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Sample records for active monomers synthesis

  1. Surface active monomers synthesis, properties, and application

    CERN Document Server

    Borzenkov, Mykola

    2014-01-01

    This brief includes information on the background?of and development of synthesis of various types of surface active monomers. The authors explain the importance of utilization of surface active monomers for creation of surface active polymers? and the various biomedical applications of such compounds . This brief introduces techniques for the synthesis of novel types of surface active monomers, their colloidal and polymerizable properties and application for needs of medicine and biology.

  2. Correction: Stereodivergent synthesis of right- and left-handed iminoxylitol heterodimers and monomers. Study of their impact on β-glucocerebrosidase activity.

    Science.gov (United States)

    Stauffert, Fabien; Serra-Vinardell, Jenny; Gómez-Grau, Marta; Michelakakis, Helen; Mavridou, Irene; Grinberg, Daniel; Vilageliu, Lluïsa; Casas, Josefina; Bodlenner, Anne; Delgado, Antonio; Compain, Philippe

    2017-09-26

    Correction for 'Stereodivergent synthesis of right- and left-handed iminoxylitol heterodimers and monomers. Study of their impact on β-glucocerebrosidase activity' by Fabien Stauffert et al., Org. Biomol. Chem., 2017, 15, 3681-3705.

  3. Synthesis and Polymerizability of Atom-Bridged Bicyclic Monomers

    Directory of Open Access Journals (Sweden)

    Henry K. Hall

    2012-12-01

    Full Text Available ¨The synthesis and polymerizability of atom-bridged bicyclic monomers was surveyed. The monomers included lactams, ureas, urethanes, lactones, carbonates, ethers, acetals, orthoesters, and amines. Despite widely-varying structures, they almost all polymerized to give polymers with monocyclic rings in the chain. The polymerizations are grouped by mechanism: uncoordinated anionic, coordinated anionic, and cationic.

  4. Influence of vinyl chloride monomer and vinyl chloride monomer derivatives on hepatic DNA synthesis

    International Nuclear Information System (INIS)

    Brenner, E.A.

    1982-01-01

    Vinyl chloride monomer (VCM) is used extensively in the chemical industry, mainly in the production of polyvinyl chloride. It has recently been found to cause hepatic angiosarcoma. As VCM has also been shown to be mutagenic after metabolic activation the effect of VCM on DNA synthesis was investigated. [ 3 H]Thymidine incorporation into DNA was used to measure the rate of DNA synthesis in regenerating rat liver. A possible direct toxic effect of VCM or its metabolites on liver cell metabolism was examined by two unrelated techniques, viz. the measurement of adenine nucleotide concentrations in regenerating livers and the influence on transmembrane potentials in hepatocytes. The distribution of radioactivity in subcellular fractions following [ 14 C]VCM administration suggested microsomal conversion of VCM to an active form which was selectively retained in the nuclear fraction. Measurement of the activities of thymidine kinase and DNA polymerase in regenerating liver indicated that the induction of these enzymes which normally occurs after partial hepatectomy was not prevented by VCM treatment. Three techniques were used to test the hypothesis that the retardation in DNA synthesis was due to DNA damage: the prophage lambda induction test for DNA damage, autoradiographic detection of unscheduled thymidine incorporation into DNA, and detection of DNA strand breaks in alkaline sucrose gradients. All three provided evidence of DNA damage and led to the development of a novel technique to confirm these findings. This involved centrifugation in neutral sucrose gradients on intact double-stranded DNA contained in hepatocyte nucleoids and showed conclusively that VCM administration causes DNA strand breaks. Subsequent repair of DNA was also assessed by this technique. The site of the VCM/metabolite: DNA reaction was characterized by DNA thermal denaturation and renaturation studies

  5. An Efficient Method for the Synthesis of Peptoids with Mixed Lysine-type/Arginine-type Monomers and Evaluation of Their Anti-leishmanial Activity.

    Science.gov (United States)

    Bolt, Hannah L; Denny, Paul W; Cobb, Steven L

    2016-11-02

    This protocol describes the manual solid-phase synthesis of linear peptoids that contain two differently functionalized cationic monomers. In this procedure amino functionalized 'lysine' and guanido functionalized 'arginine' peptoid monomers can be included within the same peptoid sequence. This procedure uses on-resin (N-(1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl) or Dde protection, orthogonal conditions to the Boc protection of lysine monomers. Subsequent deprotection allows an efficient on-resin guanidinylation reaction to form the arginine residues. The procedure is compatible with the commonly used submonomer method of peptoid synthesis, allowing simple peptoids to be made using common laboratory equipment and commercially available reagents. The representative synthesis, purification and characterization of two mixed peptoids is described. The evaluation of these compounds as potential anti-infectives in screening assays against Leishmania mexicana is also described. The protozoan parasite L. mexicana is a causative agent of cutaneous leishmaniasis, a neglected tropical disease that affects up to 12 million people worldwide.

  6. Synthesis of functional polylactide : Monomer synthesis scale-up and poly(ethylene glycol) functionalization

    OpenAIRE

    Lindman, Jonas

    2016-01-01

    This master’s degree project optimized the synthesis route to a functional lactide by increasing the total yield from 25 to 33 % and reducing the number of unit operations from 17 to 10. This was done by optimizing an existing synthetic pathway to better fit larger scale manufacturing. The monomer was also successfully copolymerized with ʟ-lactide and functionalized by attaching poly(ethylene glycol) units of varying chain lengths to the polylactide chain, which gives some antifouling propert...

  7. A CO2-switchable amidine monomer: synthesis and characterization.

    Science.gov (United States)

    Liu, Hanbin; Yin, Hongyao; Feng, Yujun

    2017-01-01

    Smart system employed CO 2 gas as new trigger has been attracting enormous attention in recent years, but few monomers that are capable of switching their hydrophobicity/hydrophility upon CO 2 stimulation have been reported. A novel CO 2 responsive monomer, 4-vinylbenzyl amidine, is designed and synthesized in this work with N,N -dimethylacetamide dimethyl acetal and 4-vinylbenzyl amine that is prepared through the Gabriel reaction. In bi-phase solvent of n -hexane and water, the monomer dissolves in n -hexane first and then transforms into water upon the CO 2 treatment, indicating a hydrophobic to hydrophilic transition. This transformation is demonstrated as reversible by monitoring the conductivity variation of its wet dimethyl formamide solution during alternate bubbling/removing CO 2 . The protonation of 4-vinylbenzyl amidine upon CO 2 treatment is demonstrated by 1 H NMR which also accounts for the dissolubility change. The reversible addition-fragmentation chain-transfer polymerization of this monomer is also performed, finding the reaction only occurs in glacial acetic acid. The reason can be ascribed to the different radical structure produced in different solvent.

  8. Methods for the synthesis of deuterated vinyl pyridine monomers

    Science.gov (United States)

    Hong, Kunlun; Yang, Jun; Bonnesen, Peter V

    2014-02-25

    Methods for synthesizing deuterated vinylpyridine compounds of the Formula (1), wherein the method includes: (i) deuterating an acyl pyridine of the Formula (2) in the presence of a metal catalyst and D.sub.2O, wherein the metal catalyst is active for hydrogen exchange in water, to produce a deuterated acyl compound of Formula (3); (ii) reducing the compound of Formula (3) with a deuterated reducing agent to convert the acyl group to an alcohol group, and (iii) dehydrating the compound produced in step (ii) with a dehydrating agent to afford the vinylpyridine compound of Formula (1). The resulting deuterated vinylpyridine compounds are also described.

  9. High-flexibility combinatorial peptide synthesis with laser-based transfer of monomers in solid matrix material.

    Science.gov (United States)

    Loeffler, Felix F; Foertsch, Tobias C; Popov, Roman; Mattes, Daniela S; Schlageter, Martin; Sedlmayr, Martyna; Ridder, Barbara; Dang, Florian-Xuan; von Bojničić-Kninski, Clemens; Weber, Laura K; Fischer, Andrea; Greifenstein, Juliane; Bykovskaya, Valentina; Buliev, Ivan; Bischoff, F Ralf; Hahn, Lothar; Meier, Michael A R; Bräse, Stefan; Powell, Annie K; Balaban, Teodor Silviu; Breitling, Frank; Nesterov-Mueller, Alexander

    2016-06-14

    Laser writing is used to structure surfaces in many different ways in materials and life sciences. However, combinatorial patterning applications are still limited. Here we present a method for cost-efficient combinatorial synthesis of very-high-density peptide arrays with natural and synthetic monomers. A laser automatically transfers nanometre-thin solid material spots from different donor slides to an acceptor. Each donor bears a thin polymer film, embedding one type of monomer. Coupling occurs in a separate heating step, where the matrix becomes viscous and building blocks diffuse and couple to the acceptor surface. Furthermore, we can consecutively deposit two material layers of activation reagents and amino acids. Subsequent heat-induced mixing facilitates an in situ activation and coupling of the monomers. This allows us to incorporate building blocks with click chemistry compatibility or a large variety of commercially available non-activated, for example, posttranslationally modified building blocks into the array's peptides with >17,000 spots per cm(2).

  10. Direct Arylation Strategies in the Synthesis of π-Extended Monomers for Organic Polymeric Solar Cells

    Directory of Open Access Journals (Sweden)

    Andrea Nitti

    2016-12-01

    Full Text Available π-conjugated macromolecules for organic polymeric solar cells can be rationally engineered at the molecular level in order to tune the optical, electrochemical and solid-state morphology characteristics, and thus to address requirements for the efficient solid state device implementation. The synthetic accessibility of monomers and polymers required for the device is getting increasing attention. Direct arylation reactions for the production of the π-extended scaffolds are gaining importance, bearing clear advantages over traditional carbon-carbon forming methodologies. Although their use in the final polymerization step is already established, there is a need for improving synthetic accessibility to implement them also in the monomer synthesis. In this review, we discuss recent examples highlighting this useful strategy.

  11. Direct Arylation Strategies in the Synthesis of π-Extended Monomers for Organic Polymeric Solar Cells.

    Science.gov (United States)

    Nitti, Andrea; Po, Riccardo; Bianchi, Gabriele; Pasini, Dario

    2016-12-26

    π-conjugated macromolecules for organic polymeric solar cells can be rationally engineered at the molecular level in order to tune the optical, electrochemical and solid-state morphology characteristics, and thus to address requirements for the efficient solid state device implementation. The synthetic accessibility of monomers and polymers required for the device is getting increasing attention. Direct arylation reactions for the production of the π-extended scaffolds are gaining importance, bearing clear advantages over traditional carbon-carbon forming methodologies. Although their use in the final polymerization step is already established, there is a need for improving synthetic accessibility to implement them also in the monomer synthesis. In this review, we discuss recent examples highlighting this useful strategy.

  12. Synthesis and Characterization of Oligodeoxyribonucleotides Modified with 2'-Amino-α-l-LNA Adenine Monomers

    DEFF Research Database (Denmark)

    Andersen, Nicolai K; Anderson, Brooke A; Wengel, Jesper

    2013-01-01

    thereof. Oligonucleotides modified with these units display greatly increased affinity toward nucleic acid targets, improved binding specificity, and enhanced enzymatic stability relative to unmodified strands. Here we present the synthesis and biophysical characterization of oligodeoxyribonucleotides....... ONs modified with pyrene-functionalized 2'-amino-α-l-LNA adenine monomers X-Z display greatly increased affinity toward DNA targets (ΔTm/modification up to +14 °C). Results from absorption and fluorescence spectroscopy suggest that the duplex stabilization is a result of pyrene intercalation....... These characteristics render N2'-pyrene-functionalized 2'-amino-α-l-LNAs of considerable interest for DNA-targeting applications....

  13. Alternate fuels and chemicals from synthesis gas: Vinyl acetate monomer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Richard D. Colberg; Nick A. Collins; Edwin F. Holcombe; Gerald C. Tustin; Joseph R. Zoeller

    1999-01-01

    There has been a long-standing desire on the part of industry and the U.S. Department of Energy to replace the existing ethylene-based vinyl acetate monomer (VAM) process with an entirely synthesis gas-based process. Although there are a large number of process options for the conversion of synthesis gas to VAM, Eastman Chemical Company undertook an analytical approach, based on known chemical and economic principles, to reduce the potential candidate processes to a select group of eight processes. The critical technologies that would be required for these routes were: (1) the esterification of acetaldehyde (AcH) with ketene to generate VAM, (2) the hydrogenation of ketene to acetaldehyde, (3) the hydrogenation of acetic acid to acetaldehyde, and (4) the reductive carbonylation of methanol to acetaldehyde. This report describes the selection process for the candidate processes, the successful development of the key technologies, and the economic assessments for the preferred routes. In addition, improvements in the conversion of acetic anhydride and acetaldehyde to VAM are discussed. The conclusion from this study is that, with the technology developed in this study, VAM may be produced from synthesis gas, but the cost of production is about 15% higher than the conventional oxidative acetoxylation of ethylene, primarily due to higher capital associated with the synthesis gas-based processes.

  14. Synthesis of new antibacterial quaternary ammonium monomer for incorporation into CaP nanocomposite

    Science.gov (United States)

    Zhou, Chenchen; Weir, Michael D.; Zhang, Ke; Deng, Dongmei; Cheng, Lei; Xu, Hockin H. K.

    2013-01-01

    Objectives Composites are the principal material for tooth cavity restorations due to their esthetics and direct-filling capabilities. However, composites accumulate biofilms in vivo, and secondary caries due to biofilm acids is the main cause of restoration failure. The objectives of this study were to: (1) synthesize new antibacterial monomers; and (2) develop nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP) and antibacterial monomer. Methods Two new antibacterial monomers were synthesized: dimethylaminohexane methacrylate (DMAHM) with a carbon chain length of 6, and dimethylaminododecyl methacrylate (DMADDM) with a chain length of 12. A spray-drying technique was used to make NACP. DMADDM was incorporated into NACP nanocomposite at mass fractions of 0%, 0.75%, 1.5%, 2.25% and 3%. A flexural test was used to measure composite strength and elastic modulus. A dental plaque microcosm biofilm model with human saliva as inoculum was used to measure viability, metabolic activity, and lactic acid production of biofilms on composites. Results The new DMAHM was more potent than a previous quaternary ammonium dimethacrylate (QADM). DMADDM was much more strongly antibacterial than DMAHM. The new DMADDM-NACP nanocomposite had strength similar to that of composite control (p > 0.1). At 3% DMADDM in the composite, the metabolic activity of adherent biofilms was reduced to 5% of that on composite control. Lactic acid production by biofilms on composite containing 3% DMADDM was reduced to only 1% of that on composite control. Biofilm colony-forming unit (CFU) counts on composite with 3% DMADDM were reduced by 2-3 orders of magnitude. Significance New antibacterial monomers were synthesized, and the carbon chain length had a strong effect on antibacterial efficacy. The new DMADDM-NACP nanocomposite possessed potent anti-biofilm activity without compromising load-bearing properties, and is promising for antibacterial and remineralizing dental

  15. Synthesis of acrylic and allylic bifunctional cross-linking monomers derived from PET waste

    International Nuclear Information System (INIS)

    Cruz-Aguilar, A; Herrera-González, A M; Vázquez-García, R A; Coreño, J; Navarro-Rodríguez, D

    2013-01-01

    An acrylic and two novel allylic monomers synthesized from bis (hydroxyethyl) terephthalate, BHET, are reported. This was obtained by glycolysis of post-consumer PET with boiling ethylene glycol. The bifunctional monomer bis(2-(acryloyloxy)ethyl) terephthalate was obtained from acryloyl chloride, while the allylic monomers 2-(((allyloxi)carbonyl)oxy) ethyl (2-hydroxyethyl) terephthalate and bis(2-(((allyloxi)carbonyl)oxy)ethyl) terephthalate, from allyl chloroformate. Cross-linking was studied in bulk polymerization using two different thermal initiators. Monomers were analyzed by means of 1 H NMR and the cross-linked polymers by infrared spectroscopy. Gel content higher than 90% was obtained for the acrylic monomer. In the case of the mixture of the allylic monomers, the cross-linked polymer was 80 % using BPO initiator, being this mixture 24 times less reactive than the acrylic monomer.

  16. Nucleoside-O-Methyl-(H)-Phosphinates: Novel Monomers for the Synthesis of Methylphosphonate Oligonucleotides Using H-Phosphonate Chemistry.

    Science.gov (United States)

    Kostov, Ondřej; Páv, Ondřej; Rosenberg, Ivan

    2017-09-18

    This unit comprises the straightforward synthesis of protected 2'-deoxyribonucleoside-O-methyl-(H)-phosphinates in both 3'- and 5'-series. These compounds represent a new class of monomers compatible with the solid-phase synthesis of oligonucleotides using H-phosphonate chemistry and are suitable for the preparation of both 3'- and 5'-O-methylphosphonate oligonucleotides. The synthesis of 4-toluenesulfonyloxymethyl-(H)-phosphinic acid as a new reagent for the preparation of O-methyl-(H)-phosphinic acid derivatives is described. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  17. Synthesis of Polymerizable Cyclodextrin Derivatives for Use in Adhesion-Promoting Monomer Formulations

    Directory of Open Access Journals (Sweden)

    Bowen, Rafael L.

    2009-01-01

    Full Text Available The synthesis of the cyclodextrin derivatives reported herein was assisted by extensive literature research together with structure-property relationships derived from three-dimensional molecular modeling. These studies led to the hypothesis that many of the 21 hydroxyl groups on beta-cyclodextrin molecules could be derivatized to form a closely related family of analogous chemical compounds containing both polymerizable groups and hydrophilic ionizable ligand (substrate-binding groups, each attached via hydrolytically-stable ether-linkages. The vinylbenzylether polymerizable groups should readily homopolymerize and also copolymerize with methacrylates. This could be highly useful for dental applications because substantially all contemporary dental resins and composites are based on methacrylate monomers. Due to hydrophilic ligands and residual hydroxyl groups, these cyclodextrin derivatives should penetrate hydrated layers of dentin and enamel to interact with collagen and tooth mineral. Analyses indicated that the diverse reaction products resulting from the method of synthesis reported herein should comprise a family of copolymerizable molecules that collectively contain about 30 different combinations of vinylbenzyl and hexanoate groups on the various molecules, with up to approximately seven of such groups combined on some of the molecules. Although the hypothesis was supported, and adhesive bonding to dentin is expected to be significantly improved by the use of these polymerizable cyclodextrin derivatives, other efforts are planned for improved synthetic methods to ensure that each of the reaction-product molecules will contain at least one copolymerizable moiety. The long-term objective is to enable stronger and more durable attachments of densely cross-linked polymers to hydrated hydrophilic substrates. Capabilities for bonding of hydrolytically stable polymers to dental and perhaps other hydrous biological tissues could provide

  18. Synthesis of three different galactose-based methacrylate monomers for the production of sugar-based polymers.

    Science.gov (United States)

    Desport, Jessica S; Mantione, Daniele; Moreno, Mónica; Sardón, Haritz; Barandiaran, María J; Mecerreyes, David

    2016-09-02

    Glycopolymers, synthetic sugar-containing macromolecules, are attracting ever-increasing interest from the chemistry community. Glycidyl methacrylate (GMA) is an important building block for the synthesis of sugar based methacrylate monomers and polymers. Normally, glycidyl methacrylate shows some advantages such as reactivity against nucleophiles or milder synthetic conditions such as other reactive methacrylate monomers. However, condensation reactions of glycidyl methacrylate with for instance protected galactose monomer leads to a mixture of two products due to a strong competition between the two possible pathways: epoxide ring opening or transesterification. In this paper, we propose two alternative routes to synthesize regiospecific galactose-based methacrylate monomers using the epoxy-ring opening reaction. In the first alternative route, the protected galactose is first oxidized to the acid in order to make it more reactive against the epoxide of GMA. In the second route, the protected sugar was first treated with epichlorohydrin followed by the epoxy ring opening reaction with methacrylic acid, to create an identical analogue of the ring-opening product of GMA. These two monomers were polymerized using conventional radical polymerization and were compared to the previously known galactose-methacrylate one. The new polymers show similar thermal stability but lower glass transition temperature (Tg) with respect to the known galactose methacrylate polymer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Highly Efficient Synthesis of Allopurinol Locked Nucleic Acid Monomer by C6 Deamination of 8-Aza-7-bromo-7-deazaadenine Locked Nucleic Acid Monomer

    DEFF Research Database (Denmark)

    Kosbar, Tamer Reda El-Saeed; Sofan, M.; Abou-Zeid, L.

    2013-01-01

    An allopurinol locked nucleic acid (LNA) monomer was prepared by a novel strategy through C6 deamination of the corresponding 8-aza-7-bromo-7-deazaadenine LNA monomer with aqueous sodium hydroxide. An 8-aza-7-deazaadenine LNA monomer was also synthesized by a modification of the new synthetic...

  20. A practical method for the synthesis of peptoids containing both lysine-type and arginine-type monomers.

    Science.gov (United States)

    Bolt, H L; Cobb, S L

    2016-01-28

    Peptoids are a promising class of peptidomimetics that exhibit the key chemical and physical properties of peptides but without being hampered by susceptibility towards enzymatic degradation. Biologically active peptoids are often designed to be amphipathic in nature, consisting of hydrophobic monomers interspersed with either cationic lysine-type or arginine-type monomers. Access to amphipathic peptoids that contain both lysine-type and arginine-type monomers is highly desirable as it offers a route to further modulate the biological properties of this class of molecule. However, the lack of a suitable synthetic route to prepare mixed cationic peptoids has meant that their biological potential has remained almost largely unexplored. Herein, we present an efficient synthetic route that can be used to access novel cationic peptoids containing both lysine-type and arginine-type monomers within the same sequence.

  1. New two-step synthesis of N-(2-ethylhexyl)-2,7-diiodocarbazole as a monomer for conjugated polymers

    Czech Academy of Sciences Publication Activity Database

    Výprachtický, Drahomír; Kmínek, Ivan; Pokorná, Veronika; Kaňková, Dana; Cimrová, Věra

    2013-01-01

    Roč. 16, č. 1 (2013), s. 31-37 ISSN 1385-772X R&D Projects: GA MŠk(CZ) 1M06031; GA ČR GAP106/12/0827 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : monomer synthesis * carbazole * ring closure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.210, year: 2013

  2. New photoresponsive (meth)acrylate (co)polymers containing azobenzene pendant sidegroups with carboxylic and dimethylamino substituents .1. Synthesis and characterization of the monomers

    NARCIS (Netherlands)

    Haitjema, HJ; Buruma, R; VanEkenstein, GORA; Tan, YY; Challa, G

    1996-01-01

    New azobenzene-based (az.b.) monomers with CO2H (acid) or N(CH3)(2) (basic) substituents were synthesized. For some of these compounds new synthetic routes had to be developed, especially for the az.b. monomers with a CO2H substituent (azoacids) where their synthesis, purification and (thermal)

  3. Synthesis and characterization of novel organotin carboxylate maleimide monomers and copolymers

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available Two novel tributyltin carboxylate maleimide monomers, tributyltin(maleimidoacetate and tributyltin(4-maleimidobenzoate, were synthesized by condensation reaction of maleimidoacetic acid or 4-maleimidobenzoic acid with bis(tributyltin oxide. Copolymerization of these monomers with styrene was carried in dioxane at 70°C using asobisisobutyronitrile as free radical initiator. The structures of monomers and copolymers were confirmed by FT-IR (Fourier Transform Infrared, 1H and 13C NMR (nuclear magnetic resonance spectroscopy and elemental analysis. The copolymers were characterized by solubility and thermal analysis.

  4. Synthesis and ATRP of novel fluorinated aromatic monomer with pendant sulfonate group

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    Novel, fluorinated monomer with pendant sulfonate group was synthesized utilizing a two-step derivatization of 2,3,4,5,6-pentafluorostyrene (FS). The first step was a nucleophilic substitution of the fluorine atom in para position by hydroxyl group followed by sulfopropylation. The monomer...... was polymerized under aqueous ATRP conditions to yield phenyl-fluorinated aromatic homopolymer bearing pendant sulfonates on each repeating unit. Furthermore, this polymer was used as macroinitiator for the ATRP of poly(ethylene glycol) methacrylate. The polymers were characterized by 1H NMR, SEC and FTIR...

  5. Production of sorption-active polypropylene fibers by radiation-induced grafting of glycidyl methacrylate as a precursor monomer

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.

    2006-01-01

    The design and development of sorption-active natural and synthetic polymer fibers and textile materials is of great scientific and practical interest. The advantages of that type of polymeric adsorbents, as their highly developed specific surface, excellent ion-exchange and adsorption parameters and ease of their use especially under continuous conditions, allow them to find a great application in the chemical, biomedical, ecological and industrial fields. To obtain functional polymer materials with the desired performance, the non-active polymer surface have to be modified. Among different innovative techniques used for the introduction of graft chains, the radiation-chemical method of initiation has some economical and ecological preferences over others. It allows to introduce into inert polymeric matrix chains of a monomer already containing a desirable functional group, or to graft chains of a precursor-monomer and subsequently its chemical modification to form required functional groups. At present an epoxy-group containing monomer, glycidyl methacrylate (GMA), is successfully used as a precursor-monomer for production of polymeric adsorbents of variety applications on the base of membranes, films, fibers and fabrics. Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of GMA, with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 deg C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. Amine groups were incorporated by treatment of the GMA

  6. Synthesis and characterization of copolymers from hindered amines and vinyl monomers

    Directory of Open Access Journals (Sweden)

    Marcelo Aparecido Chinelatto

    2014-01-01

    Full Text Available New copolymers from hindered amines and vinyl monomers were synthesized by radical chain polymerization. To obtain polymeric HALS, acrylamide-(1ATP and acrylate-(4ATP monomers, derivatives from 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethyl-4-piperidinol were synthesized. The radical chain polymerization of 1ATP with styrene (Sty using 1-butanethiol (BTN resulted in a copolymer with 95 units of Sty and 15 units of 1ATP. The radical chain polymerization of 1ATP and vinyl acetate (VAc has produced only 1ATP homopolymer. In the chain polymerization of 4ATP with Sty or VAc, the hydrogen atom bonded to the nitrogen of 4ATP is labile enough to originate another radical at this site. The steric hindrance imposed by methyl groups on this bonding site hampers its reaction with other propagating species and the formation of a copolymer or network structure will be dependent on the size of the pendent group in the vinyl monomer.

  7. Antibacterial Activity of Silver Nanoparticle-Loaded Soft Contact Lens Materials: The Effect of Monomer Composition.

    Science.gov (United States)

    Shayani Rad, Maryam; Khameneh, Bahman; Sabeti, Zahra; Mohajeri, Seyed Ahmad; Fazly Bazzaz, Bibi Sedigheh

    2016-10-01

    In the present work, the effect of monomer composition on silver nanoparticles' (SNPs) binding capacity of hydrogels was investigated and their antibacterial efficacy was evaluated. Three series of poly-hydroxyethyl methacrylate (HEMA) hydrogels were prepared using methacrylic acid (MAA), methacrylamide (MAAM), and 4-vinylpyridine (4VP) as co-monomers, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. SNPs binding capacity of hydrogels was evaluated in different concentrations (2, 10, and 20 ppm). In vitro antibacterial activity of SNP-loaded hydrogels was studied against Pseudomonas aeruginosa (P. aeruginosa) isolated from patients' eyes. Then, inhibitory effect of hydrogels in biofilm formation was evaluated in the presence of Staphylococcus epidermidis (S. epidermidis) (DSMZ 3270). Our data indicated that poly(HEMA-co-MAA-co-EGDMA) had superior binding affinity for SNPs in comparison with other hydrogels. All SNP-loaded hydrogels demonstrated excellent antimicrobial effects at all times against P. aeruginosa and S. epidermidis after soaking in 10 and 20 ppm SNP suspensions. Scanning electron microscope (SEM) images revealed excellent inhibitory effect of SNPs against biofilm formation on the surface of the hydrogels. This study indicated the effect of monomer compositions in SNP loading capacity of poly(HEMA) hydrogels and antibacterial efficacy of SNP-loaded hydrogels against P. aeruginosa and S. epidermidis, but further in vivo evaluation is necessary.

  8. Synthesis of Molecularly Imprinted Polymers for Amino Acid Derivates by Using Different Functional Monomers

    Directory of Open Access Journals (Sweden)

    Sonia Scorrano

    2011-03-01

    Full Text Available Fmoc-3-nitrotyrosine (Fmoc-3-NT molecularly imprinted polymers (MIPs were synthesized to understand the influence of several functional monomers on the efficiency of the molecular imprinting process. Acidic, neutral and basic functional monomers, such as acrylic acid (AA, methacrylic acid (MAA, methacrylamide (MAM, 2-vinylpyridine (2-VP, 4-vinylpyridine (4-VP, have been used to synthesize five different polymers. In this study, the MIPs were tested in batch experiments by UV-visible spectroscopy in order to evaluate their binding properties. The MIP prepared with 2-VP exhibited the highest binding affinity for Fmoc-3NT, for which Scatchard analysis the highest association constant (2.49 × 104 M−1 was obtained. Furthermore, titration experiments of Fmoc-3NT into acetonitrile solutions of 2-VP revealed a stronger bond to the template, such that a total interaction is observed. Non-imprinted polymers as control were prepared and showed no binding affinities for Fmoc-3NT. The results are indicative of the importance of ionic bonds formed between the –OH residues of the template molecule and the pyridinyl groups of the polymer matrix. In conclusion, 2-VP assists to create a cavity which allows better access to the analytes.

  9. Synthesis and characterization of a novel resin monomer with low viscosity.

    Science.gov (United States)

    Hong, Lihua; Wang, Yu; Wang, Lin; Zhang, Hong; Na, Hui; Zhang, Zhimin

    2017-04-01

    In this study, we designed and synthesized a novel macromolecule (tetramethyl bisphenol F acrylate, TMBPF-Ac) with low viscosity, excellent mechanical properties, and good biocompatibility. It could be used as a monomer for dental resin composites, which could reduce the risk of human exposure to bisphenol A derivatives in the oral environment. In addition, the monomer could be used without diluent, thereby avoiding the negative effect of a diluent METHODS: TMBPF-Ac was synthesized by a multistep condensation reaction. Its structure was confirmed by 1 H NMR spectra. Different resin mixtures were prepared, and then a number of performance and cytotoxicity tests were performed on these specimens. 1 H NMR spectra showed that the structure of TMBPF-Ac was in accordance with the design. The viscosity of TMBPF-Ac was obviously lower than that of bisphenol-A diglycidyl methacrylate. The three kinds of resins used in this study were in line with ISO 4049:2009 and ISO 10993-5:2009. TMBPF-Ac-based resin had better physical and biological properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Synthesis, characterization and evaluation of a fluorinated resin monomer with low water sorption.

    Science.gov (United States)

    Liu, Xue; Wang, Zengyao; Zhao, Chengji; Bu, Wenhuan; Zhang, Yurong; Na, Hui

    2018-01-01

    A fluorinated acrylate monomer (4-TF-PQEA) without BPA (bisphenol-A) structure was synthesized and mixed with triethylene glycol dimethacrylate (TEGDMA) to used as dental resin system in order to achieve lower water sorption and reduce human exposure to BPA derivatives. Double bond conversion (DC) was measured using Fourier transform infrared spectroscopy (FTIR). Water sorption (WS), water solution (WL) and depth of cure (DOC) were evaluated according to ISO 4049:2009. Water contact angle (CA) was measured using contact angle analyzer. Polymerization shrinkage (PS) was evaluated according to the Archimedes' principle and ISO 17304:2013. Flexural strength (FS) and flexural modulus (FM) were measured by three-point bending test with a universal testing machine according to ISO 4049:2009. Comprehensive strength (CS) and vickers microhardness (VM) were also investigated. Thermal stability test was measure by Thermogravimetric analyzer. Cytotoxicity of three resin systems was tested through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromid) cytotoxicity method according to the ISO 10993-5:2009. Bisphenol-A glycidyl dimethacrylate (Bis-GMA)/ TEGDMA resin system was used as a control. The results show that 4-TF-PQEA/TEGDMA resin system had lower PS, lower WS and higher DC values than those of Bis-GMA/TEGDMA resin system except some mechanical properties, such as FS, FM and CS. Moreover, properties of other 4-TF-PQEA-containing resin systems were also comparable with those of Bis-GMA/TEGDMA resin system. In particular, the overall performance of resin system consisted of 4-TF-PQEA/Bis-GMA/TEGDMA is optimized when the mixture ratio is 30/40/30(wt/wt/wt). Therefore, the 4-TF-PQEA has potential to be used as resin monomer for dental resin composites to achieve lower water sorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. N-Branched acyclic nucleoside phosphonates as monomers for the synthesis of modified oligonucleotides

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Rosenbergová, Šárka; Ménová, Petra; Páv, Ondřej; Pohl, Radek; Novák, Pavel; Rosenberg, Ivan

    2015-01-01

    Roč. 13, č. 15 (2015), s. 4449-4458 ISSN 1477-0520 R&D Projects: GA ČR GAP207/11/0108; GA ČR GA13-26526S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * oligonucleotides * solid phase synthesis Subject RIV: CC - Organic Chemistry Impact factor: 3.559, year: 2015

  12. A convenient and highly efficient synthesis of one kind of peptide nucleic acid monomer

    Directory of Open Access Journals (Sweden)

    Xuemei Tang

    2012-12-01

    Full Text Available S-Thyminyl-L-cysteine methyl ester hydrochloride (compound 1, a non-classical peptide nucleic acid monomer, was synthesized through the key intermediate, N-tert- butoxycarbonyl-S-thyminyl-L-cysteine (compound 3, which afforded from the reaction of S-thyminyl-L-cysteine hydrochloride (compound 2 with di-tert-butyl dicarbonate (Boc2O. This was followed by the esterification and deprotection of compound 3 at an overall yield of 82%. The mixture of thionyl chloride and methanol was found as an efficient reagent for simultaneous deprotection of tert-butoxycarbonyl (Boc group and esterification of carboxy group of compound 3. This high-yield two-step method was also applied to other analogues of compound 1 successfully. The chemical structures of four new compounds (5a-5d were confirmed by 1H NMR and 13C NMR.DOI: http://dx.doi.org/10.4314/bcse.v26i3.10

  13. Synthesis of none Bisphenol A structure dimethacrylate monomer and characterization for dental composite applications.

    Science.gov (United States)

    Liang, Xiaoxu; Liu, Fang; He, Jingwei

    2014-08-01

    In this study, new dimethacrylate monomer SiMA without Bisphenol A (BPA) structure was synthesized and used as base resin of dental composite materials with the aim of reducing human exposure to BPA derivatives. SiMA was synthesized through ring-opening addition reaction between 1,3-bis[2(3,4-epoxycyclohex-1-yl)ethyl]tetra-methyldisiloxane and methacrylic acid, and its structure was confirmed by FT-IR and (1)H NMR spectra. SiMA was mixed with TEGDMA (50/50, wt/wt) and photoinitiation system (0.7 wt% of CQ and 0.7 wt% of DMAEMA) to form resin system. Experimental composite EC was then prepared by SiMA based resin loading with BaAlSiO2 microfillers (72wt%). Double bond conversion (DC) was determined by FT-IR analysis. Volume shrinkage (VS) was measured through variation of density before and after irradiation. Water sorption (WS) and solubility (SL) were obtained until the mass variation of polymer in distilled water kept stable. Flexural strength (FS) and modulus (FM) of the polymer were measured using a three-point bending set up. Extract of composite was used to evaluate its cytotoxic effect on humane dental pulp cells, and relative growth rate (RGR) was obtained by CCK-8 assay. Bis-GMA/TEGDMA (50/50, wt/wt) resin system and universal dental restorative materials 3M ESPE Filtek™ Z250 were used as references for neat resin system and composite material, respectively. FT-IR and (1)H NMR spectra showed that structure of SiMA was the same as designed. For the neat resin systems: DC of SiMA based resin was higher than that of Bis-GMA based resin (p0.05); FS and FM of SiMA based resin were lower than those of Bis-GMA based resin (pcomposite materials: DC of EC was higher than that of Z250 (p0.05). SiMA had potential to replace Bis-GMA as base resin of dental composite materials. However, formulation of SiMA based resin and composite should be optimized in terms of mechanical strength to satisfy the requirements of resin based dental materials for clinical application

  14. Enzyme-catalyzed synthesis of unsaturated aliphatic polyesters based on green monomers from renewable resources.

    Science.gov (United States)

    Jiang, Yi; Woortman, Albert J J; van Ekenstein, Gert O R Alberda; Loos, Katja

    2013-08-12

    Bio-based commercially available succinate, itaconate and 1,4-butanediol are enzymatically co-polymerized in solution via a two-stage method, using Candida antarctica Lipase B (CALB, in immobilized form as Novozyme® 435) as the biocatalyst. The chemical structures of the obtained products, poly(butylene succinate) (PBS) and poly(butylene succinate-co-itaconate) (PBSI), are confirmed by 1H- and 13C-NMR. The effects of the reaction conditions on the CALB-catalyzed synthesis of PBSI are fully investigated, and the optimal polymerization conditions are obtained. With the established method, PBSI with tunable compositions and satisfying reaction yields is produced. The 1H-NMR results confirm that carbon-carbon double bonds are well preserved in PBSI. The differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) results indicate that the amount of itaconate in the co-polyesters has no obvious effects on the glass-transition temperature and the thermal stability of PBS and PBSI, but has significant effects on the melting temperature.

  15. Effects of different tannin-rich extracts and rapeseed tannin monomers on methane formation and microbial protein synthesis in vitro.

    Science.gov (United States)

    Wischer, G; Boguhn, J; Steingaß, H; Schollenberger, M; Rodehutscord, M

    2013-11-01

    Tannins, polyphenolic compounds found in plants, are known to complex with proteins of feed and rumen bacteria. This group of substances has the potential to reduce methane production either with or without negative effects on digestibility and microbial yield. In the first step of this study, 10 tannin-rich extracts from chestnut, mimosa, myrabolan, quebracho, sumach, tara, valonea, oak, cocoa and grape seed, and four rapeseed tannin monomers (pelargonidin, catechin, cyanidin and sinapinic acid) were used in a series of in vitro trials using the Hohenheim gas test, with grass silage as substrate. The objective was to screen the potential of various tannin-rich extracts to reduce methane production without a significant effect on total gas production (GP). Supplementation with pelargonidin and cyanidin did not reduce methane production; however, catechin and sinapinic acid reduced methane production without altering GP. All tannin-rich extracts, except for tara extract, significantly reduced methane production by 8% to 28% without altering GP. On the basis of these results, five tannin-rich extracts were selected and further investigated in a second step using a Rusitec system. Each tannin-rich extract (1.5 g) was supplemented to grass silage (15 g). In this experiment, nutrient degradation, microbial protein synthesis and volatile fatty acid production were used as additional response criteria. Chestnut extract caused the greatest reduction in methane production followed by valonea, grape seed and sumach, whereas myrabolan extract did not reduce methane production. Whereas chestnut extract reduced acetate production by 19%, supplementation with grape seed or myrabolan extract increased acetate production. However, degradation of fibre fractions was reduced in all tannin treatments. Degradation of dry matter and organic matter was also reduced by tannin supplementation, and no differences were found between the tannin-rich extracts. CP degradation and ammonia

  16. Enzyme-Catalyzed Synthesis of Saccharide Acrylate Monomers from Nonedible Biomass

    NARCIS (Netherlands)

    Kloosterman, Wouter M. J.; Brouwer, Sander; Loos, Katja

    Various cellulase preparations were found to catalyze the transglycosidation between cotton linters and 2-hydroxyethyl acrylate. The conversion and enzyme activity were found to be optimal in reaction mixtures that contained 5 vol% of the acrylate. The structures of the products were revealed by

  17. Cyclic fatty acid monomers from dietary heated fats affect rat liver enzyme activity.

    Science.gov (United States)

    Lamboni, C; Sébédio, J L; Perkins, E G

    1998-07-01

    This study was conducted to investigate the effects of dietary cyclic fatty acid monomers (CFAM), contained in heated fat from a commercial deep-fat frying operation, on rat liver enzyme activity. A partially hydrogenated soybean oil (PHSBO) used 7 d (7-DH) for frying foodstuffs, or 0.15% methylated CFAM diets was fed to male weanling rats in comparison to a control group fed a nonheated PHSBO (NH) diet in a 10-wk experiment. All diets were isocaloric with 15% fat. Animals fed either CFAM or 7-DH diets showed increased hepatic content of cytochrome (cyt.) b5 and P450 and increased activity of (E.C. 1.6.2.4) NADPH-cyt. P450 reductase in comparison to the control rats. In addition, the activities of (E.C. 2.3.1.21) carnitine palmitoyltransferase-I and (E.C. 1.1.1.42) isocitrate dehydrogenase were significantly decreased when compared to that of rats fed the NH diet. A significantly depressed activity of (E.C. 1.1.1.49) glucose 6-phosphate dehydrogenase was also observed for these animals compared to the control rats fed NH diet. Moreover, liver and microsomal proteins were significantly increased when CFAM or 7-DH diets were fed to animals in comparison to controls while liver glycogen was decreased significantly in experimental groups of rats. The results obtained in this study indicate that the CFAM in the diet from either synthetic sources or used fats increase the activity of liver enzyme systems that detoxify them.

  18. Synthesis of a novel fused thiophene-thieno[3,2-b]thiophene-thiophene donor monomer and co-polymer for use in OPV and OFETs.

    Science.gov (United States)

    Bronstein, Hugo; Ashraf, Raja Shahid; Kim, Youngju; White, Andrew J P; Anthopoulos, Thomas; Song, Kigook; James, David; Zhang, Weimin; McCulloch, Iain

    2011-10-18

    The synthesis of a novel fused hexacyclic electron rich monomer incorporating thieno[3,2-b]thiophene is reported and characterized by single crystal X-ray diffraction. Suzuki co-polymerization with benzothiadiazole (BT) afforded a novel low band-gap polymer P4TBT with high molecular weights and good solution processability. Bulk heterojunction solar cell devices using the P4TBT and [70]PCBM gave power conversion efficiencies of 2.5%. Top-gate, bottom-contact field effect transistors (FETs) using P4TBT displayed high hole mobilities of 0.07 cm(2) · Vs(-1) demonstrating the suitability of the novel monomer and polymer for use in high performing organic electronic devices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Design, synthesis and characterization of a highly luminescent Eu-complex monomer featuring thenoyltrifluoroacetone and 5-acryloxyethoxymethyl-8-hydroxyquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Xu Cunjin [State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China); College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Li Bogeng, E-mail: bgli@zju.edu.cn [State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China); Wan Jintao; Bu Zhiyang [State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China)

    2011-08-15

    A multi-functional ligand, 5-acryloxyethoxymethyl-8-hydroxyquinoline (Hamq), was synthesized, which contained a polymerizable C=C double bond for the copolymerization with other vinyl monomers and acted as photon antenna able to transfer energy to Eu{sup 3+} ions effectively. The triplet state energy of Hamq was determined to be 22,370 cm{sup -1} via the phosphorescence spectra of Hamq and its gadolinium complex. The title complex monomer Eu(tta){sub 2}(amq) was prepared by coordination reaction of Hamq with europium isopropoxide and 2-thenoyltrifluoroacetone (Htta) in dry organic solvents under argon atmosphere and characterized by elemental analysis and IR spectrum. The photophysical properties of the complex were studied in detail with UV-vis, luminescence spectra, luminescence lifetime and quantum yield. The complex exhibited nearly monochromatic red emission at 612 nm, a remarkable luminescence quantum yield at room temperature (30.6%) upon ligand excitation and a long {sup 5}D{sub 0} lifetime (389 {mu}s), which indicated that the ligand Hamq could sensitize the luminescence of Eu(III) ion efficiently in Eu(tta){sub 2}(amq), resulting in a strong luminescence of its copolymer poly[MMA-co-Eu(TTA){sub 2}(amq)] under UV excitation. The excellent luminescence properties of the complex made it not only a promising light-conversion molecular device but also an excellent luminescent monomer. - Highlights: >iWe designed and synthesized a highly luminescent Eu-complex monomer. > Quantum yield and lifetime of the complex are 30.6% and 389 {mu}s, respectively. > Excellent luminescence of the complex made it an excellent luminescent monomer.

  20. Conversion of photosystem II dimer to monomers during photoinhibition is tightly coupled with decrease in oxygen-evolving activity in the diatom Chaetoceros gracilis.

    Science.gov (United States)

    Nagao, Ryo; Tomo, Tatsuya; Narikawa, Rei; Enami, Isao; Ikeuchi, Masahiko

    2016-12-01

    The rapid turnover of photosystem II (PSII) in diatoms is thought to be at an exceptionally high rate compared with other oxyphototrophs; however, its molecular mechanisms are largely unknown. In this study, we examined the photodamage and repair processes of PSII in the marine centric diatom Chaetoceros gracilis incubated at 30 or 300 μmol photons m -2  s -1 in the presence of a de novo protein-synthesis inhibitor. When de novo protein synthesis was blocked by chloramphenicol (Cm), oxygen-evolving activity gradually decreased even at 30 μmol photons m -2  s -1 and could not be detected at 12 h. PSII inactivation was enhanced by higher illumination. Using Cm-treated cells, the conversion of PSII dimer to monomers was observed by blue native PAGE. The rate of PSII monomerization was very similar to that of the decrease in oxygen-evolving activity under both light conditions. Immunological detection of D1 protein in the Cm-treated cells showed that the rate of D1 degradation was slower than that of the former two events, although it was more rapid than that observed in other oxyphototrophs. Thus, the three accelerated events, especially PSII monomerization, appear to cause the unusually high rate of PSII turnover in diatoms.

  1. Production of sorption-active polypropylene fibers by radiation-induce grafting of glycidyl methacrylate as a precursor monomer

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Hong Je Kim; Yong Jin Lim

    2005-01-01

    Full text: The design and development of sorption-active natural and synthetic polymer fibers and textile materials is of great scientific and practical interest. The advantages of that type of polymeric adsorbents, such as their highly developed specific surface, excellent ion-exchange parameters and ease of use especially under continuous conditions, allow them to find a great application in the chemical, biomedical, ecological and industrial fields. To obtain functional materials with the desired performance, the non-active polymer surface have to be modified. Among different innovative techniques used for the introduction of graft chains, the radiation-chemical method of initiation has some economical and ecological preferences over others. It allows to introduce into inert polymeric matrix chains of a monomer already containing a desirable functional group, or to graft chains of a precursor-monomer and subsequently its chemical modification to form required functional groups. At present an epoxy-group containing monomer, glycidyl methacrylate (GMA), is successfully used as a precursor-monomer for production of polymeric adsorbents of variety applications on the base of membranes, films, fibers and fabrics. Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of GMA, with subsequent chemical modification of the epoxy groups of poly-GMA graft chains The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 deg. C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. Amine groups were incorporated by treatment of the GMA-grafted polypropylene

  2. Controllable synthesis, crystal structure and magnetic properties of Monomer-Dimer Cocrystallized MnIII Salen-type composite material

    Science.gov (United States)

    Wu, Qiong; Wu, Wei; Wu, Yongmei; Li, Weili; Qiao, Yongfeng; Wang, Ying; Wang, Baoling

    2018-04-01

    By the reaction of manganese-Schiff-base complexes with penta-anionic Anderson heteropolyanion, a new supramolecular architecture [Mn2(Salen)2(H2O)2][Mn(Salen)(H2O)2]2Na[IMo6O24]·8H2O (1) (salen = N,N‧-ethylene-bis (salicylideneiminate) has been isolated. Compound 1 was characterized by the single-crystal X-ray diffraction, elemental, IR and thermal gravimetric analyses. Structural analysis reveals that the unit cell simultaneously contains MnIII-Salen dimer and monomer cation fragments, for which the Anderson-type polyanions serve as counter anions. In the packing arrangement, all the MnIII dimers are well separated by polyoxometalate units and form tertiary structure together with MnIII monomers. Interestingly, different from the previous work, in the exact same reaction conditions, we are able to template MnIII-Salen complexes into different configurations by varying the charge state of polyanions. Besides, the magnetic properties of 1 were also examined by using both dc and ac magnetic field of the superconducting quantum interference devices. Most importantly, our fitting of the experimental data to a Heisenberg-type spin model shows that there exists a ferromagnetic exchange interaction ∼5 K between the spins (S = 2) on MnIII in the dimer, while antiferromagnetic ones exist among monomers and dimer (∼2 K). This meta-magnetic state could induce a slight spin frustration at low temperature, which would in turn affect the magnetic behavior. In addition, our ac field measurement of the susceptibilities suggests a typical signature for a single-molecule magnet.

  3. First liquid single crystal elastomer containing lactic acid derivative as chiral co-monomer: synthesis and properties

    Czech Academy of Sciences Publication Activity Database

    Bubnov, Alexej; Domenici, V.; Hamplová, Věra; Kašpar, Miroslav; Zalar, B.

    2011-01-01

    Roč. 52, č. 20 (2011), s. 4490-4497 ISSN 0032-3861 R&D Projects: GA AV ČR IAA100100911; GA AV ČR(CZ) GA202/09/0047; GA MŠk(CZ) OC10006; GA ČR(CZ) GAP204/11/0723 Grant - others:German Czech bilateral program(XE) D4-CZ5/2010-2011; RFASI(RU) 02.740.11.5166 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystalline elastomer * ferroelectric liquid crystalline monomer * smectic A phase * X-ray diffraction * lactate chiral group * monodomain * polymer Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.438, year: 2011

  4. Molecular dynamics approaches to the design and synthesis of PCB targeting molecularly imprinted polymers: interference to monomer-template interactions in imprinting of 1,2,3-trichlorobenzene.

    Science.gov (United States)

    Cleland, Dougal; Olsson, Gustaf D; Karlsson, Björn C G; Nicholls, Ian A; McCluskey, Adam

    2014-02-07

    The interactions between each component of the pre-polymerisation mixtures used in the synthesis of molecularly imprinted polymers (MIP) specific for 1,2,3,4,5-pentachlorobenzene (1) and 1,2,3-trichlorobenzene (2) were examined in four molecular dynamics simulations. These simulations revealed that the relative frequency of functional monomer-template (FM-T) interactions was consistent with results obtained by the synthesis and evaluation of the actual MIPs. The higher frequency of 1 interaction with trimethylstyrene (TMS; 54.7%) than 1 interaction with pentafluorostyrene (PFS; 44.7%) correlated with a higher imprinting factor (IF) of 2.1 vs. 1.7 for each functional monomer respectively. The higher frequency of PFS interactions with 2 (29.6%) than TMS interactions with 2 (1.9%) also correlated well with the observed differences in IF (3.7) of 2 MIPs imprinted using PFS as the FM than the IF (2.8) of 2 MIPs imprinted using TMS as the FM. The TMS-1 interaction dominated the molecular simulation due to high interaction energies, but the weaker TMS-2 resulted in low interaction maintenance, and thus lower IF values. Examination of the other pre-polymerisation mixture components revealed that the low levels of TMS-2 interaction was, in part, due to interference caused by the cross linker (CL) ethyleneglycol dimethylacrylate (EGDMA) interactions with TMS. The main reason was, however, attributed to MeOH interactions with TMS in both a hydrogen bond and perpendicular configuration. This positioned a MeOH directly above the π-orbital of all TMS for an average of 63.8% of MD2 creating significant interference to π-π stacking interactions between 2 and TMS. These findings are consistent with the deviation from the 'normal' molecularly imprinted polymer synthesis ratio of 1 : 4 : 20 (T : FM : CL) of 20 : 1 : 29 and 15 : 6 : 29 observed with 2 and TMS and PFS respectively. Our molecular dynamics simulations correctly predicted the high level

  5. New Phenomena in Organometallic-Mediated Radical Polymerization (OMRP) and Perspectives for Control of Less Active Monomers.

    Science.gov (United States)

    Poli, Rinaldo

    2015-05-04

    The impact of reversible bond formation between a growing radical chain and a metal complex (organometallic-mediated radical polymerization (OMRP) equilibrium) to generate an organometallic intermediate/dormant species is analyzed with emphasis on the interplay between this and other one-electron processes involving the metal complex, which include halogen transfer in atom transfer radical polymerization (ATRP), hydrogen-atom transfer in catalytic chain transfer (CCT), and catalytic radical termination (CRT). The challenges facing the controlled polymerization of "less active monomers" (LAMs) are outlined and, after reviewing the recent achievements of OMRP in this area, the perspectives of this technique are analyzed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Synthesis, hybridization characteristics, and fluorescence properties of oligonucleotides modified with nucleobase-functionalized locked nucleic acid adenosine and cytidine monomers.

    Science.gov (United States)

    Kaura, Mamta; Kumar, Pawan; Hrdlicka, Patrick J

    2014-07-03

    Conformationally restricted nucleotides such as locked nucleic acid (LNA) are very popular as affinity-, specificity-, and stability-enhancing modifications in oligonucleotide chemistry to produce probes for nucleic acid targeting applications in molecular biology, biotechnology, and medicinal chemistry. Considerable efforts have been devoted in recent years to optimize the biophysical properties of LNA through additional modification of the sugar skeleton. We recently introduced C5-functionalization of LNA uridines as an alternative and synthetically more straightforward approach to improve the biophysical properties of LNA. In the present work, we set out to test the generality of this concept by studying the characteristics of oligonucleotides modified with four different C5-functionalized LNA cytidine and C8-functionalized LNA adenosine monomers. The results strongly suggest that C5-functionalization of LNA pyrimidines is indeed a viable approach for improving the binding affinity, target specificity, and/or enzymatic stability of LNA-modified ONs, whereas C8-functionalization of LNA adenosines is detrimental to binding affinity and specificity. These insights will impact the future design of conformationally restricted nucleotides for nucleic acid targeting applications.

  7. Synthesis of poly(ethylene furandicarboxylate) polyester using monomers derived from renewable resources: thermal behavior comparison with PET and PEN.

    Science.gov (United States)

    Papageorgiou, George Z; Tsanaktsis, Vasilios; Bikiaris, Dimitrios N

    2014-05-07

    Poly(ethylene-2,5-furandicarboxylate) (PEF) is a new alipharomatic polyester that can be prepared from monomers derived from renewable resources like furfural and hydroxymethylfurfural. For this reason it has gained high interest recently. In the present work it was synthesized from the dimethylester of 2,5-furandicarboxylic acid and ethylene glycol by applying the two-stage melt polycondensation method. The thermal behavior of PEF was studied in comparison to its terephthalate and naphthalate homologues poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN), which were also synthesized following the same procedure. The equilibrium melting point of PEF was found to be 265 °C while the heat of fusion for the pure crystalline PEF was estimated to be about 137 J g(-1). The crystallization kinetics was analyzed using various models. PET showed faster crystallization rates than PEN and this in turn showed faster crystallization than PEF, under both isothermal and non-isothermal conditions. The spherulitic morphology of PEF during isothermal crystallization was investigated by polarized light microscopy (PLM). A large nucleation density and a small spherulite size were observed for PEF even at low supercoolings, in contrast to PET or PEN. Thermogravimetric analysis indicated that PEF is thermally stable up to 325 °C and the temperature for the maximum degradation rate was 438 °C. These values were a little lower than those for PET or PEN.

  8. Synthesis, rheological behavior and swelling properties of copolymer hydrogels based on poly(N-isopropylacrylamide with hydrophilic monomers

    Directory of Open Access Journals (Sweden)

    D. Aliouche

    2013-09-01

    Full Text Available In this study, hydrogels of poly(N-isopropylacrylamide-co-acrylamide and poly(N-isopropylacrylamide-co-acrylic acid having a thermoresponsive character were prepared by aqueous free-radical co-polymerization using the ammonium persulfate/N,N,N',N'-tetramethylethylenediamine (APS/TEMED redox-pair initiator system in the presence of N,N'-methylenebisacrylamide (MBAAm crosslinker. (NIPAAm-co-AAm and (NIPAAm-co-AAc hydrogels with different thermoresponsive properties were obtained by fixing the initial NIPAAm/AAm mole ratio and and (NIPAAm-co-AAc mole ratio to 80/20 and changing the crosslinker concentration. The copolymers were characterized with infrared spectroscopy (IR and differential scanning calorimetry (DSC techniques. The swelling response of the copolymers networks as a function of time, temperature and swelling environment has been observed to be dependent on both structural aspects of the polymers and swelling environment. The swelling has been observed to be decrease with increase in MBAAm in the copolypolymers networks. Rheological behavior was studies in oscillatory module. All copolymers have a viscoelastic behaviour. We note that the elastic modulus G' increases with increasing hydrophilic monomers.DOI: http://dx.doi.org/10.4314/bcse.v27i3.14

  9. Novel Microwave-Assisted Synthesis of Poly(D,L-lactide: The Influence of Monomer/Initiator Molar Ratio on the Product Properties

    Directory of Open Access Journals (Sweden)

    Ljubisa Nikolic

    2010-05-01

    Full Text Available Poly(D,L-lactide synthesis using tin(II 2-ethylhexanoate initiated ring-opening polymerization (ROP takes over 30 hours in bulk at 120 °C. The use of microwave makes the same bulk polymerization process with the same initiator much faster and energy saving, with a reaction time of about 30 minutes at 100 °C. Here, the poly(lactide synthesis was done in a microwave reactor, using frequency of 2.45 GHz and maximal power of 150 W. The reaction temperature was controlled via infra-red system for in-bulk-measuring, and was maintained at 100 °C. Different molar ratios of monomer and initiator, [M]/[I], of 1,000, 5,000 and 10,000 were used. The achieved average molar masses for the obtained polymers (determined by gel permeation chromatography were in the interval from 26,700 to 112,500 g/mol. The polydispersion index was from 2.436 to 3.425. For applicative purposes, the obtained material was purified during the procedure of microsphere preparation. Microspheres were obtained by spraying a fine fog of polymer (D,L-lactide solution in tetrahydrofuran into the water solution of poly(vinyl alcohol with intensive stirring.

  10. Conformationally locked aryl C-nucleosides: synthesis of phosphoramidite monomers and incorporation into single-stranded DNA and LNA (locked nucleic acid)

    DEFF Research Database (Denmark)

    Babu, B. Ravindra; Prasad, Ashok K.; Trikha, Smriti

    2002-01-01

    . The phosphoramidite approach was used for automated incorporation of the LNA-type beta-configured C-aryl monomers 17a-17e into short DNA and 2'-OMe-RNA/LNA strands. It is shown that universal hybridization can be obtained with a conformationally restricted monomer as demonstrated most convincingly for the pyrene LNA...... monomer 17d, both in a DNA context and in an RNA-like context. Increased binding affinity of oligonucleotide probes for universal hybridization can be induced by combining the pyrene LNA monomer 17d with affinity-enhancing 2'-OMe-RNA/LNA monomers....

  11. Synthesis of Hydrophilic and Amphiphilic Acryl Sucrose Monomers and Their Copolymerisation with Styrene, Methylmethacrylate and α- and β-Pinenes

    Directory of Open Access Journals (Sweden)

    Maria Teresa Barros

    2010-04-01

    Full Text Available Herein, we report the synthesis of monomethacryloyl sucrose esters, and their successful free radical homo- and co-polymerisation with styrene, methylmethacrylate, α- and β-pinene. The chemical, physical, structural and surface chemical properties of these polymers, containing a hydrophobic olefin backbone and hydrophilic sugar moieties as side chains, have been investigated. Biodegradation tests of the copolymer samples by a microbial fungal culture (Aspergillus niger method showed good biodegradability. The chemical structure and surface chemistry of the synthesized homo- and co-polymers demonstrate their potential technological relevance as amphiphilic and biodegradable polymers.

  12. Synthesis of New Polyether Ether Ketone Derivatives with Silver Binding Site and Coordination Compounds of Their Monomers with Different Silver Salts

    Directory of Open Access Journals (Sweden)

    Jérôme Girard

    2016-05-01

    Full Text Available Polyether ether ketone (PEEK is a well-known polymer used for implants and devices, especially spinal ones. To overcome the biomaterial related infection risks, 4-4′-difluorobenzophenone, the famous PEEK monomer, was modified in order to introduce binding sites for silver ions, which are well known for their antimicrobial activity. The complexation of these new monomers with different silver salts was studied. Crystal structures of different intermediates were obtained with a linear coordination between two pyridine groups and the silver ions in all cases. The mechanical and thermal properties of different new polymers were characterized. The synthesized PEEKN5 polymers showed similar properties than the PEEK ones whereas the PEEKN7 polymers showed similar thermal properties but the mechanical properties are not as good as the ones of PEEK. To improve these properties, these polymers were complexed with silver nitrate in order to “cross-link” with silver ions. The presence of ionic silver in the polymer was then confirmed by thermogravimetric analysis (TGA and X-ray powder diffraction (XRPD. Finally, a silver-based antimicrobial compound was successfully coated on the surface of PEEKN5.

