Vanadium(IV/V) complexes of Triapine and related thiosemicarbazones: Synthesis, solution equilibrium and bioactivity.

PubMed

Kowol, Christian R; Nagy, Nóra V; Jakusch, Tamás; Roller, Alexander; Heffeter, Petra; Keppler, Bernhard K; Enyedy, Éva A

2015-11-01

The stoichiometry and thermodynamic stability of vanadium(IV/V) complexes of Triapine and two related α(N)-heterocyclic thiosemicarbazones (TSCs) with potential antitumor activity have been determined by pH-potentiometry, EPR and (51)V NMR spectroscopy in 30% (w/w) dimethyl sulfoxide/water solvent mixtures. In all cases, mono-ligand complexes in different protonation states were identified. Dimethylation of the terminal amino group resulted in the formation of vanadium(IV/V) complexes with considerably higher stability. Three of the most stable complexes were also synthesized in solid state and comprehensively characterized. The biological evaluation of the synthesized vanadium complexes in comparison to the metal-free ligands in different human cancer cell lines revealed only minimal influence of the metal ion. Thus, in addition the coordination ability of salicylaldehyde thiosemicarbazone (STSC) to vanadium(IV/V) ions was investigated. The exchange of the pyridine nitrogen of the α(N)-heterocyclic TSCs to a phenolate oxygen in STSC significantly increased the stability of the complexes in solution. Finally, this also resulted in increased cytotoxicity activity of a vanadium(V) complex of STSC compared to the metal-free ligand. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis, antiviral evaluation and molecular docking studies of N4-aryl substituted/unsubstituted thiosemicarbazones derived from 1-indanones as potent anti-bovine viral diarrhea virus agents.

PubMed

Soraires Santacruz, María C; Fabiani, Matías; Castro, Eliana F; Cavallaro, Lucía V; Finkielsztein, Liliana M

2017-08-01

A series of N 4 -arylsubstituted thiosemicarbazones derived from 1-indanones and a set of compounds lacking such substitution in the N 4 position of the thiosemicarbazone moiety were synthesized and evaluated for their anti-bovine viral diarrhea virus (BVDV) activity. Among these, derivatives 2 and 15 displayed high activity (EC 50 =2.7±0.4 and 0.7±0.1µM, respectively) as inhibitors of BVDV replication. Novel key structural features related to the anti-BVDV activity were identified by structure-activity relationship (SAR) analysis. In a previous study, the thiosemicarbazone of 5,6-dimethoxy-1-indanone (5,6-TSC) was characterized as a non-nucleoside inhibitor (NNI) of the BVDV RNA-dependent RNA polymerase. In the present work, cross-resistance assays were performed with the most active compounds. Such studies were carried out on 5,6-TSC resistant BVDV (BVDV-TSC r T1) carrying mutations in the viral polymerase. This BVDV mutant was also resistant to compound 15. Molecular docking studies and MM/PBSA calculations were performed to assess the most active derivatives at the 5,6-TSC viral polymerase binding site. The differences in the interaction pattern and the binding affinity of derivative 15 either to the wild type or BVDV-TSC r T1 polymerase were key factors to define the mode of action of this compound. Copyright © 2017 Elsevier Ltd. All rights reserved.

Complexes of dichloro[2-(dimethylaminomethyl)phenyl-C1,N]gold(III), [Au(damp-C1,N)Cl2], with formylferrocene thiosemicarbazones: synthesis, structure and cytotoxicity.

PubMed

Casas, José S; Castaño, María V; Cifuentes, María C; García-Monteagudo, Juán C; Sánchez, Agustín; Sordo, José; Abram, Ulrich

2004-06-01

Dichloro[2-(dimethylaminomethyl)phenyl- phenyl-C1,N]gold(III), [Au(damp-C1,N)Cl2], reacts with the formylferrocene thiosemicarbazones derived from 4-methyl-, 4-phenyl-, 4-ethyl- and 4,4-dimethyl-3-thiosemicarbazides, HFcTSC, to give complexes of general formula [Au(Hdamp-1C)Cl(FcTSC)]Cl. These complexes were isolated and characterized by elemental analysis, mass spectrometry and IR, 1H NMR and (13)C NMR spectroscopy. In some cases, cyclic voltammetric studies were carried out and these showed that the complexation of gold affects the redox behaviour of the ferrocene unit. The in vitro antitumor activity against the HeLa cell line was also determined for the more soluble complexes. The IC(50) values were found to be higher than that of cisplatin but the maximum antiproliferative activity was similar.

Acenaphthenequinone thiosemicarbazone and its transition metal complexes: synthesis, structure, and biological activity.

PubMed

Rodriguez-Argüelles, M C; Belicchi Ferrari, M; Gasparri Fava, G; Pelizzi, C; Pelosi, G; Albertini, R; Bonati, A; Dall'Aglio, P P; Lunghi, P; Pinelli, S

1997-04-01

The reaction of iron, nickel, copper, and zinc chlorides or acetates with acenaphthenequinone thiosemicarbazone, Haqtsc leads to the formation of novel complexes that have been characterized by spectroscopic studies (NMR, IR) and biological properties. The crystal structures of the free ligand Haqtsc 1 and of the compound [Ni(aqtsc)2].DMF 2, have also been determined by X-ray methods from diffractometer data. In 1, the conformation of the two nonequivalent molecules is governed by intramolecular hydrogen bonds, while an intermolecular hydrogen bond is responsible for dimer-like groups formation. In 2, the coordination geometry about nickel is distorted octahedral, and the two ligand molecules are terdentate monodeprotonated. Biological studies have shown that, for the first time at least up the used doses, a free ligand is active both in the inhibition of cell proliferation and in the induced differentiation on Friend erythroleukemia cells (FLC).

Binuclear ruthenium(III) bis(thiosemicarbazone) complexes: Synthesis, spectral, electrochemical studies and catalytic oxidation of alcohol

NASA Astrophysics Data System (ADS)

Mohamed Subarkhan, M.; Ramesh, R.

2015-03-01

A new series of binuclear ruthenium(III) thiosemicarbazone complexes of general formula [(EPh3)2(X)2Ru-L-Ru(X)2(EPh3)2] (where E = P or As; X = Cl or Br; L = NS chelating bis(thiosemicarbazone ligands) has been synthesized and characterized by analytical and spectral (FT-IR, UV-Vis and EPR). IR spectra show that the thiosemicarbazones behave as monoanionic bidentate ligands coordinating through the azomethine nitrogen and thiolate sulphur. The electronic spectra of the complexes indicate that the presence of d-d and intense LMCT transitions in the visible region. The complexes are paramagnetic (low spin d5) in nature and all the complexes show rhombic distortion around the ruthenium ion with three different 'g' values (gx ≠ gy ≠ gz) at 77 K. All the complexes are redox active and exhibit an irreversible metal centered redox processes (RuIII-RuIII/RuIV-RuIV; RuIII-RuIII/RuII-RuII) within the potential range of 0.38-0.86 V and -0.39 to -0.66 V respectively, versus Ag/AgCl. Further, the catalytic efficiency of one of the complexes [Ru2Cl2(AsPh3)4(L1)] (4) has been investigated in the case of oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide(NMO) as co-oxidant. The formation of high valent RuVdbnd O species is proposed as catalytic intermediate for the catalytic cycle.

2,6-diacetylpyridine bis(thiosemicarbazones) zinc complexes: synthesis, structure, and biological activity.

PubMed

Rodriguez-Argüelles, M C; Belicchi Ferrari, M; Gasparri Fava, G; Pelizzi, C; Tarasconi, P; Albertini, R; Dall'Aglio, P P; Lunghi, P; Pinelli, S

1995-05-15

The reaction of zinc chloride, acetate, or perchlorate with two bis(thiosemicarbazones) of 2,6-diacetylpyridine [H2daptsc = 2,6-diacetylpyridine bis(thiosemicarbazone) and H2dapipt = 2,6-diacetylpyridine bis(hydrazinopyruvoylthiosemicarbazone)] leads to the formation of four novel complexes that have been characterized by spectroscopic studies (NMR, IR) and biological properties. The crystal structures of the two compounds--[Zn(daptsc)]2.2DMF (1) and [Zn(H2dapipt)(OH2)2](CIO4)2.3H2O (2)--also have been determined by x-ray methods from diffractometer data. Compound (1) is dimeric and the two zinc atoms have a distorted octahedral coordination. The ligand is deprotonated. In compound (2), the coordination geometry about zinc is pentagonal--bipyramidal and the ligand is in the neutral form. The molecular structure of (2) consists of cations [Zn(H2dapipt)(OH2)]2+, CIO4- disordered anions, and three water molecules of solvation. Biological studies have shown that the ligands and the complexes Zn(daptsc).1/2EtOH and Zn(H2daptsc)Cl2 have an effect in vitro on cell proliferation and differentiation (inhibition); both are concentration dependent. [Zn(daptsc)]2.2DMF (1) shows the effects at lower concentration values with respect to other compounds.

Inhibition of Bovine Viral Diarrhea Virus RNA Synthesis by Thiosemicarbazone Derived from 5,6-Dimethoxy-1-Indanone▿

PubMed Central

Castro, Eliana F.; Fabian, Lucas E.; Caputto, María E.; Gagey, Dolores; Finkielsztein, Liliana M.; Moltrasio, Graciela Y.; Moglioni, Albertina G.; Campos, Rodolfo H.; Cavallaro, Lucía V.

2011-01-01

In the present work, we described the activity of the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone (TSC), which we previously characterized as a new compound that inhibits bovine viral diarrhea virus (BVDV) infection. We showed that TSC acts at a point of time that coincides with the onset of viral RNA synthesis and that it inhibits the activity of BVDV replication complexes (RCs). Moreover, we have selected five BVDV mutants that turned out to be highly resistant to TSC but still susceptible to ribavirin (RBV). Four of these resistant mutants carried an N264D mutation in the viral RNA-dependent RNA polymerase (RdRp). The remaining mutant showed an A392E mutation within the same protein. Some of these mutants replicated slower than the wild-type (wt) virus in the absence of TSC, whereas others showed a partial reversion to the wt phenotype over several passages in the absence of the compound. The docking of TSC in the crystal structure of the BVDV RdRp revealed a close contact between the indane ring of the compound and several residues within the fingers domain of the enzyme, some hydrophobic contacts, and hydrogen bonds with the thiosemicarbazone group. Finally, in the mutated RdRp from resistant BVDV, these interactions with TSC could not be achieved. Interestingly, TSC inhibited BVDV replication in cell culture synergistically with RBV. In conclusion, TSC emerges as a new nonnucleoside inhibitor of BVDV RdRp that is synergistic with RBV, a feature that turns it into a potential compound to be evaluated against hepatitis C virus (HCV). PMID:21430053

Inhibition of bovine viral diarrhea virus RNA synthesis by thiosemicarbazone derived from 5,6-dimethoxy-1-indanone.

PubMed

Castro, Eliana F; Fabian, Lucas E; Caputto, María E; Gagey, Dolores; Finkielsztein, Liliana M; Moltrasio, Graciela Y; Moglioni, Albertina G; Campos, Rodolfo H; Cavallaro, Lucía V

2011-06-01

In the present work, we described the activity of the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone (TSC), which we previously characterized as a new compound that inhibits bovine viral diarrhea virus (BVDV) infection. We showed that TSC acts at a point of time that coincides with the onset of viral RNA synthesis and that it inhibits the activity of BVDV replication complexes (RCs). Moreover, we have selected five BVDV mutants that turned out to be highly resistant to TSC but still susceptible to ribavirin (RBV). Four of these resistant mutants carried an N264D mutation in the viral RNA-dependent RNA polymerase (RdRp). The remaining mutant showed an A392E mutation within the same protein. Some of these mutants replicated slower than the wild-type (wt) virus in the absence of TSC, whereas others showed a partial reversion to the wt phenotype over several passages in the absence of the compound. The docking of TSC in the crystal structure of the BVDV RdRp revealed a close contact between the indane ring of the compound and several residues within the fingers domain of the enzyme, some hydrophobic contacts, and hydrogen bonds with the thiosemicarbazone group. Finally, in the mutated RdRp from resistant BVDV, these interactions with TSC could not be achieved. Interestingly, TSC inhibited BVDV replication in cell culture synergistically with RBV. In conclusion, TSC emerges as a new nonnucleoside inhibitor of BVDV RdRp that is synergistic with RBV, a feature that turns it into a potential compound to be evaluated against hepatitis C virus (HCV).

New 1-indanone thiosemicarbazone derivatives active against BVDV.

PubMed

Finkielsztein, Liliana M; Castro, Eliana F; Fabián, Lucas E; Moltrasio, Graciela Y; Campos, Rodolfo H; Cavallaro, Lucía V; Moglioni, Albertina G

2008-08-01

Identification of new therapeutic agents for the treatment of viral diseases represents an area of active investigation. In an effort to develop new antiviral compounds, a series of 1-indanone thiosemicarbazone derivatives were synthesized. These derivatives were structurally characterized using several spectroscopic techniques and evaluated against bovine viral diarrhoea virus as a surrogate model for hepatitis C virus. Thiosemicarbazone 2m showed potent anti-bovine viral diarrhoea virus activity with a higher selectivity index (SI=80.29) than that of ribavirin (SI=11.64). This result determines the potentiality of these thiosemicarbazones as antiviral agents for the treatment of infections caused by other highly related members of Flaviviridae family, as hepatitis C virus.

A novel series of thiosemicarbazone drugs: From synthesis to structure

NASA Astrophysics Data System (ADS)

Ebrahimi, Hossein Pasha; Hadi, Jabbar S.; Alsalim, Tahseen A.; Ghali, Thaer S.; Bolandnazar, Zeinab

2015-02-01

A new series of thiosemicarbazones (TSCs) and their 1,3,4-thiadiazolines (TDZs) containing acetamide group have been synthesized from thiosemicarbazide compounds by the reaction of TSCs with cyclic ketones as well as aromatic aldehydes. The structures of newly synthesized 1,3,4-thiadiazole derivatives obtained by heterocyclization of the TSCs with acetic anhydride were experimentally characterized by spectral methods using IR, 1H NMR, 13C NMR and mass spectroscopic methods. Furthermore, the structural, thermodynamic, and electronic properties of the studied compounds were also studied theoretically by performing Density Functional Theory (DFT) to access reliable results to the experimental values. The molecular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and Mulliken atomic charges of the studied compounds have been calculated at the B3LYP method and standard 6-31+G(d,p) basis set starting from optimized geometry. The theoretical 13C chemical shift results were also calculated using the gauge independent atomic orbital (GIAO) approach and their respective linear correlations were obtained.

Synthesis, activity and pharmacophore development for isatin-β-thiosemicarbazones with selective activity towards multidrug resistant cellsa

PubMed Central

Hall, Matthew D.; Salam, Noeris K.; Hellawell, Jennifer L.; Fales, Henry M.; Kensler, Caroline B.; Ludwig, Joseph A.; Szakacs, Gergely; Hibbs, David E.; Gottesman, Michael M.

2009-01-01

We have recently identified a new class of compounds that selectively kill cells that express P-glycoprotein (P-gp, MDR1), the ATPase efflux pump that confers multidrug resistance on cancer cells. Several isatin-β-thiosemicarbazones from our initial study have been validated, and a range of analogs synthesized and tested. A number demonstrated improved MDR1-selective activity over the lead, NSC73306 (1). Pharmacophores for cytotoxicity and MDR1-selectivity were generated to delineate the structural features required for activity. The MDR1-selective pharmacophore highlights the importance of aromatic/hydrophobic features at the N4 position of the thiosemicarbazone, and the reliance on the isatin moiety as key bioisosteric contributors. Additionally, a quantitative structure-activity relationship (QSAR) model that yielded a cross-validated correlation coefficient of 0.85 effectively predicts the cytotoxicty of untested thiosemicarbazones. Together, the models serve as effective approaches for predicting structures with MDR1-selective activity, and aid in directing the search for the mechanism of action of 1. PMID:19397322

Rhenium(I) tricarbonyl compounds of bioactive thiosemicarbazones: Synthesis, characterization and activity against Trypanosoma cruzi.

PubMed

Rodríguez Arce, Esteban; Machado, Ignacio; Rodríguez, Belén; Lapier, Michel; Zúñiga, María Carolina; Maya, Juan Diego; Olea Azar, Claudio; Otero, Lucía; Gambino, Dinorah

2017-05-01

American Trypanosomiasis is a chronic infection discovered and described in 1909 by the Brazilian scientist Carlos Chagas. It is caused by the protozoan parasite Trypanosoma cruzi. Although it affects about 10million people in Latin America, the current chemotherapy is still inadequate. The discovery of new drugs is urgently needed. Our group is focused on the development of prospective metal-based drugs mainly based on bioactive ligands and pharmacologically interesting metal ions. In this work three new rhenium(I) tricarbonyl compounds fac-[Re I (CO) 3 Br(HL)] where HL=5-nitrofuryl containing thiosemicarbazones were synthesized and fully characterized in solution and in the solid state. The in vitro evaluation of the compounds on T. cruzi trypomastigotes (Dm28c strain) showed that the Re(I) compounds are 8 to 15 times more active than the reference drug Nifurtimox and show a 4 to 17 fold increase in activity in respect to the free (HL) ligands. Obtained compounds also show good selectivity indexes (IC 50 endothelial cells Ea.hy926 /IC 50 T. cruzi (Dm28c tripomastigotes) ). 1 H NMR and MS studies, performed with time, showed that the fac-[Re(CO) 3 Br(HL)] species convert into the dimers [Re 2 (CO) 6 (L) 2 ] in solution. Crystal structure of [Re I 2 (CO) 6 (L2) 2 ], the product of complexes' dimerization, was solved. Related to the mechanism of action, the studied compounds do not generate radical oxygen species in the parasite (as 5-nitrofuryl derived thiosemicarbazones do) probably due to the unfavorable nitro reduction potential of the generated dimeric species. On the contrary, the compounds produce a decrease of the oxygen consumption rate of the parasites, maybe inhibiting their mitochondrial respiration. Copyright © 2017 Elsevier Inc. All rights reserved.

A New Thiosemicarbazone-Based Fluorescence "Turn-on" Sensor for Zn(2+) Recognition with a Large Stokes Shift and its Application in Live Cell Imaging.

PubMed

Tang, Lijun; Huang, Zhenlong; Zheng, Zhuxuan; Zhong, Keli; Bian, Yanjiang

2016-09-01

Selective fluorescence turn on Zn(2+) sensor with long-wavelength emission and a large Stokes shift is highly desirable in Zn(2+) sensing area. We reported herein the synthesis and Zn(2+) recognition properties of a new thiosemicarbazone-based fluorescent sensor L. L displays high selectivity and sensitivity toward Zn(2+) over other metal ions in DMSO-H2O (1:1, v/v, HEPES 10 mM, pH = 7.4) solution with a long-wavelength emission at 572 nm and a large Stokes shift of 222 nm. Confocal fluorescence microscopy experiments demonstrate that L is cell-permeable and capable of monitoring intracellular Zn(2+). Graphical Abstract We report a new thiosemicarbazone-based fluorescent sensor (L) for selective recognition of Zn(2+) with a long wavelength emission and a large Stokes shift.

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.

PubMed

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.

Synthesis and Biochemical Evaluation of Thiochromanone Thiosemicarbazone Analogues as Inhibitors of Cathepsin L

PubMed Central

2012-01-01

A series of 36 thiosemicarbazone analogues containing the thiochromanone molecular scaffold functionalized primarily at the C-6 position were prepared by chemical synthesis and evaluated as inhibitors of cathepsins L and B. The most promising inhibitors from this group are selective for cathepsin L and demonstrate IC50 values in the low nanomolar range. In nearly all cases, the thiochromanone sulfide analogues show superior inhibition of cathepsin L as compared to their corresponding thiochromanone sulfone derivatives. Without exception, the compounds evaluated were inactive (IC50 > 10000 nM) against cathepsin B. The most potent inhibitor (IC50 = 46 nM) of cathepsin L proved to be the 6,7-difluoro analogue 4. This small library of compounds significantly expands the structure–activity relationship known for small molecule, nonpeptidic inhibitors of cathepsin L. PMID:24900494

Synthesis, biological evaluation and molecular docking of N-phenyl thiosemicarbazones as urease inhibitors.

PubMed

Hameed, Abdul; Khan, Khalid Mohammed; Zehra, Syeda Tazeen; Ahmed, Ramasa; Shafiq, Zahid; Bakht, Syeda Mahwish; Yaqub, Muhammad; Hussain, Mazhar; de la Vega de León, Antonio; Furtmann, Norbert; Bajorath, Jürgen; Shad, Hazoor Ahmad; Tahir, Muhammad Nawaz; Iqbal, Jamshed

2015-08-01

Urease is an important enzyme which breaks urea into ammonia and carbon dioxide during metabolic processes. However, an elevated activity of urease causes various complications of clinical importance. The inhibition of urease activity with small molecules as inhibitors is an effective strategy for therapeutic intervention. Herein, we have synthesized a series of 19 benzofurane linked N-phenyl semithiocarbazones (3a-3s). All the compounds were screened for enzyme inhibitor activity against Jack bean urease. The synthesized N-phenyl thiosemicarbazones had varying activity levels with IC50 values between 0.077 ± 0.001 and 24.04 ± 0.14 μM compared to standard inhibitor, thiourea (IC50 = 21 ± 0.11 μM). The activities of these compounds may be due to their close resemblance of thiourea. A docking study with Jack bean urease (PDB ID: 4H9M) revealed possible binding modes of N-phenyl thiosemicarbazones. Copyright © 2015 Elsevier Inc. All rights reserved.

Halo-substituted thiosemicarbazones and their copper(II), nickel(II) complexes: Detailed spectroscopic characterization and study of antitumour activity against HepG2 human hepatoblastoma cells

NASA Astrophysics Data System (ADS)

Jagadeesh, M.; Kalangi, Suresh K.; Sivarama Krishna, L.; Reddy, A. Varada

2014-01-01

Copper(II) and nickel(II) complexes of two different halogen substituted thiosemicarbazone ligands were synthesized. The ligands 3,4-difluoroacetophenone thiosemicarbazone (1) and 2-bromo-4'-chloroacetophenone thiosemicarbazone (2) were characterized and confirmed spectroscopically by FT-IR, FT-Raman, UV-vis and fluorescence spectral analysis, while the respective copper(II) complexes [Cu(C9H9N3F2S)2Cl2] (1a), [Cu(C9H9N3ClBrS)2Cl2] (2a) and nickel(II) complexes [Ni(C9H9N3F2S)2] (1b), [Ni(C9H9N3ClBrS)2] (2b) were characterized by FT-IR, UV-vis and electron paramagnetic spectroscopy (EPR). The EPR spectra of the Cu(II) complexes provided the rhombic octahedral and axial symmetry of the complexes 1a and 2a respectively. For the complex 1a, the g values calculated as g1 = 2.1228, g2 = 2.0706 and g3 = 2.001 between 2900 and 3300 G. While for the complex 2a, a set of two resonance absorptions were observed. The synthesized compounds were tested for antitumor activity and showed that the ability to kill liver cancer cells significantly. Out of all the synthesized compounds, copper(II) complexes 1a and 2a showed high cytotoxic effect on liver cancer cells with 67.51% and 42.77% of cytotoxicity respectively at 100 μM.

Novel heterocyclic thiosemicarbazones derivatives as colorimetric and "turn on" fluorescent sensors for fluoride anion sensing employing hydrogen bonding.

PubMed

Ashok Kumar, S L; Saravana Kumar, M; Sreeja, P B; Sreekanth, A

2013-09-01

Two novel heterocyclic thiosemicarbazone derivatives have been synthesized, and characterized, by means of spectroscopic and single crystal X-ray diffraction methods. Their chromophoric-fluorogenic response towards anions in competing solvent dimethyl sulfoxide (DMSO) was studied. The receptor shows selective recognition towards fluoride anion. The binding affinity of the receptors with fluoride anion was calculated using UV-visible and fluorescence spectroscopic techniques. Copyright © 2013 Elsevier B.V. All rights reserved.

Microwave gallium-68 radiochemistry for kinetically stable bis(thiosemicarbazone) complexes: structural investigations and cellular uptake under hypoxia.

PubMed

Alam, Israt S; Arrowsmith, Rory L; Cortezon-Tamarit, Fernando; Twyman, Frazer; Kociok-Köhn, Gabriele; Botchway, Stanley W; Dilworth, Jonathan R; Carroll, Laurence; Aboagye, Eric O; Pascu, Sofia I

2016-01-07

We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under 'cold' and 'hot' biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. (68)Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration.

Eco-Friendly Synthesis of Some Thiosemicarbazones and Their Applications as Intermediates for 5-Arylazothiazole Disperse Dyes.

PubMed

Gaffer, Hatem E; Khalifa, Mohamed E

2015-12-09

The solid-solid reactions of thiosemicarbazide with 4-formylantipyrine, 2-acetylpyrrole and camphor were performed to afford the thiosemicarbazones 1-3 which underwent hetero-cyclization with phenacyl bromide to furnish the corresponding thiazole derivatives 4-6. The yields of the reactions are quantitative in all cases and the products do not require further purification. A series of 5-arylazo-2-(substituted ylidene-hydrazinyl)-thiazole dyes 7-9 was then prepared by diazo coupling of thiazole derivatives 4-6 with several diazonium chlorides. The synthesized dyes were applied as disperse dyes for dyeing polyester fabric. The dyed fabrics exhibit good washing, perspiration, sublimation and light fastness properties, with little variation in their moderate to good rubbing fastness.

Synthesis and Cytotoxic Evaluation of Steroidal Copper (Cu (II)) Complexes

PubMed Central

Huang, Yanmin; Kong, Erbin; Zhan, Junyan; Chen, Shuang; Gan, Chunfang; Liu, Zhiping; Pang, Liping

2017-01-01

Using estrone and pregnenolone as starting materials, some steroidal copper complexes were synthesized by the condensation of steroidal ketones with thiosemicarbazide or diazanyl pyridine and then complexation of steroidal thiosemicarbazones or steroidal diazanyl pyridines with Cu (II). The complexes were characterized by IR, NMR, and HRMS. The synthesized compounds were screened for their cytotoxicity against HeLa, Bel-7404, and 293T cell lines in vitro. The results show that all steroidal copper (II) complexes display obvious antiproliferative activity against the tested cancer cells. The IC50 values of complexes 5 and 12 against Bel-7404 (human liver carcinoma) are 5.0 and 7.0 μM. PMID:29180937

Synthesis, Spectroscopic, and Antimicrobial Studies on Bivalent Nickel and Copper Complexes of Bis(thiosemicrbazone)

PubMed Central

Chandra, Sulekh; Raizada, Smriti; Tyagi, Monika; Gautam, Archana

2007-01-01

A series of metal complexes of Cu(II) and Ni(II) having the general composition [M(L)X2] with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties. PMID:18273385

Transglutaminase-mediated conjugation and nitride-technetium-99m labelling of a bis(thiosemicarbazone) bifunctional chelator.

PubMed

Salvarese, Nicola; Spolaore, Barbara; Marangoni, Selena; Pasin, Anna; Galenda, Alessandro; Tamburini, Sergio; Cicoria, Gianfranco; Refosco, Fiorenzo; Bolzati, Cristina

2018-06-01

An assessment study involving the use of the transglutaminase (TGase) conjugation method and the nitride-technetium-99m labelling on a bis(thiosemicarbazone) (BTS) bifunctional chelating agent is presented. The previously described chelator diacetyl-2-(N 4 -methyl-3-thiosemicarbazone)-3-(N 4 -amino-3-thiosemicarbazone), H 2 ATSM/A, has been functionalized with 6-aminohexanoic acid (ε-Ahx) to generate the bifunctional chelating agent diacetyl-2-(N 4 -methyl-3-thiosemicarbazone)-3-[N 4 -(amino)-(6-aminohexanoic acid)-3-thiosemicarbazone], H 2 ATSM/A-ε-Ahx (1), suitable for conjugation to glutamine (Gln) residues of bioactive molecules via TGase. The feasibility of the TGase reaction in the synthesis of a bioconjugate derivative was investigated using Substance P (SP) as model peptide. Compounds 1 and H 2 ATSM/A-ε-Ahx-SP (2) were labelled with nitride-technetium-99m, obtaining the complexes [ 99m Tc][Tc(N)(ATSM/A-ε-Ahx)] ( 99m Tc1) and [ 99m Tc][Tc(N)(ATSM/A-ε-Ahx-SP)] ( 99m Tc2). The chemical identity of 99m Tc1 and 99m Tc2 was confirmed by radio/UV-RP-HPLC combined with ESI-MS analysis on the respective carrier-added products 99g/99m Tc1 and 99g/99m Tc2. The stability of the radiolabelled complexes after incubation in various environments was investigated. All the results were compared with those obtained for the corresponding 64 Cu-analogues, 64 Cu1 and 64 Cu2. The TGase reaction allows the conjugation of 1 with the peptide, but it is not highly efficient due to instability of the chelator in the required conditions. The SP-conjugated complexes are unstable in mouse and human sera. However, indeed the BTS system can be exploited as nitride-technetium-99m chelator for highly efficient technetium labelling, thus making compound 1 worthy of further investigations for new targeted technetium and copper radiopharmaceuticals encompassing Single Photon Emission Computed Tomography and Positron Emission Tomography imaging. Copyright © 2018 Elsevier Inc. All rights reserved.

Synthesis, spectral, thermal and antimicrobial studies on cobalt(II), nickel(II), copper(II), zinc(II) and palladium(II) complexes containing thiosemicarbazone ligand

NASA Astrophysics Data System (ADS)

El-Sawaf, Ayman K.; El-Essawy, Farag; Nassar, Amal A.; El-Samanody, El-Sayed A.

2018-04-01

The coordination characteristic of new N4-morpholinyl isatin-3-thiosemicarbazone (HL) towards Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) has been studies. The structures of the complexes were described by elemental analyses, molar conductivity, magnetic, thermal and spectral (IR, UV-Vis, 1H and 13C NMR and ESR) studies. On the basis of analytical and spectral studies the ligand behaves as monobasic tridentate ONS donor forming two five membered rings towards cobalt, copper and palladium and afforded complexes of the kind [M(L)X], (Mdbnd Co, Cu or Pd; Xdbnd Cl, Br or OAc). Whereas the ligand bound to NiCl2 as neutral tridentate ONS donor and with ZnCl2 as neutral bidentate NS donor. The newly synthesized thiosemicarbazone ligand and some of its complexes were examined for antimicrobial activity against 2 gram negative bacterial strains (Escherichia coli Pseudomonas and aeruginosa), 2 gram positive bacterial strains (Streptococcus pneumoniae and Staphylococcus aureus)} and two Pathogenic fungi (Aspergillus fumigatus and Candida albicans). All metal complexes possess higher antimicrobial activity comparing with the free thiosemicarbazone ligand. The high potent activities of the complexes may arise from the coordination and chelation, which tends to make metal complexes act as more controlling and potent antimicrobial agents, thus hindering the growing of the microorganisms. The antimicrobial results also show that copper bromide complex is better antimicrobial agent as compared to the Schiff base and its metal complexes.

Microwave assisted tandem reactions for the synthesis of 2-hydrazolyl-4-thiazolidinones

PubMed Central

Saiz, Cecilia; Pizzo, Chiara; Manta, Eduardo; Wipf, Peter; Mahler, S. Graciela

2009-01-01

A tandem method for the synthesis of 2-hydrazolyl-4-thiazolidinones (5) from commercially available materials in a 3 component reaction has been developed. The reaction connects aldehydes, thiosemicarbazides and maleic anhydride, effectively assisted by microwave irradiation. The synthesis of a new type of compound, 2-hydrazolyl-5,5-diphenyl-4-thiazolidinone (7), obtained by treatment of thiosemicarbazone with benzil in basic media is also reported. HOMO/LUMO energies, orbital coefficients and charge distribution were used to explain the proposed reaction mechanism. PMID:19756224

Gold(III) bis(thiosemicarbazonate) compounds in breast cancer cells: Cytotoxicity and thioredoxin reductase targeting.

PubMed

Rodríguez-Fanjul, Vanessa; López-Torres, Elena; Mendiola, M Antonia; Pizarro, Ana María

2018-03-25

Gold(III) compounds have received increasing attention in cancer research. Three gold complexes of general formula [Au III L]Cl, where L is benzil bis(thiosemicarbazonate), compound 1, benzil bis(4-methyl-3-thiosemicarbazonate), compound 2, or benzil bis(4-cyclohexyl-3-thiosemicarbazonate), compound 3, have been synthesized and fully characterized, including the X-ray crystal structure of compound 3, confirming square-planar geometry around the gold(III) centre. Compound 1 showed moderate cytotoxicity and accumulation in MCF7 breast cancer cells but did not inhibit thioredoxin reductase (TrxR) activity and did not induce reactive oxygen species (ROS) production. Compound 2, the least cytotoxic, was found to be capable of modestly inhibiting TrxR activity and produced low levels of ROS in the MCF7 cell line. The most cytotoxic compound, 3, had the highest cellular accumulation and its distribution pattern showed a clear preference for the cytosol and mitochondria of MCF7 cells. It readily hampered intracellular TrxR activity leading to a dramatic alteration of the cellular redox state and to the induction of cell death. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

p-halo N4-phenyl substituted thiosemicarbazones: Crystal structure, supramolecular architecture, characterization and bio-assay of their Co(III) and Ni(II) complexes

NASA Astrophysics Data System (ADS)

Kotian, Avinash; Kumara, Karthik; Kamat, Vinayak; Naik, Krishna; Kokare, Dhoolesh G.; Nevrekar, Anupama; Lokanath, Neratur Krishnappagowda; Revankar, Vidyanand K.

2018-03-01

In the present work, three potential metal ion chelating ligands, p-halo N4-phenyl substituted thiosemicarbazones are synthesized and characterized. The molecular structure of all (E)-4-(4-halophenyl)-1-(3-hydroxyiminobutan-2-ylidene) thiosemicarbazones (halo = F/Cl/Br) are determined by single crystal X-ray diffraction method. All the molecules have crystallized in monoclinic crystal system with P21/n space group. The ligands show Csbnd H⋯S and Nsbnd H⋯S intermolecular interactions, which are responsible to form the supramolecular self-assemblies through R22(8), R22(12) and R22(14) ring motifs. Hirshfeld surface analysis is carried out to explore the intermolecular interactions. A series of Co(III) and Ni(II) mononuclear transition metal complexes derived from these ligands have been synthesized and characterized by various spectro-analytical methods. The metal to ligand stoichiometry has been found to be 1:2 in all the complexes. The synthesized compounds have been investigated for their in vitro antimicrobial potencies. The compounds are found to be more active than the standard used, in the case of E. coli and A. niger. Additionally, they are also screened for their in vitro antitubercular activity.

Structural and cytotoxic studies of cationic thiosemicarbazones

NASA Astrophysics Data System (ADS)

Sinniah, Saravana Kumar; Sim, Kae Shin; Ng, Seik Weng; Tan, Kong Wai

2017-06-01

Schiff bases from the thiosemicarbazones family with variable N4 substituents are known to show enhanced growth inhibitory properties. In view of these facts and as a part of our continuous interest in cationic Schiff bases, we have developed several Schiff base ligands from (3-formyl-4-hydroxyphenyl)methyltriphenylphosphonium (T) in present study. The compounds were characterized by various spectroscopic methods (infrared spectra, 1H NMR, 13C NMR, HRESIMS and X-ray crystallography). Three of the N4 substituents, namely P(tsc)T, FP(tsc)T and EP(tsc)T exerted strong growth inhibitory properties by inhibiting the highly metastasis prostate cancer growth (PC-3). The thiosemicarbazone with ethylphenyl (EP) moiety displayed most potent activity against all cell lines tested. The MTT data obtained from analysis establishes that phenyl substituent enhances the growth inhibitory properties of the compound. The result affirms that EP(tsc)T would serve as a lead scaffold for rational anticancer agent development.

Coordination behavior of ligand based on NNS and NNO donors with ruthenium(III) complexes and their catalytic and DNA interaction studies

NASA Astrophysics Data System (ADS)

Manikandan, R.; Viswnathamurthi, P.

2012-11-01

Reactions of 2-acetylpyridine-thiosemicarbazone HL1, 2-acetylpyridine-4-methyl-thiosemicarbazone HL2, 2-acetylpyridine-4-phenyl-thiosemicarbazone HL3 and 2-acetylpyridine-semicarbazone HL4 with ruthenium(III) precursor complexes were studied and the products were characterized by analytical and spectral (FT-IR, electronic, EPR and EI-MS) methods. The ligands coordinated with the ruthenium(III) ion via pyridine nitrogen, azomethine nitrogen and thiolate sulfur/enolate oxygen. An octahedral geometry has been proposed for all the complexes based on the studies. All the complexes are redox active and display an irreversible and quasireversible metal centered redox processes. Further, the catalytic activity of the new complexes has been investigated for the transfer hydrogenation of ketones in the presence of isopropanol/KOH and the Kumada-Corriu coupling of aryl halides with aryl Grignard reagents. The DNA cleavage efficiency of new complexes has also been tested.

Ternary complexes of Zn(II) and Cu(II) with 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide in the presence of heterocyclic bases as auxiliary ligands: Synthesis, spectroscopic and structural characterization and antibacterial activity

NASA Astrophysics Data System (ADS)

Azarkish, Mohammad; Akbari, Alireza; Sedaghat, Tahereh; Simpson, Jim

2018-03-01

The new ternary complexes, ZnLL‧ [L = 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide and L‧ = imidazole (1), 2, 2‧-bipyridine (2) and 2-methyimidazole (3)], Zn2L2L‧ [L‧ = 4, 4‧-bipy (4)] and CuLL‧ [L‧ = 2, 2‧-bipy (5)] have been synthesized by the reaction of a metal(II) acetate salt with the thiosemicarbazone and in presence of heterocyclic bases as auxiliary ligands. The synthesized compounds were investigated by elemental analysis and IR, 1H NMR, and 13C NMR spectroscopy and complex 5 was structurally characterized by X-ray crystallography. The results indicate the thiosemicarbazone doubly deprotonated and coordinates to metal through the thiolate sulfur, imine nitrogen and phenolic oxygen atoms. The nitrogen atom(s) of the auxiliary ligand complete the coordination sphere. Complex 4 is binuclear with 4, 4‧-bipy acting as a bridging ligand. The structure of 5 is a distorted square pyramid with one of the bipyridine nitrogen atoms in the apical position. This compound creates an inversion dimer in solid state by intermolecular hydrogen bonds of Nsbnd H⋯S type. The in vitro antibacterial activity of the synthesized compounds were evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (P. aeruginosa) bacteria and is compared to that of standard antibacterial drugs. All complexes exhibit good inhibitory effects and are significantly more effective than the parent ligand.

Copper(II) Thiosemicarbazone Complexes and Their Proligands upon UVA Irradiation: An EPR and Spectrophotometric Steady-State Study.

PubMed

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.

β-Cyclodextrin hydrogels for the ocular release of antibacterial thiosemicarbazones.

PubMed

Glisoni, Romina J; García-Fernández, María J; Pino, Marylú; Gutkind, Gabriel; Moglioni, Albertina G; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Sosnik, Alejandro

2013-04-02

Two types of hydrophilic networks with conjugated beta-cyclodextrin (β-CD) were developed with the aim of engineering useful platforms for the localized release of an antimicrobial 5,6-dimethoxy-1-indanone N4-allyl thiosemicarbazone (TSC) in the eye and its potential application in ophthalmic diseases. Poly(2-hydroxyethyl methacrylate) soft contact lenses (SCLs) displaying β-CD, namely pHEMA-co-β-CD, and super-hydrophilic hydrogels (SHHs) of directly cross-linked hydroxypropyl-β-CD were synthesized and characterized regarding their structure (ATR/FT-IR), drug loading capacity, swelling and in vitro release in artificial lacrimal fluid. Incorporation of TSC to the networks was carried out both during polymerization (DP method) and after synthesis (PP method). The first method led to similar drug loads in all the hydrogels, with minor drug loss during the washing steps to remove unreacted monomers, while the second method evidenced the influence of structural parameters on the loading efficiency (proportion of CD units, mesh size, swelling degree). Both systems provided a controlled TSC release for at least two weeks, TSC concentrations (up to 4000μg/g dry hydrogel) being within an optimal therapeutic window for the antimicrobial ocular treatment. Microbiological tests against P. aeruginosa and S. aureus confirmed the ability of TSC-loaded pHEMA-co-β-CD network to inhibit bacterial growth. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis and biological evaluation of some novel thiazole compounds as potential anti-inflammatory agents.

PubMed

Helal, M H M; Salem, M A; El-Gaby, M S A; Aljahdali, M

2013-07-01

In the present investigation, furo[2,3-d]thiazol-5(2H)-one 5 was obtained from reaction of thiosemicarbazone derivative 2 with diethyl acetylene dicarboxylate. A series of newly synthesized 2-(hydrazinyl)thiazol-4(5H)-one 6, 7 &8 and 2-(4-(substituted)-thiazol-2-yl)hydrazono derivatives 9a, b &10 were synthesized from treatment of thiosemicarbazone derivative 2 with appropriate α-halogenated compounds. Also, a one pot synthesis of thiazole derivatives 13 &15 was achieved from three components reaction of hydrazone derivative 11 with phenyl isothiocyanate and α-halogenated compounds catalyzed by DMF/KOH. 4-(4-Morpholino phenyl) thiazol-2-amino 17 was obtained via the reaction of acetophenone derivative 1 with thiourea in presence of iodine. The reactivity of 2-aminothiazole 17 toward some electrophilic reagents was investigated. The structure of the newly compounds was confirmed on the basis of elemental analysis and spectral data. The antibacterial activity towards two Gram negative (Proteus mirabilis &Serratia marcesens) and two Gram positive (Staphylococcus aureus &Bacillus cereus) bacteria was investigated. The anti-inflammatory activity was also investigated and the inhibition of the carrageenin-induced oedema by these compounds was established. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Neutral Ni(II), Pd(II) and Pt(II) ONS-pincer complexes of 5-acetylbarbituric-4N-dimethylthiosemicarbazone: synthesis, characterization and properties.

PubMed

Castiñeiras, Alfonso; Fernández-Hermida, Nuria; García-Santos, Isabel; Gómez-Rodríguez, Lourdes

2012-11-21

Octahedral 1:1 Ni(II) and square-planar 1:1 Pd(II) and Pt(II) complexes of formulae [Ni(HAcb4DM)(AcO)(H2O)2]·H2O (1), [Pd(HAcb4DM)Cl]·5H2O (2) and [Pt(HAcb4DM)Cl]·3H2O (3), where H2Acb4DM = 5-acetylbarbituric-4N-dimethylthiosemicarbazone (H2 denoting its two dissociable protons, one enolic and one thiolic), have been synthesized and characterized by elemental analysis and by 1H and 13C NMR, UV-vis, and IR spectroscopy. Crystallisation of compounds 1–3 from DMSO afforded complexes of formulae [Ni(HAcb4DM)2]·2H2O (1a), [Pd(Acb4DM)(DMSO)]·DMSO (2a) and [Pt(Acb4DM)(DMSO)]·DMSO (3a), the molecular and crystal structures of which were determined by X-ray diffractometry. The thiosemicarbazone in 1a coordinates to the metal ions in an ONS-tridentate manner in the O-enolate/S-thione form, but in complexes 2a and 3a the thiosemicarbazone binds Pd(II) or Pt(II) as an ONS-pincer ligand in the O-enolate/S-thiolate form. The 195Pt NMR spectrum of 3 shows a signal at −2950 ppm along with two new signals at −3348 and −2731 ppm, indicating the presence of solvolysis products. The catalytic activity of complex 2a has been explored in aryl–aryl Suzuki cross-coupling reactions. H2Acb4DM and complexes 2 and 3 were screened for in vitro cytotoxicity against a human tumour cell line (HeLa-229), with the clinically employed drug cisplatin as a reference.

Spectroscopic evaluation of Co(II), Ni(II) and Cu(II) complexes derived from thiosemicarbazone and semicarbazone

NASA Astrophysics Data System (ADS)

Chandra, Sulekh; Kumar, Anil

2007-12-01

Co(II), Ni(II) and Cu(II) complexes were synthesized with thiosemicarbazone (L 1) and semicarbazone (L 2) derived from 2-acetyl furan. These complexes were characterized by elemental analysis, molar conductance, magnetic moment, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO corresponds to non-electrolytic nature. All the complexes are of high-spin type. On the basis of different spectral studies six coordinated geometry may be assigned for all the complexes except Co(L) 2(SO 4) and Cu(L) 2(SO 4) [where L = L 1 and L 2] which are of five coordinated square pyramidal geometry.

Versatile chelating behavior of benzil bis(thiosemicarbazone) in zinc, cadmium, and nickel complexes.

PubMed

López-Torres, Elena; Mendiola, Ma Antonia; Pastor, César J; Pérez, Beatriz Souto

2004-08-23

Reactions of benzil bis(thiosemicarbazone), LH(6), with M(NO(3))(2).nH(2)O (M = Zn, Cd, and Ni), in the presence of LiOH.H(2)O, show the versatile behavior of this molecule. The structure of the ligand, with the thiosemicarbazone moieties on opposite sides of the carbon backbone, changes to form complexes by acting as a chelating molecule. Complexes of these metal ions with empirical formula [MLH(4)] were obtained, although they show different molecular structures depending on their coordinating preferences. The zinc complex is the first example of a crystalline coordination polymer in which a bis(thiosemicarbazone) acts as bridging ligand, through a nitrogen atom, giving a 1D polymeric structure. The coordination sphere is formed by the imine nitrogen and sulfur atoms, and the remaining position, in a square-based pyramid, is occupied by an amine group of another ligand. The cadmium derivative shows the same geometry around the metal ion but consists of a dinuclear structure with sulfur atoms acting as a bridge between the metal ions. However, in the nickel complex LH(6) acts as a N(2)S(2) ligand yielding a planar structure for the nickel atom. The ligand and its complexes have been characterized by X-ray crystallography, microanalysis, mass spectrometry, IR, (1)H, and (13)C NMR spectroscopies and for the cadmium complex by (113)Cd NMR in solution and in the solid state.

Microwave gallium-68 radiochemistry for kinetically stable bis(thiosemicarbazone) complexes: structural investigations and cellular uptake under hypoxia† †Electronic supplementary information (ESI) available. CCDC 1001632–1001634. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5dt02537k Click here for additional data file. Click here for additional data file.

PubMed Central

Alam, Israt S.; Arrowsmith, Rory L.; Cortezon-Tamarit, Fernando; Twyman, Frazer; Kociok-Köhn, Gabriele; Botchway, Stanley W.; Dilworth, Jonathan R.

2016-01-01

We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under ‘cold’ and ‘hot’ biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. 68Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration. PMID:26583314

Interaction of Triapine and related thiosemicarbazones with iron(III)/(II) and gallium(III): a comparative solution equilibrium study†

PubMed Central

Enyedy, Éva A.; Primik, Michael F.; Kowol, Christian R.; Arion, Vladimir B.; Kiss, Tamás; Keppler, Bernhard K.

2012-01-01

Stoichiometry and stability of GaIII, FeIII, FeII complexes of Triapine and five related α-N heterocyclic thiosemicarbazones with potential antitumor activity have been determined by pH-potentiometry, UV-vis spectrophotometry, 1H NMR spectroscopy, and spectrofluorimetry in aqueous solution (with 30% DMSO), together with the characterization of the proton dissociation processes. Additionally, the redox properties of the iron complexes were studied by cyclic voltammetry at various pH values. Formation of high stability bis-ligand complexes was found in all cases, which are predominant at physiological pH with FeIII/FeII, whilst only at the acidic pH range with GaIII. The results show that among the thiosemicarbazones with various substituents the N-terminal dimethylation does not exert a measurable effect on the redox potential, but has the highest impact on the stability of the complexes as well as the cytotoxicity, especially in the absence of a pyridine-NH2 group in the molecule. In addition the fluorescence properties of the ligands in aqueous solution and their changes caused by GaIII were studied. PMID:21523301

3-(1,3,4-Thiadiazole-2-yl)quinoline derivatives: synthesis, characterization and anti-microbial activity.

PubMed

Bhat, Abdul R; Tazeem; Azam, Amir; Choi, Inho; Athar, Fareeda

2011-07-01

A new series of thiadiazoles and intermediate thiosemicarbazones were synthesized from the chloroquinone molecule, with an aim to explore their effect on in vitro growth of microorganisms causing microbial infection. The chemical structures of the compound were elucidated by elemental analysis, FTIR, 1H and 13C NMR and ESI-MS spectral data. In vitro anti-microbial activity was performed against Staphylococcusaureus, Streptococcuspyogenes, Salmonellatyphimurium, and Escherichiacoli. The MIC was detected using the double dilution method. The results were compared by calculating percent inhibit area/μg of the compounds and the standard "amoxicillin". The selected compounds were tested for cytotoxic results using MTT assay H9c2 cardiac myoblasts cell line and the results showed that all the compounds offered remarkable >80% viability to a concentration of 200 μg/mL. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Spectroscopic characterization, antioxidant and antitumour studies of novel bromo substituted thiosemicarbazone and its copper(II), nickel(II) and palladium(II) complexes

NASA Astrophysics Data System (ADS)

Jagadeesh, M.; Lavanya, M.; Kalangi, Suresh K.; Sarala, Y.; Ramachandraiah, C.; Varada Reddy, A.

2015-01-01

A new, slightly distorted octahedral complex of copper(II), square planar complexes of nickel(II) and palladium(II) with 2,4‧-dibromoacetophenone thiosemicarbazone (DBAPTSC) are synthesized. The ligand and the complexes are characterized by FT-IR, FT-Raman, powder X-ray diffraction studies. The IR and Raman data are correlated for the presence of the functional groups which specifically helped in the confirmation of the compounds. In addition, the free ligand is unambiguously characterized by 1H and 13C NMR spectroscopy while the copper(II) complex is characterized by electron paramagnetic resonance spectroscopy (EPR). The g values for the same are found to be 2.246 (g1), 2.012 (g2) and 2.005 (g3) which suggested rhombic distortions. The HOMO-LUMO band gap calculations for these compounds are found to be in between 0.5 and 4.0 eV and these compounds are identified as semiconducting materials. The synthesized ligand and its copper(II), nickel(II) and palladium(II) complexes are subjected to antitumour activity against the HepG2 human hepatoblastoma cell lines. Among all the compounds, nickel(II) complex is found to exert better antitumour activity with 57.6% of cytotoxicity.

Structural, thermal and optical characterization of an organic NLO material--benzaldehyde thiosemicarbazone monohydrate single crystals.

PubMed

Santhakumari, R; Ramamurthi, K

2011-02-01

Single crystals of the organic NLO material, benzaldehyde thiosemicarbazone (BTSC) monohydrate, were grown by slow evaporation method. Solubility of BTSC monohydrate was determined in ethanol at different temperatures. The grown crystals were characterized by single crystal X-ray diffraction analysis to determine the cell parameters and by FT-IR technique to study the presence of the functional groups. Thermogravimetric and differential thermal analyses reveal the thermal stability of the crystal. UV-vis-NIR spectrum shows excellent transmission in the region of 200-1100 nm. Theoretical calculations were carried out to determine the linear optical constants such as extinction coefficient and refractive index. Further the optical nonlinearities of BTSC have been investigated by Z-scan technique with He-Ne laser radiation of wavelength 632.8 nm. Mechanical properties of the grown crystal were studied using Vickers microhardness tester. Second harmonic generation efficiency of the powdered BTSC monohydrate was tested using Nd:YAG laser and it is found to be ∼5.3 times that of potassium dihydrogen orthophosphate. Copyright © 2010 Elsevier B.V. All rights reserved.

Nickel(II) Complex of Polyhydroxybenzaldehyde N4-Thiosemicarbazone Exhibits Anti-Inflammatory Activity by Inhibiting NF-κB Transactivation

PubMed Central

Loh, Sheng Wei; Looi, Chung Yeng; Hassandarvish, Pouya; Phan, Alicia Yi Ling; Wong, Won Fen; Wang, Hao; Paterson, Ian C.; Ea, Chee Kwee; Mustafa, Mohd Rais; Maah, Mohd Jamil

2014-01-01

Background The biological properties of thiosemicarbazone have been widely reported. The incorporation of some transition metals such as Fe, Ni and Cu to thiosemicarbazone complexes is known to enhance its biological effects. In this study, we incorporated nickel(II) ions into thiosemicarbazone with N4-substitution groups H3L (H; H3L1, CH3; H3L2, C6H5; H3L3 and C2H5; H3L4) and examined its potential anti-inflammatory activity. Methodology/Principal Findings Four ligands (1–4) and their respective nickel-containing complexes (5–8) were synthesized and characterized. The compounds synthesized were tested for their effects on NF-κB nuclear translocation, pro-inflammatory cytokines secretion and NF-κB transactivation activity. The active compound was further evaluated on its ability to suppress carrageenan-induced acute inflammation in vivo. A potential binding target of the active compound was also predicted by molecular docking analysis. Conclusions/Significance Among all synthesized compounds tested, we found that complex [Ni(H2L1)(PPh3)]Cl (5) (complex 5), potently inhibited IκBα degradation and NF-κB p65 nuclear translocation in LPS-stimulated RAW264.7 cells as well as TNFα-stimulated HeLa S3 cells. In addition, complex 5 significantly down-regulated LPS- or TNFα-induced transcription of NF-κB target genes, including genes that encode the pro-inflammatory cytokines TNFα, IFNβ and IL6. Luciferase reporter assays confirmed that complex 5 inhibited the transactivation activity of NF-κB. Furthermore, the anti-inflammatory effect of complex 5 was also supported by its suppressive effect on carrageenan-induced paw edema formation in wild type C57BL/6 mice. Interestingly, molecular docking study showed that complex 5 potentially interact with the active site of IKKβ. Taken together, we suggest complex 5 as a novel NF-κB inhibitor with potent anti-inflammatory effects. PMID:24977407

Intermolecular interaction of thiosemicarbazone derivatives to solvents and a potential Aedes aegypti target

NASA Astrophysics Data System (ADS)

da Silva, João Bosco P.; Hallwass, Fernando; da Silva, Aluizio G.; Moreira, Diogo Rodrigo; Ramos, Mozart N.; Espíndola, José Wanderlan P.; de Oliveira, Ana Daura T.; Brondani, Dalci José; Leite, Ana Cristina L.; Merz, Kenneth M.

2015-08-01

DFT calculations were used to access information about structure, energy and electronic properties of series of phenyl- and phenoxymethyl-(thio)semicarbazone derivatives with demonstrated activity against the larvae of Aedes aegypti in stage L4. The way as the thiosemicarbazone derivatives can interact with solvents like DMSO and water were analyzed from the comparison between calculated and experimental 1H NMR chemical shifts. The evidences of thiosemicarbazone derivatives making H-bond interaction to solvent have provide us insights on how they can interact with a potential A. aegypti's biological target, the Sterol Carrier Protein-2.

Synthesis, in vitro β-glucuronidase inhibitory activity and in silico studies of novel (E)-4-Aryl-2-(2-(pyren-1-ylmethylene)hydrazinyl)thiazoles.

PubMed

Salar, Uzma; Khan, Khalid Mohammed; Syed, Shazia; Taha, Muhammad; Ali, Farman; Ismail, Nor Hadiani; Perveen, Shahnaz; Wadood, Abdul; Ghufran, Mehreen

2017-02-01

Current research is based on the synthesis of novel (E)-4-aryl-2-(2-(pyren-1-ylmethylene)hydrazinyl)thiazole derivatives (3-15) by adopting two steps route. First step was the condensation between the pyrene-1-carbaldehyde (1) with the thiosemicarbazide to afford pyrene-1-thiosemicarbazone intermediate (2). While in second step, cyclization between the intermediate (2) and phenacyl bromide derivatives or 2-bromo ethyl acetate was carried out. Synthetic derivatives were structurally characterized by spectroscopic techniques such as EI-MS, 1 H NMR and 13 C NMR. Stereochemistry of the iminic double bond was confirmed by NOESY analysis. All pure compounds 2-15 were subjected for in vitro β-glucuronidase inhibitory activity. All molecules were exhibited excellent inhibition in the range of IC 50 =3.10±0.10-40.10±0.90μM and found to be even more potent than the standard d-saccharic acid 1,4-lactone (IC 50 =48.38±1.05μM). Molecular docking studies were carried out to verify the structure-activity relationship. A good correlation was perceived between the docking study and biological evaluation of active compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of metabolic pathways of different α-N-heterocyclic thiosemicarbazones.

PubMed

Pelivan, Karla; Frensemeier, Lisa M; Karst, Uwe; Koellensperger, Gunda; Heffeter, Petra; Keppler, Bernhard K; Kowol, Christian R

2018-03-01

Clinical failure of novel drugs is often related to their rapid metabolism and excretion. This highlights the importance of elucidation of their pharmacokinetic profile already at the preclinical stage of drug development. Triapine, the most prominent representative of α-N-heterocyclic thiosemicarbazones, was investigated in more than 30 clinical phase I/II trials, but the results against solid tumors were disappointing. Recent investigations from our group suggested that this is, at least partially, based on the fast metabolism and excretion. In order to establish more detailed structure/activity/metabolism relationships, herein a panel of 10 different Triapine derivatives was investigated for their metabolic pathways. From the biological point of view, the panel consists of terminally dimethylated thiosemicarbazones with nanomolar IC 50 values, derivatives with micromolar cytotoxicities comparable to Triapine and a completely inactive representative. To study the oxidative metabolism, a purely instrumental approach based on electrochemistry/mass spectrometry was applied and the results were compared to the data obtained from microsomal incubations. Overall, the investigated thiosemicarbazones underwent the phase I metabolic reactions dehydrogenation, hydroxylation, oxidative desulfuration (to semicarbazone and amidrazone) and demethylation. Notably, dehydrogenation resulted in a ring-closure reaction with formation of thiadiazoles. Although strong differences between the metabolic pathways of the different thiosemicarbazones were observed, they could not be directly correlated to their cytotoxicities. Finally, the metabolic pathways for the most cytotoxic compound were elucidated also in tissues collected from drug-treated mice, confirming the data obtained by electrochemical oxidation and microsomes. In addition, the in vivo experiments revealed a very fast metabolism and excretion of the compound. Graphical abstract Structure/activity/metabolisation relationships for 10 anticancer thiosemicarbazones were established using electrochemical oxidation coupled to mass spectrometry (EC-MS) and human liver microsomes analyzed by LC-MS.

Synthesis and spectroscopic characterization of 3,4-difluoroacetophenone-thiosemicarbazone and its palladium(II) complex: Evaluation of antimicrobial and antitumour activity

NASA Astrophysics Data System (ADS)

Jagadeesh, M.; Rashmi, H. K.; Subba Rao, Y.; Sreenath Reddy, A.; Prathima, B.; Uma Maheswari Devi, P.; Reddy, A. Varada

2013-11-01

A new cis-palladium(II)diaqua(3,4-difluoroacetophenonethiosemicarbazone complex (Pd(II) complex) is synthesized using 3,4-difluoroacetophenonethiosemicarbazone(L). The L and its Pd(II) complex are characterized and confirmed by elemental analyses, electrochemical analyses, FT-IR, FT-Raman, UV-Vis, HRMS and LC-MS techniques. Ligand L is further characterized by 1H, 13C and 19F NMR spectroscopy. The crystal structure of L is unambiguously characterized by single X-ray crystallography. The ligand (L) belongs to monoclinic system with P2(1)/C space group and the unit cell parameters are a(Å) = 9.1144(7), b(Å) = 13.7928(7), c(Å) = 8.4174(5), α(°) = 90, β(°) = 100.715, γ(°) = 90 and volume V(A3) = 1039.73(11). The Raman bands observed for the L and its Pd(II) complex are in good agreement with the FT-IR spectral data. The Pd(II) complex is found to be highly efficient in inhibiting the growth of human pathogens like Salmonella typhimurium and Klebsiella pneumonia with MIC value 10.0 μg/mL whose inhibition zones are almost comparable with the standard antibiotic. The synthesized compounds have shown antiproliferative activity against the human breast cancer cell lines MDA-MB231 by intermitting the regular pathway of ribonucleotidereductase.

Indomethacin Analogs: Synthesis and Anti-inflammatory and Analgesic Activities of Indoline Derivatives.

PubMed

Amin, Mohamed M; Shaaban, Mohamed R; Al-Qurashi, Nadia T; Mahmoud, Huda K; Farghaly, Thoraya A

2018-03-29

Short reaction time and high yield was achieved for the synthesis of new hydrazonoindolines having thiazole moiety under microwave irradiation via the reaction of hydrazonoyl chlorides or halogenated activemethylene derivatives with thiosemicarbazone derivatives. Also, the utility of the versatile indoline-2,3-dione derivatives in the design of new multifunctional building blocks using condensation with hydrazine derivatives was demonstrated. The information derived from the spectral data of the formed compounds were confirmed their structures. Also, the analgesic and anti-inflammatory activities of the designed derivatives were screened and the results obtained indicated that six derivatives 4g, 9b, 4c, 10b, 4d and 11a revealed the highest anti-inflammatory and analgesic effects. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Supramolecular interactions in biologically relevant compounds. 2-Pyrazineformamide thiosemicarbazones and some products of their cyclization

NASA Astrophysics Data System (ADS)

Castiñeiras, Alfonso; García-Santos, Isabel; Nogueiras, Silvia; Rodríguez-González, Iria; Rodríguez-Riobó, Raúl

2014-09-01

Reaction of 2-cyanopyrazine with thiosemicarbazide or N-methylthiosemicarbazide afforded the (Z)-2-(amino(pyrazin-2-yl)methylene)hydrazinecarbothioamide (HPzAm4DH) and (Z)-2-(amino(pyrazin-2-yl)methylene)-N-methylhydrazine carbothioamide (HPzAm4M), respectively. (2Z,N‧E)-N‧-(4-Oxothiazolidin-2-ylidene)pyrazine-2-carbohydrazonamide (HPzAmot, 5) and (2Z,N‧E)-N‧-(3-methyl-4-oxothiazolidin-2-ylidene)pyrazine-2-carbohydrazonamide (MPzAmot, 7) have been synthesized from these thiosemicarbazones with chloroacetic or bromoacetic acids, using a conventional synthetic methodology and microwave-assisted organic reaction enhancement. The crystal structures of the thiosemicarbazones and their solvates [HPzAm4DHṡ1/2 MeOH (1), HPzAm4DHṡH2O (2), HPzAm4M (3), HPzAm4Mṡ2H2O (4)] and the 1,3-thiazolidin-4-ones (5 and 7) have been studied by X-ray diffractometry. All of the compounds were characterized by elemental analysis, mass spectrometry, FT-IR and 1H and 13C NMR spectroscopy. Several by-products have also been isolated in a crystalline form, namely 3-((Z,E)-N‧-(4-oxothiazolidin-2-ylidene)carbamohydrazonium-yl)pyrazin-1-ium dibromide monohydrate, (H3PzAmot)Br2ṡH2O (6), 2-((5-(pyrazin-2-yl)-1H-1,2,4-triazol-3-yl)thio)acetic acid, (H2Pz124ttAc) (8), 2-amino-5-(pyrazin-2-yl)-1,3,4-thiadiazol-3-ium chloride monohydrate, (HPz134tda)ClṡH2O (9), and 2-(methylamino)-5-(pyrazin-2-yl)-1,3,4-thiadiazol-3-ium chloride N-methyl-5-(pyrazin-2-yl)-1,3,4-thiadiazol-2-amine solvate, (HMPz134tda)Clṡ(MPz134tda) (10). The structures of these compounds were also analyzed by X-ray diffractometry. The microwave-assisted organic reaction method for synthesis is easy, convenient, and ecofriendly when compared to the traditional synthetic methods. Crystal analysis revealed that the compounds have extended 3D supramolecular networks through high levels of H-bonding and weak molecular interactions between the molecular moieties and solvent molecules. The novel synthons, which are sustained by Nsbnd H⋯N and Nsbnd H⋯O hydrogen bonding and other weak interactions, have been shown to assemble with 1,3-thizolidine-4-ones, 1,2,4-trizole, or 1,3,4-thiadiazole derivatives in a zigzag or herringbone architecture.

