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Sample records for dichlorobisdietyl dithiocarbamate tiniv

  1. Tin(IV) complexes of pyrrolidinedithiocarbamate: synthesis, characterisation and antifungal activity.

    PubMed

    Menezes, D C; Vieira, F T; de Lima, G M; Porto, A O; Cortés, M E; Ardisson, J D; Albrecht-Schmitt, T E

    2005-12-01

    The reaction of ammonium pyrrolidinedithiocarbamate, [NH4{S2CN(CH2)4}], with SnCl2, [Sn(C6H5)2Cl2], [Sn(C6H5)3Cl], [Sn(C4H9)2Cl2] and [Sn(C6H11)3Cl] produced in good yield the compounds [Sn{S2CN(CH2)4}2Cl2] (1), [Sn{S2CN(CH2)4}2Ph2] (2), [Sn{S2CN(CH2)4}Ph3] (3), [Sn{S2CN(CH2)4}2 n-Bu2] (4) and [Sn{S2CN(CH2)4}Cy3] (5). The complexes were characterised by infrared, multinuclear NMR (1H, 13C{1H} and 119Sn{1H}) and 119Sn Mössbauer spectroscopies. In addition, the crystal structure of 4 was determined by X-ray crystallography. The in vitro antifungal activity of the tin(IV) complexes as well of the ligand was performed on human pathogenic fungi, Candida albicans, in concentrations of 0.025; 0.050; 0.100; 0.200; 0.400; 0.800; 1.600 and 3.200 mM. The microorganism presented resistance to the dithiocarbamate ligand and all tin(IV) complexes tested were actives. The highest activity was found for compounds 1 and 4.

  2. Dithiocarbamate toxicity - An appraisal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dithiocarbamates are used as agricultural pesticides and general biocides in a variety of applications. However, acute or chronic exposure to these chemicals can produce neurotoxicity, developmental deformities, endocrine disruption, hypersensitivity, and metabolic dysfunctions in animals and human...

  3. Safety assessment of Tin(IV) oxide as used in cosmetics.

    PubMed

    Johnson, Wilbur; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2014-01-01

    Tin(IV) oxide functions as an abrasive, bulking, and opacifying agent in cosmetic products and is used at concentrations up to 0.4% in rinse-off products and up to 1.3% in leave-on products. The Cosmetic Ingredient Review Expert Panel (Panel) noted that tin(IV) oxide is a water-insoluble inorganic metal compound and should not be percutaneously absorbed; therefore, systemic exposure is not likely. Studies of dermal application of tin(IV) oxide were considered to determine toxicity at the site of application. The Panel concluded that tin(IV) oxide is safe in the present practices of use and concentration.

  4. Synthesis and Characterization of Tin(IV) Oxide Obtained by Chemical Vapor Deposition Method.

    PubMed

    Nagirnyak, Svitlana V; Lutz, Victoriya A; Dontsova, Tatiana A; Astrelin, Igor M

    2016-12-01

    The effect of precursors on the characteristics of tin oxide obtained by chemical vapor deposition (CVD) method was investigated. The synthesis of nanosized tin(IV) oxide was carried out with the use of two different precursors: tin(II) oxalate obtained using tin chloride(II) and oxalic acid; tin(II) oxalate obtained using tin chloride(II); and ammonium oxalate. The synthesized tin(IV) oxide samples were studied by electron microscopy, X-ray diffraction and optical spectra. The lattice parameters of tin(IV) oxide samples were defined, the bandgap of samples were calculated.

  5. Synthesis and Characterization of Tin(IV) Oxide Obtained by Chemical Vapor Deposition Method

    NASA Astrophysics Data System (ADS)

    Nagirnyak, Svitlana V.; Lutz, Victoriya A.; Dontsova, Tatiana A.; Astrelin, Igor M.

    2016-07-01

    The effect of precursors on the characteristics of tin oxide obtained by chemical vapor deposition (CVD) method was investigated. The synthesis of nanosized tin(IV) oxide was carried out with the use of two different precursors: tin(II) oxalate obtained using tin chloride(II) and oxalic acid; tin(II) oxalate obtained using tin chloride(II); and ammonium oxalate. The synthesized tin(IV) oxide samples were studied by electron microscopy, X-ray diffraction and optical spectra. The lattice parameters of tin(IV) oxide samples were defined, the bandgap of samples were calculated.

  6. PRACTICAL SYNTHESIS OF AROMATIC DITHIOCARBAMATES

    PubMed Central

    Padungros, Panuwat; Wei, Alexander

    2015-01-01

    GRAPHICAL ABSTRACT Oxidation-sensitive N,N-diaryl dithiocarbamates (DTCs) are synthesized in good yields by the generation of metal amide salts from N-benzoyl precursors, followed by addition of CS2. para-Substituted diphenylamines are prepared by electrophilic aromatic substitution of diphenylbenzamide and saponification. Deacylation of electron-rich species such as bis(p-dimethylaminophenyl)benzamide is challenging because of the oxidative sensitivity of the anionic intermediate but could be achieved in good yield by using n-BuLi to generate a hemiaminal adduct, prior to acidification. The N,N-diaryl DTCs are stable as alkali salts and can be used to produce densely packed monolayers on gold surfaces. PMID:25999616

  7. 40 CFR 721.10314 - Dialkyl dithiocarbamate esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Dialkyl dithiocarbamate esters... Specific Chemical Substances § 721.10314 Dialkyl dithiocarbamate esters (generic). (a) Chemical substance... dialkyl dithiocarbamate esters (PMNs P-02-778, P-02-779, and P-02-780) are subject to reporting under...

  8. 40 CFR 721.10314 - Dialkyl dithiocarbamate esters (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Dialkyl dithiocarbamate esters... Specific Chemical Substances § 721.10314 Dialkyl dithiocarbamate esters (generic). (a) Chemical substance... dialkyl dithiocarbamate esters (PMNs P-02-778, P-02-779, and P-02-780) are subject to reporting under...

  9. 40 CFR 721.10314 - Dialkyl dithiocarbamate esters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Dialkyl dithiocarbamate esters... Specific Chemical Substances § 721.10314 Dialkyl dithiocarbamate esters (generic). (a) Chemical substance... dialkyl dithiocarbamate esters (PMNs P-02-778, P-02-779, and P-02-780) are subject to reporting under...

  10. UV-visible spectroscopic estimation of photodegradation of rhodamine-B dye using tin(IV) oxide nanoparticles.

    PubMed

    Sangami, G; Dharmaraj, N

    2012-11-01

    Nanocrystalline, tin(IV) oxide (SnO(2)) particles has been prepared by thermal decomposition of tin oxalate precursor obtained from the reactions of tin(IV) chloride and sodium oxalate using eggshell membrane (ESM). The as-prepared SnO(2) nanoparticles were characterized by thermal studies, transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman, FT-IR and UV-visible studies and used as a photocatalyst for the degradation of rhodamine-B (Rh-B) dye. The size of the prepared nanoparticles was in the range of 5-12nm as identified from the TEM images. Powder XRD data revealed the presence of a tetragonal, rutile crystalline phase of the tin(IV) oxide nanoparticles. Thermal analysis showed that the decomposition of tin oxalate precursor to yield the titled tin(IV) oxide nanoparticles was completed below 500°C. The extent of degradation of Rh-B in the presence of SnO(2) monitored by absorption spectral measurements demonstrated that 94.48% of the selected dye was degraded upon irradiation with UV light for 60 min.

  11. Aromatic Ring Currents Illustrated--NMR Spectra of Tin(IV) Porphyrin Complexes. An Advanced Undergraduate Experiment.

    ERIC Educational Resources Information Center

    Arnold, Dennis P.

    1988-01-01

    Attempts to show that in the closed loops of cyclic structures the protons situated in conic regions above and below the ring will be shielded. Uses the diamagnetic and air stable octahedral tin(IV) complexes of porphyrins for study. Notes complexes crystallize easily and offer spectacular purple colors. (MVL)

  12. Synthesis and characterization of a novel layered tin(IV) phosphate with ion exchange properties

    SciTech Connect

    Bortun, A.I.; Bortun, L.N.; Clearfield, A.; Khainakov, S.A. |; Jaimez, E.; Garcia, J.R.

    1999-04-01

    A novel layered tin(IV) phosphate, Sn(NH{sub 4}PO{sub 4})(HPO{sub 4}){center_dot}2H{sub 2}O ({delta}-SnP-NH{sub 4}), was synthesized under mild hydrothermal conditions (190 C) in the presence of urea. The treatment of this compound with mineral acids gave a new phase of tin(IV) bis(monohydrogenphosphate), Sn(HPO{sub 4}){sub 2}{center_dot}3H{sub 2}O ({delta}-SnP-H). The layered nature of the solid was confirmed from amine intercalation, exfoliation in alkaline media, and the ion exchange behavior towards alkali and alkaline earth ions. High affinity (K{sub d}{sup Cs} {approximately} 5 {times} 10{sup 4} to 2 {times} 10{sup 5} mL g{sup {minus}1}) and capacity (160--200 mg Cs{sup +} per g of exchanger) for Cs{sup +} makes these materials promising for selective radioactive cesium removal from contaminated groundwater and nuclear waste.

  13. Ferrocene-o-benzosemiquinonato tin(IV) electron-transfer complexes.

    PubMed

    Ilyakina, Ekaterina V; Poddel'sky, Andrey I; Fukin, Georgy K; Bogomyakov, Artem S; Cherkasov, Vladimir K; Abakumov, Gleb A

    2013-05-06

    The interaction of ferrocene with tin(IV) o-benzosemiquinonato complexes in acetonitrile results in a reversible electron transfer (ET) from ferrocene to the redox-active ligand with the formation of electron-transfer complexes [(3,6-Cat)SnBr3](-)[Cp2Fe](+) (1) and [(3,6-Cat)(3,6-SQ)SnCl2](-)[Cp2Fe](+) (2), where 3,6-Cat is the 3,6-di-tert-butyl-catecholate dianion and 3,6-SQ is the 3,6-di-tert-butyl-o-benzosemiquinonato radical anion. The ET process and the solvent effect in the system "ferrocene-o-benzosemiquinonato tin(IV) complexes" were investigated on the basis of a combination of spectroscopic and X-ray diffraction methods. The molecular structures of 1 and 2 were confirmed by X-ray analysis. Complex 2 demonstrates the ferromagnetic coupling in the linear chain alternating ···D(+•)A(-•)D(+•)A(-•)··· motif.

  14. Investigation of the electrodialysis of an aqueous solution of tin(IV) chloride

    SciTech Connect

    Sharygin, L.M.; Zlokazova, E.I.; Shtin, A.P.

    1987-09-20

    The sol-gel method for the synthesis of sorbents on the basis of oxides of polyvalent metals calls for an investigation of the methods for obtaining aqueous sols of oxides of these metals. The purpose of this work was to investigate the polarization of an anion-exchange membrane in solutions of stannic chloride with different concentrations and during electrodialysis, as well as the current efficiency with respect to chlorine, and the transport numbers of the chloride ion as a function of the current density and the temperature. The polarization curves recorded for an MA-41L membrane in dilute solutions of tin(IV) chloride tended to show an increase in the limiting current in comparison to the case of hydrochloric acid with the same electrical conductivity owing to the ion-exchange properties of the colloidal particles of hydrated tin dioxide formed during the hydrolysis and polymerization of tin in solution.

  15. Photophysics of soret-excited tin(IV) porphyrins in solution.

    PubMed

    Ghiggino, Kenneth P; Giri, Neeraj Kumar; Hanrieder, Jordan; Martell, Jonathon D; Müller, Jens; Paige, Matthew F; Robotham, Benjamin; Szmytkowski, Jędrzej; Steer, Ronald P

    2013-08-22

    The photophysics of low-chlorin tin(IV) tetraphenylporphyrin dihydroxide, a core building block for axially substituted supramolecular tin porphyrin constructs, has been studied in a variety of hydrogen-bonding, nonpolar, and aprotic polar solvents using steady-state, nanosecond, and femtosecond time-resolved emission, and femtosecond time-resolved absorption methods. In hydrogen-bonding solvents the metalloporphyrin exists as solvated monomers, and its Soret-excited S2 state in these solvents exhibits the expected linear energy gap law relationship with first-order population decay times in the 0.8 to 1.7 ps range. Evidence is presented that this metalloporphyrin aggregates in other solvents at the concentrations typically used for these ultrafast measurements and yields species-averaged time-resolved data. Cw laser excitation in the Q-band under deaerated conditions produces weak S2-S0 fluorescence (photon upconversion) as a result of triplet-triplet annihilation.

  16. New mono-organotin (IV) dithiocarbamate complexes

    SciTech Connect

    Muthalib, Amirah Faizah Abdul; Baba, Ibrahim

    2014-09-03

    Eighteen new mono-organotin dithiocarbamate compounds derived each nine from methyltin(IV) and phenyltin(IV) reacted using in-situ method with various type of N-dialkylamine together with carbon disulphide with the ratio of 1:3:3. Elemental and gravimetric analysis showed that the general formula of these compounds were RSnCl[S{sub 2}CNR′R″]{sub 2} (R= Ph, CH{sub 3}, R′ = CH{sub 3}, C{sub 2}H{sub 5}, C{sub 7}H{sub 7} and R″ = C{sub 2}H{sub 5}, C{sub 6}H{sub 11}, iC{sub 3}H{sub 7}, C{sub 7}H{sub 7}). These compounds had been characterized by infrared spectroscopy, ultraviolet spectroscopy, {sup 1}H, {sup 13}C NMR spectroscopy and single crystal X-ray crystallography. The infrared spectra of these compounds showed three important peaks indicating the formation of dithiocarbamate compounds, ν(CN), ν(CS) and ν(Sn-S) band which present in the region of 1444–1519, 954–1098 and 318–349 cm{sup −1} respectively. The ultraviolet-visible spectra showed an absorption band for the π - π* transition of NCS group in the range of 253 – 259 nm due to the intramolecular charge transfer of the ligand. The {sup 13}C NMR spectra showed an important shift for δ(N{sup 13}CS{sub 2}) in the range of 196.8 – 201.9 ppm.. Single crystal X-ray diffraction studies showed three new structures with the general formula of PhSnCl[S{sub 2}CN(Et)(i−Pr)]{sub 2}, MeSnCl[S{sub 2}CN(Me)(Cy)]{sub 2} and MeSnCl[S{sub 2}CN(i−Pr)(CH{sub 2}Ph)]{sub 2}. All structures having a distorted octahedral geometry set by CClS{sub 4} donor atom from the two chelating dithiocarbamate ligands.

  17. New mono-organotin (IV) dithiocarbamate complexes

    NASA Astrophysics Data System (ADS)

    Muthalib, Amirah Faizah Abdul; Baba, Ibrahim

    2014-09-01

    Eighteen new mono-organotin dithiocarbamate compounds derived each nine from methyltin(IV) and phenyltin(IV) reacted using in-situ method with various type of N-dialkylamine together with carbon disulphide with the ratio of 1:3:3. Elemental and gravimetric analysis showed that the general formula of these compounds were RSnCl[S2CNR'R″]2 (R= Ph, CH3, R' = CH3, C2H5, C7H7 and R″ = C2H5, C6H11, iC3H7, C7H7). These compounds had been characterized by infrared spectroscopy, ultraviolet spectroscopy, 1H, 13C NMR spectroscopy and single crystal X-ray crystallography. The infrared spectra of these compounds showed three important peaks indicating the formation of dithiocarbamate compounds, ν(CN), ν(CS) and ν(Sn-S) band which present in the region of 1444-1519, 954-1098 and 318-349 cm-1 respectively. The ultraviolet-visible spectra showed an absorption band for the π - π* transition of NCS group in the range of 253 - 259 nm due to the intramolecular charge transfer of the ligand. The 13C NMR spectra showed an important shift for δ(N13CS2) in the range of 196.8 - 201.9 ppm.. Single crystal X-ray diffraction studies showed three new structures with the general formula of PhSnCl[S2CN(Et)(i-Pr)]2, MeSnCl[S2CN(Me)(Cy)]2 and MeSnCl[S2CN(i-Pr)(CH2Ph)]2. All structures having a distorted octahedral geometry set by CClS4 donor atom from the two chelating dithiocarbamate ligands.

  18. Blue-emitting phosphate glasses synthesized via reduction of tin(IV) by silicon

    NASA Astrophysics Data System (ADS)

    Jiménez, José A.

    2017-04-01

    The Si-reductant route to produce blue-emitting tin-doped phosphate glasses is proposed. SnO2/Si co-doped glasses were prepared in a P2O5:BaO matrix by a simple melt-quench method in ambient atmosphere. This lead to the silicon-driven reduction of tin(IV) to tin(II) resulting in the production of the luminescent glasses. While the as-prepared SnO2-doped glass appeared non-luminescent, the addition of increasing amounts of silicon powder up to 6 mol% to batch materials facilitated developing the blue-emitting character of the glasses under excitation in the ultraviolet (UV). Reductant-induced luminescent defects became readily noticeable upon addition of the highest amount of silicon. Time-resolved UV-excited emission spectra appeared consistent with the different contributors to the exhibited luminescence being the twofold-coordinated tin centers alongside silicon-related defects. Emission from the latter appeared to be analogous to that of carbon-related defects recently reported, thus supporting that the corresponding luminescence results from the presence of oxygen radicals created by the highly reductive environment irrespective of the element (C or Si).

  19. One-step synthesis of dithiocarbamates from metal powders

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Hehemann, David G.; Duraj, Stan A.; Clark, Eric B.; Eckles, William E.; Fanwick, Phillip E.

    1994-01-01

    Neutral metal dithiocarbamate complexes (M(NR2CS2)X) are well-known precursors to metal sulfides, a class of materials with numerous technological applications. We are involved in a research effort to prepare new precursors to metal sulfides using simple, reproducible synthetic procedures. We describe the results of our synthetic and characterization studies for M = Fe, Co, Ni, Cu. and In. For example, treatment of metallic indium with tetramethylthiuram disulfide (tmtd) in 4-methylpyridine (4-Mepy) at 25 deg C produces a new homoleptic indium (III) dithiocarbamate, In(N(CH3)2CS2)3(I), in yields of over 60 percent. The indium (III) dithiocarbamate was characterized by X-ray crystallography; (I) exists in the solid state as discrete distorted-octahedral molecules. Compound (I) crystallizes in the P1bar (No. 2) space group with lattice parameters: a = 9.282(1) A, b = 10.081(1) A, c = 12.502 A, alpha = 73.91(1) deg, beta = 70.21(1) deg, gamma = 85.8(1)deg, and Z = 2. X-ray diffraction and mass spectral data were used to characterize the products of the analogous reactions with Fe, Co, Ni, and Cu. We discuss both use of dithiocarbamates as precursors and our approach to their preparation.

  20. INHIBITORY ACTION OF DITHIOCARBAMATES ON ENZYMES OF ANIMAL TISSUES

    DTIC Science & Technology

    these compounds on the oxidative phase of intermediary carbohydrate metabolism. All of the compounds were effective inhibitors of the tricarboxylic...oxidase, and succinic dehydrogenase. The salts of dithiocarbamic acid were effective inhibitors of these enzymatic reactions in vivo but the disulfide...cytochrome c and inhibited tyrosinase activity in vitro. The results of this investigation suggest that the acute mammalian toxicity of the

  1. Synthesis, characterization and biocidal activities of heterobimetallic complexes having tin(IV) as a padlock

    NASA Astrophysics Data System (ADS)

    Husain, Ahmad; Nami, Shahab A. A.; Siddiqi, K. S.

    2010-04-01

    A mononuclear precursor complex, [(CH 3) 2Sn(tpdtc)] and several of its heterobimetallic derivatives of the type, [(CH 3) 2Sn(tpdtc)]MCl 2 have been synthesized by the simple addition reaction of transition metal chlorides, MCl 2· nH 2O where tpdtc = tetraethylenepentamine bis(dithiocarbamate) anion, M = Fe(II), Co(II), Ni(II), Cu(II) and Zn(II). The synthesized complexes have been systematically characterized by the physicochemical and spectroscopic techniques. A square-pyramidal geometry has been proposed for all the transition metal atoms with chloride ions occupying the axial while the three nitrogen atoms occupying the equatorial positions. A symmetrical bidentate coordination has been observed for the dithiocarbamato moiety leading to the formation of 18 member cavity. The thermal studies reveal that the mononuclear complex decomposes in three stages while its heterobimetallic analog exhibits a simple two-stage profile. The conductivity measurement data (1 mmol solution) implies a non-electrolytic behavior for all the complexes as evident by their low conductivity values obtained at room temperature. The heterobimetallic complexes have also been tested against the bacterial ( Escherichia coli and Pseudomonas aeruginosa) and antifungal strains ( Aspergillus niger and Fusarium oxysporum). All the complexes were found to be active against the test organisms and maximum activity was found for [(CH 3) 2Sn(tpdtc)]CuCl 2 complex.

  2. Compounds of tin(IV) - catalysts of amide formation. Effect of temperature and nature of leaving group

    SciTech Connect

    Oleinik, N.M.; Garkusha-Bozhko, I.P.; Usanova, I.V.

    1988-09-20

    The effect of substitution of the ester oxygen atom by sulfur in p-nitrophenyl acetate on its aminolysis rate with benzylamine in beneze at 25/degree/C in the presence of dibutyltin dibenzoate as catalyst was studied. Such substitution leads to a decrease in the catalytic activity by approximately a half, and this is explained by the smaller capacity of the sulfur atom for the formation of hydrogen bonds. The effect of temperature on the rate of the reaction of N-benzyl-oxycarbonylglycine p-nitrophenyl ester with glycine tert-butyl ester in benzene in the presence of dibutyltin dibenzoate was also investigated in the range of 10-50/degree/C. The Arrhenius equation is not fulfilled in this case. The obtained facts demonstrate the multistage character of the catalytic reaction and do not contradict the authors previously proposed bifunctional mechanism of catalysis by tin(IV) compounds.

  3. Intramolecular N→Sn coordination in tin(II) and tin(IV) compounds based on enantiopure ephedrine derivatives.

    PubMed

    Zöller, Thomas; Iovkova-Berends, Ljuba; Berends, Thorsten; Dietz, Christina; Bradtmöller, Gerrit; Jurkschat, Klaus

    2011-09-05

    The syntheses and molecular structures of the intramolecularly coordinated tin(II) compounds {CH(2)N(Me)CH(Me)CH(Ph)O}(2)SnL (2, L = lone pair; 4, L = W(CO)(5); 5, L = Cr(CO)(5)) and of the related hydroxido-substituted tin(IV) compound [{CH(2)N(Me)CH(Me)CH(Ph)O}(2)Sn(OH)](2)O, 6a, are reported. Also reported are the molecular structures of the enantiopure N,N'-ethylenebis-(1R,2S)-ephedrine, {CH(2)N(Me)CH(Me)CH(Ph)OH}(2) (1), and its hydrobromide {CH(2)N(Me)CH(Me)CH(Ph)OH}(2)·HBr (1a).

  4. A water-soluble tin(IV) porphyrin as a bioinspired photosensitiser for light-driven proton-reduction.

    PubMed

    Manke, Anne-Marie; Geisel, Karen; Fetzer, Anne; Kurz, Philipp

    2014-06-28

    The water-soluble tin(IV) porphyrin dichlorido-5,10,15,20-tetrakis(p-carboxyphenyl)-porphyrinato-tin(IV) (SnTPPC, 1) was synthesised as a mimic of biological chlorophyll photosensitisers. In natural photosynthesis, chlorophyll pigments start the multi-electron transfer processes resulting in water-oxidation and NADP(+)-reduction. The photochemical properties of compound 1 were characterised by measuring absorption and fluorescence spectra. Electrochemical measurements in water revealed well-suited redox potentials of 1 for both proton-reduction to H2 as well as water-oxidation to O2. The tin(IV) porphyrin was then used as a photosensitiser in model systems for light-induced proton-reduction in aqueous solution, where an optimization of the experimental conditions was carried out to achieve reaction rates comparable to those found for [Ru(bipy)3](2+), a standard dye in artificial photosynthesis. By employing UV/Vis-spectroelectrochemistry, we found that the porphyrin ligand of 1 is redox non-innocent in water. A complex set of reduction reactions of the porphyrin macrocycle occurs during photocatalytic experiments involving the ligand's chlorin form as a key intermediate. On the basis of these results, a potential reaction sequence for light-driven H2-formation is formulated, where the reductive quenching of 1 forms the initial reaction step and reduced forms of 1 serve as hydride transfer agents to the H2 evolution catalyst. The spectroscopic, electrochemical and catalytic properties of SnTPPC make this compound class an attractive, affordable and easily accessible choice for photosensitisers in artificial photosynthetic systems. Finally, the detected complicated redox reactions of the porphyrin ring in water offer a possible explanation of why the chlorophylls of P680 or P700 are carefully wrapped in a water-free part of the PSII and PSI proteins.

  5. χ{sup (3)} measurements of axial ligand modified high valent tin(IV) porphyrins using degenarete four wave mixing at 532nm

    SciTech Connect

    Narendran, N. K. Siji Chandrasekharan, K.; Soman, Rahul; Arunkumar, Chellaiah; Sudheesh, P.

    2014-10-15

    Porphyrins and metalloporphyrins are unique class of molecules for Nonlinear Optical applications because of their unique structure of altering the central metal atom, large extended π-system, high thermal stability, tunable shape, symmetry and synthetic versatility Here, we report χ{sup (3)} Measurements of a simple phenyl porphyrins and its highvalent tin(IV) porphyrins with Bromination characterized by UV-Visible spectroscopic method. In this study, we employed the Degenerate Four Wave Mixing technique using forward Boxcar geometry with an Nd:YAG nano second pulsed laser as source and it was found that the tin(IV) porphyrin with Bromination exhibits good χ{sup (3)} value and figure of merit.

  6. Anti-inflammatory effect of thalidomide dithiocarbamate and dithioate analogs.

    PubMed

    Talaat, Roba; El-Sayed, Waheba; Agwa, Hussein S; Gamal-Eldeen, Amira M; Moawia, Shaden; Zahran, Magdy A H

    2015-08-05

    Thalidomide has anti-inflammatory, immunomodulatory, and anti-angiogenic properties. It has been used to treat a variety of cancers and autoimmune diseases. This study aimed to characterize anti-inflammatory activities of novel thalidomide analogs by exploring their effects on splenocytes proliferation and macrophage functions and their antioxidant activity. MTT assay was used to assess the cytotoxic effect of thalidomide analogs against splenocytes. Tumor necrosis factor (TNF-α) and nuclear factor kappa B (NF-κB-P65) were determined by enzyme-linked immunosorbent assay (ELISA). Nitric oxide (NO) was estimated by colorimetric assay. Antioxidant activity was examined by ORAC assay. Our results demonstrated that thalidomide dithioate analog 2 and thalidomide dithiocarbamate analog 4 produced a slight increase in splenocyte proliferation compared with thalidomide. Thalidomide dithiocarbamate analog 1 is a potent inhibitor of TNF-α production, whereas thalidomide dithiocarbamate analog 5 is a potent inhibitor of both TNF-α and NO. Analog 2 has a pronounced inhibitory effect on NF-κB-P65 production level. All thalidomide analogs showed prooxidant activity against hydroxyl (OH) radical. Analog 1 and thalidomide dithioate analog 3 have prooxidant activity against peroxyl (ROO) radical in relation to thalidomide. On the other hand, analog 4 has a potent scavenging capacity against peroxyl (ROO) radical compared with thalidomide. Taken together, the results of this study suggest that thalidomide analogs might have valuable anti-inflammatory activities with more pronounced effect than thalidomide itself.

  7. Effects of mancozeb and other dithiocarbamate fungicides on Saccharomyces cerevisiae: the role of mitochondrial petite mutants in dithiocarbamate tolerance.

    PubMed

    Casalone, E; Bonelli, E; Polsinelli, M

    2010-11-01

    Saccharomyces cerevisiae as model system was used to evaluate the occurrence of resistant mutants and adaptation mechanism to mancozeb (MZ), a widespread fungicide of the dithiocarbamate class with a broad spectrum of action and multiple cell targets. We were unable to isolate mutants resistant to inhibitory concentration of MZ but found an unusually large number of mitochondrial defective petite mutants among cells incubated in the presence of subinhibitory MZ concentration. Similar results were obtained with two other dithiocarbamate fungicides. Comparison of wild type and petite mutants showed that the latter were more resistant to toxic effects of MZ, highlighting the role of mitochondria in MZ-tolerance. The data suggest that petite cells, arising by exposure to sub-inhibitory MZ concentration, are not induced by fungicides but are spontaneous mutants already present in the population before the contact with the fungicide.

  8. A modular synthesis of dithiocarbamate pendant unnatural α-amino acids

    EPA Science Inventory

    Unnatural α-amino acids containing dithiocarbamate side chains were synthesized by a one-pot reaction of in-situ generated dithiocarbamate anions with sulfamidates. A wide range of these anions participated in the highly regio- and stereo-selective ring opening of sulfamidates to...

  9. Nitrogen substituent polarity influences dithiocarbamate-mediated lipid oxidation, nerve copper accumulation, and myelin injury.

    PubMed

    Valentine, Holly L; Viquez, Olga M; Amarnath, Kalyani; Amarnath, Venkataraman; Zyskowski, Justin; Kassa, Endalkachew N; Valentine, William M

    2009-01-01

    Dithiocarbamates have a wide spectrum of applications in industry, agriculture, and medicine, with new applications being investigated. Past studies have suggested that the neurotoxicity of some dithiocarbamates may result from copper accumulation, protein oxidative damage, and lipid oxidation. The polarity of a dithiocarbamate's nitrogen substituents influences the lipophilicity of the copper complexes that it generates and thus potentially determines its ability to promote copper accumulation within nerve and induce myelin injury. In the current study, a series of dithiocarbamate-copper complexes differing in their lipophilicity were evaluated for their relative abilities to promote lipid peroxidation determined by malondialdehyde levels generated in an ethyl arachidonate oil-in-water emulsion. In a second component of this study, rats were exposed to either N,N-diethyldithiocarbamate or sarcosine dithiocarbamate; both generated dithiocarbamate-copper complexes that were lipid- and water-soluble, respectively. Following the exposures, brain, tibial nerve, spinal cord, and liver tissue copper levels were measured by inductively coupled mass spectroscopy to assess the relative abilities of these two dithiocarbamates to promote copper accumulation. Peripheral nerve injury was evaluated using grip strengths, nerve conduction velocities, and morphologic changes at the light microscope level. Additionally, the protein expression levels of glutathione transferase alpha and heme-oxygenase-1 in nerve were determined, and the quantity of protein carbonyls was measured to assess levels of oxidative stress and injury. The data provided evidence that dithiocarbamate-copper complexes are redox active and that the ability of dithiocarbamate complexes to promote lipid peroxidation is correlated to the lipophilicity of the complex. Consistent with neurotoxicity requiring the formation of a lipid-soluble copper complex, significant increases in copper accumulation, oxidative

  10. Nitrogen Substituent Polarity Influences Dithiocarbamate-Mediated Lipid Oxidation, Nerve Copper Accumulation, and Myelin Injury

    PubMed Central

    Valentine, Holly L.; Viquez, Olga M.; Amarnath, Kalyani; Amarnath, Venkataraman; Zyskowski, Justin; Kassa, Endalkachew N.; Valentine, William M.

    2009-01-01

    Dithiocarbamates have a wide spectrum of applications in industry, agriculture, and medicine, with new applications being investigated. Past studies have suggested that the neurotoxicity of some dithiocarbamates may result from copper accumulation, protein oxidative damage, and lipid oxidation. The polarity of a dithiocarbamate’s nitrogen substituents influences the lipophilicity of the copper complexes it generates and thus potentially determines its ability to promote copper accumulation within nerve and induce myelin injury. In the current study, a series of dithiocarbamate-copper complexes differing in their lipophilicity were evaluated for their relative abilities to promote lipid peroxidation determined by malondialdehyde levels generated in an ethyl arachidonate oil-in-water emulsion. In a second component of this study, rats were exposed to either N,N-diethyldithiocarbamate or sarcosine dithiocarbamate; both generate dithiocarbamate-copper complexes that are lipid and water soluble, respectively. Following the exposures, brain, tibial nerve, spinal cord and liver tissue copper levels were measured by inductively coupled mass spectroscopy to assess the relative abilities of these two dithiocarbamates to promote copper accumulation. Peripheral nerve injury was evaluated using grip strengths, nerve conduction velocities and morphologic changes at the light microscope level. Additionally, the protein expression levels of glutathione transferase alpha and heme-oxygenase-1 in nerve were determined and the quantity of protein carbonyls measured to assess levels of oxidative stress and injury. The data provide evidence that dithiocarbamate-copper complexes are redox active; and that the ability of dithiocarbamate complexes to promote lipid peroxidation is correlated to the lipophilicity of the complex. Consistent with neurotoxicity requiring the formation of a lipid soluble copper complex, significant increases in copper accumulation, oxidative stress and myelin

  11. Comparative effects of N,N-disubstituted dithiocarbamates and dimercaptosuccinate on mobilization of methylmercury in mice

    SciTech Connect

    Gale, G.R.; Atkins, L.M.; Smith, A.B.; Walker, E.M. Jr.; Jones, M.M.

    1984-07-01

    Diethyldithiocarbamate (DDTC) and five of its N,N-disubstituted analogs were compared with dimercaptosuccinate (DMSA) for effectiveness in mobilizing and promoting excretion of methylmercury (MeHg) following administration of a sublethal dose of MeHg labeled with Me203Hg. The previously reported effectiveness of DMSA was confirmed. Of the dithiocarbamates assessed, only di(carboxymethyl)-dithiocarbamate (DCDC) was active in mobilizing MeHg, and its activity on a molar dose basis was less than that of DMSA. The disparate structural requirements of dithiocarbamates as antagonists of MeHg and of cadmium were discussed.

  12. A 119Sn Mössbauer Study of Tin(IV) Complexes of 2- and 4-Benzoylpyridine Thiosemicarbazone and 4-Benzoylpyridine Semicarbazone

    NASA Astrophysics Data System (ADS)

    Pérez-Rebolledo, Anayive; Ardisson, José D.; de Lima, Geraldo M.; Macedo, Waldemar A. A.; Beraldo, Heloisa

    2005-06-01

    A 119Sn Mössbauer study was carried out of tin(IV) complexes with 2-benzoylpyridine thiosemicarbazone (H2Bz4DH) and its N(4)-methyl (H2Bz4M) and N(4)-phenyl (H2Bz4Ph) derivatives: [Sn(2Bz4DH)Cl3] (1), [Sn(2Bz4DH)PhCl2] (2), [Sn(2Bz4M)Cl3] (3), [H22Bz4M]2[Ph2SnCl4] (4), [Sn(2Bz4Ph)PhCl2] (5), [Sn(2Bz4Ph)Ph2Cl] (6), in which H2Bz4R stands for the neutral ligand and 2Bz4R stands for the anionic thiosemicarbazone. In addition, 119Sn Mössbauer studies of the tin(IV) complexes [Sn(H4Bz4DH)2Cl4H2O] (7), [Sn(H4BzPS)2Cl4H2O] (8) with 4-benzoylpyridine thiosemicarbazone (H4Bz4DH) and the correspondent semicarbazone (H4BzPS) were performed. The isomer shifts decrease upon coordination due to the variation in the percentage of s character as tin changes from approximately sp3 hybridization in the tin salts to sp3d2 in the octahedral or sp3d3 in the heptahedral complexes. The Mössbauer parameters of compound (4) showed the existence of two tin(IV) sites, which have been attributed to the presence of the cis and trans isomers.

  13. Detection and quantification of dithiocarbamate pesticides by Surface Enhanced Raman Spectroscopy (SERS)

    NASA Astrophysics Data System (ADS)

    Saute, Benjamin Calvin

    Dithiocarbamates are a subclass of carbamate pesticides that are widely used as insecticidal agents on food crops in the US and abroad. Quantitative determination of trace quantities of dithiocarbamates is necessary in order to mitigate potential human exposure via pesticide residues left on inadequately washed food items as well as groundwater contamination from agricultural runoff. The focus of this research is on the development and optimization of a Surface Enhanced Raman Spectroscopy (SERS) based analytical technique for the quantitative determination of trace amounts of dithiocarbamate pesticides in different matrices. Gold nanoparticles of different shapes and sizes will be investigated to determine the suitability of these materials as SERS active substrates for the trace analysis of dithiocarbamate pesticides. Analytical sensitivity will be evaluated by determining the limits of detection using established statistical methods.

  14. Self assembled homodinuclear dithiocarbamates: One pot synthesis and spectral characterization

    NASA Astrophysics Data System (ADS)

    Nami, Shahab A. A.; Husain, Ahmad; Ullah, Irfan

    2014-01-01

    Several self assembled homodinuclear complexes of the type [M2(Ldtc)2·4H2O] derived from quadridentate ligand (Ldtc), where Ldtc = 2-aminobenzoylhydrazidebis(dithiocarbamate) and M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) have been reported. The in situ procedure gives high yield with the formation of single product as evident by TLC and various other physicochemical techniques. Elemental analysis, TGA, 1H NMR, 13C NMR, ESI mass spectrometry, EPR, UV-vis. and IR spectroscopy were used to characterize the homodinuclear complexes. The spectroscopic evidences and room temperature magnetic moment values suggest that all the complexes have octahedral geometry around the transition metal atom. A symmetrical bidentate coordination of the dithiocarbamato moiety has been observed in all the complexes. The energy-minimized structure of the molecule also showed that each metal atom acquires a distorted octahedral geometry. The complexes exhibit a three-step thermolytic pattern and are non-electrolyte in nature.

  15. Antiviral Effects of Pyrrolidine Dithiocarbamate on Human Rhinoviruses

    PubMed Central

    Gaudernak, Elisabeth; Seipelt, Joachim; Triendl, Andrea; Grassauer, Andreas; Kuechler, Ernst

    2002-01-01

    Human rhinoviruses (HRVs) are the predominant cause of the common cold. The frequency of HRV infections in industrial countries and the lack of effective therapeutical treatment underline the importance of research for new antiviral substances. As viral infections are often accompanied by the generation of oxidative stress inside the infected cells, several redox-active substances were tested as potential antivirals. In the course of these studies it was discovered that pyrrolidine dithiocarbamate (PDTC) is an extremely potent compound against HRV and poliovirus infection in cell culture. Besides the ability to dramatically reduce HRV production by interfering with viral protein expression, PDTC promotes cell survival and abolishes cytopathic effects in infected cells. PDTC also protects cells against poliovirus infection. These effects were highly specific, as several other antioxidants (vitamin C, Trolox, 2-mercaptoethanol, and N-acetyl-l-cysteine) are inactive against HRV infection. Synthesis of HRV proteins and cleavage of eucaryotic initiation factor 4G responsible for host cell shutoff of cellular protein synthesis are severely inhibited in the presence of PDTC. PMID:12021333

  16. Lanthanum(III) and praseodymium(III) derivatives with dithiocarbamates derived from alpha-amino acids.

    PubMed

    Rai, Anita; Sengupta, Soumitra K; Pandey, Om P

    2006-06-01

    Lanthanum(III) and praseodymium(III) complexes with dithiocarbamates have been synthesized by the reactions of lanthanum(III) and praseodymium(III) chloride with barium dithiocarbamate and complexes of type [LnCl(L)H2O]n have been obtained (where Ln=La(III) or Pr(III); L=barium salt of dithiocarbamate derived from glycine, L-leucine, L-valine, DL-alanine). The complexes have been characterized by elemental analysis, molar conductance, electronic absorption and fluorescence, infrared, far infrared, 1H NMR spectral studies. The presence of coordinated water molecule is inferred from thermogravimetric analysis which indicates the loss of one water molecule at 150-170 degrees C. The oscillator strength, Judd-Ofelt intensity parameter, stimulated emission cross-section, etc. have been obtained for different transitions of Pr3+.

  17. Effects of substituted dithiocarbamates on distribution and excretion of inorganic mercury in mice

    SciTech Connect

    Gale, G.R.; Atkins, L.M.; Smith, A.B.; Jones, M.M.

    1985-02-01

    Diethyldithiocarbamate (DDTC) and six of its N,N-disubstituted congeners were evaluated for their relative efficacies in mobilizing and promoting excretion of mercury (Hg/sup + +/) using mice which had been given /sup 203/Hg/sup + +/; D-penicillamine (PEN) was used as a positive control compound. While none was as effective as PEN when compared on a molar dose basis, significant activity as assessed by reduction of whole body /sup 203/Hg burden, was observed following treatment with three of the analogs. The order of effectiveness was PEN greater than N-methyl-N-dithiocarboxyglucamine (MDCG) greater than di(carboxymethyl)dithiocarbamate (DCDC) greater than di(hydroxyethyl)dithiocarbamate (DHDC).

  18. Polynuclear transition metal complexes with thiocarbohydrazide and dithiocarbamates

    NASA Astrophysics Data System (ADS)

    Siddiqi, K. S.; Khan, Sadaf; Nami, Shahab A. A.; El-ajaily, M. M.

    2007-07-01

    Sn(tch) 2{MCl 2} 2 was prepared from the precursor Sn(tch) 2 and MCl 2. It was subsequently allowed to react with diethyldithiocarbamate which yielded the trinuclear complexes of the type Sn(tch) 2{M 2(dtc) 4}, where tch = thiocarbohydrazide, M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and dtc = diethyldithiocarbamate. They were characterized on the basis of microanalytical, thermal (TGA/DSC), spectral (IR, UV-vis, EPR, 1H NMR) studies, conductivity measurement and magnetic moment data. On the basis of spectral data a tetrahedral geometry has been proposed for the halide complexes, Sn(tch) 2{MCl 2} 2 except for Cu(II) which exhibits a square planar coordination although the transition metal ion in Sn(tch) 2{M 2(dtc) 4} achieves an octahedral geometry where the dithiocarbamato moiety acts as a symmetrical bidentate ligand. The bidentate nature has been established by the appearance of a sharp single ν(C-S) around 1000 cm -1. A downfield shift observed in NH a and NH b protons on moving from Sn(tch) 2 to Sn(tch) 2{MCl 2} 2 is due to the drift of electrons toward metal atoms. A two-step pyrolysis has been observed in the Sn(tch) 2{MCl 2} 2 complexes while their dithiocarbamato derivatives exhibit a three-stage degradation pattern. Finally, the in vitro antibacterial activity of Sn(tch) 2{M 2(dtc) 4} and the mononuclear Sn(tch) 2 has been carried out on bacterial strains Escherichia coli and Salmonella typhi. The compounds were found to be active against the test organisms. The activity of the complexes is enhanced with increasing concentration. The maximum activity in both the strains was achieved by cobalt(II) dithiocarbamate complex. Minimum activity was found for Sn(tch) 2 which generally increases with the introduction of transition metal ion in the complex.

  19. Toxic Epidermal Necrolysis After Exposure to Dithiocarbamate Fungicide Mancozeb.

    PubMed

    Zakharov, Sergey; Csomor, Jan; Urbanek, Petr; Pelclova, Daniela

    2016-01-01

    Toxic epidermal necrolysis (TEN) is a life-threatening mucocutaneous disease with high mortality. Dithiocarbamates (DTC) are organosulphur compounds widely used in agriculture, industry and households. We report a case of TEN after exposure to mancozeb in fungicide. A 48-year-old 75 kg b.w. man was admitted with fever and generalized skin/mucous lesions after application of fungicide in a home garden. The patient had necrotic desquamation of gastrointestinal/respiratory tract mucosa, ocular lesion and skin epidermolysis of 90% of body surface. The laboratory findings included elevation of inflammatory parameters, hyperglycaemia, increased urea, creatinine, liver enzymes, hypoalbuminemia and electrolyte disturbances. The treatment included supportive care, management of fluid/electrolyte requirements, analgesics and enteral nutrition. Skin lesions were treated with occlusive non-adhesive biological wound dressings. Due to the proof of Acinetobacter, Escherichia coli and Escherichia faecalis from skin swabs, a combination of meropenem with amikacin was administered. During the next 2 weeks, complete re-epithelialization of skin lesions occurred, mucosal lesions healed and the laboratory parameters returned to normal. The patient was discharged on day 42. TEN is a rare condition that is generally caused by medications. Nevertheless, high attention should be paid to the cases of occupational or household exposure to DTC fungicides widely used in agriculture and home gardens because of their ability to cause TEN after skin and inhalation exposure. Greater emphasis on the hazardous properties of these products is necessary to ensure non-professional users are aware of the necessity of protective clothing during mixing, loading, application and early re-entry into treated fields.

  20. Spectral, thermal and in vitro antimicrobial studies of cyclohexylamine- N-dithiocarbamate transition metal complexes

    NASA Astrophysics Data System (ADS)

    Mamba, Saul M.; Mishra, Ajay K.; Mamba, Bhekie B.; Njobeh, Patrik B.; Dutton, Mike F.; Fosso-Kankeu, Elvis

    2010-10-01

    Transition metal complexes of the type [M(L) 2] and those containing monodentate phosphines of the type [M(L) 2(PPh 3)] {M = Ni, Co, Cu and Zn; L = cyclohexylamine- N-dithiocarbamate; PPh 3 = triphenylphosphine} have been synthesized. The complexes were characterized using IR, UV-vis, NMR spectroscopy, and thermal analysis (TGA). The 1H NMR, 13C NMR and 31P NMR showed the expected signals for the dithiocarbamate and triphenylphosphine moieties. The spectral studies in all compounds revealed that the coordination of metals occurs via the sulphur atom of the dithiocarbamate ligand in a bidentate fashion. Thermal behavior of the complexes showed that the complexes were more stable than their parent ligands. The ligand moiety is lost in the first step and the rest of the organic moiety decomposes in the subsequent steps. Furthermore, the ligand and their metal complexes were screened in vitro for their antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, Enterococcus faecalis, Pseudomonas aeruginosa and Bacillus cereus and antifungal activities against Aspergillus flavus, Aspergillus carbonarius, Aspergillus niger and Aspergillus fumigatus. The metal complexes exhibited higher antimicrobial activity than the parent ligands. Generally, the zinc complexes were effective against the growth of bacteria with Zn(L) 2 displaying broad spectrum bacteriocidal activity at concentrations of 50 μg/mL; and Ni(L) 2 was more effective against the growth of fungi at concentrations of 100-400 μg/mL under laboratory conditions.

  1. Dithiocarbamate fungicides increase intracellular Zn(2+) levels by increasing influx of Zn(2+) in rat thymic lymphocytes.

    PubMed

    Kanemoto-Kataoka, Yumiko; Oyama, Tomohiro M; Ishibashi, Hitoshi; Oyama, Yasuo

    2015-07-25

    Dithiocarbamate fungicides are used as alternative antifouling agents to highly toxic organotin antifouling agents, such as tri-n-butyltin and triphenyltin. There are some concerns regarding their environmental and health risks. It has been shown that tri-n-butyltin increases intracellular Zn(2+) levels of mammalian lymphocytes. Therefore, we examined the effects of dithiocarbamate fungicides (Ziram, Thiram, and Zineb) on rat thymic lymphocytes using a flow-cytometric technique to elucidate how these fungicides affect intracellular Zn(2+) levels. We further determined whether the agents increase intracellular Zn(2+) and/or Ca(2+), because both Zn(2+) and Ca(2+) are intracellular signals in lymphocytes, and excessive increases in their intracellular concentrations can have adverse effects. Dithiocarbamate fungicides increased intracellular Zn(2+) levels, without affecting intracellular Ca(2+) levels. Ziram was the most potent compound, increasing intracellular Zn(2+) levels via Zn(2+) influx. Ziram (1μM) greatly decreased the cellular nonprotein thiol content, and Zn(2+) chelators attenuated the Ziram-induced decrease. Ziram increased the population of annexin V-positive cells in a Zn(2+)-dependent manner. Therefore, we propose that dithiocarbamate fungicides induce Zn(2+) influx, resulting in an excessive elevation of intracellular Zn(2+) levels, leading to the induction of apoptosis. This study gives a basic insight into the mechanisms of dithiocarbamate fungicide-induced adverse events.

  2. Removal of mercury species with dithiocarbamate-anchored polymer/organosmectite composites.

    PubMed

    Say, Ridvan; Birlik, Ebru; Erdemgil, Zerrin; Denizli, Adil; Ersöz, Arzu

    2008-02-11

    Mercury is one of the most toxic heavy metals found in solid and liquid waste disposed by chloro-alkali, paint, paper/pulp, battery, pharmaceutical, oil refinery and mining companies. Any form of mercury introduced to nature through any means is converted into a more toxic form such as methylmercury chloride (as produced by aquatic organisms) which usually accumulates in the tissue of fish and birds. The primary aim of this study was to investigate performance of dithiocarbamate-anchored polymer/organosmectite composites as sorbents for removal of mercury from aqueous solution. The modified smectite nanocomposites then were reacted with carbondisulfide to incorporate dithiocarbamate functional groups into the nanolayer of the organoclay. These dithiocarbamate-anchored composites were used for the removal of mercury species [Hg(II), CH(3)Hg(I) and C(6)H(5)Hg(I)]. Mercury adsorption was found to be dependent on the solution pH, mercury concentration and the type of mercury species to be adsorbed. The maximum adsorption capacities were equal to 157.3 mg g(-1) (782.5 micromol g(-1)) for Hg(II); 214.6 mg g(-1) (993.9 micromol g(-1)) for CH(3)Hg(I); 90.3 mg g(-1) (325 micromol g(-1)) for C(6)H(5)Hg(I). The competitive adsorption capacities (i.e. adsorption capacities based on solutions containing all three mercuric ions) are 7.7 mg g(-l) (38.3 micromol g(-1)), 9.2 mg g(-l) (42.6 micromol g(-1)) and 12.7 mg g(-1) (45.7 micromol g(-1)) for Hg(II), CH(3)Hg(I) and C(6)H(5)Hg(I), respectively, at 10 ppm initial concentration. The adsorption capacities on molar basis were in order of C(6)H(5)Hg(I)>CH(3)Hg(I)>Hg(II).

  3. Measurements of the solubility of metal dithiocarbamates in supercritical carbon dioxide

    SciTech Connect

    Bartle, K.D.; Cowey, C.M.; Burford, M.D.; Clifford, A.A.

    1996-10-01

    Heavy metal contamination of the environmental has been traditionally analyzed by acid digestion and organic solvent extraction methods. However, recently supercritical fluids such as carbon dioxide have been investigated as a potentially more rapid and environmentally friendly extraction procedure for metal recovery. Direct extraction of metal ions by pure supercritical carbon dioxide has previously proved ineffective as charge neutralization of the ion using a ligand is required to significantly enhance the solute solvent interactions. Commercial chelating agents such as dithiocarbamates have been extensively used in both conventional and supercritical extractions for the recovery of a wide range of heavy metal. Initial studies using diethldithiocarbamate metal complexes at low supercritical temperatures (50 {degrees}C) and pressure (100 atm.) Showed poor solubility (1x10{sup {minus}6}mol dm{sup 3}) in supercritical carbon dioxide. In this study, the solubility of Pb, Cd, Fe, Zn, and Cu dithiocarbamates were measures at both high and low supercritical fluid temperatures and pressures and a significant increase in the solubility of the metal complexes (e.g. two orders of magnitude) was achieved using 100 {degrees}C, 350 atm supercritical carbon dioxide. Increasing the alkyl chain length of the dithiocarbamate ligand was also investigated and it was shown that as the hydrocarbon content of the ligand increased and became more non-polar in nature the solubility of the corresponding metal complex increased. The results from the solubility study will be subsequently used to assists in the optimization of methods used for the extraction of metals in environmental samples.

  4. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    PubMed Central

    Lai, Yi-Ru; Lin, Pei-Yu; Chen, Chao-Ying; Huang, Chien-Jui

    2016-01-01

    Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates. PMID:27721698

  5. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides.

    PubMed

    Lai, Yi-Ru; Lin, Pei-Yu; Chen, Chao-Ying; Huang, Chien-Jui

    2016-10-01

    Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

  6. Synthesis and structural characterization of new dithiocarbamate complexes from Sb(III) and Bi(III)

    SciTech Connect

    Jamaluddin, Nur Amirah; Baba, Ibrahim

    2013-11-27

    Twenty new antimony and bismuth dithiocarbamate complexes which employed ten different type of amines have been successfully synthesized. The synthesized complexes with metal to dithiocarbamate ratio at 1:3. Elemental analysis of the complexes gave the general formula of MCl[S{sub 2}CNR’R”]{sub 2} where M = Sb(III), Bi(III); R’ = methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, benzyl; R” = ethanol, methyl, ethyl, propyl, isopropyl, cyclohexyl, benzyl. The complexes were analysed by IR and NMR spectroscopy. The crystal structure of five-coordinated antimony (III) complex have been determined by X-ray single crystal diffraction. Single crystal X-ray diffraction studies on SbCl[S{sub 2}CN(C{sub 4}H{sub 9})(C{sub 2}H{sub 5})]{sub 2} adopted a triclinic system with a space group P1 with a = 10.0141(8) Å, b = 10.1394(7) Å, c = 11.8665(9) Å, α = 67.960°, β =87.616°, γ = 80.172°.

  7. Transition metal ferrocenyl dithiocarbamates functionalized dye-sensitized solar cells with hydroxy as an anchoring group

    NASA Astrophysics Data System (ADS)

    Yadav, Reena; Waghadkar, Yogesh; Kociok-Köhn, Gabriele; Kumar, Abhinav; Rane, Sunit B.; Chauhan, Ratna

    2016-12-01

    Three new transition-metal dithiocarbamates involving ferrocene (Fc), namely [Co(FcCH2EtOHdtc)3] (Co), [M(FcCH2EtOHdtc)2] M = Ni (Ni), Cu (Cu) (EtOHdtc = N-ethanol dithiocarbamate), have been synthesized and characterized by microanalyses, FTIR, 1H and 13C NMR spectroscopies and single crystal X-ray diffraction technique. The peak broadening in the 1H spectrum of the copper complex indicates the paramagnetic behavior of this compound. The observed single quasi-reversible cyclic voltammograms for the complexes indicate the stabilization of a metal center (except copper) other than Fe in their characteristic oxidation state. These complexes have been used as photo-sensitizer in dye-sensitized solar cells which indicates that Co displays the best photosensitization property with an overall conversion efficiency of 3.25 ± 0.04%. The low cell efficiency of Ni and Cu complexes may be due to slow regeneration of the dye by iodine/iodide redox couple followed by charge injection into TiO2.

  8. An experimental study on effects of pyrrolidine dithiocarbamate on ischemia-reperfusion injury in testis

    PubMed Central

    Kemahli, Eray; Yildiz, Mevlüt; Firat, Tülin; Özyalvaçli, Mehmet Emin; Üyetürk, Uğur; Yilmaz, Burak; Gücük, Adnan

    2016-01-01

    Introduction: The aim of this experimental study was to investigate the histopathological and biochemical effects of pyrrolidine dithiocarbamate, an antioxidant and inhibitor of NF-kβ, on ischemiareperfusion injury in rats. Methods: A total of 21 male Wistar-Albino rats were randomly distributed into three groups as sham group (Group 1), ischemia-reperfusion (I/R) group (Group 2) and I/R with pyrrolidine dithiocarbamate (PDTC) group (Group 3). Left testicles of rats in Groups 2 and 3 underwent testicular torsion of 720° for four hours and 100 mg/kg of PDTC was administered intraperitoneally prior to detorsion in Group 3. An hour after detorsion process, left orchiectomies were performed and 5 ml of intracardiac blood samples were drawn from rats in all three groups. Histopathological examination of testis tissues performed and measurement of superoxide dismutase (SOD) and malondialdehyde (MDA) levels in blood samples were taken. Results: Elevated levels of MDA and decreased SOD activity, together with decreased Johnson tubular biopsy scores consistent with I/R injury were observed in Group 2 (p<0.05). Group 1 and Group 3 were similar in terms of MDA levels, SOD activity, and Johnson scores (p>0.05). Conclusions: Our results indicated that PDTC may have beneficial effects for alleviation of I/R injury in testicular tissue in rats. Understanding the underlying mechanisms and exploration of its diagnostic and therapeutic potential requires further randomized, controlled trials on a larger scale. PMID:27330576

  9. Toxicity of the dithiocarbamate fungicide mancozeb to the nontarget soil nematode, Caenorhabditis elegans.

    PubMed

    Easton, A; Guven, K; de Pomerai, D I

    2001-01-01

    We have previously shown that the dithiocarbamate fungicide, Mancozeb, strongly induces lacZ reporter expression from an endogenous heat-shock promoter (hsp16) in the PC72 transgenic strain of the nematode Caenorhabditis elegans. Such evidence of organismal stress, in a nontarget species at subapplication concentrations, was much less apparent for the related fungicide, Maneb, which only weakly induced reporter expression. We now show that reporter induction by Mancozeb is marginal (<60%) after a few hours' exposure, but increases substantially (to almost 10-fold) after overnight exposure. In conjunction with our previous results using intermediate exposure periods, this suggests that the factor limiting reporter responses is likely to be a slow rate of uptake and/or metabolism of the fungicide. We confirm that a potentially toxic metabolite of dithiocarbamate fungicides, namely ethylenethiourea (ETU), has minimal toxicity toward C. elegans, even after prolonged exposure at high concentrations. We demonstrate that exposure to Mancozeb (but not ETU) significantly inhibits larval growth in C. elegans, although this parameter is not markedly more sensitive than reporter induction as a toxicological endpoint. Finally, we have used two-dimensional electrophoresis to show that high concentrations of both Maneb and Mancozeb drastically simplify the protein spot profile compared with controls. However, only in the latter case is there evidence of novel proteins being induced. Both fungicides appear toxic to C. elegans, but only Mancozeb induces a strong heat-shock response.

  10. The ethylene bis-dithiocarbamate fungicide Mancozeb activates voltage-gated KCNQ2 potassium channel.

    PubMed

    Li, Ping; Zhu, Jin; Kong, Qingya; Jiang, Baifeng; Wan, Xia; Yue, Jinfeng; Li, Min; Jiang, Hualiang; Li, Jian; Gao, Zhaobing

    2013-06-07

    Mancozeb (manganese/zinc ethylene bis-dithiocarbamate) is an organometallic fungicide that has been associated with human neurotoxicity and neurodegeneration. In a high-throughput screen for modulators of KCNQ2 channel, a fundamental player modulating neuronal excitability, Mancozeb, was found to significantly potentiate KCNQ2 activity. Mancozeb was validated electrophysiologically as a KCNQ2 activator with an EC50 value of 0.92±0.23μM. Further examination showed that manganese but not zinc ethylene bis-dithiocarbamate is the active component for the positive modulation effects. In addition, the compounds are effective when the metal ions are substituted by iron but lack potentiation activity when the metal ions are substituted by sodium, signifying the importance of the metal ion. However, the iron (Fe(3+)) alone, organic ligands alone or the mixture of iron with the organic ligand did not show any potentiation effect, suggesting as the active ingredient is a specific complex rather than two separate additive or synergistic components. Our study suggests that potentiation on KCNQ2 potassium channels might be the possible mechanism of Mancozeb toxicity in the nervous system.

  11. Sediment washing by EDTA and its reclamation by sodium polyamidoamine-multi dithiocarbamate.

    PubMed

    Deng, Tianlin; Zhang, Bingru; Li, Fengting; Jin, Luyao

    2017-02-01

    Sodium polyamidoamine-multi dithiocarbamate (PAMAM-DTC) is a kind of heavy metals capturing agent, containing functional groups of dithiocarbamate that could strongly chelate heavy metals. In this paper, it was applied to precipitate heavy metal ions from meal-EDTA and reclaim EDTA during sediment washing process. The extracting performance of fresh EDTA was studied as a function of EDTA concentration, liquid/sediment (L/S), pH, and extraction time. Then the EDTA effluents were treated with PAMAM-DTC, Na2S and sodium diethyldithiocarbamate (DDTC) to compare their effectiveness on capturing metals from metal-EDTA complexes. Four divalent heavy metals were investigated (Pb, Cd, Cu, Zn). PAMAM-DTC shows much better performance. Pb, Cd and Cu could almost be precipitated completely by PAMAM-DTC under the dosage of 350 mg L(-1), while Zn could be only partly precipitated which may due to its failure in competition with the other three metal ions on chelation with PAMAM-DTC. The reclaimed EDTA was reused in three cycles of sediment washing, and the amount of heavy metals extracted just slightly decreased in each cycle.

  12. Quantum chemical study of a derivative of 3-substituted dithiocarbamic flavanone

    NASA Astrophysics Data System (ADS)

    Gosav, Steluta; Paduraru, Nicoleta; Maftei, Dan; Birsa, Mihail Lucian; Praisler, Mirela

    2017-02-01

    The aim of this work is to characterize a quite novel 3-dithiocarbamic flavonoid by vibrational spectroscopy in conjunction with Density Functional Theory (DFT) calculations. Quantum mechanics calculations of energies, geometries and vibrational wavenumbers in the ground state were carried out by using hybrid functional B3LYP with 6-311G(d,p) as basis set. The results indicate a remarkable agreement between the calculated molecular geometries, as well as vibrational frequencies, and the corresponding experimental data. In addition, a complete assignment of all the absorption bands present in the vibrational spectrum has been performed. In order to assess its chemical potential, quantum molecular descriptors characterizing the interactions between the 3-dithiocarbamic flavonoid and its biological receptors have been computed. The frontier molecular orbitals and the HOMO-LUMO energy gap have been used in order to explain the way in which the new molecule can interact with other species and to characterize its molecular chemical stability/reactivity. The molecular electrostatic potential (MEP) map, computed in order to identify the sites of the studied flavonoid that are most likely to interact with electrophilic and nucleophilic species, is discussed.

  13. Masked thiol sugars: chemical behavior and synthetic applications of S-glycopyranosyl-N-monoalkyl dithiocarbamates.

    PubMed

    Megia-Fernandez, Alicia; de la Torre-Gonzalez, Diego; Parada-Aliste, Jose; Lopez-Jaramillo, Francisco Javier; Hernandez-Mateo, Fernando; Santoyo-Gonzalez, Francisco

    2014-02-01

    The chemical behavior of S-glycopyranosyl-N-monoalkyl dithiocarbamates (DTCs) as masked 1-glycosyl thiols, easily prepared by the nucleophilic displacement of 1-halo sugars with dithiocarbamate salts of primary amines, has been studied and synthetically exploited. This behavior relies on the abstraction of the proton of the carbamate functionality that allows controlled access to thiolate sugar intermediates. The basic character of the DTC salts used as reagents leads to thiolates that evolve in situ to symmetrical diglycosyldisulfides (DGDSs) when long reaction times are allowed. Alternatively, controlled unmasking of the thiolate function can be efficiently attained by treatment with an external base of isolated anomeric glycosyl DTCs, the formation of which is prevalent when using short reaction times. In this manner, a second methodology for the preparation of symmetrical DGDSs and a chemical protocol for the S-glycosylation of any electrophilic substrate are established. The applications of this last strategy for the preparation of thioglycosyl vinyl sulfones, thiodisaccharides, and S-linked homo- and heterodivalent neoglycoconjugates are described as a proof-of-concept of the great potential of the sugar DTCs in any chemical scenario in which the covalent attachment of a thiol sugar is required. The evaluation of the biological functionality of some divalent sulfurated sugar systems is also described.

  14. In vitro anti-proliferative and anti-angiogenic activities of thalidomide dithiocarbamate analogs.

    PubMed

    El-Aarag, Bishoy Y A; Kasai, Tomonari; Zahran, Magdy A H; Zakhary, Nadia I; Shigehiro, Tsukasa; Sekhar, Sreeja C; Agwa, Hussein S; Mizutani, Akifumi; Murakami, Hiroshi; Kakuta, Hiroki; Seno, Masaharu

    2014-08-01

    Inhibition of angiogenesis is currently perceived as a promising strategy in the treatment of cancer. The anti-angiogenicity of thalidomide has inspired a second wave of research on this teratogenic drug. The present study aimed to investigate the anti-proliferative and anti-angiogenic activities of two thalidomide dithiocarbamate analogs by studying their anti-proliferative effects on human umbilical vein endothelial cells (HUVECs) and MDA-MB-231 human breast cancer cell lines. Their action on the expression levels of IL-6, IL-8, TNF-α, VEGF165, and MMP-2 was also assessed. Furthermore, their effect on angiogenesis was evaluated through wound healing, migration, tube formation, and nitric oxide (NO) assays. Results illustrated that the proliferation of HUVECs and MDA-MB-231 cells was not significantly affected by thalidomide at 6.25-100μM. Thalidomide failed to block angiogenesis at similar concentrations. By contrast, thalidomide dithiocarbamate analogs exhibited significant anti-proliferative action on HUVECs and MDA-MB-231 cells without causing cytotoxicity and also showed powerful anti-angiogenicity in wound healing, migration, tube formation, and NO assays. Thalidomide analogs 1 and 2 demonstrated more potent activity to suppress expression levels of IL-6, IL-8, TNF-α, VEGF165, and MMP-2 than thalidomide. Analog 1 consistently, showed the highest potency and efficacy in all the assays. Taken together, our results support further development and evaluation of novel thalidomide analogs as anti-tumor and anti-angiogenic agents.

  15. Synthesis, Structure, Characterization, and Decomposition of Nickel Dithiocarbamates: Effect of Precursor Structure and Processing Conditions on Solid-State Products

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Kulis, Michael J.; McNatt, Jeremiah S.; Duffy, Norman V.; Hoops, Michael D.; Gorse, Elizabeth; Fanwick, Philip E.; Masnovi, John; Cowen, Jonathan E.; Dominey, Raymond N.

    2016-01-01

    Single-crystal X-ray structures of four nickel dithiocarbamate complexes, the homoleptic mixed-organic bis-dithiocarbamates Ni[S2CN(isopropyl)(benzyl)]2, Ni[S2CN(ethyl)(n-butyl)]2, and Ni[S2CN(phenyl)(benzyl)]2, as well as the heteroleptic mixed-ligand complex NiCl[P(phenyl)3][(S2CN(phenyl)(benzyl)], were determined. Synthetic, spectroscopic, structural, thermal, and sulfide materials studies are discussed in light of prior literature. The spectroscopic results are routine. A slightly distorted square-planar nickel coordination environment was observed for all four complexes. The organic residues adopt conformations to minimize steric interactions. Steric effects also may determine puckering, if any, about the nickel and nitrogen atoms, both of which are planar or nearly so. A trans-influence affects the Ni-S bond distances. Nitrogen atoms interact with the CS2 carbons with a bond order of about 1.5, and the other substituents on nitrogen display transoid conformations. There are no strong intermolecular interactions, consistent with prior observations of the volatility of nickel dithiocarbamate complexes. Thermogravimetric analysis of the homoleptic species under inert atmosphere is consistent with production of 1:1 nickel sulfide phases. Thermolysis of nickel dithiocarbamates under flowing nitrogen produced hexagonal or -NiS as the major phase; thermolysis under flowing forming gas produced millerite (-NiS) at 300 C, godlevskite (Ni9S8) at 325 and 350 C, and heazlewoodite (Ni3S2) at 400 and 450 C. Failure to exclude oxygen results in production of nickel oxide. Nickel sulfide phases produced seem to be primarily influenced by processing conditions, in agreement with prior literature. Nickel dithiocarbamate complexes demonstrate significant promise to serve as single-source precursors to nickel sulfides, a quite interesting family of materials with numerous potential applications.

  16. Dithiocarbamates have a common toxic effect on zebrafish body axis formation

    SciTech Connect

    Tilton, Fred; La Du, Jane K.; Vue, Meng; Alzarban, Noor; Tanguay, Robert L. . E-mail: Robert.Tanguay@oregonstate.edu

    2006-10-01

    We previously determined that the dithiocarbamate pesticide sodium metam (NaM) and its active ingredient methylisothiocyanate (MITC) were developmentally toxic causing notochord distortions in the zebrafish. In this study, developing zebrafish were exposed to isothiocyanates (ITCs), dithiocarbamates (DTCs) and several degradation products to determine the teratogenic relationship of these chemical classes at the molecular level. All dithiocarbamates tested elicited notochord distortions with notochord NOELs from <4 to 40 ppb, while none of the ITCs caused notochord distortions with the exception of MITC. Carbon disulfide (CS{sub 2}), a common DTC degradate, also caused distortions at concentrations >200 times the DTCs. Whole mount in situ hybridization of developmental markers for collagen (collagen2a1), muscle (myoD), and body axis formation (no tail) was perturbed well after cessation of treatment with pyrolidine-DTC (PDTC), dimethyl-DTC (DMDTC), NaM, MITC, and CS{sub 2}. Therefore, distinct albeit related chemical classes share a common toxic effect on zebrafish notochord development. To test the responsiveness of the distortion to metal perturbation, five metal chelators and 2 metals were studied. The membrane permeable copper chelator neocuproine (NCu) was found to cause notochord distortions similar to DTC-related molecules. DMDTC and NCu treated animals were protected with copper, and collagen 2a1 and no tail gene expression patterns were identical to controls in these animals. PDTC, NaM, MITC, and CS{sub 2} were not responsive to copper indicating that the chelation of metals is not the primary means by which these molecules elicit their developmental toxicity. Embryos treated with DMDTC, NaM, and NCu were rescued by adding triciaine (MS-222) which abolishes the spontaneous muscle contractions that begin at 18 hpf. In these animals, only collagen 2a1 expression showed a similar pattern to the other notochord distorting molecules. This indicates that the

  17. Mechanism of action of some acrylophenones, quinolines and dithiocarbamate as potent, non-detergent spermicidal agents.

    PubMed

    Maikhuri, J P; Dwivedi, A K; Dhar, J D; Setty, B S; Gupta, G

    2003-05-01

    Some suitably substituted acrylophenones, quinolines and dithiocarbamate were synthesized as new generation, non-detergent spermicides and were studied for their mechanism of action in comparison with various known spermicides belonging to several different classes of chemical compound. Nonoxynol-9, benzalkonium chloride, Sapindus saponins, verapamil, emetine and tartaric acid were used as reference molecules to study the effect of new spermicides on human sperm motility parameters (using computer-assisted semen analyzer), plasma membrane integrity, lipid peroxidation and defense system against reactive oxygen species (ROS). Results have indicated that sperm plasma membrane remains the primary site of action of most of the spermicides, though the effect may be predominantly on the physiological integrity rather than the structural integrity in case of the new compounds. Lipid peroxidation may play an important role in disrupting sperm membrane physiology that may or may not be accompanied with a detrimental effect on the defense system of the human spermatozoa against the ROS.

  18. Dithiocarbamate Self-Assembled Monolayers as Efficient Surface Modifiers for Low Work Function Noble Metals.

    PubMed

    Meyer, Dominik; Schäfer, Tobias; Schulz, Philip; Jung, Sebastian; Rittich, Julia; Mokros, Daniel; Segger, Ingolf; Maercks, Franziska; Effertz, Christian; Mazzarello, Riccardo; Wuttig, Matthias

    2016-09-06

    Tuning the work function of the electrode is one of the crucial steps to improve charge extraction in organic electronic devices. Here, we show that N,N-dialkyl dithiocarbamates (DTC) can be effectively employed to produce low work function noble metal electrodes. Work functions between 3.1 and 3.5 eV are observed for all metals investigated (Cu, Ag, and Au). Ultraviolet photoemission spectroscopy (UPS) reveals a maximum decrease in work function by 2.1 eV as compared to the bare metal surface. Electronic structure calculations elucidate how the complex interplay between intrinsic dipoles and dipoles induced by bond formation generates such large work function shifts. Subsequently, we quantify the improvement in contact resistance of organic thin film transistor devices with DTC coated source and drain electrodes. These findings demonstrate that DTC molecules can be employed as universal surface modifiers to produce stable electrodes for electron injection in high performance hybrid organic optoelectronics.

  19. Dithiocarbamate Self-Assembled Monolayers as Efficient Surface Modifiers for Low Work Function Noble Metals

    SciTech Connect

    Meyer, Dominik; Schäfer, Tobias; Schulz, Philip; Jung, Sebastian; Rittich, Julia; Mokros, Daniel; Segger, Ingolf; Maercks, Franziska; Effertz, Christian; Mazzarello, Riccardo; Wuttig, Matthias

    2016-09-06

    Tuning the work function of the electrode is one of the crucial steps to improve charge extraction in organic electronic devices. Here, we show that N,N-dialkyl dithiocarbamates (DTC) can be effectively employed to produce low work function noble metal electrodes. Work functions between 3.1 and 3.5 eV are observed for all metals investigated (Cu, Ag, and Au). Ultraviolet photoemission spectroscopy (UPS) reveals a maximum decrease in work function by 2.1 eV as compared to the bare metal surface. Electronic structure calculations elucidate how the complex interplay between intrinsic dipoles and dipoles induced by bond formation generates such large work function shifts. Subsequently, we quantify the improvement in contact resistance of organic thin film transistor devices with DTC coated source and drain electrodes. These findings demonstrate that DTC molecules can be employed as universal surface modifiers to produce stable electrodes for electron injection in high performance hybrid organic optoelectronics.

  20. Copper uptake is required for pyrrolidine dithiocarbamate-mediated oxidation and protein level increase of p53 in cells.

    PubMed Central

    Furuta, Saori; Ortiz, Fausto; Zhu Sun, Xiu; Wu, Hsiao-Huei; Mason, Andrew; Momand, Jamil

    2002-01-01

    The p53 tumour-suppressor protein is a transcription factor that activates the expression of genes involved in cell cycle arrest, apoptosis and DNA repair. The p53 protein is vulnerable to oxidation at cysteine thiol groups. The metal-chelating dithiocarbamates, pyrrolidine dithiocarbamate (PDTC), diethyldithiocarbamate, ethylene(bis)dithiocarbamate and H(2)O(2) were tested for their oxidative effects on p53 in cultured human breast cancer cells. Only PDTC oxidized p53, although all oxidants tested increased the p53 level. Inductively coupled plasma MS analysis indicated that the addition of 60 microM PDTC increased the cellular copper concentration by 4-fold, which was the highest level of copper accumulated amongst all the oxidants tested. Bathocuproinedisulphonic acid, a membrane-impermeable Cu(I) chelator inhibited the PDTC-mediated copper accumulation. Bathocuproinedisulphonic acid as well as the hydroxyl radical scavenger d-mannitol inhibited the PDTC-dependent increase in p53 protein and oxidation. Our results show that a low level of copper accumulation in the range of 25-40 microg/g of cellular protein increases the steady-state levels of p53. At copper accumulation levels higher than 60 microg/g of cellular protein, p53 is oxidized. These results suggest that p53 is vulnerable to free radical-mediated oxidation at cysteine residues. PMID:11964141

  1. Dithiocarbamates are teratogenic to developing zebrafish through inhibition of lysyl oxidase activity

    SciTech Connect

    Boxtel, Antonius L. van; Kamstra, Jorke H.; Fluitsma, Donna M.; Legler, Juliette

    2010-04-15

    Dithiocarbamates (DTCs) are a class of compounds that are extensively used in agriculture as pesticides. As such, humans and wildlife are undoubtedly exposed to these chemicals. Although DTCs are thought to be relatively safe due to their short half lives, it is well established that they are teratogenic to vertebrates, especially to fish. In zebrafish, these teratogenic effects are characterized by distorted notochord development and shortened anterior to posterior axis. DTCs are known copper (Cu) chelators but this does not fully explain the observed teratogenic effects. We show here that DTCs cause malformations in zebrafish that highly resemble teratogenic effects observed by direct inhibition of a group of cuproenzymes termed lysyl oxidases (LOX). Additionally, we demonstrate that partial knockdown of three LOX genes, lox, loxl1 and loxl5b, sensitizes the developing embryo to DTC exposure. Finally, we show that DTCs directly inhibit zebrafish LOX activity in an ex vivo amine oxidase assay. Taken together, these results provide the first evidence that DTC induced teratogenic effects are, at least in part, caused by direct inhibition of LOX activity.

  2. Pyrrolidine Dithiocarbamate Prevents Neuroinflammation and Cognitive Dysfunction after Endotoxemia in Rats

    PubMed Central

    Kan, Min Hui; Yang, Ting; Fu, Hui Qun; Fan, Long; Wu, Yan; Terrando, Niccolò; Wang, Tian-Long

    2016-01-01

    Systemic inflammation, for example as a result of infection, often contributes to long-term complications. Neuroinflammation and cognitive decline are key hallmarks of several neurological conditions, including advance age. The contribution of systemic inflammation to the central nervous system (CNS) remains not fully understood. Using a model of peripheral endotoxemia with lipopolysaccharide (LPS) we investigated the role of nuclear factor-κB (NF-κB) activity in mediating long-term neuroinflammation and cognitive dysfunction in aged rats. Herein we describe the anti-inflammatory effects of pyrrolidine dithiocarbamate (PDTC), a selective NF-κB inhibitor, in modulating systemic cytokines including tumor necrosis factor (TNF)-α and interleukin-1β (IL-1β) and CNS markers after LPS exposure in aged rats. In the hippocampus, PDTC not only reduced neuroinflammation by modulating canonical NF-κB activity but also affected IL-1β expression in astrocytes. Parallel effects were observed on behavior and postsynaptic density-95 (PSD95), a marker of synaptic function. Taken together these changes improved acute and long-term cognitive function in aged rats after LPS exposure. PMID:27493629

  3. Interactions of nitric oxide with copper(II) dithiocarbamates in aqueous solution.

    PubMed

    Díaz, Alicia; Ortiz, Mayreli; Sánchez, Ileana; Cao, Roberto; Mederos, Alfredo; Sanchiz, Joaquin; Brito, Felipe

    2003-07-01

    This is the first report on the formation of air-stable copper nitrosyl complexes. The interaction of nitric oxide, NO, with Cu(DTC)(2).3H(2)O (DTC: dithiocarbamate) and was studied in aqueous solution at pH 7.4 and 293 K. The stability constants were determined from UV-Vis data, using LETAGROP program. The high values obtained, log beta(1)=9.743(5) and log beta(2)=15.44(2) for Cu(ProDTC)(2)-NO, (ProDTC=L-prolinedithiocarbamate) and log beta(1)=8.723(5) and log beta(2)=11.45(2) for Cu(MorDTC)(2)-NO system, (MorDTC=morpholyldithiocarbamate), indicate the formation of two stable nitrosyl complexes, Cu(DTC)(2)NO and Cu(DTC)(2)(NO)(2). Coordinated NO is neither affected by the presence of air nor when the solution is purged with Ar. Cu(MorDTC)(2)NO.3H(2)O was isolated in the solid state and its nuNO (IR) band at 1682 cm(-1), but affected by temperature variations over 333 K.

  4. Molecular mechanisms of apoptosis and cell selectivity of zinc dithiocarbamates functionalized with hydroxyethyl substituents.

    PubMed

    Tan, Yee Seng; Ooi, Kah Kooi; Ang, Kok Pian; Akim, Abdah Md; Cheah, Yoke-Kqueen; Halim, Siti Nadiah Abdul; Seng, Hoi-Ling; Tiekink, Edward R T

    2015-09-01

    In the solid state each of three binuclear zinc dithiocarbamates bearing hydroxyethyl groups, {Zn[S2CN(R)CH2CH2OH]2}2 for R = iPr (1), CH2CH2OH (2), and Me (3), and an all alkyl species, [Zn(S2CNEt2)2]2 (4), features a centrosymmetric {ZnSCS}2 core with a step topology; both 1 and 3 were isolated as monohydrates. All compounds were broadly cytotoxic, specifically against human cancer cell lines compared with normal cells, with greater potency than cisplatin. Notably, some selectivity were indicated with 2 being the most potent against human ovarian carcinoma cells (cisA2780), and 4 being more cytotoxic toward multidrug resistant human breast carcinoma cells (MCF-7R), human colon adenocarcinoma cells (HT-29), and human lung adenocarcinoma epithelial cells (A549). Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis in HT-29 cells is demonstrated via both extrinsic and intrinsic pathways. Compounds 2-4 activate the p53 gene while 1 activates both p53 and p73. Cell cycle arrest at the S and G2/M phases correlates with inhibition of HT-29 cell growth. Cell invasion is also inhibited by 1-4 which is correlated with down-regulation of NF-κB.

  5. Triazole-dithiocarbamate based, selective LSD1 inactivators inhibit gastric cancer cell growth, invasion and migration

    PubMed Central

    Ma, Jin-Lian; Xu, Rui-Min; Zi, Xiaolin; Lv, Wen-Lei; Wang, Meng-Meng; Ye, Xian-Wei; Zhu, Shun; Mobley, David; Zhu, Yan-Yan; Wang, Jun-Wei; Li, Jin-Feng; Wang, Zhi-Ru; Zhao, Wen; Liu, Hong-Min

    2013-01-01

    Lysine specific demethylase 1 (LSD1), the first identified histone demethylase, plays an important role in epigenetic regulation of gene activation and repression. The up-regulated LSD1's expression has been reported in several malignant tumors. In the current study, we designed and synthesized five series of 1, 2, 3-triazole-dithiocarbamate hybrids and screened their inhibitory activity toward LSD1. We found that some of these compounds, especially compound 26, exhibited the most specific and robust inhibition of LSD1. Interestingly, compound 26 also showed potent and selective cytotoxicity against LSD1 overexpressing gastric cancer cell lines MGC-803 and HGC-27, as well as marked inhibition of cell migration and invasion, compared to 2-PCPA. Furthermore, compound 26 effectively reduced the tumor growth bared by human gastric cancer cells in vivo with no signs of adverse side effects. These findings suggested that compound 26 deserves further investigation as a lead compound in the treatment of LSD1 overexpressing gastric cancer. PMID:24131029

  6. Dithiocarbamate-modified starch derivatives with high heavy metal adsorption performance.

    PubMed

    Xiang, Bo; Fan, Wen; Yi, Xiaowei; Wang, Zuohua; Gao, Feng; Li, Yijiu; Gu, Hongbo

    2016-01-20

    In this work, three types of dithiocarbamate (DTC)-modified starch derivatives including DTC starch (DTCS), DTC enzymolysis starch (DTCES) and DTC mesoporous starch (DTCMS) were developed, which showed the significant heavy metal adsorption performance. The adsorption ability of these three DTC modified starch derivatives followed the sequences: DTCMS>DTCES>DTCS. In single metal aqueous solutions, the uptake amount of heavy metal ions onto the modified starches obeyed the orders: Cu(II)>Ni(II)>Cr(VI)>Zn(II)>Pb(II). The adsorption mechanism was proved by the chelating between DTC groups and heavy metal ions through the pH effect measurements. A monolayer adsorption of Langmuir isotherm model for the adsorption of Cu(II) onto DTCMS was well fitted rather than the multilayer adsorption of Freundlich isotherm model. The adsorption kinetics of Cu(II) onto starch derivatives was found to be fit well with the pseudo-second-order model. Additionally, in the presence of EDTA, the adsorption ability and uptake amount of heavy metal ions onto these three DTC modified starch derivatives is identical with the results obtained in the absence of EDTA.

  7. Oxidation of dithiocarbamates to yield N-nitrosamines by water disinfection oxidants.

    PubMed

    Padhye, Lokesh P; Kim, Jae-Hong; Huang, Ching-Hua

    2013-02-01

    Two most commonly used dithiocarbamate (DTC) pesticides, dimethyldithiocarbamate (DMDTC) and diethyldithiocarbamate (DEDTC), were examined in this study to evaluate their potential to form nitrosamines when in contact with various water disinfection oxidants. Results show that DTCs can serve as nitrosamine precursors, by release of secondary amines through hydrolysis or through reactions with oxidants. The reactions of DTCs with monochloramine and ozone were found to be particularly problematic in the risk of generating nitrosamines, though all four tested oxidants, including free chlorine and chlorine dioxide, formed nitrosamines. NDEA yield from DEDTC was lower, by different degrees, than NDMA yield from DMDTC for all four oxidants, which was attributed to the steric hindrance associated with bulkier reaction intermediate that are more difficult to be further oxidized to form nitrosamine. The yield of nitrosamines increased with the oxidant dosage for both monochloramination and ozonation of DTCs. Results for nitrosamine formation from DTCs at varying pH were found to be consistent with the pH trend of nitrosamine formation from ozonation and monochloramination of secondary amines. Kinetic study results and identification and quantification of reaction products suggest that the DTCs were not significant direct precursors of nitrosamines during monochloramination or ozonation, but rather nitrosamines formed were primarily from reaction of oxidants with the amine which may be generated either through hydrolysis or through oxidation of DTCs.

  8. The effects of the endocrine disruptors dithiocarbamates on the mammalian ovary with particular regard to mancozeb.

    PubMed

    Cecconi, Sandra; Paro, Rita; Rossi, Gianna; Macchiarelli, Guido

    2007-01-01

    Many human-made chemicals are called endocrine disruptors (EDs) because they have the potential to disrupt endocrine functions in exposed organisms. Many EDs can disrupt hormonal homeostasis by interfering with hormone receptor recognition, binding and activation, while others act by still unknown mechanisms. Among the EDs specifically affecting the female reproductive system, those with steroidogenic/antisteroidogenic effects have been extensively studied and the mechanisms of toxicity clarified also at molecular level. For many others, information is restricted to few epidemiological data and in vivo/in vitro experiments with animal models. This is the case of the dithiocarbamates, and in particular of the fungicide mancozeb, an ethylenedithiocarbamate widely used to protect fruit and vegetables, ginseng included, because of its low acute toxicity in humans. Although the mechanism(s) by which mancozeb may specifically act on female reproductive organs are largely unknown, data on experimental animals in vivo have demonstrated that the fungicide can induce several disturbances on estrus cycle. When used in vitro at concentrations considered too low to cause human health injuries, the fungicide impairs mouse embryo development and meiotic spindle assembly. The possibility that the female germ cell (the oocyte) could be a specific target of mancozeb suggests a role for this fungicide as probable inductor of infertility also in exposed human populations.

  9. Validation of a GC-MS method for the estimation of dithiocarbamate fungicide residues and safety evaluation of mancozeb in fruits and vegetables.

    PubMed

    Mujawar, Sumaiyya; Utture, Sagar C; Fonseca, Eddie; Matarrita, Jessie; Banerjee, Kaushik

    2014-05-01

    A sensitive and rugged residue analysis method was validated for the estimation of dithiocarbamate fungicides in a variety of fruit and vegetable matrices. The sample preparation method involved reaction of dithiocarbamates with Tin(II) chloride in aqueous HCl. The CS2 produced was absorbed into an isooctane layer and estimated by GC-MS selected ion monitoring. Limit of quantification (LOQ) was ⩽40μgkg(-1) for grape, green chilli, tomato, potato, brinjal, pineapple and chayote and the recoveries were within 75-104% (RSD<15% at LOQ). The method could be satisfactorily applied for analysis of real world samples. Dissipation of mancozeb, the most-used dithiocarbamate fungicide, in field followed first+first order kinetics with pre-harvest intervals of 2 and 4days in brinjal, 7 and 10days in grapes and 0day in chilli at single and double dose of agricultural applications. Cooking practices were effective for removal of mancozeb residues from vegetables.

  10. Extraction of haptens from solid products and their delivery to the skin, exemplified by dithiocarbamates from rubber gloves.

    PubMed

    Bergendorff, O; Persson, C; Hansson, C

    2005-07-01

    Allergic contact dermatitis is often caused by solid products such as rubber gloves. Patch testing with the product as is often gives negative results. Extraction of the haptens into an organic solvent is commonly performed to achieve a more correct investigation. The technique used for extraction of haptens from solid materials is only sporadically described. In this study, we investigated and optimized the yields of dithiocarbamates obtained by extraction from rubber gloves. The influence of solvent, extraction time and the procedures for extraction are evaluated. The delivery of zinc dibutyldithiocarbamate from the patch test preparation to the skin is determined.

  11. Study of sulfur adlayers on Au(1 1 1) from basic hydrolysis of piperazine bis(dithiocarbamate) sodium salt

    NASA Astrophysics Data System (ADS)

    Martínez, Javier A.; Valenzuela, José; Hernandez-Tamargo, Carlos E.; Cao-Milán, Roberto; Herrera, José A.; Díaz, Jesús A.; Farías, Mario H.; Mikosch, Hans; Hernández, Mayra P.

    2015-08-01

    Sulfur adlayers on Au(1 1 1) were obtained after the interaction of a gold substrate with an alkaline solution of piperazine bis(dithiocarbamate) sodium salt. Characterization of the sulfur modified gold surface was performed by means of X-Ray Photoelectron Spectroscopy (XPS), Scanning Tunneling Microscopy (STM) and Density Functional Theory (DFT) calculations. XPS signals indicated the presence of S-Au bonds, monomeric and polymeric sulfur, and absence of nitrogen and sodium. Images from STM showed the formation of quasi-rectangular octomers in coexistence with another phase. A DFT model using the arrangement of sulfur dimers on the Au(1 1 1) surface effectively reproduced the experimental STM images.