  13. Brassinosteroids: synthesis and biological activities

    Czech Academy of Sciences Publication Activity Database

    Oklešťková, Jana; Rárová, Lucie; Kvasnica, Miroslav; Strnad, Miroslav

    2015-01-01

    Roč. 14, č. 6 (2015), s. 1053-1072 ISSN 1568-7767 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Brassinosteroids * Chemical synthesis * Plant biological activity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.686, year: 2015

  14. Effect of an Antibacterial Monomer on the Antibacterial Activity of a Pit-and-Fissure Sealant.

    Directory of Open Access Journals (Sweden)

    Fan Yu

    Full Text Available Resin-based pit-and-fissure sealants are often used to form a barrier on the occlusal surface of molars to treat caries lesions; however, bacteria can remain in the pit and fissures without detection, increasing the risk of secondary caries. Sealants with antimicrobial properties or microbial repellent actions might be advantageous. The aim of this study was to assess the inhibitory effect of a 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB-incorporated sealant against Streptococcus mutans. MAE-DB (4% wt was incorporated into a commercially available sealant, Eco-S resin-based pit-and-fissure sealant (Vericom Co., Ltd., Korea; a sealant without MAE-DB served as a negative control, and Clinpro™ Sealant (3M™ ESPE™, a fluoride-releasing resin, was used as a commercial control. The effects of the cured sealants and their eluents on the growth of S. mutans were determined according to colony-forming unit counts and metabolic tests. The effects of the cured sealants on the adherence and membrane integrity of S. mutans were investigated using confocal laser-scanning microscopy (CLSM in conjunction with fluorescent indicators. Compared with the negative control and commercial control, the cured MAE-DB-incorporated pit-and-fissure sealant exhibited a significant inhibitory effect on the growth of S. mutans (P < 0.05, whereas the eluents did not show any detectable antibacterial activity. The commercial control also showed no detectable bactericidal activity. Moreover, the aged experimental material retained its property of contact inhibition of biofilm formation. The fluorescence analysis of CLSM images demonstrated that the cured MAE-DB-incorporated sealant could hamper the adherence of S. mutans and exert a detrimental effect on bacterial membrane integrity. The incorporation of MAE-DB can render a pit-and-fissure sealant with contact antibacterial activity after polymerization via influencing the growth, adherence, and membrane

  15. Non-hazardous biocatalytic oxidation in Nylon-9 monomer synthesis on a 40 g scale with efficient downstream processing.

    Science.gov (United States)

    Milker, Sofia; Fink, Michael J; Rudroff, Florian; Mihovilovic, Marko D

    2017-08-01

    This paper describes the development of a biocatalytic process on the multi-dozen gram scale for the synthesis of a precursor to Nylon-9, a specialty polyamide. Such materials are growing in demand, but their corresponding monomers are often difficult to synthesize, giving rise to biocatalytic approaches. Here, we implemented cyclopentadecanone monooxygenase as an Escherichia coli whole-cell biocatalyst in a defined medium, together with a substrate feeding-product removal concept, and an optimized downstream processing (DSP). A previously described hazardous peracid-mediated oxidation was thus replaced with a safe and scalable protocol, using aerial oxygen as oxidant, and water as reaction solvent. The engineered process converted 42 g (0.28 mol) starting material ketone to the corresponding lactone with an isolated yield of 70% (33 g), after highly efficient DSP with 95% recovery of the converted material, translating to a volumetric yield of 8 g pure product per liter. Biotechnol. Bioeng. 2017;114: 1670-1678. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  16. Synthesis and spectroscopy of clay intercalated Cu(II) bio-monomer complexes: coordination of Cu(II) with purines and nucleotides

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Leeman, H.; Schoonheydt, R.A.

    1999-01-01

    The spectroscopic properties of Cu(bio-monomer)nm+ complexes [BM=bio-monomer (purine, adenine, guanine, hypoxanthine, 5-ADP and 5-GMP)] in saponite clays have been investigated by diffuse reflectance spectroscopy (DRS) in the UV-Vis-NIR region and electron paramagnetic resonance (EPR) at X-band.

  17. Gold and silver nanoparticle monomers are non-SERS-active: a negative experimental study with silica-encapsulated Raman-reporter-coated metal colloids.

    Science.gov (United States)

    Zhang, Yuying; Walkenfort, Bernd; Yoon, Jun Hee; Schlücker, Sebastian; Xie, Wei

    2015-09-07

    Noble metal nanoparticles (NPs) are the most commonly employed plasmonic substrates in surface-enhanced Raman scattering (SERS) experiments. Computer simulations show that monomers of Ag and Au nanocrystals ("spherical" NPs) do not exhibit a notable plasmonic enhancement, i.e., they are essentially non-SERS-active. However, in experiments, SERS enhanced by spherical NP colloids has been frequently reported. This implies that the monomers do not have strong SERS activity, but detectable enhancement should more or less be there. Because of the gap between theory and practice, it is important to demonstrate experimentally how SERS-active the metal colloid actually is and, in case a SERS signal is observed, where it originates from. In particular the aggregation of the colloid, induced by high centrifugal forces in washing steps or due to a harsh ionic environment of the suspension medium, should be controlled since it is the very high SERS activity of NP clusters which dominates the overall SERS signal of the colloid. We report here the experimental evaluation of the SERS activity of 80 nm Au and Ag NP monomers. Instead of showing fancy nanostructures and super SERS enhancement, we present the method on how to obtain negative experimental data. In this approach, no SERS signal was obtained from the colloid with a Raman reporter on the metal surface when the NPs were encapsulated carefully within a thick silica shell. Without silica encapsulation, if a very low centrifugation speed is used for the washing steps, only a negligible SERS signal can be detected even at very high NP concentrations. In contrast, strong SERS signals can be detected when the NPs are suspended in acidic solutions. These results indicate that Au and Ag NP monomers essentially exhibit no SERS activity of practical relevance.

  18. Recovery of olefin monomers

    Science.gov (United States)

    Golden, Timothy Christoph; Weist, Jr., Edward Landis; Johnson, Charles Henry

    2004-03-16

    In a process for the production of a polyolefin, an olefin monomer is polymerised said polyolefin and residual monomer is recovered. A gas stream comprising the monomer and nitrogen is subjected to a PSA process in which said monomer is adsorbed on a periodically regenerated silica gel or alumina adsorbent to recover a purified gas stream containing said olefin and a nitrogen rich stream containing no less than 99% nitrogen and containing no less than 50% of the nitrogen content of the gas feed to the PSA process.

  19. Synthesis of fluorinated poly(arylene ether)s with dibenzodioxin and spirobisindane units from new bis(pentafluorophenyl)- and bis(nonafluorobiphenyl)-containing monomers

    DEFF Research Database (Denmark)

    Tkachenko, Ihor M.; Belov, Nikolay A.; Kobzar, Yaroslav L.

    2017-01-01

    ,1′-spirobisindane. The chemical structures of the prepared monomers and polymers were determined using 1H, 13C, 19F NMR and FTIR spectroscopy techniques. All the obtained polymers were completely soluble in chloroform, tetrahydrofuran, dimethylformamide, and dimethyl sulfoxide. Polymers derived from 4,4′-bis......(nonafluorophenyl)-containing monomers have higher average molecular masses (Mw) in the range 47,000–88,300 and are able to form robust, solvent-cast films. Good thermal stabilities in air (up to 350 °C) were observed in all fluorinated polymers. The Brunauer–Emmett–Teller specific surface area and the pore size of polymers can...... be controlled by varying the type of the initial fluorinated monomers. It was shown that introduction of perfluorobiphenyl units is an effective tool for increasing the surface area up to 156.8 m2 g−1....

  20. Tyrosine-derived novel antimicrobial hydantoin polymers: synthesis and evaluation of anti-bacterial activities.

    Science.gov (United States)

    Ravichandran, Vasanthan; Rai, Rajani Kant; Kesavan, Venkitasamay; Jayakrishnan, A

    2017-12-01

    A new approach for the design and synthesis of cyclic N-halamine polymers having anti-bacterial activity based on a vinyl derivative of tyrosine-derived hydantoin is reported. The synthesis of N-halamine polymers generally involves the chemical modification of 5,5'-disubstituted hydantoin to introduce polymerizable vinyl moieties thereby restricting the halogen capture only on the amide nitrogen. Here we show the possibility of synthesizing vinyl monomers of N-halamine from α-amino acids wherein both the amide and imide nitrogens are available for halogen capture. Thus, a hydantoin monomer was synthesized from L-tyrosine and copolymerized with methyl methacrylate and 2-(hydroxyethyl)methacrylate, to obtain random co-polymers. The monomer and its co-polymers were characterized using NMR, IR, HRMS, GPC, DSC, EDAX and TGA analysis. Films of the co-polymers cast from 10% acetone solutions were exposed to sodium hypochlorite solution to activate the hydantoin moieties. The oxidative chlorine content of the films ranged from 0.6 to 0.9%. The activated films were exposed to both Gram positive (S. aureus) and Gram negative (E. coli) bacteria using standard protocols. Polymers having chlorine content as little as 0.6% exhibited 6 log reduction in the bacterial growth within 30 min of exposure. The method allows the halogenation of both amide and imide nitrogens and could be applied to the preparation of a number of vinyl hydantoins from many amino acids.

  1. Synthesis and characterization of the monomer 2,2'-dialylbisphenol-A (ABFA) for production of proton exchange membranes based on sulphonated poly(arylene ether sulphone)s reticulated

    International Nuclear Information System (INIS)

    Souza, Julio C.; Souza, Carlos H.F.B.; Silva, Maria Elisa S.R.; Sousa, Ricardo G.; Freitas, Roberto F.S.; Silva, Claudio Homero F.

    2011-01-01

    In the present work, a methodology of synthesis and characterization of the monomer 2,2'- dialylbisphenol A was developed, aiming at getting a precursor, with adequate purity, for obtaining cross-linked membranes based on sulfonated poly(arylene ether sulfone)s. The monomer 2,2'- dialylbisphenol A was obtained through Claisen rearrangement of the 2,2-Bis(4-alyloxiphenyl)propane, synthesized from Bisphenol A. All the products and reagents were characterized by Fourier Transform infrared spectroscopy, Thermo-gravimetric analysis and High-performance liquid chromatography. The thermal Claisen rearrangement process was conducted by using Differential Scanning Calorimetry technique, from a factorial experiment planning, with temperature and time being the variables. The above cited techniques were used for monitoring the Claisen rearrangement and for the characterization of the final product. The best results yield an ABFA purity between 85 and 90%. The obtained results suggest that, in the studied range, polymerization and degradation of the monomer ABFA occur, simultaneously to its formation. (author)

  2. Synthesis of Terpolymers with Homogeneous Composition by Free Radical Copolymerization of Maleic Anhydride, Perfluorooctyl and Butyl or Dodecyl Methacrylates: Application of the Continuous Flow Monomer Addition Technique

    Directory of Open Access Journals (Sweden)

    Marian Szkudlarek

    2017-11-01

    Full Text Available Terpolymers of homogeneous composition were prepared by free radical copolymerization of butyl or dodecyl methacrylate, 1H,1H,2H,2H-perfluorodecyl methacrylate and maleic anhydride using the continuous monomer addition technique. The copolymerization reactions were performed at 65 °C in the presence of azobisisobutyronitrile as an initiator in a mixture of methyl ethyl ketone and 1,3-bis (trifluoromethylbenzene. The monomers and initiator are added to the reaction mixture with the same rate they are consumed in 5- and 10-fold excess compared to the initial monomer stock. The obtained terpolymers with molecular weights Mn = 50,000–70,000 are of uniform composition, close to the composition determined in low conversion experiments, proving the principle of the chosen concept. The kinetic data necessary for the design of the continuous addition experiment were obtained from binary copolymerization experiments at low monomer conversion (to avoid compositional drift. In addition, the so-called terpolymerization parameter was determined from ternary copolymerization experiments.

  3. Recognition of double-stranded DNA using energetically activated duplexes with interstrand zippers of 1-, 2- or 4-pyrenyl-functionalized O2'-alkylated RNA monomers.

    Science.gov (United States)

    Karmakar, Saswata; Madsen, Andreas S; Guenther, Dale C; Gibbons, Bradley C; Hrdlicka, Patrick J

    2014-10-21

    Despite advances with triplex-forming oligonucleotides, peptide nucleic acids, polyamides and--more recently--engineered proteins, there remains an urgent need for synthetic ligands that enable specific recognition of double-stranded (ds) DNA to accelerate studies aiming at detecting, regulating and modifying genes. Invaders, i.e., energetically activated DNA duplexes with interstrand zipper arrangements of intercalator-functionalized nucleotides, are emerging as an attractive approach toward this goal. Here, we characterize and compare Invaders based on 1-, 2- and 4-pyrenyl-functionalized O2'-alkylated uridine monomers X-Z by means of thermal denaturation experiments, optical spectroscopy, force-field simulations and recognition experiments using DNA hairpins as model targets. We demonstrate that Invaders with +1 interstrand zippers of X or Y monomers efficiently recognize mixed-sequence DNA hairpins with single nucleotide fidelity. Intercalator-mediated unwinding and activation of the double-stranded probe, coupled with extraordinary stabilization of probe-target duplexes (ΔT(m)/modification up to +14.0 °C), provides the driving force for dsDNA recognition. In contrast, Z-modified Invaders show much lower dsDNA recognition efficiency. Thus, even very conservative changes in the chemical makeup of the intercalator-functionalized nucleotides used to activate Invader duplexes, affects dsDNA-recognition efficiency of the probes, which highlights the importance of systematic structure-property studies. The insight from this study will guide future design of Invaders for applications in molecular biology and nucleic acid diagnostics.

  4. Synthesis, Characterization and Antibacterial Activity of Imidazole ...

    African Journals Online (AJOL)

    NICO

    Synthesis, Characterization and Antibacterial Activity of. Imidazole Derivatives of 1,10-Phenanthroline and their .... Synthesis of Ligands (L1, L2). Ligands (L1. , L2) were synthesized by a method similar to one ... (50 mL). Dropwise addition of concentrated aqueaus ammonia to neutralize gave a yellow precipitate, which was ...

  5. New synthesis method for 4-MAPBA monomer and using for the recognition of IgM and mannose with MIP-based QCM sensors.

    Science.gov (United States)

    Diltemiz, Sibel Emir; Hür, Deniz; Keçili, Rüstem; Ersöz, Arzu; Say, Rıdvan

    2013-03-07

    Quartz crystal microbalance (QCM) sensors coated with molecularly imprinted polymers (MIP) have been developed for the recognition of immunoglobulin M (IgM) and mannose. In this method, methacryloylamidophenylboronic acid (MAPBA) was used as a monomer and mannose was used as a template. For this purpose, initially, QCM electrodes were modified with 2-propene-1-thiol to form mannose-binding regions on the QCM sensor surface. In the second step, the methacryloylamidophenylboronic acid-mannose [MAPBA-mannose], pre-organized monomer system, was prepared using the MAPBA monomer. Then, a molecularly imprinted film was coated on to the QCM electrode surface under UV light using ethylene glycol dimethacrylate (EDMA), and azobisisobutyronitrile (AIBN) as a cross-linking agent and an initiator, respectively. The mannose can be simultaneously bound to MAPBA and fitted into the shape-selective cavities. The binding affinity of the mannose-imprinted sensors was investigated using the Langmuir isotherm. The mannose-imprinted QCM electrodes have shown homogeneous binding sites for mannose (K(a): 3.3 × 10(4) M(-1)) and heterogeneous binding sites for IgM (K(a1): 1.0 × 10(4) M(-1); K(a2): 3.3 × 10(3) M(-1)).

  6. Synthesis and biological activities of substituted N ...

    African Journals Online (AJOL)

    use

    2011-12-07

    Dec 7, 2011 ... The present study describes the synthesis, antioxidant and antibacterial activities of substituted N'- benzoylhydrazone derivatives, to ... addition, the dramatically rising prevalence of multidrug- resistant microbial infections has ...... extract of Chinese green tea (Camellia sinensis) on Listeria monocytogenes.

  7. Synthesis and Physical Properties of Polyhydroxyalkanoate Polymers with Different Monomer Compositions by Recombinant Pseudomonas putida LS46 Expressing a Novel PHA SYNTHASE (PhaC116 Enzyme

    Directory of Open Access Journals (Sweden)

    Parveen K. Sharma

    2017-03-01

    Full Text Available A recombinant of Pseudomonas putida LS461 (deletion of the phaC1phaZphaC2 genes was constructed by introducing cosmid JC123 carrying a novel phaC116 gene from a metagenomic clone. The resulting strain, P. putida LS46123, was able to synthesize polyhydroxyalkanoate (PHA polymers with novel monomer compositions when cultured on glucose or free fatty acids, and accumulated PHAs from 9.24% to 27.09% of cell dry weight. The PHAs synthesized by P. putida LS46123 contained up to 50 mol % short chain length subunits (3-hydroxybutyrate and 3-hydroxyvalerate, with the remaining monomers consisting of various medium chain length subunits. The PhaC116 protein expressed by P. putida LS46123 had an amino acid sequence similarity of 45% with the PhaC1 protein of the parent strain, P. putida LS46. Predicted 3D structures of the PhaC116 proteins from P. putida LS46123 and P. putida LS46 revealed several differences in the numbers and locations of protein secondary structures. The physical and thermal properties of the novel polymers synthesized by P. putida LS46123 cultured with glucose or free fatty acids differed significantly from those produced by P. putida LS46 grown on the same substrates. PHA polymers with different subunit compositions, and hence different physical and thermal properties, can be tailor-made using novel PHA synthase for specific applications.

  8. Synthesis, Characterization, and Cross-Linking Strategy of a Quercetin-Based Epoxidized Monomer as a Naturally-Derived Replacement for BPA in Epoxy Resins.

    Science.gov (United States)

    Kristufek, Samantha L; Yang, Guozhen; Link, Lauren A; Rohde, Brian J; Robertson, Megan L; Wooley, Karen L

    2016-08-23

    The natural polyphenolic compound quercetin was functionalized and cross-linked to afford a robust epoxy network. Quercetin was selectively methylated and functionalized with glycidyl ether moieties using a microwave-assisted reaction on a gram scale to afford the desired monomer (Q). This quercetin-derived monomer was treated with nadic methyl anhydride (NMA) to obtain a cross-linked network (Q-NMA). The thermal and mechanical properties of this naturally derived network were compared to those of a conventional diglycidyl ether bisphenol A-derived counterpart (DGEBA-NMA). Q-NMA had similar thermal properties [i.e., glass transition (Tg ) and decomposition (Td ) temperatures] and comparable mechanical properties (i.e., Young's Modulus, storage modulus) to that of DGEBA-NMA. However, it had a lower tensile strength and higher flexural modulus at elevated temperatures. The application of naturally derived, sustainable compounds for the replacement of commercially available petrochemical-based epoxies is of great interest to reduce the environmental impact of these materials. Q-NMA is an attractive candidate for the replacement of bisphenol A-based epoxies in various specialty engineering applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A flexible loop at the dimer interface is a part of the active site of the adjacent monomer of Escherichia coli orotate phosphoribosyltransferase

    DEFF Research Database (Denmark)

    Henriksen, Annette; Aghajari, Nushin; Jensen, Kaj Frank

    1996-01-01

    is thereafter converted to uridine 5‘-monophosphate by OMP decarboxylase. We have determined the 2.4 Å structure of Escherichia coli OPRTase, ligated with sulfate, by molecular replacement and refined the structure to an R-factor of 18.3% for all data. In the structure of the E. coli enzyme we have determined...... ion. Crystalline E. coli OPRTase is a homodimer, with sulfate ions inhibiting enzyme activity bound in the dimer interface close to the flexible loop region. Although this loop is very close in space to the sulfate binding site, and sulfate is found in both interfaces of the homodimer, the loop...... structure is only traceable in one monomer. We expect that the mobility of this loop is important for catalysis, and, on the basis of the reported structure and the structure of Salmonella typhimurium OPRTase·OMP, we propose that the movement of this loop in association with the movement of OMP is vital...

  10. Synthesis, characterization and antimicrobial activity of mixed ...

    African Journals Online (AJOL)

    Synthesis, characterization and antimicrobial activity of mixed ascorbic acid - nicotinamide metal complexes. ... The result of the antimicrobial studies showed that the mixed complexes have higher inhibitory activity than the original ligands against the tested bacteria and fungi species. KEY WORDS: Ascorbic acid, ...

  11. C8-Linked Pyrrolobenzodiazepine Monomers with Inverted Building Blocks Show Selective Activity against Multidrug Resistant Gram-Positive Bacteria.

    Science.gov (United States)

    Andriollo, Paolo; Hind, Charlotte K; Picconi, Pietro; Nahar, Kazi S; Jamshidi, Shirin; Varsha, Amrit; Clifford, Melanie; Sutton, J Mark; Rahman, Khondaker Miraz

    2018-02-09

    Antimicrobial resistance has become a major global concern. Development of novel antimicrobial agents for the treatment of infections caused by multidrug resistant (MDR) pathogens is an urgent priority. Pyrrolobenzodiazepines (PBDs) are a promising class of antibacterial agents initially discovered and isolated from natural sources. Recently, C8-linked PBD biaryl conjugates have been shown to be active against some MDR Gram-positive strains. To explore the role of building block orientations on antibacterial activity and obtain structure activity relationship (SAR) information, four novel structures were synthesized in which the building blocks of previously reported compounds were inverted, and their antibacterial activity was studied. The compounds showed minimum inhibitory concentrations (MICs) in the range of 0.125-32 μg/mL against MDR Gram-positive strains with a bactericidal mode of action. The results showed that a single inversion of amide bonds reduces the activity while the double inversion restores the activity against MDR pathogens. All inverted compounds did not stabilize DNA and lacked eukaryotic toxicity. The compounds inhibit DNA gyrase in vitro, and the most potent compound was equally active against both wild-type and mutant DNA gyrase in a biochemical assay. The observed activity of the compounds against methicillin resistant S. aureus (MRSA) strains with equivalent gyrase mutations is consistent with gyrase inhibition being the mechanism of action in vivo, although this has not been definitively confirmed in whole cells. This conclusion is supported by a molecular modeling study showing interaction of the compounds with wild-type and mutant gyrases. This study provides important SAR information about this new class of antibacterial agents.

  12. In Situ Synthesis of Monomer Casting Nylon-6/Graphene-Polysiloxane Nanocomposites: Intercalation Structure, Synergistic Reinforcing, and Friction-Reducing Effect.

    Science.gov (United States)

    Li, Chengjie; Xiang, Meng; Zhao, Xiaowen; Ye, Lin

    2017-09-27

    On the basis of the industrialized graphene nanosheets (GNs) product, we synthesized monomer casting nylon-6 (MC PA6)/GN-3-aminopropyl-terminated poly(dimethylsiloxane) (APDMS) nanocomposite in situ through the anchoring effect of APDMS onto the GN surface. APDMS/PA6 molecules were confirmed to intercalate into the GN layers by the formation of strong interfacial interactions. The intercalation ratio and the average layer thickness of the grafted GN sample decreased in the presence of APDMS. Moreover, for MC PA6/GN-APDMS nanocomposite, GN-APDMS was uniformly distributed in the matrix and no phase separation was observed. The size of spherical APDMS particles was obviously reduced compared with that of MC PA6/APDMS composite, revealing a strong interaction between APDMS and GN and the enhancement of compatibility in the composite system. Compared with neat MC PA6, the addition of GN-APDMS resulted in 12% increase in the tensile strength and 37% increase in the impact strength; meanwhile, increase in both the storage modulus (E') and the glass transition temperature (T g ) indicated synergistic reinforcing and toughening effect of GN-APDMS on MC PA6. Furthermore, over 81 and 48% reduction in the friction coefficient and the specific wear rate, respectively, was achieved for the nanocomposite, and the worn surface displayed flat and smooth features with a uniform depth distribution, a low annealing effect, and a reduced friction heat, further confirming the synergistic friction-reducing effect of GN-APDMS on MC PA6.

  13. Characterization of the activity of penicillin G acylase immobilized onto nylon membranes grafted with different acrylic monomers by means of gamma-radiation

    NARCIS (Netherlands)

    Mohy Eldin, M.S.; Bencivenga, U.; Rossi, S.; Canciglia, P.; Caeta, F.S.; Tramper, J.; Mita, D.G.

    2000-01-01

    Penicillin G acylase (PGA) has been immobilized onto nylon membranes grafted with methylmethacrylate (MMA) or diethyleneglycoldimethacrylate (DGDA) monomers by means of -radiation. Hexamethylenediamine (HMDA) has been used as spacer between the grafted membranes and the enzyme. Glutaraldehyde (GA)

  14. Synthesis, characterization, antimicrobial activity and molecular ...

    African Journals Online (AJOL)

    Synthesis, characterization, antimicrobial activity and molecular docking studies of combined pyrazol-barbituric acid pharmacophores. Assem Barakat, Bandar M. Al-Qahtani, Abdullah M. Al-Majid, M. Ali Mohammed Rafi Shaik, Mohamed H.M. Al-Agamy, Abdul Wadood ...

  15. Synthesis, characterisation, nuclease and cytotoxic activity of ...

    Indian Academy of Sciences (India)

    GULZAR A BHAT

    2018-02-07

    Feb 7, 2018 ... Synthesis, characterisation, nuclease and cytotoxic activity of phosphate-free and phosphate-containing copper. 4 -(N-methylpyridinium)-2,2 :6 ,2 terpyridine complexes. GULZAR A BHATa, RAIHANA MAQBOOLb and RAMASWAMY MURUGAVELa,∗. aDepartment of Chemistry, Indian Institute of ...

  16. Impact of chemical structure of flavanol monomers and condensed tannins on in vitro anthelmintic activity against bovine nematodes

    DEFF Research Database (Denmark)

    Desrues, Olivier; Fryganas, Christos; Ropiak, Honorata M.

    2016-01-01

    Plants containing condensed tannins (CT) may have potential to control gastrointestinal nematodes (GIN) of cattle. The aim was to investigate the anthelmintic activities of four flavan-3-ols, two galloyl derivatives and 14 purified CT fractions, and to define which structural features of CT...... susceptible to all CT fractions than C. oncophora L1. The mean degree of polymerization of CT (i.e. average size) was the most important structural parameter: large CT reduced larval feeding more than small CT. The flavan-3-ols of prodelphinidin (PD)-type tannins had a stronger negative influence on parasite...

  17. Production of sorption-active polypropylene fibers by radiation-induce grafting of glycidyl methacrylate as a precursor monomer

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.; Kravets, L.I.

    2004-01-01

    Full text: Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 o C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. It was shown that for the samples with GMA grafting degree more than 50% two simultaneous processes take place during the sulfonation reaction, namely the incorporation of the sulfonate groups via opening of the GMA epoxy-rings as well as hydrolysis of the GMA epoxy-rings with the formation of α-glycol groups. Amine groups were incorporated by treatment of GMA-grafted polypropylene fibers with excess of diethylene triamine reagent. The conversion of the epoxy groups into the functional groups was investigated as a function of the degree of GMA grafting and reaction time. The ion-exchange characteristics of obtained sorption-active polypropylene fibers were determined

  18. Production of sorption-active polypropylene fiber by radiation-induce grafting of glycidyl methacrylate as a precursor monomer

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.; Kravets, L.I.

    2004-01-01

    Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 o C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. It was shown that for the samples with GMA grafting degree more than 50% two simultaneous processes take place during the sulfonation reaction, namely the incorporation of the sulfonate groups via opening of the GMA epoxy-rings as well as hydrolysis of the GMA epoxy-rings with the formation of α-glycol groups. Amine groups were incorporated by treatment of GMA-grafted polypropylene fibers with excess of diethylene triamine reagent. The conversion of the epoxy groups into the functional groups was investigated as a function of the degree of GMA grafting and reaction time. The ion-exchange characteristics of obtained sorption-active polypropylene fibers were determined. (author)

  19. SYNTHESIS AND BIOLOGICAL ACTIVITIES OF 3,6 ...

    African Journals Online (AJOL)

    SYNTHESIS AND BIOLOGICAL ACTIVITIES OF 3,6-DISUBSTITUTED-1,2,4-. TRIAZOLO-1,3 ... Thus, many chemists reported synthesis and antimicrobial activity of some 1,2,4-triazolothiadiazole derivatives in ..... N.H. Synthesis and biological activity of oxadiazole and triazolothiadiazole derivatives as tyrosinase inhibitors.

  20. Synthesis and Properties of Endohedral Aza[60]fullerenes: H₂O@C₅₉N and H₂@C₅₉N as Their Dimers and Monomers.

    Science.gov (United States)

    Hashikawa, Yoshifumi; Murata, Michihisa; Wakamiya, Atsushi; Murata, Yasujiro

    2016-03-30

    The macroscopic-scale syntheses of the first endohedral aza[60]fullerenes X@C59N (X = H2O, H2) were achieved in two different ways: (1) synthesis from endohedral fullerene H2O@C60 as a starting material and (2) molecular surgical synthesis from a C59N precursor having a considerably small opening. In the neutral state of H2O@C59N, we expected the H-bonding interaction or repulsive N-O interaction between entrapped H2O and a nitrogen atom on the C59N cage. However, an attractive electrostatic N-O interaction was suggested from the results of variable temperature NMR, nuclear magnetic relaxation times (T1, T2), and density functional theory (DFT) calculations. Upon the reaction with acetone via cationic intermediate C59N(+), we found a difference in reaction rates between H2O@C59N and H2@C59N dimers (observed reaction rates: k'(H2O)/k'(H2) = 1.74 ± 0.16). The DFT calculations showed thermal stabilization of C59N(+) by entrapped H2O through the electrostatic interaction.

  1. synthesis, physical characterization, antibacterial activity

    African Journals Online (AJOL)

    KEY WORDS: Cobalt (III) Schiff base complex, Thermodynamic parameters, Amines, Antibacterial activity. INTRODUCTION. For a long time tetradentate Schiff base complexes of transition metal ions have attracted many researchers interest in the field of coordination chemistry [1-4]. Though a large number of papers have ...

  2. Mechanochemical synthesis and antioxidant activity

    Indian Academy of Sciences (India)

    Curcumin, the active ingredient of turmeric, is a diaryl- heptanoid natural product that is endowed with much bioactivity;1 3 yet it has limited applications as a drug due to its low bioavailability.4 Structural modifi- cation of curcumin has been explored much as a strategy to circumvent this inadequacy. Among such structurally.

  3. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units

    International Nuclear Information System (INIS)

    Melinte, Violeta; Buruiana, Tinca; Aldea, Horia; Matiut, Simona; Silion, Mihaela; Buruiana, Emil C.

    2014-01-01

    Phosphate diacrylates (CO-DAP, TMP-DAP) based on castor oil or trimethylolpropane were synthesized and evaluated in dental adhesive formulations in comparison with 3-acryloyloxy-2-hydroxypropyl methacrylate phosphate (AMP-P). In an attempt to promote antibacterial activity, another photopolymerizable monomer (TCS-UMA) containing 5-chloro-2-(2,4-dichlorophenoxy)phenol moiety (triclosan) was prepared and incorporated in adhesive resins. Each of these monomers had a molecular structure confirmed by spectral methods. The photopolymerization rates for monomers (0.063–0.088 s −1 ) were lower than those determined in the monomer combinations (0.116–0.158 s −1 ) incorporating phosphate diacrylate (11 wt.%), BisGMA (33 wt.%), TEGDMA (10 wt.%), UDMA (10 wt.%) and HEMA (15 wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65–57.02 μg/mm 3 ) and water solubility (3.51–13.38 μg/mm 3 ), and the contact angle was dependent on the presence of CO-DAP (θ F1 : 66.67°), TMP-DAP (θ F2 : 55.05°) or AMP-P (θ F3 : 52.90°) in the photocrosslinked specimens compared to the sample without phosphate monomer (θ F4 : 82.14°). The scanning electron microscopy image of the dentin–resin composite interface after applying our F1 formulation (pH: 4.1) and its light-curing for 20 s supports the evidence of the formation of the hybrid layer with the tooth structure created by self-etching approach, with no gaps or cracks in the adhesive. A comparative analysis of the adhesion achieved with commercial adhesive systems (Single Bond Universal, C-Bond) rather indicates similarities than differences between them. The addition of triclosan methacrylate (1 wt.%) into the formulation inhibited the bacterial growth of the Streptococcus mutans and Escherichia coli in the direct contact area due to the covalently linked antibacterial monomer. - Highlights: • Synthesis of photopolymerizable phosphate acrylate

  4. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units

    Energy Technology Data Exchange (ETDEWEB)

    Melinte, Violeta [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Buruiana, Tinca, E-mail: tbur@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Aldea, Horia [Gr. T. Popa University of Medicine and Pharmacy, Faculty of Dentistry, Iasi (Romania); Matiut, Simona [Praxis Medical Investigations, 33 Independence, 700102 Iasi (Romania); Silion, Mihaela; Buruiana, Emil C. [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania)

    2014-01-01

    Phosphate diacrylates (CO-DAP, TMP-DAP) based on castor oil or trimethylolpropane were synthesized and evaluated in dental adhesive formulations in comparison with 3-acryloyloxy-2-hydroxypropyl methacrylate phosphate (AMP-P). In an attempt to promote antibacterial activity, another photopolymerizable monomer (TCS-UMA) containing 5-chloro-2-(2,4-dichlorophenoxy)phenol moiety (triclosan) was prepared and incorporated in adhesive resins. Each of these monomers had a molecular structure confirmed by spectral methods. The photopolymerization rates for monomers (0.063–0.088 s{sup −1}) were lower than those determined in the monomer combinations (0.116–0.158 s{sup −1}) incorporating phosphate diacrylate (11 wt.%), BisGMA (33 wt.%), TEGDMA (10 wt.%), UDMA (10 wt.%) and HEMA (15 wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65–57.02 μg/mm{sup 3}) and water solubility (3.51–13.38 μg/mm{sup 3}), and the contact angle was dependent on the presence of CO-DAP (θ{sub F1}: 66.67°), TMP-DAP (θ{sub F2}: 55.05°) or AMP-P (θ{sub F3}: 52.90°) in the photocrosslinked specimens compared to the sample without phosphate monomer (θ{sub F4}: 82.14°). The scanning electron microscopy image of the dentin–resin composite interface after applying our F1 formulation (pH: 4.1) and its light-curing for 20 s supports the evidence of the formation of the hybrid layer with the tooth structure created by self-etching approach, with no gaps or cracks in the adhesive. A comparative analysis of the adhesion achieved with commercial adhesive systems (Single Bond Universal, C-Bond) rather indicates similarities than differences between them. The addition of triclosan methacrylate (1 wt.%) into the formulation inhibited the bacterial growth of the Streptococcus mutans and Escherichia coli in the direct contact area due to the covalently linked antibacterial monomer. - Highlights: • Synthesis of

  5. Synthesis and activity of novel homodimers of Morita-Baylis-Hillman adducts against Leishmania donovani: A twin drug approach.

    Science.gov (United States)

    da Silva, Wagner A V; Rodrigues, Daniele C; de Oliveira, Ramon G; Mendes, Rhuan K S; Olegário, Tayná R; Rocha, Juliana C; Keesen, Tatjana S L; Lima-Junior, Claudio G; Vasconcellos, Mário L A A

    2016-09-15

    It is reported here the synthesis of novel Homodimers 12-19 of Morita-Baylis-Hillman adducts (MBHA) from one-pot Morita-Baylis-Hillman Reaction (MBHR) between aromatic aldehydes as eletrophiles and ethylene glycol diacrylate as Michael acceptor (35-94% yields) using cheap and green conditions. The bioactivities were evaluated against promastigote form of Leishmania donovani. All homodimers showed to be more potent than corresponding monomers. It is worth highlighting that the halogenated homodimers 17 and 18 (0.50μM) is almost 400 times more active than the corresponding monomer 10 and 1.24 times more potent than the second-line drug amphotericin B (0.62μM). Moreover, the selectivity index to 18 is very high (SIrb>400) far better than amphotericin B (SIrb=18.73). This is the first report of twin drugs strategy applied on Morita-Baylis-Hillman adducts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Recognition of double-stranded DNA using energetically activated duplexes with interstrand zippers of 1-, 2-or 4-pyrenyl-functionalized O2 '-alkylated RNA monomers

    DEFF Research Database (Denmark)

    Karmakar, Saswata; Madsen, Andreas Stahl; Guenther, Dale C.

    2014-01-01

    Despite advances with triplex-forming oligonucleotides, peptide nucleic acids, polyamides and more recently engineered proteins, there remains an urgent need for synthetic ligands that enable specific recognition of double-stranded (ds) DNA to accelerate studies aiming at detecting, regulating......'-alkylated uridine monomers X-Z by means of thermal denaturation experiments, optical spectroscopy, force-field simulations and recognition experiments using DNA hairpins as model targets. We demonstrate that Invaders with +1 interstrand zippers of X or Y monomers efficiently recognize mixed-sequence DNA...

  7. Polyester monomers lack ability to bind and activate both androgenic and estrogenic receptors as determined by in vitro and in silico methods.

    Science.gov (United States)

    Osimitz, Thomas G; Welsh, William J; Ai, Ni; Toole, Colleen

    2015-01-01

    The paper presents results from the screening of seven monomers used by Eastman Chemical to make various polymers. Ethylene glycol, diethylene glycol, polytetramethylene glycol, isophthalic acid, monosodium-5-sulfoisophthalic acid, 1,4-cyclohexanedicarboxylic acid, and dimethylcyclohexanedicarboxylate were screened for potential androgenicity or estrogenicity. The following studies were conducted: QSAR for binding to the AR and ER, in vitro Androgen Receptor Binding Assay, in vitro Estrogen Receptor Binding Assays (alpha and beta isoforms), in vitro Androgen Receptor Transactivation Assay in human cells, and in vitro Estrogen Receptor Transactivation Assay in human cells. None of the QSAR models predicted that any of the monomers possessed appreciable binding affinity for either AR or ER. Binding assays showed no evidence of interaction with either the AR or the alpha or beta ER receptors. Similarly, the AR and ER transactivation assays were negative. Moreover, six of the seven monomers have been subjected to 13-week and developmental toxicity studies in rats with no androgen- or estrogen-related effects being noted. Given the negative results of the in vitro screening assays (except PMG which demonstrated cytotoxicity) as well as available repeated dose and developmental and reproductive studies, the data suggest that none of the monomers tested exhibit androgenic or estrogenic hazards. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Activated ERK2 is a monomer in vitro with or without divalent cations and when complexed to the cytoplasmic scaffold PEA-15.

    Science.gov (United States)

    Kaoud, Tamer S; Devkota, Ashwini K; Harris, Richard; Rana, Mitra S; Abramczyk, Olga; Warthaka, Mangalika; Lee, Sunbae; Girvin, Mark E; Riggs, Austen F; Dalby, Kevin N

    2011-05-31

    The extracellular signal-regulated protein kinase, ERK2, fully activated by phosphorylation and without a His(6) tag, shows little tendency to dimerize with or without either calcium or magnesium ions when analyzed by light scattering or analytical ultracentrifugation. Light scattering shows that ~90% of ERK2 is monomeric. Sedimentation equilibrium data (obtained at 4.8-11.2 μM ERK2) with or without magnesium (10 mM) are well described by an ideal one-component model with a fitted molar mass of 40180 ± 240 Da (without Mg(2+) ions) or 41290 ± 330 Da (with Mg(2+) ions). These values, close to the sequence-derived mass of 41711 Da, indicate that no significant dimerization of ERK2 occurs in solution. Analysis of sedimentation velocity data for a 15 μM solution of ERK2 with an enhanced van Holde-Weischet method determined the sedimentation coefficient (s) to be ~3.22 S for activated ERK2 with or without 10 mM MgCl(2). The frictional coefficient ratio (f/f(0)) of 1.28 calculated from the sedimentation velocity and equilibrium data is close to that expected for an ~42 kDa globular protein. The translational diffusion coefficient of ~8.3 × 10(-7) cm(2) s(-1) calculated from the experimentally determined molar mass and sedimentation coefficient agrees with the value determined by dynamic light scattering in the absence and presence of calcium or magnesium ions and a value determined by NMR spectrometry. ERK2 has been proposed to homodimerize and bind only to cytoplasmic but not nuclear proteins [Casar, B., et al. (2008) Mol. Cell 31, 708-721]. Our light scattering data show, however, that ERK2 forms a strong 1:1 complex of ~57 kDa with the cytoplasmic scaffold protein PEA-15. Thus, ERK2 binds PEA-15 as a monomer. Our data provide strong evidence that ERK2 is monomeric under physiological conditions. Analysis of the same ERK2 construct with the nonphysiological His(6) tag shows substantial dimerization under the same ionic conditions.

  9. Ionic Liquid Epoxy Resin Monomers

    Science.gov (United States)

    Paley, Mark S. (Inventor)

    2013-01-01

    Ionic liquid epoxide monomers capable of reacting with cross-linking agents to form polymers with high tensile and adhesive strengths. Ionic liquid epoxide monomers comprising at least one bis(glycidyl) N-substituted nitrogen heterocyclic cation are made from nitrogen heterocycles corresponding to the bis(glycidyl) N-substituted nitrogen heterocyclic cations by a method involving a non-nucleophilic anion, an alkali metal cation, epichlorohydrin, and a strong base.

  10. Synthesis of Degradable Poly(vinyl alcohol) by Radical Ring-Opening Copolymerization and Ice Recrystallization Inhibition Activity.

    Science.gov (United States)

    Hedir, Guillaume; Stubbs, Christopher; Aston, Phillip; Dove, Andrew P; Gibson, Matthew I

    2017-12-19

    Poly(vinyl alcohol) (PVA) is the most active synthetic mimic of antifreeze proteins and has extremely high ice recrystallization inhibition (IRI) activity. Addition of PVA to cellular cryopreservation solutions increases the number of recovered viable cells due to its potent IRI, but it is intrinsically nondegradable in vivo . Here we report the synthesis, characterization, and IRI activity of PVA containing degradable ester linkages. Vinyl chloroacetate (VClAc) was copolymerized with 2-methylene-1,3-dioxepane (MDO) which undergoes radical ring-opening polymerization to install main-chain ester units. The use of the chloroacetate monomer enabled selective deacetylation with retention of esters within the polymer backbone. Quantitative IRI assays revealed that the MDO content had to be finely tuned to retain IRI activity, with higher loadings (24 mol %) resulting in complete loss of IRI activity. These degradable materials will help translate PVA, which is nontoxic and biocompatible, into a range of biomedical applications.

  11. Drug Development of the Antimalarial Agent Artemisinin: Total Synthesis, Analog Synthesis, and Structure-Activity Relationship Studies

    Science.gov (United States)

    1990-08-15

    jHoluenesulfonyl hydrazide in tetrahydrofuran (THF), solvolysis of the ketal group and subsequent hydrazone formation was observed. Under base...ARTEMISININ: TOTAL SYNTHESIS , ANALOG SYNTHESIS , AND STRUCTURE-ACTIVITY RELATIONSHIP STUDIES mc Mitchell A. Avery, Ph.D. SRI International...Antimalarial Agent Artemisinin: Total Synthesis , Analog Synthesis and Structure-Activity Relationship Studies 12 PERSONAL AUTHOR(S) Mitchell A

  12. Study of visible light activated polymerization in BisGMA-TEGDMA monomers with Type 1 and Type 2 photoinitiators using Raman spectroscopy.

    Science.gov (United States)

    Vaidyanathan, Tritala K; Vaidyanathan, Jayalakshmi; Lizymol, Pambadikandathil Philipose; Ariya, Saraswathy; Krishnan, Kalliyana Venketeswaran

    2017-01-01

    The goal of the study was to characterize the efficiency of polymerization of Type 1 and Type 2 initiators for visible light cure of a BisGMA-TEGDMA monomer mixture. Raman spectroscopy was used to follow conversion during polymerization of a BisGMA-TEGDMA mixture using a Type I photoinitiator diphenyl(2,4,6 dimethylbenzoyl)phosphine oxide (TPO) and a Type II photoinitiator camphorquinone (CQ) and an amine, both initiators at 0.5wt.%. Different light exposure times and storage times after light curing were used as variables. There was a significant difference between the relative exposure times of TPO and CQ/amine (5s for TPO vs. 20s for CQ/Amine) for attaining maximum % conversion (78% in TPO vs. 65% in CQ/Amine). There was also a significant difference in the effect of storage time (no effect in TPO vs. increased % conversion with CQ/Amine). These effects are attributed to differences in the rate controlling steps of free radical generation in Type 1/Type 2 initiators, and the potential for radiative and non-radiative energy losses in CQ/Amine in its excited state. The results confirm that photo-polymerization of BisGMA is much more efficient with TPO than with CQ/amine. Both exposure and storage times were important variables in CQ/amine, but not in TPO. TPO photolysis generates significantly more free radicals with potentially very little radiative and non-radiative energy loss in comparison with CQ/amine. The resulting improved monomer conversion is of major importance in resisting chemical and mechanical degradation and preventing toxicological adverse effects. Copyright © 2016. Published by Elsevier Ltd.

  13. Advances in synthetic optically active condensation polymers - A review

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available The study of optically active polymers is a very active research field, and these materials have exhibited a number of interesting properties. Much of the attention in chiral polymers results from the potential of these materials for several specialized utilizations that are chiral matrices for asymmetric synthesis, chiral stationary phases for the separation of racemic mixtures, synthetic molecular receptors and chiral liquid crystals for ferroelectric and nonlinear optical applications. Recently, highly efficient methodologies and catalysts have been developed to synthesize various kinds of optically active compounds. Some of them can be applied to chiral polymer synthesis. In a few synthetic approaches for optically active polymers, chiral monomer polymerization has essential advantages in applicability of monomer, apart from both asymmetric polymerization of achiral or prochiral monomers and enantioselective polymerization of a racemic monomer mixture. The following are the up to date successful approaches to the chiral synthetic polymers by condensation polymerization reaction of chiral monomers.

  14. Iron-substituted cubic silsesquioxane pillared clays: Synthesis, characterization and acid catalytic activity.

    Science.gov (United States)

    Potsi, Georgia; Ladavos, Athanasios K; Petrakis, Dimitrios; Douvalis, Alexios P; Sanakis, Yiannis; Katsiotis, Marios S; Papavassiliou, Georgios; Alhassan, Saeed; Gournis, Dimitrios; Rudolf, Petra

    2018-01-15

    Novel pillared structures were developed from the intercalation of iron-substituted cubic silsesquioxanes in a sodium and an acid-activated montmorillonite nanoclay and evaluated as acid catalysts. Octameric cubic oligosiloxanes were formed upon controlled hydrolytic polycondensation of the corresponding monomer (a diamino-alkoxysilane) and reacted with iron cations to form complexes that were intercalated within the layered nanoclay matrices. Upon calcination iron oxide nanoparticles are formed which are located on the silica cubes (pillars) and on the surfaces of the clay platelets. Acid activation of the nanoclay was performed in order to increase the number of acid active sites in the pristine clay and thus increase its catalytic activity. A plethora of analytical techniques including X-ray diffraction, thermal analyses, Fourier transform infrared, electron paramagnetic resonance, Raman, Mössbauer and X-ray photoelectron spectroscopies and porosimetry measurements were used in order to follow the synthesis steps and to fully characterize the final catalysts. The resulting pillared clays exhibit a high specific area and show significant acid catalytic activity that was verified using the catalytic dehydration of isopropanol asa probe reaction. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Facile Synthesis, Characterization, and In Vitro Antimicrobial and Anticancer Activities of Biscoumarin Copolyester Bearing Pendant 3-(Trifluoromethyl)Styrene.

    Science.gov (United States)

    Kandaswamy, Narendran; Raveendiran, Nanthini

    2014-01-01

    Synthesis of random biscoumarin copolyester bearing pendant 3-(trifluoromethyl)styrene was prepared by the reaction of biscoumarin monomer 3 and hydroquinone 5 with azeloyl chloride. The influence of pendant 3-(trifluoromethyl)styrene unit on the properties of copolyester such as inherent viscosity, solubility, and thermal stability was investigated and compared in detail. The inherent viscosity and polydispersity index of the copolyester were found to be 0.15 dL/g and 1.36, respectively. The chemical structure of the copolyester was investigated by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ((1)H-NMR) spectroscopy. The physical properties of copolyester were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and X-ray diffraction (XRD) technique. Agar disc diffusion method was employed to study the antimicrobial activity of the random copolyester. In vitro anticancer activity against lung cancer (Hep-2) cell line was also investigated.

  16. Synthesis, Characterization and Antimicrobial Activities of Some ...

    African Journals Online (AJOL)

    user

    of metal ions with vitamin.111: Synthesis and infrared spectra of metal complexes with pyridoxamine and pyridoxine. Inorg. Chim. Acta, 46, 191-197. Gary, J and Adeyemo, A (1981) Interaction of vitamin B1 with Zn(II), Cd (II) and Hg(II) in. Deuterated Dimethyl Sulfoxide. Inorg. Chim. Acta, 55, 93-98. Gohzalez-vergara, E ...

  17. Amiloride inhibits rat mucosal ornithine decarboxylase activity and DNA synthesis

    International Nuclear Information System (INIS)

    Ulrich-Baker, M.G.; Wang, P.; Fitzpatrick, L.; Johnson, L.R.

    1988-01-01

    Refeeding fasted rats induces a dramatic trophic response in gastrointestinal mucosa and is associated with elevations in both rate of DNA synthesis and ornithine decarboxylase (ODC) activity. The signal for these increases is unknown. Amiloride prevents cell alkalinization by blocking Na + -H + exchange at apical epithelial cell membranes. In study 1, rats were fasted 48 h, treated with amiloride (0.5 to 500 mg/kg), and refed for 4 h. Refeeding increased ODC activities in the jejunal mucosa (X8) and liver (X19) but not in the oxyntic gland mucosa. In the jejunum, but not the liver, the activation of ODC was completely abolished by 100 mg/kg amiloride. In study 2, the rate of DNA synthesis was determine by measuring the rate of [ 3 H]thymidine incorporation 16 h after refeeding. Refeeding resulted in significantly increased rates of DNA synthesis over fasted levels, and amiloride at 100 mg/kg significantly reduced the elevations in the jejenum and liver. In conclusion, amiloride inhibits the postprandial increases in jejunal ODC activity and DNA synthesis in the jejunum and liver. The results indicate that (1) the Na + -H + antiport is essential to the increased ODC activity in the jejunum and liver after a meal and (2) increases in DNA synthesis and their suppression by amiloride are not necessary linked to ODC activity

  18. Amiloride inhibits rat mucosal ornithine decarboxylase activity and DNA synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich-Baker, M.G.; Wang, P.; Fitzpatrick, L.; Johnson, L.R. (Univ. of Texas Health Science Center, Houston (USA))

    1988-03-01

    Refeeding fasted rats induces a dramatic trophic response in gastrointestinal mucosa and is associated with elevations in both rate of DNA synthesis and ornithine decarboxylase (ODC) activity. The signal for these increases is unknown. Amiloride prevents cell alkalinization by blocking Na{sup +}-H{sup +} exchange at apical epithelial cell membranes. In study 1, rats were fasted 48 h, treated with amiloride (0.5 to 500 mg/kg), and refed for 4 h. Refeeding increased ODC activities in the jejunal mucosa (X8) and liver (X19) but not in the oxyntic gland mucosa. In the jejunum, but not the liver, the activation of ODC was completely abolished by 100 mg/kg amiloride. In study 2, the rate of DNA synthesis was determine by measuring the rate of ({sup 3}H)thymidine incorporation 16 h after refeeding. Refeeding resulted in significantly increased rates of DNA synthesis over fasted levels, and amiloride at 100 mg/kg significantly reduced the elevations in the jejenum and liver. In conclusion, amiloride inhibits the postprandial increases in jejunal ODC activity and DNA synthesis in the jejunum and liver. The results indicate that (1) the Na{sup +}-H{sup +} antiport is essential to the increased ODC activity in the jejunum and liver after a meal and (2) increases in DNA synthesis and their suppression by amiloride are not necessary linked to ODC activity.

  19. The catalystic asymmetric synthesis of optically active epoxy ketones

    NARCIS (Netherlands)

    Marsman, Bertha Gerda

    1981-01-01

    In this thesis the use of catalytic asymmetric synthesis to prepare optically active epoxy ketones is described. This means that the auxiliary chirality, necessary to obtain an optically active product, is added in a catalytic quantity . In principle this is a very efficient way to make opticlly

  20. Synthesis and Antimicrobial Activities of Some New Pyrazoles ...

    African Journals Online (AJOL)

    NICO

    29 antimalarial,30 antimicrobial,31,32 antiviral,33,34 hypoglycaemic,35 anti-HIV activity,36 insecticidal,37 and anti- fungal38 activities. In view of these reports and in continuation of our previous work39 we describe here a facile synthesis of.

  1. Synthesis and anthelmintic activity of some hybrid Benzimidazolyl ...

    African Journals Online (AJOL)

    Synthesis and anthelmintic activity of some hybrid Benzimidazolyl-chalcone derivatives. ... Tropical Journal of Pharmaceutical Research ... Purpose: To synthesize hybrid benzimidazolyl-chalcone derivatives, evaluate their anthelmintic activity, and establish some structural elements which could lead to induction and ...

  2. Synthesis and Anti-inflammatory Activity of Some Novel ...

    African Journals Online (AJOL)

    Synthesis and Anti-inflammatory Activity of Some Novel Trisubstituted Thiophene Analogues. ... Ethiopian Pharmaceutical Journal ... analogues (IVa-IVf) were designed, synthesized, characterized and evaluated for their anti-inflammatory activity in carrageenin-induced rat hind paw oedema model at 10 mg/kg dose.

  3. Synthesis and antibacterial activity of sulfonamide derivatives at C-8 ...

    Indian Academy of Sciences (India)

    Synthesis and antibacterial activity of some novel biologically active sulfonamide derivatives at C-8 alkyl chain of anacardic acid (7a-7l), prepared from commercially available anacardic acid mixture (1a-d). These compounds were tested for Gram positive and Gram negative bacterial cultures; most of the compounds ...

  4. Donor And Acceptor Containing Monomers

    OpenAIRE

    Gülfidan, Damla

    2012-01-01

    Bu çalışmanın amacı; farklı zincir uzunluklarına sahip donör ve akseptör monomerlerinden oluşturulan kopolimerlerin, düşük enerji tüketimiyle iyi elektron transferi vermesini sağlamaktır. Bu konudan yola çıkarak; farklı zincir uzunluklarında, yan zincirinde karbazol ve naftalimit içeren stirene ve akrilata dayalı donör monomerler (CzMS, CEA, VBEC) ve akseptör monomer (AM) literatüre uygun olarak sentezlenmiştir. Sentezlenen monomerler ve bu monomerlerin radikal polimerizasyon yöntemi ile oluş...

  5. Activation of catalysts for synthesizing methanol from synthesis gas

    Science.gov (United States)

    Blum, David B.; Gelbein, Abraham P.

    1985-01-01

    A method for activating a methanol synthesis catalyst is disclosed. In this method, the catalyst is slurried in an inert liquid and is activated by a reducing gas stream. The activation step occurs in-situ. That is, it is conducted in the same reactor as is the subsequent step of synthesizing methanol from a methanol gas stream catalyzed by the activated catalyst still dispersed in a slurry.

  6. Flash evaporation of liquid monomer particle mixture

    Science.gov (United States)

    Affinito, John D.; Darab, John G.; Gross, Mark E.

    1999-01-01

    The present invention is a method of making a first solid composite polymer layer. The method has the steps of (a) mixing a liquid monomer with particles substantially insoluble in the liquid monomer forming a monomer particle mixture; (b) flash evaporating the particle mixture and forming a composite vapor; and (c) continuously cryocondensing said composite vapor on a cool substrate and cross-linking the cryocondensed film thereby forming the polymer layer.

  7. Synthesis and characterization of graft copolymers of chitosan with NIPAM and binary monomers for removal of Cr(VI), Cu(II) and Fe(II) metal ions from aqueous solutions.

    Science.gov (United States)

    Lalita; Singh, Anirudh P; Sharma, Rajeev Kr

    2017-06-01

    To develop pH responsive hydrogels, N-isopropylacrylamide (NIPAM) has been grafted on to chitosan by free radical initiation method using azoisobutrylnitrile (AIBN) as an initiator. The optimum grafting conditions were worked out for grafting of NIPAM onto 1g of chitosan by varying one reaction parameter at a time and keeping all other parameters constant. Binary monomers were grafted for five different concentrations of comonomers acrylic acid (AAc), acrylamide (AAm) and acrylonitrile (AN) at optimum grafting conditions evaluated for GMA alone onto chitosan. The grafted copolymers were analyzed by FTIR, TGA/DTA, XRD and SEM. The swelling studies for the grafted samples were performed at various pH in order to explore their end use in sorption of Cr(VI), Fe(II) and Cu(II) ions from water system. Metal ion sorption behaviour of polymeric samples was studied as function of time, temperature and pH. Various metal ion sorption parameters such as percent uptake (P u ), partition coefficient (K d ) and retention capacity (Q r ) were discussed. Chitosan grafted with binary monomers NIPAM-co-AAc and NIPAM-co-AAm showed best results for sorption of all three metal ions. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Synthesis and Activation of Catalysts for Biofuel Synthesis in an Environmental Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Duchstein, Linus Daniel Leonhard; Wu, Qiongxiao; Elkjær, Christian Fink

    of CuNi and NiGa catalysts for alcohol synthesis using High-Resolution TEM (HRTEM), energy electron-loss spectroscopy (EELS), Energy-Dispersive X-ray Spectroscopy (EDX). Complementary observations have been done using in-situ X-Ray Diffraction (XRD). We focus on structural changes during the catalysts...... synthesis and activation in a reducing atmosphere at elevated temperature. Changes in phase and particle size distribution with respect to the temperature can be directly observed and correlated to catalytic activity and integral phase information from the in-situ XRD....... promising candidates experimentally. Transmission electron microscopy (TEM) is used for microstructural characterization and provides feedback for both theory and synthesis. We have studied the catalysts close to their working conditions in an environmental transmission electron microscope (ETEM) equipped...

  9. [Synthesis and its application to the synthesis of biologically active natural products of new and versatile chiral building blocks].

    Science.gov (United States)

    Toyooka, N

    2001-07-01

    This article describes a design and synthesis of new and versatile chiral building blocks and its application to the biologically active natural product synthesis. The chiral building blocks were prepared using a biocatalysis in an enantiomerically pure state. As an application of the above chiral building blocks to the synthesis of biologically active natural product, we demonstrated the diastereodivergent synthesis of the 3-piperidinol alkaloids cassine, spectaline, prosafrinine, iso-6-cassine, prosophylline, prosopinine, and also established the flexible route to the 5,8-disubstituted indolizidine or 1,4-disubstituted quinolizidine type of Dendrobates alkaloids. As another application to the synthesis of biologically active alkaloids, we accomplished the first enantioselective total synthesis of marine alkaloids clavepictines A, B, and pictamine using a highly stereoselective Michael type quinolizidine ring closure reaction as the crucial step, and the first total synthesis of a marine alkaloid lepadin B was also achieved using aldol cyclization controlled by a A strain.

  10. Synthesis and antidiabetic activity of β-acetamido ketones

    Directory of Open Access Journals (Sweden)

    Xing-hua Zhang

    2011-08-01

    Full Text Available This paper reports the use of trifluoroacetic acid as a catalyst in the Dakin–West reaction for the synthesis of β-acetamido ketones. The method has several advantages such as requiring only mild conditions and a low concentration of catalyst. Screening of 19 β-acetamido ketones for antidiabetic activity in vitro showed that their activity as peroxisome proliferator-activated receptor (PPAR agonists and as dipeptidyl peptidase 4 (DPP-IV inhibitors was fairly weak.

  11. Step growth of two flexible ABf monomers

    DEFF Research Database (Denmark)

    Cameron, Colin; Fawcett, Allan H.; Hetherington, Cecil R.

    2000-01-01

    A three-dimensional lattice model was used to simulate the competition between the growth of hyperbranched structures and cycle formation that occurs when flexible ABf monomers undergo step growth. The monomers in the model are mapped onto several lattice sites. The effect of functionality was st...... was studied by performing studies with f = 2 and 4....

