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Sample records for salicylaldehyde isonicotinoyl hydrazone

  1. Structure-activity relationships of novel salicylaldehyde isonicotinoyl hydrazone (SIH analogs: iron chelation, anti-oxidant and cytotoxic properties.

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    Eliška Potůčková

    Full Text Available Salicylaldehyde isonicotinoyl hydrazone (SIH is a lipophilic, tridentate iron chelator with marked anti-oxidant and modest cytotoxic activity against neoplastic cells. However, it has poor stability in an aqueous environment due to the rapid hydrolysis of its hydrazone bond. In this study, we synthesized a series of new SIH analogs (based on previously described aromatic ketones with improved hydrolytic stability. Their structure-activity relationships were assessed with respect to their stability in plasma, iron chelation efficacy, redox effects and cytotoxic activity against MCF-7 breast adenocarcinoma cells. Furthermore, studies assessed the cytotoxicity of these chelators and their ability to afford protection against hydrogen peroxide-induced oxidative injury in H9c2 cardiomyoblasts. The ligands with a reduced hydrazone bond, or the presence of bulky alkyl substituents near the hydrazone bond, showed severely limited biological activity. The introduction of a bromine substituent increased ligand-induced cytotoxicity to both cancer cells and H9c2 cardiomyoblasts. A similar effect was observed when the phenolic ring was exchanged with pyridine (i.e., changing the ligating site from O, N, O to N, N, O, which led to pro-oxidative effects. In contrast, compounds with long, flexible alkyl chains adjacent to the hydrazone bond exhibited specific cytotoxic effects against MCF-7 breast adenocarcinoma cells and low toxicity against H9c2 cardiomyoblasts. Hence, this study highlights important structure-activity relationships and provides insight into the further development of aroylhydrazone iron chelators with more potent and selective anti-neoplastic effects.

  2. Template synthesis, characterization and antimicrobial activity of some new complexes with isonicotinoyl hydrazone ligands

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    LIVIU MITU

    2009-09-01

    Full Text Available Complexes of Cu(II, Ni(II, Co(II with the 9-anthraldehyde iso-nicotinoyl hydrazone ligand (HL1 and the 3,5-di-tert-butyl-4-hydroxy-benzaldehyde isonicotinoyl hydrazone ligand (H2L2 were synthesized by the template method. The complexes were characterized by analytical analysis, IR, UV-Vis and ESR spectroscopy, magnetic measurements, conductometry and thermal analysis and the two ligands by 1H-NMR spectroscopy. From the elemental analysis, 1:2 (metal:ligand stoichiometry for the complexes of Cu(II, Ni(II with the ligands HL1 and H2L2 and 1:1 (metal:ligand stoichiometry for the complex of Co(II with the ligand HL1 are proposed. The molar conductance data showed that the complexes are non-electrolytes. The magnetic susceptibility results coupled with the electronic and ESR spectra suggested a distorted octahedral geometry for the complexes Ni(II/HL1, Ni(II/H2L2 and Cu(II/H2L2, a tetrahedral stereochemistry for the complex Cu/HL1 and a square-planar geometry for the complex Co/HL1. The IR spectra demonstrated the bidentate coordination of the ligands HL1 and H2L2 by the O=C amide oxygen and the azomethine nitrogen, as well as monodentate coordination of the ligand HL1 by the azomethine nitrogen in the Cu(IIcomplex. The antibacterial activity of the ligands and their metallic complexes were tested against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae.

  3. Spectrophotometric determination of some metal ions using hydrazones

    International Nuclear Information System (INIS)

    Mohammed, M. S.

    2000-05-01

    In this research many starting materials were prepared, like methyl salicylate and salicylic acid hydrazide from which different derivatives of hydrazones were synthesized by coupling with carbonyl compounds like benzil monoxime and benzil mono hydrazone which are prepared and others like salicylaldehyde and benzoin. The hydrazones that were synthesized are salicylaldehyde salicylic acid hydrazone, benzoin salicylic acid hydrazone, benzil mono hydrazone salicylic acid hydrazone and benzil monoxime salicylic acid hydrazone. These reagents were determined by different methods, IR spectrophotometric determination, the nitrogen content method and melting point determination. These hydrazones act as ligands for determination of some metal ions by making different coloured complexes that were prepared for eight hydrazones with eight metal ions U (VI), Fe (II), Fe (III), Co (II), V (II), Mo (VI), Ni (II) and Cu (II). These complexes were determined by ultraviolet and visible spectrophotometer (UV/VIS) to detect their absorbance and wavelengths (λ max). The two hydrazones salicylaldehyde salicylic acid-hydrazone and benzoin salicylic acid hydrazone, were selected for determination of five metal ions (Fe (II), Fe (III), U (VI), Ni (II) and Cu (II)), using two micelles sodium n-dodecyl sulphate and pyridinium hexa decyl bromide mono hydrate. Their absorbance and wavelengths were detected using UV/VIS spectrophotometer. (Author)

  4. Structural and vibrational study of 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone - A potential metal-protein attenuating compound (MPAC) for the treatment of Alzheimer's disease

    Science.gov (United States)

    de Freitas, Leonardo Viana; da Silva, Cecilia C. P.; Ellena, Javier; Costa, Luiz Antônio Sodré; Rey, Nicolás A.

    2013-12-01

    A comprehensive structural and vibrational study of the potential metal-protein attenuating compound 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone is reported. X-ray diffraction data, as well as FT-IR and Raman frequencies, were compared with the respective theoretical values obtained from DFT calculations. Theory agrees well with experiment. In this context, an attempt of total assignment concerning the FT-IR and Raman spectra of the title compound was performed, shedding new light on previous partial assignments published elsewhere.

  5. A study of the mechanism of action of pyridoxal isonicotinoyl hydrazone at the cellular level using reticulocytes loaded with non-heme 59Fe

    International Nuclear Information System (INIS)

    Huang, A.R.; Ponka, P.; McGill Univ., Montreal, Quebec; Jewish General Hospital, Montreal, Quebec

    1983-01-01

    Pyridoxal isonicotinoyl hydrazone (PIH) has recently been identified as a new iron chelating agent with a high degree of iron mobilizing activity in vitro and in vivo which makes this compound a candidate drug in the treatment of iron overload. This study was undertaken to elucidate the mechanism of action of the iron mobilizing activity of PIH at the cellular level. An in vitro system of rabbit reticulocytes with a high level of non-heme 59 Fe was used as a model of iron overload. The effects of various biochemical and physiological manoeuvers on the mobilization of 59 Fe by PIH from the cells were studied. The fate of [ 14 C]-PIH in the in vitro system was also studied. Studies were also carried out using a crude mitochondrial fraction. (orig./AJ)

  6. Novel hydrazones – antioxidant potential and stabilization via polysaccharide particles

    International Nuclear Information System (INIS)

    Hristova-Avakumova, N; Hadjimitova, V; Nikolova-Mladenova, B; Yoncheva, K

    2017-01-01

    In this study, we aimed to: i) determine the impact of three new isonicotinoyl hydrazones derivatives in in vitro systems used to investigate free radical processes - radical scavenging approach (ABTS and DPPH) and iron induced peroxidation in lipid containing model systems and ii) evaluate the potential of polysaccharide-based particles to act as protective carriers preserving the antioxidant activity (AOA) of the tested compounds. The tested compounds revealed excellent antioxidant effectiveness in the ABTS system. In the DPPH radical scavenging assay the compounds exhibited very weak or absence of AOA. The data from the iron induced peroxidation methods disclosed better antioxidant properties of the derivatives in the system containing egg yolk homogenate which is more plausible compared to the lecithin containing one. The incorporation of a bromine atom on 5 th position in salicylaldehyde moiety is associated with diminishment of the radical scavenging activity in the systems containing stable free radicals but its AOA reduction after encapsulation during the storage was only 9.17%. The obtained data indicate that compounds have proven themselves as promising candidates for further evaluation as antioxidant agents. Their encapsulation in chitosan-alginate particles could be a useful approach for improving the stability of their antioxidant properties. (paper)

  7. Reversible photochromic system based on rhodamine B salicylaldehyde hydrazone metal complex.

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    Li, Kai; Xiang, Yu; Wang, Xiaoyan; Li, Ji; Hu, Rongrong; Tong, Aijun; Tang, Ben Zhong

    2014-01-29

    Photochromic molecules are widely applied in chemistry, physics, biology, and materials science. Although a few photochromic systems have been developed before, their applications are still limited by complicated synthesis, low fatigue resistance, or incomplete light conversion. Rhodamine is a class of dyes with excellent optical properties including long-wavelength absorption, large absorption coefficient, and high photostability in its ring-open form. It is an ideal chromophore for the development of new photochromic systems. However, known photochromic rhodamine derivatives, such as amides, exhibit only millisecond lifetimes in their colored ring-open forms, making their application very limited and difficult. In this work, rhodamine B salicylaldehyde hydrazone metal complex was found to undergo intramolecular ring-open reactions upon UV irradiation, which led to a distinct color and fluorescence change both in solution and in solid matrix. The complex showed good fatigue resistance for the reversible photochromism and long lifetime for the ring-open state. Interestingly, the thermal bleaching rate was tunable by using different metal ions, temperatures, solvents, and chemical substitutions. It was proposed that UV light promoted isomerization of the rhodamine B derivative from enol-form to keto-form, which induced ring-opening of the rhodamine spirolactam in the complex to generate color. The photochromic system was successfully applied for photoprinting and UV strength measurement in the solid state. As compared to other reported photochromic molecules, the system in this study has its advantages of facile synthesis and tunable thermal bleaching rate, and also provides new insights into the development of photochromic materials based on metal complex and spirolactam-containing dyes.

  8. Geoditin A Induces Oxidative Stress and Apoptosis on Human Colon HT29 Cells

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    Wing-Keung Liu

    2010-01-01

    Full Text Available Geoditin A, an isomalabaricane triterpene isolated from the marine sponge Geodia japonica, has been demonstrated to dissipate mitochondrial membrane potential, activate caspase 3, decrease cytoplasmic proliferating cell nuclear antigen (PCNA, and induce apoptosis of leukemia cells, but the underlying mechanism remains unclear [1]. In this study, we found fragmentation of Golgi structure, suppression of transferrin receptor expression, production of oxidants, and DNA fragmentation in human colon cancer HT29 cells after treatment with geoditin A for 24 h. This apoptosis was not abrogated by chelation of intracellular iron with salicylaldehyde isonicotinoyl hydrazone (SIH, but suppressed by N-acetylcysteine (NAC, a thiol antioxidant and GSH precursor, indicating that the cytotoxic effect of geoditin A is likely mediated by a NAC-inhibitable oxidative stress. Our results provide a better understanding of the apoptotic properties and chemotherapeutical potential of this marine triterpene.

  9. Halogenated salicylaldehyde azines: The heavy atom effect on aggregation-induced emission enhancement properties

    International Nuclear Information System (INIS)

    Chen, Xiao-tong; Tong, Ai-jun

    2014-01-01

    This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. For this purpose, a series of halogenated salicylaldehyde azine derivatives, namely, chloro-salicylaldehyde azine (1), bromo-salicylaldehyde azine (2) and iodo-salicylaldehyde azine (3) are synthesized. 1 and 2 display typical AIEE characteristics of salicylaldehyde azine compounds; whereas for the iodo-substituent in 3, is found to be effective “external” heavy atom quenchers to salicylaldehyde azine fluorescence in aggregated state. Based on its weak fluorescence in aggregated state and relative strong fluorescence in dispersed state, 3 can also be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction. -- Highlights: • This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. • Chloro- and bromo-salicylaldehyde display typical AIEE properties of salicylaldehyde azine, whereas the iodo-substitute quenches AIEE in aggregated state. • Iodo-salicylaldehyde can be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction

  10. Evidence that transferrin supports cell proliferation by supplying iron for DNA synthesis

    International Nuclear Information System (INIS)

    Laskey, J.; Webb, I.; Schulman, H.M.; Ponka, P.

    1988-01-01

    Transferrin is essential for cell proliferation and it was suggested that it may trigger a proliferative response following its interaction with receptors, serving as a growth factor. However, since the only clearly defined function of transferrin is iron transport, it may merely serve as an iron donor. To further clarify this issue, the authors took advantage of an iron chelate, ferric salicylaldehyde isonicotinoyl hydrazone (Fe-SIH), which they developed and previously demonstrated to efficiently supply iron to cells without using physiological transferrin receptor pathway. As expected, they observed that blocking monoclonal antibodies against transferrin receptors inhibited proliferation of both Raji and murine erythroleukemia cells. This inhibited cell growth was rescued upon the addition of Fe-SIH which was also shown to deliver iron to Raji cells in the presence of blocking anti-transferrin receptor antibodies. Moreover, blocking anti-transferrin receptor antibodies inhibited [ 3 H]thymidine incorporation into DNA and this inhibition could be overcome by added Fe-SIH. In addition, Fe-SIH slightly stimulated, while SIH (an iron chelator) significantly inhibited, DNA synthesis in phytohemagglutinin-stimulated peripheral blood lymphocytes. Taken together, these results indicate that the only function of transferrin supporting cell proliferation is to supply cells with iron

  11. Coordination chemistry of actinide elements: preparation of new uranium complexes with schiff bases and their characterization (Preprint No. CT-31)

    International Nuclear Information System (INIS)

    Hingorani, S.; Reddy, P.S.N.; Agarwala, B.V.

    1988-02-01

    The Schiff bases, o-vanillin semicarbazone (oVSC) and 2-pyridine carboxaldehyde isonicotinoyl hydrazone (PCINH) have been prepared and their novel complexes with dioxouranium(VI) have been synthesized and characterized by IR spectra, elemental analysis and other physico-chemical techniques. (author)

  12. Supramolecular packing and polymorph screening of N-isonicotinoyl arylketone hydrazones with phenol and amino modifications

    Science.gov (United States)

    Hean, Duane; Michael, Joseph P.; Lemmerer, Andreas

    2018-04-01

    Thirteen structural variants based on the (E)-N‧-(1-arylethylidene)pyridohydrazide template were prepared, investigated and screened for possible polymorphic behaviour. Four variants showed from Differential Scanning Calorimetry Scans thermal events indicative of new solid-state phases. The thirteen variants included substituents R = sbnd OH or sbnd NH2 placed at ortho, meta and para positions on the phenyl ring; and shifting the pyridyl nitrogen between positions 4-, 3- and 2-. The crystal structures of twelve of the compounds were determined to explore their supramolecular structures. The outcomes of these modifications demonstrated that the pyridyl nitrogen at the 2- position is 'locked' by forming a hydrogen bond with the amide hydrogen; while placing the pyridyl nitrogen at positions 3- and 4- offers a greater opportunity for hydrogen bonding with neighbouring molecules. Such interactions include Osbnd H⋯N, Nsbnd H⋯N, Osbnd H⋯O, Nsbnd H⋯O, Nsbnd H⋯π, π⋯π stacking, as well as other weaker interactions such as Csbnd H⋯N, Csbnd H⋯O, Csbnd H⋯N(pyridyl). When OH or NH2 donors are placed in the ortho position, an intramolecular hydrogen bond is formed between the acceptor hydrazone nitrogen and the respective donor. The meta- and para-positioned donors form an unpredictable array of supramolecular structures by forming hydrogen-bonded chains with the pyridyl nitrogen and carbonyl acceptors respectively. In addition to the intramolecular and chain hydrogen bond formation demonstrated throughout the crystal structures under investigation, larger order hydrogen-bonded rings were also observed in some of the supramolecular aggregations. The extent of the hydrogen-bonded ring formations range from two to six molecular participants depending on the specific crystal structure.

  13. A review exploring biological activities of hydrazones

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    Garima Verma

    2014-01-01

    Full Text Available The development of novel compounds, hydrazones has shown that they possess a wide variety of biological activities viz. antimicrobial, anticonvulsant, antidepressant, anti-inflammatory, analgesic, antiplatelet, antimalarial, anticancer, antifungal, antitubercular, antiviral, cardio protective etc., Hydrazones/azomethines/imines possess-NHN = CH- and constitute an important class of compounds for new drug development. A number of researchers have synthesized and evaluated the biological activities of hydrazones. This review aims at highlighting the diverse biological activities of hydrazones.

  14. Synthesis and studies of some magnesium complexes of aromatic hydrazones

    International Nuclear Information System (INIS)

    Adeniyi, A.A.; Oyedeji, O.O.; Aremu, J.A.; Okedeyi, J.O.; Bourne, S.A.

    2006-01-01

    Six esters were synthesized from their parent acids, while their corresponding hydrazides were subsequently synthesized from these asters. The hydrazides, on reaction with benzaldehyde, produced their respective hydrazones, namely, benzoic hydrazone (BH), m-nitrobenzoic hydrazone (m-NBH), p-nitrobenzoic hydrazone (p-NBH), 3,5 dinitrobenzoic hydrazone (3,5-dnbh), m-aminobenzoic hydrazone (m-ABH), and p-aminobenzoic hydrazone (p-ABH). These hydrazones, on interaction with magnesium chloride yielded their corresponding magnesium complexes. These complexes were off-white, grey or brownish in colour. These complexes were characterized on the basis of spectral data and metal analysis. Metal to ligand stoichiometry of 1: 3/2 and 1: 5/2 has been proposed for the complexes. The relevant infrared bands in the ligands and complexes were used to assign the probable point(s) of coordination. (author)

  15. Autoxidation of hydrazones. Some new insights.

    Science.gov (United States)

    Harej, Maja; Dolenc, Darko

    2007-09-14

    Autoxidation of hydrazones is a generally occurring reaction, leading mostly to the formation of alpha-azohydroperoxides. All structural kinds of hydrazones, having at least one hydrogen atom on nitrogen, are prone to autoxidation; however, there are marked differences in the rate of the reaction. Hydrazones of aliphatic ketones are 1-2 orders of magnitude more reactive than analogous derivatives of aromatic ketones. Even less reactive are the hydrazones of chalcones, which function also as efficient inhibitors of autoxidation of other hydrazones. These differences can be attributed to the reduction of the rate of the addition of oxygen to a hydrazonyl radical, which is a reversible reaction. In the case of conjugated ketones, it becomes endothermic, making this elementary step slow down and the chain termination reactions become important. Substituents influence the stability of hydrazonyl radicals and, consequently, the bond dissociation energies of the N-H bonds. In acetophenone phenylhydrazones, the substituents placed on the ring of hydrazine moiety exhibit a higher effect (Hammett rho = -2.8) than those on the ketone moiety (rho = -0.82), which denotes higher importance of the structure with spin density concentrated on nitrogen in delocalized hydrazonyl radical. Electronic effects of the substituents also affect the transition state for the abstraction of hydrogen atom by electrophilic peroxy radicals; NBO analysis display a negative charge transfer of about 0.4 eu from hydrazone to a peroxy radical in the transition state.

  16. Biological Activities of Hydrazone Derivatives

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    S. Güniz Küçükgüzel

    2007-08-01

    Full Text Available There has been considerable interest in the development of novel compounds with anticonvulsant, antidepressant, analgesic, antiinflammatory, antiplatelet, antimalarial, antimicrobial, antimycobacterial, antitumoral, vasodilator, antiviral and antischistosomiasis activities. Hydrazones possessing an azometine -NHN=CH- proton constitute an important class of compounds for new drug development. Therefore, many researchers have synthesized these compounds as target structures and evaluated their biological activities. These observations have been guiding for the development of new hydrazones that possess varied biological activities.

  17. Thermochemical studies on salicylaldehyde and salicylamide

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Maria D.M.C.; Araujo, Nuno R.M.

    2007-01-01

    The present work reports the values of the gaseous standard (p 0 = 0.1 MPa) molar enthalpies of formation of salicylaldehyde (2-hydroxybenzaldehyde) and salicylamide (2-hydroxybenzamide), at T = 298.15 K. For both molecules, those values were derived from measurements of the standard molar energy of combustion of the condensed compounds, using a static bomb calorimeter, together with measurements of the standard molar enthalpy of vaporization or sublimation, measured by Calvet microcalorimetry. Results are provided in a table

  18. Hydrazones as substrates for cycloaddition reactions

    International Nuclear Information System (INIS)

    Belskaya, N P; Eliseeva, A I; Bakulev, V A

    2015-01-01

    The [2+2]-, [4+2]- and [3+2]-cycloaddition reactions of hydrazones and 1,2-diazabuta-1,3-dienes, azomethine imines, nitrile imines and azomethine ylides formed upon hydrazone transformations with dienophiles, dipolarophiles and dienes are considered. The principal issues of structure and reactivity of active substrates and the influence of the reaction conditions and catalysts on the reaction regioselectivity and efficiency are discussed. The bibliography includes 288 references

  19. (Z-Selective Takai olefination of salicylaldehydes

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    Stephen M. Geddis

    2017-02-01

    Full Text Available The Takai olefination (or Takai reaction is a method for the conversion of aldehydes to vinyl iodides, and has seen widespread implementation in organic synthesis. The reaction is usually noted for its high (E-selectivity; however, herein we report the highly (Z-selective Takai olefination of salicylaldehyde derivatives. Systematic screening of related substrates led to the identification of key factors responsible for this surprising inversion of selectivity, and enabled the development of a modified mechanistic model to rationalise these observations.

  20. (Z)-Selective Takai olefination of salicylaldehydes.

    Science.gov (United States)

    Geddis, Stephen M; Hagerman, Caroline E; Galloway, Warren R J D; Sore, Hannah F; Goodman, Jonathan M; Spring, David R

    2017-01-01

    The Takai olefination (or Takai reaction) is a method for the conversion of aldehydes to vinyl iodides, and has seen widespread implementation in organic synthesis. The reaction is usually noted for its high ( E )-selectivity; however, herein we report the highly ( Z )-selective Takai olefination of salicylaldehyde derivatives. Systematic screening of related substrates led to the identification of key factors responsible for this surprising inversion of selectivity, and enabled the development of a modified mechanistic model to rationalise these observations.

  1. Synthesis of 2H-Chromenones from Salicylaldehydes and Arylacetonitriles

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    Chengcai Li

    2017-07-01

    Full Text Available An efficient and convenient protocol for the synthesis of 2H-chromenones has been developed. In the presence of tBuOK in DMF, good to excellent yields of various chromenones were obtained from the corresponding salicylaldehydes and arylacetonitriles. No protection of inert gas atmosphere is required here.

  2. Cu(II) Complexes of Isoniazid Schiff Bases: DNA/BSA Binding and Cytotoxicity Studies on A549 Cell Line

    OpenAIRE

    Ramadevi, Pulipaka; Singh, Rinky; Prajapati, Akhilesh; Gupta, Sarita; Chakraborty, Debjani

    2014-01-01

    A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II). The ligands are coordinated to Cu(II) ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds...

  3. Antimalarial Activity of Small-Molecule Benzothiazole Hydrazones.

    Science.gov (United States)

    Sarkar, Souvik; Siddiqui, Asim A; Saha, Shubhra J; De, Rudranil; Mazumder, Somnath; Banerjee, Chinmoy; Iqbal, Mohd S; Nag, Shiladitya; Adhikari, Susanta; Bandyopadhyay, Uday

    2016-07-01

    We synthesized a new series of conjugated hydrazones that were found to be active against malaria parasite in vitro, as well as in vivo in a murine model. These hydrazones concentration-dependently chelated free iron and offered antimalarial activity. Upon screening of the synthesized hydrazones, compound 5f was found to be the most active iron chelator, as well as antiplasmodial. Compound 5f also interacted with free heme (KD [equilibrium dissociation constant] = 1.17 ± 0.8 μM), an iron-containing tetrapyrrole released after hemoglobin digestion by the parasite, and inhibited heme polymerization by parasite lysate. Structure-activity relationship studies indicated that a nitrogen- and sulfur-substituted five-membered aromatic ring present within the benzothiazole hydrazones might be responsible for their antimalarial activity. The dose-dependent antimalarial and heme polymerization inhibitory activities of the lead compound 5f were further validated by following [(3)H]hypoxanthine incorporation and hemozoin formation in parasite, respectively. It is worth mentioning that compound 5f exhibited antiplasmodial activity in vitro against a chloroquine/pyrimethamine-resistant strain of Plasmodium falciparum (K1). We also evaluated in vivo antimalarial activity of compound 5f in a murine model where a lethal multiple-drug-resistant strain of Plasmodium yoelii was used to infect Swiss albino mice. Compound 5f significantly suppressed the growth of parasite, and the infected mice experienced longer life spans upon treatment with this compound. During in vitro and in vivo toxicity assays, compound 5f showed minimal alteration in biochemical and hematological parameters compared to control. In conclusion, we identified a new class of hydrazone with therapeutic potential against malaria. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  4. Synthesis of hydrazone functionalized epoxy polymers for non-linear optical device applications

    Science.gov (United States)

    Singh, Rajendra K.

    A series of twelve, thermally crosslinkable, epoxy polymers bearing covalently attached NLO-active hydrazone chromophores were synthesized. The primary focus was on the synthesis of two series of NLO-active hydroxy functionalized hydrazone chromophores. The first series, called the monohydroxy series (Hydrazones I--VI) comprised of six monohydroxy functionalized hydrazones and the second series consisted of six dihydroxy functionalized hydrazones (Hydrazones VII--XII). These hydrazone chromophores were then grafted, via the hydroxy functionality, on to a commercial epoxy polymer to obtain twelve NLO-active soluble prepolymers. The grafting reaction yields multiple secondary hydroxyl sites due to opening of the epoxide rings and these hydroxyl groups were used for further crosslinking by formulating the prepolymers with a blocked polyisocyanate commercial crosslinker. This formulation was spin coated on glass slides to form 2--2.5 m m thick uniform, defect free, transparent films. The films were corona poled, above their Tg, to align the chromophores in a noncentrosymmetric fashion and simultaneously complete the thermal cure that results in a highly crosslinked network. Finally the thermal characteristics of the second order nonlinearity of the twelve polymers are compared to illustrate the key structure-property relationships underlying the performance of the films.

  5. Spectroscopic analyses on interaction of Amantadine-Salicylaldehyde, Amantadine-5-Chloro-Salicylaldehyde and Amantadine-o-Vanillin Schiff-Bases with bovine serum albumin (BSA)

    Science.gov (United States)

    Wang, Zhiqiu; Gao, Jingqun; Wang, Jun; Jin, Xudong; Zou, Mingming; Li, Kai; Kang, Pingli

    2011-12-01

    In this work, three Tricyclo [3.3.1.1(3,7)] decane-1-amine (Amantadine) Schiff-Bases, Amantadine-Salicylaldehyde (AS), Amantadine-5-Chloro-Salicylaldehyde (AS-5-C) and Amantadine-o-Vanillin (AS-o-V), were synthesized by direct heating reflux method in ethanol solution and characterized by infrared spectrum and elementary analysis. Fluorescence quenching was used to study the interaction of these Amantadine Schiff-Bases (AS, AS-5-C and AS-o-V) with bovine serum albumin (BSA). According to fluorescence quenching calculations the bimolecular quenching constant ( Kq), apparent quenching constant ( KSV), effective binding constant ( KA) and corresponding dissociation constant ( KD), binding site number ( n) and binding distance ( r) were obtained. The results show that these Amantadine Schiff-Bases can obviously bind to BSA molecules and the binding strength order is AS < AS-5-C = AS-o-V. Synchronous fluorescence spectroscopy reveals that these Amantadine Schiff-Bases adopt different way to bind with BSA molecules. That is, the AS and AS-5-C are accessibility to tryptophan (Trp) residues more than the tyrosine (Tyr) residues, while the AS-o-V is equally close to the Tyr and Trp residues.

  6. Determination of scandium with salicylaldehyde and 2-aminobenzenearsonic acid

    International Nuclear Information System (INIS)

    Farias, P.A.M.; Hainberger, L.; Andrade, H.A.S.

    1984-01-01

    A new method for the spectrophotometric determination of scandium by means of a coloured complex formed with salicylaldehyde and 2-aminobenzenearsonic acid is described. Lambert-Beer's law is followed in the range of 0.2 - 2.0 μg/ml of the final solution. The maximum amounts of 39 ions that may be present without interfering in the method are listed. (Author) [pt

  7. Configurational and constitutional information storage: multiple dynamics in systems based on pyridyl and acyl hydrazones.

    Science.gov (United States)

    Chaur, Manuel N; Collado, Daniel; Lehn, Jean-Marie

    2011-01-03

    The C=N group of hydrazones can undergo E/Z isomerization both photochemically and thermally, allowing the generation of a closed process that can be tuned by either of these two physical stimuli. On the other hand, hydrazine-exchange reactions enable a constitutional change in a given hydrazone. The two classes of processes: 1) configurational (physically stimulated) and 2) constitutional (chemically stimulated) give access to short-term and long-term information storage, respectively. Such transformations are reported herein for two hydrazones (bis-pyridyl hydrazone and 2-pyridinecarboxaldehyde phenylhydrazone) that undergo a closed, chemically or physically driven process, and, in addition, can be locked or unlocked at will by metal-ion coordination or removal. These features also extend to acyl hydrazones derived from 2-pyridinecarboxaldehyde. Similarly to the terpydine-like hydrazones, such acyl hydrazones can undergo both constitutional and configurational changes, as well as metal-ion coordination. All these types of hydrazones represent dynamic systems capable of acting as multiple state molecular devices, in which the presence of coordination sites furthermore allows the metal ion-controlled locking and unlocking of the interconversion of the different states. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Control of heme synthesis during Friend cell differentiation: role of iron and transferrin

    International Nuclear Information System (INIS)

    Laskey, J.D.; Ponka, P.; Schulman, H.M.

    1986-01-01

    In many types of cells the synthesis of σ-aminolevulinic acid (ALA) limits the rate of heme formation. However, results from this laboratory with reticulocytes suggest that the rate of iron uptake from 125 I-transferrin (Tf), rather than ALA synthase activity, limits the rate of heme synthesis in erythroid cells. To determine whether changes occur in iron metabolism and the control of heme synthesis during erythroid cell development Friend erythroleukemia cells induced to erythroid differentiation by dimethylsulfoxide (DMSO) were studied. While added ALA stimulated heme synthesis in uninduced Friend cells (suggesting ALA synthase is limiting) it did not do so in induced cells. Therefore the possibility was investigated that, in induced cells, iron uptake from Tf limits and controls heme synthesis. Several aspects of iron metabolism were investigated using the synthetic iron chelator salicylaldehyde isonicotinoyl hydrazone (SIH). Both induced and uninduced Friend cells take up and utilize Fe for heme synthesis directly from Fe-SIH without the involvement of transferrin and transferrin receptors and to a much greater extent than from saturating levels or 59 Fe-Tf (20 μM). Furthermore, in induced Friend cells 100 μM Fe-SIH stimulated 2- 14 C-glycine incorporation into heme up to 3.6-fold as compared to the incorporation observed with saturating concentrations of Fe-Tf. These results indicate that some step(s) in the pathway of iron from extracellular Tf to protoporphyrin, rather than the activity of ALA synthase, limits and controls the overall rate of heme and possibly hemoglobin synthesis in differentiating Friend erythroleukemia cells

  9. Template synthesis, characterization and antimicrobial activity of the complex combinations of some transitional metals with isonicotinoylhydrazone -2,4,6- trimethylbenzaldehyde

    International Nuclear Information System (INIS)

    Mitu, L.ITU; Imran, M.

    2011-01-01

    The complexes of Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) with isonicotinoyl-hydrazone -2,4,6-trimethylbenzaldehyde (INHTB) are reported. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility, thermal analysis and for the Cu(II) complex the ESR spectrum has been recorded. The anti-bacterial activity of these complexes were investigated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Shigella flexneri bacteria. The INHTB ligand is coordinated at the metallic ions by oxygen amide (O=C) and the azomethine nitrogen. (author)

  10. Optimized protocol for the radioiodination of hydrazone-type polymer drug delivery systems

    International Nuclear Information System (INIS)

    Sedláček, Ondřej; Kučka, Jan; Hrubý, Martin

    2015-01-01

    Hydrazone conjugates of polymers with doxorubicin represent a very promising tool for cancer chemotherapy. However, these conjugates are very difficult to radiolabel with iodine radionuclides, which possess otherwise very advantageous nuclear properties to, e.g., follow biodistribution. In this study, we developed a robust protocol for the high-yield radioiodination of hydrazone-type drug delivery systems with doxorubicin. In particular, it is crucial that the polymer radioiodination step be performed before the deprotection of the hydrazide and doxorubicin binding. - Highlights: • Hydrazone-type drug delivery systems with doxorubicin were radioiodinated. • Radioiodination was performed via polymer-bound phenolic moiety. • Radioiodination step must be performed before deprotection and drug binding

  11. New oxozirconium(IV) complexes with the schiff bases derived from salicylaldehyde or substituted salicylaldehydes and o-aminobenzyl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Syamal, A [Kurukshetra Univ. (India). Dept. of Applied Sciences and Humanities; Kumar, D [Regional Engineering Coll., Kurukshetra (India). Dept. of Chemistry

    1980-10-01

    Several new oxozirconium(IV) complexes with the schiff bases obtained from salicylaldehyde, 5-chlorosalicylaldehyde, 5-bromosalicylaldehyde, 5-nitrosalicylaldehyde, 4-methoxysalicylaldehyde, 5-methoxysalicylaldehyde, 3-ethoxysalicylaldehyde, 3,5-dichlorosalicylaldehyde or 2-hydroxy-1-naphthaldehyde and 0-aminobenzyl alcohol have been synthesized and characterized on the basis of elemental analysis, molecular weight, electrical conductance, infrared spectral and magnetic susceptibility measurements. The schiff bases behave as monobasic, tridentate ONO donor ligands. The complexes are of the type ZrO(LH)/sub 2/ (where LH/sub 2/ = tridentate schiff base) and are seven-coordinated. The complexes are monomers, non-electrolytes and diamagnetic. Changes in the ..nu..C=N, ..nu..C-0 (phenolic) and ..nu..C-0 (alchoholic) frequencies have been followed to find out the coordination sites of the ligands.

  12. The ligational behavior of an isatinic quinolyl hydrazone towards copper(II- ions

    Directory of Open Access Journals (Sweden)

    Mousa Marwa A

    2011-04-01

    Full Text Available Abstract Background The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone. Results New homo- and heteroleptic copper(II- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL with several copper(II- salts viz. Clˉ, Brˉ, NO3ˉ, ClO4-, SO42- and AcO-. The obtained complexes have Oh, Td and D4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions. Depending on the type of the anion, the ligand coordinates the copper(II- ions either through its lactam (NO3ˉ and ClO4- or lactim (the others forms. Conclusion The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (Oh, Td and D4h or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions in consistency with the donor ability of the anions. In case of copper(II- acetate, a unique homoleptic complex (5 was obtained in which the AcO- anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.

  13. Synthesis and preliminary evaluation of antinociceptive activity of novel isoxazolyl-aryl-hydrazones

    International Nuclear Information System (INIS)

    Reis, Silvio Leandro Goncalves Bomfim; Almeida, Valderes Moraes de; Almeida, Gleybson Correia de; Boaviagem, Karinna Moura; Mendes, Charles Christophe du Barriere; Faria, Antonio Rodolfo de; Goes, Alexandre Jose da Silva; Magalhaes, Laudelina Rodrigues; Silva, Teresinha Goncalves da

    2011-01-01

    New 2-isoxazoline aldehydes were synthesized, in good yields, from cycloadduct of the 1,3-dipolar cycloaddition reaction between endocyclic enecarbamate and carboethoxyformonitrile oxide (CEFNO). Condensation of these 2-isoxazoline aldehydes with several phenyl-hydrazines produced new isoxazolyl-aryl-hydrazones, which showed low toxicity and excellent antinociceptive activity, when compared to dipyrone. The antinociceptive activity of isoxazolyl-aryl-hydrazones was performed using the acetic acid-induced mice abdominal constrictions test. (author)

  14. Density functional theory studies on the nano-scaled composites consisted of graphene and acyl hydrazone molecules

    Science.gov (United States)

    Ren, J. L.; Zhou, L.; Lv, Z. C.; Ding, C. H.; Wu, Y. H.; Bai, H. C.

    2016-07-01

    Graphene, which is the first obtained single atomic layer 2D materials, has drawn a great of concern in nano biotechnology due to the unique property. On one hand, acyl hydrazone compounds belonging to the Schif bases have aroused considerable attention in medicine, pharmacy, and analytical reagent. However, few understanding about the interaction between graphene and acyl hydrazone molecules is now available. And such investigations are much crucial for the applications of these new nano-scaled composites. The current work revealed theoretical investigations on the nano-scaled composites built by acyl hydrazone molecules loaded on the surface of graphene. The relative energy, electronic property and the interaction between the counterparts of graphene/acyl hydrazone composites are investigated based on the density functional theory calculations. According to the obtained adsorption energy, the formation of the nano-scaled composite from the isolated graphene and acyl hydrazone molecule is exothermic, and thus it is energetically favorable to form these nano composites in viewpoint of total energy change. The frontier molecular orbital for the nano composite is mainly distributed at the graphene part, leading to that the energy levels of the frontier molecular orbital of the nano composites are very close to that of isolated graphene. Moreover, the counterpart interaction for the graphene/acyl hydrazone composites is also explored based on the discussions of orbital hybridization, charge redistribution and Van der Waals interaction.

  15. New turn-on fluorescent and colorimetric probe for cyanide detection based on BODIPY-salicylaldehyde and its application in cell imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sukato, Rangsarit [Program of Petrochemistry and Polymer Science, Chulalongkorn University, Bangkok 10330 (Thailand); Sangpetch, Nuanphan; Palaga, Tanapat [Department of Microbiology, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Jantra, Suthikorn; Vchirawongkwin, Viwat; Jongwohan, Chanantida [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Sukwattanasinitt, Mongkol [Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Wacharasindhu, Sumrit, E-mail: sumrit.w@chula.ac.th [Nanotec-CU Center of Excellence on Food and Agriculture, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2016-08-15

    Highlights: • A novel salicylaldehyde-BODIPY fluorescent sensor is prepared. • The sensor shows dual colorimetric & turn-on fluorescence response to cyanide ion. • Detection limit is 0.88 μM (below WHO standard for drinking water). • It is effective for cyanide detection an in vitro cellular system. - Abstract: Development of cyanide sensor is important as the anion is harmful to human health and the environment. Herein, a new colorimetric and fluorescent probe GSB based on boron dipyrrole-methene (BODIPY) containing salicylaldehyde group for cyanide detection has been reported. GSB undergoes exclusive colorimetric change from orange to colorless and exhibits selective fluorescence turn-on at 504 nm upon the addition of cyanide. Other 13 anions give almost no interference under physiological condition. Detection limit of the new cyanide-sensing GSB is 0.88 μM, which is below World Health Organization (WHO) recommended level in drinking water. A calculation by density functional theory (DFT) shows suppression of photoinduced electron transfer (PET) mechanism along with the interruption of π-conjugation between salicylaldehyde and BODIPY core by cyanide anion. Cell imaging studies demonstrated that GSB is compatible and capable of sensing cyanide anion in living cells.

  16. New turn-on fluorescent and colorimetric probe for cyanide detection based on BODIPY-salicylaldehyde and its application in cell imaging

    International Nuclear Information System (INIS)

    Sukato, Rangsarit; Sangpetch, Nuanphan; Palaga, Tanapat; Jantra, Suthikorn; Vchirawongkwin, Viwat; Jongwohan, Chanantida; Sukwattanasinitt, Mongkol; Wacharasindhu, Sumrit

    2016-01-01

    Highlights: • A novel salicylaldehyde-BODIPY fluorescent sensor is prepared. • The sensor shows dual colorimetric & turn-on fluorescence response to cyanide ion. • Detection limit is 0.88 μM (below WHO standard for drinking water). • It is effective for cyanide detection an in vitro cellular system. - Abstract: Development of cyanide sensor is important as the anion is harmful to human health and the environment. Herein, a new colorimetric and fluorescent probe GSB based on boron dipyrrole-methene (BODIPY) containing salicylaldehyde group for cyanide detection has been reported. GSB undergoes exclusive colorimetric change from orange to colorless and exhibits selective fluorescence turn-on at 504 nm upon the addition of cyanide. Other 13 anions give almost no interference under physiological condition. Detection limit of the new cyanide-sensing GSB is 0.88 μM, which is below World Health Organization (WHO) recommended level in drinking water. A calculation by density functional theory (DFT) shows suppression of photoinduced electron transfer (PET) mechanism along with the interruption of π-conjugation between salicylaldehyde and BODIPY core by cyanide anion. Cell imaging studies demonstrated that GSB is compatible and capable of sensing cyanide anion in living cells.

  17. Mixed-ligand complexes of zirconium (IV) and uranium with salicylaldehyde and some heterocyclic azopyrazolones

    International Nuclear Information System (INIS)

    Amrallahi, A.H.

    1994-01-01

    Mixed-ligand complexes of Zr(IV) and U(IV) with salicylaldehyde (SA) and some heterocyclic azopyrazolenes have been studied spectrophotometrically. All formed chelates have ratio 1:1:1. The stoichiometry and stability of the binary mixed chelates been evaluated. Elemental analysis, molar conductance and IR spectra have been used for identification of solid mixed complexes. (author)

  18. The importance of the rotor in hydrazone-based molecular switches

    Directory of Open Access Journals (Sweden)

    Xin Su

    2012-06-01

    Full Text Available The pH-activated E/Z isomerization of a series of hydrazone-based systems having different functional groups as part of the rotor (R = COMe, CN, Me, H, was studied. The switching efficiency of these systems was compared to that of a hydrazone-based molecular switch (R = COOEt whose E/Z isomerization is fully reversible. It was found that the nature of the R group is critical for efficient switching to occur; the R group should be a moderate H-bond acceptor in order to (i provide enough driving force for the rotor to move upon protonation, and (ii stabilize the obtained Z configuration, to achieve full conversion.

  19. A Hydrazone-Based exo-Directing-Group Strategy for β C-H Oxidation of Aliphatic Amines.

    Science.gov (United States)

    Huang, Zhongxing; Wang, Chengpeng; Dong, Guangbin

    2016-04-18

    Described is a new hydrazone-based exo-directing group (DG) strategy developed for the functionalization of unactivated primary β C-H bonds of aliphatic amines. Conveniently synthesized from protected primary amines, the hydrazone DGs are shown to site-selectively promote the β-acetoxylation and tosyloxylation via five-membered exo-palladacycles. Amines with a wide scope of skeletons and functional groups are tolerated. Moreover, the hydrazone DG can be readily removed, and a one-pot C-H acetoxylation/DG removal protocol was also discovered. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Hydrazone based molecular glasses for solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Aich, R.; Tran-Van, F.; Goubard, F.; Beouch, L.; Michaleviciute, A.; Grazulevicius, J.V.; Ratier, B.; Chevrot, C.

    2008-01-01

    Biscarbazole and terthiophene based molecular glasses with hydrazone functional goups (named respectively 2CzMPH and 3TDPH) have been synthesized and the thermal, optical and electrochemical properties have been studied. Differential scanning calorimetry characterizations confirm the metastable amorphous properties of these molecules with glass transition temperatures at 80 deg. C for the 3TDPH and 93 deg. C for the 2CzMPH. Their electrochemical properties have been studied and showed the effect of the conjugated hydrazone groups on the electronic delocalization of the structures. The concept of solid state dye-sensitized solar cells using hydrazone based molecular glasses has been verified with the elaboration of a SnO 2 : F/nc-TiO 2 /Ru-dye/2CzMPH /Au devices. Under full sunlight (98 mW/cm 2 , air mass 1.5) the I-V characterization of the device give a short circuit photocurrents I sc = 0.42 mA/cm 2 , open circuit voltage V oc = 500 mV with a fill factor of 0.35

  1. Hydrazone based molecular glasses for solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Aich, R. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France); Ecole Electricite de Production et Methodes Industrielles, Cergy Pontoise (France); Tran-Van, F. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France)], E-mail: francois.tran-van@u-cergy.fr; Goubard, F.; Beouch, L. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France); Michaleviciute, A.; Grazulevicius, J.V. [Department of Organic Technology, Kaunas University of Technology, Radvilenu Plentas 19, Kaunas LT-50254 (Lithuania); Ratier, B. [X-LIM., departement MINACOM, UMR 6172, Faculte des Sciences, 123 av. Albert Thomas 87060 Limoges cedex France (France); Chevrot, C. [Laboratoire de Physicochimie des Polymeres et des Interfaces (EA 2528), Universite de Cergy-Pontoise, 5 mail Gay Lussac, 95031 Cergy Pontoise (France)

    2008-08-30

    Biscarbazole and terthiophene based molecular glasses with hydrazone functional goups (named respectively 2CzMPH and 3TDPH) have been synthesized and the thermal, optical and electrochemical properties have been studied. Differential scanning calorimetry characterizations confirm the metastable amorphous properties of these molecules with glass transition temperatures at 80 deg. C for the 3TDPH and 93 deg. C for the 2CzMPH. Their electrochemical properties have been studied and showed the effect of the conjugated hydrazone groups on the electronic delocalization of the structures. The concept of solid state dye-sensitized solar cells using hydrazone based molecular glasses has been verified with the elaboration of a SnO{sub 2}: F/nc-TiO{sub 2}/Ru-dye/2CzMPH /Au devices. Under full sunlight (98 mW/cm{sup 2}, air mass 1.5) the I-V characterization of the device give a short circuit photocurrents I{sub sc} = 0.42 mA/cm{sup 2}, open circuit voltage V{sub oc} = 500 mV with a fill factor of 0.35.

  2. Backbone-hydrazone-containing biodegradable copolymeric micelles for anticancer drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jing; Luan, Shujuan; Qin, Benkai; Wang, Yingying; Wang, Kai; Qi, Peilan; Song, Shiyong, E-mail: pharmsong@henu.edu.cn [Henan University, Institute of Pharmacy (China)

    2016-11-15

    Well-defined biodegradable, pH-sensitive amphiphilic block polymers, poly(ethylene glycol)-Hyd-poly(lactic acid) (mPEG-Hyd-PLA) which have acid-cleavable linkages in their backbones, were synthesized via ring-opening polymerization initiated from hydrazone-containing macroinitiators. Introducing a hydrazone bond onto the backbone of an amphiphilic copolymer will find a broad-spectrum encapsulation of hydrophobic drugs. Dynamic light scattering (DLS) and transmission electron microscopy showed that the diblock copolymers self-assembled into stable micelles with average diameters of 100 nm. The mean diameters and size distribution of the hydrazone-containing micelles changed obviously in mildly acidic pH (multiple peaks from 1 to 202 nm appeared under a pH 4.0 condition) than in neutral, while there were no changes in the case of non-sensitive ones. Doxorubicin (DOX) and paclitaxel (PTX) were loaded with drug loading content ranging from 2.4 to 3.5 %, respectively. Interestingly, the anticancer drugs released from mPEG-Hyd-PLA micelles could also be promoted by the increased acidity. An in vitro cytotoxicity study showed that the DOX-loaded mPEG-Hyd-PLA micelles have significantly enhanced cytotoxicity against HepG2 cells compared with the non-sensitive poly(ethylene glycol)-block-poly(lactic acid) (mPEG-PLA) micelles. Confocal microscopy observation indicated that more DOX were delivered into the nuclei of cells following 6 or 12 h incubation with DOX-loaded mPEG-Hyd-PLA micelles. In vivo studies on H22-bearing Swiss mice demonstrated the superior anticancer activity of DOX-loaded mPEG-Hyd-PLA micelles over free DOX and DOX-loaded mPEG-PLA micelles. These hydrazone-containing pH-responsive degradable micelles provide a useful strategy for antitumor drug delivery.

  3. Backbone-hydrazone-containing biodegradable copolymeric micelles for anticancer drug delivery

    International Nuclear Information System (INIS)

    Xu, Jing; Luan, Shujuan; Qin, Benkai; Wang, Yingying; Wang, Kai; Qi, Peilan; Song, Shiyong

    2016-01-01

    Well-defined biodegradable, pH-sensitive amphiphilic block polymers, poly(ethylene glycol)-Hyd-poly(lactic acid) (mPEG-Hyd-PLA) which have acid-cleavable linkages in their backbones, were synthesized via ring-opening polymerization initiated from hydrazone-containing macroinitiators. Introducing a hydrazone bond onto the backbone of an amphiphilic copolymer will find a broad-spectrum encapsulation of hydrophobic drugs. Dynamic light scattering (DLS) and transmission electron microscopy showed that the diblock copolymers self-assembled into stable micelles with average diameters of 100 nm. The mean diameters and size distribution of the hydrazone-containing micelles changed obviously in mildly acidic pH (multiple peaks from 1 to 202 nm appeared under a pH 4.0 condition) than in neutral, while there were no changes in the case of non-sensitive ones. Doxorubicin (DOX) and paclitaxel (PTX) were loaded with drug loading content ranging from 2.4 to 3.5 %, respectively. Interestingly, the anticancer drugs released from mPEG-Hyd-PLA micelles could also be promoted by the increased acidity. An in vitro cytotoxicity study showed that the DOX-loaded mPEG-Hyd-PLA micelles have significantly enhanced cytotoxicity against HepG2 cells compared with the non-sensitive poly(ethylene glycol)-block-poly(lactic acid) (mPEG-PLA) micelles. Confocal microscopy observation indicated that more DOX were delivered into the nuclei of cells following 6 or 12 h incubation with DOX-loaded mPEG-Hyd-PLA micelles. In vivo studies on H22-bearing Swiss mice demonstrated the superior anticancer activity of DOX-loaded mPEG-Hyd-PLA micelles over free DOX and DOX-loaded mPEG-PLA micelles. These hydrazone-containing pH-responsive degradable micelles provide a useful strategy for antitumor drug delivery.

  4. Perfluoroalkylation of Aryl-N,N-dimethyl Hydrazones Using Hypervalent Iodine(III) Reagents or Perfluoroalkyl Iodides.

    Science.gov (United States)

    Janhsen, Benjamin; Studer, Armido

    2017-11-17

    Radical trifluoromethylation of aryl N,N-dimethyl hydrazones using TBAI as an initiator and Togni's reagent as a trifluoromethyl radical source is described. Cascades proceed via electron-catalysis; this approach is generally more applicable to hydrazone perfluoroalkylation using perfluoroalkyl iodides as the radical precursors in combination with a base under visible-light initiation.

  5. Highly Diastereoselective Indium-Mediated Allylation of Proline-Derived Hydrazones

    International Nuclear Information System (INIS)

    Satyender, Apuri; Jang, Doo Ok

    2013-01-01

    A highly diastereoselective indium-mediated addition reaction to L-proline-derived hydrazones has been developed. The method affords an efficient and general synthesis of homoallylic amines of high optically purity in high yields and diastereomeric ratios up to 98:2. It is well known that (S)-1-amino-2-methoxymethylpyrro-lidine and (S)-4-isopropyl- or (S)-4-phenylmethyl-oxa-zolidin-2-one-derived hydrazones have been used for metal-mediated diastereoselective allylation additions to produce chiral homoallylic amines. However, the optically pure hydrazine precursors are either commercially expensive and/or involve laborious synthetic procedures employing toxic reagents for their preparation. Thus, the design of novel classes of chiral hydrazines that would further broaden the scope of asymmetric synthesis to access optically pure homoallylic amines is highly desirable

  6. Potential antisecretory antidiarrheals. 1. Alpha 2-adrenergic aromatic aminoguanidine hydrazones.

    Science.gov (United States)

    Pitzele, B S; Moormann, A E; Gullikson, G W; Albin, D; Bianchi, R G; Palicharla, P; Sanguinetti, E L; Walters, D E

    1988-01-01

    Guanabenz, a centrally acting antihypertensive agent, has been shown to have intestinal antisecretory properties. A series of aromatic aminoguanidine hydrazones was made in an effort to separate the antisecretory and cardiovascular activities. Benzaldehyde, naphthaldehyde, and tetralone derivatives were synthesized. The compounds were evaluated in the cholera toxin treated ligated jejunum of the rat and in the Ussing chamber using a rabbit ileum preparation. A number of compounds, including members of each structural class, were active upon subcutaneous administration in the rat. Active compounds were determined to be alpha 2-adrenergic agonists by yohimbine reversals of their Ussing chamber activities. The compound displaying the best separation of activities was the aminoguanidine hydrazone of 2,6-dimethyl-4-hydroxybenzaldehyde (20).

  7. Cu(II Complexes of Isoniazid Schiff Bases: DNA/BSA Binding and Cytotoxicity Studies on A549 Cell Line

    Directory of Open Access Journals (Sweden)

    Pulipaka Ramadevi

    2014-01-01

    Full Text Available A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II. The ligands are coordinated to Cu(II ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds have been investigated for their cytotoxicities on A549 human lung cancer cell. Also the mode of cell death was examined employing various staining techniques and was found to be apoptotic.

  8. Synthesis and molecular docking of new hydrazones derived from ...

    African Journals Online (AJOL)

    Synthesis and molecular docking of new hydrazones derived from ethyl isonipecotate and their biological activities. A Munir, Aziz-ur Rehman, M.A. Abbasi, S.Z. Siddiqui, A Nasir, S.G. Khan, S Rasool, S.A.A. Shah ...

  9. The use of domestic microwave oven in experimental classes of organic chemistry: salicylaldehyde nitration

    OpenAIRE

    Teixeira, Eurídes Francisco; Santos, Ana Paula Bernardo dos; Bastos, Renato Saldanha; Pinto, Angelo C.; Kümmerle, Arthur Eugen; Coelho, Roberto Rodrigues

    2010-01-01

    The use of microwave in chemistry has known benefits over conventional heating methods, e.g. reduced reaction times, chemical yield improvement and the possibility if reducing or eliminating the use of organic solvents. We describe herein a procedure for the nitration of salicylaldehyde in water using a domestic microwave oven, which can be used as an experiment in the undergraduate chemistry laboratory. The experiment involves safe and rapid preparation and identification of the position iso...

  10. Mixed ligand complexes of alkaline earth metals: Part XII. Mg(II, Ca(II, Sr(II and Ba(II complexes with 5-chlorosalicylaldehyde and salicylaldehyde or hydroxyaromatic ketones

    Directory of Open Access Journals (Sweden)

    MITHLESH AGRAWAL

    2002-04-01

    Full Text Available The reactions of alkaline earth metal chlorides with 5-chlorosalicylaldehyde and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been carried out in 1 : 1 : 1 mole ratio and the mixed ligand complexes of the type MLL’(H2O2 (where M = Mg(II, Ca(II, Sr(II and Ba(II, HL = 5-chlorosalicylaldehyde and HL’ = salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been isolated. These complexes were characterized by TLC, conductance measurements, IR and 1H-NMR spectra.

  11. A Simple Spectrophotometric Method for the Determination of Copper in Some Real, Environmental, Biological, Food and Soil Samples Using Salicylaldehyde Benzoyl Hydrazone

    Directory of Open Access Journals (Sweden)

    M. Jamaluddin Ahmed

    2012-06-01

    Full Text Available A very simple, ultra-sensitive, highly selective and non-extractive spectrophotometric method for the determination of trace amounts copper(II has been developed. Salicylaldehy debenzoyl hydrazone (SAL-BH has been proposed as a new analytical reagent for the direct non-extractive spectrophotometric determination of copper(II. SAL-BH reacts with copper in a slightly acidic (0.0001-0.005 M H2SO4 in 40% 1,4-dioxane media with copper(II to give a highly absorbent greenish yellow chelate with a molar ratio 1:1(CuII: SAL-BH The reaction is instantaneous and the maximum absorption was obtained at 404 nm and remains stable for 72 h. The average molar absorptivity and Sandell’s sensitivity were found to be 1.4×105 L mol-1 cm-1 and 5.0 ng cm-2 of copper(II, respectively. Linear calibration graphs were obtained for 0.01 – 18 mg L-1 of CuII. The detection limit and quantification limit of the reaction system were found to be 1 ng mL-1 and 10 µg L-1, respectively. A large excess of over 50 cations, anions and complexing agents (e.g., tartrate, oxalate, citrate, phosphate, thiocyanate etc. do not interfere in the determination. The method is highly selective for copper and was successfully used for the determination of copper in several standard reference materials (steels and alloys as well as in some environmental waters (portable and polluted, biological (human blood and urine, food and soil samples and solutions containing both copper(I and copper(II as well as some complex synthetic mixtures. The results of the proposed method for biological and food samples were comparable with AAS and were found to be in good agreement. The method has high precision and accuracy (s = ± 0.01 for 0.5 mg L-1.

  12. Menthone aryl acid hydrazones: a new class of anticonvulsants.

    Science.gov (United States)

    Jain, Jainendra; Kumar, Y; Sinha, Reema; Kumar, Rajeev; Stables, James

    2011-01-01

    A series of ten compounds (Compounds J(1)-J(10)) of (±) 3-menthone aryl acid hydrazone was synthesized and characterized by thin layer chromatography and spectral analysis. Synthesized compounds were evaluated for anticonvulsant activity after intraperitoneal (i.p) administration to mice by maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure method and minimal clonic seizure test. Minimal motor impairment was also determined for these compounds. Results obtained showed that four compounds out of ten afforded significant protection in the minimal clonic seizure screen at 6 Hz. Compound J(6), 4-Chloro-N-(2-isopropyl-5-methylcyclohexylidene) benzohydrazide was found to be the most active compound with MES ED(50) of 16.1 mg/kg and protective index (pI) of greater than 20, indicating that (±) 3-menthone aryl acid hydrazone possesses better and safer anticonvulsant properties than other reported menthone derivatives viz. menthone Schiff bases, menthone semicarbazides and thiosemicarbazides.

  13. Confirmation of hydrazone formation in HYNIC-peptide conjugate preparation, and its hydrolysis during labeling with 99mTc

    International Nuclear Information System (INIS)

    Gandomkar, M.; Najafi, R.; Shafiei, M.; Ebrahimi, S.E.S.

    2007-01-01

    Because of its monodenticity, 6-hydrazinopyridine-3-carboxylic acid (HYNIC) is of interest as a bifunctional chelator for labeling peptide with 99m Tc. Here, we confirm the formation of hydrazone in HYNIC-conjugated peptide. The preparative HPLC was used to purify the HYNIC conjugated somatostatin-based peptide and the result showed two peaks, even after two consecutive purifications. Analysis of these peaks by mass spectrometry indicated the presence of hydrazone, produced during preparation conjugate. Further, we have shown that presence of hydrazone really does not matter because under 99m Tc-labeling conditions, hydrazone is hydrolyzed back to HYNIC that then chelates 99m Tc. A HYNIC-peptide conjugate freeze-dried kit was also prepared in a mildly acidic or neutral condition with a final pH of 6-7. The kit was then labeled by 99m Tc and incubated in 100 dec. C for 10 min, and a labeling yield of >95% was obtained

  14. Confirmation of hydrazone formation in HYNIC-peptide conjugate preparation, and its hydrolysis during labeling with {sup 99m}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Gandomkar, M. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of)]. E-mail: msgandomkar@yahoo.com; Najafi, R. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Shafiei, M. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Ebrahimi, S.E.S. [Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2007-07-15

    Because of its monodenticity, 6-hydrazinopyridine-3-carboxylic acid (HYNIC) is of interest as a bifunctional chelator for labeling peptide with {sup 99m}Tc. Here, we confirm the formation of hydrazone in HYNIC-conjugated peptide. The preparative HPLC was used to purify the HYNIC conjugated somatostatin-based peptide and the result showed two peaks, even after two consecutive purifications. Analysis of these peaks by mass spectrometry indicated the presence of hydrazone, produced during preparation conjugate. Further, we have shown that presence of hydrazone really does not matter because under {sup 99m}Tc-labeling conditions, hydrazone is hydrolyzed back to HYNIC that then chelates {sup 99m}Tc. A HYNIC-peptide conjugate freeze-dried kit was also prepared in a mildly acidic or neutral condition with a final pH of 6-7. The kit was then labeled by {sup 99m}Tc and incubated in 100 dec. C for 10 min, and a labeling yield of >95% was obtained.

  15. Kinetics and Mechanistic Study of Permanganate Oxidation of Fluorenone Hydrazone in Alkaline Medium

    Directory of Open Access Journals (Sweden)

    Ahmed Fawzy

    2016-01-01

    Full Text Available The oxidation kinetics of fluorenone hydrazone (FH using potassium permanganate in alkaline medium were measured at a constant ionic strength of 0.1 mol dm−3 and at 25°C using UV/VIS spectrophotometer. A first-order kinetics has been monitored in the reaction of FH with respect to [permanganate]. Less-than-unit order dependence of the reaction on [FH] and [OH−] was revealed. No pronounced effect on the reaction rate by increasing ionic strength was recorded. Intervention of free radicals was observed in the reaction. The reaction mechanism describing the kinetic results was illustrated which involves formation of 1 : 1 intermediate complex between fluorenone hydrazones and the active species of permanganate. 9H-Fluorenone as the corresponding ketone was found to be the final oxidation product of fluorenone hydrazone as confirmed by GC/MS analysis and FT-IR spectroscopy. The expression rate law for the oxidation reaction was deduced. The reaction constants and mechanism have been evaluated. The activation parameters associated with the rate-limiting step of the reaction, along with the thermodynamic quantities of the equilibrium constants, have been calculated and discussed.

  16. Diprotonated hydrazones and oximes as reactive intermediates in electrochemical reductions

    Czech Academy of Sciences Publication Activity Database

    Baymak, M. S.; Celik, H.; Ludvík, Jiří; Lund, H.; Zuman, P.

    2004-01-01

    Roč. 45, č. 26 (2004), s. 5113-5115 ISSN 0040-4039 R&D Projects: GA ČR GA203/01/1093; GA AV ČR IAA4040304 Institutional research plan: CEZ:AV0Z4040901 Keywords : hydrazones * oximes * diprotonation Subject RIV: CG - Electrochemistry Impact factor: 2.484, year: 2004

  17. Photochemical and electrochemical studies on lanthanide complexes of 6-(hydroxymethylpyridine- 2-carboxaldehyde[2- methyl-pyrimidine-4,6-diyl] bis-hydrazone

    Directory of Open Access Journals (Sweden)

    María Alejandra Fernandez

    2014-01-01

    Full Text Available Herein we report the synthesis of the 6-(hydroxymethylpyridine-2- carboxaldehyde[2-methyl-pyrimidine- 4,6-diyl]bis-hydrazone by a condensation reaction between 6-(hydroxymethyl picolinaldehyde with 4,6-(bis-hydrazino-2- methylpyrimidine. This bis-hydrazone can be visualized as a two-arm system which exhibits photochemical induced [E,E]/[E,Z]/[Z,Z’] isomerizations and double coordination to metal centers. Configurational changes, upon UV light irradiation, were followed over time by 1 H NMR, establishing that isomerization, in both arms, is a consecutive reaction that follows first-order kinetics (k1 = 4.06 x 10-4 s-1 and k2 = 2.80 x 10-4 s-1. Furthermore, the synthesis of bis-hydrazone metal complexes with La (III and Sm (III ions was achieved; subsequently, the absorption and emission properties of these complexes were studied, determining the fluorescence quantum yields, La= 0.2024 and Sm= 0.1413. Electrochemical studies of the complexes were conducted by square wave voltammetry, demonstrating that the bis-hydrazone and its complexes are electroactive species between +1.5 and -2.5 V.

  18. Metal based biologically active compounds: Design, synthesis, DNA binding and antidiabetic activity of 6-methyl-3-formyl chromone derived hydrazones and their metal (II) complexes.

    Science.gov (United States)

    Philip, Jessica Elizabeth; Shahid, Muhammad; Prathapachandra Kurup, M R; Velayudhan, Mohanan Puzhavoorparambil

    2017-10-01

    Two chromone hydrazone ligands HL 1 and HL 2 were synthesized and characterized by elemental analyses, IR, 1 H NMR & 13 C NMR, electronic absorption and mass spectra. The reactions of the chromone hydrazones with transition metals such as Ni, Cu, and Zn (II) salts of acetate afforded mononuclear metal complexes. Characterization and structure elucidation of the prepared chromone hydrazone metal (II) complexes were done by elemental, IR, electronic, EPR spectra and thermo gravimetric analyses as well as conductivity and magnetic susceptibility measurements. The spectroscopic data showed that the ligand acts as a mono basic bidentate with coordination sites are azomethine nitrogen and hydrazonic oxygen, and they exhibited distorted geometry. The biological studies involved antidiabetic activity i.e. enzyme inhibition of α-amylase and α-glucosidase, Calf Thymus - DNA (CT-DNA) interaction and molecular docking. Potential capacity of synthesized compounds to inhibit the α-amylase and α-glucosidase activity was assayed whereas DNA interaction studies were carried out with the help UV-Vis absorption titration and viscosity method. The docking studies of chromone hydrazones show that they are minor groove binders. Complexes were found to be good DNA - intercalates. Chromone hydrazones and its transition metal complexes have shown comparable antidiabetic activity with a standard drug acarbose. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The stereochemistry of the condensation product of salicylaldehyde and n-butylbarbituric acid by NMR techniques

    International Nuclear Information System (INIS)

    Cruz, Elizabete R.; Villar, J. Daniel Figueroa

    1995-01-01

    Since the discovery of the 5-deazaflavin cofactor (coenzyme F 420 ) as a naturally occurring compound, a great attention has been focused on several iso steric flavin analogues. One of the simplest approaches towards the synthesis of oxadeazaflavin, compound which the nitrogen at the N-10 position of 5-deazaflavin is replaced by oxygen, is the direct condensation between barbituric acid and salicylaldehyde. In this paper, the use of some NMR techniques so as to determine the stereochemistry of the preformed isomer has been described and a possible mechanism for this isomerization discussed

  20. Tridentate hydrazone metal complexes derived from cephalexin and 2-hydrazinopyridine: Synthesis, characterization and antibacterial activity

    Science.gov (United States)

    Anacona, J. R.; Rincones, Maria

    2015-04-01

    Metal(II) coordination compounds of a tridentate hydrazone ligand (HL) derived from the condensation of cephalexin antibiotic with 2-hydrazinopyridine were synthesized. The hydrazone ligand and mononuclear [ML(OAc)(H2O)] (M(II) = Mn, Co, Ni, Cu, Zn, Ag) complexes were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral studies. The cephalexin 2-pyridinylhydrazone ligand HL behaves as a monoanionic tridentate NNO chelating agent. The biological applications of complexes have been studied on three bacteria strains (Escherichia coli, Acinetobacter baumannii and Enterococcus faecalis) by agar diffusion disc method.

  1. Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

    Science.gov (United States)

    Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

    2014-01-01

    Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

  2. Novel colorimetric sensors for cyanide based on azo-hydrazone tautomeric skeletons.

    Science.gov (United States)

    Adegoke, Olajire A; Adesuji, Temitope E; Thomas, Olusegun E

    2014-07-15

    The monoazo dyes, 4-carboxyl-2, 6-dinitrophenylazohydroxynaphthalenes dyes (AZ-01, AZ-03 and AZ-04), were evaluated as a highly selective colorimetric chemosensor for cyanide ion. The recognition of cyanide ion gave an obvious colour change from light yellow to brownish red and upon dilution with acetone produced a purple to lilac colour. Optimum conditions for the reaction between the azo dyes and cyanide ion were established at 30°C for 5 min, and different variables affecting the reaction were carefully studied and optimised. Under the optimum conditions, linear relationships between the CN(-) concentrations and light absorption were established. Using these azo-hydrazone molecular switch entities, excellent selectivity towards the detection of CN(-) in aqueous solution over miscellaneous competitive anions was observed. Such selectivity mainly results from the possibility of nucleophilic attack on the azo-hydrazone chemosensors by cyanide anions in aqueous system, which is not afforded by other competing anions. The cyanide chemosensor method described here should have potential application as a new family probes for detecting cyanide in aqueous solution. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The stereochemistry of the condensation product of salicylaldehyde and n-butylbarbituric acid by NMR techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Elizabete R.; Villar, J. Daniel Figueroa [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Dept. de Quimica

    1995-12-31

    Since the discovery of the 5-deazaflavin cofactor (coenzyme F{sub 420}) as a naturally occurring compound, a great attention has been focused on several iso steric flavin analogues. One of the simplest approaches towards the synthesis of oxadeazaflavin, compound which the nitrogen at the N-10 position of 5-deazaflavin is replaced by oxygen, is the direct condensation between barbituric acid and salicylaldehyde. In this paper, the use of some NMR techniques so as to determine the stereochemistry of the preformed isomer has been described and a possible mechanism for this isomerization discussed 12 refs., 2 figs., 1 tab.

  4. Spectral, optical and cytotoxicity studies on 2-isonicotinoyl-N-phenylhydrazine-1-carboxamide(H3L) and some of its metal complexes

    Science.gov (United States)

    Hosny, Nasser M.; Hassan, Nader Y.; Mahmoud, Heba M.; Abdel-Rhman, Mohamed H.

    2018-03-01

    The ligand 2-isonicotinoyl-N-phenylhydrazine-1-carboxamide (H3L) and its metal complexes with Co(II), Ni(II), Cu(II) and Zn(II) acetates have been synthesized. The isolated compounds have been characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR, ESR, mass, electronic spectra, electrical conductivity, effective magnetic moments and thermal analyses. The free organic ligand exists in the keto form, but in the metal complexes, it coordinates in the enol form. Four coordinated species were suggested for all the isolated metal complexes. The measured optical band gap values confirmed the presence of direct electronic transition and the semi-conductivity of the compounds. The ligand and its Zn(II) complex were examined as cytotoxic agent against HCT-116 and HePG-2. The ligand showed very strong cytotoxic effect against HePG-2, but moderate cytotoxicity against HCT-116. Zn(II) complex showed weak cytotoxicity against the two cell lines.

  5. High-yielding and photolabile approaches to the covalent attachment of biomolecules to surfaces via hydrazone chemistry.

    Science.gov (United States)

    Lee, Ju Hun; Domaille, Dylan W; Noh, Hyunwoo; Oh, Taeseok; Choi, Chulmin; Jin, Sungho; Cha, Jennifer N

    2014-07-22

    The development of strategies to couple biomolecules covalently to surfaces is necessary for constructing sensing arrays for biological and biomedical applications. One attractive conjugation reaction is hydrazone formation--the reaction of a hydrazine with an aldehyde or ketone--as both hydrazines and aldehydes/ketones are largely bioorthogonal, which makes this particular reaction suitable for conjugating biomolecules to a variety of substrates. We show that the mild reaction conditions afforded by hydrazone conjugation enable the conjugation of DNA and proteins to the substrate surface in significantly higher yields than can be achieved with traditional bioconjugation techniques, such as maleimide chemistry. Next, we designed and synthesized a photocaged aryl ketone that can be conjugated to a surface and photochemically activated to provide a suitable partner for subsequent hydrazone formation between the surface-anchored ketone and DNA- or protein-hydrazines. Finally, we exploit the latent functionality of the photocaged ketone and pattern multiple biomolecules on the same substrate, effectively demonstrating a strategy for designing substrates with well-defined domains of different biomolecules. We expect that this approach can be extended to the production of multiplexed assays by using an appropriate mask with sequential photoexposure and biomolecule conjugation steps.

  6. Potassium N-Iodo p-Toluenesulfonamide (TsNIK, Iodamine-T): A New Reagent for the Oxidation of Hydrazones to Diazo Compounds

    Science.gov (United States)

    Nicolle, Simon M; Moody, Christopher J

    2014-01-01

    A new reagent for the oxidation of hydrazones to diazo compounds is described. N-Iodo p-toluenesulfonamide (TsNIK, iodamine-T) allows the preparation of α-diazoesters, α-diazoamides, α-diazoketones and α-diazophosphonates in good yield and in high purity after a simple extractive work-up. α-Diazoesters were also obtained in high yield from the corresponding ketones through a one-pot process of hydrazone formation/oxidation. PMID:24615944

  7. Novel (-)-gossypol derived hydrazones: Synthesis and biological evaluation

    Science.gov (United States)

    Tien, Vu Dinh; Van Vu, Vu; Koeckritz, Angela; Nhung, Trinh Thi; Thao, Do Thi; Vu, Tran Khac

    2017-09-01

    A series of novel (-)-gossypol Schiff bases and hydrazones have been synthesized via an in-situ procedure in high yields. Structural data showed that all target compounds existed in enamine conformation. The bioassay result displayed that several compounds exhibited cytotoxic effects against three human cancer cell lines including HepG2, LU-1 and MCF-7 with IC50 values of 16.56, 10.75 and 7.44 µg/mL, respectively. In antibacterial test, some compounds also inhibited Staphylococcus aureus and Bacillus cereus at the same MIC values of 1024 µg/ml.

  8. Spectroscopic and theoretical study of the o-vanillin hydrazone of the mycobactericidal drug isoniazid

    Science.gov (United States)

    González-Baró, Ana C.; Pis-Diez, Reinaldo; Parajón-Costa, Beatriz S.; Rey, Nicolás A.