  12. Pyrrolidine dithiocarbamate protects the piriform cortex in the pilocarpine status epilepticus model.

    PubMed

    Soerensen, Jonna; Pekcec, Anton; Fuest, Christina; Nickel, Astrid; Potschka, Heidrun

    2009-12-01

    Pyrrolidine dithiocarbamate (PDTC) has a dual mechanism of action as an antioxidant and an inhibitor of the transcription factor kappa-beta. Both, production of reactive oxygen species as well as activation of NF-kappaB have been implicated in severe neuronal damage in different sub-regions of the hippocampus as well as in the surrounding cortices. The effect of PDTC on status epilepticus-associated cell loss in the hippocampus and piriform cortex was evaluated in the rat fractionated pilocarpine model. Treatment with 150 mg/kg PDTC before and following status epilepticus significantly increased the mortality rate to 100%. Administration of 50 mg/kg PDTC (low-dose) did not exert major effects on the development of a status epilepticus or the mortality rate. In vehicle-treated rats, status epilepticus caused pronounced neuronal damage in the piriform cortex comprising both pyramidal cells and interneurons. Low-dose PDTC treatment almost completely protected from lesions in the piriform cortex. A significant decrease in neuronal density of the hippocampal hilar formation was identified in vehicle- and PDTC-treated rats following status epilepticus. In conclusion, the NF-kappaB inhibitor and antioxidant PDTC protected the piriform cortex, whereas it did not affect hilar neuronal loss. These data might indicate that the generation of reactive oxygen species and activation of NF-kappaB plays a more central role in seizure-associated neuronal damage in the temporal cortex as compared to the hippocampal hilus. However, future investigations are necessary to exactly analyze the biochemical mechanisms by which PDTC exerted its beneficial effects in the piriform cortex.

  13. Phosphinogold(I) Dithiocarbamate Complexes: Effect of the Nature of Phosphine Ligand on Anticancer Properties

    PubMed Central

    2015-01-01

    The reactions of potassium salts of the dithiocarbamates L {where L = pyrazolyldithiocarbamate (L1), 3,5-dimethylpyrazolyldithiocarbamate (L2), or indazolyldithiocarbamate (L3)} with the gold precursors [AuCl(PPh3)], [Au2Cl2(dppe)], [Au2Cl2(dppp)], or [Au2Cl2(dpph)] lead to the new gold(I) complexes [AuL(PPh3)] (1–3), [Au2L2(dppe)] (4–6), [(Au2L2)(dppp)] (7–9), and [Au2(L)2(dpph)] (10–12) {where dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, and dpph = 1,6-bis(diphenylphosphino)hexane}. These gold compounds were characterized by a combination of NMR and infrared spectroscopy, microanalysis, and mass spectrometry; and in selected cases by single-crystal X-ray crystallography. Compounds 4–6, which have dppe ligands, are unstable in solution for prolonged periods, with 4 readily transforming to the Au18 cluster [Au18S8(dppe)6]Cl2 (4a) in dichloromethane. Compounds 1–3 and 7–12 are all active against human cervical epithelioid carcinoma (HeLa) cells, but the most active compounds are 10 and 11, with IC50 values of 0.51 μM and 0.14 μM, respectively. Compounds 10 and 11 are more selective toward HeLa cells than they are toward normal cells, with selectivities of 25.0 and 70.5, respectively. Further tests, utilizing the 60-cell-line Developmental Therapeutics Program at the National Cancer Institute (U.S.A.), showed 10 and 11 to be active against nine other types of cancers. PMID:24476103

  14. Molecular Mechanisms of Allosteric Inhibition of Brain Glycogen Phosphorylase by Neurotoxic Dithiocarbamate Chemicals.

    PubMed

    Mathieu, Cécile; Bui, Linh-Chi; Petit, Emile; Haddad, Iman; Agbulut, Onnik; Vinh, Joelle; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

    2017-02-03

    Dithiocarbamates (DTCs) are important industrial chemicals used extensively as pesticides and in a variety of therapeutic applications. However, they have also been associated with neurotoxic effects and in particular with the development of Parkinson-like neuropathy. Although different pathways and enzymes (such as ubiquitin ligases or the proteasome) have been identified as potential targets of DTCs in the brain, the molecular mechanisms underlying their neurotoxicity remain poorly understood. There is increasing evidence that alteration of glycogen metabolism in the brain contributes to neurodegenerative processes. Interestingly, recent studies with N,N-diethyldithiocarbamate suggest that brain glycogen phosphorylase (bGP) and glycogen metabolism could be altered by DTCs. Here, we provide molecular and mechanistic evidence that bGP is a target of DTCs. To examine this system, we first tested thiram, a DTC pesticide known to display neurotoxic effects, observing that it can react rapidly with bGP and readily inhibits its glycogenolytic activity (kinact = 1.4 × 10(5) m(-1) s(-1)). Using cysteine chemical labeling, mass spectrometry, and site-directed mutagenesis approaches, we show that thiram (and certain of its metabolites) alters the activity of bGP through the formation of an intramolecular disulfide bond (Cys(318)-Cys(326)), known to act as a redox switch that precludes the allosteric activation of bGP by AMP. Given the key role of glycogen metabolism in brain functions and neurodegeneration, impairment of the glycogenolytic activity of bGP by DTCs such as thiram may be a new mechanism by which certain DTCs exert their neurotoxic effects.

  15. Microglia activation and cell death in response to diethyl-dithiocarbamate acute administration.

    PubMed

    Zucconi, Gigliola Grassi; Laurenzi, Maria Assunta; Semprevivo, Massimo; Torni, Federica; Lindgren, Jan Ake; Marinucci, Eva

    2002-04-29

    An increasing body of evidence suggests a role for activated microglia in the pathogenesis of neurodegenerative disorders. Hence, it would be useful to have a better understanding of the significance of microglial activation for neuronal damage. Unfortunately, most models of microglial activation use invasive or long-lasting insults, which make it difficult to evaluate the role played by microglia. We have instead developed a model for microglial activation by using brief exposure to the widely available neurotoxin diethyl-dithiocarbamate (DDTC). Despite evidence for the neurotoxic nature of this substance, microglia involvement has not been hitherto investigated. After acute i.p. administration of DDTC at two different doses, microglia were already activated in selected areas of the rat brain (hippocampal dentate gyrus, entorhinal-pyriform cortex and hypothalamus) after 1 hour, reaching a peak at 3-6 hours and subsided within 6-48 hours, depending on the brain region. Microglia activation was associated with interleukin-1 beta immunopositivity between 3 and 6 hours and with up-regulation of major histocompatibility complex class II expression between 24 and 48 hours. No significant changes in astrocyte immunostaining were detected between 6 hours and 6 days. The TUNEL procedure revealed the death of a limited number of cells in the above-mentioned structures that peaked at 6h and then declined rapidly. Cell death was detected in sites with major, minor, or no microglial activation, indicating that these two events can occur concomitantly or independently. The study shows that the administration of DDTC provides a useful model for studying the implications of region-specific reactivity of microglia and its differential interaction with neuronal damage.

  16. Design, structural and spectroscopic elucidation, and the in vitro biological activities of new diorganotin dithiocarbamates.

    PubMed

    Ferreira, Isabella P; de Lima, Geraldo M; Paniago, Eucler B; Rocha, Willian R; Takahashi, Jacqueline A; Pinheiro, Carlos B; Ardisson, José D

    2012-12-01

    The reaction of 2,2-dimethoxy-N-methylethyllamine or 2-methyl-1,3-dioxolane with CS(2) in alkaline media produced two novel dithiocarbamate salts. Subsequent reactions with organotin halides yielded six new complexes: [SnMe(2){S(2)CNR(R(1))(2)}(2)] (1), [Sn(n-Bu)(2){S(2)CNR(R(1))(2)}(2)] (2), [SnPh(2){S(2)CNR(R(1))(2)}(2)] (3), [SnMe(2){S(2)CNR(R(2))(2)}(2)] (4), [Sn(n-Bu)(2){S(2)CNR(R(2))(2)}(2)] (5), [SnPh(2){S(2)CNR(R(2))(2)}(2)] (6), where R = methyl, R(1) = CH(2)CH(OMe)(2), and R(2) = 2-methyl-1,3-dioxolane. All compounds were identified in terms of infrared, (1)H and (13)C NMR, and the complexes were also characterized using (119)Sn NMR, (119)Sn Mössbauer and X-ray crystallography. The biological activity of all derivatives has been screened in terms of IC(90) and IC(50) against Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Penicillium citrinum, Curvularia senegalensis, Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Streptococcus sanguinis, Escherichia coli, Citrobacter freundii, Salmonella typhimurium, and Pseudomonas aeruginosa and the results correlated well with a performed study of structure-activity relationship (SAR). Complexes (3), (5) and (6) displayed the best IC(90) and IC(50) in the presence of the fungi, greater than that of miconazole, used as control drug.

  17. Dietary exposure assessment of Danish consumers to dithiocarbamate residues in food: a comparison of the deterministic and probabilistic approach.

    PubMed

    Jensen, B H; Andersen, J H; Petersen, A; Christensen, T

    2008-06-01

    Probabilistic and deterministic estimates of the acute and chronic exposure of the Danish populations to dithiocarbamate residues were performed. The Monte Carlo Risk Assessment programme (MCRA 4.0) was used for the probabilistic risk assessment. Food consumption data were obtained from the nationwide dietary survey conducted in 2000--02. Residue data for 5721 samples from the monitoring programme conducted in the period 1998--2003 were used for dithiocarbamates, which had been determined as carbon disulphide. Contributions from 26 commodities were included in the calculations. Using the probabilistic approach, the daily acute intakes at the 99.9% percentile for adults and children were 11.2 and 28.2 microg kg(-1) body weight day(-1), representing 5.6% and 14.1% of the ARfD for maneb, respectively. When comparing the point estimate approach with the probabilistic approach, the outcome of the point estimate calculations was generally higher or comparable with the outcome of the probabilistic approach at the 99.9 percentile (consumers only). The chronic exposures for adults and children were 0.35 and 0.76 microg kg(-1) body weight day(-1) at the 99.9 percentile, representing 0.7% and 1.5%, respectively, of the acceptable daily intake for mancozeb and maneb at 50 microg kg(-1) body weight.

  18. Synthesis of a novel silica-supported dithiocarbamate adsorbent and its properties for the removal of heavy metal ions.

    PubMed

    Bai, Lan; Hu, Huiping; Fu, Weng; Wan, Jia; Cheng, Xiliang; Zhuge, Lei; Xiong, Lei; Chen, Qiyuan

    2011-11-15

    Silica-supported dithiocarbamate adsorbent (Si-DTC) was synthesized by anchoring the chelating agent of macromolecular dithiocarbamate (MDTC) to the chloro-functionalized silica matrix (SiCl), as a new adsorbent for adsorption of Pb(II), Cd(II), Cu(II) and Hg(II) from aqueous solution. The surface characterization was performed by FT-IR, XPS, SEM and elemental analysis indicating that the modification of the silica surface was successfully performed. The effects of media pH, adsorption time, initial metal ion concentration and adsorption temperature on adsorption capacity of the adsorbent had been investigated. Experimental data were exploited for kinetic and thermodynamic evaluations related to the adsorption processes. The characteristics of the adsorption process were evaluated by using the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption isotherms and adsorption capacities were found to be 0.34 mmol g(-1), 0.36 mmol g(-1), 0.32 mmol g(-1) and 0.40 mmol g(-1) for Pb(II), Cd(II), Cu(II) and Hg(II), respectively. The adsorption mechanism of Hg(II) onto Si-DTC is quite different from that of Pb(II), Cd(II) or Cu(II) onto Si-DTC, which is demonstrated by the XPS and FT-IR results.

  19. Biomimetic synthesis of highly biocompatible gold nanoparticles with amino acid-dithiocarbamate as a precursor for SERS imaging

    NASA Astrophysics Data System (ADS)

    Li, Li; Liu, Jianbo; Yang, Xiaohai; Huang, Jin; He, Dinggeng; Guo, Xi; Wan, Lan; He, Xiaoxiao; Wang, Kemin

    2016-03-01

    Amino acid-dithiocarbamate (amino acid-DTC) was developed as both the reductant and ligand stabilizer for biomimetic synthesis of gold nanoparticles (AuNPs), which served as an excellent surface-enhanced Raman scattering (SERS) contrast nanoprobe for cell imaging. Glycine (Gly), glutamic acid (Glu), and histidine (His) with different isoelectric points were chosen as representative amino acid candidates to synthesize corresponding amino acid-DTC compounds through mixing with carbon disulfide (CS2), respectively. The pyrogenic decomposition of amino acid-DTC initiated the reduction synthesis of AuNPs, and the strong coordinating dithiocarbamate group of amino acid-DTC served as a stabilizer that grafted onto the surface of the AuNPs, which rendered the as-prepared nanoparticles a negative surface charge and high colloidal stability. MTT cell viability assay demonstrated that the biomimetic AuNPs possessed neglectful toxicity to the human hepatoma cell, which guaranteed them good biocompatibility for biomedical application. Meanwhile, the biomimetic AuNPs showed a strong SERS effect with an enhancement factor of 9.8 × 105 for the sensing of Rhodamine 6G, and two distinct Raman peaks located at 1363 and 1509 cm-1 could be clearly observed in the cell-imaging experiments. Therefore, biomimetic AuNPs can be explored as an excellent SERS contrast nanoprobe for biomedical imaging, and the amino acid-DTC mediated synthesis of the AuNPs has a great potential in bio-engineering and biomedical imaging applications.

  20. Synthesis, Characterization, and Processing of Copper, Indium, and Gallium Dithiocarbamates for Energy Conversion Applications

    NASA Technical Reports Server (NTRS)

    Duraj, S. A.; Duffy, N. V.; Hepp, A. F.; Cowen, J. E.; Hoops, M. D.; Brothrs, S. M.; Baird, M. J.; Fanwick, P. E.; Harris, J. D.; Jin, M. H.-C.

    2009-01-01

    Ten dithiocarbamate complexes of indium(III) and gallium(III) have been prepared and characterized by elemental analysis, infrared spectra and melting point. Each complex was decomposed thermally and its decomposition products separated and identified with the combination of gas chromatography/mass spectrometry. Their potential utility as photovoltaic materials precursors was assessed. Bis(dibenzyldithiocarbamato)- and bis(diethyldithiocarbamato)copper(II), Cu(S2CN(CH2C6H5)2)2 and Cu(S2CN(C2H5)2)2 respectively, have also been examined for their suitability as precursors for copper sulfides for the fabrication of photovoltaic materials. Each complex was decomposed thermally and the products analyzed by GC/MS, TGA and FTIR. The dibenzyl derivative complex decomposed at a lower temperature (225-320 C) to yield CuS as the product. The diethyl derivative complex decomposed at a higher temperature (260-325 C) to yield Cu2S. No Cu containing fragments were noted in the mass spectra. Unusual recombination fragments were observed in the mass spectra of the diethyl derivative. Tris(bis(phenylmethyl)carbamodithioato-S,S'), commonly referred to as tris(N,N-dibenzyldithiocarbamato)indium(III), In(S2CNBz2)3, was synthesized and characterized by single crystal X-ray crystallography. The compound crystallizes in the triclinic space group P1(bar) with two molecules per unit cell. The material was further characterized using a novel analytical system employing the combined powers of thermogravimetric analysis, gas chromatography/mass spectrometry, and Fourier transform infrared (FT-IR) spectroscopy to investigate its potential use as a precursor for the chemical vapor deposition (CVD) of thin film materials for photovoltaic applications. Upon heating, the material thermally decomposes to release CS2 and benzyl moieties in to the gas phase, resulting in bulk In2S3. Preliminary spray CVD experiments indicate that In(S2CNBz2)3 decomposed on a Cu substrate reacts to produce

  1. Design, synthesis and antiproliferative activity studies of novel 1,2,3-triazole-dithiocarbamate-urea hybrids.

    PubMed

    Duan, Ying-Chao; Zheng, Yi-Chao; Li, Xiao-Chen; Wang, Meng-Meng; Ye, Xian-Wei; Guan, Yuan-Yuan; Liu, Gai-Zhi; Zheng, Jia-Xin; Liu, Hong-Min

    2013-06-01

    A series of novel 1,2,3-triazole-dithiocarbamate-urea hybrids were designed, synthesized and their antiproliferative activities against four selected human cancer cell lines were evaluated. The results showed that a number of the hybrids exhibited potent activity in selected human cancer cell lines. Among them, compounds 27 and 34 showed broad spectrum anticancer activity with IC50 values ranging from 1.62 to 20.84 μM and 0.76 to 13.55 μM, respectively. Interestingly, compounds 27 and 34, being very potent against MGC-803 cells, exhibited no significant cytotoxicity against normal human embryonic kidney cells at up to 55 μM and 70 μM, respectively. Evidences of cell cycle arrest and apoptosis induction were obtained for the most effective compounds 27 and 34 by means of flow cytometry and microscopic techniques.

  2. Visual Identification of Light-Driven Breakage of the Silver-Dithiocarbamate Bond by Single Plasmonic Nanoprobes

    PubMed Central

    Gao, Peng Fei; Yuan, Bin Fang; Gao, Ming Xuan; Li, Rong Sheng; Ma, Jun; Zou, Hong Yan; Li, Yuan Fang; Li, Ming; Huang, Cheng Zhi

    2015-01-01

    Insight into the nature of metal-sulfur bond, a meaningful one in life science, interface chemistry and organometallic chemistry, is interesting but challenging. By utilizing the localized surface plasmon resonance properties of silver nanoparticles, herein we visually identified the photosensitivity of silver-dithiocarbamate (Ag-DTC) bond by using dark field microscopic imaging (iDFM) technique at single nanoparticle level. It was found that the breakage of Ag-DTC bond could be accelerated effectively by light irradiation, followed by a pH-dependent horizontal or vertical degradation of the DTC molecules, in which an indispensable preoxidation process of the silver was at first disclosed. These findings suggest a visualization strategy at single plasmonic nanoparticle level which can be excellently applied to explore new stimulus-triggered reactions, and might also open a new way to understand traditional organic reaction mechanisms. PMID:26493773

  3. CS(2) blinds in Brassica crops: false positive results in the dithiocarbamate residue analysis by the acid digestion method.

    PubMed

    Perz, R C; van Lishaut, H; Schwack, W

    2000-03-01

    Various members of the Brassicaceae family (cauliflower, savoy cabbage, red cabbage, turnip-rooted cabbage) grown without any application of pesticides were analyzed according to the acid digestion method commonly used for the determination of dithiocarbamate fungicide residues. Depending on postharvest treatments, high non-anthropogenic CS(2) values up to 4 mg/kg were found in some cases, especially in frozen raw cabbage samples, exceeding maximum residue limits. To explore phytogenic CS(2) occurrences, two model substances (phenylisothiocyanate and methyl tryptaminedithiocarbamate) representing natural mustard oils and brassinines, respectively, were analyzed for their acid hydrolysis decomposition products. In both cases, COS was found generally, but CS(2) was readily formed during acid digestion, too, when sulfides were present. The results obtained clearly demonstrate that CS(2) values determined by using the acid digestion method of crops rich in secondary metabolism sulfur compounds have to be interpreted carefully.

  4. Pyrrolidine dithiocarbamate reduces the progression of total kidney volume and cyst enlargement in experimental polycystic kidney disease

    PubMed Central

    Ta, Michelle H. T.; Rao, Padmashree; Korgaonkar, Mayuresh; Foster, Sheryl F.; Peduto, Anthony; Harris, David C. H.; Rangan, Gopala K.

    2014-01-01

    Abstract Heterocyclic dithiocarbamates have anti‐inflammatory and anti‐proliferative effects in rodent models of chronic kidney disease. In this study, we tested the hypothesis that pyrrolidine dithiocarbamate (PDTC) reduces the progression of polycystic kidney disease (PKD). Male Lewis polycystic kidney (LPK) rats (an ortholog of Nek8/NPHP9) received intraperitoneal injections of either saline vehicle or PDTC (40 mg/kg once or twice daily) from postnatal weeks 4 until 11. By serial magnetic resonance imaging at weeks 5 and 10, the relative within‐rat increase in total kidney volume and cyst volume were 1.3‐fold (P =0.01) and 1.4‐fold (P < 0.01) greater, respectively, in LPK + Vehicle compared to the LPK + PDTC(40 mg/kg twice daily) group. At week 11 in LPK rats, PDTC attenuated the increase in kidney weight to body weight ratio by 25% (P < 0.01) and proteinuria by 66% (P < 0.05 vs. LPK + Vehicle) but did not improve renal dysfunction. By quantitative whole‐slide image analysis, PDTC did not alter interstitial CD68+ cell accumulation, interstitial fibrosis, or renal cell proliferation in LPK rats at week 11. The phosphorylated form of the nuclear factor (NF)‐κB subunit, p105, was increased in cystic epithelial cells of LPK rats, but was not altered by PDTC. Moreover, PDTC did not significantly alter nuclear expression of the p50 subunit or NF‐κB (p65)‐DNA binding. Kidney enlargement in LPK rats was resistant to chronic treatment with a proteasome inhibitor, bortezomib. In conclusion, PDTC reduced renal cystic enlargement and proteinuria but lacked anti‐inflammatory effects in LPK rats. PMID:25501440

  5. Effect of additives on Hg2+ reduction and precipitation inhibited by sodium dithiocarbamate in simulated flue gas desulfurization solutions.

    PubMed

    Lu, Rongjie; Hou, Jiaai; Xu, Jiang; Tang, Tingmei; Xu, Xinhua

    2011-11-30

    Mercury (II) (Hg(2+)) ion can be reduced by aqueous S(IV) (sulfite and/or bisulfite) species, which leads to elemental mercury (Hg(0)) emissions in wet flue gas desulfurization (FGD) systems. Numerous reports have demonstrated the high trapping efficiency of sodium dithiocarbamate over heavy metals. In this paper, a novel sodium dithiocarbamate, DTCR, was utilized as a precipitator to control Hg(2+) reduction and Hg(0) emission against S(IV) in FGD solutions. Results indicated that Hg(2+) reduction efficiency decreased dramatically while precipitation rate peaked at around 91.0% in consistence with the increment of DTCR dosage. Initial pH and temperature had great inhibitory effects on Hg(2+) reduction: the Hg(2+) removal rate gradually increased and reached a plateau along with the increment of temperature and initial pH value. Chloride played a key role in Hg(2+) reduction and precipitation reactions. When Cl(-) concentration increased from 0 to 150 mM, Hg(2+) removal rate dropped from 93.84% to 86.05%, and the Hg(2+) reduction rate remained at a low level (<7.8%). SO(4)(2-), NO(3)(-) and other common metal ions would affect the efficiency of Hg(2+) reduction and precipitation reactions in the simulated desulfurization solutions: Hg(2+) removal rate could always be above 90%, while Hg(2+) reduction rate was maintained at below 10%. The predominance of DTCR over aqueous S(IV), indicated by the results above, has wide industrial applications in FGD systems.

  6. Biomimetic synthesis of highly biocompatible gold nanoparticles with amino acid-dithiocarbamate as a precursor for SERS imaging.

    PubMed

    Li, Li; Liu, Jianbo; Yang, Xiaohai; Huang, Jin; He, Dinggeng; Guo, Xi; Wan, Lan; He, Xiaoxiao; Wang, Kemin

    2016-03-11

    Amino acid-dithiocarbamate (amino acid-DTC) was developed as both the reductant and ligand stabilizer for biomimetic synthesis of gold nanoparticles (AuNPs), which served as an excellent surface-enhanced Raman scattering (SERS) contrast nanoprobe for cell imaging. Glycine (Gly), glutamic acid (Glu), and histidine (His) with different isoelectric points were chosen as representative amino acid candidates to synthesize corresponding amino acid-DTC compounds through mixing with carbon disulfide (CS2), respectively. The pyrogenic decomposition of amino acid-DTC initiated the reduction synthesis of AuNPs, and the strong coordinating dithiocarbamate group of amino acid-DTC served as a stabilizer that grafted onto the surface of the AuNPs, which rendered the as-prepared nanoparticles a negative surface charge and high colloidal stability. MTT cell viability assay demonstrated that the biomimetic AuNPs possessed neglectful toxicity to the human hepatoma cell, which guaranteed them good biocompatibility for biomedical application. Meanwhile, the biomimetic AuNPs showed a strong SERS effect with an enhancement factor of 9.8 × 10(5) for the sensing of Rhodamine 6G, and two distinct Raman peaks located at 1363 and 1509 cm(-1) could be clearly observed in the cell-imaging experiments. Therefore, biomimetic AuNPs can be explored as an excellent SERS contrast nanoprobe for biomedical imaging, and the amino acid-DTC mediated synthesis of the AuNPs has a great potential in bio-engineering and biomedical imaging applications.

  7. ToF-SIMS analysis of anti-fretting films generated on the surface of ball bearings containing dithiocarbamate and dithiophosphate grease additives

    NASA Astrophysics Data System (ADS)

    Duque, Ricardo G.; Wang, Zhiyu; Duell, Dave; Fowler, David E.

    2004-06-01

    During transport of hard drives from the factory to the end customer, vibrations can induce small repetitive displacements of the ball bearings giving rise to fretting corrosion at the metal surfaces. On the other hand, it has been found that some particular types of grease additives can form thin layers on steel surfaces and thus protect against fretting corrosion. ToF-SIMS has been used to study the chemical nature of layers formed on bearing surfaces containing greases with dithiocarbamates, dithiophosphates, and metal sulfonate additives. In cases where fretting was prevented, the presence of MoS 2-, FeS - and ion fragments containing Mo-Fe-S - were observed, whereas none of these ions were detected on the surfaces of fretted bearings. Finally, it is inferred that the action of metal sulfonates may have an antagonist effect on the anti-fretting activity of the dithiocarbamate and dithiophosphate compounds studied.

  8. Design and synthesis of formononetin-dithiocarbamate hybrids that inhibit growth and migration of PC-3 cells via MAPK/Wnt signaling pathways.

    PubMed

    Fu, Dong-Jun; Zhang, Li; Song, Jian; Mao, Ruo-Wang; Zhao, Ruo-Han; Liu, Ying-Chao; Hou, Yu-Hui; Li, Jia-Huan; Yang, Jia-Jia; Jin, Cheng-Yun; Li, Ping; Zi, Xiao-Lin; Liu, Hong-Min; Zhang, Sai-Yang; Zhang, Yan-Bing

    2017-02-15

    A series of novel formononetin-dithiocarbamate derivatives were designed, synthesized and evaluated for antiproliferative activity against three selected cancer cell line (MGC-803, EC-109, PC-3). The first structure-activity relationship (SAR) for this formononetin-dithiocarbamate scaffold is explored in this report with evaluation of 14 variants of the structural class. Among these analogues, tert-butyl 4-(((3-((3-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)propyl)thio)carbonothioyl)piperazine-1-carboxylate (8i) showed the best inhibitory activity against PC-3 cells (IC50 = 1.97 μM). Cellular mechanism studies elucidated 8i arrests cell cycle at G1 phase and regulates the expression of G1 checkpoint-related proteins in concentration-dependent manners. Furthermore, 8i could inhibit cell growth via MAPK signaling pathway and inhibit migration via Wnt pathway in PC-3 cells.

  9. Tris dithiocarbamate of Co(III) complexes: Synthesis, characterization, thermal decomposition studies and experimental and theoretical studies on their crystal structures

    NASA Astrophysics Data System (ADS)

    Sonia, Ayyavoo Sait; Bhaskaran, Ramalingam

    2017-04-01

    New homoleptic complexes of the form [Co(L1)3] & [Co(L2)3] where L1 = (ethylaminoethanol dithiocarbamate) 1 and L2 = (methylaminoethanol dithiocarbamate) 2 have been prepared and characterized by elemental analysis, IR, UV-visible absorption spectra, Cyclic voltammetry,1H and C13 NMR. The thermal properties were studied using a simultaneous thermal analyzer, and showed two main steps of decomposition. In addition, structures for 1 and 2 have been elucidated by X-ray crystallography. The single-crystal X-ray analysis for both the complexes showed distorted octahedral geometry. The optimized molecular structure, natural bond orbital analysis, electrostatic potential map, HOMO-LUMO energies, molecular properties, and atomic charges of these molecules have been studied by performing DFT/B3LYP/6-31G(d,p) level of theory in gas phase.

  10. Technetium-99m nitrido dithiocarbamate complex with lateral ester groups: A potential agent for cerebral perfusion. Direct labeling and kinetic results in baboons

    SciTech Connect

    Bottlaender, M.; Bourguignon, M.; Maziere, M.

    1994-05-01

    Previous studies have shown that technetium-99m-nitrido (TcN) complexes of ester derivatives of dithiocarbamate cross the brain-blood barrier and one term of this class, namely the complex formed with sarcosine methyl ester dithiocarbamate (TcN-PR13) is retained in the brain of Cynomolgus monkeys. However these compounds were obtained through an in situ esterification of preformed TcN dicarboxylic derivative. We have been able to synthesize one term of this class of ligands, the sarcosine methylester dithiocarbamate, by reacting sarcosine with thionyl chloride in methanol to give the sarcosine methyl ester, which was reacted with carbon disulfide and NaOH in methanol to give the sodium salt of the dithiocarbamate derivative which was isolated as an oil. The corresponding TcN complex was obtained with a radiochemical purity greater than 96% by a kit method. The complex was injected in baboons and its radioactive distribution compared to that obtained with Tc-HMPAO. Blood and plasma kinetics were calculated from arterial sampling whereas tissue kinetics (brain, lungs) were obtained by ROI`s analysis. The values of the half-life in the blood were comparable for the two tracers, although the absolute activity was about 20% lower for TcN-PR13. The brain uptake of TcN-PR13 was 10% lower than that observed for Tc-HMPAO, and remained stable during 2 hours. TcN-PR13 displayed lower lung uptake and faster clearance from this organ than Tc-HMPAO. Brain/Lung ratios were 1.11 and 1.65 at 30 and 60 min for TcN-PR13 compared to 0.93 and 0.99 at the same time for Tc-HMPAO.

  11. Method of removing nitrogen monoxide from a nitrogen monoxide-containing gas using a water-soluble iron ion-dithiocarbamate, xanthate or thioxanthate

    DOEpatents

    Liu, D. Kwok-Keung; Chang, Shih-Ger

    1987-08-25

    The present invention relates to a method of removing of nitrogen monoxide from a nitrogen monoxide-containing gas which method comprises contacting a nitrogen oxide-containing gas with an aqueous solution of water soluble organic compound-iron ion chelate complex. The NO absorption efficiency of ferrous urea-dithiocarbamate and ferrous diethanolamine-xanthate as a function of time, oxygen content and solution ph is presented. 3 figs., 1 tab.

  12. Determination of dithiocarbamate pesticides in occupational hygiene sampling devices using the isooctane method and comparison with an automatic thermal desorption (ATD) method.

    PubMed

    Coldwell, Matthew R; Pengelly, Ian; Rimmer, Duncan A

    2003-01-10

    Two new methods for the determination of dithiocarbamate pesticides in occupational hygiene sampling devices are described. Dithiocarbamate spiked occupational hygiene sampling devices, consisting of glass fibre (GF/A) filters, cotton pads, cotton gloves and disposable overalls, were reduced under acidic conditions and the CS2 evolved as a decomposition product was extracted into isooctane. The isooctane was then analysed using gas chromatography with mass spectrometry, for CS2, which provided a quantitative result for dithiocarbamates. Recoveries obtained were generally within a 70-110% range and reproducibilities better than 15% RSD were typically achieved. The method has been successfully applied to samples collected during occupational exposure surveys. A second method employing automatic thermal desorption-gas chromatography-mass spectrometry (ATD-GC-MS) has also been developed and applied to the direct analysis of GF/A (airborne) samples. The method relies on the thermal degradation of dithiocarbamates to release CS2, which is used to quantify the analytes. Thiram spiked GF/A filters gave an average recovery of 107% with an RSD of 4%. The performance of the two analytical methods were directly compared by analysing sub-portions of GF/A filters collected during a survey to evaluate occupational exposures to thiram during seed treatment operations. Both methods performed well for the analysis of airborne (GF/A) samples and produced results in good agreement. ATD-GC-MS is the preferred method for studies involving GF/A (airborne) samples only. Because of the wider applicability of the isooctane method for other sampling devices, it is the preferred choice when carrying out surveys which require a dermal as well as respirable exposure assessment.

  13. Mixed Ligand Complexes of N-Methyl-N-phenyl Dithiocarbamate: Synthesis, Characterisation, Antifungal Activity, and Solvent Extraction Studies of the Ligand

    PubMed Central

    Ekennia, Anthony C.; Onwudiwe, Damian C.; Ume, Cyril; Ebenso, Eno E.

    2015-01-01

    A series of mixed ligand dithiocarbamate complexes with a general formula [ML2(py)2], where M = Mn(II), Co(II), Ni(II), and Cu(II), py = pyridine, and L = N-methyl-N-phenyl dithiocarbamate have been prepared and characterised by elemental analysis, FTIR and Uv spectroscopy, magnetic moment, and thermogravimetric and conductance analysis. The infrared spectra showed that symmetrical bidentate coordination occurred with the dithiocarbamate moiety through the sulfur atoms, while neutral monodentate coordination occurred through the nitrogen atom for the pyridine molecule in the complexes. The electronic spectra, elemental analysis, and magnetic moment results proved that the complexes adopted octahedral geometry. The conductance measurement showed that the complexes are nonelectrolytes proving their nonionic nature. The compounds were screened for three human pathogenic fungi: Aspergillus flavus, Aspergillus niger, and Candida albicans. The cobalt complex showed the best antifungal activity among the test compounds. Liquid-liquid extractive abilities of the ligand towards copper and nickel ions in different solvent media were investigated. The ligand showed a strong binding affinity towards the metals ions with an extractive efficiency of about 99%. PMID:26543441

  14. Exposure to Mn/Zn ethylene-bis-dithiocarbamate and glyphosate pesticides leads to neurodegeneration in Caenorhabditis elegans.

    PubMed

    Negga, Rekek; Rudd, David A; Davis, Nathan S; Justice, Amanda N; Hatfield, Holly E; Valente, Ana L; Fields, Anthony S; Fitsanakis, Vanessa A

    2011-06-01

    Epidemiological evidence suggests positive correlations between pesticide usage and the incidence of Parkinson's disease (PD). To further explore this relationship, we used wild type (N2) Caenorhabditis elegans (C. elegans) to test the following hypothesis: Exposure to a glyphosate-containing herbicide (TD) and/or a manganese/zinc ethylene-bis-dithiocarbamate-containing fungicide (MZ) may lead to neurotoxicity. We exposed N2 worms to varying concentrations of TD or MZ for 30 min (acute) or 24h (chronic). To replicate agricultural usage, a third population was exposed to TD (acute) followed by MZ (acute). For acute TD exposure, the LC(50)=8.0% (r(2)=0.6890), while the chronic LC(50)=5.7% (r(2)=0.9433). Acute MZ exposure led to an LC(50)=0.22% (r(2)=0.5093), and chronic LC(50)=0.50% (r(2)=0.9733). The combined treatment for TD+MZ yielded an LC(50)=12.5% (r(2)=0.6367). Further studies in NW1229 worms, a pan-neuronally green fluorescent protein (GFP) tagged strain, indicated a statistically significant (p<0.05) and dose-dependent reduction in green pixel number in neurons of treated worms following each paradigm. This reduction of pixel number was accompanied by visual neurodegeneration in photomicrographs. For the dual treatment, Bliss analysis suggested synergistic interactions. Taken together, these data suggest neuronal degeneration occurs in C. elegans following treatment with environmentally relevant concentrations of TD or MZ.

  15. Pyrrolidine dithiocarbamate inhibits UVB-induced skin inflammation and oxidative stress in hairless mice and exhibits antioxidant activity in vitro.

    PubMed

    Ivan, Ana L M; Campanini, Marcela Z; Martinez, Renata M; Ferreira, Vitor S; Steffen, Vinicius S; Vicentini, Fabiana T M C; Vilela, Fernanda M P; Martins, Frederico S; Zarpelon, Ana C; Cunha, Thiago M; Fonseca, Maria J V; Baracat, Marcela M; Georgetti, Sandra R; Verri, Waldiceu A; Casagrande, Rúbia

    2014-09-05

    Ultraviolet B (UVB) irradiation may cause oxidative stress- and inflammation-dependent skin cancer and premature aging. Pyrrolidine dithiocarbamate (PDTC) is an antioxidant and inhibits nuclear factor-κB (NF-κB) activation. In the present study, the mechanisms of PDTC were investigated in cell free oxidant/antioxidant assays, in vivo UVB irradiation in hairless mice and UVB-induced NFκB activation in keratinocytes. PDTC presented the ability to scavenge 2,2'-azinobis-(3-ethyl benzothiazoline-6-sulfonic acid) radical (ABTS), 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH) and hydroxyl radical (OH); and also efficiently inhibited iron-dependent and -independent lipid peroxidation as well as chelated iron. In vivo, PDTC treatment significantly decreased UVB-induced skin edema, myeloperoxidase (MPO) activity, production of the proinflammatory cytokine interleukin-1β (IL-1β), matrix metalloproteinase-9 (MMP-9), increase of reduced glutathione (GSH) levels and antioxidant capacity of the skin tested by the ferric reducing antioxidant power (FRAP) and ABTS assays. PDTC also reduced UVB-induced IκB degradation in keratinocytes. These results demonstrate that PDTC presents antioxidant and anti-inflammatory effects in vitro, which line up well with the PDTC inhibition of UVB irradiation-induced skin inflammation and oxidative stress in mice. These data suggest that treatment with PDTC may be a promising approach to reduce UVB irradiation-induced skin damages and merits further pre-clinical and clinical studies.

  16. Primary risk assessment of dimethyldithiocarbamate, a dithiocarbamate fungicide metabolite, based on their probabilistic concentrations in a coastal environment.

    PubMed

    Hano, Takeshi; Ito, Katsutoshi; Mochida, Kazuhiko; Ohkubo, Nobuyuki; Kono, Kumiko; Onduka, Toshimitsu; Ito, Mana; Ichihashi, Hideki; Fujii, Kazunori; Tanaka, Hiroyuki

    2015-07-01

    The primary ecological risk of dimethyldithiocarbamate (DMDC), a dithiocarbamate fungicide (DTC) metabolite, was evaluated based on their probabilistic environmental concentration distributions (ECDs) in the coastal environment, Hiroshima Bay, Japan. And their behavior and temporal trends was further considered. This is the first report of the identification of DMDC from environmental seawater and sediment samples. DMDC concentrations in bottom seawater were substantially higher than those in surface seawater, which are associated with the leachability from sediments in bottom seawaters, and with photodegradation in surface seawaters. Furthermore, seasonal risks are dominated by higher concentrations from April to June, indicating temporal variation in the risk to exposed species. Hierarchical Bayesian analysis offered DMDC ECD medians and range (5th to 95th percentiles) of 0.85 ng L(-1) (0.029, 22), 12 ng L(-1) (3.2, 48) and 110 ng kg dry(-1) (9.5, 1200) in surface seawater, bottom seawater and sediment, respectively. Considering that DMDC and DTCs have similar toxicological potential to aquatic organisms, the occurrence of the compound in water is likely to be of biological relevance. In summary, this work provides the first demonstration that the ecological risk of DMDC and its derived DTCs in Hiroshima Bay is relatively high, and that DTCs should be a high priority for future research on marine contamination, especially in bottom seawaters.

  17. Results of long-term experimental studies on the carcinogenicity of ethylene-bis-dithiocarbamate (Mancozeb) in rats.

    PubMed

    Belpoggi, Fiorella; Soffritti, Morando; Guarino, Marina; Lambertini, Luca; Cevolani, Daniela; Maltoni, Cesare

    2002-12-01

    Mancozeb, an ethylene-bis-dithiocarbamate (EBDC), has been one of the most commonly used fungicides in commercial use for several decades. Nevertheless, up to now, no adequate published experimental studies on the carcinogenicity of Mancozeb have been published. Because of the importance of the compound and of the number of people potentially exposed (workers engaged in the production and use of the fungicide, people living in agricultural areas where the compound is sprayed, and people consuming polluted products), a long-term experimental study of Mancozeb was begun at the Cancer Research Center of the Ramazzini Foundation. Groups of 150 male and female Sprague-Dawley rats, 8 weeks old at the start of the treatment, were administered Mancozeb at the concentration of 1000, 500, 100, 10, and 0 ppm in feed supplied ad libitum for 104 weeks. At the end of the treatment, animals were kept under controlled conditions until spontaneous death. Mancozeb caused an increase in (1) total malignant tumors, (2) malignant mammary tumors, (3) Zymbal gland and ear duct carcinomas, (4) hepatocarcinomas, (5) malignant tumors of the pancreas, (6) malignant tumors of the thyroid gland, (7) osteosarcomas of the bones of the head, and (8) hemolymphoreticular neoplasias. On the basis of these data, Mancozeb must be considered a multipotent carcinogenic agent.

  18. Thermal Studies of Zn(II), Cd(II) and Hg(II) Complexes of Some N-Alkyl-N-Phenyl-Dithiocarbamates

    PubMed Central

    Onwudiwe, Damian C.; Ajibade, Peter A.

    2012-01-01

    The thermal decomposition of Zn(II), Cd(II) and Hg(II) complexes of N-ethyl-N-phenyl and N-butyl-N-phenyl dithiocarbamates have been studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The products of the decomposition, at two different temperatures, were further characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The results show that while the zinc and cadmium complexes undergo decomposition to form metal sulphides, and further undergo oxidation forming metal oxides as final products, the mercury complexes gave unstable volatiles as the final product. PMID:22949811

  19. Spectrophotometric determination of ferbam [iron(III) dimethyl dithiocarbamate] in commercial sample and wheat grains after extraction of its bathophenanthroline tetraphenylborate complex into molten naphthalene.

    PubMed

    Malik, A K; Rao, A L

    2000-09-01

    A procedure has been developed for the determination of iron(III) dimethyldithiocarbamate by converting it into a iron(III)-bathophenanthroline-tetraphenylborate complex, which was then extracted into molten naphthalene, and the absorbance was measured at 534 nm against a reagent blank. Beer's law is obeyed over the concentration range 0.4-20 microg mL(-)(1) in final solution. The method is sensitive and highly selective and is applied for the determination of ferbam in a commercial sample, in mixtures with various dithiocarbamates (ziram, zineb, maneb, etc.), and from wheat grains.

  20. Pyrrolidine dithiocarbamate attenuates surgery-induced neuroinflammation and cognitive dysfunction possibly via inhibition of nuclear factor κB.

    PubMed

    Zhang, J; Jiang, W; Zuo, Z

    2014-03-07

    Surgery induces learning and memory impairment. Neuroinflammation may contribute to this impairment. Nuclear factor κB (NF-κB) is an important transcription factor to regulate the expression of inflammatory cytokines. We hypothesize that inhibition of NF-κB by pyrrolidine dithiocarbamate (PDTC) reduces neuroinflammation and the impairment of learning and memory. To test this hypothesis, four-month-old male Fischer 344 rats were subjected to right carotid exploration under propofol and buprenorphine anesthesia. Some rats received two doses of 50mg/kg PDTC given intraperitoneally 30min before and 6h after the surgery. Rats were tested in the Barnes maze and fear conditioning paradigm begun 6days after the surgery. Expression of various proteins related to inflammation was examined in the hippocampus at 24h or 21days after the surgery. Here, surgery, but not anesthesia alone, had a significant effect on prolonging the time needed to identify the target hole during the training sessions of the Barnes maze. Surgery also increased the time for identifying the target hole in the long-term memory test and decreased context-related learning and memory in fear conditioning test. Also, surgery increased nuclear expression of p65, a NF-κB component, decreased cytoplasmic amount of inhibitor of NF-κB, and increased the expression of interleukin-1β, interleukin-6, ionized calcium binding adaptor molecule 1 and active matrix metalloproteinase 9 (MMP-9). Finally, surgery enhanced IgG extravasation in the hippocampus. These surgical effects were attenuated by PDTC. These results suggest that surgery, but not propofol-based anesthesia, induces neuroinflammation and impairment of learning and memory. PDTC attenuates these effects possibly by inhibiting NF-κB activation and the downstream MMP-9 activity.

  1. Pyrrolidine dithiocarbamate-zinc(II) and -copper(II) complexes induce apoptosis in tumor cells by inhibiting the proteasomal activity

    SciTech Connect

    Milacic, Vesna; Chen Di; Giovagnini, Lorena; Diez, Alejandro; Fregona, Dolores; Dou, Q. Ping

    2008-08-15

    Zinc and copper are trace elements essential for proper folding, stabilization and catalytic activity of many metalloenzymes in living organisms. However, disturbed zinc and copper homeostasis is reported in many types of cancer. We have previously demonstrated that copper complexes induced proteasome inhibition and apoptosis in cultured human cancer cells. In the current study we hypothesized that zinc complexes could also inhibit the proteasomal chymotrypsin-like activity responsible for subsequent apoptosis induction. We first showed that zinc(II) chloride was able to inhibit the chymotrypsin-like activity of a purified 20S proteasome with an IC{sub 50} value of 13.8 {mu}M, which was less potent than copper(II) chloride (IC{sub 50} 5.3 {mu}M). We then compared the potencies of a pyrrolidine dithiocarbamate (PyDT)-zinc(II) complex and a PyDT-copper(II) complex to inhibit cellular proteasomal activity, suppress proliferation and induce apoptosis in various human breast and prostate cancer cell lines. Consistently, zinc complex was less potent than copper complex in inhibiting the proteasome and inducing apoptosis. Additionally, zinc and copper complexes appear to use somewhat different mechanisms to kill tumor cells. Zinc complexes were able to activate calpain-, but not caspase-3-dependent pathway, while copper complexes were able to induce activation of both proteases. Furthermore, the potencies of these PyDT-metal complexes depend on the nature of metals and also on the ratio of PyDT to the metal ion within the complex, which probably affects their stability and availability for interacting with and inhibiting the proteasome in tumor cells.

  2. Blockade of T-cell activation by dithiocarbamates involves novel mechanisms of inhibition of nuclear factor of activated T cells.

    PubMed Central

    Martínez-Martínez, S; Gómez del Arco, P; Armesilla, A L; Aramburu, J; Luo, C; Rao, A; Redondo, J M

    1997-01-01

    Dithiocarbamates (DTCs) have recently been reported as powerful inhibitors of NF-kappaB activation in a number of cell types. Given the role of this transcription factor in the regulation of gene expression in the inflammatory response, NF-kappaB inhibitors have been suggested as potential therapeutic drugs for inflammatory diseases. We show here that DTCs inhibited both interleukin 2 (IL-2) synthesis and membrane expression of antigens which are induced during T-cell activation. This inhibition, which occurred with a parallel activation of c-Jun transactivating functions and expression, was reflected by transfection experiments at the IL-2 promoter level, and involved not only the inhibition of NF-kappaB-driven reporter activation but also that of nuclear factor of activated T cells (NFAT). Accordingly, electrophoretic mobility shift assays (EMSAs) indicated that pyrrolidine DTC (PDTC) prevented NF-kappaB, and NFAT DNA-binding activity in T cells stimulated with either phorbol myristate acetate plus ionophore or antibodies against the CD3-T-cell receptor complex and simultaneously activated the binding of AP-1. Furthermore, PDTC differentially targeted both NFATp and NFATc family members, inhibiting the transactivation functions of NFATp and mRNA induction of NFATc. Strikingly, Western blotting and immunocytochemical experiments indicated that PDTC promoted a transient and rapid shuttling of NFATp and NFATc, leading to their accelerated export from the nucleus of activated T cells. We propose that the activation of an NFAT kinase by PDTC could be responsible for the rapid shuttling of the NFAT, therefore transiently converting the sustained transactivation of this transcription factor that occurs during lymphocyte activation, and show that c-Jun NH2-terminal kinase (JNK) can act by directly phosphorylating NFATp. In addition, the combined inhibitory effects on NFAT and NF-KB support a potential use of DTCs as immunosuppressants. PMID:9343406

  3. Protective effects of the nuclear factor kappa B inhibitor pyrrolidine dithiocarbamate in bladder ischemia-reperfusion injury in rats.

    PubMed

    Yucel, Mehmet; Kucuk, Aysegul; Bayraktar, Aslihan Cavunt; Tosun, Murat; Yalcinkaya, Soner; Hatipoglu, Namik Kemal; Erkasap, Nilufer; Kavutcu, Mustafa

    2013-10-01

    The aim of the present study was to evaluate the protective effects of the NF-кB inhibition with pyrrolidine-dithiocarbamate (PDTC) in ischemia-reperfusion (I/R) injury in the rat bladder. Twenty-four Sprague-Dawley male rats were divided into three groups. Group I; (n = 8) control, group II; (n = 8) I/R group; group III (n = 8) I/R and PDTC treatment. Superoxide dismutase (SOD), catalase (CAT), and gluatathione-S-transferase (GST) enzymes was studied in bladder tissue. Lipid peroxidation (as TBARS) levels in tissue homogenate were measured with thiobarbituric acid reaction. All the slides were stained with NF-кB, p53 and HSP60 immunohistochemistry for detection genome destruction and tissue stress, respectively. Our results show that the mean TBARS levels were significantly higher in group II (p < 0.05). The TBARS levels were significantly decreased in group III compared with the group II (p < 0.05). CAT, SOD and GST activities were decreased in group II, but these enzymes levels were significantly increased in group III according to the group II (p < 0.05). Under microscopic evaluation NF-кB expression increased significantly in group II compared to the group I (p < 0.05) and then decreased in group III (p < 0.05). HSP60 and p53 expression in group II was increased significantly compared with group I. Under microscopic evaluation we detected that HSP60 and p53 expression was increased significantly in group II compared with group I. In group III PDTC administration was decreased the HSP60 and p53 expression, this difference was statistically significant (p < 0.05). The results of the present study have demonstrated that NF-кB inhibition with PDTC protects and provides beneficial effects on ischemia/reperfusion stress related bladder tissue destruction.

  4. The neonicotinoid pesticide imidacloprid and the dithiocarbamate fungicide mancozeb disrupt the pituitary-thyroid axis of a wildlife bird.

    PubMed

    Pandey, Surya Prakash; Mohanty, Banalata

    2015-03-01

    Thyroid is an important homeostatic regulator of metabolic activities as well as endocrine mechanisms including those of reproduction. Present investigation elucidated the thyroid disrupting potential of a neonicotinoid imidacloprid and a dithiocarbamate mancozeb in a seasonally breeding wildlife bird, Red Munia (Amandava amandava) who is vulnerable to these two pesticides through diet (seed grains and small insects). Adult male birds were exposed to 0.5% LD50 mgkg(-1)bwd(-1) of both the pesticides through food for 30days during the preparatory and breeding phases. Weight, volume and histopathology of thyroid gland were distinctly altered. Disruption of thyroid follicles reflected in nucleus-to-cytoplasm ratio (N/C) in epithelial and stromal cells, epithelial cell hypertrophy and altered colloid volume. Impairment of thyroid axis was pesticide and phase specific as evident from the plasma levels of thyroid (T4 and T3) and pituitary (TSH) hormones. In preparatory phase, plasma TSH was increased in response to decrease of T4 on mancozeb exposure showing responsiveness of the hypothalamic-pituitary-thyroid (HPT) axis to feedback regulation. On imidacloprid exposure, however, plasma levels of both T4 and TSH were decreased indicating non-functioning of negative feedback mechanism. Increased plasma T3 in response to both the pesticides exposure might be due to synthesis from non-thyroidal source(s) in a compensatory response to decrease level of T4. In breeding phase, impairment of HPT axis was more pronounced as plasma T4, T3 and TSH were significantly decreased in response to both mancozeb and imidacloprid. Thus, low dose pesticide exposure could affect the thyroid homeostasis and reproduction.

  5. Pyrrolidine dithiocarbamate-induced apoptosis depends on cell type, density, and the presence of Cu(2+) and Zn(2+).

    PubMed

    Erl, W; Weber, C; Hansson, G K

    2000-06-01

    Pyrrolidine dithiocarbamate (PDTC) has been found to induce or inhibit apoptosis in different cell types. Here we show that PDTC dose-dependently reduced the viability of rat smooth muscle cells (rSMC), human fibroblasts, and endothelial cells at low but not at high cell density. Endothelial cells were least sensitive, fibroblasts showed a medium sensitivity, and rSMC showed a high sensitivity to PDTC-mediated cell death. An early reduction in the mitochondrial membrane potential indicated a rapid onset of apoptosis in rSMC. Apoptosis was further confirmed by annexin V staining and DNA fragmentation analysis. Gel shift analysis demonstrated increased nuclear factor (NF)-kappaB activity in high-density rSMC compared with low-density cells. NF-kappaB has recently been shown to regulate the induction of anti-apoptotic proteins. Although PDTC is widely used as an inhibitor for NF-kappaB and a radical scavenger, our data show that PDTC rather enhanced NF-kappaB activity and, alone or in combination with menadione, induced oxygen radical generation. Notably, PDTC failed to reduce rSMC viability in medium without Cu(2+) or Zn(2+), and addition of Cu(2+) or Zn(2+) resulted in a dose-dependent increase in PDTC-induced cell death. Addition of both Cu(2+) and Zn(2+) showed synergistic effects. Our results indicate that the induction of apoptosis by PDTC requires Cu(2+) and Zn(2+) and is dependent on cell type and density. Such differential effects may have implications for studies of PDTC as an anti-atherosclerotic or immunomodulatory drug.

  6. Short-term pyrrolidine dithiocarbamate administration attenuates cachexia-induced alterations to muscle and liver in ApcMin/+ mice

    PubMed Central

    VanderVeen, Brandon N.; Enos, Reilly T.; Murphy, E. Angela; Carson, James A.

    2016-01-01

    Cancer cachexia is a complex wasting condition characterized by chronic inflammation, disrupted energy metabolism, and severe muscle wasting. While evidence in pre-clinical cancer cachexia models have determined that different systemic inflammatory inhibitors can attenuate several characteristics of cachexia, there is a limited understanding of their effects after cachexia has developed, and whether short-term administration is sufficient to reverse cachexia-induced signaling in distinctive target tissues. Pyrrolidine dithiocarbamate (PDTC) is a thiol compound having anti-inflammatory and antioxidant properties which can inhibit STAT3 and nuclear factor κB (NF-κB) signaling in mice. This study examined the effect of short-term PDTC administration to ApcMin/+ mice on cachexia-induced disruption of skeletal muscle protein turnover and liver metabolic function. At 16 weeks of age ApcMin/+ mice initiating cachexia (7% BW loss) were administered PDTC (10mg/kg bw/d) for 2 weeks. Control ApcMin/+ mice continued to lose body weight during the treatment period, while mice receiving PDTC had no further body weight decrease. PDTC had no effect on either intestinal tumor burden or circulating IL-6. In muscle, PDTC rescued signaling disrupting protein turnover regulation. PDTC suppressed the cachexia induction of STAT3, increased mTORC1 signaling and protein synthesis, and suppressed the induction of Atrogin-1 protein expression. Related to cachectic liver metabolic function, PDTC treatment attenuated glycogen and lipid content depletion independent to the activation of STAT3 and mTORC1 signaling. Overall, these results demonstrate short-term PDTC treatment to cachectic mice attenuated cancer-induced disruptions to muscle and liver signaling, and these changes were independent to altered tumor burden and circulating IL-6. PMID:27449092

  7. Pyrrolidine Dithiocarbamate Inhibits Herpes Simplex Virus 1 and 2 Replication, and Its Activity May Be Mediated through Dysregulation of the Ubiquitin-Proteasome System

    PubMed Central

    Qiu, Min; Chen, Yu; Cheng, Lin; Chu, Ying; Song, Hong-Yong

    2013-01-01

    Pyrrolidine dithiocarbamate (PDTC) is widely used as an antioxidant or an NF-κB inhibitor. It has been reported to inhibit the replication of human rhinoviruses, poliovirus, coxsackievirus, and influenza virus. In this paper, we report that PDTC could inhibit the replication of herpes simplex virus 1 and 2 (HSV-1 and HSV-2). PDTC suppressed the expression of HSV-1 and HSV-2 viral immediate early (IE) and late (membrane protein gD) genes and the production of viral progeny. This antiviral property was mediated by the dithiocarbamate moiety of PDTC and required the presence of Zn2+. Although PDTC could potently block reactive oxygen species (ROS) generation, it was found that this property did not contribute to its anti-HSV activity. PDTC showed no activity in disrupting the mitogen-activated protein kinase (MAPK) pathway activation induced by viral infection that was vital for the virus's propagation. We found that PDTC modulated cellular ubiquitination and, furthermore, influenced HSV-2-induced IκB-α degradation to inhibit NF-κB activation and enhanced PML stability in the nucleus, resulting in the inhibition of viral gene expression. These results suggested that the antiviral activity of PDTC might be mediated by its dysregulation of the cellular ubiquitin-proteasome system (UPS). PMID:23740985

  8. Synthesis and spectral studies on Pb(II) dithiocarbamate complexes containing benzyl and furfuryl groups and their use as precursors for PbS nanoparticles.

    PubMed

    Sathiyaraj, Ethiraj; Thirumaran, Subbiah

    2012-11-01

    Nine lead bis(dithiocarbamate) complexes based on benzyl and furfuryl groups have been prepared. The complexes were characterized using IR and NMR spectroscopy. All the complexes showed the expected signals in (1)H and (13)C NMR spectra associated with the dithiocarbamate ligands. IR and (13)C NMR spectral studies indicate that the S(2)CN double bond character increases with increase in length of alkyl chain bonded to nitrogen atom. Bis(N-benzyl-N-(2-phenylethyl)dithiocarbamato-S,S')lead(II) (3) and bis(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S')lead(II) (4) have been used as single source precursors for the synthesis of ethylenediamine capped PbS nanoparticles. Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), FTIR, UV-vis and fluorescence spectroscopy have been used to characterize the as-prepared lead sulfide nanoparticles. The PXRD measurements suggest that PbS nanoparticles are single phase with face-centered-cubic structure.

  9. Synthesis and spectral studies on Pb(II) dithiocarbamate complexes containing benzyl and furfuryl groups and their use as precursors for PbS nanoparticles

    NASA Astrophysics Data System (ADS)

    Sathiyaraj, Ethiraj; Thirumaran, Subbiah

    2012-11-01

    Nine lead bis(dithiocarbamate) complexes based on benzyl and furfuryl groups have been prepared. The complexes were characterized using IR and NMR spectroscopy. All the complexes showed the expected signals in 1H and 13C NMR spectra associated with the dithiocarbamate ligands. IR and 13C NMR spectral studies indicate that the S2Cpdbdtd N double bond character increases with increase in length of alkyl chain bonded to nitrogen atom. Bis(N-benzyl-N-(2-phenylethyl)dithiocarbamato-S,S')lead(II) (3) and bis(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S')lead(II) (4) have been used as single source precursors for the synthesis of ethylenediamine capped PbS nanoparticles. Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), FTIR, UV-vis and fluorescence spectroscopy have been used to characterize the as-prepared lead sulfide nanoparticles. The PXRD measurements suggest that PbS nanoparticles are single phase with face-centered-cubic structure.

  10. DFT calculations in the assignment of solid-state NMR and crystal structure elucidation of a lanthanum(iii) complex with dithiocarbamate and phenanthroline.

    PubMed

    Gowda, Vasantha; Laitinen, Risto S; Telkki, Ville-Veikko; Larsson, Anna-Carin; Antzutkin, Oleg N; Lantto, Perttu

    2016-12-06

    The molecular, crystal, and electronic structures as well as spectroscopic properties of a mononuclear heteroleptic lanthanum(iii) complex with diethyldithiocarbamate and 1,10-phenanthroline ligands (3 : 1) were studied by solid-state (13)C and (15)N cross-polarisation (CP) magic-angle-spinning (MAS) NMR, X-ray diffraction (XRD), and first principles density functional theory (DFT) calculations. A substantially different powder XRD pattern and (13)C and (15)N CP-MAS NMR spectra indicated that the title compound is not isostructural to the previously reported analogous rare earth complexes with the space group P21/n. Both (13)C and (15)N CP-MAS NMR revealed the presence of six structurally different dithiocarbamate groups in the asymmetric unit cell, implying a non-centrosymmetric packing arrangement of molecules. This was supported by single-crystal X-ray crystallography showing that the title compound crystallised in the triclinic space group P1[combining macron]. In addition, the crystal structure also revealed that one of the dithiocarbamate ligands has a conformational disorder. NMR chemical shift calculations employing the periodic gauge including projector augmented wave (GIPAW) approach supported the assignment of the experimental (13)C and (15)N NMR spectra. However, the best correspondences were obtained with the structure where the atomic positions in the X-ray unit cell were optimised at the DFT level. The roles of the scalar and spin-orbit relativistic effects on NMR shielding were investigated using the zeroth-order regular approximation (ZORA) method with the outcome that already the scalar relativistic level qualitatively reproduces the experimental chemical shifts. The electronic properties of the complex were evaluated based on the results of the natural bond orbital (NBO) and topology of the electron density analyses. Overall, we apply a multidisciplinary approach acquiring comprehensive information about the solid-state structure and the

  11. New bipyridine gold(III) dithiocarbamate-containing complexes exerted a potent anticancer activity against cisplatin-resistant cancer cells independent of p53 status

    PubMed Central

    Altaf, Muhammad; Monim-ul-Mehboob, Muhammad; Kawde, Abdel-Nasser; Corona, Giuseppe; Larcher, Roberto; Ogasawara, Marcia; Casagrande, Naike; Celegato, Marta; Borghese, Cinzia; Siddik, Zahid H.; Aldinucci, Donatella; Isab, Anvarhusein A.

    2017-01-01

    We synthesized, characterized and tested in a panel of cancer cell lines, nine new bipyridine gold(III) dithiocarbamate-containing complexes. In vitro studies demonstrated that compounds 1, 2, 4, 5, 7 and 8 were the most cytotoxic in prostate, breast, ovarian cancer cell lines and in Hodgkin lymphoma cells with IC50 values lower than the reference drug cisplatin. The most active compound 1 was more active than cisplatin in ovarian (A2780cis and 2780CP-16) and breast cancer cisplatin-resistant cells. Compound 1 determined an alteration of the cellular redox homeostasis leading to increased ROS levels, a decrease in the mitochondrial membrane potential, cytochrome-c release from the mitochondria and activation of caspases 9 and 3. The ROS scavenger NAC suppressed ROS generation and rescued cells from damage. Compound 1 resulted more active in tumor cells than in normal human Mesenchymal stromal cells. Gold compounds were active independent of p53 status: exerted cytotoxic effects on a panel of non-small cell lung cancer cell lines with different p53 status and in the ovarian A2780 model where the p53 was knocked out. In conclusion, these promising results strongly indicate the need for further preclinical evaluation to test the clinical potential of these new gold(III) complexes. PMID:27888799

  12. Theoretical investigations of the structures and electronic spectra of Zn(II) and Ni(II) complexes with cyclohexylamine-N-dithiocarbamate

    NASA Astrophysics Data System (ADS)

    Yu, Xiaohan; Wang, Na; He, Hongqing; Wang, Li

    2014-03-01

    The ground-state structures of two ligands cyclohexylamine-N-dithiocarbamate (L) and PPh3 and four complexes [Zn(L)2] (A), [Ni(L)2] (B), [Zn(L)2PPh3] (C), and [Ni(L)2PPh3] (D) are optimized by M06, B3LYP, and B3PW91 methods with the same mixed basis set. As compared with the experimental data of other complexes containing the Ni-P bond, the result obtained by M06/6-31+G(d)-LANL2DZ method is finally regarded as accurate and reliable for this project. Based on the optimized geometries, the compositions of molecular orbitals are analyzed and the absorption spectra are simulated. When one more ligand PPh3 is coordinated, the lowest-lying transition energy presents red-shift; while it shows blue-shift when the metal coordination center change from Ni to Zn with the same ligands. The detailed transition characters related with the absorption spectrum are assigned. In all the key transitions, it is hard to find the contribution from Zn atom. On the contrary, the d orbital of Ni atom contributes a lot for the HOMO and LUMO of complexes B and D. Consequently, the transition characters of Zn(II) and Ni(II) complexes are different.

  13. Cyclen dithiocarbamate-functionalized silver nanoparticles as a probe for colorimetric sensing of thiram and paraquat pesticides via host-guest chemistry

    NASA Astrophysics Data System (ADS)

    Rohit, Jigneshkumar V.; Kailasa, Suresh Kumar

    2014-11-01

    We have developed a simple and rapid colorimetric method for on-site analysis of thiram and paraquat using cyclen dithiocarbamate-functionalized silver nanoparticles (CN-DTC-Ag NPs) as a colorimetric probe. The synthesized CN-DTC-Ag NPs were characterized by UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy, dynamic light scattering, and transmission electron microscopic techniques. The CN-DTC molecules provide good supramolecular self assembly on the surfaces of Ag NPs to encapsulate thiram and paraquat selectively via "host-guest" chemistry, resulting in red-shift in surface plasmon resonance peak of CN-DTC-Ag NPs from 396 to 530 nm and 510 nm and color change from yellow to pink for thiram and to orange for paraquat, which can be naked-eye detected. The present method shows good linearity in the range of 10.0-20.0 µM and of 50.0-250 µM with limits of detection 2.81 × 10-6 M and 7.21 × 10-6 M for thiram and paraquat, respectively. This method was proved as a promising tool for on-site and real-time monitoring of thiram and paraquat in environmental water, potato, and wheat samples.

  14. Crystal structure and carrier transport properties of a new 3D mixed-valence Cu(I)-Cu(II) coordination polymer including pyrrolidine dithiocarbamate ligand.

    PubMed

    Okubo, Takashi; Tanaka, Naoya; Kim, Kyung Ho; Anma, Haruho; Seki, Shu; Saeki, Akinori; Maekawa, Masahiko; Kuroda-Sowa, Takayoshi

    2011-03-14

    A novel mixed-valence Cu(i)-Cu(ii) coordination polymer having an infinite three-dimensional (3D) structure, {[Cu(I)(4)Cu(II)(2)Br(4)(Pyr-dtc)(4)]·CHCl(3)}(n) (1) (Pyr-dtc(-) = pyrrolidine dithiocarbamate), has been prepared and structurally characterized via X-ray diffraction. This complex consists of 1D Cu(i)-Br chains and bridging mononuclear copper(ii) units of Cu(II)(Pyr-dtc)(2), which form an infinite 3D network. A magnetic study indicates that this complex includes copper(ii) ions exhibiting a weak antiferromagnetic interaction (θ = -0.086 K) between the unpaired electrons of the copper(ii) ions present in the diamagnetic Cu(i)-Br chains. The carrier transport properties of 1 are investigated using an impedance spectroscopy technique and flash-photolysis time-resolved microwave conductivity measurement (FP-TRMC). The impedance spectroscopy reveals that this complex exhibits intriguing semiconducting properties at a small activation energy (E(a) = 0.29 eV (bulk)). The sum of the mobilities of the negative and positive carriers estimated via FP-TRMC is Σμ∼ 0.4 cm(2) V(-1) s(-1).

  15. Core-shell magnetite-silica dithiocarbamate-derivatised particles achieve the Water Framework Directive quality criteria for mercury in surface waters.

    PubMed

    Lopes, C B; Figueira, P; Tavares, D S; Lin, Z; Daniel-da-Silva, A L; Duarte, A C; Rocha, J; Trindade, T; Pereira, E

    2013-09-01

    The sorption capacity of nanoporous titanosilicate Engelhard titanosilicate number 4 (ETS-4) and silica-coated magnetite particles derivatised with dithiocarbamate groups towards Hg(II) was evaluated and compared in spiked ultra-pure and spiked surface-river water, for different batch factors. In the former, and using a batch factor of 100 m(3)/kg and an initial Hg(II) concentrations matching the maximum allowed concentration in an effluent discharge, both materials achieve Hg(II) uptake efficiencies in excess of 99 % and a residual metal concentration lower than the guideline value for drinking water quality. For the surface-river water and the same initial concentration, the Hg(II) uptake efficiency of magnetite particles is outstanding, achieving the quality criteria established by the Water Framework Directive (concerning Hg concentration in surface waters) using a batch factor of 50 m(3)/kg, while the efficiency of ETS-4 is significantly inferior. The dissimilar sorbents' Hg(II) removal efficiency is attributed to different uptake mechanisms. This study also highlights the importance of assessing the effective capacity of the sorbents under realistic conditions in order to achieve trustable results.

  16. Determination of lead in blood by chelation with ammonium pyrrolidine dithio-carbamate followed by tungsten-coil atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Salido, Arthur; Sanford, Caryn L.; Jones, Bradley T.

    1999-08-01

    An inexpensive, bench-top blood Pb analyzer has been developed. The system is based on tungsten-coil atomic absorption spectrometry. Pb atomization occurs on W-coils extracted from commercially available slide projector bulbs. The system has minimal power requirements: 120 ACV and 15 A. A small, computer-controlled CCD spectrometer is used as the detector. A Pb hollow cathode lamp is used as the source. Blood Pb is chelated with ammonium pyrrolidine dithio-carbamate and extracted into methyl iso-butyl ketone (4-methyl 2-pentanone). Twenty-microliter volumes of the organic phase are deposited on the W-coil, dried at 1.4 A, charred at 2.3 A and atomized at 6.0 A. Graphite furnace atomic absorption spectrometry is used as a comparison for W-coil results. Levels 1-4 of a NIST standard reference material 955b ‘lead in bovine blood’ are used to test accuracy and precision. The analytical figures of merit for the system are: 12-pg instrument detection limit, 24-pg blood detection limit and a characteristic mass of 28 pg.

  17. Hydrido copper clusters supported by dithiocarbamates: oxidative hydride removal and neutron diffraction analysis of [Cu7(H){S2C(aza-15-crown-5)}6].

    PubMed

    Liao, Ping-Kuei; Fang, Ching-Shiang; Edwards, Alison J; Kahlal, Samia; Saillard, Jean-Yves; Liu, C W

    2012-06-18

    Reactions of Cu(I) salts with Na(S(2)CR) (R = N(n)Pr(2), NEt(2), aza-15-crown-5), and (Bu(4)N)(BH(4)) in an 8:6:1 ratio in CH(3)CN solution at room temperature yield the monocationic hydride-centered octanuclear Cu(I) clusters, [Cu(8)(H){S(2)CR}(6)](PF(6)) (R = N(n)Pr(2), 1(H); NEt(2), 2(H); aza-15-crown-5, 3(H)). Further reactions of [Cu(8)(H){S(2)CR}(6)](PF(6)) with 1 equiv of (Bu(4)N)(BH(4)) produced neutral heptanuclear copper clusters, [Cu(7)(H){S(2)CR}(6)] (R = N(n)Pr(2), 4(H); NEt(2), 5(H); aza-15-crown-5, 6(H)) and clusters 4-6 can also be generated from the reaction of Cu(BF(4))(2), Na(S(2)CR), and (Bu(4)N)(BH(4)) in a 7:6:8 molar ratio in CH(3)CN. Reformation of cationic Cu(I)(8) clusters by adding 1 equiv of Cu(I) salt to the neutral Cu(7) clusters in solution is observed. Intriguingly, the central hydride in [Cu(8)(H){S(2)CN(n)Pr(2)}(6)](PF(6)) can be oxidatively removed as H(2) by Ce(NO(3))(6)(2-) to yield [Cu(II)(S(2)CN(n)Pr(2))(2)] exploiting the redox-tolerant nature of dithiocarbamates. Regeneration of hydride-centered octanuclear copper clusters from the [Cu(II)(S(2)CN(n)Pr(2))(2)] can be achieved by reaction with Cu(I) ions and borohydride. The hydride release and regeneration of Cu(I)(8) was monitored by UV-visible titration experiments. To our knowledge, this is the first time that hydride encapsulated within a copper cluster can be released as H(2) via chemical means. All complexes have been fully characterized by (1)H NMR, FT-IR, UV-vis, and elemental analysis, and molecular structures of 1(H), 2(H), and 6(H) were clearly established by single-crystal X-ray diffraction. Both 1(H) and 2(H) exhibit a tetracapped tetrahedral Cu(8) skeleton, which is inscribed within a S(12) icosahedron constituted by six dialkyl dithiocarbamate ligands in a tetrametallic-tetraconnective (μ(2), μ(2)) bonding mode. The copper framework of 6(H) is a tricapped distorted tetrahedron in which the four-coordinate hydride is demonstrated to occupy the central site by

  18. Exposure to glyphosate- and/or Mn/Zn-ethylene-bis-dithiocarbamate-containing pesticides leads to degeneration of γ-aminobutyric acid and dopamine neurons in Caenorhabditis elegans.

    PubMed

    Negga, Rekek; Stuart, J Andrew; Machen, Morgan L; Salva, Joel; Lizek, Amanda J; Richardson, S Jayne; Osborne, Amanda S; Mirallas, Oriol; McVey, Kenneth A; Fitsanakis, Vanessa A

    2012-04-01

    Previous studies demonstrate a positive correlation between pesticide usage and Parkinson's disease (PD), which preferentially targets dopaminergic (DAergic) neurons. In order to examine the potential relationship between two common pesticides and specific neurodegeneration, we chronically (24 h) or acutely (30 min) exposed two Caenorhabditis elegans (C. elegans) strains to varying concentrations (LC(25), LC(50) or LC(75)) of TouchDown(®) (TD) as percent active ingredient (glyphosate), or Mancozeb(®) (MZ) as percent active ingredient (manganese/zinc ethylene-bis-dithiocarbamate). Furthermore, to more precisely model environmental exposure, worms were also exposed to TD for 30 min, followed by 30-min incubation with varying MZ concentrations. Previous data from out lab suggested general neuronal degeneration using the worm strain NW1229 (pan-neuronal//green fluorescent protein (GFP) construct). To determine whether distinct neuronal groups were preferentially affected, we specifically used EG1285 (GABAergic neurons//GFP construct) and BZ555 (DAergic neurons//GFP construct) worms to verify GABAergic and DAergic neurodegeneration, respectively. Results indicated a statistically significant decrease, when compared to controls (CN), in number of green pixels associated with GABAergic neurons in both chronic (*P < 0.05) and acute (*P < 0.05) treatment paradigms. Analysis of the BZ555 worms indicated a statistically significant decrease (*P < 0.05) in number of green pixels associated with DAergic neurons in both treatment paradigms (chronic and acute) when compared to CN. Taken together, our data suggest that exposure to TD and/or MZ promotes neurodegeneration in both GABAergic and DAergic neurons in the model organism C. elegans.

  19. Pyrrolidine Dithiocarbamate Inhibits Nuclear Factor κB and Toll-Like Receptor 4 Expression in Rats with Acute Necrotizing Pancreatitis

    PubMed Central

    Xu, Min; Wang, Kun-Ning; Wu, Kai; Wang, Xing-Peng

    2015-01-01

    Background/Aims To investigate the expression of Toll-like receptor 4 (TLR4) in the pancreases of rats with acute necrotizing pancreatitis (ANP) and any changes upon treatment with pyrrolidine dithiocarbamate (PDTC), an inhibitor of nuclear factor κB (NF-κB), as well as to determine the relationship between TLR4 and NF-κB in ANP pathogenesis. Methods A total of 72 SD rats were randomly divided into three groups, namely, the control (sham-operation), ANP, and ANP with PDTC pretreatment groups. The PDTC-pretreated group was intraperitoneally injected with PDTC at a dose of 100 mg/kg 1 hour before the induction of ANP. The expressions of TLR4 and NF-κB in pancreatic tissue were evaluated by immunohistochemistry and Western blot analysis. The mRNA levels of cytokines tumor necrosis factor α, interleukin (IL)-1β, and IL-6 were measured by reverse transcription polymerase chain reaction. Results The expressions of TLR4, NF-κB, and cytokine (NF-κB target) genes in the pancreatic tissue increased more significantly in the ANP groups than in the sham-operation group at 3, 6, and 12 hours. Pretreatment with PDTC alleviated the inflammatory activation in the pancreas with ANP, causing a significant decrease in the expressions of TLR4, NF-κB, and cytokine genes in the pancreatic tissue. Conclusions The expressions of TLR4 and NF-κB were increased in the pancreases of rats with ANP. PDTC not only inhibits NF-κB but also suppresses the expression of TLR4 and downregulates the expression of the related cytokine genes. PMID:25287011

  20. Separation of heavy metal from water samples--The study of the synthesis of complex compounds of heavy metal with dithiocarbamates.

    PubMed

    Kane, Sonila; Lazo, Pranvera; Ylli, Fatos; Stafilov, Trajce; Qarri, Flora; Marku, Elda

    2016-01-01

    The toxicity and persistence of heavy metal (HM) ions may cause several problems to marine organisms and human beings. For this reason, it is growing the interest in the chemistry of sulphur donor ligands such as dithiocarbamates (DDTC), due to their applications particularly in analytical chemistry sciences. The aim of this work has been the study of heavy metal complexes with DDTC and their application in separation techniques for the preconcentration and/or removing of heavy metals from the water solutions or the water ecosystems prior to their analysis. The HM-DDTC complexes were prepared and characterized by elemental analysis, FTIR and UV-Vis spectroscopic methods. The elemental analysis and the yield of the synthesis (97.5-99.9%) revealed a good purity of the complexes. High values of complex formation yields of HM-DDTC complexes is an important parameter for quantitatively removing/and or preconcentration of heavy metal ions from water solution even at low concentration of heavy metals. Significant differences founded between the characteristic parameters of UV/Vis (λmax and ϵmax) and FTIR absorption spectra of the parent DDTC and HM-DDTC complexes revealed the complex formation. The presence of the peaks at the visible spectral zone is important to M(nd(10-m))-L electron charge transfer of the new complexes. The (C=N) (1450-1500 cm(-1)) and the un-splitting (C-S) band (950-1002 cm(-1)) in HM-DDTC FTIR spectra are important to the identification of their bidentate mode (HM[S2CNC4H10]2). The total CHCl3 extraction of trace level heavy metals from water samples after their complex formation with DDTC is reported in this article.

  1. Pyrrolidine dithiocarbamate administered during ex-vivo lung perfusion promotes rehabilitation of injured donor rat lungs obtained after prolonged warm ischemia

    PubMed Central

    Francioli, Cyril; Wang, Xingyu; Parapanov, Roumen; Abdelnour, Etienne; Lugrin, Jérôme; Gronchi, Fabrizio; Perentes, Jean; Eckert, Philippe; Ris, Hans-Beat; Piquilloud, Lise

    2017-01-01

    Damaged lung grafts obtained after circulatory death (DCD lungs) and warm ischemia may be at high risk of reperfusion injury after transplantation. Such lungs could be pharmacologically reconditioned using ex-vivo lung perfusion (EVLP). Since acute inflammation related to the activation of nuclear factor kappaB (NF-κB) is instrumental in lung reperfusion injury, we hypothesized that DCD lungs might be treated during EVLP by pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB. Rat lungs exposed to 1h warm ischemia and 2 h cold ischemia were subjected to EVLP during 4h, in absence (CTRL group, N = 6) or in presence of PDTC (2.5g/L, PDTC group, N = 6). Static pulmonary compliance (SPC), peak airway pressure (PAWP), pulmonary vascular resistance (PVR), and oxygenation capacity were determined during EVLP. After EVLP, we measured the weight gain of the heart-lung block (edema), and the concentration of LDH (cell damage), proteins (permeability edema) and of the cytokines IL-6, TNF-α and CINC-1 in bronchoalveolar lavage (BAL), and we evaluated NF-κB activation by the degree of phosphorylation and degradation of its inhibitor IκBα in lung tissue. In CTRL, we found significant NF-κB activation, lung edema, and a massive release of LDH, proteins and cytokines. SPC significantly decreased, PAWP and PVR increased, while oxygenation tended to decrease. Treatment with PDTC during EVLP inhibited NF-κB activation, did not influence LDH release, but markedly reduced lung edema and protein concentration in BAL, suppressed TNFα and IL-6 release, and abrogated the changes in SPC, PAWP and PVR, with unchanged oxygenation. In conclusion, suppression of innate immune activation during EVLP using the NF-κB inhibitor PDTC promotes significant improvement of damaged rat DCD lungs. Future studies will determine if such rehabilitated lungs are suitable for in vivo transplantation. PMID:28323904

  2. Disruption of the hypothalamic-pituitary-thyroid axis on co-exposures to dithiocarbamate and neonicotinoid pesticides: Study in a wildlife bird, Amandava amandava.

    PubMed

    Pandey, Surya Prakash; Mohanty, Banalata

    2017-02-22

    Non-target organisms, including human and wildlife, are susceptible to deleterious effects of pesticide mixtures in their environment. Present study demonstrated the disruption of the hypothalamic-pituitary-thyroid (HPT) axis in a seasonally breeding wildlife bird Amandava amandava on co-exposure to dithiocarbamate mancozeb/MCZ and neonicotinoid imidacloprid/IMI, at concentrations even lower than respective environmentally realistic exposure level of each of the pesticide. Adult male birds (n=8/group) were exposed individually to 0.25% LD50 of each of MCZ (0.14mg) and IMI (2.75μl) followed by co-exposure to their equimixture as MIX-I (0.25% LD50 of each) and MIX-II (0.5% LD50 of each) through food for 30d in preparatory phase of reproductive cycle. Disruptions of thyroid gland and pituitary-thyroid axis were evident. Altered thyroid weight and volume, follicles with inactive colloids and lesions, decrease of height and nucleus-to-cytoplasm ratio of follicular epithelial cells were noted. Plasma levels of T4 and T3 were decreased, more significant in mixture groups than in individually exposed groups. Within co-exposed groups, comparatively high plasma T4 and T3 levels in MIX-II than MIX-I indicated dose non-responsiveness of the pesticides in mixtures; a characteristic displayed by endocrine disrupters. Plasma TSH level was increased in MCZ- and IMI- but decreased in MIX-I and MIX-II suggesting the disruption of the negative feedback and impairment of the HPT axis in co-exposed groups. Effects were more prominent in co-exposed groups due to combinatorial action and cumulative toxicity of pesticides. Considering the role of thyroid hormones in reproductive development, pesticides even in low dose could affect the thyroid homeostasis and reproductive axis.

  3. An analytical method for hydrogeochemical surveys: Inductively coupled plasma-atomic emission spectrometry after using enrichment coprecipitation with cobalt and ammonium pyrrolidine dithiocarbamate

    USGS Publications Warehouse

    Hopkins, D.M.

    1991-01-01

    Trace metals that are commonly associated with mineralization were concentrated and separated from natural water by coprecipitation with ammonium pyrollidine dithiocarbamate (APDC) and cobalt and determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The method is useful in hydrogeochemical surveys because it permits preconcentration near the sample sites, and selected metals are preserved shortly after the samples are collected. The procedure is relatively simple: (1) a liter of water is filtered; (2) the pH is adjusted; (3) Co chloride and APDC are added to coprecipitate the trace metals; and (4) later, the precipitate is filtered, dissolved, and diluted to 10 ml for a 100-fold concentration enrichment of the separated metals. Sb(III), As(III), Cd, Cr, Cu, Fe, Pb, Mo, Ni, Ag, V, and Zn can then be determined simultaneously by ICP-AES. In an experiment designed to measure the coprecipitation efficiency, Sb(III), Cd and Ag were recovered at 70 to 75% of their original concentration. The remaining metals were recovered at 85 to 100% of their original concentrations, however. The range for the lower limits of determination for the metals after preconcentration is 0.1 to 3.0 ??g/l. The precision of the method was evaluated by replicate analyses of a Colorado creek water and two simulated water samples. The accuracy of the method was estimated using a water reference standard (SRM 1643a) certified by the U.S. National Bureau of Standards. In addition, the method was evaluated by analyzing groundwater samples collected near a porphyry copper deposit in Arizona and by analyzing meltwater from glacier-covered areas favorable for mineralization in south-central Alaska. The results for the ICP-AES analyses compared favorably with those obtained using the sequential technique of GFAAS on the acidified but unconcentrated water samples. ICP-AES analysis of trace-metal preconcentrates for hydrogeochemical surveys is more efficient than GFAAS because a

  4. Crystal structure of tin(IV) chloride octa-hydrate.

    PubMed

    Hennings, Erik; Schmidt, Horst; Voigt, Wolfgang

    2014-12-01

    The title compound, [SnCl4(H2O)2]·6H2O, was crystallized according to the solid-liquid phase diagram at lower temperatures. It is built-up of SnCl4(H2O)2 octa-hedral units (point group symmetry 2) and lattice water mol-ecules. An intricate three-dimensional network of O-H⋯O and O-H⋯Cl hydrogen bonds between the complex molecules and the lattice water molecules is formed in the crystal structure.

  5. Synthesis, characterisation and biological aspects of copper(II) dithiocarbamate complexes, [Cu{S2CNR(CH2CH2OH)}2], (R = Me, Et, Pr and CH2CH2OH)

    NASA Astrophysics Data System (ADS)

    de Lima, Geraldo M.; Menezes, Daniele C.; Cavalcanti, Camila A.; dos Santos, Jaqueline A. F.; Ferreira, Isabella P.; Paniago, Eucler B.; Wardell, James L.; Wardell, Solange M. S. V.; Krambrock, Klaus; Mendes, Isolda C.; Beraldo, Heloisa

    2011-03-01

    Cu(II) dithiocarbamates, [Cu{S2CNR(CH2CH2OH)}2], R = Me (1), Et (2), Pr (3) and CH2CH2OH (4), have been prepared from HNR(CH2CH2OH) (R = Me, Et, Pr and CH2CH2OH), CS2 and Cu(OAc)2. Characterisation of the complexes were generally achieved by infrared and EPR spectroscopies and, in addition, for (2) and (3), by X-ray crystallography at 120 K. Complex (2) crystallises as a Cu-S linked dimer, in which the CH2CH2OH groups have a cis arrangement in each monomer but are trans to those in the other monomer partner. On the other hand complex (3) exists in the solid state in the form of two similar and independent centrosymmetric monomers. The weak antiferromagnetic coupling, present in similar complexes, was absent in complexes (1)-(3). The in vitro activity of (1)-(4) was investigated against colonies of Candida albicans, Sthaphyloccocus aureus and Pseudomonas aeruginosa. They all displayed MIC (minimal inhibitory concentration) values against C. albicans close to those found for Fluconazole. All complexes were inert towards Gram-negative or Gram-positive bacteria, S. aureus and P. auruginosa, respectively.

  6. Variation of the Molecular Conformation, Shape, and Cavity Size in Dinuclear Metalla-Macrocycles Containing Hetero-Ditopic Dithiocarbamate-Carboxylate Ligands from a Homologous Series of N-Substituted Amino Acids.

    PubMed

    Torres-Huerta, Aaron; Cruz-Huerta, Jorge; Höpfl, Herbert; Hernández-Vázquez, Luis G; Escalante-García, Jaime; Jiménez-Sánchez, Arturo; Santillan, Rosa; Hernández-Ahuactzi, Irán F; Sánchez, Mario

    2016-12-05

    A homologous series of dithiocarbamate ligands derived from N-substituted amino acids was reacted with different diorganotin dichlorides to give 18 diorganotin complexes. Spectroscopic and mass spectrometric analysis evidenced the formation of assemblies with six-coordinate tin atoms embedded in skewed-trapezoidal bipyramidal coordination environments of composition C2SnS2O2. Single-crystal X-ray diffraction analysis for three of the compounds revealed a one-dimensional polymeric structure for the complex with the ligand derived from 5-aminopentanoic acid, which through further intermolecular Sn···O interactions generated an overall two-dimensional coordination polymer containing 40-membered hexanuclear tin macrocycles. On the contrary, the ligands derived from 6-aminohexanoic and 8-aminooctanoic acid provided the expected 22- and 26-membered dinuclear macrocyclic structures. Density functional theory calculations for a representative series of macrocyclic complexes of composition [Me2SnLx]2 with Lx = ¯S2CN(Me)-(CH2)x-COO¯ (x = 3-12) enabled a detailed analysis of the variations in the molecular conformation, shape, and cavity size of the macrocycles in dependence of the aliphatic spacer. Because of odd-even effects, the difunctional ligands can adopt either a curved or a twisted-pincer shape, while the SnSxO4-x (x = 0-4) moieties can act either as linear or angular tectons with varying connectivity angles.

  7. The characteristic long-term upregulation of hippocampal NF-κB complex in PTSD-like behavioral stress response is normalized by high-dose corticosterone and pyrrolidine dithiocarbamate administered immediately after exposure.

    PubMed

    Cohen, Hagit; Kozlovsky, Nitsan; Matar, Michael A; Zohar, Joseph; Kaplan, Zeev

    2011-10-01

    Nuclear factor-κB (NF-κB) is a ubiquitously expressed transcription factor for genes involved in cell survival, differentiation, inflammation, and growth. This study examined the role of NF-κB pathway in stress-induced PTSD-like behavioral response patterns in rats. Immunohistochemical technique was used to detect the expression of the NF-κB p50 and p65 subunits, I-κBα, p38, and phospho-p38 in the hippocampal subregions at 7 days after exposure to predator scent stress. Expression of p65 nuclear translocation was quantified by western blot as the level of NF-κB activation. The effects of intraperitoneally administered corticosterone or a selective NF-κB inhibitor (pyrrolidine dithiocarbamate (PDTC)) at 1 h post exposure on behavioral tests (elevated plus-maze and acoustic startle response) were evaluated 7 days later. Hippocampal expressions of those genes were subsequently evaluated. All data were analyzed in relation to individual behavior patterns. Extreme behavioral responder animals displayed significant upregulation of p50 and p65 with concomitant downregulation of I-κBα, p38, and phospho-p38 levels in hippocampal structures compared with minimal behavioral responders and controls. Immediate post-exposure treatment with high-dose corticosterone and PDTC significantly reduced prevalence rates of extreme responders and normalized the expression of those genes. Stress-induced upregulation of NF-κB complex in the hippocampus may contribute to the imbalance between what are normally precisely orchestrated and highly coordinated physiological and behavioral processes, thus associating it with stress-related disorders.

