Protamine sulfate down-regulates thrombin generation by inhibiting factor V activation.

LENUS (Irish Health Repository)

Ni Ainle, Fionnuala

2009-08-20

Protamine sulfate is a positively charged polypeptide widely used to reverse heparin-induced anticoagulation. Paradoxically, prospective randomized trials have shown that protamine administration for heparin neutralization is associated with increased bleeding, particularly after cardiothoracic surgery with cardiopulmonary bypass. The molecular mechanism(s) through which protamine mediates this anticoagulant effect has not been defined. In vivo administration of pharmacologic doses of protamine to BALB\\/c mice significantly reduced plasma thrombin generation and prolonged tail-bleeding time (from 120 to 199 seconds). Similarly, in pooled normal human plasma, protamine caused significant dose-dependent prolongations of both prothrombin time and activated partial thromboplastin time. Protamine also markedly attenuated tissue factor-initiated thrombin generation in human plasma, causing a significant decrease in endogenous thrombin potential (41% +\\/- 7%). As expected, low-dose protamine effectively reversed the anticoagulant activity of unfractionated heparin in plasma. However, elevated protamine concentrations were associated with progressive dose-dependent reduction in thrombin generation. To assess the mechanism by which protamine mediates down-regulation of thrombin generation, the effect of protamine on factor V activation was assessed. Protamine was found to significantly reduce the rate of factor V activation by both thrombin and factor Xa. Protamine mediates its anticoagulant activity in plasma by down-regulation of thrombin generation via a novel mechanism, specifically inhibition of factor V activation.

Evaluation of Protamine as a Disinfectant for Contact Lenses.

Science.gov (United States)

Bandara, Mahesh K; Masoudi, Simin; Zhu, Hua; Bandara, Rani; Willcox, Mark D P

2016-11-01

To investigate the ability of protamine, alone or in combination with other antimicrobial agents, to kill bacteria and fungi associated with contact lens-related keratitis. The International Organization for Standardization 14729:2001 procedure was used to test the antimicrobial activity of solutions of protamine (23-228 μM) with and without polyhexamethylene biguanide (PHMB) and ethylenediamine tetra-acetic acid (EDTA). The recommended ISO panel of microbes along with six clinical isolates was tested. The effect of increasing sodium chloride concentration on the antimicrobial activity was also assessed. The cytotoxicity of the final protamine/EDTA/PHMB solution was measured using ISO 10993-5 standard assays. Protamine gave a dose-dependent antimicrobial effect, with the highest effect for most strains being at 228 μM (≥6 log reductions of viable bacteria and ≥1 log reduction of viable fungi). Addition of EDTA and PHMB increased the antimicrobial effect for all strains except Pseudomonas aeruginosa ATCC6538, which had optimum activity (≥6 log inhibition) even in protamine alone. The optimum antimicrobial activity of all microbes was achieved in 0.2% sodium chloride, but even in 0.8% sodium chloride, the activity met or exceeded the ISO standard (>3 log reductions for bacteria and >1 log reduction for fungi). None of the formulations was cytotoxic to mammalian cells. This study highlights the potential for protamine to be used for the development of effective multipurpose disinfection solutions. Further investigations such as stability, compatibility with contact lenses, and in vivo toxicity are warranted.

Impact of cigarette smoking on histone (H2B) to protamine ratio in human spermatozoa and its relation to sperm parameters.

Science.gov (United States)

Hamad, M F; Shelko, N; Kartarius, S; Montenarh, M; Hammadeh, M E

2014-09-01

Smoking is strongly associated with abnormalities in histone-to-protamine transition and with alteration of protamine expression in human spermatozoa. A proper protamine to histone ratio is, however, essential for sperm chromatin maturity and DNA integrity. Alterations in these sperm nuclear proteins were observed in infertile men. The present prospective study is aimed at evaluating the possible relationship among smoking, semen quality and the histone-to-protamine transition ratio in mature spermatozoa. Histone H2B and protamine 1 (P1) and 2 (P2) were quantified using acid-urea polyacrylamide gel electrophoresis in the spermatozoa of 35 smokers and 19 non-smokers. Levels of lipid peroxidation marker malondialdehyde (MDA) were measured in seminal plasma by thiobarbituric acid assay. Cotinine concentrations were determined in seminal plasma using an enzyme-linked immunosorbent assay. Histone H2B levels in smokers (292.27 ± 58.24 ng/10(6)) were significantly higher (p = 0.001) than that of non-smokers (109.1 ± 43.70 ng/10(6)), besides, a significant difference (p > 0.0001) was found for the P1 and P2 ratio between smokers (1.71 ± 0.071) and non-smokers (1.05 ± 0.033). The H2B/(H2B+P1 + P2) ratio (0.29 ± 0.71) of smokers were significantly higher (p = sperm count, motility (p = 0.018), vitality (p = 0.009) and membrane integrity (p = 0.0001) than non-smokers. These results reveal that patients who smoke possess a higher proportion of spermatozoa with an alteration of the histone to protamine ratio than patients who do not smoke, and suggest that cigarette smoking may inversely affect male fertility. © 2014 American Society of Andrology and European Academy of Andrology.

Single Nucleotide Polymorphism Analysis of Protamine Genes in Infertile Men

Directory of Open Access Journals (Sweden)

Ahamad Salamian

2008-01-01

Full Text Available Background: Single nucleotide polymorphism (SNPs are considered as one of the underlyingcauses of male infertility. Proper sperm chromatin packaging which involves replacement ofhistones with protamines has profound effect on male fertility. Over 20 SNPs have been reportedfor the protamine 1 and 2.Materials and Methods: The aim of this study was to evaluate the frequency of two previouslyreported SNPs using polymerase chain reaction (PCR-restriction fragment length polymorphism(RFLP approach in 35, 96 and 177 normal, oligozoospermic and azoospermic individuals. TheseSNPs are: 1. A base pair substitution (G at position 197 instead of T in protamine type 1 Openreading frame (ORF including untranslated region, which causes an Arg residue change to Serresidue in a highly conserved region. 2. cytidine nucleotide change to thymidine in position of 248of protamine type 2 ORF which caused a nonsense point mutation.Results: The two mentioned SNPs were not present in the studied population, thus concluding thatthese SNPs can not serves as molecular markers for male infertility diagnosis.Conclusion: The results of our study reveal that in a selected Iranian population, the SNP G197Tand C248T are completely absent and are not associated with male infertility and therefore theseSNPs may not represent a molecular marker for genetic diagnosis of male infertility.

Influence of Protamine Functionalization on the Colloidal Stability of 1D and 2D Titanium Oxide Nanostructures.

Science.gov (United States)

Rouster, Paul; Pavlovic, Marko; Horváth, Endre; Forró, László; Dey, Sandwip K; Szilagyi, Istvan

2017-09-26

The colloidal stability of titanium oxide nanosheets (TNS) and nanowires (TiONW) was studied in the presence of protamine (natural polyelectrolyte) in aqueous dispersions, where the nanostructures possessed negative net charge, and the protamine was positively charged. Regardless of their shape, similar charging and aggregation behaviors were observed for both TNS and TiONW. Electrophoretic experiments performed at different protamine loadings revealed that the adsorption of protamine led to charge neutralization and charge inversion depending on the polyelectrolyte dose applied. Light scattering measurements indicated unstable dispersions once the surface charge was close to zero or slow aggregation below and above the charge neutralization point with negatively or positively charged nanostructures, respectively. These stability regimes were confirmed by the electron microscopy images taken at different polyelectrolyte loadings. The protamine dose and salt-dependent colloidal stability confirmed the presence of DLVO-type interparticle forces, and no experimental evidence was found for additional interactions (e.g., patch-charge, hydrophobic, or steric forces), which are usually present in similar polyelectrolyte-particle systems. These findings indicate that the polyelectrolyte adsorbs on the TNS and TiONW surfaces in a flat and extended conformation giving rise to the absence of surface heterogeneities. Therefore, protamine is an excellent biocompatible candidate to form smooth surfaces, for instance in multilayers composed of polyelectrolytes and particles to be used in biomedical applications.

Protamine reduces bleeding complications associated with carotid endarterectomy without increasing the risk of stroke.