    2012-01-01

    A complete and detailed study of the hydrazone obtained from condensation of antituberculous isoniazid (hydrazide of the isonicotinic acid, INH) and o-vanillin (2-hydroxy-3-methoxybenzaldehyde, o-HVa) is performed. It includes structural and spectroscopic analyses, comparing experimental and theoretical results. The compound was obtained as a chloride of the pyridinic salt (INHOVA +Cl -) but it will be referred as INHOVA for the sake of simplicity. The conformational space was searched and optimized geometries were determined both in gas phase and including solvent effects. Vibrational (IR and Raman), electronic and NMR spectra were registered and assigned with the help of computational methods based on the Density Functional Theory. Isoniazid hydrazones are good candidates for therapeutic agents against tuberculosis with conserved efficiency and lower toxicity and resistance than parent INH.

  9. Synthesis and Conformational Assignment of N-(E-Stilbenyloxymethylenecarbonyl-Substituted Hydrazones of Acetone and o-(m- and p- Chloro- (nitro- benzaldehydes by Means of and NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Przemysław Patorski

    2013-01-01

    Full Text Available Eighteen new N-(E-stilbenyloxyalkylcarbonyl-substituted hydrazones of ortho- (meta- and para- chloro- (nitro- benzaldehydes 1–18 and two analogous hydrazones of acetone 19-20 were prepared. The stereochemical behavior of 1–18 in dimethyl-d6 sulfoxide solution has been studied by NMR and NMR techniques, using spectral data of 19 and 20 as supporting material. The E-geometrical isomers and cis-/trans-amide conformers have been found for these hydrazones. Energy barriers of isomers are reported.

  10. Temperature induced reversible polymorphic phase transformations in a bis-hydrazone compound

    Science.gov (United States)

    Jayant, Vikrant; Das, Dinabandhu

    2018-03-01

    Two reversible polymorphic phase transformation of 2,3-butanedione, 2,3- bis[4,4‧-bis(diethylamino)benzophenone hydrazone] (DEBH) have been identified in DSC experiment. Topotactic phase transformation of three polymorphs has been observed in variable temperature Single Crystal X-ray Diffraction experiment. The reversible phase transformation of bulk material has been confirmed by Powder X-ray diffraction study.

  11. Diclofenac-Based Hydrazones and Spirothiazolidinones: Synthesis, Characterization, and Antimicrobial Properties.

    Science.gov (United States)

    Kocabalkanlı, Ayşe; Cihan-Üstündağ, Gökçe; Naesens, Lieve; Mataracı-Kara, Emel; Nassozi, Mebble; Çapan, Gültaze

    2017-05-01

    We report here the synthesis, structural characterization, and biological evaluation of novel diclofenac-based hydrazone (4a-f) and spirothiazolidinone (5a-f, 6a-f) derivatives designed as potential antimicrobial agents. The compounds were evaluated in vitro for their antiviral activity against a wide spectrum of DNA and RNA viruses. They were further screened in vitro against different strains of bacteria and fungi. The hydrazone derivatives, 4a and 4c-f, were found to be active against herpesviruses (HSV-1, HSV-2, and HSV-1 TK - ), vaccinia virus, and Coxsackie B4 virus, with EC 50 values between 6.6 µg/mL and 14.7 μg/mL, and the selectivity index values were greater than 10 for 4a and 4f. The newly synthesized compounds (4-6) were inactive against the bacterial and the fungal strains tested, at levels below 2500, 1250, or 625 μg/mL. Interestingly, the key intermediate 3 with a free hydrazide moiety displayed antifungal properties against Candida albicans and C. parapsilosis at MIC values of 4.88 µg/mL and 78.12 μg/mL, respectively. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Preparation of catalytically active, covalent α-polylysine-enzyme conjugates via UV/vis-quantifiable bis-aryl hydrazone bond formation.

    Science.gov (United States)

    Grotzky, Andrea; Manaka, Yuichi; Kojima, Taisuke; Walde, Peter

    2011-01-10

    Covalent UV/vis-quantifiable bis-aryl hydrazone bond formation was investigated for the preparation of conjugates between α-poly-d-lysine (PDL) and either α-chymotrypsin (α-CT) or horseradish peroxidase (HRP). PDL and the enzymes were first modified via free amino groups with the linking reagents succinimidyl 6-hydrazinonicotinate acetone hydrazone (S-HyNic, at pH 7.6) and succinimidyl 4-formylbenzoate (S-4FB, at pH 7.2), respectively. The modified PDL and enzymes were then conjugated at pH 4.7, whereby polymer chains carrying several enzymes were obtained. Kinetics of the bis-aryl hydrazone bond formation was investigated spectrophotometrically at 354 nm. Retention of the enzymatic activity after conjugate formation was confirmed by using the substrates N-succinimidyl-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide (for α-CT) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS, for HRP). Thus, not only a mild and efficient preparation and convenient quantification of a conjugate between the polycationic α-polylysine and enzymes could be shown, but also the complete preservation of the enzymatic activity.

  13. Synthesis, structure and study of azo-hydrazone tautomeric equilibrium of 1,3-dimethyl-5-(arylazo)-6-amino-uracil derivatives

    Science.gov (United States)

    Debnath, Diptanu; Roy, Subhadip; Li, Bing-Han; Lin, Chia-Her; Misra, Tarun Kumar

    2015-04-01

    Azo dyes, 1,3-dimethyl-5-(arylazo)-6-aminouracil (aryl = -C6H5 (1), -p-CH3C6H4 (2), -p-ClC6H4 (3), -p-NO2C6H4 (4)) were prepared and characterized by UV-vis, FT-IR, 1H NMR, 13C NMR spectroscopic techniques and single crystal X-ray crystallographic analysis. In the light of spectroscopic analysis it evidences that of the tautomeric forms, the azo-enamine-keto (A) form is the predominant form in the solid state whereas in different solvents it is the hydrazone-imine-keto (B) form. The study also reveals that the hydrazone-imine-keto (B) form exists in an equilibrium mixture with its anionic form in various organic solvents. The solvatochromic and photophysical properties of the dyes in various solvents with different hydrogen bonding parameter were investigated. The dyes exhibit positive solvatochromic property on moving from polar protic to polar aprotic solvents. They are fluorescent active molecules and exhibit high intense fluorescent peak in some solvents like DMSO and DMF. It has been demonstrated that the anionic form of the hydrazone-imine form is responsible for the high intense fluorescent peak. In addition, the acid-base equilibrium in between neutral and anionic form of hydrazone-imine form in buffer solution of varying pH was investigated and evaluated the pKa values of the dyes by making the use of UV-vis spectroscopic methods. The determined acid dissociation constant (pKa) values increase according to the sequence of 2 > 1 > 3 > 4.

  14. Synthesis, structural studies and antituberculosis evaluation of new hydrazone derivatives of quinoline and their Zn(II complexes

    Directory of Open Access Journals (Sweden)

    Mustapha C. Mandewale

    2018-02-01

    Full Text Available The quinoline hydrazone ligands were synthesized through multi-step reactions. The 2-hydroxy-3-formylquinoline derivatives (1a–1c were prepared from acetanilide derivatives as starting materials using Vilsmeier–Haack reaction. Then the condensation of 2-hydroxy-3-formylquinoline derivatives with hydrazide derivatives (2a–2c yielded quinoline hydrazone ligands (3a–3i. The synthesis of a new series of Zn(II complexes carried out by refluxing with these quinoline hydrazone ligands (3a–3i is reported. The molecular structures of the ligands (3a–3i and the Zn complexes were characterized by elemental analysis and spectral studies like FT-IR, 1H and 13C NMR, MS, UV–Visible and fluorescence. The preliminary results of antituberculosis study showed that most of the Zn(II complexes 4a–4i demonstrated very good antituberculosis activity while the ligands 3a–3i showed moderate activity. Among the tested compounds 4e and 4g were found to be most active with minimum inhibitory concentration (MIC of 8.00μM and 7.42 μM respectively against Mycobacterium tuberculosis (H37 RV strain ATCC No-27294 which is comparable to “first and second line” drugs used to treat tuberculosis.

  15. Optimized protocol for the radioiodination of hydrazone-type polymer drug delivery systems

    Czech Academy of Sciences Publication Activity Database

    Sedláček, Ondřej; Kučka, Jan; Hrubý, Martin

    2015-01-01

    Roč. 95, January (2015), s. 129-134 ISSN 0969-8043 R&D Projects: GA MPO FR-TI4/625; GA ČR GAP304/12/0950; GA MŠk(CZ) LH14079 Grant - others:AV ČR(CZ) M200501201 Program:M Institutional support: RVO:61389013 Keywords : doxorubicin * hydrazone * polymer conjugate Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.136, year: 2015

  16. Synthesis of Two Potentially Heptadentate (N4O3 Schiff-base Ligands Derived from Condensation of Tris(3-aminopropyl-amine and Salicylaldehyde or 4-Hydroxysalicylaldehyde. Nickel(II and Copper(II Complexes of the Former Ligand

    Directory of Open Access Journals (Sweden)

    R. V. Parish

    2002-02-01

    Full Text Available Two potentially heptadentate (N4O3 tripodal Schiff-base ligands: tris(3-(salicylideneiminopropylamine (H3L1 and tris(3-(4’-hydroxysalicylideneimino-propylamine (H3L2 have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR. They are derived from the condensation reactions of tris(3-aminopropylamine (tpt, with 3 equivalents of either salicylaldehyde or the ringsubstituted salicylaldehyde, 4-hydroxysalicylaldehyde. The nickel(II and copper(II complexes of H3L1 were obtained from the its reactions Ni(II and Cu(II salts in absolute methanol. These complexes were studied by IR and FAB-Mass spectrometry.

  17. Efficient Method for Aromatic-Aldehyde Oxidation by Cleavage of Their Hydrazones Catalysed by Trimethylsilanolate

    Czech Academy of Sciences Publication Activity Database

    Bürglová, K.; Okorochenkov, S.; Buděšínský, Miloš; Hlaváč, J.

    2017-01-01

    Roč. 2017, č. 2 (2017), s. 389-396 ISSN 1434-193X R&D Projects: GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 Keywords : aldehydes * oxidation * hydrazones * solid-phase synthesis * reaction mechanisms Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.834, year: 2016

  18. Significant effect of surfactant micelles on pH dependent fluorescent off-on-off behavior of Salicylaldehyde-2,4-Dinitrophenylhydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, Priyanka [Department of Chemistry, Gauhati University, Guwahati 781 014 (India); Das, Diganta K., E-mail: digkdas@yahoo.co [Department of Chemistry, Gauhati University, Guwahati 781 014 (India)

    2011-04-15

    The fluorescence response to pH of 2,4 dinitrophenolhydrazone in 1:1 CH{sub 3}OH:H{sub 2}O and micellar mediums-negatively charged sodium dodecylsulphate (SDS), positively charged cetyltrimethyl ammonium bromide (CTAB) and neutral Triton X-100 (TX-100), is reported. At pH 4.0 the fluorescence of the molecule can be switched 'on' by selecting CTAB as the solvent. At pH 6.0 if the medium is TX-100 the fluorescence is 'off', but remains 'on' for the other three solvents. At pH 8.0, fluorescence is 'on' in the solvents except CTAB. SDS and TX-100 switch the fluorescence 'on' at pH 13.0 but for the other two solvents the fluorescence is 'off'. - Research highlights: The fluorescence response to pH of Salicylaldehyde-2,4 Dinitrophenolhydrazone in 1:1 CH{sub 3}OH:H{sub 2}O and in positively charged cetyltrimethyl ammonium bromide (CTAB) micellar medium shows 'off-on-off' behavior. In negatively charged sodium dodecylsulphate (SDS) the response of fluorescence of Salicylaldehyde-2,4 Dinitrophenolhydrazone to pH is 'off-on-on' type while in neutral Triton X-100 it is 'off-on-1/2on' type. At a given pH, fluorescence of 2,4 dinitrophenolhydrazone can be made 'on' or 'off' by selecting an appropriate pH.

  19. Interaction of dinuclear cadmium(II) 5-Cl-salicylaldehyde complexes with calf-thymus DNA

    Energy Technology Data Exchange (ETDEWEB)

    Ristovic, Maja Sumar [Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Faculty of Chemistry, University of Belgrade, Studenski Trg 12-16, Belgrade (Serbia); Zianna, Ariadni; Psomas, George; Hatzidimitriou, Antonios G. [Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Coutouli-Argyropoulou, Evdoxia [Department of Organic Chemistry and Biochemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Lalia-Kantouri, Maria, E-mail: lalia@chem.auth.gr [Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2016-04-01

    Five dinuclear Cd(II) complexes with the anion of 5-Cl-salicylaldehyde (5-Cl-saloH) were synthesized in the absence or presence of the α-diimines: 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (neoc) or 2,2′-dipyridylamine (dpamH) and characterized as [Cd(5-Cl-salo){sub 2}(CH{sub 3}OH)]{sub 2} (1), [Cd(5-Cl-salo){sub 2}(bipy)]{sub 2} (2), [Cd(5-Cl-salo){sub 2}(phen)]{sub 2} (3), [Cd(5-Cl-salo)(neoc)(ONO{sub 2})]{sub 2} (4) and [Cd(5-Cl-salo)(dpamΗ)(ONO{sub 2})]{sub 2} (5). The complexes were characterized by spectroscopic techniques (IR, UV‐vis, {sup 1}H-NMR and {sup 13}C–NMR), elemental analysis and molar conductivity measurements. The structures of four complexes (1–3 and 5) were determined by X-ray crystallography, providing all three possible coordination modes of the ligand 5-Cl-salicylaldehyde, i.e. bidentate or tridentate chelating and/or bridging mode. The complexes bind to calf-thymus (CT) DNA mainly by intercalation, as concluded by the viscosity measurements and present relatively high DNA-binding constants. The complexes exhibit significant ability to displace ethidium bromide (EB) from the EB-DNA complex, thus indirectly proving the intercalation as the most possible binding mode to CT DNA. - Graphical abstract: Cadmium complexes of the formulae [Cd(5-Cl-salo){sub 2}(CH{sub 3}OH)]{sub 2} and [Cd(5-Cl-salo){sub 2}(α-diimine)]{sub 2} or [Cd(5-Cl-salo)(α-diimine)(ONO{sub 2})]{sub 2} have been synthesized and characterized. The complexes bind tightly to CT DNA probably by intercalation competing with ethidium bromide for the intercalation site of DNA. - Highlights: • Synthesis of a series of dinuclear Cd complexes • The complexes characterized by diverse techniques. • The crystal structures of four complexes have been determined. • Intercalation is the most possible binding mode of the complexes to DNA. • The complexes compete with ethidium bromide for the DNA-intercalating sites.

  20. Synthesis and preliminary evaluation of antinociceptive activity of novel isoxazolyl-aryl-hydrazones; Sintese e avaliacao preliminar de atividade antinociceptiva de novas isoxazolil-aril-hidrazonas

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Silvio Leandro Goncalves Bomfim; Almeida, Valderes Moraes de; Almeida, Gleybson Correia de; Boaviagem, Karinna Moura; Mendes, Charles Christophe du Barriere; Faria, Antonio Rodolfo de, E-mail: rodolfo@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Ciencias Farmaceuticas; Goes, Alexandre Jose da Silva; Magalhaes, Laudelina Rodrigues; Silva, Teresinha Goncalves da [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Antibioticos

    2011-07-01

    New 2-isoxazoline aldehydes were synthesized, in good yields, from cycloadduct of the 1,3-dipolar cycloaddition reaction between endocyclic enecarbamate and carboethoxyformonitrile oxide (CEFNO). Condensation of these 2-isoxazoline aldehydes with several phenyl-hydrazines produced new isoxazolyl-aryl-hydrazones, which showed low toxicity and excellent antinociceptive activity, when compared to dipyrone. The antinociceptive activity of isoxazolyl-aryl-hydrazones was performed using the acetic acid-induced mice abdominal constrictions test. (author)

  1. Synthesis of Hydrazone-Modified Nucleotides and Their Polymerase Incorporation onto DNA for Redox Labeling

    Czech Academy of Sciences Publication Activity Database

    Raindlová, Veronika; Pohl, Radek; Klepetářová, Blanka; Havran, Luděk; Šimková, Eva; Horáková Brázdilová, Petra; Pivoňková, Hana; Fojta, Miroslav; Hocek, Michal

    2012-01-01

    Roč. 77, č. 8 (2012), s. 652-662 ISSN 2192-6506 R&D Projects: GA AV ČR(CZ) IAA400040901; GA ČR GBP206/12/G151 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50040702 Keywords : DNA * oligonucleotides * polymerase * hydrazones * nucleotides Subject RIV: CC - Organic Chemistry

  2. Structural, crystallographic, Hirshfeld surface, thermal and antimicrobial evaluation of new sulfonyl hydrazones

    Science.gov (United States)

    Bhat, Mahima; Poojary, Boja; Kumar, S. Madan; Hussain, Mumtaz M.; Pai, Nikhila; Revanasiddappa, B. C.; Kullaiah, Byrappa

    2018-05-01

    This context explains the condensation of various arylsulfonohydrazides with two pyrazole aldehydes to get corresponding hydrazones (6a-f). The hydrazones synthesized were confirmed with the help of IR, NMR, Mass and single crystal X-ray diffraction techniques. From the X-ray analysis it was observed that, all the three compounds 6a, 6c and 6f crystallizes in monoclinic crystal system with P21/c, P21/n and P21/n space group respectively. The intermolecular hydrogen bond interactions of the type Nsbnd H⋯O, Csbnd H⋯O, Csbnd H….C, Osbnd H ⋯O, Osbnd H⋯N and Csbnd H⋯N plays a significant role in the stability of the molecules. The 3D Hirshfeld analyses and 2D fingerprint plots were helpful in decoding the behavior of the interactions and their quantitative contributions towards the packing structure of the crystals. In addition to this, TGA and DTA curves were helpful in explaining the thermal stability of the compounds. Additionally, the antibacterial effectiveness of the molecules synthesized (6a-f) was analyzed against Gram-negative and Gram-positive strains. Interestingly, the compounds with fluorinated pyrazoles (6a and 6c) emerged as good bacterial inhibitors, having scope to produce potent therapeutics in future.

  3. Catalytic Oxidation of Benzophenone Hydrazone with Alumina-supported KMnO4 under Oxygen Atmosphere

    International Nuclear Information System (INIS)

    Lee, Kang Hyeok; Ko, Kwang Youn

    2006-01-01

    KMnO 4 /alumina reagent, which is cheap and environmentally safe, can serve as a catalytic oxidant under O 2 atmosphere for the oxidation of benzophenone hydrazone. To the best of our knowledge, the present works are the first example where KMnO 4 /alumina reagent acts as a catalytic oxidant under O 2 atmosphere. Diphenyldiazomethane (Ph 2 CN 2 ) is widely used for the protection of carboxylic acids by conversion to their diphenylmethyl (dpm) esters since dpm group can be easily deprotected by mild acidic condition or hydrogenolysis, especially in the field of b-lactams and peptides. Diphenyldiazomethane has been prepared by the oxidation of benzophenone hydrazone with reagents such as active manganese dioxide, mercuric oxide, peracetic acid, iodosobenzene diacetate or OXONE. However, some methods suffer from a disadvantage such as toxic nature of reagent, strong oxidative conditions or incompatibility with certain functional groups. For example, OXONE may not be employed for the in situ protection of carboxylic acid containing sulfide group due to the possibility of the concomitant oxidation of sulfide group

  4. Caffeine-hydrazones as anticancer agents with pronounced selectivity toward T-lymphoblastic leukaemia cells

    Czech Academy of Sciences Publication Activity Database

    Kaplánek, R.; Jakubek, M.; Rak, J.; Kejik, Z.; Havlík, M.; Dolenský, B.; Frydrych, I.; Hajduch, M.; Kolář, M.; Bogdanová, K.; Králová, Jarmila; Dzubak, P.; Král, V.

    2015-01-01

    Roč. 60, Jun (2015), s. 19-29 ISSN 0045-2068 Grant - others:GA MŠk(CZ) EE2.3.30.0060; GA MŠk CZ.1.07/2.3.00/30.0041; GA MŠk(CZ) LO1304 Program:EE; LD Institutional support: RVO:68378050 Keywords : Anticancer agents * Cancer treatment * Caffeine -hydrazones * Leukaemia * Selectivity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.252, year: 2015

  5. Palladium-catalyzed three-component reaction of N-tosyl hydrazones, isonitriles and amines leading to amidines.

    Science.gov (United States)

    Dai, Qiang; Jiang, Yan; Yu, Jin-Tao; Cheng, Jiang

    2015-12-04

    A palladium-catalyzed three-component reaction between N-tosyl hydrazones, aryl isonitriles and amines was developed, leading to amidines in moderate to good yields. This procedure features the rapid construction of amidine frameworks with high diversity and complexity. Ketenimines serve as intermediates, which encounter nucleophilic attack by amines to produce amidines.

  6. Tautomeric forms of PPI dendrimers functionalized with 4-(4′-ethoxybenzoyloxy)salicylaldehyde chromophores

    International Nuclear Information System (INIS)

    Franckevičius, M.; Vaišnoras, R.; Marcos, M.; Serrano, J.L.; Gruodis, A.; Galikova, N.; Gulbinas, V.

    2012-01-01

    Highlights: ► SA chromophore groups are formed by bonding terminal groups to PPI dendrimers. ► SA chromophore groups reveal four most stable tautomeric forms. ► Tautomeric properties of SA groups depend on the dendrimer generation and solvent. ► Aggregation of SA chromophores facilitates formation of the trans-keto tautomers. ► Fluorescence of PPI SA dendrimers is attributed to nπ ∗ states of keto tautomers. -- Abstract: Bonding of the promesogenic unit derived from 4-(4′-ethoxybenzoyloxy)salicylaldehyde to the amino terminated PPI dendrimer chains results in formation of the salicylidenimine chromophore groups. Absorption and fluorescence investigations of the dendrimer solutions supported by the quantum chemistry calculations revealed that the chromophore groups may exist in enol and keto tautomeric forms with relative concentrations depending on the dendrimer generation and solvent. The dendrimer fluorescence is attributed to nπ ∗ states of keto tautomers which may also be formed from excited enol tautomers.

  7. The use of a versatile o-vanilloyl hydrazone ligand to prepare SMM-like Dy3 molecular cluster pair.

    Science.gov (United States)

    Xue, Shufang; Zhao, Lang; Guo, Yun-Nan; Zhang, Peng; Tang, Jinkui

    2012-09-14

    A novel lanthanide molecular cluster pair (MCP), displaying single molecule magnet behaviour, was assembled using the novel o-vanilloyl hydrazone ligand, versatile in terms of denticity, tautomerism and the rotatable C-C bond.

  8. Supramolecular structures in N-isonicotinoyl arylaldehydehydrazones: multiple hydrogen-bonding modes in series of geometric isomers.

    Science.gov (United States)

    Wardell, Solange M S V; de Souza, Marcus V N; Wardell, James L; Low, John N; Glidewell, Christopher

    2007-12-01

    Sixteen N-isonicotinoyl arylaldehydehydrazones, NC(5)H(4)CONHN=CHC(6)H(4)R, have been studied and the structures of 14 of them have been determined, including the unsubstituted parent compound with R = H, and the complete sets of 2-, 3- and 4-substituted geometric isomers for R = F, Br and OMe, and two of the three isomers for R = Cl and OEt. The 2-chloro and 3-chloro derivatives are isostructural with the corresponding bromo isomers, and all compounds contain trans amide groups apart from the isostructural pair where R = 2-Cl and 2-Br, which contain cis amide groups. The structures exhibit a wide range of direction-specific intermolecular interactions, including eight types of hydrogen bonds, N-H...N, N-H...O, O-H...O, O-H...N, C-H...N, C-H...O, C-H...pi(arene) and C-H...pi(pyridyl), as well as pi...pi stacking interactions. The structures exhibit a very broad range of combinations of these interactions: the resulting hydrogen-bonded supramolecular structures range from one-dimensional when R = 2-F, 2-OMe or 2-OEt, via two-dimensional when R = 4-F, 3-Cl, 3-Br, 4-OMe or 3-OEt, to three-dimensional when R = H, 3-F, 2-Cl, 2-Br, 4-Br or 3-OMe. Minor changes in either the identity of the substituent or its location can lead to substantial changes in the pattern of supramolecular aggregation, posing significant problems of predictability. The new structures are compared with the recently published structures of the isomeric series having R = NO(2), with several monosubstituted analogues containing 2-pyridyl or 3-pyridyl units rather than 4-pyridyl, and with a number of examples having two or three substituents in the aryl ring: some 30 structures in all are discussed.

  9. Catalytic Oxidation of Benzophenone Hydrazone with Alumina-supported KMnO{sub 4} under Oxygen Atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Hyeok; Ko, Kwang Youn [Ajou University, Suwon (Korea, Republic of)

    2006-02-15

    KMnO{sub 4}/alumina reagent, which is cheap and environmentally safe, can serve as a catalytic oxidant under O{sub 2} atmosphere for the oxidation of benzophenone hydrazone. To the best of our knowledge, the present works are the first example where KMnO{sub 4}/alumina reagent acts as a catalytic oxidant under O{sub 2} atmosphere. Diphenyldiazomethane (Ph{sub 2}CN{sub 2}) is widely used for the protection of carboxylic acids by conversion to their diphenylmethyl (dpm) esters since dpm group can be easily deprotected by mild acidic condition or hydrogenolysis, especially in the field of b-lactams and peptides. Diphenyldiazomethane has been prepared by the oxidation of benzophenone hydrazone with reagents such as active manganese dioxide, mercuric oxide, peracetic acid, iodosobenzene diacetate or OXONE. However, some methods suffer from a disadvantage such as toxic nature of reagent, strong oxidative conditions or incompatibility with certain functional groups. For example, OXONE may not be employed for the in situ protection of carboxylic acid containing sulfide group due to the possibility of the concomitant oxidation of sulfide group.

  10. Mixed complex combinations with a new schiff base used as membranes ion-selective for copper and nickel ions, analytical applications)

    International Nuclear Information System (INIS)

    Mitu, L.; Tigae, C.

    2009-01-01

    Four electrodes with liquid membrane, Cu/sup 2+/ -selective and Ni/sup 2+/ -selective, not previously described in the literature, were prepared and characterized. Electrodes 1 and 2 are based on mixed complexes of Cu(II) and Ni(II) with isonicotinoylhydrazone-2-aldehyde pyrrole (INH2AP= HL/sup 1/) as ligand and electrodes 3 and 4 are based on the mixed complexes with isonicotinoyl- hydrazone-2-hydroxy-l-naphthaldehyde (INH2HNA = H/sub 2/L/sup 2/ ) Cu/sup 2+/. selective and Ni/sup 2+/ -selective electrodes have been used to determine the copper and nickel ions in aqueous solutions, by both direct potentiometric and potentiometric titration with EDTA. They have also been used for determining the Cu/sup 2+/ and Ni/sup 2+/ ions in industrial waters by direct potentiometry. The analytical results obtained have been checked by the standard addition method and by comparison with determinations through atomic absorption spectrometry. (author)

  11. Dynamic Combinatorial Chemistry and Organocatalysis with Thiosemicarbazones and Organocatalysts for Hydrazone and Oxime Bioconjugations

    DEFF Research Database (Denmark)

    Larsen, Dennis

    new types of catalysts were discovered: The 2-aminophenols and the 2-(aminomethyl)benzimidazoles. With aldehyde substrates none of the newly discovered catalysts were as effective as a previously discovered benzenephosphonic acid, but with aromatic ketones, an otherwise challenging class of substrates......, the 2-(aminomethyl)benzimidazoles showed promising efficacies, reaching an hitherto unseen 5-fold rate enhancement for hydrazone formation on model acetophenone at pH 7.4....

  12. Aminoguanidine hydrazones (AGH's) as modulators of norfloxacin resistance in Staphylococcus aureus that overexpress NorA efflux pump.

    Science.gov (United States)

    Dantas, Natalina; de Aquino, Thiago Mendonça; de Araújo-Júnior, João Xavier; da Silva-Júnior, Edeildo; Gomes, Ednaldo Almeida; Gomes, Antoniel Augusto Severo; Siqueira-Júnior, José Pinto; Mendonça Junior, Francisco Jaime Bezerra

    2018-01-25

    One of the promising fields for improving the effectiveness of antimicrobial agents is their combination with efflux pump inhibitors (EPIs), which besides expanding the use of existing antibiotics. The goal of this research was to evaluate a series of aminoguanidine hydrazones (AGH's, 1-19) as antibacterial agents and NorA efflux pump inhibitors in Staphylococcus aureus strain SA-1199B. Molecular modeling and docking studies were also performed in order to explain at the molecular level the interactions of the compounds with the generated NorA efflux pump model. The MICs of the antibiotic and ethidium bromide were determined by microdilution assay in absence or presence of a subinhibitory concentration of aminoguanidine hydrazones and macrophages viability was determined through MTT assay. Bioinformatic software Swiss-Model and AutoDock 4.2 were used to perform modeling and docking studies, respectively. As results, all AGH's were able to potentiate the action for the antibiotic norfloxacin, causing MIC's reduction of 16-fold and 32-fold to ethidium bromide. In the cell viability test, the concentration of 10 μg/mL showed better results than 90% and the concentration of 1000 μg/mL showed the lowest viability, reaching a maximum of 50% for the analyzed aminoguanidine hydrazones. Molecular docking studies showed that both norfloxacin and derivative 13 were recognized by the same binding site of NorA pump, suggesting a competitive mechanism. The present work demonstrated for the first time that AGH derivatives have potential to be putative inhibitors of NorA efflux pump, showing a promising activity as an antibacterial drug development. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

    Directory of Open Access Journals (Sweden)

    Volodymyr V. Tkachenko

    2014-12-01

    Full Text Available The switchable three-component reactions of 5-amino-3-methylisoxazole, salicylaldehyde and N-aryl-3-oxobutanamides under different conditions were studied and discussed. The unexpected influence of the aryl substituent in N-aryl-3-oxobutanamides on the behavior of the reaction was discovered. The key influence of ultrasonication and Lewis acid catalysts led to an established protocol to selectively obtain two or three types of heterocyclic scaffolds depending on the substituent in the N-aryl moiety.

  14. Condensed, solution and gas phase behaviour of mono- and dinuclear 2,6-diacetylpyridine (dap) hydrazone copper complexes probed by X-ray, mass spectrometry and theoretical calculations.

    Science.gov (United States)

    Neto, Brenno A D; Viana, Barbara F L; Rodrigues, Thyago S; Lalli, Priscila M; Eberlin, Marcos N; da Silva, Wender A; de Oliveira, Heibbe C B; Gatto, Claudia C

    2013-08-28

    We describe the synthesis of novel mononuclear and dinuclear copper complexes and an investigation of their behaviour in solution using mass spectrometry (ESI-MS and ESI-MS/MS) and in the solid state using X-ray crystallography. The complexes were synthesized from two widely used diacetylpryridine (dap) ligands, i.e. 2,6-diacetylpyridinebis(benzoic acid hydrazone) and 2,6-diacetylpyridinebis(2-aminobenzoic acid hydrazone). Theoretical calculations (DFT) were used to predict the complex geometries of these new structures, their equilibrium in solution and energies associated with the transformations.

  15. Synthesis of naphthalenes through three-component coupling of alkynes, Fischer carbene complexes, and benzaldehyde hydrazones via isoindole intermediates.

    Science.gov (United States)

    Duan, Shaofeng; Sinha-Mahapatra, Dilip K; Herndon, James W

    2008-04-17

    The synthesis of naphthalene derivatives through three-component coupling of 2-alkynylbenzaldehyde hydrazones with carbene complexes and electron-deficient alkynes has been examined. The reaction involves formation of an isoindole derivative, followed by intramolecular Diels-Alder reaction, followed by nitrene extrusion. The reaction was highly regioselective using unsymmetrical alkynes.

  16. Synthesis of Naphthalenes through Three-Component Coupling of Alkynes, Fischer Carbene Complexes, and Benzaldehyde Hydrazones via Isoindole Intermediates

    OpenAIRE

    Duan, Shaofeng; Sinha-Mahapatra, Dilip K.; Herndon, James W.

    2008-01-01

    The synthesis of naphthalene derivatives through three-component coupling of 2-alkynylbenzaldehyde hydrazones with carbene complexes and electron-deficient alkynes has been examined. The reaction involves formation of an isoindole derivative, followed by intramolecular Diels–Alder reaction, followed by nitrene extrusion. The reaction was highly regioselective using unsymmetrical alkynes.

  17. 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...ABSTRACT A series of novel hydrazide-hydrazone derivatives were synthesized and evaluated for their larvicidal and adult topical activity against...4b) showed noteworthy larvacidal activity against Aedes aegypti. Dose-response data of compound 4b showed LC50 and LC90 values of 30.5 (15.4 – 22.7

  18. A Highly Efficient Catalyst for Oxime Ligation and Hydrazone-Oxime Exchange Suitable for Bioconjugation

    OpenAIRE

    Rashidian, Mohammad; Mahmoodi, Mohammad M.; Shah, Rachit; Dozier, Jonathan K.; Wagner, Carston R.; Distefano, Mark D.

    2013-01-01

    Imine-based reactions are useful for a wide range of bioconjugation applications. Although aniline is known to catalyze the oxime ligation reaction under physiological conditions, it suffers from slow reaction kinetics, specifically when a ketone is being used or when hydrazone-oxime exchange is performed. Here, we report on the discovery of a new catalyst that is up to 15 times more efficient than aniline. That catalyst, m-phenylenediamine (mPDA), was initially used to analyze the kinetics o...

  19. Crystal and molecular structure of three molybdenum (6) dioxocomplexes with heterocyclic hydrazones

    International Nuclear Information System (INIS)

    Ilyukhin, A.B.; Sergienko, V.S.

    1994-01-01

    The X-ray diffraction investigation into three Mo(6) dioxocomplexes with heterocyclic hydrazones has been made. In all compounds the Mo atom has a deformed octahedral coordination by two O atoms of cis-dioxogroups, N atoms (azomethane), N (heterocyclie), O (phenol) of tridentate organic ligand. Sixth position in Mo coordination octahedron is due to O atom of methanol solvated molecule in the 1,3 structures or N atom of γ-picoline molecule in the 2 structure. The packing of structural units in the crystals of the 1-3 compounds is under consideration. 12 refs., 5 figs., 3 tabs

  20. Synthesis of Naphthalenes through Three-Component Coupling of Alkynes, Fischer Carbene Complexes, and Benzaldehyde Hydrazones via Isoindole Intermediates

    Science.gov (United States)

    Duan, Shaofeng; Sinha-Mahapatra, Dilip K.; Herndon, James W.

    2008-01-01

    The synthesis of naphthalene derivatives through three-component coupling of 2-alkynylbenzaldehyde hydrazones with carbene complexes and electron-deficient alkynes has been examined. The reaction involves formation of an isoindole derivative, followed by intramolecular Diels–Alder reaction, followed by nitrene extrusion. The reaction was highly regioselective using unsymmetrical alkynes. PMID:18351767

  1. Extractive spectrophotometric determination of molybdenum using p-chloroisonitroso acetophenone hydrazone

    International Nuclear Information System (INIS)

    Lokhande, R.S.; Agashe, A.P.; Hundiwale, D.G.

    2001-01-01

    Separation technique like solvent extraction can be advantageously employed for the determination of metals at low concentration in micrograms using spectrophotometric methods. Hydrazoxine has been used for the extraction and spectrophotometric determination of metals at trace level as well as for the studies of transition metals in complex form. In the present paper, solvent extraction technique has been used to develop methods for the separation and spectrophotometric determination of Mo(VI) with p-chloroisonitroso acetophenone hydrazone was extracted into chloroform from aqueous solution in the pH range 8 to 8.5. The absorption maxima was also tried for the extracted species and Beer's law was also studied for its applicability. In this, interference from the foreign ion has also been examined. (author)

  2. Comparing of 5-Nonylsalicylaldoxime and Salicylaldehyde Characterization Using Magnesium Salt Formylation Process

    International Nuclear Information System (INIS)

    Pouramini, Zeinab; Moradi, Ali

    2012-01-01

    5-Nonylsalicylaldoxime and salicylaldehyde are two derivatives of phenolic compounds which are very applicable materials in industries. Formerly the formylation of phenolic derivatives were carried out by Rimer-Tiemann method. In this work both of these two materials were synthesized by magnesium meditated formylation technique and their structural characterizations were compared by instrumental analysis technique. In order to achieve a selectively orthoformylated product, the hydroxyl group of nonylphenol (or phenol) was first modified by magnesium methoxide. The nonylphenol magnesium salt was then formylated by paraformaldehyde. The oximation reaction was finally applied to the prepared non-ylsalicylaldehyde magnesium salt by liquid extracting via water and acid washing and other extractions. The solvent was finally removed by evaporation under reduced pressure. Some instrumental analysis such as 1 H-NMR, GC/MS and FT-IR spectra were taken on the product in order to interpret the reaction characterization quantitatively and qualitatively. The formaldehyde and oxime functional groups of two compounds were investigated through 1 H-NMR and FT-IR spectra and were compared. The yield of methoxilation was very good and the yields of formylation and oximation reactions were about 90% and 85% respectively. The orthoselectivity of formylation reaction were evaluated by comparing of the relevant spectra. The GC/MS spectra also confirmed the obtained results

  3. Reagents for Astatination of Biomolecules. 5. Evaluation of hydrazone linkers in 211At- and 125I-labeled closo-decaborate(2-) conjugates of Fab′ as a means of decreasing kidney retention

    Science.gov (United States)

    Wilbur, D. Scott; Chyan, Ming-Kuan; Hamlin, Donald K.; Nguyen, Holly; Vessella, Robert L.

    2011-01-01

    Evaluation of monoclonal antibody (MAb) fragments (e.g. Fab′, Fab or engineered fragments) as cancer-targeting reagents for therapy with the α-particle emitting radionuclide astatine-211 (211At) has been hampered by low in vivo stability of the label and a propensity of these proteins localize to kidneys. Fortunately, our group has shown that the low stability of the 211At label, generally a meta- or para-[211At]astatobenzoyl conjugate, on MAb Fab′ fragments can be dramatically improved by use of closo-decaborate(2-) conjugates. However, the higher stability of radiolabeled MAb Fab′ conjugates appears to result in retention of the radioactivity in kidneys. This investigation was conducted to evaluate whether the retention of radioactivity in kidney might be decreased by the use of acid-cleavable hydrazone between the Fab′ and the radiolabeled closo-decaborate(2-) moiety. Five conjugation reagents containing sulfhydryl-reactive maleimide groups, a hydrazone functionality and a closo-decaborate(2-) moiety were prepared. In four of the five conjugation reagents, a discrete polyethylene glycol (PEG) linker was used, and one substituent adjacent to the hydrazone was varied (phenyl, benzoate, anisole or methyl) to provide varying acid-sensitivity. In the initial studies, the five maleimido-closo-decaborate(2-) conjugation reagents were radioiodinated (125I or 131I), then conjugated with an anti-PSMA Fab′ (107-1A4 Fab′). Biodistributions of the five radioiodinated Fab′ conjugates were obtained in nude mice at 1, 4 and 24 h post injection (pi). In contrast to closo-decaborate(2-) conjugated to 107-1A4 Fab′ through a non-cleavable linker, two conjugates containing either a benzoate or a methyl substituent on the hydrazone functionality displayed clearance rates from kidney, liver and spleen that were similar to those obtained with directly radioiodinated Fab′ (i.e. no conjugate). The maleimido-closo-decaborate(2-) conjugation reagent containing a benzoate

  4. An improved method of 18F peptide labeling: hydrazone formation with HYNIC-conjugated c(RGDyK)

    International Nuclear Information System (INIS)

    Lee, Yun-Sang; Jeong, Jae Min; Kim, Hyung Woo; Chang, Young Soo; Kim, Young Joo; Hong, Mee Kyung; Rai, Ganesha B.; Chi, Dae Yoon; Kang, Won Jun; Kang, Joo Hyun; Lee, Dong Soo; Chung, June-Key; Lee, Myung Chul; Suh, Young-Ger

    2006-01-01

    Radiolabeled α v β 3 -integrin antagonists are increasingly investigated as a means of imaging angiogenesis. Several methods of labeling α v β 3 -integrin binding peptide with 18 F have been reported recently. In the present study, we devised a straightforward means for labeling Arg-Gly-Asp (RGD) peptide with 18 F via hydrazone formation between c(RGDyK)-hydrazinonicotinic acid (HYNIC) (3) and 4-[ 18 F]-fluorobenzaldehyde ([ 18 F]4). The resulting reaction mixture was purified by HPLC to give 4'-[ 18 F]-fluorobenzylidenehydrazone-6-nicotinamide-c(RGDyK) ([ 18 F]5). The conjugation efficiency of 3 and 4 to form [ 18 F]5 was 95.2%, and the radiochemical purity of [ 18 F]5 after purification was >99%. The specific activity of [ 18 F]5 estimated by radio-HPLC was 20.5 GBq/μmol (end of synthesis). Competitive binding assay of c(RGDyK) (1) and 5 was performed using [ 125 I]iodo-c(RGDyK) as a radioligand, and K i values were found to be 2.8 and 21.7 nM, respectively. For the biodistribution study, the angiogenic mouse model was established by inducing unilateral ischemia on the left hindlimbs of ICR mice after femoral artery ablation. Seven days after inducing ischemia, [ 18 F]5 was administered to the mice through the tail vein. Ischemic muscle uptake of [ 18 F]5 was significantly higher than that of normal muscle (P 18 F]5. Here, we successfully labeled RGD peptide with 18 F via hydrazone formation between 3 and 4, resulting to [ 18 F]5. [ 18 F]5 was found to have high affinity for α v β 3 -integrin and to accumulate specifically in ischemic hindlimb muscle of mice. We suggest that 18 F labeling via formation of hydrazone between HYNIC peptide and [ 18 F]4 is a useful method for labeling c(RGDyK), which can be applied for imaging angiogenesis

  5. Fast Hydrazone Reactants: Electronic and Acid/Base Effects Strongly Influence Rate at Biological pH

    OpenAIRE

    Kool, Eric T.; Park, Do-Hyoung; Crisalli, Pete

    2013-01-01

    Kinetics studies with structurally varied aldehydes and ketones in aqueous buffer at pH 7.4 reveal that carbonyl compounds with neighboring acid/base groups form hydrazones at accelerated rates. Similarly, tests of a hydrazine with a neighboring carboxylic acid group show that it also reacts at an accelerated rate. Rate constants for the fastest carbonyl/hydrazine combinations are 2–20 M−1sec−1, which is faster than recent strain-promoted cycloaddition reactions.

  6. Chemical modification of silica gel with synthesized Schiff base hydrazone derivative and application for preconcentration and separation of U(VI) ions from aqueous solutions

    International Nuclear Information System (INIS)

    Gamze Karayel Incili; Gul Asiye Aycik

    2014-01-01

    Schiff base hydrazone derivative (HL) sorbent was synthesized according to the literature to be used in the adsorption and preconcentration of U(VI) ions from aqueous solution and it was exposed to immobilization, and new solid support material was obtained. For this purpose, Schiff base hydrazone derivative (HL) was chemically bonded to silica gel surface immobilized 3-aminopropyl trimethoxysilane, then analyzed by Fourier transform infrared, Brunauer-Emmett-Teller, scanning electron microscopy and elemental analysis. The influence of the solution pH, amount of sorbent, contact time, temperature, foreign ion effect and initial U(VI) concentration was investigated. The maximum U(VI) uptake capacity was found to be 8.46 mg/g. (author)

  7. Evaluation of antituberculosis activity and DFT study on dipyrromethane-derived hydrazone derivatives

    Science.gov (United States)

    Rawat, Poonam; Singh, R. N.; Niranjan, Priydarshni; Ranjan, Alok; Holguín, Norma Rosario Flores

    2017-12-01

    This paper evaluates the anti-tubercular activity of dipyrromethane-derived hydrazones derivatives (3a-d) against strain of Mycobacterium tuberculosis H37Rv. The newly synthesized compounds have been obtained in good yield based on the condensation of aromatic aldehyde derivatives with pyrrole hydrazone in presence of catalyst and well characterized with spectroscopic methods (1H, 13C NMR, Mass spectrometry) and elemental analysis. The singlet observed in the experimental 1H and 13C NMR spectra in the range of 5.3-5.7 ppm and 30-33.86 ppm, respectively, indicating that two pyrrole units are joined at meso position. The electronic transitions observed in the experimental spectra are n→π* and π →π* in nature. Experimental and theoretical findings corroborate well with each other. The substitution of acceptor group (-NO2) at ortho- and meta-positions of benzene ring, present at meso-position of dipyrromethane is responsible for variation in β0 values. The calculated NLO of (3a-d) are much greater than those of p-nitroaniline (PNA). The solvent induced effects on the non-linear optical properties were studied and found to enhance NLO properties of the molecules as dielectric constants of the solvents increases. On the basis of results it is anticipated that these dipyrromethanes will be useful for both antimicrobial and non-linear optical (NLO) applications. With the help of Microplate Alamar Blue assay (MABA) method all (3a-d) compounds were screened for their anti-tubercular activity and found that 3b and 3d have higher inhibitory activity against strain of M. tuberculosis H37Rv.

  8. Synthesis and biological activity evaluation of hydrazone derivatives based on a Tröger's base skeleton

    Czech Academy of Sciences Publication Activity Database

    Kaplánek, R.; Havlík, M.; Dolenský, B.; Rak, J.; Džubák, P.; Konečný, P.; Hajdúch, M.; Králová, Jarmila; Král, V.

    2015-01-01

    Roč. 23, č. 7 (2015), s. 1651-1659 ISSN 0968-0896 R&D Projects: GA ČR(CZ) GAP303/11/1291 Grant - others:GA MŠk(CZ) EE2.3.30.0060; GA MŠk(CZ) LO1304 Program:EE; LD Institutional support: RVO:68378050 Keywords : Anticancer agents * Cancer treatment * Complexation studies * Hydrazone * Troger's base Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.923, year: 2015

  9. Synthesis, crystal structure and biological activity of the Schiff base organotin(IV) complexes based on salicylaldehyde-o-aminophenol

    Science.gov (United States)

    Tan, Yu-Xing; Zhang, Zhi-Jian; Liu, Yang; Yu, Jiang-Xi; Zhu, Xiao-Ming; Kuang, Dai-Zhi; Jiang, Wu-Jiu

    2017-12-01

    Schiff base organotin(IV) complexes C1 ∼ C5b have been synthesized via the reaction of the substituted salicylaldehyde-o-aminophenol Schiff base ligands (L1 ∼ L3) with the dibenzyltin dichloride, n-butyltin trichloride or dibutyltin oxide, respectively. The complexes have been characterized by IR, UV-Vis, 1H NMR, 13C NMR spectra, elemental analysis and the crystal structures have been determined by X-ray diffraction. The anticancer activity of the Schiff base ligand and complexes C1 ∼ C5b against five species of cancer cell which are Hela, MCF7, HepG2, Colo205, NCIsbnd H460 were tested respectively, the tests showed that C1 ∼ C5b exhibited significant anticancer activity for the cancer cells in comparison with the ligand, and the activity was greater than carboplatin.

  10. Synthesis, structures, spectroscopy and antimicrobial properties of complexes of copper(II) with salicylaldehyde N-substituted thiosemicarbazones and 2,2'-bipyridine or 1,10-phenanthroline.

    Science.gov (United States)

    Lobana, Tarlok S; Indoria, Shikha; Jassal, Amanpreet Kaur; Kaur, Harpreet; Arora, Daljit S; Jasinski, Jerry P

    2014-04-09

    Among the biometals (Cu, Co, Ni-cofactors in many enzymes), copper derivatives of O, N, S-donor salicylaldehyde thiosemicarbazones have received considerable attention owing to their potential biological applications. Eight new complexes of salicylaldehyde-N-substituted thiosemicarbazones [5-MeO-2-HO-C₆H₄-C(2)(H)N(3)-N(2)H-C(1)(S)-N(1)HR; R = Me, H2L(1); Et, H₂L(1), Ph, H₂L(3), H, H₂L(4)] with copper(II), namely, [Cu(κ(3)-O,N,S-L)( κ(2)-N,N-L')] {(L)(2-) = (L(1))(2-), L' = bipy, 1, phen, 2; (L)(2-) = (L(2))(2-), L' = bipy, 3, phen, 4; (L)(2-) = (L(3))(2-), L' = bipy, 5, phen, 6; (L)(2-) = (L(4))(2-), L' = bipy, 7, phen, 8} have been isolated. Complexes have slightly distorted square pyramidal geometry around the metal center (τ parameter = 0.243-0.357) and display weak to intense fluorescence in the region, 375-475 nm. These copper complexes have shown significant growth inhibitory activity (antimicrobial activity) against Staphylococcus aureus (MTCC740), methicillin resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae 1 (MTCC109), Shigella flexneri (MTCC1457), Pseudomonas aeruginosa (MTCC741) and Candida albicans (MTCC227). The activity against MRSA is an interesting observation as the commercially available gentamycin is found to be inactive against this bacterial strain. Specifically complex 5 formed by 5-methoxysalicylaldehyde-N-phenylthiosemicatbazone has shown novel antimicrobial activity against various bacteria and yeast investigated. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  11. CATALYST-FREE REACTIONS UNDER SOLVENT-FEE CONDITIONS: MICROWAVE-ASSISTED SYNTHESIS OF HETEROCYCLIC HYDRAZONES BELOW THE MELTING POINT OF NEAT REACTANTS: JOURNAL ARTICLE

    Science.gov (United States)

    NRMRL-CIN-1437 Jeselnik, M., Varma*, R.S., Polanc, S., and Kocevar, M. Catalyst-free Reactions under Solvent-fee Conditions: Microwave-assisted Synthesis of Heterocyclic Hydrazones below the Melting Point of Neat Reactants. Published in: Chemical Communications 18:1716-1717 (200...

  12. Synthesis of 2,4,6-trichlorophenyl hydrazones and their inhibitory potential against glycation of protein.

    Science.gov (United States)

    Khan, Khalid Mohammed; Shah, Zarbad; Ahmad, Viqar Uddin; Khan, Momin; Taha, Muhammad; Rahim, Fazal; Jahan, Humera; Perveen, Shahnaz; Choudhary, M Iqbal

    2011-11-01

    2,4,6-Trichlorophenyl hydrazones 1-35 were synthesized and their in vitro antiglycation potential was evaluated. Compounds 14 (IC50 = 27.2 ± 0.00 μM), and 18 (IC50 = 55.7 ± 0.00 μM) showed an excellent activity against glycation of protein, better than the standard (rutin, IC50 = 70 ± 0.50 μM). This study thus identified a novel series of antiglycation agents. A structure-activity relationship has been studied, and all the compounds were characterized by spectroscopic techniques.

  13. Fate of 1-aminoproline and urinary excretion of 1-aminoprolyl hydrazone of pyridoxal in rats

    International Nuclear Information System (INIS)

    Tsuji, Hideaki; Moritoki, Keiko; Ogawa, Tadashi; Sasaoka, Kei

    1977-01-01

    1-Aminoproline-U- 14 C was administered to rats by intraperitoneal injection. The radioactivity was distributed in all the tissues examined. Among them, kidney, lung, liver and spleen had high specific activity. The radioactivity in the tissues and blood decreased rapidly as a function of time, except in brain. About 80% of the radioactivity administered was excreted in urine within 24 hr. Besides intact 1-aminoproline, several radioactive compounds were detected in the urine sample, and one of them was identified as 1-aminopropyl hydrazone of pyridoxal. (auth.)

  14. Synthesis, characterization and biological assay of Salicylaldehyde Schiff base Cu(II) complexes and their precursors

    Science.gov (United States)

    Iftikhar, Bushra; Javed, Kanwal; Khan, Muhammad Saif Ullah; Akhter, Zareen; Mirza, Bushra; Mckee, Vickie

    2018-03-01

    Three new Schiff base ligands were synthesized by the reaction of Salicylaldehyde with semi-aromatic diamines, prepared by the reduction of corresponding dinitro-compounds, and were further used for the formation of complexes with Cu(II) metal ion. The structural features of the synthesized compounds were confirmed by their physical properties and infrared, electronic and NMR spectroscopic techniques. The studies revealed that the synthesized Schiff bases existed as tetradentate ligands and bonded to the metal ion through the phenolic oxygen and azomethine nitrogen. One of the dinitro precursors was also analyzed by single crystal X-ray crystallography, which showed that it crystallizes in monoclinic system with space group P2/n. The thermal behavior of the Cu(II) complexes was determined by thermogravimetric analysis (TGA) and kinetic parameters were evaluated from the data. Schiff base ligands, their precursors and metal complexes were also screened for antibacterial, antifungal, antitumor, Brine shrimp lethality, DPPH free radical scavenging and DNA damage assays. The results of these analyses indicated the substantial potential of the synthesized Schiff bases, their precursors and Cu(II) complexes in biological field as future drugs.

  15. Synthesis, structure characterization and biological studies on a new aromatic hydrazone, 5-(2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)hydrazono)-2,2-dimethyl-1,3-dioxane-4,6-dione, and its transition metal complexes

    Science.gov (United States)

    Kumar, Shubha S.; Biju, S.; Sadasivan, V.

    2018-03-01

    A new aromatic hydrazone 5-(2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)hydrazono)-2,2-dimethyl-1,3-dioxane-4,6-dione has been synthesized by Japp-Klingemann reaction from diazotized 4-aminoantipyrine and Meldrum's acid. A few 3d-metal ion complexes of this hydrazone were synthesized. The compound and its complexes were characterized by UV-Visible, 1H NMR, ESR, Mass spectral, molar conductance and magnetic susceptibility measurements. The compound was found to exist in hydrazone form in solid state and solution from SXRD and 1H NMR study. The influence of pH on the molecule was studied and found that it shows azo/enol-hydrazone tautomerism in solution. This molecule act as a univalent tridentate ligand and the complexes were assigned to have a 1:2 stoichiometry (M:L). The antioxidant properties of the compounds were explored by DPPH assay and found that the ligand possesses better free radical scavenging effect than the complexes. Antimicrobial activities of these compounds were investigated and were found to be active.

  16. Spectrophotometric speciation of Fe(II) and Fe(III) using hydrazone-micelle systems and flow injections

    International Nuclear Information System (INIS)

    Khojali, Inas Osman

    1999-04-01

    Two hydrazones were synthesised, namely salicylhyrazone (SH) and trihydroxyacetophenone (THAPH) were synthesised with the objective of developing a method for determining of Fe(II) and Fe(III) in the presence of each other and hence the total iron.those hydrazones were selected so as to combine the ability of phenolic compounds to complex Fe(III) ions and the complexing characteristics of hydrazones. The complexes of Fe(II) S H and Fe(III) S H as well those of Fe(II)-THAPH and Fe(III)-THAPH had shown maximum absorbance at λ=412 nm which was not not modified by presence of micelles i.e. sodium n-dodecyl sulphate (SDS) and n-hexa dodecyl pyridinium bromide. The maximum absorbance for all complexes takes place around a neutral pH. Generally, in addition, of n-hexa dodecylpyridinium bromide to fe(II)-SH and Fe(III)-SH absorbance of the complexes increases with increasing the concentration of the micelle. The effects of the addition of sodium n-dodecyle sulphate (SDS) to Fe(III)-SH is also studied. Generally, increasing the concentration of the micelle decrease the absorbance of the complexes. To study the effect of the presence of Fe(II) and Fe(III) on the determination of each other,mixtures of Fe(II)-SH and Fe(III)-SH are studied. However, the use of ascorbic acid as a reducing reagent for Fe(III) did not produce the needed results but non reducible results, which may be due to the masking effect of ascorbic acid and thus making the metal not available to the ligand. However, conversion of Fe(II) to Fe(III) prior to the determination was avoided as this requires the use of oxidant, which will oxidise the ligand as well. To establish the condition for the maximum absorbance of THAPH complexes, the effect of the base was investigated by using sodium and ammonium hydroxide. Generally, increasing the concentration of the base decreases the abosrbance. as expected, ammonium hydroxide produced positive results than sodium hydroxide. After establishing the optimum Fi

  17. Correlation of the antimicrobial activity of salicylaldehydes with broadening of the NMR signal of the hydroxyl proton. Possible involvement of proton exchange processes in the antimicrobial activity.

    Science.gov (United States)

    Elo, Hannu; Kuure, Matti; Pelttari, Eila

    2015-03-06

    Certain substituted salicylaldehydes are potent antibacterial and antifungal agents and some of them merit consideration as potential chemotherapeutic agents against Candida infections, but their mechanism of action has remained obscure. We report here a distinct correlation between broadening of the NMR signal of the hydroxyl proton of salicylaldehydes and their activity against several types of bacteria and fungi. When proton NMR spectra of the compounds were determined using hexadeuterodimethylsulfoxide as solvent and the height of the OH proton signal was measured, using the signal of the aldehyde proton as an internal standard, it was discovered that a prerequisite of potent antimicrobial activity is that the proton signal is either unobservable or relatively very low, i.e. that it is extremely broadened. Thus, none of the congeners whose OH proton signal was high were potent antimicrobial agents. Some congeners that gave a very low OH signal were, however, essentially inactive against the microbes, indicating that although drastic broadening of the OH signal appears to be a prerequisite, also other (so far unknown) factors are needed for high antimicrobial activity. Because broadening of the hydroxyl proton signal is related to the speed of the proton exchange process(es) involving that proton, proton exchange may be involved in the mechanism of action of the compounds. Further studies are needed to analyze the relative importance of different factors (such as electronic effects, strength of the internal hydrogen bond, co-planarity of the ring and the formyl group) that determine the rates of those processes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  18. Catalytic oxidation of olefins and sulfides in the presence of hydrazone-oxidovanadium(V) complex containing VOCl.sub.2./sub..sup.+./sup. core

    Czech Academy of Sciences Publication Activity Database

    Bikas, R.; Ghorbanloo, M.; Jafari, S.; Eigner, Václav; Dušek, Michal

    2016-01-01

    Roč. 453, Nov (2016), s. 78-85 ISSN 0020-1693 R&D Projects: GA ČR(CZ) GA14-03276S; GA MŠk LO1603 Institutional support: RVO:68378271 Keywords : oxidovanadium(V) * catalytic oxidation * hydrazone ligand * crystal structure * VOCl 2 + Subject RIV: CA - Inorganic Chemistry Impact factor: 2.002, year: 2016

  19. Synthesis and Biological Evaluation of New (−-Gossypol-Derived Schiff Bases and Hydrazones

    Directory of Open Access Journals (Sweden)

    Vu Van Vu

    2017-01-01

    Full Text Available A series of 14 new (--gossypol Schiff bases and hydrazones have been synthesized via an in situ procedure in high yields. Structural data showed that all target compounds exist as the enamine tautomer. Bioassays showed that several compounds exhibited cytotoxic effects against three human cancer cell lines. Compound 8a showed the greatest cytotoxic effect against hepatocellular carcinoma (HepG2, lung carcinoma (LU-1, and breast cancer (MCF-7 cell lines with IC50 values of 20.93, 13.58, and 9.40 μM, respectively. However, in an antibacterial test, compounds 8a and 8b inhibited Staphylococcus aureus and Bacillus cereus and compound 8e inhibited only Staphylococcus aureus at the same MIC values of 1024 μg/ml.

  20. Determination of trace platinum by supramolecular catalytic kinetic spectrofluorimetry of {beta}-cyclodextrin-platinum-KBrO{sub 3}-salicylaldehyde furfuralhydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Bo; Zhang, Ning; Chen, Zhen-Zhen; Kong, Qing-Cheng [Shandong Normal University, College of Chemistry, Chemical Engineering and Materials Science, Jinan (China)

    2006-02-01

    A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of platinum(IV) and the possible mechanism of catalytic reaction was discussed. The method was based on the fluorescence-enhancing reaction of salicylaldehyde furfuralhydrazone (SAFH) with potassium bromate, which was catalysed by platinum(IV) in a water-ethanol medium. {beta}-Cyclodextrin ({beta}-CD) obviously sensitized the determination at pH 5.20 and 25 C. Under optimum conditions, the {beta}-CD-platinum-KBrO{sub 3}-SAFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 372 and 461 nm, respectively. The linear range of this method was 0.60-180 ng ml{sup -1} with a relative standard deviation of 1.2%, and the detection limit was 0.18 ng ml{sup -1}. Investigation of the mechanism and the effects of interferences is presented. The proposed method was applied successfully to determine trace platinum(IV) in the chemotherapeutic drug cisplatin and serum from patients with satisfactory results. (orig.)

  1. Synthesis and Antimicrobial Evaluation of Some Novel Thiazole, Pyridone, Pyrazole, Chromene, Hydrazone Derivatives Bearing a Biologically Active Sulfonamide Moiety

    Science.gov (United States)

    Darwish, Elham S.; Abdel Fattah, Azza M.; Attaby, Fawzy A.; Al-Shayea, Oqba N.

    2014-01-01

    This study aimed for the synthesis of new heterocyclic compounds incorporating sulfamoyl moiety suitable for use as antimicrobial agents via a versatile, readily accessible N-[4-(aminosulfonyl)phenyl]-2-cyanoacetamide (3). The 2-pyridone derivatives were obtained via reaction of cyanoacetamide with acetylacetone or arylidenes malononitrile. Cycloaddition reaction of cyanoacetamide with salicyaldehyde furnished chromene derivatives. Diazotization of 3 with the desired diazonium chloride gave the hydrazone derivatives 13a–e. Also, the reactivity of the hydrazone towards hydrazine hydrate to give Pyrazole derivatives was studied. In addition, treatment of 3 with elemental sulfur and phenyl isothiocyanate or malononitrile furnished thiazole and thiophene derivatives respectively. Reaction of 3 with phenyl isothiocyanate and KOH in DMF afforded the intermediate salt 17 which reacted in situ with 3-(2-bromoacetyl)-2H-chromen-2-one and methyl iodide afforded the thiazole and ketene N,S-acetal derivatives respectively. Finally, reaction of 3 with carbon disulfide and 1,3-dibromopropane afforded the N-[4-(aminosulfonyl) phenyl]-2-cyano-2-(1,3-dithian-2-ylidene)acetamide product 22. All newly synthesized compounds were elucidated by considering the data of both elemental and spectral analysis. The compounds were evaluated for both their in vitro antibacterial and antifungal activities and showed promising results. PMID:24445259

  2. Synthesis and Antimicrobial Evaluation of Some Novel Thiazole, Pyridone, Pyrazole, Chromene, Hydrazone Derivatives Bearing a Biologically Active Sulfonamide Moiety

    Directory of Open Access Journals (Sweden)

    Elham S. Darwish

    2014-01-01

    Full Text Available This study aimed for the synthesis of new heterocyclic compounds incorporating sulfamoyl moiety suitable for use as antimicrobial agents via a versatile, readily accessible N-[4-(aminosulfonylphenyl]-2-cyanoacetamide (3. The 2-pyridone derivatives were obtained via reaction of cyanoacetamide with acetylacetone or arylidenes malononitrile. Cycloaddition reaction of cyanoacetamide with salicyaldehyde furnished chromene derivatives. Diazotization of 3 with the desired diazonium chloride gave the hydrazone derivatives 13a–e. Also, the reactivity of the hydrazone towards hydrazine hydrate to give Pyrazole derivatives was studied. In addition, treatment of 3 with elemental sulfur and phenyl isothiocyanate or malononitrile furnished thiazole and thiophene derivatives respectively. Reaction of 3 with phenyl isothiocyanate and KOH in DMF afforded the intermediate salt 17 which reacted in situ with 3-(2-bromoacetyl-2H-chromen-2-one and methyl iodide afforded the thiazole and ketene N,S-acetal derivatives respectively. Finally, reaction of 3 with carbon disulfide and 1,3-dibromopropane afforded the N-[4-(aminosulfonyl phenyl]-2-cyano-2-(1,3-dithian-2-ylideneacetamide product 22. All newly synthesized compounds were elucidated by considering the data of both elemental and spectral analysis. The compounds were evaluated for both their in vitro antibacterial and antifungal activities and showed promising results.

  3. Stereoselective synthesis and spectral studies of some benzotriazolylacetyl hydrazones of 3-alkyl-2,6-diarylpiperidin-4-ones

    Science.gov (United States)

    Pillai, M. Velayutham; Rajeswari, K.; Kumar, C. Udhaya; Krishnan, K. Gokula; Mahendran, S.; Ramalingan, C.; Nagarajan, E. R.; Vidhyasagar, T.

    2017-12-01

    An effort to include biologically potent benzotriazole nucleus into piperidine ring is achieved through hydrazone formation. The characterization of the synthesized compounds was carried out using FT-IR, 1H &13C NMR, 1H-1H COSY, 1H-13C COSY, NOESY spectral techniques and GC-Mass spectrum. The spectral assignments were done without ambiguity using 2D-NMR techniques. The conformational preference of the piperidine ring deduced from the spectral studies is 'chair'. The diastereotopic nature of the methylene protons/methyl groups present in the molecules is revealed clearly in their spectral pattern observed.

  4. The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Moussa, M.N.H.; El-Far, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt); El-Shafei, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt)], E-mail: ashafei@mans.edu.eg

    2007-09-15

    Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation.

  5. The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

    International Nuclear Information System (INIS)

    Moussa, M.N.H.; El-Far, A.A.; El-Shafei, A.A.

    2007-01-01

    Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation

  6. Colorimetric detection of hydrogen peroxide by dioxido-vanadium(V) complex containing hydrazone ligand: synthesis and crystal structure

    Science.gov (United States)

    Kurbah, Sunshine D.; Syiemlieh, Ibanphylla; Lal, Ram A.

    2018-03-01

    Dioxido-vanadium(V) complex has been synthesized in good yield, the complex was characterized by IR, UV-visible and 1H NMR spectroscopy. Single crystal X-ray crystallography techniques were used to assign the structure of the complex. Complex crystallized with monoclinic P21/c space group with cell parameters a (Å) = 39.516(5), b (Å) = 6.2571(11), c (Å) = 17.424(2), α (°) = 90, β (°) = 102.668(12) and γ (°) = 90. The hydrazone ligand is coordinate to metal ion in tridentate fashion through -ONO- donor atoms forming a distorted square pyramidal geometry around the metal ion.

  7. Preconcentration and extraction of copper(II) on activated carbon using ethyl-2-quinolyl-β (p-carboxyphenyl hydrazone)dioxo propionate

    OpenAIRE

    Mehrorang Ghaedi; Farshid Ahmadi; M.R. Baezat; J. Safari

    2008-01-01

    Activated carbon modified method was used for the preconcentration and determination of copper content in real samples such as tap water, wastewater and a synthetic water sample by flame atomic absorption spectrometry. The copper(II) was adsorbed quantitatively on activated carbon due to its complexation with ethyl-2-quinolyl-β(p-carboxyphenyl hydrazone)dioxo propionate (EQCPDP). The adsorbed copper(II) ion on solid phase was eluted quantitatively by using nitric acid. The important parameter...

  8. An Eco-Friendly Ultrasound-Assisted Synthesis of Novel Fluorinated Pyridinium Salts-Based Hydrazones and Antimicrobial and Antitumor Screening

    Science.gov (United States)

    Rezki, Nadjet; Al-Sodies, Salsabeel A.; Aouad, Mohamed R.; Bardaweel, Sanaa; Messali, Mouslim; El Ashry, El Sayed H.

    2016-01-01

    The present work reports an efficient synthesis of fluorinated pyridinium salts-based hydrazones under both conventional and eco-friendly ultrasound procedures. The synthetic approach first involves the preparation of halogenated pyridinium salts through the condensation of isonicotinic acid hydrazide (1) with p-fluorobenzaldehyde (2) followed by the nucleophilic alkylation of the resulting N-(4-fluorobenzylidene)isonicotinohydrazide (3) with a different alkyl iodide. The iodide counteranion of 5–10 was subjected to an anion exchange metathesis reaction in the presence of an excess of the appropriate metal salts to afford a new series of fluorinated pyridinium salts tethering a hydrazone linkage 11–40. Ultrasound irradiation led to higher yields in considerably less time than the conventional methods. The newly synthesized ILs were well-characterized with FT-IR, 1H NMR, 13C NMR, 11B, 19F, 31P and mass spectral analyses. The ILs were also screened for their antimicrobial and antitumor activities. Within the series, the salts tethering fluorinated counter anions 11–13, 21–23, 31–33 and 36–38 were found to be more potent against all bacterial and fungal strains at MIC 4–8 µg/mL. The in vitro antiproliferative activity was also investigated against four tumor cell lines (human ductal breast epithelial tumor T47D, human breast adenocarcinoma MCF-7, human epithelial carcinoma HeLa and human epithelial colorectal adenocarcinoma Caco-2) using the MTT assay, which revealed that promising antitumor activity was exhibited by compounds 5, 12 and 14. PMID:27213367

  9. 1-(2-Methyl-5H-chromeno[2,3-b]pyridin-5-ylidene) hydrazone as fluorescent probes for selective zinc sensing in DMSO

    Energy Technology Data Exchange (ETDEWEB)

    Nouri, Hela [URCA—Institut de Chimie Moléculaire de Reims, CNRS UMR 7312, Groupe Chimie de Coordination, UFR Sciences, BP 1039, 51687 Reims Cedex 2 (France); LACReSNE—Université de Carthage, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte (Tunisia); Cadiou, Cyril, E-mail: cyril.cadiou@univ-reims.fr [URCA—Institut de Chimie Moléculaire de Reims, CNRS UMR 7312, Groupe Chimie de Coordination, UFR Sciences, BP 1039, 51687 Reims Cedex 2 (France); Henry, Axelle; Déchamps-Olivier, Isabelle [URCA—Institut de Chimie Moléculaire de Reims, CNRS UMR 7312, Groupe Chimie de Coordination, UFR Sciences, BP 1039, 51687 Reims Cedex 2 (France); Ternane, Riadh; Trabelsi-Ayadi, Malika [LACReSNE—Université de Carthage, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte (Tunisia); Lemercier, Gilles; Chuburu, Françoise [URCA—Institut de Chimie Moléculaire de Reims, CNRS UMR 7312, Groupe Chimie de Coordination, UFR Sciences, BP 1039, 51687 Reims Cedex 2 (France)

    2014-04-15

    Two methyl-chromeno-pyridinylidene hydrazone derivatives L1, a cyclen derivative, and L2 were studied as potential fluorescent OFF–ON sensors towards Zn{sup 2+} in DMSO. Upon addition of one equivalent of Zn{sup 2+}, L1 fluorescence was quenched, but addition of a second equivalent of Zn{sup 2+} restored partially the signal. Therefore ZnL1 behaved as a OFF–ON sensor for zinc. By comparison, L2 behaved as a very sensitive probe for zinc. ZnL1 and L2 sensor efficiencies were correlated to Zn{sup 2+} coordination via the hydrazone moiety of the fluorophore, which prevented a photoinduced electron transfer (PET), and allowed an efficient CHelation-Enhanced Fluorescence (CHEF) effect. -- Highlights: • According to Zn{sup 2+} concentration, L1 behaves as an on-off-on sensor. • Given that L1 concentration is known, its fluorescence response could give an immediate suggestion about the range of Zn{sup 2+} concentration. • L2 exhibited a strong fluorescence enhancement upon Zn{sup 2+} addition. • It was demonstrated that L2 was highly specific to Zn{sup 2+}, which rendered this very straightforward ligand as an efficient and selective probe for this ion.

  10. Synthesis, characterization and study of some physical properties of some lanthanide complexes of salicylaldehyde oxal-dihydrazone

    International Nuclear Information System (INIS)

    Shrestha, S.; Rao, T.R.; Narang, K.K.; Shrestha, S.P.