[Study of the effect of thiosemicarbazones against Toxoplasma gondii].

PubMed

Gomes, Marco Antônio G B; Carreira, Gabriela M; Souza, Daniela P V; Nogueira, Paulo Marcos R; de Melo, Edésio J T; Maria, Edmilson J

2013-04-01

Toxoplasmosis is a neglected disease, with an estimated occurrence of one-third of the population worldwide. Research in medicinal chemistry has for some years been pursuing the development of new drugs against toxoplasmosis, because current treatments cause serious side effects in the patient. The use of thiosemicarbazones as an alternative option for the treatment of various diseases has been published in recent years, due to their, among others, anticancer, antimalarial, antitrypanosomal, antibacterial, and antitoxoplasmosis activities, the latter being the subject of this study, which is based upon biological analyses and tests of the response of Toxoplasma gondii in the presence of thiosemicarbazones. Copyright © 2013 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Kinetic studies on the oxidation of oxyhemoglobin by biologically active iron thiosemicarbazone complexes: relevance to iron-chelator-induced methemoglobinemia.

PubMed

Basha, Maram T; Rodríguez, Carlos; Richardson, Des R; Martínez, Manuel; Bernhardt, Paul V

2014-03-01

The oxidation of oxyhemoglobin to methemoglobin has been found to be facilitated by low molecular weight iron(III) thiosemicarbazone complexes. This deleterious reaction, which produces hemoglobin protein units unable to bind dioxygen and occurs during the administration of iron chelators such as the well-known 3-aminopyridine-2-pyridinecarbaldehyde thiosemicarbazone (3-AP; Triapine), has been observed in the reaction with Fe(III) complexes of some members of the 3-AP structurally-related thiosemicarbazone ligands derived from di-2-pyridyl ketone (HDpxxT series). We have studied the kinetics of this oxidation reaction in vitro using human hemoglobin and found that the reaction proceeds with two distinct time-resolved steps. These have been associated with sequential oxidation of the two different oxyheme cofactors in the α and β protein chains. Unexpected steric and hydrogen-bonding effects on the Fe(III) complexes appear to be the responsible for the observed differences in the reaction rate across the series of HDpxxT ligand complexes used in this study.

The Metastasis Suppressor, N-MYC Downstream-regulated Gene-1 (NDRG1), Down-regulates the ErbB Family of Receptors to Inhibit Downstream Oncogenic Signaling Pathways*

PubMed Central

Kovacevic, Zaklina; Menezes, Sharleen V.; Sahni, Sumit; Kalinowski, Danuta S.; Bae, Dong-Hun; Lane, Darius J. R.; Richardson, Des R.

2016-01-01

N-MYC downstream-regulated gene-1 (NDRG1) is a potent growth and metastasis suppressor that acts through its inhibitory effects on a wide variety of cellular signaling pathways, including the TGF-β pathway, protein kinase B (AKT)/PI3K pathway, RAS, etc. To investigate the hypothesis that its multiple effects could be regulated by a common upstream effector, the role of NDRG1 on the epidermal growth factor receptor (EGFR) and other members of the ErbB family, namely human epidermal growth factor receptor 2 (HER2) and human epidermal growth factor receptor 3 (HER3), was examined. We demonstrate that NDRG1 markedly decreased the expression and activation of EGFR, HER2, and HER3 in response to the epidermal growth factor (EGF) ligand, while also inhibiting formation of the EGFR/HER2 and HER2/HER3 heterodimers. In addition, NDRG1 also decreased activation of the downstream MAPKK in response to EGF. Moreover, novel anti-tumor agents of the di-2-pyridylketone class of thiosemicarbazones, namely di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone and di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone, which markedly up-regulate NDRG1, were found to inhibit EGFR, HER2, and HER3 expression and phosphorylation in cancer cells. However, the mechanism involved appeared dependent on NDRG1 for di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone, but was independent of this metastasis suppressor for di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone. This observation demonstrates that small structural changes in thiosemicarbazones result in marked alterations in molecular targeting. Collectively, these results reveal a mechanism for the extensive downstream effects on cellular signaling attributed to NDRG1. Furthermore, this study identifies a novel approach for the treatment of tumors resistant to traditional EGFR inhibitors. PMID:26534963

Preparation and Biodistribution Studies of a Radiogallium-Acetylacetonate Bis (Thiosemicarbazone) Complex in Tumor-Bearing Rodents

PubMed Central

Jalilian, Amir Reza; Yousefnia, Hassan; Shafaii, Kamaleddin; Novinrouz, Aytak; Rajamand, Amir Abbas

2012-01-01

Various radiometal complexes have been developed for tumor imaging, especially Ga-68 tracer. In the present study, the development of a radiogallium bis-thiosemicarbazone complex has been reported. [67Ga] acetylacetonate bis(thiosemicarbazone) complex ([67Ga] AATS) was prepared starting [67Ga]Gallium acetate and freshly prepared acetylacetonate bis (thiosemicarbazone) (AATS) in 30 min at 90°C. The partition co-efficient and the stability of the tracer were determined in final solution (25°C) and the presence of human serum (37°C) up to 24 h. The biodistribution of the labeled compound in wild-type and fibrosarcoma-bearing rodents were determined up to 72 h. The radiolabled Ga complex was prepared in high radiochemical purity (> 97%, HPLC) followed by initial biodistribution data with the significant tumor accumulation of the tracer in 2 h which is far higher than free Ga-67 cation while the compound wash-out is significantly faster. Above-mentioned pharmacokinetic properties suggest an interesting radiogallium complex while prepared by the PET Ga radioisotope, 68Ga, in accordance with the physical half life, for use in fibrosarcoma tumors, and possibly other malignancies. PMID:24250475

Antineoplastic and cytogenetic effects of complexes of Pd (II) with 4N-substituted derivatives of 2-acetyl-pyridine-thiosemicarbazone.

PubMed

Papageorgiou, A; Iakovidou, Z; Mourelatos, D; Mioglou, E; Boutis, L; Kotsis, A; Kovala-Demertzi, D; Domopoulou, A; West, D X; Dermetzis, M A

1997-01-01

The effect of novel Pd(II) complexes with derivatives of 2-acetyl-pyridinethisemicarbazone, N4-ethyl (HAc4Et) and 3-hexamethyleneiminylthiosemicarbazone (HAchexim), on Sister Chromatid Exchange (SCE) rates and human lymphocyte proliferation kinetics was studied. Also, the effect of Pd(II) complexes on DNA synthesis of P388 and L1210 cell cultures and against Leukemia P388 was investigated. Among these compounds, the compound Bis(3-hexamethyleneiminyl-2-acetylpyridine-thisemicarbazonato++ +) palladium (II) was found to be distinctly effective against Leukemia P388, in inhibiting incorporation of 3H-thymidine into DNA and in inducing SCEs and cell division delays.

Comparative evaluation of Bis(thiosemicarbazone)- Biotin and Met-ac-TE3A for tumor imaging

NASA Astrophysics Data System (ADS)

Singh, Sweta; Tiwari, Anjani K.; Varshney, Raunak; Mathur, R.; Shukla, Gauri; Bag, N.; Singh, B.; Mishra, Anil K.

2016-01-01

2,2‧,2″-(11-(2-((4-mercapto-1-methoxy-1-oxobutan-2-yl)amino)-2-oxoethyl)-1,4,8,11-tetraaza cyclotetradecane-1,4,8-triyl)triacetic acid, Met-ac-TE3A and (E)-N-methyl-2-((E)-3-(2-(2-(5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanoyl)hydrazinecarbono-thioyl)hydrazonobutan-2-ylidene)hydrazinecarbothioamide, Bis(thiosemicarbazone)- Biotin were synthesized and evaluated for imaging application. The pharmacokinetics of these ligands were determined by tracer methods. In vitro human serum stability of 99mTc Met-ac-TE3A/99mTc Bis(thiosemicarbazone)-Biotin after 24 h was found to be 96.5% and 97.0% respectively. Blood kinetics of both ligands in normal rabbits showed biphasic clearance pattern. Ex vivo biodistribution study revealed significant initial tumor uptake and high tumor/muscles ratio which is a pre-requisite condition for a ligand to work as SPECT-radiopharmaceutical for tumor imaging.

Trypanocidal nitroimidazole derivatives: relationships among chemical structure and genotoxic activity.

PubMed

Buschini, Annamaria; Giordani, Federica; de Albuquerque, Cristina Northfleet; Pellacani, Claudia; Pelosi, Giorgio; Rossi, Carlo; Zucchi, Tânia Maria Araújo Domingues; Poli, Paola

2007-05-15

Human American trypanosomiasis is resurgent in Latin Americans, and new drugs are urgently required as current medications suffer from a number of drawbacks. Some nitroheterocycles have been demonstrated to exert a potent activity against trypanosomes. However, host toxicity issues halted their development as trypanocides. As part of the efforts to develop new compounds in order to treat parasitic infections, it is important to define their structure-activity relationship. In this study, 5-nitromegazol and two of its analogues, 4-nitromegazol, and 1-methyl-5-nitro-2-imidazolecarboxaldehyde 5-nitroimidazole-thiosemicarbazone, were tested and compared for in vitro induction of DNA damage in human leukocytes by the comet assay, performed at different pHs to better identify the types of damage. Specific oxidatively generated damage to DNA was also measured by using the comet assay with endonucleases. DNA damage was found in 5-nitromegazol-treated cells: oxidative stress appeared as the main source of DNA damage. 4-Nitromegazol did not produce any significant effect, thus confirming that 4-nitroimidazoles isomers have no important biological activity. The 5-nitroimidazole-thiosemicarbazone induced DNA damage with a higher efficiency than 5-nitromegazol. The central role in the reduction process played by the acidic hydrazine proton present in the thiosemicarbazone group but not in the cyclic (thiadiazole) form can contribute to rationalise our results. Given its versatility, thiosemicarbazone moiety could be involved in different reactions with nitrogenous bases (nucleophilic and/or electrophilic attacks).

3-methylcyclohexanone thiosemicarbazone: determination of E/Z isomerization barrier by dynamic high-performance liquid chromatography, configuration assignment and theoretical study of the mechanisms involved by the spontaneous, acid and base catalyzed processes.

PubMed

Carradori, Simone; Cirilli, Roberto; Dei Cicchi, Simona; Ferretti, Rosella; Menta, Sergio; Pierini, Marco; Secci, Daniela

2012-12-21

Here, we report on the simultaneous direct HPLC diastereo- and enantioseparation of 3-methylcyclohexanone thiosemicarbazone (3-MCET) on a polysaccharide-based chiral stationary phase under normal-phase conditions. The optimized chromatographic system was employed in dynamic HPLC experiments (DHPLC), as well as detection technique in a batch wise approach to determine the rate constants and the corresponding free energy activation barriers of the spontaneous, base- and acid-promoted E/Z diastereomerization of 3-MCET. The stereochemical characterization of four stereoisomers of 3-MCET was fully accomplished by integrating the results obtained by chemical correlation method with those derived by theoretical calculations and experimental investigations of circular dichroism (CD). As a final goal, a deepened analysis of the perturbing effect exercised by the stationary phase on rate constant values measured through DHPLC determinations as a function of the chromatographic separation factor α of the interconverting species was successfully accomplished. This revealed quite small deviations from the equivalent kinetic values obtained by off-column batch wise procedure, and suggested a possible effective correction of rate constants measured by DHPLC approach. Copyright © 2012 Elsevier B.V. All rights reserved.

Thiosemicarbazones and Phthalyl-Thiazoles compounds exert antiviral activity against yellow fever virus and Saint Louis encephalitis virus.

PubMed

Pacca, Carolina Colombelli; Marques, Rafael Elias; Espindola, José Wanderlan P; Filho, Gevânio B O Oliveira; Leite, Ana Cristina Lima; Teixeira, Mauro Martins; Nogueira, Mauricio L

2017-03-01

Arboviruses, arthropod-borneviruses, are frequency associated to human outbreak and represent a serious health problem. The genus Flavivirus, such as Yellow Fever Virus (YFV) and Saint Louis Encephalitis Virus (SLEV), are important pathogens with high morbidity and mortality worldwide. In Brazil, YFV is maintained in sylvatic cycle, but many cases are notified annually, despite the efficiency of vaccine. SLEV causes an acute encephalitis and is widely distributed in the Americas. There is no specific antiviral drugs for these viruses, only supporting treatment that can alleviate symptoms and prevent complications. Here, we evaluated the potential anti-YFV and SLEV activity of a series of thiosemicarbazones and phthalyl-thiazoles. Plaque reduction assay, flow cytometry, immunofluorescence and cellular viability were used to test the compounds in vitro. Treated cells showed efficient inhibition of the viral replication at concentrations that presented minimal toxicity to cells. The assays showed that phthalyl-thiazole and phenoxymethyl-thiosemicarbazone reduced 60% of YFV replication and 75% of SLEV replication. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Vibrational, NMR and UV-visible spectroscopic investigation and NLO studies on benzaldehyde thiosemicarbazone using computational calculations

NASA Astrophysics Data System (ADS)

Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Pandian, G. V.; Anbusrinivasan, P.

2016-04-01

In order to investigate the vibrational, electronic and NLO characteristics of the compound; benzaldehyde thiosemicarbazone (BTSC), the XRD, FT-IR, FT-Raman, NMR and UV-visible spectra were recorded and were analysed with the calculated spectra by using HF and B3LYP methods with 6-311++G(d,p) basis set. The XRD results revealed that the stabilized molecular systems were confined in orthorhombic unit cell system. The cause for the change of chemical and physical properties behind the compound has been discussed makes use of Mulliken charge levels and NBO in detail. The shift of molecular vibrational pattern by the fusing of ligand; thiosemicarbazone group with benzaldehyde has been keenly observed. The occurrence of in phase and out of phase molecular interaction over the frontier molecular orbitals was determined to evaluate the degeneracy of the electronic energy levels. The thermodynamical studies of the temperature region 100-1000 K to detect the thermal stabilization of the crystal phase of the compound were investigated. The NLO properties were evaluated by the determination of the polarizability and hyperpolarizability of the compound in crystal phase. The physical stabilization of the geometry of the compound has been explained by geometry deformation analysis.

3-[(E)-(acridin-9‧-ylmethylidene)amino]-1-substituted thioureas and their biological activity

NASA Astrophysics Data System (ADS)

Bečka, Michal; Vilková, Mária; Salem, Othman; Kašpárková, Jana; Brabec, Viktor; Kožurková, Mária

2017-06-01

This paper describes the synthesis of a novel series of acridine thiosemicarbazones through a two-step reaction between various isothiocyanates and hydrazine followed by treatment with acridin-9-carbaldehyde. The properties of this series of seven new derivatives are studied using NMR and biochemical techniques, and the DNA-binding properties of the compounds are determined using spectrophotometric studies (UV-vis absorption, fluorescence, and circular/linear dichroism) and viscometry. The binding constants K are estimated as being in the range of 2.2 to 7.8 × 104 M- 1 and the percentage of hypochromism was found to be 22.11-49.75% (from UV-vis spectral titration). Electrophoretic experiments prove that the novel compounds demonstrate moderate inhibitory effects against Topo I activity at a concentration of 60 × 10- 6 M.

Thiosemicarbazone p-Substituted Acetophenone Derivatives Promote the Loss of Mitochondrial Δψ, GSH Depletion, and Death in K562 Cells

PubMed Central

Pessoto, Felipe S.; Yokomizo, Cesar H.; Prieto, Tatiana; Fernandes, Cleverton S.; Silva, Alan P.; Kaiser, Carlos R.; Basso, Ernani A.; Nantes, Iseli L.

2015-01-01

A series of thiosemicarbazone (TSC) p-substituted acetophenone derivatives were synthesized and chemically characterized. The p-substituents appended to the phenyl group of the TSC structures were hydrogen, fluor, chlorine, methyl, and nitro, producing compounds named TSC-H, TSC-F, TSC-Cl, TSC-Me, and TSC-NO2, respectively. The TSC compounds were evaluated for their capacity to induce mitochondrial permeability, to deplete mitochondrial thiol content, and to promote cell death in the K562 cell lineage using flow cytometry and fluorescence microscopy. TSC-H, TSC-F, and TSC-Cl exhibited a bell-shaped dose-response curve for the induction of apoptosis in K562 cells due to the change from apoptosis to necrosis as the principal mechanism of cell death at the highest tested doses. TSC-Me and TSC-NO2 exhibited a typical dose-response profile, with a half maximal effective concentration of approximately 10 µM for cell death. Cell death was also evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed lower toxicity of these compounds for peripheral blood mononuclear cells than for K562 cells. The possible mechanisms leading to cell death are discussed based on the observed effects of the new TSC compounds on the cellular thiol content and on mitochondrial bioenergetics. PMID:26075034

Structure-activity relationships of mononuclear metal-thiosemicarbazone complexes endowed with potent antiplasmodial and antiamoebic activities.

PubMed

Bahl, Deepa; Athar, Fareeda; Soares, Milena Botelho Pereira; de Sá, Matheus Santos; Moreira, Diogo Rodrigo Magalhães; Srivastava, Rajendra Mohan; Leite, Ana Cristina Lima; Azam, Amir

2010-09-15

A useful concept for the rational design of antiparasitic drug candidates is the complexation of bioactive ligands with transition metals. In view of this, an investigation was conducted into a new set of metal complexes as potential antiplasmodium and antiamoebic agents, in order to examine the importance of metallic atoms, as well as the kind of sphere of co-ordination, in these biological properties. Four functionalized furyl-thiosemicarbazones (NT1-4) treated with divalent metals (Cu, Co, Pt, and Pd) to form the mononuclear metallic complexes of formula [M(L)2Cl2] or [M(L)Cl2] were examined. The pharmacological characterization, including assays against Plasmodium falciparum and Entamoeba histolytica, cytotoxicity to mammalian cells, and interaction with pBR 322 plasmid DNA was performed. Structure-activity relationship data revealed that the metallic complexation plays an essential role in antiprotozoal activity, rather than the simple presence of the ligand or metal alone. Important steps towards identification of novel antiplasmodium (NT1Cu, IC50 of 4.6 microM) and antiamoebic (NT2Pd, IC50 of 0.6 microM) drug prototypes were achieved. Of particular relevance to this work, these prototypes were able to reduce the proliferation of these parasites at concentrations that are not cytotoxic to mammalian cells. Copyright (c) 2010. Published by Elsevier Ltd.

Ultrasound-assisted dispersive magnetic solid phase extraction for preconcentration and determination of trace amount of Hg (II) ions from food samples and aqueous solution by magnetic graphene oxide (Fe3O4@GO/2-PTSC): Central composite design optimization.

PubMed

Keramat, Akram; Zare-Dorabei, Rouholah

2017-09-01

In this work, the synthesis of the magnetic graphene oxide modified by 2-pyridinecarboxaldehyde thiosemicarbazone groups (Fe 3 O 4 @GO/2-PTSC) was utilized for preconcentration and determination of mercuric ions in a trace amount by inductively coupled plasma-optical emission spectrometry (ICP-OES). Characterization of the adsorbent was performed using various techniques, such as FT-IR, VSM, SEM and XRD analysis. Central composite design (CCD) under response surface methodology (RSM) was used for obtaining the most important parameters and probable interactions in variables. The variables such as adsorbent dosage, pH, desorption time, and eluent volume was optimized. These values were 8mg, 5.4min, 0.5mL (HCl, 0.1M), respectively. Sonication had an important role in shortening the adsorption time of Hg (II) ions by enhancing the dispersion of adsorbent in solution. Under the optimal conditions, the proposed method presented high enrichment factor of 193, an extraction percentage of 96.5, a detection limit of 0.0079µgL -1 and a relative standard deviation (RSD %) of 1.63%. Finally, the application of the synthesized material was evaluated for preconcentration and determination of mercuric ions from foods and environmental waters samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Platinum(II) and palladium(II) complexes with 2-acetylpyridine thiosemicarbazone: cytogenetic and antineoplastic effects.

PubMed

Lakovidou, Z; Papageorgiou, A; Demertzis, M A; Mioglou, E; Mourelatos, D; Kotsis, A; Yadav, P N; Kovala-Demertzi, D

2001-01-01

The effect of three novel complexes of Pt(II) and three complexes of Pd(II) with 2-acetylpyridine thiosemicarbazone (HAcTsc) on sister chromatid exchange (SCE) rates and human lymphocyte proliferation kinetics on a molar basis was studied. Also, the effect of Pt(II) and Pd(II) complexes against leukemia P388 was investigated. Among these compounds, the most effective in inducing antitumor and cytogenetic effects were the complexes [Pt(AcTsc)2] x H2O and [Pd(AcTsc)2] while the rest, i.e. (HAcTsc), [Pt(AcTsc)Cl], [Pt(HAcTsc)2]Cl2 x 2H2O, [Pd(AcTsc)Cl] and [Pd(HAcTsc)2]Cl2, displayed marginal cytogenetic and antitumor effects.

Benzoin 4-ethylthiosemicarbazone.

PubMed

Dinçer, Muharrem; Ozdemir, Namik; Cukurovali, Alaaddin; Yilmaz, Ibrahim; Büyükgüngör, Orhan

2006-01-01

In the title compound, 2-hydroxy-1,2-diphenylethanone 4-ethylthiosemicarbazone, C17H19N3OS, the thiosemicarbazone moiety is planar and has an E configuration. The planar phenyl rings make dihedral angles of 82.34 (8) and 8.07 (17) degrees with the plane of the thiosemicarbazone moiety. The crystal structure contains two intramolecular (N-H...O and N-H...N) and one intermolecular interaction (O-H...S), as well as two C-H...pi(benzene) interactions. Molecules are stacked in columns running along the a axis. Molecules in each column are connected to each other by means of linear O-H...S hydrogen bonds and C-H...pi interactions. In addition, there are also C-H...pi(benzene) interactions between the columns.

New potentiometric transducer based on a Mn(II) [2-formylquinoline thiosemicarbazone] complex for static and hydrodynamic assessment of azides.

PubMed

Kamel, Ayman H

2015-11-01

A new potentiometric transducer for selective recognition of azide is characterized and developed. The PVC plasticized based sensor incorporates Mn(II) [2-formylquinoline thiosemicarbazone] complex in the presence of tri dodecyl methyl ammonium chloride (TDMAC) as a lipophilic cationic additive. The sensor displayed a near-Nernstian response for azide over 1.0×10(-2)-1.0×10(-5) mol L(-1), with an anionic slope of -55.8±0.6 mV decade(-1) and lower limit of detection 0.34 µg mL(-1). The sensor was pH independent in the range 5.5-9 and presented good selectivity features towards several inorganic anions, and it is easily used in a flow injection system and compared with a tubular detector. The intrinsic characteristics of the detector in a low dispersion manifold were determined and compared with data obtained under a hydrodynamic mode of operation. This simple and inexpensive automation, with a good potentiometric detector, enabled the analysis of ~33 samples h(-1) without requiring pre-treatment procedures. The proposed method is also applied to the analysis of trace levels of azide in primer mixtures. Significantly improved accuracy, precision, response time, stability and selectivity were offered by these simple and cost-effective potentiometric sensor compared with other standard techniques. The method has the requisite accuracy, sensitivity and precision to determine azide ions. Copyright © 2015 Elsevier B.V. All rights reserved.

Metal complexes of 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone: cytotoxic activity and investigation on the mode of action of the gold(III) complex.

PubMed

Sâmia, Luciana B P; Parrilha, Gabrieli L; Da Silva, Jeferson G; Ramos, Jonas P; Souza-Fagundes, Elaine M; Castelli, Silvia; Vutey, Venn; Desideri, Alessandro; Beraldo, Heloisa

2016-06-01

Complexes [Au(PyCT4BrPh)Cl]Cl (1), [Pt(PyCT4BrPh)Cl]0.5KCl (2), and [Pd(PyCT4BrPh)Cl]KCl (3) were obtained with 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4BrPh). Although complexes (2) and (3) did not exhibit potent cytotoxic activity, HPyCT4BrPh and its gold(III) complex (1) proved to be highly cytotoxic against HL-60 (human promyelocytic leukemia) and THP-1 (human monocytic leukemia) cells, and against MDA-MB 231 and MCF-7 (human breast adenocarcinoma) solid tumor cells. Except for HL-60 cells, upon coordination to gold(III) a 2- to 3-fold increase in the cytotoxic effect was observed. An investigation on the possible biological targets of the gold(III) complex was carried out. Complex (1) but not the free thiosemicarbazone inhibits the enzymatic activity of thioredoxin reductase (TrxR). The affinity of 1 for TrxR suggests metal binding to a selenol residue in the active site of the enzyme. While HPyCT4BrPh was inactive, 1 was able to inhibit topoisomerase IB (Topo IB) activity. Hence, inhibition of TrxR and Topo IB could contribute to the mechanism of cytotoxic action of complex (1).

Vibrational spectroscopy (FT-IR and Laser-Raman) investigation, and computational (M06-2X and B3LYP) analysis on the structure of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone.

PubMed

Sert, Yusuf; Miroslaw, Barbara; Çırak, Çağrı; Doğan, Hatice; Szulczyk, Daniel; Struga, Marta

2014-07-15

In this study, the experimental and theoretical vibrational spectral analysis of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone have been carried out. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) have been recorded for the solid state samples. The theoretical vibrational frequencies and the optimized geometric parameters (bond lengths and angles) have been calculated for gas phase using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and M06-2X (the highly parametrized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set. The diversity in molecular geometry of fluorophenyl substituted thiosemicarbazones has been discussed based on the X-ray crystal structure reports and theoretical calculation results from the literature. The assignments of the vibrational frequencies have been done on the basis of potential energy distribution (PED) analysis by using VEDA4 software. A good correlation was found between the computed and experimental geometric and vibrational data. In addition, the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbital energy levels and other related molecular energy values of the compound have been determined using the same level of theoretical calculations. Copyright © 2014 Elsevier B.V. All rights reserved.

Spectrophotometric, voltammetric and cytotoxicity studies of 2-hydroxy-5-methoxyacetophenone thiosemicarbazone and its N(4)-substituted derivatives: A combined experimental-computational study

NASA Astrophysics Data System (ADS)

Akgemci, Emine Guler; Saf, Ahmet Ozgur; Tasdemir, Halil Ugur; Türkkan, Ercan; Bingol, Haluk; Turan, Suna Ozbas; Akkiprik, Mustafa

2015-02-01

In this study, 2-hydroxy-5-methoxyacetophenone thiosemicarbazone (HMAT) and its novel N(4) substituted derivatives were synthesized and characterized by different techniques. The optical band gap of the compounds and the energy of HOMO were experimentally examined by UV-vis spectra and cyclic voltammetry measurements, respectively. Furthermore, the conformational spaces of the compounds were scanned with molecular mechanics method. The geometry optimization, HOMO and LUMO energies, the energy gap of the HOMO-LUMO, dipole moment of the compounds were theoretically calculated by the density functional theory B3LYP/6-311++G(d,p) level. The minimal electronic excitation energy and maximum wavelength calculations of the compounds were also performed by TD-DFT//B3LYP/6-311++G(d,p) level of theory. Theoretically calculated values were compared with the related experimental values. The combined results exhibit that all compounds have good electron-donor properties which affect anti-proliferative activity. The cytotoxic effects of the compounds were also evaluated against HeLa (cervical carcinoma), MCF-7 (breast carcinoma) and PC-3 (prostatic carcinoma) cell lines using the standard MTT assay. All tested compounds showed antiproliferative effect having IC50 values in different range. In comparison with that of HMAT, it was obtained that while ethyl group on 4(N)-substituted position decreased in potent anti-proliferative effect, the phenyl group on the position increased in anti-proliferative effect for the tested cancer cell line. Considering the molecular energy parameters, the cytotoxicity activities of the compounds were discussed.

Combining molecular docking and QSAR studies for modeling the anti-tyrosinase activity of aromatic heterocycle thiosemicarbazone analogues

NASA Astrophysics Data System (ADS)

Dong, Huanhuan; Liu, Jing; Liu, Xiaoru; Yu, Yanying; Cao, Shuwen

2018-01-01

A collection of thirty-six aromatic heterocycle thiosemicarbazone analogues presented a broad span of anti-tyrosinase activities were designed and obtained. A robust and reliable two-dimensional quantitative structure-activity relationship model, as evidenced by the high q2 and r2 values (0.848 and 0.893, respectively), was gained based on the analogues to predict the quantitative chemical-biological relationship and the new modifier direction. Inhibitory activities of the compounds were found to greatly depend on molecular shape and orbital energy. Substituents brought out large ovality and high highest-occupied molecular orbital energy values helped to improve the activity of these analogues. The molecular docking results provided visual evidence for QSAR analysis and inhibition mechanism. Based on these, two novel tyrosinase inhibitors O04 and O05 with predicted IC50 of 0.5384 and 0.8752 nM were designed and suggested for further research.

Gold(III) complexes with ONS-Tridentate thiosemicarbazones: Toward selective trypanocidal drugs.

PubMed

Rettondin, Andressa R; Carneiro, Zumira A; Gonçalves, Ana C R; Ferreira, Vanessa F; Oliveira, Carolina G; Lima, Angélica N; Oliveira, Ronaldo J; de Albuquerque, Sérgio; Deflon, Victor M; Maia, Pedro I S

2016-09-14

Tridentate thiosemicarbazone ligands with an ONS donor set, H2L(R) (R = Me and Et) were prepared by reactions of 1-phenyl-1,3-butanedione with 4-R-3-thiosemicarbazides. H2L(R) reacts with Na[AuCl4]·2H2O in MeOH in a 1:1 M ratio under formation of green gold(III) complexes of composition [AuCl(L(R))]. These compounds represent the first examples of gold(III) complexes with ONS chelate-bonded thiosemicarbazones. The in vitro anti-Trypanosoma cruzi activity against both trypomastigote and amastigote forms (IC50try/ama) of CL Brener strains as well as the cytotoxicity against LLC-MK2 cells of the free ligands and complexes was evaluated. The complex [AuCl(L(Me))] was found to be more active and more selective than its precursor ligand and the standard drug benznidazole with a SItry/ama value higher than 200, being considered as a lead candidate for Chagas disease treatment. Moreover the in vitro activity against the replicative amastigote form (IC50ama) of T. cruzi was additionally investigated revealing that [AuCl(L(Me))] was also more potent than benznidazole still with a similar selectivity index. Finally, docking studies showed that free ligands and complexes interact with the same residues of the parasite protease cruzain but with different intensities, suggesting that this protease could be a possible target for the trypanocidal action of the obtained compounds. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Iron-targeting antitumor activity of gallium compounds and novel insights into triapine(®)-metal complexes.

PubMed

Chitambar, Christopher R; Antholine, William E

2013-03-10

Despite advances made in the treatment of cancer, a significant number of patients succumb to this disease every year. Hence, there is a great need to develop new anticancer agents. Emerging data show that malignant cells have a greater requirement for iron than normal cells do and that proteins involved in iron import, export, and storage may be altered in cancer cells. Therefore, strategies to perturb these iron-dependent steps in malignant cells hold promise for the treatment of cancer. Recent studies show that gallium compounds and metal-thiosemicarbazone complexes inhibit tumor cell growth by targeting iron homeostasis, including iron-dependent ribonucleotide reductase. Chemical similarities of gallium(III) with iron(III) enable the former to mimic the latter and interpose itself in critical iron-dependent steps in cellular proliferation. Newer gallium compounds have emerged with additional mechanisms of action. In clinical trials, the first-generation-compound gallium nitrate has exhibited activity against bladder cancer and non-Hodgkin's lymphoma, while the thiosemicarbazone Triapine(®) has demonstrated activity against other tumors. Novel gallium compounds with greater cytotoxicity and a broader spectrum of antineoplastic activity than gallium nitrate should continue to be developed. The antineoplastic activity and toxicity of the existing novel gallium compounds and thiosemicarbazone-metal complexes should be tested in animal tumor models and advanced to Phase I and II clinical trials. Future research should identify biologic markers that predict tumor sensitivity to gallium compounds. This will help direct gallium-based therapy to cancer patients who are most likely to benefit from it.

Ribonucleotide reductase inhibition by metal complexes of Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone): A combined experimental and theoretical study

PubMed Central

Popović-Bijelić, Ana; Kowol, Christian R.; Lind, Maria E.S.; Luo, Jinghui; Himo, Fahmi; Enyedy, Éva A.; Arion, Vladimir B.; Gräslund, Astrid

2012-01-01

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone, 3-AP) is currently the most promising chemotherapeutic compound among the class of α-N-heterocyclic thiosemicarbazones. Here we report further insights into the mechanism(s) of anticancer drug activity and inhibition of mouse ribonucleotide reductase (RNR) by Triapine. In addition to the metal-free ligand, its iron(III), gallium(III), zinc(II) and copper (II) complexes were studied, aiming to correlate their cytotoxic activities with their effects on the diferric/tyrosyl radical center of the RNR enzyme in vitro. In this study we propose for the first time a potential specific binding pocket for Triapine on the surface of the mouse R2 RNR protein. In our mechanistic model, interaction with Triapine results in the labilization of the diferric center in the R2 protein. Subsequently the Triapine molecules act as iron chelators. In the absence of external reductants, and in presence of the mouse R2 RNR protein, catalytic amounts of the iron(III)–Triapine are reduced to the iron(II)–Triapine complex. In the presence of an external reductant (dithiothreitol), stoichiometric amounts of the potently reactive iron (II)–Triapine complex are formed. Formation of the iron(II)–Triapine complex, as the essential part of the reaction outcome, promotes further reactions with molecular oxygen, which give rise to reactive oxygen species (ROS) and thereby damage the RNR enzyme. Triapine affects the diferric center of the mouse R2 protein and, unlike hydroxyurea, is not a potent reductant, not likely to act directly on the tyrosyl radical. PMID:21955844

New heteroleptic Zn(II) complexes of thiosemicarbazone and diimine Co-Ligands: Structural analysis and their biological impacts

NASA Astrophysics Data System (ADS)

Mathan Kumar, Shanmugaiah; Kesavan, Mookkandi Palsamy; Vinoth Kumar, Gujuluva Gangatharan; Sankarganesh, Murugesan; Chakkaravarthi, Ganesan; Rajagopal, Gurusamy; Rajesh, Jegathalaprathaban

2018-02-01

A thiosemicarbazone ligand HL appended new Zn(II) complexes [Zn(L)(bpy)] (1) and [Zn(L)(phen)] (2) (where, HL = {2-(3-bromo-5-chloro-2-hydroxybenzylidene)-N-phenylhydrazinecarbothioamide}, bpy = 2, 2‧-bipyridine and phen = 1, 10-phenanthroline) have been synthesized and well characterized using conventional spectroscopic techniques viz.,1H NMR, FTIR and UV-Vis spectra. The crystal structures of complexes 1 and 2 have been determined by single crystal X-ray diffraction studies. Both the complex 1 (τ = 0.5) and 2 (τ = 0.37) possesses square based pyramidally distorted trigonal bipyramidal geometry. The ground state electronic structures of complexes 1 and 2 were investigated by DFT/B3LYP theoretical analysis using 6-311G (d,p) and LANL2DZ basis set level. The superior DNA binding ability of complex 2 has been evaluated using absorption and fluorescence spectral titration studies. Antimicrobial evaluation reveals that complex 2 endowed better screening than HL and complex 1 against both bacterial as well as fungal species. Consequently, complex 2 possesses highest antibacterial screening against Staphylococcus aureus (MIC = 3.0 ± 0.23 mM) and antifungal screening against Candida albicans (MIC = 6.0 ± 0.11 mM). Furthermore, the anticancer activity of the ligand HL, complexes 1 and 2 have been examined against the MCF-7 cell line (Human breast cancer cell line) using MTT assay. It is remarkable that complex 2 (12 ± 0.67 μM) show highest anticancer activity than HL (25.0 ± 0.91 μM) and complex 1 (15 ± 0.88 μM) due to the presence of phen ligand moiety.

A newly synthesized thiazole derivative as a fluoride ion chemosensor: naked-eye, spectroscopic, electrochemical and NMR studies.

PubMed

Sarıgüney, Ahmet Burak; Saf, Ahmet Özgür; Coşkun, Ahmet

2014-07-15

2,3-Indoledione 3-thiosemicarbazone (TSCI) and a novel compound 3-(2-(4-(4-phenoxyphenyl)thiazol-2-yl)hydrazono)indolin-2-one (FTHI) were synthesized with high yield and characterized by spectroscopic techniques. The complexation behaviors of TSCI and FTHI for various anionic species (F(-), Cl(-), Br(-), I(-), NO2(-), NO3(-), BzO(-), HSO4(-), ClO4(-)) in CH3CN were investigated and compared by UV-vis spectroscopy, cyclic voltammetry and (1)H NMR titration techniques. FTHI showed high degree of selectivity for fluoride over other anions. This selectivity could be easily observed by the naked eye, indicating that FTHI is potential colorimetric sensor for fluoride anion. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and isomerization of acridine substituted 1,3-thiazolidin-4-ones and 4-oxo-1,3-thiazolidin-5-ylidene acetates. An experimental and computational study

NASA Astrophysics Data System (ADS)

Bečka, Michal; Vilková, Mária; Šoral, Michal; Potočňák, Ivan; Breza, Martin; Béres, Tibor; Imrich, Ján

2018-02-01

Acridine thiosemicarbazones 3a-g, obtained through a two-step reaction between aromatic isothiocyanates and hydrazine followed by the treatment with acridin-9-carbaldehyde, in reaction with bifunctional reagents; methyl bromoacetate (MBA) and diethyl acetylenedicarboxylate (DEAD) afforded acridin-thiazolidinone derivatives 4a-g and 7a-f and not their regioisomers 6a-g and 9a-f. Derivatives 4a-g and 7a-f exhibit ZC2N6EN7C8 configuration. Upon standing in DMSO-d6 the thiazolidinones 4a-g and 7a-f spontaneously isomerized into ZC2N6ZN7C8 isomers 5a-g and 8a-f to give a mixture of the both stereoisomers. All compounds were fully characterized by multinuclear NMR, mass spectrometry (MS) and X-ray crystal structure of 4b is also described. X-ray diffraction study revealed that the representative compound 4b crystallized in the monoclinic crystal system with the C2/c space group and Z = 4. Intramolecular C1‧sbnd H1‧⋯N-7 hydrogen bond between the acridine proton H-1‧ and nitrogen N-7 of linker existed. This hydrogen bond is responsible for the E isomerism on C-8 atom which was observed in the NMR experiments. Quantum-chemical calculations and NOESY experiments confirmed ZC2N6ZN7C8 configuration of the transformed stereoisomers 5a-g and 8a-f.

Synthesis, structural, optical band gap and biological studies on iron (III), nickel (II), zinc (II) and mercury (II) complexes of benzyl α-monoxime pyridyl thiosemicarbazone

NASA Astrophysics Data System (ADS)

Bedier, R. A.; Yousef, T. A.; Abu El-Reash, G. M.; El-Gammal, O. A.

2017-07-01

New ligand, (E)-2-((E)-2-(hydroxyimino)-1,2-diphenylethylidene)-N-(pyridin-2 yl) hydrazinecarbothioamide (H2DPPT) and its complexes [Fe(DPPT)Cl(H2O)], [Ni(H2DPPT)2Cl2], [Zn(HDPPT)(OAc)] and [Hg(HDPPT)Cl](H2O)4 were isolated and characterized by various of physico-chemical techniques. IR spectra show that H2DPPT coordinates to the metal ions as neutral NN bidentate, mononegative NNS tridentate and binegative NNSN tetradentate, respectively. From the modeling studies, the bond length, bond angle, HOMO, LUMO and dipole moment had been calculated to confirm the geometry of the ligands and their investigated complexes. The thermal studies showed the type of water molecules involved in metal complexes Furthermore, the kinetic and thermodynamic parameters for the different decomposition steps were calculated using the Coats-Redfern and Horowitz-Metzger methods. Also, the optical band gap (Eg) has been calculated to elucidate the conductivity of the isolated complexes. The optical transition energy (Eg) is direct and equals 3.34 and 3.44 ev for Ni and Fe complexes, respectively. The ligand and their metal complexes were screened for antibacterial activity against the following bacterial species, Bacillus thuringiensis, Staphylococcus aureus, Pseudomonas aeuroginosa and Escherichia coli. The results revealed that the metal complexes have more potent antibacterial compared with the ligand. Also, the degradation effect of the investigated compounds was tested showing that, Ni complex exhibited powerful and complete degradation effect on DNA.

Iron-Targeting Antitumor Activity of Gallium Compounds and Novel Insights Into Triapine®-Metal Complexes

PubMed Central

Antholine, William E.

2013-01-01

Abstract Significance: Despite advances made in the treatment of cancer, a significant number of patients succumb to this disease every year. Hence, there is a great need to develop new anticancer agents. Recent Advances: Emerging data show that malignant cells have a greater requirement for iron than normal cells do and that proteins involved in iron import, export, and storage may be altered in cancer cells. Therefore, strategies to perturb these iron-dependent steps in malignant cells hold promise for the treatment of cancer. Recent studies show that gallium compounds and metal-thiosemicarbazone complexes inhibit tumor cell growth by targeting iron homeostasis, including iron-dependent ribonucleotide reductase. Chemical similarities of gallium(III) with iron(III) enable the former to mimic the latter and interpose itself in critical iron-dependent steps in cellular proliferation. Newer gallium compounds have emerged with additional mechanisms of action. In clinical trials, the first-generation-compound gallium nitrate has exhibited activity against bladder cancer and non-Hodgkin's lymphoma, while the thiosemicarbazone Triapine® has demonstrated activity against other tumors. Critical Issues: Novel gallium compounds with greater cytotoxicity and a broader spectrum of antineoplastic activity than gallium nitrate should continue to be developed. Future Directions: The antineoplastic activity and toxicity of the existing novel gallium compounds and thiosemicarbazone-metal complexes should be tested in animal tumor models and advanced to Phase I and II clinical trials. Future research should identify biologic markers that predict tumor sensitivity to gallium compounds. This will help direct gallium-based therapy to cancer patients who are most likely to benefit from it. Antioxid. Redox Signal. 00, 000–000. PMID:22900955

Gold(III) bis-thiosemicarbazonato complexes: synthesis, characterization, radiochemistry and X-ray crystal structure analysis.

PubMed

Bottenus, Brienne N; Kan, Para; Jenkins, Tyler; Ballard, Beau; Rold, Tammy L; Barnes, Charles; Cutler, Cathy; Hoffman, Timothy J; Green, Mark A; Jurisson, Silvia S

2010-01-01

A variety of (bis)thiosemicarbazone-based ligand systems have been investigated as chelating agents for Au(III) complexes with potential radiotherapeutic applications. Ligand systems containing an ethyl, propyl or butyl backbone between the two imine N donors have been synthesized to evaluate chelate ring size effects on the resultant Au(III) complex stability at the macroscopic and radiotracer levels. The Au(III) complexes were synthesized and characterized by NMR, electrospray ionization mass spectra, elemental analysis and X-ray crystallography. The (198)Au complexes were evaluated in vitro at the tracer level for stability in phosphate-buffered saline at pH 7.4 and 37 degrees C. One of these complexes [(198)Au(3,4-HxTSE)] showed high in vitro stability and was further evaluated in vivo in normal mice. [Au(ATSM)]AuCl(4).2CH(3)OH, (ATSM=diacetyl-bis(N(4)-methylthiosemicarbazone)) H(14)C(8)N(6)O(2)S(2)Cl(4)Au(2).2CH(3)OH, crystallized from methanol in the monoclinic space group P21/n with a=14.7293(13) A, b=7.7432(7) A, c=20.4363(18) A, beta=100.140(2) degrees, V=2294.4 (4) A(3), Z=4; [Au(3,4-HxTSE)]Cl.CH(3)CH(2)OH/AuCl(2), (3,4-HxTSE=3,4-hexanedione-bis(N(4)-ethylthiosemicarbazone)) H(26)C(13.6)N(6)O(0.8)S(2)Cl(1.2)Au(1.2), crystallized from ethanol in the monoclinic space group P21/c with a=10.1990(10) A, b=13.8833(14) A, c=15.1752(15) A, beta=99.353(2) degrees , V=2120.2 (4) A(3), Z=4. These studies revealed poor stability of the [(198)Au][Au(3,4-HxTSE)](+) complex; however, crystal structure data suggest potential alterations to the ligand backbone may increase stability. Copyright 2010 Elsevier Inc. All rights reserved.

Stability of the resistance to the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone, a non-nucleoside polymerase inhibitor of bovine viral diarrhea virus.

PubMed

Castro, Eliana F; Campos, Rodolfo H; Cavallaro, Lucía V

2014-01-01

Bovine viral diarrhea virus (BVDV) is the prototype Pestivirus. BVDV infection is distributed worldwide and causes serious problems for the livestock industry. The thiosemicarbazone of 5,6-dimethoxy-1-indanone (TSC) is a non-nucleoside polymerase inhibitor (NNI) of BVDV. All TSC-resistant BVDV variants (BVDV-TSCr T1-5) present an N264D mutation in the NS5B gene (RdRp) whereas the variant BVDV-TSCr T1 also presents an NS5B A392E mutation. In the present study, we carried out twenty passages of BVDV-TSCr T1-5 in MDBK cells in the absence of TSC to evaluate the stability of the resistance. The viral populations obtained (BVDV R1-5) remained resistant to the antiviral compound and conserved the mutations in NS5B associated with this phenotype. Along the passages, BVDV R2, R3 and R5 presented a delay in the production of cytopathic effect that correlated with a decrease in cell apoptosis and intracellular accumulation of viral RNA. The complete genome sequences that encode for NS2 to NS5B, Npro and Erns were analyzed. Additional mutations were detected in the NS5B of BVDV R1, R3 and R4. In both BVDV R2 and R3, most of the mutations found were localized in NS5A, whereas in BVDV R5, the only mutation fixed was NS5A V177A. These results suggest that mutations in NS5A could alter BVDV cytopathogenicity. In conclusion, the stability of the resistance to TSC may be due to the fixation of different compensatory mutations in each BVDV-TSCr. During their replication in a TSC-free medium, some virus populations presented a kind of interaction with the host cell that resembled a persistent infection: decreased cytopathogenicity and viral genome synthesis. This is the first report on the stability of antiviral resistance and on the evolution of NNI-resistant BVDV variants. The results obtained for BVDV-TSCr could also be applied for other NNIs.

Coordination of different ligands to copper(II) and cobalt(III) metal centers enhances Zika virus and dengue virus loads in both arthropod cells and human keratinocytes.

PubMed

Dutta, Shovan; Celestine, Michael J; Khanal, Supreet; Huddleston, Alexis; Simms, Colin; Arca, Jessa Faye; Mitra, Amlan; Heller, Loree; Kraj, Piotr J; Ledizet, Michel; Anderson, John F; Neelakanta, Girish; Holder, Alvin A; Sultana, Hameeda

2018-01-01

Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex with a citral-thiosemicarbazone ligand (compound 4) increased DENV2 and ZIKV replication in both mosquito C6/36 cells and human keratinocytes (HaCaT cells). Treatment of both cell lines with compounds 2 or 4 showed increased dengue viral titers at all three tested doses. Enhanced dengue viral plaque formation was also noted at the tested dose of 100μM, suggesting higher production of infectious viral particles. Treatment with the compounds 2 or 4 enhanced ZIKV and DENV2 RNA levels in HeLa cell line and primary cultures of mouse bone marrow derived dendritic cells. Also, pre- or post treatments with conjugated compounds 2 or 4 showed higher loads of ZIKV or DENV2 envelope (E) protein in HaCaT cells. No changes in loads of E-protein were found in ZIKV-infected C6/36 cells, when compounds were treated after infection. In addition, we tested bis(1,10-phenanthroline)copper(II) chloride ([Cu(phen) 2 ]Cl 2 , (compound 5) and tris(1,10-phenanthroline)cobalt(III) chloride ([Co(phen) 3 ]Cl 3 , (compound 6) that also showed enhanced DENV2 loads. Also, we found that copper(II) chloride dehydrate (CuCl 2 ·2H 2 O) or cobalt(II) chloride hexahydrate (CoCl 2 ·6H 2 O) alone had no effects as "free" cations. Taken together, these findings suggest that use of Cu(II) or Co(III) conjugation to organic compounds, in insect repellents and/or food additives could enhance DENV2/ZIKV loads in human cells and perhaps induce pathogenesis in infected individuals or individuals pre-exposed to such conjugated complexes. Mosquito-borne diseases are of great concern to the mankind. Use of chemicals/repellents against mosquito bites and transmission of microbes has been the topic of interest for many years. Here, we show that thiosemicarbazone ligand(s) derived from 2-acetylethiazole or citral or 1,10-phenanthroline upon conjugation with copper(II) or cobalt(III) metal centers enhances dengue virus (serotype 2; DENV2) and/or Zika virus (ZIKV) infections in mosquito, mouse and human cells. Enhanced ZIKV/DENV2 capsid mRNA or envelope protein loads were evident in mosquito cells and human keratinocytes, when treated with compounds before/after infections. Also, treatment with copper(II) or cobalt(III) conjugated compounds increased viral titers and number of plaque formations. These studies suggest that conjugation of compounds in repellents/essential oils/natural products/food additives with copper(II) or cobalt(III) metal centers may not be safe, especially in tropical and subtropical places, where several dengue infection cases and deaths are reported annually or in places with increased ZIKV caused microcephaly. Copyright © 2017 Elsevier B.V. All rights reserved.

Crystal structures of copper(II) chloride, copper(II) bromide, and copper(II) nitrate complexes with pyridine-2-carbaldehyde thiosemicarbazone

NASA Astrophysics Data System (ADS)

Chumakov, Yu. M.; Tsapkov, V. I.; Jeanneau, E.; Bairac, N. N.; Bocelli, G.; Poirier, D.; Roy, J.; Gulea, A. P.

2008-09-01

The crystal structures of chloro-(2-formylpyridinethiosemicarbazono)copper dimethyl sulfoxide solvate ( I), bromo-(2-formylpyridinethiosemicarbazono)copper ( II), and (2-formylpyridinethiosemicarbazono)copper(II) nitrate dimethyl sulfoxide solvate ( III) are determined using X-ray diffraction. In the crystals, complexes I and II form centrosymmetric dimers in which the thiosemicarbazone sulfur atom serves as a bridge and occupies the fifth coordination site of the copper atom of the neighboring complex related to the initial complex through the center of symmetry. In both cases, the coordination polyhedron of the complexing ion is a distorted tetragonal bipyramid. Complex III in the crystal structure forms polymer chains in which the copper atom of one complex forms the coordination bond with the thicarbamide nitrogen atom of the neighboring complex. In this structure, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid. It is established that complexes I III at a concentration of 10-5 mol/l selectively inhibit the growth of 60 to 90 percent of the cancer tumor cells of the human myeloid leukemia (HL-60).

Induction of Early Autophagic Process on Leishmania amazonensis by Synergistic Effect of Miltefosine and Innovative Semi-synthetic Thiosemicarbazone

PubMed Central

Scariot, Débora B.; Britta, Elizandra A.; Moreira, Amanda L.; Falzirolli, Hugo; Silva, Cleuza C.; Ueda-Nakamura, Tânia; Dias-Filho, Benedito P.; Nakamura, Celso V.

2017-01-01

Drug combination therapy is a current trend to treat complex diseases. Many benefits are expected from this strategy, such as cytotoxicity decrease, retardation of resistant strains development, and activity increment. This study evaluated in vitro combination between an innovative thiosemicarbazone molecule – BZTS with miltefosine, a drug already consolidated in the leishmaniasis treatment, against Leishmania amazonensis. Cytotoxicity effects were also evaluated on macrophages and erythrocytes. Synergistic antileishmania effect and antagonist cytotoxicity were revealed from this combination therapy. Mechanisms of action assays were performed in order to investigate the main cell pathways induced by this treatment. Mitochondrial dysfunction generated a significant increase of reactive oxygen and nitrogen species production, causing severe cell injuries and promoting intense autophagy process and consequent apoptosis cell death. However, this phenomenon was not strong enough to promote dead in mammalian cell, providing the potential selective effect of the tested combination for the protozoa. Thus, the results confirmed that drugs involved in distinct metabolic routes are promising agents for drug combination therapy, promoting a synergistic effect. PMID:28270805

Revisiting the thiosemicarbazonecopper(II) reaction with glutathione. Activity against colorectal carcinoma cell lines.

PubMed

García-Tojal, Javier; Gil-García, Rubén; Fouz, Víctor Ivo; Madariaga, Gotzon; Lezama, Luis; Galletero, María S; Borrás, Joaquín; Nollmann, Friederike I; García-Girón, Carlos; Alcaraz, Raquel; Cavia-Saiz, Mónica; Muñiz, Pilar; Palacios, Òscar; Samper, Katia G; Rojo, Teófilo

2018-03-01

Thiosemicarbazones (TSCs), and their copper derivatives, have been extensively studied mainly due to the potential applications as antitumor compounds. A part of the biological activity of the TSC-Cu II complexes rests on their reactivity against cell reductants, as glutathione (GSH). The present paper describes the structure of the [Cu(PTSC)(ONO 2 )] n compound (1) (HPTSC=pyridine-2-carbaldehyde thiosemicarbazone) and its spectroscopic and magnetic properties. ESI studies performed on the reaction of GSH with 1 and the analogous [{Cu(PTSC*)(ONO 2 )} 2 ] derivative (2, HPTSC*=pyridine-2-carbaldehyde 4N-methylthiosemicarbazone) show the absence of peaks related with TSC-Cu-GSH species. However GSH-Cu ones are detected, in good agreement with the release of Cu I ions after reduction in the experimental conditions. The reactivity of 1 and 2 with cytochrome c and myoglobin and their activities against HT-29 and SW-480 colon carcinoma cell lines are compared with those shown by the free HPTSC and HPTSC* ligands. Copyright © 2017 Elsevier Inc. All rights reserved.

Investigation into 64Cu-labeled Bis(selenosemicarbazone) and Bis(thiosemicarbazone) complexes as hypoxia imaging agents.

PubMed

McQuade, Paul; Martin, Katherine E; Castle, Thomas C; Went, Michael J; Blower, Philip J; Welch, Michael J; Lewis, Jason S

2005-02-01

Cu-diacetyl-bis(N4-methylthiosemicarbazone) [Cu-ATSM], although excellent for oncology applications, may not be suitable for delineating cardiovascular or neurological hypoxia. For this reason, new Cu hypoxia positron emission tomography (PET) imaging agents are being examined to search for a higher selectivity for hypoxic or ischemic tissue at higher oxygen concentrations found in these tissues. Two approaches are to increase alkylation or to replace the sulfur atoms with selenium, resulting in the formation of selenosemicarbazones. Three 64Cu-labeled selenosemicarbazone complexes were synthesized and one was screened for hypoxia selectivity in vitro using EMT-6 mouse mammary carcinoma cells. Rodent biodistribution and small animal PET images were obtained from BALB/c mice implanted with EMT-6 tumors. One alkylated thiosemicarbazone was synthesized and examined. Of the three bis(selenosemicarbazone) ligands synthesized and examined, only 64Cu-diacetyl-bis(selenosemicarbazone) [64Cu-ASSM] was isolated in high-enough radiochemical purity to undertake cell uptake experiments where uptake was shown to be independent of oxygen concentration. The bis(thiosemicarbazone) complex synthesized, 64Cu-diacetyl-bis(N4-ethylthiosemicarbazone) [64Cu-ATSE], showed hypoxia selectivity similar to 64Cu-ATSM although at a higher oxygen concentration. Biodistribution studies for 64Cu-ASSM and 64Cu-ATSE showed high tumor uptake at 20 min (64Cu-ASSM, 10.33+/-0.78% ID/g; 64Cu-ATSE, 7.71+/-0.46% ID/g). PET images of EMT-6 tumor-bearing mice visualized the tumor with 64Cu-ATSE and revealed hypoxia selectivity consistent with the in vitro data. Of the compounds synthesized, only 64Cu-ASSM and 64Cu-ATSE could be examined in vitro and in vivo. Although the stability of bis(selenosemicarbazone) complexes increased upon addition of methyl groups to the diimine backbone, the fully alkylated species, 64Cu-ASSM, demonstrated no hypoxia selectivity. However, the additional alkylation present in Cu-ATSE modifies the hypoxia selectivity and in vivo properties when compared with Cu-ATSM.

Glucose Modulation Induces Lysosome Formation and Increases Lysosomotropic Drug Sequestration via the P-Glycoprotein Drug Transporter*

PubMed Central

Seebacher, Nicole A.; Lane, Darius J. R.; Jansson, Patric J.; Richardson, Des R.

2016-01-01

Pgp is functional on the plasma membrane and lysosomal membrane. Lysosomal-Pgp can pump substrates into the organelle, thereby trapping certain chemotherapeutics (e.g. doxorubicin; DOX). This mechanism serves as a “safe house” to protect cells against cytotoxic drugs. Interestingly, in contrast to DOX, lysosomal sequestration of the novel anti-tumor agent and P-glycoprotein (Pgp) substrate, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), induces lysosomal membrane permeabilization. This mechanism of lysosomal-Pgp utilization enhances cytotoxicity to multidrug-resistant cells. Consequently, Dp44mT has greater anti-tumor activity in drug-resistant relative to non-Pgp-expressing tumors. Interestingly, stressors in the tumor microenvironment trigger endocytosis for cell signaling to assist cell survival. Hence, this investigation examined how glucose variation-induced stress regulated early endosome and lysosome formation via endocytosis of the plasma membrane. Furthermore, the impact of glucose variation-induced stress on resistance to DOX was compared with Dp44mT and its structurally related analogue, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC). These studies showed that glucose variation-induced stress-stimulated formation of early endosomes and lysosomes. In fact, through the process of fluid-phase endocytosis, Pgp was redistributed from the plasma membrane to the lysosomal membrane via early endosome formation. This lysosomal-Pgp actively transported the Pgp substrate, DOX, into the lysosome where it became trapped as a result of protonation at pH 5. Due to increased lysosomal DOX trapping, Pgp-expressing cells became more resistant to DOX. In contrast, cytotoxicity of Dp44mT and DpC was potentiated due to more lysosomes containing functional Pgp under glucose-induced stress. These thiosemicarbazones increased lysosomal membrane permeabilization and cell death. This mechanism has critical implications for drug-targeting in multidrug-resistant tumors where a stressful micro-environment exists. PMID:26601947

Substitutional impact on biological activity of new water soluble Ni(II) complexes: Preparation, spectral characterization, X-ray crystallography, DNA/protein binding, antibacterial activity and in vitro cytotoxicity.

PubMed

Umadevi, C; Kalaivani, P; Puschmann, H; Murugan, S; Mohan, P S; Prabhakaran, R

2017-02-01

A series of new water soluble nickel(II) complexes containing triphenylphosphine and 4-methoxysalicylaldehyde-4(N)-substituted thiosemicarbazones were synthesized and characterized. Crystallographic investigations confirmed the structure of the complexes (1-4) having the general structure [Ni(4-Msal-Rtsc)(PPh 3 )] (Where R=H (1); CH 3 (2); C 2 H 5 (3); C 6 H 5 (4)) which showed that thiosemicarbazone ligands coordinated to nickel(II) ion as ONS tridentate bibasic donor. DNA/BSA protein binding ability of the ligands and their new complexes were studied by taking calf-thymus DNA (CT-DNA) and Bovine serum albumin (BSA) through absorption and emission titrations. Ethidium bromide (EB) displacement study showed the intercalative binding trend of the complexes to DNA. From the albumin binding studies, the mechanism of quenching was found as static and the alterations in the secondary structure of BSA by the compounds were confirmed with synchronous spectral studies. The binding affinity of the complexes to CT-DNA and BSA has the order of [Ni(4-Msal-etsc)(PPh 3 )] (3) >[Ni(4-Msal-mtsc)(PPh 3 )] (2) >[Ni(4-Msal-tsc)(PPh 3 )] (1) >[Ni(4-Msal-ptsc)(PPh 3 )] (4). In vitro cytotoxicity of the complexes was tested on human lung cancer cells (A549), human cervical cancer cells (HeLa), human liver carcinoma cells (Hep G2). All the complexes exhibited significant activity against three cancer cells. Among them, complex 4 exhibited almost 2.5 fold activity than cisplatin in A549 and HepG2 cell lines. In HeLa cell line, the complexes exhibited significant activity which is less than cisplatin. While comparing the activity of the complexes in A549 and HepG2 cell lines it falls in the order 4>1>2>3>cisplatin. The results obtained from DNA, protein binding and cytotoxicity studies, it is concluded that the cytotoxicity of the complexes as determined by MTT assay were not unduly influenced by the complexes having different binding efficiency with DNA and protein. The complexes exhibited good spectrum of antibacterial activity against four pathogenic bacteria such as E. faecalis (gram +ve), S. aureus (gram +ve), E. coli (gram -ve) and P. aeruginosa (gram -ve). Copyright © 2016 Elsevier B.V. All rights reserved.