  12. Synthesis of Stable and Soluble One-Handed Helical Homopoly(substituted acetylenes without the Coexistence of Any Other Chiral Moieties via Two-Step Polymer Reactions in Membrane State: Molecular Design of the Starting Monomer

    Directory of Open Access Journals (Sweden)

    Takashi Kaneko

    2012-01-01

    Full Text Available A soluble and stable one-handed helical poly(substituted phenylacetylene without the coexistence of any other chiral moieties was successfully synthesized by asymmetric-induced polymerization of a chiral monomer followed by two-step polymer reactions in membrane state: (1 removing the chiral groups (desubstitution; and (2 introduction of achiral long alkyl groups at the same position as the desubstitution to enhance the solubility of the resulting one-handed helical polymer (resubstitution. The starting chiral monomer should have four characteristic substituents: (i a chiral group bonded to an easily hydrolyzed spacer group; (ii two hydroxyl groups; (iii a long rigid hydrophobic spacer between the chiral group and the polymerizing group; (iv a long achiral group near the chiral group. As spacer group a carbonate ester was selected. The two hydroxyl groups formed intramolecular hydrogen bonds stabilizing a one-handed helical structure in solution before and after the two-step polymer reactions in membrane state. The rigid long hydrophobic spacer, a phenylethynylphenyl group, enhanced the solubility of the starting polymer, and realized effective chiral induction from the chiral side groups to the main chain in the asymmetric-induced polymerization. The long alkyl group near the chiral group avoided shrinkage of the membrane and kept the reactivity of resubstitution in membrane state after removing the chiral groups. The g value (g = ([θ]/3,300/ε for the CD signal assigned to the main chain in the obtained final polymer was almost the same as that of the starting polymer in spite of the absence of any other chiral moieties. Moreover, since the one-handed helical structure was maintained by the intramolecular hydrogen bonds in a solution, direct observation of the one-handed helicity of the final homopolymer has been realized in CD for the solution for the first time.

  13. Muonium addition to vinyl monomers

    International Nuclear Information System (INIS)

    Stadlbauer, J.M.; Ng, B.W.; Walker, D.C.; Jean, Y.C.; Ito, Y.

    1981-01-01

    The chemical rate constants for the addition of the muonium atom (Mu) across the vinyl double bonds of acrylamide, acrylic acid, acrylonitrile, methylmethacrylate, and styrene were determined in aqueous solution; they are, respectively, ksub(m) = 1.9x10 10 M -1 s -1 ,1.6x10 10 M -1 s -1 , 1.1x10 10 M -1 s -1 , 9.5x10 9 M -1 s -1 , and 1.1 x 10 9 M -1 . Since muonium can be considered a very light isotope of hydrogen, the kinetic isotope effects, ksub(M)/ksub(H), for acrylamide (1.1) and acrylonitrile (2.8) were calculated. The muonium rate constants of these monomers are also compared to those of hydroxyl and methyl radical addition where available. The muonium substituted free radical formed by reaction with styrene is represented by two peaks in the Fourier Transform of the μSR spectrum at 500, 1500 and 2500 G with a hyperfine coupling constant of 213.5 MHz. This spectrum shows that Mu addition to styrene occurs at the vinyl bond only and not at the benzene ring

  14. SYNTHESIS, REACTIVITY AND BIOLOGICAL ACTIVITY OF QUINOXALIN-2-ONE DERIVATIVES

    OpenAIRE

    El Mokhtar Essassi; R. Bouhfid; Y. Kandri Rodi; S. Ferfra; H. Benzeid; Y. Ramli

    2010-01-01

    Quinoxalines have a great interest in various fields and particularly in chemistry, biology and pharmacology. It enabled the researchers to develop many methods for their preparations and to seek new fields of application. In this review, we’ll expose different methods of synthesis of the quinoxalin-2-one, its reactivity and finally we’ll discuss the various biological activities of its derivatives.

  15. Replication stress activates DNA repair synthesis in mitosis

    DEFF Research Database (Denmark)

    Minocherhomji, Sheroy; Ying, Songmin; Bjerregaard, Victoria A

    2015-01-01

    into mitotic prophase triggers the recruitment of MUS81 to CFSs. The nuclease activity of MUS81 then promotes POLD3-dependent DNA synthesis at CFSs, which serves to minimize chromosome mis-segregation and non-disjunction. We propose that the attempted condensation of incompletely duplicated loci in early...

  16. Microwave-assisted green synthesis and antimicrobial activity of ...

    African Journals Online (AJOL)

    Purpose: To synthesize and evaluate the antimicrobial activity of silver nanoparticles (AgNPs) derived from a supercritical carbon dioxide extract of the fresh aerial parts of Phyllanthus niruri. Methods: The synthesis of AgNPs of a P. niruri extract was carried out in a microwave oven. The extraction was carried out using a ...

  17. Study towards diversity oriented synthesis of optically active ...

    Indian Academy of Sciences (India)

    A study towards diversity-oriented synthesis of optically active cyclopentane fused bicyclic frameworks has been accomplished. The common intermediate was prepared from commercially available starting material (S)-carvone. The observations on competition between Grubbs-II catalyzed ring closing metathesis (RCM) ...

  18. Synthesis and antimicrobial activity of some novel thienopyrimidines ...

    Indian Academy of Sciences (India)

    Administrator

    pounds in drug discovery programs. In view of these reports and in continuation of our work on biologi- cally active nitrogen and sulfur heterocycles,. 13–15 we report here the synthesis of some novel thieno- pyrimidines and thienotriazolopyrimidines for the evaluation of their antimicrobial properties. The synthesized ...

  19. Synthesis and Antimicrobial Activities of Some New Pyrazoles ...

    African Journals Online (AJOL)

    Synthesis and Antimicrobial Activities of Some New Pyrazoles, Oxadiazoles and Isoxazole Bearing Benzofuran Moiety. ... South African Journal of Chemistry ... Twelve new compounds were synthesized and their identities have been established on the basis of elemental and spectroscopic analysis such as IR, 1H NMR, ...

  20. Synthesis and antibacterial activity of novel enolphosphate derivatives.

    Science.gov (United States)

    Grison, Claude; Barthes, Nicolas; Finance, Chantal; Duval, Raphael E

    2010-10-01

    A new class of enolphosphates derivatives, the 1-alkenyldiphosphates, was designed and a rapid and efficient synthesis for these compounds was developed. These new molecules showed interesting in vitro antibacterial activities (MIC) against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative pathogens including Pseudomonas aeruginosa and Escherichia coli. 2010 Elsevier Inc. All rights reserved.

  1. Synthesis, characterization and investigation of catalytic activity of ...

    Indian Academy of Sciences (India)

    J. Chem. Sci. Vol. 124, No. 4, July 2012, pp. 827–834. c Indian Academy of Sciences. Synthesis, characterization and investigation of catalytic activity ..... 2004 J. Catal. 222 107. 8. Rajgopal R, Vetrivel R and Rao B S 2000 Catal. Lett. 65 99. 9. Rao B S, Sreekumar K and Jyothi T M 1998 Indian. Patent 2707/98. 10.

  2. Synthesis, spectral characterization and antihaemostatic activity of 1 ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 118; Issue 2. Synthesis, spectral characterization and antihaemostatic activity of 1,2,4-triazoles ... Author Affiliations. Ravindra R Kamble1 Belgur S Sudha1. Department of Chemistry and Food Science, Yuvaraja's College, University of Mysore, Mysore 570 005 ...

  3. Synthesis, crystal structure and catecholase activity of a Ni (II ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 6. Synthesis, crystal structure and catecholase activity of a Ni(II) complex derived from a tetradentate Schiff base ligand. Pradipta Kumar Basu Merry Mitra Amrita Ghosh Latibuddin Thander Chia -Her Lin Rajarshi Ghosh. Rapid Communications Volume 126 ...

  4. Synthesis and aggregation study of optically active tetra--[()-2 ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 122; Issue 6. Synthesis and aggregation study of optically active tetra--[()-2-octanyloxy]-substituted copper and nickel phthalocyanines. Fang-Di Cong Gui Gao Jian-Xin Li Guo-Qing Huang Zhen Wei Feng-Yang Yu Xi-Guang Du Ke-Zhi Xing. Full Papers Volume ...

  5. Synthesis, Characterization and Antimicrobial Activity of Copper(II ...

    African Journals Online (AJOL)

    This study presents the synthesis, characterization and antimicrobial activity of copper(II) complexes of some ortho-substituted aniline Schiff bases (L1–L8). The Schiff bases and their respective copper(II) complexes were characterized by a combination of elemental analysis, infrared and UV/Visible studies. The structures of ...

  6. Synthesis and Antimicrobial Activity of the Essential Oil Compounds ...

    African Journals Online (AJOL)

    NICO

    2012-08-26

    Aug 26, 2012 ... Essential oil constituent, (E)- and (Z)-3-hexenyl nonanoate, antimicrobial, ester synthesis, acid-induced alkene isomerizations. Numerous studies and reviews on the subject matter of com- pounds isolated from plants have demonstrated that essential oil compounds display antimicrobial activity1–7.

  7. Synthesis, characterization and evaluation of biological activities of ...

    African Journals Online (AJOL)

    Original Research Article. Synthesis, characterization and evaluation of biological activities of manganese-doped zinc oxide nanoparticles. Shakeel Ahmad Khan1*, Sammia Shahid1, Waqas Bashir1, Sadia Kanwal2 and. Ahsan Iqbal3. 1Department of Chemistry, University of Management and Technology, Lahore-54000, ...

  8. synthesis, characterisation and antimicrobial activities of cobalt(ii)

    African Journals Online (AJOL)

    Preferred Customer

    *Corresponding author. E-mail: agwara29@yahoo.com; Tel. 237 798 75425. SYNTHESIS, CHARACTERISATION AND ANTIMICROBIAL ACTIVITIES OF. COBALT(II), COPPER(II) AND ZINC(II) MIXED-LIGAND COMPLEXES. CONTAINING 1,10-PHENANTHROLINE AND 2,2'-BIPYRIDINE. M.O. Agwara1*, P.T. Ndifon1, N.B. ...

  9. Synthesis and antimicrobial activity of cholic acid hydrazone analogues.

    Science.gov (United States)

    Rasras, Anas J M; Al-Tel, Taleb H; Al-Aboudi, Amal F; Al-Qawasmeh, Raed A

    2010-06-01

    Synthesis and antimicrobial activity of cholic acid analogues 4a-t are reported. The synthesis of 4a-t was accomplished from ethylcholate 2. The hydrazone moiety was introduced via coupling of the cholic acid hydrazide (3) with appropriately functionalized aldehyde utilizing acetic acid as a catalyst. Quiet of interest in relation to the synthesized hydrazones is the formation of two rotamers s-cis.E and s-trans.E. Most compounds showed stronger antimicrobial activity against Gram-positive bacteria than Cefaclor and Cefixime. Compounds 4d, 4i and 4j indicated 15-fold stronger antimicrobial activities against Enterobacter faecalis compared to Cefaclor and Cefixime. Some of the synthesized compounds (e.g. 4a, 4c, 4d, 4i, and 4l) reflected two-folds less activity against Escherichia coli relative to Cefixime. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  10. Fed-Batch Control and Visualization of Monomer Sequences of Individual ICAR ATRP Gradient Copolymer Chains

    Directory of Open Access Journals (Sweden)

    Dagmar R. D'hooge

    2014-04-01

    Full Text Available Based on kinetic Monte Carlo simulations of the monomer sequences of a representative number of copolymer chains (≈ 150,000, optimal synthesis procedures for linear gradient copolymers are proposed, using bulk Initiators for Continuous Activator Regeneration Atom Transfer Radical Polymerization (ICAR ATRP. Methyl methacrylate and n-butyl acrylate are considered as comonomers with CuBr2/PMDETA (N,N,N′,N′′,N′′-pentamethyldiethylenetriamine as deactivator at 80 °C. The linear gradient quality is determined in silico using the recently introduced gradient deviation ( polymer property. Careful selection or fed-batch addition of the conventional radical initiator I2 allows a reduction of the polymerization time with ca. a factor 2 compared to the corresponding batch case, while preserving control over polymer properties ( ≈ 0.30; dispersity ≈ 1.1. Fed-batch addition of not only I2, but also comonomer and deactivator (50 ppm under starved conditions yields a below 0.25 and, hence, an excellent linear gradient quality for the dormant polymer molecules, albeit at the expense of an increase of the overall polymerization time. The excellent control is confirmed by the visualization of the monomer sequences of ca. 1000 copolymer chains.

  11. Synthesis, characterization and in vitro antibacterial activity of novel ...

    Indian Academy of Sciences (India)

    MARZIEH ABBASI

    dried and activated in vacuum at 100. ◦. C. Activated diatomite. (2 g) was dispersed in dry CH2Cl2 and chlorosulfonic acid. (1 mL) was added to the solution at room temperature. After. 2 h, the white solid was filtered, washed repeatedly by dry. CH2Cl2, and dried at 120. ◦. C for 12 h. 2.3 General procedure for the synthesis of.

  12. Synthesis, characterisation, nuclease and cytotoxic activity of ...

    Indian Academy of Sciences (India)

    Complexes 1 and 2 were evaluated for their nuclease and in vitro anti-tumor activities against human breast and colorectal cancer cell lines. The DNA cleavage and cytotoxic assays revealed that both 1 and 2 are effective in cleaving DNA, while the cytotoxic activity of 1 is better than 2 in both human colon and breast cancer ...

  13. Synthesis and Biological Activities of Some Benzimidazoles ...

    African Journals Online (AJOL)

    The chemical structures of these compounds were elucidated using NMR and elemental analysis. The biological activity of these compounds as fungicides was tested against three commercially known fungicides (C. albicans, patient isolate C. glabrata and C. krusei).The biological activity of two compounds was found to be ...

  14. Design, synthesis and antiproliferative activity of hydroxyacetamide ...

    African Journals Online (AJOL)

    Results: HDAC inhibitory activity of FP10 showed higher IC50 (half-maximal concentration inhibitory activity) of 0.09 μM, whereas standard SAHA molecule showed IC50 of 0.057 μM. On the other hand, FP9 exhibited higher GI50 (50 % of maximal concentration that inhibited cell proliferation) of 22.8 μM against MCF-7 cell ...

  15. Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

    Directory of Open Access Journals (Sweden)

    Khalid Karrouchi

    2018-01-01

    Full Text Available Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. The presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antipsychotic CDPPB, the anti-obesity drug rimonabant, difenamizole, an analgesic, betazole, a H2-receptor agonist and the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. Owing to this diversity in the biological field, this nucleus has attracted the attention of many researchers to study its skeleton chemically and biologically. This review highlights the different synthesis methods and the pharmacological properties of pyrazole derivatives. Studies on the synthesis and biological activity of pyrazole derivatives developed by many scientists around the globe are reported.

  16. Synthesis of Silver nanoparticles (AgNPs) with Antibacterial Activity

    Science.gov (United States)

    Campillo Gloria, E.; Ederley, Vélez; Gladis, Morales; César, Hincapié; Jaime, Osorio; Oscar, Arnache; Uribe José, Ignacio; Franklin, Jaramillo

    2017-06-01

    The synthesis of nanomaterials is currently one of the most active in nanoscience branches; especially those help improve the human quality life. Silver nanoparticles (AgNPs) are an example of this as it is known to have inhibitory and bactericidal effects. In this work, we report the synthesis of silver nanoparticles by chemical reduction method of silver nitrate (AgNO3) from aqueous solution, using a mix of polivinyl pyrrolidone (PVP) - Aloe Vera as reducing agent and for stabilization and control of particle size. Silver nanoparticles obtained were characterized by Scanning Electron Microscopy (SEM), UV-visible spectroscopy and measurements using Zetasizer Nano ZS were applied to size estimation. The existence of surface plasmon resonance peak at λmax ~ 420 nm is evidence of silver nanoparticles formation. It was possible to standardize an appropriate protocol for the evaluation of bactericidal activity of the nanoparticles, for mesophilic microorganisms. Bactericidal activity above 90% against these kinds of bacteria was demonstrated.

  17. Synthesis of high specific activity tritium labelled compounds

    International Nuclear Information System (INIS)

    Parent, P.

    1986-01-01

    Tritiated methyl iodide of high specific activity is synthetized by Fischer-Tropsch reaction of tritium with carbon monoxide, tritiated methanol obtained is reacted with hydriodic acid. It is used for the synthesis of S-adenosyl L-methionine 3 H-methyl and of diazepam 3 H-methyl derivatives. Synthesis of 3-PPP 3 H: (hydroxy-3 phenyl)-3N-n propyl [ 3 H-2.3] piperidine [ 3 H-2.3] with a specific activity of 4.25 T Bq/mM (115 Ci/mM) and of baclofene 3 H with a specific activity of 0.925 TBq (25 Ci/mM) are also described [fr

  18. Synthesis of Silver nanoparticles (AgNPs) with Antibacterial Activity

    International Nuclear Information System (INIS)

    Gloria, E. Campillo; Ederley, Vélez; César, Hincapié; Gladis, Morales; Jaime, Osorio; Oscar, Arnache; José, Ignacio Uribe; Franklin, Jaramillo

    2017-01-01

    The synthesis of nanomaterials is currently one of the most active in nanoscience branches; especially those help improve the human quality life. Silver nanoparticles (AgNPs) are an example of this as it is known to have inhibitory and bactericidal effects. In this work, we report the synthesis of silver nanoparticles by chemical reduction method of silver nitrate (AgNO 3 ) from aqueous solution, using a mix of polivinyl pyrrolidone (PVP) – Aloe Vera as reducing agent and for stabilization and control of particle size. Silver nanoparticles obtained were characterized by Scanning Electron Microscopy (SEM), UV–visible spectroscopy and measurements using Zetasizer Nano ZS were applied to size estimation. The existence of surface plasmon resonance peak at λ max ∼ 420 nm is evidence of silver nanoparticles formation. It was possible to standardize an appropriate protocol for the evaluation of bactericidal activity of the nanoparticles, for mesophilic microorganisms. Bactericidal activity above 90% against these kinds of bacteria was demonstrated. (paper)

  19. MODERN TECHNOLOGY OF ANIONIC POLYMERIZATION MONOMERS

    Directory of Open Access Journals (Sweden)

    A. V. Tkachev

    2013-01-01

    Full Text Available The preconditions of use in the manufacture of automobile tyres of vulcanizates-based mortar butadienestyrene rubber with a high content of 1.2 links butadiene and statistical distribution of styrene are formulated. Set out scientific researches in the field of anionic co-polymerization of diene and vinyl aromatic monomers. Formulation of catalytic systems applied in processes of anionic copolymerization of monomers are given. The reasons of formation of gel in the process of anionic polymerization of monomers and terms of their elimination are considered.

  20. Template Synthesis of Tubular Nanostructures for Loading Biologically Active Molecules.

    Science.gov (United States)

    Karatas, Aysegul; Algan, Aslıhan Hilal

    2017-01-01

    The template synthesis is a low cost, simple and versatile nanofabrication method to produce cylindrical/tubular nanostructures with controllable dimensions such as length, diameter and aspect ratio. This method utilizes nanoporous membranes such as anodized aluminum oxide (AAO) or polycarbonate (PC) as templates which have nanosized specific, cylindrical and uniform inner pores to be coated with the desired material. Template synthesized nanotubular structures have been produced from variety of materials including ceramics, polymers and proteins for loading biologically active molecules. Available procedures of material deposition into the template nanopores consist of several techniques like wetting (melt or solution wetting), layer-by-layer (LbL) assembly and sol-gel chemistry. Template synthesis enables not only control of the geometry of the resulting nanostructures but also provides nanovehicles having separated inner and outer surfaces which can be variously functionalized. Tubular nanostructures fabricated by this method have numerous potential applications including delivery of biologically active molecules such as drugs, gene, enzymes and proteins. In this review we aimed to present up-to-date works on the template based synthesis which has greatly facilitated the fabrication of polymer and protein tubular nanostructures, principally. The strategies regarding the synthesis and designing of these promising tubular nanostructures together with recent approaches relevant of drug delivery was also presented. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. Synthesis and antiproliferative activity of 6-phenylaminopurines.

    Science.gov (United States)

    Canela, María-Dolores; Liekens, Sandra; Camarasa, María-José; Priego, Eva María; Pérez-Pérez, María-Jesús

    2014-11-24

    A series of novel 6-phenylaminopurines have been efficiently synthesized in 3 steps exploring different groups at positions 2, 8 and 9 of the purine ring and at the exocyclic nitrogen atom at position 6. Among the newly described purines, five compounds showed antiproliferative activity with IC50 values below 10 μM, the tetrahydroquinoline derivative at position 6 of phenylaminopurine being the most active of the series in the six cell lines tested. Moreover, the compounds induced G2/M phase arrest in human cervical carcinoma HeLa cells as reported for tubulin depolymerizing agents. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  2. Redesign of the monomer-monomer interface of Cre recombinase yields an obligate heterotetrameric complex.

    Science.gov (United States)

    Zhang, Chi; Myers, Connie A; Qi, Zongtai; Mitra, Robi D; Corbo, Joseph C; Havranek, James J

    2015-10-15

    Cre recombinase catalyzes the cleavage and religation of DNA at loxP sites. The enzyme is a homotetramer in its functional state, and the symmetry of the protein complex enforces a pseudo-palindromic symmetry upon the loxP sequence. The Cre-lox system is a powerful tool for many researchers. However, broader application of the system is limited by the fixed sequence preferences of Cre, which are determined by both the direct DNA contacts and the homotetrameric arrangement of the Cre monomers. As a first step toward achieving recombination at arbitrary asymmetric target sites, we have broken the symmetry of the Cre tetramer assembly. Using a combination of computational and rational protein design, we have engineered an alternative interface between Cre monomers that is functional yet incompatible with the wild-type interface. Wild-type and engineered interface halves can be mixed to create two distinct Cre mutants, neither of which are functional in isolation, but which can form an active heterotetramer when combined. When these distinct mutants possess different DNA specificities, control over complex assembly directly discourages recombination at unwanted half-site combinations, enhancing the specificity of asymmetric site recombination. The engineered Cre mutants exhibit this assembly pattern in a variety of contexts, including mammalian cells. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. SYNTHESIS AND FUNGICIDAL ACTIVITY OF ACETYL ...

    African Journals Online (AJOL)

    a

    large varieties of new sulfur based crop protection chemicals in development around the world. [14, 15]. Methods ... sulfur fission viz, the resonance – stabilized benzyl (or isomeric tropylium) cation [19]. The elimination of ... two well – established fungicides so as to compare their activities with those of compounds 1(a. – d).

  4. Synthesis, spectrometric characterization and trypanocidal activity of ...

    African Journals Online (AJOL)

    ... Coupled with High-Performance Liquid Chromatography) and they were characterized using spectrometry IR, NMR 1H and 13C (Nuclear Magnetic Resonance). These compounds were then tested in vitro on Trypanosoma brucei brucei according to the “LILIT, Alamar Blue” method to estimate their trypanocidal activity.

  5. Synthesis and antimicrobial activity of some 2 ...

    African Journals Online (AJOL)

    These compounds were investigated for their antimicrobial activity against ten bacteria and five fungi by serial plate dilution method using standard drugs, namely, ofloxacin and ketoconazole, respectively, and their minimum inhibitory concentrations (MICs) were also determined. Results: A total of eighteen new compounds ...

  6. Synthesis and antibacterial activity of new chiral ...

    Indian Academy of Sciences (India)

    The compounds were evaluated for their in vitro antibacterial activity against some Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia Coli, Klebsiella pneumonieae, Acinetobacter, Pseudomonas aeruginosa, Enterococcus, Salmonella sp. The compounds showed moderate to good ...

  7. The LOMOsup(R) process: a solution for residual monomers

    International Nuclear Information System (INIS)

    Derbyshire, R.L.

    1979-01-01

    Regulatory activity over the last several years has addressed the potential problems associated with the migration of residual monomers from a number of commodity food packages. Regardless of the outcome of current debates, it will always be desirable to reduce monomer levels to as low a level as economically practicable so that they do not become indirect additives. The LOMO process is a body of technology inclusive of an ionizing radiation treatment which can result in sharp reduction of residual monomer levels in commodity plastic resins. The process may be applicable to factory intermediates, raw resins, or finished articles. Depending upon the individual system and its monomers, LOMO treatment can result in reductions to levels which press today's analytical test capability. Industrial radiation processing is normally accomplished with electron beam accelerators. Electron beam processing continues to gain in understanding and acceptance as one of the very few basic methods by which energy can be imparted to an industrial process system. Typically, whole factories are constructed around one accelerator. (author)

  8. Perturbation of the Monomer-Monomer Interfaces of the Benzoylformate Decarboxylase Tetramer

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Forest H.; Rogers, Megan P.; Paul, Lake N.; McLeish, Michael J. [IUPUI; (Purdue)

    2014-08-14

    The X-ray structure of benzoylformate decarboxylase (BFDC) from Pseudomonas putida ATCC 12633 shows it to be a tetramer. This was believed to be typical of all thiamin diphosphate-dependent decarboxylases until recently when the structure of KdcA, a branched-chain 2-keto acid decarboxylase from Lactococcus lactis, showed it to be a homodimer. This lent credence to earlier unfolding experiments on pyruvate decarboxylase from Saccharomyces cerevisiae that indicated that it might be active as a dimer. To investigate this possibility in BFDC, we sought to shift the equilibrium toward dimer formation. Point mutations were made in the noncatalytic monomer–monomer interfaces, but these had a minimal effect on both tetramer formation and catalytic activity. Subsequently, the R141E/Y288A/A306F variant was shown by analytical ultracentrifugation to be partially dimeric. It was also found to be catalytically inactive. Further experiments revealed that just two mutations, R141E and A306F, were sufficient to markedly alter the dimer–tetramer equilibrium and to provide an ~450-fold decrease in kcat. Equilibrium denaturation studies suggested that the residual activity was possibly due to the presence of residual tetramer. The structures of the R141E and A306F variants, determined to <1.5 Å resolution, hinted that disruption of the monomer interfaces will be accompanied by movement of a loop containing Leu109 and Leu110. As these residues contribute to the hydrophobicity of the active site and the correct positioning of the substrate, it seems that tetramer formation may well be critical to the catalytic activity of BFDC.

  9. Copper Nanoparticles: Synthesis and Biological Activity

    Science.gov (United States)

    Satyvaldiev, A. S.; Zhasnakunov, Z. K.; Omurzak, E.; Doolotkeldieva, T. D.; Bobusheva, S. T.; Orozmatova, G. T.; Kelgenbaeva, Z.

    2018-01-01

    By means of XRD and FESEM analysis, it is established that copper nanoparticles with sizes less than 10 nm are formed during the chemical reduction, which form aggregates mainly with spherical shape. Presence of gelatin during the chemical reduction of copper induced formation of smaller size distribution nanoparticles than that of nanoparticles synthesized without gelatin and it can be related to formation of protective layer. Synthesized Cu nano-powders have sufficiently high activity against the Erwinia amylovora bacterium, and the bacterial growth inhibition depends on the Cu nanoparticles concentration. At a concentration of 5 mg / ml of Cu nanoparticles, the exciter growth inhibition zone reaches a maximum value within 72 hours and the lysis zone is 20 mm, and at a concentration of 1 mg / ml this value is 16 mm, which also indicates the significant antibacterial activity of this sample.

  10. Synthesis and antimycobacterial activity of novel heterocycles

    Directory of Open Access Journals (Sweden)

    M. ASHRAF ALI

    2007-01-01

    Full Text Available In the present investigation 4-hydroxy-3-methylacetophenone on condensation with various aromatic aldehydes in methanolic KOH solution yielded the corresponding chalcones (CI–CXI. These chalcones were further reacted with hydrazine hydrate in ethanol which led to the formation of pyrazoline derivatives (HI–HXI. The newly synthesized heterocyles were characterized on the basis of their chemical properties and spectroscopic data. All newly synthesized compounds were evaluated for their antimycobacterial activities against Mycobacterium tuberculosis H37Rv.

  11. Synthesis and pharmacological activity of diterpenylnaphthoquinone derivatives.

    Science.gov (United States)

    Pertino, Mariano Walter; Theoduloz, Cristina; Palenzuela, Jose Antonio; Afonso, Maria del Mar; Yesilada, Erdem; Monsalve, Francisco; González, Paulo; Droguett, Daniel; Schmeda-Hirschmann, Guillermo

    2011-10-13

    New diterpenylquinones, combining a diterpene diacid and a naphthoquinone, were prepared from junicedric acid and lapachol. The new derivatives were assessed as gastroprotective agents by the HCl-EtOH-induced gastric lesions model in mice as well as for basal cytotoxicity on the following human cell lines: Normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), and hepatocellular carcinoma (Hep G2). Several of the new compounds were significantly active as antiulcer agents and showed selective cytotoxicity against AGS cells.

  12. Synthesis of tritiated thymine and thymidine with high specific activity

    International Nuclear Information System (INIS)

    Shimoni, M.; Buchman, O.

    1977-05-01

    The synthesis of the following compounds is described: (a) thymine - 6 -3 H, with a specific activity of 17.5 Ci/mmol, obtained by the following steps: preparation of uracil - 6 -3 H; chloroformylation of uracil - 6 -3 H; de-halogenation of chloromethyl thymine - 6 -3 H. (b) thymine - methyl -3 H, with a specific activity of 31 Ci/mmol, obtained by reduction of 5 - formyluracil with tritium. (c) thymidine - 6 -3 H and thymidine - methyl -3 H, with specific activities of 8 Ci/mmol and 25 Ci/mmol, respectively, obtained by enzymatic reaction

  13. Synthesis and antifungal activity of new salicylic acid derivatives

    Directory of Open Access Journals (Sweden)

    Wodnicka Alicja

    2017-03-01

    Full Text Available A simple one-step procedure for synthesis of 1-methoxy-1-oxoalkan-2-yl salicylates and 1-methoxy-1-oxoalkan-2-yl 2-[(1-methoxy-1-oxoalkan-2-yloxy]benzoates by reaction of salicylic acid with several methyl 2-bromoalkanoates was developed. The reactions were carried out in N,N-dimethylformamide (DMF in the presence of anhydrous potassium carbonate. Conditions for regioselective synthesis of target compounds were established. The developed procedure could be easily applied in the industrial production process. The new salicylic acid derivatives were obtained with satisfactory yields and were characterized by MS and 1H NMR spectra. The fungicidal activity of the prepared compounds was tested in vitro against seven species of plant pathogenic fungi. The best results were observed for 1-methoxy-1-oxoalkan-2-yl salicylates which showed moderate or good activity against Botrytis cinerea and Rhizoctonia solani.

  14. Synthesis and Pharmacological Activity of Diterpenylnaphthoquinone Derivatives

    Directory of Open Access Journals (Sweden)

    Guillermo Schmeda-Hirschmann

    2011-10-01

    Full Text Available New diterpenylquinones, combining a diterpene diacid and a naphthoquinone, were prepared from junicedric acid and lapachol. The new derivatives were assessed as gastroprotective agents by the HCl-EtOH-induced gastric lesions model in mice as well as for basal cytotoxicity on the following human cell lines: Normal lung fibroblasts (MRC-5, gastric epithelial adenocarcinoma (AGS, and hepatocellular carcinoma (Hep G2. Several of the new compounds were significantly active as antiulcer agents and showed selective cytotoxicity against AGS cells.

  15. Synthesis of Chalcones with Anticancer Activities

    Directory of Open Access Journals (Sweden)

    Syam Mohan

    2012-05-01

    Full Text Available Several chalcones were synthesized and their in vitro cytotoxicity against various human cell lines, including human breast adenocarcinoma cell line MCF-7, human lung adenocarcinoma cell line A549, human prostate cancer cell line PC3, human adenocarcinoma cell line HT-29 (colorectal cancer and human normal liver cell line WRL-68 was evaluated. Most of the compounds being active cytotoxic agents, four of them with minimal IC50 values were chosen and studied in detail with MCF-7 cells. The compounds 1, 5, 23, and 25 were capable in eliciting apoptosis in MCF-7 cells as shown by multiparameter cytotoxicity assay and caspase-3/7, -8, and -9 activities (p < 0.05. The ROS level showed 1.3-fold increase (p < 0.05 at the low concentrations used and thus it was concluded that the compounds increased the ROS level eventually leading to apoptosis in MCF-7 cells through intrinsic as well as extrinsic pathways.

  16. SYNTHESIS, REACTIVITY AND BIOLOGICAL ACTIVITY OF QUINOXALIN-2-ONE DERIVATIVES

    Directory of Open Access Journals (Sweden)

    El Mokhtar Essassi

    2010-04-01

    Full Text Available Quinoxalines have a great interest in various fields and particularly in chemistry, biology and pharmacology. It enabled the researchers to develop many methods for their preparations and to seek new fields of application. In this review, we’ll expose different methods of synthesis of the quinoxalin-2-one, its reactivity and finally we’ll discuss the various biological activities of its derivatives.

  17. Chemical synthesis of biologically active monoglycosylated GM2-activator protein analogue using N-sulfanylethylanilide peptide.

    Science.gov (United States)

    Sato, Kohei; Shigenaga, Akira; Kitakaze, Keisuke; Sakamoto, Ken; Tsuji, Daisuke; Itoh, Kohji; Otaka, Akira

    2013-07-22

    Going to SEA(lide): Total chemical synthesis of a 162-residue glycoprotein analogue of the monoglycosylated human GM2-activator protein (GM2AP) was achieved. Key steps were the use of N-sulfanylethylanilide (SEAlide) peptides in the kinetic chemical ligation synthesis of a large peptide fragment, and a convergent native chemical ligation for final fragment assembly. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Green chemistry approach to the synthesis of potentially bioactive aminobenzylated Mannich bases through active hydrogen compounds

    Directory of Open Access Journals (Sweden)

    S. L. VASOYA

    2005-10-01

    Full Text Available An efficient and high yield method for the synthesis of aminobenzylated Mannich bases is described. The synthesis occurs in aqueous medium at 0 ºC. The compounds show moderate antitubercular and antimicrobial activities.

  19. Synthesis, structure and biological properties of active spirohydantoin derivatives

    Directory of Open Access Journals (Sweden)

    Lazić Anita M.

    2016-01-01

    Full Text Available Spirohidantoins represent an pharmacologically important class of heterocycles since many derivatives have been recognized that display interesting activities against a wide range of biological targets. First synthesis of cycloalkanespiro-5-hydantoins was performed by Bucherer and Lieb 1934 by the reaction of cycloalkanone, potassium cyanide and ammonium-carbonate at reflux in a mixture of ethanol and water. QSAR (Quantitative Structure-Activity Relationship studies showed that a wide range of biological activities of spirohydantoin derivatives strongly depend upon their structure. This paper describes different methods of synthesis of spirohydantoin derivatives, their physico-chemical properties and biological activity. It emphasizes the importance of cycloalkanespiro-5-hydantoins with anticonvulsant, antiproliferative, antipsychotic, antimicrobial and antiinflammatory properties as well as their importance in the treatment of diabetes. Numerous spirohydantoin compounds exhibit physiological activity such as serotonin and fibrinogen antagonist, inhibitors of the glycine binding site of the NMDA receptor also, antagonist of leukocyte cell adhesion, acting as allosteric inhibitors of the protein-protein interactions. Some spirohydantoin derivatives have been identified as antitumor agents. Their activity depends on the substituent presented at position N-3 of the hydantoin ring and increases in order alkene > ester > ether. Besides that, compounds that contain two electron withdrawing groups (e.g. fluorine or chlorine on the third and fourth position of the phenyl ring are better antitumor agents than compounds with a single electron withdrawing group. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  20. Total synthesis and allelopathic activity of cytosporones A-C

    Energy Technology Data Exchange (ETDEWEB)

    Zamberlam, Charles E.M.; Meza, Alisson; Lima, Denis P. de; Beatriz, Adilson [Centro de Ciencias Exatas e Tecnologia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil); Leite, Carla Braga; Marques, Maria Rita [Centro de Ciencias Biologicas e da Saude, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil)

    2012-07-01

    The search for efficient, environmentally friendly herbicides has been the focus of numerous studies on the organic synthesis of compounds isolated from natural sources. Cytosporones, which are phenolic lipids isolated from fungi, exhibit noteworthy biological properties. This paper reports the preparation of cytosporones A-C from the same starting material through a short synthetic route, with good yields. All compounds were tested for allelopathic activity on lettuce (Lactuca sativa L) seeds. Cytosporone A and its methylated precursor showed remarkable allelopathic activity, inhibiting seed germination and plantule growth. (author)

  1. Electrochemically Active Biofilms Assisted Nanomaterial Synthesis for Environmental Applications

    KAUST Repository

    Ahmed, Elaf

    2017-12-01

    Nanomaterials have a great potential for environmental applications due to their high surface areas and high reactivity. This dissertation investigated the use of electrochemically active biofilms (EABs) as a synthesis approach for the fabrication and environmental applications of different nanomaterials. Bacteria in EABs generate electrons upon consuming electron donor and have the ability to transport these electrons to solid or insoluble substrates through extracellular electron transport (EET) mechanism. The extracellularly transported electrons, once utilized, can lead to nanoparticle synthesis. In this dissertation, noble metal (i.e., Au, Pd, and Pt) ultra-small nanoparticles (USNPs) were first synthesized with the assistance by the EABs. The assynthesized USNPs had a size range between 2 and 7 nm and exhibited excellent catalytic performance in dye decomposition. Also in this research, a two-dimensional (2D) cobalt nanosheet was successfully synthesized in the presence of EABs. A simple biogenic route led to the transformation of cobalt acetate to produce a green, toxic free homogeneous 2D cobalt nanosheet structure. Further, TiO2 nanotubes were successfully combined with the noble metal USNPs to enhance their photocatalytic activity. In this work, for the first time, the noble metal USNPs were directly reduced and decorated on the internal surfaces of the TiO2 nanotubes structure assisted by the EABs. The USNPs modified TiO2 nanotubes generated significantly improved photoelectrocatatlyic performances. This dissertation shines lights on the use of EABs in ultra-small nanoparticle synthesis.

  2. The potential dermal irritating effect of residual (meth)acrylic monomers in pressure sensitive adhesive tapes.

    Science.gov (United States)

    Tokumura, Fumio; Matsui, Tetsuya; Suzuki, Yasuko; Sado, Masashi; Taniguchi, Masaharu; Kobayashi, Ichiro; Kamiyama, Masashi; Suda, Shin; Nakamura, Atsushi; Yamazaki, Yuhiro; Yamori, Akira; Igarashi, Ryosuke; Kawai, Jun; Oka, Keiji

    2010-01-01

    It is generally thought that residual unpolymerized (meth)acrylic monomers commonly found in pressure sensitive adhesive tapes for medical use may cause dermal irritation, but a systematic study has never been carried out. Therefore, we assessed the potential dermal irritating effect of residual (meth)acrylic monomers. We studied seven acrylic monomers, acrylic acid (AA), methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (n-BA), n-hexyl acrylate (n-HA), 2-ethylhexyl acrylate (2-EHA) and 2-hydroxyethyl acrylate (HEA), as well as three methacrylic monomers, methacrylic acid (MAA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (2-HEMA). We first examined their cytotoxic effect on a cultured dermis model using the MTT method to determine their EC(50) and then performed a primary irritation test in rabbits using the monomers at three different concentrations (i.e., EC(50) , one-tenth EC(50) and 10 times EC(50)). Marked variations were found in cytotoxic and dermal irritating activities among the (meth)acrylic monomers tested. HEA exhibited the most potent dermal irritation having the lowest erythema dose (the concentration which gives a primary dermal irritation index of 1.00) of 460 ppm. But the other monomers exhibited less potent dermal irritation (lowest erythema doses > or =1000 ppm). For the monomers, significant correlation was found between cytotoxic activity and in vivo dermal irritating activity. Our results show that residual unpolymerized (meth)acrylic monomers in adhesive tapes are unlikely to induce skin irritation except for HEA. This study also suggests that cultured skin models are extremely useful as a screening method for chemical substances that could potentially cause dermal irritating activity.

  3. Design, Synthesis, and Antibacterial Activities of Novel Heterocyclic Arylsulphonamide Derivatives.

    Science.gov (United States)

    Singh, Anuradha; Srivastava, Ritika; Singh, Ramendra K

    2017-02-13

    Design, synthesis, and antibacterial activities of a series of arylsulphonamide derivatives as probable peptide deformylase (PDF) inhibitors have been discussed. Compounds have been designed following Lipinski's rule and after docking into the active site of PDF protein (PDB code: 1G2A) synthesized later on. Furthermore, to assess their antibacterial activity, screening of the compound was done in vitro conditions against Gram-positive and Gram-negative bacterial strains. In silico, studies revealed these compounds as potential antibacterial agents and this fact was also supported by their prominent scoring functions. Antibacterial results indicated that these molecules possessed a significant activity against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli with MIC values ranging from 0.06 to 0.29 μM. TOPKAT results showed that high LD 50 values and the compounds were assumed non-carcinogenic when various animal models were studied computationally.

  4. Polymerization of Polar Monomers from a Theoretical Perspective

    KAUST Repository

    Alghamdi, Miasser

    2016-10-11

    Density functional theory calculations have been used to investigate catalytic mechanism of polymer formation containing polar groups, from the synthesis of the monomer to the synthesis of the macromolecule. In the spirit of a sustainable and green chemistry, we initially focused attention on the coupling of CO2 as economically convenient and recyclable C1 source with C2H4 to form acrylate and/or butirro-lactone, two important polar monomers. In this process formation of a mettallolactone via oxidative coupling of CO2 and C2H4 is an important intermediate. Given this background, we explored in detail (chapter-3) several Ni based catalysts for CO2 coupling with C2H4 to form acrylate. In this thesis we report on the competitive reaction mechanisms (inner vs outer sphere) for the oxidative coupling of CO2 and ethylene for a set of 11 Ni-based complexes containing bisphosphine ligands. In another effort, considering incorporation of a C=C bond into a metal-oxygen-Functional-Group moiety is a challenging step in several polymerization reactions, we explored the details of this reaction (chapter4) using two different catalysts that are capable to perform this reaction in the synthesis of heterocycles. Specifically, the [Rh]-catalyzed intramolecular alkoxyacylation ([Rh] = [RhI(dppp)+] (dppp, 1,3-Bis-diphenylphosphino-propane), and the [Pd]/BPh3 intramolecular alkoxyfunctionalizations. Rest of the thesis we worked on understanding the details of the polymerization of polar monomers using organocatalysts based on N-heterocyclic carbenes (NHC) or N-heterocyclic olefins (NHO). In particular (chapter-5) we studied the polymerization of N-methyl N-carboxy- anhydrides, towards cyclic poly(N-substituted glycine)s, promoted by NHC catalysts. In good agreement with the experimental findings, we demonstrated that NHC promoted ring opening polymerization of N-Me N-Carboxyanhydrides may proceed via two different catalytic pathways. In a similar effort we studied polymerization of

  5. Facile Synthesis, Characterization, and In Vitro Antimicrobial and Anticancer Activities of Biscoumarin Copolyester Bearing Pendant 3-(Trifluoromethyl)Styrene

    OpenAIRE

    Kandaswamy, Narendran; Raveendiran, Nanthini

    2014-01-01

    Synthesis of random biscoumarin copolyester bearing pendant 3-(trifluoromethyl)styrene was prepared by the reaction of biscoumarin monomer 3 and hydroquinone 5 with azeloyl chloride. The influence of pendant 3-(trifluoromethyl)styrene unit on the properties of copolyester such as inherent viscosity, solubility, and thermal stability was investigated and compared in detail. The inherent viscosity and polydispersity index of the copolyester were found to be 0.15?dL/g and 1.36, respectively. The...

  6. Control of DNA synthesis in inhibited and activated Agrostemma githago seeds

    International Nuclear Information System (INIS)

    Hecker, M.

    1975-01-01

    The relationships between DNA synthesis and germination capacity of Agrostemma seeds had been studied. Protein synthesis and RNA synthesis were activated at the very beginning of imbibition, whereas DNA synthesis started in the second part of the imbibition phase. Agrostemma seeds inhibited by higher temperature (30 degC), or aged seeds with a low germination capacity were characterized by a significantly reduced protein synthesis. DNA synthesis was also reduced. The inhibition of the protein synthesis of Agrostemma embryos fed with cycloheximide or actinomycin D caused a depression of DNA synthesis. The results indicated that the initiation of DNA synthesis of imbibing Agrostemma seeds depended on the synthesis of special proteins. Abscisic acid inhibited the growth as well as DNA synthesis of isolated Agrostemma embryos. Nitomycin inhibited germination and DNA synthesis to the same extent. Dormant seeds with an undiminished intensity of protein synthesis also showed a reduced incorporation of 3 H-thymidine by DNA. It is suggested that DNA synthesis of imbibed seeds, which is a necessary prerequisite for the radicle protrusion, was involved in the mechanism of ripening of the Agrostemma seeds. (author)

  7. Synthesis and Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Carmen Steluta Ciobanu

    2013-01-01

    Full Text Available The synthesis of nanosized particles of Ag-doped hydroxyapatite with antibacterial properties is of great interest for the development of new biomedical applications. The aim of this study was the evaluation of Ca10−xAgx(PO46(OH2 nanoparticles (Ag:HAp-NPs for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years and became a major health problem. Here, we report a method for synthesizing Ag doped nanocrystalline hydroxyapatite. A silver-doped nanocrystalline hydroxyapatite was synthesized at 100°C in deionised water. Also, in this paper Ag:HAp-NPs are evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and fungal strains. The specific antimicrobial activity revealed by the qualitative assay is demonstrating that our compounds are interacting differently with the microbial targets, probably due to the differences in the microbial wall structures.

  8. Synthesis and Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles

    Science.gov (United States)

    Ciobanu, Carmen Steluta; Iconaru, Simona Liliana; Chifiriuc, Mariana Carmen; Costescu, Adrian; Le Coustumer, Philippe; Predoi, Daniela

    2013-01-01

    The synthesis of nanosized particles of Ag-doped hydroxyapatite with antibacterial properties is of great interest for the development of new biomedical applications. The aim of this study was the evaluation of Ca10−xAgx(PO4)6(OH)2 nanoparticles (Ag:HAp-NPs) for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years and became a major health problem. Here, we report a method for synthesizing Ag doped nanocrystalline hydroxyapatite. A silver-doped nanocrystalline hydroxyapatite was synthesized at 100°C in deionised water. Also, in this paper Ag:HAp-NPs are evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and fungal strains. The specific antimicrobial activity revealed by the qualitative assay is demonstrating that our compounds are interacting differently with the microbial targets, probably due to the differences in the microbial wall structures. PMID:23509801

  9. Novel synthesis of highly durable and active Pt catalyst encapsulated in nitrogen containing carbon for polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Lee, Hyunjoon; Sung, Yung-Eun; Choi, Insoo; Lim, Taeho; Kwon, Oh Joong

    2017-09-01

    Novel synthesis of a Pt catalyst encapsulated in a N-containing carbon layer for use in a polymer electrolyte membrane fuel cell is described in this study. A Pt-aniline complex, formed by mixing Pt precursor and aniline monomer, was used as the source of Pt, C, and N. Heat treatment of the Pt-aniline complex with carbon black yielded 5 nm Pt nanoparticles encapsulated by a N-containing carbon layer originating from aniline carbonization. The synthesized Pt catalyst exhibited higher mass specific activity to oxygen reduction reaction than that shown by conventional Pt/C catalyst because pyridinic N with graphitic carbon in the carbon layer provided active sites for oxygen reduction reaction in addition to those provided by Pt. In single cell testing, initial performance of the synthesized catalyst was limited because the thick catalyst layer increased resistance related to mass transfer. However, it was observed that the carbon layer successfully prevented Pt nanoparticles from growing via agglomeration and Ostwald ripening under fuel cell operation, thereby improving durability. Furthermore, a mass specific performance of the synthesized catalyst higher than that of a conventional Pt/C catalyst was achieved by modifying the synthesized catalyst's layer thickness.

  10. Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available The acrylate monomer, 7-acryloyloxy-4-methyl coumarin (AMC has been synthesized by reacting 7-hydroxy-4-methyl coumarin, with acryloyl chloride in the presence of NaOH at 0–5°C. Copolymers of 7-acryloyloxy-4-methyl coumarin (AMC with vinyl acetate (VAc were synthesized in DMF (dimethyl formamide solution at 70±1°C using 2,2′-azobisisobutyronitrile (AIBN as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by Fourier transform infra red (FTIR spectroscopy. The copolymer composition was evaluated by 1H-NMR (proton nuclear magnetic resonance and was further used to determine reactivity ratios. The monomer reactivity ratios for AMC (M1-VAc (M2 pair were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 0.6924; r2 = 0.6431, Kelen-Tüdõs (r1 = 0.6776; r2 = 0.6374 and extended Kelen-Tüdõs (r1 = 0.6657; r2 = 0.6256. Thermo gravimetric analysis showed that thermal decomposition of the copolymers occurred in single stage in the temperature range of 263–458°C. The molecular weights of the polymers were determined using gel permeation chromatography. The homo and copolymers were tested for their antimicrobial properties against selected microorganisms.

  11. Softening and elution of monomers in ethanol

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, Erik; Munksgaard, E Christian

    2009-01-01

    The purpose of this study was to investigate the effect of light-curing protocol on softening and elution of monomers in ethanol as measured on a model polymer. It was a further aim to correlate the measured values with previously reported data on degree of conversion and glass transition...

  12. BD monomer and elastomer production processes.

    Science.gov (United States)

    Lynch, J

    2001-06-01

    The monomer 1,3 butadiene (BD) is a product of the petrochemical industry. It is used to make several elastomers including the very high volume styrene butadiene rubber (SBR) that comprises the bulk of automobile tires. It is also used to make polybutadiene rubber that is used in parts of tires, coatings, composites and other products. The monomer can be converted to chlorobutadiene (chloroprene) and used to make polychloroprene (neoprene). BD is one of the several olefins created by cracking hydrocarbons in the presence of steam. A mixed C4 stream from the steam cracker is then sent to a BD monomer extraction unit. Modern units typically use dimethyl formamide as the extraction solvent. SBR is commonly made by the copolymerization of BD and styrene, along with various additives to control the reaction, in a water emulsion. The reaction proceeds in a continuous chain of reactors until it is 'shortstopped' by a strong reducing agent. After removing unreacted monomers from the stabilized latex, it is blended, coagulated and dewatered. The resulting dry rubber crumb is bailed, film wrapped and stored in crates. The polymerization of BD to make polybutadiene rubber can be conducted as a water suspension type polymerization similar to SBR or in a solvent system followed by solvent recovery and transfer into water suspension.

  13. Neodymium Catalyst for the Polymerization of Dienes and Polar Vinyl Monomers.

    Science.gov (United States)

    Kularatne, Ruvanthi N; Yang, Annie; Nguyen, Hien Q; McCandless, Gregory T; Stefan, Mihaela C

    2017-10-01

    Ziegler-Natta catalysts have played a major role in industry for the polymerization of dienes and vinyl monomers. However, due to the deactivation of the catalyst, this system fails to polymerize polar vinyl monomers such as vinyl acetate, methyl methacrylate, and methyl acrylate. Herein, a catalytic system composed of NdCl 3 ⋅3TEP/TIBA is reported, which promotes a quasi-living polymerization of dienes and is also active for the homopolymerization of polar vinyl monomers. Additionally, this catalytic system generates polymyrcene-b-polyisoprene and poly(myrcene)-b-poly(methyl methacrylate) diblock copolymers by sequential monomer addition. To encourage the replacement of petroleum-based polymers by environmentally benign biobased polymers, polymerization of β-myrcene is demonstrated with a catalytic activity of ≈106 kg polymer mol Nd -1 h -1 . © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Synthesis, characteristics and antimicrobial activity of ZnO nanoparticles

    Science.gov (United States)

    Janaki, A. Chinnammal; Sailatha, E.; Gunasekaran, S.

    2015-06-01

    The utilization of various plant resources for the bio synthesis of metallic nano particles is called green technology and it does not utilize any harmful protocols. Present study focuses on the green synthesis of ZnO nano particles by Zinc Carbonate and utilizing the bio-components of powder extract of dry ginger rhizome (Zingiber officinale). The ZnO nano crystallites of average size range of 23-26 nm have been synthesized by rapid, simple and eco friendly method. Zinc oxide nano particles were characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and the presence of ZnO bonding. Antimicrobial activity of ZnO nano particles was done by well diffusion method against pathogenic organisms like Klebsiella pneumonia, Staphylococcus aureus and Candida albicans and Penicillium notatum. It is observed that the ZnO synthesized in the process has the efficient antimicrobial activity.

  15. Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

    International Nuclear Information System (INIS)

    Wang, Jilin; Gu, Yunle; Li, Zili; Wang, Weimin; Fu, Zhengyi

    2013-01-01

    Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH 4 played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B 2 O 3 and KBH 4 as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH 4 played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed

  16. Synthesis and Antibacterial Activity of Antibiotic-Functionalized Graphite Nanofibers

    Directory of Open Access Journals (Sweden)

    Madeline Rotella

    2015-01-01

    Full Text Available Surface functionalization of nanomaterials is an area of current investigation that supports the development of new biomaterials for applications in biology and medicine. Herein we describe the synthesis, characterization, and antibacterial properties of the first examples of antibiotic-labeled graphitic carbon nanofibers (GCNFs covalently functionalized with aminoglycoside and quinolone antibiotics. Ruthenium tetroxide oxidation of herringbone GCNFs gave higher amounts of surface carboxyl groups than previous methods. These carboxyl groups served as sites of attachment for antibiotics by acyl substitution. Bioassay of these novel, functionalized GCNFs using serial dilution and optical density methods demonstrated that antibiotic-labeled GCNFs possess significant antibacterial activity against Pseudomonas aeruginosa. The activity we observe for aminoglycoside-functionalized GCNFs suggests a membranolytic mechanism of action.

  17. Synthesis and Antiangiogenic Activity of N-Alkylated Levamisole Derivatives

    DEFF Research Database (Denmark)

    Hansen, Anders N.; Bendiksen, Christine D.; Sylvest, Lene

    2012-01-01

    less effective than antibody treatment and are also associated with serious side effects. The discovery of new chemotypes with efficient antiangiogenic activity is therefore of pertinent interest. (S)-Levamisole hydrochloride, an anthelminthic drug approved for human use and with a known clinical...... profile, was recently shown to be an inhibitor of angiogenesis in vitro and exhibited tumor growth inhibition in mice. Here we describe the synthesis and in vitro evaluation of a series of N-alkylated analogues of levamisole with the aim of characterizing structure-activity relationships with regard...... to inhibition of angiogenesis. N-Methyllevamisole and p-bromolevamisole proved more effective than the parent compound, (S)-levamisole hydrochloride, with respect to inhibition of angiogenesis and induction of undifferentiated cluster morphology in human umbilical vein endothelial cells grown in co...

  18. A green multicomponent synthesis of tocopherol analogues with antiproliferative activities.

    Science.gov (United States)

    Ingold, Mariana; Dapueto, Rosina; Victoria, Sabina; Galliusi, Germán; Batthyàny, Carlos; Bollati-Fogolín, Mariela; Tejedor, David; García-Tellado, Fernando; Padrón, José M; Porcal, Williams; López, Gloria V

    2018-01-01

    A one-pot efficient, practical and eco-friendly synthesis of tocopherol analogues has been developed using water or solvent free conditions via Passerini and Ugi multicomponent reactions. These reactions can be optimized using microwave irradiation or ultrasound as the energy source. Accordingly, a small library of 30 compounds was prepared for biological tests. The evaluation of the antiproliferative activity in the human solid tumor cell lines A549 (lung), HBL-100 (breast), HeLa (cervix), SW1573 (lung), T-47D (breast), and WiDr (colon) provided lead compounds with GI 50 values between 1 and 5 μM. A structure-activity relationship is also discussed. One of the studied compounds comes up as a future candidate for the development of potent tocopherol-mimetic therapeutic agents for cancer. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Synthesis and Biological Activity of Reversed Pyrimidine Nucleosides

    Directory of Open Access Journals (Sweden)

    Nataša Župančić

    2015-03-01

    Full Text Available An efficient approach to reversed nucleosides which enables their synthesis in gram quantities is described. N-1′-Pyrimidine reversed nucleosides were prepared by treating of the sodium salt of pyrimidine bases with protected 5-tosyl ribose. Additionally, N-1′,N-3′-disubstituted reversed nucleosides were isolated in the condensation reactions with the 5-halogen pyrimidines. Using the Sonogashira coupling of 5′-iodouracil reversed nucleoside with ethynyltrimethyl silane gave 5′-ethynyl derivative which was further transformed into 5′-acetyl reversed nucleoside. Biological activity of deprotected reversed nucleosides was validated on the panel of six human carcinoma cell lines (HeLa, MIAPaCa2, Hep2, NCI-H358, CaCo-2, and HT-29. 5′-Iodouracil derivative displayed moderate growth inhibition activity against human colon carcinoma (CaCo-2 cells.

  20. Synthesis and antibacterial activity of of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Maliszewska, I; Sadowski, Z [Department of Chemistry, Technical University of Wroclaw, Wybrzeze Wyspianskiego 27, 50-370 Wrocnw (Poland)], E-mail: irena.helena.maliszewska@pwr.wroc.pl

    2009-01-01

    Silver nanoparticles have been known to have inhibitory and bactericidal effects but the antimicrobial mechanism have not been clearly revealed. Here, we report on the synthesis of metallic nanoparticles of silver using wild strains of Penicillium isolated from environment. Kinetics of the formation of nanosilver was monitored using the UV-Vis. TEM micrographs showed the formation of silver nanoparticles in the range 10-100 nm. Obtained Ag nanoparticles were evaluated for their antimicrobial activity against the gram-positive and gram-negative bacteria. As results, Bacillus cereus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were effectively inhibited. Nanosilver is a promising candidate for development of future antibacterial therapies because of its wide spectrum of activity.

  1. Rheb Inhibits Protein Synthesis by Activating the PERK-eIF2α Signaling Cascade

    Directory of Open Access Journals (Sweden)

    Richa Tyagi

    2015-02-01

    Full Text Available Rheb, a ubiquitous small GTPase, is well known to bind and activate mTOR, which augments protein synthesis. Inhibition of protein synthesis is also physiologically regulated. Thus, with cell stress, the unfolded protein response system leads to phosphorylation of the initiation factor eIF2α and arrest of protein synthesis. We now demonstrate a major role for Rheb in inhibiting protein synthesis by enhancing the phosphorylation of eIF2α by protein kinase-like ER kinase (PERK. Interplay between the stimulatory and inhibitory roles of Rheb may enable cells to modulate protein synthesis in response to varying environmental stresses.

  2. New hydrazones of ferulic acid: synthesis, characterization and biological activity.

    Science.gov (United States)

    Wolszleger, Maria; Stan, Cătălina Daniela; Apotrosoaei, Maria; Vasincu, Ioana; Pânzariu, Andreea; Profire, Lenuţa

    2014-01-01

    The ferulic acid (4-hydroxy-3-methoxy-cinnamic acid) is a phenolic compound with important antioxidant effects and which nowadays is being extensively studied for his potential indications in inflammatory and neurodegenerative diseases, hypertension, atherosclerosis, etc. The synthesis of new ferulic acid compounds with potential antioxidant activity. The synthesis of the designed compounds was performed in several steps: (i) the obtaining of ferulic acid chloride by reacting of ferulic acid with thionyl chloride; (ii) the reaction between the ferulic acid chloride and hydrazine hydrate 98% to obtain the ferulic acid hydrazide; (iii) the condensation of ferrulic acid hydrazide with various benzaldehydes (2-hydroxy/3-hydroxy/4-hydroxy/2-nitro/3-nitro/4-nitro/2-methoxi/ 4-chloro/4-fluoro/4-bromo-benzaldehyde) resulting the correspond- ing hydrazones. The structure of the synthesized compounds was confirmed by FT-IR spectroscopy and the evaluation of antioxidant potential was achieved by determining the total antioxidant capacity and reducing power. In this study new hydrazones of ferulic acid have been synthesized, physic-chemical and spectral characterized. The evaluation of antioxidant potential using in vitro methods showed the favorable influence of the structural modulation on the antioxidant effects of ferulic acid.