Science.gov (United States)

Stone, David H; Nolan, Brian W; Schanzer, Andres; Goodney, Philip P; Cambria, Robert A; Likosky, Donald S; Walsh, Daniel B; Cronenwett, Jack L

2010-03-01

Controversy persists regarding the use of protamine during carotid endarterectomy (CEA) based on prior conflicting reports documenting both reduced bleeding as well as increased stroke risk. The purpose of this study was to determine the effect of protamine reversal of heparin anticoagulation on the outcome of CEA in a contemporary multistate registry. We reviewed a prospective regional registry of 4587 CEAs in 4311 patients performed by 66 surgeons from 11 centers in Northern New England from 2003-2008. Protamine use varied by surgeon (38% routine use, 44% rare use, 18% selective use). Endpoints were postoperative bleeding requiring reoperation as well as potential thrombotic complications, including stroke, death, and myocardial infarction (MI). Predictors of endpoints were determined by multivariate logistic regression after associated variables were identified by univariate analysis. Of the 4587 CEAs performed, 46% utilized protamine, while 54% did not. Fourteen patients (0.64%) in the protamine-treated group required reoperation for bleeding compared with 42 patients (1.66%) in the untreated cohort (P = .001). Protamine use did not affect the rate of MI (1.1% vs 0.91%, P = .51), stroke (0.78% vs 1.15%, P = .2), or death (0.23% vs 0.32%, P = .57) between treated and untreated patients, respectively. By multivariate analysis, protamine (odds ratio [OR] 0.32, 95% confidence interval [CI], 0.17-0.63; P = .001) and patch angioplasty (OR 0.46, 95% CI, 0.26-0.81; P = .007) were independently associated with diminished reoperation for bleeding. A single center was associated with a significantly higher rate of reoperation for bleeding (OR 6.47, 95% CI, 3.02-13.9; P < .001). Independent of protamine use, consequences of reoperation for bleeding were significant, with a four-fold increase in MI, a seven-fold increase in stroke, and a 30-fold increase in death. Protamine reduced serious bleeding requiring reoperation during CEA without increasing the risk of MI, stroke

Synthesis and characterization of 5,7-dimethyl-8-hydroxyquinoline and 2-(2-pyridyl)benzimidazole complexes of zinc(II) for optoelectronic application

Science.gov (United States)

Singh, Kapoor; Kumar, Amit; Srivastava, Ritu; Kadyan, Partap S.; Kamalasanan, Modeeparampil N.; Singh, Ishwar

2011-11-01

Bis(5,7-dimethyl-8-hydroxyquinolinato)zinc(II) (Me 2q) 2Zn and 5,7-dimethyl-8-hydroxyquinolinato(2-(2-pyridyl)benzimidazole) zinc(II) Me 2q(pbi)Zn have been synthesized and characterized by various techniques. These metal complexes have high thermal stability (>300 °C) and high glass transition temperatures (>150 °C). The vacuum deposited films of these materials show good film forming property and are suitable for opto-electronic applications. Multilayered organic electroluminescent (EL) devices have been fabricated having structure ITO/α-NPD/zinc complex/BCP/Alq 3/LiF/Al, which produce emission with chromaticity having Commission Internationale d'Eclairage (CIE) coordinates x = 0.506 and y = 0.484 for (Me 2q) 2Zn; x = 0.47 and y = 0.52 for (Me 2q)(pbi)Zn complex. The electroluminescence spectra show peak emission centered at 572 and 561 nm respectively for these materials.

A novel thiolated human-like collage zinc complex as a promising zinc supplement: physicochemical characteristics and biocompatibility.

Science.gov (United States)

Zhu, Chenhui; Ma, Xiaoxuan; Wang, Yonghui; Mi, Yu; Fan, Daidi; Deng, Jianjun; Xue, Wenjiao

2014-11-01

To improve zinc binding ability to human-like collagen (HLC) and stability of metal complex, HLC was thiolated by mercaptosuccinylation reaction with S-acetylmercaptosuccinic anhydride (S-AMSA) at pH8.0. One mole of thiolated HLC-Zn (SHLC-Zn) complex possessed 24.3mol zinc ions when pH was 8.0 and zinc concentration was 15 mM. The physicochemical properties and biocompatibility of thiolated HLC-Zn (SHLC-Zn) complex were investigated by UV-vis, CD, electrophoresis analysis, differential scanning calorimetry (DSC) and cell viability assay, respectively. The results showed that SHLC-Zn complex(1) exhibited higher zinc ions than that of native HLC and still maintained the secondary structure of HLC though interaction occurred between SHLC and zinc ions, (2) increased the apparent molecular weight when compared with native HLC, (3) exhibited greater thermal stability than native HLC, and (4) presented toxicity free for BHK cells. This study suggests that the SHLC-Zn complex is a potential nutrition as well as zinc supplement in the medical application. Copyright © 2014 Elsevier B.V. All rights reserved.

Interdependence of free zinc changes and protein complex assembly - insights into zinc signal regulation.

Science.gov (United States)

Kocyła, Anna; Adamczyk, Justyna; Krężel, Artur

2018-01-24

Cellular zinc (Zn(ii)) is bound with proteins that are part of the proteomes of all domains of life. It is mostly utilized as a catalytic or structural protein cofactor, which results in a vast number of binding architectures. The Zn(ii) ion is also important for the formation of transient protein complexes with a Zn(ii)-dependent quaternary structure that is formed upon cellular zinc signals. The mechanisms by which proteins associate with and dissociate from Zn(ii) and the connection with cellular Zn(ii) changes remain incompletely understood. In this study, we aimed to examine how zinc protein domains with various Zn(ii)-binding architectures are formed under free Zn(ii) concentration changes and how formation of the Zn(ii)-dependent assemblies is related to the protein concentration and reactivity. To accomplish these goals we chose four zinc domains with different Zn(ii)-to-protein binding stoichiometries: classical zinc finger (ZnP), LIM domain (Zn 2 P), zinc hook (ZnP 2 ) and zinc clasp (ZnP 1 P 2 ) folds. Our research demonstrated a lack of changes in the saturation level of intraprotein zinc binding sites, despite various peptide concentrations, while homo- and heterodimers indicated a concentration-dependent tendency. In other words, at a certain free Zn(ii) concentration, the fraction of a formed dimeric complex increases or decreases with subunit concentration changes. Secondly, even small or local changes in free Zn(ii) may significantly affect protein saturation depending on its architecture, function and subcellular concentration. In our paper, we indicate the importance of interdependence of free Zn(ii) availability and protein subunit concentrations for cellular zinc signal regulation.

Synthesis, characterization and thermal behavior of antibacterial and antifungal active zinc complexes of bis (3(4-dimethylaminophenyl)-allylidene-1,2-diaminoethane

International Nuclear Information System (INIS)

Montazerozohori, Morteza; Zahedi, Saeedeh; Naghiha, Asghar; Zohour, Mostafa Montazer

2014-01-01

In this work, synthesis of a new series of zinc halide/pseudohalide complexes of a bidentate Schiff base ligand entitled as bis (3-(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane(L) is described. The ligand and its zinc complexes were characterized by various techniques such as elemental analysis, FT-IR, UV–visible, 1 H and 13 C NMR spectra, cyclic voltammetry, and conductometry. Accordingly ZnLX 2 (X = Cl − , Br − , I − , SCN − and N 3 − ) was suggested as molecular formula of the complexes. Redox behaviors of ligand and its zinc complexes were investigated by cyclic voltammetry method. Furthermore, the ligand and its zinc halide/pseudohalide complexes were tested for their in vitro antibacterial activities against two gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Also in vitro antifungal activities of them against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds are antibacterial and antifungal active. Thermal behaviors of ligand and its zinc complexes were studied from room temperature to 1100 °C under argon atmosphere. It was found that the ligand and zinc iodide are decomposed completely via three and four steps respectively while other zinc complexes leave out the metal or organometallic compounds as final residuals after 3–4 decomposition steps at above temperature range. Moreover evaluation of some thermo-kinetic parameters such as activation energy (∆E ⁎ ), enthalpy (∆H ⁎ ), entropy (∆S ⁎ ) and Gibbs free energy change (∆G ⁎ ) of the thermal decomposition steps were performed based on the Coats–Redfern relation. - Highlights: • Some novel complexes of Zn(II) with a bidentate Schiff base ligand have been synthesized. • Redox behavior of ligand and zinc complexes was investigated by cyclic voltammetry. • The ligand and its zinc complexes are antibacterial and

Synthesis, characterization and thermal behavior of antibacterial and antifungal active zinc complexes of bis (3(4-dimethylaminophenyl)-allylidene-1,2-diaminoethane

Energy Technology Data Exchange (ETDEWEB)

Montazerozohori, Morteza, E-mail: mmzohori@mail.yu.ac.ir [Department of Chemistry, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Zahedi, Saeedeh [Department of Chemistry, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Naghiha, Asghar [Department of Animal Sciences, Faculty of Agriculture, Yasouj University, Yasouj (Iran, Islamic Republic of); Zohour, Mostafa Montazer [Genetics of Non-Communicable Disease Research Center, Zahedan University of Medical Sciences, Zahedan (Iran, Islamic Republic of)

2014-02-01

In this work, synthesis of a new series of zinc halide/pseudohalide complexes of a bidentate Schiff base ligand entitled as bis (3-(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane(L) is described. The ligand and its zinc complexes were characterized by various techniques such as elemental analysis, FT-IR, UV–visible, {sup 1}H and {sup 13}C NMR spectra, cyclic voltammetry, and conductometry. Accordingly ZnLX{sub 2} (X = Cl{sup −}, Br{sup −}, I{sup −}, SCN{sup −} and N{sub 3}{sup −}) was suggested as molecular formula of the complexes. Redox behaviors of ligand and its zinc complexes were investigated by cyclic voltammetry method. Furthermore, the ligand and its zinc halide/pseudohalide complexes were tested for their in vitro antibacterial activities against two gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Also in vitro antifungal activities of them against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds are antibacterial and antifungal active. Thermal behaviors of ligand and its zinc complexes were studied from room temperature to 1100 °C under argon atmosphere. It was found that the ligand and zinc iodide are decomposed completely via three and four steps respectively while other zinc complexes leave out the metal or organometallic compounds as final residuals after 3–4 decomposition steps at above temperature range. Moreover evaluation of some thermo-kinetic parameters such as activation energy (∆E{sup ⁎}), enthalpy (∆H{sup ⁎}), entropy (∆S{sup ⁎}) and Gibbs free energy change (∆G{sup ⁎}) of the thermal decomposition steps were performed based on the Coats–Redfern relation. - Highlights: • Some novel complexes of Zn(II) with a bidentate Schiff base ligand have been synthesized. • Redox behavior of ligand and zinc complexes was investigated by cyclic voltammetry. • The

Diazinon alters sperm chromatin structure in mice by phosphorylating nuclear protamines

International Nuclear Information System (INIS)

Pina-Guzman, B.; Solis-Heredia, M.J.; Quintanilla-Vega, B.