    2006-05-01

    Some Lanthanoid complexes of the type [Ln (L-2H).A.H 2 O] [Ln = Y, La, Nd, Gd, Tb, Dy, A=OAc; and L = Salicyaldehyde oxal di-hydrazone] was synthesized and characterized by various physico- chemical techniques. Dehydration study at two specific temperatures (110 deg. C and 150 deg. C) indicates the presence of water molecules only in co-ordination sphere of the metal ion. IR, electronic spectra, DTA-TG have been recorded to establish the bonding sites of the ligand. All the complexes decomposed above and not melting up to 350 deg. C. The complexes are insoluble in any common organic solvent even in DMF and DMSO. Solid state electrical conductivities at various frequencies show a semiconducting nature of the complexes. Optical band gap measurement of the complex [Dy(SODH-2H).OAc.H 2 O] shows that complex behaves as direct band gap material. No well-defined peaks, except broad humps were observed in X-ray diffractogram of these complexes, indicating an amorphous nature of the complexes. (author)

  11. The Synthesis and Crystal Structure of Two New Hydrazone Compounds

    Directory of Open Access Journals (Sweden)

    Li-Hua Wang

    2016-05-01

    Full Text Available Two new hydrazone compounds, 4-formylimidazole-4-hydroxybenzhydrazone dihydrate (1 and 2-nitrobenzaldehyde-2-furan formylhydrazone (2, were synthesized via the classical synthesis method. Their structure was determined via elemental analysis and X-ray single crystal diffraction analysis. Compound 1 crystallizes in triclinic, space group P-1 with a = 7.0321(14 Å, b = 7.3723(15 Å, c = 13.008(3 Å, α = 98.66(3°, β = 101.69(3°, γ = 92.25(3°, V = 651.2(2 Å3, Z = 2, Dc = 1.358 g·cm−3, μ = 0.106 mm−1, F(000 = 280, and final R1 = 0.0564, wR2 = 0.1420. Compound 2 crystallizes in monoclinic, space group P21/c with a = 17.3618(9 Å, b = 9.1506(4 Å, c = 15.5801(7 Å, β = 104.532(5°, V = 2396.05(19 Å3, Z = 8, Dc = 1.437 g·cm−3, μ = 0.111 mm−1, F(000 = 1072, and final R1 = 0.0633, wR2 = 0.1649. Compound 1 forms a 2D-layered structure via the interactions of 1D chains and Compound 2 forms a 3D network structure via the interactions of 1D chains.

  12. Structural characterization and antimicrobial activities of transition metal complexes of a hydrazone ligand

    Science.gov (United States)

    Bakale, Raghavendra P.; Naik, Ganesh N.; Machakanur, Shrinath S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.; Gudasi, Kalagouda B.

    2018-02-01

    A hydrazone ligand has been synthesized by the condensation of 2-nitrobenzaldehyde and hydralazine, and its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been reported. Structural characterization of the ligand and its metal complexes has been performed by various spectroscopic [IR, NMR, UV-Vis, Mass], thermal and other physicochemical methods. The structure of the ligand and its Ni(II) complex has been characterized by single crystal X-ray diffraction studies. All the synthesized compounds have been screened for in vitro antimicrobial activity. The antibacterial activity is tested against Gram-positive strains Enterococcus faecalis, Streptococcus mutans and Staphylococcus aureus and Gram-negative strains Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae using ciprofloxacin as the reference standard. Antifungal activity is tested against Candida albicans, Aspergillus fumigatus and Aspergillus niger using ketoconazole as the reference standard. The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standard. Ligand, Cu(II) and Zn(II) complexes have shown excellent activity against Candida albicans.

  13. Benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives as inhibitors of the corrosion of aluminium in hydrochloric acid.

    Science.gov (United States)

    Fouda, A S; Gouda, M M; El-Rahman, S I

    2000-05-01

    The effect of benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives on the corrosion of aluminium in hydrochloric acid has been investigated using thermometric and polarization techniques. The inhibitive efficiency ranking of these compounds from both techniques was found to be: 2>3>1>4. The inhibitors acted as mixed-type inhibitors but the cathode is more polarized. The relative inhibitive efficiency of these compounds has been explained on the basis of structure of the inhibitors and their mode of interaction at the surface. Results show that these additives are adsorbed on an aluminium surface according to the Langmuir isotherm. Polarization measurements indicated that the rate of corrosion of aluminium rapidly increases with temperature over the range 30-55 degrees C both in the absence and in the presence of inhibitors. Some thermodynamic data of the adsorption process are calculated and discussed.

  14. In silico molecular docking studies of new potential 4-phthalazinyl-hydrazones on selected Trypanosoma cruzi and Leishmania enzyme targets.

    Science.gov (United States)

    Romero, Angel H; López, Simón E

    2017-09-01

    Recently, a series of 4-phthalazinyl-hydrazones under its E-configuration have exhibited excellent in vitro antichagasic and antileishmanial profiles. Preliminary assays on both parasites suggested that the most active derivatives act through oxidative and nitrosative stress mechanisms; however, their exact mode of actions as anti-trypanosomal and anti-leishmanial agents have not been completely elucidated. This motivated to perform a molecular docking study on essential trypanosomatid enzymes such as superoxide dismutase (SOD), trypanothione reductase (TryR), cysteine-protease (CP) and pteridine reductase 1 (PTR1). In addition, to understand the experimental results of nitric oxide production obtained for infected macrophages with Leishmania parasite, a molecular docking was evaluated on nitric oxide synthase (iNOS) enzyme of Rattus norvegicus. Both diastereomers (E and Z) of the 4-phthalazinyl-hydrazones were docked on the mentioned targets. In general, molecular docking on T. cruzi enzymes revealed that the E-diastereomers exhibited lower binding energies than Z-diastereomers on the Fe-SOD and CP enzymes, while Z-diastereomers showed lower docking energies than E-isomers on TryR enzyme. For the Leishmania docking studies, the Z-isomers exhibited the best binding affinities on the PTR1 and iNOS enzymes, while the TryR enzyme showed a minor dependence with the stereoselectivity of the tested phthalazines. However, either the structural information of the ligand-enzyme complexes or the experimental data suggest that the significant antitrypanosomatid activity of the most active derivatives is not associated to the inhibition of the SOD, CP and PTR1 enzymes, while the TryR inhibition and nitric oxide generation in host cells emerge as interesting antitrypanosomatid therapeutic targets. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. 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.

  16. Design, synthesis, conformational and molecular docking study of some novel acyl hydrazone based molecular hybrids as antimalarial and antimicrobial agents.

    Science.gov (United States)

    Kumar, Parvin; Kadyan, Kulbir; Duhan, Meenakshi; Sindhu, Jayant; Singh, Vineeta; Saharan, Baljeet Singh

    2017-11-14

    Acyl hydrazones are an important class of heterocyclic compounds promising pharmacological characteristics. Malaria is a life-threatening mosquito-borne blood disease caused by a plasmodium parasite. In some places, malaria can be treated and controlled with early diagnosis. However, some countries lack the resources to do this effectively. The present work involves the design and synthesis of some novel acyl hydrazone based molecular hybrids of 1,4-dihydropyridine and pyrazole (5a-g). These molecular hybrids were synthesised by condensation of 1,4-dihydropyridin-4-yl-phenoxyacetohydrazides with differently substituted pyrazole carbaldehyde. The final compound (5) showed two conformations (the major, E, s-cis and the minor, E, s-trans) as revealed by NMR spectral data and further supported by the energy calculations (MOPAC2016 using PM7 method). All the synthesised compounds were screened for their in vitro antimalarial activities against chloroquine-sensitive malaria parasite Plasmodium falciparum (3D7) and antimicrobial activity against Gram positive bacteria i.e. Bacillus cereus, Gram negative bacteria i.e. Escherichia coli and antifungal activity against one yeast i.e. Aspergillus niger. All these compounds were found more potent than chloroquine and clotrimazole, the standard drugs. In vitro antiplasmodial IC 50 value of the most potent compound 5d was found to be 4.40 nM which is even less than all the three reference drugs chloroquine (18.7 nM), pyrimethamine (11 nM) and artimisinin (6 nM). In silico binding study of compound 5d with plasmodial cysteine protease falcipain-2 indicated the inhibition of falcipain-2 as the probable reason for the antimalarial potency of compound 5d. All the compounds had shown good to excellent antimicrobial and antifungal activities.

  17. Vibrational spectra, molecular structure, natural bond orbital, first order hyperpolarizability, thermodynamic analysis and normal coordinate analysis of Salicylaldehyde p-methylphenylthiosemicarbazone by density functional method

    Science.gov (United States)

    Porchelvi, E. Elamurugu; Muthu, S.

    2015-01-01

    The thiosemicarbazone compound, Salicylaldehyde p-methylphenylthiosemicarbazone (abbreviated as SMPTSC) was synthesized and characterized by FTIR, FT-Raman and UV. Density functional (DFT) calculations have been carried out for the title compound by performing DFT level of theory using B3LYP/6-31++G(d,p) basis set. The molecular geometry and vibrational frequencies were calculated and compared with the experimental data. The detailed interpretation of the vibrational spectra has been carried out with aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. The electronic dipole moment (μD) and the first hyperpolarizability (βtot) values of the investigated molecule were computed using density functional theory (DFT/B3LYP) with 6-311++G(d,p) basis set. The stability and charge delocalization of the molecule was studied by natural bond orbital (NBO) analysis. Thearomaticities of the phenyl rings were studied using the standard harmonic oscillator model of aromaticity (HOMA) index. Mulliken population analysis on atomic charges is also calculated. The molecule orbital contributions are studied by density of energy states (DOSs).

  18. Effects of intracellular chelatable iron and oxidative stress on transcription of classical cellular glutathione peroxidase gene in murine erythroleukemia cells

    International Nuclear Information System (INIS)

    Fuchs, O.

    1997-01-01

    The effect of intracellular chelatable iron levels and of oxidative stress on nuclear classical cellular glutathione peroxidase (GSHPx-1) RNA nascent chain elongation (run-on transcription) and on the stability of cytoplasmic GSHPx-1 mRNA was investigated in murine erythroleukemia (MEL) cells. The amount in the intracellular low molecular mass iron pool was changed by incubation of MEL cells transformed by Friend virus with iron donors or iron chelators. Transcription in vitro in isolated nuclei from treated cells showed that the treatment with chelators (desferrioxamine (DFO), pyridoxal isonicotinoyl hydrazone) decrease the rate of nuclear GSHPx-1 RNA nascent chain elongation in both un-induced and with 5 mmol hexamethylenebisacetamide to erythroid differentiation induced MEL cells. Iron donors (diferric transferrin,, Fe-PIH or their combination) and t-butyl hydroperoxide (t-BuOOH) had the opposite effect on GSHPx-1 gene transcription in run-on experiments. On the other hand, 50 μmol DFO or 2.5 μmol t-BuOOH did not change the stability of cytoplasmic GSHPx-1 mRNA in both un-induced and induced MEL cells treated with 5 μmol actinomycin D and with or without these agents for 9 h. These findings indicate that iron and oxidative stress play their role at the transcriptional level of GSHPx-1 gene expression. (author)

  19. O uso de aparelhos de micro-ondas domésticos em aulas experimentais de química orgânica: nitração de salicilaldeído The use of domestic microwave oven in experimental classes of organic chemistry: salicylaldehyde nitration

    Directory of Open Access Journals (Sweden)

    Eurídes Francisco Teixeira

    2010-01-01

    Full Text Available The use of microwave in chemistry has known benefits over conventional heating methods, e.g. reduced reaction times, chemical yield improvement and the possibility if reducing or eliminating the use of organic solvents. We describe herein a procedure for the nitration of salicylaldehyde in water using a domestic microwave oven, which can be used as an experiment in the undergraduate chemistry laboratory. The experiment involves safe and rapid preparation and identification of the position isomers by thin layer chromatography and 1H NMR, or by their melting points.

  20. Synthesis, structural, antibacterial and spectral studies of Co (II) complexes with salicylaldehyde and p-chloro-benzaldehyde 4-phenyl thiosemicarbazone

    International Nuclear Information System (INIS)

    Nur Nadia Dzulkifli; Yang Farina; Ibrahim Baba; Nazlina Ibrahim

    2012-01-01

    The Co(II) complexes derived from salicylaldehyde 4-phenyl thiosemicarbazone; SaOHtsc, p-chlorobenzaldehyde 4-phenyl thiosemicarbazone; ph-HClbtsc is reported and characterized based on elemental analysis, IR, magnetic susceptibility measurement, 1 H and 13 C NMR spectra. The Co(II) complexes have the molecular formula CoL 2 where the ligand corresponding to SaOHtsc and ph-HClbtsc. The elemental analysis for the ligands and complexes were in a good agreement with the theoretical values. The ligands coordinate to metal ions in different ways which is through mono negative bidentate or di negative tridentate. The magnetic susceptibility measurements showed that the CoL 2 complexes with ligand SaOHtsc are diamagnetic thus making this complexes suitable for NMR studies. The signals at the 10.04 ppm were assigned to N 2 H in the 1 H-NMR spectra of the free ligands was absent in the spectra of the complexes due to the deprotonation of the N 2 H and coordination to the metal centres. The absence of the band in IR spectrum which is assigned to v(N 2 -H) in the spectra of CoL 2 complexes is due to the deprotonation of the ligands upon complexation through azomethine nitrogen and thionic sulphur atom to metal ion. The thiosemicarbazones and its Co(II) complexes showed moderate inhibitory against bacteria Bacillus Subtilis, Staphylococcus Epidermis, Escherichia Coli and Proteus Mirabilis in 10 μg/ disc. (author)

  1. Synthesis, antioxidant, antifungal, molecular docking and ADMET studies of some thiazolyl hydrazones.

    Science.gov (United States)

    Kauthale, Sushama; Tekale, Sunil; Damale, Manoj; Sangshetti, Jaiprakash; Pawar, Rajendra

    2017-08-15

    Some thiazolyl hydrazones were synthesized by one pot reaction of thiophene-2-carbaldehyde or 2, 4-dichlorobenzaldehyde, thiosemicarbazide and various phenacyl bromides which were preliminarily screened for in vitro antioxidant and antifungal activities. Excellent DPPH and H 2 O 2 radical scavenged antioxidant activities were observed with almost all the tested compounds. Compounds 4a, 4b, 4c, 4e, 4f and 4i showed comparable DPPH scavenged antioxidant potential (90.26-96.56%) whereas H 2 O 2 scavenged antioxidant activity (90.98-92.08%) was noticeable in case of 4a and 4f; showing significant antioxidant potential comparable with the standard ascorbic acid (95.3%). In vitro antifungal activity of synthesized compounds against fungal species Candida albicance, Aspergillus niger and Aspergillus flavus was found to be moderate to good as compared with the standard fluconazole and MIC values were found in the range of 3.12-25μg/mL. Molecular docking studies revealed that the compounds 4a, 4b and 4c have a potential to become lead molecules in drug discovery process. In silico ADMET study was also performed for predicting pharmacokinetic and toxicity profile of the synthesized antioxidants which expressed good oral drug like behaviour and non-toxic nature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Synthesis, characterization and density functional theory study of low cost hydrazone sensitizers

    KAUST Repository

    G. Al-Sehemi, A.

    2015-01-18

    © 2015 Chemical Society of Ethiopia The 2-{4-[2-benzylidenehydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 1), 2-{4-[2-(1- naphthylmethylene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 2) and 2-{4-[2-(9-anthrylmethylene)- hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 3) were synthesized by direct tricyanovinylation of hydrazones. The bathochromic shift in absorption spectra has been observed by increasing the solvent polarity. The FTIR spectra of these new dyes exhibited three important absorption bands. The first band centered near 3260 cm-1 in System 1 while 3208 cm-1 and 3211 cm-1 in System 2 and System 3 for the vNH absorption, respectively. The second band is a sharp absorption band in the region of 2212-2209 cm-1, which was attributed to the cyano group absorption. The third is an absorption band in the region of 1611-1603 cm-1 ascribed for the C=N. Density functional theory (DFT) calculation of relative energies, relative enthalpies and free energies shows that E isomers are the most stable except System 3 in which the most stable is Z isomers. The conformational energy profile shows two maxima near (-90 and 90°) while three local minima observed at (-180, 0 and 180) for N1-N2-C1-C2 torsional angle. The highest occupied molecular orbitals (HOMOs) are localized on the whole molecules while lowest unoccupied molecular orbitals (LUMOs) are distributed on the tricarbonitrile.

  3. Ligational, analytical and biological applications on oxalyl bis(3,4-dihydroxybenzylidene) hydrazone

    Science.gov (United States)

    El-Asmy, Ahmed A.; El-Gammal, O. A.; Radwan, H. A.; Ghazy, S. E.

    2010-09-01

    The molecular modeling and parameters have been calculated to confirm the geometry of oxalyl bis(3,4-dihydroxybenzylidene) hydrazone, H 6L. The metal complexes of Cr 3+, VO 2+, ZrO 2+, HfO 2+, UO 22+ and MoO 22+ with H 6L have been prepared and characterized by partial elemental analysis, spectral studies (electronic; IR), thermal analysis and magnetic measurements. The data suggest the formation of polymer complexes with a unit [Cr(H 4L)(H 2O) 3Cl]·H 2O, [VO(H 4L)(H 2O) 2], [Hf(H 4L)(H 2O)]·H 2O [UO 2(H 4L)(H 2O) 2]·2H 2O [MoO 2(H 4L)] and [(ZrO) 2(H 2L)-(C 2H 5OH) 2]. The ligand behaves as a dibasic bidentate in all complexes except ZrO 2+ which acts as a tetrabasic tetradentate with the two ZrO 2+ ions. An octahedral geometry was proposed for the Cr 3+, HfO 2+, MoO 22+and UO 22+ complexes and square pyramid for VO 2+. The Cr 3+ is necessary to degrade the DNA of eukaryotic subject completely; the other complexes have little effect. H 6L was found suitable as a new reagent for the separation and preconcentration of ZrO 2+ ions from different water samples using flotation technique with satisfactory results.

  4. Synthesis, characterization and density functional theory study of low cost hydrazone sensitizers

    KAUST Repository

    G. Al-Sehemi, A.; Irfan, A.; M. Asiri, A.; A. Ammar, Y.

    2015-01-01

    © 2015 Chemical Society of Ethiopia The 2-{4-[2-benzylidenehydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 1), 2-{4-[2-(1- naphthylmethylene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 2) and 2-{4-[2-(9-anthrylmethylene)- hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 3) were synthesized by direct tricyanovinylation of hydrazones. The bathochromic shift in absorption spectra has been observed by increasing the solvent polarity. The FTIR spectra of these new dyes exhibited three important absorption bands. The first band centered near 3260 cm-1 in System 1 while 3208 cm-1 and 3211 cm-1 in System 2 and System 3 for the vNH absorption, respectively. The second band is a sharp absorption band in the region of 2212-2209 cm-1, which was attributed to the cyano group absorption. The third is an absorption band in the region of 1611-1603 cm-1 ascribed for the C=N. Density functional theory (DFT) calculation of relative energies, relative enthalpies and free energies shows that E isomers are the most stable except System 3 in which the most stable is Z isomers. The conformational energy profile shows two maxima near (-90 and 90°) while three local minima observed at (-180, 0 and 180) for N1-N2-C1-C2 torsional angle. The highest occupied molecular orbitals (HOMOs) are localized on the whole molecules while lowest unoccupied molecular orbitals (LUMOs) are distributed on the tricarbonitrile.

  5. Impact of physicochemical properties of porous silica materials conjugated with dexamethasone via pH-responsive hydrazone bond on drug loading and release behavior

    Science.gov (United States)

    Numpilai, Thanapha; Witoon, Thongthai; Chareonpanich, Metta; Limtrakul, Jumras

    2017-02-01

    The conjugation of dexamethasone (DEX) onto modified-porous silica materials via a pH-responsive hydrazone bond has been reported to be highly efficient method to specifically deliver the DEX to diseased sites. However, the influence of physicochemical properties of porous silica materials has not yet been fully understood. In this paper, the impact of pore sizes, particle sizes and silanol contents on surface functionalization, drug loading and release behavior of porous silica materials conjugated with dexamethasone via pH-responsive hydrazone bond was investigated. The grafting density was found to relate to the number of silanol groups on the surface of porous silica materials. The particle size and macropores of the porous silica materials played an vital role on the drug loading and release behavior. Although the porous silica materials with larger particle sizes possessed a lower grafting density, a larger amount of drug loading could be achieved. Moreover, the porous silica materials with larger particle sizes showed a slower release rate of DEX due to a longer distance for cleaved DEX diffusion out of pores. DEX release rate exhibited pH-dependent, sustained release. At pH 4.5, the amount of DEX release within 10 days could be controlled in the range of 12.74-36.41%, depending on the host material. Meanwhile, less than 1.5% of DEX was released from each of type of the porous silica materials at pH 7.4. The results of silica dissolution suggested that the degradation of silica matrix did not significantly affect the release rate of DEX. In addition, the kinetic modeling studies revealed that the DEX releases followed Korsmeyer-Peppas model with a release exponent (n) ranged from 0.3 to 0.47, indicating a diffusion-controlled release mechanism.

  6. Iron chelators ICL670 and 311 inhibit HIV-1 transcription

    International Nuclear Information System (INIS)

    Debebe, Zufan; Ammosova, Tatyana; Jerebtsova, Marina; Kurantsin-Mills, Joseph; Niu, Xiaomei; Charles, Sharroya; Richardson, Des R.; Ray, Patricio E.; Gordeuk, Victor R.; Nekhai, Sergei

    2007-01-01

    HIV-1 replication is induced by an excess of iron and iron chelation by desferrioxamine (DFO) inhibits viral replication by reducing proliferation of infected cells. Treatment of cells with DFO and 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311) inhibit expression of proteins that regulate cell-cycle progression, including cycle-dependent kinase 2 (CDK2). Our recent studies showed that CDK2 participates in HIV-1 transcription and viral replication suggesting that inhibition of CDK2 by iron chelators might also affect HIV-1 transcription. Here we evaluated the effect of a clinically approved orally effective iron chelator, 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid (ICL670) and 311 on HIV-1 transcription. Both ICL670 and 311 inhibited Tat-induced HIV-1 transcription in CEM-T cells, 293T and HeLa cells. Neither ICL670 nor 311 induced cytotoxicity at concentrations that inhibited HIV-1 transcription. The chelators decreased cellular activity of CDK2 and reduced HIV-1 Tat phosphorylation by CDK2. Neither ICL670A or 311 decreased CDK9 protein level but significantly reduced association of CDK9 with cyclin T1 and reduced phosphorylation of Ser-2 residues of RNA polymerase II C-terminal domain. In conclusion, our findings add to the evidence that iron chelators can inhibit HIV-1 transcription by deregulating CDK2 and CDK9. Further consideration should be given to the development of iron chelators for future anti-retroviral therapeutics

  7. The interaction of taurine-salicylaldehyde Schiff base copper(II) complex with DNA and the determination of DNA using the complex as a fluorescence probe

    Science.gov (United States)

    Zhang, Xiaoyan; Wang, Yong; Zhang, Qianru; Yang, Zhousheng

    2010-09-01

    The interaction of taurine-salicylaldehyde Schiff base copper(II) (Cu(TSSB) 22+) complex with DNA was explored by using UV-vis, fluorescence spectrophotometry, and voltammetry. In pH 7.4 Tris-HCl buffer solution, the binding constant of the Cu(TSSB) 22+ complex interaction with DNA was 3.49 × 10 4 L mol -1. Moreover, due to the fluorescence enhancing of Cu(TSSB) 22+ complex in the presence of DNA, a method for determination of DNA with Cu(TSSB) 22+ complex as a fluorescence probe was developed. The fluorescence spectra indicated that the maximum excitation and emission wavelength were 389 nm and 512 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range of 0.03-9.03 μg mL -1 for calf thymus DNA (CT-DNA), 0.10-36 μg mL -1 for yeast DNA and 0.01-10.01 μg mL -1 for salmon DNA (SM-DNA), respectively. The corresponding detection limits are 7 ng mL -1 for CT-DNA, 3 ng mL -1 for yeast DNA and 3 ng mL -1 for SM-DNA. Using this method, DNA in synthetic samples was determined with satisfactory results.

  8. Coordination diversity of new mononucleating hydrazone in 3d metal complexes: Synthesis, characterization and structural studies

    Directory of Open Access Journals (Sweden)

    RAJESH S. BALIGAR

    2006-12-01

    Full Text Available The mononucleating hydrazone ligand LH3, a condensation product of salicyloylhydrazine and (2-formylphenoxyacetic acid, was synthesized and its coordination behavior with first row transition metal(II ions was investigated by isolating and elucidating the structure of the complexes using elemental analysis, conductivity and magnetic susceptibility measurements, as well as IR, 1H-NMR, electronic and EPR spectral techniques. The ligand forms mononuclear metal(II complexes of the type [CoLH(H2O2], [NiLH(H2O2, [CuLH] and [ZnLH]. The ligand field parameters, Dq, B and b values, in the case of the cobalt and nickel complexes support not only the octahedral geometry around the metal ion, but also imply the covalent nature of the bonding in the complexes. The EPR study revealed the presence of a spin exchange interaction in the solid copper complex and the covalent nature of the bonding. The 1H-NMR study of the zinc(II complex indicated the non-involvement of the COOH group in the coordination. The physico-chemical study supports for the presence of octahedral geometry around cobalt(II, nickel(II and tetrahedral geometry around copper(II and zinc(II ions.

  9. Biting deterrence and insecticidal activity of hydrazide-hydrazones and their corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles against Aedes aegypti.

    Science.gov (United States)

    Tabanca, Nurhayat; Ali, Abbas; Bernier, Ulrich R; Khan, Ikhlas A; Kocyigit-Kaymakcioglu, Bedia; Oruç-Emre, Emine E; Unsalan, Seda; Rollas, Sevim

    2013-06-01

    Taking into account the improvement in insecticidal activity by the inclusion of fluorine in the hydrazone moiety, the authors synthesized new 4-fluorobenzoic acid hydrazides and 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles, substituting a phenyl group or a heteroaryl ring carrying one or two atoms of F, Cl and Br, and investigated their biting deterrent and larvicidal activities against Aedes aegypti for the first time. The compound 3-acetyl-5-(4-fluorophenyl)-2-[4-(dimethylamino)phenyl]-2,3-dihydro-1,3,4-oxadiazole (17) produced the highest biting deterrent activity (BDI = 1.025) against Ae. Aegypti, followed by 4-fluorobenzoic acid [(phenyl)methylene] hydrazide (1). These activity results were similar to those of N,N-diethyl-meta-toluamide (DEET), which showed a proportion not biting of 0.8-0.92. When compounds 1 and 17 were tested on cloth worn on human volunteers, compound 1 was not repellent for some volunteers until present in excess of 500 nmol cm(-2) , while compound 17 was not repellent at the highest concentration tested (1685 nmol cm(-2) ). In the larvicidal screening bioassays, only compounds 10, 11, 12 and 17 showed 100% mortality at the highest screening dose of 100 ppm against Ae. aegypti larvae. Compounds 11 and 12 with LD50 values of 24.1 and 30.9 ppm showed significantly higher mortality than 10 (80.3 ppm) and 17 (58.7 ppm) at 24-h post-treatment. The insecticidal and biting deterrent activities were correlated with the presence of a halogen atom on the phenyl or heteroaryl substituent of the hydrazone moiety. © 2012 Society of Chemical Industry.

  10. Structurally related hydrazone-based metal complexes with different antitumor activities variably induce apoptotic cell death.

    Science.gov (United States)

    Megger, Dominik A; Rosowski, Kristin; Radunsky, Christian; Kösters, Jutta; Sitek, Barbara; Müller, Jens

    2017-04-05

    Three new complexes bearing the tridentate hydrazone-based ligand 2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)pyridine (L) were synthesized and structurally characterized. Biological tests indicate that the Zn(ii) complex [ZnCl 2 (L)] is of low cytotoxicity against the hepatocellular carcinoma cell line HepG2. In contrast, the Cu(ii) and Mn(ii) complexes [CuCl 2 (L)] and [MnCl 2 (L)] are highly cytotoxic with EC 50 values of 1.25 ± 0.01 μM and 20 ± 1 μM, respectively. A quantitative proteome analysis reveals that treatment of the cells with the Cu(ii) complex leads to a significantly altered abundance of 102 apoptosis-related proteins, whereas 38 proteins were up- or down-regulated by the Mn(ii) complex. A closer inspection of those proteins regulated only by the Cu(ii) complex suggests that the superior cytotoxic activity of this complex is likely to be related to an initiation of the caspase-independent cell death (CICD). In addition, an increased generation of reactive oxygen species (ROS) and a strong up-regulation of proteins responsive to oxidative stress suggest that alterations of the cellular redox metabolism likely contribute to the cytotoxicity of the Cu(ii) complex.

  11. Spectroscopic studies of some lanthanide(III nitrate complexes synthesized from a new ligand 2,6-bis-(salicylaldehyde hydrazone-4-chlorophenol

    Directory of Open Access Journals (Sweden)

    A.S. Sall

    2003-06-01

    Full Text Available The ligand 2,6-bis-(salicylaldehydehydrazone-4-chlorophenol (H5L and its binuclear lanthanide(III nitrate complexes {[Ln2(H4L3(NO3](NO32.mH2O} where Ln = La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb and Y, have been synthesized. The complexes were characterized by chemical analysis, conductance, magnetic moment measurements and infrared spectra. Infrared study indicates that the ligand behaves both as neutral and ionic O donors and as neutral N donors.

  12. Infrared spectroscopy of some organocobalt (III) compounds

    International Nuclear Information System (INIS)

    Benedetti, A.V.; Mauro, A.E.

    1982-01-01

    The compounds [MeCo(DH) 2 py], [MeCo(DH) 2 H 2 O] (M = methyl; DH = dimethyl-glyoxymate; py = pyridine) and others of general formulae [Co(L)(H 2 O) 2 ] ClO 4 , where L = SALOPHEN = bis (salicylaldehyde)-o-phenylenediimine; SALCN = 1,2-bis (salicylaldehyde) cyclohexylenediimine; SALEN = bis (salicylaldehyde) ethylenediimine; BAE = bis (acetylacetone)-ethylenediimine were synthesized and studied by infrared spectroscopy. The frequencies observed have been assigned to specific group vibrations. (Author) [pt

  13. An efficient PEGylated liposomal nanocarrier containing cell-penetrating peptide and pH-sensitive hydrazone bond for enhancing tumor-targeted drug delivery

    Directory of Open Access Journals (Sweden)

    Ding Y

    2015-10-01

    Full Text Available Yuan Ding,1,* Dan Sun,1,* Gui-Ling Wang,1 Hong-Ge Yang,1 Hai-Feng Xu,1 Jian-Hua Chen,2 Ying Xie,1,3 Zhi-Qiang Wang4 1Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, 2School of Medicine, Jianghan University, Wuhan, 3State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, People’s Republic of China; 4Department of Chemistry and Biochemistry, Kent State University Geauga, Burton, OH, USA *These authors contributed equally to this work Abstract: Cell-penetrating peptides (CPPs as small molecular transporters with abilities of cell penetrating, internalization, and endosomal escape have potential prospect in drug delivery systems. However, a bottleneck hampering their application is the poor specificity for cells. By utilizing the function of hydration shell of polyethylene glycol (PEG and acid sensitivity of hydrazone bond, we constructed a kind of CPP-modified pH-sensitive PEGylated liposomes (CPPL to improve the selectivity of these peptides for tumor targeting. In CPPL, CPP was directly attached to liposome surfaces via coupling with stearate (STR to avoid the hindrance of PEG as a linker on the penetrating efficiency of CPP. A PEG derivative by conjugating PEG with STR via acid-degradable hydrazone bond (PEG2000-Hz-STR, PHS was synthesized. High-performance liquid chromatography and flow cytometry demonstrated that PHS was stable at normal neutral conditions and PEG could be completely cleaved from liposome surface to expose CPP under acidic environments in tumor. An optimal CPP density on liposomes was screened to guaranty a maximum targeting efficiency on tumor cells as well as not being captured by normal cells that consequently lead to a long circulation in blood. In vitro and in vivo studies indicated, in 4 mol% CPP of lipid modified system, that CPP exerted higher efficiency on internalizing the liposomes into

  14. Growth and characterization of benzaldehyde 4-nitro phenyl hydrazone (BPH) single crystal: A proficient second order nonlinear optical material

    Science.gov (United States)

    Saravanan, M.; Abraham Rajasekar, S.

    2016-04-01

    The crystals (benzaldehyde 4-nitro phenyl hydrazone (BPH)) appropriate for NLO appliance were grown by the slow cooling method. The solubility and metastable zone width measurement of BPH specimen was studied. The material crystallizes in the monoclinic crystal system with noncentrosymmetric space group of Cc. The optical precision in the whole visible region was found to be excellent for non-linear optical claim. Excellence of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of BPH sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The dielectric studies were executed at varied temperatures and frequencies to investigate the electrical properties. Photoconductivity measurement enumerates consummate of inducing dipoles due to strong incident radiation and also divulge the nonlinear behaviour of the material. The third order nonlinear optical properties of BPH crystals were deliberate by Z-scan method.

  15. Synthesis, Characterization, and Anti-Cancer Activity of Some New N′-(2-Oxoindolin-3-ylidene-2-propylpentane hydrazide-hydrazones Derivatives

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    Ayman El-Faham

    2015-08-01

    Full Text Available Eight novel N′-(2-oxoindolin-3-ylidene-2-propylpentane hydrazide-hydrazone derivatives 4a–h were synthesized and fully characterized by IR, NMR (1H-NMR and 13C-NMR, elemental analysis, and X-ray crystallography. The cyto-toxicity and in vitro anti-cancer evaluation of the prepared compounds have been assessed against two different human tumour cell lines including human liver (HepG2 and leukaemia (Jurkat, as well as in normal cell lines derived from human embryonic kidney (HEK293 using MTT assay. The compounds 3e, 3f, 4a, 4c, and 4e revealed promising anti-cancer activities in tested human tumour cells lines (IC50 values between 3 and 7 μM as compared to the known anti-cancer drug 5-Fluorouracil (IC50 32–50 μM. Among the tested compounds, 4a showed specificity against leukaemia (Jurkat cells, with an IC50 value of 3.14 μM, but this compound was inactive in liver cancer and normal cell lines.

  16. Synthesis and Characterization of Lanthanide(III Nitrate Complexes with Terdentate ONO Donor Hydrazone Derived from 2-Benzimidazolyl Mercaptoaceto Hydrazide and o-Hydroxy Aromatic Aldehyde

    Directory of Open Access Journals (Sweden)

    Vinayak M. Naik

    2011-01-01

    Full Text Available A few eight coordinated complexes of lanthanide(III nitrate with 2-benzimidazolyl mercaptoaceto hydrazone ligand (LH2 with the general formula [Ln(LH2NO2]H2O (where Ln = La, Pr, Nd, Sm and Gd have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, UV-Visible, IR and 1H NMR spectral studies. The experimental data sustain stoichiometry of 1:2 (metal/ligand for the complexes. The spectral data shows that the ligand reacts in keto form and behaves as monobasic terdentate in nature. The nitrate appears to coordinate in the bidentate fashion to the metal ion. The thermal stabilities of the complexes have been studied by TGA and their kinetic parameters were calculated using Coats-Redfern and MKN methods. The antimicrobial activity studies have been under taken and results are discussed.

  17. A highly selective turn-on fluorescent probe for hypochlorous acid based on hypochlorous acid-induced oxidative intramolecular cyclization of boron dipyrromethene-hydrazone

    International Nuclear Information System (INIS)

    Chen, Wei-Chieh; Venkatesan, Parthiban; Wu, Shu-Pao

    2015-01-01

    Highlights: • A BODIPY-based fluorescent probe for sensing HOCl was developed. • The probe utilizes the HOCl-promoted cyclization in response to the amount of HOCl. • The probe might have application in the investigation of HOCl in biological systems. - Abstract: A BODIPY-based fluorescent probe, HBP, was developed for the detection of hypochlorous acid based on the specific hypochlorous acid-promoted oxidative intramolecular cyclization of heterocyclic hydrazone in response to the amount of HOCl. The reaction is accompanied by a 41-fold increase in the fluorescent quantum yield (from 0.004 to 0.164). The fluorescence intensity of the reaction between HOCl and HBP is linear in the HOCl concentration range of 1–8 μM with a detection limit of 2.4 nM (S/N = 3). Confocal fluorescence microscopy imaging using RAW264.7 cells showed that the new probe HBP could be used as an effective fluorescent probe for detecting HOCl in living cells

  18. A highly selective turn-on fluorescent probe for hypochlorous acid based on hypochlorous acid-induced oxidative intramolecular cyclization of boron dipyrromethene-hydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Chieh; Venkatesan, Parthiban; Wu, Shu-Pao, E-mail: spwu@mail.nctu.edu.tw

    2015-07-02

    Highlights: • A BODIPY-based fluorescent probe for sensing HOCl was developed. • The probe utilizes the HOCl-promoted cyclization in response to the amount of HOCl. • The probe might have application in the investigation of HOCl in biological systems. - Abstract: A BODIPY-based fluorescent probe, HBP, was developed for the detection of hypochlorous acid based on the specific hypochlorous acid-promoted oxidative intramolecular cyclization of heterocyclic hydrazone in response to the amount of HOCl. The reaction is accompanied by a 41-fold increase in the fluorescent quantum yield (from 0.004 to 0.164). The fluorescence intensity of the reaction between HOCl and HBP is linear in the HOCl concentration range of 1–8 μM with a detection limit of 2.4 nM (S/N = 3). Confocal fluorescence microscopy imaging using RAW264.7 cells showed that the new probe HBP could be used as an effective fluorescent probe for detecting HOCl in living cells.

  19. Synthesis, structural, DFT studies, docking and antibacterial activity of a xanthene based hydrazone ligand

    Science.gov (United States)

    Naseem, Saira; Khalid, Muhammad; Tahir, Muhammad Nawaz; Halim, Mohammad A.; Braga, Ataualpa A. C.; Naseer, Muhammad Moazzam; Shafiq, Zahid

    2017-09-01

    Herein, we present the synthesis of novel xanthene-based hydrazone (1). The chemical structure of 1 was resolved using spectroscopic techniques such as NMR, FT-IR, UV-VIS and X-ray crystallographic approaches. X-ray diffraction analysis shows that the compound (1) crystallizes in triclinic crystal lattice with the Pbar1 space group and diffused to form multi-layered structure due to non-covalent interactions such as intramolecular hydrogen bonding (H.B). In addition to experimental investigation, density functional theory (DFT) calculation with M06-2X/6-31G(d,p) and B3LYP/6-31G(d,p) level of theories was performed on compound (1) to obtain optimized geometry, spectroscopic and electronic properties. DFT optimized geometry shows good agreement with the experimental XRD structure. The hyper conjugative interactions and hydrogen bonding network are responsible for the stability of compound (1) as revealed by natural bond orbital (NBO) calculation. Moreover, hydrogen bonding network in the dimer is confirmed by FT-IR and thermodynamic studies showing excellent agreement with XRD and NBO findings. TD-DFT/UV-VIS analysis provides insight that maximum excitation is found in 1 which shows good agreement with experimental UV-VIS result. The global reactivity parameters are calculated using the energies of frontier molecular orbitals also disclosed that the compound is more stable might be due to hydrogen bonding network. Experimental and molecular docking studies indicated that this compound has anti-bacterial and anti-diabetic properties. The binding affinity of this compound against the multidrug efflux pump subunit AcrB OS=Escherichia coli (strain K12) and Human Pancreatic Alpha-Amylase is -9.2 and -10.00 kcal/mol which are higher than the control drugs. Pi-Pi, Pi-anaion, amide-pi and pi-alkyl bonds play key role in drug-protein complexes.

  20. The Cytotoxicity of Benzaldehyde Nitrogen Mustard-2-Pyridine Carboxylic Acid Hydrazone Being Involved in Topoisomerase IIα Inhibition

    Directory of Open Access Journals (Sweden)

    Yun Fu

    2014-01-01

    Full Text Available The antitumor property of iron chelators and aromatic nitrogen mustard derivatives has been well documented. Combination of the two pharmacophores in one molecule in drug designation is worth to be explored. We reported previously the syntheses and preliminary cytotoxicity evaluation of benzaldehyde nitrogen mustard pyridine carboxyl acid hydrazones (BNMPH as extended study, more tumor cell lines (IC50 for HepG2: 26.1 ± 3.5 μM , HCT-116: 57.5 ± 5.3 μM, K562: 48.2 ± 4.0 μM, and PC-12: 19.4 ± 2.2 μM were used to investigate its cytotoxicity and potential mechanism. In vitro experimental data showed that the BNMPH chelating Fe2+ caused a large number of ROS formations which led to DNA cleavage, and this was further supported by comet assay, implying that ROS might be involved in the cytotoxicity of BNMPH. The ROS induced changes of apoptosis related genes, but the TFR1 and NDRG1 metastatic genes were not obviously regulated, prompting that BNMPH might not be able to deprive Fe2+ of ribonucleotide reductase. The BNMPH induced S phase arrest was different from that of iron chelators (G1 and alkylating agents (G2. BNMPH also exhibited its inhibition of human topoisomerase IIα. Those revealed that the cytotoxic mechanism of the BNMPH could stem from both the topoisomerase II inhibition, ROS generation and DNA alkylation.

  1. Spectro Analytical, Computational and In Vitro Biological Studies of Novel Substituted Quinolone Hydrazone and it's Metal Complexes.

    Science.gov (United States)

    Nagula, Narsimha; Kunche, Sudeepa; Jaheer, Mohmed; Mudavath, Ravi; Sivan, Sreekanth; Ch, Sarala Devi

    2018-01-01

    Some novel transition metal [Cu (II), Ni (II) and Co (II)] complexes of nalidixic acid hydrazone have been prepared and characterized by employing spectro-analytical techniques viz: elemental analysis, 1 H-NMR, Mass, UV-Vis, IR, TGA-DTA, SEM-EDX, ESR and Spectrophotometry studies. The HyperChem 7.5 software was used for geometry optimization of title compound in its molecular and ionic forms. Quantum mechanical parameters, contour maps of highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) and corresponding binding energy values were computed using semi empirical single point PM3 method. The stoichiometric equilibrium studies of metal complexes carried out spectrophotometrically using Job's continuous variation and mole ratio methods inferred formation of 1:2 (ML 2 ) metal complexes in respective systems. The title compound and its metal complexes screened for antibacterial and antifungal properties, exemplified improved activity in metal complexes. The studies of nuclease activity for the cleavage of CT- DNA and MTT assay for in vitro cytotoxic properties involving metal complexes exhibited high activity. In addition, the DNA binding properties of Cu (II), Ni (II) and Co (II) complexes investigated by electronic absorption and fluorescence measurements revealed their good binding ability and commended agreement of K b values obtained from both the techniques. Molecular docking studies were also performed to find the binding affinity of synthesized compounds with DNA (PDB ID: 1N37) and "Thymidine phosphorylase from E.coli" (PDB ID: 4EAF) protein targets.

  2. Synthesis and characterization of nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) complexes of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide

    International Nuclear Information System (INIS)

    Syamal, A.; Maurya, M.R.

    1986-01-01

    Synthesis of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide, and its coordination compounds with nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) are described. The ligand and the complexes have been characterized on the basis of analytical, conductance, molecular weight, i.r., electronic and n.m.r. spectra and magnetic susceptibility measurements. The stoichiometries of the complexes are represented as NiL . 3H 2 O, CoL . 2H 2 O, CuL, MnL . 2H 2 O, ZnL . H 2 O, Zr(OH) 2 (LH) 2 , Zr(OH) 2 L . 2MeOH, UO 2 L . MeOH and MoO 2 L . MeOH (where LH 2 =Schiff base). The copper(II) complex shows a subnormal magnetic moment due to antiferromagnetic exchange interaction while the nickel(II), cobalt(II) and manganese(II) complexes show normal magnetic moments at room temperature. The i.r. and n.m.r. spectral studies show that the Schiff base behaves as a dibasic and tridentate ligand coordinating through the deprotonated phenolic oxygen, enolic oxygen and azomethine nitrogen. (orig.)

  3. Synthesis, Characterization, Antimicrobial Screening and Free-Radical Scavenging Activity of Some Novel Substituted Pyrazoles

    Directory of Open Access Journals (Sweden)

    Nagwa Mohamed Mahrous Hamada

    2015-06-01

    Full Text Available The present work deals with the synthesis of acetoxysulfonamide pyrazole derivatives, substituted 4,5-dihydropyrazole-1-carbothioamide and 4,5-dihydropyrazole-1-isonicotinoyl derivatives starting from substituted vanillin chalcones. Acetoxysulfonamide pyrazole derivatives were prepared from the reaction of chalcones with p-sulfamylphenylhydrazine followed by treatment with acetic anhydride. At the same time 4,5-dihydropyrazole-1-carbothioamide and 4,5-dihydropyrazole-1-isonicotinoyl derivatives were prepared from the reaction of chalcones with either thiosemicarbazide or isonicotinic acid hydrazide, respectively. The synthesized compounds were structurally characterized on the basis of IR, 1H-NMR, 13C-NMR spectral data and microanalyses. All of the newly isolated compounds were tested for their antimicrobial activities. The antimicrobial screening using the agar well-diffusion method revealed that the chloro derivatives are the most active ones. Moreover, the antioxidant and anti-inflammatory activity of these chloro derivatives are also studied using the DPPH radical scavenging and NO radical scavenging methods, respectively.

  4. Simple and sensitive method for the quantification of total bilirubin in human serum using 3-methyl-2-benzothiazolinone hydrazone hydrochloride as a chromogenic probe

    Science.gov (United States)

    Nagaraja, Padmarajaiah; Avinash, Krishnegowda; Shivakumar, Anantharaman; Dinesh, Rangappa; Shrestha, Ashwinee Kumar

    2010-11-01

    We here describe a new spectrophotometric method for measuring total bilirubin in serum. The method is based on the cleavage of bilirubin giving formaldehyde which further reacts with diazotized 3-methyl-2-benzothiazolinone hydrazone hydrochloride giving blue colored solution with maximum absorbance at 630 nm. Sensitivity of the developed method was compared with Jendrassik-Grof assay procedure and its applicability has been tested with human serum samples. Good correlation was attained between both methods giving slope of 0.994, intercept 0.015, and R2 = 0.997. Beers law obeyed in the range of 0.068-17.2 μM with good linearity, absorbance y = 0.044 Cbil + 0.003. Relative standard deviation was 0.006872, within day precision ranged 0.3-1.2% and day-to-day precision ranged 1-6%. Recovery of the method varied from 97 to 102%. The proposed method has higher sensitivity with less interference. The obtained product was extracted and was spectrally characterized for structural confirmation with FT-IR, 1H NMR.

  5. Conjugation of isoniazid to a zinc phthalocyanine via hydrazone linkage for pH-dependent liposomal controlled release

    Science.gov (United States)

    Nkanga, Christian Isalomboto; Krause, Rui Werner Maçedo

    2018-05-01

    Tuberculosis (TB) remains the leading cause of mortality from infectious diseases. Extended TB treatment and frequent adverse effects, due to poor bioavailability of anti-tubercular drugs (ATBDs), represent the main rationales behind liposomal encapsulation for controlled delivery. Liposomes have been reported as potential vehicles for targeted delivery of ATBDs due to their rapid uptake by macrophages, which are known as the main host cells for TB causative agent (Mycobacterium tuberculosis). Additionally, the need for controlled release of ATBDs arises because leakage is part of the key liposome challenges for hydrophilic compounds like isoniazid (INH). In this study, INH was conjugated to a highly hydrophobic photosensitizer, zinc (II) phthalocyanine (PC), through hydrazone bonding. The obtained conjugate (PC-INH) was encapsulated in liposomes by film hydration method. PC-INH loaded liposomes (PILs) were characterized using dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectrometry and UV-Vis absorption spectrometry, which was used also for estimation of encapsulation efficiency (%EE). INH release was evaluated in different pH media using dialysis. Particle size, zeta potential and %EE of PILs were about 506 nm, - 55 mV and 72%, respectively. Over 12 h, PILs exhibited 22, 41, 97 and 100% of INH, respectively, released in pH 7.4, 6.4, 5.4 and 4.4 media. This pH-dependent behavior is attractive for site-specific delivery. These findings suggest the conjugation of chemotherapeutics to phthalocyanines using pH-labile linkages as a potential strategy for liposomal controlled release.

  6. New Pyrazole-Hydrazone Derivatives: X-ray Analysis, Molecular Structure Investigation via Density Functional Theory (DFT) and Their High In-Situ Catecholase Activity.

    Science.gov (United States)

    Karrouchi, Khalid; Yousfi, El Bekkaye; Sebbar, Nada Kheira; Ramli, Youssef; Taoufik, Jamal; Ouzidan, Younes; Ansar, M'hammed; Mabkhot, Yahia N; Ghabbour, Hazem A; Radi, Smaail

    2017-10-25

    The development of low-cost catalytic systems that mimic the activity of tyrosinase enzymes (Catechol oxidase) is of great promise for future biochemistry technologic demands. Herein, we report the synthesis of new biomolecules systems based on hydrazone derivatives containing a pyrazole moiety ( L1 - L6 ) with superior catecholase activity. Crystal structures of L1 and L2 biomolecules were determined by X-ray single crystal diffraction (XRD). Optimized geometrical parameters were calculated by density functional theory (DFT) at B3LYP/6-31G (d, p) level and were found to be in good agreement with single crystal XRD data. Copper (II) complexes of the compounds ( L1 - L6 ), generated in-situ, were investigated for their catalytic activities towards the oxidation reaction of catechol to ortho -quinone with the atmospheric dioxygen, in an attempt to model the activity of the copper containing enzyme tyrosinase. The studies showed that the activities depend on four parameters: the nature of the ligand, the nature of counter anion, the nature of solvent and the concentration of ligand. The Cu(II)-ligands, given here, present the highest catalytic activity (72.920 μmol·L -1 ·min -1 ) among the catalysts recently reported in the existing literature.

  7. Comparative ligational, optical band gap and biological studies on Cr(III) and Fe(III) complexes of hydrazones derived from 2-hydrazinyl-2-oxo-N-phenylacetamide with both vanillin and O-vanillin

    Science.gov (United States)

    Yousef, T. A.; Abu El-Reash, G. M.; Attia, M. I.; El-Tabai, M. N.

    2015-09-01

    The Cr(III) and Fe(III) complexes of hydrazones derived from the condensation of 2-hydrazinyl-2-oxo-N-phenylacetamide with both vanillin and o-vanillin synthesized and characterized by different conventional physicochemical techniques. The kinetic and thermodynamic parameters for the different decomposition steps were calculated using Coats-Redfern and Horowitz-Metzger equations. The bond lengths, bond angles, HOMO, LUMO, dipole moment and binding energy calculated by DFT calculations. The optical band gap (Eg) values equal 3.28, 3.03, 3.58 and 3.57 eV for [Cr(HL1)Cl2(H2O)2](0.75H2O), [Cr(HL2)Cl2(H2O)](H2O), [Fe(HL1)Cl2(H2O)2](0.5H2O) and [Fe(HL2)2Cl(H2O)](3H2O) complexes, respectively. The antibacterial activities tested against Bacillus subtilis and Escherichia coli bacteria.

  8. Synthesis and Structural Studies on Transition Metal Complexes Derived from 4-Hydroxy-4-methyl–2-pentanone-1H-benzimidazol-2-yl-hydrazone

    Directory of Open Access Journals (Sweden)

    M. Neelamma

    2011-01-01

    Full Text Available Transition metal complexes of Cr(III, Fe(III, Mn(II, Co(II, Ni(II, Cu(II and Zn(II with a tridentate ligand, 4-hydroxy-4-methyl-2-pentanone-1H-benzimidazole-2yl-hydrazone (H-HPBH derived from the condensation of 2-hydrazinobenzimidazole and diacetone alcohol was synthesized. Characterization has been done on the basis of analytical, conductance, thermal and magnetic data, infrared, 1H NMR, electronic, mass and ESR spectral data. From analytical and thermal data, the stoichiometry of the complexes has been found to be 1:1 (metal: ligand. Divalent complexes have the general formula [M(HPBHCl(H2O2] in octahedral geometry, [M(HPBHCl] in tetrahedral and square planar stereochemistries and trivalent complexes [M(HPBHCl2(H2O] in octahedral disposition. Infrared spectral data suggest that the ligand HPBH behaves as a monobasic tridentate ligand with N: N: O donor sequence towards the metal ions. On the basis of the above physicochemical data, octahedral, tetrahedral and square planar geometries were assigned for the complexes. The ligand and metal complexes were screened for their physiological activities against E. coli and S. aureus. The order of physiological activity has been found to be Cu(II > Ni(II > Zn(II > Co(II > Cr(III > Mn(II > Fe (III > ligand against E.coli and Ni(II > Cu(II > Zn(II > Mn(II > Cr(III > Fe(III > Co(II > ligand against S. aureus.

  9. Antischistosomal activity of acridanone- hydrazones in Cebus monkeys experimentally infected with the SJ strain of Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Paulo Marcos Zech Coelho

    1995-09-01

    Full Text Available In this study, four compounds were utilized at the dose of 12.5mg/kg body weight, p.o., to treat Cebus monkeys experimentally infected with about 200 cercariae of Schistosoma mansoni (SJ strain, via transcutaneous route. The oograms performed with rectal snips, as well as stool examinations carried out periodically, showed no viable eggs of the parasite, from day 29 to 226post-treatment. The perfusion undertaken after killing the animals showed absence of worms in the treated monkeys, whereas 83 worms were recovered from the control, thus corroborating the results obtained by means of oograms and coproscopy. These results confirm the efficacy of 9-acridanone- hydrazones previously tested against the LE strain of S. mansoni. The low curative dose and apparent absence of toxicity render these dmgs an important therapeutic reserve, taking into consideration the reports on the resistance of S. mansoni to the modern drugs oxamniquine and praziquantel.No presente trabalho, quatro compostos foram utilizados na dose de 12,5mg/kg de peso, por via oral, em macacos infectados transcutaneamente com cerca de 200 cercárias de Schistosoma mansoni. Os oogramas realizados com fragmentos de mucosa retal e os exames de fezes realizados, periodicamente, demonstraram a ausência de ovos viáveis do parasito a partir do 29- até o 226a dia pós-tratamento. A perfusão, apôs sacrifício dos animais tratados, não detectou vermes, enquanto que do macaco cotztrole 83 vermes foram recuperados, confirmando assim os resultados dos oogramas e da coproscopia. Estes resultados confirmam a eficácia das 9-acridanonas- hydrazonas já observada anteriormente contra a cepa LE de S. mansoni. A baixa dosagem curativa e aparente ausência de toxicidade colocam estas drogas como uma reserva terapêutica importante, tendo em vista o relato de resistência do S. mansoni às drogas modernas oxamniquína e praziquantel.

  10. Radioiodinated derivatives for steroid radioimmunoassay. Application to the radioimmunoassay of cortisol

    International Nuclear Information System (INIS)

    Gomez-Sanchez, C.; Milewich, L.; Holland, O.B.

    1977-01-01

    Gamma-emitting steroid tracers for use in the radioimmunoassay of steroids have a number of advantages over the more common tritiated tracers. The steroid derivatives aldosterone-3-(p-hydroxybenzoyl) hydrazone, aldosterone-3-(p-hydroxyphenylpropionyl)hydrazone, deoxycorticosterone-3-(p-hydroxyphenylpropionyl)hydrazone, and cortisol-3-(p-hydroxyphenylpropionyl)hydrazone were synthesized by a one-step procedure and iodinated ([ 125 I]). To illustrate the usefulness of these derivatives, we describe the details of a cortisol radioimmunoassay. The use of the radioiodinated tracer appeared to increase the specificity of the antigen-antibody reaction when compared with [ 3 H]cortisol. The methodology involved in the preparation of the steroid derivatives described above can be extended to other 3-oxo-4-ene-containing steroids, with the advantages of economy, simplicity, and versatility

  11. Syntheses of polystyrene supported chelating resin containing the Schiff base derived from salicylaldehyde and triethylene tetramine and its copper(II), nickel(II), cobalt(II), iron(III), zinc(II), cadmium(II), molybdenum(VI), zirconium(IV) and uranium(VI) complexes

    International Nuclear Information System (INIS)

    Syamal, A.; Singh, M.M.

    1998-01-01

    A new polymer-anchored chelating ligand has been synthesized by the reaction of chloromethylated polystyrene (containing 0.94 mmol of Cl per gram of resin and 1% cross-linked with divinylbenzene) and the Schiff base derived from salicylaldehyde and triethylenetetramine. A new series of polystyrene supported, Cu(II), Ni(II), Co(II), Fe(III), Zn(II), Cd(II), Zr(IV), dioxomolybdenum (VI) and dioxouranium (VI) complexes of the formulae PS-LCu, PS-LNi, PS-LCo, PS-LFeCl.DMF, PS-LZn, PS-LCd, PS-LZr(OH) 2 . DMF, PS L MoO 2 and PS-LUO 2 (where PS-LH 2 = polymer-anchored Schiff base and DMF dimethyl-formamide) have been synthesized and characterised by elemental analysis, infrared, electronic spectra and magnetic susceptibility measurements. The complexes PS-LCu, PS-LNi and PS-LCo have square planar structure, PS-LFeCl.DMF, PS-LMoO 2 and PS-LUO 2 have octahedral structure, PS L Zn and PS-LCd are tetrahedral and PS-LZr(OH) 2 .DMF is pentagonal bipyramidal. The polymer-anchored Cu(II), Co(II) and Fe(III) complexes are paramagnetic while Ni(II), Zn(II), Cd(II), Zr(IV), dioxomolybdenum(VI) and dioxouranium(VI) complexes are diamagnetic. The negative shift of the v (C=N) (azomethine) and the positive shift of v (C--O)(phenolic) are indicative of ONNO donor behaviour of the polymer-anchored Schiff base. (author)

  12. New entry for synthesis of N-acylhydrazones, pyridazinones, and 1,3,4-oxadiazin-6-ones from alpha-amino acid esters.

    Science.gov (United States)

    Yasui, Eiko; Wada, Masao; Takamura, Norio

    2007-11-01

    Versatile electrophiles N-acylhydrazones are synthesized via diazotization, reduction, and acylation of alpha-amino acid esters. Reduction of diazo esters with L-selectride or tributylphosphine affords the corresponding hydrazones in good yields. Both reducing agents give anti-hydrazones as the major product although the reactivity of each reductant is slightly different. The resulting hydrazones are acylated to give N-acylhydrazones, which are subjected to further reactions to give 1,3,4-oxadiazin-6-ones that serve as useful synthetic intermediates for the Diels-Alder reaction.

  13. Complex formation between uranyl and various thiosemicarbazide derivatives

    International Nuclear Information System (INIS)

    Chuguryan, D.G.; Dzyubenko, V.I.

    1987-01-01

    Complex formation between hexavalent uranium and salicylaldehyde thiosemicarbazone (H 2 L), salicylaldehyde S-methyl-isothiosemicarbazone (H 2 Q), S-methyl-N 1 ,N 4 -bis(salicylidene)isothiosemicarbazide(H 2 Z), and thiosemicarbazidodiacetic acid (H 2 R) has been studied spectrophotometrically in solution. Stability constants for complexes having the composition UO 2 A have been calculated. Solid uranyl derivatives having the composition UO 2 L x 2H 2 O, UO 2 Q x 2H 2 O, UO 2 Z x 2H 2 O, and UO 2 R x 2H 2 O have been obtained. These derivatives were isolated and their IR spectroscopic behavior and thermal properties were investigated

  14. Determination of trace amounts of nickel(II) with α-(2-Benzimidazolyl)-α',α''-(N-5-nitro-2-pyridyl hydrazone) toluene in the presence of triton X-100 by fluorescence method

    International Nuclear Information System (INIS)

    Park, Chan Il; Kim, Hyun Soo; Cha, Ki Won

    2000-01-01

    A method is described for the fluorimetric determination of nicke, based on the formation of Ni(II)-α-(2-Benzimidazolyl)-α',α''-(N-5-nitro-2-pyridyl hydrazone)-toluene complex in the presence of a non-ionic surfactant. The complex has practically no fluorescence in the absence of surfactant, but the addition of Triton X-100 makes possible the fluorimetric determination of low concentrations of Ni(II) as it enhances the fluorescence intensity of the complex by up to about 5-fold. This method is very sensitive and selective for the direct determination of nickel ion. The optimum conditions are a Triton X-100 concentration of 2.0 mL (5.0%, v/v) and pH 9.0 ± 0.2 (ammonium chloride-ammonia buffer). The fluorescence is measured at 337 nm of emission wavelength under 300 nm of excitation wavelength. The fluorescence intensity is a linear function of the concentration of Ni(II) in the range 5-70 ng/mL, and the detection limit is 2.0 ng/mL. The proposed method has been successfully applied to the determination of trace amounts of Ni(II) in food and human hair samples

  15. Synthesis and biological assessment of novel acylhydrazone derivatives of 2-methyl-1,4-naphthoquinone

    Directory of Open Access Journals (Sweden)

    Kamal Bouhadir

    2017-10-01

    Full Text Available Naphthoquinones are medicinally important molecules with a diverse array of biological properties such as antimicrobial, antifungal, antiviral, anti-inflammatory, anti-artherosclerotic and anticarcinogenic activities. In this study, we report the simple and direct preparation of a new group of novel menadione-hydrazone conjugates by reaction of 2-methyl-1,4-naphthoquinones with several aliphatic, aromatic and nucleobase hydrazides. The menadione-hydrazone conjugates were produced in excellent yields and characterized by IR, NMR and HRMS. The menadione derivatives were tested for their anticancer effects against human colon cancer HCT116 and human breast cancer MCF-7 cell lines. Interestingly, the molecules displayed disparate activities against both cell lines; the menadione hydrazones derived from the lipophilic myristic hydrazide and stearic hydrazide exhibited the most potent activity against HCT116 cell lines with IC50 of 89 and 64 μM. The most effective compounds against MCF-7 cells were the lauric hydrazide and benzoic hydrazide-derived menadione hydrazones with IC50 of 56 µM.

  16. Synthesis and characterization of Mn(III) chloro complexes with salen-type ligands

    International Nuclear Information System (INIS)

    Byun, Jong Chul; Han, Chung Hun; Lee, Nam Ho; Baik, Jong Seok; Park, Yu Chul

    2002-01-01

    A series of novel salen-type complexes ((Mn(III)(L acn )Cl): n=1∼11) containing Cl - ion were obtained by reactions of the Mn(CH 3 COO) 2 ·4H 2 O with the potentially tetradentate compartmental ligand (H 2 L acn ), prepared by condensation the of one mole of diamine (ethylenediamine, 1,3-propanediamine, o-phenylenediamine, and 2,2-dimethyl-1,3-propanediamine) with two moles of aldehyde (salicylaldehyde, 5-chloro- salicylaldehyde, 3,5-dichlorosalicylal-dehyde, and 3,5-di-tert-butyl-2-hydroxy-benzaldehyde) in a methanol solution . The resulting salen-type ligands and their Mn(III) complexes were identified and characterized by elemental analysis, conductivity, thermogravimetry and UV-VIS, IR, and NMR spectroscopy

  17. Independently recruited oxidases from the glucose-methanol-choline oxidoreductase family enabled chemical defences in leaf beetle larvae (subtribe Chrysomelina) to evolve

    Science.gov (United States)

    Rahfeld, Peter; Kirsch, Roy; Kugel, Susann; Wielsch, Natalie; Stock, Magdalena; Groth, Marco; Boland, Wilhelm; Burse, Antje

    2014-01-01

    Larvae of the leaf beetle subtribe Chrysomelina sensu stricto repel their enemies by displaying glandular secretions that contain defensive compounds. These repellents can be produced either de novo (iridoids) or by using plant-derived precursors (e.g. salicylaldehyde). The autonomous production of iridoids, as in Phaedon cochleariae, is the ancestral chrysomeline chemical defence and predates the evolution of salicylaldehyde-based defence. Both biosynthesis strategies include an oxidative step of an alcohol intermediate. In salicylaldehyde-producing species, this step is catalysed by salicyl alcohol oxidases (SAOs) of the glucose-methanol-choline (GMC) oxidoreductase superfamily, but the enzyme oxidizing the iridoid precursor is unknown. Here, we show by in vitro as well as in vivo experiments that P. cochleariae also uses an oxidase from the GMC superfamily for defensive purposes. However, our phylogenetic analysis of chrysomeline GMC oxidoreductases revealed that the oxidase of the iridoid pathway originated from a GMC clade different from that of the SAOs. Thus, the evolution of a host-independent chemical defence followed by a shift to a host-dependent chemical defence in chrysomeline beetles coincided with the utilization of genes from different GMC subfamilies. These findings illustrate the importance of the GMC multi-gene family for adaptive processes in plant–insect interactions. PMID:24943369

  18. Ethyl 4-{1-[(2,4-dinitrophenylhydrazono]ethyl}-5-(2-naphthylmethoxymethylisoxazole-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Nicholas R. Natale

    2009-01-01

    Full Text Available The title compound, C26H23N5O8, was prepared and its structure investigated to further develop a working hypothesis for the essential binding pharmacophore for ligands of the System Xc- transporter [Patel et al. (2004. Neuropharmacology, 46, 273–284]. The hydrazone group displays an E geometry and the isoxazole double bond and C=N group of the hydrazone are in an s-cis relationship. The secondary amino NH group forms an intramolecular N—H...O hydrogen bond to a ring nitro group. There is a dihedral angle of 44.27 (5° between the isoxazole plane and the hydrazone group plane.

  19. A hydrazone covalent organic polymer based micro-solid phase extraction for online analysis of trace Sudan dyes in food samples.

    Science.gov (United States)

    Zhang, Chengjiang; Li, Gongke; Zhang, Zhuomin

    2015-11-06

    Covalent organic polymers (COPs) connected by covalent bonds are a new class of porous network materials with large surface area and potential superiority in sample pretreatment. In this study, a new hydrazone linked covalent organic polymer (HL-COP) adsorbent was well-designed and synthesized based on a simple Schiff-base reaction. The condensation of 1,4-phthalaldehyde and 1,3,5-benzenetricarbohydrazide as organic building blocks led to the synthesis of HL-COP with uniform particle size and good adsorption performance. This HL-COP adsorbent with high hydrophobic property and rich stacking π electrons contained abundant phenyl rings and imine (CN) groups throughout the entire molecular framework. The adsorption mechanism was explored and discussed based on π-π affinity, hydrophobic effect, hydrogen bonding and electron-donor-acceptor (EDA) interaction, which contributed to its strong recognition affinity to target compounds. Enrichment factors were 305-757 for six Sudan dyes by HL-COP micro-solid phase extraction (μ-SPE), indicating its remarkable preconcentration ability. Furthermore, the adsorption amounts by HL-COP μ-SPE were 1.0-11.0 folds as those by three commonly used commercial adsorbents. Then, HL-COP was applied as adsorbent of online μ-SPE coupled with high performance liquid chromatography (HPLC) for enrichment and analysis of trace Sudan dyes in food samples with detection limit of 0.03-0.15μg/L. The method was successfully applied for online analysis of chilli powder and sausage samples. Sudan II and Sudan III in one positive chilli powder sample were actually found and determined with concentrations of 8.3 and 6.8μg/kg, respectively. The recoveries of chilli powder and sausage samples were in range of 75.8-108.2% and 73.8-112.6% with relative standard deviations of 1.2-8.5% and 1.9-9.4% (n=5), respectively. The proposed method was accurate, reliable and convenient for the online simultaneous analysis of trace Sudan dyes in food samples

  20. Stimulating retinal blood vessel protection with hypoxia-inducible factor stabilization: identification of novel small-molecule hydrazones to inhibit hypoxia-inducible factor prolyl hydroxylase (an American Ophthalmological Society thesis).

    Science.gov (United States)

    Sears, Jonathan E; Hoppe, George

    2013-09-01

    To discover novel small molecules that inhibit hypoxia-inducible factor (HIF) prolyl hydroxylase (PHD), a key enzyme that regulates the posttranslational stability and hence activity of HIF. NIH3T3 cell line stably transfected with firefly luciferase under a HIF-1-inducible promoter was used to screen a Chembridge library of 34,000 small molecules of molecular weight 250 to 550 Da. Positive hits were considered at 4.5-fold higher luminescence than control. Selected compounds were validated in vitro. The most effective dose was then used to treat mice expressing firefly luciferase fused to the oxygen-dependent degradation domain (lucODD) in order to determine the location of the receptor for systemic treatment with small-molecule HIF PHD inhibitors. Twenty-three novel small molecules were discovered, the majority of which were hydrazones and hydrazines. Of the 23 compounds, each had different selectivity for expression of erythropoietin or vascular endothelial growth factor, two angiogenic, HIF-regulated gene products. In addition, each showed different selectivity for hepatocytes or kidney, or both or neither, when injected intraperitoneally in an in vivo reporter gene assay. The discovery of multiple small molecules that inhibit HIF PHD identifies new reagents to develop strategies to prevent the degradation of HIF by its selective PHD. These molecules are novel hypoxia mimetics that may provide new strategies to protect retinovasculature from hyperoxia.

  1. Antiparasitic nitroimidazoles. 8. Derivatives of 2-(4-formylstyryl)-5-nitro-1-vinylimidazole.

    Science.gov (United States)

    Ross, W J; Jamieson, W B

    1975-02-01

    A series of 33 thioacetals and hydrazones of 2-(4-formylstyryl)-5-nitro-1-vinylimidazole was prepared and examined for antitrypanosomal properties. The thioacetals were inactive as antitrypanosomal agents but three hydrazones derived from N-aminoguanidine, pyridylacethohydrazide chloride (Girard reagent P), and dimethylaminoacetohydrazide (Girard reagent D) displayed good activity against Trypanosoma rhodesiense.

  2. Chemsearch Journal Volume 4 Number 1, June, 2013

    African Journals Online (AJOL)

    Magashi

    2013-06-01

    phenylenediimine was prepared by 2:1 molar condensation of 4 – (Benzeneazo) salicylaldehyde with o-phenylenediamine. The manganese(II) complex of the schiff base was prepared and characterized by determination of its solubility, ...

  3. Application of pyridine-2-carbaldehyde-2-(4-methyl-1,3-benzo thiazol-2-yl)hydrazone as a neutral ionophore in the construction of a novel Er(III) sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ganjali, Mohammad Reza; Norouzi, Parviz [University of Tehran, Tehran (Iran, Islamic Republic of). Center of Excellence in Electrochemistry; Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of). Endocrine and Metabolism Research Center; E-mail: ganjali@khayam.ut.ac.ir; Rezapour, Morteza; Rasoolipour, Solmaz [University of Tehran, Tehran (Iran, Islamic Republic of). Center of Excellence in Electrochemistry; Adib, Mehdi [University of Tehran, Tehran (Iran, Islamic Republic of). University College of Science. Faculty of Chemistry

    2007-03-15

    We found that pyridine-2-carbaldehyde-2-(4-methyl-1,3-benzothiazol-2-yl) hydrazone (PCMHT) can be used as a suitable neutral ionophore for preparing an Er(III) membrane sensor with high selectivity. The optimum composition was found to be PCMHT-PVC-KTpClPB-BA with the ratios of 6.0:30.0:5.0:59.0, respectively. The Nernstian response was of 21.8 {+-} 0.5 mV decade{sup -1} of Er(III) activity, the linear range of the sensor was found to be relatively wide (from 1.0X10{sup -5} to 1.0 X10{sup -2} mol L{sup -1}). Its applicability pH range of 2.5-12.0 seems to make it suitable for analytical applications. The lower detection limit (LDL) of the sensor was 5.0 X10{sup -6} mol L{sup -1}. The excellent Er(III)-selectivity of the proposed sensor with regard to most common metal ions, and especially, lanthanide ions is another advantage. It was successfully used as an indicator electrode for titration of 25 mL of a 1.0 X 10{sup -4} mol L{sup -1} Er(III) ions with a 1.0 X 10{sup -}2 mol L{sup -1} EDTA. The proposed sensor was used for direct monitoring of Er(III) in binary mixtures and indirect determination of fluoride ions in two mouth wash preparations. (author)

  4. Chemical signal activation of an organocatalyst enables control over soft material formation.

    Science.gov (United States)

    Trausel, Fanny; Maity, Chandan; Poolman, Jos M; Kouwenberg, D S J; Versluis, Frank; van Esch, Jan H; Eelkema, Rienk

    2017-10-12

    Cells can react to their environment by changing the activity of enzymes in response to specific chemical signals. Artificial catalysts capable of being activated by chemical signals are rare, but of interest for creating autonomously responsive materials. We present an organocatalyst that is activated by a chemical signal, enabling temporal control over reaction rates and the formation of materials. Using self-immolative chemistry, we design a deactivated aniline organocatalyst that is activated by the chemical signal hydrogen peroxide and catalyses hydrazone formation. Upon activation of the catalyst, the rate of hydrazone formation increases 10-fold almost instantly. The responsive organocatalyst enables temporal control over the formation of gels featuring hydrazone bonds. The generic design should enable the use of a large range of triggers and organocatalysts, and appears a promising method for the introduction of signal response in materials, constituting a first step towards achieving communication between artificial chemical systems.Enzymes regulated by chemical signals are common in biology, but few such artificial catalysts exist. Here, the authors design an aniline catalyst that, when activated by a chemical trigger, catalyses formation of hydrazone-based gels, demonstrating signal response in a soft material.