  3. From Delivery to Adoption of Physical Activity Guidelines: Realist Synthesis.

    Science.gov (United States)

    Leone, Liliana; Pesce, Caterina

    2017-10-08

    Evidence-based guidelines published by health authorities for the promotion of health-enhancing physical activity (PA), continue to be implemented unsuccessfully and demonstrate a gap between evidence and policies. This review synthesizes evidence on factors influencing delivery, adoption and implementation of PA promotion guidelines within different policy sectors (e.g., health, transport, urban planning, sport, education). Published literature was initially searched using PubMed, EBSCO, Google Scholar and continued through an iterative snowball technique. The literature review spanned the period 2002-2017. The realist synthesis approach was adopted to review the content of 39 included studies. An initial programme theory with a four-step chain from evidence emersion to implementation of guidelines was tested. The synthesis furthers our understanding of the link between PA guidelines delivery and the actions of professionals responsible for implementation within health services, school departments and municipalities. The main mechanisms identified for guidance implementation were scientific legitimation, enforcement, feasibility, familiarity with concepts and PA habits. Threats emerged to the successful implementation of PA guidelines at national/local jurisdictional levels. The way PA guidelines are developed may influence their adoption by policy-makers and professionals. Useful lessons emerged that may inform synergies between policymaking and professional practices, promoting win-win multisectoral strategies.

  4. Synthesis and Antibacterial Activity of Some New Phenothiazine Derivatives

    Directory of Open Access Journals (Sweden)

    Pawan Kumar Swarnkar

    2007-01-01

    Full Text Available A series of some new phenothiazine derivatives were synthesized with the objective for evaluation as antimicrobials. The title compounds were prepared by a five step synthesis scheme. 2-Amino-6-substituted benzothiazoles (1 on diazotization afford 6-substituted benzothiazolyl-2-diazonium chlorides (2. Reaction of 2 with cold solution of β-naphthol in dilute NaOH furnishes α-(2-diazo-6-substituted benzothiazolyl- β-sodionaphthoxides (3 which on acidification with concentrated HCl gives α-(2-diazo-6-substituted benzothiazolyl-β-naphthols (4. Reaction of 4 with p-substituted anilines gives α-(2-diazo-6-substituted benzothiazolyl-β-(p-substituted anilino naphthalenes (5. This synthesis besides by using conventional methods was also attempted using microwave. Fusion of 5 with sulphur in presence of iodine results in α-(2-diazo-6-substituted benzothiazolyl-6- substituted [2, 3-b] benzophenothiazines(6. The structures of all these compounds have been supported by elemental analysis and their spectral studies. All synthesized compounds were tested for their antibacterial activity using standard drugs.

  5. Oxysterol Restraint of Cholesterol Synthesis Prevents AIM2 Inflammasome Activation.

    Science.gov (United States)

    Dang, Eric V; McDonald, Jeffrey G; Russell, David W; Cyster, Jason G

    2017-11-16

    Type I interferon restrains interleukin-1β (IL-1β)-driven inflammation in macrophages by upregulating cholesterol-25-hydroxylase (Ch25h) and repressing SREBP transcription factors. However, the molecular links between lipid metabolism and IL-1β production remain obscure. Here, we demonstrate that production of 25-hydroxycholesterol (25-HC) by macrophages is required to prevent inflammasome activation by the DNA sensor protein absent in melanoma 2 (AIM2). We find that in response to bacterial infection or lipopolysaccharide (LPS) stimulation, macrophages upregulate Ch25h to maintain repression of SREBP2 activation and cholesterol synthesis. Increasing macrophage cholesterol content is sufficient to trigger IL-1β release in a crystal-independent but AIM2-dependent manner. Ch25h deficiency results in cholesterol-dependent reduced mitochondrial respiratory capacity and release of mitochondrial DNA into the cytosol. AIM2 deficiency rescues the increased inflammasome activity observed in Ch25h -/- . Therefore, activated macrophages utilize 25-HC in an anti-inflammatory circuit that maintains mitochondrial integrity and prevents spurious AIM2 inflammasome activation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Synthesis and Free Radical Scavenging Activity of New Hydroxybenzylidene Hydrazines

    Directory of Open Access Journals (Sweden)

    Frantisek Sersen

    2017-05-01

    Full Text Available Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene-N′-[2,6-dinitro-4-(trifluoromethyl]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were tested for their activity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH, galvinoxyl radical (GOR, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS radicals. The free radical scavenging activity expressed as SC50 values of these compounds varied in a wide range, from a strong to no radical scavenging effect. The most effective radical scavengers were hydroxybenzylidene hydrazines containing three hydroxyl groups in the benzylidene part of their molecules. The prepared compounds were also tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts. IC50 values of these compounds varied in wide range, from an intermediate to no inhibitory effect.

  7. Determination of caprolactam and residual vinyl caprolactam monomer in soluplus by mixed mode gel permeation chromatography.

    Science.gov (United States)

    Soman, Ashish; Jerfy, Madhuri

    2014-01-01

    Soluplus, a graft copolymer of polyethylene glycol, vinyl caprolactam and vinyl acetate, is designed to solubilize poorly soluble active pharmaceutical ingredients. A straightforward aqueous gel permeation chromatography method that exploits both size exclusion and adsorption modes of separation was used to separate and quantify the related residual vinyl caprolactam monomer and caprolactam impurity present in Soluplus. This methodology offers a single step analysis of caprolactam and the residual vinyl caprolacatam monomer, yielding similar results to reversed-phase chromatography measurements, which are time-consuming and may involve multi-step sample preparation. The results of this study demonstrate that gel permeation chromatography provides a viable option to traditional reversed-phase chromatography in the quantitative analysis of residual caprolactam and vinyl caprolactam monomers and can be extended to other monomer-polymeric systems.

  8. Resin adhesion strengths to zirconia ceramics after primer treatment with silane coupling monomer or oligomer.

    Science.gov (United States)

    Okada, Masahiro; Inoue, Kazusa; Irie, Masao; Taketa, Hiroaki; Torii, Yasuhiro; Matsumoto, Takuya

    2017-09-26

    Resin bonding to zirconia ceramics is difficult to achieve using the standard methods for conventional silica-based dental ceramics, which employ silane coupling monomers as primers. The hypothesis in this study was that a silane coupling oligomer -a condensed product of silane coupling monomers- would be a more suitable primer for zirconia. To prove this hypothesis, the shear bond strengths between a composite resin and zirconia were compared after applying either a silane coupling monomer or oligomer. The shear bond strength increased after applying a non-activated ethanol solution of the silane coupling oligomer compared with that achieved when applying the monomer. Thermal treatment of the zirconia at 110°C after application of the silane coupling agents was essential to improve the shear bond strength between the composite resin cement and zirconia.

  9. Hydrophobic Coatings on Cotton Obtained by in Situ Plasma Polymerization of a Fluorinated Monomer in Ethanol Solutions.

    Science.gov (United States)

    Molina, Ricardo; Teixidó, Josep Maria; Kan, Chi-Wai; Jovančić, Petar

    2017-02-15

    Plasma polymerization using hydrophobic monomers in the gas phase is a well-known technology to generate hydrophobic coatings. However, synthesis of functional hydrophobic coatings using plasma technology in liquids has not yet been accomplished. This work is consequently focused on polymerization of a liquid fluorinated monomer on cotton fabric initiated by atmospheric plasma in a dielectric barrier discharge configuration. Functional hydrophobic coatings on cotton were successfully achieved using in situ atmospheric plasma-initiated polymerization of fluorinated monomer dissolved in ethanol. Gravimetric measurements reveal that the amount of polymer deposited on cotton substrates can be modulated with the concentration of monomer in ethanol solution, and cross-linking reactions occur during plasma polymerization of a fluorinated monomer even without the presence of a cross-linking agent. FTIR and XPS analysis were used to study the chemical composition of hydrophobic coatings and to get insights into the physicochemical processes involved in plasma treatment. SEM analysis reveals that at high monomer concentration, coatings possess a three-dimensional pattern with a characteristic interconnected porous network structure. EDX analysis reveals that plasma polymerization of fluorinated monomers takes place preferentially at the surface of cotton fabric and negligible polymerization takes place inside the cotton fabric. Wetting time measurements confirm the hydrophobicity of cotton coatings obtained although equilibrium moisture content was slightly decreased. Additionally, the abrasion behavior and resistance to washing of plasma-coated cotton has been evaluated.

  10. New biosourced AA and AB monomers from 1,4:3,6-dianhydrohexitols, Isosorbide, Isomannide, and Isoidide.

    Science.gov (United States)

    Saadaoui, Asma; Medimagh, Raouf; Marque, Sylvain; Prim, Damien; Chatti, Saber; Casabianca, Herve; Said Zina, Mongia

    2017-01-01

    In the present work, we propose the synthesis of a new family of sugar derived 1,4:3,6-dianhydrohexitol based AA/AB-type monomers. Unprecedented diacids based on Isomannide and Isoidide were elaborated with high yields and showed interestingly high melting point ranges (240-375 °C). Optimization of reaction conditions (temperature, time of reaction, and reactant ratios) has been investigated to synthesize the key intermediate of a set of AB monomers with acid, ester, and acid chloride functionalities. Isosorbide based ether benzoic acid AB monomer was polymerized and characterized by NMR and DSC techniques. The results show a semicrystalline behavior of the obtained polymer thanks to the controlled stereoregular arrangement of the AB starting monomer.

  11. Photokopolimerisasi monomer akrilat degan kulit kras sapi

    Directory of Open Access Journals (Sweden)

    Dwi Wahini Nurhajati

    1997-06-01

    Full Text Available The research on photocopolymerization of acrylate monomer with cow crust hide had object to observe the resulted copolymer onto cow crust hide. Crust hides, saturated with aqueous emulsions containing 25 wt % of n-butyl acrylate (n-BA or tripropylene glycol diacrylate (TPGDA were irradiated by cobalt – 60 gamma rays with doses ranges from 5 to 25 kGy. The irradiated hides were washed with water, dried in air and extracted in soxhlet apparatus for 48 hours to remove homopolymer. The highest yield of photocopolymerization of n – butyl acrylate monomer with crust hides was found 17,7878% at dose 25 kGy, and for photocopolymerization of tripropylene glycol diacrylate with crust hides was found 39,4245% at dose 20 kGy.

  12. Synthesis, antimicrobial, and antiproliferative activities of substituted phenylfuranylnicotinamidines

    Directory of Open Access Journals (Sweden)

    Youssef MM

    2016-03-01

    Full Text Available Magdy M Youssef,1,2 Reem K Arafa,3,4 Mohamed A Ismail1,21Department of Chemistry, College of Science, King Faisal University, Hofuf, Saudi Arabia; 2Department of Chemistry, Faculty of Science, Mansoura University, Mansoura, 3Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Cairo University, Cairo, 4Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Cairo, EgyptAbstract: This research work deals with the design and synthesis of a series of substituted phenylfuranylnicotinamidines 4a–i. Facile preparation of the target compounds was achieved by Suzuki coupling-based synthesis of the nitrile precursors 3a–i, followed by their conversion to the corresponding nicotinamidines 4a–i utilizing LiN(TMS2. The antimicrobial activities of the newly synthesized nicotinamidine derivatives were evaluated against the Gram-negative bacterial strains Escherichia coli and Pseudomonas aeruginosa as well as the Gram-positive bacterial strains Staphylococcus aureus and Bacillus megaterium. The minimum inhibitory concentration values of nicotinamidines against all tested microorganisms were in the range of 10–20 µM. In specific, compounds 4a and 4b showed excellent minimum inhibitory concentration values of 10 µM against Staphylococcus aureus bacterial strain and were similar to ampicillin as an antibacterial reference. On the other hand, selected nicotinamidine derivatives were biologically screened for their cytotoxic activities against a panel of 60 cell lines representing nine types of human cancer at a single high dose at National Cancer Institute, Bethesda, MD, USA. Nicotinamidines showing promising activities were further assessed in a five-dose screening assay to determine their compound concentration causing 50% growth inhibition of tested cell (GI50, compound concentration causing 100% growth inhibition of tested cell (TGI, and compound concentration causing 50% lethality of tested

  13. Synthesis of high specific activity tritiated dihydropyridines: nicardipine- sup 3 H

    Energy Technology Data Exchange (ETDEWEB)

    Parnes, H.; Huang, G.T. (Syntex Research, Palo Alto, CA (USA). Inst. of Organic Chemistry)

    1991-01-01

    The synthesis of high specific activity 3-nitrobenzaldehyde-(4,6-{sup 3}H), a key intermediate in the general synthesis of tritiated 4-aryldihydropyridines, is described. This substance was then used to prepare the calcium channel entry blocker, nicardipine-(4',6'-{sup 3}H) at a specific activity of 51 Ci/mmole via the Hantzsch process. (author).

  14. Biologically Active Macrocyclic Compounds – from Natural Products to Diversity‐Oriented Synthesis

    DEFF Research Database (Denmark)

    Madsen, Charlotte Marie; Clausen, Mads Hartvig

    2011-01-01

    Macrocyclic compounds are attractive targets when searching for molecules with biological activity. The interest in this compound class is increasing, which has led to a variety of methods for tackling the difficult macrocyclization step in their synthesis. This microreview highlights some recent...... developments in the synthesis of macrocycles, with an emphasis on chemistry developed to generate libraries of putative biologically active compounds....

  15. Synthesis, characterization and catalytic activity of CdO nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Singh, G., E-mail: gsingh4us@yahoo.com [Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur 273009 (India); Kapoor, I.P.S.; Dubey, Reena; Srivastava, Pratibha [Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur 273009 (India)

    2011-02-15

    In this paper, we report the synthesis of nanocrystalline cadmium oxide (CdO) and its characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Its catalytic activity was investigated on the thermal decomposition of 1,2,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), ammonium perchlorate (AP), hydroxyl terminated polybutadiene (HTPB) and composite solid propellants (CSPs) using thermogravimetric analysis (TG), simultaneous thermogravimerty and differential scanning calorimetry (TG-DSC) and ignition delay measurements. Kinetics of thermal decomposition of AP + CdO has also been investigated using model free (isoconversional) and model-fitting approaches which have been applied to data for isothermal TG decomposition. All these studies show enhancement in the rate of decomposition of AP, HTPB and CSPs but no effect on HMX. The burning rate of CSPs has also been found to be increased with CdO nanocrystals.

  16. Synthesis and Antiproliferative Activity of Some Quinoline and Oxadiazole Derivatives

    Directory of Open Access Journals (Sweden)

    Mohamed Jawed Ahsan

    2016-01-01

    Full Text Available In continuance of our search for newer antiproliferative agents we report herein the synthesis and antiproliferative studies of two series (5a–j and 10a–c of heterocyclic compounds. All the new compounds were characterized by IR, NMR, and mass spectral data. The antiproliferative activity of 10 compounds (5a–j was carried out on HeLa (cervix cancer cell line and MDA-MB-435 (melanoma and LC50, TGI, and GI50 were calculated, while the antiproliferative activity of 3 compounds (10a–c was carried out against nine different panels of nearly 60 cell lines (NCI-60 according to the National Cancer Institute (NCI US Protocol at 10 μM. 1-(7-Hydroxy-4-methyl-2-oxoquinolin-1(2H-yl-3-(4-methoxylphenylurea (5j was found to have antiproliferative activity with GI50 of 35.1 μM against HeLa (cervix cancer cell line and 60.4 μM against MDA-MB-435 (melanoma, respectively. The compounds 10a, 10b, and 10c showed antiproliferative activity with comparatively higher selectivity towards HOP-92 (Non-Small Cell Lung Cancer with percent growth inhibitions (GIs of 34.14, 35.29, and 31.59, respectively.

  17. Highly Selective Synthesis of Catalytically Active Monodisperse Rhodium Nanocubes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Grass, M.E.; Kuhn, J.N.; Tao, F.; Habas, S.E.; Huang, W.; Yang, P.; Somorjai, G.A.

    2009-02-21

    Synthesis of monodisperse and shape-controlled colloidal inorganic nanocrystals (NCs) is of increasing scientific interest and technological significance. Recently, shape control of Pt, Pd, Ag, Au, and Rh NCs has been obtained by tuning growth kinetics in various solution-phase approaches, including modified polyol methods, seeded growth by polyol reduction, thermolysis of organometallics, and micelle techniques. Control of reduction kinetics of the noble metal precursors and regulation of the relative growth rates of low-index planes (i.e. {l_brace}100{r_brace} and {l_brace}111{r_brace}) via selective adsorption of selected chemical species are two keys for achieving shape modification of noble metal NCs. One application for noble metal NCs of well-defined shape is in understanding how NC faceting (determines which crystallographic planes are exposed) affects catalytic performance. Rh NCs are used in many catalytic reactions, including hydrogenation, hydroformylation, hydrocarbonylation, and combustion reactions. Shape manipulation of Rh NCs may be important in understanding how faceting on the nanoscale affects catalytic properties, but such control is challenging and there are fewer reports on the shape control of Rh NCs compared to other noble metals. Xia and coworkers obtained Rh multipods exhibiting interesting surface plasmonic properties by a polyol approach. The Somorjai and Tilley groups synthesized crystalline Rh multipods, cubes, horns and cuboctahedra, via polyol seeded growth. Son and colleagues prepared catalytically active monodisperse oleylamine-capped tetrahedral Rh NCs for the hydrogenation of arenes via an organometallic route. More recently, the Somorjai group synthesized sizetunable monodisperse Rh NCs using a one-step polyol technique. In this Communication, we report the highly selective synthesis of catalytically active, monodisperse Rh nanocubes of < 10 nm by a seedless polyol method. In this approach, Br{sup -} ions from trimethyl

  18. Silver nanoparticles: green synthesis and their antimicrobial activities.

    Science.gov (United States)

    Sharma, Virender K; Yngard, Ria A; Lin, Yekaterina

    2009-01-30

    This review presents an overview of silver nanoparticles (Ag NPs) preparation by green synthesis approaches that have advantages over conventional methods involving chemical agents associated with environmental toxicity. Green synthetic methods include mixed-valence polyoxometallates, polysaccharide, Tollens, irradiation, and biological. The mixed-valence polyoxometallates method was carried out in water, an environmentally-friendly solvent. Solutions of AgNO(3) containing glucose and starch in water gave starch-protected Ag NPs, which could be integrated into medical applications. Tollens process involves the reduction of Ag(NH(3))(2)(+) by saccharides forming Ag NP films with particle sizes from 50-200 nm, Ag hydrosols with particles in the order of 20-50 nm, and Ag colloid particles of different shapes. The reduction of Ag(NH(3))(2)(+) by HTAB (n-hexadecyltrimethylammonium bromide) gave Ag NPs of different morphologies: cubes, triangles, wires, and aligned wires. Ag NPs synthesis by irradiation of Ag(+) ions does not involve a reducing agent and is an appealing procedure. Eco-friendly bio-organisms in plant extracts contain proteins, which act as both reducing and capping agents forming stable and shape-controlled Ag NPs. The synthetic procedures of polymer-Ag and TiO(2)-Ag NPs are also given. Both Ag NPs and Ag NPs modified by surfactants or polymers showed high antimicrobial activity against gram-positive and gram-negative bacteria. The mechanism of the Ag NP bactericidal activity is discussed in terms of Ag NP interaction with the cell membranes of bacteria. Silver-containing filters are shown to have antibacterial properties in water and air purification. Finally, human and environmental implications of Ag NPs to the ecology of aquatic environment are briefly discussed.

  19. Elution of Monomers from Provisional Composite Materials

    Directory of Open Access Journals (Sweden)

    Simon Daniel Schulz

    2015-01-01

    Full Text Available The aim of this study was to evaluate the elution of substances from different materials used for the manufacturing of temporary indirect restorations, after storage in saliva and ethanol 75%. 10 samples of three chemically cured materials (Protemp 3 Garant, Systemp.c&b, and Trim and one light-cured material (Clip F were stored in saliva and ethanol 75% for 24 h, 7, and days 28 days. From the storage media at each time period, samples were prepared and analysed by LC-MS/MS, in order to access the elution of monomers. The results differed among the materials (P ≤ 0.05. No monomers were detected in the samples of Protemp 3 Garant and Clip F. Substances were detected only in ethanol samples of Systemp.c&b and Trim. The amount of BisGMA, TEGDMA, and UDMA 2 released from Systemp.c&b was higher compared to Trim. Storage time affected the release of substances (P ≤ 0.05. The highest release was observed within the first 24 h. It can be concluded that provisional resin composite materials do not show high release of monomers and this release is material dependent. However, the detection of additional peaks during the analysis, suggesting the formation of by-products of the eluted substances, may not be in favour of these materials with respect to their toxicity.

  20. 21 CFR 888.4220 - Cement monomer vapor evacuator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or remove...

  1. Synthesis, antibacterial and cytotoxic activity evaluation of hydroxyurea derivatives.

    Science.gov (United States)

    Kos, Ivan; Jadrijević-Mladar, Milena; Butula, Ivan; Biruš, Mladen; Maravić-Vlahoviček, Gordana; Dabelić, Sanja

    2013-06-01

    5 Synthesis and biological evaluation of a series (N = 16) of cyclic and acyclic hydroxyurea derivatives, including benzotriazole-, isocyanuric acid- and biuret-containing compounds, are disclosed. 1-N-(benzyloxycarbamoyl)benzotriazole was used as a benzyloxyisocyanate donor, a useful intermediate in the preparation of substituted hydroxyurea. Antibacterial activities of synthesized hydroxyurea derivatives were tested on three E. coli strains, i.e., a strain susceptible to antibiotics, a strain resistant to macrolide antibiotics and a strain resistant to aminoglycoside antibiotics. Six compounds (three acyclic and three cyclic hydroxyureas) showed growth inhibition of the tested E. coli strains, with different specificity toward each strain. Results of the cytotoxic activity evaluation revealed that twelve out of sixteen test compounds were cytotoxic to human acute monocytic leukemia THP-1 and/or human acute T cell leukemia Jurkat cell line. 1-(N-hydroxycarbamoyl) benzotriazole () increased the metabolic activity of both cell lines. Two compounds, 1-(N-hydroxycarbamoyl) benzotriazole (5) and N,N',N''-trihydroxybiuret (15), were identified as potential NO donors.

  2. Synthesis and biological activities of turkesterone 11?-acyl derivatives

    Directory of Open Access Journals (Sweden)

    Laurence Dinan

    2003-02-01

    Full Text Available Turkesterone is a phytoecdysteroid possessing an 11alpha-hydroxyl group. It is an analogue of the insect steroid hormone 20-hydroxyecdysone. Previous ecdysteroid QSAR and molecular modelling studies predicted that the cavity of the ligand-binding domain of the ecdysteroid receptor would possess space in the vicinity of C-11/C-12 of the ecdysteroid. We report the regioselective synthesis of a series of turkesterone 11alpha-acyl derivatives in order to explore this possibility. The structures of the analogues have been unambiguously determined by spectroscopic means (NMR and low-resolution mass spectrometry. Purity was verified by HPLC. Biological activities have been determined in Drosophila melanogaster BII cell-based bioassay for ecdysteroid agonists and in an in vitro radioligand-displacement assay using bacterially expressed D. melanogaster EcR/USP receptor proteins. The 11alpha-acyl derivatives do retain a significant amount of biological activity relative to the parent ecdysteroid. Further, although activity initially drops with the extension of the acyl chain length (C2 to C4, it then increases (C6 to C10, before decreasing again (C14 and C20. The implications of these findings for the interaction of ecdysteroids with the ecdysteroid receptor and potential applications in the generation of affinity-labelled and fluorescently-tagged ecdysteroids are discussed.

  3. Design, Synthesis and Biological Activity of Novel Reversible Peptidyl FVIIa Inhibitors Rh-Catalyzed Enantioselective Synthesis of Diaryl Amines

    DEFF Research Database (Denmark)

    Storgaard, Morten

    This thesis describes two different projects. The first project deals with the design, synthesis and biological activity of novel reversible peptidyl FVIIa inhibitors (Chapter 1–3). FVIIa was launced as NovoSeven R over a decade ago by Novo Nordisk for the treatment of hemophilia A and B complica......This thesis describes two different projects. The first project deals with the design, synthesis and biological activity of novel reversible peptidyl FVIIa inhibitors (Chapter 1–3). FVIIa was launced as NovoSeven R over a decade ago by Novo Nordisk for the treatment of hemophilia A and B...

  4. Understanding the activity of Zn-Cu sites in methanol synthesis

    NARCIS (Netherlands)

    Batyrev, E.D.

    2013-01-01

    This thesis deals with the Cu/ZnO interaction in activated methanol synthesis catalysts. A combination of classical characterization techniques and surface science techniques was applied to probe the dynamic modification of catalyst structure upon the activation in hydrogen.

  5. Synthesis, characterization and antimicrobial activity of some novel benzimidazole derivatives.

    Science.gov (United States)

    Krishnanjaneyulu, Immadisetty Sri; Saravanan, Govindaraj; Vamsi, Janga; Supriya, Pamidipamula; Bhavana, Jarugula Udaya; Sunil Kumar, Mittineni Venkata

    2014-01-01

    A series of novel N-((1H-benzoimidazol-1-yl) methyl)-4-(1-phenyl-5-substituted-4, 5-dihydro-1-benzoimidazol-1-yl) methyl)-4-(1-phenyl-5-substituted-4, 5-dihydro-1H-pyrazol-3-yl) benzenamine were synthesized by treating various 1-(4-((1H-benzoimidazol-1-yl) methylamino) phenyl)-3-substitutedprop-2-en-1-one with phenyl hydrazine in the presence of sodium acetate through a simple ring closure reaction. The starting material, 1-(4-((1H-benzoimidazol-1-yl) methylamino) phenyl)-3-substitutedprop-2-en-1-one,-benzoimidazol-1-yl) methylamino) phenyl)-3-substitutedprop-2-en-1-one, was synthesized from o-phenylenediamine by a multistep synthesis. All the synthesized compounds were characterized by spectroscopic means and elemental analyses. The title compounds were investigated for in vitro antibacterial and antifungal properties against some human pathogenic microorganisms by employing the agar streak dilution method using Ciprofloxacin and Ketoconazole as standard drugs. All title compounds showed activity against the entire strains of microorganism. Structural activity relationship studies reveal that compounds possessing an electron-withdrawing group display better activity than the compounds containing electron-donating groups, whereas the unsubstituted derivatives display moderate activity. Based on the results obtained, N-((1H-benzoimidazol-1-yl) methyl)-4-(1-phenyl-5-(4-(trifluoromethyl) phenyl)-4,5-dihydro-1H-pyrazol-3-yl) benzenamine 5i was found to be very active compared with the rest of the compounds and standard drugs that were subjected to antimicrobial assay.

  6. Synthesis, characterization and antimicrobial activity of some novel benzimidazole derivatives

    Directory of Open Access Journals (Sweden)

    Immadisetty Sri Krishnanjaneyulu

    2014-01-01

    Full Text Available A series of novel N-((1H-benzoimidazol-1-yl methyl-4-(1-phenyl-5-substituted-4, 5-dihydro-1-benzoimidazol-1-yl methyl-4-(1-phenyl-5-substituted-4, 5-dihydro-1H-pyrazol-3-yl benzenamine were synthesized by treating various 1-(4-((1H-benzoimidazol-1-yl methylamino phenyl-3-substitutedprop-2-en-1-one with phenyl hydrazine in the presence of sodium acetate through a simple ring closure reaction. The starting material, 1-(4-((1H-benzoimidazol-1-yl methylamino phenyl-3-substitutedprop-2-en-1-one,-benzoimidazol-1-yl methylamino phenyl-3-substitutedprop-2-en-1-one, was synthesized from o-phenylenediamine by a multistep synthesis. All the synthesized compounds were characterized by spectroscopic means and elemental analyses. The title compounds were investigated for in vitro antibacterial and antifungal properties against some human pathogenic microorganisms by employing the agar streak dilution method using Ciprofloxacin and Ketoconazole as standard drugs. All title compounds showed activity against the entire strains of microorganism. Structural activity relationship studies reveal that compounds possessing an electron-withdrawing group display better activity than the compounds containing electron-donating groups, whereas the unsubstituted derivatives display moderate activity. Based on the results obtained, N-((1H-benzoimidazol-1-yl methyl-4-(1-phenyl-5-(4-(trifluoromethyl phenyl-4,5-dihydro-1H-pyrazol-3-yl benzenamine 5i was found to be very active compared with the rest of the compounds and standard drugs that were subjected to antimicrobial assay.

  7. Facile synthesis of allyl resinate monomer in an aqueous solution ...

    Indian Academy of Sciences (India)

    as oligomer products such as inks and coatings. Com- pared with the oligomer from fossil resources such as acrylic resins and styrene resins, we believe the intro- duction of the resin structure into polymer products can provide specific mechanical properties, such as hardness and flexibility. GC analysis of each component ...

  8. and cobalt(III) octahedral monomer complexes: Synthesis and ...

    Indian Academy of Sciences (India)

    In compound 2 the central cobalt is in +3 oxidation state while `in' compound 2, the nickel ion is in +2 oxidation state. The two complexes are isostructural with octahedral coordination environment exhibiting helical twist topology. They also display strong H-bonding as well as CH- interactions to generate 1D chain.

  9. Facile synthesis of allyl resinate monomer in an aqueous solution ...

    Indian Academy of Sciences (India)

    rosin brings benefits to the sustainable development of the Chinese chemical industry. Nowadays, rosin has been widely used in industry in various forms. Rosin ester is one of the most important rosin derivative products and has been applied exten- sively due to its excellent properties. However, unlike common carboxylic ...

  10. Phenylethynyl Silsesquioxanes: Monomer Synthesis, Characterization,Thermolysis and Thermal Properties

    Science.gov (United States)

    2016-12-14

    Lamb , J. Reams, K. Ghiassi, J. Mabry, A. Guenthner 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...AVENUE E H IG H W A Y 14 LA N C A S TE R B LV D . 14 0t h S TR E E T E A S T RESERVATION BOUNDARY 0 5 10 SCALE IN MILES HWY 395 ROSAMOND BLVD. MERCURY...Materials Group • Dr. Jeffrey Alston • Dr. Kamran Ghiassi • Mr. Kevin Greeson • Dr. Andrew Guenthner • Dr. Timothy Haddad • Mr. Jason Lamb • Mr.

  11. Facile synthesis of allyl resinate monomer in an aqueous solution ...

    Indian Academy of Sciences (India)

    Institute of Chemical Industry of Forest Products, CAF; National Engineering Laboratory for Biomass Chemical Utilization; Key and Open Laboratory on Forest Chemical Engineering, SFA; Key Laboratory of Biomass Energy and Material, Jiangsu Province, Nanjing 210042, China; Research Institute of Forestry New ...

  12. Inhibition of odontogenic differentiation of human dental pulp cells by dental resin monomers.

    Science.gov (United States)

    Kwon, Ji Hyun; Park, Hee Chul; Zhu, Tingting; Yang, Hyeong-Cheol

    2015-01-01

    Dental resin monomers that are leached from the resin matrix due to incomplete polymerization can affect the viability and various functions of oral tissues and cells. In this study, the effects of triethylene glycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA) on odontogenic differentiation of human dental pulp cells (HDPCs) were examined. To mimic clinical situations, dental pulp cells were treated with resin monomers for 24 h prior to the analysis of alkaline phosphatase (ALP) activity and mRNA expression of genes related to pulp cell differentiation. To elucidate the underlying signaling pathways, regulation of mitogen-activated protein (MAP) kinases by resin monomers was also investigated. The ALP activity of HDPCs was reduced by TEGDMA and HEMA at noncytotoxic concentrations. The mRNA expression of dentin sialophosphoprotein (DSPP), osteocalcin (OCN), and osteopontin (OPN) was also downregulated by resin monomers. However, DSPP expression was not affected by hydrogen peroxide (H2O2). Among the MAP kinases examined, ERK activation (ERK phosphorylation) was not affected by either resin monomers or H2O2, whereas JNK was phosphorylated by TEGDMA and HEMA. Phospho-p38 was upregulated by HEMA, while TEGDMA and H2O2 suppressed p38 phosphorylation. Exposure to TEGDMA and HEMA for a limited period suppresses differentiation of HDPCs via different signaling pathways.

  13. Synthesis, Characterization and Biological Activity Studies of Mixed ...

    African Journals Online (AJOL)

    ADOWIE PERE

    is due to the coordination of the metal to the ligand by some complexes through this site. Cobalt and. Nickel complexes of the 3 mmol synthesis with. Nickel complex of the 5mmol synthesis still retain the band as seen in Paracetamol showing that they do not coordinate through this site. Another important band was observed ...

  14. SYNTHESIS, CHARACTERIZATION AND BIO-ACTIVITY OF SOME ...

    African Journals Online (AJOL)

    Preferred Customer

    Organophosphorus compounds have wide range of applications in the industrial, agricultural and medicinal chemistry owing to their unique physicochemical and biological properties. Their utility as reagents and potential synthons in organic synthesis is gaining increased attention [1]. Synthesis of a-aminophosphonates, ...

  15. Synthesis, Anticonvulsant Activity and In silco Studies of Schiff ...

    African Journals Online (AJOL)

    Georgette M, Castanedo, Daniel PS. Synthesis of tetrasubstituted thiophenes on solid support using the Gewald reaction.Tetrahedron lett 2001; 42: 7181-7184. 11. Pushyamitra M, Hardesh K, Maurya, Brijesh K, Vishnu. K, Tandon, Vishnu JR. synthesis of thiophenes and pyranone fused thiophenes by base induced inter.

  16. Synthesis and luminescence properties of Eu -activated Ca4Mg5 ...

    Indian Academy of Sciences (India)

    Synthesis and luminescence properties of Eu. 2+. -activated Ca4Mg5(PO4)6 for blue-emitting ... Abstract. Ca4Mg5(PO4)6:Eu2+ blue-emitting phosphor was synthesized by the combustion-assisted synthesis method under reductive atmosphere. .... The asymmetric emission spec- trum shows that Eu2+ have more than one ...

  17. Microwave-assisted synthesis of bio-active heterocycles in aqueous media

    KAUST Repository

    Polshettiwar, Vivek

    2010-01-01

    Synthesis of bio-active heterocycles and fine chemicals in aqueous media are one of the best solutions for the development of green and sustainable protocols. To illustrate the advantages of aqueous MW chemistry in heterocycle synthesis, in this chapter, various synthetic pathways developed in recent years in aqueous reaction media using microwave irradiation are described.

  18. Theoretical investigation on monomer and solvent selection for molecular imprinting of nitrocompounds.

    Science.gov (United States)

    Saloni, Julia; Walker, Kiara; Hill, Glake

    2013-02-21

    The aim of this work is to serve as a guideline for the initial selection of monomer and solvent for the synthesis of the nitrocompound-based molecularly imprinted polymers, MIPs. Reported data include evaluation of six systems with the ability to form noncovalently bonded monomer-template complexes. These systems are represented by the following aliphatic and aromatic molecules: acrolein, acrylonitrile, 2,6-bisacrylamide, 4-ethylenebenzoic acid, methyl methacrylate, and 2-vinylpyridine. Cave models for selected monomers are also presented and supported by binding energy analysis under various conditions. Solvent effects on monomer-template binding energy have been studied for four solvents: acetone, acetonitrile, chloroform, and methanol. Additionally, systems such as 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), pentachlorophenol (PCP), and 3,6-dichloro-2-methoxybenzoic acid (Dicamba) have been used to study selectivity of acrolein-based MIP toward TNT detection. The density functional theory, DFT, method has been used for all structural, vibrational frequency, and solvent calculations.

  19. Computational Modeling and Theoretical Calculations on the Interactions between Spermidine and Functional Monomer (Methacrylic Acid in a Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Yujie Huang

    2015-01-01

    Full Text Available This paper theoretically investigates interactions between a template and functional monomer required for synthesizing an efficient molecularly imprinted polymer (MIP. We employed density functional theory (DFT to compute geometry, single-point energy, and binding energy (ΔE of an MIP system, where spermidine (SPD and methacrylic acid (MAA were selected as template and functional monomer, respectively. The geometry was calculated by using B3LYP method with 6-31+(d basis set. Furthermore, 6-311++(d, p basis set was used to compute the single-point energy of the above geometry. The optimized geometries at different template to functional monomer molar ratios, mode of bonding between template and functional monomer, changes in charge on natural bond orbital (NBO, and binding energy were analyzed. The simulation results show that SPD and MAA form a stable complex via hydrogen bonding. At 1 : 5 SPD to MAA ratio, the binding energy is minimum, while the amount of transferred charge between the molecules is maximum; SPD and MAA form a stable complex at 1 : 5 molar ratio through six hydrogen bonds. Optimizing structure of template-functional monomer complex, through computational modeling prior synthesis, significantly contributes towards choosing a suitable pair of template-functional monomer that yields an efficient MIP with high specificity and selectivity.

  20. Highly bacterial resistant silver nanoparticles: synthesis and antibacterial activities

    International Nuclear Information System (INIS)

    Chudasama, Bhupendra; Vala, Anjana K.; Andhariya, Nidhi; Mehta, R. V.; Upadhyay, R. V.

    2010-01-01

    In this article, we describe a simple one-pot rapid synthesis route to produce uniform silver nanoparticles by thermal reduction of AgNO 3 using oleylamine as reducing and capping agent. To enhance the dispersal ability of as-synthesized hydrophobic silver nanoparticles in water, while maintaining their unique properties, a facile phase transfer mechanism has been developed using biocompatible block co-polymer pluronic F-127. Formation of silver nanoparticles is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-vis spectroscopy. Hydrodynamic size and its distribution are obtained from dynamic light scattering (DLS). Hydrodynamic size and size distribution of as-synthesized and phase transferred silver nanoparticles are 8.2 ± 1.5 nm (σ = 18.3%) and 31.1 ± 4.5 nm (σ = 14.5%), respectively. Antimicrobial activities of hydrophilic silver nanoparticles is tested against two Gram positive (Bacillus megaterium and Staphylococcus aureus), and three Gram negative (Escherichiacoli, Proteusvulgaris and Shigellasonnei) bacteria. Minimum inhibitory concentration (MIC) values obtained in the present study for the tested microorganisms are found much better than those reported for commercially available antibacterial agents.

  1. Synthesis and photocatalytic activity of poly(triazine imide)

    KAUST Repository

    Ham, Yeilin

    2012-10-22

    Poly(triazine imide) was synthesized with incorporation of Li+ and Cl- ions (PTI/Li+Cl-) to form a carbon nitride derivative. The synthesis of this material by the temperature-induced condensation of dicyandiamide was examined both in a eutectic mixture of LiCl-KCl and without KCl. On the basis of X-ray diffraction measurements of the synthesized materials, we suggest that a stoichiometric amount of LiCl is necessary to obtain the PTI/Li+Cl- phase without requiring the presence of KCl at 873 K. PTI/Li+Cl- with modification by either Pt or CoOx as cocatalyst photocatalytically produced H2 or O2, respectively, from water. The production of H2 or O2 from water indicates that the valence and conduction bands of PTI/Li+Cl- were properly located to achieve overall water splitting. The treatment of PTI/Li +Cl- with [Pt(NH3)4]2+ cations enabled the deposition of Pt through ion exchange, demonstrating photocatalytic activity for H2 evolution, while treatment with [PtCl6]2- anions resulted in no Pt deposition. This was most likely because of the preferential exchange between Li+ ions and [Pt(NH3)4]2+ cations. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Synthesis of Combretastatin A-4 Analogs and their Biological Activities.

    Science.gov (United States)

    Siebert, Agnieszka; Gensicka, Monika; Cholewinski, Grzegorz; Dzierzbicka, Krystyna

    2016-01-01

    Combretastatin A-4 (CA-4) is a natural product, which consists of two phenyl rings, linked by an ethylene bridge. CA-4, inhibitor of polymerization of tubulin to microtubules, possesses a strong antitumor and anti-vascular properties both in vitro and in vivo. Previous studies showed that disodium phosphate salt of CA-4, a water-soluble prodrug is well tolerated at therapeutically useful doses. However, it should be noted that the cis-configuration of the double bond and the 3,4,5-trimethoxy group on ring A is necessary for the biological activity of CA-4. Structure of CA-4 renders the compound readily susceptible to isomerization, which reduces the potency and bioavailability. To circumvent this problem, a lot of scientists in the world synthesized a series of cis-restricted CA-4 analogs, where the double bond has been replaced by introduction of non-heterocyclic groups or heterocyclic groups like β -lactam and oxadiazole. This paper reviews the most important approaches in analogs of combretastatin synthesis and presents structure-reactivity relationships for these compounds. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Antimicrobial activity of peptidomimetics against multidrug-resistant Escherichia coli

    DEFF Research Database (Denmark)

    Jahnsen, Rasmus D; Frimodt-Møller, Niels; Franzyk, Henrik

    2012-01-01

    -lactamase-producing Escherichia coli was assessed by testing an array comprising different types of cationic peptidomimetics obtained by a general monomer-based solid-phase synthesis protocol. Most of the peptidomimetics possessed high to moderate activity toward multidrug-resistant E. coli as opposed to the corresponding...

  4. Comparison of Cyclooxygenase-1 Crystal Structures: Cross-Talk between Monomers Comprising Cyclooxygenase-1 Homodimers

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, Ranjinder S.; Lee, Jullia Y.; Yuan, Chong; Smith, William L. (Michigan)

    2010-11-01

    Prostaglandin endoperoxide H synthases (PGHSs)-1 and -2 (also called cyclooxygenases (COXs)-1 and -2) catalyze the committed step in prostaglandin biosynthesis. Both isoforms are targets of nonsteroidal antiinflammatory drugs (NSAIDs). PGHSs are homodimers that exhibit half-of-sites COX activity; moreover, some NSAIDs cause enzyme inhibition by binding only one monomer. To learn more about the cross-talk that must be occurring between the monomers comprising each PGHS-1 dimer, we analyzed structures of PGHS-1 crystallized under five different conditions including in the absence of any tightly binding ligand and in the presence of nonspecific NSAIDs and of a COX-2 inhibitor. When crystallized with substoichiometric amounts of an NSAID, both monomers are often fully occupied with inhibitor; thus, the enzyme prefers to crystallize in a fully occupied form. In comparing the five structures, we only observe changes in the positions of residues 123-129 and residues 510-515. In cases where one monomer is fully occupied with an NSAID and the partner monomer is incompletely occupied, an alternate conformation of the loop involving residues 123-129 is seen in the partially occupied monomer. We propose, on the basis of this observation and previous cross-linking studies, that cross-talk between monomers involves this mobile 123-129 loop, which is located at the dimer interface. In ovine PGHS-1 crystallized in the absence of an NSAID, there is an alternative route for substrate entry into the COX site different than the well-known route through the membrane binding domain.

  5. Synthesis, X-ray crystal structure, DNA binding and Nuclease activity ...

    Indian Academy of Sciences (India)

    s12039-016-1125-x. Synthesis, X-ray crystal structure, DNA binding and Nuclease activity of lanthanide(III) complexes of 2-benzoylpyridine acetylhydrazone. KARREDDULA RAJA, AKKILI SUSEELAMMA and KATREDDI HUSSAIN REDDY. ∗.

  6. Synthesis and Potential Trypanocidal Activity of N, N-disubstituted-3 ...

    African Journals Online (AJOL)

    -disubstituted -3-(1-benzenesulphonylindol-2-yl and -3-yl) propagylamines and furnished their spectral analysis. Keywords: Propagylamines, spectral analysis, synthesis, trypanocidal activity. East and Central African Journal of Pharmaceutical ...

  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. Laccase catalyzed synthesis of iodinated phenolic compounds with antifungal activity.

    Directory of Open Access Journals (Sweden)

    Julian Ihssen

    Full Text Available Iodine is a well known antimicrobial compound. Laccase, an oxidoreductase which couples the one electron oxidation of diverse phenolic and non-phenolic substrates to the reduction of oxygen to water, is capable of oxidizing unreactive iodide to reactive iodine. We have shown previously that laccase-iodide treatment of spruce wood results in a wash-out resistant antimicrobial surface. In this study, we investigated whether phenolic compounds such as vanillin, which resembles sub-structures of softwood lignin, can be directly iodinated by reacting with laccase and iodide, resulting in compounds with antifungal activity. HPLC-MS analysis showed that vanillin was converted to iodovanillin by laccase catalysis at an excess of potassium iodide. No conversion of vanillin occurred in the absence of enzyme. The addition of redox mediators in catalytic concentrations increased the rate of iodide oxidation ten-fold and the yield of iodovanillin by 50%. Iodinated phenolic products were also detected when o-vanillin, ethyl vanillin, acetovanillone and methyl vanillate were incubated with laccase and iodide. At an increased educt concentration of 0.1 M an almost one to one molar ratio of iodide to vanillin could be used without compromising conversion rate, and the insoluble iodovanillin product could be recovered by simple centrifugation. The novel enzymatic synthesis procedure fulfills key criteria of green chemistry. Biocatalytically produced iodovanillin and iodo-ethyl vanillin had significant growth inhibitory effects on several wood degrading fungal species. For Trametes versicolor, a species causing white rot of wood, almost complete growth inhibition and a partial biocidal effect was observed on agar plates. Enzymatic tests indicated that the iodinated compounds acted as enzyme responsive, antimicrobial materials.

  9. The effect of monomer molecular weight on grafting reaction

    International Nuclear Information System (INIS)

    Wu Minghong; Ding Zhongli; Ma Zueteh

    1995-01-01

    In this paper, some condensed ethylene glycol acrylate monomers with different molecular weight being grafted to the PE film by means of pre-irradiation is reported. The effect of molecular weight of monomer on grafting reaction and the hydrophilicity of grafting sample have been discussed. The experimental results show: molar degrees of grafting decreased non-linearly with the increasement of molecular weight of monomer, the grafting reaction of polymer is greater effected by the swelling degree of PE film, the greater the swelling degree of grafting material, the higher the grating degree grafting is, the initial rate of grafting reaction decreased with the increasement of molecular weight of monomer. (author)

  10. Synthesis of PEDOT/ZnO Photocatalyst: Validation of Photocatalytic Activity by Degradation of Azo RR45 Dye Under Solar and UV-A Irradiation

    Directory of Open Access Journals (Sweden)

    Z. Katančić

    2018-01-01

    Full Text Available To study the photocatalytic efficiency of wastewater treatment processes, the nanocomposites of conducting polymer poly(3,4-ethylenedioxythiophene (PEDOT and ZnO nanoparticles were prepared by in-situ synthesis. ZnO is an excellent photocatalyst under UV light, but due to high band gap, photons of visible light have insufficient energy to excite electrons from valence to conductive band, which limits its activity under visible light and therefore practical usage is limited. The PEDOT conductive polymer was used to increase the photocatalytic activity of ZnO since conductive polymers are known as efficient electron donor and good electron transporters upon visible-light excitation. Polymerization of pure PEDOT and PEDOT/ZnO nanocomposites was carried out at varying monomer:oxidant ratio (1:2; 1:3; 1:5 with the ammonium persulfate (APS used as the oxidant. Samples were characterized by FTIR spectroscopy, XRD analysis, SEM microscopy, UV-Vis spectroscopy and TG analysis. Photocatalytic activity was assessed through removal of C.I. Reactive Red 45 (RR45 azo dye under simulated Solar and UV-A irradiation. Photocatalysis was monitored by measuring discoloration of RR45 using UV/Vis spectroscopy. The results indicate that very low concentration of PEDOT conductive polymer in PEDOT/ZnO nanocomposite can significantly contribute to the efficiency of the photocatalytic process during wastewater treatment.

  11. "Miswak" Based Green Synthesis of Silver Nanoparticles: Evaluation and Comparison of Their Microbicidal Activities with the Chemical Synthesis.

    Science.gov (United States)

    Shaik, Mohammed Rafi; Albalawi, Ghadeer H; Khan, Shams Tabrez; Khan, Merajuddin; Adil, Syed Farooq; Kuniyil, Mufsir; Al-Warthan, Abdulrahman; Siddiqui, Mohammed Rafiq H; Alkhathlan, Hamad Z; Khan, Mujeeb

    2016-11-06

    Microbicidal potential of silver nanoparticles (Ag-NPs) can be drastically improved by improving their solubility or wettability in the aqueous medium. In the present study, we report the synthesis of both green and chemical synthesis of Ag-NPs, and evaluate the effect of the dispersion qualities of as-prepared Ag-NPs from both methods on their antimicrobial activities. The green synthesis of Ag-NPs is carried out by using an aqueous solution of readily available Salvadora persica L. root extract (RE) as a bioreductant. The formation of highly crystalline Ag-NPs was established by various analytical and microscopic techniques. The rich phenolic contents of S. persica L. RE (Miswak) not only promoted the reduction and formation of NPs but they also facilitated the stabilization of the Ag-NPs, which was established by Fourier transform infrared spectroscopy (FT-IR) analysis. Furthermore, the influence of the volume of the RE on the size and the dispersion qualities of the NPs was also evaluated. It was revealed that with increasing the volume of RE the size of the NPs was deteriorated, whereas at lower concentrations of RE smaller size and less aggregated NPs were obtained. During this study, the antimicrobial activities of both chemically and green synthesized Ag-NPs, along with the aqueous RE of S. persica L., were evaluated against various microorganisms. It was observed that the green synthesized Ag-NPs exhibit comparable or slightly higher antibacterial activities than the chemically obtained Ag-NPs.

  12. “Miswak” Based Green Synthesis of Silver Nanoparticles: Evaluation and Comparison of Their Microbicidal Activities with the Chemical Synthesis

    Directory of Open Access Journals (Sweden)

    Mohammed Rafi Shaik

    2016-11-01

    Full Text Available Microbicidal potential of silver nanoparticles (Ag-NPs can be drastically improved by improving their solubility or wettability in the aqueous medium. In the present study, we report the synthesis of both green and chemical synthesis of Ag-NPs, and evaluate the effect of the dispersion qualities of as-prepared Ag-NPs from both methods on their antimicrobial activities. The green synthesis of Ag-NPs is carried out by using an aqueous solution of readily available Salvadora persica L. root extract (RE as a bioreductant. The formation of highly crystalline Ag-NPs was established by various analytical and microscopic techniques. The rich phenolic contents of S. persica L. RE (Miswak not only promoted the reduction and formation of NPs but they also facilitated the stabilization of the Ag-NPs, which was established by Fourier transform infrared spectroscopy (FT-IR analysis. Furthermore, the influence of the volume of the RE on the size and the dispersion qualities of the NPs was also evaluated. It was revealed that with increasing the volume of RE the size of the NPs was deteriorated, whereas at lower concentrations of RE smaller size and less aggregated NPs were obtained. During this study, the antimicrobial activities of both chemically and green synthesized Ag-NPs, along with the aqueous RE of S. persica L., were evaluated against various microorganisms. It was observed that the green synthesized Ag-NPs exhibit comparable or slightly higher antibacterial activities than the chemically obtained Ag-NPs.

  13. Ordered, microphase-separated, noncharged-charged diblock copolymers via the sequential ATRP of styrene and styrenic imidazolium monomers

    Energy Technology Data Exchange (ETDEWEB)

    Shi, ZX; Newell, BS; Bailey, TS; Gin, DL

    2014-12-15

    A series of imidazolium-based noncharged-charged diblock copolymers (1) was synthesized by the direct, sequential ATRP of styrene and styrenic imidazolium bis(trifluoromethyl)sulfonamide monomers with methyl, n-butyl, and n-decyl side-chains. Small-angle X-ray scattering studies on initial examples of 1 with a total of 50 repeat units and styrene:imidazolium-styrene repeat unit ratios of 25:25, 20:30, and 15:35 showed that their ability to form ordered nanostructures (i.e., sphere and cylinder phases) in their neat states depends on both the block ratio and the length of the alkyl side-chain on the imidazolium monomer. To our knowledge, the synthesis of imidazolium-based BCPs that form ordered, phase-separated nanostructures via direct ATRP of immiscible co-monomers is unprecedented. (C) 2014 Elsevier Ltd. All rights reserved.

  14. Synthesis, anti-microbial activity and molecular docking studies on ...

    Indian Academy of Sciences (India)

    inflammatory,6 anti-coagulant7 and as inhibitors of lipoxygenase8 and cyclooxygenase.9. Click chemistry10–12 has emerged as a reliable approach for the stereo selective synthesis of 1,2,3- triazole with desired properties. Cycloaddition of azide to alkyne in the presence of copper sulphate and sodium ascorbate to give 1 ...

  15. Synthesis, Characterization and Antibacterial Activity of New 1,2 ...

    African Journals Online (AJOL)

    Synthesis of two series of 1,2- and 1,4-bis(thioureido)benzene derivatives was accomplished by the treatment of corresponding alkanoyl/aroyl chlorides with potassium thiocyanate in dry acetone to afford the respective isothiocyanates as intermediates. The latter were treated in situ with 1,2- and 1,4-diaminobenzene, ...

  16. Synthesis and catalytic activity of metallo-organic complexes ...

    Indian Academy of Sciences (India)

    the fields of organic synthesis and pharmaceuticals.1–7. This is due to the importance of the carboximide ester structural unit as an intermediate or ligand in these fields. For example, this unit can be used as the cat- alyst for the atom transfer radical polymerization of methyl methacrylate,8 or as a new class of chiral Lewis.

  17. Effect of mechanical activation on cordierite synthesis through solid ...

    Indian Academy of Sciences (India)

    Administrator

    Synthesis of cordierite (5SiO2∙2MgO∙2Al2O3) has attracted special attention from researchers for its special characteristics. Most common method of cordierite preparation is solid-state ... 2005). Whereas 1300 °C temperature is required for full conversion of cordierite through sol–gel method (Menchi and Scian 2005).

  18. Synthesis, structural characterization and biological activity of a ...

    Indian Academy of Sciences (India)

    3.1 Synthesis and formulation. Schiff base ligand H2L was synthesized by 1:1 conden- sation of O-aminophenol and O-vanillin in dehydrated alcohol. 1 was prepared using reaction among Zn(II) salt and the ligand in methanol. Coordination geo- metry of 1 was determined by different spectroscopic characterization.

  19. Synthesis and anti-acetylcholinesterase activity of benzotriazinone ...

    Indian Academy of Sciences (India)

    An approach for the construction of benzotriazinone-triazole system is described. The synthesis is based on diazonium chemistry and subsequent intramolecular heteroatom-heteroatom bond formation. The introduction of triazole moiety occurred via click reaction catalyzed by nano-sized copper, supported on modified ...

  20. Synthesis and antibacterial activity of sulfonamide derivatives at C-8 ...

    Indian Academy of Sciences (India)

    pounds. Anacardic acid (pentadecyl salicylic acid) is a phenolic constituent present in CNSL; (Anacardium occidentale L.) and exhibits antimicrobial properties2,3 which have led to the preparation of various ana- logues.23,24 Synthesis of lasiodiplodin from the non- isoprenoid phenolic lipids of CNSL as well as the sali-.

  1. Synthesis, characterization and cytotoxic activity of palladium (II ...

    Indian Academy of Sciences (India)

    considerable cytotoxicity while the ligands were non-toxic on the tested cell lines. Keywords. Carbohydrate; pyridyl triazole; palladium complexes; cytotoxicity. 1. Introduction. Bioinorganic chemistry is a rapidly developing field dealing with the synthesis and biological investigation of inorganic complexes.1–5 In inorganic ...

  2. Green synthesis of silver nanoparticles from seed extract of Brassica nigra and its antibacterial activity

    Directory of Open Access Journals (Sweden)

    RAKSHA PANDIT

    2015-05-01

    Full Text Available Pandit R. 2015. Green synthesis of silver nanoparticles from seed extract of Brassica nigra and its antibacterial activity. Nusantara Bioscience 7: 15-19. We report the green synthesis of silver nanoparticles using seed extract of Brassica nigra. UV-visible spectroscopic analysis showed the absorbance peak at 432 nm which indicated the synthesis of silver nanoparticles. Nanoparticles Tracking and Analysis (NTA was used to determine the size of synthesized silver nanoparticles. Zeta potential analysis was carried out to study the stability of nanoparticles while FTIR analysis confirmed the presence of proteins as capping agents that provided stability to nanoparticles in colloid. Antibacterial activity of silver nanoparticles was evaluated against Propionibacterium acnes, Pseudomonas aeruginosa and Klebsiella pneumoniae. The activity of Vancomycin was significantly increased in combination with silver nanoparticles showing synergistic activity against all bacteria while the maximum activity was noted against P. acnes.

  3. Synthesis of molecular complexes for small molecule activation

    International Nuclear Information System (INIS)

    Andrez, Julie

    2016-01-01

    The redox chemistry of f-elements is drawing the attention of inorganic chemists due to their unusual reaction pathways. Notably low-valent f-element complexes have been shown to be able to activate small molecules such as CO 2 and N 2 in mild conditions. Compared to d-block metals, f-elements present a coordination chemistry dominated by electrostatic interactions and steric constraints. Molecular complexes of f-elements could thus provide new catalytic routes to transform small molecules into valuable chemicals. However the redox chemistry of low valent f-elements is dominated by single-electron transfers while the reductions of CO 2 and N 2 require multi-electronic processes. Accordingly the first approach of this PhD work was the use of redox active ligands as electron reservoir to support f-element centres increasing the electron number available for reduction events. The coordination of uranium with tridentate Schiff base ligand was investigated and led to isolation of a dinuclear electron-rich species able to undertake up to eight-electron reduction combining the redox activity of the ligands and the uranium centres. In order to obtain electron-rich compounds potentially able to polarize the C=O bond of CO 2 , the synthesis of hetero-bimetallic species supported by salophen Schiff base ligand was also studied. In a second approach we have used bulky ligands with strong donor-character to tune the reducing abilities of low valent f-elements. In this case a bimolecular electron-transfer process is often observed. The reactivity of the U(III) siloxid complex [U(OSi(OtBu) 3 ) 4 K] was further investigated. Notably, reaction with Ph 3 PS led to the formation of a terminal U(IV) sulfide complex with multiple U-S bond which was analysed by DFT studies to better understand the bonding nature. Preliminary studies on the role of the counter-cation (M) in the system [U(OSi(OtBu) 3 ) 4 M] on the outcome of the reactivity with CS 2 and CO 2 have also been performed. The

  4. Regulation of glycogen synthesis in rat skeletal muscle after glycogen-depleting contractile activity: effects of adrenaline on glycogen synthesis and activation of glycogen synthase and glycogen phosphorylase.

    OpenAIRE

    Franch, J; Aslesen, R; Jensen, J

    1999-01-01

    We investigated the effects of insulin and adrenaline on the rate of glycogen synthesis in skeletal muscles after electrical stimulation in vitro. The contractile activity decreased the glycogen concentration by 62%. After contractile activity, the glycogen stores were fully replenished at a constant and high rate for 3 h when 10 m-i.u./ml insulin was present. In the absence of insulin, only 65% of the initial glycogen stores was replenished. Adrenaline decreased insulin-stimulated glycogen s...

  5. Measurement of in situ monomer sorption in polyu(propylene)

    NARCIS (Netherlands)

    Pater, J.T.M.; Weickert, G.; Fait, Anna; Mei, Gabriele

    2005-01-01

    An experimental method has been developed to compare the amount of monomer absorbed in freshly produced poly(propylene) with the amount of monomer absorbed in the same material after degassing. It has been found that propylene sorption in freshly produced poly(propylene) is significantly higher than

  6. Design, Synthesis, and Some Aspects of the Biological Activity of Mitochondria-Targeted Antioxidants.

    Science.gov (United States)

    Korshunova, G A; Shishkina, A V; Skulachev, M V

    2017-07-01

    This review summarizes for the first time data on the design and synthesis of biologically active compounds of a new generation - mitochondria-targeted antioxidants, which are natural (or synthetic) p-benzoquinones conjugated via a lipophilic linker with (triphenyl)phosphonium or ammonium cations with delocalized charge. It also describes the synthesis of mitochondria-targeted antioxidants - uncouplers of oxidative phosphorylation - based on fluorescent dyes.

  7. The rate of synthesis and decomposition of tissue proteins in hypokinesia and increased muscular activity

    Science.gov (United States)

    Fedorov, I. V.; Chernyy, A. V.; Fedorov, A. I.

    1978-01-01

    During hypokinesia and physical loading (swimming) of rats, the radioactivity of skeletal muscle, liver, kidney, heart, and blood proteins was determined after administration of radioactive amino acids. Tissue protein synthesis decreased during hypokinesia, and decomposition increased. Both synthesis and decomposition increased during physical loading, but anabolic processes predominated in the total tissue balance. The weights of the animals decreased in hypokinesia and increased during increased muscle activity.

  8. Synthesis of Benzofuran Derivatives via Rearrangement and Their Inhibitory Activity on Acetylcholinesterase

    Directory of Open Access Journals (Sweden)

    Ling-Yi Kong

    2010-11-01

    Full Text Available During a synthesis of coumarins to obtain new candidates for treating Alzheimer’s Disease (AD, an unusual rearrangement of a benzopyran group to a benzofuran group occurred, offering a novel synthesis pathway of these benzofuran derivatives. The possible mechanism of the novel rearrangement was also discussed. All of the benzofuran derivatives have weak anti-AChE activities compared with the reference compound, donepezil.