Smallpox Antiviral Drug

DTIC Science & Technology

2007-01-01

viruses, herpes simplex virus (HSV), cytomegalovirus (CMV), varicella-zoster virus (VZV), influenza A and B viruses, and respiratory syncytial virus...Rouzioux C. 2004. Penetration of enfuvirtide, tenofovir, efavirenz, and protease inhibitors in the genital tract of HIV-1-infected men. Aids 18:1958...1968. Sensitivity of herpes simplex virus, vaccinia virus, and adenoviruses to deoxyribonucleic acid inhibitors and thiosemicarbazones in a plaque

New Coumarin Derivatives as Potent Selective COX-2 Inhibitors: Synthesis, Anti-Inflammatory, QSAR, and Molecular Modeling Studies.

PubMed

Dawood, Dina H; Batran, Rasha Z; Farghaly, Thoraya A; Khedr, Mohammed A; Abdulla, Mohamed M

2015-12-01

Two new series of coumarin derivatives incorporating thiazoline and thiazolidinone moieties were designed, synthesized, and investigated in vivo for their anti-inflammatory activities using the carrageenan-induced rat paw edema model and in vitro for their inhibitory activities against the human cyclooxygenase (COX)-1 and COX-2 isoforms. Most of the synthesized compounds demonstrated exceptionally high in vivo anti-inflammatory activity and displayed superior GI safety profiles (0-7% ulceration) as compared to indomethacin. All the bioactive compounds showed in vitro high affinity and selectivity toward the COX-2 isoenzyme, compared to the reference celecoxib with IC50 values ranging from 0.31 to 0.78 μM. The ethyl thiosemicarbazone 2b, thiazoline derivatives 3a, 3b, 5b, 6a, and 7f, and the thiazolidinone compounds 8b and 9a showed the highest in vivo and in vitro anti-inflammatory activities with remarkable COX-2 selectivity. Quantitative structure-activity relationship study (QSAR) was done and resulted in a highly predictive power R(2) (0.908). A molecular docking study revealed a relationship between the docking affinity and the biological results. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectroscopic (FT-IR, FT-Raman) and quantum mechanical studies of 3t-pentyl-2r,6c-diphenylpiperidin-4-one thiosemicarbazone

NASA Astrophysics Data System (ADS)

Savithiri, S.; Arockia doss, M.; Rajarajan, G.; Thanikachalam, V.; Bharanidharan, S.; Saleem, H.

2015-02-01

In this study, the molecular structure and vibrational spectra of 3t-pentyl2r,6c-diphenylpiperidin-4-one thiosemicarbazone (PDPOTSC) were studied. The ground-state molecular geometry was ascertained by using the density functional theory (DFT)/B3LYP method using 6-31++G(d,p) as a basis set. The vibrational (FT-IR and FT-Raman) spectra of PDPOTSC were computed using DFT/B3LYP and HF methods with 6-31++G(d,p) basis set. The fundamental vibrations were assigned on the basis of the total energy distribution (TED ⩾ 10%) of the vibrational modes, calculated with scaled quantum mechanics (SQM) methods PQS program. The electrical dipole moment (μ) and first hyperpolarizability (βo) values have been computed using DFT/B3LYP and HF methods. The calculated result (βo) shows that the title molecule might have nonlinear optical (NLO) behavior. Atomic charges of C, N, S and molecular electrostatic potential (MEP) were calculated using B3LYP/6-31G++(d,p). The HOMO-LUMO energies were calculated and natural bonding orbital (NBO) analysis has also been carried out.

Anti-Plasmodial Activity of Aroylhydrazone and Thiosemicarbazone Iron Chelators: Effect on Erythrocyte Membrane Integrity, Parasite Development and the Intracellular Labile Iron Pool

PubMed Central

Walcourt, Asikiya; Kurantsin-Mills, Joseph; Kwagyan, John; Adenuga, Babafemi B.; Kalinowski, Danuta S.; Lovejoy, David B.; Lane, Darius J. R.; Richardson, Des R.

2013-01-01

Iron chelators inhibit the growth of the malaria parasite, Plasmodium falciparum, in culture and in animal and human studies. We previously reported the anti-plasmodial activity of the chelators, 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), 2-hydroxy-1-naphthylaldehyde 4-methyl-3-thiosemicarbazone (N4mT), and 2-hydroxy-1-naphthylaldehyde 4-phenyl-3-thiosemicarbazone (N4pT). In fact, these ligands showed greater growth inhibition of chloroquine-sensitive (3D7) and chloroquine-resistant (7G8) strains of P. falciparum in culture compared to desferrioxamine (DFO). The present study examined the effects of 311, N4mT and N4pT on erythrocyte membrane integrity and asexual parasite development. While the characteristic biconcave disk shape of the erythrocytes was unaffected, the chelators caused very slight hemolysis at IC50 values that inhibited parasite growth. The chelators 311, N4mT and N4pT affected all stages of the intra-erythrocytic development cycle (IDC) of P. falciparum in culture. However, while these ligands primarily affected the ring-stage, DFO inhibited primarily trophozoite and schizont-stages. Ring, trophozoite and schizont-stages of the IDC were inhibited by significantly lower concentrations of 311, N4mT, and N4pT (IC50 = 4.45 ± 1.70, 10.30 ± 4.40, and 3.64 ± 2.00 μM, respectively) than DFO (IC50 = 23.43 ± 3.40 μM). Complexation of 311, N4mT and N4pT with iron reduced their anti-plasmodial activity. Estimation of the intracellular labile iron pool (LIP) in erythrocytes showed that the chelation efficacy of 311, N4mT and N4pT corresponded to their anti-plasmodial activity, suggesting that the LIP may be a potential source of non-heme iron for parasite metabolism within the erythrocyte. This study has implications for malaria chemotherapy that specifically disrupts parasite iron utilization. PMID:24028863

Synthesis, computational studies and enzyme inhibitory kinetics of substituted methyl[2-(4-dimethylamino-benzylidene)-hydrazono)-4-oxo-thiazolidin-5-ylidene]acetates as mushroom tyrosinase inhibitors.

PubMed

Channar, Pervaiz Ali; Saeed, Aamer; Larik, Fayaz Ali; Rafiq, Muhammad; Ashraf, Zaman; Jabeen, Farukh; Fattah, Tanzeela Abdul

2017-11-01

The present article describes the synthesis and enzyme inhibitory kinetics of methyl[2-(arylmethylene-hydrazono)-4-oxo-thiazolidin-5-ylidene]acetates 5a-j as mushroom tyrosinase inhibitors. The title compounds were synthesized via cyclocondensation of thiosemicarbazones 3a-j with dimethyl but-2-ynedioate (DMAD) 4 in good yields under solvent-free conditions. The synthesized compounds were evaluated for their potential to inhibit the activity of mushroom tyrosinase. It was unveiled that compounds 5i showed excellent enzyme inhibitory activity with IC 50 3.17µM while IC 50 of standard kojic acid is 15.91µM. The presence of heterocyclic pyridine ring in compound 5i play important role in enzyme inhibitory activity as rest of the functional groups are common in all synthesized compounds. The enzyme inhibitory kinetics of the most potent derivative 5i determined by Lineweaver-Burk plots and Dixon plots showed that it is non-competitive inhibitor with Ki value 1.5µM. It was further investigated that the wet lab results are in good agreement with the computational results. The molecular docking of the synthesized compounds was performed against tyrosinase protein (PDBID 2Y9X) to delineate ligand-protein interactions at molecular level. The docking results showed that the major interacting residues are His244, His85, His263, Val 283, His 296, Asn260, Val248, His260, His261 and Phe264 which are located in active binding site of the protein. The molecular modeling demonstrates that the oxygen atom of the compound 5i coordinated with the key residues in the active site of mushroom tyrosinase contribute significantly against inhibitory ability and diminishing the human melanin synthesis. These results evident that compound 5i is a lead structure in developing most potent mushroom tyrosinase inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spectroscopic and electrochemical characterization of some Schiff base metal complexes containing benzoin moiety

NASA Astrophysics Data System (ADS)

El-Shahawi, M. S.; Al-Jahdali, M. S.; Bashammakh, A. S.; Al-Sibaai, A. A.; Nassef, H. M.

2013-09-01

The ligation behavior of bis-benzoin ethylenediamine (B2ED) and benzoin thiosemicarbazone (BTS) Schiff bases towards Ru3+, Rh3+, Pd2+, Ni2+ and Cu2+ were determined. The bond length of M-N and spectrochemical parameters (10Dq, β, B and LFSE) of the complexes were evaluated. The redox characteristics of selected complexes were explored by cyclic voltammetry (CV) at Pt working electrode in non aqueous solvents. Au mesh (100 w/in.) optically transparent thin layer electrode (OTTLE) was also used for recording thin layer CV for selected Ru complex. Oxidation of some complexes occurs in a consecutive chemical reaction of an EC type mechanism. The characteristics of electron transfer process of the couples M2+/M3+ and M3+/M4+ (M = Ru3+, Rh3+) and the stability of the complexes towards oxidation and/or reduction were assigned. The nature of the electroactive species and reduction mechanism of selected electrode couples were assigned.

Evidence for side-chain π-delocalization in a planar substituted benzene: an experimental and theoretical charge density study on 2,5-dimethoxybenzaldehyde thiosemicarbazone.

PubMed

Farrugia, Louis J; Khalaji, Aliakbar Dehno

2011-11-17

The charge density in 2,5-dimethoxybenzaldehyde thiosemicarbazone (1) has been studied experimentally using Mo-K(α) X-ray diffraction at 100 K, and by theory using DFT calculations at the B3LYP/6-311++G(2d,2p) level. The quantum theory of atoms in molecules (QTAIM) was used to investigate the extent of π-delocalization in the thioamide side-chain, which is virtually coplanar with the benzene ring. The experimental and theoretical ellipticity profiles along the bond paths were in excellent agreement, and showed that some of the formal single bonds in the side-chain have significant π-bond character. This view was supported by the magnitudes of the topological bond orders and by the delocalization indices δ(Ω(A), Ω(B)). An orbital decomposition of δ(Ω(A), Ω(B)) demonstrated that there was significant π-character in all the interchain non-H chemical bonds. On the other hand, the source function referenced at the interchain bond critical points could not provide any evidence for π-delocalization, showing instead only limited σ-delocalization between nearest neighbors. Overall, the topological evidence and the atomic graphs of the oxygen atoms did not provide convincing evidence for π-delocalization involving the methoxy substituents.

Copper complexes containing thiosemicarbazones derived from 6-nitropiperonal: Antimicrobial and biophysical properties

NASA Astrophysics Data System (ADS)

Beckford, Floyd A.; Webb, Kelsey R.

2017-08-01

A series of four thiosemicarbazones from 6-nitropiperonal along with the corresponding copper complexes were synthesized. The biophysical characteristics of the complexes were investigated by the binding to DNA and human serum albumin. The binding to DNA is moderate; the binding constants run from (0.49-7.50) × 104 M- 1. In relation to HSA, the complexes interact strongly with binding constants on the order of 105 M- 1. The complexes also display antioxidant behavior as determined by the ability to scavenge diphenylpicrylhydrazyl (dpph) and nitric oxide radicals. The antimicrobial profiles of the compounds, tested against a panel of microbes including five of the ESKAPE pathogens (Staphylococcus aureus, MRSA, Escherichia coli, Klebsiella pneumoniae, MDR, Acinetobacter baumannii, Pseudomonas aeruginosa) and two yeasts (Candida albicans and Cryptococcus neoformans var. grubii), are also described. The compounds contain a core moiety that is similar to oxolinic acid, a quinolone antibiotic that targets DNA gyrase and topoisomerase (IV). The binding interaction between the complexes and these important antibacterial targets were studied by computational methods, chiefly docking studies. The calculated dissociation constants for the interaction with DNA gyrase B (from Staphylococcus aureus) range from 4.32 to 24.65 μM; the binding was much stronger to topoisomerase IV, with dissociation constants ranging from 0.37 to 1.27 μM.

Heteroleptic complexes of Zn(II) based on 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide: Synthesis, structural characterization, theoretical studies and antibacterial activity

NASA Astrophysics Data System (ADS)

Azarkish, Mohammad; Akbari, Alireza; Sedaghat, Tahereh; Simpson, Jim

2017-04-01

Four new ternary complexes, [ZnL (2,2‧-bipy)] (1), Zn2L2(4,4‧-bipy)] (2), [ZnL(Imd)]·H2O (3) and [ZnL3(MeImd)] (4), have been synthesized from the reaction of Zn(II) acetate with 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide (H2L) in the presence of a heterocyclic base, 2,2‧-bipyridine, 4,4‧-bipyridine, imidazole or 2-methylimidazole, as an auxiliary ligand. The complexes have been investigated by elemental analysis and FT-IR, UV-Vis and 1HNMR spectroscopy. These data show that the thiosemicarbazone acts as a tridentate dianionic ligand and coordinates via the thiol group, imine nitrogen, and phenolic oxygen. The coordination sphere was completed by the nitrogen atom(s) of the secondary ligand. The structure of 1 was also confirmed by X-ray crystallography and shown to be a five coordinate complex with coordination geometry between the square-pyramidal and trigonal-bipyramidal. Density functional theory (DFT) calculations including geometry optimization, vibrational frequencies and electronic absorptions have been performed for 1 with the B3LYP functional at the TZP(6-311G*) basis set using the Gaussian 03 or ADF 2009 packages. The optimization calculation showed that the crystallographically determined geometry parameters can be reproduced with that basis set. Experimental IR frequencies and calculated vibration frequencies also support each other. The in vitro antibacterial activities of the ligand and complexes have been evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (P. aeruginosa) bacteria and compared with the standard antibacterial drugs. The results reveal that all of the complexes show much better activity in comparison to the individual thiosemoicarbazone ligand (H2L), against all bacterial strains used, with complex 3 showing the most promising results.

Passive diffusion of naltrexone into human and animal cells and upregulation of cell proliferation.

PubMed

Cheng, Fan; McLaughlin, Patricia J; Banks, William A; Zagon, Ian S

2009-09-01

Naltrexone (NTX) is a potent opioid antagonist that promotes cell proliferation by upregulating DNA synthesis through displacement of the tonically active inhibitory peptide, opioid growth factor (OGF) from its receptor (OGFr). To investigate how NTX enters cells, NTX was fluorescently labeled [1-(N)-fluoresceinyl NTX thiosemicarbazone; FNTX] to study its uptake by living cultured cells. When human head and neck squamous cell carcinoma cell line (SCC-1) was incubated with FNTX for as little as 1 min, cells displayed nuclear and cytoplasmic staining of FNTX as determined by fluorescent deconvolution microscopy, with enrichment of fluorescent signal in the nucleus and nucleolus. The same temporal-spatial distribution of FNTX was detected in a human pancreatic cancer cell line (MIA PaCa-2), African green monkey kidney cell line (COS-7), and human mesenchymal stem cells (hMSCs). FNTX remained in cells for as long as 48 h. FNTX was internalized in SCC-1 cells when incubation occurred at 4 degrees C, with the signal being comparable to that recorded at 37 degrees C. A 100-fold excess of NTX or a variety of other opioid ligands did not alter the temporal-spatial distribution of FNTX. Neither fluorescein-labeled dextran nor fluorescein alone entered the cells. To study the effect of FNTX on DNA synthesis, cells incubated with FNTX at concentrations ranging from 10(-5) to 10(-8) M had a 5-bromo-2'-deoxyuridine index that was 39-82% greater than for vehicle-treated cells and was comparable to that of unlabeled NTX (37-70%). Taken together, these results suggested that NTX enters cells by passive diffusion in a nonsaturable manner.

A mechanism for overcoming P-glycoprotein-mediated drug resistance: novel combination therapy that releases stored doxorubicin from lysosomes via lysosomal permeabilization using Dp44mT or DpC.

PubMed

Seebacher, Nicole A; Richardson, Des R; Jansson, Patric J

2016-12-01

The intracellular distribution of a drug can cause significant variability in both activity and selectivity. Herein, we investigate the mechanism by which the anti-cancer agents, di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and the clinically trialed, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), re-instate the efficacy of doxorubicin (DOX), in drug-resistant P-glycoprotein (Pgp)-expressing cells. Both Dp44mT and DpC potently target and kill Pgp-expressing tumors, while DOX effectively kills non-Pgp-expressing cancers. Thus, the combination of these agents should be considered as an effective rationalized therapy for potently treating advanced and resistant tumors that are often heterogeneous in terms of Pgp-expression. These studies demonstrate that both Dp44mT and DpC are transported into lysosomes via Pgp transport activity, where they induce lysosomal-membrane permeabilization to release DOX trapped within lysosomes. This novel strategy of loading lysosomes with DOX, followed by permeabilization with Dp44mT or DpC, results in the relocalization of stored DOX from its lysosomal 'safe house' to its nuclear targets, markedly enhancing cellular toxicity against resistant tumor cells. Notably, the combination of Dp44mT or DpC with DOX showed a very high level of synergism in multiple Pgp-expressing cell types, for example, cervical, breast and colorectal cancer cells. These studies revealed that the level of drug synergy was proportional to Pgp activity. Interestingly, synergism was ablated by inhibiting Pgp using the pharmacological inhibitor, Elacridar, or by inhibiting Pgp-expression using Pgp-silencing, demonstrating the importance of Pgp in the synergistic interaction. Furthermore, lysosomal-membrane stabilization inhibited the relocalization of DOX from lysosomes to the nucleus upon combination with Dp44mT or DpC, preventing synergism. This latter observation demonstrated the importance of lysosomal-membrane permeabilization to the synergistic interaction between these agents. The synergistic and potent anti-tumor efficacy observed between DOX and thiosemicarbazones represents a promising treatment combination for advanced cancers, which are heterogeneous and composed of non-Pgp- and Pgp-expressing tumor cells.

Simultaneous spectrophotometric determination of copper, cobalt, nickel and iron in foodstuffs and vegetables with a new bis thiosemicarbazone ligand using chemometric approaches.

PubMed

Rohani Moghadam, Masoud; Poorakbarian Jahromi, Sayedeh Maria; Darehkordi, Ali

2016-02-01

A newly synthesized bis thiosemicarbazone ligand, (2Z,2'Z)-2,2'-((4S,5R)-4,5,6-trihydroxyhexane-1,2-diylidene)bis(N-phenylhydrazinecarbothioamide), was used to make a complex with Cu(2+), Ni(2+), Co(2+) and Fe(3+) for their simultaneous spectrophotometric determination using chemometric methods. By Job's method, the ratio of metal to ligand in Ni(2+) was found to be 1:2, whereas it was 1:4 for the others. The effect of pH on the sensitivity and selectivity of the formed complexes was studied according to the net analyte signal (NAS). Under optimum conditions, the calibration graphs were linear in the ranges of 0.10-3.83, 0.20-3.83, 0.23-5.23 and 0.32-8.12 mg L(-1) with the detection limits of 2, 3, 4 and 10 μg L(-1) for Cu(2+), Co(2+), Ni(2+) and Fe(3+) respectively. The OSC-PLS1 for Cu(2+) and Ni(2+), the PLS1 for Co(2+) and the PC-FFANN for Fe(3+) were selected as the best models. The selected models were successfully applied for the simultaneous determination of elements in some foodstuffs and vegetables. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spectroscopic and electrochemical characterization of some Schiff base metal complexes containing benzoin moiety.

PubMed

El-Shahawi, M S; Al-Jahdali, M S; Bashammakh, A S; Al-Sibaai, A A; Nassef, H M

2013-09-01

The ligation behavior of bis-benzoin ethylenediamine (B2ED) and benzoin thiosemicarbazone (BTS) Schiff bases towards Ru(3+), Rh(3+), Pd(2+), Ni(2+) and Cu(2+) were determined. The bond length of M-N and spectrochemical parameters (10Dq, β, B and LFSE) of the complexes were evaluated. The redox characteristics of selected complexes were explored by cyclic voltammetry (CV) at Pt working electrode in non aqueous solvents. Au mesh (100 w/in.) optically transparent thin layer electrode (OTTLE) was also used for recording thin layer CV for selected Ru complex. Oxidation of some complexes occurs in a consecutive chemical reaction of an EC type mechanism. The characteristics of electron transfer process of the couples M(2+)/M(3+) and M(3+)/M(4+) (M=Ru(3+), Rh(3+)) and the stability of the complexes towards oxidation and/or reduction were assigned. The nature of the electroactive species and reduction mechanism of selected electrode couples were assigned. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Synthesis, DNA Binding, and Antiproliferative Activity of Novel Acridine-Thiosemicarbazone Derivatives

PubMed Central

de Almeida, Sinara Mônica Vitalino; Lafayette, Elizabeth Almeida; Gomes da Silva, Lúcia Patrícia Bezerra; Amorim, Cézar Augusto da Cruz; de Oliveira, Tiago Bento; Gois Ruiz, Ana Lucia Tasca; de Carvalho, João Ernesto; de Moura, Ricardo Olímpio; Beltrão, Eduardo Isidoro Carneiro; de Lima, Maria do Carmo Alves; de Carvalho Júnior, Luiz Bezerra

2015-01-01

In this work, the acridine nucleus was used as a lead-compound for structural modification by adding different substituted thiosemicarbazide moieties. Eight new (Z)-2-(acridin-9-ylmethylene)-N-phenylhydrazinecarbothioamide derivatives (3a–h) were synthesized, their antiproliferative activities were evaluated, and DNA binding properties were performed with calf thymus DNA (ctDNA) by electronic absorption and fluorescence spectroscopies. Both hyperchromic and hypochromic effects, as well as red or blue shifts were demonstrated by addition of ctDNA to the derivatives. The calculated binding constants ranged from 1.74 × 104 to 1.0 × 106 M−1 and quenching constants from −0.2 × 104 to 2.18 × 104 M−1 indicating high affinity to ctDNA base pairs. The most efficient compound in binding to ctDNA in vitro was (Z)-2-(acridin-9-ylmethylene)-N-(4-chlorophenyl) hydrazinecarbothioamide (3f), while the most active compound in antiproliferative assay was (Z)-2-(acridin-9-ylmethylene)-N-phenylhydrazinecarbothioamide (3a). There was no correlation between DNA-binding and in vitro antiproliferative activity, but the results suggest that DNA binding can be involved in the biological activity mechanism. This study may guide the choice of the size and shape of the intercalating part of the ligand and the strategic selection of substituents that increase DNA-binding or antiproliferative properties. PMID:26068233

Nanoparticle Additives for Multiphase Systems: Synthesis, Formulation and Characterization

DTIC Science & Technology

2012-01-01

ADDITIVES FOR MULTIPHASE SYSTEMS: SYNTHESIS , FORMULATION AND CHARACTERIZATION Vinod Kanniah University of Kentucky, vinodkanniah@gmail.com This Doctoral...UKnowledge@lsv.uky.edu. Recommended Citation Kanniah, Vinod, "NANOPARTICLE ADDITIVES FOR MULTIPHASE SYSTEMS: SYNTHESIS , FORMULATION AND CHARACTERIZATION...00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Nanoparticle Additives for Multiphase Systems: Synthesis , Formulation and Characterization 5a

Exploring the anti-cancer activity of novel thiosemicarbazones generated through the combination of retro-fragments: dissection of critical structure-activity relationships.

PubMed

Serda, Maciej; Kalinowski, Danuta S; Rasko, Nathalie; Potůčková, Eliška; Mrozek-Wilczkiewicz, Anna; Musiol, Robert; Małecki, Jan G; Sajewicz, Mieczysław; Ratuszna, Alicja; Muchowicz, Angelika; Gołąb, Jakub; Simůnek, Tomáš; Richardson, Des R; Polanski, Jaroslaw

2014-01-01

Thiosemicarbazones (TSCs) are an interesting class of ligands that show a diverse range of biological activity, including anti-fungal, anti-viral and anti-cancer effects. Our previous studies have demonstrated the potent in vivo anti-tumor activity of novel TSCs and their ability to overcome resistance to clinically used chemotherapeutics. In the current study, 35 novel TSCs of 6 different classes were designed using a combination of retro-fragments that appear in other TSCs. Additionally, di-substitution at the terminal N4 atom, which was previously identified to be critical for potent anti-cancer activity, was preserved through the incorporation of an N4-based piperazine or morpholine ring. The anti-proliferative activity of the novel TSCs were examined in a variety of cancer and normal cell-types. In particular, compounds 1d and 3c demonstrated the greatest promise as anti-cancer agents with potent and selective anti-proliferative activity. Structure-activity relationship studies revealed that the chelators that utilized "soft" donor atoms, such as nitrogen and sulfur, resulted in potent anti-cancer activity. Indeed, the N,N,S donor atom set was crucial for the formation of redox active iron complexes that were able to mediate the oxidation of ascorbate. This further highlights the important role of reactive oxygen species generation in mediating potent anti-cancer activity. Significantly, this study identified the potent and selective anti-cancer activity of 1d and 3c that warrants further examination.

Synthesis, characterization, molecular modeling and biological activity of metal complexes derived from (E)-N'-(furan-2-ylmethylene)morpholine-4-carbothiohydrazide

NASA Astrophysics Data System (ADS)

El-Samanody, El-Sayed A.; Emam, Sanaa M.; Emara, Esam M.

2017-10-01

A new series of some biologically active Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes was synthesized from the novel thiosemicarbazone ligand; (E)-N'-(furan-2-ylmethylene)morpholine-4-carbothiohydrazide (HL). Elemental, spectral, thermal analyses, magnetic susceptibility and molar conductivity measurements were used to elucidate the structure of separated compounds. The data prove that the ligand reacts with all metal ions in a neutral thione form. The electrolytic tetra-coordinate Cu(II); Zn(II) complexes (5, 6; 10) bind through the thione sulfur, furfural oxygen and azomethine nitrogen atoms of the ligand (NSO type) to construct fused five membered rings. However, the rest non-electrolyte octahedral complexes chelate via the furfural oxygen and azomethine nitrogen atoms of the ligand (NO type). Molecular modeling was conducted for the ligand and two representative complexes (1, 5) in order to substantiate their chemical structures. Thermal analyses are compatible with molecular modeling studies to support the proposed thermal decomposition pathways of metal complexes which start with the rupture of the long and weak N-NH bond. The thermal stability of metal complexes varies according to the number of solvents of crystallization, ionic radii and steric effect of anions. The ESR spectra of Cu(II) complexes are compatible with a primarily (dx2-y2)1 ground state with axial symmetry. The ligand and its Co(II); Cu(II); Cd(II) complexes (1; 5, 8; 11) along with their mixtures with metaldehyde were screened in vitro for their molluscicidal activity against Eobania vermiculata. Combination with metaldehyde enhances the toxicity effect of the tested compounds through reducing the period required for mortality and increasing the percentage of mortality after 24 h of treatments. The tested compounds gathered with metaldehyde are strongly affecting on the activity of ACP and ALP enzymes and TP content which are very important factors in the mucous secretion of Eobania vermiculata. These effects lead to excess mucous secretion, causing dryness and death for the snails.

Jeffrey Blackburn | NREL

Science.gov Websites

-dimensional carbon and includes the synthesis, purification, separation, and characterization of single-walled conversion Synthesis, purification, separation, and characterization of single-walled carbon nanotubes Synthesis, characterization, and device integration of graphen Hydrogen storage Photovoltaic materials and

3-Acetyl-8-methoxy-2[H]-chromen-2-one derived Schiff bases as potent antiproliferative agents: Insight into the influence of 4(N)-substituents on the in vitro biological activity

NASA Astrophysics Data System (ADS)

Kalaiarasi, G.; Rex Jeya Rajkumar, S.; Aswini, G.; Dharani, S.; Fronczek, Frank R.; Prabhakaran, R.

2018-07-01

A series of 3-acetyl-8-methoxycoumarin appended thiosemicarbazones (1-4) was prepared from the reaction of 3-acetyl-8-methoxycoumarin with 4(N)-substituted thiosemicarbazides in a view of ascertaining their biological properties with the change of N-terminal substitution in the thiosemicarbazide moiety. Comprehensive characterization was brought about by various spectral and analytical methods. The molecular structures of all the compounds were determined by single crystal X-ray diffraction analysis. Binding studies with Calf thymus DNA (CT-DNA) and proteins such as Bovine Serum Albumin (BSA) and Human Serum Albumin (HSA) indicated an intercalative mode of binding with DNA and static quenching mechanism with proteins. The compounds cleaved plasmid DNA (pBR322) and acted well as free radical scavengers. A good spectrum of antimicrobial activity was observed against four bacterial and five fungal pathogens. The compounds exhibited profound antiproliferative activity on MCF-7 (human breast cancer) and A549 (human lung carcinoma) cell lines. Assay on human normal keratinocyte cell line HaCaT showed that the compounds were non-toxic to normal cells.

Functional Nanomaterial’s Synthesis and Characterization

DTIC Science & Technology

2015-04-28

synthesis and characterization of nanoparticles and polymers. Current progress is being made at Argonne National Labs (ANL) and at AFRL in characterization... currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. Florida A&M University 1700 Lee Hall Drive 400 Foote-Hilyer Admin...at Florida A&M University (FAMU) which will play a key role in synthesis and characterization of nanoparticles and polymers. Current progress is

Programmable Triplet Formation and Decay in Metal-Organic Chromophores

DTIC Science & Technology

2011-12-13

potential applications in optical limiting molecules has resulted in the synthesis and characterization of many new classes of chromophores in...Castellano, F.N. Inorg. Chem. 2006, 45, 4304-4306. Inorganic Chemistry Cover May 29, 2006. The synthesis , structural characterization, and...The synthesis , photophysics, electronic structure, and electrochemical characterization of 4′-tert- butylacetylene-2,2′:6′,2″-terpyridineplatinum(II

Raman Spectrometer for the Characterization of Advanced Materials and Nanomaterials

DTIC Science & Technology

2016-04-18

Capannelli, F. Canepa, M. Napoletano, M.R. Cimberle, et al., Synthesis and magnetic characterization of Ni nanoparticles and Ni nanoparticles in...Hennig, R.D. Robinson, Unintended phosphorus doping of nickel nanoparticles during synthesis with TOP: a discovery through structural analysis...Davar, Z. Fereshteh, M. Salavati-Niasari, Nanoparticles Ni and NiO: Synthesis , characterization and magnetic properties, J. Alloys Compd. 476 (2009) 797–801.

Spectroscopic, cyclic voltammetric and biological studies of transition metal complexes with mixed nitrogen-sulphur (NS) donor macrocyclic ligand derived from thiosemicarbazide

NASA Astrophysics Data System (ADS)

Chandra, Sulekh; Gupta, Lokesh Kumar; Sangeetika

2005-11-01

The complexation of new mixed thia-aza-oxa macrocycle viz., 2,12-dithio-5,9,14,18-tetraoxo-7,16-dithia-1,3,4,10,11,13-hexaazacyclooctadecane containing thiosemicarba-zone unit with a series of transition metals Co(II), Ni(II) and Cu(II) has been investigated, by different spectroscopic techniques. The structural features of the ligand have been studied by EI-mass, 1H NMR and IR spectral techniques. Elemental analyses, magnetic moment susceptibility, molar conductance, IR, electronic, and EPR spectral studies characterized the complexes. Electronic absorption and IR spectra of the complexes indicate octahedral geometry for chloro, nitrato, thiocyanato or acetato complexes. The dimeric and neutral nature of the sulphato complexes are confirmed from magnetic susceptibility and low conductance values. Electronic spectra suggests square-planar geometry for all sulphato complexes. The redox behaviour was studied by cyclic voltammetry, show metal-centered reduction processes for all complexes. The complexes of copper show both oxidation and reduction process. The redox potentials depend on the conformation of central atom in the macrocyclic complexes. Newly synthesized macrocyclic ligand and its transition metal complexes show markedly growth inhibitory activity against pathogenic bacterias and plant pathogenic fungi under study. Most of the complexes have higher activity than that of the metal free ligand.

Synthesis and characterization of metal oxide-polyaniline emeraldine salt based nanocomposite

NASA Astrophysics Data System (ADS)

Kumar, K. Siva; Kavitha, B.; Prabakar, K.; Srinivasu, D.; Srinivas, Ch.; Narsimlu, N.

2013-02-01

This paper describes the synthesis of TiO2 (core)/Polyaniline (shell) core-shell structured nanocomposites and characterization of the synthesized material. The morphological characterization is performed with XRD, SEM, DLS and SANS. Spectroscopic characterization is performed with FTIR, UV/Visible and ESR techniques.

Synthesis, characterization, and reactivity of pentamethylcyclopentadienyl complexes of divalent cobalt and nickel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Michael Edward

1993-10-01

The thesis is divided into the following 4 chapters: synthesis, characterization, and reactivity of trinuclear pentamethylcyclopentadienyl cobalt and nickel clusters with triply-bridging methylidyne groups; chemical and physical properties of pentamethylcyclopentadienyl acetylacetonate complexes of Co(II) and Ni(II); synthesis, characterization, and reactivity of pentamethylcyclopentadienyl halide complexes of Co and Ni; and crystallographic studies of distortions in metallocenes with C 5-symmetrical cyclopentadienyl rings.

Gary Grim | NREL

Science.gov Websites

@nrel.gov | 303-384-7781 Research Interests Synthesis and characterization of heterogeneous catalysts for Chemie (2014) "Synthesis and Characterization of sI Clathrate Hydrates Containing Hydrogen," J

Synthesis and Characterization of Compounds Related to Lisinopril

PubMed Central

Raghava Reddy, Ambati V.; Garaga, Srinivas; Takshinamoorthy, Chandiran; Naidu, Andra; Dandala, Ramesh

2016-01-01

Lisinopril is a drug of the angiotensin-converting enzyme (ACE) inhibitor class that is primarily used in the treatment of hypertension. During the scale-up of the lisinopril process, one unknown impurity was observed and is identified. The present work describes the origin, synthesis, characterization, and control of this impurity. This paper also describes the synthesis and characterization of three other impurities listed in the European Pharmacopoeia 8.4 (Impurity C, D, and F). PMID:27222603

Controlling Magnetic and Ferroelectric Order Through Geometry: Synthesis, Ab Initio Theory, Characterization of New Multi-Ferric Fluoride Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halasyamani, Shiv; Fennie, Craig

2016-11-03

We have focused on the synthesis, characterization, and ab initio theory on multi-functional mixed-metal fluorides. With funding from the DOE, we have successfully synthesized and characterized a variety of mixed metal fluoride materials.

The Synthesis and Characterization of Some Fluoride Perovskites: An Undergraduate Experiment in Solid State Chemistry.

ERIC Educational Resources Information Center

Langley, Richard H.; And Others

1984-01-01

Describes a senior-level experiment dealing with the synthesis and characterization of a perovskite. Since most perovskites are cubic, their characterization by x-ray diffraction is simplified. In addition, magnetic ordering may be observed and the effects of a Jahn-Teller distortion seen. (JN)

Synthesis and characterization of rare-earth-doped calcium tungstate nanocrystals

NASA Astrophysics Data System (ADS)

Suneeta, P.; Rajesh, Ch.; Ramana, M. V.

2018-02-01

In this paper, we report synthesis and characterization of rare-earth-ion-doped calcium tungstate (CaWO4) nanocrystals (NCs). Rare-earth ions, such as gadolinium (Gd), neodymium (Nd), praseodymium (Pr), samarium (Sm) and holmium (Ho), were successfully doped in the CaWO4 NCs by changing the synthesis conditions. The adopted synthesis route was found to be fast and eco-friendly. Structural characterizations, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and compositional analysis, were performed using energy dispersive analysis of X-rays (EDAX) on as-synthesized NCs. The results indicate the size of the NCs ranging between 47 to 68nm and incorporation of rare-earth ions in CaWO4 NCs.

Novel Magnetic Fluids for Breast Cancer Therapy

DTIC Science & Technology

2005-04-01

synthesis and characterization efforts concerning nickel-based alloys have been reported previously [5]. Nano-material has been obtained using an inverse...gar gel d ork his task regularly accompanies the synthesis work. Characterization analysis includes size, composition, magnetic pro perties. The...currently available magnetic fluids used in hyperthermia. The specific goals are: 1. Develop a synthesis process to fabricate magnetic nano

Synthesis, characterization and antibacterial studies of 2-chloro-5-fluoro-N-[dibenzyl carbamothioyl] benzamide thiourea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sapari, Suhaila; Yamin, Bohari M.; Hasbullah, Aishah

Synthesis, characterization and antibacterial studies of 2-chloro-5-fluoro-N-[dibenzyl carbamothioyl] benzamide thiourea has been reported. The compound characterized by using elementary analysis CHNS, IR, {sup 1}H NMR and {sup 13}C NMR spectroscopies. The compounds have been screened for their antibacterial studies.

Actinide Corroles: Synthesis and Characterization of Thorium(IV) and Uranium(IV) bis(-chloride) Dimers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, Ashleigh L.; Buckley, Heather L.; Gryko, Daniel T.

2013-12-01

The first synthesis and structural characterization of actinide corroles is presented. Thorium(IV) and uranium(IV) macrocycles of Mes2(p-OMePh)corrole were synthesised and characterized by single-crystal X-ray diffraction, UV-Visible spectroscopy, variable-temperature 1H NMR, ESI mass spectrometry and cyclic voltammetry.

Synthesis and characterization of luminescent materials for thermal sensing and proton dosimetry

NASA Astrophysics Data System (ADS)

Doull, Brandon Arthur

The work presented in this thesis is the materials synthesis, investigation of synthesis parameters, and basic luminescent characterizations of MgB 4O7, Li2B4O7, and MgO for the applications of thermal sensing using thermoluminescence (TL) and proton dosimetry using optically stimulated luminescence (OSL). The materials were synthesized using solution combustion synthesis and characterized by x-ray diffraction, radioluminescence, thermoluminescence, and optically stimulated luminescence. Based upon the basic characterizations MgB 4O7:Li,Dy and Li2B4O7:Cu,Ag were selected for their potential for use as TL materials for thermal sensing while MgB4O7:Li,Ce and MgO:Li were chosen for use as OSL materials in proton dosimetry. Furthermore, MgB4O7:Li,Ce and MgO:Li were fabricated into detector assemblies and exposed to a clinical proton beam for analysis.

A phase 2 consortium (P2C) trial of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) for advanced adenocarcinoma of the pancreas.

PubMed

Attia, Steven; Kolesar, Jill; Mahoney, Michelle R; Pitot, Henry C; Laheru, Daniel; Heun, James; Huang, Wei; Eickhoff, Jens; Erlichman, Charles; Holen, Kyle D

2008-08-01

3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine) is a novel small molecule inhibitor of ribonucleotide reductase (RR) with clinical signs of activity in pancreatic cancer. Therefore, the Phase 2 Consortium (P2C) initiated a trial (two single stage studies with planned interim analysis) of 3-AP at 96 mg/m(2) intravenously days 1-4 and 15-18 of a 28-day cycle in both chemotherapy-naive and gemcitabine-refractory (GR) patients with advanced pancreatic cancer. The primary endpoint was survival at six months (chemotherapy-naive) and four months (GR). Secondary endpoints were toxicity, response, overall survival, time to progression and mechanistic studies. Fifteen patients were enrolled including one chemotherapy-naïve and 14 GR. The chemotherapy-naïve patient progressed during cycle 1 with grade 3 and 4 toxicities. Of 14 GR patients, seven received two cycles, six received one cycle and one received eight cycles. Progression precluded further treatment in 11 GR patients. Additionally, one died of an ileus in cycle 1 considered related to treatment and two stopped treatment due to toxicity. Five GR patients had grade 4 toxicities possibly related to 3-AP and six GR patients had grade 3 fatigue. Toxicities and lack of meaningful clinical benefit prompted early study closure. Four-month survival in GR patients was 21% (95% CI: 8-58%). Correlative studies confirmed that 3-AP increased the percentage of S-phase buccal mucosal cells, the presence of multidrug resistance gene polymorphisms appeared to predict leukopenia, and baseline pancreatic tumor RR M2 expression was low relative to other tumors treated with 3-AP. In conclusion, this regimen appears inactive against predominantly GR pancreatic cancer. RR M2 protein may not have a critical role in the malignant potential of pancreatic cancer.

A phase 2 consortium (P2C) trial of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) for advanced adenocarcinoma of the pancreas

PubMed Central

Attia, Steven; Kolesar, Jill; Mahoney, Michelle R.; Pitot, Henry C.; Laheru, Daniel; Heun, James; Huang, Wei; Eickhoff, Jens; Erlichman, Charles

2015-01-01

Summary 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine®) is a novel small molecule inhibitor of ribonucleotide reductase (RR) with clinical signs of activity in pancreatic cancer. Therefore, the Phase 2 Consortium (P2C) initiated a trial (two single stage studies with planned interim analysis) of 3-AP at 96 mg/m2 intravenously days 1–4 and 15–18 of a 28-day cycle in both chemotherapy-naive and gemcitabine-refractory (GR) patients with advanced pancreatic cancer. The primary endpoint was survival at six months (chemotherapy-naive) and four months (GR). Secondary endpoints were toxicity, response, overall survival, time to progression and mechanistic studies. Fifteen patients were enrolled including one chemotherapy-naïve and 14 GR. The chemotherapy-naïve patient progressed during cycle 1 with grade 3 and 4 toxicities. Of 14 GR patients, seven received two cycles, six received one cycle and one received eight cycles. Progression precluded further treatment in 11 GR patients. Additionally, one died of an ileus in cycle 1 considered related to treatment and two stopped treatment due to toxicity. Five GR patients had grade 4 toxicities possibly related to 3-AP and six GR patients had grade 3 fatigue. Toxicities and lack of meaningful clinical benefit prompted early study closure. Four-month survival in GR patients was 21% (95% CI: 8–58%). Correlative studies confirmed that 3-AP increased the percentage of S-phase buccal mucosal cells, the presence of multidrug resistance gene polymorphisms appeared to predict leukopenia, and baseline pancreatic tumor RR M2 expression was low relative to other tumors treated with 3-AP. In conclusion, this regimen appears inactive against predominantly GR pancreatic cancer. RR M2 protein may not have a critical role in the malignant potential of pancreatic cancer. PMID:18278438

Organic Materials as Electrodes for Li-ion Batteries

DTIC Science & Technology

2015-09-04

Various macrocycles, their synthesis, characterization and subsequent use in lithium - ion batteries were attempted. Ellagic acid, alizarin and...Various macrocycles, their synthesis, characterization and subsequent use in lithium - ion batteries were attempted. Ellagic acid, alizarin and...characterization and subsequent use in lithium - ion batteries have been attempted to. Lithium -based batteries are at the forefront of battery

Synthesis, Characterization and Reactivity of a Hexane-Soluble Silver Salt

ERIC Educational Resources Information Center

Stockland, Robert A. Jr.; Wilson, Brian D.; Goodman, Caton C.; Giese, Barret J.; Shrimp, Frederick L., II

2007-01-01

The connectivity of a hexane-soluble silver salt is established by using NMR spectroscopy to describe the synthesis, characterization and reactivity of the salt. The results found hexane-soluble silver to be an effective transfer agent.

Thiophene-based covalent organic frameworks

PubMed Central

Bertrand, Guillaume H. V.; Michaelis, Vladimir K.; Ong, Ta-Chung; Griffin, Robert G.; Dincă, Mircea

2013-01-01

We report the synthesis and characterization of covalent organic frameworks (COFs) incorporating thiophene-based building blocks. We show that these are amenable to reticular synthesis, and that bent ditopic monomers, such as 2,5-thiophenediboronic acid, are defect-prone building blocks that are susceptible to synthetic variations during COF synthesis. The synthesis and characterization of an unusual charge transfer complex between thieno[3,2-b]thiophene-2,5-diboronic acid and tetracyanoquinodimethane enabled by the unique COF architecture is also presented. Together, these results delineate important synthetic advances toward the implementation of COFs in electronic devices. PMID:23479656

Hydrothermal Synthesis and Characterization of a Metal-Organic Framework by Thermogravimetric Analysis, Powder X-Ray Diffraction, and Infrared Spectroscopy: An Integrative Inorganic Chemistry Experiment

ERIC Educational Resources Information Center

Crane, Johanna L.; Anderson, Kelly E.; Conway, Samantha G.

2015-01-01

This advanced undergraduate laboratory experiment involves the synthesis and characterization of a metal-organic framework with microporous channels that are held intact via hydrogen bonding of the coordinated water molecules. The hydrothermal synthesis of Co[subscript 3](BTC)[subscript 2]·12H[subscript 2]O (BTC = 1,3,5-benzene tricarboxylic acid)…

Highly Efficient Flexible Hybrid Photovoltaic Cells Based on Low-Band-Gap Conjugated Polymers Sensitized by Nanoparticle-Grafted Carbon

DTIC Science & Technology

2010-09-01

modeling, synthesis , and characterization of several series functional and processable electro-active conjugated polymers with evolving frontier...tasks as a basic obligation of this award: Task #1. Low Band Gap Polymers The awardee (Professor Sun’s group at NSU) shall design, synthesis , and...design, modeling, synthesis , and characterizations of several series functional and processable electro-active conjugated polymers with evolving

[Synthesis and Characterization of a Sugar Based Electrolyte for Thin-film Polymer Batteries

NASA Technical Reports Server (NTRS)

1998-01-01

The work performed during the current renewal period, March 1,1998 focused primarily on the synthesis and characterization of a sugar based electrolyte for thin-film polymer batteries. The initial phase of the project involved developing a suitable sugar to use as the monomer in the polymeric electrolyte synthesis. The monomer has been synthesized and characterized completely. Overall the yield of this material is high and it can be produced in relatively large quantity easily and in high purity. The scheme used for the preparation of the monomer is outlined along with pertinent yields.

Synthesis and characterization of dextran-coated iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Predescu, Andra Mihaela; Matei, Ecaterina; Berbecaru, Andrei Constantin; Pantilimon, Cristian; Drăgan, Claudia; Vidu, Ruxandra; Predescu, Cristian; Kuncser, Victor

2018-03-01

Synthesis and characterization of iron oxide nanoparticles coated with a large molar weight dextran for environmental applications are reported. The first experiments involved the synthesis of iron oxide nanoparticles which were coated with dextran at different concentrations. The synthesis was performed by a co-precipitation technique, while the coating of iron oxide nanoparticles was carried out in solution. The obtained nanoparticles were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectrometry, Fourier transform infrared spectroscopy and superconducting quantum interference device magnetometry. The results demonstrated a successful coating of iron oxide nanoparticles with large molar weight dextran, of which agglomeration tendency depended on the amount of dextran in the coating solution. SEM and TEM observations have shown that the iron oxide nanoparticles are of about 7 nm in size.

Synthesis and Characterization of Cellulose Derivatives for Water Repellent Properties

USDA-ARS?s Scientific Manuscript database

In this presentation, we will discuss the synthesis and structural characterizations of nitro-benzyl cellulose (1), amino-benzyl cellulose (2) and pentafluoro –benzyl cellulose (3). All cellulose derivatives are synthesized by etherification process in lithium chloride/N,N-dimethylacetamide homogene...

Poly/diphenylsiloxy/arylazines. I - Synthesis and characterization

NASA Technical Reports Server (NTRS)

Goldsberry, R. E.; Adamson, M. J.; Reinisch, R. F.

1973-01-01

A detailed description is presented for the synthesis of poly(diphenylsiloxy)arylazines by the melt polymerization of hydroxyarylazines and bis(anilino)diphenylsilane. The resulting polymers have been characterized by elemental analysis, gel-permeation chromatography, vapor-phase osmometry, and UV-VIS-IR optical spectroscopy.

Synthesis and characterization of polycrystalline CdSiP2

NASA Astrophysics Data System (ADS)

Bereznaya, S. A.; Korotchenko, Z. V.; Sarkisov, S. Yu; Korolkov, I. V.; Kuchumov, B. M.; Saprykin, A. I.; Atuchin, V. V.

2018-05-01

A modified method is proposed for the CdSiP2 compound synthesis from elemental starting components. The developed technique allows completing the synthesis process within 30 h. The phase and chemical composition of the synthesized material were confirmed by the x-ray diffraction analysis and scanning electron microscopy with energy-dispersive spectroscopy. The transparent crystal block sized 3 × 3 × 2 mm3 was cut from the polycrystalline ingot and characterized by optical methods.

An improved divergent synthesis of comb-type branched oligodeoxyribonucleotides (bDNA) containing multiple secondary sequences.

PubMed

Horn, T; Chang, C A; Urdea, M S

1997-12-01

The divergent synthesis of branched DNA (bDNA) comb structures is described. This new type of bDNA contains one unique oligonucleotide, the primary sequence, covalently attached through a comb-like branch network to many identical copies of a different oligonucleotide, the secondary sequence. The bDNA comb structures were assembled on a solid support and several synthesis parameters were investigated and optimized. The bDNA comb molecules were characterized by polyacrylamide gel electrophoretic methods and by controlled cleavage at periodate-cleavable moieties incorporated during synthesis. The developed chemistry allows synthesis of bDNA comb molecules containing multiple secondary sequences. In the accompanying article we describe the synthesis and characterization of large bDNA combs containing all four deoxynucleotides for use as signal amplifiers in nucleic acid quantification assays.

An improved divergent synthesis of comb-type branched oligodeoxyribonucleotides (bDNA) containing multiple secondary sequences.

PubMed Central

Horn, T; Chang, C A; Urdea, M S

1997-01-01

The divergent synthesis of branched DNA (bDNA) comb structures is described. This new type of bDNA contains one unique oligonucleotide, the primary sequence, covalently attached through a comb-like branch network to many identical copies of a different oligonucleotide, the secondary sequence. The bDNA comb structures were assembled on a solid support and several synthesis parameters were investigated and optimized. The bDNA comb molecules were characterized by polyacrylamide gel electrophoretic methods and by controlled cleavage at periodate-cleavable moieties incorporated during synthesis. The developed chemistry allows synthesis of bDNA comb molecules containing multiple secondary sequences. In the accompanying article we describe the synthesis and characterization of large bDNA combs containing all four deoxynucleotides for use as signal amplifiers in nucleic acid quantification assays. PMID:9365265

Exploring the Fundamentals of Microreactor Technology with Multidisciplinary Lab Experiments Combining the Synthesis and Characterization of Inorganic Nanoparticles

ERIC Educational Resources Information Center

Emmanuel, Noemie; Emonds-Alt, Gauthier; Lismont, Marjorie; Eppe, Gauthier; Monbaliu, Jean-Christophe M.

2017-01-01

Multidisciplinary lab experiments combining microfluidics, nanoparticle synthesis, and characterization are presented. These experiments rely on the implementation of affordable yet efficient microfluidic setups based on perfluoroalkoxyalkane (PFA) capillary coils and standard HPLC connectors in upper undergraduate chemistry laboratories.…

Stereoselective Synthesis of Cyclometalated Iridium (III) Complexes: Characterization and Photophysical Properties

PubMed Central

Yang, Liangru; von Zelewsky, Alex; Nguyen, Huong P.; Muller, Gilles; Labat, Gaël; Stoeckli-Evans, Helen

2009-01-01

The stereoselective synthesis of a highly luminescent neutral Ir(III) complex comprising two bidentate chiral, cyclometalating phenylpyridine derivatives, and one acetylacetonate as ligands is described. The final complex and some intermediates were characterized by X-ray structural analysis, NMR-, CD-, and CPL-spectroscopy. PMID:20161195

Synthesis and characterization of germa[n]pericyclynes.

PubMed

Tanimoto, Hiroki; Nagao, Tomohiko; Nishiyama, Yasuhiro; Morimoto, Tsumoru; Iseda, Fumiyasu; Nagato, Yuko; Suzuka, Toshimasa; Tsutsumi, Ken; Kakiuchi, Kiyomi

2014-06-14

The synthesis and characterization of novel pericyclynes comprising germanium atoms and acetylenes, germa[n]pericyclynes, are described. The prepared germa[4]-, [6]-, and [8]pericyclynes were compared by (13)C NMR spectroscopy, X-ray crystallography, cyclic voltammetry, UV-visible spectroscopy, fluorescence emission spectroscopy, Raman spectroscopy, and density functional theory calculation analyses.

Synthesis Characterization and Decomposition Studies of tris[N-N-dibenzyidithocarbaso)Indium (III) Chemical Spray Deposition of Polycrystalline CuInS2 on Copper Films

NASA Technical Reports Server (NTRS)

Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.

2005-01-01

This paper presents the results of the synthesis characterization and decomposition studies of tris[N-N-dibenzyidithocarbaso)Indium (III) with chemical spray deposition of polycrystalline CuInS2 on Copper Films.

Synthesis, characterization and reactivity of 3-mercaptopyruvic acid.

PubMed

Galardon, Erwan; Lec, Jean-Chrstophe

2018-05-20

A synthesis of the sulfur metabolic compound 3-mercaptopyruvic acid (3-MPH) is reported and allowed its isolation and characterization for the first time. Detailed kinetic, thermodynamic and spectroscopic studies of its complex behaviour in solution are discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, Characterization, and Handling of Eu(II)-Containing Complexes for Molecular Imaging Applications

NASA Astrophysics Data System (ADS)

Basal, Lina A.; Allen, Matthew J.

2018-03-01

Considerable research effort has focused on the in vivo use of responsive imaging probes that change imaging properties upon reacting with oxygen because hypoxia is relevant to diagnosing, treating, and monitoring diseases. One promising class of compounds for oxygen-responsive imaging is Eu(II)-containing complexes because the Eu(II/III) redox couple enables imaging with multiple modalities including magnetic resonance and photoacoustic imaging. The use of Eu(II) requires care in handling to avoid unintended oxidation during synthesis and characterization. This review describes recent advances in the field of imaging agents based on discrete Eu(II)-containing complexes with specific focus on the synthesis, characterization, and handling of aqueous Eu(II)-containing complexes.

Synthesis and Characterization of Exfoliated Graphene- and Graphene Oxide-Based Composites

NASA Astrophysics Data System (ADS)

Rasmi, K. R.; Chakrapani, K.; Sampath, S.

Graphene- and graphene oxide-based composites have attracted significant research interest in recent years, owing to their important applications in various technological fields. In the present study, we report the synthesis and characterization of graphene-bimetallic alloy composite and its use in sensing of a neurotransmitter, dopamine. The preparation and characterization of graphene oxide with metal oxides such as RuOx and Co3O4 are also presented.

Synthesis and Characterization of Heterobimetallic Iridium-Aluminum and Rhodium-Aluminum Complexes.

PubMed

Brewster, Timothy P; Nguyen, Tan H; Li, Zhongjing; Eckenhoff, William T; Schley, Nathan D; DeYonker, Nathan J

2018-02-05

We demonstrate the synthesis and characterization of a new class of late-transition-metal-aluminum heterobimetallic complexes via a novel synthetic pathway. Complexes of this type are exceedingly rare. Joint experimental and theoretical data sheds light on the electronic effect of ligands containing aluminum moieties on late-transition-metal complexes.

The Self-Assembly Properties of a Benzene-1,3,5-tricarboxamide Derivative

ERIC Educational Resources Information Center

Stals, Patrick J. M.; Haveman, Jan F.; Palmans, Anja R. A.; Schenning, Albertus P. H. J.

2009-01-01

A series of experiments involving the synthesis and characterization of a benzene-1,3,5-tricarboxamide derivative and its self-assembly properties are reported. These laboratory experiments combine organic synthesis, self-assembly, and physical characterization and are designed for upper-level undergraduate students to introduce the topic of…

Biocatalyzed Regioselective Synthesis in Undergraduate Organic Laboratories: Multistep Synthesis of 2-Arachidonoylglycerol

ERIC Educational Resources Information Center

Johnston, Meghan R.; Makriyannis, Alexandros; Whitten, Kyle M.; Drew, Olivia C.; Best, Fiona A.

2016-01-01

In order to introduce the concepts of biocatalysis and its utility in synthesis to organic chemistry students, a multistep synthesis of endogenous cannabinergic ligand 2-arachidonoylglycerol (2-AG) was tailored for use as a laboratory exercise. Over four weeks, students successfully produced 2-AG, purifying and characterizing products at each…

Synthesis and Characterization of Processable Polyimides with Enhanced Thermal Stability

NASA Technical Reports Server (NTRS)

Harris, Frank W.

1999-01-01

The following is a summary report of the research carried out under NASA Grant NAG-1-448. The work was divided into four major areas: 1) Enhanced polyimide processing through the use of reactive plasticizers 2) Development of processable polyhenylquinoxalines 3) Synthesis and characterization of perfluorovinylether-terminated imide oligomers and 4) Fluorosilicones containing perfuorocyclobutane rings.

Synthesis and characterization of polypyrrole grafted chitin

NASA Astrophysics Data System (ADS)

Ramaprasad, A. T.; Latha, D.; Rao, Vijayalakshmi

2017-05-01

Synthesis and characterization of chitin grafted with polypyrrole (PPy) is reported in this paper. Chitin is soaked in pyrrole solution of various concentrations for different time intervals and polymerized using ammonium peroxy disulphate (APS) as an initiator. Grafting percentage of polypyrrole onto chitin is calculated from weight of chitin before and after grafting. Grafting of polymer is further verified by dissolution studies. The grafted polymer samples are characterized by FTIR, UV-Vis absorption spectrum, XRD, DSC, TGA, AFM, SEM and conductivity studies.

Synthesis, Characterization, and Application of Gold Nanoparticles in Green Nanochemistry Dye-Sensitized Solar Cells

DTIC Science & Technology

2012-06-01

resolution tunneling electron microscopy (HR-TEM). 2.4 DSSC Assembly Annealed TiO2 nanoparticle photoanodes were placed into 10 mL each of the blackberry ...resolution tunneling electron microscopy, and ultraviolet-visible spectroscopy. After characterization, the NPs were found to vary in shape but had... Blackberry Anthocyanin Extraction Procedure ...............................................................3 2.3 Au Nanoparticle Synthesis

The Chemistry of Formazan Dyes: Synthesis and Characterization of a Stable Verdazyl Radical and a Related Boron-Containing Heterocycle

ERIC Educational Resources Information Center

Berry, David E.; Hicks, Robin G.; Gilroy, Joe B.

2009-01-01

This experiment describes the synthesis and characterization of a formazan dye, and its subsequent conversion to a stable verdazyl radical and a boron-nitrogen heterocycle (boratatetrazine). Each of these compounds is intensely colored and is prepared and handled under aerobic conditions, which often surprises students as free radicals are…

Synthesis and Characterization of a Layered Manganese Oxide: Materials Chemistry for the Inorganic or Instrumental Methods Lab

ERIC Educational Resources Information Center

Ching, Stanton; Neupane, Ram P.; Gray, Timothy P.

2006-01-01

A three-week laboratory project involving synthesis and characterization of a layered manganese oxide provides an excellent vehicle for teaching important concepts of inorganic chemistry and instrumental methods related to non-molecular systems. Na-birnessite is an easily prepared manganese oxide with a 7 A interlayer spacing and Na[superscript +]…

Scaffolding Students' Skill Development by First Introducing Advanced Techniques through the Synthesis and [superscript 15]N NMR Analysis of Cinnamamides

ERIC Educational Resources Information Center

Shuldburg, Sara; Carroll, Jennifer

2017-01-01

An advanced undergraduate experiment involving the synthesis and characterization of a series of six unique cinnamamides is described. This experiment allows for a progressive mastery of skills students need to tackle more complex NMR structure elucidation problems. Characterization of the products involves IR spectroscopy, GCMS, and proton,…

Synthesis, Characterization, and Secondary Structure Determination of a Silk-Inspired, Self-Assembling Peptide: A Laboratory Exercise for Organic and Biochemistry Courses

ERIC Educational Resources Information Center

Albin, Tyler J.; Fry, Melany M.; Murphy, Amanda R.

2014-01-01

This laboratory experiment gives upper-division organic or biochemistry undergraduate students a comprehensive look at the synthesis, chemical characterization, self-assembly, and secondary structure determination of small, N-acylated peptides inspired by the protein structure of silkworm silk. All experiments can be completed in one 4 h lab…

Synthesis and characterization of 3-ketohexadecanoic acid-1-14-C, DL-3-hydroxyhexadecanoic acid-1-14-C, and trans-2-hexadecenoic acid-1-14-C.

PubMed

Jones, J A; Blecher, M

1966-05-01

The chemical synthesis and characterization of three intermediates in the Beta oxidation of palmitic acid-1-(14)C by rat liver mitochondria, namely, 3-ketohexadecanoic acid-1-(14)C, DL-3-hydroxyhexadecanoic acid-1-(14)C, and trans-2-hexadecenoic acid-1-(14)C, are described.

Biosynthesis of silver nanoparticles by Pseudomonas spp. isolated from effluent of an electroplating industry.

PubMed

Punjabi, Kapil; Yedurkar, Snehal; Doshi, Sejal; Deshapnde, Sunita; Vaidya, Shashikant

2017-08-01

The aim of this study was to isolate and screen bacteria from soil and effluent of electroplating industries for the synthesis of silver nanoparticles and characterize the potential isolate. Soil and effluent of electroplating industries from Mumbai were screened for bacteria capable of synthesizing silver nanoparticles. From two soils and eight effluent samples 20 bacterial isolates were obtained, of these, one was found to synthesize silver nanoparticles. Synthesis of silver nanoparticle by bacteria was confirmed by undertaking characterization studies of nanoparticles that involved spectroscopy and electron microscopic techniques. The potential bacteria was found to be Gram-negative short rods with its biochemical test indicating Pseudomonas spp . Molecular characterization of the isolate by 16S r DNA sequencing was carried out which confirmed its relation to Pseudomonas hibiscicola ATCC 19867. Stable nanoparticles synthesized were 50 nm in size and variable shapes as seen in SEM micrographs. The XRD and FTIR confirmed the crystalline structure of nanoparticles and presence of biomolecules mainly proteins as agents for reduction and capping of nanoparticles. The study demonstrates synthesis of nanoparticles by bacteria from effluent of electroplating industry. This can be used for large scale synthesis of nanoparticles by cost effective and environmentally benign mode of synthesis.

Institute for Atom-Efficient Chemical Transformations Energy Frontier

Science.gov Websites

Synthesis Search Argonne ... Search Argonne Home > Institute for Atom-Efficient Chemical Transformations Synthesis Characterization Computational Studies Evaluation and Mechanisms/Catalytic Experimentation Using

Green synthesis, characterization and evaluation of biocompatibility of silver nanoparticles

NASA Astrophysics Data System (ADS)

Ahamed, Maqusood; Majeed Khan, M. A.; Siddiqui, M. K. J.; AlSalhi, Mohamad S.; Alrokayan, Salman A.