  5. Manganese–Schiff base complex immobilized silica materials

    Indian Academy of Sciences (India)

    III)]+ and [Mn(salophen)]+: [N,N′-bis(salicylaldehyde)-1,2-phenylenediimino manganese(III)]+ were introduced into/onto the MCM-41 type silica spheres and used for the electrocatalytic reduction of oxygen. Synthesized materials were ...

  6. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    A heterocyclic hydrazone ligand, diacetyl monoxime-2-pyridyl hydrazone, HL, 1, was investigated as a new chromogenic agent for selective detection of Fe3+. The ligand 1, undergoes 1 : 2 complexation with Fe3+ and Ni2+ to form complexes [FeIII(HL)2]Cl3, 1a and [NiII(HL)2]Cl2, 1b respectively. The iron(III) complex 1a ...

  7. The features of nucleophilic substitution of the nitro group in 4-alkyl-6-nitro-1,2,4-triazolo[5,1-c][1,2,4]triazines

    Directory of Open Access Journals (Sweden)

    E. N. Ulomsky

    2017-05-01

    Full Text Available The nucleophilic substitution of the nitro group of 4-alkyl-6-nitro-4,7-dihydro-1,2,4-triazolo[5,1-c][1,2,4]triazine-7-ones on the example of interactionwith morpholine was studied. It is established that under the action of excess cycloalkylimine at room temperature the unusual easy disclosure of triazine cycle with the formation of sterically hindered hydrazones occurs which are the key intermediates for further transformations. The carrying of reaction at elevated temperatures leads to the formation of products of substitution of the nitro group with the amine and also with morpholyl hydrazones which are the products of hydrolysis of amides of hydrazones and subsequent decarboxylation. Thus, the nucleophilic substitution of the nitro group in the described triazolotriazines flows through the ANRORC mechanism.

  8. Synthesis and characterization of a chiral dimeric copper(II) complex ...

    Indian Academy of Sciences (India)

    Unknown

    Dedicated to the memory of the late Professor Bhaskar G Maiya ... a Schiff-base derived from salicylaldehyde and (S)-(+)-2-phenylglycinol are described. Compound 1 crystallizes ... Microanalytical (C, H, N) data were obtained with a. Flash EA ...

  9. synthesis, characterization and thermal degradation of oligo

    African Journals Online (AJOL)

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    NaOCl and 2200, 2500 g mol-1 and 1.136 for oxidation by air. With the optimum ... electrochemical properties. Because of these ... 4-Iodoaniline (4-IA), salicylaldehyde (SA), methanol (MeOH), ethanol, benzene, acetone, toluene, heptane ...

  10. A hydrazone Schiff base single crystal (E)-Methyl N"′-(3,4,5-trimethoxybenzylidene) hydrazine carboxylate: Physicochemical, in vitro investigation of antimicrobial activities and molecular docking with DNA gyrase protein

    International Nuclear Information System (INIS)

    Gomathi, G.; Gopalakrishnan, R.

    2016-01-01

    Hydrazone Schiff bases have been widely explored for their antimicrobial, anticancer, anticonvulsant properties. The aim of the present work is to investigate the spectroscopic, electrochemical, thermal properties, in vitro study of antimicrobial activity and molecular docking studies of the MBHC compound. Slow evaporation solution growth technique was used to grow the single crystal of the MBHC compound. Single crystal X-ray diffraction, FTIR and FT-Raman spectroscopic studies are performed and confirmed the grown MBHC compound. UV–Vis spectroscopy and electrochemical studies deduced the absorption region and HOMO-LUMO band gap value of the compound. Resazurin reduction assay method was utilized to perform antibacterial and antifungal studies which resulted in lesser effectiveness of the MBHC compound compared to the erythromycin and fluconazole tablets. Molecular docking of the MBHC compound with the DNA gyrase protein exhibited the good binding affinity with energy of − 43.196 kcal/mol and docking score of − 6.266 and having good interaction with aminoacids – ASP81 and ARG84. - Highlights: • MBHC single crystal was grown by employing slow evaporation solution growth technique. • The compound crystallizes in monoclinic crystal system with space group P2_1/c. • The HOMO-LUMO band gap value was found to be 1.96 eV. • The compound has lesser antimicrobial activity when compared to erythromycin and fluconazole. • MBHC shows better binding affinity towards DNA gyrase protein.

  11. Coordination polymers of some lanthanide(III) nitrate with schiff bases

    International Nuclear Information System (INIS)

    Dwivedi, D.K.; Shukla, B.K.; Shukla, R.K.

    1991-01-01

    The Schiff bases derived from 2-hydroxy-1-naphthaldehyde and salicylaldehyde with o-dianisidine, p-phenylene diamine and benzidine and their lanthanide(III) complexes have been synthesized and characterized by elemental, I.R., thermal, magnetic and D.R.S. studies. (author). 7 refs

  12. SYNTHESIS AND CHARACTERIZATION OF N, N'-BIS-(3 ...

    African Journals Online (AJOL)

    user

    base complexes derived from Salicylaldehyde and histidine with some divalent transition metal ions. Furthermore, Syed (1993) reported the synthesis, characterization and biological evaluation of some. Schiff base metal complexes derived from Anthranilic acid-sugar and naturally occurring amino acid-sugar. Schiff bases ...

  13. A hydrazone Schiff base single crystal (E)-Methyl N{sup ′}-(3,4,5-trimethoxybenzylidene) hydrazine carboxylate: Physicochemical, in vitro investigation of antimicrobial activities and molecular docking with DNA gyrase protein

    Energy Technology Data Exchange (ETDEWEB)

    Gomathi, G.; Gopalakrishnan, R., E-mail: krgkrishnan@annauniv.edu

    2016-07-01

    Hydrazone Schiff bases have been widely explored for their antimicrobial, anticancer, anticonvulsant properties. The aim of the present work is to investigate the spectroscopic, electrochemical, thermal properties, in vitro study of antimicrobial activity and molecular docking studies of the MBHC compound. Slow evaporation solution growth technique was used to grow the single crystal of the MBHC compound. Single crystal X-ray diffraction, FTIR and FT-Raman spectroscopic studies are performed and confirmed the grown MBHC compound. UV–Vis spectroscopy and electrochemical studies deduced the absorption region and HOMO-LUMO band gap value of the compound. Resazurin reduction assay method was utilized to perform antibacterial and antifungal studies which resulted in lesser effectiveness of the MBHC compound compared to the erythromycin and fluconazole tablets. Molecular docking of the MBHC compound with the DNA gyrase protein exhibited the good binding affinity with energy of − 43.196 kcal/mol and docking score of − 6.266 and having good interaction with aminoacids – ASP81 and ARG84. - Highlights: • MBHC single crystal was grown by employing slow evaporation solution growth technique. • The compound crystallizes in monoclinic crystal system with space group P2{sub 1}/c. • The HOMO-LUMO band gap value was found to be 1.96 eV. • The compound has lesser antimicrobial activity when compared to erythromycin and fluconazole. • MBHC shows better binding affinity towards DNA gyrase protein.

  14. Structural and Kinetic Properties of the Aldehyde Dehydrogenase NahF, a Broad Substrate Specificity Enzyme for Aldehyde Oxidation.

    Science.gov (United States)

    Coitinho, Juliana B; Pereira, Mozart S; Costa, Débora M A; Guimarães, Samuel L; Araújo, Simara S; Hengge, Alvan C; Brandão, Tiago A S; Nagem, Ronaldo A P

    2016-09-27

    The salicylaldehyde dehydrogenase (NahF) catalyzes the oxidation of salicylaldehyde to salicylate using NAD(+) as a cofactor, the last reaction of the upper degradation pathway of naphthalene in Pseudomonas putida G7. The naphthalene is an abundant and toxic compound in oil and has been used as a model for bioremediation studies. The steady-state kinetic parameters for oxidation of aliphatic or aromatic aldehydes catalyzed by 6xHis-NahF are presented. The 6xHis-NahF catalyzes the oxidation of aromatic aldehydes with large kcat/Km values close to 10(6) M(-1) s(-1). The active site of NahF is highly hydrophobic, and the enzyme shows higher specificity for less polar substrates than for polar substrates, e.g., acetaldehyde. The enzyme shows α/β folding with three well-defined domains: the oligomerization domain, which is responsible for the interlacement between the two monomers; the Rossmann-like fold domain, essential for nucleotide binding; and the catalytic domain. A salicylaldehyde molecule was observed in a deep pocket in the crystal structure of NahF where the catalytic C284 and E250 are present. Moreover, the residues G150, R157, W96, F99, F274, F279, and Y446 were thought to be important for catalysis and specificity for aromatic aldehydes. Understanding the molecular features responsible for NahF activity allows for comparisons with other aldehyde dehydrogenases and, together with structural information, provides the information needed for future mutational studies aimed to enhance its stability and specificity and further its use in biotechnological processes.

  15. Unsuitability of using the DNPH-coated solid sorbent cartridge for determination of airborne unsaturated carbonyls

    Science.gov (United States)

    Ho, Steven Sai Hang; Ho, K. F.; Liu, W. D.; Lee, S. C.; Dai, W. T.; Cao, J. J.; Ip, H. S. S.

    2011-01-01

    Measurements of aldehydes and ketones are typically conducted by derivatization using sorbent cartridges coated with 2,4-dinitrophenylhydrazine (DNPH). The collected samples are eluted with acetonitrile and analyzed by high-pressure liquid chromatography coupled with an ultra-violet detector (HPLC/UV). This paper intends to examine artifacts about its suitability in identification of unsaturated carbonyls. Kinetic tests for acrolein, crotonaldehyde, methacrolein and methyl vinyl ketone (MVK) showed formations of carbonyl-DNP-hydrazone during sampling, which could further react with DNPH, resulting in undesired UV absorption products [e.g., carbonyl-DNP-hydrazone-DNPH (dimer) and 2(carbonyl-DNP-hydrazone)-DNPH (trimer)]. The dimerization and trimerization occurred for acrolein and MVK whereas only dimerization for crotonaldehyde and methacrolein. The polymerization products undoubtedly affect the integrity of the chromatogram, leading to misidentification and inaccurate quantification. Whether precautions taken during sampling and/or sample treatment could avoid or minimize this artifact has not been thoughtfully investigated. More often, such artifacts are usually overlooked by scientists when the data are reported.

  16. Schiff base transition metal complexes for Suzuki–Miyaura cross

    Indian Academy of Sciences (India)

    Schiff base ligand and its complex with iron (Fe), cobalt (Co), nickel (Ni) and copper (Cu) ions were synthesized using 4-aminoacetophenone and salicylaldehyde and characterized. FTIR spectrum shows that bidentate coordination of metal ions with ligand where O, N are electron donating sites of azomethine group.

  17. facile, mild and convenient preparation and characterization of some

    African Journals Online (AJOL)

    B. S. Chandravanshi

    salicylaldehyde with synthetic diamines in methanol solution under mild conditions. ... (11 g, 0.19 mol) potassium hydroxide in 30 mL of water and 10 mL hydrazine ... A mixture of glacial acetic acid (100 mL), 5.8 g of p-amino acetanilide, 8 g of ...

  18. short communication reaction of ethyl acetoacetate and 2

    African Journals Online (AJOL)

    Preferred Customer

    starting materials. Thus, we describe in this paper a facile procedure for the synthesis of 9- phenyl-6H-benzo[c]chromen-6-ones involving the reaction of ethyl acetoacetate and chalcones derived from the condensation of salicylaldehyde and acetophenone derivatives. RESULTS AND DISCUSSIONS. The conditions for the ...

  19. A new approach to the synthesis of no-carrier-added fluorine-18 labeled fluorocatechols

    International Nuclear Information System (INIS)

    Chakraborty, P.K.; Kilbourn, M.R.

    1990-01-01

    A new method of synthesizing fluorine-18 labelled fluorocatechols has been developed using a salicylaldehyde as a 'synthon' for a catechol. 2-Methoxy-4-nitrobenzaldehyde was treated with [ 18 F]fluoride ion, followed by cleavage of the anisole to yield the free phenol. The phenol was oxidized to the desired fluorocatechol

  20. complexes of pyrimidine derived

    Indian Academy of Sciences (India)

    Administrator

    The ligands are prepared by the condensation of 4,6-dimethyl 2-hydrazino pyrimidine with salicylaldehyde ... 6. With the knowledge of approximate coordination sphere of Mo in the metal- loenzymes at hand, several attempts have been made to model the active sites of these enzymes and study ..... [I > 2 sigma(I)]R indices.

  1. Antimicrobial mechanism of copper (II 1,10-phenanthroline and 2,2′-bipyridyl complex on bacterial and fungal pathogens

    Directory of Open Access Journals (Sweden)

    S. Chandraleka

    2014-12-01

    Full Text Available Copper based metallo drugs were prepared and their antibacterial, antifungal, molecular mechanism of [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O complexes were investigated. The [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O were derived from the Schiff base alanine salicylaldehyde. [Cu(SAlaPhen]·H2O showed noteworthy antibacterial and antifungal activity than the [Cu(SAlabpy]·H2O and ligand alanine, salicylaldehyde. The [Cu(SAlaPhen]·H2O complex showed significant antibacterial activity against Salmonella typhi, Staphylococcus aureus, Salmonella paratyphi and the antifungal activity against Candida albicans and Cryptococcus neoformans in well diffusion assay. The mode of action of copper (II complex was analyzed by DNA cleavage activity and in silico molecular docking. The present findings provide important insight into the molecular mechanism of copper (II complexes in susceptible bacterial and fungal pathogens. These results collectively support the use of [Cu(SAlaPhen]·H2O complex as a suitable drug to treat bacterial and fungal infections.

  2. Asymmetric Radical Cyclopropanation of Alkenes with In Situ-Generated Donor-Substituted Diazo Reagents via Co(II)-Based Metalloradical Catalysis.

    Science.gov (United States)

    Wang, Yong; Wen, Xin; Cui, Xin; Wojtas, Lukasz; Zhang, X Peter

    2017-01-25

    Donor-substituted diazo reagents, generated in situ from sulfonyl hydrazones in the presence of base, can serve as suitable radical precursors for Co(II)-based metalloradical catalysis (MRC). The cobalt(II) complex of D 2 -symmetric chiral porphyrin [Co(3,5-Di t Bu-Xu(2'-Naph)Phyrin)] is an efficient metalloradical catalyst that is capable of activating different N-arylsulfonyl hydrazones for asymmetric radical cyclopropanation of a broad range of alkenes, affording the corresponding cyclopropanes in high yields with effective control of both diastereo- and enantioselectivity. This Co(II)-based metalloradical system represents the first catalytic protocol that can effectively utilize donor-type diazo reagents for asymmetric olefin cyclopropanation.

  3. Synthesis and characterization of nanocomposite NiFe2O4 ...

    African Journals Online (AJOL)

    In this work, nano ferrite spinel NiFe2O4 was synthesized by sol-gel method and characterized by SEM, XRD, FT-IR, and VSM. In second step Schiff base made from salicylaldehyde and amino propyl triethoxy silane was used for modification of the synthesized nano ferrit. In the third step removal of Ni(II) was done using ...

  4. Au3+/Au0 Supported on Chromium(III Terephthalate Metal Organic Framework (MIL-101 as an Efficient Heterogeneous Catalystfor Three-Component Coupling Synthesis of Propargylamines

    Directory of Open Access Journals (Sweden)

    Lili Liu

    2017-01-01

    Full Text Available Post-synthesis modification is a useful method for the functionalization of metal–organic frameworks (MOFs. A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde, containing coexisting Au3+ ions and Au0 nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101 were prepared successfully by the impregnation method. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au3+/Au0 = 0.9 and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs.

  5. Sodium dodecyl benzene sulphonate mediated tautomerism of Eriochrome Black-T: Effect of charge transfer interaction

    Science.gov (United States)

    Ghosh, Sumit

    2010-11-01

    Interaction between anionic surfactant, sodium dodecyl benzene sulphonate, (SDBS) and an anionic dye Eriochrome Black-T, (EBT) has been investigated by visible spectroscopy, conductometry, dynamic light scattering and zeta potential measurements. Spectral changes of EBT observed on addition of SDBS indicate formation of quinone-hydrazone tautomer at pH 7.0, whereas in absence of SDBS this change appears at pH ˜ 9.45. However, at pH 7.0 this change in tautomerism is not observed in presence of sodium dodecyl sulphate (SDS). Experimental results indicate presence of charge transfer interaction between less stable quinone-hydrazone tautomer of EBT and SDBS molecules, which is confirmed using Benesi-Hildebrand and Scott equations.

  6. Zeolite-Y entrapped Ru(III and Fe(III complexes as heterogeneous catalysts for catalytic oxidation of cyclohexane reaction

    Directory of Open Access Journals (Sweden)

    Chetan K. Modi

    2017-02-01

    Full Text Available Catalysis is probably one of the greatest contributions of chemistry to both economic growth and environmental protection. Herein we report the catalytic behavior of zeolite-Y entrapped Ru(III and Fe(III complexes with general formulae [M(VTCH2·2H2O]+-Y and [M(VFCH2·2H2O]+-Y [where, VTCH = vanillin thiophene-2-carboxylic hydrazone and VFCH = vanillin furoic-2-carboxylic hydrazone] over the oxidation of cyclohexane forming cyclohexanone and cyclohexanol. The samples were corroborated by various physico-chemical techniques. These zeolite-Y based complexes are stable and recyclable under current reaction conditions. Amongst them, [Ru(VTCH2⋅2H2O]+-Y showed higher catalytic activity (41.1% with cyclohexanone (84.6% selectivity.

  7. Immobilization methods for the rapid total chemical synthesis of proteins on microtiter plates.

    Science.gov (United States)

    Zitterbart, Robert; Krumrey, Michael; Seitz, Oliver

    2017-07-01

    The chemical synthesis of proteins typically involves the solid-phase peptide synthesis of unprotected peptide fragments that are stitched together in solution by native chemical ligation (NCL). The process is slow, and throughput is limited because of the need for repeated high performance liquid chromatography purification steps after both solid-phase peptide synthesis and NCL. With an aim to provide faster access to functional proteins and to accelerate the functional analysis of synthetic proteins by parallelization, we developed a method for the high performance liquid chromatography-free synthesis of proteins on the surface of microtiter plates. The method relies on solid-phase synthesis of unprotected peptide fragments, immobilization of the C-terminal fragment and on-surface NCL with an unprotected peptide thioester in crude form. Herein, we describe the development of a suitable immobilization chemistry. We compared (i) formation of nickel(II)-oligohistidine complexes, (ii) Cu-based [2 + 3] alkine-azide cycloaddition and (iii) hydrazone ligation. The comparative study identified the hydrazone ligation as most suitable. The sequence of immobilization via hydrazone ligation, on-surface NCL and radical desulfurization furnished the targeted SH3 domains in near quantitative yield. The synthetic proteins were functional as demonstrated by an on-surface fluorescence-based saturation binding analysis. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

  8. SYNTHESIS, CHARACTERIZATION AND CRYSTAL STRUCTURES ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    ABSTRACT. Reaction of [VO(acac)2] (acac = acetylacetonate) with ... Single crystal X-ray structural studies indicate that the hydrazone ligands coordinate to ..... Molecular structure of complex (1) at 30% probability displacement. Figure 4.

  9. Spectral, thermal, electrochemical and analytical studies on Cd(II) and Hg(II) thiosemicarbazone complexes

    Science.gov (United States)

    El-Asmy, A. A.; El-Gammal, O. A.; Saleh, H. S.

    2008-11-01

    The coordination characteristic of the investigated thiosemicarbazones towards hazard pollutants, Cd(II) and Hg(II), becomes the first goal. Their complexes have been studied by microanalysis, thermal, electrochemical and spectral (electronic, IR and MS) studies. The substitutent (salicylaldehyde, acetophenone, benzophenone, o-hydroxy- p-methoxybenzophenone or diacetylmonoxime) plays an important role in the complex formation. The coordination sites were the S for thiosemicarbazide (HTS); NN for benzophenone thiosemicarbazone (HBTS); NS for acetophenone thiosemicarbazone (HATS) and salicylaldehyde thiosemicarbazone (H 2STS); NNS or NSO for diacetylmonoxime thiosemicarbazone (H 2DMTS). The stability constants of Hg(II) complexes were higher than Cd(II). The kinetic and thermodynamic parameters for the different thermal decomposition steps in the complexes have been evaluated. The activation energy values of the first step ordered the complexes as: [Cd(H 2STS)Cl 2]H 2O > [Cd(H 2DAMTS)Cl 2] > [Cd(HBTS) 2Cl 2]2H 2O > [Cd(HATS) 2Cl 2]. The CV of [Cd(H 2STS)Cl 2]H 2O and [Hg(HBTS)Cl 2] were recorded. The use of H 2DMTS as a new reagent for the separation and determination of Cd(II) ions from water and some synthetic samples using flotation technique is aimed to be discussed.

  10. Complex formation between neptunium(V) and various thiosemicarbazide derivatives in aqueous solution

    International Nuclear Information System (INIS)

    Chuguryan, D.G.; Dzyubenko, V.I.; Gerbeleu, N.V.

    1987-01-01

    Complex formation between neptunium(V) and various thiosemicarbazide derivatives in solution has been studied spectrophotometrically in the pH range 4-10. Stepwise formation of three types of complexes, with composition NpO 2 HA, NpO 2 A - , and NpOHA 2- , has been demonstrated with salicylaldehyde thiosemicarbazone (H 2 L) and salicylaldehyde S-methyl-isothiosemicarbazone (H 2 Q) at t = 25 +/- 1 0 C and μ = 0.05. The logarithmic stability constants of the first two complexes are 5.14 +/- 0.06, 11.85 +/- 0.04 and 8.42 +/- 0.09, 13.33 +/- 0.015 for H 2 L and H 2 Q, respectively; equilibrium constants for the formation of hydroxo complexes of the form NpO 2 OHL 2- and NpO 2 OHQ 2- were also determined, and found to be equal to (2.23 +/-0.37) x 10 -5 and (5.02 +/- 0.9) x 10 -5 , respectively. In the case of S-methyl-N 1 ,N 4 -bis(salicylidene)isothiosemicarbazide (H 2 Z), only one type of complex is formed under these experimental conditions, namely, NpO 2 Z - , with a logarithmic stability constant of 4.78 +/- 0.03. Dissociation constants for H 2 Q and H 2 Z were also determined

  11. Hexacoordinated mixed-ligand complexes of vanadium(IV) and copper(II)

    International Nuclear Information System (INIS)

    Islam, M.S.; Motahera Begum; Roy, H.N.; Haroon, S.A.Q.M.

    1996-01-01

    The literature reports simple complexes of metal ions with Schiff bases derived from amino acids. But their mixed-ligand complexes are very rare. Keeping this fact in mind, some new mixed ligand complexes of V IV and Cu II with tridentate Schiff bases derived from glycine, salicylaldehyde and amino bases, e.g. quinoline (Q), isoquinoline (IQ), 2-picoline (2-pic), 4-picoline (4-pic) and pyridine (Py) were prepared and studied. 6 refs., 1 tab

  12. Chemistry of rhenium and technetium. II. Schiff base complexes with polyfunctional amino acids

    International Nuclear Information System (INIS)

    Du Preez, J.G.H.; Gerber, T.I.A.; Fourie, P.J.; Van Wyk, A.J.

    1984-01-01

    Amino acid Schiff base technetium(V) complexes of salicylaldehyde with l-cysteine, l-serine, l-histodine, l-threonine, l-glutamic acid and l-tryptophan have been preapred by direct reaction and by constituent combination. The amino acid part of the ligands coordinates to the technetium through the carboxylate group, while the other available functional group of the amino acids plays a more minor role as blocking group or in intramolecular bonding. 3 tables

  13. Synthesis and characterization of zinc(II), cadmium(II) and mercury(II) complexes with bis(bidentate) Schiff bases

    International Nuclear Information System (INIS)

    Das, Mrinal Kanti; Ghosh, Shyamali

    1998-01-01

    A few Zn(II), Cd(II) and Hg(II) complexes of the bis(bidentate) Schiff bases derived from p-phenylenediamine and salicylaldehyde (H 2 Salpphen), and o-phenylenediamine and o-vanillin (H 2 Vanophen), of the type MCl 2 .H 2 L(H 2 L = H 2 Salpphen or H 2 Vanophen) have been synthesised. The complexes have been characterized by elemental analysis, infrared, 1 H and 13 C NMR and mass spectra. (author)

  14. Extraction of Cerium (IV) Using Di–n-butylsulfoxide in Chloroform ...

    African Journals Online (AJOL)

    NICO

    2015-01-12

    Jan 12, 2015 ... Cerium is the most abundant among rare earth metals and is extracted from monazite, allanite and ... Variamine blue, 2,4, dihydroxy benzophenoe benzoic hydrazone, ... thoroughly for colour development. The reagent blank ...

  15. SYNTHESIS, CHARACTERIZATION AND CRYSTAL STRUCTURE ...

    African Journals Online (AJOL)

    Preferred Customer

    Reaction of [MoO2(acac)2] (where acac = acetylacetonate) with N'-(2-hydroxy-4- ... Single crystal X-ray structural studies indicate that the hydrazone ligand coordinates .... Molecular structure of the complex at 30% probability displacement.

  16. JCSC_128_8_1265_1275_SI.docx

    Indian Academy of Sciences (India)

    mypc

    SUPPLEMENTARY INFORMATION. Synthesis, X-Ray crystal structure, DNA binding and nuclease activity of lanthanide (III) complexes of 2-benzoylpyridine acetyl hydrazone. KARREDDULA RAJA, AKKILI SUSEELAMMA and KATREDDI HUSSAIN REDDY*. Department of Chemistry, Sri Krishnadevaraya University, ...

  17. Novel cellulose-based halochromic test strips for naked-eye detection of alkaline vapors and analytes.

    Science.gov (United States)

    Abou-Yousef, Hussein; Khattab, Tawfik A; Youssef, Yehia A; Al-Balakocy, Naser; Kamel, Samir

    2017-08-01

    A simple, portable and highly sensitive naked-eye test strip is successfully prepared for optical detection of gaseous and aqueous alkaline analytes. Novel pH-sensory tricyanofuran-hydrazone (TCFH) disperse colorant containing a hydrazone recognition functional moiety is successfully synthesized via azo-coupling reaction between active methyl-containing tricyanofuran (TCF) heterocycle and diazonium salt of 4-aminobenzaldehyde followed by Knoevenagel condensation with malononitrile. UV-vis absorption spectra display solvatochromism and reversible color changes of the TCFH solution in dimethyl sulfoxide in response to pH variations. We investigate the preparation of hydrophobic cellulose/polyethylene terephthalate composites characterized by their high affinity for disperse dyes. Composite films made from CA, Cell/CA, PET/CA, and Cell/PET-CA are produced via solvent-casting procedure using 10-30% modified cellulose or modified polyethylene terephthalate. The mechanical properties and morphologies of these composite films are investigated. The prepared pH-sensory hydrazone-based disperse dye is then applied to dye the produced cellulose-based composite films employing the high temperature pressure dyeing procedure. The produced halochromic PET-CA-TCFH test strip provide an instant visible signal from orange to purple upon exposure to alkaline conditions as proved by the coloration measurements. The sensor strip exhibits high sensitivity and quick detection toward ammonia in both of aqueous and vapor phases by naked-eye observations at room temperature and atmospheric pressure. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Study on polarities of methylphenylpolysiloxanes in gas chromatography; Estudio sobre las polaridades de metilfenilpolisiloxanos en cromatografia de gases

    Energy Technology Data Exchange (ETDEWEB)

    Pias Barbeira, J B; Gasco Sanchez, L

    1975-07-01

    When studying the correlations between molecular structure and retention parameters in alcohols, alcohol benzoyl derivatives and carbonyl 2,4-dinitrophe nyl hydrazones some anomalies probably due to polarities of methylphenylpolysiloxane stationary phases have been observed. (Author) 31 refs.

  19. Study on polarities of methylphenylpolysiloxanes in gas chromatography

    International Nuclear Information System (INIS)

    Pias Barbeira, J. B.; Gasco Sanchez, L.

    1975-01-01

    When studying the correlations between molecular structure and retention parameters in alcohols, alcohol benzoyl derivatives and carbonyl 2,4-dinitrophe nyl hydrazones some anomalies probably due to polarities of methylphenylpolysiloxane stationary phases have been observed. (Author) 31 refs

  20. Cytotoxicity and utility of 1-indanone in the synthesis of some new heterocycles.

    Science.gov (United States)

    Hegazi, Bahira; Mohamed, Hanan Ahmed; Dawood, Kamal Mohamed; Badria, Farid Abdel-Rahem

    2010-04-01

    Benzo[d]imidazole 3 and 1,2,4-triazin-5(2H)-one 6 were prepared by the reaction of starting ethyl (3-hydroxy-1H-inden-2-yl)(oxo)-acetate 2 with o-phenylenediamine and thiosemicarbazide respectively. Reaction of 1,4-dihydro-1-phenylindeno[1,2-c]pyrazole-3-carbohydrazide 8 with phenylisothiocyanate gave thiosemicarbazide 9, and its reaction with chloroacetic acid or phenacylbromides led to the formation of thiazolidinone-4-one 10 or 1,3-thiazoles 12a, b. The reactivity of hydrazide 8 towards fluorinated aldehyde, phthalic anhydride, and hydrazonoyl chlorides 15a, b was studied to give fluorinated hydrazones, imide bis-hydrazones 13-16. The newly synthesized compounds were screened for their cytotoxic activities and compounds 6, 8, 9 and 10 were found the most potentially cytotoxic. The detailed synthesis, spectroscopic and biological data are reported.

  1. [Anti-arrhythmic action of some amidinohydrazone substituted benzophenones. 1. Synthesis of new amidinohydrazone and N-phenylamidinohydrazone substituted benzophenones].

    Science.gov (United States)

    Richter, P H; Kasbohm, K; Besch, A; Hagen, A

    1992-10-01

    The title compounds are synthesized as a rule by condensation of substituted benzophenones and derivatives of aminoguanidine in the presence of up to 2.5 moles of an anorganic acid. They can be obtained alternatively via corresponding hydrazones, thiosemicarbazones or methylthiothiocarbonylhydrazones.

  2. Author Details

    African Journals Online (AJOL)

    SWCNs-COOH) as a New Catalyst for the Protection of Carbonyl Groups as Hydrazones Abstract PDF. ISSN: 0379-4350. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

  3. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. MARAVANJI S BALAKRISHNA. Articles written in Journal of Chemical Sciences. Volume 129 Issue 4 April 2017 pp 471-481 Regular Article. Hydrazone derivatives appended to diphenylphosphine oxide as anion sensors · MARUTHAI KUMARAVEL JOEL T MAGUE ...

  4. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. CHANDRASEKAR PRAVEEN. Articles written in Journal of Chemical Sciences. Volume 128 Issue 1 January 2016 pp 73-83 Regular Articles. Cycloisomerization of acetylenic oximes and hydrazones under gold catalysis: Synthesis and cytotoxic evaluation of isoxazoles and ...

  5. Hydrazine Determination in Sludge Samples by High Performance Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    G. Elias; G. A. Park

    2006-02-01

    A high-performance liquid chromatographic method using ultraviolet (UV) detection was developed to detect and quantify hydrazine in a variety of environmental matrices. The method was developed primarily for sludge samples, but it is also applicable to soil and water samples. The hydrazine in the matrices was derivatized to their hydrazones with benzaldehyde. The derivatized hydrazones were separated using high performance liquid chromatography (HPLC) with a reversed-phase C-18 column in an isocratic mode with methanol-water (95:5, v/v), and detected with UV detection at 313 nm. The detection limit (25 ml) for the new analytical method is 0.0067 mg ml-1of hydrazine. Hydrazine showed low recovery in soil samples because components in soil oxidized hydrazine. Sludge samples that contained relatively high soil content also showed lower recovery. The technique is relatively simple and cost-effective, and is applicable for hydrazine analysis in different environmental matrices.

  6. Synthesis, characterization and DFT study of methoxybenzylidene containing chromophores for DSSC materials

    KAUST Repository

    Al-Sehemi, Abdullah G.; Irfan, Ahmad; Asiri, Abdullah M.; Ammar, Yousry Ahmed

    2012-01-01

    Novel tricyanovinyl derived from hydrazones have been prepared by the reaction of tetracyanoethylene and phenylethylidene hydrazone, and these dyes showed absorption in the region of 539-650 nm. The dyes showed pronounced solvatochromic effects as the polarity of the solvents changed. The torsion in E isomer is smaller than Z and azo isomers of MBD1 and MBD2. The HOMOs are delocalized on whole of the molecule while LUMOs are distributed on the tricarbonitrile. The LUMO energies are above the conduction band of TiO 2 and HOMOs of the dyes are below the redox couple of MBD1 and MBD2. The HOMO energies, LUMO energies and HOMO-LUMO energy gap of MBD1 and MBD2 are almost same. The absorption spectra of both the dyes in different solvents are approximately same except in cyclohexane. © 2012 Elsevier B.V. All rights reserved.

  7. Synthesis of New Pyrazolo[5,1-c]triazine, Triazolo[5,1-c]triazine, Triazino[4,3-b]indazole and Benzimidazo[2,1-c]triazine Derivatives Incorporating Chromen-2-one Moiety

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Mohamed A.; Sayed, Samia M.; Raslan, Mohamed A. [Aswan Univ., Aswan (Egypt)

    2013-10-15

    The versatile, hitherto unreported 3-(4-(2-phenyldiazenyl)-2-oxo-2H-chromen-3-yl)-3-oxopropanenitrile 3 was prepared by two convenient routes: either by the reaction of ethyl 4-(2-phenyldiazenyl)-2-oxo-2H-chromen-3-carboxylate 2 with acetonitrile in the presence of sodium hydride or by treatment of 4-(2-phenyldiazenyl)-3-(2-bromoacetyl)-2H-chromen-2-one 5 with potassium cyanide. Reaction of 3 with heterocyclic diazonium salts 6, 7, 14 and 17 furnished the corresponding hydrazones 8, 9, 15 and 18. The latter hydrazones underwent intramolecular cyclization into the corresponding pyrazolo[5,1-c]-1,2,4-triazine 10, 1,2,4-triazolo[5,1-c]-1,2,4-triazine 11, 1,2,4-triazino[4,3-b]indazole 16 and imidazo[2,1-c]-1,2,4-triazine 19 derivatives, respectively upon refluxing in pyridine.

  8. Synthesis, characterization and DFT study of methoxybenzylidene containing chromophores for DSSC materials

    KAUST Repository

    Al-Sehemi, Abdullah G.

    2012-06-01

    Novel tricyanovinyl derived from hydrazones have been prepared by the reaction of tetracyanoethylene and phenylethylidene hydrazone, and these dyes showed absorption in the region of 539-650 nm. The dyes showed pronounced solvatochromic effects as the polarity of the solvents changed. The torsion in E isomer is smaller than Z and azo isomers of MBD1 and MBD2. The HOMOs are delocalized on whole of the molecule while LUMOs are distributed on the tricarbonitrile. The LUMO energies are above the conduction band of TiO 2 and HOMOs of the dyes are below the redox couple of MBD1 and MBD2. The HOMO energies, LUMO energies and HOMO-LUMO energy gap of MBD1 and MBD2 are almost same. The absorption spectra of both the dyes in different solvents are approximately same except in cyclohexane. © 2012 Elsevier B.V. All rights reserved.

  9. Synthesis, characterization and applications of polymer-metal ...

    Indian Academy of Sciences (India)

    Abstract. 4-Acryloxy acetophenone was prepared and subjected to suspension polymerization with divinyl- benzene as a cross-linking agent. The resulting network polymer was ligated with benzoyl hydrazone. The functional polymer was treated with metal ions [Cu(II), Fe(II)]. The polymer-metal complexes obtained.

  10. SHORT COMMUNICATION

    African Journals Online (AJOL)

    Preferred Customer

    2008-10-31

    2Depatrment of Chemistry, School of Sciences, Azad University, Khorasan Branch, Mashad,. Iran. (Received October 31, 2008; revised April 19, 2009). ABSTRACT. Keggin type of heteropolyacids as green reusable and efficient catalyst was used in the synthesis of benzoyl hydrazones from reaction of benzoic acid ...

  11. Strong metal-metal coupling in mixed-valent intermediates [Cl(L)Ru(mu-tppz)Ru(L)Cl](+), L = beta-diketonato ligands, tppz=2,3,5,6-tetrakis(2-pyridyl)pyrazine

    Czech Academy of Sciences Publication Activity Database

    Kundu, T.; Schweinfurth, D.; Sarkar, B.; Mondal, T. K.; Fiedler, Jan; Mobin, S. M.; Puranik, V. G.; Kaim, W.; Lahiri, G. K.

    2012-01-01

    Roč. 41, č. 43 (2012), s. 13429-13440 ISSN 1477-9226 R&D Projects: GA AV ČR IAA400400802 Institutional support: RVO:61388955 Keywords : TRIDENTATE BRIDGING LIGAND * DENSITY-FUNCTIONAL THEORY * HYDRAZONE-BASED LIGAND S Subject RIV: CG - Electrochemistry Impact factor: 3.806, year: 2012

  12. A Facile Synthesis of Pyrido[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine and Pyrido[2′,3′:3,4]pyrazolo[5,1-c][1,2,4]triazine Bearing a Thiophene Moiety

    Directory of Open Access Journals (Sweden)

    Tilal Elsaman

    2013-01-01

    Full Text Available Pyridinone derivative 8 was synthesized and transformed into the respective chloropyridine 9, which was allowed to react with hydrazine hydrate to afford pyrazolo[3,4-b]pyridin-3-amine derivative 11. Compound 11 was used as a key intermediate for a facile synthesis of the title compounds 14, 15, 17, 21a,b, and 24a–c where the reaction of 11 with some 1,3-dielecrophiles resulted in the formation of pyrido[2′,3′:3,4]pyrazolo[1,5-a]pyrimidines 14, 15, and 17, whereas diazotization of compound 11 gave the respective diazonium salt 18 which was coupled with some active methylene-containing compounds to give the corresponding hydrazones 19a,b and 22a–c. Cyclization of the latter hydrazones yielded the pyrido[2′,3′:3,4]pyrazolo[5,1-c][1,2,4]triazines 21a,b and 24a–c, respectively.

  13. Pick-up, transport and release of a molecular cargo using a small-molecule robotic arm

    Science.gov (United States)

    Kassem, Salma; Lee, Alan T. L.; Leigh, David A.; Markevicius, Augustinas; Solà, Jordi

    2016-02-01

    Modern-day factory assembly lines often feature robots that pick up, reposition and connect components in a programmed manner. The idea of manipulating molecular fragments in a similar way has to date only been explored using biological building blocks (specifically DNA). Here, we report on a wholly artificial small-molecule robotic arm capable of selectively transporting a molecular cargo in either direction between two spatially distinct, chemically similar, sites on a molecular platform. The arm picks up/releases a 3-mercaptopropanehydrazide cargo by formation/breakage of a disulfide bond, while dynamic hydrazone chemistry controls the cargo binding to the platform. Transport is controlled by selectively inducing conformational and configurational changes within an embedded hydrazone rotary switch that steers the robotic arm. In a three-stage operation, 79-85% of 3-mercaptopropanehydrazide molecules are transported in either (chosen) direction between the two platform sites, without the cargo at any time fully dissociating from the machine nor exchanging with other molecules in the bulk.

  14. Oxidized Single-Walled Carbon Nanotubes (SWCNs-COOH) as a ...

    African Journals Online (AJOL)

    Nano-materials are considered as suitable heterogeneous catalysts for many organic reactions. Herein oxidized carbon nanotube (SWCNTs-COOH) has been reported as a heterogeneous catalyst, for protection of carbonyl groups as hydrazones in EtOH at 80 °C. The reactions proceed smoothly with good to excellent ...

  15. New derivatives of alkaloids peganine, vazicinone and garmine

    International Nuclear Information System (INIS)

    Agedilova, M.T.; Turmukhambetov, A.Zh.; Kazantsev, A.V.; Shul'ts, E.E.

    2005-01-01

    It was studied the chemical modification of chinazolin alkaloids peganine and vasicinone and indolin alkaloid garmine. The corresponding halogen-, alkyl-, cetyl and hydrazone derivatives and its salts were obtained. The structure of synthesized compounds was definite by following spectral methods: IR, UV, 1 H, 13 C and 11 B NMR spectroscopy

  16. Author Details

    African Journals Online (AJOL)

    Panahandeh, M. Vol 66 (2013) - Articles Oxidized Single-Walled Carbon Nanotubes (SWCNs-COOH) as a New Catalyst for the Protection of Carbonyl Groups as Hydrazones Abstract PDF. ISSN: 0379-4350. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More ...

  17. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    A new quinoline based hydrazone was synthesized via a condensation reaction and characterized by NMR, mass and single crystal X-ray diffraction studies. It was investigated for suitability as a reversible ratiometric fluorescent pH sensor in acidic pH region. The sensor exhibits intramolecular charge transfer (ICT) type ...

  18. PREPARATION, SPECTROSCOPIC STUDIES AND X-RAY ...

    African Journals Online (AJOL)

    Molar conductance measurements in dmf indicate 1:3 electrolytes in all cases. Magnetic moment values are close proximity of the Van Vleck values. IR studies suggest the coordination of the ligand is through the azomethine, the phenolic oxygen atom and the carbonyl oxygen of the hydrazonic moiety. The nitrate ion is also ...

  19. Development and evaluation of pH-responsive single-walled carbon nanotube-doxorubicin complexes in cancer cells

    Directory of Open Access Journals (Sweden)

    Gu YJ

    2011-11-01

    Full Text Available Yan-Juan Gu1,2,*, Jinping Cheng2,*, Jiefu Jin3, Shuk Han Cheng2, Wing-Tak Wong11Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, 2Department of Biology and Chemistry, The City University of Hong Kong, 3Department of Chemistry, The University of Hong Kong, Hong Kong, China*These authors contributed equally to this workAbstract: Single-walled carbon nanotubes (SWNTs have been identified as an efficient drug carrier. Here a controlled drug-delivery system based on SWNTs coated with doxorubicin (DOX through hydrazone bonds was developed, because the hydrazone bond is more sensitive to tumor microenvironments than other covalent linkers. The SWNTs were firstly stabilized with polyethylene glycol (H2N-PEG-NH2. Hydrazinobenzoic acid (HBA was then covalently attached on SWNTs via carbodiimide-activated coupling reaction to form hydrazine-modified SWNTs. The anticancer drug DOX was conjugated to the HBA segments of SWNT using hydrazine as the linker. The resulting hydrazone bonds formed between the DOX molecules and the HBA segments of SWNTs are acid cleavable, thereby providing a strong pH-responsive drug release, which may facilitate effective DOX release near the acidic tumor microenvironment and thus reduce its overall systemic toxicity. The DOX-loaded SWNTs were efficiently taken up by HepG2 tumor cells, and DOX was released intracellularly, as revealed by MTT assay and confocal microscope observations. Compared with SWNT-DOX conjugate formed by supramolecular interaction, the SWNT-HBA-DOX featured high weight loading and prolonged release of DOX, and thus improved its cytotoxicity against cancer cells. This study suggests that while SWNTs have great potential as a drug carrier, the efficient formulation strategy requires further study.Keywords: carbon nanotubes, drug delivery, controlled release, SWNTs

  20. Synthesis, characterization and crystal structure of a ...

    African Journals Online (AJOL)

    The Mo atom in the complex is in octahedral coordination. Thermal stability of the complex has also been studied. KEY WORDS: Molybdenum complex, Hydrazone ligand, Crystal structure, X-ray diffraction, Thermal property. Bull. Chem. Soc. Ethiop. 2014, 28(3), 409-414. DOI: http://dx.doi.org/10.4314/bcse.v28i3.10 ...

  1. Synthesis of high-temperature viscosity stabilizer used in drilling fluid

    Science.gov (United States)

    Zhang, Yanna; Luo, Huaidong; Shi, Libao; Huang, Hongjun

    2018-02-01

    Abstract For a well performance drilling fluid, when it operates in deep wells under high temperature, the most important property required is the thermal stability. The drilling fluid properties under high temperature can be controlled by proper selection of viscosity stabilizer, which can capture oxygen to protect polymer agent in the drilling fluid. In this paper a viscosity stabilizer PB-854 is described, which was synthesized by 4-phenoxybutyl bromide, paraformaldehyde, and phloroglucinol using etherification method and condensation reaction. We studied the effect of catalyst dosage, temperature, time, and stirring rate on the synthetic yield. Under this condition: molar ratio of 2-tert-Butylphenol, paraformaldehyde and phloroglucinol of 2:1:2.5, reacting temperature of 100 °C, stirring rate of 100 r min-1, and mass content of catalyst of 15 %, char yield of 5-bromine-3-tert-butyl salicylaldehyde reached 86 %. Under this condition: molar ratio of 5-bromine-3-tert-butyl salicylaldehyde and phloroglucinol of 4, reacting temperature of 60 °C, reacting time of 30 min, volume content of sulphuric acid of 80 %, char yield of the target product viscosity stabilizer PB-854 is 86%. Finally, in this paper, infrared spectroscopy is adopted to analyse the structure of the synthetic product PB-854.The improvement in the stability of drilling fluid was further shown after adding the viscosity stabilizer in the common polymer drilling fluid under high temperature conditions of 120 °C ˜ 180 °C. The results show significant change in terms of fluid stability in the presence of this new stabilizer as it provides better stability.

  2. Crystal structures and DFT calculations of mixed chloride-azide zinc(II) and chloride-isocyanate cadmium(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and Girard's T reagent

    Science.gov (United States)

    Anđelković, Katarina; Pevec, Andrej; Grubišić, Sonja; Turel, Iztok; Čobeljić, Božidar; Milenković, Milica R.; Keškić, Tanja; Radanović, Dušanka

    2018-06-01

    The mixed chloride-azide [ZnL(N3)1.65Cl0.35] (1) and chloride-isocyanate [CdL(NCO)1.64Cl0.36] (2) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard's T reagent) (HLCl) have been prepared and characterized by X-ray crystallography. In complexes 1 and 2, Zn1 and Cd1 ions, respectively, are five-coordinated in a distorted square based pyramidal geometry with NNO set of donor atoms of deprotonated hydrazone ligand and two monodentate ligands N3- and/or N3- and Cl- in the case of 1 and OCN- and/or OCN- and Cl- in the case of 2. The structural parameters of 1 and 2 have been discussed in relation to those of previously reported M(II) complexes with the same hydrazone ligand. Density functional theory calculations have been employed to study the interaction between the Zn2+ and Cd2+ ions and ligands. High affinity of ligands towards the Zn2+ and Cd2+ ions are predicted for both complexes.

  3. A QSAR/QSTR Study on the Environmental Health Impact by the Rocket Fuel 1,1-Dimethyl Hydrazine and its Transformation Products

    Directory of Open Access Journals (Sweden)

    Lars Carlsen

    2008-01-01

    Full Text Available QSAR/QSTR modelling constitutes an attractive approach to preliminary assessment of the impact on environmental health by a primary pollutant and the suite of transformation products that may be persistent in and toxic to the environment. The present paper studies the impact on environmental health by residuals of the rocket fuel 1,1-dimethyl hydrazine (heptyl and its transformation products. The transformation products, comprising a variety of nitrogen containing compounds are suggested all to possess a significant migration potential. In all cases the compounds were found being rapidly biodegradable. However, unexpected low microbial activity may cause significant changes. None of the studied compounds appear to be bioaccumulating. Apart from substances with an intact hydrazine structure or hydrazone structure the transformation products in general display rather low environmental toxicities. Thus, it is concluded that apparently further attention should be given to tri- and tetramethyl hydrazine and 1-formyl 2,2-dimethyl hydrazine as well as to the hydrazones of formaldehyde and acetaldehyde as these five compounds may contribute to the overall environmental toxicity of residual rocket fuel and its transformation products.

  4. Electrospun Nanofibers from a Tricyanofuran-Based Molecular Switch for Colorimetric Recognition of Ammonia Gas.

    Science.gov (United States)

    Khattab, Tawfik A; Abdelmoez, Sherif; Klapötke, Thomas M

    2016-03-14

    A chromophore based on tricyanofuran (TCF) with a hydrazone (H) recognition moiety was developed. Its molecular-switching performance is reversible and has differential sensitivity towards aqueous ammonia at comparable concentrations. Nanofibers were fabricated from the TCF-H chromophore by electrospinning. The film fabricated from these nanofibers functions as a solid-state optical chemosensor for probing ammonia vapor. Recognition of ammonia vapor occurs by proton transfer from the hydrazone fragment of the chromophore to the ammonia nitrogen atom and is facilitated by the strongly electron withdrawing TCF fragment. The TCF-H chromophore was added to a solution of poly(acrylic acid), which was electrospun to obtain a nanofibrous sensor device. The morphology of the nanofibrous sensor was determined by SEM, which showed that nanofibers with a diameter range of 200-450 nm formed a nonwoven mat. The resultant nanofibrous sensor showed very good sensitivity in ammonia-vapor detection. Furthermore, very good reversibility and short response time were also observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Self-assembly in lanthanum(III) and calcium(II) complexes of salicylaldimines derived from putrescine

    International Nuclear Information System (INIS)

    Pospieszna-Markiewicz, Izabela; Kaczmarek, Malgorzata T.; Kubicki, Maciej; Radecka-Paryzek, Wanda

    2008-01-01

    The one-step template reaction of salicylaldehyde with putrescine, a biogenic diamine, in the presence of lanthanum(III) or calcium(II) ions produces salicylaldimine complexes containing the N,N'-bis(salicylidene)-1,4-butanediamine ligand L as a result of the [2 + 1] Schiff base condensation. The X-ray diffraction studies of the lanthanum complex reveals an infinite [La 2 L 4 (NO 3 ) 6 ] ∞ polymeric structure based on networks of 10-coordinated La(III) nodes linked by bridging unionized ligands that use exclusively the oxygens as donor atoms with the nitrogen atoms not being involved in coordination

  6. Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases

    Directory of Open Access Journals (Sweden)

    Saeed Taghvaee Ganjali

    2001-03-01

    Full Text Available Synthesis and characterization of two new Schiff bases of p-tertbuthylcalix[4]arene (H2L1 and HL2 is described. The synthesis of H2L1 and HL2 has been achieved by the condensation of salicylaldehyde with the amine group of upper rim monoamine p-tert-butylcalix[4]arene in ethanol. These compounds have been characterized on the basis of elemental analysis and spectral data. Solvatochromicity and fluorescence properties were observed and measured for H2L1 and HL2. Solvatochromicity of these ligands indicates their potential for NLO applications.

  7. Synthesis and characterizaton of some new coordination compounds of boron with mixed azines

    Directory of Open Access Journals (Sweden)

    MANISH GODARA

    2007-04-01

    Full Text Available Some new boron complexes have been synthesized by the reaction of triisopropohxyborane with the mixed azines, prepared by the condensation of salicylaldehyde and hydrazine with aldehydes/ketones in a 1:1:1 mole ratio to give a new series of (OPri2B(NO type of complexes. Their structures were confirmed on the basis of elemental analyses, ultraviolet, infrared, 1H-NMR and 11B-NMR spectral studies. The ligands and their boron complexes were also screened for their antifungal activity. Several of these complexes were found to be quite active in this respect.

  8. Bis(indenyl)zirconium(IV) complexes of monofunctional bidentate salicylidimines

    International Nuclear Information System (INIS)

    Sharma, A.K.; Khera, B.; Kaushik, N.K.

    1983-01-01

    A series of (C 9 H 7 ) 2 Zr(SB)Cl complexes where SB- is the anion of bidentate Schiff base derived from salicylaldehyde and 4-substitued anilines, viz. salicylidene-4-ansidine, salicylidene-4-phenetidine, salicylidene-4-chloroaniline, salicylidene-4-bromoaniline, salicylene-4-iodoaniline and salicylidene-4-nitroaniline, have been synthesized by the reaction of bis(indenyl)zirconium(IV) dichloride and Schiff base (SBH) in 1 : 1 molar ratio in refluxing THF in the presence of triethylamine. The new derivatives have been characterized on the basis of their elemental analyses, conductance measurements and spectral (IR, 1 H-NMR, UV-VIS) studies. (Author)

  9. Infrared spectroscopic studies of rotational isomerism in salicylaldehyde and its derivatives

    International Nuclear Information System (INIS)

    Al-Dbaj, M.

    1984-01-01

    Infrared spectra of salicyladehyde,methyl salicylate,and ethyl-salicylate have been recorded in the solid,liquid,and vapour phases.It has been found that some of the absorption bands are increasing in intensity upon moving from the solid,liquid to the vapour phase.Some other bands are found to decrease in the same direction.The important parts of their work is that concerning the thermal measurements.It was carried out by selecting couples of absorption bands for each compound known to belong to individual isomers.Then they have been recorded at different temperatures in every phase.Enthalpy differences between these two isomers were calculated in every phase for each compound.This study many be considered as a good method for the identification of isomers.(32 tabs., 39 figs., 74 refs.)

  10. Smart pH- and reduction-dual-responsive folate-PEG-coated polymeric lipid vesicles for tumor-triggered targeted drug delivery

    Science.gov (United States)

    Wang, Sheng; Wang, Hanjie; Liu, Zhongyun; Wang, Liangliang; Wang, Xiaomin; Su, Lin; Chang, Jin

    2014-06-01

    To improve their therapeutic index, designed nanocarriers should preferentially accumulate in tumor tissues and then rapidly enter tumor cells to release the encapsulated drugs in a triggered manner. In this article, a new kind of a smart pH- and reduction-dual-responsive drug delivery system based on folate-PEG-coated polymeric lipid vesicles (FPPLVs) formed from amphiphilic dextran derivatives was designed and prepared successfully. PEG chains with pH-sensitive hydrazone bonds, stearyl alcohol (SA) chains with reduction-sensitive disulfide bonds and folate were connected to a dextran main chain. The newly developed FPPLVs had a nano-sized structure (~50 nm) with a PEG coating. The in vitro DOX release profiles showed that the FPPLVs achieved a triggered drug release in response to acidic pH and reducing environments due to the cleavage of hydrazone bonds and disulfide bonds. It has also been demonstrated by an in vitro cellular uptake study that the FPPLVs lose their PEG coating as well as expose the folate in acidic conditions, which allows them to efficiently enter tumor cells through ligand-receptor interactions. In vitro cytotoxicity measurements also confirmed that FPPLVs exhibited pronounced antitumor activity against HeLa cells. These results suggest that FPPLVs are promising carriers for smart antitumor drug delivery applications.To improve their therapeutic index, designed nanocarriers should preferentially accumulate in tumor tissues and then rapidly enter tumor cells to release the encapsulated drugs in a triggered manner. In this article, a new kind of a smart pH- and reduction-dual-responsive drug delivery system based on folate-PEG-coated polymeric lipid vesicles (FPPLVs) formed from amphiphilic dextran derivatives was designed and prepared successfully. PEG chains with pH-sensitive hydrazone bonds, stearyl alcohol (SA) chains with reduction-sensitive disulfide bonds and folate were connected to a dextran main chain. The newly developed FPPLVs had a

  11. COPPER(II) COMPLEXES OF o -VANILLIN ACETYLHYDRAZONE ...

    African Journals Online (AJOL)

    A hydrazonic ligand, o-vanillin acetylhydrazone (H2L) has been prepared and used as chelating agent towards copper(II) ion. The ligand acts like a tridentate ligand in the monodeprotonated (HL-) and dideprotonated (L2-) states. Monoanionic complexes [{Cu(HL)(H2O)}2]•2BF4 and [{Cu(HL)(Hpz)(H2O)}]•NO3 have been ...

  12. Chemistry of bifunctional photoprobes. 3 -- Correlation between the efficiency of CH insertion by photolabile chelating agents and lifetimes of singlet nitrenes by flash photolysis: First example of photochemical attachment of 99mTc-complex with human serum albumin

    International Nuclear Information System (INIS)

    Pandurangi, R.S.; Lusiak, P.; Kuntz, R.R.; Volkert, W.A.; Rogowski, J.; Platz, M.S.

    1998-01-01

    Systematic functionalization of perfluoroaryl azides with chelating agents capable of complexing transition metals produces a new class of bifunctional photolabile chelating agents (BFPCAs). The strategy is shield the azide functionality from the electronic and steric influence of the electron-rich metal Pd through ester and amide bridges raised CH insertion efficiency to unprecedented levels (>92%) in a model solvent (cyclohexane). In contrast, perfluoroaryl azides attached to chelating agents via hydrazones show no significant CH insertion in cyclohexane upon photolysis. Measurements of the lifetimes of the singlet nitrenes derived from these agents by flash photolysis techniques correlate well with the efficiency of CH insertion by demonstrating longer lifetimes (10--50 times) for singlet nitrenes derived from azidotetrafluorinated esters and amides compared with the related hydrazones, which failed to yield significant CH insertion. A representative BFPCA 12 is chelated to diagnostic radionuclide 99m Tc and covalently attached to human serum albumin via photochemical activation extending the favorable bimolecular insertion characteristics of BFPCA to tracer level concentrations in buffer conditions. Flash photolysis experiments correlate singlet nitrene lifetimes with the efficiency of intermolecular insertion reactions. This work provides new photo-cross-linking technology, useful in radiodiagnostics and radiotherapy in nuclear medicine

  13. Liquid Membranes as a Tool for Chemical Speciation of Metals in Natural Waters: Organic and Inorganic Complexes of Nickel

    Directory of Open Access Journals (Sweden)

    Cristina Vergel

    2018-04-01

    Full Text Available The different species of nickel present in natural waters exhibit different transport behaviour through bulk liquid membranes (BLMs. This fact has been used to design and optimise a separation/pre-concentration system applicable to separate labile and non-labile nickel fractions. A hydrazone derivative—1,2-cyclohexanedione bis-benzoyl-hydrazone (1,2-CHBBH dissolved in toluene/dimethyl formamide (2% DMF—was used as a chemical carrier of nickel species, from an aqueous source solution (sample to a receiving acidic solution. Both chemical and hydrodynamic conditions controlling the transport system were studied and optimised. Under optimum conditions, variations in the transport of nickel ions as a function of organic (humic acids and inorganic (chloride ions ligands were studied. Relationships between the permeability coefficient (P or recovery efficiency (%R and the concentrations of ligands and nickel species were analysed using Winhumic V software. A negative correlation between P and the concentration of organic nickel complexes was found, suggesting that only labile nickel species are transported through the liquid membrane, with non-labile complexes remaining in the water sample; allowing for their separation and subsequent quantification in natural waters.

  14. Liquid Membranes as a Tool for Chemical Speciation of Metals in Natural Waters: Organic and Inorganic Complexes of Nickel.

    Science.gov (United States)

    Vergel, Cristina; Mendiguchía, Carolina; Moreno, Carlos

    2018-04-15

    The different species of nickel present in natural waters exhibit different transport behaviour through bulk liquid membranes (BLMs). This fact has been used to design and optimise a separation/pre-concentration system applicable to separate labile and non-labile nickel fractions. A hydrazone derivative-1,2-cyclohexanedione bis-benzoyl-hydrazone (1,2-CHBBH) dissolved in toluene/dimethyl formamide (2% DMF)-was used as a chemical carrier of nickel species, from an aqueous source solution (sample) to a receiving acidic solution. Both chemical and hydrodynamic conditions controlling the transport system were studied and optimised. Under optimum conditions, variations in the transport of nickel ions as a function of organic (humic acids) and inorganic (chloride ions) ligands were studied. Relationships between the permeability coefficient ( P ) or recovery efficiency (%R) and the concentrations of ligands and nickel species were analysed using Winhumic V software. A negative correlation between P and the concentration of organic nickel complexes was found, suggesting that only labile nickel species are transported through the liquid membrane, with non-labile complexes remaining in the water sample; allowing for their separation and subsequent quantification in natural waters.

  15. Study of diamagnetism in uranyl complexes of some Schiff bases

    International Nuclear Information System (INIS)

    Dodwad, S.S.; Sawant, A.S.

    1992-01-01

    Uranyl complexes of Schiff bases obtained by condensing salicylaldehyde with aromatic amines have been isolated and characterised. The complexes have the formula M (LH) 2 (NO 3 ) 2 where M = UO 2 and LH = Schiff base. The magnetic susceptibilities of these complexes have been measured on a Gouy balance. These values have been compared with the computed ones. The percentage deviation between the observed and computed values of molar magnetic susceptibilities clearly show that they are outside experimental error and therefore significant. These deviations have been discussed in the light of VanVleck's, equation for molar susceptibility of polyatomic molecule. (author). 3 refs., 1 tab

  16. Preparation of some complexes of Th(IV) and U(IV) with tetradentate Schiff bases. The crystal structure of bis(N,N'-ethylenebis(3-methoxysalicylaldiminato)) thorium(IV) monopyridine

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R J; Rickard, C E.F.; White, H E [Auckland Univ. (New Zealand). Dept. of Chemistry

    1981-01-01

    Complexes of Th(IV) and U(IV) with tetradentate Schiff bases derived from substituted salicylaldehydes have been prepared and characterised. The structure of bis(N,N'-ethylenebis(3-methoxysalicylaldiminato)) Th(IV) monopyridine has been determined by X-ray crystallographic methods. The crystals are triclinic, a = 13.468, b = 9.932, c = 16.552 A, ..cap alpha.. = 91.74, ..beta.. = 94.69, ..gamma.. = 93.03/sup 0/, space group P/sub 1//sup -/. The molecules are eight coordinate with a slightly distorted dodecahedral geometry with the imine nitrogen atoms in the dodecahedral A sites. The pyridine molecule is uncoordinated and functions in a space-filling role.

  17. Determination of binding-dioxygen in dioxygen complexes by headspace gas chromatography.

    Science.gov (United States)

    Wang, Wei; Feng, Shun; Li, Ya-ni; Wu, Meiying; Wang, Jide

    2008-06-06

    Dioxygen complexes play important roles in organisms' bodies, so the determination of binding-dioxygen has practical significance. A simple and robust method based on headspace gas chromatography was proposed to determine the binding-dioxygen in dioxygen complexes. By measuring the content change of nitrogen gas in a vial, the amount of oxygen released from dixoygen complexes can be determined. The method was validated using potassium chlorate as model sample, and the results exhibited good recoveries (90-99%) with the relative standard deviation less than 8%. It was also used to analyze dioxygen complex of cobalt bis(salicylaldehyde) ethylenediimine and polyamine cobalt complexes prepared by solid-phase reaction.

  18. A cost-effective and green aqueous synthesis of 3-substituted coumarins catalyzed by potassium phthalimide

    Directory of Open Access Journals (Sweden)

    H. Kiyani

    2015-10-01

    Full Text Available An efficient procedure for the synthesis of various 2-imino-2H-chromene-3-carbonitriles, 2-oxo-2H-chromene-3-carbonitriles as well as 2-oxo-2H-chromene-3-carboxylic acids is reported. It has been found that potassium phthalimide (PPI catalyse the Knoevenagel condensation reaction of salicylaldehydes and activated β-dicarbonyl compounds efficiently under aqueous conditions at room temperature. This approach provides many merits such as high yields of products, clean, simple work-up, waste free, mild reaction conditions, commercially available organocatalyst, and the use of water as environmentally benign solvent. DOI: http://dx.doi.org/10.4314/bcse.v29i3.13

  19. Synthesis, spectral investigation (/sup 1/H, /sup 13/C) of new (N, O and S based) schiff bases and evaluation of their antimicrobial activities

    International Nuclear Information System (INIS)

    Khosa, M.K.; Nisar, M.; Jamal, M.A.; Yousaf, M.; Chatha, S.A.S.; Zia, K.M.

    2011-01-01

    Three new series of biologically active amino substituted Schiff bases (1-12) with general formula, R/sub 1/N=CHR/sub 2/ (R/sub 1/ 2-amino-benzthiazole, 4-amino-salicylic acid and 4-aminophenol; R/sub 2/ benzaldehyde, 2-chloro-benzaldehyde, 4-chloro-benzaldehyde, salicylaldehyde and vanillin) were synthesized by the reaction of three different amino substituted compounds and substituted aldehydes in ethanol. The synthesized compounds were characterized by different physico-chemical techniques like, melting point, elemental analysis, multinuclear NMR (/sup 1/H, /sup 13/C). The compounds were subjected for bioassay screening and showed promising antibacterial and antifungal activities using Amoxicillin and Ciprofloxacin as standard drugs. (author)

  20. Diversity-Oriented Synthesis of Coumarin-Linked Benzimidazoles via a One-Pot, Three-Step, Intramolecular Knoevenagel Cyclization.

    Science.gov (United States)

    Yao, Po-Hsin Eric; Kumar, Sunil; Liu, Yu-Li; Fang, Chiu-Ping; Liu, Chia-Chen; Sun, Chung-Ming

    2017-04-10

    Diversity-oriented synthesis of coumarin-linked benzimidazoles from N-(2-aminophenyl)-2-cyanoacetamide was achieved via a one-pot, three-step sequential reaction in excellent yields. In situ intramolecular cyclization of the cyanoacetamide afforded benzimidazoles which subsequently underwent a Knoevenagel condensation of the 2-cyanomethylbenzimidazoles with salicylaldehydes promoted by triethylamine to reach the target compounds. An important intermediate, 2-(2-imino-2H-chromen-3-yl)-1H-benzimidazole was characterized by X-ray analysis and further hydrolyzed to 2-(coumarin-3-yl)benzimidazole in acidic condition. Among the synthesized compounds, some were found to be promising inhibitors of porcine kidney d-amino acid oxidase (pkDAO).

  1. Protonation constant of salicylidene (N-benzoyl)glycyl hydrazone ...

    Indian Academy of Sciences (India)

    Unknown

    ductance, magnetic susceptibility, electronic, IR, ESR, XRD (powder) and NMR studies have been car ... IR and NMR spectra suggest the tri- .... and dried at room temperature. ..... IR and NMR data can be seen on the web version of this paper.

  2. [Spectrophotometric and HPLC evaluation of ceftazidime stability].

    Science.gov (United States)

    Palade, B; Cioroiu, B; Lazăr, Doina; Corciovă, Andreia; Lazăr, M I

    2010-01-01

    In this paper we followed up the stability of ceftazidime, raw material used in drug industry. Matherials and methods: We used three spectrophotometric methods based on ceftazidime property to form complexes with p-chloranilic acid (ac. p-CA), 3-methylbenzothiazolin-2-on hydrazone (MBTH) and N-(1-naphtil) etilendiamine (NEDA) and a chromatographic method (HPLC). Our results revealed that the substances analyzed maintained minimum content allowable.

  3. Synthesis of Donor/Acceptor-Substituted Diazo Compounds in Flow and Their Application in Enantioselective Dirhodium-Catalyzed Cyclopropanation and C-H Functionalization.

    Science.gov (United States)

    Rackl, Daniel; Yoo, Chun-Jae; Jones, Christopher W; Davies, Huw M L

    2017-06-16

    A tandem reaction system has been developed for the preparation of donor/acceptor-substituted diazo compounds in continuous flow coupled to dirhodium-catalyzed C-H functionalization or cyclopropanation. Hydrazones were oxidized in flow by solid-supported N-iodo-p-toluenesulfonamide potassium salt (PS-SO 2 NIK) to generate the diazo compounds, which were then purified by passing through a column of molecular sieves/sodium thiosulfate.

  4. Synthesis of 4-fluoro-4'-trifluoromethylbenzophenone guanylhydrazone hydrochloride labeled with 14C

    International Nuclear Information System (INIS)

    Wang, T.S.T.; Fawwaz, R.A.

    1985-01-01

    Four steps were required to synthesize the antimalarial agent, 4-fluoro-4'-trifluoromethylbenzophenone. This involved carboxylation, acid chloride formation, condensation, and hydrazone formation. The overall radiochemical yield was 12.5% and the specific activity was 2.04 mCi/mmole. Because of the difficulty encountered in preparing the p-fluorobenzal-dehyde-aldehyde- 14 C, p-fluorobenzoyl chloride-carbonyl 14 C was used for the condensation reaction. (author)

  5. Thallium (III) salts utilization in organic synthesis. Part II

    International Nuclear Information System (INIS)

    Ferraz, H.M.C.

    1989-01-01

    The utilizations of thallium (III) salts in organic synthesis with carbonylic and acitylenic substrates are presented. The reactions of carbonylic substra3ts with kitones and the oxidation reactions of acetylenic substrates are shown. Others reactions including thallium (III) salts and non aromatic unsatured substracts, as cleasage of ethers and epoxide using thallium trinitrate, hydrazones treatments with thallium triacetates, etc, are also mentioned. (C.G.C.) [pt

  6. Synthesis of 4-fluoro-4'-trifluoromethylbenzophenone guanylhydrazone hydrochloride labeled with /sup 14/C

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.S.T.; Fawwaz, R.A. (Columbia Univ., New York (USA). Coll. of Physicians and Surgeons)

    1985-04-01

    Four steps were required to synthesize the antimalarial agent, 4-fluoro-4'-trifluoromethylbenzophenone. This involved carboxylation, acid chloride formation, condensation, and hydrazone formation. The overall radiochemical yield was 12.5% and the specific activity was 2.04 mCi/mmole. Because of the difficulty encountered in preparing the p-fluorobenzal-dehyde-aldehyde- /sup 14/C, p-fluorobenzoyl chloride-carbonyl /sup 14/C was used for the condensation reaction.

  7. Synthesis of 4-fluoro-4'-trifluoromethylbenzophenone guanylhydrazone hydrochloride labeled with /sup 14/C

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T S.T.; Fawwaz, R A [Columbia Univ., New York (USA). Coll. of Physicians and Surgeons

    1985-04-01

    Four steps were required to synthesize the antimalarial agent, 4-fluoro-4'-trifluoromethylbenzophenone. This involved carboxylation, acid chloride formation, condensation, and hydrazone formation. The overall radiochemical yield was 12.5% and the specific activity was 2.04 mCi/mmole. Because of the difficulty encountered in preparing the p-fluorobenzal-dehyde-aldehyde- /sup 14/C, p-fluorobenzoyl chloride-carbonyl /sup 14/C was used for the condensation reaction.

  8. Determination of Carbonyl Compounds in Cigarette Mainstream Smoke. The CORESTA 2010 Collaborative Study and Recommended Method

    Directory of Open Access Journals (Sweden)

    Intorp M

    2014-12-01

    Full Text Available A recommended method has been developed and published by CORESTA, applicable to the quantification of selected carbonyl compounds (acetaldehyde, formaldehyde, acetone, acrolein, methyl ethyl ketone, crotonaldehyde, propionaldehyde and butyraldehyde in cigarette mainstream smoke. The method involved smoke collection in impinger traps, derivatisation of carbonyls with 2,4-dinitrophenylhydrazine (DNPH, separation of carbonyl hydrazones by reversed phase high performance liquid chromatography and detection by ultra violet or diode array.

  9. High performance liquid chromatographic determination of vanadium in crude oils and cobalt and iron in pharmaceutical preparations

    International Nuclear Information System (INIS)

    Khuhawar, M.Y.; Lanjwani, S.N.; Khaskhely, G.Q.

    1993-01-01

    High performance liquid Chromatographic (HPLC) method has ben developed for the determination of vanadium in crude oils, based on acid decomposition of oils, followed by complexation with bis (salicylaldehyde) tetramethyl ethylenediamine (H2SA2Ten). The complex is extracted in organic phase and is separated from copper and nickel using normal phase HPLC column. Detection is achieved using spectrophtmetric detector. The vanadium in oil is obtained at sub microgram/g level. Similarly cobalt(II), cobalt(III) and iron(II) are separated on reversed phase HPLC column. Pre column derivatization is used to develop HPLC method for the determination of cobalt and iron in pharmaceutical preparations. Finally results are compared using atomic absorption spectrometer. (author)

  10. Chemoselective ligation and antigen vectorization.

    Science.gov (United States)

    Gras-Masse, H

    2001-01-01

    The interest in cocktail-lipopeptide vaccines has now been confirmed by phase I clinical trials: highly diversified B-, T-helper or cytotoxic T-cell epitopes can be combined with a lipophilic vector for the induction of B- and T-cell responses of predetermined specificity. With the goal of producing an improved vaccine that should ideally induce a multispecific response in non-selected populations, increasing the diversity of the immunizing mixture represents one of the most obvious strategies.The selective delivery of antigens to professional antigen-presenting cells represents another promising approach for the improvement of vaccine efficacy. In this context, the mannose-receptor represents an attractive entry point for the targeting to dendritic cells of antigens linked to clustered glycosides or glycomimetics. In all cases, highly complex but fully characterized molecules must be produced. To develop a modular and flexible strategy which could be generally applicable to a large set of peptide antigens, we elected to explore the potentialities of chemoselective ligation methods. The hydrazone bond was found particularly reliable and fully compatible with sulphide ligation. Hydrazone/thioether orthogonal ligation systems could be developed to account for the nature of the antigens and the solubility of the vector systems. Copyright 2001 The International Association for Biologicals.

