow emission with a peak emission wavelength of 576, 585 and 596 nm under excitation of 287 nm in powder state.

  10. Practical synthesis of 1-(2-Nitro-1H-imidazol-1-yl)-3-(tosyloxy)propan-2-yl acetate for the radiosynthesis of [{sup 18}F]-FMISO

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Young Do; Lim, Seok Tae; Sohn, Myung Hee; Kim, Hee Kwon [Dept. of Nuclear Medicine, Molecular Imaging and Therapeutic Medicine Rese arch Center, CyclotronResearch Center, Biomedica l Research Institute, Chonbuk National University Medical School and Hospital,Jeonju (Korea, Republic of); Seol, Eun Taek; Lee, Seung Jae [Dept. of Chemistry and Research Institute of Physics and Chemistry, Chonbuk National University,Jeonju (Korea, Republic of); Jung, Yong Ju [Dept. of Chemistry Chemical Engineering, Korea University of Technology and Education (KOREATECH),Cheonan (Korea, Republic of)

    2015-02-15

    Hypoxia is related with many tumors due to a decreased oxygen condition. Novel synthesis for 1-(2-nitro-1H-imidazol-1-yl)-3-(tosyloxy)propan-2-yl acetate for the radiosynthesis of the [{sup 18}F]-Flouromisonidazole ([{sup 18}F]-FMISO), a hypoxia imaging marker used in positron emission tomography, from the readily available starting material is described. In this approach, one-pot two-step syntheses were used for the preparation of the [{sup 18}F]-FMISO precursors that contain acetyl group. The mild reaction conditions and easy treatments are attractive features in this synthesis. This new synthetic route provides alternative choices for the preparation of hypoxia imaging marker.

  11. Synthesis, Characterization and Biological Evaluation of Mononuclear Dichloro-bis[2-(2-chloro-6,7-substituted Quinolin-3-yl-1H-benzo[d]imidazole]Co(II Complexes

    Directory of Open Access Journals (Sweden)

    Minaxi Samatbhai Maru

    2015-06-01

    Full Text Available A series of Co(II complexes 3¢a-g of 2-(2-chloro-6,7-substituted quinolin-3-yl-1H-benzo[d]imidazole ligands 3a-g were prepared and characterized by various spectroscopic and physico-chemical methods viz. FT-IR, ESI mass, 1H NMR, 13C NMR and UV-Visible spectroscopy, Thermogravimetric analysis, Magnetic susceptibility, Molar conductance and Elemental analysis. The 2-(2-chloro-6,7-substituted quinolin-3-yl-1H-benzo[d]imidazole ligands 3a-g have been synthesized by cyclocondensation of benzene-1,2-diamine with 2-chloroquinoline-3-carbaldehydes by using ceric ammonium nitrate as a catalyst in presence of hydrogen peroxide as an oxidant. The structures of all ligands were confirmed by IR, Mass, UV-Visible, 1H NMR and 13C NMR spectroscopy. All ligands 3a-g and their Co(II complexes 3¢a-g were screened for their in vitro antimicrobial activity using twofold serial dilution technique against standard MTCC strains of two Gram-positive Staphylococcus aureus and Streptococcus pyogenes, two Gram-negative Escherichia coli and Pseudomonas aeruginosa bacteria and three Candida albicans, Aspergillus niger and Aspergillus clavatus fungus in comparison with standard drugs. All ligands 3a-g and complexes 3¢a-g also evaluated for antimycobacterial activity against standard Mycobacterium tuberculosis H37Rv strain. DOI: http://dx.doi.org/10.17807/orbital.v7i2.530

  12. The structures of binary compounds

    CERN Document Server

    Hafner, J; Jensen, WB; Majewski, JA; Mathis, K; Villars, P; Vogl, P; de Boer, FR

    1990-01-01

    - Up-to-date compilation of the experimental data on the structures of binary compounds by Villars and colleagues. - Coloured structure maps which order the compounds into their respective structural domains and present for the first time the local co-ordination polyhedra for the 150 most frequently occurring structure types, pedagogically very helpful and useful in the search for new materials with a required crystal structure. - Crystal co-ordination formulas: a flexible notation for the interpretation of solid-state structures by chemist Bill Jensen. - Recent important advances in unders

  13. Catalytic applications of niobium compounds

    International Nuclear Information System (INIS)

    Wright, C.J.; England, W.A.