2011-04-01

Although green synthesis of silver nanoparticles (Ag NPs) by various plants and microorganisms has been reported, the potential of plants as biological materials for the synthesis of nanoparticles and their compatibility to biological systems is yet to be fully explored. In this study, we report a simple green method for the synthesis of Ag NPs using garlic clove extract as a reducing and stabilizing agent. In addition to green synthesis, biological response of Ag NPs in human lung epithelial A549 cells was also assessed. Ag NPs were rapidly synthesized using garlic clove extract and the formation of nanoparticles was observed within 30 min. The green synthesized Ag NPs were characterized using UV-vis spectrum, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), X-ray energy-dispersive spectroscopy (EDX) and dynamic light scattering (DLS). Characterization data demonstrated that the particles were crystalline in nature and spherical shaped with an average diameter of 12 nm. Measurements of cell viability, cell membrane integrity and intracellular production of reactive oxygen species have shown that the green synthesized Ag NPs were nontoxic to human lung epithelial A549 cells. This study demonstrated a simple, cost-effective and environmentally benign synthesis of Ag NPs with excellent biocompatibility to human lung epithelial A549 cells. This preliminary in vitro investigation needs to be followed up by future studies with various biological systems.

Synthesis and Characterization of Block Copolymers with Unique Chemical Functionalities and Entropically-Hindering Moieties

DTIC Science & Technology

2017-08-14

Synthesis and Characterization of Sulfonated Amine Block Copolymers for Energy Efficient Applications". Chemical Engineering Symposium, University of...Specialty Separations” Oral Presentation during the 2014 Chemical Engineering Department Symposium (Key Note Speaker), University of Puerto Rico, Mayaguez...Leadership Award in the College of Engineering of the University of Puerto Rico, May, 2015. 3. Distinguished Professor of Chemical Engineering

Facilitating Students' Review of the Chemistry of Nitrogen-Containing Heterocyclic Compounds and Their Characterization through Multistep Synthesis of Thieno[2,3-"b"]Pyridine Derivatives

ERIC Educational Resources Information Center

Liu, Hanlin; Zaplishnyy, Vladimir; Mikhaylichenko, Lana

2016-01-01

A multistep synthesis of thieno[2,3-"b"]pyridine derivatives is described that is suitable for the upper-level undergraduate organic laboratory. This experiment exposes students to various hands-on experimental techniques as well as methods of product characterization such as IR and [superscript 1]H NMR spectroscopy, and…

Synthesis and Characterization of Thin Film Lithium-Ion Batteries Using Polymer Electrolytes

NASA Technical Reports Server (NTRS)

Maranchi, Jeffrey P.; Kumta, Prashant N.; Hepp, Aloysius F.; Raffaelle, Ryne P.

2002-01-01

The present paper describes the integration of thin film electrodes with polymer electrolytes to form a complete thin film lithium-ion battery. Thin film batteries of the type, LiCoO2 [PAN, EC, PC, LiN(CF3SO2)2] SnO2 have been fabricated. The results of the synthesis and characterization studies will be presented and discussed.

Organic Materials as Electrodes for Li-ion Batteries

DTIC Science & Technology

2015-09-04

given for each class of materials. Various macrocycles, their synthesis, characterization and subsequent use in lithium - ion batteries were attempted...macrocycles, their synthesis, characterization and subsequent use in lithium - ion batteries have been attempted to. Lithium -based batteries are at the...organic dye can be used for storing reversibly, both lithium and sodium ions for rechargeable battery applications. In the present study, we have

Synthesis, Characterization, and Multimillion-Atom Simulation of Halogen-Based Energetic Materials for Agent Defeat

DTIC Science & Technology

2013-04-01

DTRA-TR-13-23 Synthesis, Characterization, and Multimillion -Atom Simulation of Halogen-Based Energetic Materials for Agent Defeat Approved for...reagents for the destruction of biologically active materials and a simulation of their reactions on a multimillion atom scale with quantum...explosives for destruction of chemical & biological agents. Multimillion -atom molecular dynamics simulations with quantum mechanical accuracy were

Copper(II)-bis(thiosemicarbazonato) complexes as anti-chlamydial agents.

PubMed

Marsh, James W; Djoko, Karrera Y; McEwan, Alastair G; Huston, Wilhelmina M

2017-09-29

Lipophilic copper (Cu)-containing complexes have shown promising antibacterial activity against a range of bacterial pathogens. To examine the susceptibility of the intracellular human pathogen Chlamydia trachomatis to copper complexes containing bis(thiosemicarbazone) ligands [Cu(btsc)], we tested the in vitro effect of CuII-diacetyl- and CuII-glyoxal-bis[N(4)-methylthiosemicarbazonato] (Cu(atsm) and Cu(gtsm), respectively) on C. trachomatis. Cu(atsm) and to a greater extent, Cu(gtsm), prevented the formation of infectious chlamydial progeny. Impacts on host cell viability and respiration were also observed in addition to the Chlamydia impacts. This work suggests that copper-based complexes may represent a new lead approach for future development of new therapeutics against chlamydial infections, although host cell impacts need to be fully explored. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Analysis and synthesis of abstract data types through generalization from examples

NASA Technical Reports Server (NTRS)

Wild, Christian

1987-01-01

The discovery of general patterns of behavior from a set of input/output examples can be a useful technique in the automated analysis and synthesis of software systems. These generalized descriptions of the behavior form a set of assertions which can be used for validation, program synthesis, program testing and run-time monitoring. Describing the behavior is characterized as a learning process in which general patterns can be easily characterized. The learning algorithm must choose a transform function and define a subset of the transform space which is related to equivalence classes of behavior in the original domain. An algorithm for analyzing the behavior of abstract data types is presented and several examples are given. The use of the analysis for purposes of program synthesis is also discussed.

Low Temperature Synthesis, Chemical and Electrochemical Characterization of LiNi(x)Co(1-x)O2 (0 less than x less than 1)

NASA Technical Reports Server (NTRS)

Nanjundaswamy, K. S.; Standlee, D.; Kelly, C. O.; Whiteley, R. V., Jr.

1997-01-01

A new method of synthesis for the solid solution cathode materials LiNi(x)Co(1-x)O2 (0 less than x less than 1) involving enhanced reactions at temperatures less than or equal to 700 deg. C, between metal oxy-hydroxide precursors MOOH (M = Ni, Co) and Li-salts (Li2CO3, LiOH, and LiNO3) has been investigated. The effects of synthesis conditions and sources of Li, on phase purity, microstructure, and theoretical electrochemical capacity (total M(3+) content) are characterized by powder X-ray diffraction analysis, scanning electron microscopy, chemical analysis and room temperature magnetic susceptibility. An attempt has been made to correlate the electrochemical properties with the synthesis conditions and microstructure.

Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fatimah, Soja Siti, E-mail: soja-sf@upi.edu; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang, Km. 21, Jatinangor; Bahti, Husein H.

2016-02-08

The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, andmore » using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, ({sup 1}H, and {sup 13}C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.« less

Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

NASA Astrophysics Data System (ADS)

Fatimah, Soja Siti; Bahti, Husein H.; Hastiawan, Iwan; Permanasari, Anna

2016-02-01

The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, and using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, (1H, and 13C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.

Synthesis and Characterization of Silver Nanoparticles for an Undergraduate Laboratory

ERIC Educational Resources Information Center

Orbaek, Alvin W.; McHale, Mary M.; Barron, Andrew R.

2015-01-01

The aim of this simple, quick, and safe laboratory exercise is to provide undergraduate students an introduction to nanotechnology using nanoparticle (NP) synthesis. Students are provided two procedures that allow for the synthesis of different yet controlled sizes of silver NPs. After preparing the NPs, the students perform UV-visible…

A cell-based fluorescent assay to detect the activity of AB toxins that inhibit protein synthesis

USDA-ARS?s Scientific Manuscript database

AB-type protein toxins, produced by numerous bacterial pathogens and some plants, elicit a cytotoxic effect involving the inhibition of protein synthesis. To develop an improved method to detect the inhibition of protein synthesis by AB-type toxins, the present study characterized a Vero cell line t...

Social Recognition Memory Requires Two Stages of Protein Synthesis in Mice

ERIC Educational Resources Information Center

Wolf, Gerald; Engelmann, Mario; Richter, Karin

2005-01-01

Olfactory recognition memory was tested in adult male mice using a social discrimination task. The testing was conducted to begin to characterize the role of protein synthesis and the specific brain regions associated with activity in this task. Long-term olfactory recognition memory was blocked when the protein synthesis inhibitor anisomycin was…

Preparation, characterization and catalytic properties of MCM-48 supported tungstophosphoric acid mesoporous materials for green synthesis of benzoic acid

NASA Astrophysics Data System (ADS)

Wu, Hai-Yan; Zhang, Xiao-Li; Chen, Xi; Chen, Ya; Zheng, Xiu-Cheng

2014-03-01

MCM-48 and tungstophosphoric acid (HPW) were prepared and applied for the synthesis of HPW/MCM-48 mesoporous materials. The characterization results showed that HPW/MCM-48 obtained retained the typical mesopore structure of MCM-48, and the textural parameters decreased with the increase loading of HPW. The catalytic oxidation results of benzyl alcohol and benzaldehyde with 30% H2O2 indicated that HPW/MCM-48 was an efficient catalyst for the green synthesis of benzoic acid. Furthermore, 35 wt% HPW/MCM-48 sample showed the highest activity under the reaction conditions.

Preparation, Fabrication, and Evaluation of Advanced Polymeric and Composite Materials

NASA Technical Reports Server (NTRS)

Orwoll, Robert A.

1997-01-01

The thesis titles are given below: physical and mechanical behavior of amorphous poly(arylene ether-co-imidasole)s and poly(arylene ether-co-imidasole) modification epoxies; the requirements of patentability as applied to the chemical arts; fabrication of thermoplastic polymer composite ribbon; blend of reactive diluents with phenylethynyl-terminated arylene ether oligomers; the synthesis, characterization, and application of ether-containing polyimides; the synthesis of reflective and electrically conductive polyimide films via an in-situ self-metalization procedure using silver (I) complexes; the thermal cure of phenylethynyl terminated polyimides and selected model compounds; and the synthesis, characterization, and molecular modeling of cyclic arylene ether oligomers.

Synthesis, characterizations and catalytic activities of CoFe2O4 nanoparticles

NASA Astrophysics Data System (ADS)

Verma, Divya; Sharma, Vikash; Parmar, Sarita; Okram, Gunadhor Singh; Jain, Shubha

2018-05-01

We report the synthesis of CoFe2O4 nanoparticles (NPs) through a novel one-step coprecipitation method. These NPs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared (FTIR), and Raman spectroscopy. These nano ferrites were successfully used for the synthesis of 3, 4-dihydropyrimidin-2(1H)-ones and thiones. They can be easily recovered by simple filtration and their catalytic activity remains nearly unaltered even after 4 consecutive cycles, making them ecofriendly and widely applicable due to their efficiency, ease of handling, and cost effectiveness.

Synthesis and characterization of Au incorporated Alq3 nanowires

NASA Astrophysics Data System (ADS)

Khan, Mohammad Bilal; Ahmad, Sultan; Parwaz, M.; Rahul, Khan, Zishan H.

2018-05-01

We report the synthesis and characterization of pure and Au incorporated Alq3 nanowires. These nanowires are synthesized using thermal vapor transport method. The luminescence intensity of Au incorporated Alq3 nanowires are recorded to be higher than that of pure Alq3 nanowires, which is found to increase with the increase in Au concentration. Fluorescence quenching is also observed when Au concentration is increased beyond the certain limit.

Effects of the synthesis temperature on the crystalline structure and the magnetic properties of cobalt ferrite nanoparticles prepared via coprecipitation

NASA Astrophysics Data System (ADS)

Hutamaningtyas, Evangelin; Utari; Suharyana; Purnama, Budi; Wijayanta, Agung Tri

2016-08-01

The effects of the synthesis temperature on the crystalline structure and the magnetic properties of cobalt ferrite (CoFe2O4) nanoparticles prepared via coprecipitation are discussed. The synthesis was conducted at temperatures of 75 °C, 85 °C and 95 °C. Fourier transform infrared spectroscopy characterization related to a stretching vibration at a wavenumber of 590 cm-1 indicated the formation of a CoFe2O4 metal oxide. In addition, powder X ray diffraction (XRD) characterization proved that the metal oxide was CoFe2O4. Crystallite sizes calculated using the Scherer formula at the strongest peak of the XRD spectra of the samples synthesized at 75 °C, 85 °C and 95 °C were 32 nm, 43 nm and 50.4 nm, respectively. Finally, the results of the vibrating sample magnetometer characterization showed that the saturation magnetization decreased with increasing synthesis temperature, which is related to the dominant preference of Co2+ over Fe3+ cations at the octahedral sites.

Synthesis, characterization, and application of novel biodegradable self-assembled 2-(N-phthalimido) ethyl-palmitate nanoparticles for cancer therapy

NASA Astrophysics Data System (ADS)

Kasoju, Naresh; Bora, Debajeet K.; Bhonde, Ramesh R.; Bora, Utpal

2010-03-01

We report the synthesis of novel biodegradable nanoparticles (NPs) which can kill the cancer cells without any additional drug loading. The NP was a self-assembled form of a phthalimide based conjugate, in which the phthalimide moiety was responsible for the anticancer activity. We describe the synthesis of a novel 2-(N-phthalimido) ethyl palmitate (PHEP-Pal) conjugate and subsequent preparation of NPs by a simple self assembly process. The successful synthesis of conjugate was confirmed by various characterization studies including nuclear magnetic resonance spectroscope, Fourier transform infrared spectroscope, TOF-liquid chromatography mass spectroscope, differential scanning calorimetry, and X-ray diffraction unit. The synthesis, shape, size, and size distribution of PHEP-Pal NPs were determined by transmission electron microscope, atomic force microscope, and dynamic light scattering technique. Finally, cell culture studies using A549 and HeLa cells were done to evaluate the anticancer effect of PHEP-Pal NPs, which demonstrated the potency of these NPs for use in cancer chemotherapy.

Anthrax carbohydrates, synthesis and uses thereof

DOEpatents

Carlson, Russell W.; Boons, Geert-Jan; Quinn, Conrad; Vasan, Mahalakshmi; Wolfert, Margreet A.; Choudhury, Biswa; Kannenberg, Elmar; Leoff, Christine; Mehta, Alok; Saile, Elke; Rauvolfova, Jana; Wilkins, Patricia; Harvey, Alex J.

2013-04-16

The present invention presents the isolation, characterization and synthesis of oligosaccharides of Bacillus anthracis. Also presented are antibodies that bind to such saccharide moieties and various methods of use for such saccharide moieties and antibodies.

Refined Synthesis and Characterization of Controlled Diameter, Narrow Size Distribution Microparticles for Aerospace Research Applications

NASA Technical Reports Server (NTRS)

Tiemsin, Pacita I.; Wohl, Christopher J.

2012-01-01

Flow visualization using polystyrene microspheres (PSL)s has enabled researchers to learn a tremendous amount of information via particle based diagnostic techniques. To better accommodate wind tunnel researchers needs, PSL synthesis via dispersion polymerization has been carried out at NASA Langley Research Center since the late 1980s. When utilizing seed material for flow visualization, size and size distribution are of paramount importance. Therefore, the work described here focused on further refinement of PSL synthesis and characterization. Through controlled variation of synthetic conditions (chemical concentrations, solution stirring speed, temperature, etc.) a robust, controllable procedure was developed. The relationship between particle size and salt concentration, MgSO4, was identified enabling the determination of PSL diameters a priori. Suggestions of future topics related to PSL synthesis, stability, and size variation are also described.

Immunologic and Genetic Selection of Adenovirus Vaccine Strains: Synthesis and Characterization of Adenovirus Antigens.

DTIC Science & Technology

1984-08-01

exhibited strikingly different chromatographic characteristics. 2. Effect of proflavine on the synthesis of adenovirus, type 5, and associated soluble...antigens. The synthesis of type 5 adenovirus in HeLa cells was suppressed to a considerable extent by low concentrations of proflavine , an acridine dye...chemical. Addition of proflavine to infected cells at different times during the virus growth cycle revealed that the processes leading to the synthesis

Synthesis and characterization of bis-thiourea having amino acid derivatives

NASA Astrophysics Data System (ADS)

Fakhar, Imran; Yamin, Bohari M.; Hasbullah, Siti Aishah

2016-11-01

In this article four new symmetric bis-thiourea derivatives having amino acid linkers were reported with good yield. Isophthaloyl dichloride was used as spacer and L-alanine, L-aspartic acid, L-phenylalanine and L-glutamic acid were used as linkers. Bis-thiourea derivatives were prepared from relatively stable isophthaloyl isothiocyanate intermediate. Newly synthesized bis-thiourea derivatives were characterized by FTIR, H-NMR, 13C-NMR and CHNS-O elemental analysis techniques. Characterization data was in good agreement with the expected derivatives, hence confirmed the synthesis of four new derivatives of bis-thiourea having amino acids.

Witting Reaction Using a Stabilized Phosphorus Ylid: An Efficient and Stereoselective Synthesis of Ethyl Trans-Cinnamate

ERIC Educational Resources Information Center

Speed, Traci J.; Mclntyre, Jean P.; Thamattoor, Dasan M.

2004-01-01

An instructive experiment for the synthesis of ethyl trans-cinnamate, a pleasant smelling ester used in perfumery and flavoring by the reaction of benzaldehyde with the stable ylid triphenylphosphorane is described. The synthesis, workup and characterization of trans-cinnamate may be accomplished in a single laboratory session with commonly…

Synthesis, Surface Studies, Composition and Structural Characterization of CdSe, Core/Shell, and Biologically Active Nanocrystals

PubMed Central

Rosenthal, Sandra J.; McBride, James; Pennycook, Stephen J.; Feldman, Leonard C.

2011-01-01

Nanostructures, with their very large surface to volume ratio and their non-planar geometry, present an important challenge to surface scientists. New issues arise as to surface characterization, quantification and interface formation. This review summarizes the current state of the art in the synthesis, composition, surface and interface control of CdSe nanocrystal systems, one of the most studied and useful nanostructures. PMID:21479151

Incorporation of the zosteric sodium salt in silica nanocapsules: synthesis and characterization of new fillers for antifouling coatings

NASA Astrophysics Data System (ADS)

Ruggiero, Ludovica; Crociani, Laura; Zendri, Elisabetta; El Habra, Naida; Guerriero, Paolo

2018-05-01

In the last decade many commercial biocides were gradually banned for toxicity. This work reports, for the first time, the synthesis and characterization of silica nanocontainers loaded with a natural product antifoulant (NPA), the zosteric sodium salt which is a non-commercial and environmentally friendly product with natural origin. The synthesis approach is a single step dynamic self-assembly with tetraethoxysilane (TEOS) as silica precursor. Unlike conventional mesoporous silica nanoparticles, the structure of these silica nanocontainers provides loading capacity and allows prolonged release of biocide species. The obtained nanocapsules have been characterized morphologically by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The encapsulation was checked by FTIR ATR spectroscopy and thermogravimetric analyses. The results of the release studies show the great potential of the here presented newly developed nanofillers in all applications where a controlled release of non-toxic and environmentally friendly biocides is required.

Nyctanthes arbortristis mediated synthesis of silver nanoparticles: Cytotoxicity assay against THP-1 human leukemia cell lines

NASA Astrophysics Data System (ADS)

Kumari, Priti; Kumari, Niraj; Jha, Anal K.; Singh, K. P.; Prasad, K.

2018-05-01

Green synthesis, characterizations and applications of nanoparticles have become an important branch of nanotechnology now a day. In this paper, green synthesis of silver nanoparticles (AgNPs) using the aqueous extract of Nyctanthes arbortristis as a reducing and stabilizing agent, has been discussed. Present synthetic method is very handy, cost-effective and reproducible. Formation of AgNPs was characterized by X-ray diffraction, dynamic light scattering, scanning electron microscopy and UV-visible spectroscopy techniques. The phytochemicals responsible for nano-transformation were principally flavonoids, phenols and glycosides present in the leaves. Further, the dose dependent cytotoxicity assay of biosynthesized AgNPs against THP-1 human leukemia cell lines showed the encouraging results.

Synthesis and Primary Characterization of Self-Assembled Peptide-Based Hydrogels

PubMed Central

Nagarkar, Radhika P.; Schneider, Joel P.

2009-01-01

Summary Hydrogels based on peptide self-assembly form an important class of biomaterials that find application in tissue engineering and drug delivery. It is essential to prepare peptides with high purity to achieve batch-to-batch consistency affording hydrogels with reproducible properties. Automated solid-phase peptide synthesis coupled with optimized Fmoc (9-fluorenylmethoxycarbonyl) chemistry to obtain peptides in high yield and purity is discussed. Details of isolating a desired peptide from crude synthetic mixtures and assessment of the peptide’s final purity by high-performance liquid chromatography and mass spectrometry are provided. Beyond the practical importance of synthesis and primary characterization, techniques used to investigate the properties of hydrogels are briefly discussed. PMID:19031061

Automated synthesis of arabinoxylan-oligosaccharides enables characterization of antibodies that recognize plant cell wall glycans.

PubMed

Schmidt, Deborah; Schuhmacher, Frank; Geissner, Andreas; Seeberger, Peter H; Pfrengle, Fabian

2015-04-07

Monoclonal antibodies that recognize plant cell wall glycans are used for high-resolution imaging, providing important information about the structure and function of cell wall polysaccharides. To characterize the binding epitopes of these powerful molecular probes a library of eleven plant arabinoxylan oligosaccharides was produced by automated solid-phase synthesis. Modular assembly of oligoarabinoxylans from few building blocks was enabled by adding (2-naphthyl)methyl (Nap) to the toolbox of orthogonal protecting groups for solid-phase synthesis. Conjugation-ready oligosaccharides were obtained and the binding specificities of xylan-directed antibodies were determined on microarrays. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SbCl3-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

PubMed Central

2011-01-01

Summary A simple, efficient, and mild procedure for a solvent-free one-step synthesis of various 4,4′-diaminotriarylmethane derivatives in the presence of antimony trichloride as catalyst is described. Triarylmethane derivatives were prepared in good to excellent yields and characterized by elemental analysis, FTIR, 1H and 13C NMR spectroscopic techniques. The structural and vibrational analysis were investigated by performing theoretical calculations at the HF and DFT levels of theory by standard 6-31G*, 6-31G*/B3LYP, and B3LYP/cc-pVDZ methods and good agreement was obtained between experimental and theoretical results. PMID:21445373

Reaction of the Anticancer Organometallic Ruthenium Compound, [(η6-p-Cymene)Ru(ATSC)Cl]PF6 with Human Serum Albumin

PubMed Central

Beckford, Floyd A.

2010-01-01

The reaction of [(η6-p-cymene)Ru(ATSC)Cl]PF6 (ATSC = 9-anthraldehyde thiosemicarbazone) with human serum albumin was investigated at different temperatures using fluorescence and infrared spectrophotometry. The binding constant, K, for the reaction was determined using a number of different methods. Using a modified Stern-Volmer equation, K was determined to be 9.09 × 104, 12.1 × 104, and 13.1 × 104 M−1 at 293 K, 298 K, and 308 K, respectively. A thermodynamic analysis showed that the reaction is spontaneous with ΔG being negative. The enthalpy of reaction ΔH = 16.5kJ mol−1 and the entropy of reaction ΔS = 152 Jmol−1K−1. The values of ΔH and ΔS suggest that hydrophobic forces are dominant in the mode of interaction and that the process is mostly entropy driven. PMID:20671814

Analysis and synthesis of abstract data types through generalization from examples

NASA Technical Reports Server (NTRS)

Wild, Christian

1987-01-01

The discovery of general patterns of behavior from a set of input/output examples can be a useful technique in the automated analysis and synthesis of software systems. These generalized descriptions of the behavior form a set of assertions which can be used for validation, program synthesis, program testing, and run-time monitoring. Describing the behavior is characterized as a learning process in which the set of inputs is mapped into an appropriate transform space such that general patterns can be easily characterized. The learning algorithm must chose a transform function and define a subset of the transform space which is related to equivalence classes of behavior in the original domain. An algorithm for analyzing the behavior of abstract data types is presented and several examples are given. The use of the analysis for purposes of program synthesis is also discussed.

Synthesis and characterization of novel polymers from non-petroleum sources for use in enhanced oil recovery. Progress report, July 1,1981-June 30, 1982. [Starch-g-polyacrylamide; polysaccharides and acrylamides; Schardinger-. beta. -dextrin and acrylamide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, G.B.; Hogen-Esch, T.E.

1982-01-01

Annual progress reports are presented for the following tasks: (1) synthesis and structural characterization of polysaccharide-based graft copolymers for use in tertiary oil recovery; (2) determination of physical properties of the polymers and their solutions, and screening of the polymers to determine their utility in oil recovery. Over the past year synthesis and characterization studies have continued in the following five areas: (1) starch-g-polyacrylamide (ST-g-PAM) copolymers; (2) graft copolymers of other polysaccharides (gum arabic, yellow dextrin, pectin, okra polysaccharide, and guar gum) and acrylamides; (3) a naturally occurring polysaccharide extracted from okra (Akro); (4) graft copolymers of Schardinger-..beta..-dextrin and acrylamidemore » (SD-g-PAM); (5) chemical degradation of ST-g-PAM and SD-g-PAM copolymers. For physical properties studies, the following areas were investigated: (1) characterization of copolymers by ultracentrifugation, size exclusion chromatography and nucleophore membrane filtration; (2) rheological studies on copolymers; and (3) statistical analysis of variables in graft copolymerization. (ATT)« less

Synthesis and Characterization of C-Cinnamal Calix [4] Resorsinarena from Cinnamon Oil Waste West Sumatra

NASA Astrophysics Data System (ADS)

Etika, S. B.; Nasra, E.; Rilaztika, I.

2018-04-01

Synthesis and characterization of compound C-Cinnamal Calix [4] Resorsinarena (CCCR) of cinnamon oil waste have been done. This study was aimed to synthesis and characterize C-Cinnamal Calix [4] Resorsinarena from cinnamaldehyde violated cinnamon oil waste. C-Cinnamal Calix [4] Resorsinarena was synthesized by electrophilic substitution reaction of cinnamaldehyde isolated by the acid and resorcinol at 77oC temperature for 2 hour. The data analysis spectrum UV-VIS and FT-IR showed that the compound isolated cinnamaldehyde same as pure cinnamaldehyde compound. The characterization of C-Cinnamal Calix [4] Resorsinarena in the form of reddish-colored solids with melting point 3580C by using UV-VIS showed the presence of double bond, FT-IR showed the absorption at the wave number 3323,94 cm-1 indicating the ‑OH group, the wave number 1610,94 cm-1 showed the vibration C=C, the strong region absorption of 1500,86 cm-1 indicating the presence of an aromatic ring, the at 1442,88 cm-1 wave number indicating the presence of CH3.

Interfacial Effects and Organization of Inorganic-Organic Composite Solids.

DTIC Science & Technology

1998-05-20

SITU NMR STUDY OF THE HYDROTHERMAL SYNTHESIS OF TEMPLATE-MEDIATED MICROPOROUS ALUMINOPHOSPHATE MATERIALS, Conne M Gersrdin, Pnnccton Univ, Dept...quantitatively characterize the hydrothermal medium while the synthesis proceeds can yield to a better description of the different steps of the...Inorganic-Organic Composite Solids," focused on recent applications in materials synthesis that use structure-directing agents and self-assembly

The Synthesis and Characterization of Rouaite, a Copper Hydroxy Nitrate: An Integrated First-Year Laboratory Project

ERIC Educational Resources Information Center

Bushong, Elizabeth J.; Yoder, Claude H.

2009-01-01

The synthesis and analysis of a copper hydroxy nitrate provides an exposure to a simple ionic synthesis, qualitative analysis of copper and nitrate, two gravimetric analyses (copper and nitrate), one volumetric analysis (hydroxide), and a colorimetric analysis (copper). The results allow the student to determine the identity of the double salt and…

The Synthesis of "N"-Benzyl-2-Azanorbornene via Aqueous Hetero Diels-Alder Reaction: An Undergraduate Project in Organic Synthesis and Structural Analysis

ERIC Educational Resources Information Center

Sauvage, Xavier; Delaude, Lionel

2008-01-01

The synthesis of "N"-benzyl-2-azanorbornene via aqueous hetero Diels-Alder reaction of cyclopentadiene and benzyliminium chloride formed in situ from benzylamine hydrochloride and formaldehyde is described. Characterization of the product was achieved by IR and NMR spectroscopies. The spectral data acquired are thoroughly discussed. Numerous…

Modal control theory and application to aircraft lateral handling qualities design

NASA Technical Reports Server (NTRS)

Srinathkumar, S.

1978-01-01

A multivariable synthesis procedure based on eigenvalue/eigenvector assignment is reviewed and is employed to develop a systematic design procedure to meet the lateral handling qualities design objectives of a fighter aircraft over a wide range of flight conditions. The closed loop modal characterization developed provides significant insight into the design process and plays a pivotal role in the synthesis of robust feedback systems. The simplicity of the synthesis algorithm yields an efficient computer aided interactive design tool for flight control system synthesis.

Graphene Synthesis and Characterization

DTIC Science & Technology

2015-04-08

for synthesis electrochemical. - A Scanning Electron Microscope (SEM) (EVO MA from Carl Zeiss). 6 6. RESULTS AND...5, 2332-2339, 2011, High-Quality Thin graphene films from fast electrochemical exfoliation. [13] Da Hee Jung , Cheong Kang, Ji Eun Nam, Jin-Seok Kim

Copolymers of polyaniline and poly-o-toluidine: Electrochemical synthesis and characterization

NASA Astrophysics Data System (ADS)

Yadav, Pooja C.; Deshmukh, Megha A.; Patil, Harshada K.; Bodkhe, Gajanan A.; Sayyad, Pasha W.; Ingle, Nikesh N.; Shirsat, Mahendra D.

2018-05-01

In the present study we have reported Electrochemical polymerization of poly(Aniline) (PANI), Poly(O-Toluidine) (POT) and poly(Aniline-co-O-Toluidine) (PAOT) copolymers. Electrochemical Synthesis of PANI, POT and Poly(Aniline-co-O-Toluidine) was done by using Cyclic Voltammetry technique. The morphological study done by Atomic Force Microscopy (AFM) which shows that formation of uniform granular structure and topographic changes in each respective thin film. Spectroscopic characterization was done by FTIR spectroscopy. The FT-IR study revealed the formation of PANI/POT/Poly(Aniline co O-Toluidine) with a absorption band are reported. For structural information done by X-ray diffraction(XRD) Characterization.

Novel synthesis and characterization of five isomers of (C(70))(2) fullerene dimers.

PubMed

Forman, Grant S; Tagmatarchis, Nikos; Shinohara, Hisanori

2002-01-16

The synthesis and characterization of dimers and polymers, wherein two or more cages are linked, represent an important frontier in the chemistry of fullerene derivatives. A simple and novel method that requires no special apparatus has been developed for the dimerization of [70]fullerene to (C70)2. Upon grinding [70]fullerene in a mortar and pestle in the presence of K2CO3, five structural isomers of (C70)2 have been produced. These isomers are separated from one another via high performance liquid chromatography and are characterized by 13C NMR, UV-vis-NIR absorption and mass spectroscopy.

Transition metal complexes of quinolino[3,2-b]benzodiazepine and quinolino[3,2-b]benzoxazepine: synthesis, characterization, and antimicrobial studies.

PubMed

Basavaraju, B; Naik, Halehatty S Bhojya; Prabhakara, Mustur C

2007-01-01

The synthesis and characterization of title complexes of the ligand Quinolino[3,2-b]benzodiazepine (QBD) and Quinolino[3,2-b]benzoxazepine (QBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, H1 NMR, and UV-visible studies. They have the stoichiometry [ML2C12], where M=Co(II)/Ni(II), L=QBD/QBO, and [MLC12], where M=Zn(II)/Cd(II), L=QBD/QBO. The antibacterial and antifungal activity of the metal complexes has been investigated. The complexes were found to have higher antimicrobial activity than the parent ligand.

Synthesis, characterization and optical properties of novel star azo-oligomers containing well-defined oligo(ethylene glycol) segments

NASA Astrophysics Data System (ADS)

González-Gómez, Roberto; Vonlanthen, Mireille; Ortíz-Palacios, Jesús; Ruiu, Andrea; Valderrama-García, Bianca X.; Rivera, Ernesto

2018-05-01

In this work, the synthesis and characterization of a series of star azo-oligomers bearing amino, amino-methoxy, amino-nitro and amino-cyano substituted azobenzene units and oligo(ethylene glycol) segments is reported. The full characterization of the obtained compounds was achieved by FTIR, 1H and 13C NMR spectroscopies, and their molecular weights were determined by MALDI-TOF mass spectrometry. The optical properties of these compounds were studied by absorption spectroscopy in solution. Finally, light polarized microscopy experiments as a function of the temperature were performed in order to study the liquid-crystalline behavior of these star azo-oligomers.

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

PubMed

Patil, Maheshkumar Prakash; Kim, Gun-Do

2017-01-01

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

Linear and Nonlinear Optical Response in Silver Nanoclusters: Insight from a Computational Investigation (Postprint)

DTIC Science & Technology

2016-01-05

applying DFT and TDDFT. Synthesis and optical characterization of the silver glutathione nanoclusters Ag32(SG)19 and Ag15(SG)11 were recently reported by...Ag15. Synthesis and optical characterization of the Ag32(SG)19, Ag31(SG)19, and Ag15(SG)11 silver glutathione nanoclusters have been reported.19,20 A...Barnett, R. N.; Monahan, B. M.; Kirschbaum, K.; Griffith, W. P.; Whetten, R. L.; Landman, U.; Bigioni, T. P. Ultrastable Silver Nanoparticles . Nature

Synthesis and characterization of nickel oxide/graphene sheet/graphene ribbon composite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lavanya, J.; Gomathi, N., E-mail: sivakumar.gomathi@gmail.com

2016-04-13

A novel and simple hydrothermal synthesis of nickel oxide (NiO)/graphene sheets (GNS)/graphene ribbon (GR) hybrid material is reported for the first time. The crystalline property and surface morphology of NiO/GNS/GR (NiO/HG) hybrid material is characterized by X-ray diffraction, Raman spectroscopy and Transmission electron spectroscopy. The fast electron transfer of GNS/GR along with NiO contributes an excellent electrochemical performance in the field of non-enzymatic glucose sensor.

Rapid Multistep Synthesis of 1,2,4-Oxadiazoles in a Single Continuous Microreactor Sequence

PubMed Central

Grant, Daniel; Dahl, Russell; Cosford, Nicholas D. P.

2009-01-01

A general method for the synthesis of bis-substituted 1,2,4-oxadiazoles from readily available arylnitriles and activated carbonyls in a single continuous microreactor sequence is described. The synthesis incorporates three sequential microreactors to produce 1,2,4-oxadiazoles in ~30 min in quantities (40–80 mg) sufficient for full characterization and rapid library supply. PMID:18687005

Cardiac hypoxia imaging: second-generation analogues of 64Cu-ATSM.

PubMed

Handley, Maxwell G; Medina, Rodolfo A; Mariotti, Erika; Kenny, Gavin D; Shaw, Karen P; Yan, Ran; Eykyn, Thomas R; Blower, Philip J; Southworth, Richard

2014-03-01

Myocardial hypoxia is an attractive target for diagnostic and prognostic imaging, but current approaches are insufficiently sensitive for clinical use. The PET tracer copper(II)-diacetyl-bis(N4-methylthiosemicarbazone) ((64)Cu-ATSM) has promise, but its selectivity and sensitivity could be improved by structural modification. We have therefore evaluated a range of (64)Cu-ATSM analogs for imaging hypoxic myocardium. Isolated rat hearts (n = 5/group) were perfused with normoxic buffer for 30 min and then hypoxic buffer for 45 min within a custom-built triple-γ-detector system to quantify radiotracer infusion, hypoxia-dependent cardiac uptake, and washout. A 1-MBq bolus of each candidate tracer (and (18)F-fluoromisonidazole for comparative purposes) was injected into the arterial line during normoxia, and during early and late hypoxia, and their hypoxia selectivity and pharmacokinetics were evaluated. The in vivo pharmacokinetics of promising candidates in healthy rats were then assessed by PET imaging and biodistribution. All tested analogs exhibited hypoxia sensitivity within 5 min. Complexes less lipophilic than (64)Cu-ATSM provided significant gains in hypoxic-to-normoxic contrast (14:1 for (64)Cu-2,3-butanedione bis(thiosemicarbazone) (ATS), 17:1 for (64)Cu-2,3-pentanedione bis(thiosemicarbazone) (CTS), 8:1 for (64)Cu-ATSM, P < 0.05). Hypoxic first-pass uptake was 78.2% ± 7.2% for (64)Cu-ATS and 70.7% ± 14.5% for (64)Cu-CTS, compared with 63.9% ± 11.7% for (64)Cu-ATSM. Cardiac retention of (18)F-fluoromisonidazole increased from 0.44% ± 0.17% during normoxia to 2.24% ± 0.08% during hypoxia. In vivo, normoxic cardiac retention of (64)Cu-CTS was significantly lower than that of (64)Cu-ATSM and (64)Cu-ATS (0.13% ± 0.02% vs. 0.25% ± 0.04% and 0.24% ± 0.03% injected dose, P < 0.05), with retention of all 3 tracers falling to less than 0.7% injected dose within 6 min. (64)Cu-CTS also exhibited lower uptake in liver and lung. (64)Cu-ATS and (64)Cu-CTS exhibit better cardiac hypoxia selectivity and imaging characteristics than the current lead hypoxia tracers, (64)Cu-ATSM and (18)F-fluoromisonidazole.

Green synthesis of BiVO4 nanorods via aqueous extracts of Callistemon viminalis

NASA Astrophysics Data System (ADS)

Mohamed, H. E. A.; Sone, B. T.; Fuku, X. G.; Dhlamini, M. S.; Maaza, M.

2018-05-01

Nowadays, the development of efficient green chemistry methods for synthesis of metal oxides nanoparticles has become a major focus of researchers. These methods are being investigated in order to find an eco-friendly technique for production of well-characterized nanoparticles. In this contribution we report for the first time, the synthesis and structural characterization of n-type Bismuth vanadate (BiVO4) nanoparticles using aqueous extracts of Callistemon viminalis as a chelating agent. To ascertain the formation of BiVO4, X-Ray diffraction analysis (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), Electron Dispersion X-ray Spectroscopy (EDS), Fourier Transform Infra-red Spectroscopy (FTIR), and Photoluminescence spectroscopy (PL) were carried out.

Synthesis, characterization, and photocatalytic properties of core/shell mesoporous silica nanospheres supporting nanocrystalline titania

NASA Astrophysics Data System (ADS)

Cendrowski, K.; Chen, X.; Zielinska, B.; Kalenczuk, R. J.; Rümmeli, M. H.; Büchner, B.; Klingeler, R.; Borowiak-Palen, E.

2011-11-01

The facile bulk synthesis of silica nanospheres makes them an attractive support for the transport of chemical compounds such as nanocrystalline titanium dioxide. In this contribution we present a promising route for the synthesis of mesoporous silica nanospheres (m-SiO2) with diameter in range 200 nm, which are ideal supports for nanocrystalline titanium dioxide (TiO2). The detailed microscopic and spectroscopic characterizations of core/shell structure (m-SiO2/TiO2) were conducted. Moreover, the photocatalytic potential of the nanostructures was investigated via phenol decomposition and hydrogen generation. A clear enhancement of photoactivity in both reactions as compared to commercial TiO2-Degussa P25 catalyst is detected.

Effects of ultrasonic treatment on zeolite NaA synthesized from by-product silica.

PubMed

Vaičiukynienė, Danutė; Kantautas, Aras; Vaitkevičius, Vitoldas; Jakevičius, Leonas; Rudžionis, Žymantas; Paškevičius, Mantas

2015-11-01

The synthesis of zeolite NaA from silica by-product was carried out in the presence of 20 kHz ultrasound at room temperature. Zeolites obtained in this type of synthesis were compared to zeolites obtained by performing conventional static syntheses under similar conditions. The sonication effects on zeolite NaA synthesis were characterized by phase identification, crystallinity etc. The effects of different parameters such as crystallization time and initial materials preparation methods on the crystallinity and morphology of the synthesized zeolites were investigated. The final products were characterized by XRD and FT-IR. It was possible to obtain crystalline zeolite NaA from by-product silica in the presence of ultrasound. Copyright © 2015 Elsevier B.V. All rights reserved.

Matrix Synthesis and Characterization

NASA Technical Reports Server (NTRS)

1984-01-01

The role of NASA in the area of composite material synthesis; evaluation techniques; prediction analysis techniques; solvent-resistant tough composite matrix; resistance to paint strippers; acceptable processing temperature and pressure for thermoplastics; and the role of computer modeling and fiber interface improvement were discussed.

Obtaining and characterization of La0.8Sr0.2CrO3 perovskite by the combustion method

NASA Astrophysics Data System (ADS)

Morales Rivera, A. M.; Gómez Cuaspud, J. A.; López, E. Vera

2017-01-01

This research is focused on the synthesis and characterization of a perovskite oxide based on La0.8Sr0.2CrO3 system by the combustion method. The material was obtained in order to contribute to analyse the effect of synthesis route in the obtaining of advanced anodic materials for solid oxide fuel cells (SOFC). The obtaining of solid was achieved starting from corresponding nitrate dissolutions, which were polymerized by temperature effect in presence of citric acid. The solid precursor as a foam citrate was characterized by infrared (FTIR) and ultraviolet (UV) spectroscopy, confirming the effectiveness in synthesis process. The solid was calcined in oxygen atmosphere at 800°C and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive of X-ray spectroscopy (EDX) and solid state impedance spectroscopy (IS). Results confirm the obtaining of an orthorhombic solid with space group Pnma (62) and cell parameters a=5.4590Å, b=7.7310Å and c=5.5050Å. At morphological level the solid showed a heterogeneous distribution with an optimal correspondence with proposed and obtained stoichiometry. The electrical characterization, confirm a semiconductor behaviour with a value of 2.14eV Band-gap according with previous works.

Tough Composite Materials

NASA Technical Reports Server (NTRS)

Vosteen, L. F. (Compiler); Johnson, N. J. (Compiler); Teichman, L. A. (Compiler)

1984-01-01

Papers and working group summaries are presented which address composite material behavior and performance improvement. Topic areas include composite fracture toughness and impact characterization, constituent properties and interrelationships, and matrix synthesis and characterization.

Synthesis and characterization of TiO₂ and TiO₂/Ag for use in photodegradation of methylviologen, with kinetic study by laser flash photolysis.

PubMed

Ramos, Dayana Doffinger; Bezerra, Paula C S; Quina, Frank H; Dantas, Renato F; Casagrande, Gleison A; Oliveira, Silvio C; Oliveira, Márcio R S; Oliveira, Lincoln C S; Ferreira, Valdir S; Oliveira, Samuel L; Machulek, Amilcar

2015-01-01

This paper reports the synthesis, characterization, and application of TiO2 and TiO2/Ag nanoparticles for use in photocatalysis, employing the herbicide methylviologen (MV) as a substrate for photocatalytic activity testing. At suitable metal to oxide ratios, increases in silver surface coating on TiO2 enhanced the efficiency of heterogeneous photocatalysis by increasing the electron transfer constant. The sol-gel method was used for TiO2 synthesis. P25 TiO2 was the control material. Both oxides were subjected to the same silver incorporation process. The materials were characterized by conventional spectroscopy, SEM micrography, X-ray diffraction, calculation of surface area per mass of catalyst, and thermogravimetry. Also, electron transfers between TiO2 or TiO2/Ag and MV in the absence and presence of sodium formate were investigated using laser flash photolysis. Oxides synthesized with 2.0 % silver exhibited superior photocatalytic activity for MV degradation.

Enhanced metal loading in SBA-15-type catalysts facilitated by salt addition. Synthesis, characterization and catalytic epoxide alcoholysis activity of molybdenum incorporated porous silica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Budhi, Sridhar; Peeraphatdit, Chorthip; Pylypenko, Svitlana

2014-02-07

We report a novel method to increase the metal loading in SBA-15 silica matrix via direct synthesis. It was demonstrated through the synthesis and characterization of a series of molybdenum containing SBA-15 mesoporous silica catalysts prepared with and without diammonium hydrogen phosphate (DHP) as an additive. Catalysts prepared with DHP show a 2–3 times increase in incorporation of molybdenum in the silica matrix and pore size enlargement. The synthesized catalysts were characterized using nitrogen sorption, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma–optical emission spectroscopy (ICP–OES). Themore » catalytic activity of catalysts prepared with DHP for alcoholysis of epoxides was superior than the catalyst prepared without DHP. Alcoholysis of epoxides was demonstrated for a range of alcohols and epoxides under ambient conditions in as little as 30 min with high selectivity.« less

Synthesis of Silver and Gold Nanoparticles Using Antioxidants from Blackberry, Blueberry, Pomegranate, and Turmeric Extracts

EPA Science Inventory

Greener synthesis of Ag and Au nanoparticles is described using antioxidants from blackberry, blueberry, pomegranate, and turmeric extracts. The synthesized particles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HR...

Materials-by-design: computation, synthesis, and characterization from atoms to structures

NASA Astrophysics Data System (ADS)

Yeo, Jingjie; Jung, Gang Seob; Martín-Martínez, Francisco J.; Ling, Shengjie; Gu, Grace X.; Qin, Zhao; Buehler, Markus J.

2018-05-01

In the 50 years that succeeded Richard Feynman’s exposition of the idea that there is ‘plenty of room at the bottom’ for manipulating individual atoms for the synthesis and manufacturing processing of materials, the materials-by-design paradigm is being developed gradually through synergistic integration of experimental material synthesis and characterization with predictive computational modeling and optimization. This paper reviews how this paradigm creates the possibility to develop materials according to specific, rational designs from the molecular to the macroscopic scale. We discuss promising techniques in experimental small-scale material synthesis and large-scale fabrication methods to manipulate atomistic or macroscale structures, which can be designed by computational modeling. These include recombinant protein technology to produce peptides and proteins with tailored sequences encoded by recombinant DNA, self-assembly processes induced by conformational transition of proteins, additive manufacturing for designing complex structures, and qualitative and quantitative characterization of materials at different length scales. We describe important material characterization techniques using numerous methods of spectroscopy and microscopy. We detail numerous multi-scale computational modeling techniques that complements these experimental techniques: DFT at the atomistic scale; fully atomistic and coarse-grain molecular dynamics at the molecular to mesoscale; continuum modeling at the macroscale. Additionally, we present case studies that utilize experimental and computational approaches in an integrated manner to broaden our understanding of the properties of two-dimensional materials and materials based on silk and silk-elastin-like proteins.

Synthesis and Oxidation of Silver Nano-particles

DTIC Science & Technology

2011-01-01

solution (20%wt propyl alcohol, 5%wt hydrochloric acid and 5%wt stannous chloride in water). Scheme 1b and c illustrate the sensitization and silver... Synthesis and Oxidation of Silver Nano-particles Hua Qi*, D. A. Alexson, O.J. Glembocki and S. M. Prokes* Electronics Science and Technology...energy dispersive x-ray (EDX) techniques. The results Quantum Dots and Nanostructures: Synthesis , Characterization, and Modeling VIII, edited by Kurt

Cross cultural translation and adaptation to Brazilian Portuguese of the Hearing Implant Sound Quality Index Questionnaire - (HISQUI19).

PubMed

Caporali, Priscila Faissola; Caporali, Sueli Aparecida; Bucuvic, Érika Cristina; Vieira, Sheila de Souza; Santos, Zeila Maria; Chiari, Brasília Maria

2016-01-01

Translation and cross-cultural adaptation of the instrument Hearing Implant Sound Quality Index (HISQUI19), and characterization of the target population and auditory performance in Cochlear Implant (CI) users through the application of a synthesis version of this tool. Evaluations of conceptual, item, semantic and operational equivalences were performed. The synthesis version was applied as a pre-test to 33 individuals, whose final results characterized the final sample and performance of the questionnaire. The results were analyzed statistically. The final translation (FT) was back-translated and compared with the original version, revealing a minimum difference between items. The changes observed between the FT and the synthesis version were characterized by the application of simplified vocabulary used on a daily basis. For the pre-test, the average score of the interviewees was 90.2, and a high level of reliability was achieved (0.83). The translation and cross-cultural adaptation of the HISQUI19 questionnaire showed suitability for conceptual, item, semantic and operational equivalences. For the sample characterization, the sound quality was classified as good with better performance for the categories of location and distinction of sound/voices.

Synthesis, characterization and wound healing imitation of Fe3O4 magnetic nanoparticle grafted by natural products

NASA Astrophysics Data System (ADS)

Pala, Sravan Kumar

This research focused on the study of the core-shelled magnetic nanomaterials derived from a colloidal chemistry. The goals are four-fold: (1) synthesis of Fe3O4MNMs using colloidal chemistry. The Fe 3O4 MNMs were then grafted with extracts derived from natural products, namely Olecraceavar italica (broccoli), Boletus edulis (mushroom)and Solanum lycopersicum (tomato);(2)characterization of natural products by chromatography and mass spectrometry;(3) characterization of MNMs to determine their crystallinity, morphological and elemental composition by the state-of-the-art instruments; and (4) biological evaluation using Gram-negative and Gram-positive bacteria. The approach provides advantages to precisely control the composition and homogeneity. The second advantage of the colloidal chemistry is its user friendliness and feasibility. Due to the nature of the natural products, the compatibility of MNM is anticipated to be enhanced.In this chapter, the nanomaterials will be discussed from four perspectives,§1.1 Nanotechnology (§1.1), §1.2 Synthesis of nanomaterials; §1.3 The natural product extract,; §1.4 Characterization of nanomaterials; and §1.5Biological application of nanomaterials.Fig. 1 summarized the overarching goals of this study.

Transition Metal Complexes of Quinolino[3,2-b]benzodiazepine and Quinolino[3,2-b]benzoxazepine: Synthesis, Characterization, and Antimicrobial Studies

PubMed Central

Basavaraju, B.; Bhojya Naik, Halehatty S.; Prabhakara, Mustur C.

2007-01-01

The synthesis and characterization of title complexes of the ligand Quinolino[3,2-b]benzodiazepine (QBD) and Quinolino[3,2-b]benzoxazepine (QBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, H1 NMR, and UV-visible studies. They have the stoichiometry [ML2C12], where M=Co(II)/Ni(II), L=QBD/QBO, and [MLC12], where M=Zn(II)/Cd(II), L=QBD/QBO. The antibacterial and antifungal activity of the metal complexes has been investigated. The complexes were found to have higher antimicrobial activity than the parent ligand. PMID:18273383

Synthesis and Electrochemical Properties Characterization of SnO2-coated LiNi1/3Co1/3Mn1/3O2 Cathode Material for Lithium Ion Batteries

DTIC Science & Technology

2009-01-01

Synthesis and electrochemical properties characterization of SnO2-coated LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries Ping Yang...electrochemical properties characterization of SnO2-coated LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries 5a. CONTRACT NUMBER 5b. GRANT NUMBER...electrochemical reaction. References 1. N Yabuuchi, T Ohzuku, “Novel lithium insertion material of LiCo1/3Ni1/3Mn1/3O2 for advanced lithium - ion batteries ”, J

Eco-friendly green synthesis of silver nanoparticles using salmalia malabarica: synthesis, characterization, antimicrobial, and catalytic activity studies

NASA Astrophysics Data System (ADS)

Murali Krishna, I.; Bhagavanth Reddy, G.; Veerabhadram, G.; Madhusudhan, A.

2016-06-01

An economically viable and "green" process has been developed for the synthesis of silver nanoparticles (AgNPs) with an average size of 7 nm using non-toxic and renewable salmalia malabarica gum (SMG) as reducing and capping agent without using any chemical reducing agent. The effect of various parameters such as concentration of SMG and silver nitrate and reaction time for the synthesis of AgNPs was studied. The synthesized AgNPs are systematically characterized by UV/Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and Transmission electron microscopy. The resultant SMG-capped AgNPs are highly stable and had significant antibacterial action on both Escherichia coli ( E. coli) and Staphylococcus aureus ( S. aureus). The catalytic action of the SMG-capped AgNPs to initiate the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4 has also been reported. The kinetics of the reaction was found to be of pseudo-first-order with respect to the 4-NP.

Hydrothermal synthesis of a photovoltaic material based on CuIn0.5Ga0.5Se2

NASA Astrophysics Data System (ADS)

Castellanos Báez, Y. T.; Fuquen Peña, D. A.; Gómez-Cuaspud, J. A.; Vera-López, E.; Pineda-Triana, Y.

2017-12-01

The present work report, the synthesis and characterization of the CuIn0.5Ga0.5Se2 system (abbreviated CIGS), by the implementation of a hydrothermal route, in order to obtain a solid with appropriate properties in terms of surface, morphological and texture properties for potential applications in the design of photovoltaic cells. The synthesis was carried out using the corresponding stoichiometric quantities (Cu:In:Ga:Se 1:0.5:0.5:2), which were mixed in a Teflon vessel under stirring conditions. The homogeneous solution was treated in a steel autoclave at 300°C for 72 hours at the end of which the resulting material was characterized by X-Ray Diffraction (XRD) and Rietveld refinement. The results of the structural characterization allowed to confirm the obtaining of a chalcopyrite type structure, with a I-42 d (122) structure and cell parameters a=0.570, b=0.570, c=1.140nm, α=90, β=90, γ=90° oriented along (1 0 4) facet, detecting the presence of a secondary phases, related with CuInSe and CuIn metallic selenides, derived from synthesis process. The structural refinement allowing to validate the obtaining of a nanometric crystalline material (10-20nm) for potential applications in field of photovoltaic technology.

Synthesis and characterization of luminescent aluminium selenide nanocrystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balitskii, O.A., E-mail: balitskii@electronics.wups.lviv.ua; Demchenko, P.Yu.; Mijowska, E.

Highlights: ► Synthesis procedure of size and sharp controlled Al{sub 2}Se{sub 3} nanocrystals is introduced. ► Obtained nanoparticles are highly crystalline of hexagonal wurtzite type. ► Colloidal Al{sub 2}Se{sub 3} nanocrystals are highly luminescent in the near UV spectral region. ► They can be implemented in light emitters/collectors, concurring with II–VI nanodots. -- Abstract: We propose the synthesis and characterization of colloidal aluminium selenide nanocrystals using trioctylphosphine as a solvent. The nanoparticles have several absorption bands in the spectral region 330–410 nm and are bright UV-blue luminescent, which is well demanded in light collecting and emitting devices, e.g. for tuningmore » their spectral characteristics to higher energy solar photons.« less

Synthesis and structural properties of Ba(1-x)LaxTiO3 perovskite nanoparticles fabricated by solvothermal synthesis route

NASA Astrophysics Data System (ADS)

Puli, Venkata Sreenivas; Adireddy, Shiva; Elupula, Ravinder; Molugu, Sudheer; Shipman, Josh; Chrisey, Douglas B.

2017-05-01

We report the successful synthesis and structural characterization of barium lanthanum titanate Ba(1-x)LaxTiO3 (x=0.003,0.006,0.010) nanoparticles. The colloidal nanoparticles were prepared with high yield by a solvothermal method at temperatures as low as 150°C for 24h. The as-prepared nanopowders were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy. The XRD studies revealed pseudo-cubic crystalline structure, with no impurity phases at room temperature. However ferroelectric tetragonal modes were clearly observed using Raman spectroscopy measurements. From TEM measurements, uniformly sized BLT nanoparticles were observed. Selected area diffraction TEM images revealed polycrystalline perovskite ring patterns, identified as corresponding to the tetragonal phase.

Highly Non-Linear Optical (NLO) organic crystals

NASA Technical Reports Server (NTRS)

Harris, J. Milton

1987-01-01

This research project involves the synthesis and characterization of organic materials having powerful nonlinear optical (NLO) properties and the growth of highly ordered crystals and monomolecular films of these materials. Research in four areas is discussed: theoretical design of new materials, characterization of NLO materials, synthesis of new materials and development of coupling procedures for forming layered films, and improvement of the techniques for vapor phase and solution phase growth of high quality organic crystals. Knowledge gained from these experiments will form the basis for experiments in the growth of these crystals.

Synthesis and characterization of organic-inorganic polymers from new methacrylate monomers and silane derivatives

NASA Astrophysics Data System (ADS)

Nicolescu, F. Adriana; Jerca, Victor V.; Albu, Ana M.; Vasilescu, D. Sorin; Vuluga, D. Mircea

2009-09-01

We report the synthesis of five new hybrid polymeric structures obtained by free radical copolymerization of some organic azo-based methacrylate monomers and 3-methacryloxypropyl trimethoxysilane (MEMO). The copolymers are soluble in common solvents like methylene chloride, chloroform, dichlorbenzene, dimethylsulfoxide, dimethylformamide. The copolymeric structures might be interesting from the point of view of nonlinear optical response due to a rich content in chromophoric units determined by H-NMR spectroscopy. The structures were also characterized by FT-IR spectroscopy, TGA and SEC analysis.

Synthesis and characterization of Mn-Bi alloy

NASA Astrophysics Data System (ADS)

Mishra, Ashutosh; Patil, Harsha; Jain, G.; Mishra, N.

2012-06-01

High purity MnBi low temperature phase has been prepared and analyzed using X-ray diffraction, Lorentz-Polarization Factor and Fourier transforms infrared measurement. After synthesis of samples structural characterization has done on samples by X-ray diffraction, which shows that after making the bulk sample is in no single phase MnBi has been prepared by sintering Mn and Bi powders. By Lorentz-Polarization Factor is affecting the relative intensity of diffraction lines on a powder form. And by FTIR which shows absorption peaks of MnBi alloys.

Synthesis and Characterization of New Phosphazene Polymers.

DTIC Science & Technology

1988-01-21

reaction of a poly( alkyl /arylphosphazene). In this study, one-half of the methyl groups in [Ph(Me)PN]n (chosen for its solubility in THF as opposed to...polymerization reaction ; and (5) the derivative chemistry of the preformed poly( alkyl /arylphosphazenes)., Synthesis of Poly( alkyl /arylphosphazenes) SC A... vessels , these phosphoranimines quantitatively eliminate the silyl ether byproduct, Me3SiOCH2CF 3 , to form the poly( alkyl /arylphosphazenes). The synthesis

Preparing Students for Research: Synthesis of Substituted Chalcones as a Comprehensive Guided-Inquiry Experience

NASA Astrophysics Data System (ADS)

Vyvyan, James R.; Pavia, Donald L.; Lampman, Gary M.; Kriz, George S., Jr.

2002-09-01

A guided inquiry experiment involving the synthesis and characterization of substituted benzalacetophenones (chalcones) is described. The chalcones are produced in the aldol condensation of substituted benzaldehydes with substituted acetophenones. Each student is assigned a different target chalcone and conducts online and printed literature searches on the target. After completing the synthesis and purification of their product, the students compare their data with those found in the literature.

Synthesis of 6-phosphofructose aspartic acid and some related Amadori compounds.

PubMed

Hansen, Alexandar L; Behrman, Edward J

2016-08-05

We describe the synthesis and characterization of 6-phosphofructose-aspartic acid, an intermediate in the metabolism of fructose-asparagine by Salmonella. We also report improved syntheses of fructose-asparagine itself and of fructose-aspartic acid. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis of rhodium-containing heterobimetallic hydride complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casey, C.P.; Whiteker, G.T.

1990-02-21

The reduction chemistry of heterobimetallic dihydrides are of much interest. Three heterobimetallic monohydride complexes containing Rh bound to either Re or Ta were isolated during synthetic attempts at preparing heterobimetallic dihydrides. The mode of synthesis, characterization, and reactivity of these three heterobimetallic compounds are discussed herein. 19 refs.

In vivo and in vitro characterization of σ70 constitutive promoters by real-time PCR and fluorescent measurements.

PubMed

Chappell, James; Freemont, Paul

2013-01-01

The characterization of DNA regulatory elements such as ribosome binding sites and transcriptional promoters is a fundamental aim of synthetic biology. Characterization of such DNA regulatory elements by monitoring the synthesis of fluorescent proteins is a commonly used technique to resolve the relative or absolute strengths. These measurements can be used in combination with mathematical models and computer simulation to rapidly assess performance of DNA regulatory elements both in isolation and in combination, to assist predictable and efficient engineering of complex novel biological devices and systems. Here we describe the construction and relative characterization of Escherichia coli (E. coli) σ(70) transcriptional promoters by monitoring the synthesis of green fluorescent protein (GFP) both in vivo in E. coli and in vitro in a E. coli cell-free transcription and translation reaction.

Sustainable Utilization of Bio waste towards the Green Synthesis of Nanoparticles and its Utility in the Naked Eye Detection of Metals Coupled with its Larvicidal and Antimicrobial Properties

NASA Astrophysics Data System (ADS)

Nikhila, P. S.; Satheesh, Namitha; Sreejitha, V. S.; Pillai, Anandu R.; Saritha, A.; Smitha Chandran, S.

2018-02-01

Green synthesis of nanoparticles has become a prominent zone of attention in the field of nanotechnology, as it is a nontoxic, economically feasible and green approach. In the present work we have developed an eco-friendly and zero cost method for the synthesis of silver nanoparticles using common a bio waste banana blossom peel. The well-known characteristic phenomenon of surface Plasmon resonance (SPR) has been exploited towards the characterization of the green synthesized nanoparticles. The aforementioned nanoparticles were characterized by UV spectroscopy and the behaviour of these particles towards naked eye detection of metal ions were observed. The sensitivity of the nanoparticles towards the detection of metal ions was carefully monitored by the shift in the SPR band. Moreover the larvicidal potential of these green synthesized silver nanoparticles were evaluated as per WHO standards. The synthesized silver nanoparticles were found to be an effective antibacterial agent against Gram negative bacteria-E.coli. The method we followed for the synthesis of silver nanoparticles is economically feasible as well as environment friendly and also capable of rapid synthesis of nanoparticles at ambient conditions.

Effect of the raw material type and the reaction time on the synthesis of halloysite based Zeolite Na-P1

NASA Astrophysics Data System (ADS)

Meftah, Mahdi; Oueslati, Walid; Chorfi, Nejmeddine; Ben Haj Amara, Abdesslem

Zeolites are currently one of the most important classes of inorganic materials because of their multiple applications not only as ions exchangers and molecular sieves, but also as catalysts. This works focus the synthesis and the characterization of Zeolite Na-P1 using halloysite (collected near Ain Khemouda, western Tunisia) as the starting material. Two parameters, such as the host materials type (natural or treated) and the reaction time, involved in the synthesis process are investigated. The intermediate phases and final products were characterized by X-ray diffraction, Infrared IR spectroscopy, scanning electron microscopy and high-resolution 29Si and 27Al MAS NMR. Obtained results show that the hydrothermal synthesis from natural and heated-halloysite leads to formation of homogenous Zeolite Na-P1. The difference in the crystallization/transformation time process is explained by the effect of the dissolution rate of the starting materials in sodium hydroxide solution. In the case of heated halloysite, the synthesis reaction with alkali solution occurs very readily and achieved without prior thermal activation at high temperature. The optimal conditions of Zeolite Na-P1 crystallization, from heated-halloysite, are reached at 120 °C.