  11. S-adenosylmethionine decarboxylase inhibitors: new aryl and heteroaryl analogues of methylglyoxal bis(guanylhydrazone).

    Science.gov (United States)

    Stanek, J; Caravatti, G; Capraro, H G; Furet, P; Mett, H; Schneider, P; Regenass, U

    1993-01-08

    A series of 3-acylbenzamidine (amidino)hydrazones 7a-h, the corresponding (hetero)aromatic congeners 7i-p, and 3,3'-bis-amidino-biaryls 25a-e were synthesized. The hydrazones 7a-p were prepared by conversion of the corresponding acyl nitriles 1a,c-d,i,n-p to the imido esters 3a,c-d,i and the amidines 5a,c-d,h-i, followed by a reaction with aminoguanidine, or vice versa. Similarly, the biaryl 3,3'-dinitriles 23a-e were converted, via the imino esters 24a-c or the imino thioesters 27d-e, to the diamidines 25a-e. These new products are conformationally constrained analogues of methylglyoxal bis(guanylhydrazone) (MGBG). They are up to 100 times more potent as inhibitors of rat liver S-adenosylmethionine decarboxylase (SMDC) and generally less potent inhibitors of rat small intestine diamine oxidase (DAO) than MGBG. Some of these SAMDC inhibitors, e.g., compounds 7a, 7e, 7i, 25a, and 25d, have shown antiproliferative effects against T24 human bladder carcinoma cells. These products, whose structure-activity relationships are discussed, are of interest as potential anticancer agents and drugs for the treatment of protozoal and Pneumocystis carinii infections.

  12. Synthesis and Antibacterial Activities of Novel 2,5-Diphenylindolo[2,3-e] Pyrazolo[1',5':3",4"]pyrimido[2",1"-c] [1,2,4]triazines

    Directory of Open Access Journals (Sweden)

    Mohamed G. Marei

    2011-12-01

    Full Text Available The formation of (E-3-{2-(2,5-diphenylpyrazolo[1,5-c]pyrimidin-7-ylhydrazono}indolin-2-ones 3 has been achieved by condensation of equimolar amounts of 7-hydrazino-2,5-diphenylpyrazolo[1,5-c]pyrimidine (1 and isatin (or isatin derivatives 2 at room temperature. The (E-products could be isomerized into corresponding the (Z-3 isomers. Reactions of the latter fused heterocyclic hydrazones towards different electro-philic reagents yielded the corresponding 3-substituted derivatives 4–7. Dehydrative cyclisation of the hydrazones 3 using phosphorus oxychloride afforded the 2,5-diphenyl- indolo[2,3-e]pyrazolo[1',5':3",4"]pyrimido[2",1"-c][1,2,4] triazines 13. The polyfused heterocyclic ring system 13 underwent electrophilic substitution reactions at position 4 rather than at position 3. The 3-bromo isomer of 17 was prepared by a sequence of reactions starting from 2,5-diphenylpyrazolo[1,5-c]pyrimidine-7(6H-thione (11. The orientation of the electrophilic attack was supported by spectroscopic and chemical evidence. Some of the synthesized compounds were found to possess slight to moderate activity against the microorganisms Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.

  13. Synthesis of 1-13C-1-indanone and 2-13C-1,2,3,4-tetrahydroquinoline

    International Nuclear Information System (INIS)

    Pickering, R.E.; Wysocki, M.A.; Eisenbraun, E.J.

    1985-01-01

    The synthesis of 2- 13 C-1,2,3,4-tetrahydroquinoline (5) via 1- 13 C-3-phenylpropanoic acid (1), 1- 13 C-1-indanone (2), 1- 13 C-1-indanone hydrazone (3) and 2- 13 C-3,4-dihydro-2(1H)-quinolinone (4) proceeded in 78, 96, 95, 79, and 85% individual yields respectively for 1, 2, 3, 4, 5 and 61% overall yield of the latter from 1. (author)

  14. Synthesis and antimicrobial activity of some new substituted 9-(1H-Pyrazolo [3, 4-b] Quinolin-1-YL) Acridines

    International Nuclear Information System (INIS)

    Thakor, S.; Parmar, P.; Patel, M.; Patel, R.

    2008-01-01

    2-chloro-6-methyl/methoxy-3-formylquinoline upon condensation with substituted 9-hydrazino-acridine afforded corresponding hydrazones which were cyclized under alkaline condition to give 9-(6-substituted-1H-pyrazolo [3, 4-b] quinolin-1-yl) acridine analoges. All of the synthesized compounds were characterized by their elemental analysis, IR and NMR spectral studies. Biological screenings of the prepared compounds have been screened on some strain of bacteria and fungus. (author)

  15. Exploiting the Electrophilic and Nucleophilic Dual Role of Nitrile Imines: One-Pot, Three-Component Synthesis of Furo[2,3-d]pyridazin-4(5H)-ones.

    Science.gov (United States)

    Giustiniano, Mariateresa; Mercalli, Valentina; Amato, Jussara; Novellino, Ettore; Tron, Gian Cesare

    2015-08-21

    An expeditious multicomponent reaction to synthesize tetrasubstituted furo[2,3-d]pyridazin-4(5H)-ones is reported. In brief, hydrazonoyl chlorides react with isocyanoacetamides, in the presence of TEA, to give 1,3-oxazol-2-hydrazones which, without being isolated, can react with dimethylacetylene dicarboxylate to afford furo[2,3-d]pyridazin-4(5H)-ones with an unprecedented level of complexity in a triple domino Diels-Alder/retro-Diels-Alder/lactamization reaction sequence.

  16. Room-Temperature Alternative to the Arbuzov Reaction: The Reductive Deoxygenation of Acyl Phosphonates

    OpenAIRE

    Kedrowski, Sean M. A.; Dougherty, Dennis A.

    2010-01-01

    The reductive deoxygenation of acyl phosphonates using a Wolff−Kishner-like sequence is described. This transformation allows direct access to alkyl phosphonates from acyl phosphonates at room temperature. The method can be combined with acyl phosphonate synthesis into a one pot, four-step procedure for the conversion of carboxylic acids into alkyl phosphonates. The methodology works well for a variety of aliphatic acids and shows a functional group tolerance similar to that of other hydrazon...

  17. New data on the reaction of 1,4-bifunctional derivatives of hydrazine with 1,3-diketones

    International Nuclear Information System (INIS)

    Zelenin, K.N.; Solod, O.V.; Tomchin, A.B.

    1987-01-01

    As a function of the conditions of the reaction and the structure of the reagents, mono- and bis-adducts of different structure - 5-hydroxy- and 5-hydrazino-2-pyrazolines, mono- and bis(hydrazones), and the corresponding pyrazoles - are formed in the reaction of hydrazine derivatives - aminoguanidine nitrate, 4-phenylsemicarbazide, amidrazonium iodides, and some thiosemicarbazides - with acetylacetone and dibenzoylmethane. The conditions of the formation of these products and the features of their structure were examined

  18. Synthesis and molecular docking of new hydrazones derived from ...

    African Journals Online (AJOL)

    Methods: The reaction of ethyl isonipecotate (2) with 3 ... All the synthesized compounds were structurally elucidated by proton nuclear magnetic ... International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, ...

  19. Adaptation in constitutional dynamic libraries and networks, switching between orthogonal metalloselection and photoselection processes.

    Science.gov (United States)

    Vantomme, Ghislaine; Jiang, Shimei; Lehn, Jean-Marie

    2014-07-02

    Constitutional dynamic libraries of hydrazones (a)A(b)B and acylhydrazones (a)A(c)C undergo reorganization and adaptation in response to a chemical effector (metal cations) or a physical stimulus (light). The set of hydrazones [(1)A(1)B, (1)A(2)B, (2)A(1)B, (2)A(2)B] undergoes metalloselection on addition of zinc cations which drive the amplification of Zn((1)A(2)B)2 by selection of the fittest component (1)A(2)B. The set of acylhydrazones [E-(1)A(1)C, (1)A(2)C, (2)A(1)C, (2)A(2)C] undergoes photoselection by irradiation of the system, which causes photoisomerization of E-(1)A(1)C into Z-(1)A(1)C with amplification of the latter. The set of acyl hydrazones [E-(1)A(1)C, (1)A(3)C, (2)A(1)C, (2)A(3)C] undergoes a dual adaptation via component exchange and selection in response to two orthogonal external agents: a chemical effector, metal cations, and a physical stimulus, light irradiation. Metalloselection takes place on addition of zinc cations which drive the amplification of Zn((1)A(3)C)2 by selection of the fittest constituent (1)A(3)C. Photoselection is obtained on irradiation of the acylhydrazones that leads to photoisomerization from E-(1)A(1)C to Z-(1)A(1)C configuration with amplification of the latter. These changes may be represented by square constitutional dynamic networks that display up-regulation of the pairs of agonists ((1)A(2)B, (2)A(1)B), (Z-(1)A(1)C, (2)A(2)C), ((1)A(3)C, (2)A(1)C), (Z-(1)A(1)C, (2)A(3)C) and the simultaneous down-regulation of the pairs of antagonists ((1)A(1)B, (2)A(2)B), ((1)A(2)C, (2)A(1)C), (E-(1)A(1)C, (2)A(3)C), ((1)A(3)C, (2)A(1)C). The orthogonal dual adaptation undergone by the set of acylhydrazones amounts to a network switching process.

  20. Theoretical and Experimental: The Synthetic and Anion-Binding Properties of Tripodal Salicylaldehyde Derivatives

    Directory of Open Access Journals (Sweden)

    Zhong-Jie Xu

    2016-05-01

    Full Text Available A series of colorimetric anion probes 1–6 containing OH and NO2 groups were synthesized, and their recognition properties toward various anions were investigated by visual observation, ultraviolet–visible spectroscopy, fluorescence, 1H nuclear magnetic resonance titration spectra and theoretical investigation. Nanomaterials of three compounds 2–4 were prepared successfully. Four compounds 3–6 that contain electron-withdrawing substituents showed a high binding ability for AcO−. The host–guest complex formed through a 1:1 binding ratio, and color changes were detectable during the recognition process. Theoretical investigation analysis revealed that an intramolecular hydrogen bond existed in the structures of compounds and the roles of molecular frontier orbitals in molecular interplay. These studies suggested that this series of compounds could be used as colorimetric probes to detect of AcO−.

  1. Synthesis and Biological Activity of 3-[Phenyl(1,3-thiazol-2-yl-amino]propanoic Acids and Their Derivatives

    Directory of Open Access Journals (Sweden)

    Vytautas Mickevičius

    2013-12-01

    Full Text Available New N,N-disubstituted β-amino acids and their derivatives with thiazole, aromatic, and heterocyclic substituents were synthesized from N-phenyl-N-thiocarbamoyl-β-alanine by the Hantzsch method; derivatives with hydrazone fragments were also obtained. Some of the synthesized compounds exhibited discrete antimicrobial activity, and 3-[(4-oxo-4,5-dihydro-1,3-thiazol-2-yl(phenylamino]propanoic acid was found to promote rapeseed growth and to increase seed yield and oil content.

  2. A Facile, Choline Chloride/Urea Catalyzed Solid Phase Synthesis of Coumarins via Knoevenagel Condensation

    Directory of Open Access Journals (Sweden)

    Hosanagara N. Harishkumar

    2011-01-01

    Full Text Available The influence of choline chloride/urea ionic liquid in solid phase on the Knoevenagel condensation is demonstrated. The active methylene compounds such as meldrum’s acid, diethylmalonate, ethyl cyanoacetate, dimethylmalonate, were efficiently condensed with various salicylaldehydes in presence of choline chloride/urea ionic liquid without using any solvents or additional catalyst. The reaction is remarkably facile because of the air and water stability of the catalyst, and needs no special precautions. The reactions were completed within 1hr with excellent yields (95%. The products formed were sufficiently pure, and can be easily recovered. The use of ionic liquid choline chloride/urea in solid phase offered several significant advantages such as low cost, greater selectivity and easy isolation of products.

  3. Synthesis and antibacterial activity of some heterocyclic derivatives of sulfanilamide

    Directory of Open Access Journals (Sweden)

    B.B. Subudhi

    2012-12-01

    Full Text Available Considering the promising antimicrobial potential of carbonic anhydrase inhibitors and heterocyclic compounds some heterocyclic derivatives of sulfanilamide (2a-e were synthesized. The diazotisation of sulfanilamide followed by substitution with ethylacetoacetate and further condensation yielded compounds 2a-c. Schiff base of sulfanilamide with salicylaldehyde on reaction with thioglycollic acid and chloroacetyl chloride resulted in compound 2d-e. The susceptibility of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa to the title compounds (300 μg/disc was investigated and compared to that of nitrofurantoin (300 μg/disc and ciprofloxacin (25 μg/disc. The title compounds showed good antimicrobial activity.DOI: http://dx.doi.org/10.4314/bcse.v26i3.15

  4. Genetic engineering and chemical conjugation of potato virus X.

    Science.gov (United States)

    Lee, Karin L; Uhde-Holzem, Kerstin; Fischer, Rainer; Commandeur, Ulrich; Steinmetz, Nicole F

    2014-01-01

    Here we report the genetic engineering and chemical modification of potato virus X (PVX) for the presentation of various peptides, proteins, and fluorescent dyes, or other chemical modifiers. Three different ways of genetic engineering are described and by these means, peptides are successfully expressed not only when the foot and mouth disease virus (FMDV) 2A sequence or a flexible glycine-serine linker is included, but also when the peptide is fused directly to the PVX coat protein. When larger proteins or unfavorable peptide sequences are presented, a partial fusion via the FMDV 2A sequence is preferable. When these PVX chimeras retain the ability to assemble into viral particles and are thus able to infect plants systemically, they can be utilized to inoculate susceptible plants for isolation of sufficient amounts of virus particles for subsequent chemical modification. Chemical modification is required for the display of nonbiological ligands such as fluorophores, polymers, and small drug compounds. We present three methods of chemical bioconjugation. For direct conjugation of small chemical modifiers to solvent exposed lysines, N-hydroxysuccinimide chemistry can be applied. Bio-orthogonal reactions such as copper-catalyzed azide-alkyne cycloaddition or hydrazone ligation are alternatives to achieve more efficient conjugation (e.g., when working with high molecular weight or insoluble ligands). Furthermore, hydrazone ligation offers an attractive route for the introduction of pH-cleavable cargos (e.g., therapeutic molecules).

  5. Reaction kinetics and transformation of carbadox and structurally related compounds with aqueous chlorine.

    Science.gov (United States)

    Shah, Amisha D; Kim, Jae-Hong; Huang, Ching-Hua

    2006-12-01

    The potential release of carbadox (CDX), a commonly used antibacterial agent in swine husbandry, into water systems is of a concern due to its carcinogenic and genotoxic effects. Until this study, the reactivity of carbadox (possessing quinoxaline N,N'-dioxide and hydrazone moieties) toward aqueous chlorine has yetto be investigated in depth. Chemical reactivity, reaction kinetics, and transformation pathways of carbadox and structurally related compounds with free chlorine under typical water treatment conditions were determined. This study found that only CDX and desoxycarbadox (DCDX), a main metabolite of CDX with no ring N-oxide groups, react rapidly with free chlorine while other structurally related compounds including olaquindox, quindoxin, quinoxaline N-oxide, quinoxaline, and quinoline N-oxide do not. The reaction kinetics of CDX and DCDX with chlorine are highly pH dependent (e.g., the apparent second-order rate constant, kapp, for CDX ranges from 51.8 to 3.15 x 10(4) M(-1)s(-1) at pH 4-11). The high reactivity of CDX and DCDX to chlorine involves deprotonation of their hydrazone N-H moieties where initial chlorine attack results in a reactive intermediate that is further attacked by nucleophiles in the matrix to yield non-chlorinated, hydroxylated, and larger molecular weight byproducts. All of the CDX's byproducts retain their biologically active N-oxide groups, suggesting that they may remain as active antibacterial agents.

  6. Flow chemistry as a discovery tool to access sp2-sp3 cross-coupling reactions via diazo compounds.

    Science.gov (United States)

    Tran, Duc N; Battilocchio, Claudio; Lou, Shing-Bong; Hawkins, Joel M; Ley, Steven V

    2015-02-01

    The work takes advantage of an important feature of flow chemistry, whereby the generation of a transient species (or reactive intermediate) can be followed by a transfer step into another chemical environment, before the intermediate is reacted with a coupling partner. This concept is successfully applied to achieve a room temperature sp 2 -sp 3 cross coupling of boronic acids with diazo compounds, these latter species being generated from hydrazones under flow conditions using MnO 2 as the oxidant.

  7. Flow chemistry as a discovery tool to access sp2–sp3 cross-coupling reactions via diazo compounds† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c4sc03072a Click here for additional data file.

    Science.gov (United States)

    Tran, Duc N.; Battilocchio, Claudio; Lou, Shing-Bong; Hawkins, Joel M.

    2015-01-01

    The work takes advantage of an important feature of flow chemistry, whereby the generation of a transient species (or reactive intermediate) can be followed by a transfer step into another chemical environment, before the intermediate is reacted with a coupling partner. This concept is successfully applied to achieve a room temperature sp2–sp3 cross coupling of boronic acids with diazo compounds, these latter species being generated from hydrazones under flow conditions using MnO2 as the oxidant. PMID:29560199

  8. Synthesis of Symmetrical and Asymmetrical Azines Encompassing Naphtho[2,1-b]furan by a Novel Approach

    OpenAIRE

    Veena, K.; Ramaiah, M.; Vanita, G. K.; Avinash, T. S.; Vaidya, V. P.

    2011-01-01

    The starting material 3-nitro-2-acetylnaphtho[2,1-b]furan (2) was obtained by nitration of 2-acetylnaphtho[2,1-b] furan (1), under mild condition. The compound 1 was synthesized by the reaction of 2-hydroxy-1-naphthaldehyde with chloroacetone, where in both condensation and cyclization took place in single step. The reaction of 3-nitro-2-acetylnaphtho[2,1-b]furan (2) with hydrazine hydrate produced corresponding hydrazone (3) in excellent yield, which on treatment with various aromatic aldehy...

  9. A novel highly sensitive and selective optical sensor based on a symmetric tetradentate Schiff-base embedded in PVC polymeric film for determination of Zn{sup 2+} ion in real samples

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Aziz, Ayman A., E-mail: aymanaziz31@gmail.com [Chemistry Department, Faculty of Science, Ain Shams University, 11566 Cairo (Egypt); Chemistry Department, Faculty of Science, University of Tabuk, 71421, Tabuk (Saudi Arabia)

    2013-11-15

    A novel prepared Zn{sup 2+} ion PVC membrane sensor based on a novel Schiff base; N,N′bis(salicylaldehyde)2,3-diaminonaphthalene (SDN) for the determination of Zn{sup 2+} ion was described. The chemosensor was synthesized under microwave irradiation via condensation of 2,3-diaminonaphthalene and salicylaldehyde. Photoluminescence characteristics of the novel Schiff base ligand were investigated in different solvents including dicholoromethane (DCM), tetrahydrofuran (THF) and ethanol (EtOH). SDN was found to have higher emission intensity and Stoke’s shift value (Δλ{sub ST}) in EtOH solution. The sensor exhibited a specific fluorescent on response to Zn{sup 2+}. The response of the sensor is based on the fluorescence enhancement of SDN (LH{sub 2}) by Zn{sup 2+} ion as a result of formation the rigid structure L-Zn complex. The experiment results also show that the response behavior of SDN to Zn{sup 2+} is pH independent in the range of pH 6.0–8.0. At pH 7.0, the proposed sensor displays a calibration response for Zn{sup 2+} over a wide concentration range of 1.0×10{sup −9}–2.0×10{sup −3} mol L{sup −1} with a limit of detection (LOD) 8.1×10{sup −10} mol L{sup −1} (0.0529659 μg L{sup −1}). The sensor shows excellent selectivity toward Zn{sup 2+} with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to detect Zn{sup 2+} in human hair samples, different brands of powdered milk and some pharmaceuticals. -- Highlights: • A novel Zn(II) chemosensor has been developed. • Wide linear concentration range of 1.0×10{sup −9}–2.0×10{sup −3} mol L{sup −1}. • Application for determination of Zn(II) in real samples.

  10. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

    International Nuclear Information System (INIS)

    Monier, M.; Ayad, D.M.; Sarhan, A.A.

    2010-01-01

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

  11. Measurement of trace species in the exhaust of a reverse flow combustor

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, C; Kapernaum, M [DLR, Stuttgart (Germany); Wiesen, P; Kleffmann, J; Kurtenbach, R [Bergische Univ., Wuppertal (Germany)

    1998-12-31

    This work has been carried out as a sub-task of the EU-project AEROTRACE. BUGH Wuppertal has measured the emission of hydrocarbon species and nitrous oxide. Unstable and reactive carbonyl compounds like aldehydes and ketones were measured by DLR-Stuttgart. For methane and N{sub 2}O stainless steel containers were used. Hydrocarbons were trapped on special adsorbent materials. Carbonyl compounds were stabilized as hydrazones. Analytical methods used were GC-MS, IR-diode laser absorption spectroscopy and HPLC with Photo Diode Array Detector. (author)

  12. Measurement of trace species in the exhaust of a reverse flow combustor

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, C.; Kapernaum, M. [DLR, Stuttgart (Germany); Wiesen, P.; Kleffmann, J.; Kurtenbach, R. [Bergische Univ., Wuppertal (Germany)

    1997-12-31

    This work has been carried out as a sub-task of the EU-project AEROTRACE. BUGH Wuppertal has measured the emission of hydrocarbon species and nitrous oxide. Unstable and reactive carbonyl compounds like aldehydes and ketones were measured by DLR-Stuttgart. For methane and N{sub 2}O stainless steel containers were used. Hydrocarbons were trapped on special adsorbent materials. Carbonyl compounds were stabilized as hydrazones. Analytical methods used were GC-MS, IR-diode laser absorption spectroscopy and HPLC with Photo Diode Array Detector. (author)

  13. [Diagnostic workup of fragrance allergy].

    Science.gov (United States)

    Geier, J; Uter, W

    2015-09-01

    The diagnostic workup of contact allergy to fragrances must not be limited to patch testing with the two well-established fragrance mixes. False-positive reactions to these mixes occur in up to 50 % of the patch tested patients. For the diagnostic work-up of positive reactions, and in cases of suspected fragrance allergy, patch testing with the single mix components and additional fragrances is mandatory. Frequently sensitizing fragrance materials are the 14 components of the two fragrance mixes and tree moss (Evernia furfuracea), ylang ylang oil (I + II; Cananga odorata), lemongrass oil (Cymbopogon schoenanthus), sandalwood oil (Santalum album), jasmine absolute (Jasminum spp.), and, less frequently, clove oil (Eugenia caryophyllus), cedarwood oil (Cedrus atlantica/deodara, Juniperus virginiana), Neroli oil (Citrus aurantium amara flower oil), salicylaldehyde, narcissus absolute (Narcissus spp.), and patchouli oil (Pogostemon cablin).

  14. Enhancing siRNA-based cancer therapy using a new pH-responsive activatable cell-penetrating peptide-modified liposomal system

    Directory of Open Access Journals (Sweden)

    Xiang B

    2017-03-01

    Full Text Available Bai Xiang,1,* Xue-Li Jia,1,* Jin-Long Qi,2 Li-Ping Yang,1 Wei-Hong Sun,1 Xiao Yan,1 Shao-Kun Yang,1 De-Ying Cao,1 Qing Du,1 Xian-Rong Qi3 1Department of Pharmaceutics, School of Pharmaceutical Sciences, 2Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei, 3School of Pharmaceutical Sciences, Peking University, Beijing, China *These authors contributed equally to this work Abstract: As a potent therapeutic agent, small interfering RNA (siRNA has been exploited to silence critical genes involved in tumor initiation and progression. However, development of a desirable delivery system is required to overcome the unfavorable properties of siRNA such as its high degradability, molecular size, and negative charge to help increase its accumulation in tumor tissues and promote efficient cellular uptake and endosomal/lysosomal escape of the nucleic acids. In this study, we developed a new activatable cell-penetrating peptide (ACPP that is responsive to an acidic tumor microenvironment, which was then used to modify the surfaces of siRNA-loaded liposomes. The ACPP is composed of a cell-penetrating peptide (CPP, an acid-labile linker (hydrazone, and a polyanionic domain, including glutamic acid and histidine. In the systemic circulation (pH 7.4, the surface polycationic moieties of the CPP (polyarginine are “shielded” by the intramolecular electrostatic interaction of the inhibitory domain. When exposed to a lower pH, a common property of solid tumors, the ACPP undergoes acid-catalyzed breakage at the hydrazone site, and the consequent protonation of histidine residues promotes detachment of the inhibitory peptide. Subsequently, the unshielded CPP would facilitate the cellular membrane penetration and efficient endosomal/lysosomal evasion of liposomal siRNA. A series of investigations demonstrated that once exposed to an acidic pH, the ACPP-modified liposomes showed elevated cellular uptake, downregulated expression of polo

  15. Polymeric micellar pH-sensitive drug delivery system for doxorubicin.

    Science.gov (United States)

    Hrubý, Martin; Konák, Cestmír; Ulbrich, Karel

    2005-03-02

    A novel polymeric micellar pH-sensitive system for delivery of doxorubicin (DOX) is described. Polymeric micelles were prepared by self-assembly of amphiphilic diblock copolymers in aqueous solutions. The copolymers consist of a biocompatible hydrophilic poly(ethylene oxide) (PEO) block and a hydrophobic block containing covalently bound anthracycline antibiotic DOX. The starting block copolymers poly(ethylene oxide)-block-poly(allyl glycidyl ether) (PEO-PAGE) with a very narrow molecular weight distribution (Mw/Mn ca. 1.05) were prepared by anionic ring opening polymerization using sodium salt of poly(ethylene oxide) monomethyl ether as macroinitiator and allyl glycidyl ether as functional monomer. The copolymers were covalently modified via reactive double bonds by the addition of methyl sulfanylacetate. The resulting ester subsequently reacted with hydrazine hydrate yielding polymer hydrazide. The hydrazide was coupled with DOX yielding pH-sensitive hydrazone bonds between the drug and carrier. The resulting conjugate containing ca. 3 wt.% DOX forms micelles with Rh(a)=104 nm in phosphate-buffered saline. After incubation in buffers at 37 degrees C DOX was released faster at pH 5.0 (close to pH in endosomes; 43% DOX released within 24 h) than at pH 7.4 (pH of blood plasma; 16% DOX released within 24 h). Cleavage of hydrazone bonds between DOX and carrier continues even after plateau in the DOX release from micelles incubated in aqueous solutions is reached.

  16. Ingenious pH-sensitive dextran/mesoporous silica nanoparticles based drug delivery systems for controlled intracellular drug release.

    Science.gov (United States)

    Zhang, Min; Liu, Jia; Kuang, Ying; Li, Qilin; Zheng, Di-Wei; Song, Qiongfang; Chen, Hui; Chen, Xueqin; Xu, Yanglin; Li, Cao; Jiang, Bingbing

    2017-05-01

    In this work, dextran, a polysaccharide with excellent biocompatibility, is applied as the "gatekeeper" to fabricate the pH-sensitive dextran/mesoporous silica nanoparticles (MSNs) based drug delivery systems for controlled intracellular drug release. Dextran encapsulating on the surface of MSNs is oxidized by NaIO 4 to obtain three kinds of dextran dialdehydes (PADs), which are then coupled with MSNs via pH-sensitive hydrazone bond to fabricate three kinds of drug carriers. At pH 7.4, PADs block the pores to prevent premature release of anti-cancer drug doxorubicin hydrochloride (DOX). However, in the weakly acidic intracellular environment (pH∼5.5) the hydrazone can be ruptured; and the drug can be released from the carriers. The drug loading capacity, entrapment efficiency and release rates of the drug carriers can be adjusted by the amount of NaIO 4 applied in the oxidation reaction. And from which DOX@MSN-NH-N=C-PAD 10 is chosen as the most satisfactory one for the further in vitro cytotoxicity studies and cellular uptake studies. The results demonstrate that DOX@MSN-NH-N=C-PAD 10 with an excellent pH-sensitivity can enter HeLa cells to release DOX intracellular due to the weakly acidic pH intracellular and kill the cells. In our opinion, the ingenious pH-sensitive drug delivery systems have application potentials for cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Evaluation of DNA binding, DNA cleavage, protein binding, radical scavenging and in vitro cytotoxic activities of ruthenium(II) complexes containing 2,4-dihydroxy benzylidene ligands

    Energy Technology Data Exchange (ETDEWEB)

    Mohanraj, Maruthachalam; Ayyannan, Ganesan; Raja, Gunasekaran; Jayabalakrishnan, Chinnasamy, E-mail: drcjbstar@gmail.com

    2016-12-01

    The new ruthenium(II) complexes with hydrazone ligands, 4-Methyl-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 1}), 4-Methoxy-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 2}), 4-Bromo-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 3}), were synthesized and characterized by various spectro analytical techniques. The molecular structures of the ligands were confirmed by single crystal X-ray diffraction technique. The DNA binding studies of the ligands and complexes were examined by absorption, fluorescence, viscosity and cyclic voltammetry methods. The results indicated that the ligands and complexes could interact with calf thymus DNA (CT-DNA) through intercalation. The DNA cleavage activity of the complexes was evaluated by gel electrophoresis assay, which revealed that the complexes are good DNA cleaving agents. The binding interaction of the ligands and complexes with bovine serum albumin (BSA) was investigated using fluorescence spectroscopic method. Antioxidant studies showed that the complexes have a strong radical scavenging properties. Further, the cytotoxic effect of the complexes examined on cancerous cell lines showed that the complexes exhibit significant anticancer activity. - Highlights: • Synthesis of ruthenium(II) hydrazone complexes • Molecular structure of the ligands was elucidated by single crystal X-ray diffraction method. • The ligands and complexes interact with CT-DNA via intercalation. • The complexes possess significant antioxidant activity against DPPH, OH and NO radicals. • The complex 6 shows higher IC{sub 50} value than the other complexes against cancer cells.

  18. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

    Energy Technology Data Exchange (ETDEWEB)

    Monier, M., E-mail: monierchem@yahoo.com [Chemistry Department, Drexel University, Philadelphia, PA (United States); Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Ayad, D.M.; Sarhan, A.A. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt)

    2010-04-15

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

  19. Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers.

    Science.gov (United States)

    Monier, M; Ayad, D M; Sarhan, A A

    2010-04-15

    The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction. 2009 Elsevier B.V. All rights reserved.

  20. Synthesis, Acidity Constants and Tautomeric Structure of the Diazonium Coupling Products of 2-(Benzylsulfanyl-7H-purin-6-one in Its Ground and Excited States

    Directory of Open Access Journals (Sweden)

    Hosam A. Saad

    2011-10-01

    Full Text Available A series of new 8-arylhydrazono-2-(benzylsulfanyl-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and excited states were determined spectrophotometrically. The tautomeric structures of such products were elucidated by spectral analyses and correlation of their acid dissociation constants with the Hammett equation. The results indicated that the studied compounds 6 exist predominantly in the hydrazone tautomeric form 6A in both the ground and excited states.

  1. A new approach to ferrocene derived alkenes via copper-catalyzed olefination.

    Science.gov (United States)

    Muzalevskiy, Vasily M; Shastin, Aleksei V; Demidovich, Alexandra D; Shikhaliev, Namiq G; Magerramov, Abel M; Khrustalev, Victor N; Rakhimov, Rustem D; Vatsadze, Sergey Z; Nenajdenko, Valentine G

    2015-01-01

    A new approach to ferrocenyl haloalkenes and bis-alkenes was elaborated. The key procedure involves copper catalyzed olefination of N-unsubstituted hydrazones, obtained from ferrocene-containing carbonyl compounds and hydrazine, with polyhaloalkanes. The procedure is simple, cheap and could be applied for the utilization of environmentally harmful polyhalocarbons. The cyclic voltammetry study of the representative examples of the synthesized ferrocenyl alkenes shows the strong dependence of the cathodic behavior on the amount of vinyl groups: while for the monoalkene containing molecules no reduction is seen, the divinyl products are reduced in several steps.

  2. Design, Synthesis and Evaluation of Antiproliferative Activity of New Benzimidazolehydrazones

    Directory of Open Access Journals (Sweden)

    Valentina Onnis

    2016-04-01

    Full Text Available The synthesis and antiproliferative activity of new benzimidazole derivatives bearing an hydrazone mojety at the 2-position is described. The new N′-(4-arylidene-1H-benzo[d]imidazole-2-carbohydrazides were evaluated for their cytostatic activity toward the murine leukemia (L1210, human T-cell leukemia (CEM, human cervix carcinoma (HeLa and human pancreas carcinoma cells (Mia Paca-2. A preliminary structure-activity relationship could be defined. Some of the compounds possess encouraging and consistent antiproliferative activity, having IC50 values in the low micromolar range.

  3. Symmetrical N-acylsubstituted dihydrazones containing bithiophene core - Photophysical, electrochemical and thermal characterization

    Science.gov (United States)

    Jarczyk-Jedryka, Anna; Filapek, Michal; Malecki, Grzegorz; Kula, Slawomir; Janeczek, Henryk; Boharewicz, Bartosz; Iwan, Agnieszka; Schab-Balcerzak, Ewa

    2016-04-01

    Four symmetrical N-acylsubstituted dihydrazones containing bithiophene core were synthesized from condensation of 2,2‧-bithiophene-5,5‧-dicarboxyaldehyde with benzoic, isonicotinoyl, 2-thiophenic and 2-furoic hydrazide. The obtained compounds were characterized through the data from 1H nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), elemental analysis, UV-vis absorption spectroscopy, photoluminescence (PL), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements. Additionally, the electronic properties including orbital energies and resulting energy gaps were calculated by density functional theory (DFT). Their thermal behavior was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). They were thermal sable up to 320 °C. The prepared N-acylsubstituted dihydrazones emitted light with λem in the range of 499-530 nm in solution, whereas, in solid state as blend with PMMA blue emission was observed. They undergo quasi-reversible and irreversible electrochemical reduction and oxidation processes, respectively. Additionally, the selected compounds were tested preliminary as component of active layer in organic photovoltaic cells. The highest value of power conversion efficiency, equal to 1.68% under simulated 100 mW/cm2 AM 1.5G irradiation was found for device with the architecture ITO/PEDOT:PSS/P3HT:PCBM:FBTH (1:2:2)/Al.

  4. A coumarin-based "turn-on" fluorescent sensor for the determination of Al3+: single crystal X-ray structure and cell staining properties.

    Science.gov (United States)

    Guha, Subarna; Lohar, Sisir; Sahana, Animesh; Banerjee, Arnab; Safin, Damir A; Babashkina, Maria G; Mitoraj, Mariusz P; Bolte, Michael; Garcia, Yann; Mukhopadhyay, Subhra Kanti; Das, Debasis

    2013-07-28

    An efficient Al(3+) receptor, 6-(2-hydroxybenzylideneamino)-2H-chromen-2-one (HBC), has been synthesized by condensing salicylaldehyde with 6-aminocoumarin. The molecular structure of HBC has been determined by a single crystal X-ray analysis. It was established that in the presence of Al(3+), HBC shows 25 fold enhancement of fluorescence intensity which might be attributed to the chelation-enhanced fluorescence (CHEF) process. HBC binds Al(NO3)3 in a 1 : 1 stoichiometry with a binding constant (K) of 7.9 × 10(4) M(-1). Fe(3+) and Mn(2+) quench the emission intensity of the [HBC + Al(3+)] system to an insignificant extent at a concentration 10 times higher compared to that of Al(3+). HBC is highly efficient in the detection of intracellular Al(3+) under a fluorescence microscope.

  5. A novel Schiff-base as a Cu(II) ion fluorescent sensor in aqueous solution

    Science.gov (United States)

    Gündüz, Z. Yurtman; Gündüz, C.; Özpınar, C.; Urucu, O. Aydın

    2015-02-01

    A new fluorescent Cu(II) sensor (L) obtained from the Schiff base of 5,5‧-methylene-bis-salicylaldehyde with amidol (2,4-diaminophenol) was synthesized and characterized by FT-IR, MS, 1H NMR, 13C NMR techniques. In the presence of pH 6.5 (KHPO4-Na2HPO4) buffer solutions, copper reacted with L to form a stable 2:1 complex. Fluorescence spectroscopic study showed that Schiff base is highly sensitive towards Cu(II) over other metal ions (K+, Na+, Al3+, Ni2+, Co2+, Fe3+, Zn2+, Pb2+) in DMSO/H2O (30%, v/v). The sensor L was successfully applied to the determination of copper in standard reference material. The structural properties and molecular orbitals of the complex formed between L and Cu2+ ions were also investigated using quantum chemical computations.

  6. pH and temperature dual-sensitive liposome gel based on novel cleavable mPEG-Hz-CHEMS polymeric vaginal delivery system

    Science.gov (United States)

    Chen, Daquan; Sun, Kaoxiang; Mu, Hongjie; Tang, Mingtan; Liang, Rongcai; Wang, Aiping; Zhou, Shasha; Sun, Haijun; Zhao, Feng; Yao, Jianwen; Liu, Wanhui

    2012-01-01

    Background In this study, a pH and temperature dual-sensitive liposome gel based on a novel cleavable hydrazone-based pH-sensitive methoxy polyethylene glycol 2000-hydrazone-cholesteryl hemisuccinate (mPEG-Hz-CHEMS) polymer was used for vaginal administration. Methods The pH-sensitive, cleavable mPEG-Hz-CHEMS was designed as a modified pH-sensitive liposome that would selectively degrade under locally acidic vaginal conditions. The novel pH-sensitive liposome was engineered to form a thermogel at body temperature and to degrade in an acidic environment. Results A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The dual-sensitive liposome gel with a sol-gel transition at body temperature was degraded in a pH-dependent manner, and was stable for a long period of time at neutral and basic pH, but cleavable under acidic conditions (pH 5.0). Arctigenin encapsulated in a dual-sensitive liposome gel was more stable and less toxic than arctigenin loaded into pH-sensitive liposomes. In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0. Conclusion This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery. PMID:22679372

  7. Amphipathic dextran-doxorubicin prodrug micelles for solid tumor therapy.

    Science.gov (United States)

    Jin, Rong; Guo, Xuelian; Dong, Lingli; Xie, Enyuan; Cao, Aoneng

    2017-10-01

    A group of micelles self-assembled from deoxycholic acid-doxorubicin-conjugated dextran (denoted as Dex-DCA-DOX) prodrugs were designed and prepared for pH-triggered drug release and cancer chemotherapy. These prodrugs could be successfully produced by chemically coupling hydrophobic deoxycholic acid (DCA) to dextran hydrazine (denoted as Dex-NHNH 2 ) and hydrazone linker formation between doxorubicin (DOX) and Dex-NHNH 2 . These Dex-DCA-DOX prodrugs self-assembled to form micelles under physiological conditions with varied particle sizes depending on molecular weight of dextran, degree of substitution (DS) of DCA and DOX. After optimization, Dex10k-DCA9-DOX5.5 conjugate comprising dextran of 10kDa, DCA of DS 9 and DOX loading content of 5.5wt%, formed the micelles with the smallest size (110nm). These prodrug micelles could slowly liberate DOX under physiological conditions but efficiently released the drug at an acidified endosomal pH by the hydrolysis of acid-labile hydrazone linker. In vitro cytotoxicity experiment indicated that Dex10k-DCA9-DOX5.5 micelles exerted marked antitumor activity against MCF-7 and SKOV-3 cancer cells. Besides, intravenous administration of the micelles afforded growth inhibition of SKOV-3 tumor bearing in nude mice at a dosage of 2.5mg per kg with anti-cancer efficacy comparable to free DOX-chemotherapy but low systemic toxicity. This study highlights the feasibility of bio-safe and efficient dextran-based prodrug micelles designed for cancer chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Strategies for the Activation and Release of the Membranolytic Peptide Melittin from Liposomes Using Endosomal pH as a Trigger.

    Science.gov (United States)

    Oude Blenke, E; Sleszynska, M; Evers, M J W; Storm, G; Martin, N I; Mastrobattista, E

    2017-02-15

    Endosomolytic peptides are often coupled to drug delivery systems to enhance endosomal escape, which is crucial for the delivery of macromolecular drugs that are vulnerable to degradation in the endolysosomal pathway. Melittin is a 26 amino acid peptide derived from bee venom that has a very high membranolytic activity. However, such lytic peptides also impose a significant safety risk when applied in vivo as they often have similar activity against red blood cells and other nontarget cell membranes. Our aim is to control the membrane-disrupting capacity of these peptides in time and space by physically constraining them to a nanocarrier surface in such a way that they only become activated when delivered inside acidic endosomes. To this end, a variety of chemical approaches for the coupling of lytic peptides to liposomes via functionalized PEG-lipids were explored, including maleimide-thiol chemistry, click-chemistry, and aldehyde-hydrazide chemistry. The latter enables reversible conjugation via a hydrazone bond, allowing for release of the peptide under endosomal conditions. By carefully choosing the conjugation site and by using a pH activated analog of the melittin peptide, lytic activity toward a model membrane is completely inhibited at physiological pH. At endosomal pH the activity is restored by hydrolysis of the acid-labile hydrazone bond, releasing the peptide in its most active, free form. Furthermore, using an analogue containing a nonhydrolyzable bond as a control, it was shown that the activity observed can be completely attributed to release of the peptide, validating dynamic covalent conjugation as a suitable strategy to maintain safety during circulation.

  9. NEW METHOD FOR THE SYNTHESIS OF NONSYMMETRIC DINUCLEATING LIGANDS BY AMINOMETHYLATION OF PHENOLS AND SALICYLALDEHYDES

    NARCIS (Netherlands)

    LUBBEN, M; FERINGA, BL

    1994-01-01

    Monoaminomethylated phenols 5-7 and symmetrically diaminomethylated phenols 8 and 9 were prepared in a one-step procedure-from p-cresol, formaldehyde, and a variety of secondary amines by making use of the aromatic Mannich reaction. Nonsymmetric diaminomethylated phenols 10 and 11 were prepared by a

  10. Thermally-generated reactive intermediates: Trapping of the parent ferrocene-based o-quinodimethane and reactions of diradicals generated by hydrogen-atom transfers

    International Nuclear Information System (INIS)

    Ferguson, J.M.

    1993-01-01

    Ferrocenocyclobutene is prepared by flash vacuum pyrolysis (FVP) of the N-amino-2-phenylaziridine hydrazone of 2-methylferrocenealdehyde. In the second section of this dissertation, a series of hydrocarbon rearrangements were observed. FVP of o-allyltoluene at 0.1 Torr (700--900 C) gives 2-methylindan and indene, accompanied by o-propenyltoluene. FVP of 2-methyl-2'-vinylbiphenyl gives 9-methyl-9,10-dihydrophenanthrene, which fits the proposed mechanism. However, FVP of 2-(o-methylbenzyl)styrene gives mainly anthracene and 1-methylanthracene. This cyclization reaction was also successful with o-allylphenol and o-(2-methylallyl)phenol

  11. Thermally-generated reactive intermediates: Trapping of the parent ferrocene-based o-quinodimethane and reactions of diradicals generated by hydrogen-atom transfers

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, John Michael [Iowa State Univ., Ames, IA (United States)

    1993-09-01

    Ferrocenocyclobutene is prepared by flash vacuum pyrolysis (FVP) of the N-amino-2-phenylaziridine hydrazone of 2-methylferrocenealdehyde. In the second section of this dissertation, a series of hydrocarbon rearrangements were observed. FVP of o-allyltoluene at 0.1 Torr (700--900 C) gives 2-methylindan and indene, accompanied by o-propenyltoluene. FVP of 2-methyl-2`-vinylbiphenyl gives 9-methyl-9,10-dihydrophenanthrene, which fits the proposed mechanism. However, FVP of 2-(o-methylbenzyl)styrene gives mainly anthracene and 1-methylanthracene. This cyclization reaction was also successful with o-allylphenol and o-(2-methylallyl)phenol.

  12. Identification of a selective small molecule inhibitor of breast cancer stem cells.

    Science.gov (United States)

    Germain, Andrew R; Carmody, Leigh C; Morgan, Barbara; Fernandez, Cristina; Forbeck, Erin; Lewis, Timothy A; Nag, Partha P; Ting, Amal; VerPlank, Lynn; Feng, Yuxiong; Perez, Jose R; Dandapani, Sivaraman; Palmer, Michelle; Lander, Eric S; Gupta, Piyush B; Schreiber, Stuart L; Munoz, Benito

    2012-05-15

    A high-throughput screen (HTS) with the National Institute of Health-Molecular Libraries Small Molecule Repository (NIH-MLSMR) compound collection identified a class of acyl hydrazones to be selectively lethal to breast cancer stem cell (CSC) enriched populations. Medicinal chemistry efforts were undertaken to optimize potency and selectivity of this class of compounds. The optimized compound was declared as a probe (ML239) with the NIH Molecular Libraries Program and displayed greater than 20-fold selective inhibition of the breast CSC-like cell line (HMLE_sh_Ecad) over the isogenic control line (HMLE_sh_GFP). Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Hydroxyquinoline-calix[4]arene-conjugates as ligands for lanthanide complexes. Preparation, characterization, and extraction properties

    Energy Technology Data Exchange (ETDEWEB)

    Mansel, Alexander [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Jaeschke, A.; Kischel, M.; Kersting, B. [Leipzig Univ. (Germany). Inst. fuer Anorganische Chemie

    2017-06-01

    The synthesis of a calixarene-based N{sub 4}O{sub 4} donor ligand H{sub 6}L, in which two 8-hydroxyquinoline-2-carbaldehyde units are appended via hydrazone-carbonylmethoxy linkages in a 1,3-arrangement to the lower rim of tert-butyl-calix[4]arene and its coordination properties towards Eu{sup 3+} are described. Moreover, the ligand H{sub 6}L was found to extract Eu{sup 3+} and Tb{sup 3+} at pH 7-8 from aqueous solution, as established by radiotracing using the radionuclides {sup 160}Tb and {sup 152} Eu.

  14. X-ray investigations of sulfur-containing fungicides. IV. 4'-[[Benzoyl(4-chlorophenylhydrazono)methyl]sulfonyl]acetanilide and 4'-[[benzoyl(4-methoxyphenylhydrazono)methyl]sulfonyl]acetanilide.

    Science.gov (United States)

    Wolf, W M

    2001-09-01

    The conformations of the two approximately isomorphous structures 4'-[[benzoyl(4-chlorophenylhydrazono)methyl]sulfonyl]acetanilide, C(22)H(18)ClN(3)O(4)S, and 4'-[[benzoyl(4-methoxyphenylhydrazono)methyl]sulfonyl]acetanilide, C(23)H(21)N(3)O(5)S, are stabilized by resonance-assisted intramolecular hydrogen bonds linking the hydrazone moieties and sulfonyl groups. The stronger bond is observed in the former compound. The difference in electronic properties between the Cl atom and the methoxy group is too small to significantly alter the non-bonding interactions of the sulfonyl and beta-carbonyl groups.

  15. Structure of substituted 2-(phenoxy)benzimidazoles

    Science.gov (United States)

    Pavlova, I. S.; Pervova, I. G.; Lipunova, G. N.; Novikova, R. K.; Slepukhin, P. A.; Lipunov, I. N.

    2013-03-01

    The synthesis and X-ray diffraction study of 1-benzyl-2-[2-(5-ethyltetrazole-2-yl)-phenoxy]-1H-benzimidazole and 1-benzyl-2-[2-(5-ethyltetrazole-2-yl)-4-nitrophenoxy]-1H-benzimidazole single crystals have been performed. The oxidative splitting of an azo-hydrazone group of 1-(2-hydroxy-(5-nitro)phenyl)-3-ethyl-5-(benzylbenzimidazolyl)formazans, a break in the C2-N1 bond, the interaction of o-hydroxyl group of aryl fragment with oxygen, and the formation of new 2-(phenoxy)benzimidazoles are found to occur in the presence of perchlorate iron(III).

  16. A new approach to ferrocene derived alkenes via copper-catalyzed olefination

    Directory of Open Access Journals (Sweden)

    Vasily M. Muzalevskiy

    2015-11-01

    Full Text Available A new approach to ferrocenyl haloalkenes and bis-alkenes was elaborated. The key procedure involves copper catalyzed olefination of N-unsubstituted hydrazones, obtained from ferrocene-containing carbonyl compounds and hydrazine, with polyhaloalkanes. The procedure is simple, cheap and could be applied for the utilization of environmentally harmful polyhalocarbons. The cyclic voltammetry study of the representative examples of the synthesized ferrocenyl alkenes shows the strong dependence of the cathodic behavior on the amount of vinyl groups: while for the monoalkene containing molecules no reduction is seen, the divinyl products are reduced in several steps.

  17. Redox chemistry of orange I and orange II: a pulse radiolysis study

    International Nuclear Information System (INIS)

    Yadav, P.; Sharma, K.K.; Rao, B.S.M.; O'Neill, P.; Oakes, J.; Batchelor, S.N.

    2004-01-01

    The relative reactivities of different tautomeric forms of model azo dyes (Orange I and Orange II) with oxidising and reducing radicals are investigated using pulse radiolysis technique. The rate of the reaction of N 3 with Orange I is diffusion controlled and the order of the reactivity among the tautomers is common ion > hydrazone > azo, whereas a reverse trend was seen in the reaction of e aq . The reducing alcohol radicals react with Orange II with k values in the range (1-3) x 10 9 dm 3 mol -1 s -1 . The relevant reaction mechanism is discussed. (author)

  18. Synthesis and antitumor activity of some novel thiophene, pyrimidine, coumarin, pyrazole and pyridine derivatives

    Directory of Open Access Journals (Sweden)

    Albratty Mohammed

    2017-03-01

    Full Text Available 2-Cyano-N-(thiazol-2-yl acetamide (2a and 2-cyano-N-(oxazol- 2-yl acetamide (2b were obtained via the reaction of ethyl cyanoacetate with either 2-aminothiazole (1a or 2-aminooxazole (1b. The formed products were directed toward the reaction with cyclopentanone and elemental sulfur in the presence of triethylamine to give cyclopenta[b]thiophene derivatives (3a,b. The latter products were reacted with either ethyl cyanoacetate or malononitrile to form compounds 4a,b and 5a,b, respectively. Compounds 4a,b were aimed at synthesizing some heterocyclic compounds; thus internal cyclization reactions were introduced to form compounds 6a,b. Also, compounds 4a,b reacted with salicylaldehyde, hydrazine derivatives and either urea or thiourea to produce coumarin derivatives (7a,b, pyrazole derivatives (8a-d and pyrimidine derivatives (9a-d, respectively. Reaction of either benzaldehyde or benzene diazonium chloride (11 with compounds 4a,b afforded compounds 10a,b and 12a,b, respectively. On the other hand, compounds 5a,b underwent internal cyclization to form pyrimidine derivatives 13a,b. Also, when compounds 5a,b reacted with either ethyl cyanoacetate or malononitrile, they gave pyridine derivatives (15a-d through the formation of intermediates (14a-d. Finally, formation of fused pyrimidine derivatives (17a,b was achieved through the reaction of compounds 5a,b and salicylaldehyde applying two different pathways. The first pathway used a catalytic amount of piperidine to form compounds 16a,b; the latter products underwent cyclization to give compounds 17a,b. The second pathway, using a catalytic amount of sodium ethoxide solution directly in one step, afforded compounds 17a,b. Structures of the newly synthesized compounds were established using IR, 1H NMR, 13C NMR and mass spectrometry and their antitumor activity was investigated. Some of these compounds showed promising inhibitory effects on three different cell lines. However, fused pyrimidine

  19. The DFT investigations of the electron injection in hydrazone-based sensitizers

    KAUST Repository

    Al-Sehemi, Abdullah G.; Irfan, Ahmad; Asiri, Abdullah M.

    2012-01-01

    solvent. The calculated absorption spectra in ethanol, acetonitrile, and methanol are in good agreement with experimental evidences. The absorption spectra are red shifted compared to System1. On the basis of electron injection and electronic coupling

  20. The DFT investigations of the electron injection in hydrazone-based sensitizers

    KAUST Repository

    Al-Sehemi, Abdullah G.

    2012-03-01

    Quantum chemical calculations were carried out by using density functional theory and time-dependant density functional theory at B3LYP/6-31G(d) and TD-B3LYP/6-31G(d) level of theories. The absorption spectra have been computed with and without solvent. The calculated absorption spectra in ethanol, acetonitrile, and methanol are in good agreement with experimental evidences. The absorption spectra are red shifted compared to System1. On the basis of electron injection and electronic coupling constant, we have shed light on the nature of different sensitizers. The coplanarity between the benzene near anchoring group having LUMO and the bridge (N-N) is broken in System6 and System7 that would hamper the recombination process. The electron injection of System2-System10 is superior to System1. The highest electronic coupling constant has been observed for System6 that followed the System7 and System8. The light-harvesting efficiency of all the sensitizers enlarged in acetonitrile and ethanol. The long-range-corrected functional (LC-BLYP), Coulomb-attenuating method (CAM-B3LYP), and BH and HLYP functional underestimate the excitation energies while B3LYP is good to reproduce the experimental data. Moreover, we have investigated the effect of cyanoacetic acid as anchoring group on the electron injection. © 2012 Springer-Verlag.

  1. Construction of an Asymmetric Quaternary Carbon Center via Allylation of Hydrazones

    International Nuclear Information System (INIS)

    Kim, Jin Bum; Satyender, Apuri; Jang, Doo Ok

    2013-01-01

    Asymmetric indium-mediated allylation of imine derivatives bearing a chiral auxiliary is a reliable strategy for the synthesis of chiral homoallylic amines. Various techniques for indium-mediated stereoselective allylation of imines bearing a chiral auxiliary have been reported. In 1997 Loh and co-workers reported indium-mediated allylation with imines derived from L-valine methyl ester. Since then, many forms of indium-mediated allylation bearing a chiral auxiliary have been reported, including imines derived from (S)-valinol, (R)-phenylglycinol, uracil, (R)-phenylglycinol methyl ester, N-tert-butanesufinamide, and (1R,2S)-1-amino-2-indanol. However, the synthesis of chiral auxiliaries often involves a laborious multi-step synthesis with expensive reagents. Therefore, the development of readily accessible chiral auxiliaries for asymmetric indium-mediated all-ylation is in high demand

  2. Electrochemical study on the effect of Schiff base and its cobalt complex on the acid corrosion of steel

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Gaber, A.M. [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)], E-mail: ashrafmoustafa@yahoo.com; Masoud, M.S.; Khalil, E.A.; Shehata, E.E. [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)

    2009-12-15

    The effect of the Schiff base N,N'-bis (salicylaldehyde)-1,3-diaminopropane (Salpr) and its corresponding cobalt complex on the corrosion behaviour of steel in 1 M sulphuric acid solution were studied by electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques. Spectrophotometry measurements were employed to investigate the stability of the complex in acid media. The inhibitive effect of Salpr and its stable octahedral cobalt complex is argued to their adsorption over the steel surface. Theoretical fitting of different isotherms, Langmuir, Flory-Huggins and the kinetic-thermodynamic model were tested to clarify the nature of adsorption. The data revealed that there might be non-ideal behaviour in the adsorption processes of Co(Salpr) complex on the steel surface. The Co(Salpr) could displace more water molecules from the steel surface than the corresponding Salpr. The bulky Co(Salpr) molecule could cover more than one active site.

  3. Imine derivatives of lathonones. Part I -- Reactions of neodymium (III) isopropoxide with monofunctional bidendtate and bifunctional tridentate aldimines and ketamines

    International Nuclear Information System (INIS)

    Mital, S.P.; Singh, R.V.; Tandon, J.P.

    1980-01-01

    Nd(OPrsup(i))sub(2) (SB) and Nd(Oprsup(i))(SB)sub(2) [where SBH represents the molecule of monofunctional bidentate aldimine] type of derivatives have been synthesised by 1:1 and 1:2 molar reactions of neodymium isopropoxide with the aldimines having the donor system NOH and formed by the condensation of salicylaldehyde with alkylamines. However, bifunctional tridentate Schiff bases (LH) 2 have been found to yield Nd(OPrsup(i)) (L) and Nd 2 (L) 3 type of complexes in 1:1 and 2:3 molar ratio respectively. The isopropoxy groups of the 1:1 complexes have been found to undergo replacement reactions with excess of t-butanol and the resulting complexes are hydrolytically stable. All the newly synthesized complexes have been characterized on the basis of elemental analyses, molecular weight determinations, conductance measurements and infrared and proton magnetic resonance spectral studies. (auth.)

  4. Crystal structures of salicylideneguanylhydrazinium chloride and its copper(II) and cobalt(III) chloride complexes

    International Nuclear Information System (INIS)

    Chumakov, Yu. M.; Tsapkov, V. I.; Bocelli, G.; Antosyak, B. Ya.; Shova, S. G.; Gulea, A. P.

    2006-01-01

    The crystal structures of salicylideneguanylhydrazinium chloride hydrate hemiethanol solvate (I), salicylideneguanylhydrazinium trichloroaquacuprate(II) (II), and bis(salicylideneguanylhydrazino)cobalt(III) chloride trihydrate (III) are determined using X-ray diffraction. The structures of compounds I, II, and III are solved by direct methods and refined using the least-squares procedure in the anisotropic approximation for the non-hydrogen atoms to the final factors R = 0.0597, 0.0212, and 0.0283, respectively. In the structure of compound I, the monoprotonated molecules and chlorine ions linked by hydrogen bonds form layers aligned parallel to the (010) plane. In the structure of compound II, the salicylaldehyde guanylhydrazone cations and polymer chains consisting of trichloroaquacuprate(II) anions are joined by an extended three-dimensional network of hydrogen bonds. In the structure of compound III, the [Co(LH) 2 ] + cations, chloride ions, and molecules of crystallization water are linked together by a similar network

  5. Preparation and in vivo evaluation of radioiodinated closo-decaborate(2-) derivatives to identify structural components that provide low retention in tissues

    International Nuclear Information System (INIS)

    Wilbur, D. Scott; Chyan, M.-K.; Hamlin, Donald K.; Perry, Matthew A.

    2010-01-01

    Introduction: In vivo deastatination of 211 At-labeled biomolecules can severely limit their use in endoradiotherapy. Our studies have shown that the use of closo-decaborate(2-) moiety for 211 At-labeling of biomolecules provides high in vivo stability towards deastatination. However, data from those studies have also been suggestive that some astatinated closo-decaborate(2-) catabolites may be retained in tissues. In this study, we investigated the in vivo distributions of several structurally simple closo-decaborate(2-) derivatives to gain information on the effects of functional groups if catabolites are released into the blood system from the carrier biomolecule. Methods: Thirteen closo-decaborate(2-) derivatives were synthesized and radioiodinated for evaluation. Tissue concentrations of the radioiodinated compounds were obtained in groups of five mice at 1 and 4 h postinjection (pi). Dual-label ( 125 I and 131 I) experiments permitted evaluation of two compounds in each set of mice. Results: All of the target compounds were readily synthesized. Radioiodination reactions were conducted with chloramine-T and Na[ 125/131 I]I in water to give high yields (75-96%) of the desired compounds. Biodistribution data at 1 and 4 h pi (representing catabolites released into the blood system) showed small differences in tissue concentrations for some compounds, but large differences for others. The results indicate that formal (overall) charge on the compounds could not be used as a predictor of tissue localization or retention. However, derivatives containing carboxylate groups generally had lower tissue concentrations. Acid cleavable hydrazone functionalities appeared to be the best candidates for further study. Conclusions: Further studies incorporating hydrazone functionalities into pendant groups for biomolecule radiohalogenation are warranted.

  6. MBTH: A novel approach to rapid, spectrophotometric quantitation of total algal carbohydrates.

    Science.gov (United States)

    Van Wychen, Stefanie; Long, William; Black, Stuart K; Laurens, Lieve M L

    2017-02-01

    A high-throughput and robust application of the 3-methyl-2-benzothiazolinone hydrazone (MBTH) method was developed for carbohydrate determination in microalgae. The traditional phenol-sulfuric acid method to quantify carbohydrates is strongly affected by algal biochemical components and exhibits a highly variable response to microalgal monosaccharides. We present a novel use of the MBTH method to accurately quantify carbohydrates in hydrolyzate after acid hydrolysis of algal biomass, without a need for neutralization. The MBTH method demonstrated consistent and sensitive quantitation of algae-specific monosaccharides down to 5 μg mL -1 without interference from other algae acidic hydrolyzate components. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Synthesis and Antibacterial Evaluation of Novel Heterocyclic Compounds Containing a Sulfonamido Moiety

    Directory of Open Access Journals (Sweden)

    Eman A. El-Bordany

    2013-01-01

    Full Text Available Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6-dimethylpyrimidin-2-ylsulfamoyl]phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives. Also, the reactivity of the precursor hydrazone towards hydrazine derivatives to give pyrazole and oxazole derivatives was studied. On the other hand, treatment of the same precursor with urea, thiourea and/or guanidine hydrochloride furnished pyrimidine and thiazine derivatives, respectively. The newly synthesized compounds were tested for antibacterial activity, whereby eight compounds were found to have high activities.

  8. Acquisition of iron from transferrin regulates reticulocyte heme synthesis

    International Nuclear Information System (INIS)

    Ponka, P.; Schulman, H.M.

    1985-01-01

    Fe-salicylaldehyde isonicotinoylhydrazone (SIH), which can donate iron to reticulocytes without transferrin as a mediator, has been utilized to test the hypothesis that the rate of iron uptake from transferrin limits the rate of heme synthesis in erythroid cells. Reticulocytes take up 59 Fe from [ 59 Fe]SIH and incorporate it into heme to a much greater extent than from saturating concentrations of [ 59 Fe]transferrin. Also, Fe-SIH stimulates [2- 14 C]glycine into heme when compared to the incorporation observed with saturating levels of Fe-transferrin. In addition, delta-aminolevulinic acid does not stimulate 59 Fe incorporation into heme from either [ 59 Fe]transferrin or [ 59 Fe]SIH but does reverse the inhibition of 59 Fe incorporation into heme caused by isoniazid, an inhibitor of delta-aminolevulinic acid synthase. Taken together, these results suggest the hypothesis that some step(s) in the pathway of iron from extracellular transferrin to intracellular protoporphyrin limits the overall rate of heme synthesis in reticulocytes

  9. Kinetics of the metal exchange in Bis(salicylaldiminato)-copper(II)-complexes. Pt. 3. Influence of the electron density at the donor nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, H; Wannowius, K J; Elias, H [Technische Hochschule Darmstadt (Germany, F.R.). Fachbereich Anorganische Chemie und Kernchemie

    1977-01-01

    The kinetics of isotopic copper exchange between various (bis-(N-phenyl-salicylaldiminato))copper(II)complexes (= CuL/sub 2/) and mono(pyridine)copper(II)acetate (= CuAc/sub 2/py) was studied in dichloromethane as solvent in the temperature range -20 to +20/sup 0/C. The exchange follows the experimental rate law (5), which is simplified in certain cases due to k''((CuAc/sub 2/py)/sub 2/)/sup 1///sup 2/ < 1. The variation of substituents X on the salicylaldehyde ring and of substituents Y on the N-phenyl ring leads via Hammett plots to the conclusion that substituent effects become apparent as rate increasing or rate decreasing only in those cases, in which they cause an increase or decrease in electron density at the donor oxygen. Substituents Y in 2-position, and especially in 2.6-position, reduce the rate of exchange with increasing van der Waals radius of Y. The mechanistic implications of the results are discussed. (orig.) 891 HK.

  10. DNA binding, antioxidant, cytotoxicity (MTT, lactate dehydrogenase, NO), and cellular uptake studies of structurally different nickel(II) thiosemicarbazone complexes: synthesis, spectroscopy, electrochemistry, and X-ray crystallography.

    Science.gov (United States)

    Prabhakaran, R; Kalaivani, P; Huang, R; Poornima, P; Vijaya Padma, V; Dallemer, F; Natarajan, K

    2013-02-01

    Three new nickel(II) thiosemicarbazone complexes have been synthesized and characterized by analytical, spectral, and single-crystal X-ray diffraction studies. In complex 1, the ligand 2-hydroxy-1-naphthaldehydethiosemicarbazone coordinated as a monobasic tridentate donor, whereas in complexes 2 and 3, the ligands salicylaldehyde-4(N)-ethylthiosemicarbazone and 2-hydroxy-1-naphthaldehyde-4(N)-ethylthiosemicarbazone coordinated as a dibasic tridentate donor. The DNA binding ability of the complexes in calf thymus DNA was explored by absorption and emission titration experiments. The antioxidant property of the new complexes was evaluated to test their free-radical scavenging ability. In vitro cytotoxicity assays were performed for the new complexes in A549 and HepG2 cell lines. The new compounds overcome cisplatin resistance in the A549 cell line and they were also active in the HepG2 cell line. The cellular uptake study showed the accumulation of the complexes in tumor cells depended on the nature of the ligand attached to the nickel ion.

  11. Ni(II) complexes of arginine Schiff-bases and its interaction with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Sallam, S.A., E-mail: shehabsallam@yahoo.com [Chemistry Department, Faculty of Science, Suez Canal University, Isamilia (Egypt); Abbas, A.M. [Chemistry Department, Faculty of Science, Suez Canal University, Isamilia (Egypt)

    2013-04-15

    Ni(II) complexes with Schiff-bases obtained by condensation of arginine with salicylaldehyde; 2,3-; 2,4-; 2,5-dihydroxybenzaldehyde and o-hydroxynaphthaldehyde have been synthesized using the template method in ethanol or ammonia media. They were characterized by elemental analyses, conductivity measurements, magnetic moment, UV, IR and {sup 1}H NMR spectra as well as thermal analysis (TG, DTG and DTA). The Schiff-bases are dibasic tridentate donors and the complexes have diamagnetic square planar and octahedral structures. The complexes decompose in three steps where kinetic and thermodynamic parameters of the decomposition steps were computed. The interactions of the formed complexes with FM-DNA were monitored by UV and fluorescence spectroscopy. -- Highlights: ► Arginine Schiff-bases and their nickel(II) complexes have been synthesized. ► Magnetic and spectral data show diamagnetic square planar and octahedral complexes. ► The complexes thermally decompose in three stages. Interaction with FM-DNA shows hyperchromism with blue shift.

  12. Ni(II) complexes of arginine Schiff-bases and its interaction with DNA

    International Nuclear Information System (INIS)

    Sallam, S.A.; Abbas, A.M.

    2013-01-01

    Ni(II) complexes with Schiff-bases obtained by condensation of arginine with salicylaldehyde; 2,3-; 2,4-; 2,5-dihydroxybenzaldehyde and o-hydroxynaphthaldehyde have been synthesized using the template method in ethanol or ammonia media. They were characterized by elemental analyses, conductivity measurements, magnetic moment, UV, IR and 1 H NMR spectra as well as thermal analysis (TG, DTG and DTA). The Schiff-bases are dibasic tridentate donors and the complexes have diamagnetic square planar and octahedral structures. The complexes decompose in three steps where kinetic and thermodynamic parameters of the decomposition steps were computed. The interactions of the formed complexes with FM-DNA were monitored by UV and fluorescence spectroscopy. -- Highlights: ► Arginine Schiff-bases and their nickel(II) complexes have been synthesized. ► Magnetic and spectral data show diamagnetic square planar and octahedral complexes. ► The complexes thermally decompose in three stages. Interaction with FM-DNA shows hyperchromism with blue shift

  13. Prenylcoumarins in One or Two Steps by a Microwave-Promoted Tandem Claisen Rearrangement/Wittig Olefination/Cyclization Sequence.

    Science.gov (United States)

    Schultze, Christiane; Schmidt, Bernd

    2018-05-04

    The one-pot synthesis of 8-prenylcoumarins from 1,1-dimethylallylated salicylaldehydes and the stabilized ylide [(ethoxycarbonyl)methylene]triphenylphosphorane under microwave conditions was found to have a limited scope. The sequence suffers from a difficult and sometimes low-yielding synthesis of the precursors and from a competing deprenylation upon microwave irradiation. This side reaction occurs in particular with electron rich arenes with two or more alkoxy groups at adjacent positions, a prominent substitution pattern in naturally occurring 8-prenylcoumarins. Both limitations of this one-step sequence were overcome by a two-step synthesis consisting of a microwave-promoted tandem allyl ether Claisen rearrangement/Wittig olefination and a subsequent olefin cross metathesis with 2-methyl-2-butene. The cross metathesis step proceeds with a high selectivity and yields exclusively the desired prenyl, rather than the alternative crotyl substituent. Several naturally occurring 8-prenylcoumarins that were previously inaccessible have been synthesized in good overall yields along this route.

  14. Experimental study of the energetics of tetradentate N2O2 Schiff bases derived from salicylaldehyde

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Maria D.M.C.; Goncalves, Jorge M.; Silva, Ana L.R.; Silva, Adelina M.R.O.A.; Oliveira, Paula C.F.C.; Ribeiro da Silva, Manuel A.V.

    2004-01-01

    The standard (p 0 = 0.1 MPa) molar enthalpies of formation, at T = 298.15 K, in the gaseous phase of two Schiff bases, N,N'-bis(salicylaldehydo)ethylenediimine and N,N'-bis(salicylaldehydo)tetramethylenediimine, were determined from their enthalpies of combustion and sublimation, obtained by static bomb calorimetry in oxygen and by the Knudsen effusion technique, respectively. The enthalpies of fusion of both compounds have been determined by differential scanning calorimetry

  15. Synthesis, antibacterial and cytotoxic activities of new biflorin-based hydrazones and oximes.

    Science.gov (United States)

    da S Souza, Luciana G; Almeida, Macia C S; Lemos, Telma L G; Ribeiro, Paulo R V; de Brito, Edy S; Silva, Vera L M; Silva, Artur M S; Braz-Filho, Raimundo; Costa, José G M; Rodrigues, Fábio F G; Barreto, Francisco S; de Moraes, Manoel O

    2016-01-15

    Biflorin 1 is a biologically active quinone, isolated from Capraria biflora. Five new biflorin-based nitrogen derivatives were synthesized, of which two were mixtures of (E)- and (Z)- isomers: (Z)-2a, (Z)-2b, (Z)-3a, (Z)- and (E)-3b, (Z)- and (E)-3c. The antibacterial activity was investigated using the microdilution method for determining the minimum inhibitory concentration (MIC) against six bacterial strains. Tests have shown that these derivatives have potential against all bacterial strains. The cytotoxic activity was also evaluated against three strains of cancer cells, but none of the derivatives showed activity. Copyright © 2015. Published by Elsevier Ltd.

  16. Electronic effects of substituents in o-hydroxyazo compounds and azoquinone-hydrazone tautomerism

    International Nuclear Information System (INIS)

    Raikhshtat, M.M.; Zhogina, V.V.; Savvin, S.B.

    1987-01-01

    The authors have investigated the electronic structure of p-substituted phenylazonaphthol and some o-hydroxyazo compounds of the general structure X-N=N-Y. The influence of structural changes of the X and Y radicals on the electronic structure of the o-hydroxyazo group was studied. The results are compared with experimental data, obtained by NMR 13 C, by tautomerism of these compounds in solution in CDCl 3 . The electronic structure of o-hydroxyazo compounds was calculated by the PPDP/2 method. This method satisfactorily describes the electronic structure of organic compounds and correctly reproduces electronic effects of the substituents

  17. {sup 1} H and {sup 13} C NMR of phenyl barbiturilidene; RMN de H-1 e C-13 de fenil barbiturilidenos

    Energy Technology Data Exchange (ETDEWEB)

    Villar, Jose Daniel Figueroa; Santos, Nedina Lucia dos; Cruz, Elizabete Rangel [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Quimica

    1991-12-31

    The condensation of barbituric acids with aromatic aldehydes gives the phenyl barbiturilidenes, which are studied as intermediary compounds in the synthesis of new heterocyclic compounds for pharmaceutical use. One of the most characteristic reactions of these compounds is the Michael type addition reaction, in the exocyclic carbon-carbon double binding. The reaction with 2,4-di nitrophenyl hydrazine reaction is been used as a test of this type of reactivity, which supplies the respective hydrazone and barbituric acid. In this work, preliminary studies have been performed for establishing correlations between the Brown parameter ({sigma}{sup +}), the chemical shifts ({delta}) of the barbiturilidene atoms involved in the reaction, and their reactivities 3 refs., 1 fig., 6 tabs.