  9. Asymmetric Synthesis of Optically Active Spirocyclic Indoline Scaffolds through an Enantioselective Reduction of Indoles

    KAUST Repository

    Borrmann, Ruediger

    2016-11-30

    An enantioselective synthesis of spirocyclic indoline scaffolds was achieved by applying an asymmetric iridium-catalyzed hydrogenation of 3H-indoles. Low catalyst loadings and mild reaction conditions provide a broad range of differently substituted products with excellent yields and enantioselectivities. The developed methodology allows an efficient synthesis of this important spirocyclic structural motif, which is present in numerous biologically active molecules and privileged structures in medicinal chemistry.

  10. Oligonucleotides with 1,4-dioxane-based nucleotide monomers

    DEFF Research Database (Denmark)

    Madsen, Andreas S; Wengel, Jesper

    2012-01-01

    An epimeric mixture of H-phosphonates 5R and 5S has been synthesized in three steps from known secouridine 1. Separation of the epimers has been accomplished by RP-HPLC, allowing full characterization and incorporation of monomers X and Y into 9-mer oligonucleotides using H-phosphonates building...... blocks 5R and 5S, respectively. A single incorporation of either monomer X or monomer Y in the central position of a DNA 9-mer results in decreased thermal affinity toward both DNA and RNA complements (ΔT(m) = -3.5 °C/-3.5 °C for monomer X and ΔT(m) = -11.0 °C/-6.5 °C for monomer Y). CD measurements do...

  11. Synthesis, Structure and Antioxidant Activity of Cyclohexene-Fused Selenuranes and Related Derivatives

    Directory of Open Access Journals (Sweden)

    Poonam Rajesh Prasad

    2015-07-01

    Full Text Available Synthesis, structure and antioxidant activity of new cyclohexene-fused spiroselenuranes and a spirotellurane is reported. Oxidation reactions of bis(o-formylcyclohex- 1-eneselenide/bis(2-hydroxymethylcyclohex-1-eneselenide provide the corresponding spiroselenuranes. The glutathione peroxidase-like activity of the newly synthesized compounds has been evaluated.

  12. Synthesis and evaluation of antimicrobial and anthelmintic activity of ...

    Indian Academy of Sciences (India)

    compounds were screened for antimicrobial activity and anthelmintic activity. The structural assignments of compounds were made on the basis of spectroscopic data and elemental analysis. Keywords. 10H-phenothiazines; Smiles rearrangement; sulphones; ribofuranosides; antimicrobial activity; anthelmintic activity. 1.

  13. Temporin A and its retro-analogues: synthesis, conformational analysis and antimicrobial activities.

    Science.gov (United States)

    Kamysz, Wojciech; Mickiewicz, Beata; Rodziewicz-Motowidło, Sylwia; Greber, Katarzyna; Okrój, Marcin

    2006-08-01

    Temporin A (TA) is a hydrophobic peptide isolated from the skin of the European red frog Rana temporaria. Strong antimicrobial activity against gram-positive cocci and Candida, as well as its small molecular weight (10-13 aa residues), makes TA an interesting antimicrobial compound. However, its synthesis is rather problematic. Here, the synthesis of two retro-analogues of TA--retro-TA and (6-1)(7-13)-TA--is reported. The synthesis of retro-TA was performed without any problems, while during the synthesis of (6-1)(7-13)-TA problems similar to those encountered during the synthesis of TA were faced. Antimicrobial assays showed minimal inhibitory concentration (MIC) values of retro-TA to be, in most cases, only one dilution higher than those of original TA, but still remained relatively low. An analysis of the circular dichroism spectra of the peptides shows that TA and (6-1)(7-13)-TA adopt an alpha-helical structure in a hydrophobic environment, while retro-TA forms mainly unordered conformation under both hydrophobic and hydrophilic conditions. One can postulate that differences in conformation of the peptide chain might be responsible for the lower antimicrobial activity of retro-TA as compared to that of the parent molecule. In any case, retro-TA can be interesting owing to its simple and nonproblematic synthesis. Copyright (c) 2006 European Peptide Society and John Wiley & Sons, Ltd.

  14. Inositol synthesis regulates the activation of GSK-3α in neuronal cells.

    Science.gov (United States)

    Ye, Cunqi; Greenberg, Miriam L

    2015-04-01

    The synthesis of inositol provides precursors of inositol lipids and inositol phosphates that are pivotal for cell signaling. Mood stabilizers lithium and valproic acid, used for treating bipolar disorder, cause cellular inositol depletion, which has been proposed as a therapeutic mechanism of action of both drugs. Despite the importance of inositol, the requirement for inositol synthesis in neuronal cells is not well understood. Here, we examined inositol effects on proliferation of SK-N-SH neuroblastoma cells. The essential role of inositol synthesis in proliferation is underscored by the findings that exogenous inositol was dispensable for proliferation, and inhibition of inositol synthesis decreased proliferation. Interestingly, the inhibition of inositol synthesis by knocking down INO1, which encodes inositol-3-phosphate synthase, the rate-limiting enzyme of inositol synthesis, led to the inactivation of GSK-3α by increasing the inhibitory phosphorylation of this kinase. Similarly, the mood stabilizer valproic acid effected transient decreases in intracellular inositol, leading to inactivation of GSK-3α. As GSK-3 inhibition has been proposed as a likely therapeutic mechanism of action, the finding that inhibition of inositol synthesis results in the inactivation of GSK-3α suggests a unifying hypothesis for mechanism of mood-stabilizing drugs. Inositol is an essential metabolite that serves as a precursor for inositol lipids and inositol phosphates. We report that inhibition of the rate-limiting enzyme of inositol synthesis leads to the inactivation of glycogen synthase kinase (GSK) 3α by increasing inhibitory phosphorylation of this kinase. These findings have implications for the therapeutic mechanisms of mood stabilizers and suggest that inositol synthesis and GSK 3α activity are intrinsically related. © 2014 International Society for Neurochemistry.

  15. Synthesis and Antiplatelet Activity of Antithrombotic Thiourea Compounds: Biological and Structure-Activity Relationship Studies

    Directory of Open Access Journals (Sweden)

    André Luiz Lourenço

    2015-04-01

    Full Text Available The incidence of hematological disorders has increased steadily in Western countries despite the advances in drug development. The high expression of the multi-resistance protein 4 in patients with transitory aspirin resistance, points to the importance of finding new molecules, including those that are not affected by these proteins. In this work, we describe the synthesis and biological evaluation of a series of N,N'-disubstituted thioureas derivatives using in vitro and in silico approaches. New designed compounds inhibit the arachidonic acid pathway in human platelets. The most active thioureas (compounds 3d, 3i, 3m and 3p displayed IC50 values ranging from 29 to 84 µM with direct influence over in vitro PGE2 and TXA2 formation. In silico evaluation of these compounds suggests that direct blockage of the tyrosyl-radical at the COX-1 active site is achieved by strong hydrophobic contacts as well as electrostatic interactions. A low toxicity profile of this series was observed through hemolytic, genotoxic and mutagenic assays. The most active thioureas were able to reduce both PGE2 and TXB2 production in human platelets, suggesting a direct inhibition of COX-1. These results reinforce their promising profile as lead antiplatelet agents for further in vivo experimental investigations.

  16. Biologically Active Chorionic Gonadotropin: Synthesis by the Human Fetus

    Science.gov (United States)

    McGregor, W. G.; Kuhn, R. W.; Jaffe, R. B.

    1983-04-01

    The kidney, and to a slight extent the liver, of human fetuses were found to synthesize and secrete the α subunit common to glycoprotein hormones. Fetal lung and muscle did not synthesize this protein. Since fetal kidney and liver were previously found to synthesize β chorionic gonadotropin, their ability to synthesize bioactive chorionic gonadotropin was also determined. The newly synthesized hormone bound to mouse Leydig cells and elicited a biological response: namely, the synthesis of testosterone. These results suggest that the human fetus may participate in metabolic homeostasis during its development.

  17. Flower-like Ag/AgCl microcrystals: Synthesis and photocatalytic activity

    International Nuclear Information System (INIS)

    Daupor, Hasan; Wongnawa, Sumpun

    2015-01-01

    Silver/silver chloride (Ag/AgCl) composites with a novel flower-like morphology were prepared via a hot precipitation assisted by the vinyl acetate monomer (VAM) route. An aqueous solution of AlCl 3 was mixed with the vinyl acetate monomer and acetic acid before adding a AgNO 3 solution at a temperature of 100 °C. The octapod shaped flower-like Ag/AgCl particles (or “flower-like Ag/AgCl” hereinafter) has eight petals each of which was about 7–11 μm in length. The flower-like octapods were formed by preferential overgrowth along the <111> directions of the cubic seeds. Detailed studies of the growth process at different AlCl 3 concentrations revealed that the concave cube developed into a Rubik's cube where eight corners grew further into the flower-like structures. The VAM and acetic acid concentration strongly affected the growth of the Ag/AgCl to the flower-like structure and their optimum concentrations were determined. The morphologies of these particles were carefully examined by scanning electron microscopy (SEM). The crystal structures and orientation relationship were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–visible diffused reflectance spectroscopy (DRS). The flower-like Ag/AgCl microcrystals were tested for their photocatalytic degradation of orange G dye (OG) catalyzed by visible light. From comparative test runs, the flower-like Ag/AgCl exhibited better photocatalytic activity than simple and commercial Ag/AgCl particles. - Highlights: • Interesting transformation of microcrystals Ag/AgCl from concave cube via Rubik's cube to flower-like shape. • The first to use VAM as morphology control reagent. • High photocatalytic activity under visible light irradiation

  18. The Off-rate of Monomers Dissociating from Amyloid-β Protofibrils*

    Science.gov (United States)

    Grüning, Clara S. R.; Klinker, Stefan; Wolff, Martin; Schneider, Mario; Toksöz, Küpra; Klein, Antonia N.; Nagel-Steger, Luitgard; Willbold, Dieter; Hoyer, Wolfgang

    2013-01-01

    The interconversion of monomers, oligomers, and amyloid fibrils of the amyloid-β peptide (Aβ) has been implicated in the pathogenesis of Alzheimer disease. The determination of the kinetics of the individual association and dissociation reactions is hampered by the fact that forward and reverse reactions to/from different aggregation states occur simultaneously. Here, we report the kinetics of dissociation of Aβ monomers from protofibrils, prefibrillar high molecular weight oligomers previously shown to possess pronounced neurotoxicity. An engineered binding protein sequestering specifically monomeric Aβ was employed to follow protofibril dissociation by tryptophan fluorescence, precluding confounding effects of reverse or competing reactions. Aβ protofibril dissociation into monomers follows exponential decay kinetics with a time constant of ∼2 h at 25 °C and an activation energy of 80 kJ/mol, values typical for high affinity biomolecular interactions. This study demonstrates the high kinetic stability of Aβ protofibrils toward dissociation into monomers and supports the delineation of the Aβ folding and assembly energy landscape. PMID:24247242

  19. N-Acetyl Cysteine Depletes Reactive Oxygen Species and Prevents Dental Monomer-Induced Intrinsic Mitochondrial Apoptosis In Vitro in Human Dental Pulp Cells.

    Directory of Open Access Journals (Sweden)

    Yang Jiao

    Full Text Available To investigate the involvement of intrinsic mitochondrial apoptosis in dental monomer-induced cytotoxicity and the influences of N-acetyl cysteine (NAC on this process.Human dental pulp cells (hDPCs were exposed to several dental monomers in the absence or presence of NAC, and cell viability, intracellular redox balance, morphology and function of mitochondria and key indicators of intrinsic mitochondrial apoptosis were evaluated using various commercial kits.Dental monomers exerted dose-dependent cytotoxic effects on hDPCs. Concomitant to the over-production of reactive oxygen species (ROS and depletion of glutathione (GSH, differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase were detected. Apoptosis, as indicated by positive Annexin V/propidium iodide (PI staining and activation of caspase-3, was observed after dental monomer treatment. Dental monomers impaired the morphology and function of mitochondria, and induced intrinsic mitochondrial apoptosis in hDPCs via up-regulation of p53, Bax and cleaved caspase-3, and down-regulation of Bcl-2. NAC restored cell viability, relieved oxidative stress and blocked the apoptotic effects of dental monomers.Dental monomers induced oxidative stress and mitochondrial intrinsic apoptosis in hDPCs. NAC could reduce the oxidative stress and thus protect hDPCs against dental monomer-induced apoptosis.

  20. Synthesis and anthelmintic activity of some hybrid Benzimidazolyl ...

    African Journals Online (AJOL)

    Erah

    activities at 0.68 and 0.16 µg/ml. Conclusion: Preliminary structure-activity relationship studies revealed that arylpropenone group in position 2 of the benzimidazole ring can be considered as new pharmacophore for nematicidal activity. Keywords: Benzimidazole, Chalcone, Anthelmintic activity, Haemonchus contortus.

  1. Regulation and kinetics of platelet-activating factor and leukotriene C-4 synthesis by activated human basophils

    NARCIS (Netherlands)

    Lie, W. J.; Homburg, C. H. E.; Kuijpers, T. W.; Knol, E. F.; Mul, F. P. J.; Roos, D.; Tool, A. T. J.

    2003-01-01

    Background Allergic disease is the result of an interplay of many different cell types, including basophils and mast cells, in combination with various inflammatory lipid mediators, such as platelet-activating factor (PAF) and leukotrienes (LT). LTC4 synthesis by human basophils has been studied

  2. Eco-friendly approach for nanoparticles synthesis and mechanism behind antibacterial activity of silver and anticancer activity of gold nanoparticles.

    Science.gov (United States)

    Patil, Maheshkumar Prakash; Kim, Gun-Do

    2017-01-01

    This review covers general information about the eco-friendly process for the synthesis of silver nanoparticles (AgNP) and gold nanoparticles (AuNP) and focuses on mechanism of the antibacterial activity of AgNPs and the anticancer activity of AuNPs. Biomolecules in the plant extract are involved in reduction of metal ions to nanoparticle in a one-step and eco-friendly synthesis process. Natural plant extracts contain wide range of metabolites including carbohydrates, alkaloids, terpenoids, phenolic compounds, and enzymes. A variety of plant species and plant parts have been successfully extracted and utilized for AgNP and AuNP syntheses. Green-synthesized nanoparticles eliminate the need for a stabilizing and capping agent and show shape and size-dependent biological activities. Here, we describe some of the plant extracts involved in nanoparticle synthesis, characterization methods, and biological applications. Nanoparticles are important in the field of pharmaceuticals for their strong antibacterial and anticancer activity. Considering the importance and uniqueness of this concept, the synthesis, characterization, and application of AgNPs and AuNPs are discussed in this review.

  3. Nano silver particle synthesis using Swertia paniculata herbal extract and its antimicrobial activity.

    Science.gov (United States)

    Ahluwalia, Vivek; Elumalai, Sasikumar; Kumar, Vinod; Kumar, Sandeep; Sangwan, Rajender Singh

    2018-01-01

    In the present study, green synthesis of silver nanoparticles (AgNPs) is demonstrated using medicinal herb Swertia paniculata extract. The plant extract acted both as reducing and capping agents during synthesis process, where silver nitrate was used as silver source. Subsequent analysis revealed that particles had size range between 31 and 44 nm and were spherical in shape. Among reaction parameters, temperature and time had significantly influenced the synthesis reaction. Also, synthesized nanoparticles were found stable up to 90 days. Further, antimicrobial activity against gram negative and gram positive bacterial strains was done and results showed that synthesized AgNPs had better antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae under standard incubation conditions. Study shows that these particles can be very promising in biomedical applications in future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Facile synthesis of phosphorus doped graphitic carbon nitride polymers with enhanced visible-light photocatalytic activity

    International Nuclear Information System (INIS)

    Zhang, Ligang; Chen, Xiufang; Guan, Jing; Jiang, Yijun; Hou, Tonggang; Mu, Xindong

    2013-01-01

    Graphical abstract: - Highlights: • P-doped g-C 3 N 4 has been prepared by a one-pot green synthetic approach. • The incorporation of P resulted in favorable textural and electronic properties. • Doping with P enhanced the visible-light photocatalytic activity of g-C 3 N 4 . • A postannealing treatment further enhanced the activity of P-doped g-C 3 N 4 . • Photogenerated holes were the main species responsible for the activity. - Abstract: Phosphorus-doped carbon nitride materials were prepared by a one-pot green synthetic approach using dicyandiamide monomer and a phosphorus containing ionic liquid as precursors. The as-prepared materials were subjected to several characterizations and investigated as metal-free photocatalysts for the degradation of organic pollutants (dyes like Rhodamine B, Methyl orange) in aqueous solution under visible light. Results revealed that phosphorus-doped carbon nitride have a higher photocatalytic activity for decomposing Rhodamine B and Methyl orange in aqueous solution than undoped g-C 3 N 4 , which was attributed to the favorable textural, optical and electronic properties caused by doping with phosphorus heteroatoms into carbon nitride host. A facile postannealing treatment further improved the activity of the photocatalytic system, due to the higher surface area and smaller structural size in the postcalcined catalysts. The phosphorus-doped carbon nitride showed high visible-light photocatalytic activity, making them promising materials for a wide range of potential applications in photochemistry

  5. Difunctional polyisobutylene prepared by polymerization of monomer on molecular sieve

    Science.gov (United States)

    Midler, J. A., Jr.

    1970-01-01

    Process yields difunctional isobutylene polymers ranging in molecular weight from 1150 to 3600. These polymers have the potential for copolymerization and cross-linking with other monomers to form elastomeric materials.

  6. Identification, synthesis and pharmacological activity of moxonidine metabolites.

    Science.gov (United States)

    Wirth, David D; He, Minxia M; Czeskis, Boris A; Zimmerman, Karen M; Roettig, Ulrike; Stenzel, Wolfgang; Steinberg, Mitchell I

    2002-01-01

    The metabolism of moxonidine, 4-chloro-N-(4,5-dihydro-1H-imidazol-2-yl)-6-methoxy-2-methyl-5-pyrimidinamine, LY326869, in rats, mice, dogs, and humans has been examined. At least 17 metabolites were identified or tentatively identified in the different species by HPLC, LC/MS and LC/MS/MS. The identities of seven of the major metabolites have been verified by independent synthesis. The metabolites are generally derived from oxidation and conjugation pathways. Oxidation occurred at the imidazolidine ring as well as the methyl at the 2 position of the pyrimidine ring. All seven metabolites were examined in the spontaneously hypertensive rats (3 mg kg(-1), i.v.) for pressure and heart rate. Only one, 2-hydroxymethyl-4-chloro-5-(imidazolidin-2-ylidenimino)-6-methoxypyrimidine, exerted a short-lasting decrease in blood pressure, albeit attenuated in magnitude compared to moxonidine.

  7. Synthesis and antibacterial activity of some new heterocycles incorporating phthalazine.

    Science.gov (United States)

    Khalil, A M; Berghot, M A; Gouda, M A

    2009-11-01

    3-(1,4-Dioxo-3,4,4e,5,10,10a-hexahydro-1H-5,10-benzeno-benzo[g]phthalazin-2-yl)-3-oxo-propiononitrile (1) was utilized as key intermediate for the synthesis of some new iminocoumarin 2, chromenone 3, aminothiazole 4, triazepine 5a, b and 6, hydrazono-propiononitrile 7, pyridopyrazotriazine 8, monobromo 9, dibromo 10 quinoxaline 11, ketene N,S-acetal 13, ketene S,S-diacetal 17 and 18a, b and methyl dithioate 20 derivatives, respectively. The newly synthesized compounds were characterized by IR, (1)H NMR, (13)C NMR and mass spectral studies. Representative compounds of the synthesized product were tested and evaluated as antibacterial agent.

  8. Ultrasonic cleaning reduces the residual monomer in acrylic resins

    OpenAIRE

    Charasseangpaisarn, Taksid; Wiwatwarrapan, Chairat; Leklerssiriwong, Nonthida

    2016-01-01

    Background/purpose: The residual monomer remaining in acrylic resin can cause an allergic reaction and is toxic to oral soft tissue. This study determined the effect of the duration of ultrasonic cleaning on the amount of residual methyl methacrylate monomer in one heat-polymerized acrylic resin, Meliodent, and three autopolymerized acrylic resins, Unifast Trad Ivory, Unifast Trad Pink, and Unifast III. Materials and methods: Thirty-six disc-shaped specimens of each brand were prepared and...

  9. Immobilization of enzymes by radiation-induced polymerization of glass-forming monomers

    International Nuclear Information System (INIS)

    Yoshida, M.; Kumakura, M.; Kaetsu, I.

    1979-01-01

    The effect of cooling rate of a monomeric system on the porosity and activity of an immobilized enzyme prepared by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperatures has been studied. Slow cooling gave the same effect on porosity of the polymer as decreasing the monomer concentration. A glass-forming solvent such as diethylene glycol was added to water to study the effect of the supercooling tendency of the solvent. Addition of diethylene glycol decreased porosity and also enzymic activity. Water was replaced by the miscible solvent p-dioxane and the immiscible solvent n-decane in order to clarify the effect of solvent. p-Dioxane had a similar effect to water on the relation between the monomer concentration, porosity and activity. On the other hand, polymer prepared from the system containing n-decane showed different immobilization properties owing to the presence of independent pores in the matrix. (author)

  10. Unambiguous Synthesis and Prophylactic Antimalarial Activities of Imidazolidinedione Derivatives

    National Research Council Canada - National Science Library

    Zhang, Quan; Guan, Jian; Sacci, John; Ager, Arba; Ellis, William; Mihlhous, Wilbur; Kyle, Dennis; Lin, Ai J

    2005-01-01

    .... To search for compounds with good oral efficacy, a series of carbamate derivatives of the active components were prepared by the new procedure, many of which showed profound causal prophylactic antimalarial activity against Plasmodium yoelil in mouse by oral administration.

  11. Synthesis, antibacterial and antifungal activity of some derivatives of ...

    Indian Academy of Sciences (India)

    Unknown

    -4-one; antibacterial ..... Kanamycin was used as standard antibiotic for antibacterial activities. Nutrient agar (NA) was used as ... (mould) and Penicillium sp. (blue mould). Antifun- gal activity was assessed by the poisoned food tech- nique,17.

  12. Synthesis and antimicrobial activity of amphiphilic carbohydrate derivatives

    International Nuclear Information System (INIS)

    Reis, Roberta C.N.; Oda, Simone C.; Almeida, Mauro V. de; Le Hyaric, Mireille; Barbosa, Nadia R.; Trevizani, Rafael; Santos, Priscila L.C.

    2008-01-01

    N-monoalkylated diamines were synthesised and treated with D-ribonolactone or D-gluconolactone. The resulting aldonamides were evaluated for their antimicrobial activity against S. aureus, E. coli, M. tuberculosis and C. albicans. Two hydrazides were also prepared from ribonohydrazide and their biological activity was compared to their amide analogues. All the ribono-derivatives displayed moderated antitubercular activity, and some of them were also active against S. aureus. (author)

  13. Effect of radiation combined with Chinese medicinal monomers on Me180 cells

    International Nuclear Information System (INIS)

    Geng Chuanying; Xu Bo; Li Hongyan; Chen Zhihua; Xia Qisheng; Xu Mei; Liu Xuan; Xiang Qing; Liu Yufeng

    2009-01-01

    Objective: To observe the effect of radiation treatment combined with Chinese medicinal monomers on the proliferation function, telomerase activity, expressions of apoptosis- and proliferation-related genes of Me180 cells. Methods: Me180 cells were cultured in the medium with oleanolic acid, curcumin and allicin. The survival rates of cells were detected by the methods of MTT, the telomerase activity by the method of telomeric repeat amplification protocol (TRAP) and the apoptosis -and proliferation-related genes by the method of reverse transeriptase-PCR. Me180 cells were cultured in the medium with Chinese medicinal monomers, and exposed to X-ray irradiation and the survival rates were detected. Results: The results of MTY showed that survival rates of tumor cells exposed to X rays in combination with oleanolic acid, curcumin and allicin were decreased significantly(t=2.81, 4.16, and 3.42, P<0.05). Chinese medicinal monomers inhibited the telomerase activity of MelS0 cells and the inhibiting function changed with time. At 16 h, the telomerase activities of MelS0 cells administered with oleanolic acid and allicin were reduced markedly (t=5.11 and 5.29, P<0.05). After 48 h, the telomerase activities returned to the normal level. The gene expressions of p21 and p16 in Me180 cells treated with oleanolic acid were 2.43 and 2.78 times higher than the control, respectively, while those of cyclin D1 and CDK4 were 56% and 41% of the control, respectively. Conclusions: Chinese medicinal monomers could effectively kill tumor cells, inhibit the telomerase activity and the expression of proliferation-related genes, and enhance the radiosensitivity of tumor cells. (authors)

  14. Synthesis and Antimicrobial Activity of New a-Aminophosphonic ...

    African Journals Online (AJOL)

    NJD

    The antimicrobial and antifungal activities of these compounds were evaluated and they exhibited significant activity. KEYWORDS. Phenyl glycine ethyl ester, aryl aldehydes, diethyl/dimethylphosphite, antimicrobial activity. 1. Introduction ... biologically attractive peptide mimics which have been employed, for example, as ...

  15. Tryptophan analogues. 1. Synthesis and antihypertensive activity of positional isomers.

    Science.gov (United States)

    Safdy, M E; Kurchacova, E; Schut, R N; Vidrio, H; Hong, E

    1982-06-01

    A series of tryptophan analogues having the carboxyl function at the beta-position was synthesized and tested for antihypertensive activity. The 5-methoxy analogue 46 exhibited antihypertensive activity in the rat via the oral route and was much more potent than the normal tryptophan analogue. The methyl ester was found to be a critical structural feature for activity.

  16. Activation of protein kinase C inhibits synthesis and release of decidual prolactin

    International Nuclear Information System (INIS)

    Harman, I.; Costello, A.; Ganong, B.; Bell, R.M.; Handwerger, S.

    1986-01-01

    Activation of calcium-activated, phospholipid-dependent protein kinase C by diacylglycerol and phorbol esters has been shown to mediate release of hormones in many systems. To determine whether protein kinase C activation is also involved in the regulation of prolactin release from human decidual, the authors have examined the effects of various acylglycerols and phorbol esters on the synthesis and release of prolactin from cultured human decidual cells. sn-1,2-Dioctanolyglycerol (diC 8 ), which is known to stimulate protein kinase C in other systems, inhibited prolactin release in a dose-dependent manner with maximal inhibition of 53.1% at 100 μM. Diolein (100 μM), which also stimulates protein kinase C activity in some systems, inhibited prolactin release by 21.3%. Phorbol 12-myristate 13-acetate (PMA), phorbol 12,13-didecanoate, and 4β-phorbol 12,13-dibutyrate, which activate protein kinase C in other systems, also inhibited the release of prolactin, which the protein kinase C inactivate 4α-phorbol-12,13-didecanoate was without effect. The inhibition of prolactin release was secondary to a decrease in prolactin synthesis. Although diC 8 and PMA inhibited the synthesis and release of prolactin, these agents had no effect on the synthesis or release of trichloroacetic acid-precipitable [ 35 S]methionine-labeled decidual proteins and did not cause the release of the cytosolic enzymes lactic dehydrogenase and alkaline phosphatase. DiC 8 and PMA stimulates the specific activity of protein kinase C in decidual tissue by 14.6 and 14.0-fold, respectively. The inhibition of the synthesis and release of prolactin by diC 8 and phorbol esters strongly implicates protein kinase C in the regulation of the production and release of prolactin from the decidua

  17. BASIC SYNTHESIS AND BIOLOGICAL ACTIVITY OF SOME PHOSPHORCONTATNING ORGANIC COMPOUNDS CONTAINING FRAGMENTS OF UREA AND TRYHLORETILAMID

    Directory of Open Access Journals (Sweden)

    Gushylyk B.

    2013-10-01

    Full Text Available Data about directions of synthesis and use of the phosphororganic compounds in technics, biology and medicine is presented in the paper. Antimicrobial activity of 51 phosphororganic salts and ilides containing urine and threechlor ethylenamide has been studied. Perspective of the development of effective antimicrobial substances has been determined

  18. Synthesis and in vitro antiprotozoal activity of some 2- amino-4 ...

    African Journals Online (AJOL)

    Synthesis and in vitro antiprotozoal activity of some 2- amino-4-phenyloxazole derivatives. Rubén M. Carballo, Jesús Patrón-Vázquez, David Cáceres-Castillo, Ramiro Quijano-Quiñones, Angel Herrera-España, Rosa E. Moo-Puc, Juan Chalé-Dzul, Gonzalo J. Mena-Rejón ...

  19. Synthesis and Photocatalytic Activity of Zn Cd S/TiO ...

    African Journals Online (AJOL)

    NICOLAAS

    Synthesis and Photocatalytic Activity of Zn x. Cd. 1–x. S/TiO. 2. Heterostructures Nanofibre Prepared by Combining. Electrospinning and Hydrothermal Method. Wei Changa,b,*, Xiaosai Rena, Guorui Yangb, Wei Yanb,* and Yanrong Guoa. aSchool of Environmental and Chemical Engineering, Xi'an Polytechnic University, ...

  20. Synthesis and In Vitro Cytotoxic Activity of Novel Chalcone-Like Agents

    Directory of Open Access Journals (Sweden)

    Bahram letafat

    2013-11-01

    We described synthesis and cytotoxic activity of poly-functionalized 3-benzylidenechroman-4-ones as new chalcone-like agents. These compounds can be considered as conformationally constrained congeners of chalcones to tolerate the poly-functionalization on the core structures for further optimization.

  1. Natural occurrence, biological activities and synthesis of eight-, nine-, and eleven-membered ring lactones

    Directory of Open Access Journals (Sweden)

    Helena M. C. Ferraz

    2008-01-01

    Full Text Available The natural occurrence, biological activities and synthetic approaches to natural eight-, nine-, and eleven-membered lactones is reviewed. These medium ring lactones are grouped according to ring size, and their syntheses are discussed. The structures of some natural products early identified as medium-ring lactones were revised after total synthesis.

  2. Synthesis, antimicrobial and antifungal activities of novel 1H-1,4 ...

    Indian Academy of Sciences (India)

    Administrator

    Synthesis, antimicrobial and antifungal activities of novel. 1H-1,4-diazepines containing pyrazolopyrimidinone moiety. RAJESH KUMAR and YOGESH CHANDRA JOSHI*. Department of Chemistry, University of Rajasthan, Jaipur 302 004 e-mail: rnunia@yahoo.com. MS received 20 October 2008; revised 28 May 2009; ...

  3. Variation in array size, monomer composition and expression of the macrosatellite DXZ4.

    Directory of Open Access Journals (Sweden)

    Deanna C Tremblay

    Full Text Available Macrosatellites are some of the most polymorphic regions of the human genome, yet many remain uncharacterized despite the association of some arrays with disease susceptibility. This study sought to explore the polymorphic nature of the X-linked macrosatellite DXZ4. Four aspects of DXZ4 were explored in detail, including tandem repeat copy number variation, array instability, monomer sequence polymorphism and array expression. DXZ4 arrays contained between 12 and 100 3.0 kb repeat units with an average array containing 57. Monomers were confirmed to be arranged in uninterrupted tandem arrays by restriction digest analysis and extended fiber FISH, and therefore DXZ4 encompasses 36-288 kb of Xq23. Transmission of DXZ4 through three generations in three families displayed a high degree of meiotic instability (8.3%, consistent with other macrosatellite arrays, further highlighting the unstable nature of these sequences in the human genome. Subcloning and sequencing of complete DXZ4 monomers identified numerous single nucleotide polymorphisms and alleles for the three microsatellite repeats located within each monomer. Pairwise comparisons of DXZ4 monomer sequences revealed that repeat units from an array are more similar to one another than those originating from different arrays. RNA fluorescence in situ hybridization revealed significant variation in DXZ4 expression both within and between cell lines. DXZ4 transcripts could be detected originiating from both the active and inactive X chromosome. Expression levels of DXZ4 varied significantly between males, but did not relate to the size of the array, nor did inheritance of the same array result in similar expression levels. Collectively, these studies provide considerable insight into the polymorphic nature of DXZ4, further highlighting the instability and variation potential of macrosatellites in the human genome.

  4. Synthesis, photodynamic activity, and quantitative structure-activity relationship modelling of a series of BODIPYs.

    Science.gov (United States)

    Caruso, Enrico; Gariboldi, Marzia; Sangion, Alessandro; Gramatica, Paola; Banfi, Stefano

    2017-02-01

    Here we report the synthesis of eleven new BODIPYs (14-24) characterized by the presence of an aromatic ring on the 8 (meso) position and of iodine atoms on the pyrrolic 2,6 positions. These molecules, together with twelve BODIPYs already reported by us (1-12), represent a large panel of BODIPYs showing different atoms or groups as substituent of the aromatic moiety. Two physico-chemical features ( 1 O 2 generation rate and lipophilicity), which can play a fundamental role in the outcome as photosensitizers, have been studied. The in vitro photo-induced cell-killing efficacy of 23 PSs was studied on the SKOV3 cell line treating the cells for 24h in the dark then irradiating for 2h with a green LED device (fluence 25.2J/cm 2 ). The cell-killing efficacy was assessed with the MTT test and compared with that one of meso un-substituted compound (13). In order to understand the possible effect of the substituents, a predictive quantitative structure-activity relationship (QSAR) regression model, based on theoretical holistic molecular descriptors, was developed. The results clearly indicate that the presence of an aromatic ring is fundamental for an excellent photodynamic response, whereas the electronic effects and the position of the substituents on the aromatic ring do not influence the photodynamic efficacy. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Regioselective synthesis of isoxazole-mercaptobenzimidazole hybrids and their in vivo analgesic and anti-inflammatory activity studies

    DEFF Research Database (Denmark)

    Kankala, Shravankumar; Kankala, Ranjith Kumar; Gundepaka, Prasad

    2013-01-01

    Regioselective synthesis of isoxazole-mercaptobenzimidazole hybrids and their efficiency in in vivo analgesic and anti-inflammatory activity was described. A comparison of structure-activity relationship for there compounds was also emphasized....

  6. Synthesis of a Benzodiazepine-derived Rhodium NHC Complex by C-H Bond Activation

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, Roberg G.; Gribble, Jr., Michael W.; Ellman, Jonathan A.

    2008-01-30

    The synthesis and characterization of a Rh(I)-NHC complex generated by C-H activation of 1,4-benzodiazepine heterocycle are reported. This complex constitutes a rare example of a carbene tautomer of a 1,4-benzodiazepine aldimine stabilized by transition metal coordination and demonstrates the ability of the catalytically relevant RhCl(PCy{sub 3}){sub 2} fragment to induce NHC-forming tautomerization of heterocycles possessing a single carbene-stabilizing heteroatom. Implications for the synthesis of benzodiazepines and related pharmacophores via C-H functionalization are discussed.

  7. Proanthocyanidin monomers and cyanidin 3-O-glucoside accumulation in blood-flesh peach (Prunus persica (L. Batsch fruit

    Directory of Open Access Journals (Sweden)

    Yan Juan

    2017-01-01

    Full Text Available To better understand the characteristics and mechanisms of proanthocyanidin monomers and anthocyanin synthesis in blood-flesh peach (Prunus persica (L. Batsch, the accumulation of catechin, epicatechin and cyanidin 3-O-glucoside was determined, and the expression patterns of structural genes associated with biosynthesis of those compounds were investigated in the blood-flesh peach fruit of cultivar “Dahongpao” during fruit development. Our results show that catechin concentration remained low and comparatively stable throughout fruit development. The concentration of epicatechin remained low at the early stages of fruit development and rapidly accumulated during ripening. Cyanidin 3-O-glucoside was not detected in theearly stages. Epicatechin started to rapidly accumulate during the ripening period, reaching a maximum at the mature stage. The expressions of the early and common genes, phenylalanine ammonia-lyase and chalcone isomerase, were less associated with proanthocyanidin monomers and cyanidin 3-O-glucoside accumulation. The expression of other flavonoid ‘early’ biosynthetic genes, including chalcone synthase (CHS, flavanone 3-hydroxylase, dihydroflavonol 4-reductase (DFR and leucoanthocyanidin dioxygenase (LDOX, were partly associated with proanthocyanidin monomers and cyanidin 3-O-glucoside levels, with expression quantities peaking synchronously at the mature stage. Leucoanthocyanidin reductase and anthocyanidin reductase, which were the key genes for proanthocyanidin monomer synthesis, correlated during fruit development with catechin and epicatechin accumulation respectively; UDP-glucose: flavonoid 3-O-glucosyltransferase (UGFT, the key gene for anthocyanin synthesis, was correlated with cyanidin 3-O-glucoside levels. The synchronous accumulation of epicatechin and cyanidin 3-O-glucoside in blood-flesh peach could not be explained by the current theory of competitive distribution mechanism of common substrate.

  8. On the origin of high activity of hcp metals for ammonia synthesis.

    Science.gov (United States)

    Ahmadi, Shideh; Kaghazchi, Payam

    2016-02-21

    Structure and activity of nanoparticles of hexagonal close-packed (hcp) metals are studied using first-principles calculations. Results show that, in contact with a nitrogen environment, high-index {134[combining macron]2} facets are formed on hcp metal nanoparticles. Nitrogen molecules dissociate easily at kink sites on these high-index facets (activation barriers of macron]2} facets explains the order of activity of hcp metals for ammonia synthesis: Re macron]2} facets with high activity for the dissociation of nitrogen molecules. However, quite different behavior for adsorption of dissociated N atoms leads to distinctive activity of hcp metals.

  9. Capturing Biological Activity in Natural Product Fragments by Chemical Synthesis.

    Science.gov (United States)

    Crane, Erika A; Gademann, Karl

    2016-03-14

    Natural products have had an immense influence on science and have directly led to the introduction of many drugs. Organic chemistry, and its unique ability to tailor natural products through synthesis, provides an extraordinary approach to unlock the full potential of natural products. In this Review, an approach based on natural product derived fragments is presented that can successfully address some of the current challenges in drug discovery. These fragments often display significantly reduced molecular weights, reduced structural complexity, a reduced number of synthetic steps, while retaining or even improving key biological parameters such as potency or selectivity. Examples from various stages of the drug development process up to the clinic are presented. In addition, this process can be leveraged by recent developments such as genome mining, antibody-drug conjugates, and computational approaches. All these concepts have the potential to identify the next generation of drug candidates inspired by natural products. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  10. Design, Synthesis, DFT Study and Antifungal Activity of Pyrazolecarboxamide Derivatives

    Directory of Open Access Journals (Sweden)

    Jin-Xia Mu

    2016-01-01

    Full Text Available A series of novel pyrazole amide derivatives were designed and synthesized by multi-step reactions from phenylhydrazine and ethyl 3-oxobutanoate as starting materials, and their structures were characterized by NMR, MS and elemental analysis. The antifungal activity of the title compounds was determined. The results indicated that some of title compounds exhibited moderate antifungal activity. Furthermore, DFT calculations were used to study the structure-activity relationships (SAR.

  11. Synthesis and antibacterial activity of new chiral N ...

    Indian Academy of Sciences (India)

    negative bacteria; Escherichia. Coli, Klebsiella pneumonieae, Acinetobacter, Pseudomonas aeruginosa, Enterococcus, Salmonella sp. The compounds showed moderate to good antibacterial activity. Keywords. Oxazolidinone; chlorosulfonyl ...

  12. Synthesis, antimicrobial and cytotoxic activities of sulfonamidomethane linked heterocycles.

    Science.gov (United States)

    Swapna, Mukkara; Premakumari, Chokkappagari; Reddy, Sanapalli Nagi; Padmaja, Adivireddy; Padmavathi, Venkatapuram; Kondaiah, Paturu; Krishna, Narra Siva

    2013-01-01

    A new class of sulfonamidomethane pyrrolyl-oxadiazoles/thiadiazoles and pyrazolyl-oxadiazoles/thiadiazoles was prepared from arylsulfonylaminoacetic acid hydrazides and E-cinnamic acid. The lead compounds were tested for antimicrobial and cytotoxic activities. The thiadiazole compounds having chloro substituent on the aromatic ring 4c, 8c and 10c exhibited comparable antibacterial activity against Pseudomonas aeruginosa and also antifungal activity against Penicillium chrysogenum. The styryl oxadiazole compound 3c showed appreciable cytotoxic activity on A549 lung carcinoma cells which can be used as a lead compound in the future studies.

  13. Synthesis, antimicrobial and antioxidative activity of some new isatin derivatives

    Directory of Open Access Journals (Sweden)

    Šekularac Gavrilo M.

    2014-01-01

    Full Text Available The isatin derivatives, Schiff bases, were synthesized by the reaction of isatin and various substituted primary amines and characterized by several spectroscopic methods. Investigation of the antimicrobial activity of the synthesized compounds was performed by the agar dilution method, against different strains of bacteria and one fungi. The antioxidative activity of the synthesized compounds was also determined. Some of the compounds have shown the significant activity against the selected strains of microorganisms and the antioxidative activity. [Projekat Ministarstva nauke Republike Srbije, br. 172013 i III 46010

  14. Ligustrazine monomer against cerebral ischemia-reperfusion injury

    Directory of Open Access Journals (Sweden)

    Hai-jun Gao

    2015-01-01

    Full Text Available Ligustrazine (2,3,5,6-tetramethylpyrazine is a major active ingredient of the Szechwan lovage rhizome and is extensively used in treatment of ischemic cerebrovascular disease. The mechanism of action of ligustrazine use against ischemic cerebrovascular diseases remains unclear at present. This study summarizes its protective effect, the optimum time window of administration, and the most effective mode of administration for clinical treatment of cerebral ischemia/reperfusion injury. We examine the effects of ligustrazine on suppressing excitatory amino acid release, promoting migration, differentiation and proliferation of endogenous neural stem cells. We also looked at its effects on angiogenesis and how it inhibits thrombosis, the inflammatory response, and apoptosis after cerebral ischemia. We consider that ligustrazine gives noticeable protection from cerebral ischemia/reperfusion injury. The time window of ligustrazine administration is limited. The protective effect and time window of a series of derivative monomers of ligustrazine such as 2-[(1,1-dimethylethyloxidoimino]methyl]-3,5,6-trimethylpyrazine, CXC137 and CXC195 after cerebral ischemia were better than ligustrazine.

  15. Synthesis of polystyrene@(silver-polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Science.gov (United States)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu

    2015-01-01

    We reported the synthesis of polystyrene@(silver-polypyrrole) (PS@(Ag-PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag+ and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA)2]+) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO3 and Py, the introduction of [Ag(TEA)2]+ ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag-PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA)2]+ ions resulted in the increase of Ag-PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag-PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 105 - 9×105 cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag-PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.

  16. Melatonin synthesis in the human ciliary body triggered by TRPV4 activation: Involvement of AANAT phosphorylation.

    Science.gov (United States)

    Alkozi, Hanan Awad; Perez de Lara, María J; Pintor, Jesús

    2017-09-01

    Melatonin is a substance synthesized in the pineal gland as well as in other organs. This substance is involved in many ocular functions, giving its synthesis in numerous eye structures. Melatonin is synthesized from serotonin through two enzymes, the first limiting step into the synthesis of melatonin being aralkylamine N-acetyltransferase (AANAT). In this current study, AANAT phosphorylation after the activation of TRPV4 was studied using human non-pigmented epithelial ciliary body cells. Firstly, it was necessary to determine the adequate time and dose of the TRPV4 agonist GSK1016790A to reach the maximal phosphorylation of AANAT. An increase of 72% was observed after 5 min incubation with 10 nM GSK (**p melatonin synthesis. The involvement of a TRPV4 channel in melatonin synthesis was verified by antagonist and siRNA studies as a previous step to studying intracellular signalling. Studies performed on the second messengers involved in GSK induced AANAT phosphorylation were carried out by inhibiting several pathways. In conclusion, the activation of calmodulin and calmodulin-dependent protein kinase II was confirmed, as shown by the cascade seen in AANAT phosphorylation (***p melatonin levels. In conclusion, the activation of a TRPV4 present in human ciliary body epithelial cells produced an increase in AANAT phosphorylation and a further melatonin increase by a mechanism in which Ca-calmodulin and the calmodulin-dependent protein kinase II are involved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Synthesis of Copper Nanoparticles Using a Different Method: Determination of Its Antioxidant and Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Demet Demirci Gültekin

    2016-10-01

    Full Text Available In this study, it was aimed to obtain copper oxide nanoparticles (CuO NPs with the method of green synthesis by using peroxidase enzymes which were partly purified from fig (Ficus carica. Copper (II oxide nanoparticles are successfully synthesized with the green synthesis method on the experiments we performed.  UV-VIS spectroscopy of the characterization of acquired CuO NPs were performed with Scanning Electron Microscopy (SEM and X-ray Diffraction (XRD. Optimum activation temperature for green synthesis was observed to be in 30 min, pH:8, at 25 oC and in the concentration of 1mM CuCl2. By using peroxidase enzymes with green synthesis, it was found out the results of SEM and XRD measurements that acquired CuO NPs were in the size of 50-120 nm. Afterwards, the antioxidant and antibacterial activities of these nanoparticles were measured and it was understood from the obtained results that CuO NPs had both antioxidant and antimicrobial activities.

  18. D-tyrosine negatively regulates melanin synthesis by competitively inhibiting tyrosinase activity.

    Science.gov (United States)

    Park, Jisu; Jung, Hyejung; Kim, Kyuri; Lim, Kyung-Min; Kim, Ji-Young; Jho, Eek-Hoon; Oh, Eok-Soo

    2017-11-09

    Although L-tyrosine is well known for its melanogenic effect, the contribution of D-tyrosine to melanin synthesis was previously unexplored. Here, we reveal that, unlike L-tyrosine, D-tyrosine dose-dependently reduced the melanin contents of human MNT-1 melanoma cells and primary human melanocytes. In addition, 500 μM of D-tyrosine completely inhibited 10 μM L-tyrosine-induced melanogenesis, and both in vitro assays and L-DOPA staining MNT-1 cells showed that tyrosinase activity is reduced by D-tyrosine treatment. Thus, D-tyrosine appears to inhibit L-tyrosine-mediated melanogenesis by competitively inhibiting tyrosinase activity. Furthermore, we found that D-tyrosine inhibited melanogenesis induced by α-MSH treatment or UV irradiation, which are the most common environmental factors responsible for melanin synthesis. Finally, we confirmed that D-tyrosine reduced melanin synthesis in the epidermal basal layer of a 3D human skin model. Taken together, these data suggest that D-tyrosine negatively regulates melanin synthesis by inhibiting tyrosinase activity in melanocyte-derived cells. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Green synthesis and antioxidant activity of novel γ-cyano-α- hydroxyphosphonate derivatives.

    Science.gov (United States)

    Aouani, Iyadh; Lahbib, Karima; Touil, Soufiane

    2015-01-01

    Herein we report an efficient, simple and green synthesis of novel types of α-hydroxyphosphonates bearing a nitrile group, from the reaction of γ-ketonitriles with dialkyl phosphites in the presence of magnesium oxide as solid support, under solvent-free conditions. All the title compounds were screened for their antioxidant activity by 1,1-diphenyl-2- picrylhydrazyl (DPPH), hydroxyl radical, reducing power and ferrous ion chelating (FIC) methods and they showed significant antioxidant activity.

  20. Systematic and Stereoselective Total Synthesis of Mannosylerythritol Lipids and Evaluation of Their Antibacterial Activity.

    Science.gov (United States)

    Nashida, Junki; Nishi, Nobuya; Takahashi, Yoshiaki; Hayashi, Chigusa; Igarashi, Masayuki; Takahashi, Daisuke; Toshima, Kazunobu

    2018-03-13

    The total synthesis of the 20 homogeneous members of mannosylerythritol lipids (MELs) with different alkyl chain lengths was effectively and systematically accomplished from a strategically designed common key intermediate that was stereoselectively constructed by the borinic acid catalyzed β-mannosylation reaction. In addition, their antibacterial activities against Gram-positive bacteria were evaluated. Our results demonstrated that not only the length of the alkyl chains but also the pattern of Ac groups on the mannose moiety were important factors for antibacterial activity.

  1. Synthesis of Chrysogeside B from Halotolerant Fungus Penicillium and Its Antimicrobial Activities Evaluation

    Science.gov (United States)

    Liu, Ruiquan; Wang, Lei; Li, Qibo; Liao, Min; Yang, Zhikun; Huang, Yun; Lv, Cong; Zheng, Bing; Zhong, Jiangchun; Bian, Qinghua; Wang, Min; Liu, Shangzhong

    2017-04-01

    Chrysogeside B, a natural cerebroside, was efficiently synthesized from commercial feedstocks. The bioassays showed that compounds 4, 5 and 6 exhibited enhanced biological activities compared Chrysogeside B. Further studies revealed that free hydroxyl groups and glycosidic bond have significant impact on the antimicrobial activities. The synthesis of Chrysogeside B and analogues designed to allow identification of the features of this glycolipid required for recognition by tested bacteria and Hela cells is described.

  2. Synthesis of Chrysogeside B from Halotolerant Fungus Penicillium and Its Antimicrobial Activities Evaluation

    OpenAIRE

    Liu, Ruiquan; Wang, Lei; Li, Qibo; Liao, Min; Yang, Zhikun; Huang, Yun; Lv, Cong; Zheng, Bing; Zhong, Jiangchun; Bian, Qinghua; Wang, Min; Liu, Shangzhong

    2017-01-01

    Chrysogeside B, a natural cerebroside, was efficiently synthesized from commercial feedstocks. The bioassays showed that compounds 4, 5 and 6 exhibited enhanced biological activities compared Chrysogeside B. Further studies revealed that free hydroxyl groups and glycosidic bond have significant impact on the antimicrobial activities. The synthesis of Chrysogeside B and analogues designed to allow identification of the features of this glycolipid required for recognition by tested bacteria and...

  3. Peroxidase synthesis and activity in the interaction of soybean with Phytophthora megasperma f. sp. glycinea (Pmg)

    International Nuclear Information System (INIS)

    Chibbar, R.N.; Esnault, R.; Lee, D.; van Huystee, R.B.; Ward, E.W.B.

    1986-01-01

    Changes, in peroxidase (EC1.11.1.7) have been reported following infection. However, determinations of biosynthesis of quantities of the peroxidase protein molecule have not been made! In this study hypocotyl of soybean seedlings (Glycine max; cv Harosoy, susceptible; cv Harosoy 63, resistant) were inoculated with zoospores of Pmg. Incorporation of 35 S-methionine (supplied with inoculum) in TCA precipitates was measured. Peroxidase synthesis was measured by immuno precipitation using antibodies against a cationic and an anionic peroxidase derived from peanut cells. Specific peroxidase activity increased rapidly from 5 to 9 h following infection in the resistant reaction but not in the susceptible reaction or the water controls. There was increased synthesis of the anionic peroxidase but not of the cationic peroxidase in the resistant reaction. The anionic peroxidase did not increase in the susceptible until 15 h. The ratio of peroxidase synthesis to total protein synthesis decreased in inoculated tissues compared to control. Peroxidase synthesis is, therefore, a relative minor host response to infection

  4. Synthesis and biological activity of some heterocyclic compounds ...

    Indian Academy of Sciences (India)

    A number of 1-substituted-2-methyl benzimidazole derivatives have been synthesized and tested for their antibacterial activities. The chemical structures of the newly synthesized compounds were verified on the basis of spectral and elemental methods of analyses. Investigation of antimicrobial activity of the compounds ...

  5. Design, synthesis and antibacterial activity of a novel hybrid ...

    African Journals Online (AJOL)

    ajl user 1

    2012-01-26

    Jan 26, 2012 ... triplicate. Determination of hemolysis activity of LFM23. The hemolytic activity of LFM23 was determined using human erythrocyte as described by Maher and McClean (2006). The human erythrocytes were prepared from 4 ml freshly collected human blood by centrifugation at 1500 rpm for 10 min at 4°C.

  6. Immobilization of lysozyme on cotton fabrics; synthesis, characterication, and activity

    Science.gov (United States)

    The antimicrobial activity of lysozyme derives from the hydrolysis of the bacterial cell wall polysaccharide at the glycosidic bond that links N-acetyl-glucosamine and N-acetyl-muramic acid. Maintaining the activity of lysozyme while bound to a cellulose substrate is a goal toward developing enzyme...

  7. Design, synthesis and cytotoxic activity of some novel compounds ...

    Indian Academy of Sciences (India)

    Insight into different biological activities of pyrazolo. [3,4-d]pyrimidines as antimetabolites in purine bioche- mical reactions, were gained and several mechanisms were described for their cytotoxic activities as EGFR inhibitors,3 GSK-3 inhibitors,4,5 xanthine oxidase inhi- bitors,6 Mer receptor tyrosine kinase inhibitors,7 tyro-.

  8. Synthesis and biological activity of some heterocyclic compounds ...

    Indian Academy of Sciences (India)

    Administrator

    antiprotozoal. 20,21 and anti-hepatitis B virus activity. 22. In addition, a large number of antibiotics contain the 2-azetidinone. (commonly known as β-lactam) moiety. 23 such as penicillin, cephalosporin and carbapenem (figure 2). It is also associated with a variety of therapeutic activities. 24–28. In continuation of our work to.

  9. Designer Ligands. Part 13. Synthesis and Catalytic Activity of ...

    African Journals Online (AJOL)

    Copper(I), copper(II), cobalt(II) and zinc(II) complexes of a macrocyclic, multidentate Schiff-base ligand have been prepared and, with the exception of the zinc(II) complex, have been shown to exhibit biomimetic catecholase activity. Keywords: Copper(II);Cobalt(II); Zinc(II); Biomimetic complexes; Catecholase activity

  10. Synthesis and Antifungal Activities of Some Novel Pyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Dequn Sun

    2011-06-01

    Full Text Available Three series of new pyrimidine derivatives were synthesized and their antifungal activities were evaluated in vitro against fourteen phytopathogenic fungi. The results indicated that most of the synthesized compounds possessed fungicidal activities and some of them are more potent than the control fungicides. Preliminary SAR was also discussed.

  11. Synthesis, antimicrobial activities and computational studies of some ...

    African Journals Online (AJOL)

    The quantitative structure-antibacterial activity relationship was studied using some quantum chemical parameters with the aid of Spartan 10 (V1.0.1) and XLSTAT (add-in) software. A good correlation was observed between the antibacterial activity of the compounds and the calculated quantum chemical descriptors.

  12. Synthesis and evaluation of antimicrobial and anthelmintic activity of ...

    Indian Academy of Sciences (India)

    compounds were made on the basis of spectroscopic data and elemental analysis. Keywords. 10H-phenothiazines; Smiles rearrangement; sulphones; ribofuranosides; antimicrobial activity; anthelmintic activity. 1. Introduction. A large number of publications and patents registered worldwide gave much emphasis on the ...

  13. Design, Synthesis and Insecticidal Activity of Novel Phenylurea Derivatives

    Directory of Open Access Journals (Sweden)

    Jialong Sun

    2015-03-01

    Full Text Available A series of novel phenylurea derivatives were designed and synthesized according to the method of active groups linkage and the principle of aromatic groups bioisosterism in this study. The structures of the novel phenylurea derivatives were confirmed based on ESI-MS, IR and 1H-NMR spectral data. All of the compounds were evaluated for the insecticidal activity against the third instars larvae of Spodoptera exigua Hiibner, Plutella xyllostella Linnaeus, Helicoverpa armigera Hubner and Pieris rapae Linne respectively, at the concentration of 10 mg/L. The results showed that all of the derivatives displayed strong insecticidal activity. Most of the compounds presented higher insecticidal activity against S. exigua than the reference compounds tebufenozide, chlorbenzuron and metaflumizone. Among the synthesized compounds, 3b, 3d, 3f, 4b and 4g displayed broad spectrum insecticidal activity.

  14. Design, Synthesis and Antiviral Activity Studies of Schizonepetin Derivatives

    Directory of Open Access Journals (Sweden)

    Anwei Ding

    2013-08-01

    Full Text Available A series of schizonepetin derivatives have been designed and synthesized in order to obtain potent antivirus agents. The antiviral activity against HSV-1 and influenza virus H3N2 as well as the cytotoxicity of these derivatives was evaluated by using cytopathic effect (CPE inhibition assay in vitro. Compounds M2, M4, M5 and M34 showed higher inhibitory activity against HSV-1 virus with the TC50 values being in micromole. Compounds M28, M33, and M35 showed higher inhibitory activity against influenza virus H3N2 with their TC50 values being 96.4, 71.0 and 75.4 μM, respectively. Preliminary biological activity evaluation indicated that the anti-H3N2 and anti-HSV-1 activities improved obviously through the introduction of halogen into the structure of schizonepetin.

  15. Synthesis and antimalarial activity of new haemanthamine-type derivatives.

    Science.gov (United States)

    Cedrón, Juan C; Gutiérrez, David; Flores, Ninoska; Ravelo, Ángel G; Estévez-Braun, Ana

    2012-09-15

    Thirty one derivatives were prepared from the natural alkaloids haemanthamine (1), haemanthidine (2) and 11-hydroxyvittatine (3). They were evaluated for their in vitro antimalarial activity against chloroquine-sensitive strains of Plasmodium falciparum and some structure-activity relationships were outlined. For haemanthamine derivatives having a methoxy group at C-3, the presence of a free hydroxyl group at C-11 is important for the activity. The double bond at C-1-C-2 plays also an important role to achieve good inhibitory activity. Compound 35 with two nicotinate groups at C-3 and at C-11 was the most active compound with a IC(50) = 0.8 ± 0.06 μM. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Synthesis and Antioxidant Activity of Alkyl Nitroderivatives of Hydroxytyrosol

    Directory of Open Access Journals (Sweden)

    Elena Gallardo

    2016-05-01

    Full Text Available A series of alkyl nitrohydroxytyrosyl ether derivatives has been synthesized from free hydroxytyrosol (HT, the natural olive oil phenol, in order to increase the assortment of compounds with potential neuroprotective activity in Parkinson’s disease. In this work, the antioxidant activity of these novel compounds has been evaluated using Ferric Reducing Antioxidant Power (FRAP, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS, and Oxygen Radical Scavenging Capacity (ORAC assays compared to that of nitrohydroxytyrosol (NO2HT and free HT. New compounds showed variable antioxidant activity depending on the alkyl side chain length; compounds with short chains (2–4 carbon atoms maintained or even improved the antioxidant activity compared to NO2HT and/or HT, whereas those with longer side chains (6–8 carbon atoms showed lower activity than NO2HT but higher than HT.

  17. Study of the kinetic parameters for synthesis and hydrolysis of pharmacologically active salicin isomer catalyzed by baker's yeast maltase

    Science.gov (United States)

    Veličković, D. V.; Dimitrijević, A. S.; Bihelović, F. J.; Jankov, R. M.; Milosavić, N.

    2011-12-01

    One of the key elements for understanding enzyme reactions is determination of its kinetic parameters. Since transglucosylation is kinetically controlled reaction, besides the reaction of synthesis, very important is the reaction of enzymatic hydrolysis of created product. Therefore, in this study, kinetic parameters for synthesis and secondary hydrolysis of pharmacologically active α isosalicin by baker's yeast maltase were calculated, and it was shown that specifity of maltase for hydrolysis is approximately 150 times higher then for synthesis.

  18. Possible Role of Ice in the Synthesis of Polymeric Compounds

    Science.gov (United States)

    Monnard, Pierre-Alain; Doerr, Mark; Loeffler, Philipp, M. G.