  8. Synthesis, spectral, single crystal X-ray structural, CShM and BVS characterization of iron(III) cyclohexyl dithiocarbamates and their solvothermal decomposition to nano iron(II) sulphide

    NASA Astrophysics Data System (ADS)

    Ramalingam, K.; Srinivasan, S.

    2015-11-01

    [Fe(chmdtc)3] (1), [Fe(chedtc)3] (2), [Fe(achdtc)3] (3) and [Fe(chpdtc)3] (4) (where chmdtc = cyclohexylmethylcarbodithioate, chedtc = cyclohexylethylcarbodithioate, achdtc = allylcyclohexylcarbodithioate and chpdtc = cyclohexylpiperazinecarbodithioate) have been prepared and characterisized by elemental analysis, electronic, IR spectral, magnetic susceptibility, thermogravimetric analysis. The single crystal X-ray crystal structures of [Fe(chedtc)3] (2)and [Fe(chpdtc)3] (4) have been determined. Characteristic thioureide IR bands occur at 1483, 1477, 1454 and 1479 cm-1 for (1), (2), (3) and (4) respectively. Electronic spectral bands at 514,512,510 and 510 nm for (1), (2), (3) and (4) respectively are due to dxy → dx2 - y2 transition. One electron quasi reversible reductions due to Fe(III)/Fe(II) redox process are observed in CV. Magnetic susceptibility measurements exhibit a temperature dependent variation. Final residue obtained in thermal processes is FeS, which indicates the reduction of Fe(III) → Fe(II). Single crystal X-ray structures of [Fe(chedtc)3] (2)and [Fe(chpdtc)3] (4) show that the central atom is in a distorted octahedral environment. The CShM values have been calculated from the structural data as 2.5807 and 3.2329 for (2) and (4) respectively in a scale of zero to hundred. The observed values show that compound (4) is relatively more distorted than (2) in its octahedral coordination due to the steric demands of the cyclohexyl ring attached to piperazine. Both of them prefer octahedral coordination environment over trigonal prism. Bond Valence Sum (BVS) calculations confirmed the oxidation state of iron as +3. A non conventional solvothermal formation of FeS nano particles is reported with iron dithiocarbamates as single source precursors. Morphology and composition of the nano product have been characterized by PXRD and EDX analysis.

  9. An unprecedented binuclear cadmium di-thio-carbamate adduct: bis-[μ2-N-(2-hydroxy-eth-yl)-N-iso-propyl-carbamodi-thio-ato-κ(3)S:S,S']bis-{[N-(2-hydroxy-eth-yl)-N-iso-propyl-carbamodi-thio-ato-κ(2)S,S'](3-{(1E)-[(E)-2-(pyridin-3-yl-methyl-idene)hydrazin-1-yl-idene]meth-yl}pyridine-κN)cadmium]} dihydrate.

    PubMed

    Arman, Hadi D; Poplaukhin, Pavel; Tiekink, Edward R T

    2016-09-01

    The asymmetric unit in the title binuclear compound, [Cd(C6H12NOS2)2(C12H10N4)]2·2H2O, comprises a Cd(II) atom, two di-thio-carbamate (dtc) anions, a monodentate 3-pyridine-aldazine ligand and a lattice water mol-ecule. The binuclear mol-ecule is constructed by the application of inversion symmetry. One dtc ligand simultaneously chelates one cadmium atom and bridges the centrosymmetric mate, while the other dtc ligand is chelating only. This leads to a centrosymmetric [Cd(dtc)2]2 core to which are appended two 3-pyridine-aldazine ligands. The resulting NS5 donor set is based on an octa-hedron. The three-dimensional mol-ecular packing is sustained by hydroxyl-O-H(hydrox-yl) and water-O-H⋯O(hydrox-yl) hydrogen bonding, leading to supra-molecular layers parallel to (101) which are connected by water-O-H⋯N(pyrid-yl) hydrogen bonding; additional C-H⋯O, S π(chelate ring) inter-actions are also evident. The retention of the central [Cd(dtc)2]2 core upon adduct formation is unprecedented in the structural chemistry of the zinc-triad di-thio-carbamates.

  10. Versatile Catalytic Hydrogenation Using A Simple Tin(IV) Lewis Acid

    PubMed Central

    Scott, Daniel J.; Phillips, Nicholas A.; Sapsford, Joshua S.; Deacy, Arron C.; Fuchter, Matthew J.

    2016-01-01

    Abstract Despite the rapid development of frustrated Lewis pair (FLP) chemistry over the last ten years, its application in catalytic hydrogenations remains dependent on a narrow family of structurally similar early main‐group Lewis acids (LAs), inevitably placing limitations on reactivity, sensitivity and substrate scope. Herein we describe the FLP‐mediated H2 activation and catalytic hydrogenation activity of the alternative LA iPr3SnOTf, which acts as a surrogate for the trialkylstannylium ion iPr3Sn+, and is rapidly and easily prepared from simple, inexpensive starting materials. This highly thermally robust LA is found to be competent in the hydrogenation of a number of different unsaturated functional groups (which is unique to date for main‐group FLP LAs not based on boron), and also displays a remarkable tolerance to moisture. PMID:27774711

  11. Tin(IV) derivatives of 2,6-pyridinedicarboxylate: A 119Sn Mössbauer spectroscopic investigation

    NASA Astrophysics Data System (ADS)

    Costa, Luiz C. M.; Maia, José Roberto da S.; de Lima, Geraldo M.; Ardisson, José D.

    2006-02-01

    A series of organotin(IV) derivatives of 2,6-pyridinedicarboxylate has been investigated by Mössbauer spectroscopy in order to elucidate aspects concerning bonding and structural features in the solid state. A geometrical pattern of five-fold coordination at the metal centre has been revealed for SnCl 3Bu and SnClBu 3 derivatives. Trans stereochemistry for the butyl and vinyl groups of SnCl 2Bu 2 and SnCl 2(Vin) 2 derivatives has also been identified by this method. The isomer shift for the divinyl derivative is concurrent to a 7-coordinate metal centre contrasting to that for the dibutyl one. Although there is a discrepancy in isomer shift between these compounds, both have seven-fold coordination at the Sn(IV) nucleus. The resulting data has given evidence that 2,6-pyridinedicarboxylate is acting as a tridentate ligand through pyridil and carbolxylate moiety to all derivatives except for SnClBu 3. For the latter, the coordination mode occurs via carboxylate groups. The overall data support distorted geometrical pattern to all complexes in solid state.

  12. DNA damage in Wistar rats exposed to dithiocarbamate pesticide mancozeb.

    PubMed

    Goldoni, A; Klauck, C R; Da Silva, S T; Da Silva, M D; Ardenghi, P G; Da Silva, L B

    2014-01-01

    Pesticides are used in large amounts in agriculture and the evaluation of their toxic effects is of major concern to public and environmental health. The aim of the present study was to investigate the genotoxic potential of a commercial formulation of the fungicide mancozeb by the micronucleus test in bone marrow and the comet assay in total blood of Wistar rats. Adult male Wistar rats were treated with a solution of mancozeb at a concentration of 40 mg/kg/day, administered intraperitoneally for 18 consecutive days, and compared to a control group. The results indicate that mancozeb induced significantly higher DNA damage as detected by the comet assay and increased the frequency of micronuclei. The results show that mancozeb is genotoxic and may adversely affect the DNA integrity of exposed organisms.

  13. Synthesis, characterization, structural and biological aspects of copper(II) dithiocarbamate complexes - Part II, [Cu{S2CN(Me)(R1)}2], [Cu{S2CN(Me)(R2)}2] and [Cu{S2CN(R3)(R4)}2] {R1 = CH2CH(OMe)2, R2 = 2-methyl-1,3-dioxolane, R3 = CH2(CH2)2NCHPhOCH2Ph and R4 = CH2CH2OH}

    NASA Astrophysics Data System (ADS)

    Ferreira, Isabella P.; de Lima, Geraldo M.; Paniago, Eucler B.; Takahashi, Jacqueline A.; Krambrock, Klaus; Pinheiro, Carlos B.; Wardell, James L.; Visentin, Lorenzo C.

    2013-09-01

    Three new copper(II) dithiocarbamates (DTC), [Cu{S2CN(Me)(R1)}2] (1), [Cu{S2CN(Me)(R2)}2] (2) and [Cu{S2CN(R3)(R4)}2] (3) with R1 = CH2CH(OMe)2, R2 = 2-methyl-1,3-dioxolane, R3 = CH2(CH2)2NCHPhOCH2Ph and R4 = CH2CH2OH, have been synthesized and characterized by different spectroscopic techniques. Complexes (1) and (2) display typical EPR spectra for separated Cu(II) centers, and the spectrum of (3) is characteristic of two magnetically coupled Cu(II) ions with S = 1. The X-ray crystallographic determination has shown that complexes (1) and (2) crystallise in the triclinic and monoclinic systems. In addition both complexes are monomers in which the geometry at each Cu(II) is square planar. The in vitro antimicrobial activity of the sodium salts of ligands, and of the Cu(II)-DTC complexes have been screened against Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Penicillium citrinum and Curvularia senegalensis, as well as Gram positive and Gram negative bacteria. Finally, the toxic effects of complexes (1)-(3) were performed using Chlorella vulgaris.

  14. Hybrid porous tin(IV) phosphonate: an efficient catalyst for adipic acid synthesis and a very good adsorbent for CO2 uptake.

    PubMed

    Dutta, Arghya; Pramanik, Malay; Patra, Astam K; Nandi, Mahasweta; Uyama, Hiroshi; Bhaumik, Asim

    2012-07-07

    A new porous organic-inorganic hybrid tin phosphonate material has been synthesized hydrothermally, which shows a Brunauer-Emmett-Teller surface area of 723 m(2) g(-1) and it adsorbs 4.8 mmol g(-1) CO(2) at 273 K and 5 bar pressure. The material also shows remarkable catalytic activity in one-pot liquid phase oxidation of cyclohexanone to adipic acid under eco-friendly conditions.

  15. Microemulsion-mediated solvothermal synthesis of tin(IV) hydrogen phosphate rose-like three-dimensional nanostructures and their electrochemical properties

    SciTech Connect

    Yang Hui; He Xiaoyan; Cao Minhua

    2009-03-05

    Novel rose-like three-dimensional Sn(HPO{sub 4}){sub 2}.H{sub 2}O nanostructures self-assembled by tightly stacked nanopetals were successfully synthesized by a simple cetyltrimethylammonium bromide (CTAB)/water/cyclohexane/n-pentanol microemulsion system under solvothermal conditions for the first time. A series of compared experiments were carried out to investigate the factors that influence the morphology and size of the products. It was found that the molar ratio of water to CTAB and the concentration of SnCl{sub 4} aqueous solution play important roles in the formation of the rose-like nanostructures. A possible formation mechanism of rose-like nanostructures was proposed, which may be related to the crystal structure of Sn(HPO{sub 4}){sub 2}.H{sub 2}O and the spherical micelles formed by the microemulsion. The electrochemical properties of Sn(HPO{sub 4}){sub 2}.H{sub 2}O were investigated through cyclic voltammetry (CV) measurements. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and field-emission scanning electron microscope (FE-SEM) were used to characterize the products.

  16. Template-free synthesis of a porous organic-inorganic hybrid tin(IV) phosphonate and its high catalytic activity for esterification of free fatty acids.

    PubMed

    Dutta, Arghya; Patra, Astam K; Uyama, Hiroshi; Bhaumik, Asim

    2013-10-23

    Here we have synthesized an organic-inorganic hybrid mesoporous tin phosphonate monolith (MLSnP-1) with crystalline pore walls by a template-free sol-gel route. N2 sorption analysis shows Brunauer-Emmett-Teller (BET) surface area of 347 m2 g(-1). Wide-angle powder X-ray diffraction (PXRD) pattern shows few broad diffraction peaks indicating crystalline pore wall of the material. High-resolution transmission electron microscopic (HR TEM) image further reveals the crystal fringes on the pore wall. Framework bonding and local environment around phosphorus and carbon were examined by Fourier transform infrared (FT IR) spectroscopy and solid-state MAS NMR spectroscopy. The material exhibits remarkable catalytic activity for esterification of long chain fatty acids under mild reaction conditions at room temperature.

  17. Synthesis and characterization of functionalized dithiocarbamates: New single-source precursors for CdS

    NASA Astrophysics Data System (ADS)

    Srinivasan, Narayanaswamy

    2014-01-01

    Novel single-molecular precursors for CdS are prepared by reacting functionalized secondary amine and CS2 with cadmium acetate dihydrate. All these precursors are characterized by elemental analysis, infrared spectroscopy and solid-state 13C NMR. CdS semiconductor nanoparticles are synthesized using these precursors by a single-step solvothermal method with ethylenediamine at 117 °C. The synthesized semiconductor nanoparticles are investigated by infra-red spectroscopy, powder X-ray diffraction analysis, energy-dispersive X-ray spectroscopy analysis, scanning electron microscopy, field emission scanning electron microscopy, transmission electron microscopy, high resolution transmission microscopy, selected area electron diffraction analysis and Raman spectroscopy. The synthesized CdS are hexagonal (zinc wurtzite) crystalline material, which are indicative of the reduction of particles. Comparison with the CdS and the mixture of CdS/CdSṡ0.5gl revealed that the CdS/CdSṡ0.5gl exhibited a well crystalline structure.

  18. Determination of iron in drinking water after its flotation concentration by two new dithiocarbamate collectors.

    PubMed

    Pavlovska, Gorica; Stafilov, Trajče; Čundeva, Katarina

    2015-01-01

    Two new methods for the determination of iron by atomic absorption spectrometry (AAS) are proposed for drinking water. The determination was made after flotation concentration of Fe by using of two new flotation collectors: lead(II) heptyldithiocarbamate, Pb(HpDTC)2 and cobalt(III) heptyldithiocarbamate Co(HpDTC)3. All important parameters for the two proposed procedures were optimised (pH, mass of Pb, mass of Co, amount of HpDTC(-), type of surfactant, induction time, etc.). Flotation recovery (R) of Fe was very high (from 94.4 to 104.4%) for the two proposed procedures. The detection limit of the methods was 2.17 μg L(-1) for Pb(HpDTC)2 and 2.39 μg L(-1) for Co(HpDTC)3, respectively. The proposed methods have been applied for the analysis of five samples of drinking water. The acquired AAS results for Fe by both new methods were compared with those obtained by inductively coupled plasma-atomic emission spectrometry (AES-ICP). It is shown that they are in good agreement. The results are also confirmed by the method of standard additions.

  19. DNA Binding and Antitumor Activity of α-Diimineplatinum(II) and Palladium(II) Dithiocarbamate Complexes

    PubMed Central

    Mansouri-Torshizi, Hassan; Saeidifar, Maryam; Khosravi, Fatemeh; Divsalar, Adeleh; Saboury, Ali Akbar; Hassani, Fatemeh

    2011-01-01

    The two water-soluble designed platinum(II) complex, [Pt(Oct-dtc)(bpy)]NO3 (Oct-dtc = Octyldithiocarbamate and bpy = 2,2′ -bipyridine) and palladium(II) complex, [Pd(Oct-dtc)(bpy)]NO3, have been synthesized and characterized by elemental analyses, molar conductivity measurements, IR, 1H NMR, and electronic spectra studies. Studies of antitumor activity of these complexes against human cell tumor lines (K562) have been carried out. They show Ic50 values lower than that of cisplatin. The complexes have been investigated for their interaction with calf thymus DNA (CT-DNA) by utilizing the electronic absorption spectroscopy, fluorescence spectra, and ethidium bromide displacement and gel filtration techniques. Both of these water-soluble complexes bound cooperatively and intercalatively to the CT-DNA at very low concentrations. Several binding and thermodynamic parameters are also described. PMID:22110410

  20. Synthesis, characterization and antibacterial study of cyclometalated rhodium(III) complex containing dithiocarbamate

    NASA Astrophysics Data System (ADS)

    Mansouri, Ghobad; Heidarizadi, Fateme; Naghipour, Ali; Notash, Behrouz

    2016-10-01

    The novel cyclometalated Rh(III) complex, [Rh(phpy)2(SˆS)], Where phpy is 2-phenylpyridine and (SˆS) is diethyldithiocarbamate, has been prepared and characterized by elemental analysis, IR, 13C and 1H NMR, electronic absorption and Fluorescence spectroscopies, cyclic voltammetry, and X-ray crystallography. The crystal structure of [Rh(phpy)2(SˆS)] shows that the coordination geometry around the Rh(III) is a distorted octahedron, with bite angles of 71.19-81.04° for all three bidentate ligands. Electrochemical analysis by cyclic voltammetry reveals irreversible redox behavior of the rhodium centre. Antibacterial activity of the complex has also been studied by agar disc diffusion method against three Gram-negative bacteria (Pseudomonas aeroginosa, Salmonella typhi and Escherichia coli) and two Gram-positive bacteria (Staphylococcus aureus and Corynebacterium renale).

  1. 40 CFR 180.217 - Ammoniates for [ethylenebis-(dithiocarbamato)] zinc and ethyl-enebis [dithiocarbamic acid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Ammoniates for zinc and ethyl-enebis... for zinc and ethyl-enebis bimolecular and trimolecular cyclic anhydrosulfides and disulfides... mixture of 5.2 parts by weight of ammoniates of zinc with 1 part by weight ethylenebis bimolecular...

  2. On-line continuous generation of zinc chelates in the vapor phase by reaction with sodium dithiocarbamates and determination by atomic fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Duan, Xuchuan; Sun, Rui; Fang, Jinliang

    2017-02-01

    The present study shows for the first time that a volatile zinc chelate species can be generated by the on-line continuous merging of an acidified sample solution with an aqueous sodium diethyldithiocarbamate solution followed by rapid separation using a frit-based bubble gas-liquid separator at room temperature. The operating conditions for the generation of the vaporous zinc chelate were preliminarily investigated by non-dispersive atomic fluorescence spectrometry. The possible mechanism of zinc vapor generation is discussed. The study shows that the volatile species is an intermediate species with very similar properties to diethyldithiocarbamic acid and a very short half-life in the acidic solution. Moreover, this species can only be generated by on-line mixing and rapid separation. The efficiency of generation was 33-85% depending on acidity. Under optimal conditions, the flow rates of the sample and Na-DDTC solution were 1.3 ml min- 1, the carrier argon flow rate was 225 ml min- 1, the acid concentration of the sample solution and the concentration of Na-DDTC were 0.05 M and 0.4% (m/v), respectively, the detection limit of zinc was 0.33 (3σ) ng ml- 1, and the relative standard deviation (RSD) was 1.3%. The accuracy of the method was verified by the determination of zinc in the plant reference materials GBW10015 (spinach) and GBW10045 (rice). The results were in good agreement with the certified reference values.

  3. Method of removing nitrogen monoxide from a nitrogen monoxide-containing gas using a water-soluble iron ion-dithiocarbamate, xanthate or thioxanthate

    DOEpatents

    Liu, David K.; Chang, Shih-Ger

    1989-01-01

    A method of removing nitrogen monoxide from a nitrogen monoxide-containing gas, which method comprises: (a) contacting a nitrogen oxide-containing gas with an aqueous solution of water soluble organic compound-iron ion chelate of the formula: ##STR1## wherein the water-soluble organic compound is selected from compounds of the formula: ##STR2## wherein: R is selected from hydrogen or an organic moiety having at least one polar functional group; Z is selected from oxygen, sulfur, or --N--A wherein N is nitrogen and A is hydrogen or lower alkyl having from one to four carbon atoms; and M is selected from hydrogen, sodium or potassium; and n is 1 or 2, in a contacting zone for a time and at a temperature effective to reduce the nitrogen monoxide. These mixtures are useful to provide an unexpensive method of removing NO from gases, thus reducing atmospheric pollution from flue gases.

  4. The study of applicability of dithiocarbamate-coated fullerene C 60 for preconcentration of palladium for graphite furnace atomic absorption spectrometric determination in environmental samples

    NASA Astrophysics Data System (ADS)

    Leśniewska, Barbara A.; Godlewska, Iwona; Godlewska—Żyłkiewicz, Beata

    2005-03-01

    The present method comprises an off-line enrichment of Pd on the fullerene, C 60, coated with ammonium pyrrolidinedithiocarbamate (APDC), followed by the elution of formed Pd-chelate with ethanol and the subsequent determination of Pd from the eluate by graphite furnace atomic absorption spectrometry. By using fullerene loaded with 0.1% APDC, the analytical system is simplified as the sample can be directly preconcentrated on the column. The following parameters affecting the preconcentration of Pd on C 60 were optimized: amount of ligand used for the coating of fullerene, sample pH, kind of eluent, sample and eluent flow rates, volume and number of fractions of eluent used. The sorption efficiency for Pd on coated fullerene was 99.2±1.1%. The best elution efficiency for Pd from the column was obtained with 0.6 ml of ethanol at a flow rate of 0.2 ml min -1. The limit of detection was 0.044 ng ml -1. The effect of sample pretreatment procedure on the preconcentration of Pd by evaluated method is discussed. The content of Pd in road dust (179.2±17.4 ng g -1) determined by proposed method was in agreement with the results obtained with a reference method. The low recovery of analyte (64%) was obtained for geological material CRM SARM-7 (platinum ore) due to the much higher concentration of interfering elements.

  5. MODERATING INFLUENCE OF THE DRINKING WATER DISINFECTION BY-PRODUCT DIBROMOACETIC ACID ON A DITHIOCARBAMATE-INDUCED SUPPRESSION OF THE LUTEINIZING HORMONE SURGE IN FEMALE RATS.

    EPA Science Inventory

    The disinfection by-product dibromoacetic acid (DBA) has been found in female rats to increase circulating concentrations of both estradiol (E2) and estrone (E1). This effect is apparently due, at least in part, to a suppression in hepatic catabolism. The present study investigat...

  6. Vitamin E pretreatment prevents the immunotoxicity of dithiocarbamate pesticide mancozeb in vitro: A comparative age-related assessment in mice and chick.

    PubMed

    Singh, Saurabh Kumar; Bano, Farhad; Mohanty, Banalata

    2016-01-01

    Pesticides used for crop protection cause life-threatening diseases affecting the immune system of non-target organisms including birds and mammals. Functionality of immune system is age-dependent; early- as well as old-life stages are more susceptible to toxic exposures because of less competent immune system. Vitamins are so far known to reduce toxic effect of several pesticides and/or xenobiotics. The present in vitro study elucidated immunotoxicity of fungicide mancozeb through comparable stages of immune system maturation in mice (1, 3, and 12months) and chicks (4, 8, and 11weeks). In vitro splenocytes viability on exposure to mancozeb was quantitatively assessed by MTT assay and qualitatively by acridine orange and ethidium bromide (AO/EB) double fluorescence staining. Mancozeb exposure dose dependently (250, 500, 1000, 2500, 5000 and 10,000ng/ml) decreased the splenocytes viability. The in vitro preventive effect of Vitamin E has also been explored on toxicity induced by mancozeb. The increased susceptibility observed both in early and aged groups was due to less/decline competence of the immune system.

  7. Reactive oxygen species generation by the ethylene-bis-dithiocarbamate (EBDC) fungicide mancozeb and its contribution to neuronal toxicity in mesencephalic cells.

    PubMed

    Domico, Lisa M; Cooper, Keith R; Bernard, Laura P; Zeevalk, Gail D

    2007-11-01

    Previous in vitro studies in our laboratory have shown that mancozeb (MZ) and maneb (MB), both widely used EBDC fungicides, are equipotent neurotoxicants that produce cell loss in mesencephalic dopaminergic and GABAergic cells after an acute 24h exposure. Mitochondrial uncoupling and inhibition were associated with fungicide exposure. Inhibition of mitochondrial respiration is known to increase free radical production. Here the mechanism(s) of neuronal damage associated with MZ exposure was further explored by determining the role that reactive oxygen species (ROS) played in toxicity. Damage to mesencephalic dopamine and GABA cell populations were significantly attenuated when carried out in the presence of ascorbate or SOD, indicative of a free radical-mediated contribution to toxicity. ROS generation monitored by hydrogen peroxide (H(2)O(2)) production using Amplex Red increased in a dose-dependent manner in response to MZ. Inhibition of intracellular catalase with aminotriazole had little effect on H(2)O(2) generation, whereas exogenously added catalase significantly reduced H(2)O(2) production, demonstrating a large extracellular contribution to ROS generation. Conversely, cells preloaded with the ROS indicator dye DCF showed significant MZ-induced ROS production, demonstrating an increase in intracellular ROS. Both the organic backbone of MZ as well as its associated Mn ion, but not Zn ion, were responsible and required for H(2)O(2) generation. The functionally diverse NADPH oxidase inhibitors, diphenylene iodonium chloride, apocynin, and 4-(2-aminoethyl)benzene-sulfonyl fluoride hydrochloride significantly attenuated H(2)O(2) production by MZ. In growth medium lacking cells, MZ produced little H(2)O(2), but enhanced H(2)O(2) generation when added with xanthine plus xanthine oxidase whereas, in cultured cells, allopurinol partially attenuated H(2)O(2) production by MZ. Minocycline, an inhibitor of microglial activation, modestly reduced H(2)O(2) formation in mesencephalic cells. In contrast, neuronal-enriched cultures or cultures treated with MAC-1-SAP to kill microglia, did not show an attenuation of ROS production. These findings demonstrate that Mn-containing EBDC fungicides such as MZ and MB can produce robust ROS generation that likely occurs via redox cycling with extracellular and intracellular oxidases. The findings further show that microglia may contribute to but are not required for ROS production by MZ.

  8. Normal coordinate analysis of the dithiocarbamate ligand and bis-(N,N-diethyldithiocarbamate)nickel(II), copper(II), zinc(II) and cadmium(II)

    NASA Astrophysics Data System (ADS)

    Trendafilova, N. S.; Kellner, R.; Nikolov, G. St.

    1984-03-01

    The vibrational frequencies of H 2NCS 2- (H 2dtc), Et 2dtc -, and M(Et 2dtc) 2 (M = Ni, Cu, Zn, Cd) have been calculated by performing normal coordinate analysis using Gribov's fragmentation procedure within the generalized valence force field approximation. The force field resulting from the experimental frequencies shows a high degree of mixing between the different parts of the molecules. The fragmentation approach has allowed a detailed assignment of the observed frequencies even in the highly correlated force field.

  9. Synthesis, DFT Calculation, and Antimicrobial Studies of Novel Zn(II), Co(II), Cu(II), and Mn(II) Heteroleptic Complexes Containing Benzoylacetone and Dithiocarbamate

    PubMed Central

    Ekennia, Anthony C.; Onwudiwe, Damian C.; Olasunkanmi, Lukman O.; Osowole, Aderoju A.; Ebenso, Eno E.

    2015-01-01

    Heteroleptic complexes of zinc(II), copper(II), manganese(II), and cobalt(II) of the types [MLL′(H2O)2]·nH2O and [MLL′]·nH2O have been synthesized using sodium N-methyl-N-phenyldithiocarbamate (L) and benzoylacetone (L′). The metal complexes were characterized by elemental analysis, electrical conductance, magnetic susceptibility, infrared (IR), and UV-visible spectroscopic studies. The electrical conductance measurements revealed the nonelectrolytic nature of the synthesized complexes. The results of the elemental analyses, magnetic susceptibility measurements, and electronic spectra inferred that the Zn(II) complex adopted a four-coordinate geometry while the Co(II), Cu(II), and Mn(II) complexes assumed octahedral geometries. The IR spectra showed that the metal ions coordinated with the ligands via the S- and O-donor atoms. The geometry, electronic, and thermodynamic parameters of the complexes were obtained from density functional theory (DFT) calculations. The spin density distributions, relative strength of H–bonds, and thermodynamic parameters revealed that the order of stability of the metal complexes is Mn < Co < Cu > Zn. The agar diffusion methods were used to study the antimicrobial activity of the complexes against two Gram positive bacteria (S. aureus and S. pneumoniae), one Gram negative bacterium (E. coli), and two fungi organisms (A. niger and A. candida) and the complexes showed a broad spectrum of activities against the microbes. PMID:26681931

  10. Dithiocarbamate to modify magnetic graphene oxide nanocomposite (Fe3O4-GO): A new strategy for covalent enzyme (lipase) immobilization to fabrication a new nanobiocatalyst for enzymatic hydrolysis of PNPD.

    PubMed

    Heidarizadeh, Mohammad; Doustkhah, Esmail; Rostamnia, Sadegh; Rezaei, Parisa Fathi; Harzevili, Farshad Darvishi; Zeynizadeh, Behzad

    2017-03-29

    Immobilization of lipase was successfully achieved on the surface of magnetically separable Fe3O4/graphene oxide (GO) via a post-modification. This post modification was achieved in alternation to glutaraldehyde post-modification. The activity of immobilized lipase had not a significant loss in the activity while on the other hand, it is simply extractable (by keeping its major activity) from reaction crude by a magnet. Each step of immobilization was carefully monitored by characterization and all were successfully proved. SEM, TEM, XRD, EDX, and FTIR were used to characterize the support and immobilization process.

  11. Tin-catalyzed conversion of biomass-derived triose sugar and formaldehyde to α-hydroxy-γ-butyrolactone.

    PubMed

    Yamaguchi, Sho; Motokura, Ken; Sakamoto, Yasuharu; Miyaji, Akimitsu; Baba, Toshihide

    2014-05-07

    The direct conversion of biomass-derived 1,3-dihydroxyacetone (DHA) and formaldehyde to α-hydroxy-γ-butyrolactone (HBL) was achieved through the use of tin(iv) chloride and a small amount of water and the yield reached up to 70%. The reaction mechanism was also investigated by incorporating d2-formaldehyde into the reaction mixtures.

  12. Synthesis of Tetraphenylstrannacy-clopentadienes (Stannoles). III. Attempted Route to the Parent Stannoles through Closure of 1,4-Dichlorobuta-1,3-diene.

    DTIC Science & Technology

    1980-10-01

    Journal of Organometallic Chemistry I$. SUPPLEMENTARY NOTES 19. KEY WORDS (Continue on reverse side /I necessary and Identfly by block naemb.,) Organotin ...Metalloles, Stannoles, Siloles, l,4-Dicblorobuta-1,3-diene, Lithiation, Organochlorosilanes, Organotin chlorides, Dehydrochlorination, Multiple bond...material. The infusible white solid polymer leaves no silicon or tin(IV) oxide residue on burning, and exhibits in its infrared spectrum absorption bands

  13. High temperature hydrogen sulfide removal with stannic oxide

    SciTech Connect

    Karpuk, M.E.; Copeland, R.J.; Feinberg, D.; Wickham, D.; Windecker, B.; Yu, J.

    1994-10-01

    This contract focuses on the development of sorbents and processes for removal of H{sub 2}S from hot coal gas with the product of sorbent regeneration being elemental sulfur. TDA Research`s process uses a regenerable tin(IV) oxide-based (SnO{sub 2}) sorbent as the first sorbent and zinc ferrite (or zinc titanate) as a second sorbent.

  14. Theoretical investigations on the hydrolysis pathway of tin verdoheme complexes: elucidation of tin's ring opening inhibition role.

    PubMed

    Davari, Mahdi D; Bahrami, Homayoon; Zahedi, Mansour; Safari, Nasser

    2009-11-01

    In order to obtain a better molecular understanding of inhibitory role of tin metal in the verdoheme ring opening process, hydrolysis of three possibly six, five, and four coordinate verdoheme complexes of tin(IV) and (II) have been studied using DFT method. The results of calculations indicate that, in excellent accord with experimental reports, hydrolysis of different possibly coordinated tin(IV) and (II) verdohemes does not lead to the opening of the macrocycle. Contrary to iron and zinc verdohemes, in five and four coordinate verdoheme complexes of tin(IV) and (II), formation of open ring helical complexes of tin are unfavorable both thermodynamically and kinetically. In these pathways, coordination of hydroxide nucleophile to tin metal due to the highly charged, exclusive oxophilicity nature of the Sn center, and high affinity of Sn to increase coordination state are proposed responsible as inhibiting roles of tin via the ring opening. While, in saturated six coordinate tin(IV) and (II) verdoheme complexes the ring opening of tin verdohemes is possible thermodynamically, but it is not predicted to occur from a kinetics point of view. In the six coordinate pathway, tin plays no coordination role and direct addition of hydroxide nucleophile to the positive oxo-carbon centers and formation of closed ring hydroxy compounds is proposed for preventing the verdoheme ring opening. These key points and findings have been corroborated by the results obtained from atomic charge analysis, geometrical parameters, and molecular orbital calculations. In addition, the results of inhibiting ring opening reaction of tin verdoheme complexes could support the great interest of tin porphyrin analogues as pharmacologic means of chemoprevention of neonatal jaundice by the competitive inhibitory action of tin porphyrins on heme oxygenase.

  15. N,N-diethyldithiocarbamate promotes oxidative stress prior to myelin structural changes and increases myelin copper content

    SciTech Connect

    Viquez, Olga M.; Lai, Barry; Ahn, Jae Hee; Does, Mark D.; Valentine, Holly L.; Valentine, William M.

    2009-08-15

    Dithiocarbamates are a commercially important class of compounds that can produce peripheral neuropathy in humans and experimental animals. Previous studies have supported a requirement for copper accumulation and enhanced lipid peroxidation in dithiocarbamate-mediated myelinopathy. The study presented here extends previous investigations in two areas. Firstly, although total copper levels have been shown to increase within the nerve it has not been determined whether copper is increased within the myelin compartment, the primary site of lesion development. Therefore, the distribution of copper in sciatic nerve was characterized using synchrotron X-ray fluorescence microscopy to determine whether the neurotoxic dithiocarbamate, N,N-diethyldithiocarbamate, increases copper levels in myelin. Secondly, because lipid peroxidation is an ongoing process in normal nerve and the levels of lipid peroxidation products produced by dithiocarbamate exposure demonstrated an unusual cumulative dose response in previous studies the biological impact of dithiocarbamate-mediated lipid peroxidation was evaluated. Experiments were performed to determine whether dithiocarbamate-mediated lipid peroxidation products elicit an antioxidant response through measuring the protein expression levels of three enzymes, superoxide dismutase 1, heme oxygenase 1, and glutathione transferase {alpha}, that are linked to the antioxidant response element promoter. To establish the potential of oxidative injury to contribute to myelin injury the temporal relationship of the antioxidant response to myelin injury was determined. Myelin structure in peripheral nerve was assessed using multi-exponential transverse relaxation measurements (MET{sub 2}) as a function of exposure duration, and the temporal relationship of protein expression changes relative to the onset of changes in myelin integrity were determined. Initial assessments were also performed to explore the potential contribution of

  16. N,N-diethyldithiocarbamate promotes oxidative stress prior to myelin structural changes and increases myelin copper content.

    PubMed

    Viquez, Olga M; Lai, Barry; Ahn, Jae Hee; Does, Mark D; Valentine, Holly L; Valentine, William M

    2009-08-15

    Dithiocarbamates are a commercially important class of compounds that can produce peripheral neuropathy in humans and experimental animals. Previous studies have supported a requirement for copper accumulation and enhanced lipid peroxidation in dithiocarbamate-mediated myelinopathy. The study presented here extends previous investigations in two areas. Firstly, although total copper levels have been shown to increase within the nerve it has not been determined whether copper is increased within the myelin compartment, the primary site of lesion development. Therefore, the distribution of copper in sciatic nerve was characterized using synchrotron X-ray fluorescence microscopy to determine whether the neurotoxic dithiocarbamate, N,N-diethyldithiocarbamate, increases copper levels in myelin. Secondly, because lipid peroxidation is an ongoing process in normal nerve and the levels of lipid peroxidation products produced by dithiocarbamate exposure demonstrated an unusual cumulative dose response in previous studies the biological impact of dithiocarbamate-mediated lipid peroxidation was evaluated. Experiments were performed to determine whether dithiocarbamate-mediated lipid peroxidation products elicit an antioxidant response through measuring the protein expression levels of three enzymes, superoxide dismutase 1, heme oxygenase 1, and glutathione transferase alpha, that are linked to the antioxidant response element promoter. To establish the potential of oxidative injury to contribute to myelin injury the temporal relationship of the antioxidant response to myelin injury was determined. Myelin structure in peripheral nerve was assessed using multi-exponential transverse relaxation measurements (MET(2)) as a function of exposure duration, and the temporal relationship of protein expression changes relative to the onset of changes in myelin integrity were determined. Initial assessments were also performed to explore the potential contribution of dithiocarbamate

  17. Organotin(IV) compounds as intramolecular transesterification catalysts in thermal depolymerization of poly(L-lactic acid) oligomer to form LL-lactide.

    PubMed

    Noda, M

    1999-11-01

    Mono-, di-, and tetraalkyl tin(IV) compounds were evaluated for the intramolecular transesterification reaction of the thermal depolymerization of poly(L-lactic acid) oligomer forming lactide by gas chromatography using a beta-cyclodextrin stationary phase capillary column. The most active catalyst was found to be monobutyltin trichloride (BuSnCl3) (8), which contains tin-halogen bonds, and the least effective was the coordinatively saturated monoorganotin derivative, monobutyltin tris(2-ethylhexanoate) (7). Coordination of the carbonyl group in the oligomer to the tin catalysts is an important factor influencing its activity.

  18. Synthesis, analgesic, anti-inflammatory and antibacterial activities of some novel 2-phenyl-3-substituted quinazolin-4(3H) ones.

    PubMed

    Alagarsamy, Veerachamy; Salomon, Viswas Raja; Vanikavitha, Gnanavel; Paluchamy, Veeran; Chandran, Muniyandi Ravi; Sujin, Augustin Arnald; Thangathiruppathy, Arunachalam; Amuthalakshmi, Sivaperuman; Revathi, Rajappan

    2002-11-01

    A series of novel 2-phenyl-3-substituted quinazolin-4(3H)-ones have been synthesized by treating methyl-N-(2-phenyl quinazolin-3-yl-4(3H)-one) dithiocarbamate with different amines, the starting material dithiocarbamate was synthesized from anthranilic acid. The title compounds were investigated for analgesic, anti-inflammatory and antibacterial activities. All the test compounds exhibited significant activity, the compounds A1, A2 and A3 shown more potent analgesic activity, and the compound A3 shown more potent anti-inflammatory activity than the reference standard diclofenac sodium.

  19. C-Jun N-terminal Kinase and Apoptotic Signaling in Prostate Cancer

    DTIC Science & Technology

    2002-01-01

    hydrogen peroxide (H20 2) to induce JNK activation varied in different cell types. Pyrrolidine dithiocarbamate (PDTC), a presumed antioxidant (13,14...Down-regulation of the c-Jun N-terminal kinase (JNK) phosphatase M3/6 and activation of JNK by hydrogen peroxide and pyrrolidine dithiocarbamate...and Tan, T.-H. (2001) Down-regulation of the c-Jun N-terminal kinase (JNK) phosphatase M3/6 and activation of JNK by hydrogen peroxide and pyrrolidine

  20. Intramolecular C-arylation of 2,3,5-tri-O-benzyl- and 2,3,5-tri-O-(3-methylbenzyl)-pentofuranose derivatives.

    PubMed

    Martin, O R

    1987-12-31

    Upon treatment with tin(IV) chloride, 1-O-acetyl-2,3,5-tri-O-benzyl- and 1-O-acetyl-2,3,5-tri-O-(3-methylbenzyl)pentofuranose (D-ribo, L-arabino) undergo intramolecular Friedel-Crafts alkylation of the aromatic substituent at O-2 to give unusual internal C-glycosyl compounds (isochroman derivatives) in high yield. The final products are also partially debenzylated at O-3 or O-5 (up to 25%) under these conditions. By contrast, the corresponding methyl glycosides are poor substrates for the intramolecular C-arylation reaction, as methyl 2,3,5-tri-O-(3-methylbenzyl)-beta-D-ribofuranoside was found to give preponderantly methyl 3,5-di-O-(3-methylbenzyl)-alpha-D-ribofuranoside (11) (49%), and the C-arylation product in 30% yield only in the presence of the same Lewis acid. The competitive formation of 11 is thought to be due to the anomerization of the substrate leading to a tin(IV) complex coordinated with O-1 and O-2, which promoted the cleavage of the benzyl group at O-2. These reactions provide a novel and efficient C-arylation method and suggest a new approach to selectively protected D-ribofuranose derivatives. Evidence for the uncommon C-arylated structure of the new products was gained from their 1H- and 13C(APT)-n.m.r. spectra.

  1. Microwave-assisted synthesis, characterization and biological screening of nitrogen-sulphur and nitrogen-oxygen donor ligands and their organotin(IV) complexes.

    PubMed

    Singh, R V; Chaudhary, Pratibha; Poonia, Kavita; Chauhan, Shikha

    2008-08-01

    Series of new trigonal bipyramidal and octahedral complexes of tin(IV) have been synthesized by the reaction of dimethyltin(IV) dichloride with 4-nitro-benzanilidethiosemicarbazone (L(1)H), 4-chlorobenzanilidethiosemicarbazone (L(2)H), 4-nitrobenzanilidesemicarbazone (L(3)H) and 4-chlorobenzanilidesemicarbazone (L(4)H). The unimolecular and bimolecular reactions of dimethyltin(IV) dichloride and monobasic bidentate ligands were carried out using microwave irradiations as the thermal energy source and the complexes so formed were characterized by elemental analysis, conductance measurements, molecular weight determinations and spectral data, viz. IR, UV-vis, (1)H and (13)C NMR. The complexes have also been prepared by the general thermal methods for comparison purposes. The comparison data support the synthesis using the microwave route, i.e. green chemistry route. The tin(IV) complexes show penta-coordinated structure for 1:1 complexes and hexa-coordinated for 1:2 complexes. The antifungal, antibacterial and antifertility activities have been examined and the results were indeed very encouraging.

  2. ABNORMAL FERTILIZATION IS RESPONSIBLE FOR REDUCED FECUNDITY FOLLOWING THIRAM-INDUCED OVULATORY DELAY IN THE RAT

    EPA Science Inventory

    Brief exposure to some pesticides, applied during a sensitive window for the neural regulation of ovulation, will block the preovulatory surge of LH, and thus delay ovulation. Previously, we have shown that a single i.p. injection of 50 mg/kg of thiram, a dithiocarbamate fungici...

  3. Speciation of AsIII and AsV in fruit juices by dispersive liquid–liquid microextraction and hydride generation-atomic fluorescence spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new procedure was developed to speciate and quantify As(III) and As(V) in fruit juices. At pH 3.0, As(III) and ammonium pyrrolidine dithiocarbamate (APDC) formed a complex, which was extracted into carbon tetrachloride by dispersive liquid–liquid microextraction (DLLME) and subsequently quantified...

  4. Effect of thiram on chicken growth plate cartilage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thiram is a general use dithiocarbamate pesticide. It causes tibial dyschondroplasia, a growth plate cartilage defect in poultry characterized by growth plate broadening due to the accumulation of nonviable chondrocytes which lead to lameness. Since proteins play significant roles in all aspects cel...

  5. Photochemical energy storage: studies of inorganic photoassistance agents. Progress report, October 1, 1984-September 30, 1985

    SciTech Connect

    Wrighton, M.S.

    1985-01-01

    Research activities have been directed toward four thrust areas: synthesis and characterization of linked redox reagents; study of charge transport in redox polymers derived from monomers consisting of linked viologen and quinone groups; photoelectrochemical oxidation of dithiocarbamates and thiols at CdS and CdSe photoanodes; and characterization of high surface area redox catalysts for CO/sub 2/ reduction.

  6. Size control and quantum confinement in Cu2ZnSnS4 nanocrystals.

    PubMed

    Khare, Ankur; Wills, Andrew W; Ammerman, Lauren M; Norris, David J; Aydil, Eray S

    2011-11-14

    Starting with metal dithiocarbamate complexes, we synthesize colloidal Cu(2)ZnSnS(4) (CZTS) nanocrystals with diameters ranging from 2 to 7 nm. Structural and Raman scattering data confirm that CZTS is obtained rather than other possible material phases. The optical absorption spectra of nanocrystals with diameters less than 3 nm show a shift to higher energy due to quantum confinement.

  7. Multifunctional lubricant additives and compositions thereof

    SciTech Connect

    Farng, L.O.; Horodysky, A.G.

    1991-03-26

    This paper discusses an antioxidant/ antiwear/extreme pressure/load carrying lubricant composition. It comprises a major proportion of an oil of lubricating viscosity or grease or other solid lubricant prepared therefrom and a minor amount of an ashless multifunctional antioxidant/antiwear/extreme pressure/load carrying additive product comprising a thiophosphate derived from a dihydrocarbyl dithiocarbamate.

  8. Growth of Fe2O3/SnO2 nanobelt arrays on iron foil for efficient photocatalytic degradation of methylene blue

    NASA Astrophysics Data System (ADS)

    Lei, Rui; Ni, Hongwei; Chen, Rongsheng; Zhang, Bowei; Zhan, Weiting; Li, Yang

    2017-04-01

    Tin(IV) oxide has been intensively employed in optoelectronic devices due to its excellent electrical and optical properties. But the high recombination rates of the photogenerated electron-hole pairs of SnO2 nanomaterials often results in low photocatalytic efficiency. Herein, we proposed a facile route to prepare a novel Fe2O3/SnO2 heterojunction structure. The nanobelt arrays grown on iron foil naturally form a Schottky-type contact and provide a direct pathway for the photogenerated excitons. Hence, the Fe2O3/SnO2 nanobelt arrays exhibit much improved photocatalytic performance with the degradation rate constant on the Fe2O3/SnO2 film of approximately 12 times to that of α-Fe2O3 nanobelt arrays.

  9. Utility of positron annihilation lifetime technique for the assessment of spectroscopic data of some charge-transfer complexes derived from N-(1-Naphthyl)ethylenediamine dihydrochloride.

    PubMed

    Refat, Moamen S; Adam, Abdel Majid A; Sharshar, T; Saad, Hosam A; Eldaroti, Hala H

    2014-03-25

    In this work, structural, thermal, morphological, pharmacological screening and positron annihilation lifetime measurements were performed on the interactions between a N-(1-Naphthyl)ethylenediamine dihydrochloride (NEDA·2HCl) donor and three types of acceptors to characterize these CT complexes. The three types of acceptors include π-acceptors (quinol and picric acid), σ-acceptors (iodine) and vacant orbital acceptors (tin(IV) tetrachloride and zinc chloride). The positron annihilation lifetime parameters were found to be dependent on the structure, electronic configuration, the power of acceptors and molecular weight of the CT complexes. The positron annihilation lifetime spectroscopy can be used as a probe for the formation of charge-transfer (CT) complexes.

  10. Improvement of both efficiency and working lifetime in organic photovoltaic devices by using bathophenanthroline/tin(IV) phthalocyanine dichloride as bilayer exciton blocking layers

    NASA Astrophysics Data System (ADS)

    Zhuang, Taojun; Su, Zisheng; Liu, Yadong; Chu, Bei; Li, Wenlian; Wang, Junbo; Jin, Fangming; Yan, Xingwu; Zhao, Bo; Zhang, Feng; Fan, Di

    2012-06-01

    We demonstrate that the improvement of both efficiency and lifetime of organic photovoltaic (OPV) devices by employing thinner bathophenanthroline (Bphen) and thicker tin(IV) phthalocyanine dichloride (SnCl2Pc) as the bilayer exciton blocking layers (EBLs), where Bphen and SnCl2Pc acts as the photogenerated exciton blocking layer and optical spacer, respectively. The thicker SnCl2Pc layer can be adopted due to its high electron mobility and aligned lowest unoccupied molecular orbital with the acceptor. The OPV device with such a bilayer EBL leads to an increase by 27% in power conversion efficiency compared to the device with a traditional bathocuproine EBL. Moreover, the lifetime is also improved due to the superior oxygen and moisture diffusion blocking effect of the thick SnCl2Pc layer. The operation mechanism for the improvement in PCE and lifetime was also discussed.

  11. Structure-property relationships in silica-siloxane nanocomposite materials

    SciTech Connect

    Ulibarri, T.A.; Derzon, D.K.; Wang, L.C.

    1997-03-01

    The simultaneous formation of a filler phase and a polymer matrix via in situ sol-gel techniques provides silica-siloxane nanocomposite materials of high strength. This study concentrates on the effects of temperature and relative humidity on a trimodal polymer system in an attempt to accelerate the reaction as well as evaluate subtle process- structure-property relations. It was found that successful process acceleration is only viable for high humidity systems when using the tin(IV) catalyst dibutyltin dilaurate. Processes involving low humidity were found to be very temperature and time dependent. Bimodal systems were investigated and demonstrated that the presence of a short-chain component led to enhanced material strength. This part of the study also revealed a link between the particle size and population density and the optimization of material properties.

  12. Effective 1,5-, 1,6- and 1,7-remote stereocontrol in reactions of alkoxy- and hydroxy-substituted allylstannanes with aldehydes.

    PubMed

    Carey, John S; MacCormick, Somhairle; Stanway, Steven J; Teerawutgulrag, Aphiwat; Thomas, Eric J

    2011-05-21

    Alk-2-enylstannanes with 4-, 5- and 6-alkoxy- or -hydroxy-substituents are transmetallated stereoselectively with tin(iv) halides to generate allyltin trihalides which react with aldehydes to give (Z)-alk-3-enols with useful levels of 1,5-, 1,6- and 1,7-stereocontrol. Alk-2-enylstannanes with a stereogenic centre bearing a hydroxy or alkoxy group at the 4-, 5- or 6-position, react with overall (Z)-1,5-, 1,6- and 1,7-syn-stereoselectivity with respect to the hydroxy and alkoxy substituents. The analogous reactions of alkoxy- and -hydroxyalk-2-enylstannanes with a methyl bearing stereogenic centre at the 4- or 5-position react with overall (Z)-1,5- and 1,6-anti-stereoselectivity with respect to the hydroxy and methyl substituents.

  13. Utility of positron annihilation lifetime technique for the assessment of spectroscopic data of some charge-transfer complexes derived from N-(1-Naphthyl)ethylenediamine dihydrochloride

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; Adam, Abdel Majid A.; Sharshar, T.; Saad, Hosam A.; Eldaroti, Hala H.

    2014-03-01

    In this work, structural, thermal, morphological, pharmacological screening and positron annihilation lifetime measurements were performed on the interactions between a N-(1-Naphthyl)ethylenediamine dihydrochloride (NEDA·2HCl) donor and three types of acceptors to characterize these CT complexes. The three types of acceptors include π-acceptors (quinol and picric acid), σ-acceptors (iodine) and vacant orbital acceptors (tin(IV) tetrachloride and zinc chloride). The positron annihilation lifetime parameters were found to be dependent on the structure, electronic configuration, the power of acceptors and molecular weight of the CT complexes. The positron annihilation lifetime spectroscopy can be used as a probe for the formation of charge-transfer (CT) complexes.

  14. Syntheses, characterization and antifungal activity of novel dimethylbis(N-R-sulfonyldithiocarbimato)stannate(IV) complexes

    NASA Astrophysics Data System (ADS)

    Bomfim Filho, Lucius F. O.; Oliveira, Marcelo R. L.; Miranda, Liany D. L.; Vidigal, Antonio E. C.; Guilardi, Silvana; Souza, Rafael A. C.; Ellena, Javier; Ardisson, José D.; Zambolim, Laércio; Rubinger, Mayura M. M.

    2017-02-01

    Four new complexes of the general formula: (Ph4P)2[Sn(CH3)2(RSO2Ndbnd CS2)2], where Ph4P = tetraphenylphosphonium cation and R = CH3, (1), CH3CH2 (2), C6H5 (3), 4-FC6H4 (4), were prepared by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimates, K2(RSO2Ndbnd CS2), and tetraphenylphosphonium chloride with dimethyltin dichloride. The compounds 1-4 were characterized by 1H, 13C and 119Sn NMR, 119Sn Mössbauer, vibrational spectroscopy and by elemental analyses of C, H, N and Sn. The crystal structure of 1 was determined by X-ray diffraction techniques. The in vitro antifungal activity of the tin(IV) complexes were evaluated against the fungi Rhizoctonia solani and Botrytis cinerea by the Poisoned food test. The new compounds showed comparable activities to the fungicides manzate and ziram.

  15. Process for light-driven hydrocarbon oxidation at ambient temperatures

    DOEpatents

    Shelnutt, John A.

    1990-01-01

    A photochemical reaction for the oxidation of hydrocarbons uses molecular oxygen as the oxidant. A reductive photoredox cycle that uses a tin(IV)- or antimony(V)-porphyrin photosensitizer generates the reducing equivalents required to activate oxygen. This artificial photosynthesis system drives a catalytic cycle, which mimics the cytochrome P.sub.450 reaction, to oxidize hydrocarbons. An iron(III)- or manganese(III)-porphyrin is used as the hydrocarbon-oxidation catalyst. Methylviologen can be used as a redox relay molecule to provide for electron-transfer from the reduced photosensitizer to the Fe or Mn porphyrin. The system is long-lived and may be used in photo-initiated spectroscopic studies of the reaction to determine reaction rates and intermediates.

  16. A new benzodiazepine molecule and its interactions with diorganotin(IV)chlorides

    NASA Astrophysics Data System (ADS)

    Garoufis, Achilleas; Kitos, Alexandros A.; Lymperopoulou, Smaragda; Nastopoulos, Vasileios; Plakatouras, John C.; Ypsilantis, Konstantinos

    2015-01-01

    2-Methyl-2,4-di-thiophen-2‧,2″-yl-2,3-dihydro-1H-benzo[b][1,4]diazepine (L) has been synthesized through condensation of phenylene-1,2-diamine and 2-acetylthiophene, and its reactions with dialkyltin(IV)dichlorides have been studied. Two salts formulated as (LH)[R2SnCl3] (R = Et, 1; R = Me, 2) have been isolated. L and 1 were structurally characterized. The conformation of the benzodiazepine L, changes in 1 due to H-bonds formation. [Et2SnCl3]- is one of the rare examples of five coordinated tin(IV) species and has distorted trigonal bipyramidal geometry. H-bonding interactions, in 1, lead to the formation of supramolecular helices.

  17. The solubility limited source term for cement-conditioned wastes: A status report

    SciTech Connect

    Glasser, F.P.

    1999-07-01

    An important function of the cement backfill in a nuclear waste repository is to react with aqueous waste species and reduce their solubility. However, to quantify backfill performance it is first necessary to prove the existence and establish the nature of the chemical solubility controls. This can be done by characterizing the solubility-limiting phases, determining their solubility and thermodynamic functions, and assessing their stability and persistence and solubility during backfill degradation. Much of the necessary data must be acquired experimentally. The title paper describes briefly the progress of experimental work on selected species including nickel, chromium(III,VI), tin(IV), molybdenum(VI), uranium(VI), Ce(III,IV), thorium, actinide simulants (III,IV) and chloride. Data needs are assessed and although much experimental work remains to be done, methodologies have been developed which will expedite progress. The expectation of a more quantitative performance assessment of cement barriers is, therefore, attainable.

  18. Crystal structure of 2-methyl-1H-imidazol-3-ium aqua­tri­chlorido­(oxalato-κ2 O,O′)stannate(IV)

    PubMed Central

    Diop, Mouhamadou Birame; Diop, Libasse; Plasseraud, Laurent; Maris, Thierry

    2015-01-01

    The tin(IV) atom in the complex anion of the title salt, (C4H7N2)[Sn(C2O4)Cl3(H2O)], is in a distorted octa­hedral coordination environment defined by three chlorido ligands, an oxygen atom from a water mol­ecule and two oxygen atoms from a chelating oxalate anion. The organic cation is linked through a bifurcated N—H⋯O hydrogen bond to the free oxygen atoms of the oxalate ligand of the complex [Sn(H2O)Cl3(C2O4)]− anion. Neighbouring stannate(IV) anions are linked through O—H⋯O hydrogen bonds involving the water mol­ecule and the two non-coordinating oxalate oxygen atoms. In combination with additional N—H⋯Cl hydrogen bonds between cations and anions, a three-dimensional network is spanned. PMID:25995870

  19. Ziram and sodium N,N-dimethyldithiocarbamate inhibit ubiquitin activation through intracellular metal transport and increased oxidative stress in HEK293 cells.

    PubMed

    Dennis, Kathleen E; Valentine, William M

    2015-04-20

    Ubiquitin activating enzyme E1 plays a pivotal role in ubiquitin based protein signaling through regulating the initiating step of the cascade. Previous studies demonstrated that E1 is inhibited by covalent modification of reactive cysteines contained within the ubiquitin-binding groove and by conditions that increase oxidative stress and deplete cellular antioxidants. In this study, we determined the relative contribution of covalent adduction and oxidative stress to E1 inhibition produced by ziram and sodium N,N-dimethyldithiocarbamate (DMDC) in HEK293 cells. Although no dithiocarbamate-derived E1 adducts were identified on E1 using shotgun LC/MS/MS for either ziram or DMDC, both dithiocarbamates significantly decreased E1 activity, with ziram demonstrating greater potency. Ziram increased intracellular levels of zinc and copper, DMDC increased intracellular levels of only copper, and both dithiocarbamates enhanced oxidative injury evidenced by elevated levels of protein carbonyls and expression of heme oxygenase-1. To assess the contribution of intracellular copper transport to E1 inhibition, coincubations were performed with the copper chelator triethylenetetramine hydrochloride (TET). TET significantly protected E1 activity for both of the dithiocarbamates and decreased the associated oxidative injury in HEK293 cells as well as prevented dithiocarbamate-mediated lipid peroxidation assayed using an ethyl aracidonate micelle system. Because TET did not completely ameliorate intracellular transport of copper or zinc for ziram, TET apparently maintained E1 activity through its ability to diminish dithiocarbamate-mediated oxidative stress. Experiments to determine the relative contribution of elevated intracellular zinc and copper were performed using a metal free incubation system and showed that increases in either metal were sufficient to inhibit E1. To evaluate the utility of the HEK293 in vitro system for screening environmental agents, a series of additional

  20. Process for Making a Noble Metal on Tin Oxide Catalyst

    NASA Technical Reports Server (NTRS)

    Davis, Patricia; Miller, Irvin; Upchurch, Billy

    2010-01-01

    To produce a noble metal-on-metal oxide catalyst on an inert, high-surface-area support material (that functions as a catalyst at approximately room temperature using chloride-free reagents), for use in a carbon dioxide laser, requires two steps: First, a commercially available, inert, high-surface-area support material (silica spheres) is coated with a thin layer of metal oxide, a monolayer equivalent. Very beneficial results have been obtained using nitric acid as an oxidizing agent because it leaves no residue. It is also helpful if the spheres are first deaerated by boiling in water to allow the entire surface to be coated. A metal, such as tin, is then dissolved in the oxidizing agent/support material mixture to yield, in the case of tin, metastannic acid. Although tin has proven especially beneficial for use in a closed-cycle CO2 laser, in general any metal with two valence states, such as most transition metals and antimony, may be used. The metastannic acid will be adsorbed onto the high-surface-area spheres, coating them. Any excess oxidizing agent is then evaporated, and the resulting metastannic acid-coated spheres are dried and calcined, whereby the metastannic acid becomes tin(IV) oxide. The second step is accomplished by preparing an aqueous mixture of the tin(IV) oxide-coated spheres, and a soluble, chloride-free salt of at least one catalyst metal. The catalyst metal may be selected from the group consisting of platinum, palladium, ruthenium, gold, and rhodium, or other platinum group metals. Extremely beneficial results have been obtained using chloride-free salts of platinum, palladium, or a combination thereof, such as tetraammineplatinum (II) hydroxide ([Pt(NH3)4] (OH)2), or tetraammine palladium nitrate ([Pd(NH3)4](NO3)2).

  1. Synthesis and Structural Characterization of Tris(dimethyldithicarbamate)Indium(III), In[S2CN(CH3)2]3

    NASA Technical Reports Server (NTRS)

    Clark, Eric B.; Breen, Marc L.; Fanwick, Phillip E.; Hepp, Aloysius F.; Duraj, Stan A.

    1998-01-01

    The synthesis and structure of the indium dithiocarbamate, In[S2CN(CH3)2]30 central dot 1/2 4- mepy (4-mepy = 4-methylpyridine), is described. Indium metal was oxidized by tetramethylthiuramdisulfide in 4-methylpyridine at 25 C to form a new, homoleptic indium(III) dithiocarbamate in yields exceeding 60%. In[S2CN(CH3)2]3 exists as a discrete molecule with a distorted-octahedral geometry. The compound crystallizes in the P 1-bar (No. 2) space group with a = 9.282(l) A, b = 10.081 (1) A, c, c = 12.502 A, alpha = 73.91 (1)(sup 0), beta = 70.21(1)(sup 0), gamma = 85.84(1)(sup 0), Z = 2, V (A(sup 3) = 1057.3(3), R = 0.046, and R(sub w) = 0.061.

  2. Synthesis and Structural Characterization of Tris(dimethyldithiocarbamate)Indium(III), In[S2CN(CH3)2]3

    NASA Technical Reports Server (NTRS)

    Clark, Eric B.; Breen, Marc L.; Fanwick, Phillip E.; Hepp, Aloysius F.; Duraj, Stan A.

    1998-01-01

    The synthesis and structure of the indium dithiocarbamate, In[SCN(CH3)2]3*1/2 4-mepy (4-mepy = 4-methylpyridine), is described. Indium metal was oxidized by tetramethylthiuramdisulfide in 4-methylpyridine at 25C to form a new, homoleptic indium(HI) dithiocarbamate in yields exceeding 60%. In[S2CN(CH3)213 exists as a discrete molecule with a distorted-octahedral geometry. The compound crystallizes in the P 1-bar (No. 2) space group with a = 9.282(l)A, b = 10.081(1)A, c = 12.502 A, alpha= 73.91 (1) degrees, beta = 70.21(1) degrees, gamma = 85.84(1) degrees, Z = 2,v(A(exp 3)) =1057.3(3), R = 0.046, and R(sub w) = 0.061.

  3. A solvent extraction technique for the isotopic measurement of dissolved copper in seawater.

    PubMed

    Thompson, Claire M; Ellwood, Michael J; Wille, Martin

    2013-05-02

    Stable copper (Cu) isotope geochemistry provides a new perspective for investigating and understanding Cu speciation and biogeochemical Cu cycling in seawater. In this work, sample preparation for isotopic analysis employed solvent-extraction with amino pyrollidine dithiocarbamate/diethyl dithiocarbamate (APDC/DDC), coupled with a nitric acid back-extraction, to concentrate Cu from seawater. This was followed by Cu-purification using anion-exchange. This straightforward technique is high yielding and fractionation free for Cu and allows precise measurement of the seawater Cu isotopic composition using multi-collector inductively coupled plasma mass-spectrometry. A deep-sea profile measured in the oligotrophic north Tasman Sea shows fractionation in the Cu isotopic signature in the photic zone but is relatively homogenised at depth. A minima in the Cu isotopic profile correlates with the chlorophyll a maximum at the site. These results indicate that a range of processes are likely to fractionate stable Cu isotopes in seawater.

  4. AAS and spectrophotometric methods for the determination metoprolol tartrate in tablets

    NASA Astrophysics Data System (ADS)

    Alpdoğan, Güzin; Sungur, Sidika

    1999-11-01

    Sensitive and specific atomic adsorption spectroscopy (AAS) and spectrophotometric methods have been developed for the determination of beta adrenergic blocking drug, metoprolol tartrate.The method is based on the formation of Cu(II) dithiocarbamate complex by derivatization of the secondary amino group of metoprolol with CS 2 and CuCl 2 in the presence of ammonia.The copper-bis(dithiocarbamate) complex was extracted into chloroform and the concentration of metoprolol tartrate was determined directly by spectrophotometric and indirectly by AAS measurement of copper.The two methods developed were applied to the assay of metoprolol tartrate in commercial tablet formulations.The methods were compared statistically with each other and with the high performance liquid chromatography (HPLC) method of USPXXII using t- and F-tests.

  5. Muscular contractions in the zebrafish embryo are necessary to reveal thiuram-induced notochord distortions

    SciTech Connect

    Teraoka, Hiroki . E-mail: hteraoka@rakuno.ac.jp; Urakawa, Satsuki; Nanba, Satomi; Nagai, Yuhki; Wu Dong; Imagawa, Tomohiro; Tanguay, Robert L.; Svoboda, Kurt; Handley-Goldstone, Heather M.; Stegeman, John J.; Hiraga, Takeo

    2006-04-01

    Dithiocarbamates form a large group of chemicals that have numerous uses in agriculture and medicine. It has been reported that dithiocarbamates, including thiuram (tetramethylthiuram disulfide), cause wavy distortions of the notochord in zebrafish and other fish embryos. In the present study, we investigated the mechanism underlying the toxicity of thiuram in zebrafish embryos. When embryos were exposed to thiuram (2-1000 nM: 0.48-240 {mu}g/L) from 3 h post fertilization (hpf) (30% epiboly) until 24 hpf (Prim-5), all embryos develop wavy notochords, disorganized somites, and have shortened yolk sac extensions. The thiuram response was specific and did not cause growth retardation or mortality at 24 hpf. The thiuram-dependent responses showed the same concentration dependence with a waterborne EC{sub 5} values of approximately 7 nM. Morphometric measurements revealed that thiuram does not affect the rate of notochord lengthening. However, the rate of overall body lengthening was significantly reduced in thiuram-exposed animals. Other dithiocarbamates, such as ziram, caused similar malformations to thiuram. While expression of genes involved in somitogenesis was not affected, the levels of notochord-specific transcripts were altered after the onset of malformations. Distortion of the notochord started precisely at 18 hpf, which is concomitant with onset of spontaneous rhythmic trunk contractions. Abolishment of spontaneous contractions using tricaine, {alpha}-bungarotoxin, and a paralytic mutant sofa potato, resulted in normal notochord morphology in the presence of thiuram. These results indicate that muscle activity is necessary to reveal the underlying functional deficit and suggest that the developmental target of dithiocarbamates impairs trunk plasticity through an unknown mechanism.

  6. Complexometric determination of magnesium in nodular cast iron and alloyed cast iron roll samples.

    PubMed

    Banerjee, S; Dutta, R K

    1980-02-01

    A complexometric method for the determination of magnesium in nodular cast iron, alloyed cast iron and roll samples has been developed. The bulk of the iron is removed by ether extraction and the phosphate as zirconium phosphate. The other elements are removed by extraction with dithiocarbamate into chloroform. Magnesium is then titrated with EDTA at pH 10, with Eriochrome Black T as indicator. Calcium interferes, but is very rarely present in such cast iron samples.

  7. A novel method for heterocyclic amide-thioamide transformations.

    PubMed

    Fathalla, Walid; Ali, Ibrahim A I; Pazdera, Pavel

    2017-01-01

    In this paper, we introduce a novel and convenient method for the transformation of heterocyclic amides into heteocyclic thioamides. A two-step approach was applied for this transformation: Firstly, we applied a chlorination of the heterocyclic amides to afford the corresponding chloroheterocycles. Secondly, the chloroherocycles and N-cyclohexyl dithiocarbamate cyclohexylammonium salt were heated in chloroform for 12 h at 61 °C to afford heteocyclic thioamides in excellent yields.

  8. A computational approach to the synthesis of 1,3,5-thiadiazinane-2-thiones in aqueous medium: theoretical evidence for water-promoted heterocyclization.

    PubMed

    Coro, Julieta; Alvarez-Puebla, Ramon; Montero, Ana L; Suárez, Margarita; Martin, Nazario; Perez-Pineiro, Rolando

    2008-07-01

    Based on experimental evidence and DFT studies, a probable cyclization route to 1,3,5-thiadiazinanes-2-thiones in aqueous medium is proposed. Experimental facts suggest the formation of a {[hydroxymethyl (substituted) carbamothioyl] sulfanyl}methanol intermediate via reaction of dithiocarbamate (DTC) and formaldehyde. Nucleophilic addition of glycine to this intermediate generates an adduct that undergoes intramolecular heterocyclization via an S(N)2 reaction. Computational calculations predict an active role of water in the reaction mechanism that promotes intramolecular cyclization.

  9. Structure sensitive normal coordinate analysis of metal-diethyldithiocarbamate - complexes

    NASA Astrophysics Data System (ADS)

    Mikosch, H.; Bauer, G.; Kellner, R.; Trendafilova, N. S.; St. Nikolov, G.

    1986-03-01

    Symmetry changes in the course of dissolution are assumed to produce frequency shifts in molecular spectra of N, N-Disubstituted Dithiocarbamates. Using (mass-weighted) cartesian coordinates it is possible to calculate eigenvalues both for the site- and the molecular symmetry. Calculated shifts for Cu- and Zn- complexes are of the same order of magnitude as experimental results and calculation of frequencies even for assumed structures is possible.

  10. A novel method for heterocyclic amide–thioamide transformations

    PubMed Central

    Ali, Ibrahim A I; Pazdera, Pavel

    2017-01-01

    In this paper, we introduce a novel and convenient method for the transformation of heterocyclic amides into heteocyclic thioamides. A two-step approach was applied for this transformation: Firstly, we applied a chlorination of the heterocyclic amides to afford the corresponding chloroheterocycles. Secondly, the chloroherocycles and N-cyclohexyl dithiocarbamate cyclohexylammonium salt were heated in chloroform for 12 h at 61 °C to afford heteocyclic thioamides in excellent yields. PMID:28228858

  11. Vanadium nitride functionalization and denitrogenation by carbon disulfide and dioxide.

    PubMed

    Brask, Justin K; Durà-Vilà, Víctor; Diaconescu, Paula L; Cummins, Christopher C

    2002-04-21

    A dramatic difference in behavior is observed for the dithiocarbamate and carbamate complexes [Ar(But)N]3V(NCE2)Na(THF)2(E = S or O, respectively), prepared from the corresponding nitride species ([Ar(But)N]3V identical to NNa)2 by way of a nucleophilic addition reaction involving carbon disulfide or dioxide, and is rationalized with the aid of DFT calculations.

  12. [N-Benzyl-N-(2-phenyl-eth-yl)di-thio-carbamato-κ(2)S,S']tri-phenyl-tin(IV) and [bis-(2-meth-oxy-eth-yl)di-thio-carbamato-κ(2)S,S']tri-phenyl-tin(IV): crystal structures and Hirshfeld surface analysis.

    PubMed

    Mohamad, Rapidah; Awang, Normah; Kamaludin, Nurul Farahana; Jotani, Mukesh M; Tiekink, Edward R T

    2016-10-01

    The crystal and mol-ecular structures of two tri-phenyl-tin di-thio-carbamates, [Sn(C6H5)3(C16H16NS2)], (I), and [Sn(C6H5)3(C7H14NO2S2)], (II), are described. In (I), the di-thio-carbamate ligand coordinates the Sn(IV) atom in an asymmetric manner, leading to a highly distorted trigonal-bipyramidal coordination geometry defined by a C3S2 donor set with the weakly bound S atom approximately trans to one of the ipso-C atoms. A similar structure is found in (II), but the di-thio-carbamate ligand coordinates in an even more asymmetric fashion. The packing in (I) features supra-molecular chains along the c axis sustained by C-H⋯π inter-actions; chains pack with no directional inter-actions between them. In (II), supra-molecular layers are formed, similarly sustained by C-H⋯π inter-actions; these stack along the b axis. An analysis of the Hirshfeld surfaces for (I) and (II) confirms the presence of the C-H⋯π inter-actions but also reveals the overall dominance of H⋯H contacts in the respective crystals.

  13. Synthesis, structural characterization and in vitro inhibitory studies against human breast cancer of the bis-(2,6-di-tert-butylphenol)tin(IV) dichloride and its complexes.

    PubMed

    Shpakovsky, D B; Banti, C N; Beaulieu-Houle, G; Kourkoumelis, N; Manoli, M; Manos, M J; Tasiopoulos, A J; Hadjikakou, S K; Milaeva, E R; Charalabopoulos, K; Bakas, T; Butler, I S; Hadjiliadis, N

    2012-12-28

    Four new organotin(IV) complexes of bis-(2,6-di-tert-butylphenol)tin(IV) dichloride [(tert-Bu-)(2)(HO-Ph)](2)SnCl(2) (1) with the heterocyclic thioamides 2-mercapto-pyrimidine (PMTH), 2-mercapto-4-methyl-pyrimidine (MPMTH), 2-mercapto-pyridine (PYTH) and 2-mercapto-benzothiazole (MBZTH), of formulae {[(tert-Bu-)(2)(HO-Ph)](2)Sn(PMT)(2)} (2), {[(tert-Bu-)(2)(HO-Ph)](2)Sn(MPMT)(2)} (3), {[(tert-Bu-)(2)(HO-Ph)](2)SnCl(PYT)} (4) and {[(tert-Bu-)(2)(HO-Ph)](2)SnCl(MBZT)} (5), have been synthesized and characterized by elemental analysis, (1)H-, (13)C-, (119)Sn-NMR, EPR, FT-IR, Raman and Mössbauer spectroscopic techniques. The crystal and molecular structures of compounds 1–5 have been determined by X-ray diffraction. The geometries around the metal center adopted in complexes 1–5 varied between tetrahedral in 1, trigonal bipyramidal in 3, 4, 5 and distorted octahedral in 2. Two carbon atoms from aryl groups and two chlorine atoms form a distorted tetrahedron in the case of 1. Two carbon, two sulfur and two nitrogen atoms from thione ligands form a distorted octahedral geometry around tin(IV) with trans-C(2), cis-N(2), cis-S(2)-configurations in 2. However, in the case of 4 and 5 complexes two carbon, one sulfur, one nitrogen and one chloride atom form a distorted trigonal bipyramidal arrangement. Finally, in the case of 3 the trigonal bipyramidal geometry is achieved by two carbon, two sulfur and one nitrogen atom in a unique coordination mode of thioamides toward the tin(IV) cation. Compounds 1–5 were tested for their in vitro cytotoxicity against the human breast adenocarcinoma (MCF-7) cell line. Compound 3 exhibits strong cytotoxic activity against MCF-7 cells (IC(50) = 0.58 ± 0.1 μM).

  14. Copper signaling axis as a target for prostate cancer therapeutics.

    PubMed

    Safi, Rachid; Nelson, Erik R; Chitneni, Satish K; Franz, Katherine J; George, Daniel J; Zalutsky, Michael R; McDonnell, Donald P

    2014-10-15

    Previously published reports indicate that serum copper levels are elevated in patients with prostate cancer and that increased copper uptake can be used as a means to image prostate tumors. It is unclear, however, to what extent copper is required for prostate cancer cell function as we observed only modest effects of chelation strategies on the growth of these cells in vitro. With the goal of exploiting prostate cancer cell proclivity for copper uptake, we developed a "conditional lethal" screen to identify compounds whose cytotoxic actions were manifested in a copper-dependent manner. Emerging from this screen was a series of dithiocarbamates, which, when complexed with copper, induced reactive oxygen species-dependent apoptosis of malignant, but not normal, prostate cells. One of the dithiocarbamates identified, disulfiram (DSF), is an FDA-approved drug that has previously yielded disappointing results in clinical trials in patients with recurrent prostate cancer. Similarly, in our studies, DSF alone had a minimal effect on the growth of prostate cancer tumors when propagated as xenografts. However, when DSF was coadministered with copper, a very dramatic inhibition of tumor growth in models of hormone-sensitive and of castrate-resistant disease was observed. Furthermore, we determined that prostate cancer cells express high levels of CTR1, the primary copper transporter, and additional chaperones that are required to maintain intracellular copper homeostasis. The expression levels of most of these proteins are increased further upon treatment of androgen receptor (AR)-positive prostate cancer cell lines with androgens. Not surprisingly, robust CTR1-dependent uptake of copper into prostate cancer cells was observed, an activity that was accentuated by activation of AR. Given these data linking AR to intracellular copper uptake, we believe that dithiocarbamate/copper complexes are likely to be effective for the treatment of patients with prostate cancer whose

  15. Copper Accumulation and Lipid Oxidation Precede Inflammation and Myelin Lesions in N,N-Diethyldithiocarbamate Peripheral Myelinopathy

    PubMed Central

    Viquez, Olga M.; Valentine, Holly L.; Amarnath, Kalyani; Milatovic, Dejan; Valentine, William M.

    2008-01-01

    Dithiocarbamates have a wide spectrum of applications in industry, agriculture and medicine with new applications being actively investigated. One adverse effect of dithiocarbamates is the neurotoxicity observed in humans and experimental animals. Results from previous studies have suggested that dithiocarbamates elevate copper and promote lipid oxidation within myelin membranes. In the current study, copper levels, lipid oxidation, protein oxidative damage and markers of inflammation were monitored as a function of N,N-diethyldithiocarbmate (DEDC) exposure duration in an established model for DEDC-mediated myelinopathy in the rat. Intraabdominal administration of DEDC was performed using osmotic pumps for periods of 2, 4, and 8 weeks. Metals in brain, liver and tibial nerve were measured using ICP-MS and lipid oxidation assessed through HPLC measurement of malondialdehyde in tibial nerve, and GC/MS measurement of F2 isoprostanes in sciatic nerve. Protein oxidative injury of sciatic nerve proteins was evaluated through quantification of 4-hydroxynonenal protein adducts using immunoassay, and inflammation monitored by quantifying levels of IgGs and activated macrophages using immunoassay and immunhistochemistry methods, respectively. Changes in these parameters were then correlated to the onset of structural lesions, determined by light and electron microscopy, to delineate the temporal relationship of copper accumulation and oxidative stress in peripheral nerve to the onset of myelin lesions. The data provide evidence that DEDC mediates lipid oxidation and elevation of total copper in peripheral nerve well before myelin lesions or activated macrophages are evident. This relationship is consistent with copper-mediated oxidative stress contributing to the myelinopathy. PMID:18284930

  16. Scanning tunneling microscopy studies of mixed self-assembled monolayers

    NASA Astrophysics Data System (ADS)

    Raigoza, Annette Fernandez

    This thesis examines the formation of multicomponent self-assembled mono-layers (SAMs) on the Au(111) surface using scanning tunneling microscopy. Two methods, sequential adsorption and coadsorption, are used to create these mixed SAMs. In the sequential adsorption experiments, a clean Au(111)-on-mica sub-strate is exposed to the first molecular species and then this adsorbate-covered sample is exposed to the second molecular species. Alternately, in the coadsorption experiments, a gold surface is exposed to both adsorbates simultaneously. Exposing a coronene- or dithiocarbamate-covered surface to excess thiol in the vapor phase results in a drastic restructuring of the initial surface. This is primarily driven by the kinetics of the octanethiol monolayer formation process, but the extent to which this happens is dependent on the molecule-molecule and molecule-surface interactions of the adsorbate due to the initial coverage and order of the monolayer. An octanethiolate monolayer is also substantially modified when immersed in a solution containing dithiocarbamate (DTC). Defects in the octanethiol monolayer are prime sites for molecular exchange. A surplus of DTC in the solution drives substitution that can lead to the complete removal of thiol from the surface. When a Au(111) surface is exposed to solutions containing both octanethiol and dithiocarbamate (DTC), both molecular species compete for available ad- sorption sites. At equal octanethiol-to-DTC ratios, molecular exchange hinders octanethiol monolayer formation. Higher octanethiol concentration in solution results in the incorporation of thiol into the resulting monolayer, with a strong dependence on the chain length of the DTC molecules.

  17. Copper accumulation and lipid oxidation precede inflammation and myelin lesions in N,N-diethyldithiocarbamate peripheral myelinopathy.

    PubMed

    Viquez, Olga M; Valentine, Holly L; Amarnath, Kalyani; Milatovic, Dejan; Valentine, William M

    2008-05-15

    Dithiocarbamates have a wide spectrum of applications in industry, agriculture and medicine with new applications being actively investigated. One adverse effect of dithiocarbamates is the neurotoxicity observed in humans and experimental animals. Results from previous studies have suggested that dithiocarbamates elevate copper and promote lipid oxidation within myelin membranes. In the current study, copper levels, lipid oxidation, protein oxidative damage and markers of inflammation were monitored as a function of N,N-diethyldithiocarbamate (DEDC) exposure duration in an established model for DEDC-mediated myelinopathy in the rat. Intra-abdominal administration of DEDC was performed using osmotic pumps for periods of 2, 4, and 8 weeks. Metals in brain, liver and tibial nerve were measured using ICP-MS and lipid oxidation assessed through HPLC measurement of malondialdehyde in tibial nerve, and GC/MS measurement of F(2) isoprostanes in sciatic nerve. Protein oxidative injury of sciatic nerve proteins was evaluated through quantification of 4-hydroxynonenal protein adducts using immunoassay, and inflammation monitored by quantifying levels of IgGs and activated macrophages using immunoassay and immunohistochemistry methods, respectively. Changes in these parameters were then correlated to the onset of structural lesions, determined by light and electron microscopy, to delineate the temporal relationship of copper accumulation and oxidative stress in peripheral nerve to the onset of myelin lesions. The data provide evidence that DEDC mediates lipid oxidation and elevation of total copper in peripheral nerve well before myelin lesions or activated macrophages are evident. This relationship is consistent with copper-mediated oxidative stress contributing to the myelinopathy.

  18. Determination of traces of silver in waters by anion exchange and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Fishman, M. J.; Ball, J.W.

    1969-01-01

    A method has been developed for the accurate determination of 0.1-1 ??g of silver per liter of water. The method permits stabilization of silver in water without loss to container walls. Optimum conditions have been established for the complete recovery of silver from water with an anion-exchange column, for quantitative elution of silver from the resin, and for measurement of silver by atomic absorption spectrophotometry after chelation with ammonium pyrrolidine dithiocarbamate and extraction of the chelate with MIBK. Silver in the 1-10 ??g 1 range can be determined by extraction without pre-concentration on an ion-exchange resin. ?? 1969.

  19. [Occurrence of some pesticides residues in peppermint Mentha piperita L. in 2003-2005].

    PubMed

    Sadło, Stanisław; Szpyrka, Ewa; Rogozińska, Krystyna; Rupar, Julian

    2006-01-01

    The aim of this paper was to present occurrence of pesticides residues in peppermint Mentha Piperita in 2003-2005 and to estimate of their intakes by consumer. Gas chromatographic and spectroscopy methods were used. The most frequently found were chlorpyrifos residues (16% analysed samples) followed by terbacil (11%), dithiocarbamates (10%) and diazinon (5%). Residues in 14% analysed samples exceeded the European Union Maximum Residue Levels established for tea. Assuming consumption of peppermint on the level of 4.5 g (three bags) per day, short-term intake by adult and child consumer was a few times lower then Acceptable Daily Intake.

  20. Coordination chemistry of the {sup 212}Pb/{sup 212}Bi nuclear transformation: Alpha-emitting radiopharmaceuticals. Final technical report

    SciTech Connect

    Parks, N.J.; Harris, W.R.; Keen, C.L.; Cooper, S.R.

    1992-07-01

    Subdivisions of this project are: (a) the synthesis of prototypical thiolate and dithiocarbamate based hexacoordinate complexes, (b) radiochemical engineering for generation of no-carrier-added lead and bismuth radioelements, (c) the first isolation of bismuth-binding proteins from in vivo studies with cyclotron produced {sup 205/206}Bi tracer, and (d) initial development of transport mechanisms for the intracellular radiobiological study of alpha emitting bismuth, and (e) the initiation of chemical equilibrium studies and biochemical pathways with cyclotron-produced, no-carrier-added, {sup 203}Pb (T{sub 1/2} = 51 hr).

  1. Coordination chemistry of the sup 212 Pb/ sup 212 Bi nuclear transformation: Alpha-emitting radiopharmaceuticals

    SciTech Connect

    Parks, N.J.; Harris, W.R.; Keen, C.L.; Cooper, S.R.

    1992-07-01

    Subdivisions of this project are: (a) the synthesis of prototypical thiolate and dithiocarbamate based hexacoordinate complexes, (b) radiochemical engineering for generation of no-carrier-added lead and bismuth radioelements, (c) the first isolation of bismuth-binding proteins from in vivo studies with cyclotron produced {sup 205/206}Bi tracer, and (d) initial development of transport mechanisms for the intracellular radiobiological study of alpha emitting bismuth, and (e) the initiation of chemical equilibrium studies and biochemical pathways with cyclotron-produced, no-carrier-added, {sup 203}Pb (T{sub 1/2} = 51 hr).

  2. The Determination of Trace Metals in Saline Waters and Biological Tissues Using the Heated Graphite Atomizer

    NASA Technical Reports Server (NTRS)

    Segar, D. A.

    1971-01-01

    A selective, volatalization technique utilizing the heated graphite atomizer atomic absorption technique has been developed for the analysis of iron in sea water. A similar technique may be used to determine vanadium, copper, nickel and cobalt in saline waters when their concentrations are higher than those normally encountered'in unpolluted sea waters. A preliminary solvent extraction using ammonium pyrolidine dithiocarbamate and methyl iso-butyl ketone permits the determination of a number of elements including iron, copper, zinc, nickel, cobalt and lead in sea water. The heated graphite atomized technique has also been applied to the determination of a range of trace transition elements in marine plant and animal tissues.

  3. Supercritical fluid extraction

    DOEpatents

    Wai, Chien M.; Laintz, Kenneth

    1994-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  4. Synthesis of new triazolyl-N,N-dialkyldithiocarbamates as antifungal agents.

    PubMed

    Ozkirimli, Sumru; Apak, T Idil; Kiraz, Muammer; Yegenoglu, Yildiz

    2005-11-01

    N,N-Dialkylditihiocarbamate derivatives have been well known as broad-range fungicides. In this study, the triazole derivatives of ten new N,N-disubstituted dithiocarbamates (3a-j) were synthesized and their structures were identified by spectral and elemental analysis. Results of the antifungal activity studies showed that some of the compounds tested were active against M. canis, M. gypseum, and T. rubrum at the concentration of 12.5 microg/mL when clotrimazol was used as a standard.

  5. Antibacterial structure–activity relationship studies of several tricyclic sulfur-containing flavonoids

    PubMed Central

    Bahrin, Lucian G; Hopf, Henning; Jones, Peter G; Sarbu, Laura G; Babii, Cornelia; Mihai, Alina C

    2016-01-01

    Summary A structure–activity relationship study concerning the antibacterial properties of several halogen-substituted tricyclic sulfur-containing flavonoids has been performed. The compounds have been synthesized by cyclocondensation of the corresponding 3-dithiocarbamic flavanones under acidic conditions. The influence of different halogen substituents on the antibacterial properties has been tested against Staphylococcus aureus and Escherichia coli. Amongst the N,N-dialkylamino-substituted flavonoids, those having an N,N-diethylamino moiety exhibited good to excellent antimicrobial properties against both pathogens. Fluorine-substituted flavonoids were found to be less active than those bearing other halogen atoms. PMID:27340492

  6. Multicomponent synthesis of 3,6-dihydro-2H-1,3-thiazine-2-thiones.

    PubMed

    Kruithof, Art; Ploeger, Marten L; Janssen, Elwin; Helliwell, Madeleine; de Kanter, Frans J J; Ruijter, Eelco; Orru, Romano V A

    2012-02-08

    Non-fused 3,6-dihydro-2H-1,3-thiazine-2-thiones constitute a so far rather unexplored class of compounds, with the latest report dating back more than two decades. Thiazine-2-thiones contain an endocyclic dithiocarbamate group, which is often found in pesticides, in substrates for radical chemistry and in synthetic intermediates towards thioureas and amidines. We now report the multicomponent reaction (MCR) of in situ-generated 1-azadienes with carbon disulfide. With this reaction, a one-step protocol towards the potentially interesting 3,6-dihydro-2H-1,3-thiazine-2-thiones was established and a small library was synthesized.

  7. Prevention of exposure to N-nitrosamines in the rubber industry: new vulcanization accelerators based on 'safe' amines.

    PubMed

    Wacker, C D; Spiegelhalder, B; Börzsönyi, M; Brune, G; Preussmann, R

    1987-01-01

    Introduction of 'safe' amino components into traditional accelerator molecules could be an effective measure to prevent formation of carcinogenic N-nitroso compounds during rubber production. About 20 new derivatives of the dithiocarbamate and sulfenamide class, based on 'safe' amines, were synthesized and shown to be suitable for industrial application. Some of the corresponding N-nitrosamines were prepared and investigated for mutagenicity in Salmonella typhimurium TA1535. No or weak mutagenic potential was observed in most cases. The nitrosatability of five sulfenamides derived from 'safe' amines was determined and found to be substantially lower than that of a commercial sulfenamide accelerator tested under identical conditions.

  8. Monothiocarbamates Strongly Inhibit Carbonic Anhydrases in Vitro and Possess Intraocular Pressure Lowering Activity in an Animal Model of Glaucoma.

    PubMed

    Vullo, Daniela; Durante, Mariaconcetta; Di Leva, Francesco Saverio; Cosconati, Sandro; Masini, Emanuela; Scozzafava, Andrea; Novellino, Ettore; Supuran, Claudiu T; Carta, Fabrizio

    2016-06-23

    A series of monothiocarbamates (MTCs) were prepared from primary/secondary amines and COS as potential carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, using the dithiocarbamates, the xanthates, and the trithiocarbonates as lead compounds. The MTCs effectively inhibited the pharmacologically relevant human (h) hCAs isoforms I, II, IX, and XII in vitro and showed KIs spanning between the low and medium nanomolar range. By means of a computational study, the MTC moiety binding mode on the CAs was explained. Furthermore, a selection of MTCs were evaluated in a normotensive glaucoma rabbit model for their intraocular pressure (IOP) lowering effects and showed interesting activity.