2005-01-01

Organophosphorus (OP) pesticides, widely used in agriculture and pest control, are associated with male reproductive effects, including sperm chromatin alterations, but the mechanisms underlying these effects are unknown. The main toxic action of OP is related to phosphorylation of proteins. Chemical alterations in sperm nuclear proteins (protamines), which pack DNA during the last steps of spermatogenesis, contribute to male reproductive toxicity. Therefore, in the present study, we tested the ability of diazinon (DZN), an OP compound, to alter sperm chromatin by phosphorylating nuclear protamines. Mice were injected with a single dose of DZN (8.12 mg/kg, i.p.), and killed 8 and 15 days after treatment. Quality of sperm from epididymis and vas deferens was evaluated through standard methods and chromatin condensation by flow cytometry (DNA Fragmented Index parameters: DFI and DFI%) and fluorescence microscopy using chromomycin-A 3 (CMA 3 ). Increases in DFI (15%), DFI% (4.5-fold), and CMA 3 (2-fold) were observed only at 8 days post-treatment, indicating an alteration in sperm chromatin condensation and DNA damage during late spermatid differentiation. In addition, an increase of phosphorous content (approximately 50%) in protamines, especially in the phosphoserine content (approximately 73%), was found at 8 days post-treatment. Sperm viability, motility, and morphology showed significant alterations at this time. These data strongly suggest that spermatozoa exposed during the late steps of maturation were the targets of DZN exposure. The correlation observed between the phosphorous content in nuclear protamines with DFI%, DFI, and CMA 3 provides evidence that phosphorylation of nuclear protamines is involved in the OP effects on sperm chromatin

Surface modification of paclitaxel-loaded tri-block copolymer PLGA-b-PEG-b-PLGA nanoparticles with protamine for liver cancer therapy

Energy Technology Data Exchange (ETDEWEB)

Gao, Nansha [Chinese Academy of Science, Research Center for Human Tissues and Organs Degeneration, Shenzhen Institute of Advanced Technology (China); Chen, Zhihong [Guangdong Medical College, Analysis Centre (China); Xiao, Xiaojun [Shenzhen University, Institute of Allergy and Immunology, School of Medicine (China); Ruan, Changshun [Chinese Academy of Science, Research Center for Human Tissues and Organs Degeneration, Shenzhen Institute of Advanced Technology (China); Mei, Lin [Tsinghua University, The Shenzhen Key Lab of Gene and Antibody Therapy, and Division of Life and Health Sciences, Graduate School at Shenzhen (China); Liu, Zhigang, E-mail: lzg@szu.edu.cn [Shenzhen University, Institute of Allergy and Immunology, School of Medicine (China); Zeng, Xiaowei, E-mail: zeng.xiaowei@sz.tsinghua.edu.cn [Tsinghua University, The Shenzhen Key Lab of Gene and Antibody Therapy, and Division of Life and Health Sciences, Graduate School at Shenzhen (China)

2015-08-15

In order to enhance the therapeutic effect of chemotherapy on liver cancer, a biodegradable formulation of protamine-modified paclitaxel-loaded poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-b-PEG-b-PLGA) nanoparticles (PTX-loaded/protamine NPs) was prepared. Tri-block copolymer PLGA-b-PEG-b-PLGA was synthesized by ring-opening polymerization and characterized by {sup 1}H NMR spectroscopy and gel permeation chromatography. PTX-loaded and PTX-loaded/protamine NPs were characterized in terms of size, size distribution, zeta potential, surface morphology, drug encapsulation efficiency, and drug release. Confocal laser scanning microscopy showed that coumarin 6-loaded/protamine NPs were internalized by hepatocellular carcinoma cell line HepG2. The cellular uptake efficiency of NPs was obviously elevated after protamine modification. With commercial formulation Taxol{sup ®} as the reference, HepG2 cells were also used to study the cytotoxicity of the NPs. PTX-loaded/protamine NPs exhibited significantly higher cytotoxicity than PTX-loaded NPs and Taxol{sup ®} did. All the results suggested that surface modification of PTX-loaded PLGA-b-PEG-b-PLGA NPs with protamine boosted the therapeutic efficacy on liver cancer.

The relative contribution of natural zinc complexing agents and ZnSO4 to growth and zinc nutrition of maize

International Nuclear Information System (INIS)

Kumar, M.; Prasad, B.

1989-01-01

Relative evaluation of different natural zinc-complexes indicated that application of Zn-FA 2 (PM), Zn-FA 3 (Comp), Zn-FA 1 (BGS), Zn-FA 5 (PR), Zn-FA 4 (SS) and ZnSO 4 significantly enhanced the drymatter yield and zinc uptake by maize. The natural zinc-complexes in particular increased, to a greater extent, the uptake of both native and applied sources than that observed with ZnSO 4 as zinc carrier. Significant positive relationship between self-diffusion coefficient of Zn and drymatter yield and uptake of zinc by maize suggested that diffusion is responsible for the supply of zinc from ambient soil matrix to plant roots. (author). 12 refs., 5 tabs

Mononuclear zinc(II) complexes of 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols: Synthesis, structural characterization, DNA binding and cheminuclease activities

Science.gov (United States)

Ravichandran, J.; Gurumoorthy, P.; Karthick, C.; Kalilur Rahiman, A.

2014-03-01

Four new zinc(II) complexes [Zn(HL1-4)Cl2] (1-4), where HL1-4 = 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols, have been isolated and fully characterized using various spectro-analytical techniques. The X-ray crystal structure of complex 4 shows the distorted trigonal-bipyramidal coordination geometry around zinc(II) ion. The crystal packing is stabilized by intermolecular NH⋯O hydrogen bonding interaction. The complexes display no d-d electronic band in the visible region due to d10 electronic configuration of zinc(II) ion. The electrochemical properties of the synthesized ligands and their complexes exhibit similar voltammogram at reduction potential due to electrochemically innocent Zn(II) ion, which evidenced that the electron transfer is due to the nature of the ligand. Binding interaction of complexes with calf thymus DNA was studied by UV-Vis absorption titration, viscometric titration and cyclic voltammetry. All complexes bind with CT DNA by intercalation, giving the binding affinity in the order of 2 > 1 ≫ 3 > 4. The prominent cheminuclease activity of complexes on plasmid DNA (pBR322 DNA) was observed in the absence and presence of H2O2. Oxidative pathway reveals that the underlying mechanism involves hydroxyl radical.

Rational design of protamine nanocapsules as antigen delivery carriers.

Science.gov (United States)

González-Aramundiz, José Vicente; Presas, Elena; Dalmau-Mena, Inmaculada; Martínez-Pulgarín, Susana; Alonso, Covadonga; Escribano, José M; Alonso, María J; Csaba, Noemi Stefánia

2017-01-10

Current challenges in global immunization indicate the demand for new delivery strategies, which could be applied to the development of new vaccines against emerging diseases, as well as to improve safety and efficacy of currently existing vaccine formulations. Here, we report a novel antigen nanocarrier consisting of an oily core and a protamine shell, further stabilized with pegylated surfactants. These nanocarriers, named protamine nanocapsules, were rationally designed to promote the intracellular delivery of antigens to immunocompetent cells and to trigger an efficient and long-lasting immune response. Protamine nanocapsules have nanometric size, positive zeta potential and high association capacity for H1N1 influenza hemagglutinin, a protein that was used here as a model antigen. The new formulation shows an attractive stability profile both, as an aqueous suspension or a freeze-dried powder formulation. In vitro studies showed that protamine nanocapsules were efficiently internalized by macrophages without eliciting significant toxicity. In vivo studies indicate that antigen-loaded nanocapsules trigger immune responses comparable to those achieved with alum, even when using significantly lower antigen doses, thus indicating their adjuvant properties. These promising in vivo data, alongside with their versatility for the loading of different antigens and oily immunomodulators and their excellent stability profile, make these nanocapsules a promising platform for the delivery of antigens. Protamine sulphate (PubChem SID: 7849283), Sodium Cholate (PubChem CID: 23668194), Miglyol (PubChem CID: 53471835), α tocopherol (PubChem CID: 14985), Tween® 20(PubChem CID: 443314), Tween® 80(PubChem CID: 5281955), TPGS (PubChem CID: 71406). Copyright © 2016 Elsevier B.V. All rights reserved.

Positron annihilation studies of bio-related N2S2-tetradentate ligands and their zinc complexes

International Nuclear Information System (INIS)

Shaban, S.Y.; Mahmoud, K.R.; Sharshar, T.

2013-01-01

In this study, a series of three N 2 S 2 -tetradentate ligands and their zinc complexes were investigated by positron annihilation lifetime spectroscopy. The measurements were performed at room temperature. The analysis of lifetime spectra of all samples yielded four lifetime components, except in one sample that yielded three components. The results showed that the formation probability and lifetime of ortho-positronium in this series are dependent on the structure.

Protamine 3 expressions in crossbred bull spermatozoa may not be ...