  18. Multifunctional Polymer Nanoparticles for Dual Drug Release and Cancer Cell Targeting

    Directory of Open Access Journals (Sweden)

    Yu-Han Wen

    2017-06-01

    Full Text Available Multifunctional polymer nanoparticles have been developed for cancer treatment because they could be easily designed to target cancer cells and to enhance therapeutic efficacy according to cancer hallmarks. In this study, we synthesized a pH-sensitive polymer, poly(methacrylic acid-co-histidine/doxorubicin/biotin (HBD in which doxorubicin (DOX was conjugated by a hydrazone bond to encapsulate an immunotherapy drug, imiquimod (IMQ, to form dual cancer-targeting and dual drug-loaded nanoparticles. At low pH, polymeric nanoparticles could disrupt and simultaneously release DOX and IMQ. Our experimental results show that the nanoparticles exhibited pH-dependent drug release behavior and had an ability to target cancer cells via biotin and protonated histidine.

  19. {sup 1} H and {sup 13} C NMR of phenyl barbiturilidene; RMN de H-1 e C-13 de fenil barbiturilidenos

    Energy Technology Data Exchange (ETDEWEB)

    Villar, Jose Daniel Figueroa; Santos, Nedina Lucia dos; Cruz, Elizabete Rangel [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Quimica

    1992-12-31

    The condensation of barbituric acids with aromatic aldehydes gives the phenyl barbiturilidenes, which are studied as intermediary compounds in the synthesis of new heterocyclic compounds for pharmaceutical use. One of the most characteristic reactions of these compounds is the Michael type addition reaction, in the exocyclic carbon-carbon double binding. The reaction with 2,4-di nitrophenyl hydrazine reaction is been used as a test of this type of reactivity, which supplies the respective hydrazone and barbituric acid. In this work, preliminary studies have been performed for establishing correlations between the Brown parameter ({sigma}{sup +}), the chemical shifts ({delta}) of the barbiturilidene atoms involved in the reaction, and their reactivities 3 refs., 1 fig., 6 tabs.

  20. A three-membered ring approach to carbonyl olefination.

    Science.gov (United States)

    Niyomchon, Supaporn; Oppedisano, Alberto; Aillard, Paul; Maulide, Nuno

    2017-10-23

    The carbon-carbon double bond, with its diverse and multifaceted reactivity, occupies a prominent position in organic synthesis. Although a variety of simple alkenes are readily available, the mild and chemoselective introduction of a unit of unsaturation into a functionalized organic molecule remains an ongoing area of research, and the olefination of carbonyl compounds is a cornerstone of such approaches. Here we show the direct olefination of hydrazones via the intermediacy of three-membered ring species generated by addition of sulfoxonium ylides, departing from the general dogma of alkenes synthesis from carbonyls. Moreover, the mild reaction conditions and operational simplicity of the transformation render the methodology appealing from a practical point of view.

  1. Synthesis, Structure Optimization and Antifungal Screening of Novel Tetrazole Ring Bearing Acyl-Hydrazones

    Directory of Open Access Journals (Sweden)

    Manzoor A. Malik

    2012-08-01

    Full Text Available Azoles are generally fungistatic, and resistance to fluconazole is emerging in several fungal pathogens. In an attempt to find novel azole antifungal agents with improved activity, a series of tetrazole ring bearing acylhydrazone derivatives were synthesized and screened for their in vitro antifungal activity. The mechanism of their antifungal activity was assessed by studying their effect on the plasma membrane using flow cytometry and determination of the levels of ergosterol, a fungal-specific sterol. Propidium iodide rapidly penetrated a majority of yeast cells when they were treated with the synthesized compounds at concentrations just above MIC, implying that fungicidal activity resulted from extensive lesions of the plasma membrane. Target compounds also caused a considerable reduction in the amount of ergosterol. The results also showed that the presence and position of different substituents on the phenyl ring of the acylhydrazone pendant seem to play a role on the antifungal activity as well as in deciding the fungistatic and fungicidal nature of the compounds.

  2. Synthesis and Mosquitocidal Activity of a Series of Hydrazone Derivatives against Aedes aegypti

    Science.gov (United States)

    Background: Aedes aegypti is an important mosquito vector for the transmission of several infectious diseases. Current insecticides play a vital role in controlling mosquitoes; however, the frequent use of insecticides has led to the development of insecticide resistance. In order to control mosquit...

  3. Synthesis and investigation of antimicrobial activities of nitrofurazone analogues containing hydrazide-hydrazone moiety

    Directory of Open Access Journals (Sweden)

    Łukasz Popiołek

    2017-11-01

    Full Text Available In this research we synthesized and tested for in vitro antimicrobial activity 21 nitrofurazone analogues. The compounds we obtained were identified on the basis of 1H NMR and 13C NMR spectroscopy. The in vitro screening of antimicrobial properties of synthesized compounds revealed a wide spectrum of antimicrobial activity. Compounds 28, 29, 32–43, and 45–48 showed very high bactericidal effect towards Staphylococcus spp. ATTC and Bacillus spp. ATTC (MIC = 0.002–7.81 µg/ml and MBC = 0.002–31.25 µg/ml. The levels of activity of several compounds were far better than those of nitrofurantoin, ciprofloxacin or cefuroxime.

  4. Synthesis and characterization of complexes of early actinides with tridentate Schiff base ligands

    International Nuclear Information System (INIS)

    Mansingh, P.S.; Dash, K.C.

    1995-01-01

    A series of thorium(IV) and dioxouranium(VI) complexes have been synthesised with tridentate Schiff base ligands (N 2 O donor set) obtained by in-situ condensation of N, N-dimethylethylenediamine with o-hydroxy aromatic aldehydes such as salicylaldehyde (HL) or o-hydroxy naphthaldehyde (HL'). While with dioxouranium(VI), the ligands are coordinated in a neutral manner and act as tridentate donors forming complexes of the type UO 2 (HL)X 2 or UO 2 (HL')X 2 (X=Cl,I,NCS,NO 3 ,CH 3 COO) with thorium(IV) they are coordinated as deprotonated tridentate ligands yielding complexes of the type Th(L') 2 X 2 (X=I,NCS,NO 3 ). The IR spectra show that the thiocyanate group is actually N-bonded unidentate isothiocyanate and both the nitrate and the acetate groups are bonded in bidentate manner while the ligands are bonded in tridentate manner in these complexes. The PMR spectra confirm the mode of bonding of the ligands either as neutral or as deprotonated species. The thermogravimetric analyses indicate the stability of the complexes. (author). 22 refs., 1 tab

  5. Mono-, di- and trinuclear dioxo complexes of uranium containing hydrazonato and azomethine ligands

    International Nuclear Information System (INIS)

    Gatto, C.C.; Schulz Lang, E.

    2004-01-01

    Mono-, di or trinuclear dioxouranium complexes with benzoylhydrazonato or azomethine ligands were prepared by reactions of common dioxouranium precursors such as UO 2 (NO 3 ) 2 . 6 H 2 O or [NBu 4 ] 2 [UO 2 Cl 4 ] with vanillin benzoylhydrazone (H 2 L 4 ), salicylaldehyde benzoylhydrazone (H 2 L 5 ), 2-hydroxyacetylbenzene salicylhydrazone (H 3 L 6 ) or N-(2-ethoxycarbonyl-3-oxo-but-1-en(1)yl)-2-aminophenol (H 2 L 7 ). Spectroscopic and X-ray crystallographic studies on the complexes [NBu 4 ] 2 [UO 2 Cl 4 ] . 2 H 2 L 4 , [UO 2 (HL 5 )(H 2 L 5 ) 2 ](NO 3 ), [HNEt 3 ] 2 [{UO 2 (L 6 )} 2 ] and [HNEt 3 ] 2 [{UO 2 (L 7 } 3 O)] confirm that the individual donor atom constellation, the size of the potential chelate rings and the acidity of the OH and NH functionalities of the proligands have a strong influence on the structure of the products. (Abstract Copyright [2004], Wiley Periodicals, Inc.) [de

  6. Synthesis, Thermal, Electrical and Catalytic Studies of Some Transition Metal Polychelates of Bis-bidentate Schiff Base

    Institute of Scientific and Technical Information of China (English)

    BANSOD Ashish; ASWAR Anand

    2007-01-01

    Polychelates of Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ), Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ) and Cd(Ⅱ) with the bis salen-type ligand derivedfrom 4,4'-bis[(salicylaldehyde-5)azo]biphenyl and 1,4-diaminobutane have been synthesized.All the polychelates have been characterized by elemental analysis,magnetic susceptibility measurements,IR,electronic spectra and thermogravimetric studies.All the complexes isolated in solid state are dark coloured and insoluble in water and common organic solvents.The ligand behaves as a bis-bidentate molecule coordinating through the phenolic oxygen and azomethine nitrogen atoms.The thermal decomposition of these metal complexes was investigated by thermogravimetric analysis and data have been analyzed for kinetic parameters using Broido equation.The solid-state electrical conductivity of the ligand and its polychelates in the form of compressed pellet was studied in the temperature range from 313 to 413 K.All the polychelates were found to show semiconducting nature.The Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ) and Ni(Ⅱ) polychelates have been assessed for the catalytic epoxidation of styrene.

  7. Experimental investigation of some coordination complexes using the sup(151)Eu Moessbauer resonance

    International Nuclear Information System (INIS)

    Lal, Asharfi; Rama Reddy, A.; Arvind; Ahmad, Naseer

    1979-01-01

    Several Schiff base complexes containing Eu 151 metal ions have been synthesized and their Moessbauer spectra are recorded using the constant acceleration velocity spectrometer. The least-square analysis method for the evaluation of the hyperfine field coupling constants is adopted using the computer dec system-10. From the systematic analysis of the quadrupole coupling constants (q.c.c.) and isomer shifts it has been established that the coordination number of the metal ion of Bis(acetylacetone) benzidine and thiourea complexes is five, that of bis-vanillin benzidine and bis-salicylaldehyde-o-dianisidine is six, and that of bis-vanillin-o-phenylene diamine is seven. It is also found that the q.c.c. being negative in all these complexes decreases monotonically as the coordination number increases. One unusual aspect of this experimental data is that most of the coordination complexes have very low f-factors whereas the Schiff base complexes studied here have a fairly high recoilless fractions. Attempts are in progress to synthesize and study the Fe Schiff base complexes in place of Eu. (auth.)

  8. Cometabolic Degradation of Dibenzofuran and Dibenzothiophene by a Naphthalene-Degrading Comamonas sp. JB.

    Science.gov (United States)

    Ji, Xiangyu; Xu, Jing; Ning, Shuxiang; Li, Nan; Tan, Liang; Shi, Shengnan

    2017-12-01

    Comamonas sp. JB was used to investigate the cometabolic degradation of dibenzofuran (DBF) and dibenzothiophene (DBT) with naphthalene as the primary substrate. Dehydrogenase and ATPase activity of the growing system with the presence of DBF and DBT were decreased when compared to only naphthalene in the growing system, indicating that the presence of DBF and DBT inhibited the metabolic activity of strain JB. The pathways and enzymes involved in the cometabolic degradation were tested. Examination of metabolites elucidated that strain JB cometabolically degraded DBF to 1,2-dihydroxydibenzofuran, subsequently to 2-hydroxy-4-(3'-oxo-3'H-benzofuran-2'-yliden)but-2-enoic acid, and finally to catechol. Meanwhile, strain JB cometabolically degraded DBT to 1,2-dihydroxydibenzothiophene and subsequently to the ring cleavage product. A series of naphthalene-degrading enzymes including naphthalene dioxygenase, 1,2-dihydroxynaphthalene dioxygenase, salicylaldehyde dehydrogenase, salicylate hydroxylase, and catechol 2,3-oxygenase have been detected, confirming that naphthalene was the real inducer of expression the degradation enzymes and metabolic pathways were controlled by naphthalene-degrading enzymes.

  9. Aldehyde-sequestering drugs: tools for studying protein damage by lipid peroxidation products.

    Science.gov (United States)

    Burcham, Philip C; Kaminskas, Lisa M; Fontaine, Frank R; Petersen, Dennis R; Pyke, Simon M

    2002-12-27

    Elevated levels of reactive alpha,beta-unsaturated aldehydes (e.g. malondialdehyde, 4-hydroxynonenal and acrolein) in the affected tissues of various degenerative conditions suggest these substances are active propagators of the disease process. One experimental approach to attenuating damage by these intermediates employs 'aldehyde-sequestering drugs' as sacrificial nucleophiles, thereby sparing cell macromolecules and perhaps slowing disease progression. Drugs with demonstrated trapping activity toward lipid-derived aldehydes include various amine compounds such as aminoguanidine, carnosine and pyridoxamine. We have focused on identifying scavengers of acrolein, perhaps the most toxic aldehyde formed during lipid peroxidation cascades. Various phthalazine compounds (hydralazine and dihydralazine) were found to trap acrolein readily, forming hydrazone derivatives in a rapid Schiff-type reaction. These compounds strongly protect against acrolein-mediated toxicity in isolated hepatocytes.

  10. Synthesis of New Macrocyclic Polyamides as Antimicrobial Agent Candidates

    Directory of Open Access Journals (Sweden)

    Osama I. Abd El-Salam

    2012-12-01

    Full Text Available A series of macrocyclic imides and Schiff-bases have been prepared via the cyclocondensation of pyridine-2,6-dicarbonyl dichloride (1 with L-ornithine methyl ester to give the corresponding macrocyclic bisester 2. Treatment of 2 with hydrazine hydrate gave macrocyclic bisacid hydrazide 3, which was used as starting material. Condensation of bishydrazide 3 with diacid anhydrides or aromatic aldehydes in refluxing acetic acid or ethanol gave the corresponding macrocyclic bisimides 4, 5a,b and macrocyclic bis- hydrazones 6a–j, respectively. The structure assignments of the new compounds were based on chemical and spectroscopic evidence. The antimicrobial screening showed that many of these newly synthesized compounds have good antimicrobial activities, comparable to ampicillin and ketaconazole used as reference drugs.

  11. Research into aroma changes in irradiated foodstuffs. I.- Studies on Fish

    International Nuclear Information System (INIS)

    Barrero Pinero, R.; Gasco Sanchez, L.; Valverde Garcia, F.

    1972-01-01

    Radiolytic formation of volatile compounds have been investigated in fillets of hake, codfish and bonito gamma-irradiated at a dose range of 0.1-5 Mrads. Analytical methods have been developed by gas chromatography of functional group derivatives: carbonyls as 2,4,-dinitrophenyl hydrazones, primary and secondary amines as N-alkyl benzamides, and thiols as 2,4-dinitrophenyl alkyl thioethers. The main results are as follows: increasing with the integral dose of the whole carbonyls, the most significant components being acetaldehyde, propional dehyde and formaldehyde; no significant variations with the integral dose od the traces of ammonia, methylamine, trimethylamine, ethylamine, diethylamine, propylamine, butylamine and pentylamine found in unirradiated samples; and radiolytic formation of methanethiol and dimethyl disulfide. (Author) 98 refs

  12. Chemosorption sampling and analysis of formaldehyde in air. Influence on recovery during the simultaneous sampling of formaldehyde, phenol, furfural and furfuryl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, K.; Hallgren, C.; Levin, J.O.; Nilsson, C.A.

    1981-12-01

    A method based on trapping formaldehyde on a 2,4-dinitrodinitrophenylhydrazine-coated porous polymer (Amberlite XAD-2) was evaluated for air sampling in occupational environments. The aldehyde is converted to its 2,4-dinitrophenylhydrazone on the adsorbent. The influence of some organic compounds which often occur together with formaldehyde-furfural, phenol and furfuryl alcohol--was studied. The results show that the method allows the sampling of formaldehyde in the range 0.01--1.0 mg/m3 of air, based on a 3-1 (15 min) sample and a coating of 1%. Furfural, phenol, and furfuryl alcohol do not interfere and may be conveniently sampled at the same time. Formaldehyde and furfural hydrazones were analyzed by high-performance liquid chromatography, phenol and furfuryl alcohol by gas chromatography.

  13. Research into aroma changes in irradiated foodstuffs. I.- Studies on Fish; Investigacion de Alteraciones de Aroma en alimentos irradiados. I Estudio sobre Pescado

    Energy Technology Data Exchange (ETDEWEB)

    Barreiro Pinero, R; Gasco Sanchez, L; Valverde Garcia, F

    1972-07-01

    Radiolytic formation of volatile compounds have been investigated in fillets of hake, codfish and bonito gamma-irradiated at a dose range of 0.1-5 Mrads. Analytical methods have been developed by gas chromatography of functional group derivatives: carbonyls as 2,4,-dinitrophenyl hydrazones, primary and secondary amines as N-alkyl benzamides, and thiols as 2,4-dinitrophenyl alkyl thioethers. The main results are as follows: increasing with the integral dose of the whole carbonyls, the most significant components being acetaldehyde, propional dehyde and formaldehyde; no significant variations with the integral dose od the traces of ammonia, methylamine, trimethylamine, ethylamine, diethylamine, propylamine, butylamine and pentylamine found in unirradiated samples; and radiolytic formation of methanethiol and dimethyl disulfide. (Author) 98 refs.

  14. Challenges in the development of an M4 PAM preclinical candidate: The discovery, SAR, and biological characterization of a series of azetidine-derived tertiary amides.

    Science.gov (United States)

    Tarr, James C; Wood, Michael R; Noetzel, Meredith J; Melancon, Bruce J; Lamsal, Atin; Luscombe, Vincent B; Rodriguez, Alice L; Byers, Frank W; Chang, Sichen; Cho, Hyekyung P; Engers, Darren W; Jones, Carrie K; Niswender, Colleen M; Wood, Michael W; Brandon, Nicholas J; Duggan, Mark E; Jeffrey Conn, P; Bridges, Thomas M; Lindsley, Craig W

    2017-12-01

    Herein we describe the continued optimization of M 4 positive allosteric modulators (PAMs) within the 5-amino-thieno[2,3-c]pyridazine series of compounds. In this letter, we disclose our studies on tertiary amides derived from substituted azetidines. This series provided excellent CNS penetration, which had been challenging to consistently achieve in other amide series. Efforts to mitigate high clearance, aided by metabolic softspot analysis, were unsuccessful and precluded this series from further consideration as a preclinical candidate. In the course of this study, we found that potassium tetrafluoroborate salts could be engaged in a tosyl hydrazone reductive cross coupling reaction, a previously unreported transformation, which expands the synthetic utility of the methodology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Novel synthesis on poly (vinyl alcohol): characterization, complexation a biological activity

    International Nuclear Information System (INIS)

    El-Sawy, N.M.; Elassar, A.Z.; Al-Fulaij, O.

    2002-01-01

    Poly(vinyl alcohol), PVA, readily condensed with phenyl hydrazine and malononitrile in basic medium to give the hydrazone and pyran derivatives, respectively. PVA reacted with chloroacetonitrile, biuet and thiophene carbonyl chloride to give modified polymeric materials. While addition of PVA to acrylonitrile and phenyl isothiocyanate gives the ether and thiocarbamate ester derivatives, respectively. Hydroxylamine hydrochloride reacted with the modified, carbonitrile containing, polymer to give the amidoxime derivative. The amidoximated products of PVA and carbamate ester of polymeric material were complexed with CUCL2 solution. The complex materials were confirmed by using UV and ESDS measurements. The morphology of PVA and complex with CUII was observed by SEM. Biological activity of some of the prepared compounds was investigated toward bacteria and fungi

  16. pH and temperature dual-sensitive liposome gel based on novel cleavable mPEG-Hz-CHEMS polymeric vaginal delivery system

    Directory of Open Access Journals (Sweden)

    Chen D

    2012-05-01

    Full Text Available Daquan Chen,1,2 Kaoxiang Sun,1,2 Hongjie Mu,1 Mingtan Tang,3 Rongcai Liang,1,2 Aiping Wang,1,2 Shasha Zhou,1 Haijun Sun,1 Feng Zhao,1 Jianwen Yao,1 Wanhui Liu1,21School of Pharmacy, Yantai University, 2State Key Laboratory of Longacting and Targeting Drug Delivery Systems, Yantai, 3School of Pharmaceutical Sciences, Shandong University, Jinan, People's Republic of ChinaBackground: In this study, a pH and temperature dual-sensitive liposome gel based on a novel cleavable hydrazone-based pH-sensitive methoxy polyethylene glycol 2000-hydrazone-cholesteryl hemisuccinate (mPEG-Hz-CHEMS polymer was used for vaginal administration.Methods: The pH-sensitive, cleavable mPEG-Hz-CHEMS was designed as a modified pH-sensitive liposome that would selectively degrade under locally acidic vaginal conditions. The novel pH-sensitive liposome was engineered to form a thermogel at body temperature and to degrade in an acidic environment.Results: A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The dual-sensitive liposome gel with a sol-gel transition at body temperature was degraded in a pH-dependent manner, and was stable for a long period of time at neutral and basic pH, but cleavable under acidic conditions (pH 5.0. Arctigenin encapsulated in a dual-sensitive liposome gel was more stable and less toxic than arctigenin loaded into pH-sensitive liposomes. In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0.Conclusion: This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery.Keywords: mPEG-Hz-CHEMS polymer, pH-sensitive liposomes, thermosensitive

  17. Spectrophotometric methods for the determination of benazepril hydrochloride in its single and multi-component dosage forms.

    Science.gov (United States)

    El-Yazbi, F A; Abdine, H H; Shaalan, R A

    1999-06-01

    Three sensitive and accurate methods are presented for the determination of benazepril in its dosage forms. The first method uses derivative spectrophotometry to resolve the interference due to formulation matrix. The second method depends on the color formed by the reaction of the drug with bromocresol green (BCG). The third one utilizes the reaction of benazepril, after alkaline hydrolysis, with 3-methylbenzothialozone (MBTH) hydrazone where the produced color is measured at 593 nm. The latter method was extended to develop a stability-indicating method for this drug. Moreover, the derivative method was applied for the determination of benazepril in its combination with hydrochlorothiazide. The proposed methods were applied for the analysis of benazepril in the pure form and in tablets. The coefficient of variation was less than 2%.

  18. ORGANOMETALLIC IRON(II) COMPLEXES CONTAINING P-SUBSTITUTED ACETOPHENONE-ARYLHYDRAZONE LIGANDS

    OpenAIRE

    Manzur, Carolina; Millán, Lorena; Figueroa, Walter; Hamon, Jean-René; Mata, Jose A.; Carrillo, David

    2002-01-01

    A series of twelve new organometallic acetophenone-hydrazone complexes of general formula [(h 5-Cp)Fe(h 6-o-RC6H4)-NHN=CMe-C6H4-p-R’]+PF6- (Cp= C5H5; R,R’=H,Me, [5]+PF6-; H,MeO, [6]+PF6-; H,NMe2, [7]+PF6-; Me,Me, [8]+PF6-; Me,MeO, [9]+PF6-; Me,NMe2, [10]+PF6-; MeO,Me, [11]+PF6-; MeO,MeO, [12]+PF6-; MeO,NMe2, [13]+PF6-; Cl,Me, [14]+PF6-; Cl,MeO, [15]+PF6-; Cl,NMe2, [16]+PF6-) has been prepared by reaction between their corresponding organometallic hydrazine precursors [(h 5-Cp)Fe(h 6-o-RC6H4)-...

  19. Irreversible blockade of the high and low affinity (3H) naloxone binding sites by C-6 derivatives of morphinane-6-ones

    International Nuclear Information System (INIS)

    Krizsan, D.; Varga, E.; Benyhe, S.; Szucs, M.; Borsodi, A.; Hosztafi, S.

    1991-01-01

    C-6 derivatives-hydrazones, phenylhydrazones, dinitrophenylhydrazones, oximes and semicarbazones - of morphinane-6-ones were synthesized and their binding characteristics were studied on rat brain membranes. The dihydromorphinone and oxymorphone derivatives compete for the ( 3 H)naloxone binding sites with high affinity, while the dihydrocodeinone and oxycodone derivatives are less potent. The affinity of the new compounds is decreased for the delta sites as compared to the parent ligands. The ligands bearing bulky substituents also bind with low affinity to the kappa sites. The modification decreased the Na + -index of compounds indicating their mixed agonist-antagonist character. The dihydromorphinone derivatives are all capable to block irreversibly the high affinity binding site of ( 3 H)naloxone, whereas the dihydrocodeinone derivatives block irreversibly the low affinity site. A possible mechanism for the inhibition is suggested

  20. Cytochrome P450-dependent N-hydroxylation of an aminoguanidine (amidinohydrazone) and microsomal retroreduction of the N-hydroxylated product.

    Science.gov (United States)

    Clement, B; Schultze-Mosgau, M H; Richter, P H; Besch, A

    1994-07-01

    1. The first example of a P450-dependent N-hydroxylation of an aminoguanidine (amidinohydrazone) is reported for 2-amino-5-chlorobenzophenone amidinohydrazone 1 (G 256) as substrate. 2. The N-hydroxylated metabolite 2 (2-amino-5-chlorobenzophenone N-hydroxyamidinohydrazone NOH-G256) and a further metabolite of 1, the phenol 3, were identified by tlc and ms analysis. 3. The microsomal reduction of an N-hydroxyaminoguanidine (N-hydroxy-amidino-hydrazone) was also demonstrated for the transformation of 2 to 1. 4. Both the N-hydroxylation of the aminoguanidine and the retroreduction of the N-hydroxyaminoguanidine were characterized by quantitative hplc analysis. 5. The conversion of the aminoguanidine 1 to N-hydroxyaminoguanidine 2 may be considered as an analogue of the physiological N-hydroxylation of arginine to N-hydroxyarginine by NO synthases.

  1. The reaction of some dicarbonyl sugars with aminoguanidine.

    Science.gov (United States)

    Hirsch, J; Petrakova, E; Feather, M S

    1992-07-20

    The reactions of aminoguanidine (guanylhydrazine) with 3-deoxy-D-erythro-hexos-2-ulose (1a), 3-deoxy-D-glycero-pentose-2-ulose (1b), D-erythro-hexos-2-ulose (1c), and D-glycero-pentose-2-ulose (1d) were examined at 37 degrees at a solution pH of 7.0 (phosphate buffer). For 1a and 1b, two major products were observed and shown respectively to be the 5- and 6-substituted 3-amino-1,2,4-triazine derivatives. The ratios of the products were independent of the amount of aminoguanidine present or the order of mixing the reagents prior to the experiments. For 1c and 1d, only the 5-substituted triazine derivatives were formed. No evidence for hydrazone or bishydrazone formation was observed.

  2. Synthesis, structure and solvatochromic properties of some novel 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridone dyes

    Directory of Open Access Journals (Sweden)

    Alimmari Adel

    2012-07-01

    Full Text Available Abstract Background A series of some novel arylazo pyridone dyes was synthesized from the corresponding diazonium salt and 6-hydroxy-4-phenyl-3-cyano-2-pyridone using a classical reaction for the synthesis of the azo compounds. Results The structure of the dyes was confirmed by UV-vis, FT-IR, 1H NMR and 13C NMR spectroscopic techniques and elemental analysis. The solvatochromic behavior of the dyes was evaluated with respect to their visible absorption properties in various solvents. Conclusions The azo-hydrazone tautomeric equilibration was found to depend on the substituents as well as on the solvent. The geometry data of the investigated dyes were obtained using DFT quantum-chemical calculations. The obtained calculational results are in very good agreement with the experimental data.

  3. Synthesis and X-ray structure of the dysprosium(III complex derived from the ligand 5-chloro-1,3-diformyl-2-hydroxybenzene-bis-(2-hydroxybenzoylhydrazone [Dy2(C22H16ClN4O53](SCN 3.(H2O.(CH3OH

    Directory of Open Access Journals (Sweden)

    Aliou H. Barry

    2003-12-01

    Full Text Available The title compound [Dy2(C22H16ClN4O53](SCN 3.(H2O.(CH3OH has been synthesized and its crystal structure determined by single X-ray diffraction at room temperature. The two nine coordinated Dy(III are bound to three macromolecules ligand through the phenolic oxygens of the p-chlorophenol moieties, the nitrogen atoms and the carbonyl functions of the hydrazonic moieties. The phenolic oxygen atoms of the 2-hydroxybenzoyl groups are not bonded to the metal ions. In the bases of the coordination polyhedra the six Dy-N bonds are in the range 2.563(13-2.656(13 Å and the twelve Dy-O bonds are in the range 2.281(10-2.406(10 Å.

  4. Synthesis and in vitro study of benzofuran hydrazone derivatives as novel alpha-amylase inhibitor.

    Science.gov (United States)

    Taha, Muhammad; Shah, Syed Adnan Ali; Imran, Syahrul; Afifi, Muhammad; Chigurupati, Sridevi; Selvaraj, Manikandan; Rahim, Fazal; Ullah, Hayat; Zaman, Khalid; Vijayabalan, Shantini

    2017-12-01

    The α-amylase acts as attractive target to treat type-2 diabetes mellitus. Therefore in discovering a small molecule as α-amylase inhibitor, we have synthesized benzofuran carbohydrazide analogs (1-25), characterized through different spectroscopic techniques such as 1 HNMR and EI-MS. All screened analog shows good α-amylase inhibitory potentials with IC 50 value ranging between 1.078±0.19 and 2.926±0.05µM when compared with acarbose having IC 50 =0.62±0.22µM. Only nine analogs among the series such as analogs 3, 5, 7, 8, 10, 12, 21, 23 and 24 exhibit good inhibitory potential with IC 50 values 1.644±0.128, 1.078±0.19, 1.245±0.25, 1.843±0.19, 1.350±0.24, 1.629±0.015, 1.353±0.232, 1.359±0.119 and 1.488±0.07µM when compare with standard drug acarbose. All other analogs showed good to moderate α-amylase inhibitory potentials. The SAR study was conducted on the basis of substituent difference at the phenyl ring. The binding interaction between analogs and active site of enzyme was confirmed by docking studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Synthesis and spectral characterization of hydrazone derivative of furfural using experimental and DFT methods.

    Science.gov (United States)

    Babu, N Ramesh; Subashchandrabose, S; Ali Padusha, M Syed; Saleem, H; Erdoğdu, Y

    2014-01-01

    The Spectral Characterization of (E)-1-(Furan-2-yl) methylene)-2-(1-phenylvinyl) hydrazine (FMPVH) were carried out by using FT-IR, FT-Raman and UV-Vis., Spectrometry. The B3LYP/6-311++G(d,p) level of optimization has been performed on the title compound. The conformational analysis was performed for this molecule, in which the cis and trans conformers were studied for spectral characterization. The recorded spectral results were compared with calculated results. The optimized bond parameters of FMPVH molecule was compared with X-ray diffraction data of related molecule. To study the intra-molecular charge transfers within the molecule the Lewis (bonding) and Non-Lewis (anti-bonding) structural calculation was performed. The Non-linear optical behavior of the title compound was measured using first order hyperpolarizability calculation. The atomic charges were calculated and analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Metal-ion induced amplification of three receptors from dynamic combinatorial libraries of peptide-hydrazones

    NARCIS (Netherlands)

    Roberts, Sarah L.; Furlan, Ricardo L.E.; Otto, Sijbren; Sanders, Jeremy K.M.

    2003-01-01

    Three building blocks of general structure (MeO)2CH–aromatic linker–Pro–amino acid–NHNH2 have been prepared and tested in acid-catalysed dynamic combinatorial libraries. Exposure of these libraries to LiI and NaI led to the amplification of three macrocyclic pseudopeptide receptors. The receptors

  7. Synthesis and luminescence properties of novel 4-(N-carbazole methyl) benzoyl hydrazone Schiff bases

    International Nuclear Information System (INIS)

    Guo Dongcai; Wu Panliang; Tan Hui; Xia Long; Zhou Wenhui

    2011-01-01

    4-(N-carbazole methyl) benzoyl hydrazine was synthesized on the basis of carbazole, and then nine novel carbazolyl acylhydrazone Schiff bases were synthesized by the condensation reaction between 4-(N-carbazole methyl) benzoyl hydrazine and the substituted benzaldehydes. The relationships between the substituted group types and the UV fluorescence spectral properties, as well as the fluorescence quantum yields of the title Schiff bases were also investigated. The results show that the introduction of both the donating and accepting electron groups causes various grade redshifts of the fluorescence characteristic emission peak of the title Schiff bases to occur.The fluorescence quantum yields of the title Schiff bases with the donating group are increased, and the highest fluorescence quantum yield is up to 0.703. - Highlights: → Nine novel Schiff bases have been designed and synthesized. → Introduction of the donating electron groups causes various grade red shifts of the fluorescence characteristic emission peak and the UV characteristic absorption peak of the synthesized Schiff bases. → Introduction of the donating electron groups causes the fluorescence quantum yields to be increased considerably. →Introduction of the accepting electron groups causes the fluorescence intensity and quantum yield of the synthesized Schiff bases to be reduced. → Fluorescence quantum yield of o-hydroxyl-substituted Schiff base is up to 0.703; this Schiff base is expected to be used as hole transport optical material.

  8. Synthesis, photoluminescence and forensic applications of blue light emitting azomethine-zinc (II complexes of bis(salicylidenecyclohexyl-1,2-diamino based organic ligands

    Directory of Open Access Journals (Sweden)

    M. Srinivas

    2017-06-01

    Full Text Available Various azomethine-zinc(II complexes (3a-c of bis(salicylidenecyclohexyl-1,2-diamino organic ligands were synthesized by one pot reaction of salicylaldehydes/2-hydroxy-1-naphthaldehyde (2 eq, cyclohexyl-1,2-diamine (1 eq and zinc acetate (1 eq in methanol solvent at reflux temperature. The synthesized complexes were characterized by FTIR, 1H NMR, and SEM. Their photophysical properties such as Photoluminescence (PL and Diffused Reflectance Spectra (DRS were studied. PL studies revealed that the emission peaks of the complexes in both solution and solid states appeared to occur at 395–600 nm and emitted blue light. The band gap energies determined from DRS were 2.98 eV (3a, 2.91 eV (3b, and 2.73 eV (3c. Based on these results, we ascertain that these Zn(II complexes can serve as a suitable non-dopant blue light emitting compound for flat panel display applications. Latent fingerprint detection study indicated that the powder compounds show good adhesion and finger ridge details without background staining. The demonstrated method can be applied to detect fingerprints on all types of smooth surfaces.

  9. Methyl 6-methoxycarbonylmethyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate

    Directory of Open Access Journals (Sweden)

    Lucia Veizerová

    2008-09-01

    Full Text Available The title compound, C15H16N2O5, belongs to the class of monastrol-type anti-cancer agents and was selected for crystal structure determination in order to determine the conformational details needed for subsequent structure–activity relationship studies. The central tetrahydropyrimidine ring has a flat-envelope conformation. The 4-phenyl group occupies a pseudo-axial position and is inclined at an angle of ca 90° to the mean plane of the heterocyclic ring. Of the two methyl ester groups, one (in the 5-position is in a coplanar and the other (in the 6-position in a perpendicular orientation with respect to the heterocyclic plane. The coplanar 5-ester group has its carbonyl bond oriented cis with respect to the pyrimidine C=C double bond. By comparison of the structural results for the present compound with those determined previously for its diethyl analogue, we have identified the molecular factors which control the dual course of the Biginelli reaction with salicylaldehyde. The crystal structure is dominated by two hydrogen bonds which link the molecules into chains of dimers.

  10. An efficient ab initio DFT and PCM assessment of the potentiometric selectivity of a salophen type Schiff base.

    Science.gov (United States)

    Demir, Serkan; Yilmaz, Hakan; Dilimulati, Maowulidan; Andaç, Müberra

    2014-06-01

    As a neutral carrier component for the preparation of a potentiometric membrane sensor, the affinity and selectivity of the salophen type Schiff base ligand obtained by 1:2 condensation of 2.3-diaminopyridine with salicylaldehyde toward a series of common cations has been fully examined by DFT/B3LYP and integral equation formalism polarizable continum model (IEF-PCM or only given with PCM as default input in the computations) in combination with the experimental data. Both the potentiometric measurements and DFT calculations have exhibited that the ionophore shows appreciable selectivity for Cu(2+) ion over other cations. Four different approaches where the last three are the modified version of each other have been evaluated and compared with potentiometric data. Based upon the results of comparison among the approaches suggested to verify the selective behavior of ionophore toward Cu(2+), PCM implemented approach having a whole computational groundwork has given well-matched results with the observed data and with the method augmented with experimental hydration energies. The foremost interferences were detected by determining potentiometric selectivity coefficients for each metal ion relative to Cu(2+) and compared to the results obtained by the DFT calculations.

  11. Realizing Serine/Threonine Ligation: Scope and Limitations and Mechanistic Implication Thereof

    Directory of Open Access Journals (Sweden)

    Clarence T. T. Wong

    2014-05-01

    Full Text Available Serine/Threonine ligation (STL has emerged as an alternative tool for protein chemical synthesis, bioconjugations as well as macrocyclization of peptides of various sizes. Owning to the high abundance of Ser/Thr residues in natural peptides and proteins, STL is expected to find a wide range of applications in chemical biology research. Herein, we have fully investigated the compatibility of the serine/threonine ligation strategy for X-Ser/Thr ligation sites, where X is any of the 20 naturally occurring amino acids. Our studies have shown that 17 amino acids are suitable for ligation, while Asp, Glu, and Lys are not compatible. Among the working 17 C-terminal amino acids, the retarded reaction resulted from the bulky β-branched amino acid (Thr, Val and Ile is not seen under the current ligation condition. We have also investigated the chemoselectivity involving the amino group of the internal lysine which may compete with the N-terminal Ser/Thr for reaction with the C-terminal salicylaldehyde (SAL ester aldehyde group. The result suggested that the free internal amino group does not adversely slow down the ligation rate.

  12. pH dependent fluorescence switching in salicylideneaniline: ‘off–on–off’ operation controlled by surfactant micelles

    Energy Technology Data Exchange (ETDEWEB)

    Das, Diganta Kumar, E-mail: digkdas@yahoo.com; Dutta, Kaku

    2014-01-15

    Salaniline, a condensation product of salicylaldehyde and aniline, shows “off–on” fluorescent behaviour with pH in 1:1 (v/v) CH{sub 3}CN:H{sub 2}O and when 3% (w/v) anionic sodium dodecylsulphate (SDS) surfactant is present. The fluorescent switch behaviour of salaniline is forced to “off–on–off” type by 3% (w/v) neutral triton X-100 (TX-100) and 3% (w/v) cationic cetyltrimethylammonium bromide (CTAB) surfactant. The fluorescent “on” window is observed in the pH range 8.0–12.5 for TX-100 and 7.0–11.0 for CTAB. Different charge nature of the surfactants affects the protonation/deprotonation behaviour of salaniline differently, hence the photoinduced electron transfer (PET) processes and the fluorescent switch behaviour. -- Highlights: • Salicylideneaniline act as pH dependent “off–on” fluorescent switch in 1:1 (v/v) CH{sub 3}CN:H{sub 2}O. • In surfactant micelles TX-100 (neutral) and CTAB (positive) make the fluorescent switch “off–on–off” type while in. • In surfactant micelle SDS (negative) the pH dependent fluorescent switch is “off–on” type.

  13. New ruthenium(II) carbonyl complexes bearing disulfide Schiff base ligands and their applications as catalyst for some organic transformations

    Science.gov (United States)

    Prakash, Govindan; Viswanathamurthi, Periasamy

    2014-08-01

    Schiff base disulfide ligands (H2L1-6) were synthesized from the condensation of cystamine with salicylaldehyde(H2L1), 5-chlorosalicylaldehyde(H2L2), o-vanillin(H2L3), 2-hydroxyacetophenone(H2L4), 3-methyl-2-hydroxyacetophenone(H2L5), and 2-hydroxy-1-naphthaldehyde(H2L6). H2L1-6 reacts with the ruthenium precursor complex [RuHCl(CO)(PPh3)3] in benzene giving rise to six new ruthenium(II) complexes of general formula [Ru(CO)L1-6]. Characterization of the new complexes was carried out by using elemental and spectral (IR, UV-Vis, NMR (1H and 13C) and Mass) techniques. An octahedral geometry was assigned for all the complexes based on the spectral data obtained. The catalytic efficiency of the new complexes in aldehyde to amide conversion in the presence of NaHCO3, N-alkylation of aniline in the presence of t-BuOK, and transfer hydrogenation of ketones in the presence of iPrOH/KOH reactions were studied. Furthermore, the effect of solvents and catalyst/substrate ratio on the catalytic aldehyde to amide conversion were also discussed.

  14. Bis(formylphenolatocobalt(II-Mediated Alternating Radical Copolymerization of tert-Butyl 2-Trifluoromethylacrylate with Vinyl Acetate

    Directory of Open Access Journals (Sweden)

    Sanjib Banerjee

    2017-12-01

    Full Text Available The organometallic-mediated radical polymerization (OMRP of vinyl acetate (VAc and its OMR copolymerization (OMRcoP with tert-butyl 2-trifluoromethylacrylate (MAF-TBE mediated by Co(SAL2 (SAL = 2-formylphenolato or deprotonated salicylaldehyde produced relatively well-defined PVAc and poly(VAc-alt-MAF-TBE copolymers at moderate temperature (<40 °C in bulk. The resulting alternating copolymer was characterized by 1H-, 13C- and 19F-nuclear magnetic resonance (NMR spectroscopies, and by size exclusion chromatography. The linear first-order kinetic plot, the linear evolutions of the molar mass with total monomer conversion, and the relatively low dispersity (Đ~1.55 of the resulting copolymers suggest that this cobalt complex provides some degree of control over the copolymerization of VAc and MAF-TBE. Compared to the previously investigated cobalt complex OMRP mediators having a fully oxygen-based first coordination sphere, this study emphasizes a few peculiarities of Co(SAL2: a lower ability to trap radical chains as compared to Co(acac2 and the absence of catalytic chain transfer reactions, which dominates polymerizations carried in the presence of 9-oxyphenalenone cobalt derivative.

  15. Synthesis, spectral characterization and structural studies of a novel O, N, O donor semicarbazone and its binuclear copper complex with hydrogen bond stabilized lattice

    Science.gov (United States)

    Layana, S. R.; Saritha, S. R.; Anitha, L.; Sithambaresan, M.; Sudarsanakumar, M. R.; Suma, S.

    2018-04-01

    A novel O,N,O donor salicylaldehyde-N4-phenylsemicarbazone, (H2L) has been synthesized and physicochemically characterized. Detailed structural studies of H2L using single crystal X-ray diffraction technique reveals the existence of intra and inter molecular hydrogen bonding interactions, which provide extra stability to the molecule. We have successfully synthesized a binuclear copper(II) complex, [Cu2(HL)2(NO3)(H2O)2]NO3 with phenoxy bridging between the two copper centers. The complex was characterized by elemental analysis, magnetic susceptibility and conductivity measurements, FT-IR, UV-Visible, mass and EPR spectral methods. The grown crystals of the copper complex were employed for the single crystal X-ray diffraction studies. The complex possesses geometrically different metal centers, in which the ligand coordinates through ketoamide oxygen, azomethine nitrogen and deprotonated phenoxy oxygen. The extensive intermolecular hydrogen bonding interactions of the coordinated and the lattice nitrate groups interconnect the complex units to form a 2D supramolecular assembly. The ESI mass spectrum substantiates the existence of 1:1 complex. The g values obtained from the EPR spectrum in frozen DMF suggest dx2 -y2 ground state for the unpaired electron.

  16. Salen- Zr(IV) complex grafted into amine-tagged MIL-101(Cr) as a robust multifunctional catalyst for biodiesel production and organic transformation reactions

    Science.gov (United States)

    Hassan, Hassan M. A.; Betiha, Mohamed A.; Mohamed, Shaimaa K.; El-Sharkawy, E. A.; Ahmed, Emad A.

    2017-08-01

    The synthesis of metal-organic frameworks (MOFs), porous coordination polymers with functional groups has received immense interest due to the functional groups can offer desirable properties and allow post-synthetic modification. Herein, for the first time, Zr(IV)-Sal Schiff base complex incorporated into amino-functionalized MIL-101(Cr) framework by salicylaldehyde condensing to amino group, and coordinating Zr(IV) ion have been successfully synthesized. The worthiness of the synthesized material as a catalyst has been examined for the esterification of oleic acid (free fatty acid) with methanol producing biodiesel (methyl oleate), Knoveonagel condensation reaction of aldehydes and Friedel-Crafts acylation of anisole. Our findings demonstrated that Salen-Zr(IV) grafted to framework of NH2-MIL-101(Cr) as a solid acid catalyst exhibited distinct catalytic performance for the production of biodiesel by esterification of oleic acid with methanol, Knoveonagel condensation and Friedel-Crafts acylation. These could be attributed to high surface area which allow high distribution of Zr(IV) species lead to a sufficient contact with the reactants species. Furthermore, the catalyst showed excellent recycling efficiency due to the strong interaction between the Zr(IV) ions and chelating groups in the NH2-MIL-101(Cr)-Sal.

  17. Studies of a Diazo Cyclopropanation Strategy for the Total Synthesis of (-)-Lundurine A.

    Science.gov (United States)

    Huang, Hong-Xiu; Jin, Shuai-Jiang; Gong, Jin; Zhang, Dan; Song, Hao; Qin, Yong

    2015-09-14

    The bioactive Kopsia alkaloids lundurines A-D are the only natural products known to contain indolylcyclopropane. Achieving their syntheses can provide important insights into their biogenesis, as well as novel synthetic routes for complex natural products. Asymmetric total synthesis of (-)-lundurine A has previously been achieved through a Simmons-Smith cyclopropanation strategy. Here, the total synthesis of (-)-lundurine A was carried out using a metal-catalyzed diazo cyclopropanation strategy. In order to avoid a carbene CH insertion side reaction during cyclopropanation of α-diazo- carboxylates or cyanides, a one-pot, copper-catalyzed Bamford-Stevens diazotization/diazo decomposition/cyclopropanation cascade was developed, involving hydrazone. This approach simultaneously generates the C/D/E ring system and the two chiral quaternary centers at C2 and C7. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Electrochemical Studies for Cation Recognition with Diazo-Coupled Calix[4]arenes

    Directory of Open Access Journals (Sweden)

    Bongsu Kim

    2015-01-01

    Full Text Available The electrochemical properties of diazophenylcalix[4]arenes bearing ortho-carboxyl group (o-CAC and ortho-ester group (o-EAC, respectively, in the presence of various metal ions were investigated by voltammetry in CH3CN. o-CAC and o-EAC showed voltammetric changes toward divalent metal ions and no significant changes with monovalent alkali metal ions. However, o-CAC preferentially binds with alkaline earth and transition metal ions, whereas no significant changes in voltammetric signals are observed in o-EAC with alkaline earth metal ions. o-EAC only binds with other transition metal ions. This can be explained on metal ion complexation-induced release of proton from the azophenol to the quinone-hydrazone tautomer followed by internal complexation of the metal ion with aid of nitrogen atoms and ortho-carbonyl groups in the diazophenylazocalix[4]arenes.

  19. Metallomics for Alzheimer's disease treatment: Use of new generation of chelators combining metal-cation binding and transport properties.

    Science.gov (United States)

    D'Acunto, Cosimo Walter; Kaplánek, Robert; Gbelcová, Helena; Kejík, Zdeněk; Bříza, Tomáš; Vasina, Liudmila; Havlík, Martin; Ruml, Tomáš; Král, Vladimír

    2018-04-25

    Alzheimer's disease (AD) is a progressive neurodegenerative disorder affecting tens of million people. Currently marketed drugs have limited therapeutic efficacy and only slowing down the neurodegenerative process. Interestingly, it has been suggested that biometal cations in the amyloid beta (Aβ) aggregate deposits contribute to neurotoxicity and degenerative changes in AD. Thus, chelation therapy could represent novel mode of therapeutic intervention. Here we describe the features of chelators with therapeutically relevant mechanism of action. We have found that the tested compounds effectively reduce the toxicity of exogenous Aβ and suppress its endogenous production as well as decrease oxidative stress. Cholyl hydrazones were found to be the most active compounds. In summary, our data show that cation complexation, together with improving transport efficacy may represent basis for eventual treatment strategy in AD. Copyright © 2018. Published by Elsevier Masson SAS.

  20. Self-assembled nanocomplexes of anionic pullulan and polyallylamine for DNA and pH-sensitive intracellular drug delivery

    Science.gov (United States)

    Vora, Lalit; Tyagi, Monica; Patel, Ketan; Gupta, Sanjay; Vavia, Pradeep

    2014-12-01

    The amalgamation of chemotherapy and gene therapy is promising treatment option for cancer. In this study, novel biocompatible self-assembled nanocomplexes (NCs) between carboxylmethylated pullulan t335 (CMP) with polyallylamine (CMP-PAA NCs) were developed for plasmid DNA (pDNA) and pH-sensitive doxorubicin (DOX) delivery. DOX was conjugated to CMP (DOX-CMP) via hydrazone and confirmed by FTIR and 1H-NMR. In vitro release studies of pH-sensitive DOX-CMP conjugate showed 23 and 85 % release after 48 h at pH 7.4 (physiological pH) and pH 5 (intracellular/tumoral pH), respectively. The CMP-PAA NCs or DOX-CMP-PAA NCs self-assembled into a nanosized (successful cellular uptake of DOX-CMP-PAA NCs in HEK293 cells. Thus, NCs hold great potential for targeted pDNA and pH-sensitive intratumoral drug delivery.

  1. Synthesis and Antimicrobial Activity of N-[2-(aryl/substituted aryl)-4-oxo-1,3-thiazolidin-3-yl]pyridine-4-carboxamide

    International Nuclear Information System (INIS)

    Thomas, Asha B.; Nanda, Rabindra K.; Kothapalli, Lata P.; Deshpande, Avinash D.

    2011-01-01

    A series of isonicotinyl hydrazones and their 4-thiazolidinones have been synthesized by condensation of isonicotinic acid hydrazide with various aromatic aldehydes to yield Schiff's bases, followed by the cyclocondensation of Schiff's bases with 2-mercaptoacetic acid to yield their 4-thiazolidinones. The synthesized compounds have been characterized by their elemental, analytical and spectral studies. All these compounds were evaluated for their in vitro antimicrobial activity against a spectrum of non-resistant and resistant microbial organisms. These studies proved that compounds 5e,i against B. subtilis; 5e,f,h against B. anthracis; 5g,i against S. aureus showed good activity at lower concentrations. Compounds 5d-5i displayed significant activity against resistant strain of K. pneumonia with minimum inhibitory potency in the concentration range of 2-16 ug/ml

  2. Synthesis and characterization of transition metal complexes derived from some biologically active furoic acid hydrazones

    Directory of Open Access Journals (Sweden)

    P. Venkateswar Rao

    2007-04-01

    Full Text Available Two new physiologically active ligands, N’-2-[(E-1-hydroxy-4-methyl-2-oxo-2H-8-chromenyl ethylidene-2-furan carbohydrazide (HMCFCH and N’-2-[(Z-1-(4-hydroxy-6-methyl-2-oxo-2H-pyranyl ethylidene]-furan carbohydrazide (HMPFCH and their VO(II, Mn(II, Fe(II, Co(II, Ni(II and Cu(II complexes have been prepared. The ligands and the metal complexes have been characterized by elemental analyses, electrical conductance, magnetic susceptibility measurements, UV-Vis, IR, and ESR spectroscopic data. Basing on the above data, Fe(II and Co(II complexes of HMCFCH and HMPFCH have been assigned a dimeric octahedral geometry. VO(II complexes of HMCFCH and HMPFCH have been assigned sulfate bridged dimeric square pyramidal geometry. Mn(II complex of HMCFCH has been assigned a dimeric octahedral geometry, where as Mn(II complex of HMPFCH has been ascribed to monomeric octahedral geometry. Cu(II and Ni(II complexes of HMCFCH have been ascribed to a polymeric structure. Ni(II complex of HMPFCH has been assigned a dimeric square planar geometry. Cu(II complex of HMPFCH has been proposed an octahedral geometry. The ligands and their metal chelates were screened against S. aureus and P. aeruginosa. The ligands and the metal complexes have been found to be active against these microorganisms. The ligands show more activity than the metal complexes.

  3. Controlled Folding, Motional, and Constitutional Dynamic Processes of Polyheterocyclic Molecular Strands.

    Science.gov (United States)

    Barboiu, Mihail; Stadler, Adrian-Mihail; Lehn, Jean-Marie

    2016-03-18

    General design principles have been developed for the control of the structural features of polyheterocyclic strands and their effector-modulated shape changes. Induced defined molecular motions permit designed enforcement of helical as well as linear molecular shapes. The ability of such molecular strands to bind metal cations allows the generation of coiling/uncoiling processes between helically folded and extended linear states. Large molecular motions are produced on coordination of metal ions, which may be made reversible by competition with an ancillary complexing agent and fueled by sequential acid/base neutralization energy. The introduction of hydrazone units into the strands confers upon them constitutional dynamics, whereby interconversion between different strand compositions is achieved through component exchange. These features have relevance for nanomechanical devices. We present a morphological and functional analysis of such systems developed in our laboratories. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Refuse derived bio-organics and immobilized soybean peroxidase for green chemical technology

    DEFF Research Database (Denmark)

    Magnacca, Giuliana; Laurenti, Enzo; Vigna, Erika

    2012-01-01

    in the reaction of hydrogen peroxide, 3-(dimethylamino)benzoic acid (DMAB) and 3-methyl-2-benzothiazolinone hydrazone (MBTH), by comparison with the same reaction performed with native SBP in solution. The reaction performed in the presence of immobilized SBP was slower than that catalyzed by native SBP...... Peroxidase (SBP). Compared to the pristine powder, the monolith exhibited lower specific surface area (about 30% less), total pore volume and pore size (of about 200 Å of width), and bond less SBP under the same experimental conditions. The immobilized SBP products were tested for their catalytic activity...... in solution. However, in spite of its lower SBP content, monolith immobilized SBP (M-SBP) was found kinetically more active than the powder immobilized SBP (P-SBP). Also, M-SBP allowed to achieve the same reagents conversion as native SBP (95% of reagent conversion), although in longer time, whereas...

  5. 5-Nitroimidazole Derivatives and their Antimicrobial Activity

    International Nuclear Information System (INIS)

    Khan, K.M.; Salar, U.; Yousuf, S.; Naz, F.

    2016-01-01

    5-Nitroimidazole derivatives 2-8 were synthesized from secnidazole. The syntheses were accomplished in two steps which start from the oxidation of secnidazole to the secnidazolone 1. Secnidazolone 1 was converted into its hydrazone derivative 2-8 by treating with different substituted acid hydrazide. Compounds 2-8 were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria, compounds 3 and 4 showed the significant activity against Staphylococcus epidermidis, however, compound 2 showed good inhibitions against Corynebacterium diphtheria when compared with the standard. Compound 3 showed good inhibitory potential against tested Gram-negative bacterial strains i.e. Enterobacter aerogene, Escherichia coli, Salmonella typhi, Salmonella paratyphi A, Shigella flexeneri and Vibrio choleriae. All synthetic derivatives were also tested against eight fungal stains, however, they were weekly active against Aspergillus flavus and Candida albican. The synthesized compounds were characterized by different spectroscopy techniques. (author)

  6. Iminoboronate Formation Leads to Fast and Reversible Conjugation Chemistry of α-Nucleophiles at Neutral pH.

    Science.gov (United States)

    Bandyopadhyay, Anupam; Gao, Jianmin

    2015-10-12

    Bioorthogonal reactions that are fast and reversible under physiological conditions are in high demand for biological applications. Herein, it is shown that an ortho boronic acid substituent makes aryl ketones rapidly conjugate with α-nucleophiles at neutral pH. Specifically, 2-acetylphenylboronic acid and derivatives were found to conjugate with phenylhydrazine with rate constants of 10(2) to 10(3) M(-1) s(-1) , comparable to the fastest bioorthogonal conjugations known to date. (11) B NMR analysis revealed the varied extent of iminoboronate formation of the conjugates, in which the imine nitrogen forms a dative bond with boron. The iminoboronate formation activates the imines for hydrolysis and exchange, rendering these oxime/hydrazone conjugations reversible and dynamic under physiological conditions. The fast and dynamic nature of the iminoboronate chemistry should find wide applications in biology. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Chemical speciation and equilibria of some nucleic acid compounds and their iron(III) complexes

    Science.gov (United States)

    Masoud, Mamdouh S.; Abd El-Kaway, Marwa Y.; Hindawy, Ahmed M.; Soayed, Amina A.

    The pH effect on electronic absorption spectra of some biologically active nucleic acid constituents have been studied at room temperature and the mechanism of ionization was explained. These compounds are of two categories (pyrimidines: [barbital; 5,5'-diethyl-barbituric acid], [SBA; 4,6-dihydroxy-2-mercapto-pyrimidin], [NBA; 5-nitro-2,4,6(1H,3H,5H)-pyrimidine trione] and [TU; 2,3-dihydro-2-thioxo-pyrimidin-4(1H)-one]) and (purines: [adenine; 6-amino purine], its [Schiff bases derived from adenine-acetylacetone; (Z)-4-(7H-purin-6-ylimino)pentan-2-one) and adenine-salicylaldehyde; 2-((7H-purin-6-ylimino) methyl) phenol] and its [Azo derived from adenine-resorcinol; 4-((7H-purin-6-yl)-diazenyl) benzene-1,3-diol]. The phenomena of tautomerization assigned different tautomers. Different spectrophotometric methods are applied to evaluate the pK's values that explained with their molecular structures. The interaction of Fe3+ with some selected pyrimidines (barbital, NBA and SBA) was explained using familiar six spectrophotometric methods. The data typified the existence of different absorbing species with the different stoichiometries 1:1, 1:2, 1:3 and 2:3. The stability constant of the complexes was computed. More approach was deduced to assign the existence of different species applying the distribution diagrams.

  8. Influence of irradiation time and solution concentration on the photochemical degradation of EDDHA/Fe3+: effect of its photodecomposition products on soybean growth.

    Science.gov (United States)

    Hernández-Apaolaza, Lourdes; Lucena, Juan J

    2011-08-30

    Ethylenediamine-N, N'-bis(2-hydroxyphenylacetic acid (EDDHA) is one of the most efficient iron-chelating agents employed to relieve iron chlorosis in plants. It has been well known for decades that this compound is photosensitive, but in spite of this fact its degradation pathways are virtually unknown. The aim of this work was to evaluate how the length of sunlight exposure and the concentration of irradiated EDDHA/Fe(3+) solutions influence the photostability of the chelate at constant pH. Moreover, the possible toxic effect of the chelate photodegradation products, elsewhere proposed, on soybean growth has been tested. The photodecomposition of the chelate increased as the time of sunlight exposure increased, and resulted in a partial decomposition of the organic ligand. Moreover, EDDHA/Fe(3+) photodecomposition was highly correlated with the concentration of solution exposed. Plants did not present differences in recovery from chlorosis among treatments with and without decomposition products. EDDHA/Fe(3+) undergoes photodegradation, like other aminopolycarboxylic acids, being more degraded as solution concentration decreases and exposure time increases. The photodecomposition products salicylic acid, salicylaldehide and Salicylaldehyde ethylenediamine diimine tested did not have negative effects on soybean growth, at least in the short-term hydroponic experimental design tested. Copyright © 2011 Society of Chemical Industry.

  9. Synthesis, crystal structure and bioactivity of manganese complexes with asymmetric chiral Schiff base

    Science.gov (United States)

    Zhang, Enfeng; Wei, Yi; Huang, Fuping; Yu, Qing; Bian, Hedong; Liang, Hong; Lei, Fuhou

    2018-03-01

    A couple of chiral unsymmtrical Schiff base ligands, (1R,2R) (-)chxn (salH) (naftalH) and (1S,2S) (-)chxn (salH) (naftalH) had been synthesized by the condensation of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with two isomers of (1R,2R)-trans-1,2-cyclohexanediamin and (1S,2S)-trans-1,2-cyclohexanediamin, respectively. At the same time, two manganese complexes have been synthesized and fully characterized by FT-IR spectrum, elemental analyses, single crystal X-ray diffraction. The interaction of the two Mn (III) complexes with bovine serum albumin (BSA) was investigated by spectroscopic techniques. The result reveals that the complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism. The binding constant and binding mode has been determined. The secondary structure and the amino acid residues microenvironment of BSA change in the presence of these complexes. SOD-like activity and ABTS free radical scavenging ability were also studied. The antioxidant capacity of the compounds showed that the complexes and their corresponding BSA adducts showed some SOD activity. The results of ABTS free radical scavenging showed that the activity of the BSA adduct was more obvious than that of the complex.

  10. Copper(II) Thiosemicarbazone Complexes and Their Proligands upon UVA Irradiation: An EPR and Spectrophotometric Steady-State Study.

    Science.gov (United States)

    Hricovíni, Michal; Mazúr, Milan; Sîrbu, Angela; Palamarciuc, Oleg; Arion, Vladimir B; Brezová, Vlasta

    2018-03-21

    X- and Q-band electron paramagnetic resonance (EPR) spectroscopy was used to characterize polycrystalline Cu(II) complexes that contained sodium 5-sulfonate salicylaldehyde thiosemicarbazones possessing a hydrogen, methyl, ethyl, or phenyl substituent at the terminal nitrogen. The ability of thiosemicarbazone proligands to generate superoxide radical anions and hydroxyl radicals upon their exposure to UVA irradiation in aerated aqueous solutions was evidenced by the EPR spin trapping technique. The UVA irradiation of proligands in neutral or alkaline solutions and dimethylsulfoxide (DMSO) caused a significant decrease in the absorption bands of aldimine and phenolic chromophores. Mixing of proligand solutions with the equimolar amount of copper(II) ions resulted in the formation of 1:1 Cu(II)-to-ligand complex, with the EPR and UV-Vis spectra fully compatible with those obtained for the dissolved Cu(II) thiosemicarbazone complexes. The formation of the complexes fully inhibited the photoinduced generation of reactive oxygen species, and only subtle changes were found in the electronic absorption spectra of the complexes in aqueous and DMSO solutions upon UVA steady-state irradiation. The dark redox activity of copper(II) complexes and proligand/Cu(II) aqueous solutions towards hydrogen peroxide which resulted in the generation of hydroxyl radicals, was confirmed by spin trapping experiments.

  11. A new family of NxOy pyridine-containing macrocycles: synthesis and characterization of their Y(III), Ln(III), Zn(II), and Cd(II) coordination compounds

    International Nuclear Information System (INIS)

    Lodeiro, C.; Bastida, R.; Bertolo, E.; Rodriguez, A.

    2004-01-01

    Reaction between 2,6-bis(2-formylphenoxymethyl)pyridine and N,N-bis(3-aminopropyl)methylamine or tris(2-aminoethyl)amine has been used as the starting point for the synthesis of seven oxa-aza macrocyclic ligands, five of them never reported previously. They all feature different pendant arms, which provide a wide range of coordination possibilities. The Schiff base macrocycles L 1 and L 4 and their reduced ligands L 2 and L 5 are derived from 2,6-bis(2-formylphenoxymethyl)pyridine and tris(2-aminoethyl)amine or N,N-bis(3-aminopropyl)methylamine, respectively. The reaction of L 1 with salicylaldehyde forms L 3 , which features an imine bond in the pendant arm. The ligand L 5 has been the precursor for the pendant-armed L 6 and L 7 , by alkylation of the free NH groups with methyl-imidazole or methyl-indole. By a template or a nontemplate approach, we have synthesized different mono- and dinuclear complexes with Y(III), Ln(III), Zn(II), and Cd(II) cations. Both the free macrocyclic ligands and their corresponding metal complexes have been characterized by microanalysis, IR, UV-vis, 1 H and 13 C NMR spectroscopy, FAB mass spectrometry, MS electrospray, and conductivity measurements. (author)

  12. Impact on creatinine renal clearance by the interplay of multiple renal transporters: a case study with INCB039110.

    Science.gov (United States)

    Zhang, Yan; Warren, Mark S; Zhang, Xuexiang; Diamond, Sharon; Williams, Bill; Punwani, Naresh; Huang, Jane; Huang, Yong; Yeleswaram, Swamy

    2015-04-01

    Serum creatinine is commonly used as a marker of renal function, but increases in serum creatinine might not represent changes in glomerular filtration rate (GFR). INCB039110 (2-(3-(4-(7H-pyrrolo[2,3-day]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(1-(3-fluoro-2-(trifluoromethyl)isonicotinoyl)piperidin-4-yl)azetidin-3-yl)acetonitrile) is an inhibitor of the Janus kinases (JAKs) with selectivity for JAK1. In a phase 1 study, a modest and reversible increase in serum creatinine was observed after treatment with INCB039110. However, a dedicated renal function study with INCB039110, assessed by iohexol plasma clearance, conducted in healthy volunteers indicated no change in GFR. In vitro studies were therefore conducted to investigate the interaction of INCB039110 with five transporters that are likely involved in the renal clearance of creatinine. Cell systems expressing individual or multiple transporters were used, including a novel quintuple-transporter model OAT2/OCT2/OCT3/MATE1/MATE2-K. INCB039110 potently inhibited OCT2-mediated uptake of creatinine as well as MATE1-/MATE2-K-mediated efflux of creatinine. Given the interactions of INCB039110 with multiple transporters affecting creatinine uptake and efflux, an integrated system expressing all five transporters was sought; in that system, INCB039110 caused a dose-dependent decrease in transcellular transport of creatinine with weaker net inhibition compared with the effects on individual transporters. In summary, a molecular mechanism for the increase in serum creatinine by INCB039110 has been established. These studies also underline the limitations of using serum creatinine as a marker of renal function. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  13. 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.

  14. Heterociclos 1,2,3-triazólicos: histórico, métodos de preparação, aplicações e atividades farmacológicas 1,2,3-triazolic heterocycles: history, preparations, applications and pharmacological activities

    Directory of Open Access Journals (Sweden)

    Júlio O. F. Melo

    2006-06-01

    Full Text Available The 1,2,3-triazole, known since the end of 19th century, is a very widely used heterocyclic system present in many synthetic substances and commercial pharmaceutical compounds. In fact, 1,2,3-triazoles show several applications in many areas especially as medicines against many diseases like cancer, AIDS, Parkinson and Alzheimer. Nowadays there is a large variety of known methods to obtain these heterocyclic compounds comprising mainly three synthetic routes. Nevertheless, there is no article that gives an objective overview of the synthetic methods for obtaining these kinds of azoheterocycles. This paper presents a brief history of this class of compounds, and a synthetic discussion concerning the main synthetic methods for its preparation, such as cyclization through hydrazones, concerted cycloadditon [2+3] and pseudopericyclic cyclization - and some others of restricted application, but also important. Finally, this paper also provides a brief overview on pharmacological applications of some 1,2,3-triazoles.

  15. Self-Assembly Assisted Fabrication of Dextran-Based Nanohydrogels with Reduction-Cleavable Junctions for Applications as Efficient Drug Delivery Systems

    Science.gov (United States)

    Wang, Hao; Dai, Tingting; Zhou, Shuyan; Huang, Xiaoxiao; Li, Songying; Sun, Kang; Zhou, Guangdong; Dou, Hongjing

    2017-01-01

    In order to overcome the key challenge in improving both fabrication efficiency and their drug delivery capability of anti-cancer drug delivery systems (ACDDS), here polyacrylic acid (PAA) grafted dextran (Dex) nanohydrogels (NGs) with covalent crosslinked structure bearing redox sensitive disulfide crosslinking junctions (Dex-SS-PAA) were synthesized efficiently through a one-step self-assembly assisted methodology (SAA). The Dex-SS-PAA were subsequently conjugated with doxorubicin through an acid-labile hydrazone bond (Dex-SS-PAA-DOX). The in vitro drug release behavior, anti-cancer effects in vivo, and biosafety of the as-prepared acid- and redox-dual responsive biodegradable NGs were systematically investigated. The results revealed that the Dex-SS-PAA-DOX exhibited pH- and redox-controlled drug release, greatly reduced the toxicity of free DOX, while exhibiting a strong ability to inhibit the growth of MDA-MB-231 tumors. Our study demonstrated that the Dex-SS-PAA-DOX NGs are very promising candidates as ACDDS for anti-cancer therapeutics.

  16. Synthesis of Symmetrical and Asymmetrical Azines Encompassing Naphtho[2,1-b]furan by a Novel Approach

    Directory of Open Access Journals (Sweden)

    K. Veena

    2011-01-01

    Full Text Available The starting material 3-nitro-2-acetylnaphtho[2,1-b]furan (2 was obtained by nitration of 2-acetylnaphtho[2,1-b] furan (1, under mild condition. The compound 1 was synthesized by the reaction of 2-hydroxy-1-naphthaldehyde with chloroacetone, where in both condensation and cyclization took place in single step. The reaction of 3-nitro-2-acetylnaphtho[2,1-b]furan (2 with hydrazine hydrate produced corresponding hydrazone (3 in excellent yield, which on treatment with various aromatic aldehydes under different reaction conditions resulted in the formation of symmetrical azines (4a-e and unsymmetrical azines (5a-e. All the newly synthesized compounds have been characterized by analytical and spectral studies and were screened for antibacterial antibacterial activity against Bacillus subtilus and Alcaligenes fecalies and antifungal activity against Aspergillus nidulans, Aspergillus parasiticus and Aspergillus terrus. The Second Harmonic Generation (SHG efficiency of some of the synthesized compounds was measured by powder technique using Nd:YAG laser.

  17. The mechanism and kinetics of the electrochemical cleavage of azo bond of 2-hydroxy-5-sulfophenyl-azo-benzoic acids

    International Nuclear Information System (INIS)

    Mandic, Zoran; Nigovic, Biljana; Simunic, Branimir

    2004-01-01

    The electrochemical reduction of 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(3-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(2-sulfophenyl)azo]benzoic acid and 2-hydroxy-5-azo-benzoic acid has been carried out in aqueous solutions at glassy carbon electrode using cyclic voltammetry and chronoamperometry. The position of sulfo substituent relative to azo bridge as well as pH of the solution have significant impact on the electrochemical behavior of these compounds. It has been proposed that these compounds are reduced predominantly as hydrazone tautomers resulting in corresponding hydrazo compounds. The overall electrochemical reduction follows DISP2 mechanism, ultimately leading to the 5-amino salicylic acid and sulfanilic acid. The rate determining step is the homogenous redox reaction between intermediate hydrazo compound and 5-amino salicylic acid quinoneimine. The mechanism is proposed in which activated complex of 5-amino salicylic acid quinoneimine and intermediate hydrazo compound is formed with the simultaneous loss of one proton

  18. The Chemistry of Bioconjugation in Nanoparticles-Based Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Karolina Werengowska-Ciećwierz

    2015-01-01

    Full Text Available Nanomedicine is, generally, the application of nanotechnology to medicine. The term nanomedicine includes monitoring, construction of novel drug delivery systems, and any possible future applications of nanotechnology and nanovaccinology. In this review, the most important ligand-nanocarrier and drug-nanocarrier bioconjugations are described. The detailed characterizations of covalently formed bonds between targeted ligand and nanocarrier, including amide, thioether, disulfide, acetyl-hydrazone and polycyclic groups, are described. Also, the coupling of small elements and heteroatoms in the form of R-X-R the “click chemistry” groups is shown. Physical adsorption and chemical bonding of drug to nanocarrier surface involving drug on the internal or external surfaces of nanocarriers are described throughout possibility of the formation of the above-mentioned functionalities. Moreover, the most popular nanostructures (liposomes, micelles, polymeric nanoparticles, dendrimers, carbon nanotubes, and nanohorns are characterized as nanocarriers. Building of modern drug carrier is a new method which could be effectively applied in targeted anticancer therapy.

  19. A prodrug strategy based on chitosan for efficient intracellular anticancer drug delivery

    International Nuclear Information System (INIS)

    Chen, Cheng; Zhou, Jiang-Ling; Han, Xue; Song, Fei; Wang, Xiu-Li; Wang, Yu-Zhong

    2014-01-01

    Doxorubicin (DOX), one of the most widely used anticancer drugs, is restricted in clinical application due to its severe side effects and inefficient cellular uptake. To overcome the drawbacks, herein, an endosomal pH-activated prodrug was designed and fabricated by conjugating DOX with chitosan via an acid-cleavable hydrazone bond. The resulting DOX conjugates can self-assemble into nano-sized particles, which were very stable and presented no burst release of DOX at a neutral pH condition. Notably, the nanoparticles exhibited excellent cell uptake properties and a remarkable drug accumulation in tumor cells. Once internalized into the cells, moreover, DOX can be fast released from the nanoparticles, and the release mechanism changed from the anomalous transport at pH 7.4 to the combination pattern of diffusion- and erosion-controlled release at pH 6.0 or 5.0. The prodrugs showed obvious cytotoxicity for HeLa cells with fairly low IC 50 values, offering a new platform for targeted cancer therapy. (papers)

  20. QSAR Study of Insecticides of Phthalamide Derivatives Using Multiple Linear Regression and Artificial Neural Network Methods

    Directory of Open Access Journals (Sweden)

    Adi Syahputra

    2014-03-01

    Full Text Available Quantitative structure activity relationship (QSAR for 21 insecticides of phthalamides containing hydrazone (PCH was studied using multiple linear regression (MLR, principle component regression (PCR and artificial neural network (ANN. Five descriptors were included in the model for MLR and ANN analysis, and five latent variables obtained from principle component analysis (PCA were used in PCR analysis. Calculation of descriptors was performed using semi-empirical PM6 method. ANN analysis was found to be superior statistical technique compared to the other methods and gave a good correlation between descriptors and activity (r2 = 0.84. Based on the obtained model, we have successfully designed some new insecticides with higher predicted activity than those of previously synthesized compounds, e.g.2-(decalinecarbamoyl-5-chloro-N’-((5-methylthiophen-2-ylmethylene benzohydrazide, 2-(decalinecarbamoyl-5-chloro-N’-((thiophen-2-yl-methylene benzohydrazide and 2-(decaline carbamoyl-N’-(4-fluorobenzylidene-5-chlorobenzohydrazide with predicted log LC50 of 1.640, 1.672, and 1.769 respectively.