    COSPAR Session F3.6, Bremen July 18-25, 2010 Possible role of ice in the synthesis of polymeric compounds Doerr, Mark, Loeffler, Philipp M.G and Monnard, Pierre-Alain, University of Southern Den-mark, FLinT Center, Odense M, Denmark. Email: monnard@ifk.sdu.dk Cellular life relies on a collection of linear polymers (among them DNA, RNA, proteins) to perform the functions necessary to its survival. It seems likely that catalytic and informational polymers played essential roles in the emergence of the first living entities, precursors of con-temporary cells. Thus, their detection on other planetary bodies might hint at either emerging, or extant, or past life in these environments. A non-enzymatic synthesis of such polymeric materials or their precursors likely had to rely on a supply of monomers dissolved at low concentrations in an aqueous medium. An aqueous environment represents a clear hurdle to the synthesis of long polymers as it tends to inhibit polymerization due to entropic effects and favors the reverse reaction (decomposition by hy-drolysis). It was therefore proposed that polymerization could occur in a distinct micro-or nanostructured environment that would permit a local increase in the monomer concentration, reduce water activity and protect monomers and polymers from hydrolysis. Several types of micro-or nanostructured environments, among them mineral surfaces [1], lattices of organic molecules, such as amphiphile bilayer structures [2], and the eutectic phase in water-ice [3-8] have been proposed to promote RNA and peptide formation. This last environment might be of particular interest since space exploration has established that water exists on Mars, Europa, Enceladus and comets, mostly as ice. Ice deposits may also have existed on the early Earth. When an aqueous solution is cooled below its freezing point, but above the eutectic point, two aqueous phases co-exist and form the eutectic phase system: a solid (the ice crystals made of pure water

  19. Synthesis, antiproliferative activity and molecular docking of Colchicine derivatives.

    Science.gov (United States)

    Huczyński, Adam; Majcher, Urszula; Maj, Ewa; Wietrzyk, Joanna; Janczak, Jan; Moshari, Mahshad; Tuszynski, Jack A; Bartl, Franz

    2016-02-01

    In order to create more potent anticancer agents, a series of five structurally different derivatives of Colchicine have been synthesised. These compounds were characterised spectroscopically and structurally and their antiproliferative activity against four human tumour cell lines (HL-60, HL-60/vinc, LoVo, LoVo/DX) was evaluated. Additionally the activity of the studied compounds was calculated using computational methods involving molecular docking of the Colchicine derivatives to β-tubulin. The experimental and computational results are in very good agreement indicating that the antimitotic activity of Colchicine derivatives can be readily predicted using computational modeling methods. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  20. Synthesis and antitubercular activity of isoniazid condensed with carbohydrate derivatives

    Directory of Open Access Journals (Sweden)

    Sílvia H. Cardoso

    2009-01-01

    Full Text Available A series of 13 compounds analogous of isoniazid condensed with carbohydrate was synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv using Alamar Blue susceptibility test and the activity expressed as the minimum inhibitory concentration (MIC90 in μg/mL. Several compounds exhibited antitubercular activity (0.31-3.12 μg/mL when compared with first line drugs such as isoniazid (INH and rifampicin (RIP and could be a good starting point to develop new compounds against tuberculosis.

  1. Synthesis of Diethylpropione Derivatives and Their Leukocyte-Increasing Activities

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chung Gang; Sun, Yi Ping; Wang, Guo Ping; Tan, Xiang Duan [Guilin Medical University, Guilin (China)

    2014-09-15

    In search of new antileukopenia agents, twenty dithiolopyrrolone derivatives were synthesized and evaluated for their leukocyte-increasing activities in normal mice. Among the synthesized compounds 4-23, compounds 5 and 6 showed significant leukocyte-increasing activity ( p < 0.01), and compounds 4, 9 and 16 had a moderate effect ( p < 0.05). Compound 5 also displayed stronger leukocyte-increasing activity than that of the positive recombinant human granulocyte colony stimulating factor (rhG-CSF). Above all, compound 5 would be a potential antileukopenia agent which deserved further research.

  2. Synthesis and antitubercular activity of quaternized promazine and promethazine derivatives.

    Science.gov (United States)

    Bate, Aaron B; Kalin, Jay H; Fooksman, Eric M; Amorose, Erica L; Price, Cristofer M; Williams, Heather M; Rodig, Michael J; Mitchell, Miguel O; Cho, Sang Hyun; Wang, Yuehong; Franzblau, Scott G

    2007-03-01

    Quaternized chlorpromazine, triflupromazine, and promethazine derivatives were synthesized and examined as antitubercular agents against both actively growing and non-replicating Mycobacterium tuberculosis H37Rv. Impressively, several compounds inhibited non-replicating M. tuberculosis at concentrations equal to or double their MICs against the actively growing strain. All active compounds were non-toxic toward Vero cells (IC50 > 128 microM). N-Allylchlorpromazinium bromide was only weakly antitubercular, but replacing allyl with benzyl or substituted benzyl improved potency. An electron-withdrawing substituent on the phenothiazine ring was also essential. Branching at the carbon chain decreased antitubercular activity. The optimum antitubercular structures possessed N-(4- or 3-chlorobenzyl) substitution on triflupromazine.

  3. Synthesis, Anticonvulsant Activity and In silco Studies of Schiff ...

    African Journals Online (AJOL)

    ... infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H NMR) and mass spectrometry (MS) while their anticonvulsant activity was screened against maximum electroshockinduced seizure (MES), and pentylenetetrazole-induced seizure (PTZ) against phenytoin and diazepam as reference standards.

  4. Synthesis and antibacterial activity of monocyclic 3-carboxamide tetramic acids

    Directory of Open Access Journals (Sweden)

    Yong-Chul Jeong

    2013-09-01

    Full Text Available A chemical library of carboxamide-substituted tetramates designed by analogy with antibacterial natural products, a method for their rapid construction, and the evaluation of their antibacterial activity is reported.

  5. Synthesis and Catalytic Activity of Two New Cyclic Tetraaza Ligands

    Directory of Open Access Journals (Sweden)

    Burkhard König

    2003-05-01

    Full Text Available Two new chiral cyclic tetraaza ligands were synthesized and characterized. Their catalytic activity was tested in the asymmetric addition of diethylzinc to benzaldehyde. The expected secondary alcohol was obtained in moderate yields, but with very low enantioselectivity.

  6. Synthesis, characterization and antibacterial activity of new fluorescent chitosan derivatives

    Czech Academy of Sciences Publication Activity Database

    Přichystalová, H.; Almonasy, N.; Abdel-Mohsen, A. M.; Abdel-Rahman, R. M.; Fouda, M. M. G.; Vojtova, L.; Kobera, Libor; Spotz, Z.; Burgert, L.; Jancar, J.

    2014-01-01

    Roč. 65, April (2014), s. 234-240 ISSN 0141-8130 Institutional support: RVO:61389013 Keywords : chitosan derivatives * fluorescence * antibacterial activity Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.858, year: 2014

  7. Synthesis, characterization, x-ray structure and antimicrobial activity ...

    African Journals Online (AJOL)

    Purpose: To synthesize thiosemicarbazide and determine its antimicrobial properties. Methods: Pyridine-based thiosemicarbazide was synthesized, characterized and evaluated for antimicrobial activity. The structure of the synthesized compound was established by spectral analysis, namely, Fourier transform infrared ...

  8. Thermus thermophilus Strains Active in Purine Nucleoside Synthesis

    Directory of Open Access Journals (Sweden)

    Marcos Almendros

    2009-03-01

    Full Text Available Several strains of Thermus thermophilus were tested in order to detect purine nucleoside synthase activity using pyrimidine nucleosides as the sugar-donor and adenine or hypoxanthine as bases. High productivity values (t =1 hr were obtained while completely avoiding adenosine-deaminase degradation of the products. N-2-deoxy-ribosyltransferase activity is described for the first time in hyperthermophilic bacteria.

  9. Catalytic Synthesis and Antifungal Activity of New Polychlorinated Natural Terpenes

    Directory of Open Access Journals (Sweden)

    Hana Ighachane

    2017-01-01

    Full Text Available Various unsaturated natural terpenes were selectively converted to the corresponding polychlorinated products in good yields using iron acetylacetonate in combination with nucleophilic cocatalyst. The synthesized compounds were evaluated for their in vitro antifungal activity. The antifungal bioassays showed that 2c and 2d possessed significant antifungal activity against Fusarium oxysporum f. sp. albedinis (Foa, Fusarium oxysporum f. sp. canariensis (Foc, and Verticillium dahliae (Vd.

  10. Synthesis and anti-inflammatory activity of phenylbutenoid dimer analogs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Soo; Fang, Yuan Ying; Park, Hae Eil [Kangwon National University, Chuncheon (Korea, Republic of)

    2015-06-15

    Several phenylbutenoid dimer (PBD) analogs were synthesized and evaluated for their inhibitory activities against nitric oxide (NO) production and TNF-α release. The PBD analogs were synthesized via Diels–Alder and subsequent Schlosser reactions as key steps. Among the tested compounds, two analogs (8c, 8f) exhibited much stronger inhibitory activity against LPS-stimulated NO production and TNF-α release in RAW 264.7 cells than that of wogonin.

  11. Synthesis and Antimicrobial Activity of Amino Acids Conjugated Diphenylmethylpiperazine Derivatives

    Directory of Open Access Journals (Sweden)

    K. N. Shivakumara

    2009-01-01

    Full Text Available A series of amino acid conjugated diphenylmethylpiperazine derivatives were synthesized by coupling diphenylmethylpiperazine with different Boc-amino acids using EDCI/HOBt as coupling agent and NMM as base. The synthesized compounds were characterized by 1H-NMR and elemental analysis. The Boc-deblocked derivatives were tested for their antimicrobial activity. We are here reporting that Phe and Trp conjugated diphenylmethylpiperazine showed equally good antibacterial activities as that of conventional antimicrobial drugs.

  12. Mechanically activated synthesis of PZT and its electromechanical properties

    Science.gov (United States)

    Liu, X.; Akdogan, E. K.; Safari, A.; Riman, R. E.

    2005-08-01

    Mechanical activation was successfully used to synthesize nanostructured phase-pure Pb(Zr0.7Ti0.3)O3 (PZT) powders. Lead zirconium titanium (PbZrTi) hydrous oxide precursor, synthesized from chemical co-precipitation, was mechanically activated in a NaCl matrix. The synthesized PZT particles were characterized by using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, laser-light diffraction, and nitrogen adsorption. Thermogravimetric analysis and differential thermal analysis were used to monitor dehydration and phase transformation of PbZrTi hydrous oxide precursor during mechanical activation. The best mechanical activation conditions corresponded to mechanically activating PbZrTi hydrous oxide precursor in a NaCl matrix with a NaCl/precursor weight ratio of 4:1 for 8 h. These conditions resulted in a dispersible phase-pure PZT powder with a median secondary-particle size of ˜110 nm. The properties of PZT 70/30 from mechanically activated powder, as measured on discs sintered at 1150 °C for 2 h, were found to be in close conformity to those obtained by a conventional mixed oxide solid state reaction route.

  13. Novel Triazole Hybrids of Betulin: Synthesis and Biological Activity Profile.

    Science.gov (United States)

    Bębenek, Ewa; Jastrzębska, Maria; Kadela-Tomanek, Monika; Chrobak, Elwira; Orzechowska, Beata; Zwolińska, Katarzyna; Latocha, Małgorzata; Mertas, Anna; Czuba, Zenon; Boryczka, Stanisław

    2017-11-01

    Betulin derivatives containing a 1,2,3-triazole ring possess a wide spectrum of biological activities, including antiviral, anticancer, and antibacterial activity. A series of novel triazoles were prepared by the 1,3-dipolar cycloaddition reaction between the alkyne derivatives of betulin and organic azides. The chemical structures of the obtained compounds were defined by ¹H and 13 C NMR, IR, and high-resolution mass spectrometry (HR-MS) analysis. The target triazoles were screened for their antiviral activity against DNA and RNA viruses. The cytotoxic activity of the obtained compounds 5a - k and 6a - h was determined using five human cancer cell lines (T47D, MCF-7, SNB-19, Colo-829, and C-32) by a WST-1 assay. The bistriazole 6b displayed a promising IC 50 value (0.05 μM) against the human ductal carcinoma T47D (500-fold higher potency than cisplatin). The microdilution method was applied for an evaluation of the antimicrobial activity of all of the compounds. The triazole 5e containing a 3'-deoxythymidine-5'-yl moiety exhibited antibacterial activity against two gram-negative bacteria vz. Klebsiella pneumoniae and Escherichia coli (minimal inhibitory concentration (MIC) range of 0.95-1.95 μM).

  14. Novel Triazole Hybrids of Betulin: Synthesis and Biological Activity Profile

    Directory of Open Access Journals (Sweden)

    Ewa Bębenek

    2017-11-01

    Full Text Available Betulin derivatives containing a 1,2,3-triazole ring possess a wide spectrum of biological activities, including antiviral, anticancer, and antibacterial activity. A series of novel triazoles were prepared by the 1,3-dipolar cycloaddition reaction between the alkyne derivatives of betulin and organic azides. The chemical structures of the obtained compounds were defined by 1H and 13C NMR, IR, and high-resolution mass spectrometry (HR-MS analysis. The target triazoles were screened for their antiviral activity against DNA and RNA viruses. The cytotoxic activity of the obtained compounds 5a–k and 6a–h was determined using five human cancer cell lines (T47D, MCF-7, SNB-19, Colo-829, and C-32 by a WST-1 assay. The bistriazole 6b displayed a promising IC50 value (0.05 μM against the human ductal carcinoma T47D (500-fold higher potency than cisplatin. The microdilution method was applied for an evaluation of the antimicrobial activity of all of the compounds. The triazole 5e containing a 3′-deoxythymidine-5′-yl moiety exhibited antibacterial activity against two gram-negative bacteria vz. Klebsiella pneumoniae and Escherichia coli (minimal inhibitory concentration (MIC range of 0.95–1.95 μM.

  15. Monomers of cutin biopolymer: sorption and esterification on montmorillonite surfaces

    Science.gov (United States)

    Olshansky, Yaniv; Polubesova, Tamara; Chefetz, Benny

    2013-04-01

    One of the important precursors for soil organic matter is plant cuticle, a thin layer of predominantly lipids that cover all primary aerial surfaces of vascular plants. In most plant species cutin biopolymer is the major component of the cuticle (30-85% weight). Therefore cutin is the third most abundant plant biopolymer (after lignin and cellulose). Cutin is an insoluble, high molecular weight bio-polyester, which is constructed of inter-esterified cross linked hydroxy-fatty acids and hydroxyepoxy-fatty acids. The most common building blocks of the cutin are derivatives of palmitic acid, among them 9(10),16 dihydroxy palmitic acid (diHPA) is the main component. These fatty acids and their esters are commonly found in major organo-mineral soil fraction-humin. Hence, the complexes of cutin monomers with minerals may serve as model of humin. Both cutin and humin act as adsorption efficient domains for organic contaminants. However, only scarce information is available about the interactions of cutin with soil mineral surfaces, in particular with common soil mineral montmorillonite. The main hypothesize of the study is that adsorbed cutin monomers will be reconstituted on montmorillonite surface due to esterification and oligomerization, and that interactions of cutin monomers with montmorillonite will be affected by the type of exchangeable cation. Cutin monomers were obtained from the fruits of tomato (Lycopersicon esculentum). Adsorption of monomers was measured for crude Wyoming montmorillonites and montmorillonites saturated with Fe3+ and Ca2+. To understand the mechanism of monomer-clay interactions and to evaluate esterification on the clay surface, XRD and FTIR analyses of the montmorillonite-monomers complexes were performed. Our results demonstrated that the interactions of cutin monomers with montmorillonite are affected by the type of exchangeable cation. Isotherms of adsorption of cutin monomers on montmorillonites were fitted by a dual mode model of

  16. Structural Basis of Native CXCL7 Monomer Binding to CXCR2 Receptor N-Domain and Glycosaminoglycan Heparin

    Directory of Open Access Journals (Sweden)

    Aaron J. Brown

    2017-02-01

    Full Text Available CXCL7, a chemokine highly expressed in platelets, orchestrates neutrophil recruitment during thrombosis and related pathophysiological processes by interacting with CXCR2 receptor and sulfated glycosaminoglycans (GAG. CXCL7 exists as monomers and dimers, and dimerization (~50 μM and CXCR2 binding (~10 nM constants indicate that CXCL7 is a potent agonist as a monomer. Currently, nothing is known regarding the structural basis by which receptor and GAG interactions mediate CXCL7 function. Using solution nuclear magnetic resonance (NMR spectroscopy, we characterized the binding of CXCL7 monomer to the CXCR2 N-terminal domain (CXCR2Nd that constitutes a critical docking site and to GAG heparin. We found that CXCR2Nd binds a hydrophobic groove and that ionic interactions also play a role in mediating binding. Heparin binds a set of contiguous basic residues indicating a prominent role for ionic interactions. Modeling studies reveal that the binding interface is dynamic and that GAG adopts different binding geometries. Most importantly, several residues involved in GAG binding are also involved in receptor interactions, suggesting that GAG-bound monomer cannot activate the receptor. Further, this is the first study that describes the structural basis of receptor and GAG interactions of a native monomer of the neutrophil-activating chemokine family.

  17. Synthesis and anti-microbial activity evaluation of some new 1-benzoyl-isothiosemicarbazides.

    Science.gov (United States)

    Plumitallo, A; Cardia, M C; Distinto, S; DeLogu, A; Maccioni, E

    2004-12-01

    The synthesis of some aroylisothiosemicarbazides was accomplished and their biological activity against bacteria, fungi, and mycobacteria was investigated. Different synthetic pathways were followed according to the kind of substituents that were introduced on both the aroyl ring and the sulfur atom. Anti-bacterial activity was measured against Staphylococcus aureus, S. epidermidis, Streptococcus agalactiae and S. faecalis, Escherichia coli, and Salmonella typhi, while antifungal activity was evaluated against C. albicans. Two species, Mycobacterium tuberculosis H37RV and Mycobacterium avium ATCC19421, were employed to evaluate antimycobacterial activity.

  18. Screening of activators and inhibitors of nuclear protein synthesis using labeled compounds

    International Nuclear Information System (INIS)

    Saitmuratova, O.H.

    2004-01-01

    Full text: With the purpose of definition of physiological activity of some known and yet not investigated natural and synthetic compounds (only 40 compounds) their action on protein synthesis ability (PSA) of nucleus of not sharing cells of a brain of rabbits with use of the marked amino acid - C 14 -lysine has been investigated. As a result of our researches activators of non ribosomal synthesis of protein are revealed: N-(β-chlorethyl)-decahydroquinoline, licorine, lupinine, anabasine hydrochloride, peptides: enkephalin, epitalanine, ACTH 4-7 , proteinkinase C, nitrocel, benzolaminopurine - synthetic cytokinin and inhibitors: cocaine, strychnine, aminazine, venom of a cobra snake, indolyl acetic acid, lectin like proteins, extensin like proteins, polyprenol, nitroglycerine. These received results can be used for the decision of the following problems: - Regulation of biosynthesis of the certain kinds of proteins; - Definition of a functional role of studying proteins; - he classification of studying compounds on activity for research of the certain processes in a cellular level

  19. Synthesis of novel chalcone derivatives by conventional and microwave irradiation methods and their pharmacological activities

    Directory of Open Access Journals (Sweden)

    Mohammed Rayees Ahmad

    2016-09-01

    Full Text Available Chalcones are abundant in edible plants and are considered to be the precursors of flavonoids and isoflavonoids. Chalcones belong to an important class of flavonoids, which may be prepared by Claisen–Schmidt condensation. They possess a wide range of biological activities and industrial applications. The cytotoxicity against tumour cell lines may be the result of disruption of the cell cycle, inhibition of angiogenesis, interference with p53-MDM2 interaction, mitochondrial uncoupling or induction of apoptosis. Chalcones are synthesized by conventional and microwave assisted synthesis methods. By microwave assisted synthesis, a considerable increase in the reaction rate has been observed and that too, with better yields. The compounds have been screened for cytotoxic activity and antioxidant activity.

  20. Synthesis, antimicrobial and antitubercular activities of some novel pyrazoline derivatives

    Directory of Open Access Journals (Sweden)

    Aftab Ahmad

    2016-09-01

    Full Text Available In the present study, two new series of pyrazolines (3a–h & 4a–h were synthesized starting from p-acetamidophenol (paracetamol and evaluated for their antibacterial, antifungal and antitubercular activities. Chalcones (2a–h prepared by condensing 3-acetyl-4-hydroxyphenyl acetamide (1 with different aromatic aldehydes were reacted with phenyl hydrazine and isonicotinic acid hydrazide to obtain phenyl-pyrazolines (3a–h and isoniazid-pyrazolines (4a–h, respectively. The structures of the synthesized compounds were confirmed by spectral and microanalysis studies. Newly prepared pyrazoline compounds exhibited significant antibacterial activity against the organisms Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa when compared with the standard antibiotic Ciprofloxacin. Compound 4g showed potent antibacterial activity against P. aeruginosa and S. aureus (MIC-3.12 μg/mL, however, against E. coli compound 3d, 4c, 4d, 4f & 4g were found to have an MIC of 6.25 μg/mL. Antifungal activity of compound 4d against Candida albicans and Aspergillus niger (MIC-3.12 μg/mL was found to be better than the standard drug Ketoconazole. The results of antitubercular activity of the synthesized compounds against Mycobacterium tuberculosis H37Rv by the agar microdilution method are quite promising. The antitubercular activity of compounds 4c, 4d & 4g (MIC-3.12 μg/mL was found to be superior than that of the reference drug Streptomycin which showed MIC equal to 6.25 μg/mL. It was observed that pyrazolines with chloro, nitro or methoxy substituent showed better activity. Also, the pyrazolines derived from isoniazid (4a–h were found to be better in their antibacterial, antifungal and antitubercular action than those derived from phenyl-hydrazine (3a–h.

  1. Origami-inspired active structures: a synthesis and review

    International Nuclear Information System (INIS)

    Peraza-Hernandez, Edwin A; Hartl, Darren J; Malak Jr, Richard J; Lagoudas, Dimitris C

    2014-01-01

    Origami, the ancient art of paper folding, has inspired the design of engineering devices and structures for decades. The underlying principles of origami are very general, which has led to applications ranging from cardboard containers to deployable space structures. More recently, researchers have become interested in the use of active materials (i.e., those that convert various forms of energy into mechanical work) to effect the desired folding behavior. When used in a suitable geometry, active materials allow engineers to create self-folding structures. Such structures are capable of performing folding and/or unfolding operations without being kinematically manipulated by external forces or moments. This is advantageous for many applications including space systems, underwater robotics, small scale devices, and self-assembling systems. This article is a survey and analysis of prior work on active self-folding structures as well as methods and tools available for the design of folding structures in general and self-folding structures in particular. The goal is to provide researchers and practitioners with a systematic view of the state-of-the-art in this important and evolving area. Unifying structural principles for active self-folding structures are identified and used as a basis for a quantitative and qualitative comparison of numerous classes of active materials. Design considerations specific to folded structures are examined, including the issues of crease pattern identification and fold kinematics. Although few tools have been created with active materials in mind, many of them are useful in the overall design process for active self-folding structures. Finally, the article concludes with a discussion of open questions for the field of origami-inspired engineering. (topical review)

  2. Mechanistic Study of Silver Nanoparticle's Synthesis by Dragon's Blood Resin Ethanol Extract and Antiradiation Activity.

    Science.gov (United States)

    Hasan, Murtaza; Iqbal, Javed; Awan, Umer; Saeed, Yasmeen; Ranran, Yuan; Liang, Yanli; Dai, Rongji; Deng, Yulin

    2015-02-01

    Biological synthesis of nanoparticles is best way to avoid exposure of hazardous materials as compared to chemical manufacturing process which is a severe threat not only to biodiversity but also to environment. In present study, we reported a novel method of finding antiradiation compounds by bioreducing mechanism of silver nanoparticles formation using 50% ethanol extract of Dragons blood, a famous Chinese herbal plant. Color change during silver nanoparticles synthesis was observed and it was confirmed by ultra violet (UV) visible spectroscopy at wave length at 430 nm after 30 min of reaction at 60 °C. Well dispersed round shaped silver nanoparticles with approximate size (4 nm to 50 nm) were measured by TEM and particle size analyser. Capping of biomolecules on Ag nanoparticles was characterized by FTIR spectra. HPLC analysis was carried out to find active compounds in the extract. Furthermore, antiradiation activity of this extract was tested by MTT assay in vitro after incubating the SH-SY5Y cells for 24 h at 37 °C. The results indicate that presence of active compounds in plant extract not only involves in bioreduction process but also shows response against radiation. The dual role of plant extract as green synthesis of nanoparticles and exhibit activity against radiation which gives a new way of fishing out active compounds from complex herbal plants.

  3. Synthesis and anticonvulsant activity of certain chalcone based pyrazoline compounds

    Directory of Open Access Journals (Sweden)

    Sudhakara Rao Gerapati

    2015-09-01

    Full Text Available Convulsions are involuntary, violent, spasmodic and prolonged contractions of skeletal muscles. That means a patient may have epilepsy without convulsions and vice versa. Epilepsy is a common neurological abnormality affecting about 1% of the world population. The primary objectives of these synthesized compounds are to suppress seizures and provide neuroprotection by minimizing the effects from seizure attacks. Here some of the chalcones and chalcone based various pyrazolines were evaluated for anticonvulsant activity. Their structures have been elucidated on the basis of elemental analyses and spectroscopic studies (IR, 1H-NMR & Mass spectroscopy. A preliminary evaluation of the prepared compounds has indicated that some of them exhibit moderate to significant anticonvulsant activity compared to a diazepam standard1-3.  All compounds were tested for their anticonvulsant activity using maximal electroshock induced convulsions (MES in mice at a dose level of 4 mg/kg.b.w. The compounds  Ph1, Ph2 , Py2 ,Py3 and Py4 have shown  to  good anticonvulsant activity when doses are administered as 25mg/ kg.b.w  , reduced the phases of seizures severity and  found to be active and also  increased survival rate. Remaining compounds are less efficacious.

  4. Synthesis and pharmacological activity evaluation of arctigenin monoester derivatives.

    Science.gov (United States)

    Chen, Qiulian; Yang, Limin; Han, Mei; Cai, Enbo; Zhao, Yan

    2016-12-01

    Arctigenin (ARG), a nature medicine with many pharmacological activities, was poorly soluble in water and placed restriction on practical usage. Six novel arctigenin monoester derivatives were obtained from the reflux reaction with arctigenin, carboxylic acids (crotonic acid, furoic acid, 2-naphthalene acid and indol-3-acetic acid), EDCI and DMAP in dichloromethane at 60°C for 4-6h and their properties on nitrite scavenging assay were investigated in vitro. Based on the results, the one of the most effective derivatives, arctigenin β-indolylacetate (ARG6), was selected to study anti-tumor activity in vivo at doses of 20 and 40mg/kg. The results showed that comparison with ARG group, ARG6 exhibited more anti-tumor activity in H22 tumor-bearing mice. Furthermore, ARG6 exhibited less damage to the liver, kidney, spleen and thymus when compared with those in positive group. Biochemical parameters of ALT, AST, BUN and Cre showed ARG6 had little toxicity to mice as well. ARG6 significantly improved serum cytokine levels of IL-2, IL-6, IFN-γ and TNF-α, and decreased VEGF compared with ARG. Moreover, H & E staining, TUNEL assay and immunohistochemical of tumor issues also indicated that ARG6 exhibited anti-tumor activity in vivo. In brief, the present study provide a method to improve ARG anti-tumor activity and provide a reference for new anti-tumor agent. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Design, Synthesis and Fungicidal Activities of Some Novel Pyrazole Derivatives

    Directory of Open Access Journals (Sweden)

    Xue-Ru Liu

    2014-09-01

    Full Text Available In order to discover new compounds with good fungicidal activities, 32 pyrazole derivatives were designed and synthesized. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR, and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS, and their fungicidal activities against Botrytis cinerea, Rhizoctonia solani Kuhn, Valsa mali Miyabe et Yamada, Thanatephorus cucumeris (Frank Donk, Fusarium oxysporum (S-chl f.sp. cucumerinum Owen, and Fusarium graminearum Schw were tested. The bioassay results indicated that most of the derivatives exhibited considerable antifungal activities, especially compound 26 containing a p-trifluoromethyl- phenyl moiety showed the highest activity, with EC50 values of 2.432, 2.182, 1.787, 1.638, 6.986, and 6.043 μg/mL against B. cinerea, R. solani, V. mali, T. cucumeris, F. oxysporum, and F. graminearum, respectively. Moreover, the activities of compounds such as compounds 27–32 were enhanced by introducing isothiocyanate and carboxamide moieties to the 5-position of the pyrazole ring.

  6. Design, Synthesis, and Antifungal Activity of New α-Aminophosphonates

    Directory of Open Access Journals (Sweden)

    Zahra Rezaei

    2011-01-01

    Full Text Available α-Aminophosphonates are bioisosteres of amino acids and have several pharmacological activities. These compounds have been synthesized by various routes from reaction between amine, aldehyde, and phosphite compounds. In order to synthesize α-aminophosphonates, catalytic effect of CuCl2 was compared with FeCl3. Also all designed structures as well as griseofulvin were docked into the active site of microtubule (1JFF, using Autodock program. The results showed that the reactions were carried out in the presence of CuCl2 in lower yields, and also the time of reaction was longer in comparison with FeCl3. The chemical structures of the new compounds were confirmed by spectral analyses. The compounds were investigated for antifungal activity against several fungi in comparison with griseofulvin. An indole-derived bis(α-aminophosphonates with the best negative ΔG in docking study showed maximum antifungal activity against Microsporum canis, and other investigated compounds did not have a good antifungal activity.

  7. Influence of mechanical activation on synthesis of zinc metatitanate

    Directory of Open Access Journals (Sweden)

    Labus Nebojša J.

    2005-01-01

    Full Text Available Investigations of a ZnO-TiO2 binary oxide mixture during mechanical treatment were mainly focused on obtaining orthotitanate Zn2TiO4 with a spinel structure. Due to the specific way of energy transfer during mechanical treatment using a high-energy ball mill, the system passes through low temperature ZnTiO3 metatitanate phase formation. Mechanical activation was performed on an equimolar ratio mixture of ZnO and TiO2. The anatase phase was previously submitted to heat treatment for achieving a starting mixture rich in a rutile phase. Milling conditions were preset for observing the formation of a low temperature ZnTiO3 phase with a perovskite structure. The powder microstructure was characterized using scanning electron microscopy. A nitrogen gas sorption analyzer with the BET method was used to determine the specific surface area and porosity, indicating changes of powder sample properties during mechanical activation. Also, X ray powder diffractometry was applied to obtain the phase composition. Powders were then pressed into pellets and their compressibility was observed through density changes. According to microstructures obtained by scanning electron microscopy analysis, the system underwent a primary and secondary agglomeration process. Specific surface area measurements supported that conclusion. Compressibility investigations established the difference between compressibility of the non-activated mixture and activated powders. X-ray diffraction analysis revealed that a perovskite structure forms simultaneously with a spinel phase during the process of mechanical activation.

  8. Chalcone derivatives as potential antifungal agents: Synthesis, and antifungal activity

    Directory of Open Access Journals (Sweden)

    Deepa Gupta

    2015-01-01

    Full Text Available Much research has been carried out with the aim to discover the therapeutic values of chalcone derivatives. Chalcones possess wide range of pharmacological activity such as antibacterial, antimalarial, antiprotozoal, antitubercular, anticancer, and antifungal agents etc. The presence of reactive α,β-unsaturated keto group in chalcones is found to be responsible for their biological activity. The rapid developments of resistance to antifungal agents, led to design, and synthesize the new antifungal agents. The derivatives of chalcones were prepared using Claisen-Schmidt condensation scheme with appropriate tetralone and aldehyde derivatives. Ten derivatives were synthesized and were biologically screened for antifungal activity. The newly synthesized derivatives of chalcone showed antifungal activity against fungal species, Microsporum gypseum. The results so obtained were superior or comparable to ketoconazole. It was observed that none of the compounds tested showed positive results for fungi Candida albicans nor against fungi Aspergillus niger. Chalcone derivatives showed inhibitory effect against M. gypseum species of fungus. It was found that among the chalcone derivatives so synthesized, two of them, that is, 4-chloro derivative, and unsubstituted derivative of chalcone showed antifungal activity superior to ketoconazole. Thus, these can be the potential new molecule as antifungal agent.

  9. Synthesis and antimicrobial activity of 2-chloroquinoline incorporated pyrazoline derivatives

    Directory of Open Access Journals (Sweden)

    Sandhya Bawa

    2009-01-01

    Full Text Available Purpose : A series of 2-chloroquinoline containing pyrazoline derivatives having 3,4-dichloro/ 3,4-dimethoxy in the phenyl ring were synthesized and screened for their antimicrobial activity against a panel of bacterial and fungal strains. Materials and Methods : The structures of the newly synthesized compounds were established on the basis of spectral data obtained from the FTIR, 1H and 13C-NMR, and mass spectrometry. All the compounds were evaluated for their antibacterial activity against Escherichia coli (NCTC, 10418, Staphylococcus aureus (NCTC, 65710, and Pseudomonas aeruginosa (NCTC, 10662. The compounds were also tested for antifungal activity aganist Aspergillus niger (MTCC, 281, Aspergillus flavus (MTCC, 277, Monascus purpureus (MTCC, 369 and Penicillium citrinum (NCIM, 768 by the cup-plate method. Results : Among the compounds tested, 3,4-dichloro derivatives were comparatively more active in antimicrobial screening with respect to their 3,4-dimethoxy analog. Conclusion : A careful analysis of the antimicrobial activity data of the compounds revealed that compounds 3a, 3b, 3c, and 3e exhibited potent antibacterial

  10. Synthesis and biocidal activity of modified poly(vinyl alcohol

    Directory of Open Access Journals (Sweden)

    El-Refaie Kenawy

    2014-07-01

    Full Text Available Functionalized polymers and their polymer nature give them more advantages than the corresponding small molecules. In this respect, polymeric ammonium and phosphonium salts were prepared by chemical modifications of poly(vinyl alcohol (PVA aiming to explore their antimicrobial activities against pathogenic bacteria and fungi. The modifications were performed by chloroacetylation with chloroacetyl chloride. Incorporation of the ammonium and phosphonium salts was conducted by the reaction of chloroacetylated poly(vinyl alcohol (CPVA with triethylamine (TEA, triphenylphosphine (TPP, and tributylphosphine (TBP. The antimicrobial activity of the polymers against variety of test microorganisms was examined by the cut plug and viable cell counting methods of shake cultures of 10 times dilute nutrient broth and Sabouraud’s media, seeded with the test microorganisms. It was found that the immobilized polymers exhibited antimicrobial activity against the Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Shigella sp. and Salmonella typhi and Gram positive bacteria (Bacillus subtilis and B. cereus and the dermatophyte fungus (Trichophyton rubrum. The growth inhibition of the test microorganisms (ratio of surviving cell number, M/C varied according to the composition of the active group in the polymer and the test organism. It increased by increasing the concentration of the polymer. Triphenyl phosphonium salt of the modified poly(vinyl alcohol exhibited the most biocidal activity against both Gram-negative and Gram-positive bacteria after 24 h.

  11. Long lasting protein synthesis- and activity-dependent spine shrinkage and elimination after synaptic depression.

    Directory of Open Access Journals (Sweden)

    Yazmín Ramiro-Cortés

    Full Text Available Neuronal circuits modify their response to synaptic inputs in an experience-dependent fashion. Increases in synaptic weights are accompanied by structural modifications, and activity dependent, long lasting growth of dendritic spines requires new protein synthesis. When multiple spines are potentiated within a dendritic domain, they show dynamic structural plasticity changes, indicating that spines can undergo bidirectional physical modifications. However, it is unclear whether protein synthesis dependent synaptic depression leads to long lasting structural changes. Here, we investigate the structural correlates of protein synthesis dependent long-term depression (LTD mediated by metabotropic glutamate receptors (mGluRs through two-photon imaging of dendritic spines on hippocampal pyramidal neurons. We find that induction of mGluR-LTD leads to robust and long lasting spine shrinkage and elimination that lasts for up to 24 hours. These effects depend on signaling through group I mGluRs, require protein synthesis, and activity. These data reveal a mechanism for long lasting remodeling of synaptic inputs, and offer potential insights into mental retardation.

  12. Interactions between resin monomers and commercial composite resins with human saliva derived esterases.

    Science.gov (United States)

    Jaffer, F; Finer, Y; Santerre, J P

    2002-04-01

    Cholesterol esterase (CE) and pseudocholinesterase (PCE) have been reported to degrade commercial and model composite resins containing bisphenylglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) or the latter in combination with urethane modified BisGMA monomer systems. In addition, human saliva has been shown to contain esterase like activities similar to CE and PCE. Hence, it was the aim of the current study to determine to what extent human saliva could degrade two common commercial composite resins (Z250 from 3M Inc. and Spectrum TPH from L.D. Caulk) which contain the above monomer systems. Saliva samples from different volunteers were collected, processed, pooled, and freeze-dried. TEGDMA and BisGMA monomers were incubated with human saliva derived esterase activity (HSDEA) and their respective hydrolysis was monitored using high performance liquid chromatography (HPLC). Both monomers were completely hydrolyzed within 25 h by HSDEA. Photopolymerized composites were incubated with buffer or human saliva (pH 7.0 and 37 C) for 2, 8 and 16 days. The incubation solutions were analyzed using HPLC and mass spectrometry. Surface morphology characterization was carried out using scanning electron microscopy. Upon biodegradation, the Z250 composite yielded higher amounts of BisGMA and TEGDMA related products relative to the TPH composite. However, there were higher amounts of ethoxylated bis-phenol A released from the TPH material. In terms of total mass of products released, human saliva demonstrated a greater ability to degrade Z250. In summary, HSDEA has been shown to contain esterase activities that can readily catalyze the biodegradation of current commercial composite resins.

  13. Synthesis and antibacterial activity of sulfonamides. SAR and DFT studies

    Science.gov (United States)

    Boufas, Wahida; Dupont, Nathalie; Berredjem, Malika; Berrezag, Kamel; Becheker, Imène; Berredjem, Hajira; Aouf, Nour-Eddine

    2014-09-01

    A series of substituted sulfonamide derivatives were synthesized from chlorosulfonyl isocyanate (CSI) in tree steps (carbamoylation, sulfamoylation and deprotection). Antibacterial activity in vitro of some newly formed compounds investigated against clinical strains Gram-positive and Gram-negative: Escherichia coli and Staphylococcus aureus applying the method of dilution and minimal inhibition concentration (MIC) methods. These compounds have significant bacteriostatic activity with totalities of bacterial strains used. DFT calculations with B3LYP/6-31G(d) level have been used to analyze the electronic and geometric characteristics deduced for the stable structure of three compounds presenting conjugation between a nitrogen atom N through its lone pair and an aromatic ring next to it. The principal quantum chemical descriptors have been correlated with the antibacterial activity.

  14. Antituberculosis: Synthesis and Antimycobacterial Activity of Novel Benzimidazole Derivatives

    Directory of Open Access Journals (Sweden)

    Yeong Keng Yoon

    2013-01-01

    Full Text Available A total of seven novel benzimidazoles were synthesized by a 4-step reaction starting from 4-fluoro-3-nitrobenzoic acid under relatively mild reaction conditions. The synthesized compounds were screened for their antimycobacterial activity against M. tuberculosis H37Rv (MTB-H37Rv and INH-resistant M. tuberculosis (INHR-MTB strains using agar dilution method. Three of them displayed good activity with MIC of less than 0.2 μM. Compound ethyl 1-(2-(4-(4-(ethoxycarbonyl-2-aminophenylpiperazin-1-ylethyl-2-(4-(5-(4-fluorophenylpyridin-3-ylphenyl-1H-benzo[d]imidazole-5-carboxylate (5g was found to be the most active with MIC of 0.112 μM against MTB-H37Rv and 6.12 μM against INHR-MTB, respectively.

  15. Synthesis and biological activities of diflunisal hydrazide-hydrazones.

    Science.gov (United States)

    Küçükgüzel, S Güniz; Mazi, Adil; Sahin, Fikrettin; Oztürk, Suzan; Stables, James

    2003-01-01

    Several diflunisal hydrazide-hydrazone derivatives namely 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid [(5-nitro-2-furyl/substitutedphenyl)methylene] hydrazide (3a-o) have been synthesised. Methyl 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylate (1) and 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid hydrazide (2) were also synthesised and used as intermediate compounds. All synthesised compounds were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37 Rv, antimicrobial activities against various bacteria, fungi and yeast species. Compound 3a have shown activity against Staphylococcus epidermis HE-5 and Staphylococcus aureus HE-9 at 18.75 and 37.5 microg mL(-1), respectively. Compound 3o have exhibited activity against Acinetobacter calcoaceticus IO-16 at a concentration of 37.5 microg mL(-1), whereas Cefepime, the drug used as standard, have been found less active against the microorganisms mentioned above. The synthesised compounds were found to provide 12-34% inhibition of mycobacterial growth of M. tuberculosis H37 Rv in the primary screen at 6.25 microg mL(-1). Anticonvulsant activity of the compounds were also determined by maximal electroshock (MES) and subcutaneous metrazole (scMET) tests in mice and rats following the procedures of antiepileptic drug development (ADD) program of the National Institutes of Health (NIH). Compound 3k showed 25% protection against MES induced seizures in p.o. rat screening at a dose level of 30 mg kg(-1) whereas 3n and 3o showed neurotoxicity after 4 and 0.5 h at a dose level of 100 and 300 mg kg(-1), respectively.

  16. Synthesis of Different Substituted Pyridazinone Derivatives and Their Anticonvulsant Activity

    Directory of Open Access Journals (Sweden)

    Kartick Chandra Samanta

    2011-01-01

    Full Text Available 6-Phenyl(3᾽-imino-benzylidene-2,3,4,5-tetrahydro pyridazin-3-one derivatives were synthesized from 6-(3᾽-aminophenyl-2,3,4,5-tetrahydro pyridazin-3-one by reaction with different aldehydes. The respective pyridazinone was prepared by cyclization of appropriate β-(aminophenyl propionic acid with hydrazine hydrate. The pyridazinone derivatives were tested for anticonvulsant activity by MES (maximal electro shock method and found that few of them have shown significant anticonvulsant activity.

  17. Synthesis, crystal structure and biological activity of novel diester cyclophanes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pengfei; Yang, Bingqin; Fang, Xianwen; Cheng, Zhao; Yang, Meipan, E-mail: yangbq@nwu.edu.cn [Department of Chemistry, Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Northwest University, Shaanxi (China)

    2012-10-15

    A series of novel diester cyclophanes was synthesized by esterification of 1,2-benzenedicarbonyl chloride with eight different diols under high dilution conditions. The structures of the compounds were verified by elemental analysis, {sup 1}H nuclear magnetic resonance (NMR), IR spectroscopy and high resolution mass spectrometry (HRMS). The crystal structures of two compounds were characterized by single crystal X-ray diffractometry (XRD). All the new cyclophanes were evaluated for biological activities and the results showed that some of these compounds have low antibacterial or antifungal activities (author)

  18. Synthesis and Antiplasmodial Activity of EG-Artemisinin Ethers and ...

    African Journals Online (AJOL)

    The aim of this study was to synthesize a series of ethylene glycol (EG) ethers and quinoline hybrids of the antimalarial drug artemisinin and to evaluate their antimalarial activity in vitro against Plasmodium falciparum strains. The ethers were synthesized in a ... falciparum, ethylene glycol) (EG), ethylene oxide (EO), hybrid ...

  19. Synthesis and Antiplasmodial Activity of EG-Artemisinin Ethers and ...

    African Journals Online (AJOL)

    NICO

    The aim of this study was to synthesize a series of ethylene glycol (EG) ethers and quinoline hybrids of the antimalarial drug artemisinin and to ... The IC50 values revealed that all the ethers were active against both strains but less potent than ...... Compound 19 was racemate (mixture 3''R and 3''S isomers) isolated as fluffy ...

  20. Occurrence, biological activity and synthesis of drimane sesquiterpenoids

    NARCIS (Netherlands)

    Jansen, B.J.M.; Groot, de Æ.

    2004-01-01

    In this review the names, structures and occurrence of all new drimanes and rearranged drimanes, which have been published between January 1990 and January 2003 have been collected. Subjects that have been treated are biosynthesis, analysis, biological activities, with special attention to cytotoxic

  1. Synthesis, Characterization and Antimicrobial Activity of Copper(II ...

    African Journals Online (AJOL)

    NICO

    2014-03-03

    Mar 3, 2014 ... Many Schiff base metal complexes have been prepared and screened for their antimicrobial activity. Ortho-hydroxysalicylaldimines possess N2O2 donor atoms and consequently, form stable chelates with metal ions.15,21,23–24. The configuration of the chelate group in the four coordinate complexes may ...

  2. Design, Synthesis, and Biological Evaluation of Isothiosemicarbazones with Antimycobacterial Activity

    Czech Academy of Sciences Publication Activity Database

    Novotná, E.; Waisser, K.; Kuneš, J.; Palát, K.; Skálová, L.; Szotáková, B.; Buchta, V.; Stolaříková, J.; Ulmann, V.; Pávová, Marcela; Weber, Jan; Komrsková, J.; Hašková, P.; Vokřál, I.; Wsól, V.

    2017-01-01

    Roč. 350, č. 8 (2017), č. článku e1700020. ISSN 0365-6233 Institutional support: RVO:61388963 Keywords : biological activity * cytotoxicity * isocitrate lyase * isothiosemicarbazone * tuberculosis Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.994, year: 2016

  3. Synthesis and antimicrobial activity of some novel thienopyrimidines ...

    Indian Academy of Sciences (India)

    Administrator

    In addition, it is known that antifungal drugs do not have selective activity because of the biochemical similarity between human cell and fungi forms. Therefore there are many studies focused on anti- bacterial and antifungal compounds. 1–3. Thienopyrimidines and thiadiazolothienopyri- midines have been found to exhibit ...

  4. Synthesis and Antimicrobial Activity of the Essential Oil Compounds ...

    African Journals Online (AJOL)

    In particular, it was found that the use of triethylamine as a co-solvent was necessary to avoid acid-mediated isomerization of the alkenes, which resulted in an inseparable mixture of products. The antimicrobial activity of the four hexenyl and hexyl nonanoate compounds was undertaken using microdilution minimum ...

  5. Catalytic Activation of Nitrogen Dioxide for Selective Synthesis of Nitroorganics

    Science.gov (United States)

    2015-01-15

    reactivity from electrophilic nitration to ipso nitro-deboronation. Catalysis ; nitrogen dioxide; oxidative addition; reductive elimination; nitroarenes. U U...Brown, University of Notre Dame FINAL PERFORMANCE REPORT 1 Reductive Elimination to Form Carbon-NO2 Bonds. Contemporary methods in homogeneous ...Activation. One of the most significant recent developments in organometallic catalysis is the successful functionalization of hydrocarbons under

  6. SYNTHESIS OF BIOLOGICALLY-ACTIVE 2-BENZOYL PACLITAXEL ANALOGS

    DEFF Research Database (Denmark)

    GEORG, GI; ALI, SM; BOGE, TC

    1995-01-01

    The influence of aromatic substitution at the 2-benzoyl moiety of paclitaxel on biological activity was investigated, following the Topliss Operational Scheme. Twelve paclitaxel derivatives were synthesized and evaluated in a microtubule assembly assay and for cytotoxicity against B16 melanoma ce...

  7. Synthesis, docking and anticancer activity studies of D-proline ...

    Indian Academy of Sciences (India)

    act as an anticancer drug. The collection of drug and receptor complex was identified via docking and their relative stabilities were evaluated using molecular dynamics and their binding affinities, using free energy simulations. Based on the total energy values, the anti- cancer activity of the compound was identified.

  8. Synthesis, characterization and study of catalytic activity of Silver ...

    Indian Academy of Sciences (India)

    activity was tested using liquid-phase selective oxidation of benzylic alcohols to aldehydes. The influence of some parameters such as optimum weight of Ag, catalyst dosage, ... Ag/ZnO nanocomposite; selective oxidation; benzyl alcohol; heterogeneous catalysis. ..... Rodríguez-Reyes J C F, Friend C M and Madix R J 2012.

  9. Synthesis, characterization and superoxide dismutase activity of bi ...

    Indian Academy of Sciences (India)

    activity with IC50 value 8.6×10−6 M for the complex has been observed. Keywords. phthalic anhydride; ethylene glycol; acetate; ... cient level of SOD concentration in human body is one of the reasons behind diseases and .... firm the composition and purity of the compound under investigation. The spectra displayed the ...

  10. Synthesis, stereochemistry and antimicrobial activity of copper(II ...

    African Journals Online (AJOL)

    On the basis of the analytical data, magnetic moments and spectral data, a square-planar geometry has been proposed for the nickel(II) and copper(II) complexes with these ligands. Some representative complexes of copper(II) and nickel(II) were found to have remarkable antifungal and antibacterial activity. KEY WORDS: ...

  11. Synthesis, characterization and antibacterial activity of Fe(II) mixed ...

    African Journals Online (AJOL)

    . The electronic spectrum of iron(II) complex in DMSO was recorded, and its salient features are reported. The activity studies data indicate that the complex is more potent antibacterial agent than the ligands and ciprofloxacin drug against the ...

  12. Synthesis, characterization and in vitro antibacterial activity of novel ...

    Indian Academy of Sciences (India)

    The prepared compounds were screened for antibacterial activity against Escherichia coli (E. coli ATCC 25922) and Staphylococcus aureus (S. aureus ATCC 5213) as gram negative and positive respectively. Also, in silico physicochemical parameters of synthesized compounds were studied to predict absorption and ...

  13. Synthesis, Analgesic, Anti-inflammatory and Antimicrobial Activities ...

    African Journals Online (AJOL)

    Purpose: Microbial infections often produce pain and inflammation. Chemotherapeutic, analgesic and anti-inflammatory drugs are prescribed simultaneously in normal practice. The compound possessing all three activities is not common.The purpose of the present study was to examine whether molecular modification ...

  14. Synthesis, Antimicrobial and Antitubercular Activities of Some Novel ...

    African Journals Online (AJOL)

    The newly synthesized compounds were characterized by infrared spectroscopy (IR), mass spectroscopy (MS) and proton nuclear magnetic spectroscopy (1H NMR) and elemental analysis; they were also screened for in vitro antibacterial, antifungal and antitubercular activities. Ciprofloxacin and ketoconazole were used as ...

  15. Adrenoceptor-activated nitric oxide synthesis in salivary acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia; Dissing, Steen; Tritsaris, Katerina

    2000-01-01

    We investigated the cellular regulation of nitric oxide synthase (NOS) activity in isolated acinar cells from rat parotid and human labial salivary glands, using the newly developed fluorescent nitric oxide (NO) indicator, DAF-2. We found that sympathetic stimulation with norepinephrine (NE) caused...

  16. Synthesis and Antibacterial Activity of Some 2-Substituted ...

    African Journals Online (AJOL)

    2-Substituted tinidazole analogues were designed, synthesized and characterized. The synthesized compounds were tested for their antibacterial activity against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli (entero pathogen) and S. typhimurium) bacteria using agar well diffusion method.

  17. Synthesis and characterization of redox-active ferric nontronite

    Energy Technology Data Exchange (ETDEWEB)

    Ilgen, A. G.; Kukkadapu, R. K.; Dunphy, D. R.; Artyushkova, K.; Cerrato, J. M.; Kruichak, J. N.; Janish, M. T.; Sun, C. J.; Argo, J. M.; Washington, R. E.

    2017-10-01

    Heterogeneous redox reactions on clay mineral surfaces control mobility and bioavailability of redox-sensitive nutrients and contaminants. Iron (Fe) residing in clay mineral structures can either catalyze or directly participate in redox reactions; however, chemical controls over its reactivity are not fully understood. In our previous work we demonstrated that converting a minor portion of Fe(III) to Fe(II) (partial reduction) in the octahedral sheet of natural Fe-rich clay mineral nontronite (NAu-1) activates its surface, making it redox-active. In this study we produced and characterized synthetic ferric nontronite (SIP), highlighting structural and chemical similarities and differences between this synthetic nontronite and its natural counterpart NAu-1, and probed whether mineral surface is redox-active by reacting it with arsenic As(III) under oxic and anoxic conditions. We demonstrate that synthetic nontronite SIP undergoes the same activation as natural nontronite NAu-1 following the partial reduction treatment. Similar to NAu-1, SIP oxidized As(III) to As(V) under both oxic (catalytic pathway) and anoxic (direct oxidation) conditions. The similar reactivity trends observed for synthetic nontronite and its natural counterpart make SIP an appropriate analog for laboratory studies. The development of chemically pure analogs for ubiquitous soil minerals will allow for systematic research of the fundamental properties of these minerals.

  18. A biotemplated nickel nanostructure: Synthesis, characterization and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Ashtari, Khadijeh [Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Fasihi, Javad [Department of Analytical Chemistry, Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mollania, Nasrin [Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Khajeh, Khosro, E-mail: khajeh@modares.ac.ir [Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

    2014-02-01

    Highlights: • Nickel nanostructure-encapsulated bacteria were prepared using electroless deposition. • Bacterium surface was activated by red-ox reaction of its surface amino acids. • Interfacial changes at cell surfaces were investigated using fluorescence spectroscopy. • TEM and AFM depicted morphological changes. • Antibacterial activity of nanostructure was examined against different bacteria strains. - Abstract: Nickel nanostructure-encapsulated bacteria were prepared using the electroless deposition procedure and activation of bacterium cell surface by red-ox reaction of surface amino acids. The electroless deposition step occurred in the presence of Ni(II) and dimethyl amine boran (DMAB). Interfacial changes at bacteria cell surfaces during the coating process were investigated using fluorescence spectroscopy. Fluorescence of tryptophan residues was completely quenched after the deposition of nickel onto bacteria surfaces. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) depicted morphological changes on the surface of the bacterium. It was found that the Ni coated nanostructure was mechanically stable after ultrasonication for 20 min. Significant increase in surface roughness of bacteria was also observed after deposition of Ni clusters. The amount of coated Ni on the bacteria surface was calculated as 36% w/w. The antibacterial activity of fabricated nanostructure in culture media was examined against three different bacteria strains; Escherichia coli, Bacillus subtilis and Xantomonas campestris. The minimum inhibitory concentrations (MIC) were determined as 500 mg/L, 350 mg/L and 200 mg/L against bacteria, respectively.

  19. Synthesis, docking and anticancer activity studies of D-proline ...

    Indian Academy of Sciences (India)

    and depsipeptides with unique structures involving a wide variety of unusual amino acids and other build- ing blocks.1–4 Many cyclic peptides, isolated from marine sponges, exhibited interesting biological pro- perties including a reverse of multi-drug resistance in tumour cells,5 HIV inhibition,6,7 and nematocidal activity.8.

  20. Synthesis and evaluation of antioxidant and antimicrobial activities ...

    African Journals Online (AJOL)

    Purpose: To synthesize and evaluate Schiff base Tin (II) complexes for antioxidant and antimicrobial activities. Methods: The complexes of Tin (II) chloride with various Schiff base derivative of 2-Hydroxy-1- naphthaldehyde (HN) were synthesized and characterized by various physiochemical techniques, including elemental ...

  1. Effect of the Acidic Dental Resin Monomer 10-methacryloyloxydecyl Dihydrogen Phosphate on Odontoblastic Differentiation of Human Dental Pulp Cells.

    Science.gov (United States)

    Kim, Eun-Cheol; Park, Haejin; Lee, Sang-Im; Kim, Sun-Young

    2015-11-01

    Although 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) is frequently used as an acidic resin monomer in dental adhesives, its effect on dental pulp cells (DPCs) has been rarely reported. The purpose of this study was to examine the effects of 10-MDP on the inflammatory response and odontoblastic differentiation of DPCs at minimally toxic concentrations. We found that 10-MDP caused the release of inflammatory cytokines including NO, PGE2, iNOS, COX-2, TNF-α, IL-1β, IL-6 and IL-8 in a concentration-dependent manner. In addition, 10-MDP reduced alkaline phosphatase activity, mineralization nodule formation and mRNA expression of odontoblastic differentiation markers such as dentin sialophosphoprotein, dentin matrix protein-1, osterix and Runx2 in a concentration-dependent manner with low toxicity. In addition, 10-MDP induced activation of nuclear factor-E2-related factor 2 (Nrf2) and its target gene, haeme oxygenase-1 (HO-1). We evaluated whether the effect of 10-MDP was related to the induction of HO-1 and found that treatment with a selective inhibitor of HO-1 reversed the production of 10-MDP-mediated pro-inflammatory cytokines and the inhibition of differentiation markers. Pre-treatment with either a GSH synthesis inhibitor or antioxidants blocked 10-MDP-induced mitogen-activated protein kinases (MAPKs), Nrf2 and NF-κB pathways. Taken together, the results of this study showed that minimally toxic concentrations of 10-MDP promoted an inflammatory response and suppressed odontoblastic differentiation of DPCs by activating Nrf2-mediated HO-1 induction through MAPK and NF-κB signalling. © 2015 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  2. Mechanism of prion propagation: amyloid growth occurs by monomer addition.

    Directory of Open Access Journals (Sweden)

    Sean R Collins

    2004-10-01

    Full Text Available Abundant nonfibrillar oligomeric intermediates are a common feature of amyloid formation, and these oligomers, rather than the final fibers, have been suggested to be the toxic species in some amyloid diseases. Whether such oligomers are critical intermediates for fiber assembly or form in an alternate, potentially separable pathway, however, remains unclear. Here we study the polymerization of the amyloidogenic yeast prion protein Sup35. Rapid polymerization occurs in the absence of observable intermediates, and both targeted kinetic and direct single-molecule fluorescence measurements indicate that fibers grow by monomer addition. A three-step model (nucleation, monomer addition, and fiber fragmentation accurately accounts for the distinctive kinetic features of amyloid formation, including weak concentration dependence, acceleration by agitation, and sigmoidal shape of the polymerization time course. Thus, amyloid growth can occur by monomer addition in a reaction distinct from and competitive with formation of potentially toxic oligomeric intermediates.

  3. Synthesis

    Directory of Open Access Journals (Sweden)

    Emel Pelit

    2016-05-01

    Full Text Available New optically active aminoalkylnaphthols were obtained by condensation of 2-naphthol, substituted aromatic and heteroaromatic aldehydes and (R-(+-1-phenylethylamine or (S-(−-1-phenylethylamine under conventional methods and ultrasonic irradiation. The enantiopure aminoalkylnaphthol derivatives were converted in ring-closure reaction with formaldehyde to the corresponding naphthoxazine derivatives.

  4. Synthesis and Antibiotic Activity of Mebendazole Derivatives of Pharmacological Interest

    Directory of Open Access Journals (Sweden)

    Kavita Rathore

    2007-01-01

    Full Text Available Mebendazole is a well known anti-helimintic and belongs to the benzimidazole group of medicines. In order to achieve better medicinal results, i.e. enhanced activity and low toxicity, structural modifications are made in the existing drugs. Some 5-benzoyl-N-[1-(alkoxyphthalimido benzimidazol-2-yl] carbamic acid methyl ester (3a-c and 5-benzoyl-N-[1-(2,3-bis oxyphthalimido∕oxysuccinimido propyl benzimidazol-2-yl carbamic acid methyl ester (7a-b have been synthesized from two different routes. Structures of the compounds have been established on the basis of elemental analysis and spectral studies. All the synthesized compounds (3a-c and (7a-b were assayed in vitro for antimicrobial activity against mebendazole (itself and standard [ciprofloxacin (antibacterial and fluconazole (antifungal].

  5. Facile synthesis and photocatalytic activity of zinc oxide hierarchical microcrystals

    KAUST Repository

    Xu, Xinjiang

    2013-04-04

    ZnO microcrystals with hierarchical structure have been synthesized by a simple solvothermal approach. The microcrystals were studied by means of X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Research on the formation mechanism of the hierarchical microstructure shows that the coordination solvent and precursor concentration have considerable influence on the size and morphology of the microstructures. A possible formation mechanism of the hierarchical structure was suggested. Furthermore, the catalytic activity of the ZnO microcrystals was studied by treating low concentration Rhodamine B (RhB) solution under UV light, and research results show the hierarchical microstructures of ZnO display high catalytic activity in photocatalysis, the catalysis process follows first-order reaction kinetics, and the apparent rate constant k = 0.03195 min-1.

  6. Synthesis and Herbicidal Activity of New Hydrazide and Hydrazonoyl Derivatives

    Directory of Open Access Journals (Sweden)

    František Šeršeň

    2015-08-01

    Full Text Available Three new hydrazide and five new hydrazonoyl derivatives were synthesized. The chemical structures of these compounds were confirmed by 1H-NMR, IR spectroscopy and elemental analysis. The prepared compounds were tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts and growth of the green algae Chlorella vulgaris. IC50 values of these compounds varied in wide range, from a strong to no inhibitory effect. EPR spectroscopy showed that the active compounds interfered with intermediates Z•/D•, which are localized on the donor side of photosystem II. Fluorescence spectroscopy suggested that the mechanism of inhibitory action of the prepared compounds possibly involves interactions with aromatic amino acids present in photosynthetic proteins.