African Journals Online (AJOL)

SAM

2014-05-14

May 14, 2014 ... spermatids and involves replacement of somatic histones with the transition proteins (TNP1 and TNP2). Subse- quently, in elongating spermatids, the protamines (PRM1 and PRM2) replace TNP1 and TNP2. The resulting chro- matin is highly condensed and transcriptionally silent. In bovine, PRM1, PRM2 ...

Increased accuracy in heparin and protamine administration decreases bleeding

DEFF Research Database (Denmark)

Runge, Marx; Møller, Christian H; Steinbrüchel, Daniel A

2009-01-01

Three to 5 percent of the patients undergoing cardiac surgery are reoperated because of bleeding. When a surgical cause can be excluded, heparin/protamine mismatch may be considered. Insufficient reversal of heparin and overdosing of protamine may cause postoperative bleeding. The purpose......). A reduced number of patients needed blood transfusions in the RxDx group, although this was not statistically significant (19% vs. 38%, respectively; p = .13). Initial heparin dose was significantly reduced in the RxDx group (250 mg; range, 100-375 mg) compared with the control group (300 mg; range, 200...

Changes in cell morphology of Listeria monocytogenesnes and Shewanella putrefaciens resulting from the action of protamine

DEFF Research Database (Denmark)

Johansen, Charlotte; Gill, T.; Gram, Lone

1996-01-01

cells. Immunoelectron microscopy of protamine-treated cells of both L. monocytogenes and S. putrefaciens showed great damage to the cell wall and condensation of the cytoplasm. Respiration of the cells was decreased due to treatment with sublethal concentrations of protamine, probably due to leakage...... or loss of cell envelope potential. It was concluded that protamine disrupted the outer surface structure and condensed the cytoplasm of sensitive cells and, in sublethal concentrations, altered membrane structures, thereby eliminating respiration......Protamine, which is an antibacterial basic peptide, was shown to alter the cell morphology of Listeria monocytogenes and Shewanella putrefaciens. Atomic force microscopy revealed that protamine smoothed the surface of cells, formed holes in the cell envelope, and caused fusion of S. putrefaciens...

Protamine precipitation of two reovirus particle types from polluted waters.

OpenAIRE

Adams, D J; Ridinger, D N; Spendlove, R S; Barnett, B B

1982-01-01

Two forms of virus particle are released from reovirus-infected cell cultures, infectious reovirus and potentially infectious reovirus (PIV). PIV particle forms have a complete outer coat and are not infectious until the outer coat is altered or removed. The PIV concentration in polluted waters, however, has not been determined. Protamine sulfate precipitation, using 0.25% fetal bovine serum and 0.005% protamine sulfate for the first precipitation of the sample and 0.0025% for the second, was...

Inhibition of human arterial smooth muscle (HASM) cell proliferation and collagen synthesis by protamine

International Nuclear Information System (INIS)

Drucker, D.E.; Graham, M.F.; Diegelmann, R.F.; Greenfield, L.J.

1986-01-01

Atherosclerotic plaques result from vascular smooth muscle cell proliferation and collagen deposition. The authors have been studying factors which modulate HASM cell proliferation and collagen synthesis. HASM cells were isolated from the media of normal human thoracic and infrarenal aortas and grown in vitro. Cell numbers were determined by direct counting and collagen synthesis was measured by incorporation of 3 H-proline into collagenase-digestible protein. In this study, protamine (200 μg/ml) was tested and found to cause a 55% reduction of HASM cell proliferation which was reversible when the cells were returned to control medium or when heparin (100 μg/ml) was added with protamine. Protamine caused a constant 33% decrease in non-collagen protein (NCP) synthesis per cell. In contrast, collagen synthesis was inhibited in dose dependent fashion (88% reduction at 200 μg/ml). Protamine blocks HASM cell proliferation and specifically inhibits collagen production. The exact mechanism of this inhibition is unclear but may be related to a transcriptional event since protamine has a high affinity for DNA

Naked eye detection of infertility based on sperm protamine-induced aggregation of heparin gold nanoparticles.

Science.gov (United States)

Vidya, Raj; Saji, Alex

2018-05-01

The development of an easy to use, one-pot, environmentally friendly, non-invasive and label-free colorimetric probe for the determination of semen protamines, the biochemical marker of male fertility, using heparin gold nanoparticles (HAuNPs) is presented. The affinity of HAuNPs for protamines was due to the electrostatic interactions between polycationic protamine and polyanionic heparin. The binding of HAuNPs to protamine was characterized by variation in the plasmon absorption spectra followed by a visibly observable colour change of the solution from red to blue. We observed a red shift in the plasmon peak and the method exhibited linearity in the range of 10-70 ng/mL with a detection limit of 5 ng/mL, which is much lower than that reported for colorimetric sensors of protamine. The colour change and the variation in the absorbance of HAuNPs were highly specific for protamines in the presence of different interfering compounds and the method was successfully applied for determining protamine in real samples of semen and serum. Rather than a quantitative estimation, it seems that the method provides a quick screening between a large array of positive and negative samples and, moreover, it maintains the privacy of the user. The method appears to be simple and would be very useful in third-world countries where high-tech diagnostic aids are inaccessible to the majority of the population. Graphical Abstract Heparin gold nanoparticles aided visual detection of infertility.

Protamine-based nanoparticles as new antigen delivery systems.

Science.gov (United States)

González-Aramundiz, José Vicente; Peleteiro Olmedo, Mercedes; González-Fernández, África; Alonso Fernández, María José; Csaba, Noemi Stefánia

2015-11-01

The use of biodegradable nanoparticles as antigen delivery vehicles is an attractive approach to overcome the problems associated with the use of Alum-based classical adjuvants. Herein we report, the design and development of protamine-based nanoparticles as novel antigen delivery systems, using recombinant hepatitis B surface antigen as a model viral antigen. The nanoparticles, composed of protamine and a polysaccharide (hyaluronic acid or alginate), were obtained using a mild ionic cross-linking technique. The size and surface charge of the nanoparticles could be modulated by adjusting the ratio of the components. Prototypes with optimal physicochemical characteristics and satisfactory colloidal stability were selected for the assessment of their antigen loading capacity, antigen stability during storage and in vitro and in vivo proof-of-concept studies. In vitro studies showed that antigen-loaded nanoparticles induced the secretion of cytokines by macrophages more efficiently than the antigen in solution, thus indicating a potential adjuvant effect of the nanoparticles. Finally, in vivo studies showed the capacity of these systems to trigger efficient immune responses against the hepatitis B antigen following intramuscular administration, suggesting the potential interest of protamine-polysaccharide nanoparticles as antigen delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Importance of protamine phosphorylation to histone displacement in spermatids: can the disruption of this process be used for male contraception

Energy Technology Data Exchange (ETDEWEB)

Balhorn, R.; Hud, N.V.; Corzett, M.; Mazrimas, J.

1995-06-01

Protamine is a small protein that packages DNA in the sperm of most vertebrates. Shortly after its synthesis, the serine and threonine residues in each protamine are phosphorylated and the modified proteins are deposited onto DNA, displacing the histones and other chromatin proteins. We have hypothesized that the phosphorylation of protamine 1 induces protamine dimerization and these dimers are required for efficient histone displacement. Histone displacement by protamines in late-step spermatids appears to be essential for the production of fertile sperm in man and other mammals, and the disruption of this process could provide a new approach for male contraception. As a first step towards testing this theory, we have initiated a set of in vitro experiments to determine whether of not protamine phosphorylation is essential for histone displacement. Thee results of these experiments, although incomplete, confirm that unphosphorylated protamine cannot effectively displace histone from DNA. Polyarginine molecules twice the size of a protamine molecule and salmine dimer were found to be more effective. These results are consistent with the theory that the disruption of protamine phosphorylation may prove to be a useful new approach for male contraception if it can be shown to facilitate or induce protamine dimerization.

Zinc(II) halide complexes with 2-methoxyaniline ligand: Synthesis, characterization, thermal analyses, crystal structure determination and luminescent properties

Science.gov (United States)

Amani, Vahid

2018-03-01

Three new mononuclear zinc(II) complexes, [Zn(2-MeO-C6H4NH2)2X2] (X is Cl in 1, Br in 2 and I in 3), were prepared from the reactions of ZnX2 with 2-methoxyaniline (2-MeO-C6H4NH2) ligand in methanol. Suitable crystals of these complexes were obtained for X-ray diffraction measurements by slow evaporation of methanol solution at room temperature. The three complexes were thoroughly characterized by thermogravimetric analysis, elemental analysis (CHNO), spectral methods (IR, UV-Vis, 13C{1H}NMR, 1H NMR and luminescence), and single crystal X-ray diffraction. The X-ray structural analysis indicated that in the structures of these complexes, the zinc(II) cation is four-coordinated in a distorted tetrahedral configuration by two N atoms from two 2-methoxyanyline ligands and two halide anions. Also, in these complexes intermolecular interactions, for example Nsbnd H⋯X hydrogen bonds (in 1-3), Csbnd H⋯X hydrogen bonds (in 3), Csbnd H⋯π interactions (in 1 and 2) and π⋯π interactions (in 3), are effective in the stabilization of the crystal structures. In addition, the luminescence spectra of all complexes in methanolic solution show that the intensity of their emission bands is stronger than that for free 2-methoxyaniline ligand.