  9. [Evidence-based evaluation of the effect of Type IV Allergies on the reduction of fitness for work. Survey of occupational skin diseases].

    PubMed

    Diepgen, T L; Dickel, H; Becker, D; Geier, J; Mahler, V; Schmidt, A; Schwanitz, H-J; Skudlik, C; Wagner, E; Wehrmann, W; Weisshaar, E; Werfel, T; Blome, O

    2005-03-01

    Evidence-based guidelines about the distribution of type IV allergens of the European standard series in different professions and its occupational relevance are missing. Based on published data, epidemiological investigations, work related knowledge about industrial processes, and allergen specific properties, recommendations are given about the clinical impact in the working environment for the following allergens: acrylates/methacrylates, epoxy resins, dichromate, cobalt, nickel, formaldehyde, (chlor-)methylisothiazolone, p-phenylendiamine, colophony, thiurame, mercaptobenzothiazole, dithiocarbamate, n-isopropyl-n'-phenyl-p-phenylendiamine, fragrance mix, composite mix, and neomycinsulfate. These recommendations might improve the clearance rate and allergological evaluation of the occupational relevance of different delayed type sensitizations or allergens.

  10. Analysis of residual vulcanization accelerators in baby bottle rubber teats.

    PubMed

    Yamazaki, T; Inoue, T; Yamada, T; Tanimura, A

    1986-01-01

    An analytical method was established for the determination of dialkyldithiocarbamates (DTCs) in chloroform-acetone extracts from rubber teats for baby bottles. DTCs in the extracts were derivatized into ethyl esters and analysed by gas chromatography employing nitrogen-phosphorus detection. Dimethyldithiocarbamate and diethyldithiocarbamate were detected at levels up to 3.2 micrograms/g rubber and up to 4.6 micrograms/g rubber (as dithiocarbamic acid), respectively, in the extracts from commercially available isoprene rubber tests. DTCs can form secondary amines by acid hydrolysis, although the levels of DTCs in the extracts only made a minor contribution to the total level of measured secondary amine precursors.

  11. Synthesis and structure of sulfur derivatives from 2-aminobenzimidazole.

    PubMed

    Cruz, Alejandro; Padilla-Martínez, Itzia I; García-Báez, Efrén V; Guerrero-Muñoz, Gerardo

    2014-09-04

    The reactions of the benzimidazole nitrogen atoms and the exocyclic amino group of 2-aminobenzimidazole with CS2 in NaOH basic medium followed by methylation with methyl iodide was explored. With careful control of the stoichiometric quantities and addition sequences, this set of reactions allows the selective functionalization of the benzimidazole ring with N-dithiocarbamate, S-methyldithiocarbamate or dimethyl- dithiocarboimidate groups. The products were characterized by 1H-, 13C-NMR spectroscopy and three of them by X-ray diffraction analysis. The preferred isomers, tautomers and conformers were established.

  12. Direct spectrophotometric determination of ferbam (Iron(III) dimethyldithiocarbamate) in commercial sample and wheat grains using 4,7-diphenyl-1,10-phenanthroline.

    PubMed

    Malik, A K

    2000-12-01

    A procedure has been developed for the determination of iron(III) dimethyldithiocarbamate by converting it into the iron(II)-bathophenanthroline complex, which is then dissolved in acetone-water (1:1), and the absorbance is measured at 534 nm against a reagent blank. Beer's law is obeyed over the concentration range 0.5-20 microg x mL(-1) in the final solution. The method is sensitive and highly selective and is used for the direct determination of ferbam in a commercial sample and in mixtures with various dithiocarbamates (ziram, zineb, maneb, etc.) and from wheat grains.

  13. RECOVERY OF URANIUM BY CYCLOALKYLDITHIO-CARBAMATE COMPLEXING

    DOEpatents

    Neville, O.K.

    1959-06-30

    The separation of uranium-233 from an aqueous nitric acid solution of neutron irradiated thorium by selectively complexing the uranium is described. The separation is carried out by contacting the thorium solution with a non- aromatic organic dithiocarbamate selected from the group which consists of alkali and alkaline earth cycloalkyldithiocarbamates and recovering the resulting uranyl cycloalkyldithiocarbamate complex by organic solvent extraction such as with methyl ethyl ketone. The complexed uranium may be stripped from the separated organic phase by scrubbing with one normal nitric acid solution.

  14. Copper-doped CdSe/ZnS quantum dots: controllable photoactivated copper(I) cation storage and release vectors for catalysis.

    PubMed

    Bear, Joseph C; Hollingsworth, Nathan; McNaughter, Paul D; Mayes, Andrew G; Ward, Michael B; Nann, Thomas; Hogarth, Graeme; Parkin, Ivan P

    2014-02-03

    The first photoactivated doped quantum dot vector for metal-ion release has been developed. A facile method for doping copper(I) cations within ZnS quantum dot shells was achieved through the use of metal-dithiocarbamates, with Cu(+) ions elucidated by X-ray photoelectron spectroscopy. Photoexcitation of the quantum dots has been shown to release Cu(+) ions, which was employed as an effective catalyst for the Huisgen [3+2] cycloaddition reaction. The relationship between the extent of doping, catalytic activity, and the fluorescence quenching was also explored.

  15. Effect of annealing temperature on optical properties of binary zinc tin oxide nano-composite prepared by sol-gel route using simple precursors: structural and optical studies by DRS, FT-IR, XRD, FESEM investigations.

    PubMed

    Habibi, Mohammad Hossein; Mardani, Maryam

    2015-02-25

    Binary zinc tin oxide nano-composite was synthesized by a facile sol-gel method using simple precursors from the solutions consisting of zinc acetate, tin(IV) chloride and ethanol. Effect of annealing temperature on optical and structural properties was investigated using X-ray diffraction (XRD), diffuse reflectance spectra (DRS), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). XRD results revealed the existence of the ZnO and SnO2 phases. FESEM results showed that binary zinc tin oxide nano-composites ranges from 56 to 60 nm in diameter at 400°C and 500°C annealing temperatures respectively. The optical band gap was increased from 2.72 eV to 3.11 eV with the increasing of the annealing temperature. FTIR results confirmed the presence of zinc oxide and tin oxide and the broad absorption peaks at 3426 and 1602 cm(-1) can be ascribed to the vibration of absorptive water, and the absorption peaks at 546, 1038 and 1410 cm(-1) are due to the vibration of Zn-O or Sn-O groups in binary zinc tin oxide.

  16. Novel Organotin(IV) Schiff Base Complexes with Histidine Derivatives: Synthesis, Characterization, and Biological Activity

    PubMed Central

    Garza-Ortiz, Ariadna; Camacho-Camacho, Carlos; Sainz-Espuñes, Teresita; Rojas-Oviedo, Irma; Gutiérrez-Lucas, Luis Raúl; Gutierrez Carrillo, Atilano; Vera Ramirez, Marco A.

    2013-01-01

    Five novel tin Schiff base complexes with histidine analogues (derived from the condensation reaction between L-histidine and 3,5-di-tert-butyl-2-hydroxybenzaldehyde) have been synthesized and characterized. Characterization has been completed by IR and high-resolution mass spectroscopy, 1D and 2D solution NMR (1H, 13C  and 119Sn), as well as solid state 119Sn NMR. The spectroscopic evidence shows two types of structures: a trigonal bipyramidal stereochemistry with the tin atom coordinated to five donating atoms (two oxygen atoms, one nitrogen atom, and two carbon atoms belonging to the alkyl moieties), where one molecule of ligand is coordinated in a three dentate fashion. The second structure is spectroscopically described as a tetrahedral tin complex with four donating atoms (one oxygen atom coordinated to the metal and three carbon atoms belonging to the alkyl or aryl substituents), with one molecule of ligand attached. The antimicrobial activity of the tin compounds has been tested against the growth of bacteria in vitro to assess their bactericidal properties. While pentacoordinated compounds 1, 2, and 3 are described as moderate effective to noneffective drugs against both Gram-positive and Gram-negative bacteria, tetracoordinated tin(IV) compounds 4 and 5 are considered as moderate effective and most effective compounds, respectively, against the methicillin-resistant Staphylococcus aureus strains (Gram-positive). PMID:23864839

  17. Synthesis, Characterization and In Vitro Antibacterial Studies of Organotin(IV) Complexes with 2-Hydroxyacetophenone-2-methylphenylthiosemicarbazone (H2dampt)

    PubMed Central

    Salam, M. A.; Affan, M. A.; Saha, Ramkrishna; Ahmad, Fasihuddin B.; Sam, Norrihan

    2012-01-01

    Five new organotin(IV) complexes of 2-hydroxyacetophenone-2-methylphenylthiosemicarbazone [H2dampt, (1)] with formula [RSnCln-1(dampt)] (where R = Me, n = 2 (2); R = Bu, n = 2 (3); R = Ph, n = 2 (4); R = Me2, n = 1 (5); R = Ph2, n = 1 (6)) have been synthesized by direct reaction of H2dampt (1) with organotin(IV) chloride(s) in absolute methanol. The ligand (1) and its organotin(IV) complexes (2–6) were characterized by CHN analyses, molar conductivity, UV-Vis, FT-IR, 1H, 13C, and 119Sn NMR spectral studies. H2dampt (1) is newly synthesized and has been structurally characterized by X-ray crystallography. Spectroscopic data suggested that H2dampt (1) is coordinated to the tin(IV) atom through the thiolate-S, azomethine-N, and phenoxide-O atoms; the coordination number of tin is five. The in vitro antibacterial activity has been evaluated against Staphylococcus aureus, Enterobacter aerogenes, Escherichia coli, and Salmonella typhi. The screening results have shown that the organotin(IV) complexes (2–6) have better antibacterial activities and have potential as drugs. Furthermore, it has been shown that diphenyltin(IV) derivative (6) exhibits significantly better activity than the other organotin(IV) derivatives (2–5). PMID:22611347

  18. LDRD final report on synthesis of shape-and size-controlled platinum and platinum alloy nanostructures on carbon with improved durability.

    SciTech Connect

    Shelnutt, John Allen; Garcia, Robert M.; Song, Yujiang; Moreno, Andres M.; Stanis, Ronald J.

    2008-10-01

    This project is aimed to gain added durability by supporting ripening-resistant dendritic platinum and/or platinum-based alloy nanostructures on carbon. We have developed a new synthetic approach suitable for directly supporting dendritic nanostructures on VXC-72 carbon black (CB), single-walled carbon nanotubes (SWCNTs), and multi-walled carbon nanotubes (MWCNTs). The key of the synthesis is to creating a unique supporting/confining reaction environment by incorporating carbon within lipid bilayer relying on a hydrophobic-hydrophobic interaction. In order to realize size uniformity control over the supported dendritic nanostructures, a fast photocatalytic seeding method based on tin(IV) porphyrins (SnP) developed at Sandia was applied to the synthesis by using SnP-containing liposomes under tungsten light irradiation. For concept approval, one created dendritic platinum nanostructure supported on CB was fabricated into membrane electrode assemblies (MEAs) for durability examination via potential cycling. It appears that carbon supporting is essentially beneficial to an enhanced durability according to our preliminary results.

  19. Development of immobilized Sn(4+) affinity chromatography material for highly selective enrichment of phosphopeptides.

    PubMed

    Lin, Haizhu; Deng, Chunhui

    2016-11-01

    In this work, we first immobilized tin(IV) ion on polydopamine-coated magnetic graphene (magG@PDA) to synthesize Sn(4+) -immobilized magG@PDA (magG@PDA-Sn(4+) ) and successfully applied the material to highly selective enrichment of phosphopeptides. The material gathered the advantages of large surface area of graphene, superparamagnetism of Fe3 O4 , good hydrophilicity and biocompatibility of polydopamine, and strong interaction between Sn(4+) and phosphopeptides. The enrichment performance of magG@PDA-Sn(4+) toward phosphopeptides from digested β-casein at different concentrations, with and without added digested BSA was investigated and compared with magG@PDA-Ti(4+) . The results showed high selectivity and sensitivity of the Sn(4+) -IMAC material toward phosphopeptides, as good as the Ti(4+) -IMAC material. Finally, magG@PDA-Sn(4+) was applied to the analysis of endogenous phosphopeptides from a real sample, human saliva, with both MALDI-TOF MS and nano-LC-ESI-MS/MS. The results indicated that the as-synthesized Sn(4+) -IMAC material not only has good enrichment performance, but also could serve as a supplement to the Ti(4+) -IMAC material and expand the phosphopeptide coverage enriched by the single Ti(4+) -IMAC material, demonstrating the broad application prospects of magG@PDA-Sn(4+) in phosphoproteome research.

  20. Effect of dopant concentration on visible light driven photocatalytic activity of Sn1-xAgxS2.

    PubMed

    Cui, Xiaodan; Xu, Wangwang; Xie, Zhiqiang; Dorman, James A; Gutierrez-Wing, Maria Teresa; Wang, Ying

    2016-10-18

    Tin(iv) sulfide (SnS2), as a mid-band-gap semiconductor shows good potential as an excellent photocatalyst due to its low cost, wide light spectrum response and environment-friendly nature. However, to meet the demands of large-scale water treatment, a SnS2 photocatalyst with a red-shifted band gap, increased surface area and accelerated molecule and ion diffusion is required. Doping is a facile method to manipulate the optical and chemical properties of semiconductor materials simultaneously. In this work, SnS2 photocatalysts with varied Ag doping content are synthesized through a facile one-step hydrothermal method. The product is characterized by XRD, SEM, TEM and UV-Vis spectrometry. The photocatalytic activity of the as-prepared Sn1-xAgxS2 is studied by the degradation of methylene blue (MB) dye under solar light irradiation. It is found that increasing the Ag dopant concentration can effectively increase the solar light adsorption efficiency of the photocatalyst and accelerate heterogeneous photocatalysis. The optimal concentration of Ag dopant is found to be 5% with the highest rate constant being 1.8251 hour(-1). This study demonstrates that an optimal amount of Ag doping can effectively increase the photocatalytic performance of SnS2 and will promote the commercialization of such photocatalysts in the photocatalytic degradation of organic compounds.

  1. Chemical perturbation of an intrinsically disordered region of TFIID distinguishes two modes of transcription initiation

    PubMed Central

    Zhang, Zhengjian; Boskovic, Zarko; Hussain, Mahmud M; Hu, Wenxin; Inouye, Carla; Kim, Han-Je; Abole, A Katherine; Doud, Mary K; Lewis, Timothy A; Koehler, Angela N; Schreiber, Stuart L; Tjian, Robert

    2015-01-01

    Intrinsically disordered proteins/regions (IDPs/IDRs) are proteins or peptide segments that fail to form stable 3-dimensional structures in the absence of partner proteins. They are abundant in eukaryotic proteomes and are often associated with human diseases, but their biological functions have been elusive to study. In this study, we report the identification of a tin(IV) oxochloride-derived cluster that binds an evolutionarily conserved IDR within the metazoan TFIID transcription complex. Binding arrests an isomerization of promoter-bound TFIID that is required for the engagement of Pol II during the first (de novo) round of transcription initiation. However, the specific chemical probe does not affect reinitiation, which requires the re-entry of Pol II, thus, mechanistically distinguishing these two modes of transcription initiation. This work also suggests a new avenue for targeting the elusive IDRs by harnessing certain features of metal-based complexes for mechanistic studies, and for the development of novel pharmaceutical interventions. DOI: http://dx.doi.org/10.7554/eLife.07777.001 PMID:26314865

  2. Synthesis, crystal structures HOMO-LUMO analysis and DFT calculation of new complexes of p-substituted dibenzyltin chlorides and 1,10-phenanthroline.

    PubMed

    Chandrasekar, S; Balachandran, V; Evans, Helen-Stoeckli; Latha, A

    2015-05-15

    In the present work, the complex formation of p-substituted dibenzyltin dichlorides with 1,10-phenanthroline. The reaction of (p-MeBz)2SnCl2 with 1,10-phenanthroline results (p-MeBz)2SnCl2-1,10-phenanthroline complex, (2a). Likewise (p-ClBz)2SnCl2 with 1,10-phenanthroline results (p-ClBz)2SnCl2-1,10-phenanthroline complex, (2b), in the similar reaction conditions. The IR, (1)H NMR, (13)C NMR, (119)Sn NMR spectral analyses indicate that the formation of hexacoordinated tin(IV) complexes in 1:1 ratio. The crystal structures of complexes 2a and 2b show that the tin atom is in regular octahedral geometry with the benzyl groups in the equidirectional positions. A comparison was made with the structural data of other R2SnX2-1,10-phenathroline derivatives. Fourier transforms infrared and Raman spectral studies were performed for analyzing and assigning the vibrations and to identify the functional groups. Optimized geometrical parameters, harmonic vibrational frequencies, frontier molecular orbitals were obtained by DFT/B3LYP method combined with LanL2DZ basis set.

  3. Recycled Poly(vinyl alcohol) Sponge for Carbon Encapsulation of Size-Tunable Tin Dioxide Nanocrystalline Composites.

    PubMed

    Ma, Yue; Tai, Cheuk-Wai; Gustafsson, Torbjörn; Edström, Kristina

    2015-06-22

    The recycling of industrial materials could reduce their environmental impact and waste haulage fees and result in sustainable manufacturing. In this work, commercial poly(vinyl alcohol) (PVA) sponges are recycled into a macroporous carbon matrix to encapsulate size-tunable SnO2 nanocrystals as anode materials for lithium-ion batteries (LIBs) through a scalable, flash-combustion method. The hydroxyl groups present copiously in the recycled PVA sponges guarantee a uniform chemical coupling with a tin(IV) citrate complex through intermolecular hydrogen bonds. Then, a scalable, ultrafast combustion process (30 s) carbonizes the PVA sponge into a 3D carbon matrix. This PVA-sponge-derived carbon could not only buffer the volume fluctuations upon the Li-Sn alloying and dealloying processes but also afford a mixed conductive network, that is, a continuous carbon framework for electrical transport and macropores for facile electrolyte percolation. The best-performing electrode based on this composite delivers a rate performance up to 9.72 C (4 A g(-1) ) and long-term cyclability (500 cycles) for Li(+) ion storage. Moreover, cyclic voltammograms demonstrate the coexistence of alloying and dealloying processes and non-diffusion-controlled pseudocapacitive behavior, which collectively contribute to the high-rate Li(+) ion storage.

  4. Organotin(IV) complexes of 2-pyridineformamide-derived thiosemicarbazones: antimicrobial and cytotoxic effects.

    PubMed

    Mendes, Isolda C; Moreira, Juliana P; Ardisson, José D; Santos, Raquel Gouvea Dos; da Silva, Paulo Roberto O; Garcia, Isabel; Castiñeiras, Alfonso; Beraldo, Heloisa

    2008-07-01

    Reaction of n-butyltin trichloride [(n-Bu)SnCl(3)] with 2-pyridineformamide thiosemicarbazone (H2Am4DH) and its N(4)-methyl (H2Am4Me) and N(4)-ethyl (H2Am4Et) derivatives gave [(n-Bu)Sn(2Am4DH)Cl(2)] (1), [(n-Bu)Sn(2Am4Me)Cl(2)] (2), and [(n-Bu)Sn(2Am4Et)Cl(2)] (3). Thiosemicarbazones as well as their tin complexes are active as antimicrobials against the growth of Candida albicans and Salmonella typhimurium and were highly active against malignant glioblastoma. The cytotoxic activity of complexes 1-3 is similar. Among the studied compounds [(n-Bu)Sn(2Am4DH)Cl(2)] (1) was the most active as antiproliferative (cytostatic) agent. Thiosemicarbazones and their tin(IV) complexes proved to be more potent as cytotoxic agents than cisplatin. All the compounds were able to induce apoptosis.

  5. Effect of annealing temperature on optical properties of binary zinc tin oxide nano-composite prepared by sol-gel route using simple precursors: Structural and optical studies by DRS, FT-IR, XRD, FESEM investigations

    NASA Astrophysics Data System (ADS)

    Habibi, Mohammad Hossein; Mardani, Maryam

    2015-02-01

    Binary zinc tin oxide nano-composite was synthesized by a facile sol-gel method using simple precursors from the solutions consisting of zinc acetate, tin(IV) chloride and ethanol. Effect of annealing temperature on optical and structural properties was investigated using X-ray diffraction (XRD), diffuse reflectance spectra (DRS), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). XRD results revealed the existence of the ZnO and SnO2 phases. FESEM results showed that binary zinc tin oxide nano-composites ranges from 56 to 60 nm in diameter at 400 °C and 500 °C annealing temperatures respectively. The optical band gap was increased from 2.72 eV to 3.11 eV with the increasing of the annealing temperature. FTIR results confirmed the presence of zinc oxide and tin oxide and the broad absorption peaks at 3426 and 1602 cm-1 can be ascribed to the vibration of absorptive water, and the absorption peaks at 546, 1038 and 1410 cm-1 are due to the vibration of Zn-O or Sn-O groups in binary zinc tin oxide.

  6. High-efficient mercury removal from environmental water samples using di-thio grafted on magnetic mesoporous silica nanoparticles.

    PubMed

    Mehdinia, Ali; Akbari, Maryam; Baradaran Kayyal, Tohid; Azad, Mohammad

    2015-02-01

    In this work, magnetic di-thio functionalized mesoporous silica nanoparticles (DT-MCM-41) were prepared by grafting dithiocarbamate groups within the channels of magnetic mesoporous silica nanocomposites. The functionalized nanoparticles exhibited proper magnetic behavior. They were easily separated from the aqueous solution by applying an external magnetic field. The results indicated that the functionalized nanoparticles had a potential for high-efficient removal of Hg(2+) in environmental samples. The maximum adsorption capacity of the sorbent was 538.9 mg g(-1), and it took about 10 min to achieve the equilibrium adsorption. The resulted adsorption capacity was higher than similar works for adsorption of mercury. It can be due to the presence of di-thio and amine active groups in the structure of sorbent. The special properties of MCM-41 like large surface area and high porosity also provided a facile accessibility of the mercury ions into the ligand sites. The complete removal of mercury ions was attained with dithiocarbamate groups in a wide range of mercury concentrations. The recovery studies were also applied for the river water, seawater, and wastewater samples, and the values were over of 97 %.

  7. Dopaminergic neurotoxicity of S-ethyl N,N-dipropylthiocarbamate (EPTC), molinate, and S-methyl-N,N-diethylthiocarbamate (MeDETC) in Caenorhabditis elegans.

    PubMed

    Caito, Samuel W; Valentine, William M; Aschner, Michael

    2013-12-01

    Epidemiological studies corroborate a correlation between pesticide use and Parkinson's disease (PD). Thiocarbamate and dithiocarbamate pesticides are widely used and produce neurotoxicity in the peripheral nervous system. Recent evidence from rodent studies suggests that these compounds also cause dopaminergic (DAergic) dysfunction and altered protein processing, two hallmarks of PD. However, DAergic neurotoxicity has yet to be documented. We assessed DAergic dysfunction in Caenorhabditis elegans (C. elegans) to investigate the ability of thiocarbamate pesticides to induce DAergic neurodegeneration. Acute treatment with either S-ethyl N,N-dipropylthiocarbamate (EPTC), molinate, or a common reactive intermediate of dithiocarbamate and thiocarbamate metabolism, S-methyl-N,N-diethylthiocarbamate (MeDETC), to gradual loss of DAergic cell morphology and structure over the course of 6 days in worms expressing green fluorescent protein (GFP) under a DAergic cell specific promoter. HPLC analysis revealed decreased DA content in the worms immediately following exposure to MeDETC, EPTC, and molinate. In addition, worms treated with the three test compounds showed a drastic loss of DAergic-dependent behavior over a time course similar to changes in DAergic cell morphology. Alterations in the DAergic system were specific, as loss of cell structure and neurotransmitter content was not observed in cholinergic, glutamatergic, or GABAergic systems. Overall, our data suggest that thiocarbamate pesticides promote neurodegeneration and DAergic cell dysfunction in C. elegans, and may be an environmental risk factor for PD.

  8. Technetium-99m and rhenium-188 complexes with one and two pendant bisphosphonate groups for imaging arterial calcification.

    PubMed

    Bordoloi, Jayanta Kumar; Berry, David; Khan, Irfan Ullah; Sunassee, Kavitha; de Rosales, Rafael Torres Martin; Shanahan, Catherine; Blower, Philip J

    2015-03-21

    The first (99m)Tc and (188)Re complexes containing two pendant bisphosphonate groups have been synthesised, based on the mononuclear M(v) nitride core with two dithiocarbamate ligands each with a pendant bisphosphonate. The structural identity of the (99)Tc and stable rhenium analogues as uncharged, mononuclear nitridobis(dithiocarbamate) complexes was determined by electrospray mass spectrometry. The (99m)Tc complex showed greater affinity for synthetic and biological hydroxyapatite, and greater stability in biological media, than the well-known but poorly-characterised and inhomogeneous bone imaging agent (99m)Tc-MDP. It gave excellent SPECT images of both bone calcification (mice and rats) and vascular calcification (rat model), but the improved stability and the availability of two pendant bisphosphonate groups conferred no dramatic advantage in imaging over the conventional (99m)Tc-MDP agent in which the bisphosphonate group is bound directly to Tc. The (188)Re complex also showed preferential uptake in bone. These tracers and the biological model of vascular calcification offer the opportunity to study the biological interpretation and clinical potential of radionuclide imaging of vascular calcification and to deliver radionuclide therapy to bone metastases.

  9. Oxidative Stress-Induced Apoptosis in Chronic Myelogenous Leukemia K562 Cells by an Active Compound from the Dithio- Carbamate Family.

    PubMed

    Khoshtabiat, Laya; Mahdavi, Majid; Dehghan, Gholamreza; Rashidi, Mohammad Reza

    2016-01-01

    Previous studies suggested that dithio-carbamates are potent apoptosis and anti-apoptosis inducing agents in various cancer cells. Here, the anti-proliferative and apoptosis inducing effects of a new derivative (2-NDC) from the dithio-carbamate family was examined in human leukemia K562 cells. We use thiazolyl blue tetrazolium bromide (MTT) to measure viability and cell growth inhibition. The 2-NDC showed effects on viability in a dose and time-dependent manner, inhibiting proliferation at concentrations of 10-30 μM after 24-48 hours of treatment and increasing values after 72 hours at 40-120 μM. The cytotoxic effect of the compound was calculated with an IC50 of 30 μM after 24-hour. Apoptosis induction was confirmed by acridine orange-ethidium bromide (AO/EtBr) staining, DNA fragmentation assay, flow cytometric assessment and also caspase-3 activation assay. Furthermore, enzymes level such as superoxide dismutase (SOD) and catalase (CAT) involved in oxidative stress were evaluated. The results of this study demonstrated insignificant increase of intracellular ROS levels for 24 hours and reduction after 48-72 hours. In addition to reduction of intracellular thiol, caspase-3 like activity was also decreased in a time-dependent manner in cells treated with 2-NDC. Thus 2-NDC can be considered as a good candidate for further pharmaceutical evaluations.

  10. fac-Aceto-nitrile-tricarbon-yl(di-methyl-carbamodi-thio-ato-κ(2)S,S')rhenium(I): crystal structure and Hirshfeld surface analysis.

    PubMed

    Tan, Sang Loon; Lee, See Mun; Heard, Peter J; Halcovitch, Nathan R; Tiekink, Edward R T

    2017-02-01

    The title compound, [Re(C3H6NS2)(C2H3N)(CO)3], features an octa-hedrally coordinated Re(I) atom within a C3NS2 donor set defined by three carbonyl ligands in a facial arrangement, an aceto-nitrile N atom and two S atoms derived from a symmetrically coordinating di-thio-carbamate ligand. In the crystal, di-thio-carbamate-methyl-H⋯O(carbon-yl) inter-actions lead to supra-molecular chains along [36-1]; both di-thio-carbamate S atoms participate in intra-molecular methyl-H⋯S inter-actions. Further but weaker aceto-nitrile-C-H⋯O(carbonyl) inter-actions assemble mol-ecules in the ab plane. The nature of the supra-molecular assembly was also probed by a Hirshfeld surface analysis. Despite their weak nature, the C-H⋯O contacts are predominant on the Hirshfeld surface and, indeed, on those of related [Re(CO)3(C3H6NS2)L] structures.

  11. The prepared mind. [Serendipitous discovery of demulsifier

    SciTech Connect

    Thompson, N.E.S. )

    1994-09-01

    Products derived from the work of scientists with serendipity, or an imagined faculty for making fluke discoveries by looking for one thing and finding another, include the well-known examples of Teflon, penicillin, X-rays, Velcro, nylon, saccharin, and Nutrasweet. This dream of every scientist came true for the author in the discovery of a dithiocarbamate compound that could be used as a water-clarifying agent for oil fields that produce water. The new agent enables oil companies to discharge water produced in offshore drilling facilities without upsetting the clarity of the aquatic environment. The EPA limit for oil in discharged water is 48 ppm. Failure to maintain this limit will result in shutdown of the platform. The alternative is to pipe the produced water to onshore facilities for treatment before discharge, which costs a good bit more. The serendipitous discovery of the dithiocarbamate compound discussed here as a unique water-clarifying agent has also led to important fundamental advances. The new agent allows producers to use existing water treatment equipment and remain in compliance with the latest limits on oil content. This compound has made it more economical to operate offshore oil and gas production facilities in the Gulf of Mexico and the North Sea.

  12. Carbonic anhydrase inhibitors drug design.

    PubMed

    McKenna, Robert; Supuran, Claudiu T

    2014-01-01

    Inhibition of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) has pharmacologic applications in the field of antiglaucoma, anticonvulsant, antiobesity, and anticancer agents but is also emerging for designing anti-infectives (antifungal and antibacterial agents) with a novel mechanism of action. As a consequence, the drug design of CA inhibitors (CAIs) is a very dynamic field. Sulfonamides and their isosteres (sulfamates/sulfamides) constitute the main class of CAIs which bind to the metal ion in the enzyme active site. Recently the dithiocarbamates, possessing a similar mechanism of action, were reported as a new class of inhibitors. Other families of CAIs possess a distinct mechanism of action: phenols, polyamines, some carboxylates, and sulfocoumarins anchor to the zinc-coordinated water molecule. Coumarins and five/six-membered lactones are prodrug inhibitors, binding in hydrolyzed form at the entrance of the active site cavity. Novel drug design strategies have been reported principally based on the tail approach for obtaining all these types of CAIs, which exploit more external binding regions within the enzyme active site (in addition to coordination to the metal ion), leading thus to isoform-selective compounds. Sugar-based tails as well as click chemistry were the most fruitful developments of the tail approach. Promising compounds that inhibit CAs from bacterial and fungal pathogens, of the dithiocarbamate, phenol and carboxylate types have also been reported.

  13. A Gate-to-gate Case Study of the Life Cycle Assessment of an Oil Palm Seedling.

    PubMed

    Muhamad, Halimah; Sahid, Ismail Bin; Surif, Salmijah; Ai, Tan Yew; May, Choo Yuen

    2012-05-01

    The palm oil industry has played an important role in the economic development of Malaysia and has enhanced the economic welfare of its people. To determine the environmental impact of the oil palm seedling at the nursery stage, information on inputs and outputs need to be assessed. The oil palm nursery is the first link in the palm oil supply chain. A gate-to-gate study was carried out whereby the system boundary was set to only include the process of the oil palm seedling. The starting point was a germinated seed in a small polyethylene bag (6 in × 9 in) in which it remained until the seedling was approximately 3 to 4 months old. The seedling was then transferred into a larger polyethylene bag (12 in × 15 in), where it remained until it was 10-12 months old, when it was planted in the field (plantation). The functional unit for this life cycle inventory (LCI) is based on the production of one seedling. Generally, within the system boundary, the production of an oil palm seedling has only two major environmental impact points, the polybags used to grow the seedling and the fungicide (dithiocarbamate) used to control pathogenic fungi, as both the polybags and the dithiocarbamate are derived from fossil fuel.

  14. Ferromagnetic sorbents based on nickel nanowires for efficient uptake of mercury from water.

    PubMed

    Pinheiro, Paula C; Tavares, Daniela S; Daniel-da-Silva, Ana L; Lopes, Cláudia B; Pereira, Eduarda; Araújo, João P; Sousa, Célia T; Trindade, Tito

    2014-06-11

    This work reports the preparation of ferro-magnetic nickel nanowires (NiNW) coated with dithiocarbamate-functionalized siliceous shells and its application for the uptake of aqueous Hg(II) ions by magnetic separation. NiNW with an average diameter and length of 35 nm and 5 μm, respectively, were firstly prepared by Ni electrodeposition in an anodic aluminum oxide template. The NiNW surfaces were then coated with siliceous shells containing dithiocarbamate groups via a one-step procedure consisting in the alkaline hydrolytic co-condensation of tetraethoxysilane (TEOS) and a siloxydithiocarbamate precursor (SiDTC). A small amount of these new nanoadsorbents (2.5 mg·L(-1)) removed 99.8% of mercury ions from aqueous solutions with concentration 50 μg·L(-1) and in less than 24 h of contact time. This outstanding removal ability is attributed to the high affinity of the sulfur donor ligands to Hg(II) species combined with the high surface area-to-volume ratio of the NiNW.

  15. Experimental chemotherapy of lymphatic filariasis. A review.

    PubMed

    Mak, J W; Navaratnam, V; Ramachandran, C P

    1991-02-01

    An intense global collaborative effort under the leadership of the Steering Committee of the Filariasis Scientific Working Group of the Tropical Diseases Research Programme, World Health Organization, has brought together researchers, pharmaceutical chemists and clinicians in the development and search for antifilarial compounds which are more effective and more convenient to administer than diethylcarbamazine citrate, the current drug of choice for lymphatic filariasis. The Brugia spp.-rodent model has been used extensively for the primary screening and B. pahangi infections in the dog or cat for the secondary screening, of potential filaricides. Recently, the leaf-monkey (Presbytis spp.) infected with subperiodic B. malayi or Wuchereria kalimantani has been used for the tertiary evaluation and pharmacokinetic studies of compounds which have shown effectiveness in the primary and secondary screens. Both P. cristata and P. melalophos are extremely susceptible to subperiodic B. malayi infection, but the former is a better host as a higher peak microfilaremia and adult worm recovery rate were obtained. Although more than 30 potential filaricides have been evaluated in the tertiary screen, only a few compounds have shown some promise against lymphatic filariasis. CGP 20376, a 5-methoxyl-6-dithiocarbamic-S-(2-carboxy-ethyl) ester derivative of benzothiazole, had complete adulticidal and microfilaricidal activities against the parasite at a single oral dose of 20 mg kg-1. However, as the compound or its metabolites caused hepatotoxicity, its clinical use in the present formulation is not recommended.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Purification and characterization of polyphenol oxidase from nettle (Urtica dioica L.) and inhibitory effects of some chemicals on enzyme activity.

    PubMed

    Güllçin, Ilhami; Küfrevioğlu, O Irfan; Oktay, Münir

    2005-06-01

    Polyphenol oxidase (PPO) of nettle (Urtica dioica L.) was extracted and purified through (NH4)2SO4 precipitation, dialysis, and CM-Sephadex ion-exchange chromatography and was used for its characterization. The PPO showed activity to catechol, 4-methylcatechol, L-3,4-dihydroxyphenylalanine (L-DOPA), L-tyrosine, p-cresol, pyrogallol, catechin and trans-cinnamic acid. For each of these eight substrates, optimum conditions such as pH and temperature were determined and L-tyrosine was found to be one of the most suitable substrates. Optimum pH and temperature were found at pH 4.5 and 30 degrees C respectively and Km and Vmax values were 7.90 x 10(-4) M, and 11290 EU/mL for with L-tyrosine as substrate. The inhibitory effect of several inhibitors, L-cysteine chloride, sodium azide, sodium cyanide, benzoic acid, salicylic acid, L-ascorbic acid, glutathione, thiourea, sodium diethyl dithiocarbamate, beta-mercaptoethanol and sodium metabisulfite were tested. The most effective was found to be sodium diethyl dithiocarbamate which acted as a competitive inhibitor with a Ki value of 1.79 x 10(-9)M. In addition one isoenzyme of PPO was detected by native polacrylamide slab gel electrophoresis.

  17. Speciation of inorganic arsenic in drinking water by wavelength-dispersive X-ray fluorescence spectrometry after in situ preconcentration with miniature solid-phase extraction disks.

    PubMed

    Hagiwara, Kenta; Inui, Tetsuo; Koike, Yuya; Aizawa, Mamoru; Nakamura, Toshihiro

    2015-03-01

    A rapid and simple method using wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry after in situ solid-phase extraction (SPE) was developed for the speciation and evaluation of the concentration of inorganic arsenic (As) in drinking water. The method involves the simultaneous collection of As(III) and As(V) using 13 mm ϕ SPE miniature disks. The removal of Pb(2+) from the sample water was first conducted to avoid the overlapping PbLα and AsKα spectra on the XRF spectrum. To this end, a 50 mL aqueous sample (pH 5-9) was passed through an iminodiacetate chelating disk. The filtrate was adjusted to pH 2-3 with HCl, and then ammonium pyrrolidine dithiocarbamate solution was added. The solution was passed through a hydrophilic polytetrafluoroethylene filter placed on a Zr and Ca loaded cation-exchange disk at a flow rate of 12.5 mL min(-1) to separate As(III)-pyrrolidine dithiocarbamate complex and As(V). Each SPE disk was affixed to an acrylic plate using adhesive cellophane tape, and then examined by WDXRF spectrometry. The detection limits of As(III) and As(V) were 0.8 and 0.6 μg L(-1), respectively. The proposed method was successfully applied to screening for As speciation and concentration evaluation in spring water and well water.

  18. The determination of cobalt(II) at DME using catalytic hydrogen current technique in various water samples, agricultural materials and pharmaceuticals.

    PubMed

    Kanchi, S; Saraswathi, K; Venkatasubba Naidu, N

    2011-12-01

    Two novel and facile ligands ammonium piperidine dithiocarbamate (Amm Pip-DTC) and ammonium morpholine dithiocarbamate (Amm Mor-DTC) were synthesized for the development of rapid and cost effective catalytic hydrogen current technique to analyze cobalt(II) in the presence of NH(4)Cl-NH(4)OH at pH 7.8 and 8.4 with Amm Pip-DTC and Amm Mor-DTC. These ligands produce catalytic hydrogen currents with Co(II) at peak potentials -1.24 V and -1.44 V vs. SCE respectively. Quantitative experimental conditions are developed by studying effect of pH, supporting electrolyte (NH(4)Cl), ligand and metal ion concentrations and effect of adverse ions on peak height to improve the sensitivity, selectivity and detection limits of the catalytic hydrogen current technique and compared it in terms of Student's t test and variance ratio f test with differential pulse polarographic (DPP) method. The developed technique was applied for the analysis of cobalt(II) in various water samples, agricultural materials and pharmaceuticals and the results obtained are in good agreement with the DPP data.

  19. Stabilization of inorganic mixed waste to pass the TCLP and STLC tests using clay and pH-insensitive additives

    SciTech Connect

    Bowers, J.S.; Anson, S.M.; Painter, S.M.

    1995-09-01

    Stabilization is a best demonstrated available technology, or BDAT, as defined by the U.S. Environmental Protection Agency (EPA) in Title 40, part 268, of the Code of Federal Regulations (40 CFR 268). This technology traps toxic contaminants (usually both chemically and physically) in a matrix so that they do not. leach into the environment. Typical contaminants that are trapped by stabilization are metals (mostly transition metals) that exhibit the characteristic of toxicity as defined by 40 CFR part 261. The stabilization process routinely uses pozzolanic materials. Portland cement, fly ash-lime mixes, gypsum cements, and clays are some of the most common materials. They are inexpensive, easy to use, and effective for wastes containing low concentrations of toxic materials. At the Lawrence Livermore National Laboratory (LLNL), additives such as dithiocarbamates and thiocarbonates, which are pH-insensitive and provide resistance to ligand formation are used in the waste stabilization process. Attapulgite, montmorillonite, and sepiolite clays are used because they are forgiving (recipe can be adjusted before the matrix hardens) when formulating a stabilization matrix, and they have a neutral pH. By using these clays and additives, LLNL`s highly concentrated wastewater treatment sludges have passed the TCLP and STLC tests. The most frequently used stabilization process consists of a customized recipe involving waste sludge, clay and dithiocarbamate salt, mixed with a double planetary mixer into a pasty consistency. TCLP and STLC data on this waste matrix have shown that the process matrix meets land disposal requirements.

  20. Chemically directed assembly of nanoparticles for material and biological applications

    NASA Astrophysics Data System (ADS)

    Park, Myoung-Hwan

    The unique electronic, magnetic, and optical properties of nanoparticles (NPs) make them useful building blocks for nanodevices and biofabrication. Site-selective immobilization/deposition of NPs on surfaces at desired positions is an important fabrication step in realizing the potential of nanomaterials in these applications. In this thesis, my research has focused on developing new strategies for mono- and multilayered-NP deposition on surfaces, increasing the stability of NP-assembles upon various surfaces for practical use of NP-based devices. Chemically directed dithiocarbamate binding of amine groups to NPs in the presence of CS2 was used for enhancing the robustness of NP assembles. Such patterning methodologies have allowed me to use site-directed NP immobilization in applications as diverse as microcontact printing, nanomolding in capillaries, nanoimprint lithography, and photolithography. Also, I have developed a simple and reliable one-step technique to form robust dendrimer-NP nanocomposites using dithiocarbamate-based chemistry. These composites are able to encapsulate and release various therapeutics, providing controllable sustained release and to separate small molecules and biomacromolecules.

  1. Proepithelin stimulates growth plate chondrogenesis via nuclear factor-kappaB-p65-dependent mechanisms.

    PubMed

    Wu, Shufang; Zang, Weijin; Li, Xu; Sun, Hongzhi

    2011-07-08

    Proepithelin, a previously unrecognized growth factor in cartilage, has recently emerged as an important regulator for cartilage formation and function. In the present study, we provide several lines of evidences in proepithelin-mediated induction of cell proliferation, differentiation, and apoptosis in the metatarsal growth plate. Proepithelin-mediated stimulation of metatarsal growth and growth plate chondrogenesis was neutralized by pyrrolidine dithiocarbamate, a known NF-κB inhibitor. In rat growth plate chondrocytes, proepithelin induced NF-κB-p65 nuclear translocation, and nuclear NF-κB-p65 initiated its target gene cyclin D1 to regulate chondrocyte functions. The inhibition of NF-κB-p65 expression and activity (by p65 short interfering RNA (siRNA) and pyrrolidine dithiocarbamate, respectively) in chondrocytes reversed the proepithelin-mediated induction of cell proliferation and differentiation and the proepithelin-mediated prevention of cell apoptosis. Moreover, the inhibition of the phosphatidylinositol 3-kinase and Akt abolished the effects of proepithelin on NF-κB activation. Finally, using siRNA and antisense strategies, we demonstrated that endogenously produced proepithelin by chondrocytes is important for chondrocyte growth in serum-deprived conditions. These results support the hypothesis that the induction of NF-κB activity of in growth plate chondrocytes is critical in proepithelin-mediated growth plate chondrogenesis and longitudinal bone growth.

  2. A Gate-to-gate Case Study of the Life Cycle Assessment of an Oil Palm Seedling

    PubMed Central

    Muhamad, Halimah; Sahid, Ismail Bin; Surif, Salmijah; Ai, Tan Yew; May, Choo Yuen

    2012-01-01

    The palm oil industry has played an important role in the economic development of Malaysia and has enhanced the economic welfare of its people. To determine the environmental impact of the oil palm seedling at the nursery stage, information on inputs and outputs need to be assessed. The oil palm nursery is the first link in the palm oil supply chain. A gate-to-gate study was carried out whereby the system boundary was set to only include the process of the oil palm seedling. The starting point was a germinated seed in a small polyethylene bag (6 in × 9 in) in which it remained until the seedling was approximately 3 to 4 months old. The seedling was then transferred into a larger polyethylene bag (12 in × 15 in), where it remained until it was 10–12 months old, when it was planted in the field (plantation). The functional unit for this life cycle inventory (LCI) is based on the production of one seedling. Generally, within the system boundary, the production of an oil palm seedling has only two major environmental impact points, the polybags used to grow the seedling and the fungicide (dithiocarbamate) used to control pathogenic fungi, as both the polybags and the dithiocarbamate are derived from fossil fuel. PMID:24575222

  3. Chemical changes in rubber allergens during vulcanization.

    PubMed

    Bergendorff, Ola; Persson, Christina; Lüdtke, Anna; Hansson, Christer

    2007-09-01

    Allergic contact dermatitis to rubber is caused by residues of chemicals used in manufacturing a rubber product. Several different additives are used to achieve a final product of the desired characteristics. Accelerators such as thiurams, dithiocarbamates, and mercaptobenzothiazoles are often among the additives responsible for allergic reactions recognized by dermatologists. The chemistry of the vulcanization process is complicated; as it occurs at an elevated temperature with a mixture of reactive chemicals, the compositions of the initial and final products differ. This paper investigates the changes in composition of common allergens during vulcanization, doing so by chemically analysing various rubber formulations at different stages of the process. Major changes were found in which added chemicals were consumed and new ones produced. An important observation is that thiuram disulfides rarely appear in the final rubber although they may have been used as additives. Instead, thiurams are often converted to dithiocarbamates or to products formed by addition to mercaptobenzothiazole structures, if these have been used together with thiurams as accelerators.

  4. Low severity coal liquefaction promoted by cyclic olefins

    SciTech Connect

    Curtis, C.W.

    1992-07-27

    Low severity coal liquefaction allows for solubilization of coal with reduced gas make. These lower severity conditions may result in some selective bond rupture. Promotion of coal solubilization through hydrogen transfer using highly active and effective hydrogen donors is the objective of this study. The highly effective donors being tested are cyclic olefins. Representative cyclic olefins are isotetralin, which is 1,4,5,8-tetrahydronaphthalene, and 1,4,5,8,9,10-hexahydroanthracene. These compounds are hydroaromatics without aromatic rings and have been shown to be highly effective donors. The objective of the work performed in this study during this quarter was to evaluate reaction parameters for low severity liquefaction reactions using the cyclic olefin, hexahydroanthracene, and the aromatic, anthracene. These model compounds were reacted under a variety of conditions to evaluate their reactivity without coal. The reactions were performed under both thermal and catalytic conditions. Finely divided catalysts from different molybdenum precursors were used to determine their activity in promoting hydrogenation and hydrogen transfer at low severity conditions. The catalysts used were Molyvan L, sulfurized oxymolybdenum dithiocarbamate, molybdenum naphthenate, and Molyvan 822, organo molybdenum dithiocarbamate.

  5. Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, April--June 1992

    SciTech Connect

    Curtis, C.W.

    1992-07-27

    Low severity coal liquefaction allows for solubilization of coal with reduced gas make. These lower severity conditions may result in some selective bond rupture. Promotion of coal solubilization through hydrogen transfer using highly active and effective hydrogen donors is the objective of this study. The highly effective donors being tested are cyclic olefins. Representative cyclic olefins are isotetralin, which is 1,4,5,8-tetrahydronaphthalene, and 1,4,5,8,9,10-hexahydroanthracene. These compounds are hydroaromatics without aromatic rings and have been shown to be highly effective donors. The objective of the work performed in this study during this quarter was to evaluate reaction parameters for low severity liquefaction reactions using the cyclic olefin, hexahydroanthracene, and the aromatic, anthracene. These model compounds were reacted under a variety of conditions to evaluate their reactivity without coal. The reactions were performed under both thermal and catalytic conditions. Finely divided catalysts from different molybdenum precursors were used to determine their activity in promoting hydrogenation and hydrogen transfer at low severity conditions. The catalysts used were Molyvan L, sulfurized oxymolybdenum dithiocarbamate, molybdenum naphthenate, and Molyvan 822, organo molybdenum dithiocarbamate.

  6. Comparative evaluation of chelating agents on the mobilization of cadmium: A mechanistic approach

    SciTech Connect

    Srivastava, R.C.; Gupta, S.; Ahmad, N.

    1996-02-09

    A comparative evaluation of chelating agents, namely, diethyl dithiocarbamate (DDC), dimethyl dithiocarbamate (DMDC), 1,4,8,11-tetraazacyclotetradecane (CYCLAM), 1,4,8,12-tetraazacyclopentadecane (TACPD), 2,3-dimercaptosuccinic acid (DMSA), and 2,3-dimercapto-1-propane sulfonate (DMPS) was conducted to assess their efficacy against acute cadmium (Cd) toxicity. DMSA and DMPS appeared to be most effective in reducing mortality as well as Cd burden of liver, kidneys, and brain in cadmium intoxicated mice. DMDC reduced Cd levels only in liver and kidneys, while DDC significantly enhanced its level in brain. CYCLAM and TACPD significantly increased the Cd level in liver and kidneys and were ineffective in brain. The therapeutic index as well as therapeutic efficacy was highest for DMSA followed by DMPS and DMDC. A fair degree of correlation was found to exist between (1) stability constant of Cd chelates and percent survival (r = .438), (2) stability constant and percent transport (r=.479), and (3) percent survival and percent transport (r = .447). However, the lipophilicity did not show any appreciable correlation with percent survival and stability constant of Cd chelates. 24 refs., 1 fig., 6 tabs.

  7. Total synthesis of epothilones using functionalised allylstannanes for remote stereocontrol.

    PubMed

    Martin, Nathaniel; Thomas, Eric J

    2012-10-21

    Two syntheses of the C(7)–C(16)-fragment 41 of epothilone D 2 were developed that were based on tin(IV) bromide mediated reactions of 5,6-difunctionalised hex-2-enylstannanes with aldehydes. In the first synthesis, (5S)-6-tert-butyldimethylsilyloxy-5-hydroxy-2-methylhex-2-enyl(tributyl)stannane 20 was reacted with (E)-but-2-enal to give (2S,7R,4Z,8E)-1-tert-butyldimethylsilyloxy-5-methyldeca-4,8-diene-2,7-diol 26 containing ca. 20% of its (7S)-epimer. Following desilylation, the crystalline (2S,7R)-triol 32 was protected as its acetonide 33 and esterified to give the (4-methoxybenzyloxy)acetate 34. An Ireland–Claisen rearrangement of this ester gave methyl (2R,3S,10S,4E,7Z)-3,7-dimethyl-10,11-(dimethylmethylene)dioxy-2-(4-methoxybenzyloxy)undeca-4,7-dienoate 35 that was converted into (2S,9S,6Z)-2,6-dimethyl-9,10-(dimethylmethylene)dioxydec-6-en-1-ol 41 by regioselective alkene manipulation, ester reduction and cleavage of the resulting terminal diol 40 with a reductive work-up. The second synthesis involved the tin(IV) bromide mediated reaction between the stannane 20 and (3S)-4-(4-methoxybenzyloxy)-3-methylbutanal 44 that gave (2S,7S,9S,4Z)-1-tert-butyldimethylsilyloxy-5,9-dimethyl-10-(4-methoxybenzyloxy)dec-4-ene-2,7-diol 45 containing ca. 20% of its (7R)-epimer. After desilylation and protection of the vicinal diol as its acetonide 46, a Barton–McCombie reductive removal of the remaining hydroxyl group gave the (2S,9S,6Z)-2,6-dimethyl-9,10-(dimethylmethylene)dioxydec-6-en-1-ol 41 after oxidative removal of the PMB-ether. The first of these syntheses uses just one chiral starting material, but the second is shorter and more convergent. It was therefore modified by the use of (5S)-6-tert-butyldimethylsilyloxy-5-(2-trimethylsilylethoxy)methoxy-2-methylhex-2-enyl(tributyl)stannane 49 that reacted with (3S)-4-(4-methoxybenzyloxy)-3-methylbutanal 44 to give a 50:50 mixture of the C(4)-epimers of (2S,9S,6Z)-10-tert-butyldimethylsilyloxy-1-(4-methoxybenzyloxy)-2

  8. A new continuous two-step molecular precursor route to rare-earth oxysulfides Ln{sub 2}O{sub 2}S

    SciTech Connect

    De Crom, N.

    2012-07-15

    A continuous two-step molecular precursor pathway is designed for the preparation of rare-earth oxysulfides Ln{sub 2}O{sub 2}S (Ln=Y, La, Pr, Nd, Sm-Lu). This new route involves a first oxidation step leading to the rare-earth oxysulfate Ln{sub 2}O{sub 2}SO{sub 4} which is subsequently reduced to the rare-earth oxysulfide Ln{sub 2}O{sub 2}S by switching to a H{sub 2}-Ar atmosphere. The whole process occurs at a temperature significantly lower than usual solid state synthesis (T{<=}650 Degree-Sign C) and avoids the use of dangerous sulfur-based gases, providing a convenient route to the synthesis of the entire series of Ln{sub 2}O{sub 2}S. The molecular precursors consist in heteroleptic dithiocarbamate complexes [Ln(Et{sub 2}dtc){sub 3}(phen)] and [Ln(Et{sub 2}dtc){sub 3}(bipy)] (Et{sub 2}dtc=N,N-diethyldithiocarbamate; phen=1,10-phenanthroline; bipy=2,2 Prime -bipyridine) and were synthesized by a new high yield and high purity synthesis route. The nature of the molecular precursor determines the minimum synthesis temperature and influences therefore the purity of the final Ln{sub 2}O{sub 2}S crystalline phase. - Graphical abstract: A continuous two-step molecular precursor pathway was designed for the preparation of rare-earth oxysulfides Ln{sub 2}O{sub 2}S (Ln=Y, La, Pr, Nd, Sm-Lu), starting from heteroleptic dithiocarbamate complexes. The influence of the nature of the molecular precursor on the minimum synthesis temperature and on the purity of the final Ln{sub 2}O{sub 2}S crystalline phase is discussed. Highlights: Black-Right-Pointing-Pointer A new high yield and high purity synthesis route of rare earth dithiocarbamates is described. Black-Right-Pointing-Pointer These compounds are used as precursors in a continuous process leading to rare-earth oxysulfides. Black-Right-Pointing-Pointer The oxysulfides are obtained under much more moderate conditions than previously described.

  9. Sn-doped hematite nanostructures for photoelectrochemical water splitting.

    PubMed

    Ling, Yichuan; Wang, Gongming; Wheeler, Damon A; Zhang, Jin Z; Li, Yat

    2011-05-11

    We report on the synthesis and characterization of Sn-doped hematite nanowires and nanocorals as well as their implementation as photoanodes for photoelectrochemical water splitting. The hematite nanowires were prepared on a fluorine-doped tin oxide (FTO) substrate by a hydrothermal method, followed by high temperature sintering in air to incorporate Sn, diffused from the FTO substrate, as a dopant. Sn-doped hematite nanocorals were prepared by the same method, by adding tin(IV) chloride as the Sn precursor. X-ray photoelectron spectroscopy analysis confirms Sn(4+) substitution at Fe(3+) sites in hematite, and Sn-dopant levels increase with sintering temperature. Sn dopant serves as an electron donor and increases the carrier density of hematite nanostructures. The hematite nanowires sintered at 800 °C yielded a pronounced photocurrent density of 1.24 mA/cm(2) at 1.23 V vs RHE, which is the highest value observed for hematite nanowires. In comparison to nanowires, Sn-doped hematite nanocorals exhibit smaller feature sizes and increased surface areas. Significantly, they showed a remarkable photocurrent density of 1.86 mA/cm(2) at 1.23 V vs RHE, which is approximately 1.5 times higher than that of the nanowires. Ultrafast spectroscopy studies revealed that there is significant electron-hole recombination within the first few picoseconds, while Sn doping and the change of surface morphology have no major effect on the ultrafast dynamics of the charge carriers on the picosecond time scales. The enhanced photoactivity in Sn-doped hematite nanostructures should be due to the improved electrical conductivity and increased surface area.

  10. Synthesis and characterization of highly conductive charge-transfer complexes using positron annihilation spectroscopy.

    PubMed

    Adam, Abdel Majid A; Refat, Moamen S; Sharshar, T; Heiba, Z K

    2012-09-01

    Molecular charge-transfer complexes of the tetramethylethylenediamine (TMEDA) with picric acid (Pi-OH), benzene-1,4-diol (QL), tin(IV) tetrachloride (SnCl(4)), iodine, bromine, and zinc chloride (ZnCl(2)) have been synthesized and investigated by elemental and thermal analysis, electronic, infrared, Raman and proton-NMR, energy-dispersive X-ray spectroscopy, X-ray powder diffraction and positron annihilation lifetime spectroscopy, and scanning electron microscopy. In this work, three types of acceptors π-acceptors (Pi-OH and QL), σ-acceptors (iodine and bromine), and vacant orbital acceptors (SnCl(4) and ZnCl(2)) were covered. The results of elemental analysis indicated that the CT complexes were formed with ratios 1:1 and 1:2 for QL, SnCl(4), and ZnCl(2) acceptors and iodine, Pi-OH, and Br(2) acceptors, respectively. The type of chelating between the TMEDA donor and the mentioned acceptors depends upon the behavior of both items. The positron annihilation lifetime parameters were found to be dependent on the structure, electronic configuration, and the power of acceptors. The correlation between these parameters and the molecular weight and biological activities of studied complexes was also observed. Regarding the electrical properties, the AC conductivity and the dielectric coefficients were measured as a function of frequency at room temperature. The TMEDA charge-transfer complexes were screened against antibacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa) and antifungal (Aspergillus flavus and Candida albicans) activities.

  11. Crystal structure of tetra-wickmanite, Mn(2+)Sn(4+)(OH)6.

    PubMed

    Lafuente, Barbara; Yang, Hexiong; Downs, Robert T

    2015-02-01

    The crystal structure of tetra-wickmanite, ideally Mn(2+)Sn(4+)(OH)6 [mangan-ese(II) tin(IV) hexa-hydroxide], has been determined based on single-crystal X-ray diffraction data collected from a natural sample from Långban, Sweden. Tetra-wickmanite belongs to the octa-hedral-framework group of hydroxide-perovskite minerals, described by the general formula BB'(OH)6 with a perovskite derivative structure. The structure differs from that of an ABO3 perovskite in that the A site is empty while each O atom is bonded to an H atom. The perovskite B-type cations split into ordered B and B' sites, which are occupied by Mn(2+) and Sn(4+), respectively. Tetra-wickmanite exhibits tetra-gonal symmetry and is topologically similar to its cubic polymorph, wickmanite. The tetra-wickmanite structure is characterized by a framework of alternating corner-linked [Mn(2+)(OH)6] and [Sn(4+)(OH)6] octa-hedra, both with point-group symmetry -1. Four of the five distinct H atoms in the structure are statistically disordered. The vacant A site is in a cavity in the centre of a distorted cube formed by eight octa-hedra at the corners. However, the hydrogen-atom positions and their hydrogen bonds are not equivalent in every cavity, resulting in two distinct environments. One of the cavities contains a ring of four hydrogen bonds, similar to that found in wickmanite, while the other cavity is more distorted and forms crankshaft-type chains of hydrogen bonds, as previously proposed for tetra-gonal stottite, Fe(2+)Ge(4+)(OH)6.

  12. Crystal structure of tetra­wickmanite, Mn2+Sn4+(OH)6

    PubMed Central

    Lafuente, Barbara; Yang, Hexiong; Downs, Robert T.

    2015-01-01

    The crystal structure of tetra­wickmanite, ideally Mn2+Sn4+(OH)6 [mangan­ese(II) tin(IV) hexa­hydroxide], has been determined based on single-crystal X-ray diffraction data collected from a natural sample from Långban, Sweden. Tetra­wickmanite belongs to the octa­hedral-framework group of hydroxide-perovskite minerals, described by the general formula BB’(OH)6 with a perovskite derivative structure. The structure differs from that of an ABO3 perovskite in that the A site is empty while each O atom is bonded to an H atom. The perovskite B-type cations split into ordered B and B′ sites, which are occupied by Mn2+ and Sn4+, respectively. Tetra­wickmanite exhibits tetra­gonal symmetry and is topologically similar to its cubic polymorph, wickmanite. The tetra­wickmanite structure is characterized by a framework of alternating corner-linked [Mn2+(OH)6] and [Sn4+(OH)6] octa­hedra, both with point-group symmetry -1. Four of the five distinct H atoms in the structure are statistically disordered. The vacant A site is in a cavity in the centre of a distorted cube formed by eight octa­hedra at the corners. However, the hydrogen-atom positions and their hydrogen bonds are not equivalent in every cavity, resulting in two distinct environments. One of the cavities contains a ring of four hydrogen bonds, similar to that found in wickmanite, while the other cavity is more distorted and forms crankshaft-type chains of hydrogen bonds, as previously proposed for tetra­gonal stottite, Fe2+Ge4+(OH)6. PMID:25878828

  13. Control of Surface Plasmon Resonance of Au/SnO2 by Modification with Ag and Cu for Photoinduced Reactions under Visible-Light Irradiation over a Wide Range.

    PubMed

    Tanaka, Atsuhiro; Hashimoto, Keiji; Kominami, Hiroshi

    2016-03-18

    Gold particles supported on tin(IV) oxide (0.2 wt% Au/SnO2) were modified with copper and silver by the multistep photodeposition method. Absorption around λ=550 nm, attributed to surface plasmon resonance (SPR) of Au, gradually shifted to longer wavelengths on modification with Cu and finally reached λ=620 nm at 0.8 wt% Cu. On the other hand, the absorption shifted to shorter wavelength with increasing amount of Ag and reached λ=450 nm at 0.8 wt% Ag. These Cu- and Ag-modified 0.2 wt% Au/SnO2 materials (Cu-Au/SnO2 and Ag-Au/SnO2) and 1.0 wt% Au/SnO2 were used for mineralization of formic acid to carbon dioxide in aqueous suspension under irradiation with visible light from a xenon lamp and three kinds of light-emitting diodes with different wavelengths. The reaction rates for the mineralization of formic acid over these materials depend on the wavelength of light. Apparent quantum efficiencies of Cu-Au/SnO2, Au/SnO2, and Ag-Au/SnO2 reached 5.5% at 625 nm, 5.8% at 525 nm, and 5.1% at 450 nm, respectively. These photocatalysts can also be used for selective oxidation of alcohols to corresponding carbonyl compounds in aqueous solution under visible-light irradiation. Broad responses to visible light in formic acid mineralization and selective alcohol oxidation were achieved when the three materials were used simultaneously.

  14. Binary ionic porphyrin nanosheets: electronic and light-harvesting properties regulated by crystal structure.

    PubMed

    Tian, Yongming; Beavers, Christine M; Busani, Tito; Martin, Kathleen E; Jacobsen, John L; Mercado, Brandon Q; Swartzentruber, Brian S; van Swol, Frank; Medforth, Craig J; Shelnutt, John A

    2012-03-07

    Crystalline solids self-assembled from anionic and cationic porphyrins provide a new class of multifunctional optoelectronic micro- and nanomaterials. A 1 : 1 combination of zinc(II) tetra(4-sulfonatophenyl)porphyrin (ZnTPPS) and tin(IV) tetra(N-methyl-4-pyridiniumyl)porphyrin (SnTNMePyP) gives porphyrin nanosheets with high aspect ratios and varying thickness. The room temperature preparation of the nanosheets has provided the first X-ray crystal structure of a cooperative binary ionic (CBI) solid. The unit cell contains one and one-half molecules of aquo-ZnTPPS(4-) (an electron donor) and three half molecules of dihydroxy-SnTNMePyP(4+) (an electron acceptor). Charge balance in the solid is reached without any non-porphyrinic ions, as previously determined for other CBI nanomaterials by non-crystallographic means. The crystal structure reveals a complicated molecular arrangement with slipped π-π stacking only occurring in isolated dimers of one of the symmetrically unique zinc porphyrins. Consistent with the crystal structure, UV-visible J-aggregate bands indicative of exciton delocalization and extended π-π stacking are not observed. XRD measurements show that the structure of the Zn/Sn nanosheets is distinct from that of Zn/Sn four-leaf clover-like CBI solids reported previously. In contrast with the Zn/Sn clovers that do exhibit J-aggregate bands and are photoconductive, the nanosheets are not photoconductive. Even so, the nanosheets act as light-harvesting structures in an artificial photosynthesis system capable of reducing water to hydrogen but not as efficiently as the Zn/Sn clovers.

  15. Crystal structure of catena-poly[[aquadi-n-propyl-tin(IV)]-μ-oxalato].

    PubMed

    Reichelt, Martin; Reuter, Hans

    2014-08-01

    The title compound, [Sn(C3H7)2(H2O)(C2O4)] n , represents the first diorganotin(IV) oxalate hydrate to be structurally characterized. The tin(IV) atom of the one-dimensional coordination polymer is located on a twofold rotation axis and is coordinated by two chelating oxalate ligands with two slightly different Sn-O bond lengths of 2.290 (2) and 2.365 (2) Å, two symmetry-related n-propyl groups with a Sn-C bond lengths of 2.127 (3) Å, and a water mol-ecule with a Sn-O bond length of 2.262 (2) Å. The coordination polyhedron around the Sn(IV) atom is a slightly distorted penta-gonal bipyramid with a nearly linear axis between the trans-oriented n-propyl groups [C-Sn-C = 176.8 (1)°]. The bond angles between the oxygen atoms of the equatorial plane range from 70.48 (6)° to 76.12 (8)°. A one-dimensional coordination polymer results from the less asymmetric bilateral coordination of the centrosymmetric oxalate anion, inter-nally reflected by two slightly different C-O bond lengths of 1.248 (3) and 1.254 (3) Å. The chains of the polymer propagate parallel to [001] and are held together by hydrogen bonds between water mol-ecules and oxalate anions of neighboring chains, leading to a two-dimensional network parallel to (100).

  16. Development of a novel targeting system for lethal photosensitization of antibiotic-resistant strains of Staphylococcus aureus.

    PubMed

    Embleton, Michelle L; Nair, Sean P; Heywood, Wendy; Menon, Dev C; Cookson, Barry D; Wilson, Michael

    2005-09-01

    Light-activated antimicrobial agents (photosensitizers) are promising alternatives to antibiotics for the treatment of topical infections. To improve efficacy and avoid possible damage to host tissues, targeting of the photosensitizer to the infecting organism is desirable, and this has previously been achieved using antibodies and chemical modification of the agent. In this study we investigated the possibility of using a bacteriophage to deliver the photosensitizer tin(IV) chlorin e6 (SnCe6) to Staphylococcus aureus. SnCe6 was covalently linked to S. aureus bacteriophage 75, and the ability of the conjugate to kill various strains of S. aureus when exposed to red light was determined. Substantial kills of methicillin- and vancomycin-intermediate strains of S. aureus were achieved using low concentrations of the conjugate (containing 1.5 microg/ml SnCe6) and low light doses (21 J/cm2). Under these conditions, the viability of human epithelial cells (in the absence of bacteria) was largely unaffected. On a molar equivalent basis, the conjugate was a more effective bactericide than the unconjugated SnCe6, and killing was not growth phase dependent. The conjugate was effective against vancomycin-intermediate strains of S. aureus even after growth in vancomycin. The results of this study have demonstrated that a bacteriophage can be used to deliver a photosensitizer to a target organism, resulting in enhanced and selective killing of the organism. Such attributes are desirable in an agent to be used in the photodynamic therapy of infectious diseases.

  17. Investigation of some new hydro(solvo)thermal synthesis routes to nanostructured mixed-metal oxides

    SciTech Connect

    Burnett, David L.; Harunsani, Mohammad H.; Kashtiban, Reza J.; Playford, Helen Y.; Sloan, Jeremy; Hannon, Alex C.; Walton, Richard I.

    2014-06-01

    We present a study of two new solvothermal synthesis approaches to mixed-metal oxide materials and structural characterisation of the products formed. The solvothermal oxidation of metallic gallium by a diethanolamine solution of iron(II) chloride at 240 °C produces a crystalline sample of a spinel-structured material, made up of nano-scale particles typically 20 nm in dimension. XANES spectroscopy at the K-edge shows that the material contains predominantly Fe{sup 2+} in an octahedral environment, but that a small amount of Fe{sup 3+} is also present. Careful analysis using transmission electron microscopy and powder neutron diffraction shows that the sample is actually a mixture of two spinel materials: predominantly (>97%) an Fe{sup 2+} phase Ga{sub 1.8}Fe{sub 1.2}O{sub 3.9}, but with a minor impurity phase that is iron-rich. In contrast, the hydrothermal reaction of titanium bis(ammonium lactato)dihydroxide in water with increasing amounts of Sn(IV) acetate allows nanocrystalline samples of the SnO{sub 2}–TiO{sub 2} solid solution to be prepared directly, as proved by powder XRD and Raman spectroscopy. - Graphical abstract: New solvothermal synthesis approaches to spinel and rutile mixed-metal oxides are reported. - Highlights: • Solvothermal oxidation of gallium metal in organic iron(II) solution gives a novel iron gallate spinel. • Hydrothermal reaction of titanium(IV) complex and tin(IV) acetate produces the complete SnO{sub 2}–TiO{sub 2} solid solution. • Nanostructured mixed-metal oxide phases are produced directly from solution.

  18. Photocatalytic reduction of artificial and natural nucleotide co-factors with a chlorophyll-like tin-dihydroporphyrin sensitizer.

    PubMed

    Oppelt, Kerstin T; Wöß, Eva; Stiftinger, Martin; Schöfberger, Wolfgang; Buchberger, Wolfgang; Knör, Günther

    2013-10-21

    An efficient photocatalytic two-electron reduction and protonation of nicotine amide adenine dinucleotide (NAD(+)), as well as the synthetic nucleotide co-factor analogue N-benzyl-3-carbamoyl-pyridinium (BNAD(+)), powered by photons in the long-wavelength region of visible light (λirr > 610 nm), is demonstrated for the first time. This functional artificial photosynthetic counterpart of the complete energy-trapping and solar-to-fuel conversion primary processes occurring in natural photosystem I (PS I) is achieved with a robust water-soluble tin(IV) complex of meso-tetrakis(N-methylpyridinium)-chlorin acting as the light-harvesting sensitizer (threshold wavelength of λthr = 660 nm). In buffered aqueous solution, this chlorophyll-like compound photocatalytically recycles a rhodium hydride complex of the type [Cp*Rh(bpy)H](+), which is able to mediate regioselective hydride transfer processes. Different one- and two-electron donors are tested for the reductive quenching of the irradiated tin complex to initiate the secondary dark reactions leading to nucleotide co-factor reduction. Very promising conversion efficiencies, quantum yields, and excellent photosensitizer stabilities are observed. As an example of a catalytic dark reaction utilizing the reduction equivalents of accumulated NADH, an enzymatic process for the selective transformation of aldehydes with alcohol dehydrogenase (ADH) coupled to the primary photoreactions of the system is also demonstrated. A tentative reaction mechanism for the transfer of two electrons and one proton from the reductively quenched tin chlorin sensitizer to the rhodium co-catalyst, acting as a reversible hydride carrier, is proposed.

  19. Dye-coated europium monosulfide

    SciTech Connect

    Kar, Srotoswini; Dollahon, Norman R.; Stoll, Sarah L.

    2011-05-15

    Nanoparticles of EuS were synthesized using europium dithiocarbamate complexes. The resulting nanoparticles were coated with the dye, 1-pyrene carboxylic acid and the resulting material was characterized using X-ray powder diffraction, TEM, and UV-visible spectroscopy. Fluorescence spectroscopy was used to determine the relative energy of the conduction band edge to the excited state energy of the dye. -- Graphical abstract: Dye sensitized magnetic semiconductor materials were prepared by synthesizing EuS nanoparticles using single source precursors and coating with the dye, 1-pyrene carboxylic acid. Display Omitted highlights: > Synthesized EuS nanoparticles, 11{+-}2.4 nm characterized using XRD, TEM, and UV-vis. spect. > Grafted a dye to the surface and characterized the product using XRD, FTIR, UV-vis., and TEM. > Studied the photophysical properties using fluorescence spectroscopy. > Determined the relative dye excited state to the conduction band of the semiconductor.

  20. Effective optical Faraday rotations of semiconductor EuS nanocrystals with paramagnetic transition-metal ions.

    PubMed

    Hasegawa, Yasuchika; Maeda, Masashi; Nakanishi, Takayuki; Doi, Yoshihiro; Hinatsu, Yukio; Fujita, Koji; Tanaka, Katsuhisa; Koizumi, Hitoshi; Fushimi, Koji

    2013-02-20

    Novel EuS nanocrystals containing paramagnetic Mn(II), Co(II), or Fe(II) ions have been reported as advanced semiconductor materials with effective optical rotation under a magnetic field, Faraday rotation. EuS nanocrystals with transition-metal ions, EuS:M nanocrystals, were prepared by the reduction of the Eu(III) dithiocarbamate complex tetraphenylphosphonium tetrakis(diethyldithiocarbamate)europium(III) with transition-metal complexes at 300 °C. The EuS:M nanocrystals thus prepared were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroanalysis (ICP-AES), and a superconducting quantum interference device (SQUID) magnetometer. Enhanced Faraday rotations of the EuS:M nanocrystals were observed around 550 nm, and their enhanced spin polarization was estimated using electron paramagnetic resonance (EPR) measurements. In this report, the magneto-optical relationship between the Faraday rotation efficiency and spin polarization is discussed.

  1. Peptide Bond Formation in Water Mediated by Carbon Disulfide.

    PubMed

    Leman, Luke J; Huang, Zheng-Zheng; Ghadiri, M Reza

    2015-09-01

    Demonstrating plausible nonenzymatic polymerization mechanisms for prebiotic monomers represents a fundamental goal in prebiotic chemistry. While a great deal is now known about the potentially prebiotic synthesis of amino acids, our understanding of abiogenic polymerization processes to form polypeptides is less well developed. Here, we show that carbon disulfide (CS2), a component of volcanic emission and sulfide mineral weathering, and a widely used synthetic reagent and solvent, promotes peptide bond formation in modest yields (up to ∼20%) from α-amino acids under mild aqueous conditions. Exposure of a variety of α-amino acids to CS2 initially yields aminoacyl dithiocarbamates, which in turn generate reactive 2-thiono-5-oxazolidone intermediates, the thio analogues of N-carboxyanhydrides. Along with peptides, thiourea and thiohydantoin species are produced. Amino acid stereochemistry was preserved in the formation of peptides. Our findings reveal that CS2 could contribute to peptide bond formation, and possibly other condensation reactions, in abiogenic settings.

  2. Investigation of the inhibiting action of O-, S- and N-dithiocarbamato(1,4,8,11-tetraazacyclotetradecane)cobalt(III) complexes on the corrosion of iron in HClO 4 acid

    NASA Astrophysics Data System (ADS)

    Babić-Samardžija, K.; Khaled, K. F.; Hackerman, N.

    2005-02-01

    The inhibiting properties of four macrocyclic cobalt(III) complexes of the general formula [Co III(Rdtc)cyclam](ClO 4) 2, where cyclam and Rdtc- refer to 1,4,8,11-tetraazacyclotetradecane and morpholine-, thiomorpholine-, piperazine-, N-methylpiperazine-dithiocarbamates, respectively, has been studied on the corrosion of iron in aerated 0.1 M HClO 4 solutions by potentiodynamic polarization (dc) technique and electrochemical impedance spectroscopy (ac). Inhibitor efficiency for the corrosion of iron is found to be better for cobalt complexes then for related amino-ligands. The impedance increases with inhibitor concentration. Polarization curves indicate that the inhibitors are predominantly mixed-type. Better protection by the complex inhibitors was obtained with longer immersion time. The best fit for inhibitors adsorption is obtained using the Langmuir isotherm model. Molecular modeling calculations were used to correlate structural properties of the complex species and their inhibition efficiency.

  3. Weak-link capacitor

    DOEpatents

    Dirk, Shawn M.; Johnson, Ross S.; Wheeler, David R.; Bogart, Gregory R.

    2013-04-23

    A process for making a dielectric material where a precursor polymer selected from poly(phenylene vinylene)polyacetylene, poly(p-phenylene), poly(thienylene vinylene), poly(1,4-naphthylene vinylene), and poly(p-pyridine vinylene) is energized said by exposure by radiation or increase in temperature to a level sufficient to eliminate said leaving groups contained within the precursor polymer, thereby transforming the dielectric material into a conductive polymer. The leaving group in the precursor polymer can be a chloride, a bromide, an iodide, a fluoride, an ester, an xanthate, a nitrile, an amine, a nitro group, a carbonate, a dithiocarbamate, a sulfonium group, an oxonium group, an iodonium group, a pyridinium group, an ammonium group, a borate group, a borane group, a sulphinyl group, or a sulfonyl group.

  4. Effect of chelators, monoisoamyl meso-2,3-dimercaptosuccinate and N-(4-methylbenzyl)-4-O-(beta-D-galactopyranosyl)-D-glucamine-N-carbodit hioate, on cadmium and essential element levels in mice.

    PubMed

    Eybl, V; Kotyzová, D; Koutenský, J; Jones, M M; Singh, P K

    1995-03-01

    In experiments performed on male mice (ICR) the mobilizing effect of monoisoamyl meso-2,3-dimercaptosuccinate (Mi-ADMS) and a dithiocarbamate analogue, N-(4-methylbenzyl)-4-O-(beta-D-galactopyranosyl)-D-glucamine-N-carbod ithioate (MeBLDTC) on the cadmium deposits was studied. The influence of these compounds on the changes in the level of essential elements caused by cadmium was explored. CdCl2.H2O was injected intravenously. The chelators were administered every 48 h over 12 d. Both compounds are effective in mobilizing cadmium from the body in animal experiments. On an equimolar basis MeBLDTC was superior to Mi-ADMS. Mi-ADMS can, however, be administered orally. Both compounds were able to correct, at least partly, the changes in the level of essential elements caused by cadmium.

  5. Simultaneous SERS detection of copper and cobalt at ultratrace levels.

    PubMed

    Tsoutsi, Dionysia; Guerrini, Luca; Hermida-Ramon, Jose Manuel; Giannini, Vincenzo; Liz-Marzán, Luis M; Wei, Alexander; Alvarez-Puebla, Ramon A

    2013-07-07

    We report a SERS-based method for the simultaneous and independent determination of two environmental metallic pollutants, Cu(ii) and Co(ii). This was achieved by exploiting the coordination-sensitive Raman bands of a terpyridine (TPY) derivative for detecting transition metal ions. Changes in the vibrational SERS spectra of dithiocarbamate anchored terpyridine (TPY-DTC) were correlated as a function of each metal ion concentration, with limits of detection comparable to those of several conventional analytical methods. Simultaneous detection of ultratrace levels of Co(ii) in the presence of high Cu(ii) concentration was also demonstrated, supporting the potential of this sensing strategy for monitoring potable water supplies.

  6. Positively charged and pH self-buffering quantum dots for efficient cellular uptake by charge mediation and monitoring cell membrane permeability.

    PubMed

    Wang, Suhua; Song, Haipeng; Ong, Wei Yi; Han, Ming Yong; Huang, Dejian

    2009-10-21

    Positively charged and pH self-buffering quantum dots (Tren-QDs) were achieved by surface functionalization with tris(2-aminoethyl)amine (Tren) derivatives, which are attached to the inorganic cores of QDs through bidentate chelating of dithiocarbamates. The Tren-QDs exhibit pH buffering capability by absorbing or releasing protons due to the surface polyamine groups as the surrounding pH fluctuates. Such self-buffering capability stabilizes the photoluminescence of the Tren-QDs against acid. The Tren-QDs bear positive charges through protonation of the surface polyamine groups under physiological conditions and the surface positive charges improve their cellular uptake efficiency by charge mediation, which has been demonstrated by BV-2 microglia cells. The photoluminescence of Tren-QDs shows a selective Stern-Volmer response to copper ions and this property has been preliminarily evaluated for investigating the BV-2 cell membrane structure by monitoring the photoluminescence of intracellular Tren-QDs.

  7. Positively charged and pH self-buffering quantum dots for efficient cellular uptake by charge mediation and monitoring cell membrane permeability

    NASA Astrophysics Data System (ADS)

    Wang, Suhua; Song, Haipeng; Ong, Wei Yi; Han, Ming Yong; Huang, Dejian

    2009-10-01

    Positively charged and pH self-buffering quantum dots (Tren-QDs) were achieved by surface functionalization with tris(2-aminoethyl)amine (Tren) derivatives, which are attached to the inorganic cores of QDs through bidentate chelating of dithiocarbamates. The Tren-QDs exhibit pH buffering capability by absorbing or releasing protons due to the surface polyamine groups as the surrounding pH fluctuates. Such self-buffering capability stabilizes the photoluminescence of the Tren-QDs against acid. The Tren-QDs bear positive charges through protonation of the surface polyamine groups under physiological conditions and the surface positive charges improve their cellular uptake efficiency by charge mediation, which has been demonstrated by BV-2 microglia cells. The photoluminescence of Tren-QDs shows a selective Stern-Volmer response to copper ions and this property has been preliminarily evaluated for investigating the BV-2 cell membrane structure by monitoring the photoluminescence of intracellular Tren-QDs.

  8. Simultaneous SERS detection of copper and cobalt at ultratrace levels

    NASA Astrophysics Data System (ADS)

    Tsoutsi, Dionysia; Guerrini, Luca; Hermida-Ramon, Jose Manuel; Giannini, Vincenzo; Liz-Marzán, Luis M.; Wei, Alexander; Alvarez-Puebla, Ramon A.

    2013-06-01

    We report a SERS-based method for the simultaneous and independent determination of two environmental metallic pollutants, Cu(ii) and Co(ii). This was achieved by exploiting the coordination-sensitive Raman bands of a terpyridine (TPY) derivative for detecting transition metal ions. Changes in the vibrational SERS spectra of dithiocarbamate anchored terpyridine (TPY-DTC) were correlated as a function of each metal ion concentration, with limits of detection comparable to those of several conventional analytical methods. Simultaneous detection of ultratrace levels of Co(ii) in the presence of high Cu(ii) concentration was also demonstrated, supporting the potential of this sensing strategy for monitoring potable water supplies.

  9. Fabrication of copper nanoparticles decorated multiwalled carbon nanotubes as a high performance electrochemical sensor for the detection of neotame.

    PubMed

    Bathinapatla, Ayyappa; Kanchi, Suvardhan; Singh, Parvesh; Sabela, Myalowenkosi I; Bisetty, Krishna

    2015-05-15

    A highly sensitive and novel electrochemical sensor for the detection of neotame using differential pulse voltammetry with a modified glassy carbon electrode is presented. The method was further customized by the fabrication of the electrode surface with copper nanoparticles-ammonium piperidine dithiocarbamate-mutiwalled carbon nanotubes assimilated with β-cyclodextrin. The multiwalled carbon nanotubes assimilated with β-cyclodextrin/glassy carbon electrode exhibited catalytic activity towards the oxidation of neotame at a potential of 1.3 V at pH 3.0. The transmission electron microscopy, thermogravimetric analysis, frontier transform infrared spectroscopy and cyclic voltammetry were employed to characterize the electrochemical sensor. The sensitivity and detection limits of the electrode increased two-fold in contrast to the β-CD-MWCNTs/GCE sensor. The developed method was successfully applied for the determination of neotame in food samples, with results similar to those achieved by our modified capillary electrophoresis method with a 96% confidence level.

  10. [Development of ICP-OES, ICP-MS and GF-AAS Methods for Simultaneous Quantification of Lead, Total Arsenic and Cadmium in Soft Drinks].

    PubMed

    Kataoka, Yohei; Watanabe, Takahiro; Hayashi, Tomoko; Teshima, Reiko; Matsuda, Rieko

    2015-01-01

    In this study, we developed methods to quantify lead, total arsenic and cadmium contained in various kinds of soft drinks, and we evaluated their performance. The samples were digested by common methods to prepare solutions for measurement by ICP-OES, ICP-MS and graphite furnace atomic absorption spectrometry (GF-AAS). After digestion, internal standard was added to the digestion solutions for measurements by ICP-OES and ICP-MS. For measurement by GF-AAS, additional purification of the digestion solution was conducted by back-extraction of the three metals into nitric acid solution after extraction into an organic solvent with ammonium pyrrolidine dithiocarbamate. Performance of the developed methods were evaluated for eight kinds of soft drinks.

  11. Preparation, spectroscopic characterization and antimicrobial activities of mixed metal (Sb and Bi) bridged derivatives with mixed sulfur donor ligands

    NASA Astrophysics Data System (ADS)

    Joshi, Sapana; Chauhan, H. P. S.; Carpenter, Nitin

    2017-01-01

    This article explores the syntheses of six mixed metal derivatives of antimony(III) and bismuth(III) by the reaction of ethane-1,2-dithiol and metal bis derivatives of dithiocarbamates and/or dithiophosphates ligands in 1:1:1 M stoichiometry. These derivatives have been characterized by physicochemical [elemental analysis (C, H, N, S, Sb and Bi), molecular weight and melting point determinations], spectral [UV-Visible, FTIR, NMR (1H, 13C and 31P)], powder X-ray diffraction studies. These derivatives have nano-ranged crystallite size (8.18-18.04 nm) with monoclinic crystal system. All the synthesized derivatives have two metal centers (Sb and Bi) which elevate the zone of inhibition against four bacterial and two fungal species as compared to single metal species (metal precursors) as well as standard drugs.

  12. Testing and modeling the influence of reclamation and control methods for reducing nonpoint mercury emissions associated with industrial open pit gold mines.

    PubMed

    Miller, Matthieu B; Gustin, Mae S

    2013-06-01

    Industrial gold mining is a significant source of mercury (Hg) emission to the atmosphere. To investigate ways to reduce these emissions, reclamation and dust and mercury control methods used at open pit gold mining operations in Nevada were studied in a laboratory setting. Using this information along with field data, and building off previous work, total annual Hg emissions were estimated for two active gold mines in northern Nevada. Results showed that capping mining waste materials with a low-Hg substrate can reduce Hg emissions from 50 to nearly 100%. The spraying of typical dust control solutions often results in higher Hg emissions, especially as materials dry after application. The concentrated application of a dithiocarbamate Hg control reagent appears to reduce Hg emissions, but further testing mimicking the actual distribution of this chemical within an active leach solution is needed to make a more definitive assessment.

  13. A study of some sorbents for adsorption of mancozeb residue from soil of tobacco fields of Mazandaran, Iran by analytical methods.

    PubMed

    Azizi, S N; Chaichi, M J; Asemi, N

    2008-01-01

    The purpose of this study is to accesses the efficiency of removal of pesticide Mancozeb (Dithiocarbamates family) using different sorbents (synthetic zeolite type A, Humic Acid (HA) extracted from soil of Noshahr jungle in the north of Iran and mixture of them). The adsorption efficiency of the adsorbents was evaluated by Freundlich isotherms to select the best sorbent. The main effective parameters such as the amount of sorbents, pH, agitating time and concentrations of Mancozeb were tested. The results for 1.6 ppm of pesticide at pH=5 shows the optimum values 2, 0.75, 0.5 g for HA, zeolite NaA and mixture of them, respectively. The adsorption capacity decreases as pH increases and the adsorption effect for 0.1 g of sorbents at pH=5 were obtained in the order: (mixture of sorbents) > (synthetic zeolite type A) > (extracted Humic Acid).

  14. Non-omnia moriantur-toxicity of mancozeb on dead wood microarthropod fauna.

    PubMed

    Adamski, Zbigniew; Bloszyk, Jerzy; Bruin, Jan; Ziemnicki, Kazimierz

    2007-01-01

    The effect of Dithane M-45 (dithiocarbamate fungicide; active substance: mancozeb) was studied on microarthropod fauna inhabiting dead wood. Although the exposure was almost never 100% lethal for the majority of observed taxa, almost all (Mesostigmata, Oribatida, some Uropodina, Actinedida, Collembola and Diplopoda) showed very high correlation between concentration of the fungicide and mortality (r > 0.86). Only Stigmaeidae showed low correlation (r = 0.293). For the majority of taxa LC(50 )values were close to the concentrations used during agrochemical activities in woods. Only Trachytes aegrota showed full susceptibility to the fungicide within the range of recommended field concentrations used in forestry (characterised by the low LC(95 )value). Tolerance of mesostigmatid and oribatid mites was found to differ between juveniles and adults, but not consistently. Related Uropodina species varied in susceptibility to the fungicide.

  15. Mutagenic potential of Mancozeb in Salmonella typhimurium.

    PubMed

    Shukla, Yogeshwer; Taneja, Pankaj; Arora, Annu; Sinha, Neeraj

    2004-01-01

    Mancozeb, a dithiocarbamate fungicide, was examined for its possible mutagenic activity using Salmonella typhimurium tester strains TA97a, TA98, TA100, and TA102. We found that Mancozeb exhibited toxic effects at the dose of 40 microg/plate and higher with all tester strains. Mancozeb showed dose-dependent increases in the number of revertants with and without metabolic activation when it was dissolved in DMSO or acetone with strain TA97a; however, the number of revertants at the highest dose was less than two-fold compared to control values. We postulate that the true mutagenic potential of Mancozeb may be masked by its toxic effect to the tester strain used.