  7. Synthesis of 4-Methoxybenzoylhydrazones and Evaluation of Their Antiglycation Activity

    Directory of Open Access Journals (Sweden)

    Muhammad Taha

    2014-01-01

    Full Text Available A series of 4-methoxybenzoylhydrazones 1–30 was synthesized and the structures of the synthetic derivatives elucidated by spectroscopic methods. The compounds showed a varying degree of antiglycation activity, with IC50 values ranging between 216.52 and 748.71 µM, when compared to a rutin standard (IC50 = 294.46 ± 1.50 µM. Compounds 1 (IC50 = 216.52 ± 4.2 µM, 3 (IC50 = 289.58 ± 2.64 µM, 6 (IC50 = 227.75 ± 0.53 µM, 7 (IC50 = 242.53 ± 6.1 and 11 (IC50 = 287.79 ± 1.59 all showed more activity that the standard, and these compounds have the potential to serve as possible leads for drugs to inhibit protein glycation in diabetic patients. A preliminary SAR study was performed.

  8. Synthesis and antibacterial activity of silver nanoparticles with different sizes

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Castanon, G. A., E-mail: mtzcastanon@fciencias.uaslp.m [UASLP, Maestria en Ciencias Odontologicas, Facultad de Estomatologia (Mexico); Nino-Martinez, N. [UASLP, Instituto de Metalurgia (Mexico); Martinez-Gutierrez, F., E-mail: fidel@uaslp.m [UASLP, Facultad de Ciencias Quimicas (Mexico); Martinez-Mendoza, J. R.; Ruiz, Facundo [UASLP, Facultad de Ciencias (Mexico)

    2008-12-15

    Silver nanoparticles with different sizes (7, 29, and 89 nm mean values) were synthesized using gallic acid in an aqueous chemical reduction method. The nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and ultraviolet-visible (UV-Vis) absorption spectroscopy; the antibacterial activity was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to the National Committee for Clinical Laboratory Standards. From the microscopies studies (TEM) we observed that silver nanoparticles have spherical (7 and 29 nm) and pseudospherical shape (89 nm) with a narrow size distribution. The sizes of the silver nanoparticles were controlled by varying some experimental conditions. It was found that the antibacterial activity of the nanoparticles varies when their size diminishes.

  9. Efavirenz Mannich bases: synthesis, anti-HIV and antitubercular activities.

    Science.gov (United States)

    Sriram, Dharmarajan; Banerjee, Debjani; Yogeeswari, Perumal

    2009-02-01

    A series of efavirenz Mannich bases has been synthesized by reacting efavirenz, formaldehyde, and various aryl substituted piperazines using microwave irradiation (yield 35-88%). The synthesized compounds were evaluated for in-vitro anti-HIV and antimycobacterial activities. The in-vitro antiretroviral activities indicated that compound 7-(4-((6-chloro-4-(2-cyclopropylethynyl)-4-(trifluoromethyl)-2-oxo-2H-benzo[d] [1,3]oxazin-1 (4H)-yl)methyl)-3-methylpiperazin-l -yl)-1-cyclopropyl-6-fluoro-l,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylic acid (4i) was equipotent to efavirenz with EC(50) of 2.4 nM. Compound 4i also inhibited M. tuberculosis with minimum inhibitory concentration of 0.2 microg/mL.

  10. Synthesis and antibacterial activity of silver nanoparticles with different sizes

    International Nuclear Information System (INIS)

    Martinez-Castanon, G. A.; Nino-Martinez, N.; Martinez-Gutierrez, F.; Martinez-Mendoza, J. R.; Ruiz, Facundo

    2008-01-01

    Silver nanoparticles with different sizes (7, 29, and 89 nm mean values) were synthesized using gallic acid in an aqueous chemical reduction method. The nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and ultraviolet-visible (UV-Vis) absorption spectroscopy; the antibacterial activity was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to the National Committee for Clinical Laboratory Standards. From the microscopies studies (TEM) we observed that silver nanoparticles have spherical (7 and 29 nm) and pseudospherical shape (89 nm) with a narrow size distribution. The sizes of the silver nanoparticles were controlled by varying some experimental conditions. It was found that the antibacterial activity of the nanoparticles varies when their size diminishes.

  11. Synthesis and Antimicrobial activity 2-chloro-6-methylquinoline Hydrazone derivatives

    Directory of Open Access Journals (Sweden)

    Rajiv Kumar

    2009-12-01

    Full Text Available

    A series of 2-chloro-6-methylquinoline hydrazones (3a-o were synthesized by the condensation of substituted acyl
    hydrazines, semicarbazide, thiosemicarbazide and INH with 2-chloro-3-formyl-6-methylquinoline in absolute alcohol.
    The structures of compounds were established using spectral data and elemental analysis. All the compounds were
    evaluated for their antibacterial activity against Escherichia coli (NCTC, 10418, Staphylococcus aureus (NCTC, 65710
    and Pseudomonas aeruginosa (NCTC, 10662. Compounds were also tested for antifungal activity aganist Aspergillus
    niger (MTCC, 281, Aspergillus flavus (MTCC, 277, Monascus purpureus (MTCC, 369 and Penicillium citrinum
    (NCIM, 768 by cup-plate method.

  12. Synthesis and Antimicrobial Activity of SomeNovel Benzimidazolyl Chalcones

    Directory of Open Access Journals (Sweden)

    B. A. Baviskar

    2009-01-01

    Full Text Available Some novel benzimidazolyl chalcones were synthesized by condensation of N-(4-(1H-benzo[d]imidazol-2-ylphenylacetamide with aromatic aldehydes in presence of aqueous potassium hydroxide solution at room temperature. All the synthesized compounds were characterized on the basis of their IR, 1H NMR spectroscopic data and elemental analysis. All the compounds have been screened for antimicrobial activity by the cup-plate method.

  13. New Conjugated Benzothiazole-N-oxides: Synthesis and Biological Activity

    Directory of Open Access Journals (Sweden)

    Pavlína Foltínová

    2009-12-01

    Full Text Available Eleven new 2-styrylbenzothiazole-N-oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N-oxide and para-substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as the protozoan Euglena gracilis as model microorganisms. Unlike previously prepared analogous benzothiazolium salts, only weak activity was recorded.

  14. Synthesis, antimicrobial activity of lamotrigine and its ammonium ...

    Indian Academy of Sciences (India)

    Administrator

    time, the solubility of them was also increased. All these compounds showed inactivity against E. coli and E. cloacae, although they showed mild activity against P. aeruginosa (almost all the results were. 25 μg/mL except 4j showed 12.5 μg/mL). This sug- gested that these complexes and their parent molecu- lar were similar ...

  15. Synthesis and anticancer activity of novel water soluble benzimidazole carbamates.

    Science.gov (United States)

    Cheong, Jae Eun; Zaffagni, Michela; Chung, Ivy; Xu, Yingjie; Wang, Yiqiang; Jernigan, Finith E; Zetter, Bruce R; Sun, Lijun

    2018-01-20

    Metastases account for more than 90% of all cancer deaths and respond poorly to most therapies. There remains an urgent need for new therapeutic modalities for the treatment of advanced metastatic cancers. The benzimidazole methylcarbamate drugs, commonly used as anti-helmitics, have been suggested to have anticancer activity, but progress has been stalled by their poor water solubility and poor suitability for systemic delivery to disseminated cancers. We synthesized and characterized the anticancer activity of novel benzimidazoles containing an oxetane or an amine group to enhance solubility. Among them, the novel oxetanyl substituted compound 18 demonstrated significant cytotoxicity toward a variety of cancer cell types including prostate, lung, and ovarian cancers with strong activity toward highly aggressive cancer lines (IC 50 : 0.9-3.8 μM). Compound 18 achieved aqueous solubility of 361 μM. In a mouse xenograft model of a highly metastatic human prostate cancer, compound 18 (30 mg/kg) significantly inhibited the growth of established tumors (T/C: 0.36) without noticeable toxicity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Synthesis and anticoagulant activity of the quaternary ammonium chitosan sulfates.

    Science.gov (United States)

    Fan, Lihong; Wu, Penghui; Zhang, Jinrong; Gao, Song; Wang, Libo; Li, Mingjia; Sha, Mingming; Xie, Weiguo; Nie, Min

    2012-01-01

    Quaternary ammonium chitosan sulfates with diverse degrees of substitution (DS) ascribed to sulfate groups between 0.52 and 1.55 were synthesized by reacting quaternary ammonium chitosan with an uncommon sulfating agent (N(SO(3)Na)(3)) that was prepared from sodium bisulfite (NaHSO(3)) through reaction with sodium nitrite (NaNO(2)) in the aqueous system homogeneous. The structures of the derivatives were characterized by FTIR, (1)H NMR and (13)C NMR. The factors affecting DS of quaternary ammonium chitosan sulfates which included the molar ratio of NaNO(2) to quaternary ammonium chitosan, sulfated temperature, sulfated time and pH of sulfated reaction solution were investigated in detail. Its anticoagulation activity in vitro was determined by an activated partial thromboplastin time (APTT) assay, a thrombin time (TT) assay and a prothrombin time (PT) assay. Results of anticoagulation assays showed quaternary ammonium chitosan sulfates significantly prolonged APTT and TT, but not PT, and demonstrated that the introduction of sulfate groups into the quaternary ammonium chitosan structure improved its anticoagulant activity obviously. The study showed its anticoagulant properties strongly depended on its DS, concentration and molecular weight. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  17. Synthesis, antioxidant and antibacterial activities of 3-nitrophenyl ferrocene

    Science.gov (United States)

    Benabdesselam, S.; Izza, H.; Lanez, T.; Guechi, E. K.

    2018-03-01

    The current work aims in its first part to synthesize 3-nitrophenylferrocene after diazotizing nitroaniline in the meta position by the sodium nitrite and the formation of the corresponding diazonium salt: 3-nitrobenzendiazonium sulfate, then the salt in solution was added to the ferrocene for the purpose of introducing the nitrophenyl moiety thereon (arylation) and the formation of 3-nitrophenylferrocene. The second part is devoted to the study of the antioxidant activity of 3-NPF by applying the trapping test of superoxide radical using cyclic voltammetry, the free radical DPPH trapping test by spectrophotometry. The results showed that 3-nitrophenylferrocene has a scavenging effect of DPPH radical with IC50 = 1.44mg/ml, superoxide radical with IC50=5.38mg/ml. The third part is devoted to the study of antibacterial activity of the synthesized compound tested on four strains of bacteria: Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Klebsiella pneumoniae. The obtained results clearly showed that 3-nitrophenylferrocene has low activities on the four bacterial strains with diameters of inhibition zones do not exceeding 17 mm at concentrations of 25mg/ml.

  18. Synthesis, Characterization, and Anticancer Activity of New Benzofuran Substituted Chalcones

    Directory of Open Access Journals (Sweden)

    Demet Coşkun

    2016-01-01

    Full Text Available Benzofuran derivatives are of great interest in medicinal chemistry and have drawn considerable attention due to their diverse pharmacological profiles including anticancer activity. Similarly, chalcones, which are common substructures of numerous natural products belonging to the flavonoid class, feature strong anticancer properties. A novel series of chalcones, 3-aryl-1-(5-bromo-1-benzofuran-2-yl-2-propanones propenones (3a–f, were designed, synthesized, and characterized. In vitro antitumor activities of the newly synthesized (3a–f and previously synthesized (3g–j chalcone compounds were determined by using human breast (MCF-7 and prostate (PC-3 cancer cell lines. Antitumor properties of all compounds were determined by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Cell viability assay for the tested chalcone compounds was performed and the log⁡IC50 values of the compounds were calculated after 24-hour treatment. Our results indicate that the tested chalcone compounds show antitumor activity against MCF-7 and PC-3 cell lines (p<0.05.

  19. Synthesis and Antiproliferative Activity of Thioxoflavones Mannich Base Derivatives.

    Science.gov (United States)

    Li, Wei; Li, Xueli; Liu, Manhui; Wang, Qiuan

    2017-07-01

    Two series of 12 novel thioxoflavones Mannich base derivatives 5a-f and 6a-f were synthesized via Mannich reaction of 4',7-dimethoxy-5-hydroxyflavothione (3) or 3',4',7-trimethoxy-5-hydroxyflavothione (4) with appropriate aliphatic amines or alicyclic amines and formaldehyde. Thioxoflavones 3 and 4 were prepared from 4',7-dimethoxy-5-hydroxyflavone (1) and 3',4',7-trimethoxy-5-hydroxyflavone (2) with Lawesson's reagent, respectively. Their antiproliferative activities in vitro were evaluated on a panel of three human cell lines (HeLa, HCC1954, and SK-OV-3) by CCK-8 assay. The results showed that most of the thioxoflavones and their Mannich base derivatives exhibited potential antiproliferative activities on the tested cancer cell lines, with IC 50 values ranging from 9.16 to 55.50 μM. In particular, thioxoflavone 4 and the thioxoflavone Mannich base derivatives 5a and 5d showed the best antiproliferative activity on all three human cancer cell lines; they are promising candidates worthy of further development. The structures of all synthesized compounds were confirmed by 1 H NMR, 13 C NMR, IR, and MS techniques. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Synthesis and Antibacterial Activities of Some Schiff Bases

    Directory of Open Access Journals (Sweden)

    Mohamed N. Ibrahim

    2011-01-01

    Full Text Available Schiff bases p-hydroxybenzylidene-2-carboxyaniline, p-nitrobenz-ylidene-2-carboxyaniline, p-(N, N-dimethylaminobenzylidene-2-carboxyaniline, N-(4-hydroxybezylidene-benzene-1,2-diamine, N--(4-nitrobezylidenebenzene-1,2-diamine, N-(4-(N, N-dimethylaminobezylidenebenzene-1,2-diamine, N-(4-(N,N-dimethylaminobenzylidenenaphthalen-1-amine,N-(4-nitrobenzylidenenaphthalen-1-amine,N--(4-chlorobenzylidenenaphthalen-1-amine,sodium-4-(4-(N,N-dimethyl aminobenzylideneaminonaphthalene-1-sulfonate,sodium -4-(4-nitrobenzylidene-aminonaphthalene-1-sulfonate and sodium-4-(4-chlorobenzylideneamino naphthalene-1-sulfonate obtained by condensation of aniline and naphthyl-amine derivatives with some aromatic aldehydes were characterized by physical and spectral methods. The biological activity of these products were as antibacterial agents against three species of human pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Klebsiella sp. Nearly 50% of these compounds showed reasonable activity against the bacterial species investigated and we found that the antibacterial activity is dependent on the molecular structure of the compounds.

  1. Evaluation of level of impregnation monomers in hydrotalcite

    International Nuclear Information System (INIS)

    Carmo, Danieli M. do; Machado, Jacson S.C.; Oliveira, Marcelo F.L.; Oliveira, Marcia G.; Soares, Bluma G.

    2011-01-01

    To evaluate the impregnation degree of 1,6-hexamethylene diisocyanate and 1,4-butanediol monomers in hydrotalcite clays it was prepared dispersions with mixing ratio 1:100 (clay/monomer), using the Ultraturrax and Ultrasound. Subsequently the samples were characterized by Fourier Transform Infrared Spectroscopy and X-ray Diffraction. Swelling tests and Tyndall effect were used to illustrate the different dispersions. The results indicated a strong interaction between the hydrotalcite with 1,6-hexamethylene diisocyanate, favoring the formation of intercalated structures. (author)

  2. Green synthesis and anxiolytic activity of some new dibenz-[1,4] diazepine-1-one analogues

    Directory of Open Access Journals (Sweden)

    Jaiprakash N. Sangshetti

    2017-02-01

    Full Text Available A facile, green approach for the synthesis of some new dibenz[1,4]-diazepine-1-one by a three component reaction of Diamine, 1,3 diketone and aromatic aldehyde using oxalic acid as catalyst in water is described. The products are formed in good yields (92–94%. Newly synthesized dibenz [1,4]-diazepine-1-one analogues were evaluated for the anxiolytic activity by the elevated plus maze method. From the activity data it is observed that compounds, 4g, 4h and 4k show promising anxiolytic activity.

  3. Synthesis and activities towards resistant cancer cells of sulfone and sulfoxide griseofulvin derivatives.

    Science.gov (United States)

    Liéby-Muller, Frédéric; Heudré Le Baliner, Quentin; Grisoni, Serge; Fournier, Emmanuel; Guilbaud, Nicolas; Marion, Frédéric

    2015-01-01

    Griseofulvin, an antifungal drug, has been shown in recent years to have anti-proliferative activities. We report here the synthesis of new analogs of griseofulvin, substituted in 2' by a sulfonyl group or in 3' by a sulfinyl or sulfonyl group. These compounds exhibit good anti-proliferative activities against SCC114 cells, an oral squamous carcinoma cell line showing pronounced centrosome amplification, and unexpected cytotoxic activities on HCC1937 cells, a triple negative breast cancer cell line resistant to microtubule inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Synthesis and antimalarial activity of new chloroquine analogues carrying a multifunctional linear side chain

    Science.gov (United States)

    Iwaniuk, Daniel P.; Whetmore, Eric D.; Rosa, Nicholas; Ekoue-Kovi, Kekeli; Alumasa, John; de Dios, Angel C.; Roepe, Paul D.; Wolf, Christian

    2009-01-01

    We report the synthesis and in vitro antimalarial activity of several new 4-amino-and 4-alkoxy-7-chloroquinolines carrying a linear dibasic side chain. Many of these chloroquine analogues have submicromolar antimalarial activity versus HB3 (chloroquine sensitive) and Dd2 (chloroquine resistant strain of P. falciparum) and low resistance indices were obtained in most cases. Importantly, compounds 11–15 and 24 proved to be more potent against Dd2 than chloroquine. Branching of the side chain structure proved detrimental to the activity against the CQR strain. PMID:19703776

  5. synthesis and characterization of some poly functionalized heterocyclic derivatives of expected biological activity

    International Nuclear Information System (INIS)

    El-sayed, M.S.

    2001-01-01

    The present work was aimed and designed to fulfil The following objectives : 1- Continuation of the effort done by our research group in the field of chemistry of pyridinethione derivatives and their biological activities. 2- Synthesis of several new heterocyclic derivatives containing N and/or S using the laboratory available reagents. 3- Establishment of the structures of the newly synthesized heterocyclic compounds by the data of IR, 1 H-NMR, mass spectra in addition to the elemental analysis. 4- Synthesis of some of these heterocyclic derivatives via alternative routs and this used as a tool to confirm the structures of the newly synthesized heterocyclic derivatives. 5- study of the most probable mechanisms leading to the formation of the new heterocyclic derivatives. 6- The antimicrobial activity of some of the newly synthesized heterocyclic derivatives was tested against several types of organisms

  6. Promoted Iron Nanocrystals Obtained via Ligand Exchange as Active and Selective Catalysts for Synthesis Gas Conversion.

    Science.gov (United States)

    Casavola, Marianna; Xie, Jingxiu; Meeldijk, Johannes D; Krans, Nynke A; Goryachev, Andrey; Hofmann, Jan P; Dugulan, A Iulian; de Jong, Krijn P

    2017-08-04

    Colloidal synthesis routes have been recently used to fabricate heterogeneous catalysts with more controllable and homogeneous properties. Herein a method was developed to modify the surface composition of colloidal nanocrystal catalysts and to purposely introduce specific atoms via ligands and change the catalyst reactivity. Organic ligands adsorbed on the surface of iron oxide catalysts were exchanged with inorganic species such as Na 2 S, not only to provide an active surface but also to introduce controlled amounts of Na and S acting as promoters for the catalytic process. The catalyst composition was optimized for the Fischer-Tropsch direct conversion of synthesis gas into lower olefins. At industrially relevant conditions, these nanocrystal-based catalysts with controlled composition were more active, selective, and stable than catalysts with similar composition but synthesized using conventional methods, possibly due to their homogeneity of properties and synergic interaction of iron and promoters.

  7. In Silico Study, Synthesis, and Cytotoxic Activities of Porphyrin Derivatives

    Directory of Open Access Journals (Sweden)

    Fransiska Kurniawan

    2018-01-01

    Full Text Available Five known porphyrins, 5,10,15,20-tetrakis(p-tolylporphyrin (TTP, 5,10,15,20-tetrakis(p-bromophenylporphyrin (TBrPP, 5,10,15,20-tetrakis(p-aminophenylporphyrin (TAPP, 5,10,15-tris(tolyl-20-mono(p-nitrophenylporphyrin (TrTMNP, 5,10,15-tris(tolyl-20-mono(p-aminophenylporphyrin (TrTMAP, and three novel porphyrin derivatives, 5,15-di-[bis(3,4-ethylcarboxymethylenoxyphenyl]-10,20-di(p-tolylporphyrin (DBECPDTP, 5,10-di-[bis(3,4-ethylcarboxymethylenoxyphenyl]-15,20-di-(methylpyrazole-4-ylporphyrin (cDBECPDPzP, 5,15-di-[bis(3,4-ethylcarboxymethylenoxyphenyl]-10,20-di-(methylpyrazole-4-ylporphyrin (DBECPDPzP, were used to study their interaction with protein targets (in silico study, and were synthesized. Their cytotoxic activities against cancer cell lines were tested using 3-(4,5-dimetiltiazol-2-il-2,5-difeniltetrazolium bromide (MTT assay. The interaction of porphyrin derivatives with carbonic anhydrase IX (CAIX and REV-ERBβ proteins were studied by molecular docking and molecular dynamic simulation. In silico study results reveal that DBECPDPzP and TrTMNP showed the highest binding interaction with REV- ERBβ and CAIX, respectively, and both complexes of DBECPDPzP-REV-ERBβ and TrTMNP-CAIX showed good and comparable stability during molecular dynamic simulation. The studied porphyrins have selective growth inhibition activities against tested cancer cells and are categorized as marginally active compounds based on their IC50.

  8. Synthesis, characterization and antibacterial activity of new salicylhydrazide containing azopyrazoles

    Directory of Open Access Journals (Sweden)

    Bhupendra P. Patel

    2011-03-01

    Full Text Available Various ethyl-2-substituted phenyl hydrazono-3-oxobutyrate (2a-h condensation with 2-hydroxy benzoic acid hydrazide (3 to afford 1-(2-hydroxybenzoyl-3-methyl-4-(2- substituted phenyl hydrazono-1H-pyrazol-5(4H-one (4a-h. The structures of all these compounds (4a-h were recognized on basis of analytical and spectral data. The newly synthesized compounds were evaluated for their antimicrobial activity against various bacteria and fungi.

  9. Synthesis of novel ferrocenyl Mannich bases and their antibacterial activities

    Science.gov (United States)

    Liu, Yuting; Xin, Hong; Yin, Jingyi; Yin, Dawei; Yang, Zijiang; Li, Jie

    2018-04-01

    In this work, a series of Mannich bases bearing ferrocenyl groups were synthesized via Mannich reactions. The effects of different conditions on the reaction were explored, and the newly synthesized compounds were well characterized by NMR and FT-IR. All compounds have been screened for in vitro antibacterial and antifungal, and the compounds 1-ferrocenyl-3-phenyl-3-(m-nitrophenylamino)-1-acetone (2f) and 1-ferrocenyl-3-phenyl-3-(p-nitrophenylamino)-1-acetone (2g) were shown to be significant activity against all the tested bacterial strains, such as Staphylococcus aureus, Streptococcus, Actinomycete, Escherichia coli, Saccharomyces cerevisiae.

  10. Synthesis and Antimicrobial Activity of Some New Benzimidazole Derivatives

    Directory of Open Access Journals (Sweden)

    S. H. Ali Abdelwahed

    2000-12-01

    Full Text Available Reaction of 3-(2-methylbenzimidazol-1-ylpropanoic acid hydrazide (1 with CS2/KOH gave oxadiazole 2 which underwent Mannich reaction to give 3. Compound 2 was treated with hydrazine hydrate to give triazole 4 which was treated with both aldehydes and acetic anhydride to give 5 and 6, respectively. Carbohydrazide 1 was reacted with ethyl acetoacetate, acetylacetone and aldehydes to give 7, 8 and 9, respectively. Cyclocondensation of 9 with thioglycolic and thiolactic acids gave 10 and 11, respectively. Some of these compounds showed potential antimicrobial activities.

  11. Synthesis and biological activity of pyridazine amides, hydrazones and hydrazides.

    Science.gov (United States)

    Buysse, Ann M; Yap, Maurice Ch; Hunter, Ricky; Babcock, Jonathan; Huang, Xinpei

    2017-04-01

    Optimization studies on compounds initially designed to be herbicides led to the discovery of a series of [6-(3-pyridyl)pyridazin-3-yl]amides exhibiting aphicidal properties. Systematic modifications of the amide moiety as well as the pyridine and pyridazine rings were carried out to determine if these changes could improve insecticidal potency. Structure-activity relationship (SAR) studies showed that changes to the pyridine and pyridazine rings generally resulted in a significant loss of insecticidal potency against green peach aphids [Myzus persicae (Sulzer)] and cotton aphids [(Aphis gossypii (Glover)]. However, replacement of the amide moiety with hydrazines, hydrazones, or hydrazides appeared to be tolerated, with small aliphatic substituents being especially potent. A series of aphicidal [6-(3-pyridyl)pyridazin-3-yl]amides were discovered as a result of random screening of compounds that were intially investigated as herbicides. Follow-up studies of the structure-activity relationship of these [6-(3-pyridyl)pyridazin-3-yl]amides showed that biosteric replacement of the amide moiety was widely tolerated suggesting that further opportunities for exploitation may exist for this new area of insecticidal chemistry. Insecticidal efficacy from the original hit, compound 1, to the efficacy of compound 14 produced greater than 10-fold potency improvement against Aphis gossypii and greater than 14-fold potency improvement against Myzus persicae. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Synthesis, DNA interaction and antimicrobial activities of three rimantadine analogues

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bing-Mi; Zhang, Jun [Department of Pharmacy, Liaoning University, Shenyang 110036 (China); Wang, Xin, E-mail: wangxinlnu@163.com [Department of Pharmacy, Liaoning University, Shenyang 110036 (China); Zhang, Li-Ping; Liu, Yang [Department of Pharmacy, Liaoning University, Shenyang 110036 (China); Niu, Hua-Ying [Jinan Dachpharm Development Co., Ltd., Jinan 250100 (China); Liu, Bin, E-mail: liubinzehao@163.com [Department of Pharmacy, Liaoning University, Shenyang 110036 (China)

    2015-03-15

    The interactions of three rimantadine analogues (RAs) with calf thymus deoxyribonucleic acid (ct-DNA) in buffer solution (pH 7.4) were investigated using berberine (BR) as a probe by various methods. Fluorescence studies revealed that the RAs interacted with DNA in vitro and the quenchings were all static. Furthermore, the binding modes of these compounds to DNA were disclosed as groove binding supported by absorption spectroscopy, viscosity measurement and denatured DNA experiment. The antimicrobial activities of the RAs were also evaluated in Staphylococcus aureus and Escherichia coli, and they all exhibited good bacteriostasic effects. The results might provide an important reference for investigation of the molecular mechanism associated with the DNA binding of the RAs. - Highlights: • Three rimantadine analogues were synthesized. • The RAs effectively quenched the intrinsic fluorescence of DNA via a static combination. • These analogues can bind to DNA via groove binding mode. • The antimicrobial activities of three analogues were also evaluated by the disk diffusion method.

  13. Green synthesis, spectroscopic investigation and photocatalytic activity of lead nanoparticles

    Science.gov (United States)

    Elango, Ganesh; Roopan, Selvaraj Mohana

    2015-03-01

    Most of researcher focused their research towards synthesize of nanoparticles by the method of applied chemical method which was one of the costliest method. We have focused cheapest and simplest method for the synthesizing of lead nanoparticles (Pb-NPs) using cocos nucifera L extract. The methanolic extract of cocos nucifera L was efficiently used as a reducing agent for synthesizing Pb-NPs. On treatment of lead acetate with cocos nucifera coir extracts, stable Pb-NPs were formed. The synthesized Pb-NPs were further confirmed by UV-visible spectroscopy, X-ray diffraction (XRD), Transmission electron microscope (TEM) and Energy Dispersive (EDAX) analysis. The secondary metabolites present in methanolic extract which can mainly act as a reducing and capping agents for the formation of Pb-NPs were identified by GC-MS. Anti-microbial activity for Pb-NPs against four pathogenic strain's such as Staphylococcus aureus, Escheria coli, Staphylococcus epidermis and Bacillus subtilis. Result states that Pb-NPs size was 47 nm and also shows good activity against S. aureus. Further we report on photocatalytic absorption of malachite green dye processed in short UV wavelength at 254 nm. UV spectral analysis showed peak absorbance at 613 nm with special reference to the excitation of surfaces plasmon vibration by Pb-NPs.

  14. Study on Synthesis and Photocatalytic Activity of Porous Titania Nanotubes

    Directory of Open Access Journals (Sweden)

    Huang Liu

    2016-01-01

    Full Text Available Using the common natural cellulose substance (filter paper and triblock copolymer (Pluronic P123 micelles as dual templates, porous titania nanotubes with enhanced photocatalytic activity have been successfully synthesized through sol-gel methods. Firstly, P123 micelles were adsorbed onto the surfaces of cellulose nanofibers of filter paper, followed by hydrolysis and condensation of tetrabutyl titanate around these micelles to form titania layer. After calcination to remove the organic templates, hierarchical titania nanotubes with pores in the walls were obtained. The sample was characterized by X-ray diffraction pattern (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, nitrogen adsorption/desorption, Fourier Transform Infrared Spectroscopy (FT-IR, Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS, and X-ray photoelectron spectroscopy (XPS. As compared with commercial P25 catalyst, the porous titania nanotubes prepared by this method displayed significantly enhanced photocatalytic activity for degrading methyl orange under UV irradiation. Within 10 minutes, the porous titania nanotubes are able to degrade over 70% of the original MO, while the value for the commercial Degussa P25 is only about 33%.

  15. Synthesis and Larvicidal Activity of Novel Thenoylhydrazide Derivatives

    Science.gov (United States)

    Song, Gao-Peng; Hu, De-Kun; Tian, Hao; Li, Ya-Sheng; Cao, Yun-Shen; Jin, Hong-Wei; Cui, Zi-Ning

    2016-03-01

    A pair of chemical isomeric structures of novel N-tert-butylphenyl thenoylhydrazide compounds I and II were designed and synthesized. Their structures were characterized by MS, IR, 1H NMR, elemental analysis and X-ray single crystal diffraction. The regioselectivity of the Meerwein arylation reaction and the electrophilic substitution reaction of N-tert-butyl hydrazine were studied by density functional theory (DFT) quantum chemical method. The larvicidal tests revealed that some compounds I had excellent larvicidal activity against Culex pipiens pallens. As the candidates of insect growth regulators (IGRs), the larval growth inhibition and regulation against Culex pipiens pallens were examined for some compounds, especially I1 and I7. Compounds I1 and I7 were further indicated as an ecdysteroid agonist by reporter gene assay on the Spodoptera frugiperda cell line (Sf9 cells). Finally, a molecular docking study of compound I7 was conducted, which was not only beneficial to understand the structure-activity relationship, but also useful for development of new IGRs for the control of mosquitos.

  16. Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia

    Science.gov (United States)

    Sherly, K. B.; Rakesh, K.

    2014-01-01

    Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl2ṡ8H2O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with the theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.

  17. Synthesis and Antimicrobial Activity of Sulfur Derivatives of Quinolinium Salts

    Directory of Open Access Journals (Sweden)

    Anna Empel

    2018-01-01

    Full Text Available A novel method for cleavage of the dithiine ring in 5,12-(dimethyl-thioqinantrenium bis-chloride 1 “via” reaction with sodium hydrosulfide leads to 1-methyl-3-mercaptoquinoline-4(1H-thione 2. Further transformation of thiol and thione functions of compound 2 leads to a series of sulfide and disulfide derivatives of quinolinium salts 4 and 6. 1-Methyl-4-chloro-3-benzylthioquinoline chloride 8 was obtained by N-alkylating 4-chloro-3-benzylthioquinoline using dimethyl sulfate. Antimicrobial activity of the obtained compounds was investigated using six Gram-positive and six Gram-negative bacterial strains, as well as Candida albicans yeast. Greater activity was demonstrated towards Gram-positive strains. MIC values for compounds and with benzylthio 4d and benzoylthio 4f substituents in 3-quinoline position were found to be in the 0.5–1 μg/mL range, at a level similar to that of ciprofloxacin (reference. Compounds 4d and 4f also demonstrated interesting antifungal properties (MIC = 1.

  18. Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Sherly, K. B.; Rakesh, K. [Mahatma Gandhi University Regional Research Center in Chemistry, Department of Chemistry, Mar Athanasius College, Kothamangalam-686666, Kerala (India)

    2014-01-28

    Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl{sub 2}⋅8H{sub 2}O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with the theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.

  19. Synthesis and Antitumor Activity of New Group 3 Metallocene Complexes.

    Science.gov (United States)

    Caporale, Angelamaria; Palma, Giuseppe; Mariconda, Annaluisa; Del Vecchio, Vitale; Iacopetta, Domenico; Parisi, Ortensia Ilaria; Sinicropi, Maria Stefania; Puoci, Francesco; Arra, Claudio; Longo, Pasquale; Saturnino, Carmela

    2017-03-28

    The quest for alternative drugs with respect to the well-known cis -platin and its derivatives, which are still used in more than 50% of the treatment regimens for patients suffering from cancer, is highly needed. In this context, organometallic compounds, which are defined as metal complexes containing at least one direct covalent metal-carbon bond, have recently been found to be promising anticancer drug candidates. A series of new metallocene complexes with scandium, yttrium, and neodymium have been prepared and characterized. Some of these compounds show a very interesting anti-proliferative activity in triple negative breast cancer cell line (MDA.MB231) and the non-hormone sensitive prostate cancer cell line (DU145). Moreover, the interaction of some of them with biological membranes, evaluated using liposomes as bio-membrane mimetic model systems, seems to be relevant. The biological activity of these compounds, particularly those based on yttrium, already effective at low concentrations on both cancer cell lines, should be taken into account with regard to new therapeutic approaches in anticancer therapy.

  20. Green synthesis, characterization and catalytic activity of silver nanoparticles using Cassia auriculata flower extract separated fraction

    Science.gov (United States)

    Muthu, Karuppiah; Priya, Sethuraman

    2017-05-01

    Cassia auriculata L., the flower aqueous extract was fractionated by separating funnel using n-hexane (A1), chloroform (A2), ethyl acetate (A3) and triple distilled water (A4). The A4 fraction was concentrated and determined the presence of preliminary phytochemicals such as tannins, flavonoids, glycosides, carbohydrates and polyphenolic compounds. These phytochemical compounds acted as reducing as well as a stabilizing agent in the green synthesis of Ag NPs from aqueous silver ions. Initially, the colour change and UV-vis absorbance surface Plasmon resonance strong, wide band located at 435 nm has confirmed the synthesis of Ag NPs. The X-ray diffraction (XRD) pattern of Ag NPs shows a face-centered cubic crystal structure. The observed values were calculated by Debye-Scherrer equation to theoretical confirms the particle size of 18 nm. The surface morphology of Ag NPs was viewed by HRTEM, the particles are spherical and triangle shapes with sizes from 10 to 35 nm. Further, the Ag NPs was effective catalytic activity in the reduction of highly environmental polluted organic compounds of 4-nitrophenol and methyl orange. The green synthesis of Ag NPs seems to eco-friendly, cost-effective, conventional one spot synthesis and greater performance of catalytic degradation of environmentally polluted organic dyes.

  1. Inhibition of acetaminophen oxidation by cimetidine and the effects on glutathione and activated sulphate synthesis rates

    DEFF Research Database (Denmark)

    Dalhoff, K; Poulsen, H E

    1993-01-01

    The aim of the present study was to examine the effects of the hepatotoxic drug, acetaminophen, on the synthesis rates of glutathione, activated sulphate (PAPS, adenosine 3'-phosphate 5'-phosphosulphate) and the acetaminophen metabolites, acetaminophen-glutathione and acetaminophen-sulphate after...... with 60 micrograms/ml cimetidine for 30 min. did not affect PAPS (1.71 versus 1.78 nmol/10(6) cells) nor glutathione concentration (16.0 versus 16.4 nmol/10(6) cells). The subsequent incubation with 5 mM acetaminophen resulted in decreased PAPS synthesis in the cimetidine treated cells [0.79 x 10......(3) versus 0.92 x 10(3) nmol/(10(6) cells.hr)] (P acetaminophen-sulphate synthesis [1.73 versus 1.79 nmol/10(6) cells and 13.0 versus 12.9 nmol/(10(6) cells.hr), respectively]. Decreased PAPS synthesis may be related to decreased ATP supply or may...

  2. Manufacturing of Porous Al-Cr Preforms for Composite Reinforcing Using Microwave Activated Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    Naplocha K.

    2014-10-01

    Full Text Available The combustion synthesis of porous skeletons (preforms of intermetallic Al–Cr compounds intended for metal matrix composite MMC reinforcing was developed. Mixture of Al and Cr powders with granularity of −10, −44, −74mm were cold isostatic pressed and next ignited and synthetized in a microwave reactor under argon atmosphere (microwave-activated combustion synthesis MACS. In order to ignite the synthesis, microwave energy was focused by a tuner on the specimen. The analysis of reaction temperature diagrams revealed that the synthesis proceeded through the following peritectic transformations: L(liquidus+Al7Cr→L+Al11Cr2→L+Al4Cr. Moreover, EDS and XRD examinations showed that the reaction proceeded between a solid Cr and a liquid Al to create a distinct envelope of Al9Cr4 on Cr particle which next extended and spreaded over the entire structure. The produced preforms with uniform structure and interconnected porosity were infiltrated with liquid Cu and Al alloy. The obtained composite materials exhibited high hardness, wear and distinct temperature oxidation resistance.

  3. Methods for the synthesis of aza(deaza)xanthines as a basis of biologically active compounds

    International Nuclear Information System (INIS)

    Babkov, D A; Geisman, A N; Novikov, M S; Khandazhinskaya, A L

    2016-01-01

    The review covers methods for the synthesis of aza(deaza)xanthines, i.e., fused pyrrolo-, pyrazolo- and triazolopyrimidine heterocyclic systems, which are common core structures of various biologically active compounds. The extensive range of modern synthetic approaches is organized according to target structures and starting building blocks. The presented material is intended to benefit broad audience of specialists in the fields of organic, medicinal and pharmaceutical chemistry. The bibliography includes 195 references

  4. Green Adeptness in the Synthesis and Stabilization of Copper Nanoparticles: Catalytic, Antibacterial, Cytotoxicity, and Antioxidant Activities.

    Science.gov (United States)

    Din, Muhammad Imran; Arshad, Farhan; Hussain, Zaib; Mukhtar, Maria

    2017-12-28

    Copper nanoparticles (CuNPs) are of great interest due to their extraordinary properties such as high surface-to-volume ratio, high yield strength, ductility, hardness, flexibility, and rigidity. CuNPs show catalytic, antibacterial, antioxidant, and antifungal activities along with cytotoxicity and anticancer properties in many different applications. Many physical and chemical methods have been used to synthesize nanoparticles including laser ablation, microwave-assisted process, sol-gel, co-precipitation, pulsed wire discharge, vacuum vapor deposition, high-energy irradiation, lithography, mechanical milling, photochemical reduction, electrochemistry, electrospray synthesis, hydrothermal reaction, microemulsion, and chemical reduction. Phytosynthesis of nanoparticles has been suggested as a valuable alternative to physical and chemical methods due to low cytotoxicity, economic prospects, environment-friendly, enhanced biocompatibility, and high antioxidant and antimicrobial activities. The review explains characterization techniques, their main role, limitations, and sensitivity used in the preparation of CuNPs. An overview of techniques used in the synthesis of CuNPs, synthesis procedure, reaction parameters which affect the properties of synthesized CuNPs, and a screening analysis which is used to identify phytochemicals in different plants is presented from the recent published literature which has been reviewed and summarized. Hypothetical mechanisms of reduction of the copper ion by quercetin, stabilization of copper nanoparticles by santin, antimicrobial activity, and reduction of 4-nitrophenol with diagrammatic illustrations are given. The main purpose of this review was to summarize the data of plants used for the synthesis of CuNPs and open a new pathway for researchers to investigate those plants which have not been used in the past. Graphical abstract Proposed Mechanism for Antibacterial activity of copper nanoparticles.

  5. Methanol utilization by a strain of Aspergillus niger: influence on the synthesis and activity of pectinases.

    Science.gov (United States)

    Maldonado, M C; Strasser de Saad, A M; Callieri, D A

    1993-03-01

    During the production of pectinases by a strain of Aspergillus niger isolated from rotten lemons, methanol was liberated into the medium due to the cleavage of the pectin molecule used as the carbon source. The methanol was subsequently consumed by the microorganism but neither the synthesis nor the activity of pectinesterase and polygalacturonase was affected. Although not studied in detail, the mechanism involved in the utilization of methanol is similar to that described for methylotrophic yeasts.

  6. Synthesis and Larvicidal and Adult Topical Activity of Some Hydrazide-Hydrazone Derivatives Against Aedes aegypti

    Science.gov (United States)

    2014-01-01

    anticancer, antifungal, antiviral , antitumoral, antibacterial and antimalarial activities [11-13]. Recently, our group has been investigating the...h showed Table 1. Some properties of compounds 4a-h Comp. Ar Molecular Formula Melting point (oC) Yield (%) Molecular weight 4a 4-OCH3-C6H...quinoxalinone-3-hydrazone derivatives. Bioorg Med Chem 2010; 18: 214–21. 11. Abdel-Aal MT, El-Sayed WA, El-Ashry EH. Synthesis and antiviral evaluation of

  7. Synthesis, characterization and luminescence spectroscopy of oxide nanopowders activated with trivalent lanthanide ions: The garnet family

    Science.gov (United States)

    Speghini, Adolfo; Piccinelli, Fabio; Bettinelli, Marco

    2011-01-01

    In this review, we deal with the preparation, structural investigation and especially optical spectroscopy of the garnet family of oxide materials activated with trivalent lanthanide ions, in the nanocrystalline form. In particular, attention is devoted here to the important garnet hosts; their synthesis, structure and luminescence spectroscopy are presented and discussed, with particular emphasis given to the possibility of obtaining efficient luminescence from trivalent lanthanide ions at the nanoscale, and to the potential and envisaged technological applications of this class of materials.

  8. Methods for the synthesis of aza(deaza)xanthines as a basis of biologically active compounds

    Science.gov (United States)

    Babkov, D. A.; Geisman, A. N.; Khandazhinskaya, A. L.; Novikov, M. S.

    2016-03-01

    The review covers methods for the synthesis of aza(deaza)xanthines, i.e., fused pyrrolo-, pyrazolo- and triazolopyrimidine heterocyclic systems, which are common core structures of various biologically active compounds. The extensive range of modern synthetic approaches is organized according to target structures and starting building blocks. The presented material is intended to benefit broad audience of specialists in the fields of organic, medicinal and pharmaceutical chemistry. The bibliography includes 195 references.

  9. Easy Access to Evans’ Oxazolidinones. Stereoselective Synthesis and Antibacterial Activity of a New 2-Oxazolidinone Derivative

    Directory of Open Access Journals (Sweden)

    Gaspar Diaz

    2014-06-01

    Full Text Available An interesting new approach was developed for the synthesis of Evans’ chiral auxiliaries with excellent yields. In turn, another new stereoselective and efficient strategy has also allowed for the preparation of a 2-oxazolidinone derivative in 34% overall yield from the Morita-Baylis-Hillman adduct. The antibacterial activity of this oxazolidinone was tested against Staphylococcus aureus strains isolated from animals with mastitis infections.

  10. Synthesis and Characterization of New Surface Active Azo Initiators for Radical Reactions

    Directory of Open Access Journals (Sweden)

    Klaus Tauer

    2000-04-01

    Full Text Available The synthesis of a water soluble azo initiators from 2,2’-azodiisobutyronitrile (AIBN was performed in three steps: reaction of dinitrile with aromatic alcohols in the presence of HCl to form bisiminoesters hydrochlorides which are hydrolyzed to the esters and final regioselective sulfonation of the aromatic esters. The thermal decomposition of the azo initiators obtained leads to formation of two surface active radicals which can start the chain reaction.

  11. Synthesis of high specific activity tritium labelled [2-3H]-adenosine-5'-triphosphate

    International Nuclear Information System (INIS)

    Jaiswal, D.K.; Morimoto, H.; Trump, E.L.; Williams, P.G.; Wemmer, D.E.

    1996-01-01

    A procedure for high level tritium labelling at the C2-H position of adenosine 5'-triphosphate ([2- 3 H]-ATP, 1), based on the tritiodehalogenation reaction of 2-bromoadenosine 5'-triphosphate (2) has been elaborated. This precursor was prepared in a six-step synthesis from guanosine. The tritiodehalogenation of (2) for three hours over palladium oxide in phosphate buffer yielded tritium labelled ATP with high specific activity, in good chemical yield. (author)

  12. Synthesis of furanone-based natural product analogues with quorum sensing antagonist activity

    DEFF Research Database (Denmark)

    Hjelmgaard, Thomas; Persson, T.; Rasmussen, Thomas Bovbjerg

    2003-01-01

    The synthesis of 5- and 3-(1'-hydroxyalkyl)-substituted 5H-furan-2-ones 4a-d and 8a-d as well as 5-alkylidene-5H-furan-2-ones 5a-d is described. A study of the structure-activity relationship of these furanone-based natural product analogues towards two different quorum sensing systems is reported...

  13. Syntheses of new functionalized monomers for .pi.-conjugated polymers

    Czech Academy of Sciences Publication Activity Database

    Výprachtický, Drahomír; Cimrová, Věra; Pavlačková, Petra; Kmínek, Ivan

    2007-01-01

    Roč. 46, 5-6 (2007), s. 811-811 ISSN 0427-7104. [IUPAC International Symposium on Novel Materials and Synthesis /3./ and International Symposium on Fine Chemistry and Functional Polymers /17./. Shanghai, 17.10.2007-21.10.2007] R&D Projects: GA AV ČR IAA4050409; GA MŠk(CZ) 1M06031 Institutional research plan: CEZ:AV0Z40500505 Keywords : substituted thiophene * activated ester * pyrene derivative * quinoline Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  14. Silver Nanocube and Nanobar Growth via Anisotropic Monomer Addition and Particle Attachment Processes.

    Science.gov (United States)

    Xiao, Dongdong; Wu, Zhigang; Song, Miao; Chun, Jaehun; Schenter, Gregory K; Li, Dongsheng

    2018-01-30

    Understanding the growth mechanism of noble metal nanocrystals during solution synthesis is of significant importance for shape and property control. However, much remains unknown about the growth pathways of metal nanoparticles due to the lack of direct observation. Using an in situ transmission electron microscopy technique, we directly observed Ag nanocube and nanobar growth in an aqueous solution through both classical monomer-by-monomer addition and nonclassical particle attachment processes. During the particle attachment process, Ag nanocubes and nanobars were formed via both oriented and nonoriented attachment. Our calculations, along with the dynamics of the observed attachment, showed that the van der Waals force overcomes hydrodynamic and friction forces and drives the particles toward each other at separations of 10-100 nm in our experiments. During classical growth, anisotropic growth was also revealed, and the resulting unsymmetrical shape constituted an intermediate state for Ag nanocube growth. We hypothesized that the temporary symmetry breaking resulted from different growth rates on (001) surfaces due to a local surface concentration variation caused by the imbalance between the consumption of Ag + near the surface and the diffusion of Ag + from the bulk to the surface.

  15. Silver Nanocube and Nanobar Growth via Anisotropic Monomer Addition and Particle Attachment Processes

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Dongdong [Physical; Wu, Zhigang [School; Song, Miao [Physical; Chun, Jaehun [Physical; Schenter, Gregory K. [Physical; Li, Dongsheng [Physical

    2018-01-11

    Understanding the growth mechanism of noble metal nanocrystals during solution synthesis is of significant importance for shape and property control. However, much remains unknown about the growth pathways of metal nanoparticles due to lack of direct observation. Using an in-situ transmission electron microscopy technique, we directly observed Ag nanocube and nanobar growth in aqueous solution through both classical monomer-by-monomer addition and non-classical particle attachment processes. During the particle attachment process, Ag nanocubes and nanobars formed via both oriented and non-oriented attachment. Our calculations, along with dynamics of the observed attachment, showed that van der Waals force overcame hydrodynamic and friction forces and drove the particles toward each other. During classical growth, an anisotropic growth was also revealed, and the resulting unsymmetrical shape constituted an intermediate state for Ag nanocube growth. We hypothesized that the temporary symmetry breaking resulted from different growth rates on {001} surfaces due to a local surface concentration variation caused by the imbalance between the consumption of Ag+ near the surface and the diffusion of Ag+ from bulk to surface.

  16. Radical Copolymerization Kinetics of Bio-Renewable Butyrolactone Monomer in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Sharmaine B. Luk

    2017-10-01

    Full Text Available The radical copolymerization kinetics of acrylamide (AM and the water-soluble monomer sodium 4-hydroxy-4-methyl-2-methylene butanoate (SHMeMB, formed by saponification of the bio-sourced monomer γ-methyl-α-methylene-γ-butyrolactone (MeMBL, are investigated to explain the previously reported slow rates of reaction during synthesis of superabsorbent hydrogels. Limiting conversions were observed to decrease with increased temperature during SHMeMB homopolymerization, suggesting that polymerization rate is limited by depropagation. Comonomer composition drift also increased with temperature, with more AM incorporated into the copolymer due to SHMeMB depropagation. Using previous estimates for the SHMeMB propagation rate coefficient, the conversion profiles were used to estimate rate coefficients for depropagation and termination (kt. The estimate for kt,SHMeMB was found to be of the same order of magnitude as that recently reported for sodium methacrylate, with the averaged copolymerization termination rate coefficient dominated by the presence of SHMeMB in the system. In addition, it was found that depropagation still controlled the SHMeMB polymerization rate at elevated temperatures in the presence of added salt.

  17. Highly antioxidant carotene-lipid nanocarriers: synthesis and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Lacatusu, Ioana; Badea, Nicoleta, E-mail: nicoleta.badea@gmail.com; Ovidiu, Oprea [University POLITEHNICA of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania); Bojin, Dionezie [Faculty of Engineering and Materials Science (Romania); Meghea, Aurelia [University POLITEHNICA of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania)

    2012-06-15

    The objective of this study was to explore the potential of two natural oils (squalene-Sq and grape seed oil-GSO) to prepare biocompatible antioxidant nanostructured lipid carriers-NLCs as a safety and protective formulation for sensitive {beta}-carotene. For this purpose different oil-in-water nanoemulsions stabilized by a combination of alkylpolyoxy ethylene sorbitans, lecithin and a block copolymer, were prepared using a melt high-shear homogenization process. The physico-chemical characteristics of the carotene-loaded NLCs were firstly investigated in detail. The smaller lipid nanoparticles have been obtained by using Tween 20 as main non-ionic surfactant, with average diameters of about 85 nm for GSO and 89 nm for Sq, with a polydispersity index <0.19. The developed carotene-NLCs presented an excellent physical stability with almost all zeta potential values ranging between -29 Division-Sign -40 mV. The differential scanning calorimetry analysis showed that the {beta}-carotene incorporation has led to a perturbation of solid lipid matrix with a less ordered arrangement. By UV-Vis spectroscopy it was evidenced that after encapsulation {beta}-carotene adopts a supramolecular structure demonstrated by appearance of a shoulder at 530 nm related to a {beta}-carotene triplet-triplet absorption. The carotene-NLCs have been also evaluated in terms of in vitro antioxidant properties. The presence of Sq and GSO produced a significant effect on the antioxidant capacity of developed NLCs. The samples prepared with GSO and Tween 80 as main surfactant showed the highest antioxidant activity (AA %) against free oxygen radicals, exhibiting an enhancement of 35 % for loaded NLCs, as comparing to pure carotene. In addition to these properties, the ability of NLCs to manifest antibacterial activity was tested against Escherichiacoli bacteria. The antibacterial analysis shown that loaded-NLCs develop an effective inhibition zone against bacteria growth and it was dependent in a

  18. Synthesis of some new hydrazone derivatives as biologically active agents.

    Science.gov (United States)

    Sen Gupta, A K; Rastogi, A

    1986-05-01

    A series of [4-(6H/bromo-4-oxo-2-phenyl-3(4H)-quinazolinyl)phenoxy]acetic acid (1,2-dihydro-1-H/methyl-2-oxo-3H-indol-3-ylidene)hydrazides (VII1-16) were synthesised by condensing 1-H/methyl-5-substituted indoline-2,3-diones with [4-(6H/bromo-4-oxo-2-phenyl-3(4H)-quinazolinyl) phenoxy]acetic acid hydrazides (IV1-2) which in turn were obtained by reacting ethyl [4-(6H/bromo-4-oxo-2-phenyl-3(4H)-quinazolinyl)phenoxy]acetates (III1-2) with hydrazine hydrate. All the synthesised compounds (VIII1-16) were screened for their antibacterial, acetylcholinesterase enzyme inhibitory and antiviral activities.

  19. Synthesis and Antimicrobial Activity of a Silver-Hydroxyapatite Nanocomposite

    Directory of Open Access Journals (Sweden)

    Marcos Díaz

    2009-01-01

    Full Text Available A silver-hydroxyapatite nanocomposite has been obtained by a colloidal chemical route and subsequent reduction process in H2/Ar atmosphere at 350∘C. This material has been characterized by TEM, XRD, and UV-Visible spectroscopy, showing the silver nanoparticles (∼65 nm supported onto the HA particles (∼130 nm surface without a high degree of agglomeration. The bactericidal effect against common Gram-positive and Gram-negative bacteria has been also investigated. The results indicated a high antimicrobial activity for Staphylococcus aureus, Pneumococcus and Escherichia coli, so this material can be a promising antimicrobial biomaterial for implant and reconstructive surgery applications.

  20. Synthesis, characterization and SERS activity of biosynthesized silver nanoparticles

    Science.gov (United States)

    Bindhu, M. R.; Sathe, V.; Umadevi, M.

    2013-11-01

    Silver nanoparticles were rapidly synthesized using Moringa oleifera flower extract as the reducing agent shows surface plasmon resonance peak at 439 nm. The size and shape of the nanoparticles controlled by varying the concentration of M. oleifera flower extract in the reaction medium. The synthesized silver nanoparticles were well-dispersed spherical nanoparticles with the average size of 14 nm. The retinoic acid present in M. oleifera flower extract used as reducing agent and proteins was responsible for capping of the bioreduced silver nanoparticles. The obtained nanoparticle shows size-dependent SERS activity. The SERS spectrum indicates that the pyridine adsorbed on the silver surface in a stand-on orientation via its nitrogen lone pair electrons.

  1. Synthesis and antifungal activity of two novel spermidine analogues.

    Science.gov (United States)

    Mackintosh, C A; Slater, L A; McClintock, C A; Walters, D R; Havis, N D; Robins, D J

    1997-03-01

    Two spermidine analogues were synthesised and examined for antifungal activity. Both compounds used as 1 mM post-inoculation sprays reduced infection of barley seedlings by the powdery mildew fungus, Erysiphe graminis f.sp. hordei, infection of broad bean seedlings by the rust fungus, Uromyces viciae-fabae, and infection of apple seedlings by the powdery mildew fungus, Podosphaera leucotricha. Since these fungal pathogens cannot be cultured axenically, the effects of the two spermidine analogues on mycelial growth in vitro, as well as preliminary investigations on polyamine biosynthesis, were undertaken using the oat stripe pathogen, Pyrenophora avenae. Although neither compound affected radial growth of the fungus on plates, both analogues reduced fungal biomass in liquid culture substantially. The two spermidine analogues, used at a concentration of 1 mM, had no significant effect on the conversion of labelled ornithine into polyamines in P. avenae.

  2. Synthesis of Silver Polymer Nanocomposites and Their Antibacterial Activity

    Science.gov (United States)

    Gavade, Chaitali; Shah, Sunil; Singh, N. L.

    2011-07-01

    PVA (Polyvinyl Alcohol) silver nanocomposites of different sizes were prepared by chemical reduction method. Silver nitrate was taken as the metal precursor and amine hydrazine as a reducing agent. The formation of the silver nanoparticles was noticed using UV- visible absorption spectroscopy. The UV-visible spectroscopy revealed the formation of silver nanoparticles by exhibiting the surface plasmon resonance. The bactericidal activity due to silver release from the surface was determined by the modification of conventional diffusion method. Salmonella typhimurium, Serratia sps and Shigella sps were used as test bacteria which are gram-negative type bacteria. Effect of the different sizes of silver nano particles on antibacterial efficiency was discussed. Zones of inhibition were measured after 24 hours of incubation at 37 °C which gave 20 mm radius for high concentration of silver nanoparticles.

  3. Synthesis of geranylhydroquinone derivatives with potential cytotoxic activity

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, Evelyn; Catalan, Karen; Pena-Cortes, Hugo; Espinoza, Luis, E-mail: luis.espinozac@usm.cl [Departamento de Quimica, Universidad Tecnica Federico Santa Maria, Valparaiso (Chile); Villena, Joan [Facultad de Medicina, Universidad de Valparaiso, Centro Regional de Estudios en Alimentos Saludables, Valparaiso (Chile); Carrasco, Hector [Departamento de Ciencias Quimicas, Universidad Andres Bello, Campus Vina del Mar (Chile)

    2012-07-01

    Natural geranylhydroquinone 1 and geranyl-p-methoxyphenol 2 were prepared by Electrophilic Aromatic Substitution (EAS) reactions between geraniol and 1,4-hydroquinone or p-methoxyphenol respectively, using BF{sub 3} {center_dot}Et{sub 2}O as a catalyst. Furthermore, natural geranylquinone 3, geranyl-1,4-dimethoxyquinone 4 and the new geranyl-4-methoxyphenyl acetate 5 were obtained by chemical transformations of 1 and 2. The compounds were evaluated for their in vitro cytotoxicity activities against cultured human cancer cells of PC-3 human prostate cancer, MCF-7 and MDA-MB-231 breast carcinoma, and Dermal Human ibroblasts DHF. IC{sub 50} values were in the {mu}M range. (author)

  4. Synthesis, characterization and SERS activity of Au-Ag nanorods

    Science.gov (United States)

    Philip, Daizy; Gopchandran, K. G.; Unni, C.; Nissamudeen, K. M.

    2008-09-01

    The formation mechanism and morphology of Au-Ag bimetallic colloidal nanoparticles depend on the composition. Ag coated Au colloidal nanoparticles have been prepared by deposition of Ag through chemical reduction on performed Au colloid. The composition of the Au 100- x-Ag x particles was varied from x = 0 to 50. The obtained colloids were characterized by UV-vis spectroscopy and transmission electron microscopy (TEM). The Au 80-Ag 20 colloid consists of alloy nanorods with dimension of 25 nm × 100 nm. The activity of these nanorods in surface enhanced Raman spectroscopy (SERS) was checked by using sodium salicylate as an adsorbate probe. Intense SERS bands are observed indicating its usefulness as a SERS substrate in near infrared (NIR) laser excitation.

  5. MMS 1001 inhibits melanin synthesis via ERK activation.

    Science.gov (United States)

    Lee, Hyun-E; Song, Jiho; Kim, Su Yeon; Park, Kyoung-Chan; Min, Kyung Hoon; Kim, Dong-Seok

    2013-03-01

    Melanin plays major a role in pigmentation of hair, eyes, and skin in mammals. In this study, the inhibitory effects of MMS 1001 on alpha-MSH-stimulated melanogenesis were investigated in B16F10 melanoma cells. MMS 1001 did not show cytotoxic effects up to 10 microM. Melanin content and intracellular tyrosinase activity were inhibited by MMS 1001 treatment in a dose-dependent manner. In Western blot analysis, MITF expression was decreased by MMS 1001. In addition, tyrosinase expressions were also reduced after MMS 1001 treatment. Further results showed that the phosphorylation of ERK was induced by MMS 1001. Moreover, a specific MEK inhibitor, PD98059, abrogated the inhibitory effects of MMS 1001 on melanin production and tyrosinase expression. These results indicate that the hypopigmentary effects of MMS 1001 resulted from the inhibition of MITF and tyrosinase expression via phosphorylation of ERK. Thus, MMS 1001 could be developed as a new effective skin-whitening agent.