  1. Memristors in the electrical network of Aloe vera L.

    Science.gov (United States)

    Volkov, Alexander G; Reedus, Jada; Mitchell, Colee M; Tucket, Clayton; Forde-Tuckett, Victoria; Volkova, Maya I; Markin, Vladislav S; Chua, Leon

    2014-01-01

    A memristor is a resistor with memory, which is a non-linear passive two-terminal electrical element relating magnetic flux linkage and electrical charge. Here we found that memristors exist in vivo. The electrostimulation of the Aloe vera by bipolar sinusoidal or triangle periodic waves induce electrical responses with fingerprints of memristors. Uncouplers carbonylcyanide-3-chlorophenylhydrazone and carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone decrease the amplitude of electrical responses at low and high frequencies of bipolar periodic sinusoidal or triangle electrostimulating waves. Memristive behavior of an electrical network in the Aloe vera is linked to the properties of voltage gated ion channels: the K+ channel blocker TEACl reduces the electric response to a conventional resistor. Our results demonstrate that a voltage gated K+ channel in the excitable tissue of plants has properties of a memristor. The discovery of memristors in plants creates a new direction in the modeling and understanding of electrical phenomena in plants. PMID:25763487

  2. Features of fatty acid synthesis in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, M [Tokyo Univ. (Japan). Coll. of General Education; Nakamura, Y

    1975-07-01

    In the biosynthesis of fatty acid in the presence of /sup 3/H/sub 2/O, /sup 3/H is incorporated into the hydrocarbon chain of the fatty acid. The features in the fatty acid synthesis of higher plants were investigated by applying /sup 3/H/sub 2/O method to the measurement of the ability of spinach leaves synthesizing fatty acid. Sucrose, acetate, pyruvate, PGA, PEP, OAA, citrate, etc. were employed as the substrates of fatty acid synthesis to trace the process of synthesis of each fatty acid. The demand of various cofactors related to the ability of spinach chloroplast fatty acid synthesizing was also examined. Light dependence of the fatty acid synthesis of chloroplast as well as the influences of N,N'-dicyclohexyl carbodiimide, carbonylcyanide-4-trifluoromethoxy phenyl hydrazone and NH/sub 4/Cl were discussed. The results were compared with the reports on the fatty acid synthesis of avocado pear, castor bean, etc.

  3. Cellular uptake: lessons from supramolecular organic chemistry.

    Science.gov (United States)

    Gasparini, Giulio; Bang, Eun-Kyoung; Montenegro, Javier; Matile, Stefan

    2015-07-04

    The objective of this Feature Article is to reflect on the importance of established and emerging principles of supramolecular organic chemistry to address one of the most persistent problems in life sciences. The main topic is dynamic covalent chemistry on cell surfaces, particularly disulfide exchange for thiol-mediated uptake. Examples of boronate and hydrazone exchange are added for contrast, comparison and completion. Of equal importance are the discussions of proximity effects in polyions and counterion hopping, and more recent highlights on ring tension and ion pair-π interactions. These lessons from supramolecular organic chemistry apply to cell-penetrating peptides, particularly the origin of "arginine magic" and the "pyrenebutyrate trick," and the currently emerging complementary "disulfide magic" with cell-penetrating poly(disulfide)s. They further extend to the voltage gating of neuronal potassium channels, gene transfection, and the delivery of siRNA. The collected examples illustrate that the input from conceptually innovative chemistry is essential to address the true challenges in biology beyond incremental progress and random screening.

  4. Cellular Automata Modelling of Photo-Induced Oxidation Processes in Molecularly Doped Polymers

    Directory of Open Access Journals (Sweden)

    David M. Goldie

    2016-11-01

    Full Text Available The possibility of employing cellular automata (CA to model photo-induced oxidation processes in molecularly doped polymers is explored. It is demonstrated that the oxidation dynamics generated using CA models exhibit stretched-exponential behavior. This dynamical characteristic is in general agreement with an alternative analysis conducted using standard rate equations provided the molecular doping levels are sufficiently low to prohibit the presence of safe-sites which are impenetrable to dissolved oxygen. The CA models therefore offer the advantage of exploring the effect of dopant agglomeration which is difficult to assess from standard rate equation solutions. The influence of UV-induced bleaching or darkening upon the resulting oxidation dynamics may also be easily incorporated into the CA models and these optical effects are investigated for various photo-oxidation product scenarios. Output from the CA models is evaluated for experimental photo-oxidation data obtained from a series of hydrazone-doped polymers.

  5. Molecular design of new hydrazone dyes for dye-sensitized solar cells: Synthesis, characterization and DFT study

    KAUST Repository

    Al-Sehemi, Abdullah G.; Irfan, Ahmad; Asiri, Abdullah M.; Ammar, Yousry Ahmed

    2012-01-01

    }ethylene-1,1,2-tricarbonitrile (BBHPET) have been synthesized. The dyes showed pronounced solvatochromic effects as the polarity of the solvents increased. The structures have been optimized at B3LYP/6-31G(d) level of theory. The torsion in E

  6. Molecular design of new hydrazone dyes for dye-sensitized solar cells: Synthesis, characterization and DFT study

    KAUST Repository

    Al-Sehemi, Abdullah G.

    2012-07-01

    Three new sensitizers 2-{4-[2-(4-Nitrobenzylidene)hydrazino)]phenyl} ethylene-1,1,2-tricarbonitrile (NBHPET), 2-{4-[2-p-Chlorobenzylidenehydrazino] phenyl}- ethylene-1,1,2-tri carbonitrile (CBHPET) and 2-{4-[2-p- Bromobenzylidenehydrazino] phenyl}ethylene-1,1,2-tricarbonitrile (BBHPET) have been synthesized. The dyes showed pronounced solvatochromic effects as the polarity of the solvents increased. The structures have been optimized at B3LYP/6-31G(d) level of theory. The torsion in E-isomer is smaller than Z-isomer and azo isomers. The highest occupied molecular orbitals are delocalized on whole molecule while lowest unoccupied molecular orbitals are distributed on the tricarbonitrile. The lowest unoccupied molecular orbital energies are above the conduction band of titanium dioxide, highest occupied molecular orbitals of the dyes are below the redox couple of new synthesized dyes and small energy gap revealed these dyes would be better sensitizers for dye-sensitized solar cells. © 2012 Elsevier B.V. All rights reserved.

  7. Some aromatic hydrazone derivatives as inhibitors for the corrosion of C-steel in phosphoric acid solution.

    Science.gov (United States)

    Fouda, Abd El-Aziz S; Al-Sarawy, Ahmed A; Radwan, Mohamed S

    2006-01-01

    The effect of furfural benzoylhydrazone and its derivatives (I-VII) as corrosion inhibitors for C-steel in 1M phosphoric acid solution has been studied by weight-loss and galvanostatic polarization techniques. A significant decrease in the corrosion rate of C-steel was observed in the presence of the investigated inhibitors. This study revealed that, the inhibition efficiency increases with increasing the inhibitor concentration, and the addition of iodide ions enhances it to a considerable extent. The effect of temperature on the inhibition efficiency of these compounds was studied using weight-loss method. Activation energy (E(a)*) and other thermodynamic parameters for the corrosion process were calculated and discussed. The galvanostatic polarization data indicated that, the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The adsorption of these compounds on C-steel surface has been found to obey Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

  8. Synthesis, magnetic and spectral studies of lanthanide(III) chloride complexes of hydrazones of isonicotinic acid hydrazide

    International Nuclear Information System (INIS)

    Agarwal, R.K.; Agarwal, Himanshu; Prasad, Ram

    1996-01-01

    The synthesis, magnetic and spectral properties of trivalent lanthanide chlorides with N-isonicotinamidobenzalaldimine (INH-BENZ), N-isonicotinamidoanisalaldimine (INH-ANSL) and N-isonicotinamido-p-dimethylaminobenzalaldimine (INH-PDAB) are described. 13 refs., 2 tabs

  9. Inspired by nonenveloped viruses escaping from endo-lysosomes: a pH-sensitive polyurethane micelle for effective intracellular trafficking

    Science.gov (United States)

    Song, Nijia; Zhou, Lijuan; Li, Jiehua; Pan, Zhicheng; He, Xueling; Tan, Hong; Wan, Xinyuan; Li, Jianshu; Ran, Rong; Fu, Qiang

    2016-03-01

    A multifunctional drug delivery system (DDS) for cancer therapy still faces great challenges due to multiple physiological barriers encountered in vivo. To increase the efficacy of current cancer treatment a new anticancer DDS mimicking the response of nonenveloped viruses, triggered by acidic pH to escape endo-lysosomes, is developed. Such a smart DDS is self-assembled from biodegradable pH-sensitive polyurethane containing hydrazone bonds in the backbone, named pHPM. The pHPM exhibits excellent micellization characteristics and high loading capacity for hydrophobic chemotherapeutic drugs. The responses of the pHPM in acidic media, undergoing charge conversion and hydrophobic core exposure, resulting from the detachment of the hydrophilic polyethylene glycol (PEG) shell, are similar to the behavior of a nonenveloped virus when trapped in acidic endo-lysosomes. Moreover, the degradation mechanism was verified by gel permeation chromatography (GPC). The endo-lysosomal membrane rupture induced by these transformed micelles is clearly observed by transmission electron microscopy. Consequently, excellent antitumor activity is confirmed both in vitro and in vivo. The results verify that the pHPM could be a promising new drug delivery tool for the treatment of cancer and other diseases.A multifunctional drug delivery system (DDS) for cancer therapy still faces great challenges due to multiple physiological barriers encountered in vivo. To increase the efficacy of current cancer treatment a new anticancer DDS mimicking the response of nonenveloped viruses, triggered by acidic pH to escape endo-lysosomes, is developed. Such a smart DDS is self-assembled from biodegradable pH-sensitive polyurethane containing hydrazone bonds in the backbone, named pHPM. The pHPM exhibits excellent micellization characteristics and high loading capacity for hydrophobic chemotherapeutic drugs. The responses of the pHPM in acidic media, undergoing charge conversion and hydrophobic core

  10. Synthesis of 3-(4, 5-dihydro-1-phenyl-5-substituted phenyl-1H-pyrazol-3-yl-2H-chromen-2-one derivatives and evaluation of their anticancer activity

    Directory of Open Access Journals (Sweden)

    Nitin Kumar

    2017-05-01

    Full Text Available A novel series of 3-(4, 5-dihydro-1-phenyl-5-substituted phenyl-1H-pyrazol-3-yl-2H-chromen-2-one derivatives were synthesized. In the first step salicylaldehyde was reacted with ethylacetoacetate at room temperature by stirring which gives compound (I. Compound (I when refluxed with substituted benzaldehyde and diethylamine in the presence of n-butanol for 4–5 h gives substituted derivatives (IIa–d. Compounds synthesized in step 2 when refluxed with phenyl hydrazine in the presence of pyridine for 6–7 h gives the title compounds (IIIa–d. All the synthesized compounds were sent to NCI for anticancer activity. Synthesized compounds were tested for anticancer activity against 60 different cell lines. From the data thus obtained it was observed that simple coumarin ring derivatives were more effective in inhibiting the growth of cancerous cell lines, than coumarin-pyrazoline derivatives. Among all the synthesized compounds, irrespective of compounds having simple coumarin ring and coumarin-pyrazoline combination, compounds IIa–c, IIIb and IIId were potent anticancer agents. Compounds were active for the single dose therapeutic program at the dose of 1.00E-5 molar concentration. The main anti cancer activity is assumed to be due to the presence of the lactone structure in coumarin moiety.

  11. Synthesis of metal complexes involving Schiff base ligand with methylenedioxy moiety: spectral, thermal, XRD and antimicrobial studies.

    Science.gov (United States)

    Sundararajan, M L; Jeyakumar, T; Anandakumaran, J; Karpanai Selvan, B

    2014-10-15

    Metal complexes of Zn(II), Cd(II), Ni(II), Cu(II), Fe(III), Co(II), Mn(II) Hg(II), and Ag(I) have been synthesized from Schiff base ligand, prepared by the condensation of 3,4-(methylenedioxy)aniline and 5-bromo salicylaldehyde. All the compounds have been characterized by using elemental analysis, molar conductance, FT-IR, UV-Vis, (1)H NMR, (13)C NMR, mass spectra, powder XRD and thermal analysis (TG/DTA) technique. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectral data suggest that the ligand coordinate to the metal atom by imino nitrogen and phenolic oxygen as bidentate manner. Mass spectral data further support the molecular mass of the compounds and their structure. Powder XRD indicates the crystalline state and morphology of the ligand and its metal complexes. The thermal behaviors of the complexes prove the presence of lattice as well as coordinated water molecules in the complexes. Melting point supports the thermal stability of all the compounds. The in vitro antimicrobial effects of the synthesized compounds were tested against five bacterial and three fungal species by well diffusion method. Antioxidant activities have also been performed for all the compounds. Metal complexes show more biological activity than the Schiff base. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Studies on complexation of a tridentate ONS Schiff base with lighter and heavier metals ions, and investigation into their biological properties

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Ali, A.M.; Juan, W.D.; Crouse, K.A.; Silong, S.

    1999-05-01

    Several new complexes of a tridentate ONS Schiff base derived from the condensation of S-benzyldithiocarbazate with salicylaldehyde have been characterised by elemental analyses, molar conductivity measurements, infrared, and electronic spectral studies. The tridentate Schiff base (HONSH) behaves as a dinegatively charged ligand coordinating through the thiolo sulphur, the azomethine nitrogen atom and the hydroxyl oxygen atom. It forms mono-ligand complexes of the general formula, [M(ONS)X], [M = Ni(II), Cu(II), Cr(III), Sb(III), Zn(II), Zr(IV) or U(VI) and X = H 2 O, Cl]. The ligand produced bis-chelated complex with Th(IV) of composition, [Th(ONS) 2 ]. Square-planar structures were proposed for the Ni(II) and Cu(II) complexes. Antimicrobial tests indicated that the Schiff base and five of the metal complexes of Cu(II), Ni(II), U(VI), Zn(II) and Sb(III) were found to be strongly active against bacteria. Ni(II) and Sb(III) complexes were the most effective against Pseudomonas aeruginosa (gram negative) while the Cu(II) complex proved to be the best against Bacillus cereus (gram positive bacteria). Antifungal activities were also noted with the Schiff base and the U(VI) complex. These compounds have shown results against Candida albicans fungi. But none of these compounds were effective against Aspergillus ochraceous fungi. (author)

  13. Synthesis, structure, DNA/BSA binding and antibacterial studies of NNO tridentate Schiff base metal complexes

    Science.gov (United States)

    Sakthi, Marimuthu; Ramu, Andy

    2017-12-01

    A new salicylaldehyde derived 2,4-diiodo-6-((2-phenylaminoethylimino)methyl)phenol Schiff base(L) and its transition metal complexes of the type MLCl where, M = Cu(II), Ni(II), Co(II), Mn(II) and Zn(II) have been synthesized. The coordination mode of Schiff base holding NNO donor atoms with metal ions was well investigated by elemental analysis, ESI-mass as well as IR, UV-vis, CV and NMR spectral studies. The binding efficiency and mode of these complexes with biological macromolecules viz., herring sperm DNA (HS- DNA) and bovine serum albumin (BSA) have been explored through various spectroscopic techniques. The characteristic changes in absorption, emission and, circular dichroism spectra of the complexes with DNA indicate the noticeable interaction between them. From the all spectral information complexes could interact with DNA via non-intercalation mode of binding. The hyperchromisim in absorption band and hypochromisim in emission intensity of BSA with different complex concentrations shown significant information, and the binding affinity value has been predicted from Stern-Volmer plots. Further, all the complexes could cleave the circular plasmid pUC19 DNA efficiently by using an activator H2O2. The ligand and all metal(II) complexes showed good antibacterial activities. The molecular docking studies of the complexes with DNA were performed in order to make a comparison and conclusion with spectral technic results.

  14. Syntheses, structural elucidation, thermal properties, theoretical quantum chemical studies (DFT and biological studies of barbituric–hydrazone complexes

    Directory of Open Access Journals (Sweden)

    Amina A. Soayed

    2015-03-01

    Full Text Available Condensation of barbituric acid with hydrazine hydrate yielded barbiturichydrazone (L which was characterized using IR, 1H NMR and mass spectra. The Co(II, Ni(II and Cu(II complexes derived from this ligand have been synthesized and structurally characterized by elemental analyses, spectroscopic methods (IR, UV–Vis and ESR and thermal analyses (TGA, DTG and DTA and the structures were further elucidated using quantum chemical density functional theory. Complexes of L were found to have the ML.nH2O stoichiometry with either tetrahedral or octahedral geometry. The ESR data showed the Cu(II complex to be in a tetragonal geometry. Theoretical investigation of the electronic structure of metal complexes at the TD-DFT/B3LYP level of theory has been carried out and discussed. The fundamental vibrational wavenumbers were calculated and a good agreement between observed and scaled calculated wavenumbers was achieved. Thermal studies were performed to deduce the stabilities of the ligand and complexes. Thermodynamic parameters, such as the order of reactions (n, activation energy ΔE∗, enthalpy of reaction ΔH∗ and entropy ΔS∗ were calculated from DTA curves using Horowitz–Metzger method. The ligand L and its complexes have been screened for their antifungal and antibacterial activities and were found to possess better biological activities compared to those of unsubstituted barbituric acid complexes.

  15. Synthesis: Small library of hybrid scaffolds of benzothiazole having hydrazone and evaluation of their β-glucuronidase activity.

    Science.gov (United States)

    Taha, Muhammad; Arbin, Mastura; Ahmat, Norizan; Imran, Syahrul; Rahim, Fazal

    2018-04-01

    Due to the great biological importance of β-glucuronidase inhibitors, here in this study, we have synthesized a library of novel benzothiazole derivatives (1-30), characterized by different spectroscopic methods and evaluated for β-glucuronidase inhibitory potential. Among the series sixteen compounds i.e.1-6, 8, 9, 11, 14, 15, 20-23 and 26 showed outstanding inhibitory potential with IC 50 value ranging in between 16.50 ± 0.26 and 59.45 ± 1.12 when compared with standard d-Saccharic acid 1,4-lactone (48.4 ± 1.25 µM). Except compound 8 and 23 all active analogs showed better potential than the standard. Structure activity relationship has been established. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Microwave Assisted Condensation Reactions of 2-Aryl Hydrazonopropanals with Nucleophilic Reagents and Dimethyl Acetylenedicarboxylate

    Directory of Open Access Journals (Sweden)

    Rita M. Borik

    2007-08-01

    Full Text Available The reaction of methyl ketones 1a-g with dimethylformamide dimethylacetal (DMFDMA afforded the enaminones 2a-g, which were coupled with diazotized aromatic amines 3a,b to give the corresponding aryl hydrazones 6a-h. Condensation of compounds 6a-h with some aromatic heterocyclic amines afforded iminoarylhydrazones 9a-m. Enaminoazo compounds 12a,b could be obtained from condensation of 6c with secondary amines. The reaction of 6e,h with benzotriazolylacetone yielded 14a,b. Also, the reaction of 6a,b,d-f,h with glycine and hippuric acid in acetic anhydride afforded pyridazinone derivatives 17a-f. Synthesis of pyridazine carboxylic acid derivatives 22a,b from the reaction of 6b,e with dimethyl acetylenedicarboxylate (DMAD in the presence of triphenylphosphine at room temperature is also reported. Most of these reactions were conducted under irradiation in a microwave oven in the absence of solvent in an attempt to improve the product yields and to reduce the reaction times.

  17. Suppression of Kasha's rule as a mechanism for fluorescent molecular rotors and aggregation-induced emission

    Science.gov (United States)

    Qian, Hai; Cousins, Morgan E.; Horak, Erik H.; Wakefield, Audrey; Liptak, Matthew D.; Aprahamian, Ivan

    2017-01-01

    Although there are some proposed explanations for aggregation-induced emission, a phenomenon with applications that range from biosensors to organic light-emitting diodes, current understanding of the quantum-mechanical origin of this photophysical behaviour is limited. To address this issue, we assessed the emission properties of a series of BF2-hydrazone-based dyes as a function of solvent viscosity. These molecules turned out to be highly efficient fluorescent molecular rotors. This property, in addition to them being aggregation-induced emission luminogens, enabled us to probe deeper into their emission mechanism. Time-dependent density functional theory calculations and experimental results showed that the emission is not from the S1 state, as predicted from Kasha's rule, but from a higher energy (>S1) state. Furthermore, we found that suppression of internal conversion to the dark S1 state by restricting the rotor rotation enhances fluorescence, which leads to the proposal that suppression of Kasha's rule is the photophysical mechanism responsible for emission in both viscous solution and the solid state.

  18. Regulation of proteolysis in Bacillus subtilis: effects of calcium ions and energy poisons

    International Nuclear Information System (INIS)

    O'Hara, M.B.; Hageman, J.H.

    1987-01-01

    Bacillus subtilis cells carry out extensive intracellular proteolysis (k = 0.15-0.23/h) during sporulation. Protein degradation was measured in cells growing in chemically defined sporulation medium, by following the release of [ 14 C]-leucine from the cells during spore formation. Sodium arsenate, carbonyl cyanide 3-chlorophenyl hydrazone, and sodium azide strongly inhibited proteolysis without altering cell viability greatly, which suggested that bulk proteolysis in B. subtilis is energy dependent. The authors have tested the hypothesis that the energy requirement may be for pumping in Ca 2+ . When [Ca 2+ ] was -6 , rates of proteolysis in sporulating cells were reduced 4-8 times that in cells in calcium ion- sufficient medium. Further, omission of Ca 2+ from the medium prevented the increase in the activity of the major intracellular serine protease. However, the presence of energy poisons in the media at levels which inhibited proteolysis, had no detectable effect on the uptake of by cells [ 45 Ca]. The authors concluded that B. subtilis cells required both metabolic energy and calcium ions for normal proteolysis

  19. A single pH fluorescent probe for biosensing and imaging of extreme acidity and extreme alkalinity.

    Science.gov (United States)

    Chao, Jian-Bin; Wang, Hui-Juan; Zhang, Yong-Bin; Li, Zhi-Qing; Liu, Yu-Hong; Huo, Fang-Jun; Yin, Cai-Xia; Shi, Ya-Wei; Wang, Juan-Juan

    2017-07-04

    A simple tailor-made pH fluorescent probe 2-benzothiazole (N-ethylcarbazole-3-yl) hydrazone (Probe) is facilely synthesized by the condensation reaction of 2-hydrazinobenzothiazole with N-ethylcarbazole-3-formaldehyde, which is a useful fluorescent probe for monitoring extremely acidic and alkaline pH, quantitatively. The pH titrations indicate that Probe displays a remarkable emission enhancement with a pK a of 2.73 and responds linearly to minor pH fluctuations within the extremely acidic range of 2.21-3.30. Interestingly, Probe also exhibits strong pH-dependent characteristics with pK a 11.28 and linear response to extreme-alkalinity range of 10.41-12.43. In addition, Probe shows a large Stokes shift of 84 nm under extremely acidic and alkaline conditions, high selectivity, excellent sensitivity, good water-solubility and fine stability, all of which are favorable for intracellular pH imaging. The probe is further successfully applied to image extremely acidic and alkaline pH values fluctuations in E. coli cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Development and optimization of the synthesis of new thiazolidin-4-one derivatives of ibuprofen.

    Science.gov (United States)

    Vasincu, Ioana; Apotrosoaei, Maria; Panzariu, Andreea; Buron, F; Routier, S; Profire, Lenuta

    2014-01-01

    Ibuprofen, an important nonsteroidal anti-inflammatory agent, is one of the most prescribed drugs for the treatment of pain and inflammation from various rheumatic diseases, but some side effects can occur on long-term use. The method for synthesis optimization of new derivatives of Ibuprofen with thiazolidin-4-one moiety, with improved pharmacological and toxicological profile. To optimize the derivatization method of free carboxyl group of Ibuprofen (2-(4-isobutylphenyl)propionic acid) the reaction conditions were varied (reagent ratio, catalyst, reaction medium). The most favorable method was proved to be the reaction between ibuprofen hydrazone and mercaptoacetic acid, in excess, at 80-85 degrees C, for 6 h with 96% conversion rate. The synthesis of 2-phenyl-3-[2-(4-(isobutyl)phenyl)-2-methyl]acetamido-thiazolidin-4-one derivative was optimized in view of applying it as a general procedure for the synthesis of other derivatives with related structure. The chemical structure and molecular weight of the synthesized compound were confirmed by spectral methods (IR, 1H NMR, 13C NMR, HR-MS).

  1. Spectrophotometric Determination of Lamivudine in Pure and Tablet Forms

    Directory of Open Access Journals (Sweden)

    A. Biksham Babu

    2012-01-01

    Full Text Available Two visible spectrophotometric methods have been developed for the determination of Lamivudine(LMV in pure and tablet forms. Method-A is based on oxidation of 3-methyl-2-benzathiazolinone hydrazone (MBTH in the presence of iodoso benzene diacetate (IBDA to form electrophilic intermediate which is an active coupling species that reacts with the coupler (LMV by electrophillic attack on the most nucleophilic site on cyclic ring of the coupler. Method-B depends on diazonium salt formation and consequent reaction with resorcinol producing colored product. The absorbances are measured at 590 nm and 540 nm for Method-A and Method-B respectively. Beer's law is obeyed in the concentration range of 10.0-60.0 μg/mL for both the methods. The correlation coefficient which is very close to unity indicates that there is good correlation between concentration and absorbance. LOD, LOQ, confidence levels and relative standard deviation are calculated for the developed methods. The developed methods were successfully applied to tablet forms.

  2. Kinetic spectrophotometric determination of ethamsylate in dosage forms.

    Science.gov (United States)

    El-Enany, Nahed; Belal, Fathalla; Rizk, Mohamed

    2007-01-01

    A simple and sensitive kinetic method has been developed for the determination of ethamsylate (ESL) in its pharmaceutical preparations. The method is based upon oxidation of ESL with 3-methyl-2-benzothiazolinone hydrazone hydrochloride in presence of cerium (IV) ammonium sulfate at room temperature for 20 min. The absorbance of the reaction product is measured at 514 nm. The absorbance-concentration plot was rectilinear over the range of 4-30 microg/mL (r = 0.9999). The lower detection limit was 0.267 microl/mL (9.110 x 10(-6) M) and the lower quantitation limit was 0.808 microg/mL. The different experimental parameters affecting the development and stability of the reaction product were studied and optimized. The proposed method was applied to the determination of ESL in formulations, and the results obtained were in good agreement with those obtained using a reference method. The proposed method was also used for the in vitro detection of ESL in spiked human plasma at its therapeutic concentration level.

  3. Synthesis of bis-indolylmethanes as new potential inhibitors of β-glucuronidase and their molecular docking studies.

    Science.gov (United States)

    Taha, Muhammad; Ullah, Hayat; Al Muqarrabun, Laode Muhammad Ramadhan; Khan, Muhammad Naseem; Rahim, Fazal; Ahmat, Norizan; Ali, Muhammad; Perveen, Shahnaz

    2018-01-01

    Thirty-two (32) bis-indolylmethane-hydrazone hybrids 1-32 were synthesized and characterized by 1 HNMR, 13 CNNMR and HREI-MS. All compounds were evaluated in vitro for β-glucuronidase inhibitory potential. All analogs showed varying degree of β-glucuronidase inhibitory potential ranging from 0.10 ± 0.01 to 48.50 ± 1.10 μM when compared with the standard drug d-saccharic acid-1,4-lactone (IC 50 value 48.30 ± 1.20 μM). Derivatives 1-32 showed the highest β-glucuronidase inhibitory potentials which is many folds better than the standard drug d-saccharic acid-1,4-lactone. Further molecular docking study validated the experimental results. It was proposed that bis-indolylmethane may interact with some amino acid residues located within the active site of β-glucuronidase enzyme. This study has culminated in the identification of a new class of potent β-glucuronidase inhibitors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Gas chromatographic analysis of reactive carbonyl compounds formed from lipids upon UV-irradiation

    International Nuclear Information System (INIS)

    Dennis, K.J.; Shibamoto, T.

    1990-01-01

    Peroxidation of lipids produces carbonyl compounds; some of these, e.g., malonaldehyde and 4-hydroxynonenal, are genotoxic because of their reactivity with biological nucleophiles. Analysis of the reactive carbonyl compounds is often difficult. The methylhydrazine method developed for malonaldehyde analysis was applied to simultaneously measure the products formed from linoleic acid, linolenic acid, arachidonic acid, and squalene upon ultraviolet-irradiation (UV-irradiation). The photoreaction products, saturated monocarbonyl, alpha,beta-unsaturated carbonyls, and beta-dicarbonyls, were derivatized with methylhydrazine to give hydrazones, pyrazolines, and pyrazoles, respectively. The derivatives were analyzed by gas chromatography and gas chromatography-mass spectrometry. Lipid peroxidation products identified included formaldehyde, acetaldehyde, acrolein, malonaldehyde, n-hexanal, and 4-hydroxy-2-nonenal. Malonaldehyde levels formed upon 4 hr of irradiation were 0.06 micrograms/mg from squalene, 2.4 micrograms/mg from linolenic acid, and 5.7 micrograms/mg from arachidonic acid. Significant levels of acrolein (2.5 micrograms/mg) and 4-hydroxy-2-nonenal (0.17 micrograms/mg) were also produced from arachidonic acid upon 4 hr irradiation

  5. Microbial and chemical transformation studies of the bioactive marine sesquiterpenes (S)-(+)-curcuphenol and -curcudiol isolated from a deep reef collection of the Jamaican sponge Didiscus oxeata.

    Science.gov (United States)

    El Sayed, Khalid A; Yousaf, Muhammad; Hamann, Mark T; Avery, Mitchell A; Kelly, Michelle; Wipf, Peter

    2002-11-01

    Microbial and chemical transformation studies of the marine sesquiterpene phenols (S)-(+)-curcuphenol (1) and (S)-(+)-curcudiol (2), isolated from the Jamaican sponge Didiscus oxeata, were accomplished. Preparative-scale fermentation of 1 with Kluyveromyces marxianus var. lactis (ATCC 2628) has resulted in the isolation of six new metabolites: (S)-(+)-15-hydroxycurcuphenol (3), (S)-(+)-12-hydroxycurcuphenol (4), (S)-(+)-12,15-dihydroxycurcuphenol (5), (S)-(+)-15-hydroxycurcuphenol-12-al (6), (S)-(+)-12-carboxy-10,11-dihydrocurcuphenol (7), and (S)-(+)-12-hydroxy-10,11-dihydrocurcuphenol (8). Fourteen-days incubation of 1 with Aspergillus alliaceus (NRRL 315) afforded the new compounds (S)-(+)-10beta-hydroxycurcudiol (9), (S)-(+)-curcudiol-10-one (10), and (S)-(+)-4-[1-(2-hydroxy-4-methyl)phenyl)]pentanoic acid (11). Rhizopus arrhizus (ATCC 11145) and Rhodotorula glutinus (ATCC 15125) afforded (S)-curcuphenol-1alpha-D-glucopyranoside (12) and (S)-curcudiol-1alpha-D-glucopyranoside (13) when incubated for 6 and 8 days with 1 and 2, respectively. The absolute configuration of C(10) and C(11) of metabolites 7-9 was established by optical rotation computations. Reaction of 1 with NaNO(2) and HCl afforded (S)-(+)-4-nitrocurcuphenol (14) and (S)-(+)-2-nitrocurcuphenol (15) in a 2:1 ratio. Acylation of 1 and 2 with isonicotinoyl chloride afforded the expected esters (S)-(+)-curcuphenol-1-O-isonicotinate (16) and (S)-(+)-curcudiol-1-O-isonicotinate (17), respectively. Curcuphenol (1) shows potent antimicrobial activity against Candida albicans, Cryptococcus neoformans, methicillin-resistant Staphylococcus aureus, and S. aureus with MIC and MFC/MBC ranges of 7.5-25 and 12.5-50 microg/mL, respectively. Compounds 1 and 3 also display in vitro antimalarial activity against Palsmodium falciparium (D6 clone) with MIC values of 3600 and 3800 ng/mL, respectively (selectivity index >1.3). Both compounds were also active against P. falciparium (W2 clone) with MIC values of 1800 (S

  6. A novel fluorescent probe based on rhodamine hydrazone derivatives bearing a thiophene group for Al³⁺.

    Science.gov (United States)

    Li, Meng-xiao; Zhang, Xia; Fan, Yu-hua; Bi, Cai-feng

    2016-05-01

    In the present work, a novel 5-methyl-thiophene-carbaldehyde-functionalized rhodamine 6G Schiff base (RA) was designed and easily prepared as an Al(3+) fluorescent and colorimetric probe, which could selectively and sensitively detect Al(3+) by showing enhanced fluorescence emission. Meanwhile distinct color variation from colorless to pink also provided 'naked eye' detection of Al(3+), due to the ring spirolactam opening of the rhodamine derivative. Other metal ions (including K(+), Mg(2+), Na(+), Ba(2+), Mn(2+), Cd(2+), Fe(2+), Ni(2+), Pb(2+), Zn(2+), Hg(2+), Co(2+), Li(+), Sr(2+) and Cu(2+)) could only induce limited interference. The detection limit of the fluorescent probe was estimated to be 4.17 × 10(-6) M, the binding constant of the RA-Al(3+) complex was 1.4 × 10(6)  M(-1). Moreover, this fluorescent probe RA possessed high reversibility. As aluminum is a ubiquitous metal in nature and plays vital roles in many biological processes, this chemosensor could be explored for biological study applications. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Targeting the Oxidative Stress Response System of Fungi with Redox-Potent Chemosensitizing Agents

    Science.gov (United States)

    Kim, Jong H.; Chan, Kathleen L.; Faria, Natália C. G.; Martins, M. de L.; Campbell, Bruce C.

    2012-01-01

    The cellular antioxidant system is a target in the antifungal action of amphotericin B (AMB) and itraconazole (ITZ), in filamentous fungi. The sakAΔ mutant of Aspergillus fumigatus, a mitogen-activated protein kinase (MAPK) gene deletion mutant in the antioxidant system, was found to be more sensitive to AMB or ITZ than other A. fumigatus strains, a wild type and a mpkCΔ mutant (a MAPK gene deletion mutant in the polyalcohol sugar utilization system). Complete fungal kill (≥99.9%) by ITZ or AMB was also achieved by much lower dosages for the sakAΔ mutant than for the other strains. It appears msnA, an Aspergillus ortholog to Saccharomyces cerevisiae MSN2 (encoding a stress-responsive C2H2-type zinc-finger regulator) and sakA and/or mpkC (upstream MAPKs) are in the same stress response network under tert-butyl hydroperoxide (t-BuOOH)-, hydrogen peroxide (H2O2)- or AMB-triggered toxicity. Of note is that ITZ-sensitive yeast pathogens were also sensitive to t-BuOOH, showing a connection between ITZ sensitivity and antioxidant capacity of fungi. Enhanced antifungal activity of AMB or ITZ was achieved when these drugs were co-applied with redox-potent natural compounds, 2,3-dihydroxybenzaldehyde, thymol or salicylaldehyde, as chemosensitizing agents. We concluded that redox-potent compounds, which target the antioxidant system in fungi, possess a chemosensitizing capacity to enhance efficacy of conventional drugs. PMID:22438852

  8. Characterization of a meso-chiral isomer of a hexanuclear Cu(II) cage from racemization of the L-alanine Schiff base.

    Science.gov (United States)

    Rajesh, Chinnaiyan Mahalingam; Ray, Manabendra

    2014-09-14

    We are reporting structural characterization of two new hexanuclear cages (H3O)2[Cu3(μ3-OH)(μ3-NH3)(0.5)(L)3]2·8H2O (1) and (H3O)2[Cu3(μ3-OH)(μ3-H2O)(0.5)(L)3]2·8H2O (1a) where L(2-) is the dianionic form of the Schiff base of L-alanine and salicylaldehyde. The complex 1 has two C3 symmetric hydroxo bridged trinuclear halves joined by an ammonia or water molecule at the center through H-bonding. Each of the trinuclear halves is enantiopure but of opposite chirality to the other half, making the hexanuclear unit a meso isomer. Temperature dependent magnetic measurements showed the presence of ferromagnetic interactions among trinuclear Cu(II) units, a rare occurrence among trinuclear Cu(II) complexes. Characterization of the LiHL showed it to be enantiopure. Addition of a base, monitored using optical rotation, showed that racemization occurs as a result of base addition. The racemization depends on the base as well as the temperature. Base or Cu(II) induced racemization of amino acid derivatives has been indicated in a number of cases in the past but structural characterization of the products or formation of this type of chiral hexanuclear architecture was never reported. Structures of the complex and the ligand have a number of interesting H-bonding situations.

  9. Production, Isolation and Radiolabeling Methods for 211AT- Labeling of Biomolecules

    International Nuclear Information System (INIS)

    Wilbur, D.S.; Hamlin, D.K.; Chyan, M.

    2009-01-01

    boron cage molecules as pendant groups for labeling more rapidly metabolized biomolecules. After extensive study, we found that closo-decaborate(2-) moieties were uniquely suited for 211 At labeling, as they underwent very fast (within 30 seconds) and efficient (>70% yields) labeling, were non-toxic, and had minimal affect on the in vivo behavior of the biomolecule that it was attached to. Studies of closo-decaborate(2-) containing different functional groups have been conducted to determine the best candidates for pendant groups to be conjugated with biomolecules. A number of conjugation molecules containing the closo-decaborate(2-) moiety have been prepared and tested. In those studies, intact MAb, Fab' fragments, a peptide (bombesin), biotin derivatives and a small molecule (PSMA) inhibitor have been labeled with both 125 I and 211 At to determine in vivo stability and equivalence of biodistributions. In every example, the 211 At label was found to be very stable to in vivo deastatination. Likewise, the 211 At and 125 I distributions were essentially equivalent in all but a couple of examples. Although the 125 I and 211 At had equivalent distributions, it was found that the closo-decaborate(2-) moiety appears to be retained in some tissues (e.g. kidney and liver) longer than MAb that did not contain that moiety. To circumvent this problem, closo-decaborate(2-) derivatives were prepared that contained a hydrazone functionality between the decaborate(2-) and the biomolecule. In subsequent biodistribution studies, it was shown that the hydrazone linkage was efficiently cleaved in vivo, releasing the radioactivity from kidney. In the examples where the biodistributions of 125 I and 211 At were not equivalent, a hydrazone and phenacyl-closo-decaborate(2-) derivative were involved. Studies are planned to determine why the biodistribution in these examples was not equivalent. In the presentation, examples showing equivalency in biodistributions will be presented, as will

  10. Research on Synthesis of New Azo Calix[4]arene and its Dyeing Properties

    Directory of Open Access Journals (Sweden)

    Tang Jun

    2015-01-01

    Full Text Available With the raw materials of calix[4]arene, benzocaine, tricaine and procaine hydrochloride, three new azo calix[4]arene derivatives—6a, 6b and 6c are synthesized by diazotization–coupling reaction of an aromatic amine, with its yield of 83%, 81% and 83% respectively. The structural characterization is in a way of IR, 1H NMR and elemental analysis. This paper investigates the spectral properties of azo calix[4]arene derivatives under different solution pH conditions through the UV–visible spectroscopy, and researches the dyeing properties through the dyeing curve, color yield test and fastness test. The results show that, with the increase of pH value, the azo calix[4]arene derivatives—6a, 6b and 6c form azo–hydrazone tautomeric isomers with the maximum absorption peak redshift; the dyeing effect of the compound is good, of which the dye–uptake rate of the compound 6a is as high as 78%; the surface depth of color yield is 2.798, and the dry and wet rubbing fastness and the soaping fastness are respectively 4, which is a better disperse dye.

  11. The comparison of spectra and dyeing properties of new azonaphthalimide with analogues azobenzene dyes on natural and synthetic polymers

    Directory of Open Access Journals (Sweden)

    Mozhgan Hosseinnezhad

    2017-05-01

    Full Text Available The aim of the present research was to prepare new acid dyes based on naphthalimides. In this respect a series of monoazo acid dyes have been obtained using 4-amino-N-methyl (alternatively N-butyl-1,8-naphthalimide, aniline and p-nitroaniline as diazo components. 2-Naphthol-6-sulfonic acid (Schaeffer’s acid and 1-naphthol-8-amino-3,6-disulfonic acid (H-acid were used as coupling components. The spectrophotometric properties of the synthesized dyes were investigated in various solvents and compared with analogues azobenzene dyes. It is found, when acid dyes are applied in various solvents and different pH, additional bathochromically shifted bands of different intensity appear in the electronic spectra. This effect is caused by the occurrence of the equilibrium of azo and hydrazone forms in the dyes. The synthesized acid dyes were applied on wool fabrics in order to consider their dyeing properties, fastnesses and the obtainable color gamut. The synthesized dyes represented that they have the ability of dyeing wool and polyamide fabrics and give red to violet hues with good wash, medium light, and good milling and perspiration fastnesses.

  12. Mechanisms of asbestos-induced squamous metaplasia in tracheobronchial epithelial cells

    International Nuclear Information System (INIS)

    Cameron, G.; Woodworth, C.D.; Edmondson, S.; Mossman, B.T.

    1989-01-01

    Within 1 to 4 weeks after exposure to asbestos, differentiated rodent and human tracheobronchial epithelial cells in organ culture undergo squamous metaplasia, a putative preneoplastic lesion characterized by conversion of mucociliary cell types to keratinizing cells. The exogenous addition of retinal acetate (RA) to culture medium of hamster tracheal organ cultures reverses preestablished, asbestos-induced squamous metaplasia, although data suggest that the effectiveness of RA decreases as the length of time between exposure to asbestos and initial application of RA increases. Difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), inhibits squamous metaplasia caused by asbestos or vitamin A deficiency, whereas addition of methylglyoxal bis(guanyl-hydrazone) (MGBG), a structural analog of spermidine and inhibitor of S-adenosylmethionine decarboxylase, causes an enhancement of metaplasia under both circumstances. Basal cell hyperplasia and increased incorporation of 3 H-thymidine by tracheal epithelial cells also are seen after addition of the polyamines, putrescine or spermidine, to tracheal organ cultures, an observation supporting the importance of polyamines in the development of this lesion. The use of retinoids and inhibitors of ODC could be promising as preventive and/or therapeutic approaches for individuals at high risk for development of asbestos-associated diseases

  13. Design and Synthesis of Novel Antimicrobial Acyclic and Heterocyclic Dyes and Their Precursors for Dyeing and/or Textile Finishing Based on 2-N-Acylamino-4,5,6,7-tetrahydro-benzo[b]thiophene Systems

    Directory of Open Access Journals (Sweden)

    Rafat Milad Mohareb

    2011-07-01

    Full Text Available A series of novel polyfunctionalized acyclic and heterocyclic dye precursors and their respective azo (hydrazone counterpart dyes and dye precursors based on conjugate enaminones and/or enaminonitrile moieties were synthesized. The dyes and their precursors are based on 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide, 2-ethoxycarbonyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide or 2-phenylcarbamoyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide systems as precursors. The latter compounds were used to synthesize polyfunctional thiophene-, thiazole-, pyrazole, pyridine-, pyrimidine-, oxazine-, as well as acyclic moieties. The dyes and dye precursors were characterized by elemental analysis and spectral methods. All dyes and their precursors were screened in vitro and evaluated for both their antibacterial and antifungal activities. MIC data of the novel dye systems and their respective precursors showed significant antimicrobial activity against most tested organisms. Some compounds exhibited comparable or even higher efficiency than selected standards. Dyes were applied at 5% depth for disperse dyeing of nylon, acetate and polyester fabrics. Their spectral characteristics and fastness properties were measured and evaluated.

  14. Highly Efficient Release of Glycopeptides from Hydrazide Beads by Hydroxylamine Assisted PNGase F Deglycosylation for N-Glycoproteome Analysis.

    Science.gov (United States)

    Huang, Junfeng; Wan, Hao; Yao, Yating; Li, Jinan; Cheng, Kai; Mao, Jiawei; Chen, Jin; Wang, Yan; Qin, Hongqiang; Zhang, Weibing; Ye, Mingliang; Zou, Hanfa

    2015-10-20

    Selective enrichment of glycopeptides from complex sample followed by cleavage of N-glycans by PNGase F to expose an easily detectable mark on the former glycosylation sites has become the popular protocol for comprehensive glycoproteome analysis. On account of the high enrichment specificity, hydrazide chemistry based solid-phase extraction of N-linked glycopeptides technique has sparked numerous interests. However, the enzymatic release of glycopeptides captured by hydrazide beads through direct incubation of the beads with PNGase F is not efficient due to the inherent steric hindrance effect. In this study, we developed a hydroxylamine assisted PNGase F deglycosylation (HAPD) method using the hydroxylamine to release glycopeptides captured on the hydrazide beads through the cleavage of hydrazone bonds by transamination followed with the PNGase F deglycosylation of the released glycopeptides in the free solution. Because of the homogeneous condition for the deglycosylation, the recovery of deglycosylated peptides (deglycopeptides) was improved significantly. It was found that 27% more N-glycosylation sites were identified by the HAPD strategy compared with the conventional method. Moreover, the ratio of identified N-terminal glycosylated peptides was improved over 5-fold.

  15. Role of protein-bound carbonyl groups in the formation of advanced glycation endproducts.

    Science.gov (United States)

    Liggins, J; Furth, A J

    1997-08-22

    Several mechanisms have been postulated for the formation of advanced glycation endproducts (AGEs) from glycated proteins; they all feature protein-bound carbonyl intermediates. Using 2,4-dinitrophenylhydrazine (DNPH), we have detected these intermediates on bovine serum albumin, lysozyme and beta-lactoglobulin after in vitro glycation by glucose or fructose. Carbonyls were formed in parallel with AGE-fluorophores, via oxidative Maillard reactions. Neither Amadori nor Heyns products contributed to the DNPH reaction. Fluorophore and carbonyl yields were much enhanced in lipid-associated proteins, but both groups could also be detected in lipid-free proteins. When pre-glycated proteins were incubated in the absence of free sugar, carbonyl groups were rapidly lost in a first-order reaction, while fluorescence continued to develop beyond the 21 days of incubation. Another unexpected finding was that not all carbonyl groups were blocked by aminoguanidine, although there was complete inhibition of reactions leading to AGE-fluorescence. It is suggested that carbonyls acting as fluorophore precursors react readily with aminoguanidine, while others are resistant to this hydrazine, possibly because they are involved in ring closure. Factors influencing the relative rates of acyclisation and hydrazone formation are discussed, together with possible implications for antiglycation therapy.

  16. A selectively rhodamine-based colorimetric probe for detecting copper(II) ion.

    Science.gov (United States)

    Zhang, Jiangang; Zhang, Li; Wei, Yanli; Chao, Jianbing; Shuang, Shaomin; Cai, Zongwei; Dong, Chuan

    2014-11-11

    A novel rhodamine derivative 3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone (BMSRH) has been synthesized by reacting rhodamine B hydrazide with 3-bromo-5-methylsalicylaldehyde and developed as a new colorimetric probe for the selective and sensitive detection of Cu2+. Addition of Cu2+ to the solution of BMSRH results in a rapid color change from colorless to red together with an obvious new band appeared at 552 nm in the UV-vis absorption spectra. This change is attributed to the spirocycle form of BMSRH opened via coordination with Cu2+ in a 1:1 stoichiometry and their association constant is determined as 3.2×10(4) L mol(-1). Experimental results indicate that the BMSRH can provide a rapid, selective and sensitive response to Cu2+ with a linear dynamic range 0.667-240 μmol/L. Common interferent ions do not show any interference on the Cu2+ determination. It is anticipated that BMSRH can be a good candidate probe and has potential application for Cu2+ determination. The proposed probe exhibits the following advantages: a quick, simple and facile synthesis. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Evaluation of the concentrations and distribution of carbonyl compounds in selected areas of a Brazilian bus terminal.

    Science.gov (United States)

    de Mendonça Ochs, Soraya; de Almeida Furtado, Leonardo; Pereira Netto, Annibal Duarte

    2015-06-01

    This study describes the determination of 30 carbonyl compounds (CCs) in three areas (bus boarding platform, passenger circulation area, and a pastry shop) of the Presidente João Goulart Bus Terminal, located at Niterói City, RJ, Brazil, and in an open area 700 m distant from the terminal. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, during May to July 2012. The hydrazones formed were analyzed using rapid resolution liquid chromatography with UV detection. The studied locations showed distinct profiles of distribution of CC. The circulation area, which is influenced by different pollution sources, presented an intermediate profile between that of the pastry shop and boarding platform. Formaldehyde and acetaldehyde were the most abundant CC, but acetaldehyde predominated in the pastry shop once it is a by-product of baking yeast fermentation. Samples taken in the pastry shop and circulation area showed significant concentrations of hexanaldehyde and nonanaldehyde emitted during cooking. The pastry shop showed the largest level of total CC among the studied areas followed by the circulation area, the boarding platform, and the open area.

  18. Preparation and Characterization of Space Durable Polymer Nanocomposite Films from Functionalized Carbon Nanotubes

    Science.gov (United States)

    Delozier, D. M.; Connell, J. W.; Smith, J. G.; Watson, K. A.

    2003-01-01

    Low color, flexible, space durable polyimide films with inherent, robust electrical conductivity have been under investigation as part of a continuing materials development activity for future NASA space missions involving Gossamer structures. Electrical conductivity is needed in these films to dissipate electrostatic charge build-up that occurs due to the orbital environment. One method of imparting conductivity is through the use of single walled carbon nanotubes (SWNTs). However, the incompatibility and insolubility of the SWNTs severely hampers their dispersion in polymeric matrices. In an attempt to improve their dispersability, SWNTs were functionalized by the reaction with an alkyl hydrazone. After this functionalization, the SWNTs were soluble in select solvents and dispersed more readily in the polymer matrix. The functionalized SWNTs were characterized by Raman spectroscopy and thermogravimetric analysis (TGA). The functionalized nanotubes were dispersed in the bulk of the films using a solution technique. The functionalized nanotubes were also applied to the surface of polyimide films using a spray coating technique. The resultant polyimide nanocomposite films were evaluated for nanotube dispersion, electrical conductivity, mechanical, and optical properties and compared with previously prepared polyimide-SWNT samples to assess the effects of SWNT functionalization.

  19. Memristors: Memory elements in potato tubers.

    Science.gov (United States)

    Volkov, Alexander G; Nyasani, Eunice K; Blockmon, Avery L; Volkova, Maya I

    2015-01-01

    A memristor is a nonlinear element because its current-voltage characteristic is similar to that of a Lissajous pattern for nonlinear systems. This element was postulated recently and researchers are looking for it in different biosystems. We investigated electrical circuitry of red Irish potato tubers (Solanum tuberosum L.). The goal was to discover if potato tubers might have a new electrical component - a resistor with memory. The analysis was based on a cyclic current-voltage characteristic where the resistor with memory should manifest itself. We found that the electrostimulation by bipolar sinusoidal or triangle periodic waves induces electrical responses in the potato tubers with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in potato tubers. Our results demonstrate that a voltage gated K(+) channel in the excitable tissue of potato tubers has properties of a memristor. Uncoupler carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone decreases the amplitude of electrical responses at low and high frequencies of bipolar periodic sinusoidal or triangle electrostimulating waves. The discovery of memristors in plants creates a new direction in the understanding of electrical phenomena in plants.

  20. C-H Activation and Alkyne Annulation via Automatic or Intrinsic Directing Groups: Towards High Step Economy.

    Science.gov (United States)

    Zheng, Liyao; Hua, Ruimao

    2018-06-01

    Direct transformation of carbon-hydrogen bond (C-H) has emerged to be a trend for construction of molecules from building blocks with no or less prefunctionalization, leading high atom and step economy. Directing group (DG) strategy is widely used to achieve higher reactivity and selectivity, but additional steps are usually needed for installation and/or cleavage of DGs, limiting step economy of the overall transformation. To meet this challenge, we proposed a concept of automatic DG (DG auto ), which is auto-installed and/or auto-cleavable. Multifunctional oxime and hydrazone DG auto were designed for C-H activation and alkyne annulation to furnish diverse nitrogen-containing heterocycles. Imidazole was employed as an intrinsic DG (DG in ) to synthesize ring-fused and π-extended functional molecules. The alkyne group in the substrates can also be served as DG in for ortho-C-H activation to afford carbocycles. In this account, we intend to give a review of our progress in this area and brief introduction of other related advances on C-H functionalization using DG auto or DG in strategies. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. An injectable and biodegradable hydrogel based on poly(α,β-aspartic acid) derivatives for localized drug delivery.

    Science.gov (United States)

    Lu, Caicai; Wang, Xiaojuan; Wu, Guolin; Wang, Jingjing; Wang, Yinong; Gao, Hui; Ma, Jianbiao

    2014-03-01

    An injectable hydrogel via hydrazone cross-linking was prepared under mild conditions without addition of cross-linker or catalyst. Hydrazine and aldehyde modified poly(aspartic acid)s were used as two gel precursors. Both of them are water-soluble and biodegradable polymers with a protein-like structure, and obtained by aminolysis reaction of polysuccinimide. The latter can be prepared by thermal polycondensation of aspartic acid. Hydrogels were prepared in PBS solution and characterized by different methods including gel content and swelling, Fourier transformed-infrared spectroscopy, and in vitro degradation experiment. A scanning electron microscope viewed the interior morphology of the obtained hydrogels, which showed porous three-dimensional structures. Different porous sizes were present, which could be well controlled by the degree of aldehyde substitution in precursor poly(aspartic acid) derivatives. The doxorubicin-loaded hydrogels were prepared and showed a pH-sensitive release profile. The release rate can be accelerated by decreasing the environmental pH from a physiological to a weak acidic condition. Moreover, the cell adhesion and growth behaviors on the hydrogel were studied and the polymeric hydrogel showed good biocompatibility. Copyright © 2013 Wiley Periodicals, Inc.

  2. In silico validation and structure activity relationship study of a series of pyridine-3-carbohydrazide derivatives as potential anticonvulsants in generalized and partial seizures.

    Science.gov (United States)

    Sinha, Reema; Sara, Udai Vir Singh; Khosa, Ratan Lal; Stables, James; Jain, Jainendra

    2013-06-01

    A series of twelve compounds (Compounds RNH1-RNH12) of acid hydrazones of pyridine-3-carbohydrazide or nicotinic acid hydrazide was synthesized and evaluated for anticonvulsant activity by MES, scPTZ, minimal clonic seizure and corneal kindling seizure test. Neurotoxicity was also determined for these compounds by rotarod test. Results showed that halogen substitution at meta and para position of phenyl ring exhibited better protection than ortho substitution. Compounds RNH4 and RNH12, were found to be the active analogs displaying 6Hz ED50 of 75.4 and 14.77 mg/kg while the corresponding MES ED50 values were 113.4 and 29.3 mg/kg respectively. In addition, compound RNH12 also showed scPTZ ED50 of 54.2 mg/kg. In the series, compound RNH12 with trifluoromethoxy substituted phenyl ring was the most potent analog exhibiting protection in all four animal models of epilepsy. Molecular docking study has also shown significant binding interactions of these two compounds with 1OHV, 2A1H and 1PBQ receptors. Thus, N-[(meta or para halogen substituted) benzylidene] pyridine-3-carbohydrazides could be used as lead compounds in anticonvulsant drug design and discovery.

  3. Evidence for a specific glutamate/H+ cotransport in isolated mesophyll cells

    International Nuclear Information System (INIS)

    McCutcheon, S.L.; Bown, A.W.

    1987-01-01

    Mechanically isolated Asparagus sprengeri Regel mesophyll cells were suspended in 1 millimolar CaSO 4 . Immediate alkalinization of the medium occurred on the addition of 1 millimolar concentrations of L-glutamate (Glu) and its analog L-methionine-D,L-sulfoximine (L-MSO). D-Glu and the L isomers of the protein amino acids did not elicit alkalinization. L-Glu dependent alkalinization was transient and acidification resumed after approximately 30 to 45 minutes. At pH 6.0, 5 millimolar L-Glu stimulated initial rates of alkalinization that varied between 1.3 to 4.1 nmol H + /10 6 cells minute. L-Glu dependent alkalinization was saturable, increased with decreasing pH, was inhibited by carbonyl cyanide-p-trichloromethoxyphenyl hydrazone (CCCP), and was not stimulated by light. Uptake of L-[U- 14 C]glutamate increased as the pH decreased from 6.5 to 5.5, and was inhibited by L-MSO. L-Glu had no influence on K + efflux. Although evidence for multiple amino acid/proton cotransport systems has been found in other tissues, the present report indicates that a highly specific L-Glu/proton uptake process is present in Asparagus mesophyll cells

  4. Preparation, spectroscopic studies and X-ray structure of homobinuclear lanthanide(III complexes derived from 2,6-diformyl-4-chlorophénol-bis-(2’-hydroxy-benzoylhydrazone

    Directory of Open Access Journals (Sweden)

    Pepe Marcel Haba

    2006-06-01

    Full Text Available Reaction of the 2,6-diformyl-4-chlorophenol-bis-(2'-hydroxy-benzoylhydrazone with Ln(NO33.nH2O (n = 5 or 6 and Ln = Y, La, Ce, Pr, Nd, Sm, Gd, Dy, Er and Yb produces homobinuclear complexes. These complexes have been characterized by analysis, molar conductance, magnetic measurements, infrared spectral studies and X-ray diffraction. The analytical data showed 1:3 (metal:ligand stoichiometry. Molar conductance measurements in dmf indicate 1:3 electrolytes in all cases. Magnetic moment values are close proximity of the Van Vleck values. IR studies suggest the coordination of the ligand is through the azomethine, the phenolic oxygen atom and the carbonyl oxygen of the hydrazonic moiety. The nitrate ion is also found to be ionic in all the complexes. An X-ray structure determination of [C66H48N12O15Cl3Er2]Cl2NO3.5H2O confirms the conclusion from the spectroscopic studies and show that the erbium is at the centre of a tricapped trigonal prism with coordination number nine. In all the complexes the lanthanide ions have substantially similar coordination.

  5. A Simple and Selective Spectrophotometric Method for the Determination of Trace Gold in Real, Environmental, Biological, Geological and Soil Samples Using Bis (Salicylaldehyde Orthophenylenediamine

    Directory of Open Access Journals (Sweden)

    Rubina Soomro

    2008-01-01

    Full Text Available A simple high sensitive, selective, and rapid spectrophotometric method for the determination of trace gold based on the rapid reaction of gold(III with bis(salicylaldehydeorthophenylenediamine (BSOPD in aqueous and micellar media has been developed. BSOPD reacts with gold(III in slightly acidic solution to form a 1:1 brownish-yellow complex, which has an maximum absorption peak at 490 nm in both aqueous and micellar media. The most remarkable point of this method is that the molar absorptivities of the gold-BSOPD complex form in the presence of the nonionic TritonX-100 surfactant are almost a 10 times higher than the value observed in the aqueous solution, resulting in an increase in the sensitivity and selectivity of the method. The apparent molar absorptivities were found to be 2.3 × 104 L mol−1 cm−1 and 2.5 × 105 L mol−1 cm−1 in aqueous and micellar media, respectively. The reaction is instantaneous and the maximum absorbance was obtained after 10 min at 490 nm and remains constant for over 24 h at room temperature. The linear calibration graphs were obtained for 0.1 –30 mg L−1 and 0.01 –30 mg L−1 of gold(III in aqueous and surfactant media, respectively. The interference from over 50 cations, anions and complexing agents has been studied at 1 mg L−1 of Au(III; most metal ions can be tolerated in considerable amounts in aqueous micellar solutions. The Sandell’s sensitivity, the limit of detection and relative standard deviation (n = 9 were found to be 5 ng cm−2, 1 ng mL−1 and 2%, respectively in aqueous micellar solutions. Its sensitivity and selectivity are remarkably higher than that of other reagents in the literature. The proposed method was successfully used in the determination of gold in several standard reference materials (alloys and steels, environmental water samples (potable and polluted, and biological samples (blood and urine, geological, soil and complex synthetic mixtures. The results obtained agree well with those samples analyzed by atomic absorption spectrophotometry (AAS.

  6. Studies in stability constants of schiff base hydrazone complexes with transition metal ions. Effect of ligand on seed germination

    Science.gov (United States)

    Meshram, U. P.; Pethe, G. B.; Yaul, A. R.; Khobragade, B. G.; Narwade, M. L.

    2017-10-01

    Spectrophotometric investigation of Cu (II), Ni(II), Co(II), and Fe(III) complexes with 2,4-dihydroxyacetophonone 2,4-dichlorobenzoylhydrazone (H2L1) and 2,4-didydroxy-5-nitroacetophenone 2,4-dichlorobenzoylhydrazone (H2L2) shows 1: 1 and 1: 2 complex formation between the pH range of 3.0 to 6.0 and also studied by jobs variation method at 0.1 M ionic strength at 30 ± 1°C specrtophotometrically. The conditional stability constants are determined for 1: 1 complexes. Effect of H2L1 and H2L2 ligand and its complexes on seed germination is studied.

  7. Imaging and Targeted Therapy of Multidrug Resistance. Final Report

    International Nuclear Information System (INIS)

    Piwnica-Worms, David

    2009-01-01

    One focus area of DOE Office of Science was the Imaging of Gene Expression in Health and Disease in real time in tissue culture, whole animals and ultimately patients. Investigators of the Molecular Imaging Group, Washington University Medical School, ascribed to this objective and a major focus of this group directly tied into the DOE program through their efforts targeting the multidrug resistance gene (MDR1). Our plans for continuation of the program were to extend and build on this line of investigation, incorporating new molecular tools into our methodology to selectively inhibit MDR1 gene expression with novel modulation strategies. Two approaches were to be pursued: (1) high throughput screening of compounds that disrupted mutant p53 transactivation of the MDR1 promoter, and (2) knockdown of MDR1 messenger RNA with retroviral-mediated delivery of small interfering RNA constructs. These would be combined with our continuing effort to synthesize ligands and examine structure-activity relationships of bis-salicylaldehydes labeled with gallium-68 to generate PET agents for imaging MDR1 P-glycoprotein function. We would be uniquely positioned to correlate therapeutic modulation of MDR1 gene expression and protein function in the same systems in vivo using PET and bioluminescence reporters. Use of animal models such as the mdr1a/1b(-/-) gene deleted mice would also have enabled refined analysis of modulation and tracer pharmacokinetics in vivo. Overall, this DOE program and resultant tools would enable direct monitoring of novel therapeutic strategies and the MDR phenotype in relation to gene expression and protein function in vivo.

  8. Highly selective probe based on imine linkage for Zn{sup 2+} and HSO{sub 3}{sup −} in mixed aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Kamaljot; Chaudhary, Savita; Singh, Sukhjinder; Mehta, S.K., E-mail: skmehta@pu.ac.in

    2015-04-15

    A simple salicylaldehyde derived Schiff base N, N′- bis (p-chloro salicylidene)-1, 2- ethylenediamine (L) was synthesized and characterized. The receptor demonstrates simultaneous dual channel chromogenic and fluorogenic signaling towards HSO{sub 3}{sup −} and Zn{sup 2+} in mixed aqueous media. Solvatochromism was employed systematically for modulating its optoelectronic properties. The probe was successfully assessed to monitor HSO{sub 3}{sup −} detection via UV–vis spectroscopy. DFT calculations and {sup 1}H NMR spectroscopy further support the results based on shifting of equilibrium. Moreover, the sensor showed large fluorescence enhancement with blue-shift of 48 nm after addition of Zn{sup 2+}. The probe exhibits high selectivity over other competitive ions with high detection limit of 6.54×10{sup −5} M and 3.21×10{sup −6} M for HSO{sub 3}{sup −} and Zn{sup 2+}, respectively. Importantly, this is one of the rare reports in which Schiff base was utilized for the fabrication of chromogenic or fluorogenic sensor using solvent effect for multianalyte detection. - Highlights: • Easy synthesis of highly selective and sensitive Salicylideneaniline moiety. • Solvatochromism induced tautomerism between the enol-imine and keto-amine forms. • Computational studies revealing the effect of solvent on stability of NH form. • Discriminative detection of HSO{sub 3}{sup −} and Zn{sup 2+} by different spectroscopic techniques. • Optical feedbacks as absorption transitions with HSO{sub 3}{sup −} on bisulphite adduct formation. • Fluorescence enhancement for Zn{sup 2+} based on imine binding mechanism.

  9. Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone.

    Science.gov (United States)

    Bajusz, S; Janaky, T; Csernus, V J; Bokser, L; Fekete, M; Srkalovic, G; Redding, T W; Schally, A V

    1989-08-01

    Metal complexes related to the cytotoxic complexes cisplatin [cis-diamminedichloroplatinum(II)] and transbis(salicylaldoximato)copper(II) were incorporated into suitably modified luteinizing hormone-releasing hormone (LH-RH) analogues containing D-lysine at position 6. Some of the metallopeptides thus obtained proved to be highly active LH-RH agonists or antagonists. For instance, SB-40, a PtCl2-containing metallopeptide in which platinum is coordinated to an N epsilon-(DL-2,3-diaminopropionyl)-D-lysine residue [D-Lys(DL-A2pr] at position 6, showed 50 times higher LH-releasing potency than the native hormone. SB-95, [Ac-D-Nal(2)1,D-Phe(pCl)2, D-Pal(3)2, Arg5,D-Lys[DL-A2pr(Sal2Cu)]6,D-Ala10]LH-RH, where Nal(2) is 3-(2-naphthyl)alanine, Pal(3) is 3-(3-pyridyl)alanine, and copper(II) is coordinated to the salicylideneimino moieties resulting from condensation of salicylaldehyde with D-Lys(DL-A2pr)6, caused 100% inhibition of ovulation at a dose of 3 micrograms in rats. Most metallopeptide analogues of LH-RH showed high affinities for the membrane receptors of rat pituitary and human breast cancer cells. Some of these metallopeptides had cytotoxic activity against human breast cancer and prostate cancer cell lines in vitro (this will be the subject of a separate paper on cytotoxicity evaluation). Such cytostatic metallopeptides could be envisioned as targeted chemotherapeutic agents in cancers that contain receptors for LH-RH-like peptides.

  10. Synthesis, crystal structure and photophysical properties of (E)-4-(4-(2-hydroxybenzylideneamino)benzyl)oxazolidin-2-one

    International Nuclear Information System (INIS)

    Kumari, Rekha; Varghese, Anitha; George, Louis

    2016-01-01

    A new Schiff base, (4-(benzylideneamino)benzyl)oxazolidin-2-one has been synthesised from 4-(4-aminobenzyl)oxazolidin-2-one and salicylaldehyde by a simple condensation reaction. Single-crystal X-ray analysis of (E)-4-(4-(2-hydroxybenzylideneamino) benzyl)oxazolidin-2-one (HBOA) revealed that there is a 1-D, slipped, face-to-face motif with off-set, head-to-tail stacked columns. Detailed studies on photophysical properties of the synthesised compound in solutions indicate their potential applications in the field of organic light emitting devices and nonlinear optical materials. Absorption and fluorescence study of HBOA has been conducted in a series of solvents with increasing polarity at room temperature. Ground and excited state dipole moments have been determined experimentally by using Lippert–Mataga polarity function, Bakhshiev solvent polarity parameter, Kawskii–Chamma–Viallet solvent polarity parameter and RichardtГ—Віs microscopic solvent polarity parameter. Due to the considerable π-electron density redistribution, the excited state dipole moment was found to be larger than that of the ground state. The ground state dipole moment value was determined by quantum chemical method which was used to estimate excited state dipole moment through solvatochromic correlations. Kamlet–Taft and Catalan methods were used to get the information of both non-specific solute–solvent interactions and hydrogen bonding interactions. TD-DFT (B3LYP/6-311G(d,p)) has been used for the determination of HOMO–LUMO energies. Mulliken charges and Molecular electrostatic potential were also evaluated from DFT calculations.

  11. Peroxo complexes of molybdenum(VI), tungsten(VI), uranium(VI), zirconium(IV) and thorium(IV) ions containing tridentate Schiff bases derived from salicylaldehyde and amino acids

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Khan, A.R.

    1997-01-01

    The synthesis of peroxo complexes of molybdenum(VI), tungsten(VI), uranium(VI), zirconium(IV), thorium(IV) and their possible oxygen transfer reactions is presented. An attempt has also been made to study the size of the metal ions and the electronic effect derived from the tridentate Schiff bases on the v 1 (O-O) mode of the complexes in their IR spectra

  12. CATALYST-FREE REACTIONS UNDER SOLVENT-FEE CONDITIONS: MICROWAVE-ASSISTED SYNTHESIS OF HETEROCYCLIC HYDRAZONES BELOW THE MELTING POINT OF NEAT REACTANTS

    Science.gov (United States)

    The reaction of neat 5- or 8-oxobenzopyran-2(1H)-ones with a variety of aromatic and heteroaromatic hydrazines are remarkable accelerated upon irradiation in a household microwave oven in the absence of any catalyst, solid support or solvent thus providing an environmentally frie...

  13. Synthesis, Molecular Docking Studies, In Vitro Antimicrobial and Antifungal Activities of Novel Dipeptide Derivatives Based on N-(2-(2-Hydrazinyl-2-oxoethylamino-2-oxoethyl-Nicotinamide

    Directory of Open Access Journals (Sweden)

    Gaber Moustafa

    2018-03-01

    Full Text Available A series of linear dipeptide derivatives (4–10 were prepared and evaluated as antimicrobial agents via the synthesis of N-(2-(2-hydrazinyl-2-oxoethylamino-2-oxoethyl nicotinamide (4. Compound 4 was reacted with 4-chlorobenzaldehyde or 4-hydroxybenzaldehyde, to give the hydrazones 5 and 6, respectively. On the other hand, Compound 4 was coupled with phenylisocyanate or methylisothiocyanate to give Compounds 7 and 8, respectively. The latter compounds (7 and 8 were coupled with chloroacetic acid to give oxazolidine (9 and thiazolidine (10, respectively. The newly synthesized dipeptide compounds were confirmed by means of their spectral data. The antimicrobial activity of the newly synthesized compounds 4–10 was evaluated by agar well diffusion, and they showed good activity. Compounds 4, 5, and 9 gave the most promising activity in this study. Most of the tested compounds possessed MIC values ranging from 50 to 500 µg/mL. Furthermore, docking studies were carried out on enoyl reductase from E. coli and cytochrome P450 14 α-sterol demethylase (Cyp51 from Candida albicans active sites. The MolDock scores of the seven tested compounds ranged between −117 and −171 and between −107 and −179, respectively.

  14. Systematic Comparison of Reverse Phase and Hydrophilic Interaction Liquid Chromatography Platforms for the Analysis of N-linked Glycans

    Science.gov (United States)

    Walker, S. Hunter; Carlisle, Brandon C.; Muddiman, David C.

    2013-01-01

    Due to the hydrophilic nature of glycans, reverse phase chromatography has not been widely used as a glycomic separation technique coupled to mass spectrometry. Other approaches such as hydrophilic interaction chromatography and porous graphitized carbon chromatography are often employed, though these strategies frequently suffer from decreased chromatographic resolution, long equilibration times, indefinite retention, and column bleed. Herein, it is shown that through an efficient hydrazone formation derivatization of N-linked glycans (∼4 hr of additional sample preparation time which is carried out in parallel), numerous experimental and practical advantages are gained when analyzing the glycans by online reverse phase chromatography. These benefits include an increased number of glycans detected, increased peak capacity of the separation, and the ability to analyze glycans on the identical liquid chromatography-mass spectrometry platform commonly used for proteomic analyses. The data presented show that separation of derivatized N-linked glycans by reverse phase chromatography significantly out-performs traditional separation of native or derivatized glycans by hydrophilic interaction chromatography. Furthermore, the movement to a more ubiquitous separation technique will afford numerous research groups the opportunity to analyze both proteomic and glycomic samples on the same platform with minimal time and physical change between experiments, increasing the efficiency of ‘multi-omic’ biological approaches. PMID:22954204

  15. Spectroscopic studies of the reaction between bovine serum amine oxidase (copper-containing) and some hydrazides and hydrazines.