  16. Is matching ruthenium with dithiocarbamato ligands a potent chemotherapeutic weapon in oncology?

    PubMed

    Nardon, Chiara; Brustolin, Leonardo; Fregona, Dolores

    2016-01-01

    In the last years, several metal-based compounds have been designed and biologically investigated worldwide in order to obtain chemotherapeutics with a better toxicological profile and comparable or higher antiblastic activity than the clinically-established platinum-based drugs. In this context, researchers have addressed their attention to alternative nonplatinum derivatives able to maximize the anticancer activity of the new drugs and to minimize the side effects. Among them, a number of ruthenium complexes have been developed, including the compounds NAMI-A and KP1019, now in clinical trials. Here, we report the results collected so far for a particular class of ruthenium complexes - the ruthenium(II/III)-dithiocarbamates - which proved more potent than cisplatin in vitro, even at nanomolar concentrations, against a wide panel of human tumor cell lines.

  17. Novel Patterned Films by Free-Radical Polymerization Techniques

    NASA Astrophysics Data System (ADS)

    Ward, Jennifer H.; Peppas, Nicholas A.

    2000-03-01

    We have developed novel techniques for the preparation of micropatterned structures by the block copolymerization of thin layers using UV free-radical polymerizations. The process involves polymerizing the first layer in the presence of an iniferter (initiator-transfer agent-terminator) with a dithiocarbamate group to make a photosensitive polymer. Upon application of a second monomer layer on the first polymer layer and irradiation, a copolymer is formed between the two layers. Patterns are created on the films by applying a mask and selectively irradiating the surface. Applications of this type of material are in biomaterials and biosensors for the selective adhesion of cells and proteins. We have successfully polymerized poly(ethylene glycol) (PEG) onto a layer of poly(methyl methacrylate) (PMMA) in the presence of tetraethylthiuran disulfide. Cells will adhere to the exposed PMMA areas but not to the PEG surfaces. This work has been supported by National Science Foundation grant No. DGE-9972770.

  18. Chemical Control of Nematodes and Soil-borne Plant-Pathogenic Fungi on Cabbage Tranplants

    PubMed Central

    Johnson, A. W.; McCarter, S. M.; Jaworski, C. A.; Williamson, R. E.

    1979-01-01

    Six general-purpose fumigants and one fungicide were applied by different methods and evaluated for control of nematode-fungus complexes on cabbage grown for transplant production. All chemicals reduced populations of nematodes and soil-borne fungi but varied greatly in effectiveness. Methyl bromide + chloropicrin (98% methyl bromide + 2% chloropicrin) (MBR-CP gas), DD + methyl isothiocyanate (DD-MENCS), methyl bromide + chloropicrin (67% methyl bromide + 31.75% cbloropicrin) (MBR-CP gel), and chloropicrin were more effective than sodium methyl dithiocarbamate (metham), pentachloronitrobenzene (PCNB), and potassium N-hydroxy-methyl-N-methyldithiocarbamate (Bunema) against Meloidogyne incognita. Populations of Pythium spp. and Fusarium spp. were reduced markedly by all treatments except PCNB. Plant growth, uniformity, and yield were greater when nematodes and fungi were controlled. PMID:19305547

  19. Stimulation of Ethylene Production in Apple Tissue Slices by Methionine

    PubMed Central

    Lieberman, Morris; Kunishi, Alice; Mapson, L. W.; Wardale, D. A.

    1966-01-01

    Methionine can induce more than a 100% increase in ethylene production by apple tissue slices. The increased amount of ethylene derives from carbons 3 and 4 of methionine. Only post-climacteric fruit tissues are stimulated by methionine, and stimulation is optimum after 8 months' storage. Copper chelators such as sodium diethyl dithiocarbamate and cuprizone very markedly inhibit ethylene production by tissue slices. Carbon monoxide does not effect ethylene production by the slices. These data suggest that the mechanism for the conversion of methionine to ethylene, in apple tissues, is similar to the previously described model system for producing ethylene from methionine and reduced copper. Therefore, it is suggested that one of the ethylene-forming systems in tissues derives from methionine and proceeds to ethylene via a copper enzyme system which may be a peroxidase. PMID:16656267

  20. Recent patents and advances on applications of magnetic nanoparticles and thin films in cell manipulation.

    PubMed

    Abedini-Nassab, Roozbeh; Eslamian, Morteza

    2014-01-01

    Cell manipulation is instrumental in most biological applications. One of the most promising methods in handling cells and other biological particles is the magnetic manipulation technique. In this technique, magnetic nanoparticles are employed to magnetize cells. Such cells then can be manipulated, sorted, or separated by applying an external magnetic field. In this work, first recent works and patents on the synthesis methods used for producing magnetic nanoparticles are investigated. These methods include co-precipitation, solvothermal, electrical wire explosion, microemulsion, laser pyrolysis, spray pyrolysis and carbon reduction. Then recent patents and articles on surface modification and functionalization of magnetic nanoparticles using polymers, dithiocarbamate, superparamagnetic shells, antibodies, graphene shells, and fluorescent materials are reviewed. Finally, different techniques on magnetic cell manipulation, such as direct attaching of magnetic particles to cells, employing intercellular markers or extra support molecules, as well as magnetic thin films, microfluidic channels and magnetic beads, are studied.

  1. Cyclization of nitriles. XXIV. Reactions of cyanamide derivatives of thiocarbamic acids with cyanothioacetamide. Crystal structure of 2-allylamino-4-amino-5-benzoyl-1,3-thiazole

    SciTech Connect

    Nesterov, V.N.; Sharanin, Yu.A.; Shestopalov, A.M.; Shklover, V.E.; Struchkov, Yu.T.

    1988-09-20

    2-Allylamino-4-amino-5-aroyl-1,3-thiazoles were obtained from S-alkylisoureas. An x-ray crystallographic investigation of 2-allylamino-4-amino-5-benzoyl-1,3-thiazole was undertaken. Dimethyl dithiocarbamate was used in the synthesis of 2-amino-4-methylthio-5-cyano-1H-pyrimidine-6-thione and, from the latter, 4-allylthio-2-amino-6-methylthio-5-cyanopyrimidine. The latter is easily quaternized by the action of iodine to 4-amino-3-iodomethyl-7-methylthio-8-cyano-2,3-dihydrothiazolo(3,2-c)pyrimidinium triiodide. In reaction with iodine 2-allyl-amino-1,3-thiazoles form N-allyl-N-iodo derivatives of 1,3-thiazole and not imidazo(2,3-b)thiazolium salts.

  2. Role of cytochrome P sub 450 in the control of the production of erythropoietin

    SciTech Connect

    Fandrey, J.; Seydel, F.P.; Siegers, C.P.; Jelkmann, W. )

    1990-01-01

    Effects of agents affecting cytochrome P{sub 450} were studied on the production of erythropoietin (Epo) in cultures of the human hepatoma cell line HepG2. Epo was measured by radioimmunoassay of the culture media after 24 h of incubation. The addition of phenobarbital or 3-methylcholanthrene, which induce cytochrome P{sub 450}, significantly enhanced the formation of Epo. Likewise, the thyroid hormones T{sub 3} and T{sub 4} stimulated the rate of the production of Epo. On the other hand, the formation of Epo was lowered following the addition of diethyl-dithiocarbamate or cysteamine chloride, which inhibit cytochrome P{sub 450}. These findings support the idea that O{sub 2} sensitive hemoproteins of the microsomal mixed-functional oxidases play a role in the control of the synthesis of Epo.

  3. Weak-link capacitor

    SciTech Connect

    Dirk, Shawn M.; Johnson, Ross S.; Wheeler, David R.; Bogart, Gregory R.

    2011-06-07

    A process for making a dielectric material where a precursor polymer selected from poly(phenylene vinylene) polyacetylene, poly(p-phenylene), poly(thienylene vinylene), poly(1,4-naphthylene vinylene), and poly(p-pyridine vinylene) is energized said by exposure by radiation or increase in temperature to a level sufficient to eliminate said leaving groups contained within the precursor polymer, thereby transforming the dielectric material into a conductive polymer. The leaving group in the precursor polymer can be a chloride, a bromide, an iodide, a fluoride, an ester, an xanthate, a nitrile, an amine, a nitro group, a carbonate, a dithiocarbamate, a sulfonium group, an oxonium group, an iodonium group, a pyridinium group, an ammonium group, a borate group, a borane group, a sulphinyl group, or a sulfonyl group.

  4. Synthesis of chitosan derivative with diethyldithiocarbamate and its antifungal activity.

    PubMed

    Qin, Yukun; Xing, Ronge; Liu, Song; Li, Kecheng; Hu, Linfeng; Yu, Huahua; Chen, Xiaolin; Li, Pengcheng

    2014-04-01

    With an aim to discover novel chitosan derivatives with enhanced antifungal properties compared with chitosan. Diethyl dithiocarbamate chitosan (EtDTCCS) was investigated and its structure was well identified. The antifungal activity of EtDTCCS against Alternaria porri (A. porri), Gloeosporium theae sinensis Miyake (G. theae sinensis), and Stemphylium solani Weber (S. solani) was tested at 0.25, 0.5, and 1.0 mg/mL, respectively. Compared with plain chitosan, EtDTCCS shows better inhibitory effect with 93.2% inhibitory index on G. theae sinensis at 1.0 mg/mL, even stronger than for polyoxin (82.5%). It was inferred derivatives of this kind may find potential applications for the treatment of various crop-threatening diseases.

  5. Method for separating metal chelates from other materials based on solubilities in supercritical fluids

    DOEpatents

    Wai, Chien M.; Smart, Neil G.; Phelps, Cindy

    2001-01-01

    A method for separating a desired metal or metalloi from impurities using a supercritical extraction process based on solubility differences between the components, as well as the ability to vary the solvent power of the supercritical fluid, is described. The use of adduct-forming agents, such as phosphorous-containing ligands, to separate metal or metalloid chelates in such processes is further disclosed. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones; phosphine oxides, such as trialkylphosphine oxides, triarylphosphine oxides and alkylarylphosphine oxides; phosphinic acids; carboxylic acids; phosphates, such as trialkylphosphates, triarylphosphates and alkylarylphosphates; crown ethers; dithiocarbamates; phosphine sulfides; phosphorothioic acids; thiophosphinic acids; halogenated analogs of these chelating agents; and mixtures of these chelating agents. In especially preferred embodiments, at least one of the chelating agents is fluorinated.

  6. Stabilization of inorganic mixed waste to pass the TCLP and STLC tests using clay and pH-insensitive additives

    SciTech Connect

    Bowers, J.S.; Anson, J.R.; Painter, S.M.

    1995-12-31

    Stabilization is a best demonstrated available technology, or BDAT. This technology traps toxic contaminants in a matrix so that they do not leach into the environment. The stabilization process routinely uses pozzolanic materials. Portland cement, fly ash-lime mixes, gypsum cements, and clays are some of the most common materials. In many instances, materials that can pass the Toxicity Characteristic Leaching Procedure (TCLP the federal leach test) or the Soluble Threshold Leachate Concentration (STLC the California leach test) must have high concentrations of lime or other caustic material because of the low pH of the leaching media. Both leaching media, California`s and EPA`s, have a pH of 5.0. California uses citric acid and sodium citrate while EPA uses acetic acid and sodium acetate. The concentration in the leachate is approximately ten times higher for the STLC procedure than the TCLP. These media can form ligands that provide excellent metal leaching. Because of the aggressive nature of the leaching medium, stabilized wastes in many cases will not pass the leaching tests. At the Lawrence Livermore National Laboratory (LLNL), additives such as dithiocarbamates and thiocarbonates, which are pH-insensitive and provide resistance to ligand formation, are used in the waste stabilization process. Attapulgite, montmorillonite, and sepiolite clays are used because they are forgiving (recipe can be adjusted before the matrix hardens) when formulating a stabilization matrix, and they have a neutral pH. By using these clays and additives, LLNL`s highly concentrated wastewater treatment sludges have passed the TCLP and STLC tests. The most frequently used stabilization process consists of a customized recipe involving waste sludge, clay and dithiocarbamate salt, mixed with a double planetary mixer into a pasty consistency. TCLP and STLC data on this waste matrix have shown that the process matrix meets land disposal requirements.

  7. Stabilization of inorganic mixed waste to pass the TCLP and STLC tests using clay and pH-insensitive additives

    SciTech Connect

    Bowers, J.S.; Anson, J.R.; Painter, S.M.; Maitino, R.E.

    1995-03-01

    Stabilization traps toxic contaminants (usually both chemically and physically) in a matrix so that they do not leach into the environment. Typical contaminants are metals (mostly transition metals) that exhibit the characteristic of toxicity. The stabilization process routinely uses pozzolanic materials. Portland cement, fly ash-lime mixes, gypsum cements, and clays are some of the most common materials. In many instances, materials that can pass the Toxicity Characteristic Leaching Procedure (TCLP-the federal leach test) or the Soluble Threshold Leachate Concentration (STLC-the California leach test) must have high concentrations of lime or other caustic material because of the low pH of the leaching media. Both leaching media, California`s and EPA`s, have a pH of 5.0. California uses citric acid and sodium citrate while EPA uses acetic acid and sodium acetate. These media can form ligands that provide excellent metal leaching. Because of the aggressive nature of the leaching medium, stabilized wastes in many cases will not pass the leaching tests. At the Lawrence Livermore National Laboratory, additives such as dithiocarbamates and thiocarbonates, which are pH-insensitive and provide resistance to ligand formation, are used in the waste stabilization process. Attapulgite, montmorillonite, and sepiolite clays are used because they are forgiving (recipe can be adjusted before the matrix hardens). The most frequently used stabilization process consists of a customized recipe involving waste sludge, clay and dithiocarbamate salt, mixed with a double planetary mixer into a pasty consistency. TCLP and STLC data on this waste matrix have shown that the process matrix meets land disposal requirements.

  8. Herbicide and pesticide occurrence in the soils of children's playgrounds in Sarajevo, Bosnia and Herzegovina.

    PubMed

    Sapcanin, Aida; Cakal, Mirsada; Imamovic, Belma; Salihovic, Mirsada; Pehlic, Ekrem; Jacimovic, Zeljko; Jancan, Gordan

    2016-08-01

    Pesticide pollution in Sarajevo public playgrounds is an important health and environmental issue, and the lack of information about it is causing concerns amongst the general population as well as researchers. Since children are in direct contact with surface soils on children's playgrounds, such soils should be much more carefully examined. Furthermore, herbicides and pesticides get transmitted from soil surfaces brought from outside the urban areas, or they get dispersed following their direct applications in urban areas. Infants' and children's health can be directly affected by polluted soils because of the inherent toxicity and widespread use of the different pesticides in urban environments such as playgrounds. In addition to that, the presence of chromated copper arsenate (CCA) wood preservative pesticide found as soil pollutant in playing equipment was also documented. Soil samples from playgrounds were collected and analyzed for triazines, carbamates, dithiocarbamates, phenolic herbicides and organochlorine pesticides. Samples for the determination of heavy metals Cu, Cr and As were prepared by microwave-assisted acid digestion, and the findings were determined by using an inductively coupled plasma optical emission spectrometer. Triazines, carbamates, dithiocarbamates, chlorphenoxy compounds, phenolic herbicides, organochlorine pesticides and organotin compounds were detected in playground soils and their determined concentrations (mg/kg) were respectively found as follows: <0.005, <0.05, <0.5, < 0.4, <0.1, <0.001 and <0.004. The determined contents (mg/kg) of Cu, Cr and As were in the ranges from 16.77 to 80.21, from 7.14 to 15.45 and from 3.31 to 4.43, respectively. Our preliminary results raise concerns about potential adverse effects of herbicides and pesticides on human health, which strengthens the case for a more preventative and protective approach to the uncontrolled presence of herbicides and pesticides in Sarajevo's playground soils.

  9. Oxidative stress responses in blood and gills of Carassius auratus exposed to the mancozeb-containing carbamate fungicide Tattoo.

    PubMed

    Kubrak, Olga I; Atamaniuk, Tetiana M; Husak, Viktor V; Drohomyretska, Ivanna Z; Storey, Janet M; Storey, Kenneth B; Lushchak, Volodymyr I

    2012-11-01

    Intensive use of pesticides, particularly dithiocarbamates, in agriculture often leads to contamination of freshwater ecosystems. To our knowledge, the mechanisms of toxicity to fish by the carbamate fungicide Tattoo that contains mancozeb [ethylenebis(dithiocarbamate)] have not been studied. The present study aimed to evaluate the effects of Tattoo on goldfish gills and blood, tissues that would have close early contact with the pollutant. Exposure of goldfish Carassius auratus to 3, 5 or 10mgL(-1) of Tattoo for 96h resulted in moderate lymphopenia (by 8 percent) with a concomitant increase in both stab (by 66-88 percent) and segmented (by 166 percent) neutrophils. An increase in the content of protein carbonyl groups in blood (by 137-184 percent) together with decreased levels of protein thiols (by 23 percent) and an enhancement of lipid peroxide concentrations (by 29 percent) in gills after exposure to 10mgL(-1) of Tattoo demonstrated the induction of mild oxidative stress in response to Tattoo exposure. At the same time, the activities of selected antioxidant enzymes were enhanced in gills: superoxide dismutase by 18-25 percent and catalase by 27 percent. A 34 percent increment in low molecular mass thiol concentrations (mainly represented by glutathione) also occurred in gills and could be related to increased activity (by 13-30 percent) of glucose-6-phosphate dehydrogenase. The results indicate that Tattoo exposure perturbs free radical processes, i.e. induces mild oxidative stress and enhances the activity of certain antioxidant and associated enzymes in goldfish gills. It is clear that goldfish respond to the presence of waterborne pesticide by adjusting antioxidant defenses through upregulation of activities of antioxidant and associated enzymes.

  10. Copper diethyldithiocarbamate as an activator of Nrf2 in cultured vascular endothelial cells.

    PubMed

    Fujie, Tomoya; Murakami, Masaki; Yoshida, Eiko; Tachinami, Tadashi; Shinkai, Yasuhiro; Fujiwara, Yasuyuki; Yamamoto, Chika; Kumagai, Yoshito; Naka, Hiroshi; Kaji, Toshiyuki

    2016-04-01

    The interest in organic-inorganic hybrid molecules as molecular probes for biological systems has been growing rapidly. Such hybrid molecules exhibit unique biological activities. Herein, copper(II) bis(diethyldithiocarbamate) (Cu10) was found to activate the transcription factor NF-E2-related factor 2 (Nrf2), which is responsible for regulating antioxidant and phase II xenobiotic enzymes, in vascular endothelial cells. The copper complex rapidly accumulated within cells and induced nuclear translocation of Nrf2, leading to upregulation of the expression of downstream proteins without cytotoxic effects. However, while copper bis(2-hydroxyethyl)dithiocarbamate activated Nrf2, copper ion, diethyldithiocarbamate ligand with or without zinc or iron failed to exhibit this activity. Intracellular accumulation of Cu10 was higher than that of Cu(II) and Cu(I). While the accumulation of copper(II) bis(dimethyldithiocarbamate) was reduced by small interfering RNA (siRNA)-mediated knockdown of the copper transporter CTR1, the knockdown did not affect Cu10 accumulation, indicating that Cu10 rapidly enters vascular endothelial cells via CTR1-independent mechanisms. In addition, copper and iron complexes with other ligands tested could not activate Nrf2, suggesting that the intramolecular interaction between copper and dithiocarbamate ligand is important for the activation of the transcription factor. Cu10 induced the expression of heme oxygenase-1, NAD(P)H quinone oxidoreductase 1, and γ-glutamylcysteine synthetase, downstream proteins of Nrf2. It was suggested that Cu10-induced activation of Nrf2 was due to proteasome inhibition as well as binding to Kelch-like ECH-associated protein 1. Since the effects of Cu10 on vascular endothelial cells are unique and diverse, the copper complex may be a good molecular probe to analyze the functions of the cells.

  11. Diethylcarbamazine: possible therapeutic alternative in the treatment of alcoholic liver disease in C57BL/6 mice.

    PubMed

    Rodrigues, Gabriel Barros; Rocha, Sura Wanessa Santos; Dos Santos, Laise Aline Martins; de Oliveira, Wilma Helena; Gomes, Fabiana Oliveira Dos Santos; de França, Maria Eduarda da Rocha; Lós, Deniele Bezerra; Peixoto, Christina Alves

    2015-04-01

    Alcoholic liver disease is a major cause of chronic liver disease worldwide. Diethylcarbamazine (DEC) is a drug that has anti-inflammatory properties due to its effects on the metabolism of arachidonic acid. The present study examined the anti-inflammatory effects of DEC on the mechanisms of alcoholic liver disease. C57BL/6 mice were divided into seven groups: (i) control; (ii) DEC 50 mg/kg; (iii) alcohol; (iv) alcohol + DEC 50 mg/kg; (v) alcohol + celecoxib 50 mg/kg; (vi) alcohol + pyrrolidine dithiocarbamate 100 mg/kg; and (vii) alcohol + pyrrolidine dithiocarbamate 100 mg/kg + DEC 50 mg/kg. Liver fragments were stained with haemotoxylin-eosin and Sirius red, and processed for immunofluorescence, western blot, and immunohistochemistry. Serum was also collected for biochemical measurements. Alcohol induced liver damage, elevated collagen content, and increased expression of nuclear factor kappa-light-chain-enhancer of activated B cells and inflammatory markers (tumour necrosis factor-α, interferon-γ, interleukin-1β, inducible nitric oxide synthase, cyclooxygenases-2, and transforming growth factor-β). Treatment with DEC was able to reduce liver damage, collagen content, the expression of nuclear factor kappa-light-chain-enhancer of activated B cells and inflammatory markers; it also ameliorated biochemistry parameters (total cholesterol, high-density lipoprotein cholesterol, triglyceride content and aspartate aminotransferase) and increased the expression of anti-inflammatory markers (p-5' adenosine monophosphate-activated protein kinase and interleukin-10). Future clinical trials may demonstrate that oral administration of DEC may be suitable for the treatment of alcoholic liver disease and other liver diseases.

  12. On-line UV-photooxidation with peroxodisulfate for automated flow injection and for high-performance liquid chromatography coupled to hydride generation atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Tsalev, Dimiter L.; Sperling, Michael; Welz, Bernhard

    2000-04-01

    An automated on-line UV photooxidation with peroxodisulfate of some environmentally relevant organoarsenic and organotin compounds in a system built from commercially available modules has been studied and optimised with a view to both species-independent quantification of the total arsenic or tin in samples containing different organic species by flow injection hydride generation atomic absorption spectrometry (FI-HGAAS) and speciation analysis by coupled high-performance liquid chromatography (HPLC) with HGAAS detection. For organoarsenicals, the reaction with alkaline peroxodisulfate in a 10-15-m knotted reactor for >1.5 min insures >90% transformation of inorganic As(III) and six organoarsenic species to arsenate: monomethylarsonate, dimethylarsinate, arsenobetaine, arsenocholine, trimethylarsine oxide and tetramethylarsonium. For organotins, the UV photooxidation with acidic peroxodisulfate at 95-100°C provides recoveries of >80% for the inorganic tin, dimethyltin, trimethyltin, triethyltin, tripropyltin, triphenyltin, monobutyltin, dibutyltin and tributyltin but only approximately 15% for tetrabutyltin. The best characteristic masses in integrated absorbance ( Aint) and peak-height ( Ap) measurements, respectively, are 30 pg and 480 pg for arsenic(V) and 22 pg and 410 pg for tin(IV), employing 100-μl injections. The RSDs are 5.5% and 8.5% at 5 ng As(V) levels and 4.3% and 6.4% at 10 ng Sn(IV) levels in Aint and Ap modes, respectively. The limits of detection (LOD, 3σ) for As are 7 μg l -1 and 4 μg l -1 in FI-UV-HGAAS and HPLC-UV-HGAAS, respectively. The LODs for i-Sn(IV) are 2 μg l -1 in FI-UV-HGAAS, with both Aint and Ap measurements. The sample throughput rates are 20 and 12 samples per hour with 10-m and 15-m knotted reactors (i.d. 0.5 mm), respectively. Urine certified reference materials containing 0.052-0.48 μg ml -1 As have been analysed for their total arsenic content.

  13. Straightforward synthesis of novel cyclic metallasiloxanes supported by an N,C,N-chelating ligand.

    PubMed

    Fridrichová, Adéla; Mairychová, Barbora; Padělková, Zdeňka; Lyčka, Antonín; Jurkschat, Klaus; Jambor, Roman; Dostál, Libor

    2013-12-14

    The reaction of an N,C,N-intramolecularly coordinated tin(IV) carbonate LSn(Ph)(CO3) (1) and antimony(III) and bismuth(III) oxides (LMO)2 (where M = Sb (2), Bi (3) and L = C6H3-2,6-(CH2NMe2)2) with (HO)SiPh2(O)SiPh2(OH) in 1 : 1 (in the case of 1) or 1 : 2 molar ratio (in the cases of 2 and 3) gave the metallasiloxanes cyclo-LSn(Ph)(OSiPh2)2O (4) and cyclo-LM(OSiPh2)2O (where M = Sb (6) and Bi (7)) containing six-membered MSi2O3 rings. Alternatively, the compounds 4, 6 and 7 can be also prepared reacting Ph2Si(OH)2 and compounds 1, 2 and 3, respectively, in the molar ratio of either 2 : 1 (for 4) or 4 : 1 (for 6 and 7). The reaction of Ph2Si(OH)2 with 1 in 1 : 1 molar ratio gave cyclo-Ph2Si(OSnL(Ph)O)2SiPh2 (5) containing an eight-membered Sn2Si2O4 stannasiloxane ring. The analogous eight-membered stibasiloxane derivative cyclo-Ph2Si(OSbLO)2SiPh2 (8) was obtained as well, while attempts to synthesize the bismuth analogue failed. Compounds 1-3 react with the siloxane cyclo-(Me2SiO)3 providing either eight-membered metallasiloxanes cyclo-LSn(Ph)(OSiMe2O)2SiMe2 (9) and cyclo-LSb(OSiMe2O)2SiMe2 (10) or the six-membered bismutasiloxane cyclo-LBi(OSiMe2)2O (11). All compounds were characterized with the help of elemental analysis, (1)H, (13)C, (29)Si and (119)Sn NMR spectroscopy, and single crystal X-ray diffraction analyses (except 9 and 10).

  14. Quercetin Suppresses the Migration and Invasion in Human Colon Cancer Caco-2 Cells Through Regulating Toll-like Receptor 4/Nuclear Factor-kappa B Pathway

    PubMed Central

    Han, Mingyang; Song, Yucheng; Zhang, Xuedong

    2016-01-01

    Objective: The migration and invasion features, which were associated with inflammatory response, acted as vital roles in the development of colon cancer. Quercetin, a bioflavonoid compound, was widely spread in vegetables and fruits. Although quercetin exerts antioxidant and anticancer activities, the molecular signaling pathways in human colon cancer cells remain unclear. Hence, the present study was conducted to investigate the suppression of quercetin on migratory and invasive activity of colon cancer and the underlying mechanism. Materials and Methods: The effect of quercetin on cell viability, migration, and invasion of Caco-2 cells was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, wound-healing assay, and transwell chambers assay, respectively. The protein expressions of toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF-κB) p65, mitochondrial membrane potential-2 (MMP-2), and MMP-9 were detected by Western blot assay. The inflammatory factors, such as tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (Cox-2), and interleukin-6 (IL-6), in cell supernatant were detected by enzyme-linked immunosorbent assay. Results: The concentration of quercetin <20 μM was chosen for further experiments. Quercetin (5 μM) could remarkably suppress the migratory and invasive capacity of Caco-2 cells. The expressions of metastasis-related proteins of MMP-2, MMP-9 were decreased, whereas the expression of E-cadherin protein was increased by quercetin in a dose-dependent manner. Interestingly, the anti-TLR4 (2 μg) antibody or pyrrolidine dithiocarbamate (PDTC; 1 μM) could affect the inhibition of quercetin on cell migration and invasion, as well as the protein expressions of MMP-2, MMP-9, E-cadherin, TLR4, and NF-κB p65. In addition, quercetin could reduce the inflammation factors production of TNF-α, Cox-2, and IL-6. Conclusion: The findings suggested for the 1st time that quercetin might exert its anticolon cancer activity via

  15. Surface and coordination chemistry related to GaAs

    NASA Astrophysics Data System (ADS)

    Keys, Andrea

    The vapor phase structures of Al(tBU)3 and Ga(tBU)3 have been investigated by gas phase electron diffraction and consist of planar three-coordinate monomers. Salient structural parameters (ra) include: Al-C = 2.005(3) A, Ga-C = 2.034(2) A. The geometries are controlled by inter-ligand interactions. The electron diffraction structures are compared to those determined by ab initio calculations for M(tBU)3 (M = Al, Ga, In). To understand the most suitable linkages for the surface of GaAs, model compounds were synthesized by reacting Ga(tBU)3 and [tBu2Ga(mu-Cl]2 with one molar equivalent of varying ligands. The synthesized compounds include chlorides, benzenethiolate, dithiocarbamates, carboxylates, amides, benzohydroxamate, and phenylphosphonate. The Ga ⋯ Ga and Ga-ligand interatomic distances for these compounds, as well as Group 15 and 16 donor bridging ligands, are compared to the values for the surface of GaAs and cubic-GaS in order to determine their suitability as linkage groups for self-assembled monolayers. The most suitable linkages were determined to be benzenethiol and phenylphophonic acid, and these were used to grow self-assembled monolayers on {100} GaAs. Carboxylic acid was also used, to determine the success of the organometallic model compounds in predicting the suitability of ligands for surface reaction. Self-assembled monolayers were also grown on Al2O3, using carboxylic acids and phenylphosphonic acids as the surface linkages. Metallo-organic chemical vapor deposition was performed using single-source precursors ( tBU)2Ga(S2CNR2). The tert -butyl gallium bis-dialkyl-dithiocarbamate compounds, (tBu)Ga(S2CNR2)2, are formed as minor products via ligand disproportionation reactions. Gallium sulfide (GaS) thin films have been grown at 375-425°C by atmospheric pressure metal-organic chemical vapor deposition using compounds (tBu) 2Ga(S2CNMe2) and (tBu)2Ga(S 2CNEt2) as single source precursors. Polycrystalline samples of the chalcogenides InSe, In2Se3

  16. Synthesis of Doped Semiconductor Nanocrystals and Conductive Coatings

    NASA Astrophysics Data System (ADS)

    Wills, Andrew Wilke

    measurements reveal that the nanocrystal Fermi level rises with increasing Al content. The third thrust is achieved by the use of primary dithiocarbamates as ligands to stabilize CdSe, and PbSe / CdSe core/shell nanoparticles. Primary dithiocarbamates bind well to metals but include a weak chemical bond that can be broken with gentle heating. This enables us to bind them to nanoparticles, process the particles into devices, then remove the ligand via gentle heating. Characterization of the ligand-particle interactions show excellent ligand binding to the particle surface and easy ligand removal with heating. After ligand removal, the inter-particle spacing shrinks. Transistor measurements reveal that this reduces the barrier to interparticle electron transport, enhancing the conductivity of the film.

  17. Complexation of the vulcanization accelerator tetramethylthiuram disulfide and related molecules with zinc compounds including zinc oxide clusters (Zn4O4).

    PubMed

    Steudel, Ralf; Steudel, Yana; Wong, Ming Wah

    2008-01-01

    Zinc chemicals are used as activators in the vulcanization of organic polymers with sulfur to produce elastic rubbers. In this work, the reactions of Zn(2+), ZnMe(2), Zn(OMe)(2), Zn(OOCMe)(2), and the heterocubane cluster Zn(4)O(4) with the vulcanization accelerator tetramethylthiuram disulfide (TMTD) and with the related radicals and anions Me(2)NCS(2)(*), Me(2)NCS(3)(*), Me(2)NCS(2)(-), and Me(2)NCS(3)(-) have been studied by quantum chemical methods at the MP2/6-31+G(2df,p)//B3LYP/6-31+G* level of theory. More than 35 zinc complexes have been structurally characterized and the energies of formation from their components calculated for the first time. The binding energy of TMTD as a bidendate ligand increases in the order ZnMe(2)dithiocarbamate (dtc) complexes such as [Zn(dtc)(2)] and [Zn(2)(dtc)(4)], but exothermic in the case of polynuclear zinc oxide species containing bridging ligands as in [Zn(4)O(4)(mu-S(2)CNMe(2))] and [Zn(4)O(4)(mu-dtc)]. Therefore, zinc oxide as a polynuclear species is predicted to promote the formation of trisulfido complexes, which are generally assumed to serve as catalysts for the transfer of

  18. Binary ionic porphyrin nanosheets: electronic and light-harvesting properties regulated by crystal structure

    NASA Astrophysics Data System (ADS)

    Tian, Yongming; M. Beavers, Christine; Busani, Tito; Martin, Kathleen E.; Jacobsen, John L.; Mercado, Brandon Q.; Swartzentruber, Brian S.; van Swol, Frank; Medforth, Craig J.; Shelnutt, John A.

    2012-02-01

    Crystalline solids self-assembled from anionic and cationic porphyrins provide a new class of multifunctional optoelectronic micro- and nanomaterials. A 1 : 1 combination of zinc(ii) tetra(4-sulfonatophenyl)porphyrin (ZnTPPS) and tin(iv) tetra(N-methyl-4-pyridiniumyl)porphyrin (SnTNMePyP) gives porphyrin nanosheets with high aspect ratios and varying thickness. The room temperature preparation of the nanosheets has provided the first X-ray crystal structure of a cooperative binary ionic (CBI) solid. The unit cell contains one and one-half molecules of aquo-ZnTPPS4- (an electron donor) and three half molecules of dihydroxy-SnTNMePyP4+ (an electron acceptor). Charge balance in the solid is reached without any non-porphyrinic ions, as previously determined for other CBI nanomaterials by non-crystallographic means. The crystal structure reveals a complicated molecular arrangement with slipped π-π stacking only occurring in isolated dimers of one of the symmetrically unique zinc porphyrins. Consistent with the crystal structure, UV-visible J-aggregate bands indicative of exciton delocalization and extended π-π stacking are not observed. XRD measurements show that the structure of the Zn/Sn nanosheets is distinct from that of Zn/Sn four-leaf clover-like CBI solids reported previously. In contrast with the Zn/Sn clovers that do exhibit J-aggregate bands and are photoconductive, the nanosheets are not photoconductive. Even so, the nanosheets act as light-harvesting structures in an artificial photosynthesis system capable of reducing water to hydrogen but not as efficiently as the Zn/Sn clovers.Crystalline solids self-assembled from anionic and cationic porphyrins provide a new class of multifunctional optoelectronic micro- and nanomaterials. A 1 : 1 combination of zinc(ii) tetra(4-sulfonatophenyl)porphyrin (ZnTPPS) and tin(iv) tetra(N-methyl-4-pyridiniumyl)porphyrin (SnTNMePyP) gives porphyrin nanosheets with high aspect ratios and varying thickness. The room

  19. 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.; Kulis, Michael J.; Gaier, James R.

    2009-01-01

    We describe several related studies where simple iron, nickel, and cobalt complexes were prepared, decomposed, and characterized for aeronautics (Fischer-Tropsch catalysts) and space (high-fidelity lunar regolith simulant additives) applications. We describe the synthesis and decomposition of several new nickel dithiocarbamate complexes. Decomposition resulted in a somewhat complicated product mix with NiS predominating. The thermogravimetric analysis of fifteen tris(diorganodithiocarbamato)iron(III) has been investigated. Each undergoes substantial mass loss upon pyrolysis in a nitrogen atmosphere between 195 and 370 C, with major mass losses occurring between 279 and 324 C. Steric repulsion between organic substituents generally decreased the decomposition temperature. The product of the pyrolysis was not well defined, but usually consistent with being either FeS or Fe2S3 or a combination of these. Iron nanoparticles were grown in a silica matrix with a long-term goal of introducing native iron into a commercial lunar dust simulant in order to more closely simulate actual lunar regolith. This was also one goal of the iron and nickel sulfide studies. Finally, cobalt nanoparticle synthesis is being studied in order to develop alternatives to crude processing of cobalt salts with ceramic supports for Fischer-Tropsch synthesis.

  20. Chronic Normobaric Hypoxia Induces Pulmonary Hypertension in Rats: Role of NF-κB.

    PubMed

    Fan, Junming; Fan, Xiaofang; Li, Yang; Ding, Lu; Zheng, Qingqing; Guo, Jinbin; Xia, Dongmei; Xue, Feng; Wang, Yongyu; Liu, Shufang; Gong, Yongsheng

    2016-03-01

    To investigate whether nuclear factor-kappa B (NF-κB) activation is involved in chronic normobaric hypoxia-induced pulmonary hypertension (PH), rats were treated with saline or an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC, 150 mg/kg, sc, twice daily), and exposed to normoxia or chronic normobaric hypoxia with a fraction of inspired oxygen of ∼0.1 for 14 days. Lung tissue levels of NF-κB activity, and interleukin (IL)-1β, IL-6, and cyclooxygenase-2 mRNAs, were determined, and mean pulmonary arterial pressure, right ventricular hypertrophy, and right heart function were evaluated. Compared to the normoxia exposure group, rats exposed to chronic normobaric hypoxia showed an increased NF-κB activity, measured by increased nuclear translocation of p50 and p65 proteins, an increased inflammatory gene expression in the lungs, elevated mean pulmonary arterial blood pressure and mean right ventricular pressure, right ventricular hypertrophy, as assessed by right ventricle-to-left ventricle plus septum weight ratio, and right heart dysfunction. Treatment of hypoxia-exposed rats with PDTC inhibited NF-κB activity, decreased pulmonary arterial blood pressure and right ventricular pressure, and ameliorated right ventricular hypertrophy and right heart dysfunction. Hypoxia exposure increased protein kinase C activity and promoted pulmonary artery smooth muscle cell proliferation in vitro. Our data suggest that NF-κB activation may contribute to chronic normobaric hypoxia-induced PH.

  1. Design of a Hole Trapping Ligand

    DOE PAGES

    La Croix, Andrew D.; O’Hara, Andrew; Reid, Kemar R.; ...

    2017-01-18

    A new ligand that covalently attaches to the surface of colloidal CdSe/ CdS nanorods and can simultaneously chelate a molecular metal center is described. The dithiocarbamate$-$bipyridine ligand system facilitates hole transfer through energetic overlap at the inorganic$-$organic interface and conjugation through the organic ligand to a chelated metal center. Density functional theory calculations show that the coordination of the free ligand to a CdS surface causes the formation of two hybridized molecular states that lie in the band gap of CdS. The further chelation of Fe(II) to the bipyridine moiety causes the presence of seven midgap states. Hole transfer frommore » the CdS valence band to the midgap states is dipole allowed and occurs at a faster rate than what is experimentally known for the CdSe/CdS band-edge radiative recombination. In the case of the ligand bound with iron, a two-step process emerges that places the hole on the iron, again at rates much faster than band gap recombination. The system was experimentally assembled and characterized via UV$-$vis absorbance spectroscopy, fluorescence spectroscopy, time-resolved photoluminescence spectroscopy, and energy dispersive X-ray spectroscopy. Lastly, theoretically predicted red shifts in absorbance were observed experimentally, as well as the expected quench in photoluminescence and lifetimes in time-resolved photoluminescence« less

  2. Protective effects of resveratrol against mancozeb induced apoptosis damage in mouse oocytes

    PubMed Central

    Liu, Yu; Chen, Ming-Huang; Zhang, Zhen; Fu, Xian-Pei; Fu, Bin-Bin; Liao, Bao-Qiong; Lin, Yan-Hong; Qi, Zhong-Quan; Wang, Hai-Long

    2017-01-01

    Mancozeb, a mixture of ethylene-bis-dithiocarbamate manganese and zinc salts, is one of the most widely used fungicides in agriculture. Mancozeb could lead to mitochondria dysfunction, cellular anti-oxidation enzymes depletion and apoptotic pathways activation. Previous studies indicated the exposure of mancozeb through mother would lead to irregular estrous cycles, decreased progesterone levels, reduced litter sizes, and more frequent delivery of dead fetuses. In this study, we investigated mancozeb inducing reproductive toxicity, especially focusing on its apoptotic effect and epigenetic modifications. We also showed that resveratrol, a kind of phytoalexin found in peanuts and grapes, can alleviate mancozeb's adverse effects, such as declined fertility, decreased ovary weight and primary follicles. Besides, mancozeb treated oocytes displayed suboptimal developmental competence and this can also be improved by treatment of resveratrol. More detailed investigation of these processes revealed that mancozeb increased reactive oxygen species, causing cell apoptosis and abnormal epigenetic modifications, and resveratrol can block these cytotoxic changes. Collectively, our results showed that resveratrol can alleviate mancozeb induced infertility and this was mainly through the correction of apoptotic tendency and the abnormity of cellular epigenetic modification. PMID:28031523

  3. A Novel Micellar Electrokinetic Chromatographic Method for Separation of Metal-DDTC Complexes

    PubMed Central

    Mallah, Arfana; Memon, Saima Q.; Solangi, Amber R.; Memon, Najma; Abbassi, Kulsoom; Khuhawar, Muhammad Yar

    2012-01-01

    Micellar electrokinetic chromatography (MEKC) was examined for the separation and determination of Mo(VI), Cr(VI), Ni(II), Pd(II), and Co(III) as diethyl dithiocarbamate (DDTC) chelates. The separation was achieved from fused silica capillary (52 cm × 75 μm id) with effective length 40 cm, background electrolyte (BGE) borate buffer pH 9.1 (25 mM), CTAB 30% (100 mM), and 1% butanol in methanol (70 : 30 : 5 v/v/v) with applied voltage of −10 kV using reverse polarity. The photodiode array detection was achieved at 225 nm. The linear calibration for each of the element was obtained within 0.16–10 μg/mL with a limit of detection (LOD) 0.005–0.0167 μg/mL. The separation and determination was repeatable with relative standard deviation (RSD) within 2.4–3.3% (n = 4) in terms of migration time and peak height/peak area. The method was applied for the determination of Mo(VI) from potatoes and almond, Ni(II) from hydrogenated vegetable oil, and Co(III) from pharmaceutical preparations with RSD within 3.9%. The results obtained were checked by standard addition and rechecked by atomic absorption spectrometry. PMID:22649320

  4. Di-n-butyl-bis-[N-(2-meth-oxy-eth-yl)-N-methyl-dithio-carbamato-κ(2)S,S']tin(IV): crystal structure and Hirshfeld surface analysis.

    PubMed

    Mohamad, Rapidah; Awang, Normah; Kamaludin, Nurul F; Jotani, Mukesh M; Tiekink, Edward R T

    2017-02-01

    The complete mol-ecule of the title compound, [Sn(C4H9)2(C5H10NOS2)2], is generated by a crystallographic mirror plane, with the Sn(IV) atom and the two inner methyl-ene C atoms of the butyl ligands lying on the mirror plane; statistical disorder is noted in the two terminal ethyl groups, which deviate from mirror symmetry. The di-thio-carbamate ligand coordinates to the metal atom in an asymmetric mode with the resulting C2S4 donor set defining a skew trapezoidal bipyramidal geometry; the n-butyl groups are disposed to lie over the longer Sn-S bonds. Supra-molecular chains aligned along the a-axis direction and sustained by methyl-ene-C-H⋯S(weakly coordinating) inter-actions feature in the mol-ecular packing. A Hirshfeld surface analysis reveals the dominance of H⋯H contacts in the crystal.

  5. Accumulation of argpyrimidine, a methylglyoxal-derived advanced glycation end product, increases apoptosis of lens epithelial cells both in vitro and in vivo.

    PubMed

    Kim, Junghyun; Kim, Ohn Soon; Kim, Chan-Sik; Sohn, Eunjin; Jo, Kyuhyung; Kim, Jin Sook

    2012-02-29

    The formation of advanced glycation end products (AGEs) has been considered to be a potential causative factor of injury to lens epithelial cells (LECs). Damage of LECs is believed to contribute to cataract formation. The purpose of this study was to investigate the cytotoxic effect of AGEs on LECs both in vitro and in vivo. We examined the accumulation of argpyrimidine, a methylglyoxal-derived AGE, and the expression of apoptosis-related molecules including nuclear factor- kappaB (NF-κB), Bax, and Bcl-2 in the human LEC line HLE-B3 and in cataractous lenses of Zucker diabetic fatty (ZDF) rats, an animal model of type 2 diabetes. In cataractous lenses from twenty-oneweek- old ZDF rats, LEC apoptosis was markedly increased, and the accumulation of argpyrimidine as well as subsequent activation of NF-κB in LECs were significantly enhanced. The ratio of Bax to Bcl-2 protein levels was also increased. In addition, the accumulation of argpyrimidine triggered apoptosis in methylglyoxal- treated HLE-B3 cells. However, the presence of pyridoxamine (an AGEs inhibitor) and pyrrolidine dithiocarbamate (a NF-κB inhibitor) prevented apoptosis in HLE-B3 cells through the inhibition of argpyrimidine formation and the blockage of NF-κB nuclear translocalization, respectively. These results suggest that the cellular accumulation of argpyrimidine in LECs is NF-κB-dependent and pro-apoptotic.

  6. Icotinib inhibits the invasion of Tca8113 cells via downregulation of nuclear factor κB-mediated matrix metalloproteinase expression

    PubMed Central

    YANG, CAILING; YAN, JIANGUO; YUAN, GUOYAN; ZHANG, YINGHUA; LU, DERONG; REN, MINGXIN; CUI, WEIGANG

    2014-01-01

    Icotinib is an epidermal growth factor receptor tyrosine kinase inhibitor, which has been revealed to inhibit proliferation in tumor cells. However, the effect of icotinib on cancer cell metastasis remains to be explained. This study examines the effect of icotinib on the migration and invasion of squamous cells of tongue carcinoma (Tca8113 cells) in vitro. The results of the Boyden chamber invasion assay demonstrated that icotinib reduced cell invasion, suppressed the protein levels of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, and increased the expression of tissue inhibitor of metalloproteinase-1. In addition, icotinib was found to significantly decrease the protein levels of nuclear factor κB (NF-κB) p65, which suggested that icotinib inhibits NF-κB activity. Furthermore, treatment with the NF-κB inhibitor, pyrrolidine dithiocarbamate, suppressed cell invasion and MMP-2 expression. These results suggested that icotinib inhibits the invasion of Tca8113 cells by downregulating MMP via the inactivation of the NF-κB signaling pathways. PMID:25120710

  7. Exploiting Metalloporphyrins for Selective Living Radical Polymerization Tunable over Visible Wavelengths.

    PubMed

    Shanmugam, Sivaprakash; Xu, Jiangtao; Boyer, Cyrille

    2015-07-22

    The use of metalloporphyrins has been gaining popularity particularly in the area of medicine concerning sensitizers for the treatment of cancer and dermatological diseases through photodynamic therapy (PDT), and advanced materials for engineering molecular antenna for harvesting solar energy. In line with the myriad functions of metalloporphyrins, we investigated their capability for photoinduced living polymerization under visible light irradiation over a broad range of wavelengths. We discovered that zinc porphyrins (i.e., zinc tetraphenylporphine (ZnTPP)) were able to selectively activate photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization of trithiocarbonate compounds for the polymerization of styrene, (meth)acrylates and (meth)acrylamides under a broad range of wavelengths (from 435 to 655 nm). Interestingly, other thiocarbonylthio compounds (dithiobenzoate, dithiocarbamate and xanthate) were not effectively activated in the presence of ZnTPP. This selectivity was likely attributed to a specific interaction between ZnTPP and trithiocarbonates, suggesting novel recognition at the molecular level. This interaction between the photoredox catalyst and trithiocarbonate group confers specific properties to this polymerization, such as oxygen tolerance, enabling living radical polymerization in the presence of air and also ability to manipulate the polymerization rates (kp(app) from 1.2-2.6 × 10(-2) min(-1)) by varying the visible wavelengths.

  8. Activated NF-κB in Bone Marrow Mesenchymal Stem Cells from Systemic Lupus Erythematosus Patients Inhibits Osteogenic Differentiation Through Downregulating Smad Signaling

    PubMed Central

    Tang, Yu; Xie, Hao; Chen, Jinyun; Geng, Linyu; Chen, Haifeng; Li, Xia; Hou, Yayi; Lu, Liwei; Shi, Songtao

    2013-01-01

    Osteoporosis in patients with systemic lupus erythematosus (SLE) is thought to be the result of accelerated osteoclastogenesis induced by pro-inflammatory cytokines such as tumor necrosis factor (TNF). However, the molecular mechanisms involved in the osteoblastogenesis in SLE patients are not fully understood. We investigated the bone morphogenetic protein-2 (BMP-2)-induced osteoblastic capacity of bone marrow-derived mesenchymal stem cells (BMMSCs) from SLE patients and the TNF signaling system in determining BMP-2-induced regulatory pathways. It showed that the capacity of osteogenic differentiation of BMMSCs from SLE patients was reduced compared with that from healthy controls. The nuclear factor κB (NF-κB) signaling was activated while the BMP/Smad pathway was repressed in BMMSCs from SLE patients. TNF activated NF-κB pathway and inhibited the phosphorylation of Smad 1/5/8 and BMP-2-induced osteoblastic differentiation in BMMSCs from normal controls, while addition of pyrollidine dithiocarbamate (PDTC), an NF-κB inhibitor, to SLE-BMMSCs could partially reverse these effects. Thus, our findings have shown that the activated NF-κB pathway in SLE-BMMSCs inhibits the BMP-2-induced osteoblastic differentiation through BMP/Smad signaling pathway, suggesting that the impaired osteoblastic differentiation may participate in the pathology of osteoporosis in SLE patients. PMID:22897816

  9. Level of contamination by metallic trace elements and organic molecules in the seagrass beds of Guadeloupe Island.

    PubMed

    Bouchon, Claude; Lemoine, Soazig; Dromard, Charlotte; Bouchon-Navaro, Yolande

    2016-01-01

    Seagrass bed ecosystems occupy the most important part of coastal shelf in the French West Indies. They also constitute nurseries for many invertebrates and fishes harvested by local fisheries. In Guadeloupe, coastal fish stocks are declining meanwhile several agroecosystems revealed to be heavily contaminated by pollutants (agricultural lands, rivers, mangroves, seagrass beds, and coral reefs). Considering these facts, a study of the contamination of seagrass beds (8000 ha) of the Grand Cul-de-Sac Marin (GCSM) bay was conducted on their sediments and marine phanerogams. The analyses concerned six metals (Cd, Cu, Hg, Pb, V, Zn), tributyltin, 18 polycyclic aromatic hydrocarbons (PAHs), eight polybrominated diphenyl ethers (PBDEs), 38 polychlorobiphenyls (PCBs), dithiocarbamates (CS2 residues), and 225 pesticide molecules.Overall, the level of contamination of the seagrass beds was low for both sediments and phanerogams. Metallic trace elements were the main pollutants but with higher concentrations recorded in coastal sites, and their distribution can be explained by the proximity of river mouths and current patterns. The level of contamination was lower in plants than in sediments. However, the level of contamination between these two compartments was significantly correlated. The conclusion of this study is that, unlike other coastal ecosystems of Guadeloupe such as mangroves, the seagrass beds in the GCSM present a low degree of pollution. The observed level of contaminants does not seem to threaten the role of nursery played by the seagrass beds and does not likely present a risk for the reintroduction of manatees.

  10. Photo induced surface heparin immobilization.

    PubMed

    Nakayama, Y; Matsuda, T

    1993-01-01

    This paper describes a novel method providing durable layering of heparin immobilized hydrogels on fabricated devices. The preparation method is based on photochemistry of a dithiocarbamate group that is dissociated into a highly reactive radical pair upon ultraviolet (UV) irradiation. By taking advantage of characteristics of the photo generated radicals, hydrogel formation and its fixation onto a substrate surface were attained. The immobilization of heparin onto poly(ethylene terephtalate) was demonstrated. First, a mixed aqueous solution containing a photoreactive water soluble poly(N,N-dimethylacrylamide-covinylbenzyl N,N-diethyldithiocarbamate) and heparin was coated on the substrate. Subsequent UV irradiation resulted in the simultaneous formation of a heparin immobilized hydrogel and its chemical fixation onto the substrate. No delamination was found after vigorous washing with water. Significant inhibition of platelet adhesion and markedly prolonged blood coagulation times were observed, which are apparently derived from the surface hydrogel, and from released and chemically fixed surface heparin. Thus, it is expected that the photochemical method developed here provides potent antithrombogenicity to artificial organs.

  11. Synthesis, Optical and Structural Properties of Copper Sulfide Nanocrystals from Single Molecule Precursors

    PubMed Central

    Ajibade, Peter A.; Botha, Nandipha L.

    2017-01-01

    We report the synthesis and structural studies of copper sulfide nanocrystals from copper (II) dithiocarbamate single molecule precursors. The precursors were thermolysed in hexadecylamine (HDA) to prepare HDA-capped CuS nanocrystals. The optical properties of the nanocrystals studied using UV–visible and photoluminescence spectroscopy showed absorption band edges at 287 nm that are blue shifted, and the photoluminescence spectra show emission curves that are red-shifted with respect to the absorption band edges. These shifts are as a result of the small crystallite sizes of the nanoparticles leading to quantum size effects. The structural studies were carried out using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy. The XRD patterns indicates that the CuS nanocrystals are in hexagonal covellite crystalline phases with estimated particles sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes, with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microspheres on the surfaces, and EDS spectra confirmed the presence of CuS nanoparticles. PMID:28336865

  12. A dual-template imprinted polymer-modified carbon ceramic electrode for ultra trace simultaneous analysis of ascorbic acid and dopamine.

    PubMed

    Bali Prasad, Bhim; Jauhari, Darshika; Tiwari, Mahavir Prasad

    2013-12-15

    A dual-template imprinted polymer film containing dispersed multiwalled carbon nanotubes was exploited in the fabrication of a typical, reproducible, and rugged carbon ceramic electrode, adopting "surface grafting from" approach for the growth of a nanometer thin coating on its surface. For this, chloro groups were first introduced at the exterior surface of silica-carbon composite electrode through sol-gel modification using (3-chloropropyl)-trimethoxysilane, followed by an iniferter (sodium diethyl dithiocarbamate) initiated photopolymerization of functional monomer (2,4,6-trisacrylamido-1,3,5-triazine), mixed templates (ascorbic acid and dopamine), and cross-linker (ethylene glycol dimethacrylate), in the presence of multiwalled carbon nanotubes. The modified sensor was validated for the simultaneous analysis of ascorbic acid and dopamine in aqueous, blood serum, cerebrospinal fluid, and pharmaceutical samples, using differential pulse anodic stripping voltammetric technique. The oxidation peak potentials for both analytes were found to be well apart approximately by 300 mV, which was large enough to allow selective and sensitive analysis of one in the presence of other, without any cross reactivity, interferences and false-positives. The detection limits realized by the proposed sensor, under optimized conditions, were found to be as low as 2.24 ng mL(-1) for ascorbic acid and 0.21 ng mL(-1) for dopamine (S/N=3). Such stringent limits could be considered suitable for the primitive diagnosis of several chronic diseases, in clinical settings.

  13. Redox reactivity of mononuclear and binuclear rhenium complexes

    SciTech Connect

    Holder, G.N.

    1988-01-01

    Six different classes of monomeric and dimeric rhenium complexes containing substituted nitriles, substituted pyridines, dithiocarbamates, and substituted phosphines as ligands were synthesized. Monomers had the general formula ReCl{sub 3} (NCR) (PPh{sub 3}){sub 2}, ReCl{sub 3}-(NCCH{sub 3})(P-(aryl-R){sub 3}){sub 2}, and ReOCl{sub 3} (P-(aryl-R){sub 3}){sub 2}. Dimers had the general formula Re{sub 2}Cl{sub 4} (dppm){sub 2} (NCR) and (Re{sub 2}Cl{sub 3}(dppm){sub 2}-(NCR){sub 2}){sup +} (dppm = bis(diphenylphosphino)methane) and Re{sub 2}O{sub 3}Cl{sub 4}-(py){sub 4}, where R was an alkyl or halogenated substituent chosen to systematically vary the donor-acceptor properties of the nitrile, pyridine, or phosphine ligand. The effects of this structural change on the function of the molecule was monitored both spectrally and electrochemically. Rate constants for addition of nitriles to the metal-metal bridged dimeric complex were found to vary linearly with the identity of the substitutent. Spectroscopic data followed these trends as well. The structure-function relationships derived from this work will aid in the design of future Technetium and Rhenium-based organ selective radioimaging agents.

  14. Gliadins induce TNFalpha production through cAMP-dependent protein kinase A activation in intestinal cells (Caco-2).

    PubMed

    Laparra Llopis, José Moisés; Sanz Herranz, Yolanda

    2010-06-01

    Celiac disease is an autoimmune enteropathy caused by a permanent intolerance to gliadins. In this study the effects of two gliadin-derived peptides (PA2, PQPQLPYPQPQLP and PA9, QLQPFPQPQLPY) on TNFalpha production by intestinal epithelial cells (Caco-2) and whether these effects were related to protein kinase A (PKA) and/or -C (PKC) activities have been evaluated. Caco-2 cell cultures were challenged with several sets of gliadin peptides solutions (0.25 mg/mL), with/without different activators of PKA or PKC, bradykinin (Brdkn) and pyrrolidine dithiocarbamate (PDTC). The gliadin-derived peptides assayed represent the two major immunodominant epitopes of the peptide 33-mer of alpha-gliadin (56-88) (LQLQPFPQPQLPYPQPQLPYPQPQLPYPQPQPF). Both peptides induced the TNFalpha production triggering the inflammatory cell responses, the PA2 being more effective. The addition of the peptides in the presence of dibutyril cyclic AMP (cAMP), Brdkn or PDTC, inhibited the TNFalpha production. The PKC-activator phorbol 12-myristate 13-diacetate additionally increased the PA2- and PA9-induced TNFalpha production. These results link the gliadin-derived peptides induced TNFalpha production through cAMP-dependent PKA activation, where ion channels controlling calcium influx into cells could play a protective role, and requires NF-kappaB activation.

  15. Synthesis of epoxy jatropha oil and its evaluation for lubricant properties.

    PubMed

    Sammaiah, Arukali; Padmaja, Korlipara Venkata; Prasad, Rachapudi Badari Narayna

    2014-01-01

    Vegetable oils are being investigated as potential source of environmentally favorable lubricants over synthetic products. Jatropha curcas L. oil (JO) identified as a potential raw material for biodiesel was explored for its use as a feedstock for biolubricants. Epoxidized jatropha oil (EJO) was prepared by peroxyformic acid generated in situ by reacting formic acid and hydrogen peroxide in the presence of sulfuric acid as catalyst. Almost complete conversion of unsaturated bonds in the oil into oxirane was achieved with oxirane value 5.0 and iodine value of oil reduced from 92 to 2 mg I2/g. EJO exhibited superior oxidative stability compared to JO. This study employed three antioxidants such as butylated hydroxy toluene (BHT), zinc dimethyl dithiocarbamate (ZDDC), and diphenyl amine (DPA) and found that DPA antioxidant performed better than ZDDC and BHT over EJO compared to JO. The lubricating properties of EJO and epoxy soybean oil (ESBO) are comparable. Hence, EJO can be projected as a potential lubricant basestock for high temperature applications.

  16. NF-kappaB activation by triphenyltin triggers apoptosis in HL-60 cells.

    PubMed

    Marinovich, M; Viviani, B; Corsini, E; Ghilardi, F; Galli, C L

    1996-07-10

    Trisubstituted organotin pesticides are lethal for different cell types. In this study we investigated whether triphenyltin chloride (TPT) causes apoptosis in HL-60 promyelocytic cells and, if so, by what mechanisms. We report that 5 microM TPT increased intracellular Ca2+ in HL-60 cells within seconds; concomitantly actin depolymerization was detected 30 s and 1 min after the treatment. This was followed 15 min later by NF-kappaB activation, and apoptotic bodies and DNA fragmentation were evident after 3 and 6 h, respectively. At these times TPT also induced the release of tumor necrosis factor-alpha (TNF-alpha). Prior treatment of the cells with a polyclonal antibody to human TNF-alpha abolished TPT-induced DNA fragmentation, which suggests that the ultimate effect of TPT may be mediated by TNF-alpha. Prior treatment of the cells with 100 microM pyrrolidine dithiocarbamate, an antioxidant and potent inhibitor of NF-kappaB activation, prevented actin depolymerization, NF-kappaB activation, and DNA fragmentation, although it did not affect TPT-induced Ca2+ mobilization. These findings suggest that TPT increases intracellular Ca2+, alters actin polymerization and the cytoskeleton, and induces NF-kappaB activation, TNF-alpha synthesis, DNA degradation, and apoptosis. Reactive oxygen species seem to be essential to NF-kappaB activation, TNF-alpha synthesis, and the subsequent steps.

  17. Synthesis and characterisation of nano-pore antimony imprinted polymer and its use in the extraction and determination of antimony in water and fruit juice samples.

    PubMed

    Shakerian, Farid; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Nili Ahmad Abadi, Maryam

    2014-02-15

    A solid phase extraction method using antimony ion imprinted polymer (IIP) sorbent combined with electrothermal atomic absorption spectrometry (ETAAS) was developed for the extraction and speciation of antimony. The sorbent has been synthesised in the presence of Sb(III) and ammonium pyrrolidine dithiocarbamate (APDC) using styrene as the monomer and ethylene glycol dimethacrylate (EGDMA) as the cross linker. The imprinted Sb(III) ions were removed by leaching with HCl (50%v/v) and the polymer was characterised by FT-IR and scanning electron microscopy. The maximum sorption capacity of the IIP for Sb(III) ions was found to be 6.7 mg g(-1). With preconcentration of 60 mL of sample, an enhancement factor of 232 and detection limit of 3.9 ng L(-1) was obtained. Total antimony was determined after the reduction of Sb(V) to Sb(III). The method was successfully applied to the determination of antimony species in water samples and total antimony in fruit juices.

  18. The role of TNF-alpha/NF-kappa B pathway on the up-regulation of voltage-gated sodium channel Nav1.7 in DRG neurons of rats with diabetic neuropathy.

    PubMed

    Huang, Yangliang; Zang, Ying; Zhou, Lijun; Gui, Wenshan; Liu, Xianguo; Zhong, Yi

    2014-09-01

    Diabetic neuropathy (DN) is a common form of peripheral neuropathy, yet the mechanisms responsible for chronic pain in this disease are poorly understood. The up-regulation of the expression and function of voltage-gated sodium channel Nav1.7 has been implicated in DN, however, the exact mechanism is unclear. In the present study, we found that a proportion of streptozotocin (STZ)-treated rats suffered from mechanical allodynia and thermal hyperalgesia for a long-lasting time. Nav1.7 was up-regulated in spinal dorsal root ganglia (DRG) of rats with DN, double immunofluorescence staining showed that the increased Nav1.7 was co-localized with large and small sized neurons but not satellite glial cells. Inhibiting the synthesis of tumor necrosis factor-α (TNF-α) by thalidomide prevented DN, accompanied by strongly blocking the up-regulation of Nav1.7, TNF-α and p-nucleus factor-kappa B (p-NF-κB) in DRG. Intrathecal injection of NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) significantly attenuated the pain behaviors and over-expression of Nav1.7 in DRG neurons. These data suggest that increased TNF-α may be responsible for up-regulation of Nav1.7 in DRG neurons of rats with DN, and NF-κB signal pathway is involved in this process. The findings might provide potential target for preventing diabetic neuropathy.

  19. Formation of mono(dithiolene)-thiocarboxamido complexes in reactions of thio(dithiocarbamato)-Mo/W complexes and dimethyl acetylenedicarboxylate.

    PubMed

    Lim, Patrick J; Slizys, Damian A; Tiekink, Edward R T; Young, Charles G

    2005-01-10

    Reactions of TpMS(S(2)CNEt(2)) with dimethyl acetylenedicarboxylate in dichloromethane produce olive green/black TpM{S(2)C(2)(CO(2)Me)(2)}(SCNEt(2)-kappa(2)S,C) (M = Mo (1), W (2); Tp = hydrotris(3,5-dimethylpyrazol-1-yl)borate). The seven-coordinate complexes exhibit pseudo-octahedral (1) and distorted pentagonal bipyramidal (2) coordination spheres comprised of tridentate fac-Tp, bidentate dithiolene, and thiocarboxamido-kappa(2)S,C ligands. In the solid state, molecules of 1 exhibit pseudo-C(s)() symmetry, with the thiocarboxamide NEt(2) group in a cleft in the Tp ligand. Molecules of 2 have C(1) symmetry in the solid state; here, the thiocarboxamide unit is orientated along one of the W-S(dithiolene) bonds with its NEt(2) group projecting away from the Tp ligand. Both complexes possess effective C(s)() symmetry in solution. Reaction of TpMoI(CO)(3) with AgS(2)CNEt(2) affords olive green TpMo(S(2)CNEt(2))(CO)(2) (3), which reacts with propylene sulfide in a new synthesis for TpMoS(S(2)CNEt(2)), the starting material for 1. Complex 3 exhibits a distorted pentagonal bipyramidal structure, the axial sites being defined by a Tp nitrogen atom and a carbonyl ligand, the pentagonal plane by the remaining nitrogen and carbonyl donors and the two sulfur atoms of the bidentate dithiocarbamate ligand.

  20. Palmitic acid induces production of proinflammatory cytokines interleukin-6, interleukin-1β, and tumor necrosis factor-α via a NF-κB-dependent mechanism in HaCaT keratinocytes.

    PubMed

    Zhou, Bing-rong; Zhang, Jia-an; Zhang, Qian; Permatasari, Felicia; Xu, Yang; Wu, Di; Yin, Zhi-qiang; Luo, Dan

    2013-01-01

    To investigate whether palmitic acid can be responsible for the induction of inflammatory processes, HaCaT keratinocytes were treated with palmitic acid at pathophysiologically relevant concentrations. Secretion levels of interleukin-6 (IL-6), tumor necrosis factor- α (TNF- α), interleukin-1 β (IL-1 β), NF- κ B nuclear translocation, NF- κ B activation, Stat3 phosphorylation, and peroxisome proliferator-activated receptor alpha (PPAR α) mRNA and protein levels, as well as the cell proliferation ability were measured at the end of the treatment and after 24 hours of recovery. Pyrrolidine dithiocarbamate (PDTC, a selective chemical inhibitor of NF- κ B) and goat anti-human IL-6 polyclonal neutralizing antibody were used to inhibit NF- κ B activation and IL-6 production, respectively. Our results showed that palmitic acid induced an upregulation of IL-6, TNF- α , IL-1 β secretions, accompanied by NF- κ B nuclear translocation and activation. Moreover, the effect of palmitic acid was accompanied by PPAR α activation and Stat3 phosphorylation. Palmitic acid-induced IL-6, TNF- α , IL-1 β productions were attenuated by NF- κ B inhibitor PDTC. Palmitic acid was administered in amounts able to elicit significant hyperproliferation and can be attenuated by IL-6 blockage. These data demonstrate for the first time that palmitic acid can stimulate IL-6, TNF- α , IL-1 β productions in HaCaT keratinocytes and cell proliferation, thereby potentially contributing to acne inflammation and pilosebaceous duct hyperkeratinization.

  1. Aldehyde dehydrogenase variation enhances effect of pesticides associated with Parkinson disease

    PubMed Central

    Fitzmaurice, Arthur G.; Rhodes, Shannon L.; Cockburn, Myles; Ritz, Beate

    2014-01-01

    Objective: The objective of this study was to determine whether environmental and genetic alterations of neuronal aldehyde dehydrogenase (ALDH) enzymes were associated with increased Parkinson disease (PD) risk in an epidemiologic study. Methods: A novel ex vivo assay was developed to identify pesticides that can inhibit neuronal ALDH activity. These were investigated for PD associations in a population-based case-control study, the Parkinson's Environment & Genes (PEG) Study. Common variants in the mitochondrial ALDH2 gene were genotyped to assess effect measure modification (statistical interaction) of the pesticide effects by genetic variation. Results: All of the metal-coordinating dithiocarbamates tested (e.g., maneb, ziram), 2 imidazoles (benomyl, triflumizole), 2 dicarboxymides (captan, folpet), and 1 organochlorine (dieldrin) inhibited ALDH activity, potentially via metabolic byproducts (e.g., carbon disulfide, thiophosgene). Fifteen screened pesticides did not inhibit ALDH. Exposures to ALDH-inhibiting pesticides were associated with 2- to 6-fold increases in PD risk; genetic variation in ALDH2 exacerbated PD risk in subjects exposed to ALDH-inhibiting pesticides. Conclusion: ALDH inhibition appears to be an important mechanism through which environmental toxicants contribute to PD pathogenesis, especially in genetically vulnerable individuals, suggesting several potential interventions to reduce PD occurrence or slow or reverse its progression. PMID:24491970

  2. Residential Agricultural Pesticide Exposures and Risk of Neural Tube Defects and Orofacial Clefts Among Offspring in the San Joaquin Valley of California

    PubMed Central

    Yang, Wei; Carmichael, Suzan L.; Roberts, Eric M.; Kegley, Susan E.; Padula, Amy M.; English, Paul B.; Shaw, Gary M.

    2014-01-01

    We examined whether early gestational exposures to pesticides were associated with an increased risk of anencephaly, spina bifida, cleft lip with or without cleft palate (CLP), or cleft palate only. We used population-based data along with detailed information from maternal interviews. Exposure estimates were based on residential proximity to agricultural pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley, California (1997–2006). Analyses included 73 cases with anencephaly, 123 with spina bifida, 277 with CLP, and 117 with cleft palate only in addition to 785 controls. A total of 38% of the subjects were exposed to 52 chemical groups and 257 specific chemicals. There were relatively few elevated odds ratios with 95% confidence intervals that excluded 1 after adjustment for relevant covariates. Those chemical groups included petroleum derivatives for anencephaly, hydroxybenzonitrile herbicides for spina bifida, and 2,6-dinitroaniline herbicides and dithiocarbamates-methyl isothiocyanate for CLP. The specific chemicals included 2,4-D dimethylamine salt, methomyl, imidacloprid, and α-(para-nonylphenyl)-ω-hydroxypoly(oxyethylene) phosphate ester for anencephaly; the herbicide bromoxynil octanoate for spina bifida; and trifluralin and maneb for CLP. Adjusted odds ratios ranged from 1.6 to 5.1. Given that such odds ratios might have arisen by chance because of the number of comparisons, our study showed a general lack of association between a range of agricultural pesticide exposures and risks of selected birth defects. PMID:24553680

  3. Prenatal Exposure to Lipopolysaccharide Alters Renal DNA Methyltransferase Expression in Rat Offspring

    PubMed Central

    Chen, Rui; Deng, Youcai; Liao, Xi; Wei, Yanling; Li, Xiaohui; Su, Min; Yu, Jianhua; Yi, Ping

    2017-01-01

    Prenatal exposure to inflammation results in hypertension during adulthood but the mechanisms are not well understood. Maternal exposure to lipopolysaccharide (LPS) alters interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels in the fetal environment. As reported in many recent studies, IL-6 regulates DNA methyltransferases (DNMTs) through the transcription factor friend leukemia virus integration 1 (Fli-1). The present study explores the role of intrarenal DNMTs during development of hypertension induced by prenatal exposure to LPS. Pregnant rats were randomly divided into four treatment groups: control, LPS, pyrrolidine dithiocarbamate (PDTC, a NF-κB inhibitor), and the combination of LPS and PDTC. Expression of IL-6, Fli-1, TNF-α, DNMT1 and DNMT3B was significantly increased in the offspring of LPS-treated rats. Global DNA methylation level of renal cortex also increased dramatically in rat offspring of the LPS group. Prenatal PDTC administration reversed the increases in gene expression and global DNA methylation level. These findings suggest that prenatal exposure to LPS may result in changes of intrarenal DNMTs through the IL-6/Fli-1 pathway and TNF-α, which probably involves hypertension in offspring due to maternal exposure to inflammation. PMID:28103274

  4. Antioxidants prevent ethanol-induced contractions of canine cerebral vascular smooth muscle: relation to alcohol-induced brain injury.

    PubMed

    Li, W; Zheng, T; Altura, B T; Altura, B M

    2001-03-30

    The present study was designed to test the hypothesis that alpha-tocopherol (Vit. E) and pyrrolidine dithiocarbamate (PDTC) might exert direct effects on alcohol-induced contractions of canine basilar cerebral arteries. After precontraction of arterial ring segments with ethanol, PDTC (10(-8)-10(-6) M) and Vit. E (10(-6)-10(-4) M) induced concentration-dependent relaxations of cerebral arteries, compared to untreated controls. The effective concentrations producing approximately 50% of the maximal relaxation responses (EC(50) values) were about 2.48+/-0.09 x 10(-7) M for PDTC, and 1.87+/-0.10 x 10(-5) mM for Vit. E, respectively. Preincubation of these arterial rings with EC(50)'s of PDTC or Vit. E for 40 min attenuate markedly the contractions produced by alcohol, at concentrations of 1-400 mM. However, both PDTC and Vit.E do not relax equi-potent precontractions induced by either KCl or prostaglandin F(2alpha) (PGF(2alpha)) or inhibit their contractions. These data suggest that alcohol-induced contractions of cerebral arteries are mediated via excitation-contraction coupling pathways different from those used by KCl or receptor-mediated agonists such as PGF(2alpha). The present results, when viewed in light of other recently published data, suggest that antioxidants may prove useful in the amelioration and treatment of alcohol-induced brain damage and strokes.

  5. Antioxidants prevent depletion of [Mg2+]i induced by alcohol in cultured canine cerebral vascular smooth muscle cells: possible relationship to alcohol-induced stroke.

    PubMed

    Li, W; Zheng, T; Altura, B T; Altura, B M

    2001-07-01

    Low serum concentrations of Mg(2+) ions have been reported, recently, in patients with coronary disease, atherosclerosis, and stroke as well as in patients with cerebral hemorrhage. The aim of the present study was to determine whether potent antioxidants [alpha-tocopherol and pyrrolidine dithiocarbamate (PDTC)] can prevent or ameliorate intracellular Mg(2+) ([Mg(2+)](i)) depletion associated with cerebral vascular injury induced by alcohol. Exposure of cultured canine cerebral vascular smooth muscle cells to alcohol (10-100 mM) for 24 h induced marked depletion in [Mg(2+)](i) (i.e., approximately 30-65%, depending upon alcohol concentration). Treatment of the cultured cells with either PDTC (0.1 microM) or alpha-tocopherol (15 microM) for 24 h, alone, failed to interfere with basal [Mg(2+)](i) levels. However, preincubation of the cells with either alpha-tocopherol or PDTC for 24 h completely inhibited the depletion of [Mg(2+)](i) induced by exposure to 10-100 mM ethanol. These results indicate that alpha-tocopherol and PDTC prevent decreases in [Mg(2+)](i) produced by ethanol. Moreover, these new results suggest that such protective effects of alpha-tocopherol and PDTC on cerebral vascular cells might be useful therapeutic tools in prevention and amelioration of cerebral vascular injury and stroke in alcoholics.

  6. Ethanol induces rapid lipid peroxidation and activation of nuclear factor-kappa B in cerebral vascular smooth muscle: relation to alcohol-induced brain injury in rats.

    PubMed

    Altura, Burton M; Gebrewold, Asefa; Zhang, Aimin; Altura, Bella T

    2002-06-07

    The present study was designed to test the hypothesis that acute administration of alcohol (ethanol) to primary cultured cerebral vascular smooth muscle cells will cause lipid peroxidation, inhibition of IkappaB phosphorylation, and inhibition of nuclear transcription factor-kappa B (NF-kappaB). Ethanol (10, 25, 100 mM) resulted in concentration-dependent rises in malondialdehyde in as little as 30-45 min after exposure to the alcohol, rising to levels 2.5-10x normal after 18-24 h. Using EMSA assays and specific antibodies, ethanol caused three DNA-binding proteins (p50, p65, c-Rel) to rise in nuclear extracts in a concentration-dependent manner. Using a rabbit antibody, IkappaB phosphorylation (and degradation) was stimulated by ethanol (in a concentration-dependent manner) and inhibited by a low concentration of the NF-kappaB inhibitor, pyrrolidine dithiocarbamate. These new biochemical and molecular data indicate that ethanol, even in physiologic concentrations, can elicit rapid lipid peroxidation and activation of NF-kappaB in cerebral vascular muscle cells. The present results when viewed in light of other recently published data suggest that ethanol-induced lipid peroxidation and activation of nuclear transcription factors probably play important roles in alcohol-induced brain-vascular damage, neurobehavioral actions and stroke.

  7. Expression of the leukocyte early activation antigen CD69 is regulated by the transcription factor AP-1.

    PubMed

    Castellanos, M C; Muñoz, C; Montoya, M C; Lara-Pezzi, E; López-Cabrera, M; de Landázuri, M O

    1997-12-01

    The leukocyte Ag CD69, one of the earliest cell surface activation Ags, is up-regulated at the transcriptional level by proinflammatory stimuli involving the NF-kappaB/Rel family of transcription factors. However, promoter fragments lacking a critical kappaB motif respond to other stimuli such as phorbol esters and triggering Abs against TCR/CD3. Since the 5' promoter flanking region of the CD69 gene contains several putative binding sequences for transcription factor activating protein-1 (AP-1), we explored its role in the inducible expression of CD69. Stimuli that induce AP-1, but not NF-kappaB, such as pyrrolidine dithiocarbamate, augmented the cell surface expression of CD69 as well as its mRNA levels, and the promoter activity of the CD69 gene. This up-regulation is accompanied by an increased binding of jun and fos family members to a consensus AP-1 binding site of the proximal (-16) CD69 promoter region, which seems to be functionally responsive to different activation signals and is trans activated by c-jun expression vectors. Furthermore, cotransfection of a dominant negative version of c-jun, but not IkappaB, abolished the inducible transcriptional activity of the CD69 promoter. In conclusion, the inducible expression of the CD69 gene by mitogenic signals is regulated by the transcription factor AP-1.

  8. Posttranslational Regulation of O(6)-Methylguanine-DNA Methyltransferase (MGMT) and New Opportunities for Treatment of Brain Cancers.

    PubMed

    Srivenugopal, Kalkunte S; Rawat, Amit; Niture, Suryakant K; Paranjpe, Ameya; Velu, Chinavenmani; Venugopal, Sanjay N; Madala, Hanumantha Rao; Basak, Debasish; Punganuru, Surendra R

    2016-01-01

    O(6)-Methylguanine-DNA-methyltransferase (MGMT) is an antimutagenic DNA repair protein highly expressed in human brain tumors. Because MGMT repairs the mutagenic, carcinogenic and cytotoxic O(6)-alkylguanine adducts, including those generated by the clinically used anticancer alkylating agents, it has emerged as a central and rational target for overcoming tumor resistance to alkylating agents. Although the pseudosubstrates for MGMT [O(6)-benzylguanine, O(6)-(4- bromothenyl)guanine] have gained attention as powerful and clinically-relevant inhibitors, bone marrow suppression due to excessive alkylation damage has diminished this strategy. Our laboratory has been working on various posttranslational modifications of MGMT that affect its protein stability, DNA repair activity and response to oxidative stress. While these modifications greatly impact the physiological regulation of MGMT, they also highlight the opportunities for inactivating DNA repair and new drug discovery in this specific area. This review briefly describes the newer aspects of MGMT posttranslational regulation by ubiquitination, sumoylation and glutathionylation and reveals how the reactivity of the active site Cys145 can be exploited for potent inhibition and depletion of MGMT by thiol-reacting drugs such as the disulfiram and various dithiocarbamate derivatives. The possible repurposing of these nontoxic and safe drugs for improved therapy of pediatric and adult brain tumors is discussed.

  9. Pesticide usage and its association with health symptoms among farmers in rural villages in West Java, Indonesia.

    PubMed

    Sekiyama, Makiko; Tanaka, Mika; Gunawan, Budhi; Abdoellah, Oekan; Watanabe, Chiho

    2007-01-01

    The improper handling of pesticides in agriculture has caused serious health problems in many developing countries. In this study, we report the pesticide usage condition among Indonesian farmers and its association with symptoms of pesticide toxicity. A questionnaire survey on personal history regarding agricultural labor, pesticide storage and disposal, pesticide use and health history was conducted using a structured questionnaire in rural Sundanese villages in West Java, Indonesia. The most frequently used pesticides included dithiocarbamates, pyrethroids and organophosphates. In approximately 80% of sprayings, category II pesticides (World Health Organization (WHO) categorization; "moderately hazardous") were used. Many of the subject farmers worked in a highly unsafe occupational environment; protective measures and safe handling were rarely observed, whereas smoking and drinking during spraying were frequently practiced. Correlation analysis revealed that farmers who wore a long sleeve shirt and headgear showed health symptoms less frequently. Moreover, farmers who had skin contact with the spray solution during measuring or mixing (excluding the hands), who wore wet clothing (skin exposure to pesticide), and who smoked and rubbed their eyes during spraying showed more symptoms. Among these factors, headgear use, wearing wet clothing (skin exposure to pesticide), and smoking during spraying were the significant determining factors for developing health symptoms. Preventing such behaviors will be an effective method of reducing health problems among the subject farmers.

  10. Delayed ovulation and pregnancy outcome: effect of environmental toxicants on the neuroendocrine control of the ovary(1).

    PubMed

    Stoker, T E.; Goldman, J M.; Cooper, R L.

    2001-01-01

    In the female rat, we have shown that a burst exposure to environmental toxicants known to alter noradrenergic function will block the ovulatory surge of LH when administered during a sensitive period on the day of vaginal proestrus. Such treatments will delay ovulation by 24 h and affect embryo survival. These results demonstrate clearly that brief, appropriately timed, toxicant exposure can initiate a cascade of changes that can alter reproductive outcome. However, we also found that continued exposure to the same compound is without an apparent influence on the reproductive capacity of the female, indicating that the female can become tolerant to such adverse reproductive effects. These observations raise a number of questions concerning the approaches currently used to examine potential reproductive toxicants. In this review, we describe the consequences of appropriately timed exposures to chlordimeform and dithiocarbamates on the timing of ovulation and subsequent alterations in pregnancy outcome. We also review the available literature on phenobarbital delays in ovulation and oocyte function in the rodent and the relevance to ovulatory delays in the human.

  11. Differential effect of buffer on the spin trapping of nitric oxide by iron chelates.

    PubMed

    Porasuphatana, S; Weaver, J; Budzichowski, T A; Tsai, P; Rosen, G M

    2001-11-01

    Nitric oxide synthase (NOS) generates nitric oxide (NO*) by the oxidation of l-arginine. Spin trapping in combination with electron paramagnetic resonance (EPR) spectroscopy using ferro-chelates is considered one of the best methods to detect NO* in real time and at its site of generation. The spin trapping of NO* from isolated NOS I oxidation of L-arginine by ferro-N-dithiocarboxysarcosine (Fe(DTCS)2) and ferro-N-methyl-d-glucamide dithiocarbamate (Fe(MGD)2) in different buffers was investigated. We detected NO-Fe(DTCS)2, a nitrosyl complex, resulting from the reaction of NO* and Fe(DTCS)2, in phosphate buffer. However, Hepes and Tris buffers did not allow formation of NO-Fe(DTCS)2. Instead, both of these buffers reacted with Fe2+, generating sparingly soluble complexes in the absence of molecular oxygen. Fe(DTCS)2 and Fe(MGD)2 were found to inhibit, to a small degree, NOS I activity with a greater effect observed with Fe(MGD)2. In contrast, Fe(MGD)2 was more efficient at spin trapping NO* from the lipopolysaccharide-activated macrophage cell line RAW264.7 than was Fe(DTCS)2. Data suggested that Fe(DTCS)2 and Fe(MGD)2 are efficient at spin trapping NO* but their maximal efficiency may be affected by experimental conditions.

  12. Atomic-absorption spectrometric determination of cobalt, nickel, and copper in geological materials with matrix masking and chelation-extraction

    USGS Publications Warehouse

    Sanzolone, R.F.; Chao, T.T.; Crenshaw, G.L.

    1979-01-01

    An atomic-absorption spectrometric method is reported for the determination of cobalt, nickel, and copper in a variety of geological materials including iron- and manganese-rich, and calcareous samples. The sample is decomposed with HP-HNO3 and the residue is dissolved in hydrochloric acid. Ammonium fluoride is added to mask iron and 'aluminum. After adjustment to pH 6, cobalt, nickel, and copper are chelated with sodium diethyl-dithiocarbamate and extracted into methyl isobutyl ketone. The sample is set aside for 24 h before analysis to remove interferences from manganese. For a 0.200-g sample, the limits of determination are 5-1000 ppm for Co, Ni, and Cu. As much as 50% Fe, 25% Mn or Ca, 20% Al and 10% Na, K, or Mg in the sample either individually or in various combinations do not interfere. Results obtained on five U.S. Geological Survey rock standards are in general agreement with values reported in the literature. ?? 1979.

  13. Evaluation of surface-enhanced Raman scattering detection using a handheld and a bench-top Raman spectrometer: a comparative study.

    PubMed

    Zheng, Jinkai; Pang, Shintaro; Labuza, Theodore P; He, Lili

    2014-11-01

    Surface enhanced Raman scattering (SERS) detection using a handheld Raman spectrometer and a bench-top Raman spectrometer was systemically evaluated and compared in this study. Silver dendrites were used as the SERS substrate, and two pesticides, maneb and pyrrolidine dithiocarbamate-ammonium salt (PDCA) were used as the analytes. Capacity and performance were evaluated based on spectral resolution, signal variation, quantitative capacity, sensitivity, flexibility and intelligence for SERS detection. The results showed that the handheld Raman spectrometer had better data consistency, more accurate quantification capacity, as well as the capacity of on-site and intelligence for qualitative and semi-quantitative analysis. On the other hand, the bench-top Raman spectrometer showed about 10 times higher sensitivity, as well as flexibility for optimization of the SERS measurements under different parameters such as laser power output, collective time, and objective magnification. The study on the optimization of SERS measurements on a bench-top spectrometer provides a useful guide for designing a handheld Raman spectrometer, specifically for SERS detection. This evaluation can advance the application of a handheld Raman spectrometer for the on-site measurement of trace amounts of pesticides or other chemicals.

  14. Inorganic selenium speciation analysis in Allium and Brassica vegetables by ionic liquid assisted liquid-liquid microextraction with multivariate optimization.

    PubMed

    Castro Grijalba, Alexander; Martinis, Estefanía M; Wuilloud, Rodolfo G

    2017-03-15

    A highly sensitive vortex assisted liquid-liquid microextraction (VA-LLME) method was developed for inorganic Se [Se(IV) and Se(VI)] speciation analysis in Allium and Brassica vegetables. Trihexyl(tetradecyl)phosphonium decanoate phosphonium ionic liquid (IL) was applied for the extraction of Se(IV)-ammonium pyrrolidine dithiocarbamate (APDC) complex followed by Se determination with electrothermal atomic absorption spectrometry. A complete optimization of the graphite furnace temperature program was developed for accurate determination of Se in the IL-enriched extracts and multivariate statistical optimization was performed to define the conditions for the highest extraction efficiency. Significant factors of IL-VA-LLME method were sample volume, extraction pH, extraction time and APDC concentration. High extraction efficiency (90%), a 100-fold preconcentration factor and a detection limit of 5.0ng/L were achieved. The high sensitivity obtained with preconcentration and the non-chromatographic separation of inorganic Se species in complex matrix samples such as garlic, onion, leek, broccoli and cauliflower, are the main advantages of IL-VA-LLME.

  15. Ionic liquid-linked dual magnetic microextraction of lead(II) from environmental samples prior to its micro-sampling flame atomic absorption spectrometric determination.

    PubMed

    Yilmaz, Erkan; Soylak, Mustafa

    2013-11-15

    A novel and rapid microextraction approach termed as ionic liquid-linked dual magnetic microextraction (IL-DMME), was developed for the atomic absorption spectrometric determination of lead. The developed method based on a combination of dispersive liquid-liquid microextraction (DLLME) and dispersive micro solid-phase extraction (D-μ-SPE). In the first DLLME step, 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], was selected to extract the lead-pyrrolidine-dithiocarbamate (Pb-PDC) complex from sample solution by the assistance of vortex agitator. After the first step, fifty milligrams of Fe3O4 magnetic nanoparticles (MNPs) were added to extraction of the ionic liquid and Pb-PDC complex in aqueous solution. The effective factors in proposed IL-DMME procedure, including volume of 1-butyl-3-methylimidazolium hexafluorophosphate, amount of Fe3O4 magnetic nanoparticles, vortex time, amount of ammonium pyrrolidinedithiocarbamate, sample volume and matrix effect were optimized in details. Under the optimal conditions, the method present has low detection limit (0.57 μg L(-1)), high preconcentration factor (160) and good repeatability (<7.5%, n=10). The accuracy of the developed method was evaluated by the analysis of the certified reference materials and addition-recovery tests. The method was successfully applied to the determination of lead in water, plant and hair samples.