1 SUPPLEMENTARY INFORMATION A novel zinc(II) complex ...

Indian Academy of Sciences (India)

BİLGİSAYAR

1. SUPPLEMENTARY INFORMATION. A novel zinc(II) complex containing square pyramidal, octahedral and tetrahedral geometries on the same polymeric chain constructed from pyrazine-2,3-dicarboxylic acid and 1-vinylimidazole. HAKAN YILMAZ* and OMER ANDAC. Department of Chemistry, Ondokuz Mayis University, ...

Preconcentration and Determination of Copper and Zinc in Natural Water Samples by ICP-AES After Complexation and Sorption on Amberlite XAD-2

Directory of Open Access Journals (Sweden)

Ferreira Sérgio Luis Costa

1998-01-01

Full Text Available The present paper describes a procedure for separation, preconcentration and sequential determination of trace amounts of copper and zinc in natural water samples, by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES. The proposed method is based on the complexation of copper(II and zinc(II ions by 1-(2-thiazolylazo-2-naphthol (TAN and sorption on to Amberlite XAD-2 resin. Parameters such as: TAN amount, pH effect on the complexation and sorption of TAN complexes, agitation time for complete sorption, concentration of metal ion, mass of Amberlite XAD-2, desorption of metal ions from XAD-2 resin and sample volume were studied. The results demonstrated that the copper(II and zinc(II ions, in the range of 0.10 to 100.00 mug, contained in a solution sample volume of 400 mL, in the pH range of 5.7 to 8.3, on the form of TAN complexes had been quantitatively retained on to XAD-2 resin. The shaking time required for sorption is 1 h using a resin mass of 1.4 g. The solution for determination of copper and zinc by ICP-AES is obtained, after desorption of the ions from the XAD-2 resin, using 5 mL of 2 mol L-1 hydrochloric acid and shaking the system for 5 min. The procedure was applied to the determination of copper and zinc in several natural water samples. The standard addition technique was applied and the obtained recoveries revealed that the proposed procedure has a good accuracy. A high enrichment factor (80 and simplicity are the main advantages in this analytical protocol.

Comparison of topical use of protamine and tranexamic acid in surgical patients requiring cardio-pulmonary bypass

International Nuclear Information System (INIS)

Siddiqeh, M.; Siddiqi, R.; Ali, N.; Iqbal, A.; Younus, Z.; Haq, I.U.

2015-01-01

To determine the effectiveness of local protamine in reducing post-operative blood loss compared to local tranexamic acid. Study Design: Randomized controlled trial. Place and Duration of Study: Armed Forces Institute of Cardiology/National Institute of Heart Diseases Rawalpindi from January 2011 to September 2011. Patients and Methods: One hundred and twenty cardiac surgical patients were randomly divided into two equal groups, one receiving local protamine while the other group receiving local tranexamic acid before chest closure. The efficiency was measured as post-operative blood loss and requirement of blood and blood products in the post-surgical ICU. Results: Average blood loss in protamine group was significantly less (252.97 ml) compared to tranexamic acid group (680.67 ml). Number of patients requiring no post-operative blood transfusion was significantly higher in protamine group (76.7%) compared to tranexamic acid group (53.3%). Conclusion: Local protamine is more effective in reducing post-operative blood loss than local tranexamic acid. (author)

Glucose-lowering effect and glycaemic variability of insulin glargine, insulin detemir and insulin lispro protamine in people with type 1 diabetes.

Science.gov (United States)

Derosa, G; Franzetti, I; Querci, F; Romano, D; D'Angelo, A; Maffioli, P

2015-06-01

To compare, using a continuous glucose monitoring (CGM) system, the effect on glycaemic variability of insulin glargine, detemir and lispro protamine. A total of 49 white people with type 1 diabetes, not well controlled by three times daily insulin lispro, taken for at least 2 months before study and on a stable dose, were enrolled. The study participants were randomized to add insulin glargine, detemir or lispro protamine, once daily, in the evening. We used a CGM system, the iPro Digital Recorder (Medtronic MiniMed, Northridge, CA, USA) for 1 week. Glycaemic control was assessed according to mean blood glucose values, the area under the glucose curve above 3.9 mmol/l (AUC(>3.9)) or above 10.0 mmol/l (AUC(>10.0)), and the percentage of time spent with glucose values >3.9 or >10.0 mmol/l. Intraday glycaemic variability was assessed using standard deviation (s.d.) values, the mean amplitude of glycaemic excursions and continuous overlapping of net glycaemic action. Day-to-day glycaemic variability was assessed using the mean of daily differences. The s.d. was found to be significantly lower with insulin lispro protamine and glargine compared with insulin detemir. AUC(>3.9) was higher and AUC(>10.0) was lower with insulin lispro protamine and glargine compared with detemir. The mean amplitude of glycaemic excursions and continuous overlapping net glycaemic action values were lower with insulin lispro protamine and glargine compared with detemir. In addition, the mean of daily differences was significantly lower with insulin lispro protamine and glargine compared with detemir. Fewer hypoglycaemic events were recorded during the night-time with insulin lispro protamine compared with glargine and detemir. The results suggest that insulin lispro protamine and glargine are more effective than detemir in reducing glycaemic variability and improving glycaemic control in people with type 1 diabetes. Insulin lispro protamine seems to lead to fewer hypoglycaemic

Understanding the mechanism of protamine in solid lipid nanoparticle-based lipofection: the importance of the entry pathway.

Science.gov (United States)

Delgado, Diego; del Pozo-Rodríguez, Ana; Solinís, Maria Ángeles; Rodríguez-Gascón, Alicia

2011-11-01

The aim of our study was to evaluate the effect of protamine on the transfection capacity of solid lipid nanoparticles (SLNs) by correlating it to the internalization mechanisms and intracellular trafficking of the vectors. Vectors were prepared with SLN, DNA, and protamine. ARPE-19 and HEK-293 cells were used for the evaluation of the formulations. Protamine induced a 6-fold increase in the transfection of SLNs in retinal cells due to the presence of nuclear localization signals (NLS), its protection capacity, and a shift in the internalization mechanism from caveolae/raft-mediated to clathrin-mediated endocytosis. However, protamine produced an almost complete inhibition of transfection in HEK-293 cells. In spite of the high DNA condensation capacity of protamine and its content in NLS, this does not always lead to an improvement in cell transfection since it may impair some of the limiting steps of the transfection processes. Copyright © 2011 Elsevier B.V. All rights reserved.

Fabrication of an Organic Light-Emitting Diode from New Host π Electron Rich Zinc Complex

Science.gov (United States)

Jafari, Mohammad Reza; Janghouri, Mohammad; Shahedi, Zahra

2017-01-01

A new π electron rich zinc complex was used as a fluorescent material in organic light-emitting diodes (OLEDs). Devices with a structure of indium tin oxide/poly (3,4-ethylenedi-oxythiophene):poly(styrenesulfonate) (PEDOT: PSS) (50 nm)/polyvinylcarbazole (60 nm)/Zn: %2 porphyrin derivatives (45 nm)/Al (150 nm) were fabricated. Porphyrin derivatives accounting for 2 wt.% in the π electron rich zinc complex were used as a host. The electroluminescence (EL) spectra of porphyrin derivatives indicated a red shift, as π electron rich zinc complex EL spectra. The device (4) has also a luminance of 3420 cd/m2 and maximum efficiency of 1.58 cd/A at 15 V, which are the highest values among four devices. The result of Commission International del'Eclairage (CIE) (X, Y) coordinate and EL spectrum of device (3) indicated that it is more red shifted compared to other devices. Results of this work indicate that π electron rich zinc complex is a promising host material for high efficiency red OLEDs and has a simple structure compared to Alq3-based devices.

Complement C5a receptor antagonism by protamine and poly-L-Arg on human leukocytes.

Science.gov (United States)

Olsen, U B; Selmer, J; Kahl, J U

1988-01-01

It is shown that protamine selectively and dose-dependently inhibits complement C5a-induced leukocyte responses such as histamine release from basophils, chemiluminescence and beta-glucuronidase release from neutrophils. Protamine produces parallel rightward displacements of the C5a dose-response curves. The inhibitory capacity of the polypeptide is reversible and disappears following repeated washing of exposed cells. In neutrophils poly-L-Arg similarly and specifically antagonizes C5a-induced chemiluminescence and enzyme release. This polymer alone, however, degranulates basophils and neutrophils, leading to histamine and enzyme release, respectively. It is concluded that on human neutrophils the arginine-rich polycations protamine and poly-L-Arg exhibit a competitive C5a receptor antagonism. In addition, protamine inhibits the C5a receptors on basophils. It is hypothesized that molecular conformations of the arginine-rich polycations might bind reversibly to, and block negatively charged groups at the C5a-receptor sites.

Zinc removal from wastewater by complexation-microfiltration process

Directory of Open Access Journals (Sweden)

Trivunac Katarina

2012-01-01

Full Text Available As a result of its wide industrial applications, zinc has become an important contaminant in aquatic environment since it is a toxic heavy metal and some of its compounds such as zinc arsenate and zinc cyanide, may be extremely hazardous. Therefore, there is a growing need for developing simple methods capable of separating and recovering trace zinc from environmental waters. Nowadays, the ultra and microfiltration method for trace metals removal from waters by the addition of water-soluble polymers into the aqueous solutions has become a significant research area. The choice of watersoluble macroligands remains important for developing this technology. Sodium carboxymethyl cellulose (Na-CMC was selected as complexing agent. The microfiltration experiments were carried out in stirred dead-end cell. To separate formed polymer-metal complex Versapor membranes were used. The concentration of heavy metal ions after microfiltration in aqueous solution was determined using atomic absorption spectroscopy (AAS. Effects of amount of complexing agent, pH value, type of anion, ionic strength and operating pressure on the flux (J and rejection coefficient (R were investigated. Experimental results indicate a considerable influence of the pH, ionic strength and type of anion on the rejection coefficient, while effect of amount of complexing agent is relatively insignificant. The Na-CMC used in the research proved to be very effective, which may be supported by the high rejection coefficients obtained (99%.