Cell-free synthesis of functional human epidermal growth factor receptor: Investigation of ligand-independent dimerization in Sf21 microsomal membranes using non-canonical amino acids

PubMed Central

Quast, Robert B.; Ballion, Biljana; Stech, Marlitt; Sonnabend, Andrei; Varga, Balázs R.; Wüstenhagen, Doreen A.; Kele, Péter; Schiller, Stefan M.; Kubick, Stefan

2016-01-01

Cell-free protein synthesis systems represent versatile tools for the synthesis and modification of human membrane proteins. In particular, eukaryotic cell-free systems provide a promising platform for their structural and functional characterization. Here, we present the cell-free synthesis of functional human epidermal growth factor receptor and its vIII deletion mutant in a microsome-containing system derived from cultured Sf21 cells. We provide evidence for embedment of cell-free synthesized receptors into microsomal membranes and asparagine-linked glycosylation. Using the cricket paralysis virus internal ribosome entry site and a repetitive synthesis approach enrichment of receptors inside the microsomal fractions was facilitated thereby providing analytical amounts of functional protein. Receptor tyrosine kinase activation was demonstrated by monitoring receptor phosphorylation. Furthermore, an orthogonal cell-free translation system that provides the site-directed incorporation of p-azido-L-phenylalanine is characterized and applied to investigate receptor dimerization in the absence of a ligand by photo-affinity cross-linking. Finally, incorporated azides are used to generate stable covalently linked receptor dimers by strain-promoted cycloaddition using a novel linker system. PMID:27670253

Recent Advances in the Synthesis and Stabilization of Nickel and Nickel Oxide Nanoparticles: A Green Adeptness

PubMed Central

Rani, Aneela

2016-01-01

Green protocols for the synthesis of nanoparticles have been attracting a lot of attention because they are eco-friendly, rapid, and cost-effective. Nickel and nickel oxide nanoparticles have been synthesized by green routes and characterized for impact of green chemistry on the properties and biological effects of nanoparticles in the last five years. Green synthesis, properties, and applications of nickel and nickel oxide nanoparticles have been reported in the literature. This review summarizes the synthesis of nickel and nickel oxide nanoparticles using different biological systems. This review also provides comparative overview of influence of chemical synthesis and green synthesis on structural properties of nickel and nickel oxide nanoparticles and their biological behavior. It concludes that green methods for synthesis of nickel and nickel oxide nanoparticles are better than chemical synthetic methods. PMID:27413375

“Synthesis-on” and “synthesis-off” modes of carbon arc operation during synthesis of carbon nanotubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yatom, Shurik; Selinsky, Rachel S.; Koel, Bruce E.

Arc discharge synthesis of single-walled carbon nanotubes (SWCNTs) remains largely uncontrollable, due to incomplete understanding of the synthetic process itself. Here, we show that synthesis of SWCNTs by a carbon arc may not constitute a single continuous process, but may instead consist of two distinct modes. One of these, a “synthesis-on” mode, produces the majority of the nanomaterials. During the synthesis-on mode, proportionally more carbon nanotubes are collected than in another mode, a “synthesis-off” mode. Both synthesis-on and synthesis-off modes for a typical arc configuration, employing a hollow anode filled with a mixture of powdered metal catalyst and graphite, weremore » characterized by using in situ electrical, imaging, and spectroscopic diagnostics, along with ex situ imaging and spectroscopy. The synthesis-on mode duration is rare compared to the total arc run-time, helping to explain the poor selectivity found in the final collected products, a known inadequacy of arc synthesis. Finally, the rarity of the synthesis on mode occurence may be due to the synthesis off mode being more favorable energetically.« less

“Synthesis-on” and “synthesis-off” modes of carbon arc operation during synthesis of carbon nanotubes

DOE PAGES

Yatom, Shurik; Selinsky, Rachel S.; Koel, Bruce E.; ...

2017-09-09

Arc discharge synthesis of single-walled carbon nanotubes (SWCNTs) remains largely uncontrollable, due to incomplete understanding of the synthetic process itself. Here, we show that synthesis of SWCNTs by a carbon arc may not constitute a single continuous process, but may instead consist of two distinct modes. One of these, a “synthesis-on” mode, produces the majority of the nanomaterials. During the synthesis-on mode, proportionally more carbon nanotubes are collected than in another mode, a “synthesis-off” mode. Both synthesis-on and synthesis-off modes for a typical arc configuration, employing a hollow anode filled with a mixture of powdered metal catalyst and graphite, weremore » characterized by using in situ electrical, imaging, and spectroscopic diagnostics, along with ex situ imaging and spectroscopy. The synthesis-on mode duration is rare compared to the total arc run-time, helping to explain the poor selectivity found in the final collected products, a known inadequacy of arc synthesis. Finally, the rarity of the synthesis on mode occurence may be due to the synthesis off mode being more favorable energetically.« less

Synthesis and characterization of the Cu2ZnSnS4 system for photovoltaic applications

NASA Astrophysics Data System (ADS)

Sánchez Pinzón, D. L.; Soracá Perez, G. Y.; Gómez Cuaspud, J. A.; López, E. Vera

2017-01-01

This paper focuses on the synthesis and characterization of a ceramic material based on the Cu2ZnSnS4 system, through the implementation of a hydrothermal route. For this purpose, we started from nitrate dissolutions in a 1.0mol L-1 concentration, which were mixed and treated in a teflon lined vessel steel at 280°C for 48h. The Physicochemical characterization of the solid was evaluated by means of ultraviolet visible spectroscopy (UV-VIS), X-ray diffraction (XRD), Raman spectroscopy, scanning and transmission electron microscopy (SEM-TEM) and solid state impedance spectroscopy (IS). The initial characterization through UV measurements confirms a Band-gap around 1.46eV obtained by the Kubelka-Munk method, which demonstrates the effectiveness of the synthesis method in the obtaining of a semiconductor material. The XRD results confirm the obtaining of a crystalline material of pure phase with tetragonal geometry and I-42m space group. The preferential crystalline orientation was achieved along (2 2 0) facet, with crystallite sizes of nanometric order (6.0nm). The morphological aspects evaluated by means electron microscopy, confirmed the homogeneity of the material, showing specifically a series of textural and surface properties of relevant importance. Finally, the electrical characterizations allow to validate the semiconductor behaviour of CZTS system for development of photovoltaic technologies.

Semi-Microscale Williamson Ether Synthesis and Simultaneous Isolation of an Expectorant from Cough Tablets

NASA Astrophysics Data System (ADS)

Stabile, Ryan G.; Dicks, Andrew P.

2003-03-01

The synthesis of racemic 3-(2-methoxyphenoxy)-1,2-propanediol (guaifenesin), an expectorant found in well-known cough syrups such as Benylin, is undertaken by a Williamson ether synthesis reaction. The same compound is simultaneously isolated and characterized from commercially available Guai-Aid cough tablets. The experiment is well-suited towards the introductory part of an advanced organic laboratory course and complements typical lecture topics in a stimulating manner. Consideration is given towards reaction mechanisms, stereochemistry, optical activity, pharmaceutical synthesis, and spectroscopic analysis. Discussion of the merits or disadvantages of marketing a drug as a racemic mixture, with reference to the notorious thalidomide case study, and the concept of enantioselective synthesis is possible.

Study of various synthesis techniques of nanomaterials

NASA Astrophysics Data System (ADS)

Patil, Madhuri; Sharma, Deepika; Dive, Avinash; Mahajan, Sandeep; Sharma, Ramphal

2018-05-01

Development of synthesis techniques of realizing nano-materials over a range of sizes, shapes, and chemical compositions is an important aspect of nanotechnology. The remarkable size dependent physical & chemical properties of particles have fascinated and inspired research activity in this direction. This paper describes some aspects on synthesis and characterization of particles of metals, metal alloys, and oxides, either in the form of thin films or bulk shapes. A brief discussion on processing of thin-films is also described.

Synthesis, characterization and electrospinning of corn cob cellulose-graft-polyacrylonitrile and their clay nanocomposites.

PubMed

Kalaoğlu, Özlem I; Ünlü, Cüneyt H; Galioğlu Atıcı, Oya

2016-08-20

This study aims at evaluation of cellulose recovered from agricultural waste (corn cob) in terms of synthesis of graft copolymers, polymer/clay nanocomposites, and nanofibers. The copolymers and nanocomposites were synthesized in aqueous solution using Ce(4+) initiator. Conditions (concentrations of the components, reaction temperature, and period) were determined first for copolymer synthesis to obtain the highest conversion ratio. Then found parameters were used to synthesize nanocomposites adding clay mineral to reaction medium. Although there was a decrease in conversion in nanocomposites syntheses, thermal and rheologic measurements indicated enhancements compared to pristine copolymer. Obtained polymeric materials have been successfully electrospun into nanofibers and characterized. Average diameter of the nanofibers was about 650nm and was strongly influenced by NaMMT amount in the nanocomposite sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and characterization of microporous titanosilicate ETS-10 obtained with different Ti sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casado, Clara; Amghouz, Zakariae; Garcia, Jose R.

2009-06-03

Titanosilicate ETS-10 crystals were prepared by hydrothermal synthesis varying Ti source (TiCl{sub 3} and commercial TiO{sub 2}-anatase), time in autoclave and seeding with previously prepared ETS-10 crystals. The crystalline powders were characterized by X-ray diffraction, N{sub 2} adsorption, thermogravimetric analysis, and scanning and transmission electron microscopies. Control of the particle size of ETS-10 crystals ranging from 0.32 {mu}m x 0.41 {mu}m to 16.4 {mu}m x 32.5 {mu}m was successfully achieved varying the seeding and synthesis conditions. In particular, it was found that the use of TiO{sub 2}-anatase alone or together with TiCl{sub 3} promotes heterogeneous primary nucleation. Transmission electron microscopymore » demonstrated that the largest crystals obtained here were twinned.« less

Facile synthesis of SiO{sub 2} nanoparticles for biomedical applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scano, A., E-mail: alescano80@tiscali.it; Pilloni, M., E-mail: alescano80@tiscali.it; Cabras, V., E-mail: alescano80@tiscali.it

Silica nanoparticles (SiO{sub 2} NPs) for biomedical applications have been prepared by using a facile modified Stöber-synthesis. Potassium borohydride (KBH{sub 4}) has been introduced in the synthesis procedure in order to control NP size. Several samples have been prepared varying tetraethylorthosilicate (TEOS) concentration, and using different process conditions (temperature, reaction time and atmosphere). In order to study the influence of the process conditions on the NP size, morphology and properties, several characterization techniques were used. Size and morphology of the as-prepared SiO{sub 2} NPs have been studied by using Transmission Electron Microscope (TEM) and Dynamic Light Scattering (DLS) techniques. Structuralmore » characterization was carried out by X-ray powder diffraction. To investigate the SiO{sub 2} NP fluorescence emission properties the fluorescence spectroscopy was also used.« less

A synthetic biology approach to engineer a functional reversal of the β-oxidation cycle.

PubMed

Clomburg, James M; Vick, Jacob E; Blankschien, Matthew D; Rodríguez-Moyá, María; Gonzalez, Ramon

2012-11-16

While we have recently constructed a functional reversal of the β-oxidation cycle as a platform for the production of fuels and chemicals by engineering global regulators and eliminating native fermentative pathways, the system-level approach used makes it difficult to determine which of the many deregulated enzymes are responsible for product synthesis. This, in turn, limits efforts to fine-tune the synthesis of specific products and prevents the transfer of the engineered pathway to other organisms. In the work reported here, we overcome the aforementioned limitations by using a synthetic biology approach to construct and functionally characterize a reversal of the β-oxidation cycle. This was achieved through the in vitro kinetic characterization of each functional unit of the core and termination pathways, followed by their in vivo assembly and functional characterization. With this approach, the four functional units of the core pathway, thiolase, 3-hydroxyacyl-CoA dehydrogenase, enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydratase, and acyl-CoA dehydrogenase/trans-enoyl-CoA reductase, were purified and kinetically characterized in vitro. When these four functional units were assembled in vivo in combination with thioesterases as the termination pathway, the synthesis of a variety of 4-C carboxylic acids from a one-turn functional reversal of the β-oxidation cycle was realized. The individual expression and modular construction of these well-defined core components exerted the majority of control over product formation, with only highly selective termination pathways resulting in shifts in product formation. Further control over product synthesis was demonstrated by overexpressing a long-chain thiolase that enables the operation of multiple turns of the reversal of the β-oxidation cycle and hence the synthesis of longer-chain carboxylic acids. The well-defined and self-contained nature of each functional unit makes the engineered reversal of the β-oxidation cycle "chassis neutral" and hence transferrable to the host of choice for efficient fuel or chemical production.

Characterization of PDMS samples with variation of its synthesis parameters for tunable optics applications

NASA Astrophysics Data System (ADS)

Marquez-Garcia, Josimar; Cruz-Félix, Angel S.; Santiago-Alvarado, Agustin; González-García, Jorge

2017-09-01

Nowadays the elastomer known as polydimethylsiloxane (PDMS, Sylgard 184), due to its physical properties, low cost and easy handle, have become a frequently used material for the elaboration of optical components such as: variable focal length liquid lenses, optical waveguides, solid elastic lenses, etc. In recent years, we have been working in the characterization of this material for applications in visual sciences; in this work, we describe the elaboration of PDMSmade samples, also, we present physical and optical properties of the samples by varying its synthesis parameters such as base: curing agent ratio, and both, curing time and temperature. In the case of mechanical properties, tensile and compression tests were carried out through a universal testing machine to obtain the respective stress-strain curves, and to obtain information regarding its optical properties, UV-vis spectroscopy is applied to the samples to obtain transmittance and absorbance curves. Index of refraction variation was obtained through an Abbe refractometer. Results from the characterization will determine the proper synthesis parameters for the elaboration of tunable refractive surfaces for potential applications in robotics.

Synthesis and characterization of mangan oxide coated sand from Capkala kaolin

NASA Astrophysics Data System (ADS)

Destiarti, Lia; Wahyuni, Nelly; Prawatya, Yopa Eka; Sasri, Risya

2017-03-01

Synthesis and characterization of mangan oxide coated sand from quartz sand fraction of Capkala kaolin has been conducted. There were two methods on synthesis of Mangan Oxide Coated Sand (MOCS) from Capkala Kaolin compared in this research. Characterization of MOCS was done by using Scanning Electron Microscope/Energy Dispersive X-Ray Spectrometer (SEM/EDX) and X-Ray Diffraction (XRD). The MOCS was tested to reduce phosphate in laundry waste. The result showed that the natural sand had bigger agregates and a relatively uniform structural orientation while both MOCS had heterogen structural orientation and manganese oxide formed in cluster. Manganese in first and second methods were 1,93% and 2,63%, respectively. The XRD spectrum showed clear reflections at 22,80°, 36,04°, 37,60° and a broad band at 26,62° (SiO2). Based on XRD spectrum, it can be concluded that mineral constituents of MOCS was verified corresponding to pyrolusite (MnO2). The former MOCS could reduce almost 60% while the later could reduce 70% phosphate in laundry waste.

Solventless synthesis, morphology, structure and magnetic properties of iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Das, Bratati; Kusz, Joachim; Reddy, V. Raghavendra; Zubko, Maciej; Bhattacharjee, Ashis

2017-12-01

In this study we report the solventless synthesis of iron oxide through thermal decomposition of acetyl ferrocene as well as its mixtures with maliec anhydride and characterization of the synthesized product by various comprehensive physical techniques. Morphology, size and structure of the reaction products were investigated by scanning electron microscopy, transmission electron microscopy and X-ray powder diffraction technique, respectively. Physical characterization techniques like FT-IR spectroscopy, dc magnetization study as well as 57Fe Mössbauer spectroscopy were employed to characterize the magnetic property of the product. The results observed from these studies unequivocally established that the synthesized materials are hematite. Thermal decomposition has been studied with the help of thermogravimetry. Reaction pathway for synthesis of hematite has been proposed. It is noted that maliec anhydride in the solid reaction environment as well as the gaseous reaction atmosphere strongly affect the reaction yield as well as the particle size. In general, a method of preparing hematite nanoparticles through solventless thermal decomposition technique using organometallic compounds and the possible use of reaction promoter have been discussed in detail.

Green synthesis and characterization of novel gold nanocomposites for electrochemical sensing applications.

PubMed

Tanwar, Shivani; Ho, Ja-an Annie; Magi, Emanuele

2013-12-15

Synthesis, characterization and application of Au-PANI-Calix and Au-PANI-Nap nanocomposites, is reported herein. An easy template free green synthesis is proposed and discussed for easy expediency. A variety of analytical techniques were used to characterize the nanocomposites: UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Dynamic light scattering (DLS), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were used to characterize the nanocomposites. Surface morphology was studied by transmission electron microscopy (TEM). The nanocomposites were immobilized on screen-printed electrode and showed electroactivity in neutral pH, making them promising candidates for various analytical applications. A sensitive and selective detection of Cu(2+) was perceived on the Au-PANI-Calix modified electrode with no interference from ions K(+), Ni(2+), Co(2+), Pb(2+), Cr(3+) with a detection limit of 10nM. The copper detection is facilitated for accessible ligation with 4-sulfocalix[4]arene, so as the Cu(II)-Calix complex formed. The electrode modified with Au-PANI-Nap showed sensing application towards H2O2 with a detection limit of 1 μM. The modified electrodes were reproducible and stable for 2 months. © 2013 Elsevier B.V. All rights reserved.

Synthesis and Characterization Pectin-Carboxymethyl Chitosan crosslinked PEGDE as biosorbent of Pb(II) ion

NASA Astrophysics Data System (ADS)

Hastuti, Budi; Siswanta, Dwi; Mudasir; Triyono

2018-01-01

Pectin and chitosan are biodegradable polymers, potentially applied as a heavy metal adsorbents. Unfortunately both biosorbents pectin and chitosan have a weakness in acidic media. For this purpose required modified pectin and chitosan. The modified adsorben is intended to obtain a stable adsorbent and resistance under acid. The research was done by experimental method in laboratory. The stages of this research are the synthesis of carboxymethyl chitosan (CMC), synthesis of Pec-CMC-PEGDE film adsorbent, stabily test under acid, the characterization of active group using FTIR, stability characterization of Pec-CMC-PEGDE powder adsorbent using XRD, termo stability using DTA-TGA. The results of the research have shown that: pectin and CMC can be cross-linked using PEGDE crosslinking agent, the film adsorbent was stable under HCl 1 M, the film adsorbent have active group comprise of carboxylate and amine groups. The result of characterization using XRD, shows that the adsorbent is semi-crystalline. Base on termo stability, the film adsorbent Pec-CMC-PEGDE stable up to 600°C. The film can be applied as an adsobent of Pb (II) ion remediation. The optimum pH of pec-CMC-PEGDE in adsorbed of Pb(II) was reached at pH 5 with 99.99% absorbent adsorbed and of and adsorption capacity was 46.11 mg/g.

Synthesis and Characterization of Mimosa Pudica Leaves Shaped α-Iron Oxide Nanostructures for Ethanol Chemical Sensor Applications.

PubMed

Kim, S H; Ibrahim, Ahmed A; Kumar, R; Umar, Ahmad; Abaker, M; Hwang, S W; Baskoutas, S

2016-03-01

Herein, the synthesis of mimosa pudica leaves shaped a-iron oxide (α-Fe2O3) nanostructures is reported through simple and facile hydrothermal process. The prepared α-Fe2O3 nanostructures were characterized in terms of their morphological, structural, compositional and optical properties through a variety of characterization techniques such as FESEM, EDS, XRD, FTIR and Raman spectroscopy. The detailed characterizations revealed the well-crystallinity and dense growth of mimosa pudica leaf shaped α-Fe2O3 nanostructures. Further, the prepared nanomaterials were used as efficient electron mediator to fabricate sensitive ethanol chemical sensor. The fabricated sensor exhibited a high sensitivity of -30.37 μAmM(-1) cm(-2) and low detection limit of -0.62 μM. The observed linear dynamic range (LDR) was in the range from 10 μM-0.625 μM.

Synthesis and characterization of novel low density polyethylene-multiwall carbon nanotube porous composites

NASA Astrophysics Data System (ADS)

Rizvi, Reza; Kim, Jae-Kyung; Naguib, Hani

2009-10-01

This study details the synthesis and characterization of novel porous composites of low density polyethylene (PE) and multiwalled carbon nanotubes (MWNT). PE-MWNT composites were prepared by melt blending the components in a twin screw compounder and porous structures were produced by a batch technique using CO2 as the solvent. The composites were characterized for dispersion using scanning electron microscopy and transmission electron microscopy; the results indicate a finely dispersed MWNT phase in PE. Thermal, rheological, electrical and mechanical properties of the composites were characterized and results indicate an electrical and rheological percolation threshold concentration of between 1 and 2 wt% MWNT in PE. Substantial improvements in the mechanical and electrical properties of PE were observed with the addition of 5 wt% MWNT. The porous PE-MWNT composites fabricated in this study were found to be conductive and have potential applications as anti-static materials for electrostatic discharge prevention.

Synthesis and Characterization of Functionalized Metal-organic Frameworks

PubMed Central

Karagiaridi, Olga; Bury, Wojciech; Sarjeant, Amy A.; Hupp, Joseph T.; Farha, Omar K.

2014-01-01

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy. PMID:25225784

Synthesis, characterization and electrochemical studies of some Ni(II)Cu(II) heterobimetallic complexes derived from succinoyldihydrazones.

PubMed

Borthakur, R; Kumar, A; Lal, R A

2015-10-05

Synthesis, structural characterization and redox properties of three heterobimetallic complexes with formule {[NiCu(L(n))(CH3OH)3]·CH3OH} using [Cu(H2L(n))(H2O)] as metalloligand have been demonstrated in the present paper. Electronic spectroscopy suggests that the copper center has a pseudo square pyramidal stereochemistry in all the complexes while the nickel center has a distorted octahedral stereochemistry. The electron transfer reactions of the complexes have been investigated by cyclic voltammetry. Copyright © 2015 Elsevier B.V. All rights reserved.

Preparation, characterization and properties of ZnO nanomaterials

NASA Astrophysics Data System (ADS)

Luo, Jiaolian; Zhang, Xiaoming; Chen, Ruxue; Wang, Xiaohui; Zhu, Ji; Wang, Xiaomin

2017-06-01

In this paper, using the hydrothermal synthesis method, NaOH, Zn(NO3)2, anhydrous ethanol, deionized water as raw material to prepare ZnO nanomaterial, and by X ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL) on the synthesis of nano materials, surface morphology and phase luminescence characterization. The results show that the nano materials synthesized for single-phase ZnO, belonging to the six wurtzite structure; material surface shaped, arranged evenly distributed, and were the top six party structure; ZnO nano materials synthesized with strong emission spectra, emission peak is located at 394nm.

Microwave Synthesis and Characterization of Waste Soybean Oil-Based Gemini Imidazolinium Surfactants with Carbonate Linkage

NASA Astrophysics Data System (ADS)

Tripathy, Divya Bajpai; Mishra, Anuradha

Gemini surfactants are presently gaining attention due to their unusual self-assembling characteristics and incomparable interfacial activity. Current research work involves the cost-effective microwave (MW) synthesis of waste soybean oil-based gemini imidazolinium surfactants (GIS) having a carbonate linkage in its spacer moiety. Structural characterizations of the materials have been done using FT-IR, 1H-NMR and 13C-NMR. Using indigenous and natural material as base and MW as energy source for synthesizing the GIS with easily degradable chemical moiety make them to be labeled as green surfactants.

1,3,4-Thiadiazole derivatives of R-(+)-limonene benzaldehyde-thiosemicarbazones cause death in Trypanosoma cruzi through oxidative stress.

PubMed

Martins, Solange C; Lazarin-Bidóia, Danielle; Desoti, Vânia C; Falzirolli, Hugo; da Silva, Cleuza C; Ueda-Nakamura, Tania; Silva, Sueli de O; Nakamura, Celso V

2016-12-01

This work evaluated the in vitro and in vivo activity of TDZ 2 on Trypanosoma cruzi amastigotes and determined the possible mechanism of action of this compound on T. cruzi death. TDZ 2 inhibited T. cruzi proliferation in vitro and had low haemolytic potential. It also induced morphological and ultrastructural alterations. We observed a reduction of cell volume, the depolarization of the mitochondrial membrane, an increase in ROS production, lipoperoxidation of the cell membrane, lipid bodies formation and production of nitric oxide, a decrease in reduced thiols levels and, presence of autophagic vacuoles. The in vivo study found a reduction of parasitemia in animals treated with TDZ 2 alone or combined with benznidazole. Altogether, the alterations induced by TDZ 2 point to an oxidative stress condition that lead to T. cruzi cell death. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Effect of Antiviral Agents in Equine Abortion Virus-Infected Hamsters1

PubMed Central

Lieberman, Melvin; Pascale, Andrea; Schafer, Thomas W.; Came, Paul E.

1972-01-01

Equine abortion virus, a member of the herpesvirus group, produces a lethal infection in hamsters. With this system, the protective effect of certain inhibitors of deoxyribonucleic acid viruses, inducers of interferon and exogenous interferon, was evaluated. Of the various agents studied, 9-β-d-arabinofuranosyladenine markedly suppressed mortality, and 5-iodo-2′-deoxyuridine, distamycin A, and N-ethylisatin β-thiosemicarbazone were inactive. Of the inducers tested, statolon, ultraviolet-irradiated Newcastle disease virus, and polyriboinosinic:polyribocytidylic acid (poly I:C) were protective, and endotoxin, polyacrylic acid, and polymethacrylic acid did not protect. Administration of exogenous interferon did not afford protection. Statolon and ultraviolet-irradiated Newcastle disease virus induced circulating interferon in hamsters, whereas poly I:C, endotoxin, and polyacrylic acid did not produce interferon. Because of the severity of the disease produced in hamsters by equine abortion virus, lack of protective activity by an agent in this system should not preclude possible efficacy against other members of the herpesvirus group. PMID:4376907

A Two-Step Synthesis of Virstatin, a Virulence Inhibitor of "Vibrio cholerae"

ERIC Educational Resources Information Center

McDonald, Chriss E.

2009-01-01

Virstatin, an "N"-butanoic acid substituted naphthalimide, inhibits the ability of "Vibrio cholerae" to cause disease. A three-week experiment involving synthesis, purification, and spectral characterization of this compound is described. This experiment is appropriate for organic chemistry. It has been performed with three lab sections of about…

Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization in Undergraduate Polymer Science Lab

ERIC Educational Resources Information Center

Nguyen, T. L. U.; Bennet, Francesca; Stenzel, Martina H.; Barner-Kowollik, Christopher

2008-01-01

This 8-hour experiment (spread over two 4-hour sessions) is designed to equip students with essential skills in polymer synthesis, particularly in synthesizing polymers of well-defined molecular weight. The experiment involves the synthesis and characterization of poly(vinyl neodecanoate) via living free radical polymerization, specifically the…

Characterization and optimization of cathodic conditions for H2O2 synthesis in microbial electrochemical cells

EPA Science Inventory

Cathode potential and O2 supply methods were investigated to improve H2O2 synthesis in an electrochemical cell, and optimal cathode conditions were applied for microbial electrochemical cells (MECs). Using aqueous O2 for the cathode significantly improved current density, but H2...

A facile solvothermal synthesis of octahedral Fe 3O 4 nanoparticles

DOE PAGES

DuChene, Joseph S.; Qiu, Jingjing; Graham, Jeremy O.; ...

2015-01-26

Anisotropic Fe 3O 4 octahedrons are obtained via a simple solvothermal synthesis with appropriate sizes for various technological applications. Here, a complete suite of materials characterization methods confirms the magnetite phase for these structures, which exhibit substantial saturation magnetization and intriguing morphologies for a wide range of applications.

Synthesis and Characterization of Copper Complexes with a Tridentate Nitrogen-Donor Ligand: An Integrated Research Experiment for Undergraduate Students

ERIC Educational Resources Information Center

Bussey, Katherine A.; Cavalier, Annie R.; Connell, Jennifer R.; Mraz, Margaret E.; Holderread, Ashley S.; Oshin, Kayode D.; Pintauer, Tomislav

2015-01-01

An integrated laboratory experiment applying concepts and techniques developed in organic chemistry, inorganic chemistry, and instrumental analysis is presented for use by students interested in undergraduate research. The experiment incorporates some advanced laboratory practices such as multistep organic synthesis and purification, detailed…

Synthesis of an Albendazole Metabolite: Characterization and HPLC Determination

ERIC Educational Resources Information Center

Mahler, Graciela; Davyt, Danilo; Gordon, Sandra; Incerti, Marcelo; Nunez, Ivana; Pezaroglo, Horacio; Scarone, Laura; Serra, Gloria; Silvera, Mauricio; Manta, Eduardo

2008-01-01

In this laboratory activity, students are introduced to the synthesis of an albendazole metabolite obtained by a sulfide oxidation reaction. Albendazole as well as its metabolite, albendazole sulfoxide, are used as anthelmintic drugs. The oxidation reagent is H[subscript 2]O[subscript 2] in acetic acid. The reaction is environmental friendly,…

Purification, characterization, and bioinformatics studies of phosphatidic acid phosphohydrolase from Lagenaria siceraria

USDA-ARS?s Scientific Manuscript database

Phosphatidic acid phosphohydrolase (PAP), EC 3.1.3.4, is the penultimate step in the Kennedy pathway of triacyl glycerol (TAG) synthesis leading to the formation of diacyl glycerol (DAG), which is a key intermediate in TAG synthesis. We partially purified a soluble PAP from mid maturing seeds of bot...

Catalase anabolism in yeast: loss of regulation by oxygen of catalase apoprotein synthesis after mutation.

PubMed

Berte, C; Sels, A

1979-04-17

A mutant of Saccharomyces cerevisiae which displays catalase activity when grown under strictly anaerobic conditions has been selected on solid media. Although some preformed holoenzyme has accumulated in anaerobic cells, a sharp increase of activity is still measured during adaptation to oxygen in glucose-buffer; however, a striking difference with the wild-type strain is that in the mutant, catalase formation is observed in the presence of cycloheximide that totally inhibits cytoplasmic translation. It is concluded that kat 80 mutant has lost the regulatory control by oxygen of apocatalase synthesis; the later precursor, characterized as apocatalase synthesis; the latter precursor, characterized as apocatalase T, is thought to be activated in vivo, under aerobic conditions, by inclusion of prosthetic group. Regulation of enzyme synthesis by catabolite repression (glucose erfect) persists, unmodified by reference to the wild-type parental strain. Mutation kat 80 specifically hits catalase anabolism, as no significant variations were observed for the edification of the respiratory system and (apo)cytochrome c peroxidase production. Genetic analysis shows that kat 80 phenotype, recessive in heterozygotes, results from a single nuclear mutation.

Chemical synthesis and characterization of branched oligodeoxyribonucleotides (bDNA) for use as signal amplifiers in nucleic acid quantification assays.

PubMed

Horn, T; Chang, C A; Urdea, M S

1997-12-01

The divergent synthesis of bDNA structures is described. This new type of branched DNA contains one unique oligonucleotide, the primary sequence, covalently attached through a comb-like branching network to many identical copies of a different oligonucleotide, the secondary sequence. The bDNA comb molecules were assembled on a solid support using parameters optimized for bDNA synthesis. The chemistry was used to synthesize bDNA comb molecules containing 15 secondary sequences. The bDNA comb molecules were elaborated by enzymatic ligation into branched amplification multimers, large bDNA molecules (a total of 1068 nt) containing an average of 36 repeated DNA oligomer sequences, each capable of hybridizing specifically to an alkaline phosphatase-labeled oligonucleotide. The bDNA comb molecules were characterized by electrophoretic methods and by controlled cleavage at periodate-cleavable moieties incorporated during synthesis. The branched amplification multimers have been used as signal amplifiers in nucleic acid quantification assays for detection of viral infection. It is possible to detect as few as 50 molecules with bDNA technology.

Chemical synthesis and characterization of branched oligodeoxyribonucleotides (bDNA) for use as signal amplifiers in nucleic acid quantification assays.

PubMed Central

Horn, T; Chang, C A; Urdea, M S

1997-01-01

The divergent synthesis of bDNA structures is described. This new type of branched DNA contains one unique oligonucleotide, the primary sequence, covalently attached through a comb-like branching network to many identical copies of a different oligonucleotide, the secondary sequence. The bDNA comb molecules were assembled on a solid support using parameters optimized for bDNA synthesis. The chemistry was used to synthesize bDNA comb molecules containing 15 secondary sequences. The bDNA comb molecules were elaborated by enzymatic ligation into branched amplification multimers, large bDNA molecules (a total of 1068 nt) containing an average of 36 repeated DNA oligomer sequences, each capable of hybridizing specifically to an alkaline phosphatase-labeled oligonucleotide. The bDNA comb molecules were characterized by electrophoretic methods and by controlled cleavage at periodate-cleavable moieties incorporated during synthesis. The branched amplification multimers have been used as signal amplifiers in nucleic acid quantification assays for detection of viral infection. It is possible to detect as few as 50 molecules with bDNA technology. PMID:9365266

Synthesis and characterization of novel chiral ionic liquids and investigation of their enantiomeric recognition properties.

PubMed

Bwambok, David K; Marwani, Hadi M; Fernand, Vivian E; Fakayode, Sayo O; Lowry, Mark; Negulescu, Ioan; Strongin, Robert M; Warner, Isiah M

2008-02-01

We report the synthesis and characterization of amino acid ester based chiral ionic liquids, derived from L- and D-alanine tert butyl ester chloride. The synthesis was accomplished via an anion metathesis reaction between commercially available L- and D-alanine tert butyl ester chloride using a variety of counterions such as lithium bis (trifluoromethane) sulfonimide, silver nitrate, silver lactate, and silver tetrafluoroborate. Both enantiomeric forms were obtained as confirmed by bands of opposite sign in the circular dichroism spectra. The L- and D-alanine tert butyl ester bis (trifluoromethane) sulfonimide were obtained as liquids at room temperature and intriguingly exhibited the highest thermal stability (up to 263 degrees C). In addition, the ionic liquids demonstrated enantiomeric recognition ability as evidenced by splitting of racemic Mosher's sodium salt signal using a liquid state (19)F nuclear magnetic resonance (NMR) and fluorescence spectroscopy. The L- and D-alanine tert butyl ester chloride resulted in solid salts with nitrate, lactate, and tetrafluoroborate anions. This illustrates the previously observed tunability of ionic liquid synthesis, resulting in ionic liquids of varying properties as a function of varying the anion.

Synthesis and characterization of hexaarylbenzenes with five or six different substituents enabled by programmed synthesis

NASA Astrophysics Data System (ADS)

Suzuki, Shin; Segawa, Yasutomo; Itami, Kenichiro; Yamaguchi, Junichiro

2015-03-01

Since its discovery in 1825, benzene has served as one of the most used and indispensable building blocks of chemical compounds, ranging from pharmaceuticals and agrochemicals to plastics and those used in organic electronic devices. Benzene has six hydrogen atoms that can each be replaced by different substituents, which means that the structural diversity of benzene derivatives is intrinsically extraordinary. The number of possible substituted benzenes from n different substituents is (2n + 2n2 + 4n3 + 3n4 + n6)/12. However, owing to a lack of general synthetic methods for making multisubstituted benzenes, this potentially huge structural diversity has not been fully exploited. Here, we describe a programmed synthesis of hexaarylbenzenes using C-H activation, cross-coupling and [4+2] cycloaddition reactions. The present method allows for the isolation and structure-property characterization of hexaarylbenzenes with distinctive aryl substituents at all positions for the first time. Moreover, the established protocol can be applied to the synthesis of tetraarylnaphthalenes and pentaarylpyridines.

Anticancer potential of new steroidal thiazolidin-4-one derivatives. Mechanisms of cytotoxic action and effects on angiogenesis in vitro.

PubMed

Živković, Marijana B; Matić, Ivana Z; Rodić, Marko V; Novaković, Irena T; Krivokuća, Ana M; Sladić, Dušan M; Krstić, Natalija M

2017-11-01

The synthesis and cytotoxic activities determination of new steroidal mono- and bis(thiazolidin-4-ones) 4a-f and 5a-f have been performed. Their anticancer action was also evaluated in comparison to previously synthesized and reported corresponding steroidal thiosemicarbazones. All compounds were obtained as stereoisomeric mixtures with different configuration (E or Z) in the hydrazone moiety at the C-3 position. After several consecutive crystallizations diastereomerically pure major (E)-isomers of mono-thiazolidin-4-ones were isolated. The structure and stereochemistry of 2,4-thiazolidinedione,2-[(17-oxoandrost-4-en-3-ylidene)hydrazone] were confirmed by X-ray analysis. A pathway for the formation of thiazolidin-4-one ring was proposed. The steroid thiazolidinone derivatives examined in this study exerted selective concentration-dependent cytotoxic activities on six tested malignant cell lines. Ten out of twelve examined compounds exhibited strong cytotoxic effects on K562 cells (IC 50 values from 8.5μM to 14.9μM), eight on HeLa cells (IC 50 values ranging from 8.9μM to 15.1μM) while against MDA-MB-361 cells six compouds exerted similar or even higher cytotoxic action (IC 50 values from 12.7μM to 25.6μM) than cisplatin (21.5μM) which served as a positive control. Eight of these ten compounds showed high selectivity in the cytotoxic action against HeLa and K562 cancer cell lines when compared with normal human fibroblasts MRC-5 and normal human PBMC. The study of mechanisms of the anticancer activity of the two selected compounds, mono- and bis(thiazolidin-4-one) derivatives of 19-norandrost-4-ene-3,17-dione 4a and 5a, revealed that both of these compounds induced apoptosis in HeLa cells through extrinsic and intrinsic signalling pathways. Treatment of EA.hy926 cells with sub-toxic concentrations of these compounds led to the inhibition of cell connecting and sprouting, and tube formation. The synthesized compounds exhibited poor antioxidant activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis and Agonistic Activity at the GPR35 of 5,6-Dihydroxyindole-2-carboxylic Acid Analogues

PubMed Central

2012-01-01

5,6-Dihydroxyindole-2-carboxylic acid (DHICA), an intermediate of melanin synthesis and an eumelanin building block, was recently discovered to be a GPR35 agonist with moderate potency. Here, we report the synthesis and pharmacological characterization of a series of DHICA analogues against GPR35 using both label-free dynamic mass redistribution and Tango β-arrestin translocation assays. This led to identification of novel GPR35 agonists with improved potency and/or having biased agonism. PMID:24900508

Kinesin spindle protein (KSP) inhibitors. Part 7: Design and synthesis of 3,3-disubstituted dihydropyrazolobenzoxazines as potent inhibitors of the mitotic kinesin KSP.

PubMed

Garbaccio, Robert M; Tasber, Edward S; Neilson, Lou Anne; Coleman, Paul J; Fraley, Mark E; Olson, Christy; Bergman, Jeff; Torrent, Maricel; Buser, Carolyn A; Rickert, Keith; Walsh, Eileen S; Hamilton, Kelly; Lobell, Robert B; Tao, Weikang; South, Vicki J; Diehl, Ronald E; Davide, Joseph P; Yan, Youwei; Kuo, Lawrence C; Li, Chunze; Prueksaritanont, Thomayant; Fernandez-Metzler, Carmen; Mahan, Elizabeth A; Slaughter, Donald E; Salata, Joseph J; Kohl, Nancy E; Huber, Hans E; Hartman, George D

2007-10-15

Observations from two structurally related series of KSP inhibitors led to the proposal and discovery of dihydropyrazolobenzoxazines that possess ideal properties for cancer drug development. The synthesis and characterization of this class of inhibitors along with relevant pharmacokinetic and in vivo data are presented. The synthesis is highlighted by a key [3+2] cycloaddition to form the pyrazolobenzoxazine core followed by diastereospecific installation of a quaternary center.

Bifunctional Bisphosphonates for Delivering Biomolecules to Bone

DTIC Science & Technology

2012-01-13

targeted PTH stimulated greater synthesis of cAMP in preosteoblasts compared to surfaces with simply adsorbed PTH. HBPs were also found to have similar pro...targeted PTH stimulated greater synthesis of cAMP in pre- osteoblasts compared to surfaces with simply adsorbed PTH. HBPs were also found to have similar...30 Chapter Two: Synthesis and Characterization of Bifunctional Bisphosphonates….31 Experimental Section……………………………………………………….……38 Reagents

Synthesis of Bisindole Alkaloids from the Apocynaceae Which Contain a Macroline or Sarpagine Unit: A Review

PubMed Central

Rahman, Md Toufiqur; Phani Babu Tiruveedhula, Veera V. N.; Cook, James M.

2016-01-01

Bisindole natural products consist of two monomeric indole alkaloid units as their obligate constituents. Bisindoles are more potent with respect to their biological activity than their corresponding monomeric units. In addition, the synthesis of bisindoles are far more challenging than the synthesis of monomeric indole alkaloids. Herein is reviewed the enantiospecific total and partial synthesis of bisindole alkaloids isolated primarily from the Alstonia genus of the Apocynaceae family. The monomeric units belong to the sarpagine, ajmaline, macroline, vobasine, and pleiocarpamine series. An up-to-date discussion of their isolation, characterization, biological activity as well as approaches to their partial and total synthesis by means of both synthetic and biosynthetic strategies are presented. PMID:27854259

L-shaped benzimidazole fluorophores: synthesis, characterization and optical response to bases, acids and anions.

PubMed

Lirag, Rio Carlo; Le, Ha T M; Miljanić, Ognjen Š

2013-05-14

Nine L-shaped benzimidazole fluorophores have been synthesized, computationally evaluated and spectroscopically characterized. These "half-cruciform" fluorophores respond to bases, acids and anions through changes in fluorescence that vary from moderate to dramatic.

Effects of anaerobiosis on in vivo protein synthesis in the roots of a marine angiosperm zostera marina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, R.D.; Alberte, R.S.

1989-04-01

The roots of the temperate seagrass Zostera marina undergo daily periods of anaerobiosis at night. These diurnal periods of anoxia alter many metabolic processes in the roots including carbon and nitrogen metabolism, amino acid synthesis, and synthesis and levels of ATP, ADP and AMP. To further characterize the effects of anaerobiosis, we determined in vivo rates of protein synthesis by measuring the relative incorporation of {sup 35}S-MET in TCA precipitated protein samples. Results from these studies show that in vivo protein synthesis decreases continuously during 12 h of anaerobiosis and correlates with changes in ATP levels under similar conditions. Furthermore,more » polypeptide patterns obtained by SDS-PAGE and 2D-SDSPAGE indicate that anaerobiosis leads to differential protein synthesis in the roots.« less

Characterization of dopamine releasable and reserve pools in Drosophila larvae using ATP/P2X2-mediated stimulation

PubMed Central

Xiao, Ning; Venton, B. Jill

2015-01-01

Dopaminergic signaling pathways are conserved between mammals and Drosophila, but the factors important for maintaining the functional pool of synaptic dopamine are not fully understood in Drosophila. In this study, we characterized the releasable and reserve dopamine pools in Drosophila larvae using ATP/ P2X2-mediated stimulation. Dopamine release was stable with stimulations performed at least every 5 min but decayed with stimulations performed 2 min apart or less, indicating the replenishment of the releasable pool occurred on a time scale between 2 and 5 min. Dopamine synthesis or uptake were pharmacologically inhibited with 3-iodotyrosine and cocaine, respectively, to evaluate their contributions to maintaining the releasable dopamine pool. We found that both synthesis and uptake were needed to maintain the releasable dopamine pool, with synthesis playing a major part in long-term replenishment and uptake being more important for short-term replenishment. These effects of synthesis and uptake on different time scales in Drosophila are analogous to mammals. However, unlike in mammals, cocaine did not activate a reserve pool of dopamine in Drosophila when using P2X2 stimulations. Our study shows that both synthesis and uptake replenish the releasable pool, providing a better understanding of dopamine regulation in Drosophila. PMID:25951875

Synthesis, Characterization, and Theoretical Considerations of 1,2-bis(oxyamino)ethane Salts

NASA Technical Reports Server (NTRS)

Crake, Greg; Hawkins, Tom; Hall, Leslie; Tollison, Kerri; Brand, Adam

2003-01-01

The synthesis, characterization, theoretical calculations, and safety studies of energetic salts of 1,2- bis(oxyamino) ethane, (H2N-O-CH2-CH2-O-NH2), were carried out. The salts were characterized by vibrational (infrared, Raman), multinuclear nmr studies (1H, 13C), differential scanning calorimetry (DSC); elemental analysis; and initial safety testing (impact and friction sensitivity) . Theoretical calculations on the neutral, monoprotonated, and doubly protonated species of ethylene bisoxyamine were carried out using xxxx level of theory for the lowest energy structure and these theoretical results compared with the experimentally observed bond distances and vibrational (ir, Raman) frequency values. The single crystal X-ray diffraction study was carried out on the mono-perchlorate salt revealing a high degree of hydrogen bonding with an unexpected structure.

Nanomaterial synthesis and characterization for toxicological studies: TiO2 case study

USGS Publications Warehouse

Valsami-Jones, E.; Berhanu, D.; Dybowska, A.; Misra, S.; Boccaccini, A.R.; Tetley, T.D.; Luoma, S.N.; Plant, J.A.

2008-01-01

In recent years it has become apparent that the novel properties of nanomaterials may predispose them to a hitherto unknown potential for toxicity. A number of recent toxicological studies of nanomaterials exist, but these appear to be fragmented and often contradictory. Such discrepancies may be, at least in part, due to poor description of the nanomaterial or incomplete characterization, including failure to recognise impurities, surface modifications or other important physicochemical aspects of the nanomaterial. Here we make a case for the importance of good quality, well-characterized nanomaterials for future toxicological studies, combined with reliable synthesis protocols, and we present our efforts to generate such materials. The model system for which we present results is TiO2 nanoparticles, currently used in a variety of commercial products. ?? 2008 The Mineralogical Society.

The effect of reactor geometry on the synthesis of graphene materials in plasma jets

NASA Astrophysics Data System (ADS)

Shavelkina, M. B.; Amirov, R. H.; Shatalova, T. B.

2017-05-01

The possibility of synthesis of graphene and graphane (hydrogenated graphene) using the decomposition of hydrocarbons by thermal plasma has been investigated. Investigations of the influence of the plasma-forming gas on the efficiency of synthesis and the morphology of graphene materials were carried out. The synthesis products have been characterized by the methods of scanning microscopy, Raman spectroscopy and thermal analysis. It is found that the morphology of graphene materials is affected by the geometry of the reactor. It was demonstrated that the obtained graphene materials are uniformly distributed in the volume of plastic based on cyanate ester resins under mixing.

Phosphine-free synthesis and characterization of type-II ZnSe/CdS core-shell quantum dots

NASA Astrophysics Data System (ADS)

Ghasemzadeh, Roghayyeh; Armanmehr, Mohammad Hasan; Abedi, Mohammad; Fateh, Davood Sadeghi; Bahreini, Zaker

2018-01-01

A phosphine-free route for synthesis of type-II ZnSe/CdS core-shell quantum dots, using green, low cost and environmentally friendly reagents and phosphine-free solvents such as 1-octadecene (ODE) and liquid paraffin has been reported. Hot-injection technique has been used for the synthesis of ZnSe core quantum dots. The CdS shell quantum dots prepared by reaction of CdO precursor and S powder in 1-octadecene (ODE). The ZnSe/CdS core-shell quantum dots were synthesized via successive ion layer adsorption and reaction (SILAR) technique. The characterization of produced quantum dots were performed by absorption and fluorescence spectroscopy, X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The results showed the formation of type-II ZnSe/CdS core-shell quantum dots with FWHM 32 nm and uniform size distribution.

Green Synthesis of Silver Nanoparticles using Extract of Pinus merkusii Jungh & De Vriese Cone Flower

NASA Astrophysics Data System (ADS)

Azkiya, N. I.; Masruri, M.; Ulfa, S. M.

2018-01-01

The paper studies recent application of cone flower waste from Pinus merkusii Jungh & De Vriese for an environmentally unclear method for synthesis silver nanoparticle. Phytochemical characterization using iron trichloride solution showed the extract of Pinus merkusii cone flower contains of phenolic group of secondary metabolite. This group acts as both reducing and stabilizing agents. For the synthesis of silver nanoparticle, solution of silver nitrate is added to the extract at 60°C. The effect of extract concentration (5-20%) and time reaction (15-60 min) is investigated. The formation of silver nanoparticle is confirmed by the color change from yellowish to brown. Meanwhile, UV-Vis characterization of silver nanoparticle in extract 20% and 60 min reaction showed surface plasmon resonance (SPR) at 431 nm, and transmission electron microscope (TEM) revealed the particle size range in between 8 and 23 nm with a spherical in shape.

Biocatalytic and antibacterial visualization of green synthesized silver nanoparticles using Hemidesmus indicus.

PubMed

Latha, M; Sumathi, M; Manikandan, R; Arumugam, A; Prabhu, N M

2015-05-01

In the present investigation, we described the green synthesis of silver nanoparticles using plant leaf extract of Hemidesmus indicus. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). TEM images proved that the synthesized silver nanoparticles were spherical in shape with an average particle size of 25.24 nm. To evaluate antibacterial efficacy, bacteria was isolated from poultry gut and subjected to 16S rRNA characterization and confirmed as Shigella sonnei. The in vitro antibacterial efficacy of synthesized silver nanoparticles was studied by agar bioassay, well diffusion and confocal laser scanning microscopy (CLSM) assay. The H. indicus mediated synthesis of silver nanoparticles shows rapid synthesis and higher inhibitory activity (34 ± 0.2 mm) against isolated bacteria S. sonnei at 40 μg/ml. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis procedure optimization and characterization of europium (III) tungstate nanoparticles

NASA Astrophysics Data System (ADS)

Rahimi-Nasrabadi, Mehdi; Pourmortazavi, Seied Mahdi; Ganjali, Mohammad Reza; Reza Banan, Ali; Ahmadi, Farhad

2014-09-01

Taguchi robust design as a statistical method was applied for the optimization of process parameters in order to tunable, facile and fast synthesis of europium (III) tungstate nanoparticles. Europium (III) tungstate nanoparticles were synthesized by a chemical precipitation reaction involving direct addition of europium ion aqueous solution to the tungstate reagent solved in an aqueous medium. Effects of some synthesis procedure variables on the particle size of europium (III) tungstate nanoparticles were studied. Analysis of variance showed the importance of controlling tungstate concentration, cation feeding flow rate and temperature during preparation of europium (III) tungstate nanoparticles by the proposed chemical precipitation reaction. Finally, europium (III) tungstate nanoparticles were synthesized at the optimum conditions of the proposed method. The morphology and chemical composition of the prepared nano-material were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy and fluorescence.

Green and microwave synthesis of SrAl2O4 nanoparticles by application of pomegranate juice: study and characterization

NASA Astrophysics Data System (ADS)

Riahi-Madvaar, Ramin; Taher, Mohammad Ali; Fazelirad, Hamid

2017-11-01

In the present paper, a green method was applied for the synthesis of SrAl2O4 nanostructures with the aid of microwave irradiation and pomegranate juice. SrAl2O4 nanocrystals were obtained when the raw materials were irradiated with 720-900 W for 6-10 min and then calcinated at 550 °C for 5 h. Using pomegranate juice as a dispersion and stabilizing agent, SrAl2O4 nanoparticles have been made with better properties in view of morphology and particle size. Also, the effect of some parameters affecting synthesis process such as microwave power and reaction time on the morphology and particle size of product was studied and optimized. X-ray diffraction and field emission-scanning electron microscopy were used to study and characterize the manufactured SrAl2O4 nanoparticles.

Two Alternative Pathways for the Synthesis of the Rare Compatible Solute Mannosylglucosylglycerate in Petrotoga mobilis▿

PubMed Central

Fernandes, Chantal; Mendes, Vitor; Costa, Joana; Empadinhas, Nuno; Jorge, Carla; Lamosa, Pedro; Santos, Helena; da Costa, Milton S.

2010-01-01

The compatible solute mannosylglucosylglycerate (MGG), recently identified in Petrotoga miotherma, also accumulates in Petrotoga mobilis in response to hyperosmotic conditions and supraoptimal growth temperatures. Two functionally connected genes encoding a glucosyl-3-phosphoglycerate synthase (GpgS) and an unknown glycosyltransferase (gene Pmob_1143), which we functionally characterized as a mannosylglucosyl-3-phosphoglycerate synthase and designated MggA, were identified in the genome of Ptg. mobilis. This enzyme used the product of GpgS, glucosyl-3-phosphoglycerate (GPG), as well as GDP-mannose to produce mannosylglucosyl-3-phosphoglycerate (MGPG), the phosphorylated precursor of MGG. The MGPG dephosphorylation was determined in cell extracts, and the native enzyme was partially purified and characterized. Surprisingly, a gene encoding a putative glucosylglycerate synthase (Ggs) was also identified in the genome of Ptg. mobilis, and an active Ggs capable of producing glucosylglycerate (GG) from ADP-glucose and d-glycerate was detected in cell extracts and the recombinant enzyme was characterized, as well. Since GG has never been identified in this organism nor was it a substrate for the MggA, we anticipated the existence of a nonphosphorylating pathway for MGG synthesis. We putatively identified the corresponding gene, whose product had some sequence homology with MggA, but it was not possible to recombinantly express a functional enzyme from Ptg. mobilis, which we named mannosylglucosylglycerate synthase (MggS). In turn, a homologous gene from Thermotoga maritima was successfully expressed, and the synthesis of MGG was confirmed from GDP-mannose and GG. Based on the measurements of the relevant enzyme activities in cell extracts and on the functional characterization of the key enzymes, we propose two alternative pathways for the synthesis of the rare compatible solute MGG in Ptg. mobilis. PMID:20061481

One-dimensional zinc oxide nanomaterials synthesis and photovoltaic applications

NASA Astrophysics Data System (ADS)

Weintraub, Benjamin A.

As humanly engineered materials systems approach the atomic scale, top-down manufacturing approaches breakdown and following nature's example, bottom-up or self-assembly methods have the potential to emerge as the dominant paradigm. Synthesis of one-dimensional nanomaterials takes advantage of such self-assembly manufacturing techniques, but until now most efforts have relied on high temperature vapor phase schemes which are limited in scalability and compatibility with organic materials. The solution-phase approach is an attractive low temperature alternative to overcome these shortcomings. To this end, this thesis is a study of the rationale solution-phase synthesis of ZnO nanowires and applications in photovoltaics. The following thesis goals have been achieved: rationale synthesis of a single ZnO nanowire on a polymer substrate without seeding, design of a wafer-scale technique to control ZnO nanowire array density using layer-by-layer polymers, determination of optimal nanowire field emitter density to maximize the field enhancement factor, design of bridged nanowires across metal electrodes to order to circumvent post-synthesis manipulation steps, electrical characterization of bridged nanowires, rationale solution-phase synthesis of long ZnO nanowires on optical fibers, fabrication of ZnO nanowire dye-sensitized solar cells on optical fibers, electrical and optical characterization of solar cell devices, comparison studies of 2-D versus 3-D nanowire dye-sensitized solar cell devices, and achievement of 6-fold solar cell power conversion efficiency enhancement using a 3-D approach. The thesis results have implications in nanomanufacturing scale-up and next generation photovoltaics.

High-pressure synthesis of mesoporous stishovite: potential applications in mineral physics

NASA Astrophysics Data System (ADS)

Stagno, Vincenzo; Mandal, Manik; Landskron, Kai; Fei, Yingwei

2015-06-01

Recently, we have described a successful synthesis route to obtain mesoporous quartz and its high-pressure polymorph coesite by nanocasting at high pressure using periodic mesostructured precursors, such as SBA-16 and FDU-12/carbon composite as starting materials. Periodic mesoporous high-pressure silica polymorphs are of particular interest as they combine transport properties and physical properties such as hardness that potentially enable the industrial use of these materials. In addition, synthesis of mesoporous crystalline silica phases can allow more detailed geology-related studies such as water/mineral interaction, dissolution/crystallization rate and the surface contribution to the associated thermodynamic stability (free energy and enthalpy) of the various polymorphs and their crossover. Here, we present results of synthesis of mesoporous stishovite from cubic large-pore periodic mesoporous silica LP-FDU-12/C composite as precursor with an fcc lattice. We describe the synthesis procedure using multi-anvil apparatus at 9 GPa (about 90,000 atm) and temperature of 500 °C. The synthetic mesoporous stishovite is, then, characterized by wide and small-angle X-ray diffraction, scanning/transmission electron microscopy and gas adsorption. Results show that this new material is characterized by accessible mesopores with wide pore size distribution, surface area of ~45 m2/g and volume of pores of ~0.15 cm3/g. Results from gas adsorption indicate that both porosity and permeability are retained at the high pressures of synthesis but with weak periodic order of the pores.

Endophytic synthesis of silver chloride nanoparticles from Penicillium sp. of Calophyllum apetalum

NASA Astrophysics Data System (ADS)

Chandrappa, C. P.; Govindappa, M.; Chandrasekar, N.; Sarkar, Sonia; Ooha, Sepuri; Channabasava, R.

2016-06-01

In the present study, Penicillium species extract isolated from Calophyllum apetalum was used for the synthesis of silver nanoparticles and it was confirmed by changing the color of the silver nitrate UV-Vis spectrum. The synthesized nanoparticles have been characterized by biophysical techniques such as scanning electron microscopy and x-ray diffraction.

SYNTHESIS AND CHARACTERIZATION OF A NOVEL SOLID ACID CATALYST FOR IMPROVED USE OF WASTE OIL FEEDSTOCK FOR BIODIESEL PRODUCTION

EPA Science Inventory

Carbon Catalyst Synthesis - Sucrose was treated directly with excess sulfuric acid sulfuric acid (9:1 mol/mol, 25°C). A carbon foam (nearly 20 fold increase in bulk volume) was immediately formed. The foam was then washed until no sulfate was dete...

Synthesis, structural characterization and antitumor activity of a Ca(II) coordination polymer based on 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tai, Xi-Shi, E-mail: taixs@wfu.edu.cn; Wang, Xin

2017-03-15

A new Ca(II) coordination polymer, ([CaL(H{sub 2}O){sub 4}] · (H{sub 2}O){sub 4}){sub n} (L = 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide) has been prepared by one-pot synthesis method. And it was characterized by elemental analysis, IR and thermal analysis. The result of X-ray single-crystal diffraction analysis shows that the Ca(II) complex molecules form one-dimensional chain structure by the bridging oxygen atoms. The anti-tumor activity of L ligand and the Ca(II) coordination polymer has also been studied.

Selective synthesis and characterization of chlorins as sensitizers for photodynamic therapy

NASA Astrophysics Data System (ADS)

Montforts, Franz-Peter; Kusch, Dirk; Hoper, Frank; Braun, Stefan; Gerlach, Benjamin; Brauer, Hans-Dieter; Schermann, Guido; Moser, Joerg G.

1996-04-01

Chlorin type sensitizers have ideal photophysical properties for an application in PDT. The basic chlorin framework of these sensitizers has to be modified by attachment of lipophilic and hydrophilic residues to achieve a good cell uptake and tumor enrichment. In the present study we describe the selective synthesis of amphiphilic chlorins starting from the readily accessible red blood pigment heme. The photophysical properties of the well defined synthetic chlorins are characterized by photophysical investigations. The kinetic of cell uptake, the localization in the cell and the photodynamic behavior of the amphiphilic sensitizers are demonstrated by incubation of A 375 cancer cell lines with structurally different chlorins.

Synthesis and characterization of silver nanoparticles using Caesalpinia pulcherrima flower extract and assessment of their in vitro antimicrobial, antioxidant, cytotoxic, and genotoxic activities.

PubMed

Moteriya, Pooja; Chanda, Sumitra

2017-12-01

Caesalpinia pulcherrima flower extract mediated synthesis of silver nanoparticles was attempted in the present work including optimization of some procedure parameters. Characterization of synthesized silver nanoparticles was done by various spectral analyses. The size of synthesized silver nanoparticles was 12 nm and they were spherical in shape. The green synthesized silver nanoparticles were further evaluated for antimicrobial, antioxidant, cytotoxic, and genotoxic activities; they showed good antimicrobial, antioxidant, and cytotoxic effects. Genotoxic study revealed non-toxic nature at lower concentration. Overall results suggest that the synthesized silver nanoparticles have pronounced applicability in pharmaceutical and biomedical field.

Vibrational properties of gold nanoparticles obtained by green synthesis

NASA Astrophysics Data System (ADS)

Alvarez, Ramón A. B.; Cortez-Valadez, M.; Bueno, L. Oscar Neira; Britto Hurtado, R.; Rocha-Rocha, O.; Delgado-Beleño, Y.; Martinez-Nuñez, C. E.; Serrano-Corrales, Luis Ivan; Arizpe-Chávez, H.; Flores-Acosta, M.

2016-10-01

This study reports the synthesis and characterization of gold nanoparticles through an ecological method to obtain nanostructures from the extract of the plant Opuntia ficus-indica. Colloidal nanoparticles show sizes that vary between 10-20 nm, and present various geometric morphologies. The samples were characterized through optical absorption, Raman Spectroscopy and Transmission Electron Microscopy (TEM). Additionally, low energy metallic clusters of Aun (n=2-20 atoms) were modeled by computational quantum chemistry. The theoretical results were obtained with Density Functional Theory (DFT). The predicted results of Au clusters show a tendency and are correlated with the experimental results concerning the optical absorption bands and Raman spectroscopy in gold nanoparticles.

Synthesis and characterization of a new porphyrin-polyoxometalate hybrid material and investigation of its catalytic activity.

PubMed

Araghi, Mehdi; Mirkhani, Valiollah; Moghadam, Majid; Tangestaninejad, Shahram; Mohammdpoor-Baltork, Iraj

2012-03-14

In the present work, the preparation of a new organic-inorganic hybrid material in which tetrakis(p-aminophenylporphyrin) is covalently linked to a Lindqvist structure of polyoxometalate, is reported. This new porphyrin-polyoxometalate hybrid material was characterized by (1)H NMR, FT-IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided spectral data of the synthesis of this compound. Cyclic voltammetry showed the influence of the porphyrin on the redox process of the polyoxometalate. The catalytic activity of this hybrid material was investigated in the alkene epoxidation with NaIO(4).

Synthesis of two fluorescent GTPγS molecules and their biological relevance.