    Science.gov (United States)

    Morpurgo, L; Befani, O; Sabatini, S; Mondovì, B; Artico, M; Corelli, F; Massa, S; Stefancich, G; Avigliano, L

    1988-01-01

    The carbonyl cofactor of bovine serum amine oxidase, recently identified as pyrroloquinoline quinone [Ameyama, Hayashi, Matsushita, Shinagawa & Adachi (1984) Agric. Biol. Chem. 48, 561-565; Lobenstein-Verbeek, Jongejan, Frank & Duine (1984) FEBS Lett. 170, 305-309], reacts stoichiometrically and irreversibly with hydrazides of phenylacetic acid and of benzoic acid. With the phenylacetic hydrazides a reversible intermediate step was detected by competition with substrate, carbonylic reagents or phenylhydrazine, a typical inhibitor of the enzyme. All hydrazides form an intense broad band with maximum absorbance in a narrow wavelength range (350-360 nm), irrespective of the acyl group, suggesting that the transition is located on the organic cofactor. A different situation is found with some phenylhydrazines, where extended conjugation can occur between the cofactor and the phenyl pi-electron system via the azo group, as shown by the lower energy and higher intensity of the transition. In this case the transition is sensitive to substituents in the phenyl ring. The c.d. spectrum of the adducts is influenced by the type of hydrazide (derived from phenylacetic acid or benzoic acid), by pH and by NN-diethyldithiocarbamate binding to copper, probably as a result of shifts of equilibria between hydrazone-azo tautomers. PMID:3146976

  16. Flow injection determination of hydrogen peroxide using catalytic effect of cobalt(II) ion on a dye formation reaction.

    Science.gov (United States)

    Kurihara, Makoto; Muramatsu, Miyuki; Yamada, Mari; Kitamura, Naoya

    2012-07-15

    A novel flow injection photometric method was developed for the determination of hydrogen peroxide in rainwater. This method is based on a cobalt(II)-catalyzed oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone (MBTH) with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline (DAOS) as a modified Trinder's reagent to produce intensely colored dye (λ(max)=530nm) in the presence of hydrogen peroxide at pH 8.4. In this method, 1,2-dihydroxy-3,5-benzenedisulfonic acid (Tiron) acted as an activator for the cobalt(II)-catalyzed reaction and effectively increased the peak height for hydrogen peroxide. The linear calibration graphs were obtained in the hydrogen peroxide concentration range 5×10(-8) to 2.2×10(-6)mol dm(-3) at a sampling rate of 20h(-1). The relative standard deviations for ten determinations of 2.2×10(-6) and 2×10(-7)mol dm(-3) hydrogen peroxide were 1.1% and 3.7%, respectively. The proposed method was successfully applied to the determination of hydrogen peroxide in rainwater samples and the analytical results agreed fairly well with the results obtained by different two reference methods; peroxidase method and hydrogen peroxide electrode method. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Self-assembled nanocomplexes of anionic pullulan and polyallylamine for DNA and pH-sensitive intracellular drug delivery

    International Nuclear Information System (INIS)

    Vora, Lalit; Tyagi, Monica; Patel, Ketan; Gupta, Sanjay; Vavia, Pradeep

    2014-01-01

    The amalgamation of chemotherapy and gene therapy is promising treatment option for cancer. In this study, novel biocompatible self-assembled nanocomplexes (NCs) between carboxylmethylated pullulan t335 (CMP) with polyallylamine (CMP–PAA NCs) were developed for plasmid DNA (pDNA) and pH-sensitive doxorubicin (DOX) delivery. DOX was conjugated to CMP (DOX–CMP) via hydrazone and confirmed by FTIR and 1 H-NMR. In vitro release studies of pH-sensitive DOX–CMP conjugate showed 23 and 85 % release after 48 h at pH 7.4 (physiological pH) and pH 5 (intracellular/tumoral pH), respectively. The CMP–PAA NCs or DOX–CMP–PAA NCs self-assembled into a nanosized (<250 nm) spherical shape as confirmed by DLS and TEM. The hemolysis and cytotoxicity study indicated that the CMP–PAA NCs did not show cytotoxicity in comparison with plain polyallylamine. Gel retardation assay showed complete binding of pDNA with CMP–PAA NCs at 1:2 weight ratio. CMP–PAA NCs/pDNA showed significantly higher transfection in HEK293 cells compared to PAA/pDNA complexes. Confocal imaging demonstrated successful cellular uptake of DOX–CMP–PAA NCs in HEK293 cells. Thus, NCs hold great potential for targeted pDNA and pH-sensitive intratumoral drug delivery

  18. Facile synthesis and antimicrobial evaluation of some new heterocyclic compounds incorporating a biologically active sulfamoyl moiety.

    Science.gov (United States)

    Darwish, Elham S

    2014-01-01

    A facile and convenient synthesis of new heterocyclic compounds containing a sulfamoyl moiety suitable for use as antimicrobial agents was reported. The precursor 3-oxo-3-phenyl-N-(4-sulfamoylphenyl)propionamide was coupled smoothly with arenediazonium salt producing hydrazones which reacted with malononitrile or triethylorthoformate affording pyridazine and triazine derivatives, respectively. Also, the reactivity of the same precursor with DMF-DMA was followed by aminotriazole; aromatic aldehydes was followed by hydrazine hydrate, triethylorthoformate, or thiourea affording triazolo[1,5-a]pyrimidine, pyrazole, acrylamide, and dihydropyrimidine derivatives, respectively. On the other hand, treatment of the precursor propionamide with phenyl isothiocyanate and KOH in DMF afforded the intermediate salt which was treated with dilute HCl followed by 2-bromo-1-phenylethanone affording carboxamide derivative. While the same intermediate salt reacted in situ with chloroacetone, ethyl 2-chloroacetate, 3-(2-bromoacetyl)-2H-chromen-2-one, methyl iodide, or 2-oxo-N-phenylpropane hydrazonoyl chloride afforded the thiophene, ketene N,S-acetal, and thiadiazole derivatives, respectively. The structure of the new products was established based on elemental and spectral analysis. Antimicrobial evaluation of some selected examples from the synthesized products was carried out whereby four compounds were found to have moderate activities and one compound showed the highest activity.

  19. Spectral and cyclic voltammetric studies on some intramolecularly hydrogen bonded arylhydrazones: Crystal and molecular structure of 2-(2-(3-nitrophenyl)hydrazono)-5,5-dimethylcyclohexane-1,3-dione

    Science.gov (United States)

    Sethukumar, A.; Arul Prakasam, B.

    2010-01-01

    A series of arylhydrazone derivatives ( 1- 7) were prepared by the coupling of acetylacetone/dimedone with respective aromatic diazonium salts and characterized by IR, 1H and 13C NMR spectra. The IR and NMR spectral data clearly manifests the effective intramolecular hydrogen bonding in all the cases. Cyclic voltammetric studies certainly indicate that in all the cases the reduced center is C dbnd N bond of hydrazonic moiety. The single crystal X-ray structural analysis of 2-(2-(3-nitrophenyl)hydrazono)-5,5-dimethylcyclohexane-1,3-dione ( 6) is also reported. Single crystal X-ray analysis of 6 evidences the intramolecular hydrogen bonding with the N(2)⋯O(4) distance of 2.642(15) Å, which can be designated as S(6) according to Etter's graph nomenclature. The cyclohexane ring conformation in the molecule ( 6) can be described as an envelope. RAHB studies suggest that the resonance assistance for hydrogen bonding is significantly reduced for the compound ( 6) due to the non-planarity of the six atoms which are involved in resonant cycle S(6) of Etter's graph. The planarity of the resonant cycle S(6) is very much disturbed by the conformational requirement of the cyclohexane ring and hence RAHB concept is less operative in this case.

  20. Synthesis, anti-inflammatory, analgesic and anticonvulsant activities of some new 4,6-dimethoxy-5-(heterocyclesbenzofuran starting from naturally occurring visnagin

    Directory of Open Access Journals (Sweden)

    E.R. El-Sawy

    2014-12-01

    Full Text Available Novel 3-(4,6-dimethoxybenzofuran-5-yl-1-phenyl-1H-pyrazole-4-carboxaldehyde (3 and 3-chloro-3-(4,6-dimethoxybenzofuran-5-ylpropenal (4 were prepared via Vilsmeier–Haack reaction of 1-(4,6-dimethoxybenzofuran-5-ylethanone (1 and its hydrazone derivative 2. Reaction of compound 4 with some hydrazine derivatives, namely hydrazine hydrate, phenylhydrazine and benzylhydrazine hydrochloride led to the formation of pyrazole derivatives 5–8, respectively. On the other hand, reaction of compound 4 with thiourea, urea or guanidine gave the pyrimidine derivatives 9–11, respectively. Reaction of amino compound 11 with acetic anhydride, benzoyl chloride and benzenesulphonyl chloride yielded N-substituted pyrimidine derivatives 12–14, respectively. Reaction of diazonium salt of compound 11 with sodium azide afforded azidopyrimidine derivative 15, which upon reaction with ethyl acetoacetate gave 1,2,3-triazole derivative 16. Acid catalyzed reaction of 11 with p-nitrobenzaldehyde gave Schiff base 17, which cyclized upon reaction with thioglycolic acid or chloroacetyl chloride to give thiazolidin-4-one 18 and azetidin-2-one 19, respectively. The newly synthesized compounds were tested for their anti-inflammatory, analgesic and anticonvulsant activities. Depending on the obtained results, the newly synthesized compounds possess significant anti-inflammatory, analgesic and anticonvulsant activities.

  1. Injectable Anisotropic Nanocomposite Hydrogels Direct in Situ Growth and Alignment of Myotubes

    International Nuclear Information System (INIS)

    De France, Kevin J.; Yager, Kevin G.; Chan, Katelyn J. W.; Corbett, Brandon; Cranston, Emily D.; Hoare, Todd

    2017-01-01

    Here, while injectable in situ cross-linking hydrogels have attracted increasing attention as minimally invasive tissue scaffolds and controlled delivery systems, their inherently disorganized and isotropic network structure limits their utility in engineering oriented biological tissues. Traditional methods to prepare anisotropic hydrogels are not easily translatable to injectable systems given the need for external equipment to direct anisotropic gel fabrication and/or the required use of temperatures or solvents incompatible with biological systems. Herein, we report a new class of injectable nanocomposite hydrogels based on hydrazone cross-linked poly(oligoethylene glycol methacrylate) and magnetically aligned cellulose nanocrystals (CNCs) capable of encapsulating skeletal muscle myoblasts and promoting their differentiation into highly oriented myotubes in situ. CNC alignment occurs on the same time scale as network gelation and remains fixed after the removal of the magnetic field, enabling concurrent CNC orientation and hydrogel injection. The aligned hydrogels show mechanical and swelling profiles that can be rationally modulated by the degree of CNC alignment and can direct myotube alignment both in two- and three-dimensions following coinjection of the myoblasts with the gel precursor components. As such, these hydrogels represent a critical advancement in anisotropic biomimetic scaffolds that can be generated noninvasively in vivo following simple injection.

  2. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis

    International Nuclear Information System (INIS)

    Graaf, Aniek O. de; Heuvel, Lambert P. van den; Dijkman, Henry B.P.M.; Abreu, Ronney A. de; Birkenkamp, Kim U.; Witte, Theo de; Reijden, Bert A. van der; Smeitink, Jan A.M.; Jansen, Joop H.

    2004-01-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity

  3. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis.

    Science.gov (United States)

    de Graaf, Aniek O; van den Heuvel, Lambert P; Dijkman, Henry B P M; de Abreu, Ronney A; Birkenkamp, Kim U; de Witte, Theo; van der Reijden, Bert A; Smeitink, Jan A M; Jansen, Joop H

    2004-10-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity.

  4. Lanthanide complexes of 2-aminoacetophenone and 2-acetylaminoacetophenone 2-thenoylhydrazone

    International Nuclear Information System (INIS)

    Singh, Praveen K.; Singh, B.

    1998-01-01

    The reaction of lanthanide chlorides with 2-aminoacetophenone-2-thenoyl- hydrazone and 2-acetylaminoacetophenone-2-thenoylhydrazone yield complexes of the type [Ln(aath) 2 Cl 2 (H 2 )O]Cl and [Ln(acaath) 2 Cl 2 ]Cl. These complexes have been characterized by molar conductance, magnetic susceptibility, TGA, DTA and various spectroscopic techniques such as mass, IR, NMR, UV - visible and emission spectra. Mass spectral data indicate the aath complexes to be monomeric. Thermal stability of the complexes and presence of one water molecule in aath complex is indicated by TGA and DTA studies. Electronic spectra of Pr(III) and Nd(III) complexes show the coordination number to be nine and eight around the metal ions in the aath and acaath complexes, respectively. This has also been inferred from the spectral features of the hypersensitive transition in the Nd(III) complexes. The lowering in coordination number from aath to acaath complexes may be attributed to increase in chelate ring size and/or steric/inductive effect of methyl group. Emission spectral studies of the [Eu(aath) 2 Cl 2 (H 2 O)]Cl and [Eu(acaath) 2 Cl 2 ]Cl suggest tricapped trigonal prismatic (D 3h ) and square antiprismatic (D 4d ) geometry, respectively. (author)

  5. Synthesis and Properties of Star HPMA Copolymer Nanocarriers Synthesised by RAFT Polymerisation Designed for Selective Anticancer Drug Delivery and Imaging.

    Science.gov (United States)

    Chytil, Petr; Koziolová, Eva; Janoušková, Olga; Kostka, Libor; Ulbrich, Karel; Etrych, Tomáš

    2015-06-01

    High-molecular-weight star polymer drug nanocarriers intended for the treatment and/or visualisation of solid tumours were synthesised, and their physico-chemical and preliminary in vitro biological properties were determined. The water-soluble star polymer carriers were prepared by the grafting of poly(amido amine) (PAMAM) dendrimers by hetero-telechelic N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers, synthesised by the controlled radical Reversible Addition Fragmentation chain Transfer (RAFT) polymerisation. The well-defined star copolymers with Mw values ranging from 2 · 10(5) to 6 · 10(5) showing a low dispersity (approximately 1.2) were prepared in a high yield. A model anticancer drug, doxorubicin, was bound to the star polymer through a hydrazone bond, enabling the pH-controlled drug release in the target tumour tissue. The activated polymer arm ends of the star copolymer carrier enable a one-point attachment for the targeting ligands and/or a labelling moiety. In this study, the model TAMRA fluorescent dye was used to prove the feasibility of the polymer carrier visualisation by optical imaging in vitro. The tailor-made structure of the star polymer carriers should facilitate the synthesis of targeted polymer-drug conjugates, even polymer theranostics, for simultaneous tumour drug delivery and imaging. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Lipophilic hexadentate Gallium, indium and iron complexes of new phenolate derivatized cyclohexanetriamine ligands as potential in vivo metal transfer reagents

    International Nuclear Information System (INIS)

    Bollinger, J.E.; Roundhill, D.M.

    1995-01-01

    The compounds (RsalH 2 ) 3 tachH 3 (R=H, NO 2 , OMe) have been synthesized by Schiff base condensation between cis-1,3,5-triaminocyclohexane and a substituted salicylaldehyde, followed by reduction with KBH 4 . Reaction of these compounds with gallium(III), indium(III) and iron(III) salts neutral hexacoordinate N 3 O 3 complexes of type M(RsalH 2 )3tach (M = Ga, In, Fe). The complexes have been characterized by a combination of infrared, 1 H and 13 C [ 1H] NMR and mass spectroscopy. The distribution coefficient between 1-octanol and water indicate that complexes are lipophilic. The electronic absorption spectra of the high spin Fe(III) complexes show LMCT bands in the 450-500 nm range. The structures of (RsalH 2 ) 3 tachH 3 (R=H, NO 2 , OMe), and In(SalH 2 ) 3 tach have been confirmed by single-crystal X-ray crystallography. Solutions of the three ligands ((salH 2 ) 3 tach, (NO 2 salH 2 ) 3 tach) and (MeOsalH 2 ) 3 tach) complexed to radioactive 59 were prepared in a fashion similar to solutions of ligands complexed with non-radioactive iron, except on a much smaller scale. Biodistribution data for 5 9Fe(RsalH 2 ) 3 tach (R=H, NO 2 , and OMe) complexes over a 24 hour period ere obtained. These 24 hour data show that the complexes are more effectively cleared from the body than is the control solution of 59 Fe. These data will be discussed and possible medical applications for these compounds will be offered. (authors), 2 tabs., 1 figs., 7 refs

  7. Biosynthesis of heme in immature erythroid cells. The regulatory step for heme formation in the human erythron

    International Nuclear Information System (INIS)

    Gardner, L.C.; Cox, T.M.

    1988-01-01

    Heme formation in reticulocytes from rabbits and rodents is subject to end product negative feedback regulation: intracellular free heme has been shown to control acquisition of transferrin iron for heme synthesis. To identify the site of control of heme biosynthesis in the human erythron, immature erythroid cells were obtained from peripheral blood and aspirated bone marrow. After incubation with human 59Fe transferrin, 2-[14C]glycine, or 4-[14C]delta-aminolevulinate, isotopic incorporation into extracted heme was determined. Addition of cycloheximide to increase endogenous free heme, reduced incorporation of labeled glycine and iron but not delta-aminolevulinate into cell heme. Incorporation of glycine and iron was also sensitive to inhibition by exogenous hematin (Ki, 30 and 45 microM, respectively) i.e. at concentrations in the range which affect cell-free protein synthesis in reticulocyte lysates. Hematin treatment rapidly diminished incorporation of intracellular 59Fe into heme by human erythroid cells but assimilation of 4-[14C]delta-aminolevulinate into heme was insensitive to inhibition by hematin (Ki greater than 100 microM). In human reticulocytes (unlike those from rabbits), addition of ferric salicylaldehyde isonicotinoylhydrazone, to increase the pre-heme iron pool independently of the transferrin cycle, failed to promote heme synthesis or modify feedback inhibition induced by hematin. In human erythroid cells (but not rabbit reticulocytes) pre-incubation with unlabeled delta-aminolevulinate or protoporphyrin IX greatly stimulated utilization of cell 59Fe for heme synthesis and also attenuated end product inhibition. In human erythroid cells heme biosynthesis is thus primarily regulated by feedback inhibition at one or more steps which lead to delta-aminolevulinate formation

  8. Morita-Baylis-Hillman Route to Dimethyl 2,3-Dihydrobenzo[b]oxepine-2,4- dicarboxylates and Methyl 2-(2-Carbomethoxybenzo[b]furan-3-yl)propanoates from Salicylaldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang Hyun; Jang, Seung Soon; Kim, Young Keun; Lee, Kee Jung [Hanyang University, Seoul (Korea, Republic of)

    2012-01-15

    A new synthetic method for dimethyl 2,3-dihydrobenzo[b]oxepine-2,4-dicarboxylates and methyl 2-(2- carbomethoxybenzo[b]furan-3-yl)propanoates by an intramolecular conjugate displacement reaction or an S{sub N}2 reaction of acetates of Morita-Baylis-Hillman adducts of methyl (2-formylphenoxy)acetates has been described.

  9. Morita-Baylis-Hillman Route to Dimethyl 2,3-Dihydrobenzo[b]oxepine-2,4- dicarboxylates and Methyl 2-(2-Carbomethoxybenzo[b]furan-3-yl)propanoates from Salicylaldehydes

    International Nuclear Information System (INIS)

    Ahn, Sang Hyun; Jang, Seung Soon; Kim, Young Keun; Lee, Kee Jung

    2012-01-01

    A new synthetic method for dimethyl 2,3-dihydrobenzo[b]oxepine-2,4-dicarboxylates and methyl 2-(2- carbomethoxybenzo[b]furan-3-yl)propanoates by an intramolecular conjugate displacement reaction or an S N 2 reaction of acetates of Morita-Baylis-Hillman adducts of methyl (2-formylphenoxy)acetates has been described

  10. A core-shell albumin copolymer nanotransporter for high capacity loading and two-step release of doxorubicin with enhanced anti-leukemia activity.

    Science.gov (United States)

    Wu, Yuzhou; Ihme, Susann; Feuring-Buske, Michaela; Kuan, Seah Ling; Eisele, Klaus; Lamla, Markus; Wang, Yanran; Buske, Christian; Weil, Tanja

    2013-06-01

    The native transportation protein serum albumin represents an attractive nano-sized transporter for drug delivery applications due to its beneficial safety profile. Existing albumin-based drug delivery systems are often limited by their low drug loading capacity as well as noticeable drug leakage into the blood circulation. Therefore, a unique albumin-derived core-shell doxorubicin (DOX) delivery system based on the protein denaturing-backfolding strategy was developed. 28 DOX molecules were covalently conjugated to the albumin polypeptide backbone via an acid sensitive hydrazone linker. Polycationic and pegylated human serum albumin formed two non-toxic and enzymatically degradable protection shells around the encapsulated DOX molecules. This core-shell delivery system possesses notable advantages, including a high drug loading capacity critical for low administration doses, a two-step drug release mechanism based on pH and the presence of proteases, an attractive biocompatibility and narrow size distribution inherited from the albumin backbone, as well as fast cellular uptake and masking of epitopes due to a high degree of pegylation. The IC50 of these nanoscopic onion-type micelles was found in the low nanomolar range for Hela cells as well as leukemia cell lines. In vivo data indicate its attractive potential as anti-leukemia treatment suggesting its promising profile as nanomedicine drug delivery system. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Tunable pH and redox-responsive drug release from curcumin conjugated γ-polyglutamic acid nanoparticles in cancer microenvironment.

    Science.gov (United States)

    Pillarisetti, Shameer; Maya, S; Sathianarayanan, S; Jayakumar, R

    2017-11-01

    Tunable pH and redox responsive polymer was prepared using γ-polyglutamic acid (γ-PGA) with linker 3-mercaptopropionic acid (3-MPA) (γ-PGA_SH) via oxidation to obtain redox responsive disulfide (γ-PGA_SS) backbone and adipic acid dihydrazide (ADH) (γ-PGA_SS_ADH) with hydrazide functional group for pH responsiveness. Further curcumin (Cur) was conjugated through hydrazone bond of the γ-PGA_SS_ADH via Schiff base reaction to obtain (γ-PGA_SS_ADH_Cur). The prepared systems were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Qq-TOF-MS/MS) and Solid state nuclear magnetic resonance (SS NMR) techniques. γ-PGA_SS_ADH_Cur formed self-assembled core shell nanoparticles (NPs) in existence of stabilized aqueous medium. γ-PGA_SS_ADH_Cur NPs maintained its stability in physiological condition. NPs tunable Cur release and cytotoxicity were observed for γ-PGA_SS_ADH_Cur NPs in both acidic and redox conditions mimicking the cancer microenvironment. γ-PGA_SS_ADH_Cur NPs uptake study showed via endocytosis mechanism resulted in the lysosomal entrapment of these NPs within the cell. γ-PGA_SS_ADH_Cur NPs exhibited a dual stimuli responsive drug delivery and can be used as a smart and potential drug delivery system in cancer microenvironment. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Short-term effects of carbon dioxide on carnation callus cell respiration

    International Nuclear Information System (INIS)

    Palet, A.; Ribas-Carbo, M.; Argiles, J.M.; Azcon-Bieto, J.

    1991-01-01

    The addition of potassium bicarbonate to the electrode cuvette immediately stimulated the rate of dark O 2 uptake of photomixotrophic and heterotrophic carnation (Dianthus caryophyllus L.) callus, of Elodea canadensis (Minchx) leaves, and of other plant tissues. This phenomenon occurred at pH values lower than 7.2 to 7.8, and the stimulation depended on the concentration of gaseous CO 2 in the solution. These stimulatory responses lasted several minutes and then decreased, but additional bicarbonate or gaseous CO 2 again stimulated respiration, suggesting a reversible effect. Carbonic anhydrase in the solution increased the stimulatory effect of potassium bicarbonate. The CO 2 /bicarbonate dependent stimulation of respiration did not occur in animal tissues such as rat diaphragm and isolated hepatocytes, and was inhibited by salicylhydroxamic acid in carnation callus cells and E. canadensis leaves. This suggested that the alternative oxidase was engaged during the stimulation in plant tissues. The cytochrome pathway was severely inhibited by CO 2 /bicarbonate either in the absence or in the presence of the uncoupler carbonylcyanide m-chlorophenyl hydrazone. The activity of cytochrome c oxidase of callus tissue homogenates was also inhibited by CO 2 /bicarbonate. The results suggested that high carbon dioxide levels (mainly free CO 2 ) partially inhibited the cytochrome pathway (apparently at the oxidase level), and this block in electron transport elicited a large transient engagement of the alternative oxidase when present uninhibited

  13. Anion recognition using newly synthesized hydrogen bonding disubstituted phenylhydrazone-based receptors: poly(vinyl chloride)-based sensor for acetate.

    Science.gov (United States)

    Gupta, Vinod K; Goyal, Rajendra N; Sharma, Ram A

    2008-08-15

    A potentiometric acetate-selective sensor, based on the use of butane-2,3-dione,bis[(2,4-dinitrophenyl)hydrazone] (BDH) as a neutral carrier in poly(vinyl chloride) (PVC) matrix, is reported. Effect of various plasticizers and cation excluder, cetryaltrimethylammonium bromide (CTAB) was studied. The best performance was obtained with a membrane composition of PVC:BDH:CTAB ratio (w/w; mg) of 160:8:8. The sensor exhibits significantly enhanced selectivity toward acetate ions over a wide concentration range 5.0 x 10(-6) to 1.0 x 10(-1)M with a lower detection limit of 1.2 x 10(-6)M within pH range 6.5-7.5 with a response time of Fast and stable response, good reproducibility and long-term stability are demonstrated. The sensor has a response time of 15s and can be used for at least 65 days without any considerable divergence in their potential response. Selectivity coefficients determined with the separate solution method (SSM) and fixed interference method (FIM) indicate that high selectivity for acetate ion. The proposed electrode shows fairly good discrimination of acetate from several inorganic and organic anions. It was successfully applied to direct determination of acetate within food preservatives. Total concentration of acetic acid in vinegar samples were determined by direct potentiometry and the values agreed with those mentioned by the manufacturers.

  14. Structural, absorption, and molecular properties of o,o'-dihydroxyazo resorcinol dyes bearing an acryloyloxy group

    Science.gov (United States)

    Özkınalı, Sevil; Çavuş, M. Serdar; Ceylan, Abdullah; Gür, Mahmut

    2017-12-01

    To the best of our knowledge, this is the first study reporting the synthesis and characterization of o,o‧-dihydroxyazo dyes bearing an acryloyl group. The o,o‧-dihydroxyazo dyes were synthesized through coupling of resorcinol with the diazonium salts of 2-amino-4-methylphenol, 2-aminophenol, 2-amino-4-chlorophenol, and 2-amino-4-nitrophenol. Their acryloyl derivatives were synthesized using metallic sodium and acryloyl chloride under an inert atmosphere. Characterization of the compounds was conducted using infrared (IR), ultraviolet-visible (UV-vis), proton nuclear magnetic resonance (1H NMR), and carbon nuclear magnetic resonance (13C NMR) spectroscopic methods. The tautomerism of the synthesized compounds' was also evaluated. The results were compared with theoretical results obtained by density functional theory (DFT). The DFT calculations were performed to obtain ground-state optimized geometries and calculate the relevant electronic and chemical reactivity parameters. Furthermore, possible tautomers deduced from the UV-vis spectra were investigated using theoretical calculations. Both the IR and NMR spectral data showed that azo tautomers predominate in the solid state and DMSO solvent. The effects of pH, solvent, and substituent on the predominant tautomers were further investigated through UV-vis spectroscopy. The results indicate that hydrazone tautomers were dominant at pH 12 in dimethylformamide (DMF), whereas azo tautomers were dominant at pH 2 in EtOH or CHCl3.

  15. Spectrophotometric Determination of the Trace Amount of Thallium in Water and Urine Samples by Novel Oxidative Coupling Reaction

    Directory of Open Access Journals (Sweden)

    P. Nagaraja

    2009-01-01

    Full Text Available A novel, simple, rapid, sensitive and selective method has been proposed for the trace determination of thallium by spectrophotometric detection. This method is based on the oxidation of MBTH (3-methyl-2-benzothiazolinone hydrazone hydrochloride by thallium(III to form diazonium cation, which couples with IPH (Imipramine hydrochloride in phosphoric acid medium at room temperature giving a blue colored species having a maximum absorption at 635 nm. The reagents and manifold variables influences on the sensitivity were investigated and the optimum reaction conditions have been established. The calibration curve was found to be linear over the range 0.1-5 μg mL-1 with the molar absorptivity and Sandell’s sensitivity of 2.9x104 L mol-1 cm-1, 0.0071 μg cm-2 respectively. The tolerance limit of the method towards various ions usually associated with thallium has been detected. The relative standard deviation for five replicate determination of 2μg mL-1 thallium was 0.47%. The method has been successfully applied for the determination of thallium(ІΙΙ and thallium(I in synthetic, standard reference materials, water and urine samples with satisfactory results. The performance of the proposed method was evaluated in terms of student’s t-test and variance ratio F-test, to find out the significance of proposed method over the reported methods.

  16. In vitro and in silico Approaches to the Identification of New Compounds with Antibacterial Profile

    Directory of Open Access Journals (Sweden)

    Carlos R. Rodrigues

    2013-06-01

    Full Text Available The emergence of multidrug-resistant bacterial strains is a world problem that increases the need for new and more effective antimicrobials. On that purpose, derivatives of cyclic systems may serve as new leads for discovering new active molecules. In this work we evaluated the antibacterial profile of 243 molecules derived from the systems thienopyridine, pyrazolopiridine, quinolone, chalcone, hydrazone and lapachone against Gram-positive and Gram-negative susceptible and multiresistant strains also comparing them with antibiotics of clinical use. Our results showed that among the 243 molecules tested, only eight derivatives were active with promissing MIC values (2-64mg/mL. Our theoretical in silico analysis showed that all active compounds fulfilled Lipinski rule of five (molecular weight = 344.37–409.24, clogP = 3.15–4.11, nHBA = 6–7, and nHBD = 2, similarly to commercial drugs as well as presented better druglikeness values (from -3.68 to 0.12 than chloramphenicol (-4.61 and linezolid (-4.08. Most of the active derivatives presented a low in silico toxicity risk profile, similar to oxacillin, ampicillin, and penicillin G, and even lower than that observed for chloramphenicol and linezolid. Theoretically HOMO and the electrostatic protential distribution may be contributing for this safer profile. This study used computacional tools and may help to deal with an important world health problem.

  17. Performance evaluation of a colorimetric hydrazine dosimeter

    Science.gov (United States)

    Brenner, Karen P.; Rose-Pehrsson, Susan L.

    1994-06-01

    A dosimeter for real-time, colorimetric detection of hydrazine in air has been developed. The passive badge consists of a dosimeter card containing a vanillin solution coated on a thin paper substrate. The active patch consists of a thick cellulose substrate coated with a vanillin solution. When placed in a plastic sample holder attached to a personnel pump, up to 5 L/min can be drawn through the active badge substrate. Through a condensation reaction, vanillin reacts with hydrazine to form a colored product that absorbs in the visible region. The hydrazone formed in the reaction is yellow; its intensity is proportional to the dose. When exposed passively to hydrazine, the experimental detection limit is less than 20 ppb-hrs. Extrapolated results indicate a detection limit of less than 5 ppb-hrs for long sampling periods. Actively sampling of hydrazine vapors gives an experimental detection limit of less than 100 ppb-L at a sample rate of 5 L/min. Relative humidity effects on badge response were minor. High humidity enhanced the color development on the vanillin badge; while low humidity had no effect on badge response. Interference testing of the dosimeters revealed a tobacco smoke interference. Preliminary shelf life tests indicated no decrease in sensitivity to hydrazine when stored at room temperature for 6 months.

  18. Synthesis, Biological Activity, and Docking Study of Novel Isatin Coupled Thiazolidin-4-one Derivatives as Anticonvulsants.

    Science.gov (United States)

    Nikalje, Anna P; Ansari, Altamash; Bari, Sanjay; Ugale, Vinod

    2015-06-01

    A series of 2-(substituted-phenyl)-3-(2-oxoindolin-3-ylidene)amino)-thiazolidin-4-one derivatives were designed and synthesized under microwave irradiation, using an eco-friendly, efficient, microwave-assisted synthetic protocol that involves cyclocondensation of 3-substituted benzylidine-hydrazono-indolin-2-one 3a-j with thioglycolic acid in dimethyl formamide (DMF) as solvent and anhydrous zinc chloride as a catalyst, keeping in view the structural requirement of the pharmacophore. The intermediate compounds 3a-j were obtained by condensation of the hydrazone of indoline-2,3-dione with aromatic aldehydes. The synthesized derivatives were evaluated for CNS depressant activity and anticonvulsant activity in mice using the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (sc-PTZ) induced seizure tests. All the derivatives showed good CNS depressant activity and showed protection in the MES test, indicative of their ability to inhibit the seizure spread. A histopathological study was performed to evaluate liver toxicity caused by the synthesized compounds. The compounds were nontoxic. A computational study was performed, in which log P values were calculated experimentally. Virtual screening was performed by molecular docking of the designed compounds into the ATP binding sites of the NMDA and AMPA receptors, to predict if these compounds have analogous binding modes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Improved Stability of Tuberculosis Drug Fixed-Dose Combination Using Isoniazid-Caffeic Acid and Vanillic Acid Cocrystal.

    Science.gov (United States)

    Battini, Swapna; Mannava, M K Chaitanya; Nangia, Ashwini

    2018-06-01

    The classic fixed-dose combination (FDC) of 4 tuberculosis drugs, namely rifampicin (RIF), isoniazid (INH), pyrazinamide (PZA), and ethambutol dihydrochloride (EDH) has the twin issues of physical stability and RIF cross-reaction in the 4-FDC. The major reason for these quality issues is the interaction between RIF and INH to yield isonicotinyl hydrazone in drug tablets. Pharmaceutical cocrystals of INH with caffeic acid (CFA) (PZA + EDH + RIF + INH-CFA cocrystal) and vanillic acid (VLA) (PZA + EDH + RIF + INH-VLA cocrystal) are able to stabilize the FDC formulation compared with the reference batch (PZA + EDH + RIF + INH). Stability studies under accelerated humidity and temperature stress conditions of 40°C and 75% relative humidity showed that the physical stability of the cocrystal formulation was superior by powder X-ray diffraction and scanning electron microscopy analysis, and chemical purity was analyzed by high-performance liquid chromatography. Changes in the composition and structure were monitored on samples drawn at 7, 15, 22, and 30 days of storage. FDC-INH-CFA cocrystal batch exhibited greater stability compared with FDC-INH-VLA cocrystal and FDC reference drug batches. The superior stability of INH-CFA cocrystal is attributed to the presence of stronger hydrogen bonds and cyclic O-H⋯O synthon in the crystal structure. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  20. Redox-responsive core cross-linked prodrug micelles prepared by click chemistry for pH-triggered doxorubicin delivery

    Directory of Open Access Journals (Sweden)

    X. T. Cao

    2017-10-01

    Full Text Available A pH-triggered drug delivery system of degradable core cross-linked (CCL prodrug micelles was prepared by click chemistry. Doxorubicin conjugated block copolymers of azido functional poly(ethylene oxide-b-poly(glycidyl methacrylate were synthesized by the combination of RAFT polymerization, epoxide ring-opening reaction, and acid-cleavable hydrazone linkages. The CCL prodrug micelles were produced by the reaction of dipropargyl 3,3′-dithiodipropionate and dipropargyl adipate cross-linking agents with the azido groups of the micellar core via alkyne-azide click reaction, which were denoted as CCL/SS and CCL/noSS, respectively. The TEM images of CCL/SS prodrug micelles showed a spherical shape with the average diameter of 61.0 nm from water, and the shape was maintained with an increased diameter upon dilution with 5-fold DMF. The high DOX conjugation efficiency was 88.4%. In contrast to a very slow DOX release from CCL/SS prodrug micelles under the physiological condition (pH 7.4, the drug release is much faster (90% at pH 5.0 and 10 mM of GSH after 96 h. The cytotoxicity test and confocal laser scanning microscopy analysis revealed that CCL/SS prodrug micelles had much enhanced intracellular drug release capability in HepG2 cells than CCL/noSS prodrug micelles.

  1. Rationally engineered nanoparticles target multiple myeloma cells, overcome cell-adhesion-mediated drug resistance, and show enhanced efficacy in vivo

    International Nuclear Information System (INIS)

    Kiziltepe, T; Ashley, J D; Stefanick, J F; Qi, Y M; Alves, N J; Handlogten, M W; Suckow, M A; Navari, R M; Bilgicer, B

    2012-01-01

    In the continuing search for effective cancer treatments, we report the rational engineering of a multifunctional nanoparticle that combines traditional chemotherapy with cell targeting and anti-adhesion functionalities. Very late antigen-4 (VLA-4) mediated adhesion of multiple myeloma (MM) cells to bone marrow stroma confers MM cells with cell-adhesion-mediated drug resistance (CAM-DR). In our design, we used micellar nanoparticles as dynamic self-assembling scaffolds to present VLA-4-antagonist peptides and doxorubicin (Dox) conjugates, simultaneously, to selectively target MM cells and to overcome CAM-DR. Dox was conjugated to the nanoparticles through an acid-sensitive hydrazone bond. VLA-4-antagonist peptides were conjugated via a multifaceted synthetic procedure for generating precisely controlled number of targeting functionalities. The nanoparticles were efficiently internalized by MM cells and induced cytotoxicity. Mechanistic studies revealed that nanoparticles induced DNA double-strand breaks and apoptosis in MM cells. Importantly, multifunctional nanoparticles overcame CAM-DR, and were more efficacious than Dox when MM cells were cultured on fibronectin-coated plates. Finally, in a MM xenograft model, nanoparticles preferentially homed to MM tumors with ∼10 fold more drug accumulation and demonstrated dramatic tumor growth inhibition with a reduced overall systemic toxicity. Altogether, we demonstrate the disease driven engineering of a nanoparticle-based drug delivery system, enabling the model of an integrative approach in the treatment of MM

  2. Interaction of HIV-1 reverse transcriptase ribonuclease H with an acylhydrazone inhibitor.

    Science.gov (United States)

    Gong, Qingguo; Menon, Lakshmi; Ilina, Tatiana; Miller, Lena G; Ahn, Jinwoo; Parniak, Michael A; Ishima, Rieko

    2011-01-01

    HIV-1 reverse transcriptase is a bifunctional enzyme, having both DNA polymerase (RNA- and DNA-dependent) and ribonuclease H activities. HIV-1 reverse transcriptase has been an exceptionally important target for antiretroviral therapeutic development, and nearly half of the current clinically used antiretrovirals target reverse transcriptase DNA polymerase. However, no inhibitors of reverse transcriptase ribonuclease H are on the market or in preclinical development. Several drug-like small molecule inhibitors of reverse transcriptase ribonuclease H have been described, but little structural information is available about the interactions between reverse transcriptase ribonuclease H and inhibitors that exhibit antiviral activity. In this report, we describe NMR studies of the interaction of a new ribonuclease H inhibitor, BHMP07, with a catalytically active HIV-1 reverse transcriptase ribonuclease H domain fragment. We carried out solution NMR experiments to identify the interaction interface of BHMP07 with the ribonuclease H domain fragment. Chemical shift changes of backbone amide signals at different BHMP07 concentrations clearly demonstrate that BHMP07 mainly recognizes the substrate handle region in the ribonuclease H fragment. Using ribonuclease H inhibition assays and reverse transcriptase mutants, the binding specificity of BHMP07 was compared with another inhibitor, dihydroxy benzoyl naphthyl hydrazone. Our results provide a structural characterization of the ribonuclease H inhibitor interaction and are likely to be useful for further improvements of the inhibitors. © 2010 John Wiley & Sons A/S.

  3. Synthesis and photoluminescence properties of novel Schiff base type polymer-rare earth complexes containing furfural-based bidentate Schiff base ligands

    Science.gov (United States)

    Gao, Baojiao; Zhang, Dandan; Li, Yanbin

    2018-03-01

    Luminescent polymer-rare earth complexes are an important class of photoluminescence and electroluminescence materials. Via molecular design, two furfural-based bidentate Schiff base ligands, furfural-aniline (FA) type ligand and furfural-cyclohexylamine (FC) type ligand, were bonded on the side chains of polysulfone (PSF), respectively, forming two functionalized macromolecules, PSF-FA and PSF-FC. And then through respective coordination reactions of the two functionalized macromolecules with Eu(Ⅲ) ion and Tb(Ⅲ) ion, novel luminescent binary and ternary (with 1,10-phenanthroline as the second ligand) polymer-rare earth complexes were synthesized. For these complexes, on basis of the characterization of their chemical structures, they photoluminescence properties were main researched, and the relationship between their luminescent properties and structures was explored. The experimental results show that the complexes coming from PSF-FA and Eu(Ⅲ) ion including binary and ternary complexes emit strong red luminescence, indicating that the bonded bidentate Schiff base ligand FA can sensitize the fluorescence emission of Eu(III) ion. While the complexes coming from PSF-FC and Tb(Ⅲ) ion produce green luminescence, displaying that the bonded bidentate Schiff base ligand FC can sensitize the fluorescence emission of Tb(Ⅲ) ion. The fluorescence emission intensities of the ternary complexes were stronger than that of binary complexes, reflecting the important effect of the second ligand. The fluorescence emission of the solid film of complexes is much stronger than that of the solutions of complexes. Besides, by comparison, it is found that the furfural (as a heteroaromatic compound)-based Schiff base type polymer-rare earth complexes have stronger fluorescence emission and higher energy transfer efficiency than salicylaldehyde (as a common aromatic compound)-based Schiff base type polymer-rare earth complexes.

  4. Meadowsweet Teas as New Functional Beverages: Comparative Analysis of Nutrients, Phytochemicals and Biological Effects of Four Filipendula Species

    Directory of Open Access Journals (Sweden)

    Daniil N. Olennikov

    2016-12-01

    Full Text Available In recent years, the increased popularity of functional beverages such as herbal teas and decoctions has led to the search for new sources of raw materials that provide appropriate taste and functionality to consumers. The objective of this study was to investigate the nutritional, phytochemical profiles and bioactivities of possible functional beverages produced from F. ulmaria and its alternative substitutes (F. camtschatica, F. denudata, F. stepposa. The investigated decoctions were analyzed regarding their macronutrient, carbohydrate, organic acid, amino acid and mineral composition. Quantification of the main phenolic compounds in the decoctions of meadowsweet floral teas was performed by a microcolumn RP-HPLC-UV procedure; the highest content was revealed in F. stepposa tea. The investigation of the essential oil of four meadowsweet teas revealed the presence of 28 compounds, including simple phenols, monoterpenes, sesquiterpenes and aliphatic components. The dominance of methyl salicylate and salicylaldehyde was noted in all samples. Studies on the water soluble polysaccharides of Filipendula flowers allowed us to establish their general affiliation to galactans and/or arabinogalactans with an admixture of glucans of the starch type and galacturonans as minor components. The bioactivity data demonstrated a good ability of meadowsweet teas to inhibit amylase, α-glucosidase and AGE formation. Tea samples showed antioxidant properties by the DPPH•, ABTS•+ and Br• free radicals scavenging assays and the carotene bleaching assay, caused by the presence of highly active ellagitannins. The anti-complement activity of the water-soluble polysaccharide fraction of meadowsweet teas indicated their possible immune-modulating properties. Filipendula beverage formulations can be expected to deliver beneficial effects due to their unique nutritional and phytochemical profiles. Potential applications as health-promoting functional products may be

  5. Synthesis and radiofluorination of putative NMDA receptor ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kronenberg, U

    2011-01-15

    In the course of this work on the synthesis of radioligands for the NMDA receptor the authentic standards and labeling precursors of four compounds with an amidine structure was performed. Synthesis of the precursors followed reaction conditions given in the literature and was successful. The imidoesters used for the synthesis were obtained from their nitriles in a Pinner synthesis, while 2-hydroxybenzylamine was synthesized in a reduction of 2-hydroxybenzonitrile using borane as a reducing agent. After a coupling reaction of the amine and the imidoester in DMF using triethylamine as base the precursors were obtained in good yields and purified by crystallization from methanol. The cyclic standard compound was synthesized directly from 2-(bromomethyl)- benzonitrile and 2-hydroxybenzylamine in a ring closing reaction. Similar to the other precursors, crystallization from methanol produced a pure compound. The authentic standards were synthesized starting from salicylaldehyde. In a four step synthesis the desired ortho-fluoroethoxybenzylamine was obtained in good yield. Coupling of the amine with the respective imidoester or in the case of the cyclic compound 2-(bromomethyl)-benzonitrile gave the desired product which was then purified by column chromatography or by crystallization from ethanol and water. For the labeling procedure 1-bromo-2-[{sub 18}F]fluoroethane was synthesized following a previously published pathway starting from 1,2-dibromoethane. An alternative route of radiosynthesis for this prosthetic group was tested using ethyleneglycole- 1,2-ditosylate. The labeling reaction was performed on one of the precursors testing both DMF and DMSO as solvents and using NaOH as base. Yields of N-(2-fluoroethoxybenzyl)- cinnamamidine were about 78 % at 80 C after 30 minutes in DMSO. The desired product can now be synthesized in sufficient yields for in vitro and in vivo evaluation studies. Labeling on the cyclic precursor was attempted utilizing DMSO as solvent

  6. Synthesis and radiofluorination of putative NMDA receptor ligands

    International Nuclear Information System (INIS)

    Kronenberg, U.

    2011-01-01

    In the course of this work on the synthesis of radioligands for the NMDA receptor the authentic standards and labeling precursors of four compounds with an amidine structure was performed. Synthesis of the precursors followed reaction conditions given in the literature and was successful. The imidoesters used for the synthesis were obtained from their nitriles in a Pinner synthesis, while 2-hydroxybenzylamine was synthesized in a reduction of 2-hydroxybenzonitrile using borane as a reducing agent. After a coupling reaction of the amine and the imidoester in DMF using triethylamine as base the precursors were obtained in good yields and purified by crystallization from methanol. The cyclic standard compound was synthesized directly from 2-(bromomethyl)- benzonitrile and 2-hydroxybenzylamine in a ring closing reaction. Similar to the other precursors, crystallization from methanol produced a pure compound. The authentic standards were synthesized starting from salicylaldehyde. In a four step synthesis the desired ortho-fluoroethoxybenzylamine was obtained in good yield. Coupling of the amine with the respective imidoester or in the case of the cyclic compound 2-(bromomethyl)-benzonitrile gave the desired product which was then purified by column chromatography or by crystallization from ethanol and water. For the labeling procedure 1-bromo-2-[ 18 F]fluoroethane was synthesized following a previously published pathway starting from 1,2-dibromoethane. An alternative route of radiosynthesis for this prosthetic group was tested using ethyleneglycole- 1,2-ditosylate. The labeling reaction was performed on one of the precursors testing both DMF and DMSO as solvents and using NaOH as base. Yields of N-(2-fluoroethoxybenzyl)- cinnamamidine were about 78 % at 80 C after 30 minutes in DMSO. The desired product can now be synthesized in sufficient yields for in vitro and in vivo evaluation studies. Labeling on the cyclic precursor was attempted utilizing DMSO as solvent, but no

  7. Cytogenotoxic effects of two potential anticancer Ruthenium(III Schiff Bases complexes

    Directory of Open Access Journals (Sweden)

    Izet Eminovic

    2016-10-01

    Full Text Available Introduction: Treatment of cancer has been subject of great interest. Researchers are continuously searching for new medicines. In this sense, ruthenium complexes have big potential. Some evidences suggest that ruthenium compounds possess anticancer activities. We synthesized two recently published ruthenium(III complexes with bidentate O,N and tridentate O,O,N Schiff bases derived from 5-substituted salicylaldehyde and aminophenol or anilineare. These compounds showed affinity for binding to the DNA molecule, however, insufficient data are available regarding their possible toxic effects on biological systems.Methods: In the present study we evaluated genotoxic, cytotoxic, and cytostatic effects of Na[RuCl2(L12] and Na[Ru(L22], using the Allium cepa assay.Results: Different toxic effects were observed depending on the substance, tested concentration, and endpoint measured. In general, the tested compounds significantly lowered the root growth and mitotic index values as compared to the control group. Additionally, a wide range of abnormal mitotic stages, both clastogenic and non-clastogenic were observed in the treated cells. Na[RuCl2(L12] significantly increased the frequency of sticky metaphases, chromosome bridges, micronuclei, impaired chromosome segregation, as well as number of apoptotic and necrotic cells over the controls. In contrast, Na[Ru(L22] did not show significant evidence of genotoxicity with regard to chromosome aberrations and micronuclei, however, significant differences were detected in the number of apoptotic and necrotic cells when the highest concentration was applied.Conclusions: In this study we demonstrated antiproliferative effects of Na[RuCl2(L12] and Na[Ru(L22]. At clinical level, these results could be interesting for further studies on anticancer potential of the ruthenium(III complexes using animal models.

  8. Synthesis and characterization of ligands and bifunctional chelating agents by modification of cysteine for complexation studies with 99mTc

    International Nuclear Information System (INIS)

    Pillai, M.R.A.; Kothari, K.; Banerjee, S.; Samuel, G.; Suresh, M.; Sarma, H.D.

    1998-01-01

    The synthesis of four novel ligands using the amino-acid cysteine and its ethyl carboxylate derivative is described. The synthetic method involves a two-step procedure, wherein the intermediate Schiff base formed by the condensation of the amino group of the cysteine substrate and salicylaldehyde is reduced to give the target ligands. The intermediates and the final products are characterised by high resolution NMR spectroscopy. Complexation studies of the ligands with 99m Tc are standardised using stannous tartrate as the reducing agent at varying reaction conditions. The complexes are characterised using standard quality control techniques such as TLC, paper electrophoresis and PC. Lipophilicities of the complexes are estimated by solvent extraction into chloroform. Substantial changes in net charge and lipophilicity in the 99m Tc complexes are observed on substituting the carboxylic acid residue in ligand I and II with the ethyl carboxylate groups (ligands III and IV). All the ligands formed complexes in high yield. While the complexes of ligand I and II are observed to be hydrophilic in nature and are not extractable into CHCl 3 , ligands III and IV gave neutral and lipophilic complexes. Though the distribution ratios of the complexes of ligands III and IV in CHCl 3 /saline system are observed to be very high, considerable differences in lipophilicities are also observed as evidenced by the difference in their respective extractabilities in chloroform. On storage, the complex of ligand III exhibit a tendency to get converted to a hydrophilic and non-extractable species. The bio-distribution of the complexes of ligands I and II showed that they have predominantly renal clearances whereas the complexes of ligands III and IV exhibited a significant hepatobiliary uptake and did not show much uptake in brain in spite of its favourable properties such as neutrality, lipophilicity and conversion into a hydrophilic species. (author)

  9. Merging constitutional and motional covalent dynamics in reversible imine formation and exchange processes.

    Science.gov (United States)

    Kovaříček, Petr; Lehn, Jean-Marie

    2012-06-06

    The formation and exchange processes of imines of salicylaldehyde, pyridine-2-carboxaldehyde, and benzaldehyde have been studied, showing that the former has features of particular interest for dynamic covalent chemistry, displaying high efficiency and fast rates. The monoimines formed with aliphatic α,ω-diamines display an internal exchange process of self-transimination type, inducing a local motion of either "stepping-in-place" or "single-step" type by bond interchange, whose rate decreases rapidly with the distance of the terminal amino groups. Control of the speed of the process over a wide range may be achieved by substituents, solvent composition, and temperature. These monoimines also undergo intermolecular exchange, thus merging motional and constitutional covalent behavior within the same molecule. With polyamines, the monoimines formed execute internal motions that have been characterized by extensive one-dimensional, two-dimensional, and EXSY proton NMR studies. In particular, with linear polyamines, nondirectional displacement occurs by shifting of the aldehyde residue along the polyamine chain serving as molecular track. Imines thus behave as simple prototypes of systems displaying relative motions of molecular moieties, a subject of high current interest in the investigation of synthetic and biological molecular motors. The motional processes described are of dynamic covalent nature and take place without change in molecular constitution. They thus represent a category of dynamic covalent motions, resulting from reversible covalent bond formation and dissociation. They extend dynamic covalent chemistry into the area of molecular motions. A major further step will be to achieve control of directionality. The results reported here for imines open wide perspectives, together with other chemical groups, for the implementation of such features in multifunctional molecules toward the design of molecular devices presenting a complex combination of

  10. Comparative study of ZnO nanorods and thin films for chemical and biosensing applications and the development of ZnO nanorods based potentiometric strontium ion sensor

    Science.gov (United States)

    Khun, K.; Ibupoto, Z. H.; Chey, C. O.; Lu, Jun.; Nur, O.; Willander, M.

    2013-03-01

    In this study, the comparative study of ZnO nanorods and ZnO thin films were performed regarding the chemical and biosensing properties and also ZnO nanorods based strontium ion sensor is proposed. ZnO nanorods were grown on gold coated glass substrates by the hydrothermal growth method and the ZnO thin films were deposited by electro deposition technique. ZnO nanorods and thin films were characterised by field emission electron microscopy [FESEM] and X-ray diffraction [XRD] techniques and this study has shown that the grown nanostructures are highly dense, uniform and exhibited good crystal quality. Moreover, transmission electron microscopy [TEM] was used to investigate the quality of ZnO thin film and we observed that ZnO thin film was comprised of nano clusters. ZnO nanorods and thin films were functionalised with selective strontium ionophore salicylaldehyde thiosemicarbazone [ST] membrane, galactose oxidase, and lactate oxidase for the detection of strontium ion, galactose and L-lactic acid, respectively. The electrochemical response of both ZnO nanorods and thin films sensor devices was measured by using the potentiometric method. The strontium ion sensor has exhibited good characteristics with a sensitivity of 28.65 ± 0.52 mV/decade, for a wide range of concentrations from 1.00 × 10-6 to 5.00 × 10-2 M, selectivity, reproducibility, stability and fast response time of 10.00 s. The proposed strontium ion sensor was used as indicator electrode in the potentiometric titration of strontium ion versus ethylenediamine tetra acetic acid [EDTA]. This comparative study has shown that ZnO nanorods possessed better performance with high sensitivity and low limit of detection due to high surface area to volume ratio as compared to the flat surface of ZnO thin films.

  11. The preparation and use of metal salen complexes derived from cyclobutane diamine

    Science.gov (United States)

    Patil, Smita

    The helix is an important chiral motif in nature, there is increasing development in field of helical transition metal complexes and related supramolecular structures. Hence, the goals of this work are to apply the principles of helicity in order to produce metal complexes with predictable molecular shapes and to study their properties as asymmetric catalysts. Computational studies suggest that the (1R,2 R)-cyclobutyldiamine unit can produce highly twisted salen complexes with a large energy barrier between the M and P helical forms. To test this prediction, the tartrate salt of (1R,2R)-cyclobutyldiamine was synthesized and condensed with a series of saliclaldehydes to produce novel salen ligands. The salicylaldehydes chosen have extended phenanthryl or benz[a]anthryl sidearms to encourage formation of helical coordination complexes. These ligands were metallated with zinc, iron and manganese salts to produce salen metal complexes which were characterized by NMR analysis, high-resolution mass spectrometry, and IR spectroscopy. A second ligand type, neutral bis(pyridine-imine) has also been synthesized from (1R,2R)-cyclobutyldiamine and quinolylaldehydes. The synthesis of bis(pyridine-imine) ligands was conducted using greener method, solvent assisted grinding. These ligands, in-situ with nickel metal salts, showed good catalytic activity for asymmetric Diels-Alder reactions. The third ligand type studied was chiral acid-functionalized Schiff-base ligands. These were synthesized by the condensation of 3-formyl-5-methyl salicylic acid and (1R,2R)-cyclobutyldiamine. With this type of ligand, there is possibility of producing both mono and dinuclear metal complexes. In our studies, we were only able to synthesize mononuclear complexs. These were tested as catalysts for asymmetric direct Mannich-type reaction, but were found to be ineffective.

  12. Direct Comparison of the Enzymatic Characteristics and Superoxide Production of the Four Aldehyde Oxidase Enzymes Present in Mouse.

    Science.gov (United States)

    Kücükgöze, Gökhan; Terao, Mineko; Garattini, Enrico; Leimkühler, Silke

    2017-08-01

    Aldehyde oxidases (AOXs) are molybdoflavoenzymes with an important role in the metabolism and detoxification of heterocyclic compounds and aliphatic as well as aromatic aldehydes. The enzymes use oxygen as the terminal electron acceptor and produce reduced oxygen species during turnover. Four different enzymes, mAOX1, mAOX3, mAOX4, and mAOX2, which are the products of distinct genes, are present in the mouse. A direct and simultaneous comparison of the enzymatic properties and characteristics of the four enzymes has never been performed. In this report, the four catalytically active mAOX enzymes were purified after heterologous expression in Escherichia coli The kinetic parameters of the four mouse AOX enzymes were determined and compared with the use of six predicted substrates of physiologic and toxicological interest, i.e., retinaldehyde, N 1 -methylnicotinamide, pyridoxal, vanillin, 4-(dimethylamino)cinnamaldehyde ( p- DMAC), and salicylaldehyde. While retinaldehyde, vanillin, p- DMAC, and salycilaldehyde are efficient substrates for the four mouse AOX enzymes, N 1 -methylnicotinamide is not a substrate of mAOX1 or mAOX4, and pyridoxal is not metabolized by any of the purified enzymes. Overall, mAOX1, mAOX2, mAOX3, and mAOX4 are characterized by significantly different K M and k cat values for the active substrates. The four mouse AOXs are also characterized by quantitative differences in their ability to produce superoxide radicals. With respect to this last point, mAOX2 is the enzyme generating the largest rate of superoxide radicals of around 40% in relation to moles of substrate converted, and mAOX1, the homolog to the human enzyme, produces a rate of approximately 30% of superoxide radicals with the same substrate. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  13. Chiral halogenated Schiff base compounds: green synthesis, anticancer activity and DNA-binding study

    Science.gov (United States)

    Ariyaeifar, Mahnaz; Amiri Rudbari, Hadi; Sahihi, Mehdi; Kazemi, Zahra; Kajani, Abolghasem Abbasi; Zali-Boeini, Hassan; Kordestani, Nazanin; Bruno, Giuseppe; Gharaghani, Sajjad

    2018-06-01

    Eight enantiomerically pure halogenated Schiff base compounds were synthesized by reaction of halogenated salicylaldehydes with 3-Amino-1,2-propanediol (R or S) in water as green solvent at ambient temperature. All compounds were characterized by elemental analyses, NMR (1H and 13C), circular dichroism (CD) and FT-IR spectroscopy. FS-DNA binding studies of these compounds carried out by fluorescence quenching and UV-vis spectroscopy. The obtained results revealed that the ligands bind to DNA as: (Rsbnd ClBr) > (Rsbnd Cl2) > (Rsbnd Br2) > (Rsbnd I2) and (Ssbnd ClBr) > (Ssbnd Cl2) > (Ssbnd Br2) > (Ssbnd I2), indicating the effect of halogen on binding constant. In addition, DNA-binding constant of the Ssbnd and R-enantiomers are different from each other. The ligands can form halogen bonds with DNA that were confirmed by molecular docking. This method was also measured the bond distances and bond angles. The study of obtained data can have concluded that binding affinity of the ligands to DNA depends on strength of halogen bonds. The potential anticancer activity of ligands were also evaluated on MCF-7 and HeLa cancer cell lines by using MTT assay. The results showed that the anticancer activity and FS-DNA interaction is significantly dependent on the stereoisomers of Schiff base compounds as R-enantiomers displayed significantly higher activity than S-enantiomers. The molecular docking was also used to illustrate the specific DNA-binding of synthesized compounds and groove binding mode of DNA interaction was proposed for them. In addition, molecular docking results indicated that there are three types of bonds (Hsbnd and X-bond and hX-bond) between synthesized compounds and base pairs of DNA.

  14. Is IQG-607 a Potential Metallodrug or Metallopro-Drug With a Defined Molecular Target in Mycobacterium tuberculosis?

    Directory of Open Access Journals (Sweden)

    Bruno L. Abbadi

    2018-05-01

    Full Text Available The emergence of strains of Mycobacterium tuberculosis resistant to isoniazid (INH has underscored the need for the development of new anti-tuberculosis agents. INH is activated by the mycobacterial katG-encoded catalase-peroxidase, forming an acylpyridine fragment that is covalently attached to the C4 of NADH. This isonicotinyl-NAD adduct inhibits the activity of 2-trans-enoyl-ACP(CoA reductase (InhA, which plays a role in mycolic acid biosynthesis. A metal-based INH analog, Na3[FeII(CN5(INH]·4H2O, IQG-607, was designed to have an electronic redistribution on INH moiety that would lead to an intramolecular electron transfer to bypass KatG activation. HPLC and EPR studies showed that the INH moiety can be oxidized by superoxide or peroxide yielding similar metabolites and isonicotinoyl radical only when associated to IQG-607, thereby supporting redox-mediated drug activation as a possible mechanism of action. However, IQG-607 was shown to inhibit the in vitro activity of both wild-type and INH-resistant mutant InhA enzymes in the absence of KatG activation. IQG-607 given by the oral route to M. tuberculosis-infected mice reduced lung lesions. Experiments using early and late controls of infection revealed a bactericidal activity for IQG-607. HPLC and voltammetric methods were developed to quantify IQG-607. Pharmacokinetic studies showed short half-life, high clearance, moderate volume of distribution, and low oral bioavailability, which was not altered by feeding. Safety and toxic effects of IQG-607 after acute and 90-day repeated oral administrations in both rats and minipigs showed occurrence of mild to moderate toxic events. Eight multidrug-resistant strains (MDR-TB were resistant to IQG-607, suggesting an association between katG mutation and increasing MIC values. Whole genome sequencing of three spontaneous IQG-607-resistant strains harbored katG gene mutations. MIC measurements and macrophage infection experiments with a laboratorial

  15. Detection and localization of markers of oxidative stress by in situ methods: application in the study of Alzheimer disease.

    Science.gov (United States)

    Moreira, Paula I; Sayre, Lawrence M; Zhu, Xiongwei; Nunomura, Akihiko; Smith, Mark A; Perry, George

    2010-01-01

    Oxidative stress is a key factor involved in the development and progression of Alzheimer disease (AD), and it is well documented that free radical oxidative damage, particularly of neuronal lipids, proteins, nucleic acids, and sugars, is extensive in brains of AD patients. The complex chemistry of peroxynitrite has been the subject of intense study and is now evident that there are two principal pathways for protein modification: the first one involves homolytic hydroxyl radical-like chemistry that results in protein-based carbonyls and the second involves electrophilic nitration of vulnerable side chains, in particular the electron-rich aromatic rings of Tyr and Trp. In the presence of buffering bicarbonate, peroxynitrite forms a CO(2) adduct, which augments its reactivity. Formation of 3-nitrotyrosine by this route has become the classical protein marker specifically for the presence of peroxynitrite. Protein-based carbonyls can be detected by two methods: (i) derivatization with 2,4-dinitrophenylhydrazine (DNPH) and detection of the protein-bound hydrazones using an enzyme-linked anti-2,4-dinitrophenyl antibody and (ii) derivatization with biotin-hydrazide and detection of the protein-bound acyl hydrazone with enzyme-linked avidin or streptavidin. Glycation of proteins by reducing sugars (Maillard reaction) results in a profile of time-dependent adduct evolution rendering susceptibility to oxidative elaboration. In addition, oxidative stress can result in oxidized sugar derivatives which can subsequently modify protein through a process known as glycoxidation. Of more general importance, oxidative stress results in lipid peroxidation and the production of a range of electrophilic and mostly bifunctional aldehydes that modify numerous proteins. The more important protein modifications are referred to as advanced glycation end products (AGEs) and advanced lipoxidation end products (ALEs). Protein modification can result in both non-cross-link and cross-link AGEs

  16. Selective recognition of sulfate anions in a 95% ethanol solvent with a simple neutral salicylaldehyde dansyl hydrazine Schiff base tuned by Brønsted-Lowry acid-base reaction

    Science.gov (United States)

    Wei, Gao-Ning; Zhang, Jing-Li; Jia, Cang; Fan, Wei-Zhen; Lin, Li-Rong

    2014-07-01

    A new Schiff base compound, 5-(dimethylamino)-N‧-(2-hydroxybenzylidene)naphthalene-1-sulfonohydrazide (R), has been synthesized, characterized, and employed as a selective fluorescence receptor for the recognition of sulfate anions. UV-vis absorption, fluorescence emission, 1H NMR spectra and DFT calculation studies on the system have been carried out to determine the nature of the interactions between R and anions. The results reveal that the deprotonation of the phenol without the need of a strong base leads to the formation of a hydrogen-bonding complex with a sbnd SO2sbnd NHsbnd group, which is responsible for the spectra changes. The deprotonation process for the selectivity recognition of sulfate can be tuned by the Brønsted-Lowry acid-base reaction in nonaqueous solutions, revealing that suitable phenolic hydroxyl acidity is the key factor for anion recognition selectivity.

  17. Enhanced Mechanical Properties in Cellulose Nanocrystal-Poly(oligoethylene glycol methacrylate) Injectable Nanocomposite Hydrogels through Control of Physical and Chemical Cross-Linking.

    Science.gov (United States)

    De France, Kevin J; Chan, Katelyn J W; Cranston, Emily D; Hoare, Todd

    2016-02-08

    While injectable hydrogels have several advantages in the context of biomedical use, their generally weak mechanical properties often limit their applications. Herein, we describe in situ-gelling nanocomposite hydrogels based on poly(oligoethylene glycol methacrylate) (POEGMA) and rigid rod-like cellulose nanocrystals (CNCs) that can overcome this challenge. By physically incorporating CNCs into hydrazone cross-linked POEGMA hydrogels, macroscopic properties including gelation rate, swelling kinetics, mechanical properties, and hydrogel stability can be readily tailored. Strong adsorption of aldehyde- and hydrazide-modified POEGMA precursor polymers onto the surface of CNCs promotes uniform dispersion of CNCs within the hydrogel, imparts physical cross-links throughout the network, and significantly improves mechanical strength overall, as demonstrated by quartz crystal microbalance gravimetry and rheometry. When POEGMA hydrogels containing mixtures of long and short ethylene oxide side chain precursor polymers were prepared, transmission electron microscopy reveals that phase segregation occurs with CNCs hypothesized to preferentially locate within the stronger adsorbing short side chain polymer domains. Incorporating as little as 5 wt % CNCs results in dramatic enhancements in mechanical properties (up to 35-fold increases in storage modulus) coupled with faster gelation rates, decreased swelling ratios, and increased stability versus hydrolysis. Furthermore, cell viability can be maintained within 3D culture using these hydrogels independent of the CNC content. These properties collectively make POEGMA-CNC nanocomposite hydrogels of potential interest for various biomedical applications including tissue engineering scaffolds for stiffer tissues or platforms for cell growth.

  18. Poly(2-ethyl-2-oxazoline) conjugates with doxorubicin for cancer therapy: In vitro and in vivo evaluation and direct comparison to poly[N-(2-hydroxypropyl)methacrylamide] analogues.

    Science.gov (United States)

    Sedlacek, Ondrej; Monnery, Bryn D; Mattova, Jana; Kucka, Jan; Panek, Jiri; Janouskova, Olga; Hocherl, Anita; Verbraeken, Bart; Vergaelen, Maarten; Zadinova, Marie; Hoogenboom, Richard; Hruby, Martin

    2017-11-01

    We designed and synthesized a new delivery system for the anticancer drug doxorubicin based on a biocompatible hydrophilic poly(2-ethyl-2-oxazoline) (PEtOx) carrier with linear architecture and narrow molar mass distribution. The drug is connected to the polymer backbone via an acid-sensitive hydrazone linker, which allows its triggered release in the tumor. The in vitro studies demonstrate successful cellular uptake of conjugates followed by release of the cytostatic cargo. In vivo experiments in EL4 lymphoma bearing mice revealed prolonged blood circulation, increased tumor accumulation and enhanced antitumor efficacy of the PEtOx conjugate having higher molecular weight (40 kDa) compared to the lower molecular weight (20 kDa) polymer. Finally, the in vitro and in vivo anti-cancer properties of the prepared PEtOx conjugates were critically compared with those of the analogous system based on the well-established PHPMA carrier. Despite the relatively slower intracellular uptake of PEtOx conjugates, resulting also in their lower cytotoxicity, there are no substantial differences in in vivo biodistribution and anti-cancer efficacy of both classes of polymer-Dox conjugates. Considering the synthetic advantages of poly(2-alkyl-2-oxazoline)s, the presented study demonstrates their potential as a versatile alternative to well-known PEO- or PHPMA-based materials for construction of drug delivery systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Synthesis, characterization and theranostic evaluation of Indium-111 labeled multifunctional superparamagnetic iron oxide nanoparticles

    International Nuclear Information System (INIS)

    Zolata, Hamidreza; Abbasi Davani, Fereydoun; Afarideh, Hossein

    2015-01-01

    Indium-111 labeled, Trastuzumab-Doxorubicin Conjugated, and APTES-PEG coated magnetic nanoparticles were designed for tumor targeting, drug delivery, controlled drug release, and dual-modal tumor imaging. Superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by thermal decomposition method to obtain narrow size particles. To increase SPIONs circulation time in blood and decrease its cytotoxicity in healthy tissues, SPIONs surface was modified with 3-Aminopropyltriethoxy Silane (APTES) and then were functionalized with N-Hydroxysuccinimide (NHS) ester of Polyethylene Glycol Maleimide (NHS-PEG-Mal) to conjugate with thiolated 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-3,6, 9,-triacetic acid (PCTA) bifunctional chelator (BFC) and Trastuzumab antibody. In order to tumor SPECT/MR imaging, SPIONs were labeled with Indium-111 (T 1/2 = 2.80d). NHS ester of monoethyl malonate (MEM-NHS) was used for conjugation of Doxorubicin (DOX) chemotherapeutic agent onto SPIONs surface. Mono-Ethyl Malonate allows DOX molecules to be attached to SPIONs via pH-sensitive hydrazone bonds which lead to controlled drug release in tumor region. Active and passive tumor targeting were achieved through incorporated anti-HER2 (Trastuzumab) antibody and EPR effect of solid tumors for nanoparticles respectively. In addition to in vitro assessments of modified SPIONs in SKBR3 cell lines, their theranostic effects were evaluated in HER2 + breast tumor bearing BALB/c mice via biodistribution study, dual-modal molecular imaging and tumor diameter measurements

  20. Bent CNN bond of diazo compounds, RR'(Cdbnd N+dbnd N-)

    Science.gov (United States)

    Akita, Motoko; Takahashi, Mai; Kobayashi, Keiji; Hayashi, Naoto; Tukada, Hideyuki

    2013-02-01

    The reaction of ninhydrin with benzophenone hydrazone afforded 2-diazo-3-diphenylmethylenehydrazono-1-indanone 1 and 2-diazo-1,3-bis(diphenylmethylenehydrazono)indan 2. X-ray crystal structure analyses of these products showed that the diazo functional group Cdbnd N+dbnd N- of 1 is bent by 172.9°, while that of 2 has a linear geometry. The crystal structure data of diazo compounds have been retrieved from the Cambridge Structural Database (CSD), which hit 177 entries to indicate that the angle of 172.9° in 1 lies in one of the most bent structures. The CSD search also indicated that diazo compounds consisting of a distorted diazo carbon tend to bend the Cdbnd N+dbnd N- bond. On the basis of DFT calculations (B3LYP/6-311++G(d,p)) of model compounds, it was revealed that the bending of the CNN bond is principally induced by steric factors and that the neighboring carbonyl group also plays a role in bending toward the carbonyl side owing to an electrostatic attractive interaction. The potential surface along the path of Cdbnd N+dbnd N- bending in 2-diazopropane shows a significantly shallow profile with only 4 kcal/mol needed to bend the Cdbnd N+dbnd N- bond from 180° to 160°. Thus, the bending of the diazo group in 1 is reasonable as it is provided with all of the factors for facile bending disclosed in this investigation.