  16. Profiling 976 ToxCast Chemicals across 331 Enzymatic and Receptor Signaling Assays

    PubMed Central

    2013-01-01

    Understanding potential health risks is a significant challenge due to the large numbers of diverse chemicals with poorly characterized exposures and mechanisms of toxicities. The present study analyzes 976 chemicals (including failed pharmaceuticals, alternative plasticizers, food additives, and pesticides) in Phases I and II of the U.S. EPA’s ToxCast project across 331 cell-free enzymatic and ligand-binding high-throughput screening (HTS) assays. Half-maximal activity concentrations (AC50) were identified for 729 chemicals in 256 assays (7,135 chemical–assay pairs). Some of the most commonly affected assays were CYPs (CYP2C9 and CYP2C19), transporters (mitochondrial TSPO, norepinephrine, and dopaminergic), and GPCRs (aminergic). Heavy metals, surfactants, and dithiocarbamate fungicides showed promiscuous but distinctly different patterns of activity, whereas many of the pharmaceutical compounds showed promiscuous activity across GPCRs. Literature analysis confirmed >50% of the activities for the most potent chemical–assay pairs (54) but also revealed 10 missed interactions. Twenty-two chemicals with known estrogenic activity were correctly identified for the majority (77%), missing only the weaker interactions. In many cases, novel findings for previously unreported chemical–target combinations clustered with known chemical–target interactions. Results from this large inventory of chemical–biological interactions can inform read-across methods as well as link potential targets to molecular initiating events in adverse outcome pathways for diverse toxicities. PMID:23611293

  17. Effect of heavy metals on the stabilization of mercury(II) by DTCR in desulfurization solutions.

    PubMed

    Hou, Jiaai; Lu, Rongjie; Sun, Mingyang; Baig, Shams Ali; Tang, Tingmei; Cheng, Lihua; Xu, Xinhua

    2012-05-30

    Several heavy metals, including Cu(2+), Ni(2+), Pb(2+), and Zn(2+), were investigated in simulated desulfurization solutions to evaluate their interferences with Hg(2+) during the reaction with dithiocarbamate type chelating resin (DTCR). Appropriate DTCR dosage and the effect of pH were also explored with respect to restoration of high Hg(2+) precipitation efficiency and reduction of mercury concentrations. The experimental results suggested that increasing heavy metal concentration inhibited Hg(2+) precipitation efficiency to a considerable extent and the inhibition order of the four heavy metals was Cu(2+)>Ni(2+)>Pb(2+)>Zn(2+). However, the coordination ability was closely related to the configuration and the orbital hybridization of each metal. In the cases of Cu(2+) and Pb(2+), increased DTCR dosage was beneficial to Hg(2+) precipitation, which could lay the foundation of practical applications of DTCR dosage for industrial wastewater treatment. The enhanced Hg(2+) precipitation performance seen for increasing pH might have come from the deprotonation of sulfur atoms on the DTCR functional groups and the formation of metal hydroxides (M(OH)(2), M=Cu, Pb, Hg).

  18. Separation-preconcentration of nickel and lead in food samples by a combination of solid-liquid-solid dispersive extraction using SiO2 nanoparticles, ionic liquid-based dispersive liquid-liquid micro-extraction.

    PubMed

    Jalbani, Nusrat; Soylak, Mustafa

    2015-01-01

    A microextraction method for the determination of nickel and lead using solid-liquid-solid dispersive extraction followed by ionic liquid-based dispersive liquid-liquid microextraction (SLSDE-ILDLLME) was presented. It was applied to the extraction of nickel and lead from food samples. Ammonium pyrrolidine dithiocarbamate (APDC) as complexing agent, [C4MIM][PF6] as ionic liquid, SiO2 as nanoparticles and 2 mol L(-1) HNO3 as eluent were used. Several important parameters such as amount of IL, extraction time, pH and volume of the complexing agent were investigated. The quantitative recoveries were obtained at pH 7.0 for analytes. Under the optimum conditions, the limits of detection (LODs) calculated using 3(Sd)blank/m were 0.17 for Ni(II) and 0.79 µg L(-1) for Pb(II) for aqueous solutions with 125 enrichment factor (EF). The limit of detections of the analyte ions (3(Sd)blank/m) for solid samples were 0.09 µg g(-1) (Ni) and 0.40 µg g(-1) (Pb). The accuracy of the proposed method was confirmed by the analysis of standard reference material (1577c bovine liver) and spiked recovery test. The proposed method was applied to determine nickel and lead levels in chicken, fish and meat samples.

  19. Tribological behaviors of diamond-like carbon coatings on plasma nitrided steel using three BN-containing lubricants

    NASA Astrophysics Data System (ADS)

    Jia, Zheng-feng; Wang, Peng; Xia, Yan-qiu; Zhang, Hao-bo; Pang, Xian-juan; Li, Bin

    2009-04-01

    In this work, diamond-like carbon (DLC) coatings were deposited on plasma nitrided AISI 1045 steel by magnetron sputtering. Three BN-containing additives and molybdenum dithiocarbamate (MoDTC) were added to poly-alpha-olefin (PAO) as additives. The additive content (mass fraction) in PAO was fixed at 0.5 wt%. The friction and wear characters of DLC coatings on nitrided steel discs sliding against AISI 52100 steel balls were tested under the lubricated conditions. It was found that borate esters have a higher load carrying capacity and much better anti-wear and friction-reducing ability than that of MoDTC. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were employed to explore the properties of the worn surface and the mechanism of friction and wear. According to the XPS analysis, the adsorbed organic N-containing compounds and BN are, possibly, the primary reason for the novel borate esters to possess a relatively constant coefficient of friction and lower wear rate. On the other hand, possibly, the MoDTC molecules break down during sliding and produce many Mo-oxides, and then the Mo-oxides destroy the DLC coating because of its sharp edge crystalline solid structure. After destroying the DLC coating, the MoDTC react with metals and form MoS 2 tribofilm, and decrease coefficient of friction of rubbing pairs.

  20. Determination of arsenic in various environmental and oil samples by differential pulse polarography after adsorption of its morpholine-4-carbodithioate on to microcrystalline naphthalene or morpholine-4-dithio-carbamate-CTMAB-naphthalene adsorbent

    SciTech Connect

    Dubey, R.K.; Puri, B.K.; Hussain, M.F.

    1997-01-01

    A highly selective, sensitive, rapid and economical differential pulse-polarographic (DPP) method has been developed for the quantitative determination of trace amounts of arsenic in various environmental and crude oil samples. The morpholine-4-carbodithioate of arsenic was quantitatively adsorbed on microcystalline naphthalene in the pH range of 6.0- 9.5. The metal complex along with naphthalene was shaken with 10 ml of 1 M HCl and arsenic determined with a differential pulse polarograph using HCl-pyridine-NaCl as the supporting electrolyte. Arsenic may also be adsorbed quantitatively under similar conditions on morpholine-4-dithiocarbamate-cetyltrimethylammonium bromide-naphthalene adsorbent packed in a column at a flow rate of 0.5-5.0 ml/min and determined similarly. The detection limit is 0.016 ppm at the minimum instrumental setting (signal to noise ratio=2). Arsenic is being determined in the concentration range of 0.08- 9.0 ppm with a correlation factor of 0.9996 and a relative standard deviation of {plus_minus} 0.81%(n=8). Various parameters such as the effect of pH, volume of aqueous phase, and interference of a number of metal ions and anions on the estimation of arsenic have been evaluated to optimize the conditions for the estimation of arsenic in various environmental and crude oil samples.

  1. A Versatile Strategy for Shish-Kebab-like Multi-heterostructured Chalcogenides and Enhanced Photocatalytic Hydrogen Evolution.

    PubMed

    Hu, Jianqiang; Liu, Aili; Jin, Huile; Ma, Dekun; Yin, Dewu; Ling, Pengsheng; Wang, Shun; Lin, Zhiqun; Wang, Jichang

    2015-09-02

    A series of multi-heterostructured metal chalcogenides (CdS-Te, NiS/CdS-Te, and MoS2/CdS-Te) with a surprising shish-kebab-like structure have been synthesized via a one-step microwave-assisted pyrolysis of dithiocarbamate precursors in ethylene glycol. Subsequently, CdS-Te composites were exploited as a self-sacrificial template to craft various CdS-Te@(Pt, Pd) multi-heterostructures. Highly uniform dispersion and intimate interactions between CdS and multicomponent cocatalysts, together with improved separation of photogenerated carriers due to the presence of Te nanotubes (NTs) and trace CdTe, enable CdS-based heterostructured photocatalysts to exhibit greatly enhanced efficiency and stability in the photocatalytic production of H2. Thorough morphological characterizations revealed that the growth of metal sulfide/Te heterostructures originates from the growth of Te tubes, which is likely governed by diffusion-limited depletion of the Te precursor and the dissolution-crystallization process of Te seeds followed by the formation of metal sulfide kebabs.

  2. Reference values for ethylenethiourea in urine in Northern Italy: results of a pilot study.

    PubMed

    Colosio, Claudio; Visentin, Sara; Birindelli, Sarah; Campo, Laura; Fustinoni, Silvia; Mariani, Franco; Tiramani, Manuela; Tommasini, Michele; Brambilla, Gabri; Maroni, Marco

    2006-04-10

    This study was carried out to define reference values for urinary ethylenethiourea (ETU) in the Northern Italy population and to identify the sources of exposure. Ninety-five healthy subjects were selected. A spot urine sample was collected in the morning, and analyzed using GC/MS in the EI/SIM mode. Thirty-nine subjects showed urinary ETU concentrations lower than the limit of detection (LOD, 0.4 microg/g creatinine), and the remainders ETU concentrations ranging from 0.5 to 11.6 microg/g creatinine. No correlation was shown between smoke or alcohol intake and urinary ETU concentrations. Based on data on ethylene-bis-dithiocarbamate (EBDC) concentrations in food, we estimated a total EBDCs intake of 31.7-50.1 microg/day. These values are largely below the ADIs, but explain the presence of small amounts of ETU in the urine samples we have analyzed. Finally, it was estimated that the mean ETU in urine in the Italian general population is 0.6-0.8 microg/g creatinine, with a 95th percentile of 4.5-5.0 microg/g creatinine. These values can be used as reference, to compare the results of biological monitoring activities carried out on EBDCs occupationally and environmentally exposed populations.

  3. Palmitate-induced interleukin 6 production is mediated by protein kinase C and nuclear-factor kappaB activation and leads to glucose transporter 4 down-regulation in skeletal muscle cells.

    PubMed

    Jové, Mireia; Planavila, Anna; Laguna, Juan Carlos; Vázquez-Carrera, Manuel

    2005-07-01

    The mechanisms by which elevated levels of free fatty acids cause insulin resistance are not well understood. In addition, accumulating evidence suggests a link between inflammation and type 2 diabetes. Here, we report that exposure of C2C12 skeletal muscle cells to 0.5 mm palmitate results in increased mRNA levels (3.5-fold induction; P < 0.05) and secretion (control 375 +/- 57 vs. palmitate 1129 +/- 177 pg/ml; P < 0.001) of the proinflammatory cytokine IL-6. Palmitate increased nuclear factor-kappaB activation and coincubation of the cells with palmitate and the nuclear factor-kappaB inhibitor pyrrolidine dithiocarbamate prevented both IL-6 expression and secretion. Furthermore, incubation of palmitate-treated cells with calphostin C, a strong and specific inhibitor of protein kinase C, and phorbol myristate acetate, that down-regulates protein kinase C in long-term incubations, abolished induction of IL-6 production. Finally, exposure of skeletal muscle cells to palmitate caused a fall in the mRNA levels of glucose transporter 4 and insulin-stimulated glucose uptake, whereas in the presence of anti-IL-6 antibody, which neutralizes the biological activity of mouse IL-6 in cell culture, these reductions were prevented. These findings suggest that IL-6 may mediate several of the prodiabetic effects of palmitate.

  4. Antioxidant modulation of skin inflammation: preventing inflammatory progression by inhibiting neutrophil influx

    PubMed Central

    McGilvray, Ian D.; Rotstein, Ori D.

    1999-01-01

    Objective To test the hypothesis that antioxidants might affect local inflammation by impairing inflammatory cell influx. Design A laboratory study using a Swiss–Webster mouse model of local inflammation. Setting A university-affiliated hospital. Methods Intradermal injection of 30 μg of S. minnesota endotoxin (LPS) to Swiss–Webster mice initiates a local inflammatory reaction characterized by an early rise in vascular permeability and a later influx of neutrophils. Animals were pretreated intraperitoneally with either pyrrolidine dithiocarbamate (PDTC, 2 mmol/kg), which inhibits free radical generation, or dimethylthiourea (DMTU, 450 mg/kg), a free radical scavenger. Main outcome measures Histologic findings of tissue samples taken at sites of injection; local changes in tissue vascular permeability (PI) determined by iodine-125 albumin injection before sacrifice; neutrophil accumulation quantified by tissue myeloperoxidase levels; tissue levels of the endothelial adhesion molecules intercellular adhesion molecule-1 protein (ICAM-1) and vascular cell adhesion molecule-1 protein (VCAM-1) assessed by immunohistochemistry and Western blot, respectively. Results Neither antioxidant had a significant effect on the early increase in PI, but both decreased the late rise in PI and reduced neutrophil influx. Both ICAM-1 and VCAM-1 were upregulated in response to LPS; however, only the increase in VCAM-1 was attenuated by antioxidant pretreatment. Conclusion These data suggest that antioxidants disrupt the propagation phase of an inflammatory response, possibly by altering neutrophil migration. PMID:10223071

  5. Synthesis and biodistribution of a novel [99mTcN(PNP5)(DMCHDTC)]+ complex as a potential myocardial perfusion imaging agent.

    PubMed

    Zhang, JunBo; Song, ZhiXin; Jinfeng, Chu; Wang, XueBin

    2009-09-01

    The [(99m)TcN(PNP5)(DMCHDTC)](+)(DMCHDTC: 2,3-dimethyl cyclohexyl dithiocarbamate, PNP5:bis(dimethoxypropylphosphinoethyl)ethoxyethylamine) complex was synthesized through a ligand-exchange reaction. The two-step procedure involved the initial reaction of (99m)TcO(4)(-) with succinic dihydrazide (SDH) as a donor of nitride nitrogen atom (N(3-)) in the presence of stannous chloride dihydrate as reducing agent and propylenediamine tetraacetic acid (PDTA) as complexant, followed by the addition of the PNP5 ligand and the DMCHDTC ligand. The radiochemical purity (RCP) of the product was over 90% as measured by thin layer chromatography (TLC). No decomposition of the complex at room temperature was observed over a period of 6 h. Its partition coefficient indicated that it was a lipophilic complex. The electrophoresis results showed the complex was cationic. The biodistribution results in mice indicated that [(99m)TcN(PNP5)(DMCHDTC)](+) was significantly retained into the heart. The heart uptake (ID%/g) was 14.47, 12.23 and 8.76 at 5, 30 and 60 min post-injection, respectively. The heart/liver, heart/lung and heart/blood ratios of the complex were 1.24, 3.62 and 23.05 at 60 min post-injection, suggesting it will be a potential myocardial imaging agent.

  6. Synthesis and biodistribution of a new 99mTc nitrido complex as a potential myocardial and cerebral imaging agent.

    PubMed

    Zhang, JunBo; Wang, XueBin; Li, ChunYun

    2002-06-01

    The bis(N-methyl, N-cyclohexyl dithiocarbamato) nitrido technetium-99m complex [99mTcN(MECHDTC)2] (MECHDTC: N-methyl, N-cyclohexyl dithiocarbamato) has been synthesized through a ligand-exchange reaction. The two-step procedure consisted of an initial reaction of 99mTcO4- with succinic dihydrazide in the presence of stannous chloride as reducing agent and propylenediamine tetraacetic acid as complexant, and successive addition of sodium salt of N-methyl, N-cyclohexyl dithiocarbamate. The radiochemical purity of the complex was over 90%, as measured by thin layer chromatography. No decomposition of the complex at room temperature was observed over a period of 6 h. Its partition coefficient indicated that it was a lipophilic complex. The electrophoresis results showed that the complex was neutral. Biodistribution in mice showed that the complex accumulated in the heart and brain with high uptake. The heart/blood, heart/lung and brain/blood ratios were 5.55, 2.11 and 1.10, respectively, at 30 min post-injection, suggesting that this compound is a potential myocardial and cerebral imaging agent.

  7. RAGE/NF-κB pathway mediates lipopolysaccharide-induced inflammation in alveolar type I epithelial cells isolated from neonate rats.

    PubMed

    Li, Yuhong; Wu, Rong; Zhao, Sai; Cheng, Huaipin; Ji, Ping; Yu, Min; Tian, Zhaofang

    2014-10-01

    Alveolar type I epithelial cells (AECIs) play an important role in the pathogenesis of acute lung injury. The receptor for advanced glycation end-products (RAGEs) is expressed at a high basal level in AECIs, and its soluble isoform is suggested as a marker of AECI injury. However, the molecular mechanism by which RAGE mediates inflammatory injury in AECIs remains elusive. In this study, we established lipopolysaccharide (LPS)-induced inflammation in AECIs isolated from neonate rats as the experimental model and investigated the role of RAGE/NF-κB signaling in mediating inflammatory response in AECIs. We found that LPS increased RAGE expression and the secretion of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) in AECIs in a dose-dependent manner. Knockdown of RAGE significantly decreased TNF-α and IL-1β levels in conditioned medium of AECIs. Electrophoretic mobility shift assay (EMSA) showed that NF-κB activation was increased in AECIs treated by LPS. However, knockdown of RAGE inhibited both basic and LPS-induced NF-κB activity in AECIs. Finally, NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) significantly reduced LPS-induced upregulation of RAGE expression at both protein and messenger RNA (mRNA) levels in AECIs. Our results suggest that RAGE mediates inflammatory response in AECIs via activating NF-κB, and RAGE/NF-κB pathway presents potential target for the prevention and therapy of acute lung injury.

  8. Ultratrace Determination of Cr(VI) and Pb(II) by Microsample Injection System Flame Atomic Spectroscopy in Drinking Water and Treated and Untreated Industrial Effluents.

    PubMed

    Baig, Jameel Ahmed; Kazi, Tasneem Gul; Elci, Latif; Afridi, Hassan Imran; Khan, Muhammad Irfan; Naseer, Hafiz Muhammad

    2013-01-01

    Simple and robust analytical procedures were developed for hexavalent chromium (Cr(VI)) and lead (Pb(II)) by dispersive liquid-liquid microextraction (DLLME) using microsample injection system coupled with flame atomic absorption spectrophotometry (MIS-FAAS). For the current study, ammonium pyrrolidine dithiocarbamate (APDC), carbon tetrachloride, and ethanol were used as chelating agent, extraction solvent, and disperser solvent, respectively. The effective variables of developed method have been optimized and studied in detail. The limit of detection of Cr(VI) and Pb(II) were 0.037 and 0.054 µg/L, respectively. The enrichment factors in both cases were 400 with 40 mL of initial volumes. The relative standard deviations (RSDs, n = 6) were <4%. The applicability and the accuracy of DLLME were estimated by the analysis of Cr(VI) and Pb(II) in industrial effluent wastewater by standard addition method (recoveries >96%). The proposed method was successfully applied to the determination of Cr(VI) and Pb(II) at ultratrace levels in natural drinking water and industrial effluents wastewater of Denizli. Moreover, the proposed method was compared with the literature reported method.

  9. Prenatal inflammation-induced NF-κB dyshomeostasis contributes to renin-angiotensin system over-activity resulting in prenatally programmed hypertension in offspring

    PubMed Central

    Deng, Youcai; Deng, Yafei; He, Xiaoyan; Chu, Jianhong; Zhou, Jianzhi; Zhang, Qi; Guo, Wei; Huang, Pei; Guan, Xiao; Tang, Yuan; Wei, Yanling; Zhao, Shanyu; Zhang, Xingxing; Wei, Chiming; Namaka, Michael; Yi, Ping; Yu, Jianhua; Li, Xiaohui

    2016-01-01

    Studies involving the use of prenatally programmed hypertension have been shown to potentially contribute to prevention of essential hypertension (EH). Our previous research has demonstrated that prenatal inflammatory stimulation leads to offspring’s aortic dysfunction and hypertension in pregnant Sprague-Dawley rats challenged with lipopolysaccharide (LPS). The present study found that prenatal LPS exposure led to NF-κB dyshomeostasis from fetus to adult, which was characterized by PI3K-Akt activation mediated degradation of IκBα protein and impaired NF-κB self-negative feedback loop mediated less newly synthesis of IκBα mRNA in thoracic aortas (gestational day 20, postnatal week 7 and 16). Prenatal or postnatal exposure of the IκBα degradation inhibitor, pyrollidine dithiocarbamate, effectively blocked NF-κB activation, endothelium dysfunction, and renin-angiotensin system (RAS) over-activity in thoracic aortas, resulting in reduced blood pressure in offspring that received prenatal exposure to LPS. Surprisingly, NF-κB dyshomeostasis and RAS over-activity were only found in thoracic aortas but not in superior mesenteric arteries. Collectively, our data demonstrate that the early life NF-κB dyshomeostasis induced by prenatal inflammatory exposure plays an essential role in the development of EH through triggering RAS over-activity. We conclude that early life NF-κB dyshomeostasis is a key predictor of EH, and thus, NF-κB inhibition represents an effective interventional strategy for EH prevention. PMID:26877256

  10. High-mobility group box 1 protein and its role in severe acute pancreatitis

    PubMed Central

    Shen, Xiao; Li, Wei-Qin

    2015-01-01

    The high mobility group box 1 (HMGB1), which belongs to the subfamily of HMG-1/-2, is a highly conserved single peptide chain consisting of 215 amino acid residues with a molecular weight of approximately 24894 Da. HMGB1 is a ubiquitous nuclear protein in mammals and plays a vital role in inflammatory diseases. Acute pancreatitis is one of the most common causes of acute abdominal pain with a poor prognosis. Acute pancreatitis is an acute inflammatory process of the pancreas (duration of less than six months), for which the severe form is called severe acute pancreatitis (SAP). More and more studies have shown that HMGB1 has a bidirectional effect in the pathogenesis of SAP. Extracellular HMGB1 can aggravate the pancreatic inflammatory process, whereas intracellular HMGB1 has a protective effect against pancreatitis. The mechanism of HMGB1 is multiple, mainly through the nuclear factor-κB pathway. Receptors for advanced glycation end-products and toll-like receptors (TLR), especially TLR-2 and TLR-4, are two major types of receptors mediating the inflammatory process triggered by HMGB1 and may be also the main mediators in the pathogenesis of SAP. HMGB1 inhibitors, such as ethyl pyruvate, pyrrolidine dithiocarbamate and Scolopendra subspinipes mutilans, can decrease the level of extracellular HMGB1 and are the promising targets in the treatment of SAP. PMID:25663762

  11. Decontamination of uranium-contaminated waste oil using supercritical fluid and nitric acid.

    PubMed

    Sung, Jinhyun; Kim, Jungsoo; Lee, Youngbae; Seol, Jeunggun; Ryu, Jaebong; Park, Kwangheon

    2011-07-01

    The waste oil used in nuclear fuel processing is contaminated with uranium because of its contact with materials or environments containing uranium. Under current law, waste oil that has been contaminated with uranium is very difficult to dispose of at a radioactive waste disposal site. To dispose of the uranium-contaminated waste oil, the uranium was separated from the contaminated waste oil. Supercritical R-22 is an excellent solvent for extracting clean oil from uranium-contaminated waste oil. The critical temperature of R-22 is 96.15 °C and the critical pressure is 49.9 bar. In this study, a process to remove uranium from the uranium-contaminated waste oil using supercritical R-22 was developed. The waste oil has a small amount of additives containing N, S or P, such as amines, dithiocarbamates and dialkyldithiophosphates. It seems that these organic additives form uranium-combined compounds. For this reason, dissolution of uranium from the uranium-combined compounds using nitric acid was needed. The efficiency of the removal of uranium from the uranium-contaminated waste oil using supercritical R-22 extraction and nitric acid treatment was determined.

  12. Toxicological effects of cigarette smoke on Ana-1 macrophages in vitro.

    PubMed

    Yuan, Fengjiao; Dong, Ping; Wang, Xiang; Fu, Xiao; Dai, Mingjun; Zhang, Weiyun

    2013-11-01

    Cigarette smoke exposure is associated with increased risk of different disorders. Immunological dysfunction especially in macrophages is one of important reasons in the initiation, progression and exacerbation of smoke-related pulmonary illnesses. However, it is still obscure how cigarette smoke impacts the vitality and functions of macrophages. In the present study, we examined the effects of cigarette smoke extract (CSE) on mouse Ana-1 macrophages and tried to elucidate the involved mechanism. The results showed CSE induced cell apoptosis accompanied by increased releasing of lactate dehydrogenase (LDH), mitochondrial injury and oxidative stress. It also inhibited anti-apoptosis protein Bcl-2 expression and promoted pro-apoptosis protein Bax and Bad expressions. Moreover, low-dose CSE increased nuclear NF-κB levels of macrophages; on the contrary, high-dose CSE or long-time treatment decreased it. These observations were in correspondence with changes of intracellular ROS level and antioxidant enzymes' activity. Furthermore, pretreatment with 10μM of NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) for 1h significantly enhanced macrophage apoptosis. Taken together, these data implied that mitochondrial dysfunction and oxidative stress played important roles in the injury of Ana-1 cells caused by CSE, which was related to NF-κB pathway; an anti-apoptotic program played a dominant role at low doses/short-term exposure to CSE, whereas a pro-apoptotic program was initiated at high doses/long-term exposure.

  13. Inhibition on hepatitis B virus in vitro of lectin from Musca domestica pupa via the activation of NF-κB.

    PubMed

    Cao, Xiaohong; Zhou, Minghui; Wang, Songxue; Wang, Chunling; Hou, Lihua; Luo, Yiqing; Chen, Linye

    2012-12-01

    The present study reported that the secretions of HBsAg and HBeAg in HepG2.2.15 cells were significantly decreased under the treatment of lectin from Musca domestica pupa (MPL). Both the replication of hepatitis B virus (HBV) DNA and HBV cccDNA in cells, and the copies of extracellular HBV DNA were inhibited by MPL. The mRNA expressions of interleukin-2 (IL-2), gamma interferon (INF-γ) and MxA were up-regulated by MPL treatments, but down-regulated when nuclear factor-κB (NF-κB) signal pathway was blocked by pyrrolidine dithiocarbamate (PDTC). Subsequent investigation revealed that nuclear factor-κB inhibitory κB (IκB) in endochylema was inhibited and NF-κB was translocated into the nucleus. These findings indicate that MPL could inhibit HBV replication via the induction of the expression of IL-2, INF-γ and MxA through the activation of NF-κB.

  14. Effects of hydrochemistry variables on the half-life of mancozeb and on the hazard index associated to the sum of mancozeb and ethylenethiourea.

    PubMed

    López-Fernández, O; Pose-Juan, E; Rial-Otero, R; Simal-Gándara, J

    2017-04-01

    Mancozeb is a dithiocarbamate non-systemic agricultural fungicide with multi-site, protective action. It helps to control many fungal diseases in a wide range of field crops, fruits, nuts, vegetables, and ornamental plants. We have investigated the stability profiles of mancozeb in aqueous solutions to determine the effect of pH, temperature and light on the degradation process of mancozeb. In addition, the toxicological risk for humans associated with the joint intake of mancoze7b and its final degradation product, ethylenethiourea (ETU), was calculated and modelled as a function of the experimental conditions. Stability study results showed a very low stability profile of mancozeb in all the aqueous solutions with rapid degradation that varied with experimental conditions. The process followed first order kinetics. The study of the degradation kinetics showed a significant effect of pH*temperature interaction on the degradation process. The results also expressed that light has a greater impact on the stability of mancozeb and the formation of ETU. The current study concludes that mancozeb is unstable in aqueous solutions, particularly at an acid pH, in addition to presenting both severe light and lower temperature sensitivity. The toxicological risk associated with mancozeb degradation increases with time and temperature, being higher at basic pH and in absence of light.

  15. The fungicide mancozeb induces toxic effects on mammalian granulosa cells.

    PubMed

    Paro, Rita; Tiboni, Gian Mario; Buccione, Roberto; Rossi, Gianna; Cellini, Valerio; Canipari, Rita; Cecconi, Sandra

    2012-04-15

    The ethylene-bis-dithiocarbamate mancozeb is a widely used fungicide with low reported toxicity in mammals. In mice, mancozeb induces embryo apoptosis, affects oocyte meiotic spindle morphology and impairs fertilization rate even when used at very low concentrations. We evaluated the toxic effects of mancozeb on the mouse and human ovarian somatic granulosa cells. We examined parameters such as cell morphology, induction of apoptosis, and p53 expression levels. Mouse granulosa cells exposed to mancozeb underwent a time- and dose-dependent modification of their morphology, and acquired the ability to migrate but not to proliferate. The expression level of p53, in terms of mRNA and protein content, decreased significantly in comparison with unexposed cells, but no change in apoptosis was recorded. Toxic effects could be attributed, at least in part, to the presence of ethylenthiourea (ETU), the main mancozeb catabolite, which was found in culture medium. Human granulosa cells also showed dose-dependent morphological changes and reduced p53 expression levels after exposure to mancozeb. Altogether, these results indicate that mancozeb affects the somatic cells of the mammalian ovarian follicles by inducing a premalignant-like status, and that such damage occurs to the same extent in both mouse and human GC. These results further substantiate the concept that mancozeb should be regarded as a reproductive toxicant.

  16. The protective role of chelators and antioxidants on mancozeb-induced toxicity in rat hippocampal astrocytes.

    PubMed

    Tsang, M M; Trombetta, L D

    2007-09-01

    Mancozeb, manganese ethylene-bis-dithiocarbamate with zinc salts, is one of the most commonly used fungicides in the United States. Epidemiological and experimental data showed that mancozeb causes detrimental effects on various organ systems including the reproductive, endocrine, immune, and central nervous system. Increasing evidence has shown a strong association between pesticides and neurodegenerative diseases. In this study, we examined the neurotoxic potential of mancozeb in rat hippocampal astrocytes. The cytotoxicity of mancozeb was found to be dose dependent and recovery studies showed that cells exposed to mancozeb for 1 h did not recover from mancozeb-induced insult. Atomic absorption data showed a significant accumulation of manganese in astrocytes after 1 h of treatment. This study further investigated whether various chelators and antioxidants could prevent mancozeb-induced cytotoxicity. Our data reported that butylated hydroxytoluene (BHT) was the most effective agent in protecting against mancozeb insult. BHT also increased total cellular antioxidants of astrocytes after 1-h mancozeb exposure. In summary, this study reported for the first time that the manganese portion of mancozeb might be, at least in part, responsible for the toxicity. Mancozeb-induced cytotoxicity in astroyctes can be protected by BHT and that this antioxidant increased the total cellular antioxidant capacity.

  17. Protective effects of resveratrol against mancozeb induced apoptosis damage in mouse oocytes.

    PubMed

    Liu, Yu; Wang, Ya-Long; He, Shu-Wen; Chen, Ming-Huang; Zhang, Zhen; Fu, Xian-Pei; Fu, Bin-Bin; Liao, Bao-Qiong; Lin, Yan-Hong; Qi, Zhong-Quan; Wang, Hai-Long

    2017-01-24

    Mancozeb, a mixture of ethylene-bis-dithiocarbamate manganese and zinc salts, is one of the most widely used fungicides in agriculture. Mancozeb could lead to mitochondria dysfunction, cellular anti-oxidation enzymes depletion and apoptotic pathways activation. Previous studies indicated the exposure of mancozeb through mother would lead to irregular estrous cycles, decreased progesterone levels, reduced litter sizes, and more frequent delivery of dead fetuses. In this study, we investigated mancozeb inducing reproductive toxicity, especially focusing on its apoptotic effect and epigenetic modifications. We also showed that resveratrol, a kind of phytoalexin found in peanuts and grapes, can alleviate mancozeb's adverse effects, such as declined fertility, decreased ovary weight and primary follicles. Besides, mancozeb treated oocytes displayed suboptimal developmental competence and this can also be improved by treatment of resveratrol. More detailed investigation of these processes revealed that mancozeb increased reactive oxygen species, causing cell apoptosis and abnormal epigenetic modifications, and resveratrol can block these cytotoxic changes. Collectively, our results showed that resveratrol can alleviate mancozeb induced infertility and this was mainly through the correction of apoptotic tendency and the abnormity of cellular epigenetic modification.

  18. SUBCHRONIC MANCOZEB TREATEMENT INDUCED LIVER TOXICITY VIA OXIDATIVE STRESS IN MALE WISTAR RATS.

    PubMed

    Yahia, E; Aiche, M A; Chouabbia, A; Boulakoud, M S

    2014-01-01

    Mancozeb is a manganese/zinc ethylene-bis-dithiocarbamate fungicide that is widely used in agriculture to control a broad variety of fungal infections of both vegetables and ornamental plants. The present study has been carried out to investigate the possible effect of mancozeb on animal the oxidative stress and some of the biochemical markers in male Wistar rats. In this experiment, adult male rats weighing between 200 and 250 g were treated per os for 4 weeks with two different doses of 800 and 1200 mg/kg per day. Reduced glutathione (GSH) levels were decreased in all treated groups compared to control ones. It has been observed a significant increase in the fresh weight of liver in individuals of both doses. Moreover, mancozeb exposure caused a significant (p < 0.05) fall in aspartic aminotransferase (AST) and alanine aminotransferase (ALT) in group treated with 1200 and 800 mg/kg/day. Similarly, alkaline phosphatase (ALP) activity underwent a significant (p < 0.05) increase in both groups. The obtained observations clearly reveal hepatotoxic effects of mancozeb in rats and constitute, therefore, an environmental health risks to living organisms.

  19. Mancozeb, a fungicide routinely used in agriculture, worsens nonalcoholic fatty liver disease in the human HepG2 cell model.

    PubMed

    Pirozzi, Anna Virginia Adriana; Stellavato, Antonietta; La Gatta, Annalisa; Lamberti, Monica; Schiraldi, Chiara

    2016-05-13

    Mancozeb, a manganese/zinc ethylene-bis-dithiocarbamate, is a fungicide routinely used in pest control programs. However, it has been found to have deleterious effects on human health and on the environment. Indeed, its massive use has raised the issue of possible health risks for agrarian communities; the molecule can also reach human cells via the food chain and alter metabolism, endocrine activity and cell survival. In particular, mancozeb induces many toxic effects on hepatic cell metabolism. For this reason, we investigated its effect in an in vitro model of hepatic damage, namely fatty acid-induced nonalcoholic fatty liver disease in the HepG2 cell line. We found that the hepatic toxicity of the fungicide exacerbated fatty acid-induced steatosis, as manifested by an increase in intracellular lipid droplet accumulation. Furthermore, mancozeb altered cell metabolism and induced cell death through upregulation of lactate dehydrogenase and cytochrome c, respectively, in dose-dependent manners. Therefore, mancozeb may play an important role in the pathogenesis and progression of chronic disease in humans and represents a danger for human health in high doses.

  20. Results from two years of field studies to determine Mancozeb based spray programmes with minimal impact on predatory mites in European vine cultivation.

    PubMed

    Miles, M; Kemmitt, G; Valverde, P

    2006-01-01

    Mancozeb is a dithiocarbamate fungicide with contact activity against a wide range of economically important fungal diseases. Its multi-site mode of action means that to date there have been no recorded incidences of resistance developing despite many years of use on high risk diseases. One such disease, Grape downy mildew (Plasmopara viticola) has developed resistance to a wide range of important oomycete specific fungicides following their introduction onto the market. The role of Mancozeb either as a mixing or alternation partner in helping to manage these resistance situations remains critically important. Historical use patterns for mancozeb in tree and vine crops involved many applications of product at high use rates. Although this gave excellent disease control, a negative impact on predatory mites was often reported by researchers. This has lead to the development of mancozeb spray programmes in vines and other crops with a much reduced impact on predatory mites. A range of field studies was conducted over two years in France, Germany, Italy, Portugal and Spain where 2, 3 or 4 applications of mancozeb containing products were made per season at different spray timings. In this paper findings from field studies over two years in five different vine growing regions in Europe indicated that two to four applications of mancozeb at 1.6 kg a.i./ha as part of a spray programme caused minimal impact on naturally occurring populations of predatory mites which in turn was compatible with Integrated Pest Management programmes and the conservation of predatory mites.

  1. The Effect of Ascorbic Acid on Mancozeb-Induced Toxicity in Rat Thymocytes.

    PubMed

    Pavlovic, V; Cekic, S; Kamenov, B; Ciric, M; Krtinic, D

    2015-01-01

    Mancozeb, as a dithiocarbamate fungicide, has been found to exhibit toxicological manifestations in different cells, mainly by generation of free radicals which may alter antioxidant defence systems in cells. The effect of mancozeb on the cells of a primary lymphoid organ has not been studied. In the present study, the effects of mancozeb (0.2, 2 and 5 μg/ml) or mancozeb+ascorbic acid (100 μg/ml), or ascorbic acid alone or control medium alone on the levels of cell viability, apoptosis, intracellular reactive oxygen species production (ROS), mitochondrial membrane potential (MMP) and ATP levels in rat thymocytes were examined in vitro. Cells treated with mancozeb displayed a concentration-dependent increase of hypodiploid cells and ROS production followed by markedly decreased viability of the cells, MMP and ATP levels. Application of ascorbic acid significantly reduced cytotoxicity in cell cultures treated with 0.2 and 2 μg/ml of mancozeb, together with significantly decreased ROS levels and increased MMP and ATP levels. In cells treated with 5 μg/ml of mancozeb, ascorbic acid failed to reduce toxicity while simultaneously increasing the apoptosis rate of thymocytes. These results suggest that ROS plays a significant role in mancozeb-induced toxicity, through alteration of mitochondrial function. Ascorbic acid administration reduced the toxicity rate in cells treated with lower mancozeb concentrations, while it may have the ability to shift cells from necrosis to apoptosis in the presence of highest mancozeb concentrations.

  2. The fungicide Mancozeb induces metacaspase-dependent apoptotic cell death in Saccharomyces cerevisiae BY4741.

    PubMed

    Scariot, F J; Jahn, L M; Maianti, J P; Delamare, A P L; Echeverrigaray, S

    2016-07-01

    Mancozeb (MZ), a mixture of ethylene-bis-dithiocarbamate manganese and zinc salts, is one of the most widely used fungicides in agriculture. Toxicologic studies in mammals and mammalian cells indicate that this fungicide can cause neurological and cytological disorders, putatively associated with pro-oxidant and apoptotic effects. Yeast adaptation to sub-inhibitory concentrations of MZ has been correlated with oxidative response, proteins degradation, and energy metabolism, and its main effect on yeast has been attributed to its high reactivity with thiol groups in proteins. Herein, we show that acute MZ treatments on aerobic exponentially growing yeast of wild type (BY4741) and deletion mutant strains, coupled with multiplex flow cytometry analysis, conclusively demonstrated that MZ displays the typical features of pro-oxidant activity on Saccharomyces, elevating mitochondrial ROS, and causing hyper-polarization of mitochondrial membranes leading to apoptosis. A drastic reduction of cellular viability associated with the maintenance of cell membrane integrity, as well as phosphatidyl serine externalization on yeast cells exposed to MZ, also supports an apoptotic mode of action. Moreover, abrogation of the apoptotic response in yca1 deficient mutants indicates that metacaspase-1 is involved in the programmed cell death mechanism induced by MZ in yeast.

  3. RTP801 regulates maneb- and mancozeb-induced cytotoxicity via NF-κB.

    PubMed

    Cheng, Shu-Yuan; Oh, Seon; Velasco, Marcela; Ta, Christine; Montalvo, Jessica; Calderone, Alyssa

    2014-07-01

    Environmental factors have been implicated in the pathogenesis of neurodegenerative diseases. Maneb (MB) and mancozeb (MZ) have been extensively used as pesticides. Exposure to MB lowers the threshold for dopaminergic damage triggered by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. MB and MZ potentiate 1-methyl-4-phenylpyridium (MPP(+))-induced cytotoxicity in rat pheochromocytoma (PC12) cells partially via nuclear factor kappa B (NF-κB) activation. RTP801 dramatically increased by oxidative stresses and DNA damage is the possible mechanism of neurotoxins-induced cell death in many studies. This study demonstrated that MB and MZ induced DNA damage as seen in comet assay. The expressions of RTP801 protein and mRNA were elevated after MB and MZ exposures. By knocking down RTP801 using shRNA, we demonstrated that NF-κB activation by MB and MZ was regulated by RTP801 and cell death triggered by MB and MZ was associated with RTP801 elevation. This revealed that the toxic mechanisms of dithiocarbamates are via the cross talk between RTP801 and NF-κB.

  4. Pyrithione, a zinc ionophore, inhibits NF-kappaB activation.

    PubMed

    Kim, C H; Kim, J H; Moon, S J; Chung, K C; Hsu, C Y; Seo, J T; Ahn, Y S

    1999-06-16

    Pyrrolidine dithiocarbamate (PDTC) suppresses NF-kappaB activity and exhibits cytotoxic effects in bovine cerebral endothelial cells (BCECs), and we have previously reported that these PDTC effects were accompanied by an increase in intracellular zinc levels. To further explore the role of zinc in the modulation of NF-kappaB activation, we studied the effect of pyrithione, a zinc ionophore, on NF-kappaB activation in BCECs. Pyrithione inhibited NF-kappaB activity in a time- and dose-dependent manner. Ca-EDTA, but not Zn-EDTA, prevented pyrithione inhibition of NF-kappaB activity. Pyrithione increased the intracellular zinc level within 15 min. This effect was also abolished by Ca-EDTA, but not by Zn-EDTA. The potency of pyrithione on NF-kappaB inhibition and zinc influx was approximately one order of magnitude more potent than PDTC. These findings establish the regulatory role of intracellular zinc levels on NF-kappaB activity in BCECs.

  5. Antiviral activity of the zinc ionophores pyrithione and hinokitiol against picornavirus infections.

    PubMed

    Krenn, B M; Gaudernak, E; Holzer, B; Lanke, K; Van Kuppeveld, F J M; Seipelt, J

    2009-01-01

    We have discovered two metal ion binding compounds, pyrithione (PT) and hinokitiol (HK), that efficiently inhibit human rhinovirus, coxsackievirus, and mengovirus multiplication. Early stages of virus infection are unaffected by these compounds. However, the cleavage of the cellular eukaryotic translation initiation factor eIF4GI by the rhinoviral 2A protease was abolished in the presence of PT and HK. We further show that these compounds inhibit picornavirus replication by interfering with proper processing of the viral polyprotein. In addition, we provide evidence that these structurally unrelated compounds lead to a rapid import of extracellular zinc ions into cells. Imported Zn(2+) was found to be localized in punctate structures, as well as in mitochondria. The observed elevated level of zinc ions was reversible when the compounds were removed. As the antiviral activity of these compounds requires the continuous presence of the zinc ionophore PT, HK, or pyrrolidine-dithiocarbamate, the requirement for zinc ions for the antiviral activity is further substantiated. Therefore, an increase in intracellular zinc levels provides the basis for a new antipicornavirus mechanism.

  6. IFN-γ regulates human dental pulp stem cells behavior via NF-κB and MAPK signaling

    PubMed Central

    He, Xinyao; Jiang, Wenkai; Luo, Zhirong; Qu, Tiejun; Wang, Zhihua; Liu, Ningning; Zhang, Yaqing; Cooper, Paul R.; He, Wenxi

    2017-01-01

    During caries, dental pulp expresses a range of pro-inflammatory cytokines in response to the infectious challenge. Interferon gamma (IFN-γ) is a dimerized soluble cytokine, which is critical for immune responses. Previous study has demonstrated that IFN-γ at relative high concentration (100 ng/mL) treatment improved the impaired dentinogenic and immunosuppressive regulatory functions of disease-derived dental pulp stem cells (DPSCs). However, little is known about the regulatory effects of IFN-γ at relative low concentration on healthy DPSC behavior (including proliferation, migration, and multiple-potential differentiation). Here we demonstrate that IFN-γ at relatively low concentrations (0.5 ng/mL) promoted the proliferation and migration of DPSCs, but abrogated odonto/osteogenic differentiation. Additionally, we identified that NF-κB and MAPK signaling pathways are both involved in the process of IFN-γ-regulated odonto/osteogenic differentiation of DPSCs. DPSCs treated with IFN-γ and supplemented with pyrrolidine dithiocarbamate (PDTC, an NF-κB inhibitor) or SB203580 (a MAPK inhibitor) showed significantly improved potential for odonto/osteogenic differentiation of DPSCs both in vivo and in vitro. These data provide important insight into the regulatory effects of IFN-γ on the biological behavior of DPSCs and indicate a promising therapeutic strategy for dentin/pulp tissue engineering in future endodontic treatment. PMID:28098169

  7. Anti-inflammatory and Antiosteoporosis Flavonoids from the Rhizomes of Helminthostachys zeylanica.

    PubMed

    Huang, Yu-Ling; Shen, Chien-Chang; Shen, Yuh-Chiang; Chiou, Wen-Fei; Chen, Chien-Chih

    2017-02-24

    Chemical investigation of the rhizomes of Helminthostachys zeylanica led to the isolation of eight new flavonoids including six cyclized geranylflavonoids, ugonins V-X (1-3), (10R,11S)-ugonin N (4), (10R,11S)-ugonin S (5), and ugonin Y (6), as well as two quercetin glucosides, quercetin-4'-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranoside (7) and quercetin-3-O-β-d-glucopyranosyl-4'-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranoside (8). The structures of these compounds were established by spectroscopic analyses and acid hydrolysis of the sugar moiety. Among the isolated compounds, 1, 2, 5, 6, ugonins J-S (9-13), ugonstilbene A (14), and ugonin L (23) were evaluated for their anti-inflammatory activity on lipopolysaccharide-induced nitric oxide (NO) production in microglial cells. Except for 1, 5, and 13, all other compounds inhibited NO production with IC50 values of 6.2-10.1 μM and were more potent than the positive control, pyrrolidine dithiocarbamate. Compounds 1, 2, 5, 6, and 10-13 were tested for antiosteoporotic activities, and ugonin K (10) exhibited the highest inhibitory activity against RANKL-induced osteoclast differentiation in RAW264.7 cells with an IC50 value of 1.8 ± 0.2 μM.

  8. Genetic depletion of glutathione peroxidase-1 potentiates nephrotoxicity induced by multiple doses of cocaine via activation of angiotensin II AT1 receptor.

    PubMed

    Mai, Huynh Nhu; Chung, Yoon Hee; Shin, Eun-Joo; Kim, Dae-Joong; Jeong, Ji Hoon; Nguyen, Thuy-Ty Lan; Nam, Yunsung; Lee, Yu Jeung; Nah, Seung-Yeol; Yu, Dae-Yeul; Jang, Choon-Gon; Ho, Ye-Shih; Lei, Xin Gen; Kim, Hyoung-Chun

    2016-01-01

    We investigated the possible roles of angiotensin II type 1 receptor (AT1R) and oxidative stress responsive nuclear factor κB (NFκB) in renal damage caused by multiple doses of cocaine in glutathione peroxidase (GPx)-1 gene-depleted mice. Treatment with cocaine resulted in significant increases in malondialdehyde, protein carbonyl, and pro-apoptotic Bax expression and decreases in the ratio of glutathione (GSH) and its oxidized form (GSSG), GSH-dependent enzymes, and anti-apoptotic factors in the kidney. These alterations were more pronounced in GPx-1 knockout (-/-) mice than in wild type (WT) mice. Notably, the AT1R antagonist losartan protected against the renal toxicity induced by cocaine, whereas the NFκB inhibitor pyrrolidine dithiocarbamate was not protective. The toxicity was more pronounced in GPx-1 (-/-) mice than in WT mice. The protective effect afforded by losartan against cocaine toxicity appeared to be more sensitive in GPx-1 (-/-) mice than that in WT mice. These losartan-mediated protective effects were inhibited by the phosphatidyl-inositol-3-kinase (PI3K) inhibitor LY294002, indicating that losartan provides significant protection from cocaine-induced renal toxicity through PI3K/Akt signaling. Our results suggest that genetic inhibition of GPx-1 potentiates cocaine-induced renal damage via activation of AT1R by inhibition of PI3K-Akt signaling, and that AT1R can be a therapeutic target against renal toxicity induced by cocaine.

  9. Method of bonding functional surface materials to substrates and applications in microtechnology and anti-fouling

    DOEpatents

    Feng, Xiangdong; Liu, Jun; Liang, Liang

    2001-01-01

    A simple and effective method to bond a thin coating of poly(N-isopropylacylamide) (NIPAAm) on a glass surface by UV photopolymerization, and the use of such a coated surface in nano and micro technology applications. A silane coupling agent with a dithiocarbamate group is provided as a photosensitizer preferably, (N,N'-diethylamine) dithiocarbamoylpropyl-(trimethoxy) silane (DATMS). The thiocarbamate group of the sensitizer is then bonded to the glass surface by coupling the silane agent with the hydroxyl groups on the glass surface. The modified surface is then exposed to a solution of NIPAAm and a crosslinking agent which may be any organic molecule having an acrylamide group and at least two double bonds in its structure, such as N, N'-methylenebisacrylamide, and a polar solvent which may be any polar liquid which will dissolve the monomer and the crosslinking agent such as acetone, water, ethanol, or combinations thereof. By exposing the glass surface to a UV light, free radicals are generated in the thiocarbamate group which then bonds to the crosslinking agent and the NIPAAm. Upon bonding, the crosslinking agent and the NIPAAm polymerize to form a thin coating of PNIPAAm bonded to the glass. Depending upon the particular configuration of the glass, the properties of the PNIPAAm allow applications in micro and nano technology.

  10. Method of bonding functional surface materials to substrates and applications in microtechnology and antifouling

    DOEpatents

    Feng, Xiangdong; Liu, Jun; Liang, Liang

    1999-01-01

    A simple and effective method to bond a thin coating of poly(N-isopropylacylamide) (NIPAAm) on a glass surface by UV photopolymerization, and the use of such a coated surface in nano and micro technology applications. A silane coupling agent with a dithiocarbamate group is provided as a photosensitizer, preferably, (N,N'-diethylamine)dithiocarbamoylpropyl-(trimethoxy)silane (DATMS). The thiocarbamate group of the sensitizer is then bonded to the glass surface by coupling the silane agent with the hydroxyl groups on the glass surface. The modified surface is then exposed to a solution of NIPAAm and a crosslinking agent which may be any organic molecule having an acrylamide group and at least two double bonds in its structure, such as N,N'-methylenebisacrylamide, and a polar solvent which may be any polar liquid which will dissolve the monomer and the crosslinking agent such as acetone, water, ethanol, or combinations thereof. By exposing the glass surface to a UV light, free radicals are generated in the thiocarbamate group which then bonds to the crosslinking agent and the NIPAAm. Upon bonding, the crosslinking agent and the NIPAAm polymerize to form a thin coating of PNIPAAm bonded to the glass. Depending upon the particular configuration of the glass, the properties of the PNIPAAm allow applications in micro and nano technology.

  11. Stimulatory effects of insulin-like growth factor-I on growth plate chondrogenesis are mediated by nuclear factor-kappaB p65.

    PubMed

    Wu, Shufang; Fadoju, Doris; Rezvani, Geoffrey; De Luca, Francesco

    2008-12-05

    Insulin-like growth factor-I (IGF-I) is an important regulator of endochondral ossification. However, little is known about the signaling pathways activated by IGF-I in growth plate chondrocytes. We have previously shown that NF-kappaB-p65 facilitates growth plate chondrogenesis. In this study, we first cultured rat metatarsal bones with IGF-I and/or pyrrolidine dithiocarbamate (PDTC), a known NF-kappaB inhibitor. The IGF-I-mediated stimulation of metatarsal growth and growth plate chondrogenesis was neutralized by PDTC. In rat growth plate chondrocytes, IGF-I induced NF-kappaB-p65 nuclear translocation. The inhibition of NF-kappaB-p65 expression and activity (by p65 short interfering RNA and PDTC, respectively) in chondrocytes reversed the IGF-I-mediated induction of cell proliferation and differentiation and the IGF-I-mediated prevention of cell apoptosis. Moreover, the inhibition of the phosphatidylinositol 3-kinase and Akt abolished the effects of IGF-I on NF-kappaB activation. In conclusion, our findings indicate that IGF-I stimulates growth plate chondrogenesis by activating NF-kappaB-p65 in chondrocytes.

  12. Effects of NF-κB and hypoxia on the biological behavior of Y79 retinoblastoma cells

    PubMed Central

    Li, Peng; Li, Zhaohui

    2015-01-01

    We aimed to investigate the influence of nuclear factor-κB (NF-κB) on the biological behavior of Y79 retinoblastoma cells exposed to hypoxia and its possible mechanism. The cells were administrated with hypoxia, and/or 5 μM pyrrolidine dithiocarbamate (PDTC) (a selective NF-κB inhibitor) to inhibit the NF-κB activity, expressions of NF-κB was measured by western blot, and the translocation of NF-κB was detected. To examine the proliferation of Y79 cells, MTT assay was applied. Transwell assay was used to detect the invasion and migration ability of cells. The expressions of molecules involved in invasion was analyzed including HIF-1α, MMP-2, 9, and VEGF. We found that hypoxia significantly activated NF-κB activity. While once the NF-κB was inhibited, the proliferation, invasion and migration ability of Y79 cells were also blocked. Interestingly, the expressions of invasion-involved molecules elevated by hypoxia induction were also decreased when NF-κB was inhibited. Hypoxia could significantly change the adhesive and invasive ability of Y79 retinoblastoma cells, NF-κB signal might be one of the main mediators for these hypoxia induced cell changes of biological behavior via downregulation of HIF-1α and the invasion related molecules, and the mechanism still needs further investigation. PMID:25973060

  13. Disulfiram induces copper-dependent stimulation of reactive oxygen species and activation of the extrinsic apoptotic pathway in melanoma.

    PubMed

    Morrison, Brian W; Doudican, Nicole A; Patel, Kirtesh R; Orlow, Seth J

    2010-02-01

    Melanoma is the most aggressive and deadly form of skin cancer. The current standard of care produces response rates of less than 20%, underscoring the critical need for identification of new effective, nontoxic therapies. Disulfiram (DSF) was identified using a drug screen as one of the several compounds that preferentially decreased proliferation in multiple melanoma subtypes compared with benign melanocytes. DSF, a member of the dithiocarbamate family, is a copper (Cu) chelator, and Cu has been shown previously to enhance DSF-mediated growth inhibition and apoptosis in cancer cells. Here, we report that in the presence of free Cu, DSF inhibits cellular proliferation and induces apoptosis in a panel of cell lines representing primary and metastatic nodular and superficial spreading melanoma. Both decreased cellular proliferation and increased apoptosis were seen at 50-500 nmol/l DSF concentrations that are achievable through oral dosing of the medication. In the presence of Cu, DSF caused activation of the extrinsic pathway of apoptosis as measured by caspase-8 cleavage. The addition of Z-IETD-FMK, a selective caspase-8 inhibitor, was protective against DSF-Cu-induced apoptosis. Production of reactive oxygen species (ROS) in response to DSF-Cu treatment preceded the induction of apoptosis. Both ROS production and apoptosis were prevented by coincubation of N-acetyl cysteine, a free radical scavenger. Our study shows that DSF might be used to target both nodular and superficial spreading melanoma through ROS production and activation of the extrinsic pathway of apoptosis.

  14. Environmental effects of supplemental wood preservative treatments of electric utility poles. Final report

    SciTech Connect

    Horn, M.E.

    1995-12-01

    A field study and associated risk assessment was conducted to evaluate the potential ecological and human health impacts related to the standard application of five supplemental wood preservatives to 20 electric utility transmission poles. Post-application monitoring for chemical residuals and microbiological effects was conducted over a 17 month post-application period (June 6, 1990--November 7, 1991). The utility wood poles in the study were located in wetland sites of the New York State Adirondack Park. All poles were western red cedar and all had been treated with pentachlorophenol (PCP) prior to installation. At the time supplemental preservatives were applied, the poles had been in service for approximately 40 years. Groundwater, surface water, and soil around each treated pole were monitored for release of active ingredients, organic carriers and subsequent degradation products of the commercial wood preservatives. The analytes were as follows: chlorpyrifos, 1,1,1-trichloroethane, creosote, 2,4-dinitrophenol, fluoride, chromium, arsenic, copper, naphthenate, sodium methyl dithiocarbamate and methyl isothiocyanate. Ecological response to chemical exposure was estimated by means of measuring soil gases (carbon dioxide and methane), soil macroinvertebrate populations and soil microbial biomass. Results from near-pole post-treatment sampling were compared to pre-treatment samples and reference plots used to establish preapplication biological conditions and background levels of wood preservative constituents.

  15. Synthesis, crystal structure and photoconductivity of the first [60]fullerene complex with metal diethyldithiocarbamate: {CuII(dedtc)2}2.C60.

    PubMed

    Konarev, Dmitri V; Kovalevsky, Andrey Y; Lopatin, Dmitri V; Umrikhin, Alexey V; Yudanova, Evgeniya I; Coppens, Philip; Lyubovskaya, Rimma N; Saito, Gunzi

    2005-05-21

    The first molecular complex of fullerene C60 with metal dithiocarbamate, namely, {CuII(dedtc)2}2.C60(dedtc: diethyldithiocarbamate) (1) was obtained as single crystals. Butterfly-shaped CuII(dedtc)2 molecules efficiently co-crystallized with spherical fullerene molecules to form a layered structure, in which closely packed hexagonal C60 layers alternate with the layers composed of CuII(dedtc)2 dimers. The formation of the complex with C60 changes geometry and the EPR spectrum of starting CuII(dedtc)2. Magnetic susceptibility of 1 follows the Curie-Weiss law in the 300-1.9 K range with the negative Weiss constant of -2.5 K showing a weak antiferromagnetic interaction between CuII centers in the dimers. The crystals of 1 have low dark conductivity of 10(-11) S cm-1, which is consistent with a neutral ground state of the complex. Illumination of the crystals by white light increases the photocurrent by 20-50 times. The photoconductivity spectrum of 1 has a maximum at 470 nm showing that both intermolecular charge transfer between neighboring C60 molecules and photoexcitation of CuII(dedtc)2 can contribute to photogeneration of free charge carriers. The effect of a weak magnetic field with Bo<0.5 T on the photoconductivity of 1 has been found.

  16. Toxicity Assessment of Expired Pesticides to Green Algae Pseudokirchneriella subcapitata

    PubMed Central

    Satyavani, G.; Chandrasehar, G.; Varma, K. Krishna; Goparaju, A.; Ayyappan, S.; Reddy, P. Neelakanta; Murthy, P. Balakrishna

    2012-01-01

    In order to investigate the effect of expired pesticides on the yield and growth rate of green algae Pseudokirchneriella subcapitata, a study was conducted as per the Organisation for Economic Cooperation and Development (OECD) guideline number 201. Fifteen expired pesticide formulations, most commonly used in Indian agriculture, were tested in comparison with their unexpired counterparts. The expired pesticide formulations studied belonged to various class and functional groups: organophosphate, pyrethroid-based insecticides; azole-based fungicides; acetamide, propionate, acetic acid-based herbicides; fungicides mixtures containing two actives—azole and dithiocarbamate. The toxicity endpoints of yield (EyC50: 0–72 h) and growth rate (ErC50: 0–72 h) of Pseudokirchneriella subcapitata for each pesticide formulation (both expired and unexpired pesticides) were determined statistically using TOXSTAT 3.5 version software. The results pointed out that some expired pesticide formulations exhibited higher toxicity to tested algal species, as compared to the corresponding unexpired pesticides. These data thus stress the need for greater care to dispose expired pesticides to water bodies, to avoid the effects on aquatic ecospecies tested. PMID:23762633

  17. Speciation of very low amounts of arsenic and antimony in waters using dispersive liquid-liquid microextraction and electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Rivas, Ricardo E.; López-García, Ignacio; Hernández-Córdoba, Manuel

    2009-04-01

    A new procedure for the determination of inorganic arsenic (III,V) and antimony (III,V) in water samples by dispersive liquid-liquid micro extraction separation and electrothermal atomic absorption spectrometry (ETAAS) is presented. At pH 1, As(III) and Sb(III) are complexed with ammonium pyrrolidine dithiocarbamate and extracted into the fine droplets formed when mixing carbon tetrachloride (extraction solvent), methanol (disperser solvent) and the sample solution. After extraction, the phases are separated by centrifugation, and As(III) and Sb(III) are determined in the organic phase. As(V) and Sb(V) remain in the aqueous layer. Total inorganic As and Sb are determined after the reduction of the pentavalent forms with sodium thiosulphate. As(V) and Sb(V) are calculated by difference. The detection limits are 0.01 and 0.05 µg L - 1 for As(III) and Sb(III), respectively, with an enrichment factor of 115. The relative standard deviation is in the 2.9-4.5% range. The procedure has been applied to the speciation of inorganic As and Sb in bottled, tap and sea water samples with satisfactory results.

  18. Abnormal sperm morphology in mouse germ cells after short-term exposures to acetamiprid, propineb, and their mixture.

    PubMed

    Rasgele, Pinar Göç

    2014-03-01

    Pesticides are one of the most potent environmental contaminants, which accumulate in biotic and abiotic components of ecosystems. Acetamiprid (Acm), a neonicotinoid insecticide, and Propineb (Pro), a dithiocarbamate fungicide, are widely used to control sucking insects and fungal infections on crops, respectively. The present study was undertaken to investigate the genotoxic effects of these compounds, individually and in mixtures, in mouse germ cells by using the sperm morphology assay. Mice were injected intraperitoneally with 0.625, 1.25, and 2.50 μg mL⁻¹ of Acm, 12.5, 25, and 50 μg mL⁻¹ of Pro, and their mixture at the same concentrations over 24 and 48 h. Acm did not significantly increase the percentage of abnormal sperm at any concentration. The frequency of abnormal sperm significantly increased after 24 and 48 h of exposure to 50 μg mL⁻¹ of Pro. The mixtures of 2.50 μg mL⁻¹ of Acm and 50 μg mL⁻¹ of Pro induced sperm abnormalities antagonistically both after 24 and 48 h of exposure. Results suggest that Acm was non-genotoxic for mouse germ cells, while Pro may have been a germ cell mutagen due to the observed increase in the frequency of sperm abnormalities. However, to gain better insight into the mutagenicity and DNA damaging potential of both of these pesticides, further studies at molecular level should be done.

  19. A roadmap to uranium ionic liquids: Anti-crystal engineering

    SciTech Connect

    Yaprak, Damla; Spielberg, Eike T.; Bäcker, Tobias; Richter, Mark; Mallick, Bert; Klein, Axel; Mudring, Anja -Verena

    2014-04-15

    In the search for uranium-based ionic liquids, tris(N,N-dialkyldithiocarbamato)uranylates have been synthesized as salts of the 1-butyl-3-methylimidazolium (C4mim) cation. As dithiocarbamate ligands binding to the UO22+ unit, tetra-, penta-, hexa-, and heptamethylenedithiocarbamates, N,N-diethyldithiocarbamate, N-methyl-N-propyldithiocarbamate, N-ethyl-N-propyldithiocarbamate, and N-methyl-N-butyldithiocarbamate have been explored. X-ray single-crystal diffraction allowed unambiguous structural characterization of all compounds except N-methyl-N-butyldithiocarbamate, which is obtained as a glassy material only. In addition, powder X-ray diffraction as well as vibrational and UV/Vis spectroscopy, supported by computational methods, were used to characterize the products. Differential scanning calorimetry was employed to investigate the phase-transition behavior depending on the N,N-dialkyldithiocarbamato ligand with the aim to establish structure–property relationships regarding the ionic liquid formation capability. Compounds with the least symmetric N,N-dialkyldithiocarbamato ligand and hence the least symmetric anions, tris(N-methyl-N-propyldithiocarbamato)uranylate, tris(N-ethyl-N-propyldithiocarbamato)uranylate, and tris(N-methyl-N-butyldithiocarbamato)uranylate, lead to the formation of (room-temperature) ionic liquids, which confirms that low-symmetry ions are indeed suitable to suppress crystallization. As a result, these materials combine low melting points, stable complex formation, and hydrophobicity and are therefore excellent candidates for nuclear fuel purification and recovery.

  20. A roadmap to uranium ionic liquids: Anti-crystal engineering

    DOE PAGES

    Yaprak, Damla; Spielberg, Eike T.; Bäcker, Tobias; ...

    2014-04-15

    In the search for uranium-based ionic liquids, tris(N,N-dialkyldithiocarbamato)uranylates have been synthesized as salts of the 1-butyl-3-methylimidazolium (C4mim) cation. As dithiocarbamate ligands binding to the UO22+ unit, tetra-, penta-, hexa-, and heptamethylenedithiocarbamates, N,N-diethyldithiocarbamate, N-methyl-N-propyldithiocarbamate, N-ethyl-N-propyldithiocarbamate, and N-methyl-N-butyldithiocarbamate have been explored. X-ray single-crystal diffraction allowed unambiguous structural characterization of all compounds except N-methyl-N-butyldithiocarbamate, which is obtained as a glassy material only. In addition, powder X-ray diffraction as well as vibrational and UV/Vis spectroscopy, supported by computational methods, were used to characterize the products. Differential scanning calorimetry was employed to investigate the phase-transition behavior depending on the N,N-dialkyldithiocarbamato ligand with the aim tomore » establish structure–property relationships regarding the ionic liquid formation capability. Compounds with the least symmetric N,N-dialkyldithiocarbamato ligand and hence the least symmetric anions, tris(N-methyl-N-propyldithiocarbamato)uranylate, tris(N-ethyl-N-propyldithiocarbamato)uranylate, and tris(N-methyl-N-butyldithiocarbamato)uranylate, lead to the formation of (room-temperature) ionic liquids, which confirms that low-symmetry ions are indeed suitable to suppress crystallization. As a result, these materials combine low melting points, stable complex formation, and hydrophobicity and are therefore excellent candidates for nuclear fuel purification and recovery.« less

  1. Fabrication of cube-like Fe3O4@SiO2@Ag nanocomposites with high SERS activity and their application in pesticide detection

    NASA Astrophysics Data System (ADS)

    Li, Lei; Zhao, Aiwu; Wang, Dapeng; Guo, Hongyan; Sun, Henghui; He, Qinye

    2016-07-01

    The cube-like Fe3O4@SiO2@Ag (FSA) nanocomposites with great SERS activity have been successfully synthesized by a layer-by-layer procedure in this paper. The cube-like Fe3O4@SiO2 core-shell structures were prepared via a new route and Ag nanoparticles were introduced onto their surface through a one-pot hydrothermal reaction. By controlling the reaction time, the coverage rate of Ag on the FSA surface could be tuned, and then a series of FSA composites were obtained. The SERS properties of these FSA composites were investigated using p-aminothiophenol ( p-ATP) as the probe molecule. It was found that the FSA composites synthesized with a reaction time of 6 h showed the best SERS performance, and the detection limit for p-ATP could reach 1 × 10-7 M. For practical application, the FSA composites were also used to detect thiram, one of the dithiocarbamate fungicides that has been widely used as a pesticide in agriculture. The detection limit is as low as 1 × 10-6 M (0.24 ppm), lower than the maximal residue limit of 7 ppm in fruit prescribed by the US Environmental Protection Agency. The resulting substrate with high SERS activity, stability and strong magnetic responsivity makes the FSA composite a perfect choice for practical SERS detection applications.

  2. Small GTPases and Stress Responses of vvran1 in the Straw Mushroom Volvariella volvacea

    PubMed Central

    Yan, Jun-Jie; Xie, Bin; Zhang, Lei; Li, Shao-Jie; van Peer, Arend F.; Wu, Ta-Ju; Chen, Bing-Zhi; Xie, Bao-Gui

    2016-01-01

    Small GTPases play important roles in the growth, development and environmental responses of eukaryotes. Based on the genomic sequence of the straw mushroom Volvariella volvacea, 44 small GTPases were identified. A clustering analysis using human small GTPases as the references revealed that V. volvacea small GTPases can be grouped into five families: nine are in the Ras family, 10 are in the Rho family, 15 are in the Rab family, one is in the Ran family and nine are in the Arf family. The transcription of vvran1 was up-regulated upon hydrogen peroxide (H2O2) stress, and could be repressed by diphenyleneiodonium chloride (DPI), a NADPH oxidase-specific inhibitor. The number of vvran1 transcripts also increased upon cold stress. Diphenyleneiodonium chloride, but not the superoxide dismutase (SOD) inhibitor diethy dithiocarbamate (DDC), could suppress the up-regulation of vvran1 gene expression to cold stress. These results combined with the high correlations between gene expression and superoxide anion (O2−) generation indicated that vvran1 could be one of the candidate genes in the downstream of O2− mediated pathways that are generated by NADPH oxidase under low temperature and oxidative stresses. PMID:27626406

  3. Synthesis and evaluation of glycopolymeric decorated gold nanoparticles functionalized with gold-triphenyl phosphine as anti-cancer agents.

    PubMed

    Adokoh, Christian K; Quan, Stephen; Hitt, Mary; Darkwa, James; Kumar, Piyush; Narain, Ravin

    2014-10-13

    In this study, statistical glyco-dithiocarbamate (DTC) copolymers were synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT) and subsequently used to prepare glyconanoparticles and conjugated glyconanoparticles with the anticancer drug, gold(I) triphenylphosphine. These glyconanoparticles and the corresponding conjugates were then tested for their in vitro cytotoxicity in both normal and cancer cell lines using Neutral Red assay. The glyconanoparticles and their Au(I)PPh3 conjugates were all active against MCF7 and HepG2 cells, but galactose-functionalized glyconanoparticles {P(GMA-EDAdtc(AuPPh3)-st-LAEMA)AuNP} were found to be the most cytotoxic to HepG2 cells (IC50 ∼ 4.13 ± 0.73 μg/mL). The p(GMA-EDAdtc(AuPPh3)-st-LAEMA)AuNP was found to be a 4-fold more potent antitumor agent in HepG2 cells, and the overexpressed asialoglycoprotein (ASGPR) receptors revealed to play an important role in the cytotoxicity, presumably by the enhanced uptake. In addition, the glyconanoparticles Au(I) conjugates are found to be significantly more toxic as compared to the standard chemotherapeutic reagents such as cisplatin and cytarabine.

  4. Our recent experiences with sarin poisoning cases in Japan and pesticide users with references to some selected chemicals.

    PubMed

    Yokoyama, Kazuhito

    2007-03-01

    Attention has been paid to neurobehavioral effects of occupational and environmental exposures to chemicals such as pesticides, heavy metals and organic solvents. The area of research that includes neurobehavioral methods and effects in occupational and environmental health has been called "Occupational and Environmental Neurology and Behavioral Medicine." The methods, by which early changes in neurological, cognitive and behavioral function can be assessed, include neurobehavioral test battery, neurophysiological methods, questionnaires and structured interview, biochemical markers and imaging techniques. The author presents his observations of neurobehavioral and neurophysiological effects in Tokyo subway sarin poisoning cases as well as in pesticide users (tobacco farmers) in Malaysia in relation to Green Tobacco Sickness (GTS). In sarin cases, a variety effects were observed 6-8 months after exposure, suggesting delayed neurological effects. Studies on pesticide users revealed that organophosphorus and dithiocarbamate affected peripheral nerve conduction and postural balance; subjective symptoms related to GTS were also observed, indicating the effects of nicotine absorbed from wet tobacco leaves. In addition, non-neurological effects of pesticides and other chemicals are presented, in relation to genetic polymorphism and oxidative stress.

  5. Pesticide residues in cashew apple, guava, kaki and peach: GC-μECD, GC-FPD and LC-MS/MS multiresidue method validation, analysis and cumulative acute risk assessment.

    PubMed

    Jardim, Andréia Nunes Oliveira; Mello, Denise Carvalho; Goes, Fernanda Caroline Silva; Frota Junior, Elcio Ferreira; Caldas, Eloisa Dutra

    2014-12-01

    A multiresidue method for the determination of 46 pesticides in fruits was validated. Samples were extracted with acidified ethyl acetate, MgSO4 and CH3COONa and cleaned up by dispersive SPE with PSA. The compounds were analysed by GC-FPD, GC-μECD or LC-MS/MS, with LOQs from 1 to 8 μg/kg. The method was used to analyse 238 kaki, cashew apple, guava, and peach fruit and pulp samples, which were also analysed for dithiocarbamates (DTCs) using a spectrophotometric method. Over 70% of the samples were positive, with DTC present in 46.5%, λ-cyhalothrin in 37.1%, and omethoate in 21.8% of the positive samples. GC-MS/MS confirmed the identities of the compounds detected by GC. None of the pesticides found in kaki, cashew apple and guava was authorised for these crops in Brazil. The risk assessment has shown that the cumulative acute intake of organophosphorus or pyrethroid compounds from the consumption of these fruits is unlikely to pose a health risk to consumers.

  6. Cytogenetic and microtubule array effects of the zineb-containing commercial fungicide formulation Azzurro(®) on meristematic root cells of Allium cepa L.

    PubMed

    Andrioli, Nancy B; Soloneski, Sonia; Larramendy, Marcelo L; Mudry, Marta D

    2012-02-18

    Zineb [ethylene bis(dithiocarbamate) zinc] is a widely employed foliar fungicide for agricultural and industrial applications. Allium cepa L. is a reliable model for the assessment of xenobiotic genotoxicity and cytotoxicity. We evaluated the effects of the zineb-containing commercial formulation Azzurro(®) (70% zineb) in cell cycle stages of the meristem root cells of A. cepa. The mitotic index (MI), chromosomal aberrations at anaphase/telophase (CAs), micronuclei (MN), and abnormalities in immunodetected microtubule structures, e.g., preprophasic band (PPB), mitotic spindle (MS), and phragmoplast (Phrag), were used as end-points. Azzurro(®) (1 and 10μg/ml) induced a significant increase in the frequency of CAs (P<0.05), and the higher concentration inhibited the MI (P<0.05) compared to control values. The frequency of MN did not differ from control values at any concentration. Treatment with 1μg/ml Azzurro(®) induced a significant increase in the frequency of abnormal PPB (P<0.01), MS (P<0.001), and Phrag (P<0.01) and, at 10μg/ml, enhancements in the frequencies of abnormal MS (P<0.05) and Phrag (P<0.05) were seen. A tubulin immunodetection assay showed that exposure to Azzurro(®) interferes with normal assembly of microtubule structures during mitosis.

  7. Synthesis, characterization, cytotoxicity and antimicrobial studies on bis(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S')zinc(II) and its nitrogen donor adducts.

    PubMed

    Rani, Palanisamy Jamuna; Thirumaran, Subbiah

    2013-04-01

    [Zn(fpedtc)2] (1), [Zn(fpedtc)2(py)] (2), [Zn(fpedtc)2(1,10-phen)] (3) and [Zn(fpedtc)2(2,2'-bipy)] (4) (where fpedtc = N-furfuryl-N-(2-phenylethyl)dithiocarbamate, py = pyridine, 1,10-phen = 1,10-phenanthroline and 2,2'-bipy = 2,2'-bipyridine) were synthesized. Characterization of the complexes were achieved by IR and NMR ((1)H and (13)C) spectra and in addition, for 2 and 3, by X-ray crystallography. Single crystal X-ray structural analysis of 2 and 3 showed that complex 2 is almost half way between trigonal bipyramidal and square pyramidal and complex 3 has a distorted octahedral geometry. Zn-N distances in 2 is shorter than that found in a six coordinate complex 3 due to the change in coordination number. These complexes were also screened for in vitro antibacterial and antifungal activities and significant activities have been found. In vitro cytotoxic activity of all the synthesized complexes was evaluated on HeLa cell line. Complex 1 exhibits maximum inhibitory effect at a concentration of 40 μg mL(-1) on HeLa cell line.

  8. Solid phase extraction of lead, cadmium and zinc on biodegradable polyhydroxybutyrate diethanol amine (PHB-DEA) polymer and their determination in water and food samples.

    PubMed

    Tuzen, Mustafa; Sahiner, Samet; Hazer, Baki

    2016-11-01

    A new biodegradable polyhydroxybutyrate diethanol amine (PHB-DEA) polymer was used as adsorbent for the sensitive and selective separation, preconcentration and determination of Pb(II), Cd(II) and Zn(II) by using atomic absorption spectrometry. Diethyl dithiocarbamate was used as chelating reagent. Analytical parameters such as pH, eluent type and its volume, flow rates of sample solution, ligand amount, sample volume were optimized. Effects of some cations, anions and transition metal ions were also investigated. Enrichment factor and relative standard deviation were found to be 100 and 3%, respectively. The limits of detection based on three times standard deviation of blanks (N=21) were found 1.05μgL(-1) for Pb(II), 0.42μgL(-1) for Cd(II) and 0.13μgL(-1) for Zn(II). Limits of quantification (10s, N=21) were found 3.47μgL(-1) for Pb(II), 1.39μgL(-1) for Cd(II) and 0.43μgL(-1) for Zn(II). Accuracy evaluation of the method was confirmed with analyses of certified reference materials (NIST SRM 1515 Apple leaves, IAEA 336 Lichen, GBW 07605 Tea). Optimized method was applied to tap water and food samples after microwave digestion method. Cadmium and lead values in some samples were found higher than legal limits.

  9. Carbon disulfide. Just toxic or also bioregulatory and/or therapeutic?

    PubMed

    DeMartino, Anthony W; Zigler, David F; Fukuto, Jon M; Ford, Peter C

    2017-01-03

    The overview presented here has the goal of examining whether carbon disulfide (CS2) may play a role as an endogenously generated bioregulator and/or has therapeutic value. The neuro- and reproductive system toxicity of CS2 has been documented from its long-term use in the viscose rayon industry. CS2 is also used in the production of dithiocarbamates (DTCs), which are potent fungicides and pesticides, thus raising concern that CS2 may be an environmental toxin. However, DTCs also have recognized medicinal use in the treatment of heavy metal poisonings as well as having potency for reducing inflammation. Three known small molecule bioregulators (SMBs) nitric oxide, carbon monoxide, and hydrogen sulfide were initially viewed as environmental toxins. Yet each is now recognized as having intricate, though not fully elucidated, biological functions at concentration regimes far lower than the toxic doses. The literature also implies that the mammalian chemical biology of CS2 has broader implications from inflammatory states to the gut microbiome. On these bases, we suggest that the very nature of CS2 poisoning may be related to interrupting or overwhelming relevant regulatory or signaling process(es), much like other SMBs.

  10. Stabilizing Agents for Calibration in the Determination of Mercury Using Solid Sampling Electrothermal Atomic Absorption Spectrometry

    PubMed Central

    Zelinková, Hana; Červenka, Rostislav; Komárek, Josef

    2012-01-01

    Tetramethylene dithiocarbamate (TMDTC), diethyldithiocarbamate (DEDTC), and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK) extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L−1 TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants. PMID:22654606

  11. Ultratrace Determination of Cr(VI) and Pb(II) by Microsample Injection System Flame Atomic Spectroscopy in Drinking Water and Treated and Untreated Industrial Effluents

    PubMed Central

    Baig, Jameel Ahmed; Kazi, Tasneem Gul; Elci, Latif; Afridi, Hassan Imran; Khan, Muhammad Irfan; Naseer, Hafiz Muhammad

    2013-01-01

    Simple and robust analytical procedures were developed for hexavalent chromium (Cr(VI)) and lead (Pb(II)) by dispersive liquid-liquid microextraction (DLLME) using microsample injection system coupled with flame atomic absorption spectrophotometry (MIS-FAAS). For the current study, ammonium pyrrolidine dithiocarbamate (APDC), carbon tetrachloride, and ethanol were used as chelating agent, extraction solvent, and disperser solvent, respectively. The effective variables of developed method have been optimized and studied in detail. The limit of detection of Cr(VI) and Pb(II) were 0.037 and 0.054 µg/L, respectively. The enrichment factors in both cases were 400 with 40 mL of initial volumes. The relative standard deviations (RSDs, n = 6) were <4%. The applicability and the accuracy of DLLME were estimated by the analysis of Cr(VI) and Pb(II) in industrial effluent wastewater by standard addition method (recoveries >96%). The proposed method was successfully applied to the determination of Cr(VI) and Pb(II) at ultratrace levels in natural drinking water and industrial effluents wastewater of Denizli. Moreover, the proposed method was compared with the literature reported method. PMID:24163779

  12. Surface-modified polystyrene beads as photografting imprinted polymer matrix for chromatographic separation of proteins.

    PubMed

    Qin, Lei; He, Xi-Wen; Zhang, Wei; Li, Wen-You; Zhang, Yu-Kui

    2009-01-30

    A new and facile fabricating method for lysozyme molecularly imprinted polymer beads (lysozyme-MIP beads) in aqueous media was presented. Mesoporous chloromethylated polystyrene beads (MCP beads) containing dithiocarbamate iniferter (initiator transfer agent terminator) were used as supports for the grafting of lysozyme imprinted copolymers with acrylamide and N,N'-methylenebisacrylamide through surface initiated living-radical polymerization (SIP). After the polymerization, a layer of lysozyme-MIP was formed on the MCP beads. The SIP allowed an efficient control of the grafting process and suppressed solution propagation. Therefore, the obtained lysozyme-MIP beads had a large quantity of well-distributed pores on the surface without any visible gel formation in solution and were more advantageous comparing with traditional MIPs which were prepared by traditionally initiated radical polymerization. The obtained composites were characterized by Fourier transform infrared spectroscopy, elemental analysis, nitrogen sorption analysis and scanning electron microscopy. Chromatographic behaviors of the column packed with lysozyme-MIP beads exhibited ability in separating lysozyme from competitive protein (bovine hemoglobin, bovine serum albumin, ovalbumin or cytochrome c) in aqueous mobile phase.

  13. Activation of IKK/NF-κB provokes renal inflammatory responses in guanylyl cyclase/natriuretic peptide receptor-A gene-knockout mice

    PubMed Central

    Das, Subhankar; Periyasamy, Ramu

    2012-01-01

    The present study was aimed at determining the consequences of the disruption of guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) gene (Npr1) on proinflammatory responses of nuclear factor kappa B, inhibitory kappa B kinase, and inhibitory kappa B alpha (NF-κB, IKK, IκBα) in the kidneys of mutant mice. The results showed that the disruption of Npr1 enhanced the renal NF-κB binding activity by 3.8-fold in 0-copy (−/−) mice compared with 2-copy (+/+) mice. In parallel, IKK activity and IκBα protein phosphorylation were increased by 8- and 11-fold, respectively, in the kidneys of 0-copy mice compared with wild-type mice. Interestingly, IκBα was reduced by 80% and the expression of proinflammatory cytokines and renal fibrosis were significantly enhanced in 0-copy mice than 2-copy mice. Treatment of 0-copy mice with NF-κB inhibitors andrographolide, pyrrolidine dithiocarbamate, and etanercept showed a substantial reduction in renal fibrosis, attenuation of proinflammatory cytokines gene expression, and significantly reduced IKK activity and IkBα phosphorylation. These findings indicate that the systemic disruption of Npr1 activates the renal NF-κB pathways in 0-copy mice, which transactivates the expression of various proinflammatory cytokines to initiate renal remodeling; however, inhibition of NF-κB pathway repairs the abnormal renal pathology in mutant mice. PMID:22318993

  14. Pesticide mass budget in a stormwater wetland.

    PubMed

    Maillard, Elodie; Imfeld, Gwenaël

    2014-01-01

    Wetlands are reactive landscape zones that provide ecosystem services, including the improvement of water quality. Field studies distinguishing pesticide degradation from retention to evaluate the sink and source functions of wetlands are scarce. This study evaluated based on a complete mass budget the partitioning, retention, and degradation of 12 pesticides in water, suspended solids, sediments, and organisms in a wetland receiving contaminated runoff. The mass budget showed the following: (i) dissolved pesticides accounted for 95% of the total load entering the wetland and the pesticide partitioning between the dissolved phase and the suspended solids varied according to the molecules, (ii) pesticides accumulated primarily in the <250 μm bed sediments during spring and late summer, and (iii) the hydrological regime or the incoming pesticide loads did not influence the pesticide dissipation, which varied according to the molecules and the wetland biogeochemical conditions. The vegetation enhanced the pesticide degradation during the vegetative phase and the pesticides were released during plant senescence. The dithiocarbamates were degraded under oxic conditions in spring, whereas glyphosate and aminomethylphosphonic acid (AMPA) degradation occurred under reducing conditions during the summer. The complete pesticide mass budget indicates the versatility of the pesticide sink and source functions of wetland systems.

  15. Diisononyl phthalate aggravates allergic dermatitis by activation of NF-kB.

    PubMed

    Kang, Jun; Song, Jing; Shen, Shiping; Li, Baizhan; Yang, Xu; Chen, Mingqing

    2016-12-20

    Several epidemiological studies have suggested a possible link between exposure to Diisononyl phthalate (DINP) and the development of allergies. These findings remain controversial since there is insufficient scientific evidence to assess the ability of DINP to influence allergic immune responses. In addition, the mechanisms behind DINP-caused allergic diseases have not been fully elucidated. In this study, Balb/c mice were orally exposed to DINP for 3 weeks and were then sensitized with fluorescein isothiocyanate (FITC). We showed that oral exposure to DINP could aggravate allergic-dermatitis-like lesions, indicated by an increase in the number of mast cells, and in increased skin edema in FITC-induced contact hypersensitivity. This deterioration was concomitant with increased total serum immunoglobulin-E and Th2 cytokines. We determined the oxidative damage and the activation of nuclear factor-kb (NF-kB). The data demonstrated that DINP could promote oxidative damage and the activation of NF-kB in the skin. The expression of thymic stromal lymphopoietin and the activation of signal transducer and activator of transcriptions 3, 5 and 6 were enhanced concomitant with exacerbated allergic dermatitis effects and the activation of NF-kB induced by DINP. These effects were alleviated by pyrollidine dithiocarbamate, an inhibitor of NF-kB. The results suggest that oral exposure to DINP aggravated allergic contact dermatitis, which was positively regulated via NF-kB.

  16. Nuclear Factor-Kappa B Activity Regulates Brain Expression of P-Glycoprotein in the Kainic Acid-Induced Seizure Rats

    PubMed Central

    Yu, Nian; Di, Qing; Liu, Hao; Hu, Yong; Jiang, Ying; Yan, Yu-kui; Zhang, Yan-fang; Zhang, Ying-dong

    2011-01-01

    This study was aimed to investigate the effect of NF-κB activity on the seizure susceptibility, brain damage, and P-gp expression in kainic acid- (KA-) induced seizure rats. Male SD rats were divided into saline control group (NS group), KA induced epilepsy group (EP group), and epilepsy group intervened with NF-κB inhibitor-pyrrolidine dithiocarbamate salt (PDTC group) or with dexamethasone (DEX group). No seizures were observed in the rats of NS group. Compared with NS group, increased P-gp expression and NF-κB activation in the rat brain of the EP group were observed after KA micro-injection. Both PDTC and DEX pre-treatment significantly increased the latency to grade III or V seizure onset compared to EP group but failed to show neuron-protective effect as the number of survival neurons didn't significantly differ from that in EP group. Furthermore, PDTC pre-treatment significantly decreased P-gp expression along with NF-κB activation in the hippocampus CA3 area and amygdala complex of rats compared with the EP group, implying that NF-κB activation involved in the seizure susceptibility and seizure induced brain P-gp over-expression. Additionally, DEX pre-treatment only decreased P-gp expression level without inhibition of NF-κB activation, suggesting NF-κB independent pathway may also participate in regulating seizure induced P-gp over-expression. PMID:21403895

  17. Urease from Helicobacter pylori is inactivated by sulforaphane and other isothiocyanates

    PubMed Central

    Fahey, Jed W.; Stephenson, Katherine K.; Wade, Kristina L.; Talalay, Paul

    2013-01-01

    Infections by Helicobacter pylori are very common, causing gastroduodenal inflammation including peptic ulcers, and increasing the risk of gastric neoplasia. The isothiocyanate (ITC) sulforaphane [SF; 1-isothiocyanato-4-(methylsulfinyl)butane] derived from edible crucifers such as broccoli is potently bactericidal against Helicobacter, including antibiotic-resistant strains, suggesting a possible dietary therapy. Gastric H. pylori infections express high urease activity which generates ammonia, neutralizes gastric acidity, and promotes inflammation. The finding that SF inhibits (inactivates) urease (jack bean and Helicobacter) raised the issue of whether these properties might be functionally related. The rates of inactivation of urease activity depend on enzyme and SF concentrations and show first order kinetics. Treatment with SF results in time-dependent increases in the ultraviolet absorption of partially purified Helicobacter urease in the 280–340 nm region. This provides direct spectroscopic evidence for the formation of dithiocarbamates between the ITC group of SF and cysteine thiols of urease. The potencies of inactivation of Helicobacter urease by isothiocyanates structurally related to SF were surprisingly variable. Natural isothiocyanates closely related to SF, previously shown to be bactericidal (berteroin, hirsutin, phenethyl isothiocyanate, alyssin, and erucin), did not inactivate urease activity. Furthermore, SF is bactericidal against both urease positive and negative H. pylori strains. In contrast, some isothiocyanates such as benzoyl-ITC, are very potent urease inactivators, but are not bactericidal. The bactericidal effects of SF and other ITC against Helicobacter are therefore not obligatorily linked to urease inactivation, but may reduce the inflammatory component of Helicobacter infections. PMID:23583386

  18. Thymoquinone chemosensitizes colon cancer cells through inhibition of NF-κB

    PubMed Central

    Zhang, Lida; Bai, Yangqiu; Yang, Yuxiu

    2016-01-01

    In the present study, the effects and molecular mechanisms of thymoquinone (TQ) on colon cancer cells were investigated. Cell viability was determined using a Cell Counting Kit-8 assay, and the results revealed that treatment with TQ significantly decreased cell viability in COLO205 and HCT116 cells in a dose-dependent manner. TQ treatment additionally sensitized COLO205 and HCT116 cells to cisplatin therapy in a concentration-dependent manner. To investigate the molecular mechanisms of TQ action, western blot analysis was used to determine the levels of phosphorylated p65 and nuclear factor-κB (NF-κB)-regulated gene products vascular endothelial growth factor (VEGF), c-Myc and B-cell lymphoma 2 (Bcl-2). The results indicated that TQ treatment significantly decreased the level of phosphorylated p65 in the nucleus, which indicated the inhibition of NF-κB activation by TQ treatment. Treatment with TQ also decreased the expression levels of VEGF, c-Myc and Bcl-2. In addition, the inhibition of NF-κB activation with a specific inhibitor, pyrrolidine dithiocarbamate, potentiated the induction of cell death and caused a chemosensitization effect of TQ in colon cancer cells. Overall, the results of the present study suggested that TQ induced cell death and chemosensitized colon cancer cells by inhibiting NF-κB signaling. PMID:27698868

  19. Mechanism of colon cancer cell apoptosis mediated by pyropheophorbide-a methylester photosensitization.

    PubMed

    Matroule, J Y; Carthy, C M; Granville, D J; Jolois, O; Hunt, D W; Piette, J

    2001-07-05

    Pyropheophorbide-a methylester (PPME) is a second generation of photosensitizers used in photodynamic therapy (PDT). We demonstrated that PPME photosensitization triggered apoptosis of colon cancer cells as measured by using several classical parameters such as DNA laddering, PARP cleavage, caspase activation and mitochondrial release of cytochrome c. Preincubation of cells with N-acetyl cysteine (NAC) or pyrolidine dithiocarbamate (PDTC) protected against apoptosis mediated by PPME photosensitization showing that reactive oxygen species (ROS) are involved as second messengers. On the other hand, photosensitization carried out in the presence of deuterium oxide (D2O) which enhances singlet oxygen (1O2) lifetime only increases necrosis without affecting apoptosis. Since PPME was localized in the endoplasmic reticulum (ER)/Golgi system and lysosomes, other messengers than ROS were tested such as calcium, Bid, Bap31, phosphorylated Bcl-2 and caspase-12 but none was clearly identified as being involved in triggering cytochrome c release from mitochondria. On the other hand, we demonstrated that the transduction pathways leading to NF-kappaB activation and apoptosis were clearly independent although NF-kappaB was shown to counteract apoptosis mediated by PPME photosensitization.