The impact of tertiary wastewater treatment on copper and zinc complexation.

Science.gov (United States)

Constantino, C; Gardner, M; Comber, S D W; Scrimshaw, M D; Ellor, B

2015-01-01

Tightening quality standards for European waters has seen a move towards enhanced wastewater treatment technologies such as granulated organic carbon treatment and ozonation. Although these technologies are likely to be successful in degrading certain micro-organic contaminants, these may also destroy compounds which would otherwise complex and render metals significantly less toxic. This study examined the impact of enhanced tertiary treatment on the capacity of organic compounds within sewage effluents to complex copper and zinc. The data show that granulated organic carbon treatment removes a dissolved organic carbon (DOC) fraction that is unimportant to complexation such that no detrimental impact on complexation or metal bioavailability is likely to occur from this treatment type. High concentrations of ozone (>1 mg O3/mg DOC) are, however, likely to impact the complexation capacity for copper although this is unlikely to be important at the concentrations of copper typically found in effluent discharges or in rivers. Ozone treatment did not affect zinc complexation capacity. The complexation profiles of the sewage effluents show these to contain a category of non-humic ligand that appears unaffected by tertiary treatment and which displays a high affinity for zinc, suggesting these may substantially reduce the bioavailability of zinc in effluent discharges. The implication is that traditional metal bioavailability assessment approaches such as the biotic ligand model may overestimate zinc bioavailability in sewage effluents and effluent-impacted waters.

Influence of structural and surface properties of whey-derived peptides on zinc-chelating capacity, and in vitro gastric stability and bioaccessibility of the zinc-peptide complexes.

Science.gov (United States)

Udechukwu, M Chinonye; Downey, Brianna; Udenigwe, Chibuike C

2018-02-01

Gastrointestinal stability of zinc-peptide complexes is essential for zinc delivery. As peptide surface charge can influence their metal complex stability, we evaluated the zinc-chelating capacity and stability of zinc complexes of whey protein hydrolysates (WPH), produced with Everlase (WPH-Ever; ζ-potential, -39mV) and papain (WPH-Pap; ζ-potential, -7mV), during simulated digestion. WPH-Ever had lower amount of zinc-binding amino acids but showed higher zinc-chelating capacity than WPH-Pap. This is attributable to the highly anionic surface charge of WPH-Ever for electrostatic interaction with zinc. Release of zinc during peptic digestion was lower for WPH-Ever-zinc, and over 50% of zinc remained bound in both peptide complexes after peptic-pancreatic digestion. Fourier transform infrared spectroscopy suggests the involvement of carboxylate ion, and sidechain carbon-oxygen of aspartate/glutamate and serine/threonine in zinc-peptide complexation. The findings indicate that strong zinc chelation can promote gastric stability and impede intestinal release, for peptides intended for use as dietary zinc carriers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Increased accuracy in heparin and protamine administration decreases bleeding: a pilot study

DEFF Research Database (Denmark)

Runge, Marx; Møller, Christian H; Steinbrüchel, Daniel A

2009-01-01

Three to 5 percent of the patients undergoing cardiac surgery are reoperated because of bleeding. When a surgical cause can be excluded, heparin/protamine mismatch may be considered. Insufficient reversal of heparin and overdosing of protamine may cause postoperative bleeding. The purpose......). A reduced number of patients needed blood transfusions in the RxDx group, although this was not statistically significant (19% vs. 38%, respectively; p = .13). Initial heparin dose was significantly reduced in the RxDx group (250 mg; range, 100-375 mg) compared with the control group (300 mg; range, 200...

Evaluation of intracellular anion superoxide level, heat shock protein A2 and protamine positive spermatozoa percentages in teratoasthenozoospermia

Directory of Open Access Journals (Sweden)

Parvin Sabeti

2017-09-01

Full Text Available Background: Teratoasthenozoospermia (TA is a severe form of male infertility with no clear etiology. Objective: To compare the level of intracellular anion superoxide (O2–, heat shock protein A2 (HSPA2 and protamine deficiencies in ejaculated spermatozoa between teratoasthenozoospermic and normozoospermic men. Materials and Methods: In this case- control study, semen samples of 20 infertile men, with TA (with normal morphology lower than 4%_ and total motility lower than 40% as the case group and 20 normozoospermic fertile men as the control group were evaluated for intracellular O2 – and HSPA2 by flow cytometry and protamine deficiency by Chromomycin A3 (CMA3 test. Results: The rate of CMA3+ spermatozoa in the case group was higher than controls (p=0.001. The percentages of HSPA2+ spermatozoa in the cases were significantly lower than controls (p=0.001. Also, intracellular O2 – levels in the case group were significantly higher than controls (p=0.001 and had positive correlations with sperm apoptosis (r=0.79, p=0.01 and CMA3 positive sperm (r=0.76, p=0.01, but negative correlations with normal morphology (r=-0.81, p=0.01 and motility (r=-0.81, p=0.01. There was no significant correlation between intracellular O2 – and HSPA2 in the case group (r=0.041, p=0.79. Conclusion: We suggest that the increase in intracellular O2 –, decrease in spermatozoa HSPA2+, and high percentages of spermatozoa with immature chromatin might be considered as etiologies of infertility in TA patients

Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria

DEFF Research Database (Denmark)

Johansen, Charlotte; Verheul, A.; Gram, Lone

1997-01-01

carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope...

ynthesis, theoretical study on Zinc (II and Ni(II complexes of 5-methoxyisatin 3-[N-(4-chlorophenyl thiosemicarbazone

Directory of Open Access Journals (Sweden)

Fatma Kandemirli

2012-03-01

Full Text Available Zinc(II and nickel(II-complexes of 5-methoxyisatin 3-[N-(4-chlorophenyl thiosemicarbazone] (H2MICP were synthesized and characterized by infrared, ultraviolet and 1H-NMR spectroscopies as well as elemental analysis. Model of H2MICP and its zinc(II and nickel(II-complexes were optimized with B3LYP method using 6-31G(d,p, 6-311G(d,p, 6-311++G(d,p, 6-311++G(2d,2p basis sets. The calculated 1H-NMR, UV and IR spectra data were compared with experimental results. In addition to the Natural Bond Orbital (NBO analysis of H2MICP and its Zinc(II and Nickel(II complexes, Fukui functions of H2MICP were also reported.

Reactivity of Zinc Halide Complexes Containing Camphor-Derived Guanidine Ligands with Technical rac-Lactide

Directory of Open Access Journals (Sweden)

Angela Metz

2017-11-01

Full Text Available Three new zinc complexes with monoamine–guanidine hybridligands have been prepared, characterized by X-ray crystallography and NMR spectroscopy, and tested in the solvent-free ring-opening polymerization of rac-lactide. Initially the ligands were synthesized from camphoric acid to obtain TMGca and DMEGca and then reacted with zinc(II halides to form zinc complexes. All complexes have a distorted tetrahedral coordination. They were utilized as catalysts in the solvent-free polymerization of technical rac-lactide at 150 °C. Colorless polylactide (PLA can be produced and after 2 h conversion up to 60% was reached. Furthermore, one zinc chlorido complex was tested with different qualities of lactide (technical and recrystallized and with/without the addition of benzyl alcohol as a co-initiator. The kinetics were monitored by in situ FT-IR or 1H NMR spectroscopy. All kinetic measurements show first-order behavior with respect to lactide. The influence of the chiral complexes on the stereocontrol of PLA was examined. Moreover, with MALDI-ToF measurements the end-group of the obtained polymer was determined. DFT and NBO calculations give further insight into the coordination properties. All in all, these systems are robust against impurities and water in the lactide monomer and show great catalytic activity in the ROP of lactide.

Studies on the Interaction between Zinc-Hydroxybenzoite Complex and Genomic DNA

Directory of Open Access Journals (Sweden)

Hacali Necefoglu

2006-04-01

Full Text Available Zinc-Hydroxybenzoite ([Zn (H206] (p-HO-C6H4COO22H20 complex which wassynthesized and characterized by instrumental methods and the DNA samples which hadbeen isolated from cattle were allowed to interact at 37 oC for different time periods. Theinteraction of genomic DNA with this complex has been followed by agarose gelelectrophoresis at 50 V for 2 h. When DNA samples were allowed to interact with this metalcomplex, it was found that band intensities changed with the concentrations of the complex.In the result of interaction between this complex and genomic DNA samples, it wasdetermined that the intensities of bands were changed at the different concentrations of thecomplex. The brightness of the bands was increased and mobility of the bands wasdecreased, indicating the occurrence of increased covalent binding of the metal complexwith DNA. In this study it was concluded that the damage effect of ascorbate was reducedby Zinc-Hydroxybenzoite.