    1984-01-01

    This article examines the potential uses of niobium, and its compounds, as catalysts in chemical processing. The word potential is deliberately chosen because in 1978 none of the world's twenty-five major catalysts (1) contained niobium. On the other hand, catalysts containing molybdenum and vanadium, neighbors of niobium in the periodic table, realized over 80 x 10 6 of sales in that same year. At the same time many of the patents for niobium catalysts cover applications in which niobium improves the activity of, or substitutes for, molybdenum based compounds. With favorable cost differentials and improvements in understanding, niobium may be able to replace molybdenum in some its traditional uses

  14. Cytotoxic Compounds from Aloe megalacantha

    Directory of Open Access Journals (Sweden)

    Negera Abdissa

    2017-07-01

    Full Text Available Phytochemical investigation of the ethyl acetate extract of the roots of Aloe megalacantha led to the isolation of four new natural products—1,8-dimethoxynepodinol (1, aloesaponarin III (2, 10-O-methylchrysalodin (3 and methyl-26-O-feruloyl-oxyhexacosanate (4—along with ten known compounds. All purified metabolites were characterized by NMR, mass spectrometric analyses and comparison with literature data. The isolates were evaluated for their cytotoxic activity against a human cervix carcinoma cell line KB-3-1 and some of them exhibited good activity, with aloesaponarin II (IC50 = 0.98 µM being the most active compound.

  15. Antiprotozoal compounds from Asparagus africanus

    DEFF Research Database (Denmark)

    Oketch-Rabah, H A; Dossaji, S F; Christensen, S B

    1997-01-01

    Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl)-bisphenol.......Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl...

  16. Compound

    Indian Academy of Sciences (India)

    Selen Bilgea,*, Zeynel Kılıça, Zeliha Hayvalıa, Tuncer Hökelekb and Serap Safranb. aDepartment of Chemistry, Faculty of Science, Ankara University, Tandoğan, Ankara 06100, Turkey. bDepartment of Physics, Hacettepe University, Beytepe, Ankara 06800, Turkey. e-mail: sbilge@science.ankara.edu.tr. Contents: Tables.

  17. Bacterial degradation of fluorinated compounds

    NARCIS (Netherlands)

    Ferreira, Maria Isabel Martins

    2007-01-01

    Fluorine was produced for the first time by Henri Moissan in 1886, for which he received the Nobel Prize in chemistry in 1906. The unique properties of fluorine have led to the development of fluorine chemistry and numerous synthetic fluorinated compounds have been prepared and tested for different

  18. Moessbauer spectroscopy in neptunium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Tadahiro; Nakada, Masami; Masaki, Nobuyuki; Saeki, Masakatsu [Japan Atomic Energy Research Inst., Tokyo (Japan)

    1997-03-01

    Moessbauer effects are observable in seven elements of actinides from {sup 232}Th to {sup 247}Cm and Moesbauer spectra have been investigated mainly with {sup 237}Np and {sup 238}U for the reasons of availability and cost of materials. This report describes the fundamental characteristics of Moessbauer spectra of {sup 237}Np and the correlation between the isomer shift and the coordination number of Np(V) compounds. The isomer shifts of Np(V) compounds had a tendency to increase as an increase of coordination number and the isomer shifts of Np(V) compounds showed broad distribution as well as those of Np(VI) but {delta} values of the compounds with the same coordination number were distributed in a narrow range. The {delta} values of Np(VI) complexes with O{sub x} donor set suggest that the Np atom in its hydroxide (NpO{sub 2}(OH){center_dot}4H{sub 2}O)might have pentagonal bipyramidal structure and at least, pentagonal and hexagonal bipyramidal structures might coexist in its acetate and benzoate. Really, such coexistence has been demonstrated in its nitrate, (NpO{sub 2}){sub 2}(NO{sub 3}){sub 2}{center_dot}5H{sub 2}O. (M.N.)

  19. Antifouling Compounds from Marine Macroalgae.

    Science.gov (United States)

    Dahms, Hans Uwe; Dobretsov, Sergey

    2017-08-28

    Marine macroalgae produce a wide variety of biologically-active metabolites that have been developed into commercial products, such as antibiotics, immunosuppressive, anti-inflammatory, cytotoxic agents, and cosmetic products. Many marine algae remain clean over longer periods of time, suggesting their strong antifouling potential. Isolation of biogenic compounds and the determination of their structure could provide leads for the development of environmentally-friendly antifouling paints. Isolated substances with potent antifouling activity belong to fatty acids, lipopeptides, amides, alkaloids, lactones, steroids, terpenoids, and pyrroles. It is unclear as yet to what extent symbiotic microorganisms are involved in the synthesis of these compounds. Algal secondary metabolites have the potential to be produced commercially using genetic and metabolic engineering techniques. This review provides an overview of publications from 2010 to February 2017 about antifouling activity of green, brown, and red algae. Some researchers were focusing on antifouling compounds of brown macroalgae, while metabolites of green algae received less attention. Several studies tested antifouling activity against bacteria, microalgae and invertebrates, but in only a few studies was the quorum sensing inhibitory activity of marine macroalgae tested. Rarely, antifouling compounds from macroalgae were isolated and tested in an ecologically-relevant way.

  20. Students' Categorizations of Organic Compounds

    Science.gov (United States)

    Domin, Daniel S.; Al-Masum, Mohammad; Mensah, John

    2008-01-01

    Categorization is a fundamental psychological ability necessary for problem solving and many other higher-level cognitive tasks. In organic chemistry, students must establish groupings of different chemical compounds in order not only to solve problems, but also to understand course content. Classic models of categorization emphasize similarity as…