  20. Extraction of chromium(III) and chromium(VI) species from solid matrices using green solvent supercritical carbon dioxide.

    PubMed

    Wang, Joanna Shaofen; Chiu, Kong-Hwa

    2007-11-01

    Supercritical fluid extraction (SFE) provides an environmentally green technique to decontaminate chromium species from solid matrices using supercritical fluid carbon dioxide (ScCO2). Methanol and a small amount of water were found to significantly improve the extraction efficiency. The fluorinated chelating agent lithium bis(trifluoroethyl)-dithiocarbamate (LiFDDC) was effective in removing Cr ions in methanol-modified CO2 via in situ chelation/SFE technique. This paper indicates that the extraction efficiencies of Cr(III) and Cr(VI) from solid matrices can be greatly increased to more than 92% in the presence of a small amount of water, using 5% methanol-modified CO2 containing LiFDDC as an extractant. Chromium species in a wood waste sample in the form of chromated copper arsenate (CCA) can be extracted, but the extraction efficiency is not as good as expected, possibly due to the complications of the chemistry of Cr species in different oxidation states and to matrix effects.

  1. A Mechanism-based 3D-QSAR Approach for Classification ...

    EPA Pesticide Factsheets

    Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a serine residue in the enzyme active site, and their inhibitory potency depends largely on affinity for the enzyme and the reactivity of the ester. Despite this understanding, there has been no mechanism-based in silico approach for classification and prediction of the inhibitory potency of ether OPs or carbamates. This prompted us to develop a three dimensional prediction framework for OPs, carbamates, and their analogs. Inhibitory structures of a compound that can form the covalent bond were identified through analysis of docked conformations of the compound and its metabolites. Inhibitory potencies of the selected structures were then predicted using a previously developed three dimensional quantitative structure-active relationship. This approach was validated with a large number of structurally diverse OP and carbamate compounds encompassing widely used insecticides and structural analogs including OP flame retardants and thio- and dithiocarbamate pesticides. The modeling revealed that: (1) in addition to classical OP metabolic activation, the toxicity of carbamate compounds can be dependent on biotransformation, (2) OP and carbamate analogs such as OP flame retardants and thiocarbamate herbicides can act as AChEI, (3) hydrogen bonds at the oxyanion hole is critical for AChE inhibition through the covalent bond, and (4) π–π interaction with Trp86

  2. Controlled synthesis of SBR elastomers

    NASA Astrophysics Data System (ADS)

    Zhou, Jin-Ping

    to a great extent on the amount of block styrene. With constant styrene and vinyl contents, the copolymer with the larger and longer blocky styrene gave a lower Tg value but produced a higher loss tangent, tan delta, and thus higher hysteresis loss. The second objective of this research was to synthesize well-defmed, tin-linked, star-branched elastomers. It was found that the tetraallyltin could be used as a reversible chain transfer agent in alkyllithium-initiated diene polymerization, as a consequence of lithium/tin exchange reactions. The polymers produced had very different combinations of linear and star branched polymer, depending on the [Sn]/[Li] ratio and the polymerization procedures. Hydrolysis of these polymer mixtures by HCl in THF resulted in a single peak with a narrow molecular weight distribution, which indicates that the exchange reaction is fast and reversible. In general, the presence of alkyl-tin compounds has little, if any, effect on the polybutadiene microstructures. The linking reaction of poly(dienyl)lithium with Tin(IV) chloride proceeds as a "living" reaction because the coupled polymer chain ends can still grow when more monomer is added. Kinetic study of the interaction of poly(dienyl)lithium with tin-linked polybutadiene showed redistribution of arms and linear polymers. The mechanism of transmetallation is proposed to occur via a stable penta-coordinated alkyl-tin lithium intermediate.

  3. Graphene oxide embedded sandwich nanostructures for enhanced Raman readout and their applications in pesticide monitoring

    NASA Astrophysics Data System (ADS)

    Zhang, Lulu; Jiang, Changlong; Zhang, Zhongping

    2013-04-01

    Analytical techniques based on surface-enhanced Raman scattering (SERS) suffer from a lack of reproducibility and reliability, thus hampering their practical applications. Herein, we have developed a SERS-active substrate based on a graphene oxide embedded sandwich nanostructure for ultrasensitive Raman signal readout. By using this novel Au@Ag NPs/GO/Au@Ag NPs sandwich nanostructure as a SERS substrate, the Raman signals of analytes were dramatically enhanced due to having plenty of hot spots on their surfaces and the unique structure of the graphene oxide sheets. These features make the sandwich nanostructured film an ideal SERS substrate to improve the sensitivity, reproducibility and reliability of the Raman readout. The sandwich nanostructure film can be applied to detect rhodamine-6G (R6G) with an enhancement factor (EF) of ~7.0 × 107 and the pesticide thiram in commercial grape juice with a detection limit of as low as 0.1 μM (0.03 ppm), which is much lower than the maximal residue limit (MRL) of 7 ppm in fruit prescribed by the U.S. Environmental Protection Agency (EPA). The GO embedded sandwich nanostructure also has the ability to selectively detect dithiocarbamate compounds over other types of agricultural chemical. Furthermore, spiked tests show that the sandwich nanostructure can be used to monitor thiram in natural lake water and commercial grape juice without further treatment. In addition, the GO enhanced Raman spectroscopic technique offers potential practical applications for the on-site monitoring and assessment of pesticide residues in agricultural products and environments.Analytical techniques based on surface-enhanced Raman scattering (SERS) suffer from a lack of reproducibility and reliability, thus hampering their practical applications. Herein, we have developed a SERS-active substrate based on a graphene oxide embedded sandwich nanostructure for ultrasensitive Raman signal readout. By using this novel Au@Ag NPs/GO/Au@Ag NPs sandwich

  4. Multimetallic complexes and functionalized gold nanoparticles based on a combination of d- and f-elements.

    PubMed

    Sung, Simon; Holmes, Holly; Wainwright, Luke; Toscani, Anita; Stasiuk, Graeme J; White, Andrew J P; Bell, Jimmy D; Wilton-Ely, James D E T

    2014-02-17

    The new DO3A-derived dithiocarbamate ligand, DO3A-(t)Bu-CS2K, is formed by treatment of the ammonium salt [DO3A-(t)Bu]HBr with K2CO3 and carbon disulfide. DO3A-(t)Bu-CS2K reacts with the ruthenium complexes cis-[RuCl2(dppm)2] and [Ru(CH═CHC6H4Me-4)Cl(CO)(BTD)(PPh3)2] (BTD = 2,1,3-benzothiadiazole) to yield [Ru(S2C-DO3A-(t)Bu)(dppm)2](+) and [Ru(CH═CHC6H4Me-4)(S2C-DO3A-(t)Bu)(CO)(PPh3)2], respectively. Similarly, the group 10 metal complexes [Pd(C,N-C6H4CH2NMe2)Cl]2 and [PtCl2(PPh3)2] form the dithiocarbamate compounds, [Pd(C,N-C6H4CH2NMe2)(S2C-DO3A-(t)Bu)] and [Pt(S2C-DO3A-(t)Bu)(PPh3)2](+), under the same conditions. The linear gold complexes [Au(S2C-DO3A-(t)Bu)(PR3)] are formed by reaction of [AuCl(PR3)] (R = Ph, Cy) with DO3A-(t)Bu-CS2K. However, on reaction with [AuCl(tht)] (tht = tetrahydrothiophene), the homoleptic digold complex [Au(S2C-DO3A-(t)Bu)]2 is formed. Further homoleptic examples, [M(S2C-DO3A-(t)Bu)2] (M = Ni, Cu) and [Co(S2C-DO3A-(t)Bu)3], are formed from treatment of NiCl2·6H2O, Cu(OAc)2, or Co(OAc)2, respectively, with DO3A-(t)Bu-CS2K. The molecular structure of [Ni(S2C-DO3A-(t)Bu)2] was determined crystallographically. The tert-butyl ester protecting groups of [M(S2C-DO3A-(t)Bu)2] (M = Ni, Cu) and [Co(S2C-DO3A-(t)Bu)3] are cleaved by trifluoroacetic acid to afford the carboxylic acid products, [M(S2C-DO3A)2] (M = Ni, Cu) and [Co(S2C-DO3A)3]. Complexation with Gd(III) salts yields trimetallic [M(S2C-DO3A-Gd)2] (M = Ni, Cu) and tetrametallic [Co(S2C-DO3A-Gd)3], with r(1) values of 11.5 (Co) and 11.0 (Cu) mM(-1) s(-1) per Gd center. DO3A-(t)Bu-CS2K can also be used to prepare gold nanoparticles, Au@S2C-DO3A-(t)Bu, by displacement of the surface units from citrate-stabilized nanoparticles. This material can be transformed into the carboxylic acid derivative Au@S2C-DO3A by treatment with trifluoroacetic acid. Complexation with Gd(OTf)3 or GdCl3 affords Au@S2C-DO3A-Gd with an r(1) value of 4.7 mM(-1) s(-1) per chelate and 1500 mM(-1) s(-1) per

  5. The fungicide mancozeb induces toxic effects on mammalian granulosa cells

    SciTech Connect

    Paro, Rita; Tiboni, Gian Mario; Buccione, Roberto; Rossi, Gianna; Cellini, Valerio; Canipari, Rita; Cecconi, Sandra

    2012-04-15

    The ethylene-bis-dithiocarbamate mancozeb is a widely used fungicide with low reported toxicity in mammals. In mice, mancozeb induces embryo apoptosis, affects oocyte meiotic spindle morphology and impairs fertilization rate even when used at very low concentrations. We evaluated the toxic effects of mancozeb on the mouse and human ovarian somatic granulosa cells. We examined parameters such as cell morphology, induction of apoptosis, and p53 expression levels. Mouse granulosa cells exposed to mancozeb underwent a time- and dose-dependent modification of their morphology, and acquired the ability to migrate but not to proliferate. The expression level of p53, in terms of mRNA and protein content, decreased significantly in comparison with unexposed cells, but no change in apoptosis was recorded. Toxic effects could be attributed, at least in part, to the presence of ethylenthiourea (ETU), the main mancozeb catabolite, which was found in culture medium. Human granulosa cells also showed dose-dependent morphological changes and reduced p53 expression levels after exposure to mancozeb. Altogether, these results indicate that mancozeb affects the somatic cells of the mammalian ovarian follicles by inducing a premalignant-like status, and that such damage occurs to the same extent in both mouse and human GC. These results further substantiate the concept that mancozeb should be regarded as a reproductive toxicant. Highlights: ► The fungicide mancozeb affects oocyte spindle morphology and fertilization rate. ► We investigated the toxic effects of mancozeb on mouse and human granulosa cells. ► Granulosa cells modify their morphology and expression level of p53. ► Mancozeb induces a premalignant-like status in exposed cells.

  6. s-Ethyl Cysteine and s-Methyl Cysteine Protect Human Bronchial Epithelial Cells Against Hydrogen Peroxide Induced Injury.

    PubMed

    Hsia, Te-chun; Yin, Mei-chin

    2015-09-01

    Protective effects and actions from s-ethyl cysteine (SEC) and s-methyl cysteine (SMC) for BEAS-2B cells were examined. BEAS-2B cells were pretreated with SEC or SMC at 4, 8, or 16 μmol/L, and followed by hydrogen peroxide (H2 O2 ) treatment. Data showed that H2 O2 enhanced Bax, caspase-3 and caspase-8 expression, and declined Bcl-2 expression. However, SEC or SMC dose-dependently decreased caspase-3 expression and reserved Bcl-2 expression. H2 O2 increased reactive oxygen species (ROS) production, and lowered glutathione level, glutathione peroxide, and glutathione reductase activities in BEAS-2B cells. SEC or SMC pretreatments reduced ROS generation, and maintained glutathione redox cycle in those cells. H2 O2 upregulated the expression of both p47(phox) and gp91(phox) . SEC and SMC downregulated p47(phox) expression. SEC or SMC at 8 and 16 μmol/L decreased H2 O2 -induced release of inflammatory cytokines. H2 O2 stimulated the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase. SEC and SMC pretreatments dose-dependently downregulated NF-κB p65 and p-p38 expression. Pyrrolidine dithiocarbamate or SB203580 inhibited NF-κB activation and p38 phosphorylation; thus, SEC or SMC pretreatments failed to affect protein expression of these factors. These novel findings suggest that SEC or SMC could protect bronchial cells and benefit respiratory epithelia stability and functions.

  7. Minimization of mass interferences in quadrupole inductively coupled plasma mass spectrometric (ICP-MS) determination of palladium using a flow injection on-line displacement solid-phase extraction protocol

    NASA Astrophysics Data System (ADS)

    Fang, Jing; Liu, Li-Wen; Yan, Xiu-Ping

    2006-07-01

    A flow injection on-line displacement solid-phase extraction protocol was employed to minimize mass interferences with determination of palladium by inductively coupled plasma mass spectrometry (ICP-MS). The developed method involved in on-line complexing of Ag + with pyrrolidine dithiocarbamate (PDC), presorption of the resultant Ag-PDC onto a microcolumn packed with the cigarette filter, displacement sorption of Pd 2+ through loading the sample solution onto the microcolumn due to on-line displacement reaction between Pd 2+ and the presorbed Ag-PDC, elution of the retained Pd 2+ with 50 μL of ethanol for on-line ICP-MS detection. Interferences from co-existing heavy metal ions with lower stability of their PDC complexes relative to Ag-PDC were minimized/eliminated. No interferences from 5 mg L - 1 Zn and 3 mg L - 1 Pb for 104Pd, 0.4 mg L - 1 Cu for 105Pd, 6 mg L - 1 Zn and 2 mg L - 1 Cd for 106Pd, 6 mg L - 1 Zn and 3 mg L - 1 Cd for 108Pd, and 2 mg L - 1 Cd for 110Pd were observed for the determination of 100 ng L - 1 Pd. The enhancement factors of 71-75, sample throughput of 23 samples h - 1 and detection limits of 2.8-3.5 ng L - 1 were achieved with the consumption of 3.0 mL of sample solution. The precision (RSD) for eleven replicate determinations of Pd at the 100 ng L - 1 level was 1.8-2.7%. The developed method was applied to the determination of palladium in rock samples.

  8. Exendin-4 ameliorates oxidized-LDL-induced inhibition of macrophage migration in vitro via the NF-κB pathway

    PubMed Central

    Ma, Ge-fei; Chen, Song; Yin, Lei; Gao, Xiang-dong; Yao, Wen-bing

    2014-01-01

    Aim: To investigate the effects of the glucagon-like peptide-1 (GLP-1) receptor agonist exendin-4 on oxidized low-density lipoprotein (ox-LDL)-induced inhibition of macrophage migration and the mechanisms underlying the effects of exendin-4. Methods: Primary peritoneal macrophages were extracted from the peritoneal cavity of mice treated with 3% thioglycollate (2 mL, ip). Migration of the macrophages was examined using a cell migration assay. Macrophage migration-related factors including leptin-like ox-LDL receptor (LOX-1), cyclooxygenase 2 (COX-2), tumor necrosis factor (TNF)-α, interleukin-1 (IL-1)β, matrix metalloproteinase-2 (MMP-2), intercellular adhesion molecule (ICAM)-1 and macrophage migration inhibitory factor (MIF) were measured using semi-quantitative RT-PCR. Expression of MIF and ICAM-1 proteins was examined with ELISA. Gelatin zymography was used to evaluate the activity of MMP-9. Activation of the NF-κB pathway was determined by confocal laser scanning microscopy. Results: Treatment of the macrophages with ox-LDL (50 μg/mL) markedly suppressed the macrophage migration. Furthermore, ox-LDL treatment substantially increased the expression of the macrophage migration-related factors, the activity of MMP-9 and the translocation of the NF-κB p65 subunit. These effects of ox-LDL were significantly ameliorated by pretreatment with the specific NF-κB inhibitor ammonium pyrrolidine dithiocarbamate (100 μmol/L). These effects of ox-LDL were also significantly ameliorated by pretreatment with exendin-4 (25 and 50 nmol/L). Conclusion: Exendin-4 ameliorates the inhibition of ox-LDL on macrophage migration in vitro, via suppressing ox-LDL-induced expression of ICAM-1 and MIF, which is probably mediated by the NF-κB pathway. PMID:24335838

  9. Distinct coordination geometries in bis-[N,N-bis-(2-meth-oxy-eth-yl)di-thio-carbamato-κ(2) S,S']di-phenyltin(IV) and bis-[N-(2-meth-oxy-eth-yl)-N-methyl-dithio-carbamato-κ(2) S,S']di-phenyl-tin(IV): crystal structures and Hirshfeld surface analysis.

    PubMed

    Mohamad, Rapidah; Awang, Normah; Jotani, Mukesh M; Tiekink, Edward R T

    2016-08-01

    The crystal and mol-ecular structures of two di-phenyl-tin bis-(di-thio-carbamate)s, [Sn(C6H5)2(C5H10NOS2)2], (I), and [Sn(C6H5)2(C7H14NO2S2)2], (II), are described. In (I), in which the metal atom lies on a twofold rotation axis, the di-thio-carbamate ligand coordinates with approximately equal Sn-S bond lengths and the ipso-C atoms of the Sn-bound phenyl groups occupy cis-positions in the resulting octa-hedral C2S4 donor set. A quite distinct coordination geometry is noted in (II), arising as a result of quite disparate Sn-S bond lengths. Here, the four S-donors define a trapezoidal plane with the ipso-C atoms lying over the weaker of the Sn-S bonds so that the C2S4 donor set defines a skewed trapezoidal bipyramid. The packing of (I) features supra-molecular layers in the ab plane sustained by methyl-ene-C-H⋯π(Sn-ar-yl) inter-actions; these stack along the c-axis direction with no specific inter-actions between them. In (II), supra-molecular chains along the b-axis direction are formed by methyl-ene-C-O(ether) inter-actions; these pack with no directional inter-actions between them. A Hirshfeld surface analysis was conducted on both (I) and (II) and revealed the dominance of H⋯H inter-actions contributing to the respective surfaces, i.e. >60% in each case, and other features consistent with the description of the mol-ecular packing above.

  10. Excitation dependent multicolor emission and photoconductivity of Mn, Cu doped In2S3 monodisperse quantum dots.

    PubMed

    Ghosh, Sirshendu; Saha, Manas; Ashok, Vishal Dev; Chatterjee, Arijit; De, S K

    2016-04-15

    Indium sulphide (In2S3) quantum dots (QDs) of average size 6 ± 2 nm and hexagonal nanoplatelets of average size 37 ± 4 nm have been synthesized from indium myristate and indium diethyl dithiocarbamate precursors respectively. The absorbance and emission band was tuned with variation of nanocrytal size from very small in the strong confinement regime to very large in the weak confinement regime. The blue emission and its shifting with size has been explained with the donor-acceptor recombination process. The 3d element doping (Mn(2+) and Cu(2+)) is found to be effective for formation of new emission bands at higher wavelengths. The characteristic peaks of Mn(2+) and Cu(2+) and the modification of In(3+) peaks in the x-ray photoelectric spectrum (XPS) confirm the incorporation of Mn(2+) and Cu(2+) into the In2S3 matrix. The simulation of the electron paramagnetic resonance signal indicates the coexistence of isotropic and axial symmetry for In and S vacancies. Moreover, the majority of Mn(2+) ions and sulphur vacancies (VS ) reside on the surface of nanocrystals. The quantum confinement effect leads to an enhancement of band gap up to 3.65 eV in QDs. The formation of Mn 3d levels between conduction band edge and shallow donor states is evidenced from a systematic variation of emission spectra with the excitation wavelength. In2S3 QDs have been established as efficient sensitizers to Mn and Cu emission centers. Fast and slow components of photoluminescence (PL) decay dynamics in Mn and Cu doped QDs are interpreted in terms of surface and bulk recombination processes. Fast and stable photodetctors with high photocurrent gain are fabricated with Mn and Cu doped QDs and are found to be faster than pure In2S3. The fastest response time in Cu doped QDs is an indication of the most suitable system for photodetector devices.

  11. Excitation dependent multicolor emission and photoconductivity of Mn, Cu doped In2S3 monodisperse quantum dots

    NASA Astrophysics Data System (ADS)

    Ghosh, Sirshendu; Saha, Manas; Ashok, Vishal Dev; Chatterjee, Arijit; De, S. K.

    2016-04-01

    Indium sulphide (In2S3) quantum dots (QDs) of average size 6 ± 2 nm and hexagonal nanoplatelets of average size 37 ± 4 nm have been synthesized from indium myristate and indium diethyl dithiocarbamate precursors respectively. The absorbance and emission band was tuned with variation of nanocrytal size from very small in the strong confinement regime to very large in the weak confinement regime. The blue emission and its shifting with size has been explained with the donor-acceptor recombination process. The 3d element doping (Mn2+ and Cu2+) is found to be effective for formation of new emission bands at higher wavelengths. The characteristic peaks of Mn2+ and Cu2+ and the modification of In3+ peaks in the x-ray photoelectric spectrum (XPS) confirm the incorporation of Mn2+ and Cu2+ into the In2S3 matrix. The simulation of the electron paramagnetic resonance signal indicates the coexistence of isotropic and axial symmetry for In and S vacancies. Moreover, the majority of Mn2+ ions and sulphur vacancies (VS ) reside on the surface of nanocrystals. The quantum confinement effect leads to an enhancement of band gap up to 3.65 eV in QDs. The formation of Mn 3d levels between conduction band edge and shallow donor states is evidenced from a systematic variation of emission spectra with the excitation wavelength. In2S3 QDs have been established as efficient sensitizers to Mn and Cu emission centers. Fast and slow components of photoluminescence (PL) decay dynamics in Mn and Cu doped QDs are interpreted in terms of surface and bulk recombination processes. Fast and stable photodetctors with high photocurrent gain are fabricated with Mn and Cu doped QDs and are found to be faster than pure In2S3. The fastest response time in Cu doped QDs is an indication of the most suitable system for photodetector devices.

  12. Interleukin-18-induced cell adhesion molecule expression is associated with feedback regulation by PPAR-γ and NF-κB in Apo E-/- mice.

    PubMed

    Bhat, Owais Mohammad; Uday Kumar, P; Harishankar, N; Ravichandaran, L; Bhatia, A; Dhawan, Veena

    2017-02-07

    Focal recruitment of monocytes and lymphocytes is one of the earliest detectable cellular responses in atherosclerotic lesion formation. Endothelium may regulate leukocyte recruitment by expressing specific adhesion molecules. Interleukin-18 is a proinflammatory cytokine that plays an important role in vascular pathologies. The present study highlights the modulation of adhesion molecules and PPAR-γ by IL-18 and proposes a novel feedback mechanism by which PPAR-γ may regulate IL-18 expression. Three groups of normal chow diet-fed, male Apo E-/- mice, aged 12 weeks (n = 6/group) were employed: Gp I, phosphate-buffered saline (PBS) (2 mo): Gp II, recombinant IL-18 (rIL-18) (1 mo) followed by PBS (1 mo); Gp III, rIL-18 (1 mo) followed by pyrrolidine dithiocarbamate (PDTC) (1 mo). Significantly augmented mRNA expression of ICAM-1 (~5.7-fold), VCAM-1 (~3.6-fold), and NF-κB (~7-fold) was observed in Gp II mice as compared to Gp I, whereas PPAR-γ expression was not altered. PDTC treatment caused a significant downregulation of ICAM-1 (~4.2-fold), VCAM-1(~2-fold), and NF-κB (~4.5-fold) and upregulation of PPAR-γ expression (~5-fold) in Gp III mice. A similar trend was observed in protein expression. In vivo imaging results demonstrated a marked increase in probe (CF750 dye conjugated to VCAM-1 antibody) fluorescence intensity for VCAM-1 expression in Gp II mice, whereas it was moderately decreased in Gp III. PPAR-γ was found to significantly downregulate both IL-18 levels and IL-18-induced adhesion molecules. The underlying mechanism was found to be via inhibition of NF-κB activity by PDTC, thereby leading to decreased adherence of monocytes to the activated endothelial cells and a step to halt the progression and development of atherosclerotic lesions.

  13. Tomatidine inhibits invasion of human lung adenocarcinoma cell A549 by reducing matrix metalloproteinases expression.

    PubMed

    Yan, Kun-Huang; Lee, Liang-Ming; Yan, Shao-Han; Huang, Hsiang-Ching; Li, Chia-Chen; Lin, Hui-Ting; Chen, Pin-Shern

    2013-05-25

    Tomatidine is an aglycone of glycoalkaloid tomatine in tomato. Tomatidine is found to possess anti-inflammatory properties and may serve as a chemosensitizer in multidrug-resistant tumor cells. However, the effect of tomatidine on cancer cell metastasis remains unclear. This study examines the effect of tomatidine on the migration and invasion of human lung adenocarcinoma A549 cell in vitro. The data demonstrates that tomatidine does not effectively inhibit the viability of A549 cells. When treated with non-toxic doses of tomatidine, cell invasion is markedly suppressed by Boyden chamber invasion assay, while cell migration is not affected. Tomatidine reduces the mRNA level of matrix metalloproteinase-2 (MMP-2), MMP-9 and increases the expression of reversion-inducing cysteine-rich protein with kazal motifs (RECK), as well as tissue inhibitor of metalloproteinase-1 (TIMP-1). The immunoblotting assays indicate that tomatidine is very effective in suppressing the phosphorylation of Akt and extracellular signal regulating kinase (ERK). In addition, tomatidine significantly decreases the nuclear level of nuclear factor kappa B (NF-κB), which suggests that tomatidine inhibits NF-κB activity. Furthermore, the treatment of inhibitors specific for PI3K/Akt (LY294002), ERK (U0126), or NF-κB (pyrrolidine dithiocarbamate) to A549 cells reduced cell invasion and MMP-2/9 expression. The results suggest that tomatidine inhibits the invasion of A549 cells by reducing the expression of MMPs. It also inhibits ERK and Akt signaling pathways and NF-κB activity. These findings demonstrate a new therapeutic potential for tomatidine in anti-metastatic therapy.

  14. Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong Total Diet Study.

    PubMed

    Wong, Waiky W K; Yau, Arthur T C; Chung, Stephen W C; Lam, Chi-ho; Ma, Stephanie; Ho, Y Y; Xiao, Ying

    2014-01-01

    The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites - organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites - is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared "as consumed". A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 μg kg⁻¹) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population.

  15. MicroRNA-181b stimulates inflammation via the nuclear factor-κB signaling pathway in vitro.

    PubMed

    Wang, Yazhen; Mao, Genxiang; Lv, Yuandong; Huang, Qingdong; Wang, Guofu

    2015-10-01

    Acute lung injury (ALI) is characterized by severe lung edema and an increase in the inflammatory reaction. Considerable evidence has indicated that microRNAs (miRNAs or miRs) are involved in various human diseases; however, the expression profile and function of miRNAs in ALI have been rarely reported. The present study used miRNA microarray and reverse transcription-quantitative polymerase chain reaction to demonstrate that miR-181b is the one of the most significantly upregulated miRNA after lipopolysaccharide (LPS) stimulation in human bronchial epithelial cells, BEAS-2B. To elaborate the role of miR-181b in ALI, an assay was performed to investigate the overexpression of miR-181b in BEAS-2B cells, and the expression of inflammatory factors was then analyzed. The overexpression of miR-181b resulted in the induction of an increment in interleukin (IL)-6 levels. p65 was identified to be a primary component of NF-κB, since it was upregulated in the miR-181b overexpression in the BEAS-2B cells, while pyrrolidine dithiocarbamate, a specific inhibitor of NF-κB, was found to be able to abrogate the upregulation of the expression of p65. In conclusion, the findings of the present study suggested that miR-181b may be involved in the process of LPS-induced inflammation in BEAS-2B cells by activating the NF-κB signaling pathway, which implies that it may serve as a potential therapeutic target for ALI.

  16. Endothelial lipase is upregulated by interleukin-6 partly via the p38 MAPK and p65 NF-κB signaling pathways

    PubMed Central

    Yue, Xin; Wu, Minghui; Jiang, Hong; Hao, Jing; Zhao, Qinghao; Zhu, Qing; Saren, Gaowa; Zhang, Yun; Zhang, Xiaoli

    2016-01-01

    To investigate the effects of inflammatory factor interleukin (IL)-6 on the expression of endothelial lipase (EL) and its potential signaling pathways in atherosclerosis, a primary culture of human umbilical vein endothelial cells (HUVECs) was established and treated as follows: i) Control group without any treatment; ii) recombinant human (rh)IL-6 treatment (10 ng/ml) for 0, 4, 8, 12 and 24 h; iii) p38 mitogen-activated protein kinases (MAPKs) inhibitor (SB203580, 10 µmol/l) pretreatment for 1 h prior to rhIL-6 (10 ng/ml) treatment; iv) nuclear factor (NF)-κB activation inhibitor (pyrrolidine dithiocarbamate, 10 mmol/l) pretreatment for 1 h prior to rhIL-6 (10 ng/ml) treatment. EL levels were detected by immunocytochemical staining and western blot analysis. Proliferation of HUVECs was detected by immunostaining of proliferating cell nuclear antigen (PCNA) and an MTT assay. p38 MAPK and NF-κB p65 levels were detected by western blotting. The results showed that rhIL-6 treatment increased EL expression and proliferation of HUVECs. NF-κB p65 and MAPK p38 protein levels also increased in a time-dependent manner in HUVECs after rhIL-6 treatment. NF-κB inhibitor and MAPK p38 inhibitor prevented the effects of rhIL-6 on EL expression. In conclusion, inflammatory factor IL-6 may participate in the pathogenesis of atherosclerosis by increasing EL expression and the proliferation of endothelial cells via the p38 MAPK and NF-κB signaling pathways. PMID:27430252

  17. Enhanced binding capability of nuclear factor-κB with demethylated P2X3 receptor gene contributes to cancer pain in rats.

    PubMed

    Zhou, You-Lang; Jiang, Guo-Qin; Wei, Jinrong; Zhang, Hong-Hong; Chen, Wei; Zhu, Hongyan; Hu, Shufen; Jiang, Xinghong; Xu, Guang-Yin

    2015-10-01

    Nuclear factor-kappa B (NF-κB) signaling is implicated in both cancer development and inflammation processes. However, the roles and mechanisms of NF-κB signaling in the development of cancer-induced pain (CIP) remain unknown. This study was designed to investigate the roles of the p65 subunit of NF-κB in regulation of the purinergic receptor (P2X3R) plasticity in dorsal root ganglion (DRG) of CIP rats. We showed here that tumor cell injection produced mechanical and thermal hyperalgesia, and an enhanced body weight-bearing difference, which was correlated with an upregulation of p65 and P2X3R expression in lumber DRGs and a potentiation of ATP-evoked responses of tibia-innervating DRG neurons. Inhibition of NF-κB signaling using p65 inhibitor pyrrolidine dithiocarbamate, BAY-11-7082, or lentiviral-p65 short-hairpin RNA significantly attenuated CIP and reversed the activities of P2X3R. Interestingly, tumor cell injection led to a significant demethylation of CpG island in p2x3r gene promoter and enhanced ability of p65 to bind the promoter of p2x3r gene. Our findings suggest that upregulation of P2X3R expression was mediated by the enhanced binding capability of p65 with demethylated promoter of p2x3r gene, thus contributing to CIP. NF-κBp65 might be a potential target for treating CIP, a neuropathic pain generated by tumor cell-induced injury to nerves that innervate the skin.

  18. Downregulation of pro-inflammatory mediators by a water extract of Schisandra chinensis (Turcz.) Baill fruit in lipopolysaccharide-stimulated RAW 264.7 macrophage cells.

    PubMed

    Dilshara, Matharage Gayani; Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Kang, Chang-Hee; Lee, Seungheon; Park, Sang Rul; Jeong, Jin-Woo; Choi, Yung Hyun; Seo, Yong Taek; Jang, Young Pyo; Kim, Gi-Young

    2013-09-01

    Schisandra chinensis has a long-standing history of medicinal use as a tonic, a sedative, an anti-tussive, and an anti-aging drug. Nevertheless, the antagonistic effects of S. chinensis against lipopolysaccharide (LPS)-stimulated responses have not yet been studied. In this study, we investigated whether water extract of S. chinensis fruit (WESC) has the ability to attenuate the expression of pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor-α (TNF-α) in LPS-stimulated RAW 264.7 macrophage cells. WESC inhibited the expression of LPS-induced pro-inflammatory mediators, namely, NO, PGE2, and TNF-α. Furthermore, gene expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α was inhibited both at mRNA and protein synthesis levels, without any cytotoxic effect. Moreover, WESC significantly suppressed LPS-induced DNA-binding activity of NF-κB by inhibiting degradation of IκBα. It was found that pyrrolidine dithiocarbamate (PDTC), a specific NF-κB inhibitor, downregulates the expression of these pro-inflammatory genes to be closely regulated by NF-κB activity. Furthermore, we found that WESC retains dephosphorylation of Akt in response to LPS, and consequently suppressed the DNA-binding activity of NF-κB in RAW 264.7 macrophage cells. LY294002, a specific Akt inhibitor, attenuated LPS-induced pro-inflammatory gene expression via suppression of NF-κB activity. Taken together, our results indicate that WESC downregulates the expression of pro-inflammatory genes involved in the synthesis of NO, PGE2, and TNF-α in LPS-stimulated RAW 264.7 macrophage cells by suppressing Akt-dependent NF-κB activity.

  19. Development of a sequential injection dispersive liquid-liquid microextraction system for electrothermal atomic absorption spectrometry by using a hydrophobic sorbent material: determination of lead and cadmium in natural waters.

    PubMed

    Anthemidis, Aristidis N; Ioannou, Kallirroy-Ioanna G

    2010-05-23

    A novel on-line sequential injection (SI) dispersive liquid-liquid microextraction (DLLME) system coupled to electrothermal atomic absorption spectrometry (ETAAS) was developed for metal preconcentration in micro-scale, eliminating the laborious and time consuming procedure of phase separation with centrifugation. The potentials of the system were demonstrated for trace lead and cadmium determination in water samples. An appropriate disperser solution which contains the extraction solvent (xylene) and the chelating agent (ammonium pyrrolidine dithiocarbamate) in methanol is mixed on-line with the sample solution (aqueous phase), resulting thus, a cloudy solution, which is consisted of fine droplets of xylene, dispersed throughout the aqueous phase. Three procedures are taking place simultaneously: cloudy solution creation, analyte complex formation and extraction from aqueous phase into the fine droplets of xylene. Subsequently the droplets were retained on the hydrophobic surface of PTFE-turnings into the column. A part of 30 microL of the eluent (methyl isobutyl ketone) was injected into furnace graphite for analyte atomization and quantification. The sampling frequency was 10 h(-1), and the obtained enrichment factor was 80 for lead and 34 for cadmium. The detection limit was 10 ng L(-1) and 2 ng L(-1), while the precision expressed as relative standard deviation (RSD) was 3.8% (at 0.5 microg L(-1)) and 4.1% (at 0.03 microg L(-1)) for lead and cadmium respectively. The proposed method was evaluated by analyzing certified reference materials and was applied to the analysis of natural waters.

  20. Multielement trace determinations in A1 2O 3 ceramic powders by inductively coupled plasma mass spectrometry with special reference to on-line trace preconcentration

    NASA Astrophysics Data System (ADS)

    Pollmann, D.; Leis, F.; Tölg, G.; Tschöpel, P.; Broekaert, J. A. C.

    1994-12-01

    The use of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of trace elements in Al 2O 3 powders is reported. Special interest is given to a preconcentration of the trace elements by on-line coupling of chromatography to ICP-MS. This is based on the complexation of Co, Cu, Cr, Fe, Ga, Mn, Ni, V and Zn with hexamethylene-dithiocarbamate (HMDC), their preconcentration on a C18 RP column by reversed phase liquid chromatography and their elution with CH 3OH-H 2O mixtures. A direct coupling of the HPLC system to the ICP-MS has been realized by high pressure pneumatic nebulization using desolvation. With the Chromatographie method developed, removal of the AI by at least 99% was achieved. For the trace elements V, Fe, Ni, Co, Cu and Ga, high and reproducible recoveries (ranging from 96-99%) were reached. The method developed has been shown to considerably enhance the power of detection as compared with direct procedures, namely down to 0.02-0.16 ( μg/g for V and Fe, respectively. The possibilities of the method are shown by the determinations of V, Mn, Fe, Ni, Co, Cu, Zn and Ga at the μg/g level in A1 2O 3 powders. The accuracy of the method at the 0.06 to 9.0 μg/g level for Co and Fe, respectively, is demonstrated by a comparison with results of independent methods from the literature.

  1. Synthesis, in vitro anticancer and antibacterial activities and in silico studies of new 4-substituted 1,2,3-triazole-coumarin hybrids.

    PubMed

    Kraljević, Tatjana Gazivoda; Harej, Anja; Sedić, Mirela; Pavelić, Sandra Kraljević; Stepanić, Višnja; Drenjančević, Domagoj; Talapko, Jasminka; Raić-Malić, Silvana

    2016-11-29

    The 4-substituted 1,2,3-triazole core in designed coumarin hybrids (4-35) with diverse physicochemical properties was introduced by eco-friendly copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition under microwave irradiation. Coumarin-1,2,3-triazole-benzofused heterocycle hybrids emerged as the class of compounds exhibiting the highest antiproliferative activity. The strong relationship between lipophilicity and antiproliferative activities was observed indicating that lipophilic 1,2,3-triazole-coumarin hybrids containing phenylethyl (13), 3,5-difluorophenyl (14), 5-iodoindole (30) and benzimidazole (33 and 35) subunits showed the most potent cytostatic effects. The 7-methylcoumarin-1,2,3-triazole-2-methylbenzimidazole hybrid 33 can be highlighted as a lead that exerted the highest cytotoxicity against hepatocellular carcinoma HepG2 cells with IC50 value of 0.9 μM and high selectivity (SI = 50). This compound induced cell death, mainly due to early apoptosis. Strong antiproliferative effect of 33 could be associated with its inhibition of 5-lipoxygenase (5-LO) activity and perturbation of sphingolipid signaling by interfering with intracellular acid ceramidase (ASAH) activity. Outlined considerable effect of lipophilicity on antiproliferative activity was not observed for antibacterial activity. The compounds with p-pentylphenyl (17), 2-chloro-4-fluorobenzenesulfonamide (23) and dithiocarbamate (27) moiety were endowed with high selectivity against Enterococcus species. Moreover, these compounds were found to be superior in inhibiting the growth of clinically isolated vancomycin-resistant Enterococcus faecium, while the reference antibiotics exhibited the lack of activity. Our findings indicate that coumarin-1,2,3-triazole could be used as the scaffold for structural optimization to develop more potent and selective anticancer agents and encourage further development of novel structurally related analogs of 33 as more effective 5-LO inhibitors.

  2. Neurotoxicity of the Parkinson Disease-Associated Pesticide Ziram Is Synuclein-Dependent in Zebrafish Embryos

    PubMed Central

    Lulla, Aaron; Barnhill, Lisa; Bitan, Gal; Ivanova, Magdalena I.; Nguyen, Binh; O’Donnell, Kelley; Stahl, Mark C.; Yamashiro, Chase; Klärner, Frank-Gerrit; Schrader, Thomas; Sagasti, Alvaro; Bronstein, Jeff M.

    2016-01-01

    Background: Exposure to the commonly used dithiocarbamate (DTC) pesticides is associated with an increased risk of developing Parkinson disease (PD), although the mechanisms by which they exert their toxicity are not completely understood. Objective: We studied the mechanisms of ziram’s (a DTC fungicide) neurotoxicity in vivo. Methods: Zebrafish (ZF) embryos were utilized to determine ziram’s effects on behavior, neuronal toxicity, and the role of synuclein in its toxicity. Results: Nanomolar-range concentrations of ziram caused selective loss of dopaminergic (DA) neurons and impaired swimming behavior. Because ziram increases α-synuclein (α-syn) concentrations in rat primary neuronal cultures, we investigated the effect of ziram on ZF γ-synuclein 1 (γ1). ZF express 3 synuclein isoforms, and ZF γ1 appears to be the closest functional homologue to α-syn. We found that recombinant ZF γ1 formed fibrils in vitro, and overexpression of ZF γ1 in ZF embryos led to the formation of neuronal aggregates and neurotoxicity in a manner similar to that of α-syn. Importantly, knockdown of ZF γ1 with morpholinos and disruption of oligomers with the molecular tweezer CLR01 prevented ziram’s DA toxicity. Conclusions: These data show that ziram is selectively toxic to DA neurons in vivo, and this toxicity is synuclein-dependent. These findings have important implications for understanding the mechanisms by which pesticides may cause PD. Citation: Lulla A, Barnhill L, Bitan G, Ivanova MI, Nguyen B, O’Donnell K, Stahl MC, Yamashiro C, Klärner FG, Schrader T, Sagasti A, Bronstein JM. 2016. Neurotoxicity of the Parkinson disease-associated pesticide ziram is synuclein-dependent in zebrafish embryos. Environ Health Perspect 124:1766–1775; http://dx.doi.org/10.1289/EHP141 PMID:27301718

  3. SDF‑1/CXCR4 axis induces apoptosis of human degenerative nucleus pulposus cells via the NF‑κB pathway.

    PubMed

    Liu, Zongchao; Ma, Chuan; Shen, Jieliang; Wang, Dawu; Hao, Jie; Hu, Zhenming

    2016-07-01

    Intervertebral disc degeneration (IVDD) is a major cause of lower back pain, and increased cell apoptosis is a key characteristic of IVDD. The present study aimed to investigate the effects and mechanism of the stromal cell‑derived factor‑1 (SDF‑1)/C‑X‑C motif chemokine receptor 4 (CXCR4) axis on apoptosis in human degenerative nucleus pulposus cells (NPCs). The expression levels of SDF‑1 and CXCR4 in human intervertebral discs (IVD) were determined using immunohistochemistry and western blot analysis. Apoptosis of primary cultured NPCs was quantified by Annexin V/propidium iodide staining following stimulation with SDF‑1 and knockdown of CXCR4 using small interfering RNA (siRNA). The association with the nuclear factor‑κB (NF‑κB) signaling pathway was investigated using CXCR4‑siRNA and NF‑κB inhibitor, pyrrolidine dithiocarbamate (PDTC), treatment. The results demonstrated that SDF‑1 and its receptor, CXCR4, were upregulated in degenerative IVD samples compared with normal samples. Stimulation with SDF‑1 increased the level of apoptosis in cultured NPCs, and conversely, the apoptosis level was suppressed post‑transfection with CXCR4 siRNA compared with SDF‑1 stimulation alone. Furthermore, SDF‑1 treatment increased the level of phosphorylated NF‑κB subunit P65, which was downregulated following CXCR4 siRNA and PDTC treatment. In addition, CXCR4 siRNA and PDTC inhibited the nuclear translocation of P65, which was induced by SDF‑1. Taken together, SDF‑1‑mediated apoptosis was suppressed by NF‑κB inhibition using PDTC. In conclusion, the SDF‑1/CXCR4 axis promoted cell apoptosis in human degenerative NPCs via the NF‑κB pathway, thus suggesting that SDF‑1/CXCR signaling may be a therapeutic target for the treatment of degenerative IVD diseases.

  4. TLR4/NF-κB signaling pathway-mediated and oxLDL-induced up-regulation of LOX-1, MCP-1, and VCAM-1 expressions in human umbilical vein endothelial cells.

    PubMed

    Feng, Y; Cai, Z R; Tang, Y; Hu, G; Lu, J; He, D; Wang, S

    2014-01-28

    This study aimed to investigate the function and signaling pathway of Toll-like receptor 4 (TLR4) in oxidized low-density lipoprotein (oxLDL)-induced up-regulated expressions of oxidized LDL receptor 1 (LOX-1), monocyte chemoattractant protein 1 (MCP-1), and vascular cell adhesion molecule 1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs). HUVECs were incubated with different oxLDL concentrations (0, 20, 40, 60, and 80 μg/mL) for 24 and 48 h. The influence of oxLDL on TLR4, LOX-1, MCP-1, and VCAM-1 expressions in HUVECs was detected by real-time polymerase chain reaction and Western blot analysis. HUVECs were transfected with small interfering RNA targeting TLR4 (siTLR4), in which protein expressions of LOX-1, MCP-1, and VCAM-1, and the nuclear translocation of NF-kB (P50) were detected by Western blot. After 48 h of processing HUVECs with pyrrolidine dithiocarbamate (PDTC), protein expressions of TLR4, LOX-1, MCP-1, and VCAM- 1 were detected by Western blot. OxLDL induced a concentration-dependent up-regulation of mRNA and protein expressions of TLR4, LOX-1, MCP-1, and VCAM-1 in HUVECs (P < 0.001). siTLR4 significantly reduced protein expressions of LOX-1, MCP-1, VCAM-1, and reduced the NF-kB (P50) nuclear translocation (P < 0.001). PDTC significantly inhibited protein expressions of TLR4, LOX-1, MCP- 1, and VCAM-1 (P < 0.001). Results of this study demonstrate that the TLR4/NF-κB signaling pathway has an important function in the up-regulation of oxLDL-induced expressions of LOX-1, MCP-1, and VCAM-1 in HUVECs.

  5. A dominant-negative F-box deleted mutant of E3 ubiquitin ligase, β-TrCP1/FWD1, markedly reduces myeloma cell growth and survival in mice

    PubMed Central

    Gupta, Anjana; McCluskey, Brandon; Bhaskaran, Shylesh; Muñoz, Steve; Oyajobi, Babatunde O.

    2015-01-01

    Treatment of multiple myeloma with bortezomib can result in severe adverse effects, necessitating the development of targeted inhibitors of the proteasome. We show that stable expression of a dominant-negative F-box deleted (ΔF) mutant of the E3 ubiquitin ligase, SCFβ-TrCP/FWD1, in murine 5TGM1 myeloma cells dramatically attenuated their skeletal engraftment and survival when inoculated into immunocompetent C57BL/KaLwRij mice. Similar results were obtained in immunodeficient bg-nu-xid mice, suggesting that the observed effects were independent of host recipient immune status. Bone marrow stroma offered no protection for 5TGM1-ΔF cells in cocultures treated with tumor necrosis factor (TNF), indicating a cell-autonomous anti-myeloma effect. Levels of p100, IκBα, Mcl-1, ATF4, total and cleaved caspase-3, and phospho-β-catenin were elevated in 5TGM1-ΔF cells whereas cIAP was down-regulated. TNF also activated caspase-3 and downregulated Bcl-2, correlating with the enhanced susceptibility of 5TGM1-ΔF cells to apoptosis. Treatment of 5TGM1 tumor-bearing mice with a β-TrCP1/FWD1 inhibitor, pyrrolidine dithiocarbamate (PDTC), significantly reduced tumor burden in bone. PDTC also increased levels of cleaved Mcl-1 and caspase-3 in U266 human myeloma cells, correlating with our murine data and validating the development of specific β-TrCP inhibitors as an alternative therapy to nonspecific proteasome inhibitors for myeloma patients. PMID:26009993

  6. The role of NF-kappaB in the angiogenic response of coronary microvessel endothelial cells.

    PubMed Central

    Stoltz, R A; Abraham, N G; Laniado-Schwartzman, M

    1996-01-01

    The activation of nuclear factor (NF)-kappaB by 12(R)-hydroxyeicosatrienoic acid [12(R)-HETrE], an arachidonic acid metabolite with potent stereospecific proinflammatory and angiogenic properties, was examined and its role in the angiogenic response was determined in capillary endothelial cells derived from coronary microvessels. Electrophoretic mobility-shift assay of nuclear protein extracts from cells treated with 12(R)-HETrE demonstrated a rapid and stereospecific time- and concentration-dependent increase in the binding activity of NF-kappaB, which was inhibitable by the antioxidants N-acetylcysteine, butylated hydroxyanisole, and pyrrolidine dithiocarbamate and was partially attenuated by the protein kinase C inhibitors, staurosporine and calphostin C. Neither 12(S)-HETrE nor other related eicosanoids--e.g., 12(R)-HETE, 12(S)-HETE, and leukotriene B4--stimulated the activation of NF-kappaB relative to 12(R)-HETrE, substantiating the claim for a specific receptor-mediated mechanism. 12(R)-HETrE stimulated the formation of capillary-like cords of microvessel endothelial cells distinguishable from a control; this effect was comparable to that observed with basic fibroblast growth factor (bFGF). Inhibition of NF-kappaB activation resulted in inhibition of capillary-like formation of endothelial cells treated with 12(R)-HETrE by 80% but did not affect growth observed with bFGF. It is suggested that 12(R)-HETrE's angiogenic activity involves the activation of NF-kappaB, possibly via protein kinase C stimulation and the generation of reactive oxygen intermediates for downstream signaling. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:8610127

  7. SDF-1/CXCR4 axis induces apoptosis of human degenerative nucleus pulposus cells via the NF-κB pathway

    PubMed Central

    LIU, ZONGCHAO; MA, CHUAN; SHEN, JIELIANG; WANG, DAWU; HAO, JIE; HU, ZHENMING

    2016-01-01

    Intervertebral disc degeneration (IVDD) is a major cause of lower back pain, and increased cell apoptosis is a key characteristic of IVDD. The present study aimed to investigate the effects and mechanism of the stromal cell-derived factor-1 (SDF-1)/C-X-C motif chemokine receptor 4 (CXCR4) axis on apoptosis in human degenerative nucleus pulposus cells (NPCs). The expression levels of SDF-1 and CXCR4 in human intervertebral discs (IVD) were determined using immunohistochemistry and western blot analysis. Apoptosis of primary cultured NPCs was quantified by Annexin V/propidium iodide staining following stimulation with SDF-1 and knockdown of CXCR4 using small interfering RNA (siRNA). The association with the nuclear factor-κB (NF-κB) signaling pathway was investigated using CXCR4-siRNA and NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), treatment. The results demonstrated that SDF-1 and its receptor, CXCR4, were upregulated in degenerative IVD samples compared with normal samples. Stimulation with SDF-1 increased the level of apoptosis in cultured NPCs, and conversely, the apoptosis level was suppressed post-transfection with CXCR4 siRNA compared with SDF-1 stimulation alone. Furthermore, SDF-1 treatment increased the level of phosphorylated NF-κB subunit P65, which was downregulated following CXCR4 siRNA and PDTC treatment. In addition, CXCR4 siRNA and PDTC inhibited the nuclear translocation of P65, which was induced by SDF-1. Taken together, SDF-1-mediated apoptosis was suppressed by NF-κB inhibition using PDTC. In conclusion, the SDF-1/CXCR4 axis promoted cell apoptosis in human degenerative NPCs via the NF-κB pathway, thus suggesting that SDF-1/CXCR signaling may be a therapeutic target for the treatment of degenerative IVD diseases. PMID:27220474

  8. Catalase prevents elevation of [Ca(2+)](i) induced by alcohol in cultured canine cerebral vascular smooth muscle cells: Possible relationship to alcohol-induced stroke and brain pathology.

    PubMed

    Li, Wenyan; Liu, Weimin; Altura, Bella T; Altura, Burton M

    2003-01-15

    Several studies have suggested that alcohol-induced brain injury is associated with generation of reactive oxygen species (ROS). The recent findings, that antioxidants (Vitamin E and pyrrolidine dithiocarbamate (PDTC)) prevent intracellular Ca(2+) ([Ca(2+)](i)) overload in cerebral vascular smooth muscle cells, induced by alcohol, demonstrate indirectly that ROS formation is related to cerebral vascular injury. The present experiments were designed to test the hypothesis that catalase, an hydrogen peroxide (H(2)O(2)) scavenging enzyme, can prevent or ameliorate alcohol-induced elevation of [Ca(2+)](i). Preincubation of cultured canine cerebral vascular smooth muscle cells with catalase (20-1000 units/ml) didn't produce any apparent changes from controls in resting levels of [Ca(2+)](i) after 1-3 days. Exposure of the cerebral vascular cells to culture media containing 10-100mM ethanol resulted in significant rises in [Ca(2+)](i) (p<0.01). Although exposure of these cells to a low concentration of catalase (20 units/ml) failed to prevent the increased level of [Ca(2+)](i) induced by ethanol, concomitant addition of higher concentrations of catalase (100-1000 units/ml) and ethanol (10-100mM) inhibited or ameliorated the rises of [Ca(2+)](i) induced by ethanol either at 24h or at 3 days, in a concentration-dependent manner. Catalase, in the range of 100-200 units/ml, inhibited approximately 50% of the [Ca(2+)](i) increases caused by ethanol in the first 24h. Catalase at a concentration of 1000 units/ml inhibited completely excessive [Ca(2+)](i) accumulation. The present results when viewed in light of other recently published data suggest that H(2)O(2) generation may be one of the earliest events triggered by alcohol in alcohol-induced brain-vascular damage, neurobehavioral actions and stroke.

  9. Low extracellular magnesium ions induce lipid peroxidation and activation of nuclear factor-kappa B in canine cerebral vascular smooth muscle: possible relation to traumatic brain injury and strokes.

    PubMed

    Altura, Burton M; Gebrewold, Asefa; Zhang, Aimin; Altura, Bella T

    2003-05-08

    The present study was designed to test the hypothesis that administration of low extracellular levels of magnesium ions ([Mg(2+)](o)) to primary cultured cerebral vascular smooth muscle cells will cause lipid peroxidation, degradation of IkappaB-alpha, and activation of nuclear transcription factor kappa B (NF-kappaB) in cultured cerebral vascular smooth muscle cells. Low [Mg(2+)](o) (0, 0.15, 0.3 and 0.48 mM) resulted in concentration-dependent rises in malondialdehyde (MDA) in as little as 3 h after exposure to low [Mg(2+)](o), rising to levels 3-12xnormal after 18-24 h; the lower the [Mg(2+)](o), the higher the MDA level. Using electrophoretic mobility shift assays and specific antibodies, low [Mg(2+)](o) caused two DNA-binding proteins (p50, p65) to rise in nuclear extracts in a concentration-dependent manner. High [Mg(2+)](o) (i.e. 4.8 mM) downregulated p50 and p65. Using a rabbit antibody, IkappaB phosphorylation (and degradation) was stimulated by low [Mg(2+)](o) (in a concentration-dependent manner) and inhibited by a low concentration of the NF-kappaB inhibitor, pyrrolidine dithiocarbamate. These new biochemical and molecular data indicate that low [Mg(2+)](o), in concentrations found in the blood of patients, after traumatic brain injury (TBI) and diverse types of strokes, can elicit rapid lipid peroxidation and activation of NF-kappaB in cerebral vascular smooth muscle cells. The present results, when viewed in light of other recently published data, suggest that low [Mg(2+)](o)-induced lipid peroxidation and activation of NF-kappaB play important roles in TBI and diverse types of strokes.

  10. TLR4/NF-κB/Ceramide signaling contributes to Ox-LDL-induced calcification of human vascular smooth muscle cells.

    PubMed

    Song, Yan; Hou, Menglin; Li, Zhenlin; Luo, Chufan; Ou, Jing-Song; Yu, Huimin; Yan, Jianyun; Lu, Lihe

    2017-01-05

    Vascular calcification is a major feature of advanced atherosclerosis and highly associated with cardiovascular diseases. Oxidized low density lipoprotein (Ox-LDL) has been recognized as a critical risk factor for atherosclerosis and osteogenic differentiation of vascular smooth muscle cells (VSMCs). Previous studies have demonstrated that toll like receptor 4 (TLR4) is highly expressed in atherosclerotic lesions and participates in the progression of atherosclerosis. However, the role of TLR4 in vascular calcification remains unknown. In this study, we investigated whether TLR4 modulates vascular calcification induced by Ox-LDL. TLR4 expression was up-regulated in cultured human VSMCs treated with Ox-LDL. Knockdown of TLR4 by small interfering RNA (siRNA) significantly reduced Ox-LDL-induced calcification, detected by alizarin red staining and calcium content assay. TLR4 siRNA also decreased the mRNA expression of bone-related proteins including Msx2, osterix, BMP2 and KLF4, but increased the expression of VSMC contractile proteins including SMA and SM22α in VSMCs. In addition, Ox-LDL stimulated nuclear translocation of nuclear factor kappa B (NK-κB) p65. These effects of Ox-LDL on VSMCs were reversed by TLR4 siRNA. Furthermore, NK-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), attenuated Ox-LDL-induced VSMC calcification, which was rescued by C2-ceramide treatment. In conclusion, these findings suggest that TLR4 regulates VSMC calcification induced by Ox-LDL through activation of NK-κB, highlighting the critical role of TLR4/NK-κB signaling in vascular calcification.

  11. Co-Activation of Nuclear Factor-κB and Myocardin/Serum Response Factor Conveys the Hypertrophy Signal of High Insulin Levels in Cardiac Myoblasts*

    PubMed Central

    Madonna, Rosalinda; Geng, Yong-Jian; Bolli, Roberto; Rokosh, Gregg; Ferdinandy, Peter; Patterson, Cam; De Caterina, Raffaele

    2014-01-01

    Hyperinsulinemia contributes to cardiac hypertrophy and heart failure in patients with the metabolic syndrome and type 2 diabetes. Here, high circulating levels of tumor necrosis factor (TNF)-α may synergize with insulin in signaling inflammation and cardiac hypertrophy. We tested whether high insulin affects activation of TNF-α-induced NF-κB and myocardin/serum response factor (SRF) to convey hypertrophy signaling in cardiac myoblasts. In canine cardiac myoblasts, treatment with high insulin (10−8 to 10−7 m) for 0–24 h increased insulin receptor substrate (IRS)-1 phosphorylation at Ser-307, decreased protein levels of chaperone-associated ubiquitin (Ub) E3 ligase C terminus of heat shock protein 70-interacting protein (CHIP), increased SRF activity, as well as β-myosin heavy chain (MHC) and myocardin expressions. Here siRNAs to myocardin or NF-κB, as well as CHIP overexpression prevented (while siRNA-mediated CHIP disruption potentiated) high insulin-induced SR element (SRE) activation and β-MHC expression. Insulin markedly potentiated TNF-α-induced NF-κB activation. Compared with insulin alone, insulin+TNF-α increased SRF/SRE binding and β-MHC expression, which was reversed by the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) and by NF-κB silencing. In the hearts of db/db diabetic mice, in which Akt phosphorylation was decreased, p38MAPK, Akt1, and IRS-1 phosphorylation at Ser-307 were increased, together with myocardin expression as well as SRE and NF-κB activities. In response to high insulin, cardiac myoblasts increase the expression or the promyogenic transcription factors myocardin/SRF in a CHIP-dependent manner. Insulin potentiates TNF-α in inducing NF-κB and SRF/SRE activities. In hyperinsulinemic states, myocardin may act as a nuclear effector of insulin, promoting cardiac hypertrophy. PMID:24855642

  12. Decrease of glial cell-derived neurotrophic factor contributes to anesthesia- and surgery-induced learning and memory dysfunction in neonatal rats.

    PubMed

    Gui, Lingli; Lei, Xi; Zuo, Zhiyi

    2017-04-01

    Long duration of anesthesia may induce toxicity in the developing brain. However, little is known about the effects of the combination of surgery and anesthesia on the developing brain. The mechanisms for the effects are not clear. To determine these effects, postnatal day 7 male and female Sprague-Dawley rats were exposed to 3% sevoflurane for 2 h with or without right common carotid exposure. Pyrrolidine dithiocarbamate (PDTC), an anti-inflammatory agent, was given 30 min before and 6 h after the carotid exposure. Anti-glial cell-derived neurotrophic factor (GDNF) antibody or GDNF was given at the end of sevoflurane exposure. We found that anesthesia-surgery induced learning and memory impairment assessed by Barnes maze and fear conditioning. Anesthesia-surgery also induced neuroinflammation and reduced the level of glial cell-derived neurotrophic factor (GDNF, 10.6 ± 0.6 pg/mg protein of control rats vs. 7.7 ± 0.4 pg/mg protein of anesthesia-surgery rats, n = 17, p = 0.007) and neurogenesis in the hippocampus. PDTC inhibited these surgical effects (GDNF level 9.7 ± 0.6 pg/mg protein of anesthesia-surgery plus PDTC rats, n = 17, p = 0.763 vs. control rats). Intracerebroventricular injection of an anti-GDNF antibody but not its heat-inactivated form induced learning and memory impairment in control rats. Intracerebroventricular injection of GDNF attenuated learning and memory impairment after anesthesia-surgery. We conclude that anesthesia-surgery in neonatal rats induces neuroinflammation, which then leads to a decreased level of GDNF and neurogenesis in the hippocampus and cognitive impairment. GDNF decrease plays an important role in anesthesia-surgery-induced cognitive impairment.

  13. AICAR Attenuates TNFα-Induced Inappropriate Secretion of Monocyte Chemoattractant Protein-1 and Adiponectin in 3T3-L1 Adipocytes

    PubMed Central

    Nagahara, Keiko; Ishikawa, Takuya; Nakano, Yuya; Abe, Yoshifusa; Tanaka, Daisuke; Itabashi, Kazuo

    2016-01-01

    Aim: The increase in monocyte chemoattractant protein-1 (MCP-1) and the decrease in adiponectin production from hypertrophic adipocytes are associated with adipose tissue inflammation and its metabolic complications. The aim of this study was to determine whether 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR), an adenosine monophosphate-activated protein kinase (AMPK) activator, modulates these adipocytokine productions in tumor necrosis factor-α (TNFα)-treated adipocytes. Methods: AICAR and/or other reagents were added to the culture medium, and then, TNFα was added to fully differentiated 3T3-L1 adipocytes. The MCP-1 and adiponectin production in the culture supernatant was measured by ELISA. AMPK, phosphatidylinositol 3-kinase (PI3K), and nuclear factor-κB (NF-κB) activities were also assayed. Results: Treatment with TNFα increased MCP-1 and decreased adiponectin secretion dose-dependently in the 3T3-L1 adipocytes, and AICAR significantly inhibited these TNFα-mediated changes. Interestingly, metformin, another AMPK activator, did not have such effects on these adipocytokines. Both the AMPK and PI3K systems in the cells were significantly activated by the AICAR treatment, but the effects of AICAR on adipocytokines were not weakened by the addition of dorsomorphin, an AMPK inhibitor, or LY294002, a PI3K inhibitor. Pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor, showed protective effects similar to those as AICAR. AICAR, but not metformin, significantly inhibited the TNFα-stimulated activation of NF-κB, and dorsomorphin did not change AICAR's effect. Conclusion: AICAR attenuates the TNFα-induced secretion of MCP-1 and adiponectin in 3T3-L1 adipocytes. The observed effects of AICAR seem to be mainly due to the inhibition of NF-κB activation rather than the activation of the AMPK pathway, at least in TNFα-treated adipocytes. PMID:27170207

  14. Sirtuin1 (SIRT1) Regulates Tumor Necrosis Factor-alpha (TNF-α-Induced) Aquaporin-2 (AQP2) Expression in Renal Medullary Collecting Duct Cells Through Inhibiting the NF-κB Pathway

    PubMed Central

    Lin, Qinqin; Geng, Yuanwen; Lin, Shuaishuai; Tian, Zhenjun

    2016-01-01

    Background Aquaporin-2 (AQP2) plays a major role in water reabsorption in the renal collecting duct, and is involved in a variety of renal disease. Recent studies have indicate that sirtuin1 (SIRT1) exerts renoprotective properties against kidney diseases. This study aimed to determine the potential role of SIRT1 in AQP2 expression induced by tumor necrosis factor-alpha (TNF-α) and to disclose the underlying mechanism in renal inner medullary collecting duct (IMCD) cells. Material/Methods Quantitative real-time PCR and Western blotting were respectively identified mRNA and protein expression. Immunofluorescence staining was used to detect the localization of AQP2. Small-interfering RNA (siRNA) was carried out for mechanism study. Results Results showed that AQP2 was clearly increased in the plasma membrane and decreased in the cytoplasm of IMCD cells treated with AVP. TNF-α treatment in IMCD cells significantly reduced SIRT1 and AQP2 expression, and increased acetylated NF-κBp65 protein level in time- and concentration-dependent manners. Moreover, SIRT1 overexpression or the activator SRT1720 augmented AQP2 expression and reduced the acetylation of NF-κBp65, which was reversed by SIRT1 siRNA or the inhibitors Ex527 and sirtinol in TNF-α-induced IMCD cells. Knockdown of NF-κBp65 or NF-κBp65 inhibition by pyrrolidine dithiocarbamate (PDTC) enhanced AQP2 expression in IMCD cells exposed to TNF-α. Importantly, knockdown of NF-κBp65 augmented the up-regulation of SIRT1 on AQP2 expression in IMCD cells induced by TNF-α. Conclusions These findings indicate that SIRT1 increases AQP2 expression in TNF-α-induced IMCD cells via the NF-κB-dependent signalling pathway, which might provide novel insight to understanding the renoprotective effects of SIRT1 in kidney diseases. PMID:27980322

  15. Evaluation of the aneugenic potential of the fungicide Ferbam in mice.

    PubMed

    Shanthi, R; Krishnamoorthy, M

    2002-01-01

    Ferbam, a potent dithiocarbamate fungicide is used as a protectant against a wide variety of fungal diseases in fruits, vegetables, and ornamental plants. The wide-spread use of this chemical is likely to pollute the environment. Hence, it was planned to test the possible genotoxicity of Ferbam through its aneugenic potential in the in vivo mouse (Mus musculus) test system. Four different doses of Ferbam, namely, 7.5, 15.0, 30.0, 60.0 mg/kg body weight were administered orally to mice Mus musculus suspended in gum tragacanth representing, respectively, 1/16, 1/8, 1/4;, 1/2 th of the LD50 value. They were sacrificed at 6-, 12-, 24-, and 48-h intervals along with a distilled water negative control at 2 mg/kg body weight. Colchicine treated animals were used as positive controls. Bone marrow preparations were made following the standard Hypotonic flame dry Giemsa staining technique to study the dose and time yield effect of Ferbam. The aneugenic potential was evaluated for C-mitotic effects by scoring the mitotic index, c-mitoses frequency, anaphase reduction, and hyper/hypodiploidy induction. Ferbam showed a significant increase in the mitotic index and C-mitoses effects and anaphase decreased at the highest doses of 30 and 60 mg/kg at 12- and 24-h intervals. Colchicine induced significant effects in all the aneugenic parameters observed at all the time intervals. There was no significant induction of either hyperdiploidy or hypodiploidy by Ferbam, unlike colchicine, indicating that the fungicide Ferbam is not aneugenic in the mouse test system.

  16. Secondary production of freshwater zooplankton communities exposed to a fungicide and to a petroleum distillate in outdoor pond mesocosms.

    PubMed

    Bayona, Yannick; Roucaute, Ana; Roucaute, Marc; Gorzerino, Caroline; Cailleaud, Kevin; Lagadic, Laurent; Bassères, Anne; Caquet, Thierry

    2014-04-01

    Ecological risk assessment of chemicals in mesocosms requires measurement of a large number of parameters at the community level. Studies on invertebrate communities usually focus on taxonomic approaches, which only provide insights into taxonomic structure changes induced by chemicals. In the present study, abundance, biomass (B), theoretical production (P), and instantaneous P/B ratio were used as endpoints to assess the effects of the commercial form of the dithiocarbamate fungicide thiram (35 µg/L and 170 µg/L nominal concentrations) and of the hydrocarbon water accommodated fraction (HWAF) of a petroleum distillate (0.01 mg/L, 0.4 mg/L, 2 mg/L, and 20 mg/L loadings) on the zooplankton community in freshwater pond mesocosms. Endpoints were measured during a 4-wk treatment period (1 pulse/wk) followed by a 5-mo posttreatment period to evaluate zooplankton population recovery. The chlorophyll a concentration in water was significantly increased after treatment with HWAF, whereas it was not affected by thiram treatment. Zooplankton abundance-based analysis showed effects on a limited number of taxa, whereas other endpoints (mainly the P/B ratio) revealed that more taxa were impacted, with recovery depending on the chemical and concentration. Exposure to HWAF mainly had a negative impact on cladocerans, which resulted in top-down effects (between cladocerans and phytoplankton). Thiram negatively affected rotifers and copepods, suggesting more direct toxic effects. The results show that the use of secondary production as an endpoint provides a more comprehensive assessment of potential direct and indirect effects of chemicals on a community, and they also support evidence of alteration in functional processes.

  17. Decreased epithelial barrier function evoked by exposure to metabolic stress and nonpathogenic E. coli is enhanced by TNF-alpha.

    PubMed

    Lewis, Kimberley; Caldwell, Jackie; Phan, Van; Prescott, David; Nazli, Aisha; Wang, Arthur; Soderhölm, Johan D; Perdue, Mary H; Sherman, Philip M; McKay, Derek M

    2008-03-01

    A defect in mitochondrial activity contributes to many diseases. We have shown that monolayers of the human colonic T84 epithelial cell line exposed to dinitrophenol (DNP, uncouples oxidative phosphorylation) and nonpathogenic Escherichia coli (E. coli) (strain HB101) display decreased barrier function. Here the impact of DNP on macrophage activity and the effect of TNF-alpha, DNP, and E. coli on epithelial permeability were assessed. DNP treatment of the human THP-1 macrophage cell line resulted in reduced ATP synthesis, and, although hyporesponsive to LPS, the metabolically stressed macrophages produced IL-1beta, IL-6, and TNF-alpha. Given the role of TNF-alpha in inflammatory bowel disease (IBD) and the association between increased permeability and IBD, recombinant TNF-alpha (10 ng/ml) was added to the DNP (0.1 mM) + E. coli (10(6) colony-forming units), and this resulted in a significantly greater loss of T84 epithelial barrier function than that elicited by DNP + E. coli. This increased epithelial permeability was not due to epithelial death, and the enhanced E. coli translocation was reduced by pharmacological inhibitors of NF-kappabeta signaling (pyrrolidine dithiocarbamate, NF-kappabeta essential modifier-binding peptide, BAY 11-7082, and the proteosome inhibitor, MG132). In contrast, the drop in transepithelial electrical resistance was unaffected by the inhibitors of NF-kappabeta. Thus, as an integrative model system, our findings support the induction of a positive feedback loop that can severely impair epithelial barrier function and, as such, could contribute to existing inflammation or trigger relapses in IBD. Thus metabolically stressed epithelia display increased permeability in the presence of viable nonpathogenic E. coli that is exaggerated by TNF-alpha released by activated immune cells, such as macrophages, that retain this ability even if they themselves are experiencing a degree of metabolic stress.

  18. Pharmacological analysis for mechanisms of GPI-80 release from tumour necrosis factor-alpha-stimulated human neutrophils.

    PubMed

    Nitto, Takeaki; Araki, Yoshihiko; Takeda, Yuji; Sendo, Fujiro

    2002-10-01

    1 GPI-80, a glycosylphosphatidylinositol (GPI)-anchored protein initially identified on human neutrophils, plays a role(s) in the regulation of beta2 integrin function. Previous studies have shown that GPI-80 is sublocated in secretory vesicles. It is also found in soluble form in the synovial fluid of rheumatoid arthritis patients, and in the culture supernatant of formyl-methionyl-leucyl-phenylalanine-stimulated neutrophils. To understand the behaviour of GPI-80 under conditions of stimulation, we investigated the effects of tumour necrosis factor (TNF)-alpha on its expression and release. We also probed the mechanism of its release with various pharmacologic tools. 2 TNF-alpha induced the release of GPI-80 from human neutrophils in a concentration- and time-dependent manner (in the range of 1-100 u ml(-1) and 30-120 min, respectively), but did not affect surface GPI-80 levels. 3 Cytochalasin B, genistein, and SB203580 but not PD98059 inhibited TNF-alpha-stimulated GPI-80 release and neutrophil adherence at the same concentration. In addition, TNF-alpha-induced GPI-80 release was inhibited by blocking monoclonal antibodies specific to components of Mac-1 (CD11b and CD18). 4 Antioxidants (pyrrolidine dithiocarbamate and N-acetyl-L-cysteine) inhibited GPI-80 release by TNF-alpha stimulation, but superoxide dismutase did not. Antioxidants but not superoxide dismutase reduced an intracellular oxidation state. 5 These findings indicate that TNF-alpha-stimulated GPI-80 release from human neutrophils depends upon adherence via beta2 integrins. They also suggest that cytochalasin B, genistein, and SB203580 inhibit GPI-80 release by suppressing signals for cell adherence, rather than by a direct effect on its secretion. Finally, we suggest that GPI-80 release involves an intracellular change in a redox state.

  19. Perinatal Exogenous Nitric Oxide in Fawn-Hooded Hypertensive Rats Reduces Renal Ribosomal Biogenesis in Early Life

    PubMed Central

    Wesseling, Sebastiaan; Essers, Paul B.; Koeners, Maarten P.; Pereboom, Tamara C.; Braam, Branko; van Faassen, Ernst E.; MacInnes, Alyson W.; Joles, Jaap A.

    2011-01-01

    Nitric oxide (NO) is known to depress ribosome biogenesis in vitro. In this study we analyzed the influence of exogenous NO on ribosome biogenesis in vivo using a proven antihypertensive model of perinatal NO administration in genetically hypertensive rats. Fawn-hooded hypertensive rat (FHH) dams were supplied with the NO-donor molsidomine in drinking water from 2 weeks before to 4 weeks after birth, and the kidneys were subsequently collected from 2 day, 2 week, and 9 to 10-month-old adult offspring. Although the NO-donor increased maternal NO metabolite excretion, the NO status of juvenile renal (and liver) tissue was unchanged as assayed by EPR spectroscopy of NO trapped with iron-dithiocarbamate complexes. Nevertheless, microarray analysis revealed marked differential up-regulation of renal ribosomal protein genes at 2 days and down-regulation at 2 weeks and in adult males. Such differential regulation of renal ribosomal protein genes was not observed in females. These changes were confirmed in males at 2 weeks by expression analysis of renal ribosomal protein L36a and by polysome profiling, which also revealed a down-regulation of ribosomes in females at that age. However, renal polysome profiles returned to normal in adults after early exposure to molsidomine. No direct effects of molsidomine were observed on cellular proliferation in kidneys at any age, and the changes induced by molsidomine in renal polysome profiles at 2 weeks were absent in the livers of the same rats. Our results suggest that the previously found prolonged antihypertensive effects of perinatal NO administration may be due to epigenetically programmed alterations in renal ribosome biogenesis during a critical fetal period of renal development, and provide a salient example of a drug-induced reduction of ribosome biogenesis that is accompanied by a beneficial long-term health effect in both males and females. PMID:22303348

  20. Comparative effects of chelating agents on distribution, excretion, and renal toxicity of inorganic mercury in rats

    SciTech Connect

    Kojima, S.; Shimada, H.; Kiyozumi, M. )

    1989-06-01

    The effects of three chelating agents, sodium N-benzyl-D-glucamine dithiocarbamate(NBG-DTC), 2,3-dimercaptopropanol(BAL), and D-penicillamine(D-PEN), on the distribution, excretion, and renal toxicity of inorganic mercury were compared in rats exposed to HgCl2. Rats were injected i.p. with 203HgCl2 (300 micrograms of Hg and 2 microCi of 203Hg/kg) and 30 min or 24 h later they were injected with a chelating agent (a quarter of an LD50). The injection of the chelating agents significantly enhanced the biliary and urinary excretions of mercury. BAL was the most effective for removal of mercury from the body at 30 min after mercury treatment. The extent of enhancing effect of the chelating agents for removal of mercury at 24 h after mercury was in the order NBG-DTC = BAL greater than D-PEN. The injection of BAL at 24 h after mercury treatment caused the redistribution of mercury to the heart and lung. NBG-DTC did not result in the redistribution of mercury to the heart, lung, and brain. Urinary excretion of protein and AST significantly increased 24-48 h after mercury treatment and decreased to the control values 72 h after mercury. The injection of the chelating agents at 30 min after mercury treatment significantly decreased the urinary excretion of protein and AST. In rats pretreated with mercury 24 h earlier, the chelating agents significantly decreased the urinary protein at 48 h after mercury treatment, but did not decrease the urinary AST. The results of this study indicate that the chelating agents are effective in removing mercury from the body, resulting in the protective effect against the mercury-induced renal damage.

  1. NF-κB activation mediates crystal translocation and interstitial inflammation in adenine overload nephropathy.

    PubMed

    Okabe, Cristiene; Borges, Raquel Lerner; de Almeida, Danilo Candido; Fanelli, Camilla; Barlette, Grasiela Pedreira; Machado, Flavia Gomes; Arias, Simone Costa Alarcon; Malheiros, Denise Maria Avancini Costa; Camara, Niels Olsen Saraiva; Zatz, Roberto; Fujihara, Clarice Kazue

    2013-07-15

    Adenine overload promotes intratubular crystal precipitation and interstitial nephritis. We showed recently that these abnormalities are strongly attenuated in mice knockout for Toll-like receptors-2, -4, MyD88, ASC, or caspase-1. We now investigated whether NF-κB activation also plays a pathogenic role in this model. Adult male Munich-Wistar rats were distributed among three groups: C (n = 17), receiving standard chow; ADE (n = 17), given adenine in the chow at 0.7% for 1 wk and 0.5% for 2 wk; and ADE + pyrrolidine dithiocarbamate (PDTC; n = 14), receiving adenine as above and the NF-κB inhibitor PDTC (120 mg·kg⁻¹·day⁻¹ in the drinking water). After 3 wk, widespread crystal deposition was seen in tubular lumina and in the renal interstitium, along with granuloma formation, collagen accumulation, intense tubulointerstitial proliferation, and increased interstitial expression of inflammatory mediators. Part of the crystals were segregated from tubular lumina by a newly formed cell layer and, at more advanced stages, appeared to be extruded to the interstitium. p65 nuclear translocation and IKK-α increased abundance indicated activation of the NF-κB system. PDTC treatment prevented p65 migration and normalized IKK-α, limited crystal shift to the interstitium, and strongly attenuated interstitial fibrosis/inflammation. These findings indicate that the complex inflammatory phenomena associated with this model depend, at least in part, on NF-κB activation, and suggest that the NF-κB system may become a therapeutic target in the treatment of chronic kidney disease.

  2. Increased reactive oxygen species production down-regulates peroxisome proliferator-activated alpha pathway in C2C12 skeletal muscle cells.

    PubMed

    Cabrero, Agatha; Alegret, Marta; Sanchez, Rosa M; Adzet, Tomas; Laguna, Juan C; Carrera, Manuel Vazquez

    2002-03-22

    Generation of reactive oxygen species may contribute to the pathogenesis of diseases involving intracellular lipid accumulation. To explore the mechanisms leading to these pathologies we tested the effects of etomoxir, an inhibitor of carnitine palmitoyltransferase I which contains a fatty acid-derived structure, in C2C12 skeletal muscle cells. Etomoxir treatment for 24 h resulted in a down-regulation of peroxisome proliferator-activated receptor alpha (PPARalpha) mRNA expression, achieving an 87% reduction at 80 microm etomoxir. The mRNA levels of most of the PPARalpha target genes studied were reduced at 100 microm etomoxir. By using several inhibitors of de novo ceramide synthesis and C(2)-ceramide we showed that they were not involved in the effects of etomoxir. Interestingly, the addition of triacsin C, a potent inhibitor of acyl-CoA synthetase, to etomoxir-treated C2C12 skeletal muscle cells did not prevent the down-regulation in PPARalpha mRNA levels, suggesting that the active form of the drug, etomoxir-CoA, was not involved. Given that saturated fatty acids may generate reactive oxygen species (ROS), we determined whether the addition of etomoxir resulted in ROS generation. Etomoxir increased ROS production and the activity of the well known redox transcription factor NF-kappaB. In the presence of the pyrrolidine dithiocarbamate, a potent antioxidant and inhibitor of NF-kappaB activity, etomoxir did not down-regulate PPARalpha mRNA in C2C12 skeletal muscle cells. These results indicate that ROS generation and NF-kappaB activation are responsible for the down-regulation of PPARalpha and may provide a new mechanism by which intracellular lipid accumulation occurs in skeletal muscle cells.

  3. Speciation and determination of ultra trace amounts of inorganic tellurium in environmental water samples by dispersive liquid-liquid microextraction and electrothermal atomic absorption spectrometry.

    PubMed

    Najafi, Nahid Mashkouri; Tavakoli, Hamed; Alizadeh, Reza; Seidi, Shahram

    2010-06-18

    A simple and powerful method has been developed for the rapid and selective determination of Te(IV) and Te(VI), employing dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry using palladium as permanent modifier. Under acidic conditions pH 1, only Te(IV) can form a complex with ammonium pyrrolidine dithiocarbamate (APDC) and therefore be extracted into fine droplets of carbon tetrachloride (extraction solvent) which are dispersed with ethanol into the water sample solution. After centrifugation, Te(IV) was determined in the sedimented organic phase while Te(VI) remained in the aqueous phase. Total inorganic tellurium was determined after the reduction of the Te(VI) to Te(IV). Te(VI) was calculated as the difference between the measured total inorganic tellurium and Te(IV) content. The effective parameters for improving the efficiency of microextraction process were investigated by using experimental and central composite designs. Under optimal conditions the enrichment factor was 125 and the calibration graph was linear in the range of 0.015-1 ng mL(-1) with detection limit and characteristic mass of 0.004 ng mL(-1) and 0.033 pg, respectively. The relative standard deviation for 0.5 ng mL(-1) of tellurium measurement was 3.6% (n=6) at ash and atomization temperature, 900 and 2600 degrees C, respectively. The recoveries of spiked Te(IV) and Te(VI) to the environmental water samples were 89.6-101.3% and 96.6-99.1%, respectively. The accuracy is also evaluated by applying the proposed method to certified reference material (NIST SRM 1643e), for which the result was in a good agreement with the certified values reported for this CRM (95% confidence level).

  4. Development of new portable miniaturize solid phase microextraction of silver-APDC complex using micropipette tip in-syringe system couple with electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Naeemullah; Kazi, Tasneem Gul; Afridi, Hassan Imran; Shah, Faheem; Arain, Sadaf Sadia; Arain, Salma Aslam; Panhwar, Abdul Haleem; Arain, Mariam Shahzadi; Samoon, Muhammad Kashif

    2016-02-01

    An innovative and simple miniaturized solid phase microextraction (M-SPME) method, was developed for preconcentration and determination of silver(I) in the fresh and waste water samples. For M-SPME, a micropipette tip packed with activated carbon cloth (ACC) as sorbent, in a syringe system. The size, morphology and elemental composition of ACC before and after adsorption of analyte have been characterized by scanning electron microscopy and energy dispersive spectroscopy. The sample solution treated with a complexing reagent, ammonium pyrrolidine dithiocarbamate (APDC), was drawn into the syringe filled with ACC and dispensed manually for 2 to 10 aspirating/dispensing cycle. Then the Ag- complex sorbed on the ACC in micropipette was quantitatively eluted by drawing and dispensing of different concentrations of acids for 2 to 5 aspirating/dispensing cycles. The extracted Ag ions with modifier were injected directly into the electrothermal atomic absorption spectrometry for analysis. The influence of different variables on the extraction efficiency, including the concentration of ligand, pH, sample volume, eluent type, concentration and volume was investigated. Validity and accuracy of the developed method was checked by the standard addition method. Reliability of the proposed methodology was checked by the relative standard deviation (%RSD), which was found to be < 5%. Under the optimized experimental variables, the limits of detection (LOD) and enhancement factors (EF), were obtained to be 0.86 ng L- 1 and 120, respectively. The proposed method was successfully applied for the determination of trace levels of silver ions in fresh and waste water samples.

  5. IFN-γ regulates xanthine oxidase-mediated iNOS-independent oxidative stress in maneb- and paraquat-treated rat polymorphonuclear leukocytes.

    PubMed

    Singh, Deepali; Kumar, Vinod; Singh, Chetna

    2017-03-01

    Maneb (MB) and paraquat (PQ) provoke oxidative stress-mediated cell damage. Role of xanthine oxidase (XO) in oxidative stress and its association with nitric oxide (NO)/NO synthase (NOS) have been widely reported. While inducible NOS (iNOS) is implicated in MB+PQ-induced toxicity in rat polymorphonuclear leukocytes (PMNs), role of XO and its alliance with iNOS have not yet been established. The study investigated the role of XO in MB+PQ-induced oxidative stress in rat PMNs and its regulation by iNOS and inflammatory cytokines. MB+PQ-augmented reactive oxygen species (ROS), superoxide, nitro-tyrosine, lipid peroxidation (LPO), and nitrite levels along with the catalytic activity of iNOS, superoxide dismutase (SOD), and XO. XO inhibitor, allopurinol (AP), alleviated MB+PQ-induced changes except nitrite content and iNOS activity. Conversely, an iNOS inhibitor, aminoguanidine, mitigated MB+PQ-induced LPO, nitrite, iNOS, and nitro-tyrosine levels; however, no change was observed in ROS, SOD, and XO. Nuclear factor-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), tumor necrosis factor-alpha (TNF-α) inhibitor, pentoxyfylline, and an anti-inflammatory agent, dexamethasone, attenuated MB+PQ-induced increase in XO, superoxide, and ROS with parallel reduction in the expression of interferon-gamma (IFN-γ), TNF-α, and interleukin-1β (IL-1β) in rat PMNs. Exogenous IFN-γ, TNF-α, and IL-1β enhanced superoxide, ROS, and XO in the PMNs of control and MB+PQ-treated rats; however, IFN- γ was found to be the most potent inducer. Moreover, AP ameliorated cytokine-induced free radical generation and restored XO activity towards normalcy. The results thus demonstrate that XO mediates oxidative stress in MB+PQ-treated rat PMNs via iNOS-independent but cytokine (predominantly IFN-γ)-dependent mechanism.

  6. Down-regulation of MMP-2 through the p38 MAPK-NF-kappaB-dependent pathway by aloe-emodin leads to inhibition of nasopharyngeal carcinoma cell invasion.