Manufacturing of a Secretoneurin Drug Delivery System with Self-Assembled Protamine Nanoparticles by Titration

Science.gov (United States)

Scheicher, Bernhard; Lorenzer, Cornelia; Gegenbauer, Katrin; Partlic, Julia; Andreae, Fritz; Kirsch, Alexander H.; Rosenkranz, Alexander R.; Werzer, Oliver

2016-01-01

Since therapeutic peptides and oligonucleotides are gathering interests as active pharmaceutical ingredients (APIs), nanoparticulate drug delivery systems are becoming of great importance. Thereby, the possibility to design drug delivery systems according to the therapeutic needs of APIs enhances clinical implementation. Over the last years, the focus of our group was laid on protamine-oligonucleotide-nanoparticles (so called proticles), however, the possibility to modify the size, zeta potential or loading efficiencies was limited. Therefore, at the present study we integrated a stepwise addition of protamine (titration) into the formation process of proticles loaded with the angiogenic neuropeptide secretoneurin (SN). A particle size around 130 nm was determined when proticles were assembled by the commonly used protamine addition at once. Through application of the protamine titration process it was possible to modify and adjust the particle size between approx. 120 and 1200 nm (dependent on mass ratio) without influencing the SN loading capacity. Dynamic light scattering pointed out that the difference in particle size was most probably the result of a secondary aggregation. Initially-formed particles of early stages in the titration process aggregated towards bigger assemblies. Atomic-force-microscopy images also revealed differences in morphology along with different particle size. In contrast, the SN loading was only influenced by the applied mass ratio, where a slight saturation effect was observable. Up to 65% of deployed SN could be imbedded into the proticle matrix. An in-vivo biodistribution study (i.m.) showed a retarded distribution of SN from the site of injection after the application of a SN-proticle formulation. Further, it was demonstrated that SN loaded proticles can be successfully freeze-dried and resuspended afterwards. To conclude, the integration of the protamine titration process offers new possibilities for the formulation of proticles in

(Pyridine)(tetrahydroborato)zinc complex, (Zn(BH4)2(py)), as a new stable, efficient and chemoselective reducing agent for reduction of carbonyl compounds

International Nuclear Information System (INIS)

Zeynizadeh, Behzad; Faraji, Fariba

2003-01-01

(Pyridine)(tetrahydroborato)zinc complex, (Zn(BH 4 ) 2 (py)), as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and α,β-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent

Synthesis, photoluminescence and forensic applications of blue light emitting azomethine-zinc (II complexes of bis(salicylidenecyclohexyl-1,2-diamino based organic ligands

Directory of Open Access Journals (Sweden)

M. Srinivas

2017-06-01

Full Text Available Various azomethine-zinc(II complexes (3a-c of bis(salicylidenecyclohexyl-1,2-diamino organic ligands were synthesized by one pot reaction of salicylaldehydes/2-hydroxy-1-naphthaldehyde (2 eq, cyclohexyl-1,2-diamine (1 eq and zinc acetate (1 eq in methanol solvent at reflux temperature. The synthesized complexes were characterized by FTIR, 1H NMR, and SEM. Their photophysical properties such as Photoluminescence (PL and Diffused Reflectance Spectra (DRS were studied. PL studies revealed that the emission peaks of the complexes in both solution and solid states appeared to occur at 395–600 nm and emitted blue light. The band gap energies determined from DRS were 2.98 eV (3a, 2.91 eV (3b, and 2.73 eV (3c. Based on these results, we ascertain that these Zn(II complexes can serve as a suitable non-dopant blue light emitting compound for flat panel display applications. Latent fingerprint detection study indicated that the powder compounds show good adhesion and finger ridge details without background staining. The demonstrated method can be applied to detect fingerprints on all types of smooth surfaces.

Synthesis, structure and luminescence properties of zinc (II) complexes with terpyridine derivatives as ligands

International Nuclear Information System (INIS)

Chen Xuegang; Zhou Quanguo; Cheng Yanxiang; Geng Yanhou; Ma Dongge; Xie Zhiyuan; Wang Lixiang

2007-01-01

Five zinc (II) complexes (1-5) with 4'-phenyl-2,2':6',2''-terpyridine (ptpy) derivatives as ligands have been synthesized and fully characterized. The para-position of phenyl in ptpy is substituted by the group (R), i.e. tert-butyl (t-Bu), hexyloxy (OHex), carbazole-9-yl (Cz), naphthalen-1-yl-phenyl-amine-N-yl (NPA) and diphenyl amine-N-yl (DPA), with different electron-donating ability. With increasing donor ability of the R, the emission color of the complexes in film was modulated from violet (392 nm) to reddish orange (604 nm). The photoexcited luminescence exhibits significant solvatochromism because the emission of the complexes involves the intra-ligand charge transfer (ILCT) excited state. The electrochemical investigations show that the complexes with stronger electro-donating substituent have lower oxidation potential and then higher HOMO level. The electroluminescence (EL) properties of these zinc (II) complexes were studied with the device structure of ITO/PEDOT/Zn (II) complex: PBD:PMMA/BCP/AlQ/LiF/Al. Complexes 3, 4 and 5 exhibit EL wavelength at 552, 600 and 609 nm with maximum current efficiency of 5.28, 2.83 and 2.00 cd/A, respectively

Preparation of Zinc Oxide (ZnO) Thin Film as Transparent Conductive Oxide (TCO) from Zinc Complex Compound on Thin Film Solar Cells: A Study of O2 Effect on Annealing Process

Science.gov (United States)

Muslih, E. Y.; Kim, K. H.

2017-07-01

Zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) for thin film solar cell application was successfully prepared through two step preparations which consisted of deposition by spin coating at 2000 rpm for 10 second and followed by annealing at 500 °C for 2 hours under O2 and ambient atmosphere. Zinc acetate dehydrate was used as a precursor which dissolved in ethanol and acetone (1:1 mol) mixture in order to make a zinc complex compound. In this work, we reported the O2 effect, reaction mechanism, structure, morphology, optical and electrical properties. ZnO thin film in this work shows a single phase of wurtzite, with n-type semiconductor and has band gap, carrier concentration, mobility, and resistivity as 3.18 eV, 1.21 × 10-19cm3, 11 cm2/Vs, 2.35 × 10-3 Ωcm respectively which is suitable for TCO at thin film solar cell.

The in vitro transcription of a rainbow trout (Salmo gairdnerii) protamine gene. II. Controlled mutation of the cap site region.

Science.gov (United States)

Jankowski, J M; Dixon, G H

1985-02-01

A series of plasmids containing new fusion genes in which the trout protamine gene is placed under the control of the complete herpes virus (HSV-1) tk promoter Pvu II-Bgl II fragment (pM8), or a shortened thymidine kinase (tk) promoter in which the region between the TATA box and the cap site is altered by using the Pvu II-Mlu I fragment (pM7), have been constructed. An additional recombinant plasmid was constructed in which the Bgl II-Ava II fragment of the protamine gene containing the entire protamine promoter but missing the protamine coding region was cloned into pBR322 between the Xho II 1666 and Hind III sites (pP5). For in vitro transcription, a HeLa cell lysate system was prepared and the RNA transcription products, after glyoxalation, were electrophoretically analyzed on 5% polyacrylamide gels. In constructing pM8 the DNA sequence between the tk promoter and the cap site was present while in pM7 it was deleted. Similar multiple transcripts were seen in both cases, indicating that the region between the promoter and the cap site has no effect upon transcription in vitro. The multiple transcripts appear to be due to the presence of a cryptic promoter in the complementary strand of the protamine gene. The activity of this cryptic promoter has been confirmed by comparison of the transcription of plasmid pP5, in which the protamine mRNA coding region has been deleted, with a previously described plasmid, pJBRP (Jankowski JM and Dixon GH (1984) Can. J. Biochem. Cell. Biol. 62, 291-300), containing the intact protamine gene.

The important role of protamine in spermatogenesis and quality of sperm: A mini review

Directory of Open Access Journals (Sweden)

Muslim Akmal

2016-09-01

Conclusion: Our results of a study in mice confirmed that inhibin B injection caused a reduction in the expression of protamine 2 in cauda epididymis. It has implications in the decrease of motility, concentration, and spermatozoa viability so that it affects the fertilization ability and the number of child production.

Mechanism and degradation kinetics of zinc complex containing isophthalato and 2,2‧-dipyridylamine ligands under different atmospheres

Science.gov (United States)

Zdravković, J. D.; Radovanović, L.; Poleti, D.; Rogan, J. R.; Vulić, P. J.; Radovanović, Ž.; Minić, D. M.

2018-06-01

The design of mixed-ligand complexes are of increasing interest from fundamental as well as technological and curative aspects. Having that in mind, we studied zinc complex containing 2,2‧-dipyridylamine (dipya) and dianion of isophthalic acid (ipht), [Zn(dipya)(ipht)]n, as promising precursor for synthesis of nanostructured metal oxide. In that sense, the mechanism and degradation kinetics of [Zn(dipya)(ipht)]n was analyzed under non-isothermal conditions in nitrogen and in air atmospheres. Peak deconvolution of the [Zn(dipya)(ipht)]n decomposition profile, in the form of a derivative thermogram (DTG), in nitrogen atmosphere, revealed the presence of three decomposition steps, while in air five single steps were isolated. In both cases ZnO is formed as residue at 530 °C: pure (in air) or in amorphous matrix (nitrogen). In air we obtained well crystalized ZnO nanospheres (∼25 nm), by thermal treatment in temperature range 370-530 °C showing that this complex could be considered as good precursor for production of nanosized ZnO.