  6. AMP-activated kinase restricts Rift Valley fever virus infection by inhibiting fatty acid synthesis.

    Directory of Open Access Journals (Sweden)

    Theresa S Moser

    Full Text Available The cell intrinsic innate immune responses provide a first line of defense against viral infection, and often function by targeting cellular pathways usurped by the virus during infection. In particular, many viruses manipulate cellular lipids to form complex structures required for viral replication, many of which are dependent on de novo fatty acid synthesis. We found that the energy regulator AMPK, which potently inhibits fatty acid synthesis, restricts infection of the Bunyavirus, Rift Valley Fever Virus (RVFV, an important re-emerging arthropod-borne human pathogen for which there are no effective vaccines or therapeutics. We show restriction of RVFV both by AMPK and its upstream activator LKB1, indicating an antiviral role for this signaling pathway. Furthermore, we found that AMPK is activated during RVFV infection, leading to the phosphorylation and inhibition of acetyl-CoA carboxylase, the first rate-limiting enzyme in fatty acid synthesis. Activating AMPK pharmacologically both restricted infection and reduced lipid levels. This restriction could be bypassed by treatment with the fatty acid palmitate, demonstrating that AMPK restricts RVFV infection through its inhibition of fatty acid biosynthesis. Lastly, we found that this pathway plays a broad role in antiviral defense since additional viruses from disparate families were also restricted by AMPK and LKB1. Therefore, AMPK is an important component of the cell intrinsic immune response that restricts infection through a novel mechanism involving the inhibition of fatty acid metabolism.

  7. Rhodium mediated bond activation: from synthesis to catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Hung-An [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    Recently, our lab has developed monoanionic tridentate ligand, ToR, showing the corresponding coordination chemistry and catalyst reactivity of magnesium, zirconium, zinc and iridium complexes. This thesis details synthetic chemistry, structural study and catalytic reactivity of the ToR-supported rhodium compounds. Tl[ToR] has been proved to be a superior ligand transfer agent for synthesizing rhodium complexes. The salt metathesis route of Tl[ToM] with [Rh(μ-Cl)(CO)]2 and [Rh(μ- Cl)(COE)]2 gives ToMRh(CO)2 (2.2) and ToMRhH(β3-C8H13) (3.1) respectively while Tl[ToM] with [Rh(μ-Cl)(CO)]2 affords ToPRh(CO)2 (2.3). 2.2 reacts with both strong and weak electrophiles, resulting in the oxazoline N-attacked and the metal center-attacked compounds correspondingly. Using one of the metal center-attacked electrophiles, 2.3 was demonstrated to give high diastereoselectivity. Parallel to COE allylic C-H activation complex 3.1, the propene and allylbenzene allylic C-H activation products have also been synthesized. The subsequent functionalization attempts have been examined by treating with Brønsted acids, Lewis acids, electrophiles, nucleophiles, 1,3-dipolar reagents and reagents containing multiple bonds able to be inserted. Various related complexes have been obtained under these conditions, in which one of the azide insertion compounds reductively eliminates to give an allylic functionalization product stoichiometrically. 3.1 reacts with various primary alcohols to give the decarbonylation dihydride complex ToMRh(H)2CO (4.1). 4.1 shows catalytic reactivity for primary alcohol decarbonylation under a photolytic condition. Meanwhile, 2.2 has been found to be more reactive than 4.1 for catalytic alcohol decarbonylation under the same condition. Various complexes and primary

  8. Final synthesis of Sarnet (Phase 1) corium activities

    International Nuclear Information System (INIS)

    Journeau, Ch.; Steinbruck, M.; Repetto, G.; Duriez, Ch.; Koundy, V.; Ma, W.M.; Burger, M.; Spindler, B.

    2009-01-01

    Within the SARNET Severe Accident Research Network of excellence, the Corium topic covers all the behaviour of corium (mixture formed by the molten materials arising from a postulated nuclear reactor severe accident) from early phase of core degradation to in or ex-vessel corium recovery with the exception of corium interaction with water, direct containment heating and fission product release. The Corium topic regroups in three work packages the critical mass of competence to improve significantly the corium behaviour knowledge. The spirit of the SARNET networking is to share the knowledge, the facilities and the simulation tools for severe accidents, so to reach a better efficiency and to rationalize the R and D effort at European level. Extensive benchmarking has been launched in most of the areas of research. These benchmarks were mainly dedicated to the recalculation of analytical experiments, integral experiments or reactor applications. Eventually, all the knowledge will be accumulated in the ASTEC severe accident simulation code through physical model improvements and extension of validation database. This report summarizes the progress that has been achieved in the frame of the networking activities for the four and half years of the FP6 project. (authors)

  9. Synthesis and Antimicrobial Activities of Some Novel Quinoxalinone Derivatives

    Directory of Open Access Journals (Sweden)

    Y. A. Ammar

    2000-06-01

    Full Text Available Condensation of 4-benzoyl-1,2-phenylenediamine with sodium pyruvate in acetic acid furnished two products which were identified as 6-benzoyl and 7-benzoyl-3-methyl-2(1Hquinoxalinones (1a,b. Fusion of 1a with aromatic aldehydes furnished the styryl derivatives 2a-c. Alkylation of 1a,b with dimethyl sulphate or ethyl chloroacetate produced the N-alkyl derivatives 3a,b and 4a,b. Hydrazinolysis of the ester derivative 4a with hydrazine hydrate afforded the hydrazide derivative 5 which underwent condensation with aldehydes to give the corresponding hydrazone derivatives 6a,b. In addition, chlorination of 1a with thionyl chloride afforded the 2-chloro derivative 7 which was subjected to reaction with sodium azide and n-butylamine to yield the corresponding tetrazolo (8 and n-butylamino (9 derivatives, respectively. The structures of the compounds prepared were confirmed by analytical and spectral data. Also, some of the synthesized compounds were screened for antimicrobial activity.

  10. Gamma radiation treatment activates glucomoringin synthesis in Moringa oleifera

    Directory of Open Access Journals (Sweden)

    Tsifhiwa Ramabulana

    Full Text Available Abstract Plants are a very rich source of pharmacologically relevant metabolites. However, the relative concentrations of these compounds are subject to the genetic make-up, the physiological state of the plant as well as environmental effects. Recently, metabolic perturbations through the use of abiotic stressors have proven to be a valuable strategy for increasing the levels of these compounds. Oxidative stress-associated stressors, including ionizing radiation, have also been reported to induce metabolites with various biological activities in plants. Hence, the aim of the current study was to investigate the effect of gamma radiation on the induction of purported anti-cancerous metabolites, glucomoringin and its derivatives, in Moringa oleifera Lam., Moringaceae. Here, an UHPLC-qTOF-MS-based targeted metabolic fingerprinting approach was used to evaluate the effect of gamma radiation treatment on the afore-mentioned health-beneficial secondary metabolites of M. oleifera. Following radiation, an increase in glucomoringin and three acylated derivatives was noted. As such, these molecules can be regarded as components of the inducible defense mechanism of M. oleifera as opposed to being constitutive components as it has previously been assumed. This might be an indication of a possible, yet unexplored role of moringin against the effects of oxidative stress in M. oleifera plants. The results also suggest that plants undergoing photo-oxidative stress could accumulate higher amounts of glucomoringin and related molecules.

  11. Synthesis, characterization and catalytic activity of nanosized Ni complexed aminoclay

    Science.gov (United States)

    Ranchani, A. Amala Jeya; Parthasarathy, V.; Devi, A. Anitha; Meenarathi, B.; Anbarasan, R.

    2017-11-01

    A novel Ni complexed aminoclay (AC) catalyst was prepared by complexation method followed by reduction reaction. Various analytical techniques such as FTIR spectroscopy, UV-visible spectroscopy, DSC, TGA, SEM, HRTEM, EDX, XPS and WCA measurement are used to characterize the synthesized material. The AC-Ni catalyst system exhibited improved thermal stability and fiber-like morphology. The XPS results declared the formation of Ni nanoparticles. Thus, synthesized catalyst was tested towards the Schiff base formation reaction between various bio-medical polymers and aniline under air atmosphere at 85 °C for 24 h. The catalytic activity of the catalyst was studied by varying the % weight loading of the AC-Ni system towards the Schiff base formation. The Schiff base formation was quantitatively calculated by the 1H-NMR spectroscopy. While increasing the % weight loading of the AC-Ni catalyst, the % yield of Schiff base was also increased. The k app and Ti values were determined for the reduction of indole and α-terpineol in the presence of AC-Ni catalyst system. The experimental results were compared with the literature report.

  12. Synthesis and anti-Trypanosoma cruzi activity of diaryldiazepines.

    Science.gov (United States)

    Menezes, Júlio César L; Vaz, Luana Beatriz A; de Abreu Vieira, Paula Melo; da Silva Fonseca, Kátia; Carneiro, Cláudia Martins; Taylor, Jason G

    2014-12-23

    Chagas disease is a so-called "neglected disease" and endemic to Latin America. Nifurtimox and benznidazole are drugs that have considerable efficacy in the treatment of the acute phase of the disease but cause many significant side effects. Furthermore, in the Chronic Phase its efficiency is reduced and their therapeutic effectiveness is dependent on the type of T. cruzi strain. For this reason, the present work aims to drive basic research towards the discovery of new chemical entities to treat Chagas disease. Differently substituted 5,7-diaryl-2,3-dihydro-1,4-diazepines were synthesized by cyclocondensation of substituted flavones with ethylenediamine and tested as anti-Trypanosoma cruzi candidates. Epimastigotes of the Y strain from T. cruzi were used in this study and the number of parasites was determined in a Neubauer chamber. The most potent diaryldiazepine that reduced epimastigote proliferation exhibited an IC50 value of 0.25 μM, which is significantly more active than benznidazole.

  13. Synthesis and Anti-Trypanosoma cruzi Activity of Diaryldiazepines

    Directory of Open Access Journals (Sweden)

    Júlio César L. Menezes

    2014-12-01

    Full Text Available Chagas disease is a so-called “neglected disease” and endemic to Latin America. Nifurtimox and benznidazole are drugs that have considerable efficacy in the treatment of the acute phase of the disease but cause many significant side effects. Furthermore, in the Chronic Phase its efficiency is reduced and their therapeutic effectiveness is dependent on the type of T. cruzi strain. For this reason, the present work aims to drive basic research towards the discovery of new chemical entities to treat Chagas disease. Differently substituted 5,7-diaryl-2,3-dihydro-1,4-diazepines were synthesized by cyclocondensation of substituted flavones with ethylenediamine and tested as anti-Trypanosoma cruzi candidates. Epimastigotes of the Y strain from T. cruzi were used in this study and the number of parasites was determined in a Neubauer chamber. The most potent diaryldiazepine that reduced epimastigote proliferation exhibited an IC50 value of 0.25 μM, which is significantly more active than benznidazole.

  14. Synthesis and antiproliferative activity of various novel indole Mannich bases

    Directory of Open Access Journals (Sweden)

    Mardia T El Sayed

    2015-11-01

    Full Text Available Various secondary and primary amines were converted into bis-indolyl Mannich bases with good to excellent yields via double condensation reactions with indole and glutaraldehyde. The expected bis-indolyl Mannich bases (2, 3 and 4 were formed by using piperazinehexahydrate and 4,4′-trimethylenedipiperidine. Whereas, the use of primary amines, phenylhydrazine, amino acids and primary diamine produced the corresponding bis-indolyl-1,2,6-trisubstituted pipridines (5a-e and indolyl-quinolizine (6 and dibis-indolyl-1,2,6-trisubstituted pipridines (7. All analytical and spectral data of these bis-indolyl Mannich bases have been determined. Six of the synthesized bis-indolyl Mannich bases have been subjected for antiproliferative activity screening at National Cancer Institute (NCI, Egypt, towards three human tumor cell lines representing different tumor types: breast adenocarcinoma cell (MCF-7, non-small lung cancer cell (NCI-H460, and central nervous system (CNS cancer cell (SF-268. Compound (4 indicated the best and highest inhibitory effect against all three tested tumor cell lines with inhibition of 50% concentration (IC50 for MCF-7 (0.08µmol/L, NCI-H460(0.05µmol/L and SF-268 (0.01 µmol/L.

  15. Synthesis and antimicrobial activity of gold nanoparticle conjugates with cefotaxime

    Science.gov (United States)

    Titanova, Elena O.; Burygin, Gennady L.

    2016-04-01

    Gold nanoparticles (GNPs) have attracted significant interest as a novel platform for various applications to nanobiotechnology and biomedicine. The conjugates of GNPs with antibiotics and antibodies were also used for selective photothermal killing of protozoa and bacteria. Also the conjugates of some antibiotics with GNPs decreased the number of bacterial growing cells. In this work was made the procedure optimization for conjugation of cefotaxime (a third-generation cephalosporin antibiotic) with GNPs (15 nm) and we examined the antimicrobial properties of this conjugate to bacteria culture of E. coli K-12. Addition of cefotaxime solution to colloidal gold does not change their color and extinction spectrum. For physiologically active concentration of cefotaxime (3 μg/mL), it was shown that the optimum pH for the conjugation was more than 9.5. A partial aggregation of the GNPs in saline medium was observed at pH 6.5-7.5. The optimum concentration of K2CO3 for conjugation cefotaxime with GNPs-15 was 5 mM. The optimum concentration of cefotaxime was at 0.36 μg/mL. We found the inhibition of the growth of E. coli K12 upon application cefotaxime-GNP conjugates.

  16. Catalytic synthesis of enantiopure mixed diacylglycerols - synthesis of a major M. tuberculosis phospholipid and platelet activating factor

    NARCIS (Netherlands)

    Fodran, Peter; Minnaard, Adriaan J.

    2013-01-01

    An efficient catalytic one-pot synthesis of TBDMS-protected diacylglycerols has been developed, starting from enantiopure glycidol. Subsequent migration-free deprotection leads to stereo- and regiochemically pure diacylglycerols. This novel strategy has been applied to the synthesis of a major

  17. Base-catalyzed depolymerization of lignin : separation of monomers

    Energy Technology Data Exchange (ETDEWEB)

    Vigneault, A. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; Johnson, D.K. [National Renewable Energy Laboratory, Golden, CO (United States); Chornet, E. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; National Renewable Energy Laboratory, Golden, CO (United States)

    2007-12-15

    Biofuels produced from residual lignocellulosic biomass range from ethanol to biodiesel. The use of lignin for the production of alternate biofuels and green chemicals has been studied with particular emphasis on the structure of lignin and its oxyaromatic nature. In an effort to fractionate lignocellulosic biomass and valorize specific constitutive fractions, the authors developed a strategy for the separation of 12 added value monomers produced during the hydrolytic base catalyzed depolymerization (BCD) of a Steam Exploded Aspen Lignin. The separation strategy was similar to vanillin purification to obtain pure monomers, but combining more steps after the lignin depolymerization such as acidification, batch liquid-liquid-extraction (LLE), followed by vacuum distillation, liquid chromatography (LC) and crystallization. The purpose was to develop basic data for an industrial size process flow diagram, and to evaluate both the monomer losses during the separation and the energy requirements. Experimentally testing of LLE, vacuum distillation and flash LC in the laboratory showed that batch vacuum distillation produced up to 4 fractions. Process simulation revealed that a series of 4 vacuum distillation columns could produce 5 distinct monomer streams, of which 3 require further chromatography and crystallization operations for purification. 22 refs., 4 tabs., 8 figs.

  18. INSIGHTS INTO THE MONOMERS AND SINGLE DRUGS OF ...

    African Journals Online (AJOL)

    Chinese herbal drugs have been proved to be effective agents in myocardial protection by preventing ischemia-reperfusion injury. The underlying mechanisms as to how these agents work were however poorly elucidated. Studies on the monomers or on the single drugs have highlighted the possible rationales, leading to ...

  19. Influence of the Diene Monomer on Devulcanization of EPDM Rubber

    NARCIS (Netherlands)

    Verbruggen, M.A.L.; van der Does, L.; Noordermeer, Jacobus W.M.; van Duin, M.

    2008-01-01

    Ethylene–propylene–diene rubbers (EPDM) with 2-ethylidene-5-norbornene (ENB), dicyclopentadiene (DCPD), and 1,4-hexadiene (HD) as third monomers have been vulcanized with peroxide and with a conventional sulfur vulcanization recipe, and their devulcanization was subsequently investigated for

  20. Plasma-Enhanced Copolymerization of Amino Acid and Synthetic Monomers

    Science.gov (United States)

    2011-12-16

    dielectrics to successfully deposit a wide range of monomers covering many traditional polymers, ranging from styrene , acrylonitrile, and benzene to...dispersive spectroscopy (EDS) was performed with an Oxford system on a Hitachi S-3400 scanning electron microscope. Fourier transform infrared ( FTIR ...spectroscopy measurements were conducted using a Bruker FTIR spectrometer (Vertex 70) equipped with a narrow-band mercury cadmium telluride detector

  1. Low temperature irradiation of vitrifiable mixtures of unsaturated monomers

    International Nuclear Information System (INIS)

    Kaetsu, I.; Ito, A.; Hayashi, K.

    1975-01-01

    A specific mixture containing at least one polymerizable unsaturated monomer which is not vitrifiable by itself can advantageously be polymerized by irradiating the mixture at a temperature not higher than 100 0 C above glass transition temperature of the mixture with an ionizing radiation and/or a light. 12 claims, 6 drawings, figures

  2. Two Populations Mean-Field Monomer-Dimer Model

    Science.gov (United States)

    Alberici, Diego; Mingione, Emanuele

    2018-04-01

    A two populations mean-field monomer-dimer model including both hard-core and attractive interactions between dimers is considered. The pressure density in the thermodynamic limit is proved to satisfy a variational principle. A detailed analysis is made in the limit of one population is much smaller than the other and a ferromagnetic mean-field phase transition is found.

  3. Epoxy resin monomers with reduced skin sensitizing potency.

    Science.gov (United States)

    O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese

    2014-06-16

    Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis.

  4. Green Adeptness in the Synthesis and Stabilization of Copper Nanoparticles: Catalytic, Antibacterial, Cytotoxicity, and Antioxidant Activities

    Science.gov (United States)

    Din, Muhammad Imran; Arshad, Farhan; Hussain, Zaib; Mukhtar, Maria

    2017-12-01

    Copper nanoparticles (CuNPs) are of great interest due to their extraordinary properties such as high surface-to-volume ratio, high yield strength, ductility, hardness, flexibility, and rigidity. CuNPs show catalytic, antibacterial, antioxidant, and antifungal activities along with cytotoxicity and anticancer properties in many different applications. Many physical and chemical methods have been used to synthesize nanoparticles including laser ablation, microwave-assisted process, sol-gel, co-precipitation, pulsed wire discharge, vacuum vapor deposition, high-energy irradiation, lithography, mechanical milling, photochemical reduction, electrochemistry, electrospray synthesis, hydrothermal reaction, microemulsion, and chemical reduction. Phytosynthesis of nanoparticles has been suggested as a valuable alternative to physical and chemical methods due to low cytotoxicity, economic prospects, environment-friendly, enhanced biocompatibility, and high antioxidant and antimicrobial activities. The review explains characterization techniques, their main role, limitations, and sensitivity used in the preparation of CuNPs. An overview of techniques used in the synthesis of CuNPs, synthesis procedure, reaction parameters which affect the properties of synthesized CuNPs, and a screening analysis which is used to identify phytochemicals in different plants is presented from the recent published literature which has been reviewed and summarized. Hypothetical mechanisms of reduction of the copper ion by quercetin, stabilization of copper nanoparticles by santin, antimicrobial activity, and reduction of 4-nitrophenol with diagrammatic illustrations are given. The main purpose of this review was to summarize the data of plants used for the synthesis of CuNPs and open a new pathway for researchers to investigate those plants which have not been used in the past.

  5. Antifreeze glycopeptides: from structure and activity studies to current approaches in chemical synthesis.

    Science.gov (United States)

    Urbańczyk, Małgorzata; Góra, Jerzy; Latajka, Rafał; Sewald, Norbert

    2017-02-01

    Antifreeze glycopeptides (AFGPs) are a class of biological antifreeze agents found predominantly in Arctic and Antarctic species of fish. They possess the ability to regulate ice nucleation and ice crystal growth, thus creating viable life conditions at temperatures below the freezing point of body fluids. AFGPs usually consist of 4-55 repetitions of the tripeptide unit Ala-Ala-Thr that is O-glycosylated at the threonine side chains with β-D-galactosyl-(1 → 3)-α-N-acetyl-D-galactosamine. Due to their interesting properties and high antifreeze activity, they have many potential applications, e.g., in food industry and medicine. Current research is focused towards understanding the relationship between the structural preferences and the activity of the AFGPs, as well as developing time and cost efficient ways of synthesis of this class of molecules. Recent computational studies in conjunction with experimental results from NMR and THz spectroscopies were a possible breakthrough in understanding the mechanism of action of AFGPs. At the moment, as a result of these findings, the focus of research is shifted towards the analysis of behaviour of the hydration shell around AFGPs and the impact of water-dynamics retardation caused by AFGPs on ice crystal growth. In the field of organic synthesis of AFGP analogues, most of the novel protocols are centered around solid-phase peptide synthesis and multiple efforts are made to optimize this approach. In this review, we present the current state of knowledge regarding the structure and activity of AFGPs, as well as approaches to organic synthesis of these molecules with focus on the most recent developments.

  6. Efficient method for polymerization of diallycarbonate and hexa(allylcarbonate) monomers and their thermal properties

    International Nuclear Information System (INIS)

    Herrera-González, A M; García-Serrano, J; Pelaez-Cid, A A; Montalvo-Sierra, I

    2013-01-01

    Polymers have had a significant increase in the industrial field, and polycarbonates (PCs) are an example. PCs have important properties such as high impact resistance, high heat capability, hardness, toughness, optical clarity, heat resistance, abrasion resistance and high refractive index. PCs with these properties have a variety of applications, for example, astronaut helmets, CDs/ DVDs, automobile parts, bulletproof windows, ophthalmic lenses and welding masks. In the present work we report the synthesis and characterization of network polycarbonates, based (1,1'-biphenyl)-4,4'-diyldiallylcarbonate (I) and hexa(4-allylcarbonatephenoxy) cyclotriphosphazene (III). The polycarbonates were obtained by bulk polymerization technique. The polymers obtained with thermal initiators showed degrees of cross-linking greater than 80%. The PCs obtained have thermal stability to 250 °C. The polycarbonate obtained from the monomer III showed a limiting oxygen index of 46.3%, therefore this polymer can be considered potentially useful as flame-retardant.

  7. Role of Monomer Sequence, Hydrogen Bonding and Mesoscale Architecture in Marine Antifouling Coatings

    Science.gov (United States)

    Segalman, Rachel

    Polypeptoids are non-natural, sequence specific polymers that offer the opportunity to probe the effect of monomer sequence, chirality, and chain shape on self-assembly and surface properties. Additionally, polypeptoid synthesis is more scaleable than traditional polypeptides suggesting their utility in large area applications. We have designed efficient marine anti-fouling coatings by using triblock copolymer scaffolds to which polypeptoids are tethered in order to tune both the modulus and surface energies with great precision. Surprisingly, when short sequences are tethered to a polymer backbone, polypeptoids consistently outperform analogous polypeptides in antifouling properties. We hypothesize that the hydrogen bonding inherent to the polypeptide backbone drives the observed differences in performance. We also find that the polymer scaffold housing the polypeptoids also plays a crucial role in directing surface presentation and therefore the overall coating properties.

  8. Chemical synthesis of human papillomavirus type 16 E7 oncoprotein: autonomous protein domains for induction of cellular DNA synthesis and for trans activation.

    Science.gov (United States)

    Rawls, J A; Pusztai, R; Green, M

    1990-12-01

    The human papillomavirus type 16 E7 protein belongs to a family of nuclear oncoproteins that share amino acid sequences and functional homology. To localize biochemical activities associated with E7, we chemically synthesized the full-length 98-amino-acid polypeptide and several deletion mutant peptides. We show that the E7 polypeptide is biologically active and possesses at least two functional domains; the first induces cellular DNA synthesis in quiescent rodent cells, and the second trans activates the adenovirus E1A-inducible early E2 promoter and binds zinc. Further, each domain is autonomous and can function on separate peptides. DNA synthesis induction activity maps within the N-terminal portion of the molecule, which contains sequences related to adenovirus E1A conserved domains 1 and 2 required for cell transformation and binding of the retinoblastoma gene product. trans-Activation and Zn-binding activities map within the C-terminal portion of the molecule, a region which contains Cys-X-X-Cys motifs. trans Activation does not require protein synthesis, implying a mechanism that involves interaction with a preexisting cellular factor(s). E7 trans activates the adenovirus E2 promoter but not other E1A-inducible viral promoters, suggesting the possibility that E7 trans activation involves interaction, directly or indirectly, with cellular transcription factor E2F.

  9. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis.

    Science.gov (United States)

    Shaw, Gregory; Lee-Barthel, Ann; Ross, Megan Lr; Wang, Bing; Baar, Keith

    2017-01-01

    Musculoskeletal injuries are the most common complaint in active populations. More than 50% of all injuries in sports can be classified as sprains, strains, ruptures, or breaks of musculoskeletal tissues. Nutritional and/or exercise interventions that increase collagen synthesis and strengthen these tissues could have an important effect on injury rates. This study was designed to determine whether gelatin supplementation could increase collagen synthesis. Eight healthy male subjects completed a randomized, double-blinded, crossover-design study in which they consumed either 5 or 15 g of vitamin C-enriched gelatin or a placebo control. After the initial drink, blood was taken every 30 min to determine amino acid content in the blood. A larger blood sample was taken before and 1 h after consumption of gelatin for treatment of engineered ligaments. One hour after the initial supplement, the subjects completed 6 min of rope-skipping to stimulate collagen synthesis. This pattern of supplementation was repeated 3 times/d with ≥6 h between exercise bouts for 3 d. Blood was drawn before and 4, 24, 48, and 72 h after the first exercise bout for determination of amino-terminal propeptide of collagen I content. Supplementation with increasing amounts of gelatin increased circulating glycine, proline, hydroxyproline, and hydroxylysine, peaking 1 h after the supplement was given. Engineered ligaments treated for 6 d with serum from samples collected before or 1 h after subjects consumed a placebo or 5 or 15 g gelatin showed increased collagen content and improved mechanics. Subjects who took 15 g gelatin 1 h before exercise showed double the amino-terminal propeptide of collagen I in their blood, indicating increased collagen synthesis. These data suggest that adding gelatin to an intermittent exercise program improves collagen synthesis and could play a beneficial role in injury prevention and tissue repair. This trial was registered at the Australian New Zealand Clinical

  10. Synthesis and Cytotoxic Activities of Difluoro-Dimethoxy Chalcones.

    Science.gov (United States)

    Yamali, Cem; Gul, Halise Inci; Ozgun, Dilan Ozmen; Sakagam, Hiroshi; Umemura, Naoki; Kazaz, Cavit; Gul, Mustafa

    2017-01-01

    Although anticancer chemotherapeutics are available in markets, side effects related to the drugs in clinical use lead to researchers to investigate new drug candidates which are more safe, potent and selective than others. Chalcones are popular with their anticancer activities with the several reported mechanisms including inhibition of angiogenesis, inhibition of tubulin polymerization, and induction of apoptosis etc. This study was focused on to synthesize of 1-(2,4/2,6-difluorophenyl)-3-(2,3/2,4/2,5/3,4- dimethoxyphenyl)-2-propen-1-ones (1-8) and investigate their cytotoxic properties with possible mechanism of action. The compounds were synthesized by Claisen-Schmidt condensation. The chemical structures were confirmed by 1H NMR, 13C NMR, DEPT, COSY, HMQC, HMBC, 19F NMR and HRMS. In vitro cytotoxic effects of the compounds against human tumour cell lines [gingival carcinoma (Ca9-22), oral squamous cell carcinoma (HSC-2)] and human normal oral cells [gingival fibroblasts (HGF), periodontal ligament fibroblasts (HPLF)] were evaluated via MTT test. All compounds had higher cytotoxicity than reference compound 5-Fluorouracil (5-FU). The compounds 3-7 had higher potency selectivity expression values (PSE) than 5-FU and PSE values of the compounds were over 100. All chalcone derivatives seem good candidates for further studies according to very remarkable and high PSE values. It was clearly demonstrated that compound 7 can induce early apoptosis at a concentration of 10 µM and dose-dependent late apoptosis starting at 10 µM. Compound 7 induced cleavage of the apoptosis marker PARP. The results indicate that new chalcones reported here can promote apoptosis in human tumour cell lines. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Synthesis,

    Directory of Open Access Journals (Sweden)

    Ganesan Vanangamudi

    2017-02-01

    Full Text Available Twelve 2,5-dimethyl-3-thienyl chalcones [E-1-(2,5-dimethyl-3-thienyl-3-(substituted phenyl-2-propen-1-ones] have been synthesized by Claisen–Schmidt condensation of 3-acetyl-2,5-dimethyl furon and substituted benzaldehydes. Yields of the chalcones are more than 80%. These chalcones were characterized by their physical constants and spectral data. The group frequencies of infrared ν(cm−1 of CO s-cis and s-trans, CH in-plane and out of plane, CHCH out of plane, >CC< out of plane modes, NMR chemical shifts δ(ppm of Hα, Hβ, CO, Cα and Cβ of these chalcones were correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituents on the group frequencies are explained. Antibacterial, antifungal, antioxidant and insect antifeedant activities of these chalcones have been studied.

  12. Binding interactions between suberin monomer components and pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Olivella, M.À., E-mail: angels.olivella@udg.edu [Department of Chemical Engineering, Escola Politècnica Superior, Universitat de Girona, Maria Aurèlia Capmany, 61, 17071 Girona (Spain); Bazzicalupi, C.; Bianchi, A. [Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia, 3, 50019 Sesto Fiorentino (Italy); Río, J.C. del [Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, P.O. Box 1052, 41080 Seville (Spain); Fiol, N.; Villaescusa, I. [Department of Chemical Engineering, Escola Politècnica Superior, Universitat de Girona, Maria Aurèlia Capmany, 61, 17071 Girona (Spain)

    2015-09-15

    Understanding the role of biomacromolecules and their interactions with pollutants is a key for elucidating the sorption mechanisms and making an accurate assessment of the environmental fate of pollutants. The knowledge of the sorption properties of the different constituents of these biomacromolecules may furnish a significant contribution to this purpose. Suberin is a very abundant biopolymer in higher plants. In this study, suberin monomers isolated from cork were analyzed by thermally-assisted methylation with tetramethylammonium hydroxide (TMAH) in a pyrolysis unit coupled to gas chromatography–mass spectrometry (GC/MS). The isolated monomer mixture was used to study the sorption of three pesticides (isoproturon, methomyl and oxamyl). The modes of pesticide–sorbent interactions were analyzed by means of two modeling calculations, the first one representing only the mixture of suberin monomers used in the sorption study, and the second one including glycerol to the mixture of suberin monomers, as a building block of the suberin molecule. The results indicated that the highest sorption capacity exhibited by the sorbent was for isoproturon (33%) being methomyl and oxamyl sorbed by the main suberin components to a lesser extent (3% and < 1%, respectively). In addition to van der Waals interactions with the apolar region of sorbent and isoproturon, modeling calculations evidenced the formation of a hydrogen bond between the isoproturon NH group and a carboxylic oxygen atom of a suberin monomer. In the case of methomyl and oxamyl only weak van der Waals interactions stabilize the pesticide–sorbent adducts. The presence of glycerol in the model provoked significant changes in the interactions with isoproturon and methomyl. - Highlights: • Suberin has low affinity to retain pesticides of aliphatic character. • Suberin has a moderate affinity to adsorb isoproturon. • Modeling calculations show that apolar portion of suberin interacts with isoproturon.

  13. Design, synthesis, antinociceptive and anti-inflammatory activities of novel piroxicam analogues.

    Science.gov (United States)

    de Miranda, Amanda Silva; Bispo Júnior, Walfrido; da Silva, Yolanda Karla Cupertino; Alexandre-Moreira, Magna Suzana; Castro, Rosane de Paula; Sabino, José Ricardo; Lião, Luciano Morais; Lima, Lídia Moreira; Barreiro, Eliezer J

    2012-11-28

    In this paper we report the design, synthesis, antinociceptive and anti-inflammatory activities of a series of benzothiazine N-acylhydrazones 14a–h, planned by structural modification of piroxicam (1), a non steroidal anti-inflammatory drug. Among the synthesized analogues, compounds 14f (LASSBio-1637) and 14g (LASSBio-1639) were identified as novel antinociceptive and anti-inflammatory prototypes, active by oral administration, acting by a mechanism of action that seems to be different from that of piroxicam, since they were inactive as an inhibitor of cyclooxygenase (COX-1 and COX-2) at concentrations of 10 mM.

  14. Design, Synthesis, Antinociceptive and Anti-Inflammatory Activities of Novel Piroxicam Analogues

    Directory of Open Access Journals (Sweden)

    Eliezer J. Barreiro

    2012-11-01

    Full Text Available In this paper we report the design, synthesis, antinociceptive and anti-inflammatory activities of a series of benzothiazine N-acylhydrazones 14a–h, planned by structural modification of piroxicam (1, a non steroidal anti-inflammatory drug. Among the synthesized analogues, compounds 14f (LASSBio-1637 and 14g (LASSBio-1639 were identified as novel antinociceptive and anti-inflammatory prototypes, active by oral administration, acting by a mechanism of action that seems to be different from that of piroxicam, since they were inactive as an inhibitor of cyclooxygenase (COX-1 and COX-2 at concentrations of 10 mM.

  15. Synthesis and antibacterial activity of 2-amino chromenes arising cyanoiminocoumarins and β-naphthol

    Directory of Open Access Journals (Sweden)

    Lamia Dammak

    2017-01-01

    Full Text Available The synthesis of 2-amino chromene, reported in our previous paper, has been accomplished by the reaction of cyanoiminocoumarin and β-naphthol . The obtained compound was reacted with various electrophilic or nucleophilic reagents. All the new homologous 2-amino-4H-chromenes have been characterized on the basis of their spectral (IR, 1H and 13C NMR data and microanalysis. Four compounds were evaluated in vitro for their preliminary antibacterial activities against five different pathogenic bacterial strains such as Bacillus thuringiensis , Escherichia coli , Staphylococcus aureus, klebsiella pneumonia and Salmonella Sp . Antibacterial activity of each compound was compared with standard drug, Penicillin .

  16. Synthesis of furanone-based natural product analogues with quorum sensing antagonist activity

    DEFF Research Database (Denmark)

    Hjelmgaard, Thomas; Persson, T.; Rasmussen, Thomas Bovbjerg

    2003-01-01

    The synthesis of 5- and 3-(1'-hydroxyalkyl)-substituted 5H-furan-2-ones 4a-d and 8a-d as well as 5-alkylidene-5H-furan-2-ones 5a-d is described. A study of the structure-activity relationship of these furanone-based natural product analogues towards two different quorum sensing systems is reporte....... Although the synthesized compounds are not as potent quorum sensing inhibitors as some natural counterparts and a synthetic analogue hereof, interesting structure-activity relationships are seen....

  17. Dioscorea bulbifera Mediated Synthesis of Novel AucoreAgshell Nanoparticles with Potent Antibiofilm and Antileishmanial Activity

    Directory of Open Access Journals (Sweden)

    Sougata Ghosh

    2015-01-01

    Full Text Available Dioscorea bulbifera is a potent medicinal plant used in both Indian and Chinese traditional medicine owing to its rich phytochemical diversity. Herein, we report the rapid synthesis of novel AucoreAgshell nanoparticles by D. bulbifera tuber extract (DBTE. AucoreAgshell NPs synthesis was completed within 5 h showing a prominent peak at 540 nm. HRTEM analysis revealed 9 nm inner core of elemental gold covered by a silver shell giving a total particle diameter upto 15 nm. AucoreAgshellNPs were comprised of 57.34±1.01% gold and 42.66±0.97% silver of the total mass. AucoreAgshellNPs showed highest biofilm inhibition upto 83.68±0.09% against A. baumannii. Biofilms of P. aeruginosa, E. coli, and S. aureus were inhibited up to 18.93±1.94%, 22.33±0.56%, and 30.70±1.33%, respectively. Scanning electron microscopy (SEM and atomic force microscopy (AFM confirmed unregulated cellular efflux through pore formation leading to cell death. Potent antileishmanial activity of AucoreAgshellNPs (MIC=32 µg/mL was confirmed by MTT assay. Further SEM micrographs showed pronounced deformity in the spindle shaped cellular morphology changing to spherical. This is the first report of synthesis, characterization, antibiofilm, and antileishmanial activity of AucoreAgshellNPs synthesized by D. bulbifera.

  18. Synthesis of monodispersed silver nanoparticles using Hibiscus cannabinus leaf extract and its antimicrobial activity

    Science.gov (United States)

    Bindhu, M. R.; Umadevi, M.

    2013-01-01

    Synthesis of silver nanoparticles using leaf extract of Hibiscus cannabinus has been investigated. The influences of different concentration of H. cannabinus leaf extract, different metal ion concentration and different reaction time on the above cases on the synthesis of nanoparticles were evaluated. The synthesized nanoparticles were characterized using UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). The prepared silver nanoparticles were monodispersed, spherical in shape with the average particle size of 9 nm and shows surface plasmon peak at 446 nm. The study also reveals that the ascorbic acid present in H. cannabinus leaf extract has been used as reducing agent. The prepared silver nanoparticle shows good antimicrobial activity against Escherichia coli, Proteus mirabilis and Shigella flexneri.

  19. Eco-friendly synthesis and potent antifungal activity of 2-substituted coumaran-3-ones

    Directory of Open Access Journals (Sweden)

    PRABHA SOLANKI

    2012-11-01

    Full Text Available Solanki P, Shekhawat P. 2012. Eco-friendly synthesis and potent antifungal activity of 2-substituted coumaran-3-ones. Nusantara Bioscience 4: 101-104. 3-halochromones (IIa-c and IIIa-c have been synthesized by treating 1- (2-hydroxyphenyl-3-methyl-1,3-propanediones (Ia-c with bromine or sulphuryl chloride in dioxane respectively. These chromones were employed in the synthesis of 2-acetyl-coumaran-3-ones (IVa-f. These were subjected to Knoevenagel condensation to give 2-cinnamoyl coumaran-3-ones. In vitro assay and field trials of these compounds against Fusarium oxysporum were carried out to study the antifungal effect of target compounds. Compound Va was the most effective growth inhibitor of the pathogen, whereas Vc showd a little tendency and Vb, Vd, Ve and Vf hardly inhibits the growth

  20. Antibacterial Activity of Green Synthesis of Iron Nanoparticles Using Lawsonia inermis and Gardenia jasminoides Leaves Extract

    Directory of Open Access Journals (Sweden)

    Tayyaba Naseem

    2015-01-01

    Full Text Available Recently, development of reliable experimental protocols for synthesis of metal nanoparticles with desired morphologies and sizes has become a major focus of researchers. Green synthesis of metallic nanoparticles has accumulated an ultimate interest over the last decade due to their distinctive properties that make them applicable in various fields of science and technology. Metal nanoparticles that are synthesized by using plants have emerged as nontoxic and ecofriendly. In this study a very cheap and simple conventional heating method was used to obtain the iron nanoparticles (FeNPs using the leaves extract of Lawsonia inermis and Gardenia jasminoides plant. The iron nanoparticles were characterized by thermal gravimetric analysis (TGA, Fourier transform infrared spectroscopy (FT-IR, transmission electron microscopy (TEM, scanning electron microscopy (SEM, atomic force microscopy (AFM, and X-ray diffraction (XRD. The antibacterial activity was studied against Escherichia coli, Salmonella enterica, Proteus mirabilis, and Staphylococcus aureus by using well-diffusion method.

  1. Stereoselective Catalytic Synthesis of Active Pharmaceutical Ingredients in Homemade 3D-Printed Mesoreactors.

    Science.gov (United States)

    Rossi, Sergio; Porta, Riccardo; Brenna, Davide; Puglisi, Alessandra; Benaglia, Maurizio

    2017-04-03

    3D-printed flow reactors were designed, fabricated from different materials (PLA, HIPS, nylon), and used for a catalytic stereoselective Henry reaction. The use of readily prepared and tunable 3D-printed reactors enabled the rapid screening of devices with different sizes, shapes, and channel dimensions, aimed at the identification of the best-performing reactor setup. The optimized process afforded the products in high yields, moderate diastereoselectivity, and up to 90 % ee. The method was applied to the continuous-flow synthesis of biologically active chiral 1,2-amino alcohols (norephedrine, metaraminol, and methoxamine) through a two-step sequence combining the nitroaldol reaction with a hydrogenation. To highlight potential industrial applications of this method, a multistep continuous synthesis of norephedrine has been realized. The product was isolated without any intermediate purifications or solvent switches. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Tryptophan-Assisted Synthesis Reduces Bimetallic Gold/Silver Nanoparticle Cytotoxicity and Improves Biological Activity

    Directory of Open Access Journals (Sweden)

    Igor O. Shmarakov

    2014-10-01

    Full Text Available Aiming to reduce the potential in vivo hepato-and nephrotoxicity of Ag/Au bimetallic nanoparticles (NPs stabilized by sodium dodecyl sulphate (SDS, an approach involving a simultaneous reduction of silver nitrate and tetrachlorauratic acid using tryptophan (Trp as a reducing/stabilizing agent was applied during NP synthesis. The obtained Ag/Au/Trp NPs (5–15 nm sized were able to form stable aggregates with an average size of 370–450 nm and were potentially less toxic than Ag/Au/SDS in relation to a mouse model system based on clinical biochemical parameters and oxidative damage product estimation. Ag/Au/Trp NPs were shown to exhibit anticancer activity in relation to a Lewis lung carcinoma model. The data generated from the present study support the fact that the use of tryptophan in NP synthesis is effective in attenuating the potential hepatotoxicity and nephrotoxicity of NPs during their in vivo application.

  3. Synthesis activity-based zymography for detection of lipases and esterases.

    Science.gov (United States)

    Kwon, Min-A; Kim, Hyun Suk; Hahm, Dae-Hyun; Song, Jae Kwang

    2011-04-01

    A new zymography method for lipases and esterases was developed on the basis of the esterification reaction between fatty acids and alcohols. The enzymes were separated by SDS-PAGE and native PAGE. The gel was washed and then incubated in an aqueous solution containing fatty acids (oleic acid 18:1 or caprylic acid 8:0) and dodecanol. Synthesis was visualized by in situ precipitation of water-insoluble and non-diffusible fatty acid esters, such as dodecyl oleate and dodecyl octanoate. The synthesis activity-based zymography was confirmed with different enzyme samples, including commercial lipase preparations, purified recombinant lipase and cutinase, and crude culture supernatants of lipolytic enzyme-producing soil bacteria.

  4. DNA polymerase-α regulates type I interferon activation through cytosolic RNA:DNA synthesis

    Science.gov (United States)

    Starokadomskyy, Petro; Gemelli, Terry; Rios, Jonathan J.; Xing, Chao; Wang, Richard C.; Li, Haiying; Pokatayev, Vladislav; Dozmorov, Igor; Khan, Shaheen; Miyata, Naoteru; Fraile, Guadalupe; Raj, Prithvi; Xu, Zhe; Xu, Zigang; Ma, Lin; Lin, Zhimiao; Wang, Huijun; Yang, Yong; Ben-Amitai, Dan; Orenstein, Naama; Mussaffi, Huda; Baselga, Eulalia; Tadini, Gianluca; Grunebaum, Eyal; Sarajlija, Adrijan; Krzewski, Konrad; Wakeland, Edward K.; Yan, Nan; de la Morena, Maria Teresa; Zinn, Andrew R.; Burstein, Ezra

    2016-01-01

    Aberrant nucleic acids generated during viral replication are the main trigger for antiviral immunity, and mutations disrupting nucleic acid metabolism can lead to autoinflammatory disorders. Here we investigated the etiology of X-linked reticulate pigmentary disorder (XLPDR), a primary immunodeficiency with autoinflammatory features. We discovered that XLPDR is caused by an intronic mutation that disrupts expression of POLA1, the gene encoding the catalytic subunit of DNA polymerase-α. Unexpectedly, POLA1 deficiency results in increased type I interferon production. This enzyme is necessary for RNA:DNA primer synthesis during DNA replication and strikingly, POLA1 is also required for the synthesis of cytosolic RNA:DNA, which directly modulates interferon activation. Altogether, this work identified POLA1 as a critical regulator of the type I interferon response. PMID:27019227

  5. Phoenix dactylifera L. leaf extract phytosynthesized gold nanoparticles; controlled synthesis and catalytic activity

    Science.gov (United States)

    Zayed, Mervat F.; Eisa, Wael H.

    2014-03-01

    A green synthesis route was reported to explore the reducing and capping potential of Phoenix dactylifera extract for the synthesis of gold nanoparticles. The processes of nucleation and growth of gold nanoparticles were followed by monitoring the absorption spectra during the reaction. The size and morphology of these nanoparticles was typically imaged using transmission electron microscopy (TEM). The particle size ranged between 32 and 45 nm and are spherical in shape. Fourier transform infrared (FTIR) analysis suggests that the synthesized gold nanoparticles might be stabilized through the interactions of hydroxyl and carbonyl groups in the carbohydrates, flavonoids, tannins and phenolic acids present in P. dactylifera. The as-synthesized Au colloids exhibited good catalytic activity for the degradation of 4-nitrophenol.

  6. Microbially supported synthesis of catalytically active bimetallic Pd-Au nanoparticles

    DEFF Research Database (Denmark)

    Hosseinkhani, Baharak; Søbjerg, Lina Sveidal; Rotaru, Amelia-Elena

    2012-01-01

    Bimetallic nanoparticles are considered the next generation of nanocatalysts with increased stability and catalytic activity. Bio-supported synthesis of monometallic nanoparticles has been proposed as an environmentally friendly alternative to the conventional chemical and physical protocols....... In this study we synthesize bimetallic bio-supported Pd-Au nanoparticles for the first time using microorganisms as support material. The synthesis involved two steps: (1) Formation of monometallic bio-supported Pd(0) and Au(0) nanoparticles on the surface of Cupriavidus necator cells, and (2) formation...... of bimetallic bio-supported nanoparticles by reduction of either Au(III) or Pd(II) on to the nanoparticles prepared in step one. Bio-supported monometallic Pd(0) or Au(0) nanoparticles were formed on the surface of C. necator by reduction of Pd(II) or Au(III) with formate. Addition of Au(III) or Pd...

  7. Synthesis of gold nanoparticles using renewable Punica granatum juice and study of its catalytic activity

    Science.gov (United States)

    Dash, Shib Shankar; Bag, Braja Gopal

    2014-01-01

    Punica granatum juice, a delicious multivitamin drink of great medicinal significance, is rich in different types of phytochemicals, such as terpenoids, alkaloids, sterols, polyphenols, sugars, fatty acids, aromatic compounds, amino acids, tocopherols, etc. We have demonstrated the use of the juice for the synthesis of gold nanoparticles (AuNPs) at room temperature under very mild conditions. The synthesis of the AuNPs was complete in few minutes and no extra stabilizing or capping agents were necessary. The size of the nanoparticles could be controlled by varying the concentration of the fruit extract. The AuNPs were characterized by surface plasmon resonance spectroscopy, high resolution transmission electron microscopy, fourier transform infrared spectroscopy and X-ray diffraction studies. Catalytic activity of the synthesized colloidal AuNPs has also been demonstrated.

  8. Controlled green synthesis of silver nanoparticles by Allium cepa and Musa acuminata with strong antimicrobial activity

    Science.gov (United States)

    Sahni, Geetika; Panwar, Amit; Kaur, Balpreet

    2015-02-01

    A controlled "green synthesis" approach to synthesize silver nanoparticles by Allium cepa and Musa acuminata plant extract has been reported. The effect of different process parameters, such as pH, temperature and time, on synthesis of Ag nanoparticles from plant extracts has been highlighted. The work reports an easy approach to control the kinetics of interaction of metal ions with reducing agents, stabilized by ammonia to achieve sub-10 nm particles with narrow size distribution. The nanoparticles have been characterized by UV-Visible spectra and TEM analysis. Excellent antimicrobial activity at extremely low concentration of the nanoparticles was observed against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Fusarium oxysporum which may allow their exploitation as a new generation nanoproduct in biomedical and agricultural applications.

  9. Coleus aromaticus leaf extract mediated synthesis of silver nanoparticles and its bactericidal activity

    Science.gov (United States)

    Vanaja, Mahendran; Annadurai, Gurusamy

    2013-06-01

    The utilization of various plant resources for the biosynthesis of metallic nanoparticles is called green nanotechnology, and it does not utilize any harmful chemical protocols. The present study reports the plant-mediated synthesis of silver nanoparticles using the plant leaf extract of Coleus aromaticus, which acts as a reducing and capping agent. The silver nanoparticles were characterized by ultraviolet visible spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and the size of the silver nanoparticles is 44 nm. The bactericidal activity of the silver nanoparticles was carried out by disc diffusion method that showed high toxicity against Bacillus subtilis and Klebsiella planticola. Biosynthesis of silver nanoparticles by using plant resources is an eco-friendly, reliable process and suitable for large-scale production. Moreover, it is easy to handle and a rapid process when compared to chemical, physical, and microbe-mediated synthesis process.

  10. Synthesis, antileishmanial activity and QSAR studies of 2-chloro- N -arylacetamides

    Directory of Open Access Journals (Sweden)

    Stefânia Neiva Lavorato

    2017-04-01

    Full Text Available ABSTRACT We describe herein the synthesis and evaluation of the antileishmanial activity against promastigote forms of Leishmania amazonensis and cytotoxicity to murine macrophages of a series of 2-chloro-N-arylacetamide derivatives. All compounds were active, except one (compound 3. Compound 5 presented the most promising results, showing good antileishmanial activity (CI50=5.39±0.67 µM and moderate selectivity (SI=6.36, indicating that further development of this class is worthwhile. Preliminary QSAR studies, although not predictive, furnished some insights on the importance of electronic character of aryl substituent to biological activity, as well as an indirect influence of hydrophobicity on activity.

  11. Multifunctional monomers based on vinyl sulfonates and vinyl sulfonamides for crosslinking thiol-Michael polymerizations: monomer reactivity and mechanical behavior.

    Science.gov (United States)

    Sinha, Jasmine; Podgórski, Maciej; Huang, Sijia; Bowman, Christopher N

    2018-03-25

    Multifunctional vinyl sulfonates and vinyl sulfonamides were conveniently synthesized and assessed in thiol-Michael crosslinking polymerizations. The monomer reactivities, mechanical behavior and hydrolytic properties were analyzed and compared with those of analogous thiol-acrylate polymerizations. Materials with a broad range of mechanical properties and diverse hydrolytic stabilities were obtained.

  12. Novel 2-(ω-phosphonooxy-2-oxaalkylacrylate monomers for self-etching self-priming one part adhesive

    Directory of Open Access Journals (Sweden)

    Joachim E. Klee

    2010-09-01

    Full Text Available Novel hydrolysis stable 2-(ω-phosphonooxy-2-oxaalkylacrylate monomers 3 with phosphoric acid moieties were synthesized by a three step synthesis via Baylis–Hillman reaction of ethyl acrylate and formaldehyde, and subsequent etherification of the obtained product with diols and phosphorylation using POCl3. The polymerization enthalpy of 2-(ω-phosphonooxy-2-oxaalkylacrylates 3 as measured by DSC ranges from −29 to −53 kJ·mol−1. The shear bond strength of adhesive compositions 4, comprising of polymerizable acids 3, ranges from 5.8 to 19.3 MPa on enamel and from 8.7 to 16.9 MPa on dentin.

  13. Calcineurin /NFAT activation-dependence of leptin synthesis and vascular growth in response to mechanical stretch

    Directory of Open Access Journals (Sweden)

    Nadia Soudani

    2016-09-01

    Full Text Available Background and Aims- Hypertension and obesity are important risk factors of cardiovascular disease. They are both associated with high leptin levels and have been shown to promote vascular hypertrophy, through the RhoA/ROCK and ERK1/2 phosphorylation. Calcineurin/NFAT activation also induces vascular hypertrophy by upregulating various genes. This study aimed to decipher whether a crosstalk exists between the RhoA/ROCK pathway, Ca+2/calcineurin/NFAT pathway, and ERK1/2 phosphorylation in the process of mechanical stretch-induced vascular smooth muscle cell (VSMC hypertrophy and leptin synthesis. Methods and Results- Rat portal vein (RPV organ culture was used to investigate the effect of mechanical stretch and exogenous leptin (3.1 nM on VSMC hypertrophy and leptin synthesis. Results showed that stretching the RPV significantly upregulated leptin secretion, mRNA and protein expression, which were inhibited by the calcium channel blocker nifedipine (10 μM, the selective calcineurin inhibitor FK506 (1 nM and the ERK1/2 inhibitor PD98059 (1 μM. The transcription inhibitor actinomycin D (0.1M and the translation inhibitor cycloheximide (1 mM significantly decreased stretch-induced leptin protein expression. Mechanical stretch or leptin caused an increase in wet weight changes and protein synthesis, considered as hypertrophic markers, while they were inhibited by FK506 (0.1 nM; 1 nM. In addition, stretch or exogenous leptin significantly increased calcineurin activity and MCIP1 expression whereas leptin induced NFAT nuclear translocation in VSMCs. Moreover, in response to stretch or exogenous leptin, the Rho inhibitor C3 exoenzyme (30 ng/mL, the ROCK inhibitor Y-27632 (10 μM, and the actin depolymerization agents Latrunculin B (50 nM and cytochalasin D (1 μM reduced calcineurin activation and NFAT nuclear translocation. ERK1/2 phosphorylation was inhibited by FK506 and C3. Conclusions- Mechanical stretch-induced VSMC hypertrophy and leptin

  14. Chemical synthesis of human papillomavirus type 16 E7 oncoprotein: autonomous protein domains for induction of cellular DNA synthesis and for trans activation.

    OpenAIRE

    Rawls, J A; Pusztai, R; Green, M

    1990-01-01

    The human papillomavirus type 16 E7 protein belongs to a family of nuclear oncoproteins that share amino acid sequences and functional homology. To localize biochemical activities associated with E7, we chemically synthesized the full-length 98-amino-acid polypeptide and several deletion mutant peptides. We show that the E7 polypeptide is biologically active and possesses at least two functional domains; the first induces cellular DNA synthesis in quiescent rodent cells, and the second trans ...

  15. [Synthesis of phosphonic acid and phosphinic acid derivatives for development of biologically active compounds].

    Science.gov (United States)

    Shibuya, Shiroshi

    2004-11-01

    -difluoromethylenenphosphonates. The method was applied to a synthesis of PNP-inhibitory active compounds by combination of the purine base and alcohols containing difluoromethylenephosphonate. The methodology for the beta-selective N-glycosylation of 2,3-dideoxy glucoside was established by introducing phosphonothioates at the 3-position of glycosyl doners instead of phosphonate. Synthesis of new acylic nucleotide analogues designed based on the structural modification of ARS2267 is also described. Finally, kiral synthesis of some phosphonates was achieved using lipase through kinetic resolution.

  16. Mechanism of plant-mediated synthesis of silver nanoparticles - A review on biomolecules involved, characterisation and antibacterial activity.

    Science.gov (United States)

    Rajeshkumar, S; Bharath, L V

    2017-08-01

    Engineering a reliable and eco-accommodating methodology for the synthesis of metal nanoparticles is a crucial step in the field of nanotechnology. Plant-mediated synthesis of metal nanoparticles has been developed as a substitute to defeat the limitations of conventional synthesis approaches such as physical and chemical methods. Biomolecules, such as proteins, amino acids, enzymes, flavonoids, and terpenoids from several plant extracts have been used as a stabilising and reducing agents for the synthesis of AgNPs. Regardless of an extensive range of biomolecules assistance in the synthesis procedure, researchers are facing a significant challenge to synthesise stable and geometrically controlled AgNPs. In the past decade, several efforts were made to develop Plant-mediated synthesis methods to produce stable, cost effective and eco-friendly AgNPs. More than hundred different plants extract sources for synthesising AgNPs were described in the last decade by several researchers. Most of the reviews were focused on various plant sources for synthesis, various characterization techniques for characteristic analysis, and antibacterial activity against bacterial. There are many reviews are available for the plant-mediated synthesis of AgNPs as well as antibacterial activity of AgNPs but this is the first review article mainly focused on biomolecules of plants and its various parts and operating conditions involved in the synthesis. Apart from, this review includes the characterisation of AgNPs and antibacterial activity of such nanoparticles with size, shape and method used for this study. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Indatraline: Synthesis and Effect on the Motor Activity of Wistar Rats

    Directory of Open Access Journals (Sweden)

    Luiz F. Silva, Jr.

    2011-11-01

    Full Text Available A new approach for the synthesis of indatraline was developed using as the key step an iodine(III-mediated ring contraction of a 1,2-dihydronaphthalene derivative. Behavioral tests were conducted to evaluate the effect of indatraline and of its precursor indanamide on the motor activity of Wistar rats. Specific indexes for ambulation, raising and stereotypy were computed one, two and three hours after i.p. drug administration. Indatraline effects on motor activity lasted for at least three hours. On the other hand, no significant differences in motor activity were observed using indanamide. The results suggest that indatraline has a long lasting effect on motor activity and add evidence in favor of the potential use of that compound as a substitute in cocaine addiction.

  18. Article Synthesis and Trypanocidal Activity of Novel 2,4,5-Triaryl-N-Hydroxylimidazole Derivatives

    Directory of Open Access Journals (Sweden)

    Edson Ferreira da Silva

    2013-03-01

    Full Text Available Herein, we report the design, synthesis and trypanocidal activity of some novel trisubstituted imidazole derivatives. These heterocyclic derivatives were structurally planned by exploring the concept of molecular hybridisation between two arylhydrazones derived from megazol, which has potent trypanocidal activity. The trypanocidal activity of these triarylimidazole derivatives was evaluated against infective trypomastigote forms of T. cruzi and the derivative 2'-(4-bromophenyl-1-methyl-5'-phenyl-1H,3'H-2,4'-biimidazol-3'-ol showed moderate biological activity (IC50 = 23.9 µM when compared to benznidazole, a standard trypanocidal drug. These compounds did not present cytotoxic effects at concentrations near the trypanocidal IC50, being considered a good starting point for the development of new anti-Chagas drug candidates.

  19. Synthesis and biological activity of sulfur compounds showing structural analogy with combretastatin A-4

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Edson dos A. dos; Prado, Paulo C.; Carvalho, Wanderley R. de; Lima, Ricardo V. de; Beatriz, Adilson; Lima, Denis P. de, E-mail: denis.lima@ufms.br [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Departamento de Quimica; Hamel, Ernest [Screening Technologies Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD (United States); Dyba, Marzena A. [Basic Science Program , SAIC-Frederick, Inc., Structural Biophysics Laboratory National Cancer Institute, Frederick, MD (United States); Albuquerque, Sergio [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas

    2013-09-01

    We extended our previous exploration of sulfur bridges as bioisosteric replacements for atoms forming the bridge between the aromatic rings of combretastatin A-4. Employing coupling reactions between 5-iodo-1,2,3-trimethoxybenzene and substituted thiols, followed by oxidation to sulfones with m-CPBA, different locations for attaching the sulfur atom to ring A through the synthesis of nine compounds were examined. Antitubulin activity was performed with electrophoretically homogenous bovine brain tubulin, and activity occurred with the 1,2,3-trimethoxy-4-[(4-methoxyphenyl)thio]benzene (12), while the other compounds were inactive. The compounds were also tested for leishmanicidal activity using promastigote forms of Leishmania braziliensis (MHOM/BR175/M2904),and the greatest activity was observed with 1,2,3-trimethoxy-4-(phenylthio)benzene (10) and 1,2,3-trimethoxy-4-[(4-methoxyphenyl) sulfinyl]benzene (15). (author)

  20. Synthesis, antiproliferative and antimicrobial activity of new Mannich bases bearing 1,2,4-triazole moiety.

    Science.gov (United States)

    Popiołek, Łukasz; Rzymowska, Jolanta; Kosikowska, Urszula; Hordyjewska, Anna; Wujec, Monika; Malm, Anna

    2014-12-01

    Abstract This study presents the synthesis, antiproliferative and antimicrobial evaluation of a new series of Mannich base derivatives containing 1,2,4-triazole system. New compounds were prepared by the reaction of 4,5-disubstituted 1,2,4-triazole-3-thiones with formaldehyde and various amines. The structures of the prepared compounds were confirmed by means of (1)H NMR, (13)C NMR and elemental analyses. Twelve compounds were evaluated for their in vitro antiproliferative activities against six chosen cancer cell lines. All synthesized compounds were screened for their in vitro antimicrobial activity by using the agar dilution technique. For 17 potentially active compounds, their antibacterial activity was confirmed on the basis of MIC (minimal inhibitory concentration) by broth microdilution method using the reference Gram-positive and Gram-negative bacterial strains.