    PubMed

    Lin, Meng-Liang; Lu, Yao-Cheng; Chung, Jing-Gung; Wang, Shyang-Guang; Lin, Hsin-Ting; Kang, Shang-En; Tang, Chih-Hsin; Ko, Jiunn-Liang; Chen, Shih-Shun

    2010-09-01

    Aloe-emodin (AE), extracted from the rhizome of Rheum palmatum, has an anti-proliferative effect on different human cancer cell lines. Nonetheless, the underlying mechanism by which AE inhibits nasopharyngeal carcinoma (NPC) cell invasion is still unclear. The results of this study show that treatment of NPC cells with growth suppressive concentrations of AE caused cell cycle arrest at the S-G(2)/M phase. Coimmunoprecipitation and small interfering RNA (siRNA) studies demonstrated that AE-induced cell cycle arrest in NPC cells was associated with increasing levels of cyclin B1 bound to cyclin-dependent kinase 1. The inhibition of NPC cell invasion by AE was evidenced through the suppression of matrix metalloproteinases-2 (MMP-2) expression. MMP-2 promoter activity and cell invasion were inhibited by p38 mitogen-activated protein kinase (MAPK) siRNA, inhibitor 4-(4-Fluorophenyl)-2-[4-(methylsulfinyl)phenyl]-5-(4-pyridyl)-1H-imidazole (SB203580), and AE, but not by JNK siRNA and inhibitor 1,9-pyrazoloanthrone. Treatment with AE, SB203580, NF-kappaB inhibitors N-p-tosyl-(L)-phenylalanine chloromethyl ketone (TPCK) and pyrrolidine dithiocarbamate (PDTC) or transfection with p38 MAPK siRNA significantly inhibited NF-kappaB transcriptional activity. In addition, TPCK and PDTC treatment inhibited the expression and promoter activity of MMP-2 and thereby significantly inhibited cell invasion activity. The involvement of p38 MAPK activity in NF-kappaB-mediated MMP-2 function was further confirmed through the attenuation of p38 MAPK by SB203580 and NF-kappaB ectopic expression. Collectively, our results indicate that AE inhibits invasion of NPC cells by suppressing the expression of MMP-2 via the p38 MAPK-NF-kappaB signaling pathway.

  7. Enhanced binding capability of nuclear factor-κB with demethylated P2X3 receptor gene contributes to cancer pain in rats

    PubMed Central

    Zhou, You-Lang; Jiang, Guo-Qin; Wei, Jinrong; Zhang, Hong-Hong; Chen, Wei; Zhu, Hongyan; Hu, Shufen; Jiang, Xinghong; Xu, Guang-Yin

    2015-01-01

    Abstract Nuclear factor-kappa B (NF-κB) signaling is implicated in both cancer development and inflammation processes. However, the roles and mechanisms of NF-κB signaling in the development of cancer-induced pain (CIP) remain unknown. This study was designed to investigate the roles of the p65 subunit of NF-κB in regulation of the purinergic receptor (P2X3R) plasticity in dorsal root ganglion (DRG) of CIP rats. We showed here that tumor cell injection produced mechanical and thermal hyperalgesia, and an enhanced body weight–bearing difference, which was correlated with an upregulation of p65 and P2X3R expression in lumber DRGs and a potentiation of ATP-evoked responses of tibia-innervating DRG neurons. Inhibition of NF-κB signaling using p65 inhibitor pyrrolidine dithiocarbamate, BAY-11-7082, or lentiviral-p65 short-hairpin RNA significantly attenuated CIP and reversed the activities of P2X3R. Interestingly, tumor cell injection led to a significant demethylation of CpG island in p2x3r gene promoter and enhanced ability of p65 to bind the promoter of p2x3r gene. Our findings suggest that upregulation of P2X3R expression was mediated by the enhanced binding capability of p65 with demethylated promoter of p2x3r gene, thus contributing to CIP. NF-κBp65 might be a potential target for treating CIP, a neuropathic pain generated by tumor cell–induced injury to nerves that innervate the skin. PMID:26049406

  8. Rosiglitazone via PPARγ-dependent suppression of oxidative stress attenuates endothelial dysfunction in rats fed homocysteine thiolactone.

    PubMed

    Yang, Xu-Hong; Li, Peng; Yin, Ya-Ling; Tu, Jiang-Hua; Dai, Wen; Liu, Li-Ying; Wang, Shuang-Xi

    2015-04-01

    To explore whether rosiglitazone (RSG), a selective peroxisome proliferator-activated receptor γ (PPARγ) agonist, exerts beneficial effects on endothelial dysfunction induced by homocysteine thiolactone (HTL) and to investigate the potential mechanisms. Incubation of cultured human umbilical vein endothelial cells with HTL (1 mM) for 24 hrs significantly reduced cell viabilities assayed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, as well as enhanced productions of reactive oxygen species, activation of nuclear factor kappa B, and increased intercellular cell adhesion molecule-1 secretion. Pre-treatment of cells with RSG (0.001-0.1 mM), pyrollidine dithiocarbamate (PDTC, 0.1 mM) or apocynin (0.1 mM) for 1 hr reversed these effects induced by HTL. Furthermore, co-incubation with GW9662 (0.01 mM) abolished the protective effects of RSG on HTL-treated cells. In ex vivo experiments, exposure of isolated aortic rings from. rats to HTL (1 mM) for 1 hr dramatically impaired acetylcholine-induced endothelium-dependent relaxation, reduced release of nitric oxide and activity of superoxide dismutase, and increased malondialdehyde content in aortic tissues. Preincubation of aortic rings with RSG (0.1, 0.3, 1 mM), PDTC or apocynin normalized the disorders induced by HTL. In vivo analysis indicated that administration of RSG (20 mg/kg/d) remarkably suppressed oxidative stress and prevented endothelial dysfunction in rats fed HTL (50 mg/kg/d) for 8 weeks. RSG improves endothelial functions in rats fed HTL, which is related to PPARγ-dependent suppression of oxidative stress.

  9. Cyclosporin A promotes proliferating cell nuclear antigen expression and migration of human cytotrophoblast cells via the mitgen-activated protein kinase-3/1-mediated nuclear factor-κB signaling pathways.

    PubMed

    Wang, Song-Cun; Yu, Min; Li, Yan-Hong; Piao, Hai-Lan; Tang, Chuan-Lin; Sun, Chan; Zhu, Rui; Li, Ming Qing; Jin, Li-Ping; Li, Da-Jin; Du, Mei-Rong

    2013-01-01

    Our previous studies have demonstrated that cyclosporin A (CsA) promotes the proliferation and migration of human trophoblasts via the mitgen-activated protein kinase-3/1 (MAPK3/1) pathway. In the present study, we further investigated the role of nuclear factor (NF)-κB in the CsA-induced trophoblast proliferating cell nuclear antigen (PCNA) expression and migration, and its relationship to MAPK3/1 signal. Flow cytometry was used to analyze the expression of PCNA in trophoblasts. The migration of human primary trophoblasts was determined by wound-healing assay and transwell migration assay. Western blot analysis was performed to evaluate the activation of NF-κB p65 and NF-κB inhibitory protein I-κB in human trophoblasts. We found that treatment with CsA promotes PCNA expression and migration of human trophoblast in a dose-associated manner. Blocking of the MAPK3/1 signal abrogated the enhanced PCNA expression and migration in trophoblasts by CsA. In addition, CsA increased the phosphorylation of NF-κB p65 and the inhibitor I-κB in human trophoblasts in a time-related manner. Pretreatment with MAPK3/1 inhibitor U0126 abrogated the phosphorylation of NF-κB p65 and I-κB. Accordingly, the CsA-induced enhancement of PCNA expression and migration in trophoblasts was also decreased. This CsA-induced enhancement in the expression and migration of trophoblasts was abolished by pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor. Thus, our results suggest that CsA promotes PCNA expression and migration of human trophoblasts via MAPK-mediated NF-κB activation.

  10. Humic acid in drinking well water induces inflammation through reactive oxygen species generation and activation of nuclear factor-κB/activator protein-1 signaling pathways: a possible role in atherosclerosis.

    PubMed

    Hseu, You-Cheng; Senthil Kumar, K J; Chen, Chih-Sheng; Cho, Hsin-Ju; Lin, Shu-Wei; Shen, Pei-Chun; Lin, Cheng-Wen; Lu, Fung-Jou; Yang, Hsin-Ling

    2014-01-15

    Humic acid (HA) has been implicated as one of the etiological factors in the peripheral vasculopathy of blackfoot disease (BFD) in Taiwan. However, the underlying pathophysiological mechanisms of BFD are not well defined. In this study, we used an in vitro and in vivo model, in which HA (25-200μg/mL) activated macrophages to produce pro-inflammatory molecules by activating their transcriptional factors. HA exposure induced NO and PGE2 production followed by induction of iNOS and COX-2 through NF-κB/AP-1 transactivation in macrophages. In addition, the production of TNF-α and IL-1β was significantly increased by HA. Moreover, HA-induced iNOS and COX-2 expression were down-regulated by the NF-κB and AP-1 inhibitors pyrrolidine dithiocarbamate (PDTC) and Tanshinone, respectively. Furthermore, generations of ROS and nitrotyrosine, as well as activation of the AKT and MAPKs signaling cascades were observed after HA exposure. Specifically, HA-induced NF-κB activation was mediated by ROS and AKT, and that HA-induced AP-1 activation was mediated by JNK and ERK. Notably, HA-mediated AKT, JNK, and ERK activation was ROS-independent. The inflammatory potential of HA was correlated with increased expression of HO-1 and Nrf2. Furthermore, an in vivo study confirms that mice exposed to HA, the serum levels of TNF-α and IL-1β was significantly increased in a dose-dependent manner. This report marks the first confirmation that environmental exposure of HA induces inflammation in macrophages, which may be one of the main causes of early atherogenesis in blackfoot disease.

  11. The use of a cis-dioxomolybdenum(VI) dinuclear complex with quadradentate 1,4-benzenediylbis(benzyldithiocarbamate)(2-) as model compound for the active site of oxo transfer molybdoenzymes: reactivity, kinetics, and catalysis.

    PubMed

    Moradi-Shoeili, Zeinab; Boghaei, Davar M

    2012-03-01

    Dinuclear cis-dioxomolybdenum(VI) complex [{MoO(2)(Bz(2)Benzenediyldtc)}(2)] coordinated by a quadradentate dithiocarbamate (Bz(2)Benzenediyldtc(2-)=1,4-benzenediylbis(benzyldithiocarbamate)(2-)) has been prepared and characterized by elemental analysis, (13)C NMR, IR and UV-vis spectroscopy. The kinetics of the oxygen atom transfer between [{MoO(2)(Bz(2)Benzenediyldtc)}(2)] and PPh(3) was studied spectrophotometrically in CH(2)Cl(2) medium at 520 nm and four different temperatures, 288, 293, 298 and 303 K, respectively. The reaction follows second order kinetics with the rate constant k=0.163(2)M(-1)S(-1) and its increasingly strong absorption at 520 nm clearly indicate the formation of a μ-oxo molybdenum(V) species as a product. Despite the steric restrictions imposed by the ligand structure to prevent the formation of Mo(V) species, experimental evidence confirms its interference during the process. The product can then be formulated as [MoO(2)(Bz(2)Benzenediyldtc)(2)Mo(2)O(3)(Bz(2)Benzenediyldtc)(2)MoO(2)] which has one μ-oxomolybdenum(V) moiety. An Eyring plot allows the activation parameters ΔH(‡)=64.2(1) kJ mol(-1) and ΔS(‡)=-45.1(6) J K(-1) mol(-1) to be determined from the temperature dependence of the rate constant, suggesting an associative transition state for the oxo transfer reaction. Catalytic oxygen atom transfer reaction from DMSO to PPh(3) was also followed by monitoring the chemical shift changes in (31)P NMR spectroscopy. The substrate oxidation process follows a well-defined catalytic cycle capable of 100% conversion for the reaction of PPh(3) and DMSO without intervention of Mo(V) formation during about 36 h.

  12. Iminophosphorane-organogold(III) complexes induce cell death through mitochondrial ROS production

    PubMed Central

    Vela, Laura; Contel, María; Palomera, Luis; Azaceta, Gemma; Marzo, Isabel

    2011-01-01

    Gold compounds are being investigated as potential antitumor drugs. Some gold(III) derivatives have shown to induce cell death in solid tumors but their mechanism of action differs from that of cisplatin, since most of these compounds do not bind to DNA. We have explored cellular events triggered by three different iminophosphorane-organo gold(III) compounds in leukemia cells (a neutral compound with two chloride ligands [Au{κ2-C,N-C6H4(PPh2=N(C6H5)-2}Cl2] 1, and two cationic compounds with either a dithiocarbamate ligand [Au{κ2-C,N-C6H4(PPh2=N(C6H5)-2}(S2CN-Me2)]PF6 2, or a water-soluble phosphine and a chloride ligand [Au{κ2-C,N-C6H4(PPh2=N(C6H5)-2}(P{Cp(m-C6H4-SO3Na)2}3) Cl]PF6 3). All three compounds showed higher toxicity against leukemia cells when compared to normal T-lymphocytes. Compounds 1 and 2 induced both necrosis and apoptosis, while 3 was mainly apoptotic. Necrotic cell death induced by 1 and 2 was Bax/Bak- and caspase-independent, while apoptosis induced by 3 was Bax/Bak-dependent. Reactive oxygen species (ROS) production at the mitochondrial level was a critical step in the antitumor effect of these compounds. PMID:21864808

  13. Cartilage and bone malformations in the head of zebrafish (Danio rerio) embryos following exposure to disulfiram and acetic acid hydrazide

    SciTech Connect

    Strecker, Ruben; Weigt, Stefan; Braunbeck, Thomas

    2013-04-15

    In order to investigate teratogenic effects, especially on cartilage and bone formation, zebrafish embryos were exposed for 144 h to the dithiocarbamate pesticide disulfiram (20–320 μg/L) and acetic acid hydrazide (0.375–12 g/L), a degradation product of isoniazid. After fixation and full-mount staining, disulfiram could be shown to induce strong cartilage malformations after exposure to ≥ 80 μg/L, whereas acetic acid hydrazide caused cartilage alterations only from 1.5 g/L. Undulating notochords occurred after exposure to disulfiram even at the lowest test concentration of 20 μg/L, whereas at the two lowest concentrations of acetic acid hydrazide (0.375 and 0.75 g/L) mainly fractures of the notochord were observed. Concentrations of acetic acid hydrazide ≥ 1.5 g/L resulted in undulated notochords similar to disulfiram. Cartilages and ossifications of the cranium, including the cleithrum, were individually analyzed assessing the severity of malformation and the degree of ossification in a semi-quantitative approach. Cartilages of the neurocranium such as the ethmoid plate proved to be more stable than cartilages of the pharyngeal skeleton such as Meckel's cartilage. Hence, ossification proved significantly more susceptible than cartilage. The alterations induced in the notochord as well as in the cranium might well be of ecological relevance, since notochord malformation is likely to result in impaired swimming and cranial malformation might compromise regular food uptake. - Highlights: ► Disulfiram and acetic acid hydrazide as notochord, cartilage and bone teratogens ► Zebrafish embryos to model effects on single cartilages and bones in the head ► LC50 calculation and head length measurements after six days post-fertilization ► Lethality, head length and teratogenic effects are dose-dependent. ► Cartilages of the neurocranium are the most stable elements in the head.

  14. Palmitate induces tumor necrosis factor-alpha expression in C2C12 skeletal muscle cells by a mechanism involving protein kinase C and nuclear factor-kappaB activation.

    PubMed

    Jové, Mireia; Planavila, Anna; Sánchez, Rosa M; Merlos, Manuel; Laguna, Juan Carlos; Vázquez-Carrera, Manuel

    2006-01-01

    The mechanisms responsible for increased expression of TNF-alpha in skeletal muscle cells in diabetic states are not well understood. We examined the effects of the saturated acid palmitate on TNF-alpha expression. Exposure of C2C12 skeletal muscle cells to 0.75 mm palmitate enhanced mRNA (25-fold induction, P < 0.001) and protein (2.5-fold induction) expression of the proinflammatory cytokine TNF-alpha. This induction was inversely correlated with a fall in GLUT4 mRNA levels (57% reduction, P < 0.001) and glucose uptake (34% reduction, P < 0.001). PD98059 and U0126, inhibitors of the ERK-MAPK cascade, partially prevented the palmitate-induced TNF-alpha expression. Palmitate increased nuclear factor (NF)-kappaB activation and incubation of the cells with the NF-kappaB inhibitors pyrrolidine dithiocarbamate and parthenolide partially prevented TNF-alpha expression. Incubation of palmitate-treated cells with calphostin C, a strong and specific inhibitor of protein kinase C (PKC), abolished palmitate-induced TNF-alpha expression, and restored GLUT4 mRNA levels. Palmitate treatment enhanced the expression of phospho-PKCtheta, suggesting that this PKC isoform was involved in the changes reported, and coincubation of palmitate-treated cells with the PKC inhibitor chelerythrine prevented the palmitate-induced reduction in the expression of IkappaBalpha and insulin-stimulated Akt activation. These findings suggest that enhanced TNF-alpha expression and GLUT4 down-regulation caused by palmitate are mediated through the PKC activation, confirming that this enzyme may be a target for either the prevention or the treatment of fatty acid-induced insulin resistance.

  15. Silica glass modified with flavonoid derivatives for preconcentration of some toxic metal ions in water samples and their determination with ICP-MS.

    PubMed

    Hassanien, Mohamed M

    2010-08-01

    Quercetin (3,3',4',5,7-pentahydroxyflavone) chemically bonded through pyran rearrangement on modified controlled pore silica glass (QCPSG) with a capacity 0.213 mmol/g was used for solid phase extraction of some toxic metal and metalloid ions. The newly designed QCPSG quantitatively sorbs As(V), Cd(II), Hg(II), and Pb(II) at the pH range 7.5-8.5 after 10 min of stirring. HCl (1 mol L(-1)) instantaneously elutes all the metal ions. The sorption capacity of the ion collector is 0.42, 0.46, 0.53, and 0.49 mmol g(-1) for As(V), Cd(II), Hg(II), and Pb(II), respectively, whereas the preconcentration factor is 200. The effect of NaCl, Na2SO4, NaF, NaBr, Na3PO4, and other interfering salts on the sorption of metal ions (50 microg L(-1)) was reported. Analytical detection limits of As(V), Cd(II), Hg(II), and Pb(II) were 4.18, 2.44, 15.86, and 25.00 pg mL(-1), respectively. QCPSG was used in the separation of the investigated metal ions from some natural water samples collected from diverse origins followed by determination by inductively coupled plasma-mass spectrometry. The data were compared with those obtained by the standard methods of determination using atomic absorption (hydride generation, HGAAS and after solvent extraction with ammonium pyrolidine dithiocarbamate/methyl isobutyl ketone). The suggested solid phase extraction method was found accurate with no random error.

  16. Role of nuclear factor-kappa B in the regulation of intercellular adhesion molecule 1 after infection of human bronchial epithelial cells by Bordetella pertussis.

    PubMed

    Ishibashi, Yoshio; Nishikawa, Akemi

    2003-10-01

    Previous work has demonstrated that infection of human bronchial epithelial cells by Bordetella pertussis up-regulates intercellular adhesion molecule-1 (ICAM-1) gene and protein expression. It has also been shown that interaction of the Arg-Gly-Asp (RGD) site of filamentous hemagglutinin (FHA) with host cell very late antigen (VLA)-5 (alpha 5 beta 1 integrin) is required for the up-regulation of epithelial ICAM-1 expression, and that pertussis toxin (PT) impairs this response. We therefore examined the molecular mechanisms leading to B. pertussis-induced ICAM-1 up-regulation in BEAS-2B human bronchial epithelial cells. A colorimetric nuclear factor kappa B (NF-kappa B) activation assay demonstrated that NF-kappa B was activated in response to infection of these cells with B. pertussis. This activation occurred in an FHA(RGD)-dependent manner, and was blocked by an antibody against VLA-5, implying that binding of the RGD to VLA-5 integrin is involved in NF-kappa B activation. Western blot analysis revealed that the activation of NF-kappa B by B. pertussis was preceded by degradation of I kappa B alpha, a major cytoplasmic inhibitor of NF-kappa B. Pretreatment of the BEAS-2B cells with the NF-kappa B inhibitors pyrrolidine dithiocarbamate (PDTC), MG-132, and SN50 resulted in a marked decrease in B. pertussis-induced ICAM-1 expression, implying the involvement of NF-kappa B in ICAM-1 expression. Purified PT abrogated both NF-kappa B activation and I kappa B alpha degradation. These results suggest that ligation of VLA-5 integrin by FHA induces RGD-dependent NF-kappa B activation, thus leading to the up-regulation of epithelial ICAM-1 expression, and that a PT-sensitive G protein may be involved in this signaling pathway.

  17. Insights into yeast adaptive response to the agricultural fungicide mancozeb: a toxicoproteomics approach.

    PubMed

    Santos, Pedro M; Simões, Tânia; Sá-Correia, Isabel

    2009-02-01

    Toxicogenomics has the potential to elucidate gene-environment interactions to identify genes that are affected by a particular chemical at the early stages of the toxicological response and to establish parallelisms between different organisms. The fungicide mancozeb, widely used in agriculture, is an ethylene-bis-dithiocarbamate complex with manganese and zinc. Exposure to this pesticide has been linked to the development of idiopathic Parkinson's disease and cancer. Given that many signalling pathways and their molecular components are substantially conserved among eukaryotic organisms, we used Saccharomyces cerevisiae to get insights into the molecular mechanisms of mancozeb toxicity and adaptation based on expression proteomics. The early global response to mancozeb was analysed by quantitative proteomics using 2-DE. The target genes (e.g. TSA1, TSA2, SOD1, SOD2, AHP1, GRE2, GRX1, CYS3, PRE3, PRE6, PRE8, PRE9, EFT1, RPS5, TIF11, HSP31, HSP26, HSP104, HSP60, HSP70-family) and the putative main transcription activators (e.g. Yap1, Msn2/Msn4, Met4, Hsf1, Aft1, Pdr1, Skn7, Rpn4p, Gcn4) of the complex mancozeb-induced expression changes are related with yeast response to stress, in particular to oxidative stress, protein translation initiation and protein folding, disassembling of protein aggregates and degradation of damaged proteins. Our results also suggest that this study provided powerful indications that may be useful to expand the knowledge obtained in yeast not only to the global response to mancozeb toxicity in phytopathogenic fungi but also to humans.

  18. Pesticides in mixture disrupt metabolic regulation: in silico and in vivo analysis of cumulative toxicity of mancozeb and imidacloprid on body weight of mice.

    PubMed

    Bhaskar, Rakesh; Mohanty, Banalata

    2014-09-01

    Pesticides acting as endocrine disrupting chemicals disrupt the homeostasis of body metabolism. The present study elucidated that the low dose coexposure of thyroid disrupting dithiocarbamate fungicide mancozeb (MCZ) and neonicotinoid insecticide imidacloprid (IMI) during lactation increased the risk of body weight gain in mice later in life. Body weight gain has been linked to pesticide-induced hypothyroidism and hyperprolactinemia and alteration of lipid profiles. In vivo results were substantiated with in silico molecular docking (MD) analysis that predicted the binding affinity of pesticides with thyroid hormone receptors (TRα and TRβ) and peroxisome proliferator activated receptor gamma (PPARγ), the major nuclear receptors of peripheral fat metabolism. Binding potency of MCZ and IMI was compared with that of T3, and its antagonist ethylene thiourea (ETU) as well as PPARγ agonist (rosiglitazone) and antagonist (HL005). MD simulation predicted that both MCZ and IMI may compete with T3 for binding with TRs. Imidazole group of IMI formed hydrogen bonds with TRs like that of ETU. MCZ may compete with rosiglitazone and HL005 for PPARγ, but IMI showed no affinity. Thus while both MCZ and IMI could disrupt the TRs functioning, MCZ alone may affect PPARγ. Coexposure of pesticides decreased the plasma thyroid hormones and increased the cholesterol and triglyceride. Individual pesticide exposure in low dose might not exert the threshold response to affect the receptors signaling further to cause hormonal/metabolic impairment. Thus, cumulative response of the mixture of thyroid disrupting pesticides can disrupt metabolic regulation through several pathways and contribute to gain in body weight.

  19. Acute neurotoxic effects of mancozeb and maneb in mesencephalic neuronal cultures are associated with mitochondrial dysfunction.

    PubMed

    Domico, Lisa M; Zeevalk, Gail D; Bernard, Laura P; Cooper, Keith R

    2006-09-01

    Recent studies suggest that exposure to agrochemicals may contribute to the development of idiopathic Parkinson's disease. Maneb (MB), a widely used Mn-containing ethylene-bis-dithiocarbamate (EBDC) fungicide, has been implicated in selective dopaminergic neurotoxicity. In this study, we examine the potential neurotoxicity of mancozeb (MZ), a widely used EBDC fungicide that is structurally similar to MB, but contains both Zn and Mn. Primary mesencephalic cells isolated from Sprague-Dawley embryonic day 15 rat embryos were exposed in vitro to either MZ or MB to compare their cytotoxic potential. Exposure to 10-120 microM MZ or MB for 24h resulted in a dose-dependent toxicity in both the dopamine (DA) and GABA mesencephalic populations as assessed by a functional assay for high affinity transporter activity. Consistent with this, cell viability as well as tyrosine hydroxylase-positive neurons decreased with increasing doses of MZ or MB. Toxic potencies for MZ and MB were similar and no difference in sensitivity between the DA and GABA populations was observed with the fungicides. Exposure to ethylene thiourea, the major metabolite of either MZ or MB, was not toxic, implicating the parent compound in toxicity. Both the organic and Mn metal components of the fungicides were found to contribute to toxicity. Non-toxic exposures to the fungicides decreased ATP levels in a dose-dependent manner suggesting impairment of energy metabolism. In whole mitochondrial preparations isolated from adult rat brains, MZ and MB inhibited NADH-linked state 3 respiration. Mild to moderate mitochondrial uncoupling was also observed in response to the fungicides. In conclusion, our findings indicate that acute exposure to high doses of MZ and MB produce equipotent toxic effects in both DA and GABA neurons that may be associated with perturbations in mitochondrial respiration.

  20. Neoplastic alterations induced in mammalian skin following mancozeb exposure using in vivo and in vitro models.

    PubMed

    Tyagi, Shilpa; George, Jasmine; Singh, Richa; Bhui, Kulpreet; Shukla, Yogeshwer

    2011-03-01

    Mancozeb, ethylene(bis)dithiocarbamate fungicides, has been well documented in the literature as a multipotent carcinogen, but the underlying mechanism remains unrevealed. Thus, mancozeb has been selected in this study with the objective to decipher the molecular mechanism that culminates in carcinogenesis. We employed two-dimensional gel electrophoresis and mass spectrometry to generate a comparative proteome profile of control and mancozeb (200 mg/kg body weight) exposed mouse skin. Although many differentially expressed proteins were found, among them, two significantly upregulated proteins, namely, S100A6 (Calcyclin) and S100A9 (Calgranulin-B), are known markers of keratinocyte differentiation and proliferation, which suggested their role in mancozeb-induced neoplastic alterations. Therefore, we verified these alterations in the human system by using HaCaT cells as an in vitro model for human skin keratinocyte carcinogenesis. Upregulation of these two proteins upon mancozeb (0.5 μg/mL) exposure in HaCaT cells indicated its neoplastic potential in human skin also. This potential was confirmed by increase in number of colonies in colony formation and anchorage-independent growth assays. Modulation of S100A6/S100A9 targets, elevated phosphorylation of extracellular signal regulated kinase (ERK1/2), Elk1, nuclear factor- kappa B and cell division cycle 25 C phosphatase, and cyclin D1 and cyclooxygenase-2 upregulation was seen. In addition, PD98059 (ERK1/2 inhibitor) reduced cell proliferation induced by mancozeb, confirming the involvement of ERK1/2 signaling. Conclusively, we herein present the first report asserting that the mechanism involving S100A6 and S100A9 regulated ERK1/2 signaling underlies the mancozeb-induced neoplastic potential in human skin.

  1. Syntheses, spectral characterization, X-ray studies and in vitro cytotoxic activities of triorganotin(IV) derivatives of p-substituted N-methylbenzylaminedithiocarbamates

    NASA Astrophysics Data System (ADS)

    Khan, Naqeebullah; Farina, Yang; Mun, Lo Kong; Rajab, Nor Fadilah; Awang, Normah

    2014-11-01

    Two new organotin(IV) complexes of the type R3SnL, where (L = p-bromo-N-methylbenzylaminedithiocarbamate and p-fluoro-N-methylbenzylaminedithiocarbamate, and R = phenyl) have been synthesized in 1:1 molar ratio with good yields and isolated as crystalline solids. The newly synthesized compounds gave fairly sharp melting points indicating that the compounds were pure. A systematic investigation of the derivatives were carried out both in solid and in solution and were suitably characterized by elemental analysis, FT-IR, 1H, 13C, 119Sn NMR spectroscopies. The dithiocarbamate ligands chelated to the tin metal monodentately using only one sulfur atom showing a pair of bands due to ν(Cdbnd S) below 1000 cm-1. This phenomenon was supported by the occurrence of new medium to weak absorptions in the region 411-545, in the spectra of complexes, assigned to ν(Snsbnd S) and ν(Snsbnd C). The crystal structures of the two triorganotin(IV) complexes have been determined by X-ray crystallography. Both the complexes crystallized in the monoclinic, P2(1)/n space group. The spectral investigations and single crystal X-ray diffraction data illustrate that the two dithiocarbamato ligands in the triphenyltin(IV) derivatives 1 and 2 are monodentate and the geometry at tin is best described as a distorted tetrahedron. The in vitro antiproliferative tests of these two derivatives on three human cell lines, leukemic lymphoblastoma Jurkat cells, lymphoblastoma K-562 cells, hepatoblastoma HepG2 cells and one mouse fibroblast cells L929 show dose-dependent decrease of cell proliferation in all cell lines.

  2. Total reflection X-ray fluorescence trace mercury determination by trapping complexation: Application in advanced oxidation technologies

    NASA Astrophysics Data System (ADS)

    Custo, Graciela; Litter, Marta I.; Rodríguez, Diana; Vázquez, Cristina

    2006-11-01

    It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 μg/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these volatile species in liquid samples by using complexing agents is proposed. Acetate, oxalic acid, ethylenediaminetetracetic acid and ammonium pyrrolidine-dithiocarbamate were assayed for trapping the analytes into the solution during the preparation of the sample and onto the reflector during total reflection X-ray fluorescence measurements. The proposed method was applied to evaluate Hg concentration during TiO 2-heterogeneous photocatalysis, one of the most known advanced oxidation technologies. Advanced oxidation technologies are processes for the treatment of effluents in waters and air that involve the generation of very active oxidative and reductive species. In heterogeneous photocatalysis, Hg is transformed to several species under ultraviolet illumination in the presence of titanium dioxide. Total reflection X-ray fluorescence was demonstrated to be applicable in following the extent of the heterogeneous photocatalysis reaction by determining non-transformed Hg in the remaining solution.

  3. A mechanism-based 3D-QSAR approach for classification and prediction of acetylcholinesterase inhibitory potency of organophosphate and carbamate analogs

    NASA Astrophysics Data System (ADS)

    Lee, Sehan; Barron, Mace G.

    2016-04-01

    Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a serine residue in the enzyme active site, and their inhibitory potency depends largely on affinity for the enzyme and the reactivity of the ester. Despite this understanding, there has been no mechanism-based in silico approach for classification and prediction of the inhibitory potency of ether OPs or carbamates. This prompted us to develop a three dimensional prediction framework for OPs, carbamates, and their analogs. Inhibitory structures of a compound that can form the covalent bond were identified through analysis of docked conformations of the compound and its metabolites. Inhibitory potencies of the selected structures were then predicted using a previously developed three dimensional quantitative structure-active relationship. This approach was validated with a large number of structurally diverse OP and carbamate compounds encompassing widely used insecticides and structural analogs including OP flame retardants and thio- and dithiocarbamate pesticides. The modeling revealed that: (1) in addition to classical OP metabolic activation, the toxicity of carbamate compounds can be dependent on biotransformation, (2) OP and carbamate analogs such as OP flame retardants and thiocarbamate herbicides can act as AChEI, (3) hydrogen bonds at the oxyanion hole is critical for AChE inhibition through the covalent bond, and (4) π-π interaction with Trp86 is necessary for strong inhibition of AChE. Our combined computation approach provided detailed understanding of the mechanism of action of OP and carbamate compounds and may be useful for screening a diversity of chemical structures for AChE inhibitory potency.

  4. Disulfiram Suppresses Growth of the Malignant Pleural Mesothelioma Cells in Part by Inducing Apoptosis

    PubMed Central

    Muthu, Magesh; Jamal, Shazia; Chen, Di; Yang, Huanjie; Polin, Lisa A.; Tarca, Adi L.; Pass, Harvey I.; Dou, Q. Ping; Sharma, Sunita; Wali, Anil; Rishi, Arun K.

    2014-01-01

    Dithiocarbamate compound Disulfiram (DSF) that binds with copper and functions as an inhibitor of aldehyde dehydrogenase is a Food and Drug Administration approved agent for treatment of alcoholism. Copper complexed DSF (DSF-Cu) also possesses anti-tumor and chemosensitizing properties; however, its molecular mechanisms of action remain unclear. Here we investigated malignant pleural mesothelioma (MPM) suppressive effects of DSF-Cu and the molecular mechanisms involved. DSF-Cu inhibited growth of the murine as well as human MPM cells in part by increasing levels of ubiquitinated proteins. DSF-Cu exposure stimulated apoptosis in MPM cells that involved activation of stress-activated protein kinases (SAPKs) p38 and JNK1/2, caspase-3, and cleavage of poly-(ADP-ribose)-polymerase, as well as increased expression of sulfatase 1 and apoptosis transducing CARP-1/CCAR1 protein. Gene-array based analyses revealed that DSF-Cu suppressed cell growth and metastasis-promoting genes including matrix metallopeptidase 3 and 10. DSF inhibited MPM cell growth and survival by upregulating cell cycle inhibitor p27Kip1, IGFBP7, and inhibitors of NF-κB such as ABIN 1 and 2 and Inhibitory κB (IκB)α and β proteins. DSF-Cu promoted cleavage of vimentin, as well as serine-phosphorylation and lysine-63 linked ubiquitination of podoplanin. Administration of 50 mg/kg DSF-Cu by daily i.p injections inhibited growth of murine MPM cell-derived tumors in vivo. Although podoplanin expression often correlates with metastatic disease and poor prognosis, phosphorylation of serines in cytoplasmic domain of podoplanin has recently been shown to interfere with cellular motility and migration signaling. Post-translational modification of podoplanin and cleavage of vimentin by DSF-Cu underscore a metastasis inhibitory property of this agent and together with our in vivo studies underscore its potential as an anti-MPM agent. PMID:24690739

  5. Pioglitazone inhibits high glucose-induced expression of receptor for advanced glycation end products in coronary artery smooth muscle cells

    PubMed Central

    DI, BEI-BING; LI, HONG-WEI; LI, WEI-PING; SHEN, XU-HUA; SUN, ZHI-JUN; WU, XING

    2015-01-01

    Receptor for advanced glycation end products (RAGE) is critical in inflammatory diseases, including diabetes and atherosclerosis. The mechanism underlying the effect of peroxisome proliferator-activated receptor γ (PPARγ) agonist pioglitazone (PIO) on RAGE expression in coronary artery smooth muscle cells (SMCs) stimulated by high glucose concentrations remains to be elucidated. In the present study, the effect and mechanism of action of PIO on RAGE expression in SMCs was investigated following treatment with high glucose concentrations. Rat coronary artery SMCs were pretreated with PIO alone, PIO and GW9662 (a PPARγ antagonist), diphenyleneiodonium (DPI; a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor) or the antioxidant pyrrolidine dithiocarbamate (PDTC; a nuclear factor-κB (NF-κB) inhibitor), followed by treatment with high glucose. RAGE mRNA and protein expression, reactive oxygen species (ROS) production and NF-κB nuclear translocation were investigated. Glucose induced RAGE expression in a dose-dependent manner, with maximal effect at a concentration of 25 mmol/l following treatment for 48 h. PIO, DPI and PDTC reduced high glucose-induced increases in RAGE protein and mRNA expression. PIO prominently downregulated RAGE expression and inhibited high glucose-induced increases in ROS production and NF-κB activation (P<0.05). Pretreatment with PIO and GW9662 did not exhibit this inhibitory effect. High glucose may stimulate RAGE expression in coronary artery SMCs through NADPH oxidase-mediated ROS generation and NF-κB activation. PIO downregulated RAGE expression and inhibited ROS production and NF-κB activation via PPARγ activation, which may prevent the inflammatory effect of AGE/RAGE system in diabetes. PMID:25523934

  6. Pesticide exposure and thyroid function in an agricultural population in Brazil.

    PubMed

    Piccoli, Camila; Cremonese, Cleber; Koifman, Rosalina J; Koifman, Sergio; Freire, Carmen

    2016-11-01

    Although numerous pesticides may interfere with thyroid function, however, epidemiological evidence supporting this relationship is limited, particularly regarding modern non-persistent pesticides. We sought to evaluate the association of agricultural work practices, use of contemporary-use pesticides, and OC pesticides residue levels in serum with circulating thyroid hormone levels in an agricultural population. A cross-sectional study was conducted with a random sample of 275 male and female farm residents in Farroupilha, South of Brazil. Information on sociodemographics, lifestyle and agricultural work was obtained through questionnaire. Blood samples were collected on all participants and analyzed for cholinesterase activity, serum residues of OC pesticides, and levels of free T4 (FT4), total T3 (TT3) and TSH. Non-persistent pesticides exposure assessment was based on questionnaire information on current use of pesticides, and frequency and duration of use, among others. Associations were explored using multivariate linear regression models. Total lifetime years of use of fungicides, herbicides and dithiocarbamates in men was associated with increased TSH accompanied by decrease in FT4, with evidence of a linear trend. In addition, there was an association between being sampled in the high pesticide-use season and increased TSH levels. Conversely, farm work and lifetime use of all pesticides were related with slight decrease in TSH and increased TT3 and FT4, respectively. In general, pesticide use was not associated with thyroid hormones in women. Subjects with detected serum concentrations of β-hexachlorocyclohexane, endrin, dieldrin, heptachlor epoxide B, γ-chlordane, transnonachlor, heptachlor, p,p'-dichlorodiphenylethane and endosulfan II experienced slight changes in TT3; however, associations were weak and inconsistent. These findings suggest that both cumulative and recent occupational exposure to agricultural pesticides may affect the thyroid function

  7. Exposure to non-persistent pesticides and thyroid function: A systematic review of epidemiological evidence.

    PubMed

    Campos, Élida; Freire, Carmen

    2016-08-01

    Numerous pesticides are recognized for their endocrine-disrupting properties. Non-persistent pesticides such as organophosphates, dithiocarbamates and pyrethroids may interfere with thyroid function as suggested by animal studies. However, the influence of chronic exposure to these compounds on thyroidal functions in humans remains to be determined. The present study aimed to review epidemiological evidence for an association between exposure to non-persistent pesticides and circulating levels of thyroid hormones (thyroxin [T4] and triiodothyronine [T3]) and thyroid-stimulating hormone (TSH). A systematic review was conducted using MEDLINE, SCOPUS and Virtual Health Library (BVS) databases. Articles were limited to original studies and reports published in English, Portuguese or Spanish. Nineteen epidemiological studies were identified, 17 of which were cross-sectional, 14 were of occupationally exposed workers and 11 used exposure biomarkers. Fungicides and organophosphates (OP) insecticides were the most studied pesticides. Although methodological heterogeneity between studies was noted, particularly regarding study design, exposure assessment, and control of confounding, most of them showed associations with changes in T3 and T4, and/or TSH levels, while results from a few of these are consistent with experimental data supporting the findings that non-persistent pesticide exposure exerts hypothyroid-like effects. However, reporting quality was moderate to poor in 50% of the studies, particularly regarding method of selection of participants and discussion of external validity. Overall, current knowledge regarding the impact of non-persistent pesticides on human thyroid function is still limited. Given the widespread use of pesticides, future research should assess effects of exposure to currently-used pesticides in cohort studies combining comprehensive questionnaire-based assessment and biomarkers. Investigators need to pay particular attention to exposure

  8. Hydrogen sulfide attenuates gastric mucosal injury induced by restraint water-immersion stress via activation of KATP channel and NF-κB dependent pathway

    PubMed Central

    Sun, Hong-Zhao; Zheng, Shan; Lu, Kai; Hou, Feng-Tian; Bi, Jie-Xue; Liu, Xue-Lian; Wang, Shan-Shan

    2017-01-01

    AIM To explore the effect of hydrogen sulfide (H2S) on restraint water-immersion stress (RWIS)-induced gastric lesions in rats and the influence of adenosine triphosphate (ATP)-sensitive potassium (KATP) channels and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway on such an effect. METHODS Male Wistar rats were randomly divided into a control group, a physiological saline (PS) group, a sodium hydrosulfide (NaHS) group, a glibenclamide (Gl) group, Gl plus NaHS group, a pyrrolidine dithiocarbamate (PDTC) group, and a PDTC plus NaHS group. Gastric mucosal injury was induced by RWIS for 3 h in rats, and gastric mucosal damage was analyzed after that. The PS, NaHS (100 μmol/kg body weight), Gl (100 μmol/kg body weight), Gl (100 μmol/kg or 150 μmol/kg body weight) plus NaHS (100 μmol/kg body weight), PDTC (100 μmol/kg body weight), and PDTC (100 μmol/kg body weight) plus NaHS (100 μmol/kg body weight) were respectively injected intravenously before RWIS. RESULTS RWIS induced serious gastric lesions in the rats in the PS pretreatment group. The pretreatment of NaHS (a H2S donor) significantly reduced the damage induced by RWIS. The gastric protective effect of the NaHS during RWIS was attenuated by PDTC, an NF-κB inhibitor, and also by glibenclamide, an ATP-sensitive potassium channel blocker, in a dose-dependent manner. CONCLUSION These results suggest that exogenous H2S plays a protective role against RWIS injury in rats, possibly through modulation of KATP channel opening and the NF-κB dependent pathway. PMID:28104983

  9. SDF-1 promotes ox-LDL induced vascular smooth muscle cell proliferation.

    PubMed

    Li, Ling-Xing; Zhang, Xian-Feng; Bai, Xue; Tong, Qian

    2013-09-01

    The mechanism of the regulatory roles of stromal cell derived factor-1 (SDF-1)/C-X-C motif receptor 4 (CXCR4) on cell proliferation and apoptosis in vascular smooth muscle cells (VSMCs) via the protein kinase C (PKC) and nuclear factor-kappa B (NF-κB) signalling pathways have been investigated. Rat aortic VSMCs were treated with control or an oxidised low-density lipoprotein (ox-LDL) atherosclerosis (AS) model. Cells exposed to the AS model were treated with SDF-1 plus inhibitors specific for PKC (Ro31-8220), CXCR4 (12G5) or NF-κB (pyrrolidine dithiocarbamate, PDTC). Cell proliferation was measured with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and apoptosis by flow cytometry. NF-κB protein expression was analysed using Western blotting. The proliferation rate in the AS model group was significantly higher than the control group, but lower than the SDF-1 group (P < 0.05). Apoptosis in the AS model group (ox-LDL) was significantly higher than the normal control group (P < 0.05). In addition, the apoptosis rate in the SDF-1 group was significantly lower than the normal control group (P < 0.05); however, there was no difference from the Ro31-8220 group. NF-κB protein expression in the SDF-1 group was significantly higher than the AS model (ox-LDL) group (P < 0.05). In conclusion, SDF-1 can promote the proliferation of VSMCs induced by ox-LDL and inhibit cell apoptosis, via the SDF-1/CXCR4 axis.

  10. The Mancozeb-containing carbamate fungicide tattoo induces mild oxidative stress in goldfish brain, liver, and kidney.

    PubMed

    Atamaniuk, Tetiana M; Kubrak, Olga I; Husak, Viktor V; Storey, Kenneth B; Lushchak, Volodymyr I

    2014-11-01

    Tattoo belongs to the group of carbamate fungicides and contains Mancozeb (ethylene(bis)dithiocarbamate) as its main constituent. The toxicity of Mancozeb to living organisms, particularly fish, is not resolved. This work investigated the effects of 96 h of exposure to 3, 5, or 10 mg L(-1) of Tattoo (corresponding to 0.9, 1.5, or 3 mg L(-1) of Mancozeb) on the levels of oxidative stress markers and the antioxidant enzyme system of brain, liver, and kidney of goldfish, Carassius auratus). In liver, Tattoo exposure resulted in increased activities of superoxide dismutase (SOD) by 70%-79%, catalase by 23%-52% and glutathione peroxidase (GPx) by 49%. The content of protein carbonyls (CP) in liver was also enhanced by 92%-125% indicating extensive damage to proteins. Similar increases in CP levels (by 98%-111%) accompanied by reduced glucose-6-phosphate dehydrogenase activity (by 13%-15%) was observed in kidney of fish exposed to Tattoo; however, SOD activity increased by 37% in this tissue after treatment with 10 mg L(-1) Tattoo. In brain, a rise in lipid peroxide level (by 29%) took place after exposure to 10 mg L(-1) Tattoo and was accompanied by elevation of high-molecular mass thiols (by 14%). Tattoo exposure also resulted in a concentration-dependent decrease in glutathione reductase activity (by 26%-37%) in brain. The data collectively show that exposure of goldfish to 3-10 mg L(-1) of the carbamate fungicide Tattoo resulted in the development of mild oxidative stress and activation of antioxidant defense systems in goldfish tissues.

  11. Novel intracellular N-terminal truncated matrix metalloproteinase-2 isoform in skeletal muscle ischemia-reperfusion injury.

    PubMed

    Joshi, Sunil K; Lee, Lawrence; Lovett, David H; Kang, Heejae; Kim, Hubert T; Delgado, Cynthia; Liu, Xuhui

    2016-03-01

    Ischemia-reperfusion injury (IRI) occurs when blood returns to tissues following a period of ischemia. Reintroduction of blood flow results in the production of free radicals and reactive oxygen species that damage cells. Skeletal muscle IRI is commonly seen in orthopedic trauma patients. Experimental studies in other organ systems have elucidated the importance of extracellular and intracellular matrix metalloproteinase-2 (MMP-2) isoforms in regulating tissue damage in the setting of oxidant stress resulting from IRI. Although the extracellular full-length isoform of MMP-2 (FL-MMP-2) has been previously studied in the setting of skeletal muscle IRI, studies investigating the role of the N-terminal truncated isoform (NTT-MMP-2) in this setting are lacking. In this study, we first demonstrated significant increases in FL- and NTT-MMP-2 gene expression in C2C12 myoblast cells responding to re-oxygenation following hypoxia in vitro. We then evaluated the expression of FL- and NTT-MMP-2 in modulating skeletal muscle IRI using a previously validated murine model. NTT-MMP-2, but not FL-MMP-2 expression was significantly increased in skeletal muscle following IRI. Moreover, the expression of toll-like receptors (TLRs) -2 and -4, IL-6, OAS-1A, and CXCL1 was also significantly up-regulated following IRI. Treatment with the potent anti-oxidant pyrrolidine dithiocarbamate (PDTC) significantly suppressed NTT-MMP-2, but not FL-MMP-2 expression and improved muscle viability following IRI. This data suggests that NTT-MMP-2, but not FL-MMP-2, is the major isoform of MMP-2 involved in skeletal muscle IRI.

  12. N,N-diethyldithiocarbamate produces copper accumulation, lipid peroxidation, and myelin injury in rat peripheral nerve.

    PubMed

    Tonkin, Elizabeth G; Valentine, Holly L; Milatovic, Dejan M; Valentine, William M

    2004-09-01

    Previous studies have demonstrated the ability of the dithiocarbamate, disulfiram, to produce a peripheral neuropathy in humans and experimental animals and have also provided evidence that N,N-diethyldithiocarbamate (DEDC) is a proximate toxic species of disulfiram. The ability of DEDC to elevate copper levels in the brain suggests that it may also elevate levels of copper in peripheral nerve, possibly leading to oxidative stress and lipid peroxidation from redox cycling of copper. The study presented here investigates the potential of DEDC to promote copper accumulation and lipid peroxidation in peripheral nerve. Rats were administered either DEDC or deionized water by ip osmotic pumps and fed a normal diet or diet containing elevated copper, and the levels of metals, isoprostanes, and the severity of lesions in peripheral nerve and brain were assessed by ICP-AES/AAS, GC/MS, and light microscopy, respectively. Copper was the only metal that demonstrated any significant compound-related elevations relative to controls, and total copper was increased in both brain and peripheral nerve in animals administered DEDC on both diets. In contrast, lesions and elevated F2-isoprostanes were significantly increased only in peripheral nerve for the rats administered DEDC on both diets. Autometallography staining of peripheral nerve was consistent with increased metal content along the myelin sheath, but in brain, focal densities were observed, and a periportal distribution occurred in liver. These data are consistent with the peripheral nervous system being more sensitive to DEDC-mediated demyelination and demonstrate the ability of DEDC to elevate copper levels in peripheral nerve. Additionally lipid peroxidation appears to either be a contributing event in the development of demyelination, possibly through an increase of redox active copper, or a consequence of the myelin injury.

  13. alpha-Chaconine inhibits angiogenesis in vitro by reducing matrix metalloproteinase-2.

    PubMed

    Lu, Ming-Kun; Chen, Pei-Hsieng; Shih, Yuan-Wei; Chang, Ya-Ting; Huang, En-Tze; Liu, Cheng-Ruei; Chen, Pin-Shern

    2010-01-01

    alpha-Chaconine, a naturally occurring steroidal glycoalkaloid in potato sprouts, was found to possess anti-carcinogenic properties, such as inhibiting proliferation, migration, invasion, and inducing apoptosis of tumor cells. However, the effect of alpha-chaconine on tumor angiogenesis remains unclear. In the present study, we examined the effect of alpha-chaconine on angiogenesis in vitro. Data demonstrated that alpha-chaconine inhibited proliferation of bovine aortic endothelial cells (BAECs) in a dose-dependent manner. When treated with non-toxic doses of alpha-chaconine, cell migration, invasion and tube formation were markedly suppressed. Furthermore, alpha-chaconine reduced the expression and activity of matrix metalloproteinase-2 (MMP-2), which is involved in angiogenesis. Our biochemical assays indicated that alpha-chaconine potently suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositide-3 kinase (PI3K) and Akt, while it did not affect phosphorylation of extracellular signal regulating kinase (ERK) and p38. In addition, alpha-chaconine significantly increased the cytoplasmic level of inhibitors of kappaBalpha (IkappaBalpha) and decreased the nuclear level of nuclear factor kappa B (NF-kappaB), suggesting that alpha-chaconine could inhibit NF-kappaB activity. Furthermore, the treatment of inhibitors specific for JNK (SP600125), PI3K (LY294002) or NF-kappaB (pyrrolidine dithiocarbamate) to BAECs reduced tube formation. Taken together, the results suggested that alpha-chaconine inhibited migration, invasion and tube formation of BAECs by reducing MMP-2 activities, as well as JNK and PI3K/Akt signaling pathways and inhibition of NF-kappaB activity. These findings reveal a new therapeutic potential for alpha-chaconine on anti-angiogenic therapy.

  14. Recovery of axonal myelination sheath and axonal caliber in the mouse corpus callosum following damage induced by N,N-diethyldithiocarbamate.

    PubMed

    Utrera, Juana; Romero, Rafael; Verdaguer, Ester; Junyent, Fèlix; Auladell, Carme

    2011-12-01

    Disulfiram is an aldehyde dehydrogenase inhibitor used for the treatment of alcohol dependence and of cocaine addiction. It has been demonstrated that subchronic administration of disulfiram or N,N-diethyldithiocarbamate (DEDTC), the main derivative of disulfiram, to rats can produce central-peripheral distal axonopathy. However, few data regarding the axonal effects of these compounds in the central nervous system exist. Our previous studies have revealed DEDTC-induced axonal damage in the mouse brain during the course of postnatal development, together with alterations in axonal pathfinding and in the myelination process, with partial recovery during the post-treatment period. In order to gather new data about how this axonal damage and recovery occurs in the central nervous system, we performed an ultrastructural analysis of the axons located in the corpus callosum from mice treated with DEDTC during postnatal development. The axonal caliber throughout the axonal area, the maximum axonal diameter, the maximum fiber diameter, and the axonal circularity, at different postnatal stages [from postnatal day (P)9 to P30], were analyzed. In addition, parameters related to the myelinization process (number of myelinated axons, sheath thickness, and the ratio of myelinated axons to total axons) were evaluated. A reduction in the average value of axonal caliber during treatment and a delay in the axonal myelination process were detected. Whereas early recovery of individual axons occurred after treatment (P22), complete recovery of myelinated axons occurred at late postnatal stages (P42). Therefore, chronic treatment with dithiocarbamates requires periods of rest to encourage the recovery of myelinated axons.

  15. NF kappa B and Matrix Metalloproteinase induced Receptor Cleavage in the Spontaneously Hypertensive Rat

    PubMed Central

    Wu, Kwan-I Sharon; Schmid-Schönbein, Geert W.

    2011-01-01

    Recent evidence suggests that inflammation in the spontaneously hypertensive rat (SHR) is associated with an uncontrolled matrix metalloproteinase (MMP) activity. We hypothesize that the transcription factor nuclear factor kappa B (NF–κB) is overexpressed in the SHR, enhancing its MMP activity and enzymatic cleavage of the beta-2 adrenergic receptor (β2AR), thereby diminishing catecholamine-mediated arteriolar vasodilation. NF-κB expression level and translocation were compared between Wistar Kyoto rat (WKY) and SHR kidney, heart and brain. The animals were treated with a NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), for ten weeks and correlations between NF-κB and MMP activity were determined. Immunohistochemistry showed that NF-κB expression is increased in untreated SHR kidney (~ 14%) and brain hypothalamus (~ 22%) compared to that in WKY (p <0.05), but not in myocardium and cerebral cortex. After PDTC treatment, the SHR systolic blood pressure was reduced close to WKY levels. NF-κB expression level in treated-SHR was also decreased in kidney and hypothalamus compared to non-treated animals (p <0.05). Furthermore, MMP-2 and -9 activities in SHR plasma were significantly reduced (~41%) by PDTC treatment. Additionally, zymographic analyses and in situ zymography showed decreased MMP-2 activity in kidney homogenates and decreased MMP-1,-9 activities in brain. The level of the β2AR extracellular, but not intracellular, domain density was found reduced in kidney showing a receptor cleavage process that can be blocked by PDTC treatment. These results suggest NF-κB is an important transcription factor in the SHR and may be involved in the enhanced MMP activity and consequently receptor cleavage. PMID:21220710

  16. Piceatannol inhibits MMP-9-dependent invasion of tumor necrosis factor-α-stimulated DU145 cells by suppressing the Akt-mediated nuclear factor-κB pathway

    PubMed Central

    JAYASOORIYA, RAJAPAKSHA GENDARA PRASAD THARANGA; LEE, YONG-GAB; KANG, CHANG-HEE; LEE, KYOUNG-TAE; CHOI, YUNG HYUN; PARK, SUNG-YONG; HWANG, JAE-KWAN; KIM, GI-YOUNG

    2013-01-01

    Piceatannol has potent anti-inflammatory, immunomodulatory, anticancer and antiproliferative effects. However, little is known about the mechanism by which piceatannol inhibits invasion and metastasis. The aim of the current study was to investigate the effects of piceatannol on the expression of matrix metalloproteinase-9 (MMP-9) in DU145 human prostate cancer cells. The results revealed that MMP-9 activity was significantly increased in response to tumor necrosis factor-α (TNF-α). However, treatment with piceatannol reversed TNF-α- and MMP-9-induced gelatin zymography and its gene expression. In addition, a Matrigel invasion assay determined that piceatannol reduces the TNF-α-induced invasion of DU145 cells. Nuclear factor-κ B (NF-κB) is a significant transcription factor that regulates numerous genes involved in tumor cell invasion and metastasis. Therefore, whether piceatannol acts on NF-κB to regulate MMP-9 gene expression was analyzed. The results revealed that piceatannol attenuates MMP-9 gene expression via the suppression of NF-κB activity. Using a specific NF-κB inhibitor, pyrrolidine dithiocarbamate, it was confirmed that TNF-α-induced MMP-9 gene expression is primarily regulated by NF-κB activation. Piceatannol inhibited NF-κB activity by suppressing nuclear translocation of the NF-κB p65 and p50 subunits. Furthermore, TNF-α-induced Akt phosphorylation was significantly downregulated in the presence of piceatannol. The Akt inhibitor LY294002 caused a significant decrease in TNF-α-induced NF-κB activity and MMP-9 gene expression. Overall, these data suggest that piceatannol inhibits TNF-α-induced invasion by suppression of MMP-9 activation via the Akt-mediated NF-κB pathway in DU145 prostate cancer cells. PMID:23255946

  17. NO accounts completely for the oxygenated nitrogen species generated by enzymic L-arginine oxygenation.

    PubMed Central

    Mülsch, A; Vanin, A; Mordvintcev, P; Hauschildt, S; Busse, R

    1992-01-01

    We have assessed the stoichiometry of the nitric oxide (NO) synthase reaction by using a novel e.p.r. technique. NO generated by crude and partially purified NO synthase from endothelial cells and Escherichia coli-lipopolysaccharide-activated macrophages was trapped by a ferrous diethyldithiocarbamate complex dispersed in yeast. The paramagnetic ferrous mononitrosyl dithiocarbamate complex formed exhibited a characteristic e.p.r. signal at g perpendicular = 2.035 and g parallel = 2.02 with a triplet hyperfine structure (hfs) at g perpendicular. NO, 3-morpholinosydnonimine and S-nitroso-L-cysteine, but not nitrite or hydroxylamine, generated a similar e.p.r. signal. NO generated by NO synthase and by SIN-1 accumulated at a constant rate for 1 h, as measured by continuous e.p.r. registration at 37 degrees C. The formation of e.p.r.-detectable NO by NO synthases was inhibited by NG-nitro-L-arginine. Incubation with [15N]NG-L-arginine caused an e.p.r. signal with doublet hfs, indicating that the nitrosyl nitrogen derived exclusively from the guanidino nitrogen. The amount of NO generated by NO synthase as measured by e.p.r. technique was compared with formation of L-[3H]citrulline from L-[3H]arginine. NO and L-citrulline were detected at a 1:1 ratio with both NO synthase preparations. GSH and thiol depletion did not significantly affect NO synthase activity, excluding S-nitrosothiols as intermediates in the NO synthase reaction. We conclude that NO fully accounts for the immediate oxygenated nitrogen species derived from the enzymic oxygenation of L-arginine. PMID:1281408

  18. Dioscin alleviates alcoholic liver fibrosis by attenuating hepatic stellate cell activation via the TLR4/MyD88/NF-κB signaling pathway

    PubMed Central

    Liu, Min; Xu, Youwei; Han, Xu; Yin, Lianhong; Xu, Lina; Qi, Yan; Zhao, Yanyan; Liu, Kexin; Peng, Jinyong

    2015-01-01

    The present work aimed to investigate the activities and underlying mechanisms of dioscin against alcoholic liver fibrosis (ALF). In vivo liver fibrosis in mice was induced by an alcoholic liquid diet, and in vitro studies were performed on activated HSC-T6 and LX2 cells treated with lipopolysaccharide. Our results showed that dioscin significantly attenuated hepatic stellate cells (HSCs) activation, improved collagen accumulation, and attenuated inflammation through down-regulating the levels of myeloid differentiation factor 88 (MyD88), nuclear factor κB (NF-κB), interleukin (IL)-1, IL-6 and tumour necrosis factor-α by decreasing Toll-like receptor (TLR)4 expression both in vivo and in vitro. TLR4 overexpression was also decreased by dioscin, leading to the markedly down-regulated levels of MyD88, NF-κB, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) in cultured HSCs. Suppression of cellular MyD88 by ST2825 or abrogation of NF-κB by pyrrolidine dithiocarbamate eliminated the inhibitory effects of dioscin on the levels of TGF-β1, α-SMA and COL1A1. In a word, dioscin exhibited potent effects against ALF via altering TLR4/MyD88/NF-κB signaling pathway, which provided novel insights into the mechanisms of this compound as an antifibrogenic candidate for the treatment of ALF in the future. PMID:26655640

  19. Isobutyrylshikonin inhibits lipopolysaccharide-induced nitric oxide and prostaglandin E2 production in BV2 microglial cells by suppressing the PI3K/Akt-mediated nuclear transcription factor-κB pathway.

    PubMed

    Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Lee, Kyoung-Tae; Kang, Chang-Hee; Dilshara, Matharage Gayani; Lee, Hak-Ju; Choi, Yung Hyun; Choi, Il-Whan; Kim, Gi-Young

    2014-12-01

    Microglia are important macrophages to defend against pathogens in the central nervous system (CNS); however, persistent or acute inflammation of microglia lead to CNS disorders via neuronal cell death. Therefore, we theorized that a good strategy for the treatment of CNS disorders would be to target inflammatory mediators from microglia in disease. Consequently, we investigated whether isobutyrylshikonin (IBS) attenuates the production of proinflammatory mediators, such as nitric oxide (NO) and prostaglandin E2, in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Treatment with IBS inhibited the secretion of NO and prostaglandin E2 (as well as the expression of their key regulatory genes), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2). Isobutyrylshikonin also suppressed LPS-induced DNA-binding activity of nuclear transcription factor-κB (NF-κB), by inhibiting the nuclear translocation of p50 and p65 in addition to blocking the phosphorylation and degradation of IκBα. Pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor, showed the down-regulation of LPS-induced iNOS and COX-2 messenger RNA by suppressing NF-κB activity. This indirectly suggests that IBS-mediated NF-κB inhibition is the main signaling pathway involved in the inhibition of iNOS and COX-2 expression. In addition, IBS attenuated LPS-induced phosphorylation of PI3K and Akt, which are upstream molecules of NF-κB, in LPS-stimulated BV2 microglial cells. The functional aspects of the PI3K/Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor that attenuated LPS-induced iNOS and COX-2 expression by suppressing NF-κB activity. These data suggest that an IBS-mediated anti-inflammatory effect may be involved in suppressing the PI3K/Akt-mediated NF-κB signaling pathway.

  20. Molecular regulation of monocyte chemoattractant protein-1 expression in pancreatic beta-cells.

    PubMed

    Kutlu, Burak; Darville, Martine I; Cardozo, Alessandra K; Eizirik, Décio L

    2003-02-01

    Pancreatic beta-cells are selectively destroyed during the course of type 1 diabetes. In the early stages of the disease, inflammatory infiltrates of mononuclear cells, containing predominantly monocytes and T-cells, are present in the islets (insulitis). Chemokines, such as monocyte chemoattractant protein-1 (MCP-1), play a key role in the recruitment and activation of these immunocytes. We have previously described cytokine-induced MCP-1 gene expression in human and rat pancreatic islets. In the present study, the transcriptional regulation by cytokines of the rat MCP-1 gene in fluorescence-activated cell sorting-purified rat beta-cells, insulin-producing INS-1E cells, and RINm5F cells was investigated. Transient transfections with luciferase-reporter constructs identified an interleukin (IL)-1beta-responsive enhancer region between -2,180 bp and -2,478 bp. Mutation of either of the two nuclear factor (NF)-kappaB sites present in this region abrogated IL-1beta-induced MCP-1 promoter activity. Binding of NF-kappaB to the two sites was shown in vitro by gel shift assays, while supershift assays revealed the presence of p65/p50 heterodimers and p65 homodimers. In vivo binding of NF-kappaB was confirmed by chromatin immunoprecipitation assay. Blocking of NF-kappaB activation in cytokine-exposed primary beta-cells by an adenovirus overexpressing a nondegradable form of IkappaBalpha or by pyrrolidine dithiocarbamate decreased IL-1beta-induced MCP-1 mRNA expression. We conclude that NF-kappaB plays an important role for MCP-1 expression in beta-cells. This transcription factor may be an interesting target for ex vivo gene therapy before islet transplantation.

  1. The phase 2 enzyme inducers ethacrynic acid, DL-sulforaphane, and oltipraz inhibit lipopolysaccharide-induced high-mobility group box 1 secretion by RAW 264.7 cells.

    PubMed

    Killeen, Meaghan E; Englert, Joshua A; Stolz, Donna Beer; Song, Mingchen; Han, Yusheng; Delude, Russell L; Kellum, John A; Fink, Mitchell P

    2006-03-01

    The diuretic ethacrynic acid (EA) has been shown to inhibit signaling by the proinflammatory transcription factor nuclear factor-kappaB (NF-kappaB). Accordingly, we sought to determine whether this compound is capable of inhibiting the release of cytokines [interleukin (IL)-6 and IL-10] and NO from RAW 264.7 murine macrophage-like cells stimulated with lipopolysaccharide (LPS). Additionally, we sought to determine whether EA can inhibit secretion of high-mobility group box 1 (HMGB1), a nuclear protein that is secreted by immunostimulated macrophages and functions in the extracellular milieu as a proinflammatory mediator. In a concentration-dependent manner, EA inhibited secretion of IL-6, IL-10, nitric oxide, and HMGB1. As expected, EA inhibited NF-kappaB DNA binding in LPS-stimulated RAW 264.7 cells. Treating these cells with pyrrolidine dithiocarbamate, SN50 (amino acid sequence AAVALLPAVLLALLAPVQRKRQKLMP) or 5-(thien-3-yl)-3-aminothiophene-2-carboxamide (SC-514) also inhibited LPS-induced NF-kappaB DNA binding, but these compounds failed to inhibit LPS-induced HMGB1 secretion. These findings suggested that inhibition of HMGB1 secretion by EA might occur via a mechanism unrelated to the NF-kappaB signaling pathway. Because EA is an electrophilic compound that is known to be capable of inducing expression of so-called phase 2 proteins, we sought to determine whether two other phase 2 enzyme inducers, oltipraz and DL-sulforaphane, also are capable of inhibiting HMGB1 release from immunostimulated macrophages. Incubating RAW 264.7 cells with either oltipraz or DL-sulforaphane inhibited LPS-induced HMGB1 secretion. Moreover, both EA and DL-sulforaphane inhibited relocalization of nuclear HMGB1 into the cytoplasm of LPS-stimulated RAW 264.7 cells. These data suggest that phase 2 inducers may exert anti-inflammatory effects by inhibiting secretion of the cytokine-like nuclear protein HMGB1.

  2. Determination of trace elements in dolomite and gypsum by atomic absorption spectrometry: overcoming the matrix interference by flotation separation

    NASA Astrophysics Data System (ADS)

    Stafilov, Trajče; Zendelovska, Dragica; Pavlovska, Gorica; Čundeva, Katarina

    2002-05-01

    The interferences of Ca and Mg as matrix elements in dolomite and gypsum on Ag, Cd, Cr, Mn, Tl and Zn absorbances during their electrothermal atomic absorption spectrometric (ETAAS) determination are investigated. The results reveal that Ca and Mg do not interfere on Zn and Mn, tend to decrease absorbances of Ag, Cd and Cr, while Tl suffers the most significant influence. A flotation separation method is proposed to eliminate matrix interferences. Hydrated iron(III) oxide, Fe 2O 3· xH 2O, and iron(III) hexamethylenedithiocarbamate, Fe(HMDTC) 3, are applied as flotation collectors. The influence of hydrophobic dithiocarbamate anion, HMDTC, on flotation recoveries of each analyte is studied. The most suitable concentrations of dolomite and gypsum solutions for flotation are determined. To avoid flotation suppression due to the reaction of Ca 2+ and Mg 2+ with surfactant ions, a fit foaming agent was selected. The elements present in dolomite and gypsum as traces have been analyzed by ETAAS. Their ETAAS limits of detection following flotation are found to be 0.021 μg·g -1 for Ag, 0.019 μg·g -1 for Cd, 0.014 μg·g -1 for Cr and 0.11 μg·g -1 for Tl. The determination of Mn and Zn can be performed by flame AAS (FAAS). The limit of detection for Mn is 1.5 μg·g -1, while for Zn 0.8 μg·g -1.

  3. Dispersive liquid-liquid microextraction using diethyldithiocarbamate as a chelating agent and the dried-spot technique for the determination of Fe, Co, Ni, Cu, Zn, Se and Pb by energy-dispersive X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Kocot, Karina; Zawisza, Beata; Sitko, Rafal

    2012-07-01

    Dispersive liquid-liquid microextraction (DLLME) using sodium diethyldithiocarbamate (DDTC) as a chelating agent was investigated for the simultaneous determination of iron, cobalt, nickel, copper, zinc, selenium and lead ions in water samples. The procedure was performed using 5 mL of the sample, 100 μL of a 0.5% solution of DDTC, 30 μL of carbon tetrachloride (extraction phase) and 500 μL of methanol (disperser solvent). The experiments showed that Fe, Co, Ni, Cu, Zn and Pb can be simultaneously extracted at a pH of 5 and that Se can be extracted at a pH of 2-3. The results were compared with those obtained using ammonium pyrrolidine dithiocarbamate as a chelating agent. For all analytes, a linear range was observed up to 0.4 μg mL- 1. If Fe and Zn are present in concentrations 10 times higher than those of the other analytes, then the linearity is observed up to 0.2 μg mL- 1. In the present study, the organic phase that contained preconcentrated elements was deposited onto a Millipore filter and measured using energy-dispersive X-ray fluorescence spectrometry. The obtained detection limits were 2.9, 1.5, 2.0, 2.3, 2.5, 2.0 and 3.9 ng mL- 1 for Fe, Co, Ni, Cu, Zn, Se and Pb, respectively. This combination of DLLME and the dried-spot technique is promising for multielement analyses using other spectroscopy techniques, such as laser ablation-inductively coupled plasma-mass spectrometry, laser-induced breakdown spectroscopy or total-reflection X-ray fluorescence spectrometry.

  4. Cloning, promoter analysis and expression in response to bacterial exposure of sea bass (Dicentrarchus labrax L.) interleukin-12 p40 and p35 subunits.

    PubMed

    Nascimento, Diana S; do Vale, Ana; Tomás, Ana M; Zou, Jun; Secombes, Christopher J; dos Santos, Nuno M S

    2007-03-01

    Interleukin-12 (IL-12) is a heterodimeric cytokine pivotal in resistance to microbial and viral infections. In the search for immunoregulatory genes in sea bass the genes for the two IL-12 subunits p40 and p35 were cloned and sequenced. Molecular characterization of these two genes was performed at both the cDNA and genomic levels. Sea bass IL-12 p40 and p35 conserve most cysteines involved in the intra-chain disulfide bonds of human IL-12 subunits as well as the important structural residues for human IL-12 heterodimerization. The gene organization of sea bass IL-12 p40 is similar to the human orthologue, whilst the sea bass IL-12 p35 gene structure, as reported for pufferfish, differs from the human one in containing an additional exon and lacking a second copy of a duplicated exon present in the mammalian genes. The promoter analysis of both sea bass and pufferfish IL-12 genes showed the presence of the main cis-acting elements involved in the transcriptional regulation of human and mouse orthologues. The involvement of IL-12 in sea bass anti-bacterial immune responses was demonstrated by investigating the expression profiles of IL-1beta, IL-12 p40 and p35 in the head-kidney and spleen following intraperitoneal injection of UV-killed and live Photobacterium damselae ssp. piscicida (Phdp). Finally, the importance of nuclear factor (NF)-kappaB on UV-killed Phdp-induced IL-12 p40 and p35 gene transcription was shown by the use of pyrrolidine dithiocarbamate (PDTC).

  5. The restrained expression of NF-kB in renal tissue ameliorates folic acid induced acute kidney injury in mice.

    PubMed

    Kumar, Dev; Singla, Surinder K; Puri, Veena; Puri, Sanjeev

    2015-01-01

    The Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) represent family of structurally-related eukaryotic transcription factors which regulate diverse array of cellular processes including immunological responses, inflammation, apoptosis, growth & development. Increased expression of NF-kB has often been seen in many diverse diseases, suggesting the importance of genomic deregulation to disease pathophysiology. In the present study we focused on acute kidney injury (AKI), which remains one of the major risk factor showing a high rate of mortality and morbidity. The pathology associated with it, however, remains incompletely known though inflammation has been reported to be one of the major risk factor in the disease pathophysiology. The role of NF-kB thus seemed pertinent. In the present study we show that high dose of folic acid (FA) induced acute kidney injury (AKI) characterized by elevation in levels of blood urea nitrogen & serum creatinine together with extensive tubular necrosis, loss of brush border and marked reduction in mitochondria. One of the salient observations of this study was a coupled increase in the expression of renal, relA, NF-kB2, and p53 genes and proteins during folic acid induced AKI (FA AKI). Treatment of mice with NF-kB inhibitor, pyrrolidine dithio-carbamate ammonium (PDTC) lowered the expression of these transcription factors and ameliorated the aberrant renal function by decreasing serum creatinine levels. In conclusion, our results suggested that NF-kB plays a pivotal role in maintaining renal function that also involved regulating p53 levels during FA AKI.

  6. On the nature of a compound formed from dinitrosyl-iron complexes with cysteine and responsible for a long-lasting vasorelaxation.

    PubMed

    Mokh, Vladimir P; Poltorakov, Alexander P; Serezhenkov, Vladimir A; Vanin, Anatoly F

    2010-05-15

    The nature of a compound able to induce long-lasting (> or =20 min) relaxation of rat abdominal aorta rings after addition of rapidly (within several minutes) disappeared mono- and binuclear dinitrosyl iron complexes with cysteine (M- and B-DNICs, respectively) (10 micromol) to the Krebs medium has been investigated. It has been found that long-lasting vasorelaxation is not induced either by S-nitrosocysteine formed upon decomposition of DNICs or by accumulation of free nitric oxide molecules or nitrite remaining in the incubation medium. Long-term air bubbling of the Krebs medium initially containing M-DNIC is accompanied by conversion of the complex first into B-DNIC, which represents a Roussin's red salt cysteine ester and then into a more stable diamagnetic compound X, which displays an intense absorption band at 278 nm. Compound X is decomposed after treatment with the strong bivalent iron chelator bathophenanthroline disulfonate (BPDS) and N-methyl-D-glucamine dithiocarbamate (MGD). The MGD-induced decomposition of compound X is concomitant with the formation of EPR-detectable mononitrosyl iron complexes with MGD. Treatment of compound X with cysteine results in its decomposition and the appearance of optical absorption bands characteristic of M- and B-DNICs. Evidently, compound X, has an iron-nitrosyl origin similar to that of M- and B-DNICs and its formation in oxygenated DNIC solutions is determined by the lowering cysteine content in them. It is hypothesized that compound X represents a cysteine ester of nitrosyl iron complexes, namely, a black Roussin's salt cysteine ester responsible for long-lasting vasorelaxation initiated by addition of M- and B-DNICs that are rapidly decomposed to compound X to the incubation medium.

  7. Transcriptional up-regulation of nitric oxide synthase II by nuclear factor-kappaB at rostral ventrolateral medulla in a rat mevinphos intoxication model of brain stem death.

    PubMed

    Chan, Julie Y H; Wu, Carol H Y; Tsai, Ching-Yi; Cheng, Hsiao-Lei; Dai, Kuang-Yu; Chan, Samuel H H; Chang, Alice Y W

    2007-06-15

    As the origin of a 'life-and-death' signal that reflects central cardiovascular regulatory failure during brain stem death, the rostral ventrolateral medulla (RVLM) is a suitable neural substrate for mechanistic delineation of this vital phenomenon. Using a clinically relevant animal model that employed the organophosphate pesticide mevinphos (Mev) as the experimental insult, we evaluated the hypothesis that transcriptional up-regulation of nitric oxide synthase I or II (NOS I or II) gene expression by nuclear factor-kappaB (NF-kappaB) on activation of muscarinic receptors in the RVLM underlies brain stem death. In Sprague-Dawley rats maintained under propofol anaesthesia, co-microinjection of muscarinic M2R (methoctramine) or M4R (tropicamide), but not M1R (pirenzepine) or M3R (4-diphenylacetoxy-N-dimethylpiperidinium) antagonist significantly reduced the enhanced NOS I-protein kinase G signalling ('pro-life' phase) or augmented NOS II-peroxynitrite cascade ('pro-death' phase) in ventrolateral medulla, blunted the biphasic increase and decrease in baroreceptor reflex-mediated sympathetic vasomotor tone that reflect the transition from life to death, and diminished the elevated DNA binding activity or nucleus-bound translocation of NF-kappaB in RVLM neurons induced by microinjection of Mev into the bilateral RVLM. However, NF-kappaB inhibitors (diethyldithiocarbamate or pyrrolidine dithiocarbamate) or double-stranded kappaB decoy DNA preferentially antagonized the augmented NOS II-peroxynitrite cascade and the associated cardiovascular depression exhibited during the 'pro-death' phase. We conclude that transcriptional up-regulation of NOS II gene expression by activation of NF-kappaB on selective stimulation of muscarinic M2 or M4 subtype receptors in the RVLM underlies the elicited cardiovascular depression during the 'pro-death' phase in our Mev intoxication model of brain stem death.

  8. Characterization of Pesticide Exposure in a Sample of Pregnant Women in Ecuador.

    PubMed

    Handal, Alexis J; Hund, Lauren; Páez, Maritza; Bear, Samantha; Greenberg, Carolyn; Fenske, Richard A; Barr, Dana Boyd

    2016-05-01

    Few studies have detailed the prenatal pesticide exposure levels of women employed in or residing near large-scale agricultural industries. This study reports pesticide metabolite levels during and shortly after pregnancy in a pilot study of workers in Ecuador. Urine samples were collected for 16 rose workers and 10 nonagricultural workers enrolled into the study in early pregnancy. We measured six nonspecific organophosphatedialkylphosphate (DAP) pesticide metabolites, two alkylenebis-dithiocarbamate pesticide metabolites [ethylene thiourea (ETU) and propylene thiourea (PTU)], 3,5,6-trichloro-2-pyridinol (TCPy), malathion dicarboxylic acid, and two pyrethroid metabolites (2,2-dimethylcyclo propanecarboxylic acid and 3-phenooxybenzoic acid). We collected 141 urine samples (mean: 5.4 per woman). We observed high detection frequencies for five DAP metabolites and ETU, PTU, and TCPy. We report elevated levels of ETU in the entire sample (median 4.24 ng/mL, IQR 2.23, 7.18), suggesting other possible non-occupational pathways of exposure. We found no statistical differences in pesticide levels by current employment status, although the highest pesticide levels were among rose workers. We observed within-woman correlation in TCPy and PTU levels, but not in ETU or DAP levels. The present study is the first to characterize prenatal pesticide exposure levels among working women in Ecuador. Limitations include a small sample size and use of a convenience sample. Strengths include a longitudinal design and multiple urine samples per woman. Results provide an initial characterization of prenatal pesticide exposure levels and how these levels vary over pregnancy in a community impacted by agricultural industry and will inform further studies in the region.

  9. Activation of the canonical nuclear factor-κB pathway is involved in isoflurane-induced hippocampal interleukin-1β elevation and the resultant cognitive deficits in aged rats

    SciTech Connect

    Li, Zheng-Qian; Rong, Xiao-Ying; Liu, Ya-Jie; Ni, Cheng; Tian, Xiao-Sheng; Mo, Na; Chui, De-Hua; Guo, Xiang-Yang

    2013-09-06

    Highlights: •Isoflurane induces hippocampal IL-1β elevation and cognitive deficits in aged rats. •Isoflurane transiently activates the canonical NF-κB pathway in aged rat hippocampus. •NF-κB inhibitor mitigates isoflurane-induced IL-1β elevation and cognitive deficits. •We report a linkage between NF-κB signaling, IL-1β expression, and cognitive changes. -- Abstract: Although much recent evidence has demonstrated that neuroinflammation contributes to volatile anesthetic-induced cognitive deficits, there are few existing mechanistic explanations for this inflammatory process. This study was conducted to investigate the effects of the volatile anesthetic isoflurane on canonical nuclear factor (NF)-κB signaling, and to explore its association with hippocampal interleukin (IL)-1β levels and anesthetic-related cognitive changes in aged rats. After a 4-h exposure to 1.5% isoflurane in 20-month-old rats, increases in IκB kinase and IκB phosphorylation, as well as a reduction in the NF-κB inhibitory protein (IκBα), were observed in the hippocampi of isoflurane-exposed rats compared with control rats. These events were accompanied by an increase in NF-κB p65 nuclear translocation at 6 h after isoflurane exposure and hippocampal IL-1β elevation from 1 to 6 h after isoflurane exposure. Nevertheless, no significant neuroglia activation was observed. Pharmacological inhibition of NF-κB activation by pyrrolidine dithiocarbamate markedly suppressed the IL-1β increase and NF-κB signaling, and also mitigated the severity of cognitive deficits in the Morris water maze task. Overall, our results demonstrate that isoflurane-induced cognitive deficits may stem from upregulation of hippocampal IL-1β, partially via activation of the canonical NF-κB pathway, in aged rats.

  10. Activation of AMPA receptor promotes TNF-α release via the ROS-cSrc-NFκB signaling cascade in RAW264.7 macrophages

    SciTech Connect

    Cheng, Xiu-Li; Ding, Fan; Li, Hui; Tan, Xiao-Qiu; Liu, Xiao; Cao, Ji-Min; Gao, Xue

    2015-05-29

    The relationship between glutamate signaling and inflammation has not been well defined. This study aimed to investigate the role of AMPA receptor (AMPAR) in the expression and release of tumor necrosis factor-alpha (TNF-α) from macrophages and the underlying mechanisms. A series of approaches, including confocal microscopy, immunofluorescency, flow cytometry, ELISA and Western blotting, were used to estimate the expression of AMPAR and downstream signaling molecules, TNF-α release and reactive oxygen species (ROS) generation in the macrophage-like RAW264.7 cells. The results demonstrated that AMPAR was expressed in RAW264.7 cells. AMPA significantly enhanced TNF-α release from RAW264.7 cells, and this effect was abolished by CNQX (AMPAR antagonist). AMPA also induced elevation of ROS production, phosphorylation of c-Src and activation of nuclear factor (NF)-κB in RAW264.7 cells. Blocking c-Src by PP2, scavenging ROS by glutathione (GSH) or inhibiting NF-κB activation by pyrrolidine dithiocarbamate (PDTC) decreased TNF-α production from RAW264.7 cells. We concluded that AMPA promotes TNF-α release in RAW264.7 macrophages likely through the following signaling cascade: AMPAR activation → ROS generation → c-Src phosphorylation → NF-κB activation → TNF-α elevation. The study suggests that AMPAR may participate in macrophage activation and inflammation. - Highlights: • AMPAR is expressed in RAW264.7 macrophages and is upregulated by AMPA stimulation. • Activation of AMPAR stimulates TNF-α release in macrophages through the ROS-cSrc-NFκB signaling cascade. • Macrophage AMPAR signaling may play an important role in inflammation.

  11. Response surface methodology based on central composite design as a chemometric tool for optimization of dispersive-solidification liquid-liquid microextraction for speciation of inorganic arsenic in environmental water samples.

    PubMed

    Asadollahzadeh, Mehdi; Tavakoli, Hamed; Torab-Mostaedi, Meisam; Hosseini, Ghaffar; Hemmati, Alireza

    2014-06-01

    Dispersive-solidification liquid-liquid microextraction (DSLLME) coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for preconcentration and determination of inorganic arsenic (III, V) in water samples. At pH=1, As(III) formed complex with ammonium pyrrolidine dithiocarbamate (APDC) and extracted into the fine droplets of 1-dodecanol (extraction solvent) which were dispersed with ethanol (disperser solvent) into the water sample solution. After extraction, the organic phase was separated by centrifugation, and was solidified by transferring into an ice bath. The solidified solvent was transferred to a conical vial and melted quickly at room temperature. As(III) was determined in the melted organic phase while As(V) remained in the aqueous layer. Total inorganic As was determined after the reduction of the pentavalent forms of arsenic with sodium thiosulphate and potassium iodide. As(V) was calculated by difference between the concentration of total inorganic As and As(III). The variable of interest in the DSLLME method, such as the volume of extraction solvent and disperser solvent, pH, concentration of APDC (chelating agent), extraction time and salt effect, was optimized with the aid of chemometric approaches. First, in screening experiments, fractional factorial design (FFD) was used for selecting the variables which significantly affected the extraction procedure. Afterwards, the significant variables were optimized using response surface methodology (RSM) based on central composite design (CCD). In the optimum conditions, the proposed method has been successfully applied to the determination of inorganic arsenic in different environmental water samples and certified reference material (NIST RSM 1643e).

  12. Anti-inflammatory and hepatoprotective effects of glycyrrhetinic acid on CCl4-induced damage in precision-cut liver slices from Jian carp (Cyprinus carpio var. jian) through inhibition of the nf-kƁ pathway.

    PubMed

    Cao, Liping; Ding, Weidong; Jia, Rui; Du, Jingliang; Wang, Tao; Zhang, Chunyun; Gu, Zhengyan; Yin, Guojun

    2017-03-10

    In order to evaluate the antioxidant and anti-inflammatory effects of glycyrrhetinic acid (GA) on carbon tetrachloride (CCl4)-induced damage in precision-cut liver slices (PCLS) from Jian carp (Cyprinus carpio. Jian), an acute liver damage model was established in this study. The viability of PCLS, levels of anti-oxidases in liver homogenates, expression of inflammation-related genes including nuclear factor-κB (nf-κB)/c-rel, inducible nitric oxide synthase (inos), interleukin-1β (il-1β), interleukin-6 (il-6) and interleukin-8 (il-8), and protein levels of (nf-κB)/c-rel in liver tissues were measured. The results showed that pretreatment of PCLS with GA at 5 and 10 μg/mL for 6 h significantly inhibited the cytotoxicity of CCl4. GA attenuated CCl4-induced oxidative stress in PCLS through promoting the recovery of superoxide dismutase (SOD) and glutathione (GSH) levels, and inhibiting malondialdehyde (MDA) synthesis. In inflammatory response, GA at both 5 and 10 μg/mL significantly inhibited the increase in mRNA levels of inflammatory cytokines including nf-kƁ/c-rel, inos, il-1β, il-6 and il-8, and the protein level of Nf-kƁ/C-rel induced by CCl4. Furthermore, treatment with pyrrolyl dithiocarbamate (PDTC, 4 μg/mL), an inhibitor of nuclear transcription factor nf-kB, significantly inhibited nf-kB levels, and transcription of downstream cytokines inos, il-1β, il-6 and il-8, also the viability of PCLS was significantly increased. These results indicated that GA suppressed inflammation and reduced cytotoxicity by inhibiting the nf-kƁ signaling pathway, and plays a role in liver protection.

  13. Antiproliferative and apoptotic effects of two new Pd(II) methylsarcosinedithiocarbamate derivatives on human acute myeloid leukemia cells in vitro.

    PubMed

    Aldinucci, Donatella; Cattaruzza, Lara; Lorenzon, Debora; Giovagnini, Lorena; Fregona, Dolores; Colombatti, Alfonso

    2008-01-01

    -GM, respectively). These data suggest that leukemic cells of myelomonoblast lineage might represent a preferential target for its cytotoxic activity compared to normal committed hemopoietic progenitor cells. Altogether, our results indicate that these new Pd(II) dithiocarbamate derivatives might represent novel potentially active drugs for the management of some selected myeloid leukemia strains, able to conjugate cytostatic and apoptotic activity with reduced toxicity.

  14. Rescheduling the process of nanoparticle removal used for water mercury remediation can increase the risk to aquatic organism: evidence of innate immune functions modulation in European eel (Anguilla anguilla L.).

    PubMed

    Costa, Leonor C; Mohmood, Iram; Trindade, Tito; Saleem, Mohammad; Duarte, Armando C; Pereira, Eduarda; Ahmad, Iqbal

    2015-12-01

    This study aimed to assess the mechanisms of innate immune function responses to silica-coated iron oxide nanoparticle functionalized with dithiocarbamate groups (IONP) exposure alone and its associated mercury (Hg) in European eel (Anguilla anguilla L.) phagocytes isolated from peritoneum (P-phagocytes), gill (G-phagocytes), head kidney (HK-phagocytes) and spleen (S-phagocytes). The study evaluated viability, phagocytosis, oxidative burst activity (OBA) and lipid peroxidation (LPO). Four groups were made: (1) 2 × 10(6) phagocytes + RPMI-1640 (control), (2) 2 × 10(6) phagocytes + IONP (2.5 mg L(-1)), (3) 2 × 10(6) phagocytes + Hg (50 μg L(-1)) and (4) 2 × 10(6) phagocytes + IONP + Hg. Samplings were performed at 0, 2, 4, 8, 16, 24, 48 and 72 h of exposure. A. anguilla P-, G-, HK- and S-phagocytes in vitro exposure to IONP alone revealed either increased (except HK-phagocytes at 16 h) or no change in viability, suggesting that the cells are metabolically active and resistant to IONP exposure alone. In terms of phagocytes overactivation and reactive oxygen species (ROS) production as an indirect mechanism of immunotoxicity, the phagocytes responded in the following manner: P- > S- > HK- = G-phagocytes for IONP exposure alone, S- > HK- > P- = G-phagocytes for Hg exposure alone and HK- > G- = S- > P-phagocytes for concomitant exposure. Overall, considering Hg as a surrogate for metals and its association with IONP, as well as the likelihood that it could pose a serious threat to aquatic organisms by modulating their immune defense mechanisms if accidentally discharged into the aquatic environment, current results suggest that the step of IONP-metal complex removal must not be underrated and should be processed without any more ado.

  15. Enhanced expression of two discrete isoforms of matrix metalloproteinase-2 in experimental and human diabetic nephropathy

    PubMed Central

    Bae, Sun Sik; Lee, Min Young; Rhee, Harin; Kim, Il Young; Seong, Eun Young; Lee, Dong Won; Lee, Soo Bong; Kwak, Ihm Soo; Lovett, David H.

    2017-01-01

    Background We recentl