PubMed

Trans, Denise J; Bai, Ruoli; Addison, J Bennet; Liu, Ruiwu; Hamel, Ernest; Coleman, Matthew A; Henderson, Paul T

2017-06-03

Fluorescent GTP analogues are utilized for an assortment of nucleic acid and protein characterization studies. Non-hydrolysable analogues such as GTPγS offer the advantage of keeping proteins in a GTP-bound conformation due to their resistance to hydrolysis into GDP. Two novel fluorescent GTPγS molecules were developed by linking fluorescein and tetramethylrhodamine to the γ-thiophosphate of GTPγS. Chemical and biological analysis of these two compounds revealed their successful synthesis and ability to bind to the nucleotide-binding site of tubulin. These two new fluorescent non-hydrolysable nucleotides offer new possibilities for biophysical and biochemical characterization of GTP-binding proteins.

Design, synthesis, and characterization of fluorine-free PAGs for 193-nm lithography

NASA Astrophysics Data System (ADS)

Liu, Sen; Glodde, Martin; Varanasi, Pushkara R.

2010-04-01

Photoacid generators (PAGs) are a key component in chemically amplified resists used in photolithography. Perfluorooctanesulfonates (PFOS) and other perfluoroalkylsulfonates (PFAS) have been well adopted as PAGs in 193 nm photoresist. Recently, concerns have been raised about their environmental impact due to their chemical persistency, bioaccumulation and toxicity. It is a general interest to find environmentally benign PAGs that are free of fluorine atoms. Here we describe the design, synthesis and characterization of a series of novel fluorine-free onium salts as PAGs for 193 nm photoresists. These PAGs demonstrated desirable physical and lithography properties when compared with PFAS-based PAGs for both dry and immersion exposures.

Mechanochemical synthesis and structural characterization of three novel cocrystals of dimethylglyoxime with N-heterocyclic aromatic compounds and acetamide

NASA Astrophysics Data System (ADS)

Abidi, Syed Sibte Asghar; Azim, Yasser; Gupta, Abhishek Kumar; Pradeep, Chullikkattil P.

2017-12-01

With an aim to explore the interactions of (RR'Cdbnd Nsbnd OH) oxime moiety of dimethylglyoxime (DMG) with pyridyl ring of N-heterocyclic aromatic compounds and acetamide, three novel cocrystals of dimethylglyoxime with acridine (ACR), 1,10-phenanthroline monohydrate (PT) and acetamide (ACT) are reported. These three cocrystals were obtained with a mechanochemical synthesis approach and were characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), fourier transform-infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Additionally, Hirshfeld surface analysis is used to investigate the intermolecular interaction and the crystal packing of cocrystals.

A series of fluorene-based two-photon absorbing molecules: synthesis, linear and nonlinear characterization, and bioimaging

PubMed Central

Andrade, Carolina D.; Yanez, Ciceron O.; Rodriguez, Luis; Belfield, Kevin D.

2010-01-01

The synthesis, structural, and photophysical characterization of a series of new fluorescent donor–acceptor and acceptor-acceptor molecules, based on the fluorenyl ring system, with two-photon absorbing properties is described. These new compounds exhibited large Stokes shifts, high fluorescent quantum yields, and, significantly, high two-photon absorption cross sections, making them well suited for two-photon fluorescence microscopy (2PFM) imaging. Confocal and two-photon fluorescence microscopy imaging of COS-7 and HCT 116 cells incubated with probe I showed endosomal selectivity, demonstrating the potential of this class of fluorescent probes in multiphoton fluorescence microscopy. PMID:20481596

Synthesis and characterization of guar-alginate hybrid bead templated mercury sorbing titania spheres.

PubMed

Singh, Vandana; Preeti; Singh, Angela; Singh, Devendra; Singh, Yadveer; Pandey, Arvind Kumar

2015-01-01

Present communication reports on the synthesis and characterization of Hg(II) sorbing millimeter sized porous titania spheres (TSP). The synthesis utilizes guar gum-alginate hybrid beads as sacrificial template to polymerize titanium(IV) isopropoxide. The hybrid beads are crafted by pouring guar-alginate mixed solution to calcium bath. The mechanical strength of the beads depended on guar to alginate ratio in the mixed solution. The equal weight ratio of the two polysaccharides is appropriate for adequate mechanical strength beads. The unique performance of the templating beads is attributed to the synergistic interaction between guar gum and sodium alginate. FTIR, BET, SEM, TEM, XRD, TGA, and DTG analyses have been used for the characterization of the optimum performance TSP (TSPAG2). TSPAG2 is a mesoporous material that has higher surface area and narrower pore size distribution than pure alginate derived titania spheres (TSPA). TEM study demonstrated that TSPAG2 spheres are constituted of aggregated TiO2 nanoparticles of ∼ 10 nm size. TSPAG2 is able to capture >95% Hg(II) from synthetic Hg(II) solution in 10h at pH 5 as opposed to only 68% removal by TSPA. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis, spectroscopic characterizations, crystal structures and DFT studies of nalidixic acid carbonyl hydrazones derivatives

NASA Astrophysics Data System (ADS)

Bergamini, F. R. G.; Ribeiro, M. A.; Lancellotti, M.; Machado, D.; Miranda, P. C. M. L.; Cuin, A.; Formiga, A. L. B.; Corbi, P. P.

2016-09-01

This article describes the synthesis and characterization of the 1-ethyl-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carbohydrazide (hzd) and six carbonyl hydrazones derivatives of the nalidixic with 1H-pyrrol-2-ylmethylidene (hpyrr), 1H-imidazol-2-ylmethylidene (h2imi), pyridin-2-ylmethylidene (h2py), pyridin-3-ylmethylidene (h3py), pyridin-4-ylmethylidene(h4py) and (2-hydroxyphenyl)methylidene (hsali). The carbonyl hydrazones were characterized by elemental and ESI-QTOF-MS analyses, IR and detailed NMR spectroscopic measurements. The 2D NMR experiments allowed the unambiguous assignment of the hydrogen, carbon and nitrogen atoms, which have not been reported for nalidixic acid carbonyl hydrazone derivatives so far. Crystal structures of hzd and the new carbonyl hydrazones h2imi, hpyrr and h3py were determined by X-ray diffraction studies. Although the synthesis of hzd was reported decades ago, the hzd crystal structure have not been reported yet. Geometric optimizations of all the characterized structures were performed with the aid of DFT studies. Despite the fact that the hydrazones with 2-pyridine carboxylic acid (h2py) and salicyl aldehyde (hsali) were already reported by literature, a detailed spectroscopic study followed by DFT studies are also reported for such compounds in this manuscript. Antimicrobial studies of the compounds are also presented.

Electrochemical synthesis and characterization of zinc oxalate nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shamsipur, Mojtaba, E-mail: mshamsipur@yahoo.com; Roushani, Mahmoud; Department of Chemistry, Ilam University, Ilam

2013-03-15

Highlights: ► Synthesis of zinc oxalate nanoparticles via electrolysis of a zinc plate anode in sodium oxalate solutions. ► Design of a Taguchi orthogonal array to identify the optimal experimental conditions. ► Controlling the size and shape of particles via applied voltage and oxalate concentration. ► Characterization of zinc oxalate nanoparticles by SEM, UV–vis, FT-IR and TG–DTA. - Abstract: A rapid, clean and simple electrodeposition method was designed for the synthesis of zinc oxalate nanoparticles. Zinc oxalate nanoparticles in different size and shapes were electrodeposited by electrolysis of a zinc plate anode in sodium oxalate aqueous solutions. It was foundmore » that the size and shape of the product could be tuned by electrolysis voltage, oxalate ion concentration, and stirring rate of electrolyte solution. A Taguchi orthogonal array design was designed to identify the optimal experimental conditions. The morphological characterization of the product was carried out by scanning electron microscopy. UV–vis and FT-IR spectroscopies were also used to characterize the electrodeposited nanoparticles. The TG–DTA studies of the nanoparticles indicated that the main thermal degradation occurs in two steps over a temperature range of 350–430 °C. In contrast to the existing methods, the present study describes a process which can be easily scaled up for the production of nano-sized zinc oxalate powder.« less

Synthesis and Characterization of Cobalt Containing Nanoparticles on Alumina A Potential Catalyst for Gas to Liquid Fuels Production

NASA Technical Reports Server (NTRS)

Cowen, Jonathan; Hepp, Aloysius F.

2016-01-01

Fisher-Tröpsch synthesis (FTS) is a century-old gas-to-liquid (GTL) technology that commonly employs cobalt (Co, on an oxide support) or iron (supported or not) species catalysts. It has been well established that the activity of the Co catalyst depends directly upon the number of surface Co atoms. The addition of promoter (mainly noble) metals has been widely utilized to increase the fraction of Co that is available for surface catalysis. Direct synthesis of Co nanoparticles is a possible alternative approach; our preliminary synthesis and characterization efforts are described. Materials were characterized by various transmission microscopies and energy dispersive spectroscopy. Tri-n-octylphosphine oxide (TOPO) and dicobalt octacarbonyl were heated under argon to a temperature of 180 deg with constant stirring for 1 hr. Quenching the reaction in toluene produced Co-containing nanoparticles with a diameter of 5 to 10 nm. Alternatively, an alumina support (SBA-200 Al2O3) was added; the reaction was further stirred and the temperature was decreased to 140 deg to reduce the rate of further growth/ripening of the nucleated Co nanoparticles. A typical size of Co-containing NPs was also found to be in the range of 5 to 10 nm. This can be contrasted with a range of 50 to 200 nm for conventionally-produced Co-Al2O3 Fischer-Tröpsch catalysts. This method shows great potential for production of highly dispersed catalysts that are either supported or unsupported.

Silver nanostructures from Ag(CN) 2 - reduction by citrate ions in the presence of dodecyl sulfate and Cu2+ ions. Synthesis and characterization

NASA Astrophysics Data System (ADS)

López-Miranda, A.; Viramontes-Gamboa, G.; López-Valdivieso, A.

2014-02-01

The synthesis of silver nanoparticles has been investigated using Ag(CN) 2 - species as precursor, citrate ions as reducing agent, and dodecyl sulfate ions as stabilizer, at pH 11 and 97 °C, in a batch stirred glass reactor. The role of Cu2+ ions in the synthesis was also studied. Bird- of- paradise flower-type nanostructures composed of AgCN nanowires having inside Ag and AgCN nanoparticles were produced in the absence of Cu2+ ions. The nanostructures slowly grew and transformed to AgCN nanowires with embedded Ag and AgCN nanoparticles, having a mean size of 9.7 ± 3.6 nm. The presence of Cu2+ ions in the synthesis significantly enhanced the production of the nanostructures. Nanowires having a thickness of 63 ± 33 nm and length of up to 20 μm were produced. Cu2+ ions also simultaneously lead to the synthesis of ordinary free Ag nanoparticles with a bimodal size distribution (mean sizes of 9.9 ± 3.9 and 65.5 ± 27 nm) and a low experimental formation kinetic rate constant of 1.22 × 10-4 s-1. Feasible mechanisms are presented for the origin of the AgCN nanowires, Ag and AgCN nanoparticles inside the nanowires, and for the free Ag nanoparticles. UV/Vis spectrometry was used to measure the surface plasmon resonance of the nanoparticles and the synthesis kinetic rate constant of the free Ag nanoparticles. ATR-FTIR spectroscopy, EDS-SEM, EDS-TEM, and HRTEM were used to characterize the size, crystal structure, texture, and chemical composition of the synthesis products.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2008-01-30

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

New Synthesis and Tritium Labeling of a Selective Ligand for Studying High-affinity γ-Hydroxybutyrate (GHB) Binding Sites

PubMed Central

Vogensen, Stine B.; Marek, Aleš; Bay, Tina; Wellendorph, Petrine; Kehler, Jan; Bundgaard, Christoffer; Frølund, Bente; Pedersen, Martin H.F.; Clausen, Rasmus P.

2013-01-01

3-Hydroxycyclopent-1-enecarboxylic acid (HOCPCA, 1) is a potent ligand for the high-affinity GHB binding sites in the CNS. An improved synthesis of 1 together with a very efficient synthesis of [3H]-1 is described. The radiosynthesis employs in situ generated lithium trimethoxyborotritide. Screening of 1 against different CNS targets establishes a high selectivity and we demonstrate in vivo brain penetration. In vitro characterization of [3H]-1 binding shows high specificity to the high-affinity GHB binding sites. PMID:24053696

Synthesis of soil geochemical characteristics and organic carbon degradation in Arctic polygon tundra, Barrow, Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Jianqiu; RoyChowdhury, Taniya; Herndon, Elizabeth

This is a synthesis data product that reports (1) the results of soil geochemical characterization and (2) organic carbon degradation in low temperature soil incubations on cores collected on the NGEE Arctic Study Area near Utqiaġvik (Barrow), Alaska. The study area consists of thaw lakes, drained thaw lake basins and interstitial tundra with a polygonal landscape of microtopographic features created by ice wedges. Integrated geochemical and organic carbon degradation data from 9 individual soil cores are included in the synthesis product.

Synthesis of the diazonium (perfluoroalkyl) benzenesulfonimide monomer from Nafion monomer for proton exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Mei, Hua; D'Andrea, Dan; Nguyen, Tuyet-Trinh; Nworie, Chima

2014-02-01

One diazonium (perfluoroalkyl) benzenesulfonimide monomer, perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide, has been synthesized from Nafion monomer for the first time. With trifluorovinyl ether and diazonium precursors, the partially-fluorinated diazonium PFSI monomer can be polymerized and will provide chemically bonding with carbon electrode in proton exchange membrane fuel cells. A systematic study of the synthesis and characterization of this diazonium PFSI monomer has been conducted by varying reaction conditions. The optimized synthesis method has been established in the lab.

Hydrothermal synthesis, characterization, and thermal properties of alumino silicate azide sodalite, Na8[AlSiO4]6(N3)2

NASA Astrophysics Data System (ADS)

Borhade, A. V.; Wakchaure, S. G.; Dholi, A. G.; Kshirsagar, T. A.

2017-07-01

First time we report the synthesis, structural characterization and thermal behavior of an unusual N3 - containing alumino-silicate sodalite mineral. Azide sodalite, Na8[AlSiO4]6(N3)2 has been synthesized under hydrothermal conditions at 433 K in steel lined Teflon autoclave. The structural and microstructural properties of azide sodalite mineral was characterized by various methods including FT-IR, XRD, SEM, TGA, and MAS NMR. Crystal structure have been refined by Rietveld method in P\\bar 43n space group, indicating that the N3 - sodalite has cubic in lattice. High temperature study was carried out to see the effect of thermal expansion on cell dimension ( a o) of azide sodalite. Thermal behavior of sodalite was also assessed by thermogravimetric method.

Green synthesis and spectral characterization of silver nanoparticles from Lakshmi tulasi (Ocimum sanctum) leaf extract

NASA Astrophysics Data System (ADS)

Subba Rao, Y.; Kotakadi, Venkata S.; Prasad, T. N. V. K. V.; Reddy, A. V.; Sai Gopal, D. V. R.

2013-02-01

A simple method for the green synthesis of silver nanoparticles (AgNPs) using aqueous extract of Lakshmi tulasi (Ocimum sanctum) leaf as a reducing and stabilizing agent. AgNPs were rapidly synthesized using aqueous extract of tulasi leaf with AgNO3 solution within 15 min. The green synthesized AgNPs were characterized using physic-chemical techniques viz., UV-Vis, X-ray diffraction (XRD), scanning electron microscope (SEM) coupled with X-ray energy dispersive spectroscopy (EDX) and Fourier transform-infrared spectroscopy (FT-IR). Characterization data reveals that the particles were crystalline in nature and triangle shaped with an average size of 42 nm. The zeta potential of AgNPs were found to be -55.0 mV. This large negative zeta potential value indicates repulsion among AgNPs and their dispersion stability.

Synthesis and performance characterization of 2-(dinitromethylene)-1-nitro-1, 3-diazacyclopentane

NASA Astrophysics Data System (ADS)

Liu, Pan; Qin, Weiyan

2018-04-01

The present paper described an new effort to synthesis 2-(dinitromethylene)-l-nitro-1, 3-diaza-cyclopentane (iv), characterization an thermal studies of (iv) are also reported. 2-(dinitromethylene)-1, 3-diazacyclo-pentane (i) was synthesized from the nucleophilic substitution of ethylenediamine and 1,1-diamino-2,2-dinitroethylene (FOX-7) catalyzed by Mg(OAc)2. Then i was transformed to iv through reactions of nitration, reduction and hydrolysis. The structure of iv was characterized by IR, NMR, MS and elemental analysis. Thermal stability of iv was investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC) which revealed that decomposed at 131 °C. The experimentally determined sensitivity parameters indicated that iv is sensitive towards external stimuli. The performance of iv had been calculated using VLW equation and its crystal morphology was investigated by scanning electron microscopy (SEM).

Synthesis and characterization of gillespite

NASA Astrophysics Data System (ADS)

Bloise, A.

2018-04-01

The synthesis of gillespite BaFeSi4O10 was investigated under various experimental conditions: temperature 300-400 °C; pressure 0.1-1 kbar; duration of treatment 92-160 h. The run products were characterized by X-ray powder diffraction, scanning and transmission electron microscopy with an energy-dispersive spectrometer and differential scanning calorimetry (DSC). At 1 kbar for 160 h of treatment, an increase in temperature from 300 to 400 °C was found to increase the abundance and degree of crystallinity of gillespite even if a further decrease in pressure or reaction time may hinder gillespite formations. The effects of experimental conditions on the presence of other accessory phases and the yield and size of gillespite crystals were also discussed. Further characterization by DSC was carried out to determine the thermal stability of synthesized gillespite.

Synthesis and Characterization of Molybdenum Based Colloidal Particles.

PubMed

Moreno; Vidoni; Ovalles; Chaudret; Urbina; Krentzein

1998-11-15

The synthesis and characterization of molybdenum colloidal particles were evaluated using thermal and sonochemical methods and starting from different metal precursors, Mo(CO)6 and (NH4)2MoS4. The products were characterized by elemental analysis, spectroscopic (UV, FTIR), and surface analysis (XPS) techniques, as well as by transmission electron microscopy (TEM) for determining the particle sizes. Using Mo(CO)6 as metal source, particle sizes with an average diameter of 1.5 nm can be obtained using tert-amyl alcohol as solvent and tetrahydrothiophene as sulfurating ligand. The characterization of these particles showed that they are composed of molybdenum oxide MoO3. Using (NH4)2MoS4 as metal precursor, particles with average diameters of 4.7 and 2.5 nm were synthesized using thermal and sonochemical methods, respectively. The characterization of these particles showed them to be composed of molybdenum sulfide, MoS2. The sonochemical method proved to be the fastest and most convenient synthetic pathway of obtaining small colloidal particles at low temperatures and with control of the average size. Copyright 1998 Academic Press.

Synthesis of ent-kaurane diterpene monoglycosides.

PubMed

Chaturvedula, Venkata Sai Prakash; Klucik, Josef; Upreti, Mani; Prakash, Indra

2011-10-03

Synthesis of two ent-kaurane diterpene glycosides, steviol 19-O-β-D-glucopyranosiduronic acid (steviol glucuronide, 5), and 13-hydroxy ent-kaur-16-en-19-oic acid-β-D-glucopyranosyl ester (7) has been achieved from a common starting material, steviol, using phase transfer catalyst. Also, synthesis of an additional 17-nor-ent-kaurane glycoside, namely 13-methyl-16-oxo-17-nor-ent-kauran-19-oic acid-β-D-glucopyranosyl ester (10) was performed using the starting material isosteviol and similar synthetic methodology. Synthesis of all three steviol glycosides was performed using straightforward chemistry and their structures were characterized on the basis of 1D and 2D NMR as well as mass spectral (MS) data.

Some further studies on the synthesis of glycopeptide derivatives: 2-acetamido-2-deoxy-β-d-glucopyranosylamine derivatives

PubMed Central

Bolton, C. H.; Hough, L.; Khan, M. Y.

1966-01-01

1. The isolation, characterization and properties of two by-products in the preparation of 2-acetamido-3,4,6-tri-O- acetyl-2-deoxy-β-d-glucopyranosylamine are described. They are bis(2-acetamido-2-deoxy-d-glucopyranosyl)amines. 2. An independent synthesis of the bis-glycopyranosylamines is reported and conditions are given for their preparation in high yield. 3. Further improvements are given for the synthesis of 2-acetamido-1-N-(β-l- aspartyl)-2-deoxy-β-d-glucopyranosylamine and the α-l-aspartyl isomer. 4. The synthesis of 2-acetamido-1-N-acetyl-2-deoxy-β-d-glucopyranosylamine is described. PMID:5971780

Synthesis and Characterization of Ca, Mg, La- PMMA Polymer Composites for Phosphate Removal

EPA Science Inventory

In this study calcium, magnesium and lanthanum- PMMA polymer composites were synthesized, characterized and investigated for phosphate removal from wastewater using rapid small scale column tests. Theoretical and experimental capacity of the media was determined and unused and sp...

Synthesis and Characterization of 2-Phenylimidazo[1,2-a]pyridine: A Privileged Structure for Medicinal Chemistry

ERIC Educational Resources Information Center

Santaniello, Brandi S.; Price, Matthew J.; Murray, James K., Jr.

2017-01-01

A straightforward synthesis of 2-phenylimidazo[1,2-a]pyridine is described. The reaction is designed to demonstrate to students the preparation of a bridged N-heterocycle, in which the heteroatom occupies a bridgehead position. The product is obtained in moderate to high yield and is highly crystalline. The compound can be purified either by…

Transformation of a Dwarf "Arabidopsis" Mutant Illustrates Gibberellin Hormone Physiology and the Function of a Green Revolution Gene

ERIC Educational Resources Information Center

Molina, Isabel; Weber, Katrin; Alves Cursino dos Santos, Deborah Y.; Ohlrogge, John

2009-01-01

The introduction of dwarfing traits into crops was a major factor in increased grain yields during the "Green Revolution." In most cases those traits were the consequence of altered synthesis or response to the gibberellin (GA) plant hormones. Our current understanding of GA synthesis and physiology has been facilitated by the characterization of…

Synthesis and optimization of thiadiazole derivatives as a novel class of substrate competitive c-Jun N-terminal kinase inhibitors

PubMed Central

De, Surya K.; Chen, Vida; Stebbins, John L.; Chen, Li-Hsing; Cellitti, Jason F.; Machleidt, Thomas; Barile, Elisa; Riel-Mehan, Megan; Dahl, Russell; Yang, Li; Emdadi, Aras; Murphy, Ria; Pellecchia, Maurizio

2009-01-01

A series of thiadiazole derivatives has been designed as potential allosteric, substrate competitive inhibitors of the protein kinase JNK. We report on the synthesis, characterization and evaluation of a series of compounds that resulted in the identification of potent and selective JNK inhibitors targeting its JIP-1 docking site. PMID:20045647

Synthesis, chemical characterization, and economical feasibility of poly-phenolic-branched-chain fatty acids: Synthesis of poly-phenolic-branched-chain fatty acids

USDA-ARS?s Scientific Manuscript database

New poly-phenolic branched-chain fatty acid (poly-PBC-FA) products were synthesized from a combination of soybean fatty acids and phenolic materials through a highly efficient zeolite catalyzed arylation method. These poly-PBC-FAs are liquid at room temperature and do not have the unpleasant odor li...

Introducing Plastics in the Laboratory: Synthesis of a Plasticizer, Dioctylphthalate and Evaluation of its Effects on the Physical Properties of Polystyrenes.

ERIC Educational Resources Information Center

Caspar, A.; And Others

1986-01-01

Proposes a two-stage experimental approach that combines preparative chemistry and polymer characterization. Describes the simple organic synthesis of a plasticizer, the dioctylphthalate, and its direct use in the preparation of a styrene/divinylbenzene network copolymer. Discusses how to evaluate the physical properties of the resulting plastic.…

Immobilization of isolated FI catalyst on polyhedral oligomeric silsesquioxane-functionalized silica for the synthesis of weakly entangled polyethylene.

PubMed

Li, Wei; Yang, Huaqin; Zhang, Jingjing; Mu, Jingshan; Gong, Dirong; Wang, Xiaodong

2016-09-25

Polyhedral oligomeric silsesquioxanes (POSSs) were adsorbed on methylaluminoxane-activated silica for the immobilization of fluorinated bis(phenoxyimine)Ti complexes (FI catalyst). These POSSs have been characterized as horizontal spacers isolating the active sites and hindering the chain overlap in polymerization. The heterogeneous catalyst exhibits considerable activity in the synthesis of weakly entangled polyethylene.

RESEARCH INVESTIGATIONS ON THE PROTEOME: 1. MECHANISMS OF REGULATING PROTEIN SYNTHESIS, AND 2. GLOBAL CHARACTERIZATION OF PROTEOMIC RESPONSES TO ARSENIC EXPOSURES

EPA Science Inventory

Eukaryotic Elongation Factor 2 (eEF2) mediates translocation in protein synthesis. eEF2 is modified by two post-translational modifications: the phosphorylation of Thr57 in the G domain and a unique conversion of His699 to diphthamide at the tip of domain IV. Diphthamide is the t...

Establishment of process technology for the manufacture of dinitrogen pentoxide and its utility for the synthesis of most powerful explosive of today--CL-20.

PubMed

Talawar, M B; Sivabalan, R; Polke, B G; Nair, U R; Gore, G M; Asthana, S N

2005-09-30

This paper reviews the recent work done on the synthesis as well as characterization of dinitrogen pentoxide (DNPO). The physico-chemical characteristics of DNPO are also discussed. The review brings out the key aspects of N2O5 technology with relevance to realize modern and novel HEMs. The paper also includes the aspects related with establishing the synthesis facility of dinitrogen pentoxide at HEMRL by gas phase interaction of N2O4 with O3. The process parameters for the synthesis of N2O5 at 50 g/batch have been optimized. The synthesized dinitrogen pentoxide has been characterized by UV [204, 213, 258 nm (pi-->pi*) 378 and 384 nm (n-->pi*)] and IR (1428, 1266, 1249, 1206, 1044, 822, 750, 546 and 454 cm(-1)) spectroscopy. The DSC clearly showed the sublimation of N2O5 at 32 degrees C. The nitration studies on 2,6,8,12-tetraacetylhexaaza tetracyclo[5,5,0,0(3,11)0(5,9)]dodecane (TAIW) proved its viability in 2,4,6,8,10,12-hexanitro-2,4,6,8(10,12))-hexaazatetracyclo [5,5,0,0(3,11)0(5,9)]dodecane (CL-20) synthesis. The synthesized CL-20 and its precursors have also been subjected to hyphenated TG-FTIR studies to understand decomposition pattern.

Green synthesis, characterization and antibacterial efficacy of palladium nanoparticles synthesized using Filicium decipiens leaf extract

NASA Astrophysics Data System (ADS)

Sharmila, G.; Farzana Fathima, M.; Haries, S.; Geetha, S.; Manoj Kumar, N.; Muthukumaran, C.

2017-06-01

Synthesis of metal nanoparticles through green chemistry route is an emerging eco-friendly approach in the present days. An eco-friendly, biogenic synthesis of palladium nanoparticles (PdNPs) using Filicium decipiens leaf extract was reported in the present study. The synthesized PdNPs were characterized by UV-visible spectroscopy, Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The PdNPs formation was confirmed by UV-visible spectrophotometer and spherical shaped PdNPs with size range of 2-22 nm was observed in TEM analysis. Energy dispersive X-ray spectroscopy (EDS) analysis confirmed the presence of palladium in the synthesized nanoparticles. The crystalline nature of PdNPs was confirmed by XRD pattern and compared with the standard. The phytochemicals and proteins were identified by their functional groups in FT-IR spectrum and revealed the amide, amine groups present in F. decipiens may have involved in the bio-reduction reaction for PdNPs synthesis. Prepared PdNPs showed potential antibacterial activity against both Gram-positive and Gram-negative bacteria. F. decipiens leaf extract based PdNPs showed high bactericidal activity against Escherichia coli, Pseudomonas aeruginosa as compared to Staphylococcus aureus and Bacillus subtilis Results showed that phytochemicals rich F. decipiens leaf extract may be utilized as an effective non-toxic reducing agent for PdNPs synthesis and prepared PdNPs may useful in biomedical applications.

Methodology for the specification of communication activities within the framework of a multi-layered architecture: Toward the definition of a knowledge base

NASA Astrophysics Data System (ADS)

Amyay, Omar

A method defined in terms of synthesis and verification steps is presented. The specification of the services and protocols of communication within a multilayered architecture of the Open Systems Interconnection (OSI) type is an essential issue for the design of computer networks. The aim is to obtain an operational specification of the protocol service couple of a given layer. Planning synthesis and verification steps constitute a specification trajectory. The latter is based on the progressive integration of the 'initial data' constraints and verification of the specification originating from each synthesis step, through validity constraints that characterize an admissible solution. Two types of trajectories are proposed according to the style of the initial specification of the service protocol couple: operational type and service supplier viewpoint; knowledge property oriented type and service viewpoint. Synthesis and verification activities were developed and formalized in terms of labeled transition systems, temporal logic and epistemic logic. The originality of the second specification trajectory and the use of the epistemic logic are shown. An 'artificial intelligence' approach enables a conceptual model to be defined for a knowledge base system for implementing the method proposed. It is structured in three levels of representation of the knowledge relating to the domain, the reasoning characterizing synthesis and verification activities and the planning of the steps of a specification trajectory.

One-step synthesis of highly-biocompatible spherical gold nanoparticles using Artocarpus heterophyllus Lam. (jackfruit) fruit extract and its effect on pathogens.

PubMed

Basavegowda, Nagaraj; Dhanya Kumar, Gowri; Tyliszczak, Bozena; Wzorek, Zbigniew; Sobczak-Kupiec, Agnieszka

2015-01-01

Novel approaches for the synthesis of gold nanoparticles (AuNPs) are of great importance due to its vast spectrum of applications in diverse fields, including medical diagnostics and therapeutics. Te presented study reports the successful AuNPs' synthesis using Artocarpus heterophyllus Lam. extract, and provides detailed characterization and evaluation of its antibacterial potential. The aim was to develop a cost-effective and environmentally friendly synthesis method of gold nanoparticles using aqueous fruit extract of Artocarpus heterophyllus Lam. as a reducing and capping agent, which has proven activity against human pathogens, such as microbial species E.coli and Streptobacillus sps. Characterizations were carried out using ultraviolet-visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray and Fourier-Transform infra-red spectroscopy (FT-IR). SEM images showed the formation of gold nanoparticles with an average size of 20-25 nm. Spectra collected while infra-red analysis contained broad peaks in ranges from 4000-400 cm -1 . It can be concluded that the fruit of Artocarpus heterophyllus Lam. can be good source for synthesis of gold nanoparticles which showed antimicrobial activity against investigated microbes, in particul E. coli, and Streptobacillus. An important outcome of this study will be the development of value-added products from the medicinal plant Artocarpus heterophyllus Lam. for the biomedical and nanotechnology-based industries.

Synthesis and characterization of a potential prebiotic trisaccharide from cheese whey permeate and sucrose by Leuconostoc mesenteroides dextransucrase.

PubMed

Díez-Municio, Marina; Montilla, Antonia; Jimeno, M Luisa; Corzo, Nieves; Olano, Agustín; Moreno, F Javier

2012-02-29

The production of new bioactive oligosaccharides is currently garnering much attention for their potential use as functional ingredients. This work addresses the enzymatic synthesis and NMR structural characterization of 2-α-D-glucopyranosyl-lactose derived from sucrose:lactose and sucrose:cheese whey permeate mixtures by using a Leuconostoc mesenteroides B-512F dextransucrase. The effect of synthesis conditions, including concentration of substrates, molar ratio of donor/acceptor, enzyme concentration, reaction time, and temperature, on the formation of transfer products is evaluated. Results indicated that cheese whey permeate is a suitable material for the synthesis of 2-α-D-glucopyranosyl-lactose, giving rise to yields around 50% (in weight respect to the initial amount of lactose) under the optimum reaction conditions. According to its structure, this trisaccharide is an excellent candidate for a new prebiotic ingredient, due to the reported high resistance of α-(1→2) linkages to the digestive enzymes in humans and animals, as well as to its potential selective stimulation of beneficial bacteria in the large intestine mainly attributed to the two linked glucose units located at the reducing end that reflects the disaccharide kojibiose (2-α-D-glucopyranosyl-D-glucose). These findings could contribute to broadening the use of important agricultural raw materials, such as sucrose or cheese whey permeates, as renewable substrates for enzymatic synthesis of oligosaccharides of nutritional interest.

Synthesis and characterization of silver nanoparticles using crystal compound of sodium para-hydroxybenzoate tetrahydrate isolated from Vitex negundo. L leaves and its apoptotic effect on human colon cancer cell lines.

PubMed

Durai, Prabhu; Chinnasamy, Arulvasu; Gajendran, Babu; Ramar, Manikandan; Pappu, Srinivasan; Kasivelu, Govindaraju; Thirunavukkarasu, Ashokkumar

2014-09-12

Metallic nanoparticles are major concern, particularly silver nanoparticles (AgNPs) are used in various applications. In the present investigation, we report a novel strategy with biological approach for synthesis of AgNPs using sodium para-hydroxybenzoate tetrahydrate (SPHT) isolated from Vitex negundo leaves. The synthesized SPHT-AgNPs were characterized by UV-vis spectroscopy, high resolution transmission electron microscopy (HRTEM) with selected area electron diffraction (SAED) pattern, field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDX), zeta potential and Fourier transform infrared spectroscopy (FT-IR) analysis. The various pH and temperature were evaluated to find their stability effects on SPHT-AgNPs synthesis peak at 430 nm. The size of SPHT-AgNPs were ranging from 26 to 39 nm and were spherical in shape. The hydroxyl and carboxylic functional groups from bio-reducing mediators of SPHT have a stronger ability towards synthesis of AgNPs, which was confirmed using FT-IR spectrum. In addition, anticancer activity were determined by MTT assay, Annexin V-FITC/PI and cell cycle analysis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Exogenous energy supply to the plasma membrane of dark anaerobic cyanobacterium Anacystis nidulans: thermodynamic and kinetic characterization of the ATP synthesis effected by an artificial proton motive force.

PubMed

Peschek, G A; Hinterstoisser, B; Riedler, M; Muchl, R; Nitschmann, W H

1986-05-15

The net synthesis of ATP in dark anaerobic cells of Anacystis nidulans subjected to acid jumps and/or valinomycin pulses was characterized thermodynamically and kinetically. Maximum initial rates of 75 nmol ATP/min per mg dry weight at an applied proton motive force of -350 mV were obtained, the flow-force relationship (rate of ATP synthesis vs applied proton motive force) being linear between -240 and -320 mV irrespective of the source of the proton motive force. The pulse-induced ATP synthesis was inhibited by uncouplers (H+ ionophores) and F0F1-ATPase inhibitors but not by KCN or CO. In order to obtain maximum rates of pulse-induced ATP synthesis both a favorable stationary delta psi (-100 mV at pHo 9, preceding the acid jumps) and a favorable stationary delta pH (+2 units at pHo 4.1, preceding the valinomycin pulse) of the plasma membrane were obligatory, the effects of delta psi and delta pH being strictly additive. Moreover, the pulse-induced ATP synthesis required a minimum total proton motive force of -200 to -250 mV across the plasma membrane; it also required low preexisting phosphorylation potentials corresponding to -400 mV in dark anaerobic, i.e., energy-depleted, cells. The results are discussed in terms of both a reversible H+-ATPase and a respiratory electron transport system occurring in the plasma membrane of intact Anacystis nidulans.

Synthesis of Plaster for moulers's elaboration of imprint denture

NASA Astrophysics Data System (ADS)

Hamiane, M.; Rabahi, N.; Saidi, M.; Salhi, M.

2012-02-01

Our goal was the synthesis of plaster from local raw materials to be used in denture mouler's. The plaster type α and β was synthesis by hydrothermal and dry method from gypsum (CaSO4. 2H2O) of the west Algerian. After crushing and mineralogical analysis, gypsum has undergone through cooking in an oven at a temperature (T = 200 ° C), for a time t = 4 hours. The synthesis and characterization of the product has involved several ways investigated as diffraction RX, X-ray fluorescence, time taken, electron microscope (MEB), hardness, SSB, compressive and bending strength and Ph. A digester horizontal type Toni - technical laboratory was used for the synthesis of plasterα. The results are conformable with the standard and plaster synthesized can be a basic material in the manufacture of moulers imprint denture.

Coupled, circumferential motions of the cell wall synthesis machinery and MreB filaments in B. subtilis.

PubMed

Garner, Ethan C; Bernard, Remi; Wang, Wenqin; Zhuang, Xiaowei; Rudner, David Z; Mitchison, Tim

2011-07-08

Rod-shaped bacteria elongate by the action of cell wall synthesis complexes linked to underlying dynamic MreB filaments. To understand how the movements of these filaments relate to cell wall synthesis, we characterized the dynamics of MreB and the cell wall elongation machinery using high-precision particle tracking in Bacillus subtilis. We found that MreB and the elongation machinery moved circumferentially around the cell, perpendicular to its length, with nearby synthesis complexes and MreB filaments moving independently in both directions. Inhibition of cell wall synthesis by various methods blocked the movement of MreB. Thus, bacteria elongate by the uncoordinated, circumferential movements of synthetic complexes that insert radial hoops of new peptidoglycan during their transit, possibly driving the motion of the underlying MreB filaments.

Preparation and Characterization of Polymeric Nanoparticles: An Interdisciplinary Experiment

ERIC Educational Resources Information Center

Ramalho, Maria J.; Pereira, M. Carmo

2016-01-01

In this work, a laboratory experiment to introduce graduate students to nanotechnology is described. Students prepared poly(lactic-"co"-glycolic acid) (PLGA) nanoparticles using two different synthesis procedures, a single and a double emulsion-solvent evaporation method. The students also performed a physicochemical characterization of…

Synthesis and Characterization of Polyimides with Ether Linkages

NASA Technical Reports Server (NTRS)

Chuang, Kathy C.; Fu, Joyce; Scheiman, Daniel A.

1998-01-01

A series of polyimides derived from a newly synthesized diamine, namely, 4,4-bis(4-aminophenoxy)-2,2-dimethylbiphenyl (BAPD), were developed and characterized. Their physical and thermal properties were compared to polyimides based on'commercially available 2,2-bis(4-(4-aminophenoxy)phenyl)propane (BAPP).

Ellipsometric studies of synthetic albumin-binding chitosan-derivatives and selected blood plasma proteins

NASA Astrophysics Data System (ADS)

Sarkar, Sabyasachi

This dissertation summarizes work on the synthesis of chitosan-derivatives and the development of ellipsometric methods to characterize materials of biological origin. Albumin-binding chitosan-derivatives were synthesized via addition reactions that involve amine groups naturally present in chitosan. These surfaces were shown to have an affinity towards human serum albumin via ELISA, UV spectroscopy and SDS PAGE. Modified surfaces were characterized with IR ellipsometry at various stages of their synthesis using appropriate optical models. It was found that spin cast chitosan films were anisotropic in nature. All optical models used for characterizing chitosan-derivatives were thus anisotropic. Chemical signal dependence on molecular structure and composition was illustrated via IR spectroscopic ellipsometry (IRSE). An anisotropic optical model of an ensemble of Lorentz oscillators were used to approximate material behavior. The presence of acetic acid in spin-cast non-neutralized chitosan samples was thus shown. IRSE application to biomaterials was also demonstrated by performing a step-wise chemical characterizations during synthesis stages. Protein adsorbed from single protein solutions on these modified surfaces was monitored by visible in-situ variable wavelength ellipsometry. Based on adsorption profiles obtained from single protein adsorption onto silicon surfaces, lumped parameter kinetic models were developed. These models were used to fit experimental data of immunoglobulin-G of different concentrations and approximate conformational changes in fibrinogen adsorption. Biomaterial characterization by ellipsometry was further extended to include characterization of individual protein solutions in the IR range. Proteins in an aqueous environment were characterized by attenuated total internal reflection (ATR) IR ellipsometry using a ZnSe prism. Parameterized dielectric functions were created for individual proteins using Lorentz oscillators. These parameterized dielectric functions were then used to describe the growth and eventual enzymatic degradation of a multilayered IgG structure by dynamic ATR-IR ellipsometry measurements. ATR-IR ellipsometry was also used to observe the specificity of anti-bodies to antigens.

Aerosol Route Synthesis and Applications of Doped Nanostructured Materials

NASA Astrophysics Data System (ADS)

Sahu, Manoranjan

Nanotechnology presents an attractive opportunity to address various challenges in air and water purification, energy, and other environment issues. Thus, the development of new nanoscale materials in low-cost scalable synthesis processes is important. Furthermore, the ability to independently manipulate the material properties as well as characterize the material at different steps along the synthesis route will aide in product optimization. In addition, to ensure safe and sustainable development of nanotechnology applications, potential impacts need to be evaluated. In this study, nanomaterial synthesis in a single-step gas phase reactor to continuously produce doped metal oxides was demonstrated. Copper-doped TiO2 nanomaterial properties (composition, size, and crystal phase) were independently controlled based on nanoparticle formation and growth mechanisms dictated by process control parameters. Copper dopant found to significantly affect TiO2 properties such as particle size, crystal phase, stability in the suspension, and absorption spectrum (shift from UV to visible light absorption). The in-situ charge distribution characterization of the synthesized nanomaterials was carried out by integrating a tandem differential mobility analyzer (TDMA) set up with the flame reactor synthesis system. Both singly- and doubly- charged nanoparticles were measured, with the charged fractions dependent on particle mobility and dopant concentration. A theoretical calculation was conducted to evaluate the relative importance of the two charging mechanisms, diffusion and thermo-ionization, in the flame. Nanoparticle exposure characterization was conducted during synthesis as a function of operating condition, product recovery and handling technique, and during maintenance of the reactors. Strategies were then indentified to minimize the exposure risk. The nanoparticle exposure potential varied depending on the operating conditions such as precursor feed rate, working conditions of the fume hood, ventilation system, and distance from the reactors. Nanoparticle exposure varied during product recovery and handling depending on the quantity of nanomaterial handled. Most nanomaterial applications require nanomaterials to be in solution. Thus, the role of nanomaterial physio-chemical properties (size, crystal phase, dopant types and concentrations) on dispersion properties was investigated based on hydrodynamic size and surface charge. Dopant type and concentration were found to significantly affect iso-electric point (IEP)-shifting the IEP to a high or lower pH value compared to pristine TiO2 based on the oxidation state of the dopant. The microbial inactivation effectiveness of as-synthesized nanomaterials was investigated under different light irradiation conditions. Microbial inactivation was found to strongly depend on the light irradiation condition as well as on material properties such chemical composition, crystal phase, and particle size. The potential interaction mechanisms of copper-doped TiO2 nanomaterial with microbes were also explored. The studies conducted as part of this dissertation addressed issues in nanomaterial synthesis, characterization and their potential environmental applications.

Preparation, characterization and catalytic application of CoFe2O4 nanoparticles in the synthesis of benzimidazoles

NASA Astrophysics Data System (ADS)

Borade, Ravikumar M.; Shinde, Pavan R.; Kale, Swati B.; Pawar, Rajendra P.

2018-05-01

A highly efficient magnetically recoverable cobalt ferrite nano-catalyst was prepared by sol-gel autocombustion method using glycine as green fuel. The prepared material has been characterized by X-ray powder diffraction and scanning. An investigation of its catalytic activity showed it to be a heterogeneous Lewis acid catalyst for the synthesis of substituted benzimidazoles. The aqueous ethanol used as green solvent for the reaction. The nm size range of these particles facilitates the catalysis process, as an increased surface area available for the reaction. The easy separation of the catalyst by an external magnet and their recovery and reuse in next cycle reaction are additional benefits.

Ionic liquid catalyzed one-pot multi-component synthesis, characterization and antibacterial activity of novel chromeno[2,3-d]pyrimidin-8-amine derivatives

NASA Astrophysics Data System (ADS)

Kanakaraju, Sankari; Prasanna, Bethanamudi; Basavoju, Srinivas; Chandramouli, G. V. P.

2012-06-01

An efficient, simple and convenient method for the one-pot multi-component synthesis of novel chromeno[2,3-d]pyrimidin-8-amine derivatives has been accomplished by starting from α-naphthol, aryl aldehydes, malononitrile and NH4Cl. The reaction has been catalyzed by 1-butyl-3-methylimidazolium tetrafluoroborate [bmim]BF4 ionic liquid. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, mass spectra, and elemental analysis. The structure of compound 4a was confirmed by single-crystal X-ray diffraction. All the synthesized compounds were evaluated for their in vitro antibacterial activity.

Characterization of a 1,4-. beta. -D-glucan synthase from Dictyostelium discoideum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanton, R.L.

1992-01-15

Various aspects of research concerning Dictyostelium discoideum are presented. The initial focus of this project was upon: the characterization of potential probes for the cellulose synthase (antibody and nucleic acid), the determination of the cultural induction conditions of cellulose synthesis, the solubilization of the enzyme activity, the development of a non-inhibitory disruption buffer, the generation and isolation of mutant strains deficient in cellulose synthesis, and the development of the capability to determine the degree of polymerization of the in vitro product. I have briefly summarized our most significant findings with only selected data sets being shown in this report inmore » the interest of brevity.« less

Identification and characterization of multiple curcumin synthases from the herb Curcuma longa.

PubMed

Katsuyama, Yohei; Kita, Tomoko; Horinouchi, Sueharu

2009-09-03

Curcuminoids are pharmaceutically important compounds isolated from the herb Curcuma longa. Two additional type III polyketide synthases, named CURS2 and CURS3, that are capable of curcuminoid synthesis were identified and characterized. In vitro analysis revealed that CURS2 preferred feruloyl-CoA as a starter substrate and CURS3 preferred both feruloyl-CoA and p-coumaroyl-CoA. These results suggested that CURS2 synthesizes curcumin or demethoxycurcumin and CURS3 synthesizes curcumin, bisdemethoxycurcumin and demethoxycurcumin. The availability of the substrates and the expression levels of the three different enzymes capable of curcuminoid synthesis with different substrate specificities might influence the composition of curcuminoids in the turmeric and in different cultivars.

The Synthesis and Characterization of a Group of Transition Metal Octabutoxynaphthalocyanines and the Absorption and Emission Properties of the Co, Rh, Ir, Ni, Pd and Pt Members of This Group

PubMed Central

Kim, Junhwan; Soldatova, Alexandra V.; Rodgers, Michael A. J.; Kenney, Malcolm E.

2013-01-01

The synthesis and photophysical properties of new metallo-octabutoxynaphthalocyanines with Rh(III), Ir(III), and Pt(II) are reported. Various metals were inserted into the metal-free octabutoxynaphthalocyanine and the resultant metal complexes were fully characterized by NMR, UV-vis spectroscopy, and mass spectrometry. The absorption and emission properties of these new complexes were also examined and compared to those of Co(II), Ni(II), and Pd(II) octabutoxynaphthalocyanines. The results provide useful information to understand the effect of these transition metals on the properties of this macrocyclic ring. PMID:23745014

Synthesis and transport characterization of electrochemically deposited CdTe nanowires

NASA Astrophysics Data System (ADS)

Kaur, Jaskiran; Kaur, Harmanmeet; Singh, R. C.

2018-04-01

This paper reports the synthesis and characterization of CdTe nanowires. A thin polymeric films were irradiated with 80MeV Ag ions at a fluence of 8E7 ions/cm2, followed by UV irradiation and chemically etching in aqueous NaOH. Nanosizes go-through pores so formed were filled using a specially designed cell via electrodeposition. Nanowires so formed were further studied using SEM, I-V, UV and XRD analysis. SEM images show very smooth and uniform CdTe nanowires freely standing on the substrate. The in-situ I-V characteristics of nano-/micro structures was carried out at room temperature by leaving the structures embedded in the insulating template membrane itself.

Synthesis and characterization of black ceramic pigments by recycling of two hazardous wastes

NASA Astrophysics Data System (ADS)

Du, Minxing; Du, Yi; Chen, Zhongtao; Li, Zhongfu; Yang, Kai; Lv, Xingjie; Feng, Yibing

2017-09-01

In this study, two different industrial wastes, namely vanadium tailing and leather sludge, were used as less expensive alternative raw materials for the synthesis of black ceramic pigments to be used in commercial glazes. The pigments were based on hematite structure (FexCr1-x)2O3 and prepared by the common solid-state reaction method, under optimal formulation and processing conditions. The synthesized pigments were characterized in typical ceramic glazes and ceramic tile bodies. Optimal color development was achieved when the Fe/Cr mole ratios were 2.0 with 40 wt% content of vanadium tailing at 1200 °C. The coloring properties were similar to those imparted by a commercial black pigment.

Synthesis and characterization of colloidal ZnTe nanocrystals and ZnTe/ZnSe quantum dots

NASA Astrophysics Data System (ADS)

Gonzales, Gavin P.; Alas, Gema; Senthil, Arjun; Withers, Nathan J.; Minetos, Christina; Sandoval, Alejandro; Ivanov, Sergei A.; Smolyakov, Gennady A.; Huber, Dale L.; Osiński, Marek

2018-02-01

Quantum dots (QDs) emitting in the visible are of interest for many biomedical applications, including bioimaging, biosensing, drug targeting, and photodynamic therapy. However, a significant limitation is that QDs typically contain cadmium, which makes prospects for their FDA approval very unlikely. Previous work has focused on InP and ZnO as alternative semiconductor materials for QDs. However, these nanoparticles have also been shown to be cytotoxic. High-efficiency luminescent ZnTe-based QDs could be a reasonable alternative to Cd-containing QDs. In this paper, we present preliminary results of our recent studies of ZnTe-based QDs, including their synthesis, structural characterization, and optical properties.

Sonochemically synthesized iron-doped zinc oxide nanoparticles: Influence of precursor composition on characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Anirban; Maitra, Saikat; Ghosh, Sobhan

Highlights: • Sonochemical synthesis of iron-doped zinc oxide nanoparticles. • Green synthesis without alkali at room temperature. • Characterization by UV–vis spectroscopy, FESEM, XRD and EDX. • Influence of precursor composition on characteristics. • Composition and characteristics are correlated. - Abstract: Iron-doped zinc oxide nanoparticles have been synthesized sonochemically from aqueous acetyl acetonate precursors of different proportions. Synthesized nanoparticles were characterized with UV–vis spectroscopy, X-ray diffraction and microscopy. Influences of precursor mixture on the characteristics have been examined and modeled. Linear correlations have been proposed between dopant dosing, extent of doping and band gap energy. Experimental data corroborated with themore » proposed models.« less

Synthesis and characterization of Allium cepa L. as photosensitizer of dye-sensitized solar cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sutikno, E-mail: smadnasri@yahoo.com; Afrian, Noverdi; Supriadi,

The synthesis and characterization of Allium cepa L. used as natural pigment for natural dye sensitizer of solar cell has successfully done and anthocyanin is extracted. Anthocynin is color pigment of plant which has characteristic absorption spectrum of photon and excites electrons up to pigment molecules. As the anthocyanin absorbed light increases the excited electrons increase as well. The generated current also increases and it leads to the efficiency increase. The energy conversion efficiency of the cells sensitized with dye of Allium cepa L. was 3,045 x 10{sup −4}%. A simple technique was taken to fabricate dye sensitizer solar cellmore » is spincoating.« less

Synthesis of improved moisture resistant polymers

NASA Technical Reports Server (NTRS)

Scola, D. A.; Pater, R. H.

1978-01-01

The synthesis and characterization of novel moisture resistant aliphatic polyimides are described. Several novel aliphatic imides of diversified functionalities were synthesized, purified, and characterized, they include: (1) N-(12-aminododecyl)-5-norbornene-2,3-dicarboximide; (2) N,N'-2,2,2-trifluoro-1-(trifluoromethyl)ethylidene bis (1,3-dioxo-5,2-iosoindolinediyl)dodecamethylene di-5-norbornene-2,3-dicarboximide; (3) N,N'-dodecamethylenedi-5-nobornene-2,3-dicarbonoximide; (4) N,N'-dodecamethylenebis 5,6-epoxy-2,3-norbornanedicarboximide ; and (5) N,N'-Bis 12-(5-norbornene-2, 3-dicarboximidido)dodecyl - 1,2,3,4- butanetetracarboxylic 1,2:3,4-diimide. The structures of these compounds were established by elemental analysis, IR, NMR, and mass spectra.

Green synthesis of silver nanoparticles: characterization and determination of antibacterial potency

NASA Astrophysics Data System (ADS)

Annamalai, Jayshree; Nallamuthu, Thangaraju

2016-02-01

Silver ions (Ag+) and its compounds are highly toxic to microorganisms, exhibiting strong biocidal effects on many species of bacteria but have a low toxicity toward animal cells. In the present study, silver nanoparticles (SNPs) were biosynthesized using aqueous extract of Chlorella vulgaris as reducing agent and size of SNPs synthesized ranged between 15 and 47 nm. SNPs were characterized by UV-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Fourier infrared spectroscopy, and analyzed for its antibacterial property against human pathogens. This approach of SNPs synthesis involving green chemistry process can be considered for the large-scale production of SNPs and in the development of biomedicines.

Synthesis, characterization and biological activities of copper(II) complex of 2-Benzimidazolyl-urea and the nitrate salt of 2-Benzimidazolyl-urea

NASA Astrophysics Data System (ADS)

Poyraz, Mehmet; Sari, Musa; Banti, Christina N.; Hadjikakou, Sotiris K.

2017-10-01

The synthesis of the complex {[Cu(BZIMU)2](NO3)2} (1) (BZIMU = 2-Benzimidazolyl-urea) is reported here. The complex 1 was characterized by elemental analysis, FT-IR, magnetic susceptibility and molar conductance measurements. The crystal structures of 1 and of the nitrate salt of [(BZIMUH+)(NO3)-] (2) were determined by X-ray diffraction analysis. The copper complex 1 and [(BZIMUH+)(NO3)-] (2) were evaluated for their in vitro cytotoxic activity (cell viability) against human cervix adenocarcinoma (HeLa) and human breast adenocarcinoma (MCF-7) cell line and normal human fetal lung fibroblast cells (MRC-5) with SRB assay.

Synthesis and photoelectrochemical properties of a novel CuO/ZnO nanorod photocathode for solar hydrogen generation

NASA Astrophysics Data System (ADS)

Shaislamov, Ulugbek; Lee, Heon-Ju

2016-10-01

Here, we present a facile synthesis method and photoelectrochemical characterizations of a p-type CuO-nanorod array photoelectrode with ZnO nanorod branches. Vertically-aligned CuO nanorods were synthesized by using direct oxidation of metallic Cu nanorods grown on a Cu substrate by using a facile template-assisted electrodeposition method. The formed CuONR/ZnONB hierarchically-structured photoelectrode exhibited remarkable photoelectrodechemical performance and outstanding stability compared to the CuO NR photoelectrode without ZnO NR branches. Morphological, optical and electrochemical characterizations were carried out in order to examine the effects of ZnO nanorod branches on the stability and the overall electrochemical performance of the electrode.

Synthesis and characterization of covalent diphenylalanine nanotube-folic acid conjugates

NASA Astrophysics Data System (ADS)

Castillo, John J.; Rindzevicius, Tomas; Wu, Kaiyu; Schmidt, Michael S.; Janik, Katarzyna A.; Boisen, Anja; Svendsen, Winnie; Rozlosnik, Noemi; Castillo-León, Jaime

2014-07-01

Herein, we describe the synthesis and characterization of a covalent nanoscale assembly formed between diphenylalanine micro/nanotubes (PNT) and folic acid (FA). The conjugate was obtained via chemical functionalization through coupling of amine groups of PNTs and carboxylic groups of FA. The surface analysis of PNT-FA indicated the presence of FA aggregates on the surface of PNTs. The covalent interaction between FA and self-assembled PNTs was further investigated using fluorescence microscopy, Raman and surface-enhanced Raman scattering (SERS) spectroscopies. The SERS experiments were performed on a large area silver-capped (diameter of 62 nm) silicon nanopillars with an approximate height of 400 nm and a width of 200 nm. The results showed that the PNT-FA synthesis procedure preserves the molecular structure of FA. The PNT-FA conjugate presented in this study is a promising candidate for applications in the detection and diagnosis of cancer or tropical diseases such as leishmaniasis and as a carrier nanosystem delivering drugs to malignant tumors that overexpress folate receptors.

Green synthesis and characterization of silver nanoparticles by leaf extracts of Cycas circinalis, Ficus amplissima, Commelina benghalensis and Lippia nodiflora

NASA Astrophysics Data System (ADS)

Johnson, I.; Prabu, H. Joy

2015-01-01

Biosynthesis of nanoparticles is a kind of bottom-up approach where the main reaction occurring is reduction. Since silver nanoparticles (AgNPs) have been used for infection prevention in medical field, it is more relevant to reduce their size using ancient Indian herbal plants. This method is good in anti-microbial efficiency against bacteria, viruses and other microorganisms and hence clearly enhances the medicinal usage of AgNPs. This type of green biosynthesis of nanoparticles has received increasing attention due to the growing need to develop safe, cost-effective and environmental-friendly technologies for nano-materials synthesis. In the process of synthesizing AgNPs, we observed a rapid reduction of silver ions leading to the formation of stable crystalline AgNPs in the solution. Plant extracts from Cycas circinalis, Ficus amplissima, Commelina benghalensis and Lippia nodiflora were used for the synthesis of AgNPs from silver nitrate solution. AgNPs were characterized by different techniques.

Synthesis, Characterization and Applications of One-Dimensional Metal Oxide Nanostructures

NASA Astrophysics Data System (ADS)

Santulli, Alexander

Nanomaterials have been of keen research interest, owing to their exciting and unique properties (e.g. optical, magnetic, electronic, and mechanical). These properties allow nanomaterials to have many applications in areas of medicine, alternative energy, catalysis, and information storage. In particular, one-dimensional (1D) nanomaterials are highly advantageous, owing to the inherent anisotropic nature, which allows for effective transport and study of properties on the nanoscale. More specifically, 1D metal oxide nanomaterials are of particular interest, owing to their high thermal and chemical stability, as well as their intriguing optical, electronic, and magnetic properties. Herein, we will investigate the synthesis and characterization of vanadium oxide, lithium niobate and chromium oxide. We will explore the methodologies utilized for the synthesis of these materials, as well as the overall properties of these unique nanomaterials. Furthermore, we will explore the application of titanium dioxide nanomaterials as the electron transport layer in dye sensitized solar cells (DSSCs), with an emphasis on the effect of the nanoscale morphology on the overall device efficiency.

Synthesis and characterization of novel silver nanoparticles using Chamaemelum nobile extract for antibacterial application

NASA Astrophysics Data System (ADS)

Erjaee, Hoda; Rajaian, Hamid; Nazifi, Saeed

2017-06-01

The present study reports green synthesis of silver nanoparticles (AgNPs) at room temperature using aqueous Chamaemelum nobile extract for the first time. The effect of silver nitrate concentration, quantity of the plant extract and the reaction time on particle size was optimized and studied by UV-Vis spectroscopy and dynamic light scattering. The appearance of brownish color with λ max of 422 nm confirmed the formation of AgNPs. Synthesized nanoparticles were further characterized by Fourier transform infrared spectroscopy, x-ray diffraction and transmission electron microscopy. In addition, antimicrobial activity of the AgNPs against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Bacillus subtilis was evaluated based on the inhibition zone using the disc-diffusion assay and measurement of minimal inhibition concentration and minimal bactericidal concentration by standard microdilution method. In conclusion, synthesis of nanoparticle with aqueous Chamaemelum nobile extract is simple, rapid, environmentally benign and inexpensive. Moreover, these synthesized nanoparticles exhibit significant antibacterial activity.

Synthesis, Characterization, and Electrochemical Behavior of LiMnxFe(1−x)PO4 Composites Obtained from Phenylphosphonate-Based Organic-Inorganic Hybrids

PubMed Central

Dell’Era, Alessandro; Pasquali, Mauro; Bauer, Elvira Maria; Lupi, Carla

2017-01-01

The synthesis of organic-inorganic hybrid compounds based on phenylphosphonate and their use as precursors to form LiMnxFe(1−x)PO4 composites containing carbonaceous substances with sub-micrometric morphology are presented. The experimental procedure includes the preliminary synthesis of Fe2+ and/or Mn2+ phenylphosphonates with the general formula Fe(1−x)Mnx[(C6H5PO3)(H2O)] (with 0 < x < 1), which are then mixed at different molar ratios with lithium carbonate. In this way the carbon, obtained from in situ partial oxidation of the precursor organic part, coats the LiMnxFe(1−x)PO4 particles. After a structural and morphological characterization, the electrochemical behavior of lithium iron manganese phosphates has been compared to the one of pristine LiFePO4 and LiMnPO4, in order to evaluate the doping influence on the material. PMID:29301206

Green synthesis and characterization of alginate nanoparticles and its role as a biosorbent for Cr(VI) ions

NASA Astrophysics Data System (ADS)

Geetha, P.; Latha, M. S.; Pillai, Saumya S.; Deepa, B.; Santhosh Kumar, K.; Koshy, Mathew

2016-02-01

Green synthesis of nanoparticles has attained considerable attention in recent years because of its myriad of applications including drug delivery, tissue engineering and water purification. In the present study, alginate nanoparticles stabilized by honey were prepared by cross-linking aqueous solution of alginate with calcium ions. Honey mediated synthesis has been reported earlier for the production of metal nanoparticles. However no literature is available on the use of this technique for polymeric nanoparticles. Highly stable nanoparticles of 10-100 nm size were generated by this technique. The synthesised nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, atomic force microscopy, dynamic light scattering and Fourier transform infrared spectroscopic techniques. Potential of using these nanoparticles for heavy metal removal was studied by using Cr(VI) from aqueous solution, where a maximum removal efficiency of 93.5% was obtained. This method was also successfully employed for the production of other polymeric nanoparticles like casein, chitosan and albumin.

NASA Fundamental Remote Sensing Science Research Program

NASA Technical Reports Server (NTRS)

1984-01-01

The NASA Fundamental Remote Sensing Research Program is described. The program provides a dynamic scientific base which is continually broadened and from which future applied research and development can draw support. In particular, the overall objectives and current studies of the scene radiation and atmospheric effect characterization (SRAEC) project are reviewed. The SRAEC research can be generically structured into four types of activities including observation of phenomena, empirical characterization, analytical modeling, and scene radiation analysis and synthesis. The first three activities are the means by which the goal of scene radiation analysis and synthesis is achieved, and thus are considered priority activities during the early phases of the current project. Scene radiation analysis refers to the extraction of information describing the biogeophysical attributes of the scene from the spectral, spatial, and temporal radiance characteristics of the scene including the atmosphere. Scene radiation synthesis is the generation of realistic spectral, spatial, and temporal radiance values for a scene with a given set of biogeophysical attributes and atmospheric conditions.

Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

NASA Astrophysics Data System (ADS)

Salvatore, Marcella; Carotenuto, Gianfranco; De Nicola, Sergio; Camerlingo, Carlo; Ambrogi, Veronica; Carfagna, Cosimo

2017-03-01

Different chemical formulations for the synthesis of highly intercalated graphite bisulfate have been tested. In particular, nitric acid, potassium nitrate, potassium dichromate, potassium permanganate, sodium periodate, sodium chlorate, and hydrogen peroxide have been used in this synthesis scheme as the auxiliary reagent (oxidizing agent). In order to evaluate the presence of delamination, and pre-expansion phenomena, and the achieved intercalation degree in the prepared samples, the obtained graphite intercalation compounds have been characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), micro-Raman spectroscopy ( μ-RS), and thermal analysis (TGA). Delamination and pre-expansion phenomena were observed only for nitric acid, sodium chlorate, and hydrogen peroxide, while the presence of strong oxidizers (KMnO4, K2Cr2O7) led to stable graphite intercalation compounds. The largest content of intercalated bisulfate is achieved in the intercalated compounds obtained from NaIO4 and NaClO3.

Combinatorial materials approach to accelerate materials discovery for transportation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Tong, Wei

2017-04-01

Combinatorial material research offers fast and efficient solutions to identify promising and advanced materials. It has revolutionized the pharmaceutical industry and now is being applied to accelerate the discovery of other new compounds, e.g. superconductors, luminescent materials, catalysts etc. Differing from the traditional trial-and-error process, this approach allows for the synthesis of a large number of compositionally diverse compounds by varying the combinations of the components and adjusting the ratios. It largely reduces the cost of single-sample synthesis/characterization, along with the turnaround time in the material discovery process, therefore, could dramatically change the existing paradigm for discovering and commercializing new materials. This talk outlines the use of combinatorial materials approach in the material discovery in transportation sector. It covers the general introduction to the combinatorial material concept, state of art for its application in energy-related research. At the end, LBNL capabilities in combinatorial materials synthesis and high throughput characterization that are applicable for material discovery research will be highlighted.

Synthesis and Characterization of Highly Intercalated Graphite Bisulfate.

PubMed

Salvatore, Marcella; Carotenuto, Gianfranco; De Nicola, Sergio; Camerlingo, Carlo; Ambrogi, Veronica; Carfagna, Cosimo

2017-12-01

Different chemical formulations for the synthesis of highly intercalated graphite bisulfate have been tested. In particular, nitric acid, potassium nitrate, potassium dichromate, potassium permanganate, sodium periodate, sodium chlorate, and hydrogen peroxide have been used in this synthesis scheme as the auxiliary reagent (oxidizing agent). In order to evaluate the presence of delamination, and pre-expansion phenomena, and the achieved intercalation degree in the prepared samples, the obtained graphite intercalation compounds have been characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), micro-Raman spectroscopy (μ-RS), and thermal analysis (TGA). Delamination and pre-expansion phenomena were observed only for nitric acid, sodium chlorate, and hydrogen peroxide, while the presence of strong oxidizers (KMnO 4 , K 2 Cr 2 O 7 ) led to stable graphite intercalation compounds. The largest content of intercalated bisulfate is achieved in the intercalated compounds obtained from NaIO 4 and NaClO 3 .

Identification and Functional Characterization of the Glycogen Synthesis Related Gene Glycogenin in Pacific Oysters (Crassostrea gigas).

PubMed

Li, Busu; Meng, Jie; Li, Li; Liu, Sheng; Wang, Ting; Zhang, Guofan

2017-09-06

High glycogen levels in the Pacific oyster (Crassostrea gigas) contribute to its flavor, quality, and hardiness. Glycogenin (CgGN) is the priming glucosyltransferase that initiates glycogen biosynthesis. We characterized the full sequence and function of C. gigas CgGN. Three CgGN isoforms (CgGN-α, β, and γ) containing alternative exon regions were isolated. CgGN expression varied seasonally in the adductor muscle and gonadal area and was the highest in the adductor muscle. Autoglycosylation of CgGN can interact with glycogen synthase (CgGS) to complete glycogen synthesis. Subcellular localization analysis showed that CgGN isoforms and CgGS were located in the cytoplasm. Additionally, a site-directed mutagenesis experiment revealed that the Tyr200Phe and Tyr202Phe mutations could affect CgGN autoglycosylation. This is the first study of glycogenin function in marine bivalves. These findings will improve our understanding of glycogen synthesis and accumulation mechanisms in mollusks. The data are potentially useful for breeding high-glycogen oysters.

Synthesis and characterization of carbon cryogel microspheres from lignin-furfural mixtures for biodiesel production.

PubMed

Zainol, Muzakkir Mohammad; Amin, Nor Aishah Saidina; Asmadi, Mohd

2015-08-01

The aim of this work was to study the potential of biofuel and biomass processing industry side-products as acid catalyst. The synthesis of carbon cryogel from lignin-furfural mixture, prepared via sol-gel polycondensation at 90°C for 0.5h, has been investigated for biodiesel production. The effect of lignin to furfural (L/F) ratios, lignin to water (L/W) ratios and acid concentration on carbon cryogel synthesis was studied. The carbon cryogels were characterized and tested for oleic acid conversion. The thermally stable amorphous spherical carbon cryogel has a large total surface area with high acidity. Experimental results revealed the optimum FAME yield and oleic acid conversion of 91.3wt.% and 98.1wt.%, respectively were attained at 65°C for 5h with 5wt.% catalyst loading and 20:1 methanol to oleic acid molar ratio. Therefore, carbon cryogel is highly potential for heterogeneous esterification of free fatty acid to biodiesel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification of Non-Pertechnetate Species In Hanford Tank Waste, Their Synthesis, Characterization, And Fundamental Chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenneth R. Ashely; Norman Schroeder; Jose A. Olivares

2004-12-10

This proposal had three major goals: (1) develop capillary electrophoresis mass spectrometry as a characterization technique, (2) separate a non-pertechnetate fraction from a waste sample and identify the non-pertechnetate species in it by CEMS, and (3) synthesize and characterize bulk quantities of the identified non-pertechnetate species and study their ligand substitution and redox chemistry.

Extended germa[N]pericyclynes: synthesis and characterization.

PubMed

Tanimoto, Hiroki; Fujiwara, Taro; Mori, Junta; Nagao, Tomohiko; Nishiyama, Yasuhiro; Morimoto, Tsumoru; Ito, Shunichiro; Tanaka, Kazuo; Chujo, Yoshiki; Kakiuchi, Kiyomi

2017-02-14

We herein describe the syntheses and characterization of extended germa[N]pericyclynes, which are macrocycles composed of germanium-butadiyne units. The obtained novel extended germa[4]-[8]pericyclynes were characterized by X-ray crystallography, UV-Vis spectroscopy, fluorescence and phosphorescence emission spectroscopy, and cyclic voltammetry, and exhibited characteristic absorptions and emissions. Density functional theory (DFT) calculations suggested smaller HOMO-LUMO gap energy compared to that of general germapericyclynes.

Synthesis and structural characterization of two half-sandwich nickel(II) complexes with the scorpionate ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G.-F., E-mail: wgf1979@126.com, E-mail: s-shuwen@163.com; Zhang, X., E-mail: zhangx@hit.edu.cn; Sun, S.-W.

The synthesis and characterization of two new halfsandwich mononuclear nickel(II) complexes with the scorpionate ligands, [k{sup 3}-N, N',N''-Tp{sup t-Bu}, {sup Me}NiI] (1) and [k{sup 3}-N,N',N''-Tp{sup t-Bu}, {sup Me}NiNO{sub 3}] (2), are reported. These complexes have been fully characterized by elemental analyses and infrared spectra. Their molecular structures were determined by single crystal X-ray diffraction. The nickel(II) ion of complex 1 is in a four-coordinate environment, in which the donor atoms are provided by three nitrogen atoms of a hydrotris(pyrazolyl) borate ligand and one iodide atom, while that of complex 2 is in a five-coordinate environment with three nitrogen atoms frommore » a hydrotris(pyrazolyl)borate ligand and two oxygen atoms from a nitrate ion.« less

Distinguishing molecular environments in supported Pt catalysts and their influences on activity and selectivity

NASA Astrophysics Data System (ADS)

Jones, Louis Chin

This thesis entails the synthesis, automated catalytic testing, and in situ molecular characterization of supported Pt and Pt-alloy nanoparticle (NP) catalysts, with emphasis on how to assess the molecular distributions of Pt environments that are affecting overall catalytic activity and selectivity. We have taken the approach of (a) manipulating nucleation and growth of NPs using oxide supports, surfactants, and inorganic complexes to create Pt NPs with uniform size, shape, and composition, (b) automating batch and continuous flow catalytic reaction tests, and (c) characterizing the molecular environments of Pt surfaces using in situ infrared (IR) spectroscopy and solid-state 195Pt NMR. The following will highlight the synthesis and characterization of Ag-doped Pt NPs and their influence on C 2H2 hydrogenation selectivity, and the implementation of advanced solid-state 195Pt NMR techniques to distinguish how distributions of molecular Pt environments vary with nanoparticle size, support, and surface composition.

Synthesis of five- and six-coordinate tris(pentafluoroethyl)fluorosilicates.

PubMed

Steinhauer, Simon; Stammler, Hans-Georg; Neumann, Beate; Ignat'ev, Nikolai; Hoge, Berthold

2014-01-07

The research area of perfluoroalkylsilanes is still in its infancy. Although there are already many examples of difluorotriorganylsilicates, the first example of a completely characterized trifluorotriorganylsilicate is presented, the dianion [Si(C2 F5 )3 F3 ](2-) . The strongly electron-withdrawing influence of the pentafluoroethyl groups appears to be a fundamental cause of the stability of this compound. This dianion is also the first structurally characterized example of a tris(pentafluoroethyl)silicon compound. The synthesis and complete characterization of [PPh4 ]2 [Si(C2 F5 )3 F3 ] and [PPh4 ][Si(C2 F5 )3 F2 ] along with the precursor [H(OEt2 )2 ][Si(C2 F5 )3 F2 ] was achieved from SiCl4 and LiC2 F5 . Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Expanding frontiers in materials chemistry and physics with multiple anions.

PubMed

Kageyama, Hiroshi; Hayashi, Katsuro; Maeda, Kazuhiko; Attfield, J Paul; Hiroi, Zenji; Rondinelli, James M; Poeppelmeier, Kenneth R

2018-02-22

During the last century, inorganic oxide compounds laid foundations for materials synthesis, characterization, and technology translation by adding new functions into devices previously dominated by main-group element semiconductor compounds. Today, compounds with multiple anions beyond the single-oxide ion, such as oxyhalides and oxyhydrides, offer a new materials platform from which superior functionality may arise. Here we review the recent progress, status, and future prospects and challenges facing the development and deployment of mixed-anion compounds, focusing mainly on oxide-derived materials. We devote attention to the crucial roles that multiple anions play during synthesis, characterization, and in the physical properties of these materials. We discuss the opportunities enabled by recent advances in synthetic approaches for design of both local and overall structure, state-of-the-art characterization techniques to distinguish unique structural and chemical states, and chemical/physical properties emerging from the synergy of multiple anions for catalysis, energy conversion, and electronic materials.

Development of High ZT Thermoelectric Materials with Nanostructure for Energy Applications

DTIC Science & Technology

2010-03-03

film and nanowires array (embedded in alumina template) were fabricated by potentiostatically electrodeposition . The Seebeck coefficient, electrical...by potentiostatically electrodeposition . The followings are our reports on the synthesis and characterizations of these nano-materials. B1...Synthesis of the nanomaterials Bi2Te3 films were electrodeposited potentiostatically at -150 mV onto an ITO glass substrate from 1 M HNO3 solution

Synthesis and Properties of Chelating N-Heterocyclic Carbene Rhodium(I) Complexes: Synthetic Experiments in Current Organometallic Chemistry

ERIC Educational Resources Information Center

Mata, Jose A.; Poyatos, Macarena; Mas-Marza, Elena

2011-01-01

The preparation and characterization of two air-stable Rh(I) complexes bearing a chelating N-heterocyclic carbene (NHC) ligand is described. The synthesis involves the preparation of a Ag(I)-NHC complex and its use as carbene transfer agent to a Rh(I) precursor. The so obtained complex can be further reacted with carbon monoxide to give the…

Synthesis of Stable Microcapsules from Trematode Eggshell Components

DTIC Science & Technology

1990-06-30

NO Arlington, VA 22217-5000 61153N RR4106 11 TITLE (Include Security Classification) (u) Synthesis of Stable Microcapsules from Trematode Eggshell...Continue on reverse if necessary and identify by block number) The trematode Fasciola hepatica produces a unique protein eggshell or microcapsule the...proteins to produce a hard quinone tanned microcapsule with unusual properties. The focus of this project is to i) characterize the protein components

Synthesis and Degradation of Schiff Bases Containing Heterocyclic Pharmacophore

PubMed Central

Ledeţi, Ionuţ; Alexa, Anda; Bercean, Vasile; Vlase, Gabriela; Vlase, Titus; Şuta, Lenuţa-Maria; Fuliaş, Adriana

2015-01-01

This paper reports on the synthesis and characterization of two Schiff bases bearing 1,2,4-triazolic moieties, namely 4H-4-(2-hydroxy-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole and 4H-4-(4-nitro-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole using thin layer chromatography, melting interval, elemental analysis, spectroscopy and thermal stability studies. PMID:25590299

Elucidation of the surface characteristics and electrochemistry of high-performance LiNiO 2

DOE PAGES

Xu, Jing; Lin, Feng; Nordlund, Dennis; ...

2016-02-25

Phase pure LiNiO 2 was prepared using a solid-state method and the optimal synthesis conditions led to a remarkably high capacity of 200 mA h g $-$1 with excellent retention. The combination of bulk and surface characterization elucidated an essential role of the excess Li in phase formation during synthesis and the subsequent electrochemical performance.

Synthesis of gold nanoparticles on the surface of pyrolytic graphite using penicillin as a stabilizing reagent and the catalytic oxidation of α-naphthylamine

NASA Astrophysics Data System (ADS)

Song, Y. Z.; Song, Y.; Cheng, Z. P.; Zhou, J. F.; Wei, C.

2013-01-01

Electrochemical synthesis of gold nanoparticles on the surface of pyrolytic graphite using penicillin as a stabilizing reagent was proposed. The gold nanoparticles were characterized by scanning electron microscopy, cyclic voltammetry, IR spectra, UV spectra, and powder X-ray diffraction spectra. The electro-chemical catalysis of penicillin for α-naphthylamine was demonstrated.

Catalytic Production of Ethanol from Biomass-Derived Synthesis Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trewyn, Brian G.; Smith, Ryan G.

2016-06-01

Heterogeneous catalysts have been developed for the conversion of biomass-derived synthetic gas (syngas) to ethanol. The objectives of this project were to develop a clean synthesis gas from biomass and develop robust catalysts with high selectivity and lifetime for C 2 oxygenate production from biomass-derived syngas and surrogate syngas. During the timeframe for this project, we have made research progress on the four tasks: (1) Produce clean bio-oil generated from biomass, such as corn stover or switchgrass, by using fast pyrolysis system, (2) Produce clean, high pressure synthetic gas (syngas: carbon monoxide, CO, and hydrogen, H 2) from bio-oil generatedmore » from biomass by gasification, (3) Develop and characterize mesoporous mixed oxide-supported metal catalysts for the selective production of ethanol and other alcohols, such as butanol, from synthesis gas, and (4) Design and build a laboratory scale synthesis gas to ethanol reactor system evaluation of the process. In this final report, detailed explanations of the research challenges associated with this project are given. Progress of the syngas production from various biomass feedstocks and catalyst synthesis for upgrading the syngas to C 2-oxygenates is included. Reaction properties of the catalyst systems under different reaction conditions and different reactor set-ups are also presented and discussed. Specifically, the development and application of mesoporous silica and mesoporous carbon supports with rhodium nanoparticle catalysts and rhodium nanoparticle with manganese catalysts are described along with the significant material characterizations we completed. In addition to the synthesis and characterization, we described the activity and selectivity of catalysts in our micro-tubular reactor (small scale) and fixed bed reactor (larger scale). After years of hard work, we are proud of the work done on this project, and do believe that this work will provide a solid foundation for the future production of syngas from biomass and the development of heterogeneous catalysts for the syngas to C 2-oxygenate process and for the commercialization of this process. Potential future directions for this research are also discussed within the report.« less

Zeolite catalysis in the synthesis of isobutylene from hydrous ethanol

NASA Astrophysics Data System (ADS)

Phillips, Cory Bernard

1999-11-01

This work deals with the synthesis of isobutylene from a hydrous ethanol feedstock over zeolites. The synthesis is accomplished in three steps: (1) low-temperature direct ethanol conversion to ethylene on H-ZSM-5 zeolite, (2) ethylene conversion to butene products over metal-exchanged zeolites, and (3) butene skeletal rearrangement to isobutylene over FER zeolites. The key to understanding and optimizing each synthesis step lies in the ability to control and regulate the zeolite acidity (Bronsted and Lewis)---both strength and number. Therefore, the continuous temperature programmed amine desorption (CTPAD) technique was further developed to simultaneously count the Bronsted acid sites and quantitatively characterize their strength. The adsorption of ethanol, reaction products, amines, coke and ethanol-derived residue (EDR) were monitored gravimetrically using the highly sensitive, novel Tapered Element Oscillating Microreactor (TEOM) apparatus. The TEOM was also used also in conjunction with CTPAD to characterize Bronsted acidity which is a new application for the instrument. For the first synthesis step, a parallel reaction exists which simultaneously produces diethyl ether and ethylene directly over H-ZSM-5. The reaction rates for each pathway were measured directly using a differential reactor operating at low temperatures (<473 K). Water in the ethanol feed enhances the rate of ethylene formation. A mechanism and kinetic expression are proposed for this reaction over H-ZSM-5, with diethyl-ether desorption and ethylene formation as the rate limiting steps. Heat of adsorption values measured from the independent microcalorimetry work reported in the literature are incorporated into the kinetic analysis which reduces the number of regressed parameters. For the remaining synthesis steps, several zeolite structures (ZSM-5, Y, FER) partially exchanged with Pd, Ti, Ni and Au were prepared and tested. It was determined from this screening study that the zeolites containing Pd are the most efficient catalysts for the dimerization reaction. Characterization results from x-ray diffraction (XRD), electron paramagnetic resonance (EPR) spectroscopy, and CTPAD suggest a stable, Pd species with a low oxidation state as part of the active site in Pd-exchanged zeolites. Isobutylene was present in the C4 fraction at reasonable quantities for most of the catalyst candidates, especially those containing an alkali metal co-cation.

Preparation, Characterization, and Selectivity Study of Mixed-Valence Sulfites

ERIC Educational Resources Information Center

Silva, Luciana A.; de Andrade, Jailson B.

2010-01-01

A project involving the synthesis of an isomorphic double sulfite series and characterization by classical inorganic chemical analyses is described. The project is performed by upper-level undergraduate students in the laboratory. This compound series is suitable for examining several chemical concepts and analytical techniques in inorganic…

Resin characterization

Treesearch

Robert L. Geimer; Robert A. Follensbee; Alfred W. Christiansen; James A. Koutsky; George E. Myers

1990-01-01

Currently, thermosetting adhesives are characterized by physical andchemical features such as viscosity, solids content, pH, and molecular distribution, and their reaction in simple gel tests. Synthesis of a new resin for a particular application is usually accompanied by a series of empirical laboratory and plant trials. The purpose of the research outlined in this...

Synthesis and characterization of estolide esters containing epoxy and cyclic carbonate groups

USDA-ARS?s Scientific Manuscript database

The unsaturated sites in oleic 2-ethylhexyl estolide esters (containing 35% monoenic fatty acids) were converted into epoxide and five-membered cyclic carbonate groups and the products characterized by Fourier transform infrared spectra (FTIR), 1H-, and 13C-nuclear magnetic resonance (NMR) spectrosc...

Placing Tighter Constraints on Mercurian Surface Fe Abundances Through the Synthesis and Characterization of Fe-Poor Silicates

NASA Astrophysics Data System (ADS)

Vander Kaaden, K. E.; McCubbin, F. M.; Rowland, R. L.; Morris, R. V.; Reppart, J. J.; Klima, R. L.

2018-05-01

We have crystallized and characterized synthetic Fe-poor minerals to make advancements towards reconciling the discrepancy between the lack of a 1-µm absorption band observed on the surface of Mercury, despite wt% levels of Fe observed by XRS.

One-step, low-temperature fabrication of CdS quantum dots by watermelon rind: a green approach

PubMed Central

Lakshmipathy, Rajasekhar; Sarada, Nallani Chakravarthula; Chidambaram, K; Pasha, Sk Khadeer

2015-01-01

We investigated the one-step synthesis of CdS nanoparticles via green synthesis that used aqueous extract of watermelon rind as a capping and stabilizing agent. Preliminary phytochemical analysis depicted the presence of carbohydrates which can act as capping and stabilizing agents. Synthesized CdS nanoparticles were characterized using UV-visible, Fourier transform infrared spectroscopy, X-ray diffraction, EDX, dynamic light scattering, transmission electron microscopy, and atomic force microscopy techniques. The CdS nanoparticles were found to be size- and shape-controlled and were stable even after 3 months of synthesis. The results suggest that watermelon rind, an agro-waste, can be used for synthesis of CdS nanoparticles without any addition of stabilizing and capping agents. PMID:26491319

Green chemical synthesis of silver nanomaterials with maltodextrin.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tallant, David Robert; Lu, Ping; Lambert, Timothy N.

2010-11-01

Silver nanomaterials have significant application resulting from their optical properties related to surface enhanced Raman spectroscopy, high electrical conductivity, and anti-microbial impact. A 'green chemistry' synthetic approach for silver nanomaterials minimizes the environmental impact of silver synthesis, as well as lowers the toxicity of the reactive agents. Biopolymers have long been used for stabilization of silver nanomaterials during synthesis, and include gum Arabic, heparin, and common starch. Maltodextrin is a processed derivative of starch with lower molecular weight and an increase in the number of reactive reducing aldehyde groups, and serves as a suitable single reactant for the formation ofmore » metallic silver. Silver nanomaterials can be formed under either a thermal route at neutral pH in water or by reaction at room temperature under more alkaline conditions. Deposited silver materials are formed on substrates from near neutral pH solutions at low temperatures near 50 C. Experimental conditions based on material concentrations, pH and reaction time are investigated for development of deposited films. Deposit morphology and optical properties are characterized using SEM and UV-vis techniques. Silver nanoparticles are generated under alkaline conditions by a dissolution-reduction method from precipitated silver (II) oxide. Synthesis conditions were explored for the rapid development of stable silver nanoparticle dispersions. UV-vis absorption spectra, powder X-ray diffraction (PXRD), dynamic light scattering (DLS), and transmission electron microscopy (TEM) techniques were used to characterize the nanoparticle formation kinetics and the influence of reaction conditions. The adsorbed content of the maltodextrin was characterized using thermogravimetric analysis (TGA).« less

Nestin upregulation characterizes vascular remodeling secondary to hypertension in the rat.

PubMed

Tardif, Kim; Hertig, Vanessa; Duquette, Natacha; Villeneuve, Louis; El-Hamamsy, Ismail; Tanguay, Jean-François; Calderone, Angelino

2015-05-15

Proliferation and hypertrophy of vascular smooth muscle cells represent hallmark features of vessel remodeling secondary to hypertension. The intermediate filament protein nestin was recently identified in vascular smooth muscle cells and in other cell types directly participated in proliferation. The present study tested the hypothesis that vessel remodeling secondary to hypertension was characterized by nestin upregulation in vascular smooth muscle cells. Two weeks after suprarenal abdominal aorta constriction of adult male Sprague-Dawley rats, elevated mean arterial pressure increased the media area and thickness of the carotid artery and aorta and concomitantly upregulated nestin protein levels. In the normal adult rat carotid artery, nestin immunoreactivity was observed in a subpopulation of vascular smooth muscle cells, and the density significantly increased following suprarenal abdominal aorta constriction. Filamentous nestin was detected in cultured rat carotid artery- and aorta-derived vascular smooth muscle cells and an analogous paradigm observed in human aorta-derived vascular smooth muscle cells. ANG II and EGF treatment of vascular smooth muscle cells stimulated DNA and protein synthesis and increased nestin protein levels. Lentiviral short-hairpin RNA-mediated nestin depletion of carotid artery-derived vascular smooth muscle cells inhibited peptide growth factor-stimulated DNA synthesis, whereas protein synthesis remained intact. These data have demonstrated that vessel remodeling secondary to hypertension was characterized in part by nestin upregulation in vascular smooth muscle cells. The selective role of nestin in peptide growth factor-stimulated DNA synthesis has revealed that the proliferative and hypertrophic responses of vascular smooth muscle cells were mediated by divergent signaling events. Copyright © 2015 the American Physiological Society.

Solid State Division progress report for period ending September 30, 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, P.H.; Hinton, L.W.

1994-08-01

This report covers research progress in the Solid State Division from April 1, 1992, to September 30, 1993. During this period, the division conducted a broad, interdisciplinary materials research program with emphasis on theoretical solid state physics, neutron scattering, synthesis and characterization of materials, ion beam and laser processing, and the structure of solids and surfaces. This research effort was enhanced by new capabilities in atomic-scale materials characterization, new emphasis on the synthesis and processing of materials, and increased partnering with industry and universities. The theoretical effort included a broad range of analytical studies, as well as a new emphasismore » on numerical simulation stimulated by advances in high-performance computing and by strong interest in related division experimental programs. Superconductivity research continued to advance on a broad front from fundamental mechanisms of high-temperature superconductivity to the development of new materials and processing techniques. The Neutron Scattering Program was characterized by a strong scientific user program and growing diversity represented by new initiatives in complex fluids and residual stress. The national emphasis on materials synthesis and processing was mirrored in division research programs in thin-film processing, surface modification, and crystal growth. Research on advanced processing techniques such as laser ablation, ion implantation, and plasma processing was complemented by strong programs in the characterization of materials and surfaces including ultrahigh resolution scanning transmission electron microscopy, atomic-resolution chemical analysis, synchrotron x-ray research, and scanning tunneling microscopy.« less

Production of nanocrystalline metal powders via combustion reaction synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frye, John G.; Weil, Kenneth Scott; Lavender, Curt A.

Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

Synthesis of long T₁ silicon nanoparticles for hyperpolarized ²⁹Si magnetic resonance imaging.

PubMed

Atkins, Tonya M; Cassidy, Maja C; Lee, Menyoung; Ganguly, Shreyashi; Marcus, Charles M; Kauzlarich, Susan M

2013-02-26

We describe the synthesis, materials characterization, and dynamic nuclear polarization (DNP) of amorphous and crystalline silicon nanoparticles for use as hyperpolarized magnetic resonance imaging (MRI) agents. The particles were synthesized by means of a metathesis reaction between sodium silicide (Na₄Si₄) and silicon tetrachloride (SiCl₄) and were surface functionalized with a variety of passivating ligands. The synthesis scheme results in particles of diameter ∼10 nm with long size-adjusted ²⁹Si spin-lattice relaxation (T₁) times (>600 s), which are retained after hyperpolarization by low-temperature DNP.

Synthesis of Long-T1 Silicon Nanoparticles for Hyperpolarized 29Si Magnetic Resonance Imaging

PubMed Central

Atkins, Tonya M.; Cassidy, Maja C.; Lee, Menyoung; Ganguly, Shreyashi; Marcus, Charles M.; Kauzlarich, Susan M.

2013-01-01

We describe the synthesis, materials characterization and dynamic nuclear polarization (DNP) of amorphous and crystalline silicon nanoparticles for use as hyperpolarized magnetic resonance imaging (MRI) agents. The particles were synthesized by means of a metathesis reaction between sodium silicide (Na4Si4) and silicon tetrachloride (SiCl4) and were surface functionalized with a variety of passivating ligands. The synthesis scheme results in particles of diameter ~10 nm with long size-adjusted 29Si spin lattice relaxation (T1) times (> 600 s), which are retained after hyperpolarization by low temperature DNP. PMID:23350651

Synthesis and Characterization of Polymers for Fuel Cells Application

NASA Technical Reports Server (NTRS)

Tytko, Stephen F.

2003-01-01

The goal of this summer research is to prepare Polymer Exchange Membranes (PEM s) for fuel cell application. Several high temperature polymers such as polybenzimidazoles and polyether ketones were known to possess good high temperature stability and had been investigated by post-sulfonation to yield sulfonated polymers. The research project will involve two approaches: 1. Synthesis of polybenzimidazoles and then react with alkyl sultonse to attach an aliphatic sulfonic groups. 2. Synthesis of monomers containing sulfonic acid units either on a aromatic ring or on an aliphatic chain and then polymerize the monomers to form high molecular weight sulfonate polymers.

Nanoscale zero-valent metals: a review of synthesis, characterization, and applications to environmental remediation.

PubMed

Li, Lingyun; Hu, Jiwei; Shi, Xuedan; Fan, Mingyi; Luo, Jin; Wei, Xionghui

2016-09-01

Engineered nanoscale zero-valent metals (NZVMs) representing the forefront of technologies have been considered as promising materials for environmental remediation and antimicrobial effect, due to their high reducibility and strong adsorption capability. This review is focused on the methodology for synthesis of bare NZVMs, supported NZVMs, modified NZVMs, and bimetallic systems with both traditional and green methods. Recent studies have demonstrated that self-assembly methods can play an important role for obtaining ordered, controllable, and tunable NZVMs. In addition to common characterization methods, the state-of-the-art methods have been developed to obtain the properties of NZVMs (e.g., granularity, size distribution, specific surface area, shape, crystal form, and chemical bond) with the resolution down to subnanometer scale. These methods include spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM), electron energy-loss spectroscopy (EELS), and near edge X-ray absorption fine structure (NEXAFS). A growing body of experimental data has proven that nanoscale zero-valent iron (NZVI) is highly effective and versatile. This article discusses the applications of NZVMs to treatment of heavy metals, halogenated organic compounds, polycyclic aromatic hydrocarbons, nutrients, radioelements, and microorganisms, using both ex situ and in situ methods. Furthermore, this paper briefly describes the ecotoxicological effects for NZVMs and the research prospects related to their synthesis, modification, characterization, and applications.

Photobactericidal porphyrin-cellulose nanocrystals: synthesis, characterization, and antimicrobial properties.

PubMed

Feese, Elke; Sadeghifar, Hasan; Gracz, Hanna S; Argyropoulos, Dimitris S; Ghiladi, Reza A

2011-10-10

Adherence and survival of pathogenic bacteria on surfaces leading to concomitant transmission to new hosts significantly contributes to the proliferation of pathogens, which in turn considerably increases the threat to human health, particularly by antibiotic-resistant bacteria. Consequently, more research into effective surface disinfection and alternative materials (fabrics, plastics, or coatings) with antimicrobial and other bioactive characteristics is desirable. This report describes the synthesis and characterization of cellulose nanocrystals that were surface-modified with a cationic porphyrin. The porphyrin was appended onto the cellulose surface via the Cu(I)-catalyzed Huisgen-Meldal-Sharpless 1,3-dipolar cycloaddition having occurred between azide groups on the cellulosic surface and porphyrinic alkynes. The resulting, generally insoluble, crystalline material, CNC-Por (5), was characterized by infrared and diffusion (1)H NMR spectroscopies, gel permeation chromatography, and thermogravimetric analysis. Although only suspended, and not dissolved, in an aqueous system, CNC-Por (5) showed excellent efficacy toward the photodynamic inactivation of Mycobacterium smegmatis and Staphylococcus aureus , albeit only slight activity against Escherichia coli . The synthesis, properties, and activity of CNC-Por (5) described herein serve as a benchmark toward our overall objectives of developing novel, potent, bioactive, photobactericidal materials that are effective against a range of bacteria, with potential utilization in the health care and food preparation industries.

Synthesis and Characterization of Thermoelectric Oxides at Macro- and Nano-scales

NASA Astrophysics Data System (ADS)

Ma, Feiyue

Thermoelectric materials can directly convert a temperature difference into electrical voltage and vice versa. Due to this unique property, thermoelectric materials are widely used in industry and scientific laboratories for temperature sensing and thermal management applications. Waste heat harvesting, another potential application of thermoelectric materials, has long been limited by the low conversion efficiency of the materials. Potential high temperature applications, such as power plant waste heat harvesting and combustion engine exhaust heat recovery, make thermoelectric oxides a very promising class of thermoelectric materials. In this thesis, the synthesis and characterization of thermoelectric oxide materials are explored. In the first part of this thesis, the measurement methodologies and instrumentation processes employed to investigate different thermoelectric properties, such as the Seebeck coefficient and carrier concentration at the bulk scale and the thermal conductivity at the nanoscale, are detailed. Existing scientific and engineering challenges associated with these measurements are also reviewed. To overcome such problems, original parts and methodologies have been designed. Three fully functional systems were ultimately developed for the characterization of macroscale thermoelectric properties as well as localized thermal conductivity. In the second part of the thesis, the synthesis of NaxCo 2O4, a thermoelectric oxide material, is discussed. Modification of both composition and structure were carried out so as to optimize the thermoelectric performance of NaxCo2O4. Nanostructuring methods, such as ball milling, electrospinning, auto-combustion synthesis, and core-shell structure fabrication, have been developed to refine the grain size of NaxCo2O4 in order to reduce its thermal conductivity. However, the structure of the nanostructured materials is very unstable at high temperature and limited improvement on thermoelectric performance is observed. Therefore, another technique was adopted to address this issue. A texturing process was also explored to optimize the NaxCo 2O4 structure. It was found that a highly textured structure can be obtained using a combined process of combustion synthesis, chemical demixing, and a flux method.

The Synthesis and Characterization of Gold-Core/LDH-Shell Nanoparticles

NASA Astrophysics Data System (ADS)

Rearick, Colton

In recent years, the field of nanomedicine has progressed at an astonishing rate, particularly with respect to applications in cancer treatment and molecular imaging. Although organic systems have been the frontrunners, inorganic systems have also begun to show promise, especially those based upon silica and magnetic nanoparticles (NPs). Many of these systems are being designed for simultaneous therapeutic and diagnostic capabilities, thus coining the term, theranostics. A unique class of inorganic systems that shows great promise as theranostics is that of layered double hydroxides (LDH). By synthesis of a core/shell structures, e.g. a gold nanoparticle (NP) core and LDH shell, the multifunctional theranostic may be developed without a drastic increase in the structural complexity. To demonstrate initial proof-of-concept of a potential (inorganic) theranostic platform, a Au-core/LDH-shell nanovector has been synthesized and characterized. The LDH shell was heterogeneously nucleated and grown on the surface of silica coated gold NPs via a coprecipitation method. Polyethylene glycol (PEG) was introduced in the initial synthesis steps to improve crystallinity and colloidal stability. Additionally, during synthesis, fluorescein isothiocyanate (FITC) was intercalated into the interlayer spacing of the LDH. In contrast to the PEG stabilization, a post synthesis citric acid treatment was used as a method to control the size and short-term stability. The heterogeneous core-shell system was characterized with scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), dynamic light scattering (DLS), and powder x-ray diffraction (PXRD). A preliminary in vitro study carried out with the assistance of Dr. Kaushal Rege's group at Arizona State University was to demonstrate the endocytosis capability of homogeneously-grown LDH NPs. The DLS measurements of the core-shell NPs indicated an average particle size of 212nm. The PXRD analysis showed that PEG greatly improved the crystallinity of the system while simultaneously preventing aggregation of the NPs. The preliminary in vitro fluorescence microscopy revealed a moderate uptake of homogeneous LDH NPs into the cells.

Synthesis of potassium ferrate using residual ferrous sulfate as iron bearing material

NASA Astrophysics Data System (ADS)

Kanari, N.; Filippov, L.; Diot, F.; Mochón, J.; Ruiz-Bustinza, I.; Allain, E.; Yvon, J.

2013-03-01

This paper summarizes the results obtained during potassium ferrate (K2FeVIO4) synthesis which is a high added value material. This compound that contains iron in the rare hexavalent state is becoming a substance of growing importance for the water and effluent treatment industries. This is due to its multi-functional nature (oxidation, flocculation, elimination of heavy metals, decomposition of organic matter, etc.). The most well known synthesis methods for potassium ferrate synthesis are those involving the chemical and/or electrochemical oxidation of iron (II) and (III) from aqueous solutions having a high alkali concentration. These methods are generally characterized by a low FeVI efficiency due to the reaction of the potassium ferrate with water, leading to the reduction of FeVI into FeIII. Concerning the work pertinent to this paper, the synthesis of K2FeVIO4 was achieved by a simultaneous reaction of two solids (iron sulfate and KOH) and one gaseous oxidant (chlorine). The synthesis process is performed in a rotary reactor at room temperature and the global synthesis reaction is exothermic. The effects of different experimental parameters on the potassium ferrate synthesis are investigated to determine the optimal conditions for the process.

Gnidia glauca flower extract mediated synthesis of gold nanoparticles and evaluation of its chemocatalytic potential

PubMed Central

2012-01-01

Background Novel approaches for synthesis of gold nanoparticles (AuNPs) are of utmost importance owing to its immense applications in diverse fields including catalysis, optics, medical diagnostics and therapeutics. We report on synthesis of AuNPs using Gnidia glauca flower extract (GGFE), its detailed characterization and evaluation of its chemocatalytic potential. Results Synthesis of AuNPs using GGFE was monitored by UV-Vis spectroscopy and was found to be rapid that completed within 20 min. The concentration of chloroauric acid and temperature was optimized to be 0.7 mM and 50°C respectively. Bioreduced nanoparticles varied in morphology from nanotriangles to nanohexagons majority being spherical. AuNPs were characterized employing transmission electron microscopy, high resolution transmission electron microscopy. Confirmation of elemental gold was carried out by elemental mapping in scanning transmission electron microscopic mode, energy dispersive spectroscopy and X-ray diffraction studies. Spherical particles of size ~10 nm were found in majority. However, particles of larger dimensions were in range between 50-150 nm. The bioreduced AuNPs exhibited remarkable catalytic properties in a reduction reaction of 4-nitrophenol to 4-aminophenol by NaBH4 in aqueous phase. Conclusion The elaborate experimental evidences support that GGFE can provide an environmentally benign rapid route for synthesis of AuNPs that can be applied for various purposes. Biogenic AuNPs synthesized using GGFE exhibited excellent chemocatalytic potential. PMID:22548753

Anchoring of Cu(II) onto surface of porous metal-organic framework through post-synthesis modification for the synthesis of benzimidazoles and benzothiazoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kardanpour, Reihaneh; Tangestaninejad, Shahram, E-mail: stanges@sci.ui.ac.ir; Mirkhani, Valiollah, E-mail: mirkhani@sci.ui.ac.ir

2016-03-15

Efficient synthesis of various benzimidazoles and benzothiazoles under mild conditions catalyzed by Cu(II) anchored onto UiO-66–NH{sub 2} metal organic framework is reported. In this manner, first, the aminated UiO-66 was modified with thiophene-2-carbaldehyde and then the prepared Schiff base was reacted with CuCl{sub 2}. The prepared catalyst was characterized by FT-IR, UV–vis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N{sub 2} adsorption, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and field emission scanning electron microscopy (FE-SEM). The UiO-66–NH{sub 2}–TC–Cu was applied as a highly efficient catalyst for synthesis of benzimidazole and benzothiazole derivatives by the reaction of aldehydes with 1,2-diaminobenzenemore » or 2-aminothiophenol. The Cu(II)-containing MOF was reused several times without any appreciable loss of its efficiency. - Graphical abstract: Efficient synthesis of benzimidazoles and benzothiazoles catalyzed by Cu(II) anchored onto UiO-66–NH{sub 2} metal organic framework is reported. - Highlights: • A copper Schiff base was immobilized on UiO-66 via postsynthetic modification. • The modified MOFs were fully characterized by a variety of methods. • The catalyst was used for the preparation of benzimidazoles and benzothiazoles. • In comparison of other catalysts, our catalyst was more efficient and forceful.« less

Evidence of desulfurization in the oxidative cyclization of thiosemicarbazones. Conversion to 1,3,4-oxadiazole derivatives.

PubMed

Gómez-Saiz, Patricia; García-Tojal, Javier; Maestro, Miguel A; Arnaiz, Francisco J; Rojo, Teófilo

2002-03-25

The addition of pyridine-2-carbaldehyde 4N-methylthiosemicarbazone (C8H10N4S) to an aqueous solution of copper(II) nitrate yields [[Cu(C8H9N4S)(NO3)]2] (1). This complex consists of centrosymmetric dinuclear entities containing square-pyramidal copper(II) ions bridged through the sulfur thioamide atoms. The oxidation of 1 with KBrO3 or KIO3 gives rise to a compound with formula [[Cu(C8H8N4O)(H2O)2(SO4)]2]*2H2O (2) (C8H8N4O = 2-methylamino-5-pyridin-2-yl-1,3,4-oxadiazole). The structure of 2 is made up of centrosymmetric dimers where the copper(II) ions exhibit a distorted octahedral coordination and are connected by the oxadiazole moiety. The metal ions in 2 can be removed by addition of K4[Fe(CN)6], and then the oxadiazole ligand can be isolated and recrystallized as (C8H8N4O)*3H2O (3).

Stabilities and Biological Activities of Vanadium Drugs: What is the Nature of the Active Species?

PubMed

Levina, Aviva; Lay, Peter A

2017-07-18

Diverse biological activities of vanadium(V) drugs mainly arise from their abilities to inhibit phosphatase enzymes and to alter cell signaling. Initial interest focused on anti-diabetic activities but has shifted to anti-cancer and anti-parasitic drugs. V-based anti-diabetics are pro-drugs that release active components (e.g., H 2 VO 4 - ) in biological media. By contrast, V anti-cancer drugs are generally assumed to enter cells intact; however, speciation studies indicate that nearly all drugs are likely to react in cell culture media during in vitro assays and the same would apply in vivo. The biological activities are due to V V and/or V IV reaction products with cell culture media, or the release of ligands (e.g., aromatic diimines, 8-hydroxyquinolines or thiosemicarbazones) that bind to essential metal ions in the media. Careful consideration of the stability and speciation of V complexes in cell culture media and in biological fluids is essential to design targeted V-based anti-cancer therapies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biological evaluation and molecular docking of some chromenyl-derivatives as potential antimicrobial agents.

PubMed

Ionuţ, Ioana; Vodnar, Dan Cristian; Oniga, Ilioara; Oniga, Ovidiu; Tiperciuc, Brînduşa; Tamaian, Radu

2016-01-01

Various thiosemicarbazones (TSCs) and their heterocyclic thiadiazolines (TDZ) possess important biological effects. In addition, chromenyl derivatives exhibit a wide range of pharmacological activities. Based on these findings and as a continuation of our research on nitrogen and sulfur containing compounds, we investigated a series of previously reported chromenyl-TSCs (1a-j) and chromenyl-TDZs (2a-j) for their in vitro antimicrobial activities against two bacterial and four fungal strains. MIC and MBC/MFC (µg/mL) values of these compounds were evaluated and compared to those of Spectinomycin, Moxifloxacin and Fluconazole, used as reference drugs. For a better understanding of the drug-receptor interactions, all the compounds were further subjected to molecular docking against four targets that were chosen based on the specific mechanism of action of the reference drugs used in the antimicrobial screening. All compounds tested showed equal or higher antibacterial/antifungal activities relative to the used reference drugs. In silico studies (molecular docking) revealed that all the investigated compounds showed good binding energies towards four receptor protein targets and supported their antimicrobial properties.

Pulsed laser vaporization synthesis of boron loaded few layered graphene (Conference Presentation)

NASA Astrophysics Data System (ADS)

Tennyson, Wesley D.; Tian, Mengkun; More, Karren L.; Geohegan, David B.; Puretzky, Alexander A.; Papandrew, Alexander B.; Rouleau, Christopher M.; Yoon, Mina

2017-02-01

The bulk production of loose graphene flakes and its doped variants are important for energy applications including batteries, fuel cells, and supercapacitors as well as optoelectronic and thermal applications. While laser-based methods have been reported for large-scale synthesis of single-wall carbon nanohorns (SWNHs), similar large-scale production of graphene has not been reported. Here we explored the synthesis of doped few layered graphene by pulsed laser vaporization (PLV) with the goal of producing an oxidation resistant electrode support for solid acid fuel cells. PLV of graphite with various amounts of boron was carried out in mixtures in either Ar or Ar/H2 at 0.1 MPa at elevated temperatures under conditions typically used for synthesis of SWNHs. Both the addition of hydrogen to the background argon, or the addition of boron to the carbon target, was found to shift the formation of carbon nanohorns to two-dimensional flakes of a new form of few-layer graphene material, with sizes up to microns in dimension as confirmed by XRD and TEM. However, the materials made with boron exhibited superior resistance to carbon corrosion in the solid acid fuel cell and thermal oxidation resistance in air compared to similar product made without boron. Mechanisms for the synthesis and oxidation resistance of these materials will be discussed based upon detailed characterization and modeling. •Synthesis science was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (BES), Materials Sciences and Engineering Division. Material processing and characterization science supported by ARPA-E under Cooperative Agreement Number DE-AR0000499 and as a user project at the Center for Nanophase Materials Sciences, a Department of Energy Office of Science User Facility.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boppana, Venkata Bharat Ram; Hould, Nathan D.; Lobo, Raul F., E-mail: lobo@udel.ed

We report the first instance of a hydrothermal synthesis of zinc germanate (Zn{sub 2}GeO{sub 4}) nano-materials having a variety of morphologies and photochemical properties in surfactant, template and catalyst-free conditions. A systematic variation of synthesis conditions and detailed characterization using X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, Raman spectroscopy, electron microscopy, X-ray photoelectron spectroscopy and small angle X-ray scattering led to a better understanding of the growth of these particles from solution. At 140 {sup o}C, the zinc germanate particle morphology changes with pH from flower-shaped at pH 6.0, to poly-disperse nano-rods at pH 10 when the Zn to Ge ratiomore » in the synthesis solution is 2. When the Zn to Ge ratio is reduced to 1.25, mono-disperse nano-rods could be prepared at pH 7.5. Nanorod formation is also independent of the addition of cetyltrimethylammonium bromide (CTAB), in contrast to previous reports. Photocatalytic tests show that Zn{sub 2}GeO{sub 4} nano-rods (by weight) and flower shaped (by surface area) are the most active for methylene blue dye degradation among the synthesized zinc germanate materials. -- Graphical abstract: Zinc germanate materials were synthesized possessing unique morphologies dependent on the hydrothermal synthesis conditions in the absence of surfactant, catalyst or template. These novel materials are characterized and evaluated for their photocatalytic activities. Display Omitted highlights: > Zinc germanate synthesized hydrothermally (surfactant free) with unique morphologies. > Flower-shaped, nano-rods, globular particles obtained dependent on synthesis pH. > At 140 {sup o}C, they possess the rhombohedral crystal irrespective of synthesis conditions. > They are photocatalytically active for the degradation of methylene blue. > Potential applications could be photocatalytic water splitting and CO{sub 2} reduction.« less

Synthesis of a Chloroamide-Hyperbranched Polymer Additive for Self-Decontaminating Surfaces

DTIC Science & Technology

2012-04-01

dissolved in dichloromethane (DCM) (30 mL) and the solution was dried with anhydrous sodium sulfate (Na2SO4) before being used in the next step...infrared spectroscopy N2 nitrogen Na2SO4 anhydrous sodium sulfate NMP 1-methyl-2-pyrrolidinone PFOA perfluorinated octanoic acid PMMA poly(methyl...16 3.6.1 Synthesis and Characterization of Chlorinated 5,5-Dimethylhydantoin Sodium Salt

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

DTIC Science & Technology

2016-12-14

thermal, mechanical and surface properties of many polymeric systems. A useful analogy is that a POSS is nano-sized particle of silica solubilzed...with organic modifiers (RSiO1.5)n; the organic periphery determines how well the POSS can interact with any host polymer , while the siliceous core adds...various materials affects polymer properties. Herein is reported a synthesis strategy to produce POSS-containing, thermosetting phenylethynyls to yield

Synthesis, Transfer, and Characterization of Nanoscale 2-Dimensional Materials

DTIC Science & Technology

2015-09-01

deposition systems, leading to reduced operating costs. Transfer has been achieved using polymer-assisted methods , and material quality has been...Introduction and Background 1 2. Materials and Methods 1 3. Results and Discussion 2 3.1 Copper Foil Preparation 2 3.2 Graphene Synthesis and...magnification. a) 10 K, b) 18 K, c) 20 K, and d) 40 K. The red arrows indicate wrinkles in the film

Polarization and Piezoelectric Properties of a Nitrile Substituted Polyimide

NASA Technical Reports Server (NTRS)

Simpson, Joycelyn; Ounaies, Zoubeida; Fay, Catharine

1997-01-01

This research focuses on the synthesis and characterization of a piezoelectric (beta-CN)- APB/ODPA polyimide. The remanent polarization and piezoelectric d(sub 31) and g(sub 33) coefficients are reported to assess the effect of synthesis variations. Each of the materials exhibits a level of piezoelectricity which increases with temperature. The remanent polarization is retained at temperatures close to the glass transition temperature of the polyimide.

Synthesis of Oligoimides and Oligoimide Anion Radicals

DTIC Science & Technology

1992-01-01

University of Minnesota 0 Minneapolis, MN A. Synthesis of Ollgolmides and Oligoimide Anion Radicals. Key to the results described in parts B-D are compounds ...could be synthesized as single molecular weight, pure and usually soluble compounds . 6 ,7.16 Although rotation about the single bonds along the...could be attached and unsymmetrical rigid rods (different end groups) could be prepared. The compounds were characterized by NMR, IR, MS and HPLC, In

Instrumentation for Nano-porous, Nano-particulate Geopolymeric Materials Research

DTIC Science & Technology

2008-11-04

and their composites . This grant was used to procure equipment to synthesize and characterize the nano- and meso-porous geopolymers , and study their...and meso-porosity and microstructure of geopolymers and their composites is part of an ongoing research project in the PIs research group, which has...the synthesis and processing of geopolymers and geopolymer composites . The attritor mill enables synthesis Technical Report of nano-sized high

LOGIC NETS, THEIR CHARACTERIZATION, RELIABILITY, AND EFFICIENT SYNTHESIS.

DTIC Science & Technology

The report consists of two parts. The first discusses a problem in the dual-support approach to network synthesis using threshold gates, gives new...asymptotic results on the number of threshold gates and the size of threshold gate networks, and summarizes the work in threshold logic supported by...this contract, including programs to facilitate experimentation in the design of networks of threshold gates. The second summarizes CDL1 - Computer

Synthesis and characterization of zinc borophosphates with ANA-zeotype framework by the microwave method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Yu, E-mail: songyu@dlpu.edu.cn; Ding, Ling; An, Qingda

2013-06-15

Zinc borophosphate (NH{sub 4}){sub 16}[Zn{sub 16}B{sub 8}P{sub 24}O{sub 96}] (denoted as ZnBP-ANA) with ANA-zeotype structure has been synthesized by employing microwave-assisted solvothermal synthesis in the reaction system ZnCl{sub 2}∙6H{sub 2}O-(NH{sub 4}){sub 2}HPO{sub 4}–H{sub 3}BO{sub 3} using ethylene glycol as a co-solvent. The influences of various experimental parameters, such as reaction temperature, solvent ratio, zinc precursors and reactive power, have been systematically investigated. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA), and so on. Small and homogeneous ZnBP-ANA single crystal with regular cube morphology are crystallized by using microwave solvothermal synthesis method withinmore » a shorter time, and its grain size decreases with power. - Graphical abstract: Tailor-made ANA zeolites with varied size can be prepared by simply changing the reaction power. - Highlights: • Zinc borophosphate zeolites with ANA-zeotype structures were prepared by microwave technique. • The size of crystals could be controlled by tuning power. • Synthesis period can be significantly reduced by raising reaction temperature.« less

Perspectives and challenges of photon-upconversion nanoparticles - Part I: routes to brighter particles and quantitative spectroscopic studies.

PubMed

Resch-Genger, Ute; Gorris, Hans H

2017-10-01

Lanthanide-doped photon-upconversion nanoparticles (UCNPs) have been the focus of many research activities in materials and life sciences in the last 15 years because of their potential to convert light between different spectral regions and their unique photophysical properties. To fully exploit the application potential of these fascinating nanomaterials, a number of challenges have to be overcome, such as the low brightness, particularly of small UCNPs, and the reliable quantification of the excitation-power-density-dependent upconversion luminescence. In this series of critical reviews, recent developments in the design, synthesis, optical-spectroscopic characterization, and application of UCNPs are presented with special focus on bioanalysis and the life sciences. Here we guide the reader from the synthesis of UCNPs to different concepts to enhance their luminescence, including the required optical-spectroscopic assessment to quantify material performance; surface modification strategies and bioanalytical applications as well as selected examples of the use of UCNPs as reporters in different assay formats are addressed in part II. Future trends and challenges in the field of upconversion are discussed with special emphasis on UCNP synthesis and material characterization, particularly quantitative luminescence studies. Graphical Abstract Both synthesis and spectroscopy as well bioanalytical applications of UCNPs are driven and supported by COST Action CM1403 "The European Upconversion Network".

Ecofriendly Synthesis of nano Zero Valent Iron from Banana Peel Extract

NASA Astrophysics Data System (ADS)

Sunardi; Ashadi; Budi Rahardjo, Sentot; Inayati

2017-01-01

In this study, nano Zero Valent Iron (nZVI) were synthesized from banana peel extract (BPE) and ferrous sulfate. During the synthesis of nZVI both the precursor and the reducing agent were mixed in a clean sterilized flask in 1:1 proportion. For the reduction of Fe ions, 5 ml of filtered BPE was mixed to 5 ml of freshly prepared 0.001 M - 0.005 M aqueous of FeSO4 solution with constant stirring at room temperature. Within a particular time change in colour from brown to black color obtained by nanoparticles synthesis. A systematic characterization of nZVI was performed using UV-Vis. UV-visible absorption is used to investigate SPR. Characteristic surface plasmon absorption band was observed at 210 nm for the black colored nZVI synthesized from 0.001-0.005 M ferrous sulfate with BPE concentration 5 ml. It has been found that the optimum concentration for the synthesis of nZVI is 0.001M Fe2+ ions. There is small decrease in the intensity of SPR band from 0.001 to 0.005 M. The characterization size of nZVI was performed using TEM. The result shows that formation of particles size of nZVI was more 100 nm.

Fluorescent silica nanoparticles with chemically reactive surface: Controlling spatial distribution in one-step synthesis.

PubMed

Vera, María L; Cánneva, Antonela; Huck-Iriart, Cristián; Requejo, Felix G; Gonzalez, Mónica C; Dell'Arciprete, María L; Calvo, Alejandra

2017-06-15

The encapsulation of fluorescent dyes inside silica nanoparticles is advantageous to improve their quality as probes. Inside the particle, the fluorophore is protected from the external conditions and its main emission parameters remains unchanged even in the presence of quenchers. On the other hand, the amine-functionalized nanoparticle surface enables a wide range of applications, as amino groups could be easily linked with different biomolecules for targeting purposes. This kind of nanoparticle is regularly synthesized by methods that employ templates, additional nanoparticle formation or multiple pathway process. However, a one-step synthesis will be an efficient approach in this sort of bifunctional hybrid nanoparticles. A co-condensation sol-gel synthesis of hybrid fluorescent silica nanoparticle where developed. The chemical and morphological characterization of the particles where investigated by DRIFTS, XPS, SEM and SAXS. The nanoparticle fluorescent properties were also assessed by excitation-emission matrices and time resolved experiments. We have developed a one-pot synthesis method that enables the simultaneous incorporation of functionalities, the fluorescent molecule and the amino group, by controlling co-condensation process. An exhaustive characterization allows the definition of the spatial distribution of the fluorescent probe, fluorescein isothiocyanate, inside the particle and reactive amino groups on the surface of the nanoparticle with diameter about 100nm. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel synthesis and characterization of a collagen-based biopolymer initiated by hydroxyapatite nanoparticles.

PubMed

Bhuiyan, D; Jablonsky, M J; Kolesov, I; Middleton, J; Wick, T M; Tannenbaum, R

2015-03-01

In this study, we developed a novel synthesis method to create a complex collagen-based biopolymer that promises to possess the necessary material properties for a bone graft substitute. The synthesis was carried out in several steps. In the first step, a ring-opening polymerization reaction initiated by hydroxyapatite nanoparticles was used to polymerize d,l-lactide and glycolide monomers to form poly(lactide-co-glycolide) co-polymer. In the second step, the polymerization product was coupled with succinic anhydride, and subsequently was reacted with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide as the cross-linking agent, in order to activate the co-polymer for collagen attachment. In the third and final step, the activated co-polymer was attached to calf skin collagen type I, in hydrochloric acid/phosphate buffer solution and the precipitated co-polymer with attached collagen was isolated. The synthesis was monitored by proton nuclear magnetic resonance, infrared and Raman spectroscopies, and the products after each step were characterized by thermal and mechanical analysis. Calculations of the relative amounts of the various components, coupled with initial dynamic mechanical analysis testing of the resulting biopolymer, afforded a preliminary assessment of the structure of the complex biomaterial formed by this novel polymerization process. Copyright © 2015. Published by Elsevier Ltd.

PETI-298 Prepared by Microwave Synthesis: Neat Resin and Composite Properties

NASA Technical Reports Server (NTRS)

Smith, Joseph G.; Connell, John W.; Li, Chao-Jun; Wu, Wei; Criss, Jim M., Jr.

2004-01-01

PETI-298 is a high temperature/high performance matrix resin that is processable into composites by resin transfer molding (RTM), resin infusion and vacuum assisted RTM techniques. It is typically synthesized in a polar aprotic solvent from the reaction of an aromatic anhydride and a combination of diamines and endcapped with phenylethynylphthalic anhydride. Microwave synthesis of PETI-298 was investigated as a means to eliminate solvent and decrease reaction time. The monomers were manually mixed and placed in a microwave oven for various times to determine optimum reaction conditions. The synthetic process was subsequently scaled-up to 330g. Three batches were synthesized and combined to give 1 kg of material that was characterized for thermal and rheological properties and compared to PETI-298 prepared by the classic solution based synthetic method. The microwave synthesized PETI-298 was subsequently used to fabricate flat laminates on T650 carbon fabric by RTM. The composite panels were analyzed and mechanical properties determined and compared with those fabricated from PETI-298 prepared by the classic solution method. The microwave synthesis process and characterization of neat resin and carbon fiber reinforced composites fabricated by RTM will be presented. KEY WORDS: Resin Transfer Molding, High Temperature Polymers, Phenylethynyl Terminated Imides, Microwave Synthesis

Synthesis of second phase hybrid ceramics using two different bio-source and a comparative study on their morphological characterization

NASA Astrophysics Data System (ADS)

Karivaratharajan, Adhitya; Baskaran, Sidharth; Thillairajan, K.

2018-02-01

Ceramics are generally synthesized with various sources and methods. The most common method for synthesis of ceramics with reduced cost and energy is SOL-GEL method. Combustion synthesis is also a most widely used method for ceramic synthesis. In general, ceramics have enhanced hardness and dimensional stability even at elevated temperatures. For this reason, they are used in the production of refractories, thermal barrier coatings, chemical resistant coatings, wear resistant coatings, and also as reinforcement material to produce metal matrix composites and polymer matrix composites. This work concentrates on the comparison of morphological characterization of such reinforcement particles synthesized from different sources. The particles size range varying from 7 μm to 250 μm with flaky and spongy structures are observed in the ash of Vicia faba. However, the ash of Cocos nucífera resulted in fibrous structure with a diameter of 50 μm to length above 600 μm, particles size ranging from 10 μm to 70 μm micro tubes of diameter 3.6 μm to length of 150 μm. The EDX and XRD analysis of Vicia faba showed the presence of carbon as the major element with a few other elements.

Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs

PubMed Central

Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M. A.; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E.; Casadevall, Arturo

2015-01-01

The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. PMID:26711773

Synthesis, Decomposition and Characterization of Fe and Ni Sulfides and Fe and CO Nanoparticles for Aerospace Applications

NASA Technical Reports Server (NTRS)

Cowen, Jonathan E.; Hepp, Aloysius F.; Duffy, Norman V.; Jose, Melanie J.; Choi, D. B.; Brothers, Scott M.; Baird, Michael F.; Tomsik, Thomas M.; Duraj, Stan A.; Williams, Jennifer N.;

Identification, synthesis, isolation and characterization of new impurity in metoprolol tartrate tablets.

PubMed

Reddy, R Buchi; More, Kishor R; Gupta, Leena; Jha, Mukesh S; Magar, Laki

2016-01-05

A new unknown impurity was observed in accelerated stability studies of Metoprolol tartrate tablets. This impurity has been identified, synthesized and characterized through different spectral studies and confirmed as an adduct of lactose and Metoprolol formed by Maillard reaction. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and Characterization of Metal Complexes with Schiff Base Ligands

ERIC Educational Resources Information Center

Wilkinson, Shane M.; Sheedy, Timothy M.; New, Elizabeth J.

2016-01-01

In order for undergraduate laboratory experiments to reflect modern research practice, it is essential that they include a range of elements, and that synthetic tasks are accompanied by characterization and analysis. This intermediate general chemistry laboratory exercise runs over 2 weeks, and involves the preparation of a Schiff base ligand and…

Synthesis and Characterization of Cerium(IV) Metallocenes

DOE PAGES

Sutton, Andrew; Clark, David Lewis; Scott, Brian Lindley; ...

2015-12-11

In this study, by applying a salt metathesis approach between Ce(OtBu 3) 2(NO 3) 2(THF) 2 and the potassium salts of mono- and ditrimethylsilyl substituted cyclopentadienes, we were able to isolate two new Ce(IV) metallocenes, including to the best of our knowledge, the first structurally characterized bis-cyclopentadiene Ce(IV) compound.

Reasoning Maps: A Generally Applicable Method for Characterizing Hypothesis-Testing Behaviour. Research Report

ERIC Educational Resources Information Center

White, Brian

2004-01-01

This paper presents a generally applicable method for characterizing subjects' hypothesis-testing behaviour based on a synthesis that extends on previous work. Beginning with a transcript of subjects' speech and videotape of their actions, a Reasoning Map is created that depicts the flow of their hypotheses, tests, predictions, results, and…

Synthesis and characterization of carbon nanospheres obtained by hydrothermal carbonization of wood-derived and other saccharides

Treesearch

Qiangu Yan; Rui Li; Hossein Toghiani; Zhiyong Cai; Jilei Zhang

2015-01-01

Carbon nanospheres were synthesized by hydrothermal carbonization (HTC) of four different carbon sources: xylose, glucose, sucrose, and pine wood derived saccharides. The obtained carbon nanospheres were characterized for particle morphology and size, and surface functional groups. Morphological and structural differences among these saccharides derived HTC carbons...

Imidazolium tagged acridines: Synthesis, characterization and applications in DNA binding and anti-microbial activities

NASA Astrophysics Data System (ADS)

Raju, Gembali; Vishwanath, S.; Prasad, Archana; Patel, Basant K.; Prabusankar, Ganesan

2016-03-01

New water soluble 4,5-bis imidazolium tagged acridines have been synthesized and structurally characterized by multinuclear NMR and single crystal X-ray diffraction techniques. The DNA binding and anti-microbial activities of these acridine derivatives were investigated by fluorescence and far-UV circular dichroism studies.

Uncommon and Emissive {[Au2(C3H6NS2)2][Au(C3H6NS2)2]2(PF6)2} Mixed Au+ and Au3+ Pseudotetranuclear Crystalline Compound: Synthesis, Structural Characterization, and Optical Properties.

PubMed

Langaro, Ana P; Souza, Ana K R; Morassuti, Claudio Y; Lima, Sandro M; Casagrande, Gleison A; Deflon, Victor M; Nunes, Luiz A O; Da Cunha Andrade, Luis H

2016-11-23

An uncommon emissive pseudotetranuclear compound, {[Au 2 (C 3 H 6 NS 2 ) 2 ][Au(C 3 H 6 NS 2 ) 2 ] 2 (PF 6 ) 2 }, was synthesized and characterized in terms of its structure and optical properties. The synthesis produced a crystalline compound composed of four gold atoms with two different oxidation states (Au + and Au 3+ ) in the same crystalline structure. The title complex belonged to a triclinic crystalline system involving the centrosymmetric P1̅ space group. X-ray diffractometry and vibrational spectroscopy (infrared, Raman, and SERS) were used for structural characterization of the new crystal. The vibrational spectroscopy techniques supported the X-ray diffraction results and confirmed the presence of bonds including Au-Au and Au-S. Optical characterization performed using UV-vis spectroscopy showed that under ultraviolet excitation, the emissive crystalline complex presented characteristic broad luminescent bands centered at 420 and 670 nm.

Light-Induced Activation of a Molybdenum Oxotransferase Model within a Ru(II)-Mo(VI) Dyad.

PubMed

Ducrot, Aurélien B; Coulson, Ben A; Perutz, Robin N; Duhme-Klair, Anne-Kathrin

2016-12-19

Nature uses molybdenum-containing enzymes to catalyze oxygen atom transfer (OAT) from water to organic substrates. In these enzymes, the two electrons that are released during the reaction are rapidly removed, one at a time, by spatially separated electron transfer units. Inspired by this design, a Ru(II)-Mo(VI) dyad was synthesized and characterized, with the aim of accelerating the rate-determining step in the cis-dioxo molybdenum-catalyzed OAT cycle, the transfer of an oxo ligand to triphenyl phosphine, via a photo-oxidation process. The dyad consists of a photoactive bis(bipyridyl)-phenanthroline ruthenium moiety that is covalently linked to a bioinspired cis-dioxo molybdenum thiosemicarbazone complex. The quantum yield and luminescence lifetimes of the dyad [Ru(bpy) 2 (L 2 )MoO 2 (solv)] 2+ were determined. The major component of the luminescence decay in MeCN solution (τ = 1149 ± 2 ns, 67%) corresponds closely to the lifetime of excited [Ru(bpy) 2 (phen-NH 2 )] 2+ , while the minor component (τ = 320 ± 1 ns, 31%) matches that of [Ru(bpy) 2 (H 2 -L 2 )] 2+ . In addition, the (spectro)electrochemical properties of the system were investigated. Catalytic tests showed that the dyad-catalyzed OAT from dimethyl sulfoxide to triphenyl phosphine proceeds significantly faster upon irradiation with visible light than in the dark. Methylviologen acts as a mediator in the photoredox cycle, but it is regenerated and hence only required in stoichiometric amounts with respect to the catalyst rather than sacrificial amounts. It is proposed that oxidative quenching of the photoexcited Ru unit, followed by intramolecular electron transfer, leads to the production of a reactive one-electron oxidized catalyst, which is not accessible by electrochemical methods. A significant, but less pronounced, rate enhancement was observed when an analogous bimolecular system was tested, indicating that intramolecular electron transfer between the photosensitizer and the catalytic center is more efficient than intermolecular electron transfer between the separate components.

Nucleic Acid-Based Nanoconstructs

Cancer.gov

Focuses on the design, synthesis, characterization, and development of spherical nucleic acid constructs as effective nanotherapeutic, single-entity agents for the treatment of glioblastoma multiforme and prostate cancers.

Nicholas Cleveland | NREL

Science.gov Websites

tools for complex sample analysis Affiliated Research Programs Biochemical Catalysis Working Group The synthesis Catalyst characterization Catalyst testing and reaction screening Analysis of complex organics

Synthesis and photophysical characterizations of thermal-stable naphthalene benzimidazoles.

PubMed

Erten-Ela, Sule; Ozcelik, Serdar; Eren, Esin

2011-07-01

Microwave-assisted synthesis, photophysical and electrochemical properties of thermal-stable naphthalene benzimidazoles and naphthalimides are studied in this paper. Microwave-assisted synthesis of naphthalene benzimidazoles provide higher yields than the conventional thermal synthesis. Comparative photophysical properties of naphthalene benzimidazoles and naphthalimides are revealed that conjugation of electron-donating group onto naphthalimide moiety increases fluorescence quantum yields. Fluorophore-solvent interactions are also investigated using Lippert-Mataga equation for naphthalimides and naphthalene benzimidazoles. Thermal stabilities of naphthalene benzimidazoles are better than naphthalimides due to increased aromaticity. The experimental E(LUMO) levels of naphthalene benzimidazoles are found to be between 3.15 and 3.28 eV. Therefore, naphthalene benzimidazole derivatives consisting of anchoring groups are promising materials in organic dye sensitized solar cells. © Springer Science+Business Media, LLC 2011

Aloe barbadensis Miller mediated green synthesis of mono-disperse copper oxide nanoparticles: Optical properties

NASA Astrophysics Data System (ADS)

Gunalan, Sangeetha; Sivaraj, Rajeshwari; Venckatesh, Rajendran

2012-11-01

In this paper, we report on the synthesis of nanostructured copper oxide particles by both chemical and biological method. A facile and efficient synthesis of copper oxide nanoparticles was carried out with controlled surface properties via green chemistry approach. The CuO nanoparticles synthesized are monodisperse and versatile and were characterized with the help of UV-Vis, PL, FT-IR, XRD, SEM, and TEM techniques. The particles are crystalline in nature and average sizes were between 15 and 30 nm. The morphology of the nanoparticles can be controlled by tuning the amount of Aloe vera extract. This new eco-friendly approach of synthesis is a novel, cheap, and convenient technique suitable for large scale commercial production and health related applications of CuO nanoparticles.

Polymers containing nickel(II) complexes of Goedken's macrocycle: optimized synthesis and electrochemical characterization.

PubMed

Paquette, Joseph A; Sauvé, Ethan R; Gilroy, Joe B

2015-04-01

The synthesis and characterization of a new class of nickel-containing polymers is described. The optimized copolymerization of alkyne-bearing nickel(II) complexes of Goedken's macrocycle (4,11-dihydro-5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecine) and brominated 9,9-dihexylfluorene produced polymers with potential application as functional redox-active materials. The title polymers exhibit electrochemically reversible, ligand-centered oxidation events at 0.24 and 0.73 V versus the ferrocene/ferrocenium redox couple. They also display exceptional thermal stability and interesting absorption properties due to the presence of the macrocyclic nickel(II) complexes and π-conjugated units incorporated in their backbones. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, spectroscopic, biological activity and thermal characterization of ceftazidime with transition metals

NASA Astrophysics Data System (ADS)

Masoud, Mamdouh S.; Ali, Alaa E.; Elasala, Gehan S.; Kolkaila, Sherif A.

2018-03-01

Synthesis, physicochemical characterization and thermal analysis of ceftazidime complexes with transition metals (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)) were discussed. It's obtained that ceftazidime act as bidentate ligand. From magnetic measurement and spectral data, octahedral structures were proposed for all complexes except for cobalt, nickel and mercury had tetrahedral structural. Hyper chemistry program confirmed binding sites of ceftazidime. Ceftazidime complexes show higher activity than ceftazidime for some strains. From TG and DTA curves the thermal decomposition mechanisms of ceftazidime and their metal complexes were suggested. The thermal decomposition of the complexes ended with the formation of metal oxides as a final product except in case of Hg complex.

Synthesis and characterization of nanostructured titanium carbide for fuel cell applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Paviter; Singh, Harwinder; Singh, Bikramjeet

2016-04-13

Titanium carbide (TiC) nanoparticles have been successfully synthesized by carbo-thermic reaction of titanium and acetone at 800 °C. This method is relatively low temperature synthesis route. It can be used for large scale production of TiC. The synthesized nanoparticles have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analyzer (DTA) techniques. XRD analysis confirmed the formation of single phase TiC. XRD analysis confirmed that the particles are spherical in shape with an average particle size of 13 nm. DTA analysis shows that the phase is stable upto 900 °C and the material can be used formore » high temperature applications.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rioux, Robert M.

In this work, we have primarily utilized isothermal titration calorimetry (ITC) and complimentary catalyst characterization techniques to study and assess the impact of solution conditions (i.e., solid-liquid) interface on the synthesis of heterogeneous and electro-catalysts. Isothermal titration calorimetry is well-known technique from biochemistry/physics, but has been applied to a far lesser extent to characterize buried solid-liquid interfaces in materials science. We demonstrate the utility and unique information provided by ITC for two distinct catalytic systems. We explored the thermodynamics associated catalyst synthesis for two systems: (i) ion-exchange or strong electrostatic adsorption for Pt and Pd salts on silica and aluminamore » materials (ii) adsorption to provide covalent attachment of metal and metal-oxo clusters to Dion-Jacobsen perovskite materials.« less

Synthesis and characterization of intercalated polyaniline-clay nanocomposite using supercritical CO2

NASA Astrophysics Data System (ADS)

Abdelraheem, A.; El-Shazly, A. H.; Elkady, M. F.

2018-05-01

Lately, supercritical CO2 (SCCO2) have been getting great interest. It can be used in numerous applications because it is environmentally friendly, safe, comparatively low cost, and nonflammable. One of its applications is being a solvent in the synthesis of polymeric-clay nanocomposite. In this paper, intercalated polyaniline-clay nanocomposite (PANC) was prepared using SCCO2. The intercalation structure of polyaniline chains between clay layers was verified by various characterization techniques. Scanning electron microscope and transmission electron microscope (SEM-TEM) were used to show the morphology of the synthesized nanocomposite. The molecular structure of PANC nanocomposite was confirmed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The BET surface area and the conductivity of the nanocomposite were determined.

Characterization of a 1,4-{beta}-D-glucan synthase from Dictyostelium discoideum. Progress report, May 1990--January 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanton, R.L.

1992-01-15

Various aspects of research concerning Dictyostelium discoideum are presented. The initial focus of this project was upon: the characterization of potential probes for the cellulose synthase (antibody and nucleic acid), the determination of the cultural induction conditions of cellulose synthesis, the solubilization of the enzyme activity, the development of a non-inhibitory disruption buffer, the generation and isolation of mutant strains deficient in cellulose synthesis, and the development of the capability to determine the degree of polymerization of the in vitro product. I have briefly summarized our most significant findings with only selected data sets being shown in this report inmore » the interest of brevity.« less

Synthesis of TiO2 nanoparticles by hydrolysis and peptization of titanium isopropoxide solution

NASA Astrophysics Data System (ADS)

Mahata, S.; Mahato, S. S.; Nandi, M. M.; Mondal, B.

2012-07-01

Here we report the synthesis and characterization of a stable suspension of modified titania nanoparticles. Phase-pure TiO2 nanocrystallites with narrow particle-size distributions were selectively prepared by hydrolysis-peptization of modified alkoxide followed by hydrothermal treatment. Autoclaving modified TiO2 in the presence of HNO3 as cooperative catalysts led to the formation of crystalline TiO2 with narrow-sized distribution. Following the hydrothermal treatment at 150°C, X-ray diffraction shows the particles to be exclusively anatase. Synthesized powder is characterized by FT-IR, scanning electron microscopy (FESEM) and transmission electron microscopy (HRTEM). The photocatalytic activity in the degradation of orange-II is quite comparable to good anatase and rutile nanocrystallites.

Synthesis, microstructure, and magnetic properties of monosized Mn x Zn y Fe3 − x − y O4 ferrite nanocrystals

PubMed Central

2013-01-01

We report the synthesis and characterization of ferrite nanocrystals which exhibit high crystallinity and narrow size distributions. The three types of samples including Zn ferrite, Mn ferrite, and Mn-Zn ferrite were prepared via a non-aqueous nanoemulsion method. The structural, chemical, and magnetic properties of the nanocrystals are analyzed by transmission electron microscopy, X-ray diffraction, X-ray fluorescence, and physical property measurement system. The characterization indicates that the three types of ferrite nanocrystals were successfully produced, which show well-behaved magnetic properties, ferrimagnetism at 5 K and superparamagnetism at 300 K, respectively. In addition, the magnetization value of the ferrites increases with the increasing concentration of Mn. PMID:24344630

Synthesis and characterization of a novel potato starch derivative with cationic acetylcholine groups.

PubMed

Zhang, Bing; Ni, Boli; Lü, Shaoyu; Cui, Dapeng; Liu, Mingzhu; Gong, Honghong; Han, Fei

2012-04-01

A novel substance, cationic acetylcholine potato starch (CAPS), was developed for the first time. The synthesis process had three steps: first, carboxymethyl potato starch (CMPS) was synthesized under sodium hydroxide alkaline condition and in isopropyl alcohol organic media; second, bromocholine chloride (BCC) was synthesized with sulphuric acid as a catalytic agent; finally, CAPS was synthesized by the reaction of CMPS with BCC in N,N'-dimethylformamide (DMF). The degree of substitution (DS) of CAPS was determined by ammonia gas-sensing electrode and elemental analysis. CAPS was characterized by Fourier transformed infrared (FTIR) and near infrared (FTNIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Copyright © 2012 Elsevier B.V. All rights reserved.

Toward Engineering Synthetic Microbial Metabolism

PubMed Central

McArthur, George H.; Fong, Stephen S.

2010-01-01

The generation of well-characterized parts and the formulation of biological design principles in synthetic biology are laying the foundation for more complex and advanced microbial metabolic engineering. Improvements in de novo DNA synthesis and codon-optimization alone are already contributing to the manufacturing of pathway enzymes with improved or novel function. Further development of analytical and computer-aided design tools should accelerate the forward engineering of precisely regulated synthetic pathways by providing a standard framework for the predictable design of biological systems from well-characterized parts. In this review we discuss the current state of synthetic biology within a four-stage framework (design, modeling, synthesis, analysis) and highlight areas requiring further advancement to facilitate true engineering of synthetic microbial metabolism. PMID:20037734

Synthesis of Zeolite-X from Bottom Ash for H2 Adsorption

NASA Astrophysics Data System (ADS)

Kurniawan, R. Y.; Romadiansyah, T. Q.; Tsamarah, A. D.; Widiastuti, N.

2018-01-01

Zeolite-X was synthesized from bottom ash power plant waste using fusion method on air atmosphere. The fused product dissolved in demineralized water and aluminate solution was added to adjust the SiO2/Al2O3 molar ratio gel prior hydrothermal process. The synthesis results were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FTIR). The results showed that the zeolite-X has a high crystallinity with octahedral particle. The pure-form zeolite-X then was characterized and tested for H2 gas adsorption by gravimetric method to determine the H2 gas adsorption capacity of zeolite-X from bottom ash and it was compared to synthetic zeolite-X.

Synthesis and characterization of non-hydrolysable diphosphoinositol polyphosphate second messengers.

PubMed

Wu, Mingxuan; Dul, Barbara E; Trevisan, Alexandra J; Fiedler, Dorothea

2013-01-01

The diphosphoinositol polyphosphates (PP-IPs) are a central group of eukaryotic second messengers. They regulate numerous processes, including cellular energy homeostasis and adaptation to environmental stresses. To date, most of the molecular details in PP-IP signalling have remained elusive, due to a lack of appropriate methods and reagents. Here we describe the expedient synthesis of methylene-bisphosphonate PP-IP analogues. Their characterization revealed that the analogues exhibit significant stability and mimic their natural counterparts very well. This was further confirmed in two independent biochemical assays, in which our analogues potently inhibited phosphorylation of the protein kinase Akt and hydrolytic activity of the Ddp1 phosphohydrolase. The non-hydrolysable PP-IPs thus emerge as important tools and hold great promise for a variety of applications.

Synthesis and Characterization of Modified Phenylethynyl Terminated Polyimides

NASA Technical Reports Server (NTRS)

Chang, Alice C.

1998-01-01

As an ongoing effort to develop structural adhesives for high performance aerospace applications, recent work has focused on phenylethynyl terminated imide (PETI) oligomers. The work reported herein involves the synthesis and characterization of a series of phenylethynyl containing oligomers designated LARC (TM) MPEI (Modified Phenylethynyl Terminated Polyimide). These oligomers contain mixtures of linear, branched and star-shaped molecules. The fully imidized polymers exhibited minimum melt viscosity as low as 600 poise at 335 C. Ti/Ti lap shear specimens processed at 288 C under 15 psi showed tensile shear strength of approx. 6000 psi and 5200 psi at ambient and 350 F temperatures, respectively. The chemistry and properties of these new MPEIs are presented and compared to an optimized linear PETI, LaRC(Tm) -PETI-5.

Synthesis and characterization of Ni doped ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Tamgadge, Y. S.; Gedam, P. P.; Ganorkar, R. P.; Mahure, M. A.; Pahurkar, V. G.; Muley, G. G.

2018-05-01

In this paper, we present synthesis of L-valine assisted surface modification of Ni doped ZnO nanoparticles (NPs) using chemical precipitation method. Samples were calcined at 500oC for 2h. Uncalcined and calcined samples were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet-visible (UV-vis) spectroscopy. Ni doped ZnO NPs with average particle size of 8 nm have been successfully obtained using L-valine as surface modifying agent. Increase in the particle size was observed after the calcination. XRD and TEM studies confirmed the purity, surface morphology and hexagonal wurtzite crystal structure of ZnO NPs. UV-vis spectroscopy indicated the blue shift of excitons absorption wavelength and surface modification by L-valine.

Synthesis and structural characterization of ZnO and CuO nanoparticles supported mesoporous silica SBA-15

NASA Astrophysics Data System (ADS)

El-Nahhal, Issa M.; Salem, Jamil K.; Selmane, Mohamed; Kodeh, Fawzi S.; Ebtihan, Heba A.

2017-01-01

Zinc oxide (ZnO) and copper oxide (CuO) nanoparticles were loaded into mesoporous silica SBA-15 by post-synthesis and direct methods. The structural properties were characterized using wide and small angle X-ray diffraction (WXRD & SXRD), X-ray photoelectron spectroscopy (XPS) and N2-adsorption desorption (BET). The WXRD showed that, the loaded zinc and copper oxides were present in crystalline forms (impregnation). The mesoporosity properties of SBA-15 silica were well maintained even after the introduction of metal oxide nanoparticles. BET analysis indicate that the impregnated and condensed ZnO and CuO supported SBA-15 nanocomposites have a lower surface area than that of its parent SBA-15.

Synthesis and Characterization of Potassium Tris(oxalato)ferrate(III) Trihydrate: A Spectrophotometric Method of Iron Analysis

NASA Astrophysics Data System (ADS)

Dallinger, Richard F.

1995-10-01

A previous Journal article [J. Chem. Educ. 1984, 61, 1098--1099] described a potassium tris(oxalato)ferrate(III) trihydrate empirical formula experiment that offered an excellent integrative experience in synthesis and characterization for general chemistry laboratory students. However, we have introduced a fast and accurate spectrophotometric method for the determination of iron in the product that takes the place of the photochemical-gravimetric procedure described in the article. Besides the pedagogic interest of bringing three different types of chemical analysis (titrimetric, gravimetric, and spectrophotometric) to bear on one compound, the new iron determination allows students to complete the experiment in 2, 3-hr laboratory periods rather than the 5 periods allotted in the original experiment.

Synthesis of t-Butyl (2R)-Hydroxyisovalerate, A Precursor of Aureobasidin B

NASA Astrophysics Data System (ADS)

Maharani, R.; Puspitasari, D.; Taufiqqurahman; Huspa, D. H. P.; Hidayat, A. T.; Sumiarsa, D.; Hidayat, I. W.

2017-02-01

Aureobasidins are a family of cyclodepsipeptides have antifungal properties. They were isolated from the black yeast Aureobasidium pullulans R106 and over 30 derivatives have been successfully characterized. There are few publications reporting the total synthesis of aureobasidins. The limited reports of the synthesis of the aureobasidin derivatives are due to the difficult access to the preparations of precursors. The aim of this research is to synthesise a precursor of aureobasidin B, t-butyl (2R)-hydroxyisovalerate (t-Bu-Hiv), that is prepared for the total synthesis of aureobasidin B. The synthesis of AbB is planned to be undertaken by using a solid phase method, so the ester formation between t-Bu-Hiv and the Fmoc-β-hydroxymethylvaline will be carried out in solution phase to form depsidipeptide. The t-butyl group was used as protecting agent that is due to the straightforward elimination of the protecting group from the Fmoc-depsidipeptide. The t-Bu-Hiv acid was prepared from D-valine through diazotisation to form (2R)-acetyloxyisovaleric acid in 62.7% yield. Product of the first step was then protected by t-butyl group by using Boc-anhydride in t-butanol to give t-butil (2R)-acetyloxyisovalerate in 44% yield. In the last step, the acetyloxy group was eliminated by using potassium carbonate in methanol/water to give the desired product, t-Bu-Hiv in 33.5% yield. The t-Bu-Hiv is ready to be combined with Fmoc-β-hydroxymethylvaline to result in depsidipeptide that will be attached to the resin in the total synthesis of AbB. Each stage of this synthesis was controlled by thin layer chromatography and all products were purified by open column chromatography. All the synthesized products were characterized by various spectroscopic techniques, including infrared spectrophotometer, mass spectroscopy (ESI-MS), 1H-NMR and 13C-NMR.

Derek R. Vardon | NREL

Science.gov Websites

reaction engineering. Derek's research interests include: Catalytic conversion of biomass to fuels and synthesis Catalyst characterization Catalyst testing and reaction engineering Analysis of complex organics

Synthesis of gold nanoparticles using silk fibroin and their characterization

NASA Astrophysics Data System (ADS)

Gowda, Mahadeva; Harisha, K. S.; Ranjana, T.; Harish, K. V.; Narayana, B.; Byrappa, K.; Sangappa, Y.

2018-05-01

The synthesis of metal nanoparticales by environmentally friendly processes is an important aspect of nanotechnology today. One such approach that shows immense potential is based on the in situ synthesis of gold nanoparticles (AuNPs) using naturally available materials such as aqueous silk fibroin (SF) obtained from Bombyx mori silk. The UV-visible absorption study revealed the formation of AuNPs by showing characteristic surface plasmon resonance (SPR) band at 525 nm. The X-ray diffraction (XRD) analysis study suggests the synthesized gold nanoparticles are FCC crystal structure. The transmission electron microscopy (TEM) images showed that the formed AuNPs are spherical in shape with smooth edges.

Green synthesis of silver nanoparticles using tannins

NASA Astrophysics Data System (ADS)

Raja, Pandian Bothi; Rahim, Afidah Abdul; Qureshi, Ahmad Kaleem; Awang, Khalijah

2014-09-01

Colloidal silver nanoparticles were prepared by rapid green synthesis using different tannin sources as reducing agent viz. chestnut (CN), mangrove (MG) and quebracho (QB). The aqueous silver ions when exposed to CN, MG and QB tannins were reduced which resulted in formation of silver nanoparticles. The resultant silver nanoparticles were characterized using UV-Visible, X-ray diffraction (XRD), scanning electron microscopy (SEM/EDX), and transmission electron microscopy (TEM) techniques. Furthermore, the possible mechanism of nanoparticles synthesis was also derived using FT-IR analysis. Spectroscopy analysis revealed that the synthesized nanoparticles were within 30 to 75 nm in size, while XRD results showed that nanoparticles formed were crystalline with face centered cubic geometry.

Application of low-temperature plasma for the synthesis of hydrogenated graphene (graphane)

NASA Astrophysics Data System (ADS)

Shavelkina, M. B.; Amirov, R. H.; Katarzhis, V. A.; Kiselev, V. I.

2017-12-01

The possibility of a direct synthesis of hydrogenated graphene in decomposition of methane by means of low-temperature plasma was investigated. A DC plasma torch with an expanding channel-anode, a vortex gas supply and a self-setting arc length was used as a generator of low-temperature plasma. Argon was used as the plasma-forming gas. The temperatures of argon plasma and with methane addition to it were determined on the basis of spectral measurements. The synthesis products were characterized by electron microscopy and thermogravimetry. The effect of hydrogenated graphene as a nanomodifier on the properties of the cubic boron nitride based functional ceramics was investigated.

The Preparation and Characterization of Natrolite Synthetized by Purified Attapulgite

NASA Astrophysics Data System (ADS)

Li, H. J.; Zhou, X. D.; Zhang, J. M.; Wu, X. Y.; Gao, H. B.

2017-06-01

This paper mainly researched the hydrothermal synthesis of Natrolite, using amorphous silicon source from the purified attapulgite. The effects of silicon source, silicon aluminum ratio, crystallization time and crystallization temperature on the synthesis of natrolite were investigated. The results showed that the optimal synthesis condition of natrolite was: Hydrothermal activated ATP with NaOH was silicon source, silicon aluminum ratio was 10:1, crystallization time lasted to 72h and crystallization temperature was 150°C, the template was removed by calcining 8 hours at 550°C. The structural formula of obtained natrolite is Na2Al2Si3O10•2H2O.

Rapid Construction of a Benzo-Fused Indoxamycin Core Enabled by Site-Selective C-H Functionalizations.

PubMed

Bedell, T Aaron; Hone, Graham A B; Valette, Damien; Yu, Jin-Quan; Davies, Huw M L; Sorensen, Erik J

2016-07-11

Methods for functionalizing carbon-hydrogen bonds are featured in a new synthesis of the tricyclic core architecture that characterizes the indoxamycin family of secondary metabolites. A unique collaboration between three laboratories has engendered a design for synthesis featuring two sequential C-H functionalization reactions, namely a diastereoselective dirhodium carbene insertion followed by an ester-directed oxidative Heck cyclization, to rapidly assemble the congested tricyclic core of the indoxamycins. This project exemplifies how multi-laboratory collaborations can foster conceptually novel approaches to challenging problems in chemical synthesis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

POROUS ALUMINOPHOSPHATES :From Molecular Sieves to Designed Acid Catalysts

NASA Astrophysics Data System (ADS)

Pastore, H. O.; Coluccia, S.; Marchese, L.

2005-08-01

This review covers the synthesis, characterization, and physico-chemical properties of microporous and mesoporous aluminophosphates and silicoaluminophosphates molecular sieves. Particular emphasis is given to the materials that have found applications as acid catalysts. We consider the evolution of the synthesis procedures from the first discoveries to the current methodologies and give perspectives for new possible synthesis strategies. Emphasis is given to the use of specially prepared precursors/reactants designed for the use as molecular sieves. Experimental (especially MAS-NMR and FTIR spectroscopy) and theoretical approaches to the description of the Si insertion into the ALPO framework and to the acidic properties of SAPOs and MeAPSOs materials are discussed.

Nonlinear multivariable design by total synthesis. [of gas turbine engine control systems

NASA Technical Reports Server (NTRS)

Sain, M. K.; Peczkowski, J. L.

1982-01-01

The Nominal Design Problem (NDP) is extended to nonlinear cases, and a new case study of robust feedback synthesis for gas turbine control design is presented. The discussion of NDP extends and builds on earlier Total Synthesis Problem theory and ideas. Some mathematical preliminaries are given in which a bijection from a set S onto a set T is considered, with T admitting the structure of an F-vector space. NDP is then discussed for a nonlinear plant, and nonlinear nominal design is defined and characterized. The design of local controllers for a turbojet and the scheduling of these controls into a global control are addressed.

Synthesis of LiNiO2 cathode materials with homogeneous Al doping at the atomic level

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Zengcai; Zhen, Honghe; Kim, Yoongu

2011-01-01

Aluminum doped LiNiO2 cathode materials are synthesized by using Raney nickel as the starting material. The structure and composition are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with elemental mapping. The lithium deficiency is analyzed by Rieveld refinement. The initial capacity and retention of capacity are correlated to the lithium deficiency of the resulting cathode material. Using strong oxidant of Li2O2 in the synthesis results in materials with improved electrochemical cyclability. The improvement is related to the diminishing of lithium deficiency in strong oxidizing synthesis conditions.

Effect of the Polymeric Stabilizer in the Aqueous Phase Fischer-Tropsch Synthesis Catalyzed by Colloidal Cobalt Nanocatalysts

PubMed Central

Delgado, Jorge A.; Claver, Carmen; Castillón, Sergio; Curulla-Ferré, Daniel; Godard, Cyril

2017-01-01

A series of small and well defined cobalt nanoparticles were synthesized by the chemical reduction of cobalt salts in water using NaBH4 as a reducing agent and using various polymeric stabilizers. The obtained nanocatalysts of similar mean diameters (ca. 2.6 nm) were fully characterized and tested in the aqueous phase Fischer-Tropsch Synthesis (AFTS). Interestingly, the nature and structure of the stabilizers used during the synthesis of the CoNPs affected the reduction degree of cobalt and the B-doping of these NPs and consequently, influenced the performance of these nanocatalysts in AFTS. PMID:28336892

Synthesis, characterization and monoamine transporter activity of the new psychoactive substance mexedrone and its N-methoxy positional isomer, N-methoxymephedrone

PubMed Central

McLaughlin, Gavin; Morris, Noreen; Kavanagh, Pierce V.; Power, John D.; Dowling, Geraldine; Twamley, Brendan; O'Brien, John; Talbot, Brian; Walther, Donna; Partilla, John S.; Baumann, Michael H.; Brandt, Simon D.

2017-01-01

3-Methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one (mexedrone) appeared in 2015 and was advertised by UK Internet retailers as a non-controlled mephedrone derivative (2-(methylamino)-1-(4-methylphenyl)propan-1-one), which was of particular interest to countries who operate generic drugs legislation. This study describes the synthesis and analytical characterization of mexedrone and the differentiation from its isomer, N-methoxymephedrone, which was predicted to be a suitable candidate before the identity of mexedrone was revealed. A full analytical characterization is described using various chromatographic, spectroscopic and mass spectrometric platforms and X-ray crystal structure analysis. The analytical data obtained for a vendor sample were consistent with the synthesized mexedrone reference standard and analytical differentiation between the mexedrone and N-methoxymephedrone positional isomers was achieved. Furthermore, α-chloromethylmephedrone was identified as a by-product during mexedrone synthesis. All three substances were also studied for their uptake and releasing properties at dopamine transporters (DAT), norepinephrine transporters (NET) and serotonin transporters (SERT) using in vitro monoamine transporter assays in rat brain synaptosomes and compared to mephedrone. Mexedrone was a weak non-selective uptake blocker with IC50 values in the low μM range. It was also devoid of releasing activity at DAT and NET but displayed weak releasing activity at SERT (EC50= 2.5 μM). The isomer N-methoxymephedrone was found to be a weak uptake blocker at DAT, NET and SERT, as well as a fully efficacious substrate-type releasing agent across all three transporters with EC50 values in the low micromolar range. The synthesis by-product α-chloromethylmephedrone was inactive in all assays. PMID:27524685

Synthesis, characterization and monoamine transporter activity of the new psychoactive substance mexedrone and its N-methoxy positional isomer, N-methoxymephedrone.

PubMed

McLaughlin, Gavin; Morris, Noreen; Kavanagh, Pierce V; Power, John D; Dowling, Geraldine; Twamley, Brendan; O'Brien, John; Talbot, Brian; Walther, Donna; Partilla, John S; Baumann, Michael H; Brandt, Simon D

2017-03-01

3-Methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one (mexedrone) appeared in 2015 and was advertised by UK Internet retailers as a non-controlled mephedrone derivative (2-(methylamino)-1-(4-methylphenyl)propan-1-one), which was of particular interest to countries who operate generic drugs legislation. This study describes the synthesis and analytical characterization of mexedrone and the differentiation from its isomer, N-methoxymephedrone, which was predicted to be a suitable candidate before the identity of mexedrone was revealed. A full analytical characterization is described using various chromatographic, spectroscopic and mass spectrometric platforms and X-ray crystal structure analysis. The analytical data obtained for a vendor sample were consistent with the synthesized mexedrone reference standard and analytical differentiation between the mexedrone and N-methoxymephedrone positional isomers was achieved. Furthermore, α-chloromethylmephedrone was identified as a by-product during mexedrone synthesis. All three substances were also studied for their uptake and releasing properties at dopamine transporters (DAT), norepinephrine transporters (NET) and serotonin transporters (SERT) using in vitro monoamine transporter assays in rat brain synaptosomes and compared to mephedrone. Mexedrone was a weak non-selective uptake blocker with IC 50 values in the low μM range. It was also devoid of releasing activity at DAT and NET but displayed weak releasing activity at SERT (EC 50  = 2.5 μM). The isomer N-methoxymephedrone was found to be a weak uptake blocker at DAT, NET and SERT, as well as a fully efficacious substrate-type releasing agent across all three transporters with EC 50 values in the low micromolar range. The synthesis by-product α-chloromethylmephedrone was inactive in all assays. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

One-Dimensional Perovskite Manganite Oxide Nanostructures: Recent Developments in Synthesis, Characterization, Transport Properties, and Applications

NASA Astrophysics Data System (ADS)

Li, Lei; Liang, Lizhi; Wu, Heng; Zhu, Xinhua

2016-03-01

One-dimensional nanostructures, including nanowires, nanorods, nanotubes, nanofibers, and nanobelts, have promising applications in mesoscopic physics and nanoscale devices. In contrast to other nanostructures, one-dimensional nanostructures can provide unique advantages in investigating the size and dimensionality dependence of the materials' physical properties, such as electrical, thermal, and mechanical performances, and in constructing nanoscale electronic and optoelectronic devices. Among the one-dimensional nanostructures, one-dimensional perovskite manganite nanostructures have been received much attention due to their unusual electron transport and magnetic properties, which are indispensable for the applications in microelectronic, magnetic, and spintronic devices. In the past two decades, much effort has been made to synthesize and characterize one-dimensional perovskite manganite nanostructures in the forms of nanorods, nanowires, nanotubes, and nanobelts. Various physical and chemical deposition techniques and growth mechanisms are explored and developed to control the morphology, identical shape, uniform size, crystalline structure, defects, and homogenous stoichiometry of the one-dimensional perovskite manganite nanostructures. This article provides a comprehensive review of the state-of-the-art research activities that focus on the rational synthesis, structural characterization, fundamental properties, and unique applications of one-dimensional perovskite manganite nanostructures in nanotechnology. It begins with the rational synthesis of one-dimensional perovskite manganite nanostructures and then summarizes their structural characterizations. Fundamental physical properties of one-dimensional perovskite manganite nanostructures are also highlighted, and a range of unique applications in information storages, field-effect transistors, and spintronic devices are discussed. Finally, we conclude this review with some perspectives/outlook and future researches in these fields.

One-Dimensional Perovskite Manganite Oxide Nanostructures: Recent Developments in Synthesis, Characterization, Transport Properties, and Applications.

PubMed

Li, Lei; Liang, Lizhi; Wu, Heng; Zhu, Xinhua

2016-12-01

One-dimensional nanostructures, including nanowires, nanorods, nanotubes, nanofibers, and nanobelts, have promising applications in mesoscopic physics and nanoscale devices. In contrast to other nanostructures, one-dimensional nanostructures can provide unique advantages in investigating the size and dimensionality dependence of the materials' physical properties, such as electrical, thermal, and mechanical performances, and in constructing nanoscale electronic and optoelectronic devices. Among the one-dimensional nanostructures, one-dimensional perovskite manganite nanostructures have been received much attention due to their unusual electron transport and magnetic properties, which are indispensable for the applications in microelectronic, magnetic, and spintronic devices. In the past two decades, much effort has been made to synthesize and characterize one-dimensional perovskite manganite nanostructures in the forms of nanorods, nanowires, nanotubes, and nanobelts. Various physical and chemical deposition techniques and growth mechanisms are explored and developed to control the morphology, identical shape, uniform size, crystalline structure, defects, and homogenous stoichiometry of the one-dimensional perovskite manganite nanostructures. This article provides a comprehensive review of the state-of-the-art research activities that focus on the rational synthesis, structural characterization, fundamental properties, and unique applications of one-dimensional perovskite manganite nanostructures in nanotechnology. It begins with the rational synthesis of one-dimensional perovskite manganite nanostructures and then summarizes their structural characterizations. Fundamental physical properties of one-dimensional perovskite manganite nanostructures are also highlighted, and a range of unique applications in information storages, field-effect transistors, and spintronic devices are discussed. Finally, we conclude this review with some perspectives/outlook and future researches in these fields.

Purification and Characterization of Methyl Phthalyl Ethyl Glycolate (MPEG)

DTIC Science & Technology

2014-11-21

LIST OF FIGURES Heading Page Figure 1. Monsanto Method of MPEG Synthesis 2 Figure 2. Incon Method of MPEG Synthesis 2 Figure 3. Possible...least 1942 (Van Antwerpen, 1942), known then as Santicizer M-17 by the Monsanto Chemical Company. MPEG is used in HES 5808, a high solids-loading...characteristics vary from lot to lot. This situation has emerged since Monsanto no longer produces MPEG, and alternative vendors are currently being used

Synthesis of Trimagnetic Multishell MnFe2 O4 @CoFe2 O4 @NiFe2 O4 Nanoparticles.

PubMed

Gavrilov-Isaac, Véronica; Neveu, Sophie; Dupuis, Vincent; Taverna, Dario; Gloter, Alexandre; Cabuil, Valérie

2015-06-10

The synthesis and characterization of original ferrite multishell magnetic nanoparticles made of a soft core (manganese ferrite) covered with two successive shells, a hard one (cobalt ferrite) and then a soft one (nickel ferrite), are described. The results demonstrate the modulation of the coercivity when new magnetic shells are added. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and Characteristics of Radiation Curable Polyurethanes Containing Pendant Acrylate Groups.

DTIC Science & Technology

1986-10-09

diethoxylacetophenone (DEAP) and N - methyldiethanolamine ( MDEA ). The films were left in a vacuum oven for one week at room temperature to remove residual solvent...LF.Ol4.er6OlSECURITY CLASSIFICATION OF THIS PAGE (ohen De Knieved) -. " N SYNTHESIS AND CHARACTERIZATION OF RADIATION CURABLE POLYURETHANES CONTAINING...butanone-2, N , N dimethylacetamide (DMA), and toluene were --..- purchased from Aldrich Chemical Company, and stored over molecular sieve (type 3A

Characterization of the tumor-promoting activity of m-chloroperoxybenzoic acid in SENCAR mouse skin and its inhibition by gallotannin, oligomeric proanthocyanidin, and their monomeric units

Treesearch

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Fatima K. Johnson; Amy W. Davis; Steven W. Newell; Richard W. Hemingway; Vittorio Bottari; Jean-Pierre Perchellett

1996-01-01

m-Chloroperoxybenzoic acid (CPBA). Which induces ornithine decarboxylase activity as much as 12-0- terradecanoyIp horbol-13-acetate (TPA ). was tested for its ability to induce DNA synthesis. bydroperoxide (HPx) production. and tumor promotion in mouse epidermis in vivo. After an early inhibition. CPBA stimulates DNA synthesis. A response which is maintained between 16...

Gold(III) complexes with hydroxyquinoline, aminoquinoline and quinoline ligands: Synthesis, cytotoxicity, DNA and protein binding studies.

PubMed

Martín-Santos, Cecilia; Michelucci, Elena; Marzo, Tiziano; Messori, Luigi; Szumlas, Piotr; Bednarski, Patrick J; Mas-Ballesté, Rubén; Navarro-Ranninger, Carmen; Cabrera, Silvia; Alemán, José

2015-12-01

In this article, we report on the synthesis and the chemical and biological characterization of novel gold(III) complexes based on hydroxyl- or amino-quinoline ligands that are evaluated as prospective anticancer agents. To gain further insight into their reactivity and possible mode of action, their interactions with model proteins and standard nucleic acid molecules were investigated. Copyright © 2015 Elsevier Inc. All rights reserved.

Sulfur-Doped Zinc Oxide (ZnO) Nanostars: Synthesis and Simulation of Growth Mechanism

DTIC Science & Technology

2011-10-01

Zinc Oxide ( ZnO ) Nanostars: Synthesis and Simulation of Growth Mechanism Jinhyun Cho1, Qiubao Lin2,3, Sungwoo...characterization, and ab initio simulations of star-shaped hexagonal zinc oxide ( ZnO ) nanowires. The ZnO nanostructures were synthesized by a low...Introduction Zinc oxide ( ZnO ) is a wide bandgap (3.37 eV), Ⅱ–Ⅵ semiconductor of great interest for optoelectronic applications [1–3]. Its

Design and Synthesis of a Novel Class of Flavonoid Derivatives via Sequential Phosphorylation and its Application for Greener Nanoparticle Synthesis

NASA Astrophysics Data System (ADS)

Osonga, Francis Juma

Flavonoids exhibit arrays of biological effects that are beneficial to humans, including anti-viral, anti-oxidative, anti-inflammatory and anti-carcinogenic effects. However, these applications have been hindered by their poor stability and solubility in common solvents. Consequently, there is significant interest in the modification of flavonoids to improve their solubility. This poor solubility is also believed to be responsible for its permeability and bioavailability. Hence the central goal of this work is to design synthetic strategies for the sequential protection of the -OH groups in order to produce phosphorylated quercetin and apigenin derivatives. This work is divided into two parts: the first part presents the design, synthesis, and characterization of novel flavonoid derivatives via global and sequential phosphorylation. The second part focuses on the application of the synthesized derivatives for greener nanoparticle synthesis. This work shows for the first time that sequential phosphorylation of Quercetin is feasible through the design of 4 new derivatives namely: 5,4'-O-Quercetin Diphosphate (QDPI), 4'-O-phosphate Quercetin (4'-QPI), 5,4'-Quercetin Diphosphate (5,4'-QDP) and monophosphate 4-QP. The synthesis of 4'-QP and 5, 4'-QDP was successful with 85% and 60.5% yields respectively. In addition, the progress towards the total synthesis of apigenin phosphate derivatives (7, 4'-ADP and 7-AP) is presented. The synthesized derivatives were characterized using 1H, 13C, and 31P NMR. The phosphorylated derivatives were subsequently explored as reducing agents for sustainable synthesis of gold, silver and copper nanoparticles. We have successfully demonstrated the photochemical synthesis of gold nanoplates of sizes ranging from 10 - 200 nm using water soluble QDP in the presence of sunlight. This work contributes immensely in promoting the ideals of green nanosynthesis by (i) eliminating the use of organic solvents in the nanosynthesis, (ii) exploiting the naturally-derived flavonoids as reducing and stabilizing reagents without any other extraneous reagents, and (iii) achieving anisotropic nanosynthesis using sunlight and at room temperature.

Simultaneous Hypoxia and Low Extracellular pH Suppress Overall Metabolic Rate and Protein Synthesis In Vitro.

PubMed

Sørensen, Brita Singers; Busk, Morten; Overgaard, Jens; Horsman, Michael R; Alsner, Jan

2015-01-01

The tumor microenvironment is characterized by regions of hypoxia and acidosis which are linked to poor prognosis. This occurs due to an aberrant vasculature as well as high rates of glycolysis and lactate production in tumor cells even in the presence of oxygen (the Warburg effect), which weakens the spatial linkage between hypoxia and acidosis. Five different human squamous cell carcinoma cell lines (SiHa, FaDuDD, UTSCC5, UTSCC14 and UTSCC15) were treated with hypoxia, acidosis (pH 6.3), or a combination, and gene expression analyzed using microarray. SiHa and FaDuDD were chosen for further characterization of cell energetics and protein synthesis. Total cellular ATP turnover and relative glycolytic dependency was determined by simultaneous measurements of oxygen consumption and lactate synthesis rates and total protein synthesis was determined by autoradiographic quantification of the incorporation of 35S-labelled methionine and cysteine into protein. Microarray analysis allowed differentiation between genes induced at low oxygen only at normal extracellular pH (pHe), genes induced at low oxygen at both normal and low pHe, and genes induced at low pHe independent of oxygen concentration. Several genes were found to be upregulated by acidosis independent of oxygenation. Acidosis resulted in a more wide-scale change in gene expression profiles than hypoxia including upregulation of genes involved in the translation process, for example Eukaryotic translation initiation factor 4A, isoform 2 (EIF4A2), and Ribosomal protein L37 (RPL37). Acidosis suppressed overall ATP turnover and protein synthesis by 50%. Protein synthesis, but not total ATP production, was also suppressed under hypoxic conditions. A dramatic decrease in ATP turnover (SiHa) and protein synthesis (both cell lines) was observed when hypoxia and low pHe were combined. We demonstrate here that the influence of hypoxia and acidosis causes different responses, both in gene expression and in de novo protein synthesis, depending on whether the two factors induced alone or overlapping, and as such it is important for in vivo studies to take this into account.

Simultaneous Hypoxia and Low Extracellular pH Suppress Overall Metabolic Rate and Protein Synthesis In Vitro

PubMed Central

Sørensen, Brita Singers; Busk, Morten; Overgaard, Jens; Horsman, Michael R.; Alsner, Jan

2015-01-01

Background The tumor microenvironment is characterized by regions of hypoxia and acidosis which are linked to poor prognosis. This occurs due to an aberrant vasculature as well as high rates of glycolysis and lactate production in tumor cells even in the presence of oxygen (the Warburg effect), which weakens the spatial linkage between hypoxia and acidosis. Methods Five different human squamous cell carcinoma cell lines (SiHa, FaDuDD, UTSCC5, UTSCC14 and UTSCC15) were treated with hypoxia, acidosis (pH 6.3), or a combination, and gene expression analyzed using microarray. SiHa and FaDuDD were chosen for further characterization of cell energetics and protein synthesis. Total cellular ATP turnover and relative glycolytic dependency was determined by simultaneous measurements of oxygen consumption and lactate synthesis rates and total protein synthesis was determined by autoradiographic quantification of the incorporation of 35S-labelled methionine and cysteine into protein. Results Microarray analysis allowed differentiation between genes induced at low oxygen only at normal extracellular pH (pHe), genes induced at low oxygen at both normal and low pHe, and genes induced at low pHe independent of oxygen concentration. Several genes were found to be upregulated by acidosis independent of oxygenation. Acidosis resulted in a more wide-scale change in gene expression profiles than hypoxia including upregulation of genes involved in the translation process, for example Eukaryotic translation initiation factor 4A, isoform 2 (EIF4A2), and Ribosomal protein L37 (RPL37). Acidosis suppressed overall ATP turnover and protein synthesis by 50%. Protein synthesis, but not total ATP production, was also suppressed under hypoxic conditions. A dramatic decrease in ATP turnover (SiHa) and protein synthesis (both cell lines) was observed when hypoxia and low pHe were combined. Conclusions We demonstrate here that the influence of hypoxia and acidosis causes different responses, both in gene expression and in de novo protein synthesis, depending on whether the two factors induced alone or overlapping, and as such it is important for in vivo studies to take this into account. PMID:26274822

NETL - Fuel Reforming Facilities

ScienceCinema

None

2018-01-26

Research using NETL's Fuel Reforming Facilities explores catalytic issues inherent in fossil-energy related applications, including catalyst synthesis and characterization, reaction kinetics, catalyst activity and selectivity, catalyst deactivation, and stability.

Hydrocortisone Stimulation of RNA Synthesis in Induction of Hepatic Enzymes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenney, Francis T.; Wicks, Wesley D.; Greenman, David L.

Increased synthesis of hepatic enzymes due to hydrocortisone is preceded by an increase in the rate of synthesis of nuclear RNA. Pulse-labeled RNA from liver nuclei was fractionated by a differential thermal phenol procedures, and the labeled RNA of each fraction was characterized by sucrose gradient centrifugation and base composition analysis. Hormone treatment increases the rate of synthesis of three types of RNA: (1) the nuclear precursor to ribosomal RNA, (2) a rapid turnover component with base composition similar to the tissue DNA, and (3) transfer RNA. Much of the total isotope incorporation into transfer RNA can be traced tomore » turnover of the terminal adenylate residue, but this type of labeling is insensitive to the hormone. The steroid also stimulates isotope incorporation into tissue precursor pools. The effect is abolished by actinomycin and thus is secondary to the hormonal stimulation of RNA synthesis. Growth hormone stimulates RNA synthesis in both intact and adrenalectomized rats, but induces the rapid turnover enzymes (tyrosine transaminase and tryptophan pyrrolase) only in the presence of functional adrenals. It therefore seems that glucocorticoids initiate both a generalized increase in synthesis of RNA and a selective induction of specific enzymes.« less

Novel LLM series high density energy materials: Synthesis, characterization, and thermal stability

NASA Astrophysics Data System (ADS)

Pagoria, Philip; Zhang, Maoxi; Tsyshevskiy, Roman; Kuklja, Maija

Novel high density energy materials must satisfy specific requirements, such as an increased performance, reliably high stability to external stimuli, cost-efficiency and ease of synthesis, be environmentally benign, and be safe for handling and transportation. During the last decade, the attention of researchers has drifted from widely used nitroester-, nitramine-, and nitroaromatic-based explosives to nitrogen-rich heterocyclic compounds. Good thermal stability, the low melting point, high density, and moderate sensitivity make heterocycle materials attractive candidates for use as oxidizers in rocket propellants and fuels, secondary explosives, and possibly as melt-castable ingredients of high explosive formulations. In this report, the synthesis, characterization, and results of quantum-chemical DFT study of thermal stability of LLM-191, LLM-192 and LLM-200 high density energy materials are presented. Work performed under the auspices of the DOE by the LLNL (Contract DE-AC52-07NA27344). This research is supported in part by ONR (Grant N00014-12-1-0529) and NSF. We used NSF XSEDE (Grant DMR-130077) and DOE NERSC (Contract DE-AC02-05CH11231) resources.

Synthesis and characterization of immobilized Ni-Co bimetallic using Tapanuli clay for catalyst application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuryanti,; Juwono, Ariadne L., E-mail: ariadne@sci.ui.ac.id; Krisnandi, Yuni K.

2016-04-19

Heterogeneous catalysts hold various advantages, namely, easy to separate from their products, reusable and regarded as environmental friendly materials. The synthesis of immobilized Ni monometallic, Co monometallic and Ni-Co bimetallic by Tapanuli clay were carried out using intercalation method. Firstly, the synthesis of Na-Bentonite was conducted to provide sufficient area to immobilize bimetal in the clay interlayer. Secondly, Ni, Co and Ni-Co were immobilized in the Tapanuli clay interlayer. Several techniques, such as X-Ray Diffraction, Fourier Transform Infra Red and Energy Dispersive X-Ray Analysis were applied to characterize and compare the properties of the synthesized materials. The results showed thatmore » the insertion of Ni, Co and Ni-Co in the clay interlayer occurred through a cation exchange reaction. The Energy Dispersive X-Ray analysis for Ni-Co bimetallic showed that the immobilized Ni and Co in the clay is in the ratio of 1:1. Catalytic test with Gas Chromatography showed that Ni-Co bimetallic generates a higher yield percentage compared to Ni and Co monometallic.« less

Endocrine and metabolic aspects of the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorski, J.R.

1988-01-01

Toxic responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were characterized in male Sprague-Dawley rats in order to elucidate the mechanism of acute toxicity of this potent halogenated hydrocarbon. Studies in TCDD-treated, pair-fed control and ad libitum-fed control rates, as well as in thyroidectomized, adrenalectomized and hypophysectomized, revealed differential hormonal, toxicologic and histophathologic responses suggesting that these manifestations of TCDD exposure are the results of an insult to intermediary metabolism. Tissue specific alterations in de novo fatty acid synthesis were directly related to differential changes observed in thyroid hormone homeostasis. The increased hepatic de novo fatty acid synthesis provided a likely mechanism for themore » documented fact that TCDD-treated rats lose more body weight than corresponding pair-fed controls because de novo fatty acid synthesis represents an energy inefficient metabolic process. Experiments in adrenalectomized and hypophysectomized rats led to the hypothesis that severe hypoglycemia due to inhibition of gluconeogenesis is the cause of TCDD-induced death. A subsequent characterization of gluconeogenesis in TCDD-treated rats confirmed this hypothesis.« less

Electrolytic synthesis of aqueous aluminum nanoclusters and in situ characterization by femtosecond Raman spectroscopy and computations

PubMed Central

Wang, Wei; Liu, Weimin; Chang, I-Ya; Wills, Lindsay A.; Zakharov, Lev N.; Boettcher, Shannon W.; Cheong, Paul Ha-Yeon; Fang, Chong; Keszler, Douglas A.

2013-01-01

The selective synthesis and in situ characterization of aqueous Al-containing clusters is a long-standing challenge. We report a newly developed integrated platform that combines (i) a selective, atom-economical, step-economical, scalable synthesis of Al-containing nanoclusters in water via precision electrolysis with strict pH control and (ii) an improved femtosecond stimulated Raman spectroscopic method covering a broad spectral range of ca. 350–1,400 cm−1 with high sensitivity, aided by ab initio computations, to elucidate Al aqueous cluster structures and formation mechanisms in real time. Using this platform, a unique view of flat [Al13(μ3-OH)6(μ2-OH)18(H2O)24](NO3)15 nanocluster formation is observed in water, in which three distinct reaction stages are identified. The initial stage involves the formation of an [Al7(μ3-OH)6(μ2-OH)6(H2O)12]9+ cluster core as an important intermediate toward the flat Al13 aqueous cluster. PMID:24167254

Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arianie, Lucy, E-mail: lucy205@yahoo.com; Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id; Nurrachman, Zeily, E-mail: deana@chem.itb.ac.id

The decrease of cellulose crystallinity index of palm empty fruit bunch is crucial for the next application of cellulose as raw material for various biofuel and its derivatives. The aim of this research is to decrease the cellulose crystallinity index of palm empty fruit bunch using 1-butyl-3-methylimidazoliumbromide or [BMIM] bromide which has been synthesized using Microwave-Assisted Organic Synthesis (MAOS) method. Conventional reaction method has also been carried out to synthesize [BMIM]bromide for comparison as well. The characterization of synthesized product using FTIR, {sup 1}H-NMR, {sup 13}C-NMR and LC-MS showed that these reactions have been carried out successfully. The results showedmore » that MAOS method is up to 90% faster in producing [BMIM]bromide compare to the conventional method. The application of [BMIM]bromide for dissolution of palm empty fruit bunch showed that cellulose and lignin could be extracted using stirring process for 20 hours. The decrease of cellulose crystallinity index and its morphology changes were identified using FTIR and Scanning Electron Microscope.« less

Synthesis, stability range and characterization of Pr2Cu2O5

NASA Astrophysics Data System (ADS)

Fernández-Sanjulián, Javier; Morán, Emilio; Ángel Alario-Franco, Miguel

2010-03-01

A novel Pr2Cu2O5 phase has been prepared under high-pressure and high-temperature conditions (P ∼6 GPa and T ∼1673 K) in a Belt-type apparatus and characterized by X-ray diffraction and electron microscopy. The crystal structure appears to be an orthorhombic "oxygen-deficient perovskite" (M.T. Anderson, J.T. Vaughey, and K.R. Poeppelmeier, Structural similarities among oxygen-deficient perovskites, Chem. Mater. 5 (1993), pp. 151-165) isostructural with La2Cu2O5 (J.F. Bringley, B.A. Scott, S.J. La Placa, R.F. Boheme, T.M. Shaw, M.W. McElfresh, S.S. Trail, and D.E. Cox, Synthesis of the defect perovskite series LaCuO 3-δ with copper valence varying from 2+to 3+, Nature 347 (1990), pp. 263-265) and Nd2Cu2O5 (B.-H. Chen, D. Walker, E. Suard, B.A. Scott, B. Mercey, M. Hervieu, and B. Raveau, High pressure synthesis of NdCuO3-δ perovskites (0≤δ≤0.5). Inorg. Chem. 34 (1995), pp. 2077-2083).

Mesoporous CdS via Network of Self-Assembled Nanocrystals: Synthesis, Characterization and Enhanced Photoconducting Property.

PubMed

Patra, Astam K; Banerjee, Biplab; Bhaumik, Asim

2018-01-01

Semiconduction nanoparticles are intensively studied due to their huge potential in optoelctronic applications. Here we report an efficient chemical route for hydrothermal synthesis of aggregated mesoporous cadmium sulfide (CdS) nanoparticles using supramolecular-assembly of ionic and water soluble sodium salicylate as the capping agent. The nanostructure, mesophase, optical property and photoconductivity of these mesoporous CdS materials have been characterized by using small and wide angle powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2-sorption, Raman analysis, Fourier transformed infrared (FT-IR), UV-Visible DSR spectroscopy, and photoconductivity measurement. Wide angle XRD pattern and high resolution TEM image analysis suggested that the particle size of the materials is within 10 nm and the nanoparticles are in well-crystallized cubic phase. Mesoporous CdS nanoparticles showed drastically enhanced photoelectrochemical response under visible light irradiation on entrapping a photosensitizer (dye) molecule in the interparticle spaces. Efficient synthesis strategy and the enhanced photo response in the mesoporous CdS material could facilitate the designing of other porous semiconductor oxide/sulfide and their applications in photon-to-electron conversion processes.

Early stage structural development of prototypical zeolitic imidazolate framework (ZIF) in solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terban, Maxwell W.; Banerjee, Debasis; Ghose, Sanjit

Given the wide-ranging potential applications of metal organic frameworks (MOFs), an emerging imperative is to understand their formation with atomic scale precision. This will aid in designing syntheses for next-generation MOFs with enhanced properties and functionalities. Major challenges are to characterize the early-stage seeds, and the pathways to framework growth, which require synthesis coupled with in situ structural characterization sensitive to nanoscale structures in solution. Here we report measurements of an in situ synthesis of a prototypical MOF, ZIF-8, utilizing synchrotron X-ray atomic pair distribution function (PDF) analysis optimized for sensitivity to dilute species, complemented by mass spectrometry, electron microscopy,more » and density functional theory calculations. We observe that despite rapid formation of the crystalline product, a high concentration of Zn(2-MeIm) 4(2-MeIm=2-methylimidazolate) initially forms and persists as stable clusters over long times. A secondary, amorphous phase also pervades during the synthesis, which has a structural similarity to the final ZIF-8 and may act as an intermediate to the final product.« less

Copper nanoparticles mediated by chitosan: synthesis and characterization via chemical methods.

PubMed

Usman, Muhammad Sani; Ibrahim, Nor Azowa; Shameli, Kamyar; Zainuddin, Norhazlin; Yunus, Wan Md Zin Wan

2012-12-14

Herein we report a synthesis of copper nanoparticles (Cu-NPs) in chitosan (Cts) media via a chemical reaction method. The nanoparticles were synthesized in an aqueous solution in the presence of Cts as stabilizer and CuSO(4)·5H(2)O precursor. The synthesis proceeded with addition of NaOH as pH moderator, ascorbic acid as antioxidant and hydrazine( )as the reducing agent. The characterization of the prepared NPs was done using ultraviolet-visible spectroscopy, which showed a 593 nm copper band. The Field Emission Scanning Electron Microscope (FESEM) images were also observed, and found to be in agreement with the UV-Vis result, confirming the formation of metallic Cu-NPs. The mean size of the Cu-NPs was estimated to be in the range of 35-75 nm using X-ray diffraction. XRD was also used in analysis of the crystal structure of the NPs. The interaction between the chitosan and the synthesized NPs was studied using Fourier transform infrared (FT-IR) spectroscopy, which showed the capping of the NPs by Cts.

Preparation and characterization of Ni based on natural zeolite catalyst for citronellol conversion to 3,7-Dimethyl-1-Octanol

NASA Astrophysics Data System (ADS)

Sudiyarmanto, Hidayati, Luthfiana N.; Kristiani, Anis; Ghaisani, Almira; Sukandar, Dede; Adilina, Indri B.; Tursiloadi, Silvester

2017-11-01

Citronella oil is a kind of essential oil that contains three main components, namely citronellal, citronellol, and geraniol. The high demand of citronellal and geraniol derivative prompted scientists to develop methods which are stereo-selective synthesis. A hydrogenation reaction using heterogeneous catalyst is one way of synthesis of citronella oil derivatives. In this research, synthesis of citronellol oil derivatives using Ni based on natural zeolite (Ni/ZAB) catalyst which is expected to produce the compound of 3,7-dimethyl-1-octanol. The catalyst was prepared by supporting Ni on natural zeolite by impregnation method. The physical and chemical properties of Ni/ZAB catalyst have been characterized by TGA, BET, XRD and FTIR instrumentations. Variation of pressure and temperature reactions were conducted to determine the optimum conditions for the hydrogenation of citronellol. The products from this reaction were analyzed using GC-MS instrumentation. The yield and selectivity of 3,7-dimethyl-1-octanol compound were achieved with optimum conditions at 200°C and 20 bar during 3 hours which produced around 51.97% and 47.81% respectively.

Early stage structural development of prototypical zeolitic imidazolate framework (ZIF) in solution

DOE PAGES

Terban, Maxwell W.; Banerjee, Debasis; Ghose, Sanjit; ...

2018-02-05

Given the wide-ranging potential applications of metal organic frameworks (MOFs), an emerging imperative is to understand their formation with atomic scale precision. This will aid in designing syntheses for next-generation MOFs with enhanced properties and functionalities. Major challenges are to characterize the early-stage seeds, and the pathways to framework growth, which require synthesis coupled with in situ structural characterization sensitive to nanoscale structures in solution. Here we report measurements of an in situ synthesis of a prototypical MOF, ZIF-8, utilizing synchrotron X-ray atomic pair distribution function (PDF) analysis optimized for sensitivity to dilute species, complemented by mass spectrometry, electron microscopy,more » and density functional theory calculations. We observe that despite rapid formation of the crystalline product, a high concentration of Zn(2-MeIm) 4(2-MeIm=2-methylimidazolate) initially forms and persists as stable clusters over long times. A secondary, amorphous phase also pervades during the synthesis, which has a structural similarity to the final ZIF-8 and may act as an intermediate to the final product.« less