Anti-inflammatory, antinociceptive and ulcerogenic activity of a zinc-diclofenac complex in rats

Directory of Open Access Journals (Sweden)

L.H. Santos

2004-08-01

Full Text Available We investigated the anti-inflammatory, antinociceptive and ulcerogenic activity of a zinc-diclofenac complex (5.5 or 11 mg/kg in male Wistar rats (180-300 g, N = 6 and compared it to free diclofenac (5 or 10 mg/kg and to the combination of diclofenac (5 or 10 mg/kg and zinc acetate (1.68 or 3.5 mg/kg. The carrageenin-induced paw edema and the cotton pellet-induced granulomatous tissue formation models were used to assess the anti-inflammatory activity, and the Hargreaves model of thermal hyperalgesia was used to assess the antinociceptive activity. To investigate the effect of orally or intraperitoneally (ip administered drugs on cold-induced gastric lesions, single doses were administered before exposing the animals to a freezer (-18ºC for 45 min in individual cages. We also evaluated the gastric lesions induced by multiple doses of the drugs. Diclofenac plus zinc complex had the same anti-inflammatory and antinociceptive effects as diclofenac alone. Gastric lesions induced by a single dose administered per os and ip were reduced in the group treated with zinc-diclofenac when compared to the groups treated with free diclofenac or diclofenac plus zinc acetate. In the multiple dose treatment, the complex induced a lower number of the most severe lesions when compared to free diclofenac and diclofenac plus zinc acetate. In conclusion, the present study demonstrates that the zinc-diclofenac complex may represent an important therapeutic alternative for the treatment of rheumatic and inflammatory conditions, as its use may be associated with a reduced incidence of gastric lesions.

(Pyridine)(tetrahydroborato)zinc complex, (Zn(BH{sub 4}){sub 2}(py)), as a new stable, efficient and chemoselective reducing agent for reduction of carbonyl compounds

Energy Technology Data Exchange (ETDEWEB)

Zeynizadeh, Behzad; Faraji, Fariba [Urima Univ., Urima (Iran, Islamic Republic of)

2003-04-01

(Pyridine)(tetrahydroborato)zinc complex, (Zn(BH{sub 4}){sub 2}(py)), as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, {alpha}-diketones and {alpha},{beta}-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent.

The effect of tetrabromobisphenol A on protamine content and DNA integrity in mouse spermatozoa

Czech Academy of Sciences Publication Activity Database

Žatecká, Eva; Castillo, J.; Elzeinová, Fatima; Kubátová, Alena; Děd, Lukáš; Pěknicová, Jana; Oliva, R.

2014-01-01

Roč. 2, č. 6 (2014), s. 910-917 ISSN 2047-2927 R&D Projects: GA ČR(CZ) GAP503/12/1834; GA MŠk(CZ) ED1.1.00/02.0109 Institutional research plan: CEZ:AV0Z50520701 Institutional support: RVO:86652036 Keywords : protamines * spermatozoa * tetrabromobisphenol A * TUNAL assay Subject RIV: EB - Genetics ; Molecular Biology

Fabrication and characterization of organic light-emitting diodes using zinc complexes as hole-blocking layer.

Science.gov (United States)

Kim, Won Sam; You, Jung Min; Lee, Burm-Jong; Jang, Yoon-Ki; Kim, Dong-Eun; Kwon, Young-Soo

2006-11-01

2-(2-Hydroxyphenyl)benzoxazole (HPB) was employed as organic ligand and the corresponding zinc complexes (Zn(HPB)2 and Zn(HPB)q) were synthesized. And their EL properties were characterized. The structures of zinc complexes were determined with FT-NMR, FT-IR, UV-Vis, and XPS. The thermal stability showed up to about 300 degrees C under nitrogen flow, which was measured by TGA. The photoluminescence (PL) of zinc complexes were measured from the DMF solution. The PL emitted in blue and yellow region, respectively. The EL devices were fabricated by the vacuum deposition. Two kinds of OLEDs devices were fabricated; ITO/NPB (40 nm)/Zn complexes (60 nm)/LiF/Al and ITO/NPB (40 nm)/Alq3 (60 nm)/Zn complexes (5 nm)/LiF/Al. Both of the EL properties as the emitting and the hole-blocking layer were investigated. The EL emission of Zn(HPB)q exhibited green light centered at 532 nm. The device showed a turn-on voltage at 5 V and a luminance of 6073 cd/m2 at 10 V. Meanwhile, the maximum EL the emission of the Zn(HPB)2 device was found to be at 447 nm. And the device showed a luminance of 2813 cd/m2 at 10 V. The ITO/NPB (40 nm)/Alq3 (60 nm)/Zn(HPB)2 (5 nm)/LiF/Al device showed increased luminance of L=17000 cd/m2 compared to L=12000 cd/m2 for similar device fabricated without the hole-blocking layer. And the turn-on voltage was significantly affected by the existence of the hole-blocking layer.

Structural zinc(II thiolate complexes relevant to the modeling of Ada repair protein: Application toward alkylation reactions

Directory of Open Access Journals (Sweden)

Mohamed M. Ibrahim

2014-11-01

Full Text Available The TtZn(II-bound perchlorate complex [TtZn–OClO3] 1 (Ttxyly = hydrotris[N-xylyl-thioimidazolyl]borate was used for the synthesis of zinc(II-bound ethanthiothiol complex [TtZn–SCH2CH3] 2 and its hydrogen-bond containing analog Tt–ZnSCH2CH2–NH(COOC(CH33 3. These thiolate complexes were examined as structural models for the active sites of Ada repair protein toward methylation reactions. The Zn[S3O] coordination sphere in complex 1 includes three thione donors from the ligand Ttixyl and one oxygen donor from the perchlorate coligand in ideally tetrahedral arrangement around the zinc center. The average Zn(1–S(thione bond length is 2.344 Å, and the Zn(1–O(1 bond length is 1.917 Å.

Synthesis and characterization of monomeric and dimeric manganese(II and zinc(II complexes of pyridine-2-carbaldoxime

Directory of Open Access Journals (Sweden)

Jørgen Glerup

2000-12-01

Full Text Available The syntheses and characterization of two complexes of manganese(II and one complex of zinc(II with the ligand pyridine-2-carbaldoxime, C6H6N2O, are described. The monomeric manganese(II complex cis-[Mn(C6H6N2O 2Cl2] (1 crystallizes in the orthorhombic space group Pbcn with 4 formula units in a cell of dimensions a = 12.479(3 Å, b = 10.348(2 Å, and c = 11. 974(2 Å. The structure has been refined to a final value of the conventional R-factor of 0.0330 based on 1513 observed independent reflections. The analogous zinc(II complex, cis-[Zn(C6H6N2O2Cl2] (2 also crystallizes in the orthorhombic space group Pbcn with 4 formula units in a cell of dimensions a = 12.215(2 Å, b = 10.383(2 Å, and c = 12. 016(2 Å. The structure has been refined to a final value of the conventional R-factor of 0.0377 based on 1117 observed independent reflections. The two complexes are isostructural, with the central metal atom lying on a crystallographic 2-fold axis. Both complexes are approximately octahedral, the coordination being provided by two trans pyridine nitrogen atoms and two cis amine nitrogen atoms from the oxime ligands, and by two cis chlorides. The dimeric manganese(II complex [(C6H6N2O(CH3OHClMnCl2MnCl(CH3OH(C6H6N2O] (3 crystallizes in the monoclinic space group P21/n with 2 formula units in a cell of dimensions a = 7.895(2 Å, b = 11.196(3 Å, and c = 12. 544(2 Å, and b = 98.39(2o. The structure has been refined to a final value of the conventional R-factor of 0.0312 based on 1568 observed independent reflections. There is a crystallographic inversion center in the middle of the dimer relating one manganese center to the other. The geometry at each manganese(II center is again roughly octahedral, coordination being provided by two nitrogen atoms from the oxime ligand, a terminal chloride ion trans to the amine nitrogen, the oxygen atom of the coordinated methanol molecule, and two bridging chlorides that link the two halves of the dimer. The Mn

Zinc Enolate/Sulfinate Prepared from a Single-Run Reaction Using Zinc Dust with O-Tosylated 4-Hydroxy Coumarin and Pyrone

Energy Technology Data Exchange (ETDEWEB)

Shin, Ueon Sang; Joo, Seong-Ryu; Kim, Seung-Hoi [Dankook University, Cheonan (Korea, Republic of)

2016-07-15

We demonstrated the preparation of new zinc complexes, 2-oxo-2H-chromen-4-yloxy tosylzinc (I), and 6-methyl-2-oxo-2H-pyran-4-yloxy tosylzinc (II), by the oxidative addition of readily available zinc dust into the corresponding 4-tosylated coumarin (A) and pyrone (B), respectively. Of special interest, the thus-obtained zinc complexes showed an electrophile-dependent reactivity. The subsequent coupling reactions of I and II with a variety of acid chlorides provided the O-acylation product in moderate yields. More interestingly, it should be emphasized that the thus-prepared zinc complexes (I and II) functioned both as zinc enolate and zinc sulfinate, providing C(3)-disubstituted product (b) and sulfone (c), respectively, from a single-run reaction when I or II was treated with benzyl halides. Even though somewhat low yields were achieved under the nonoptimized conditions, the novel zinc complexes present another potential application for zinc reagents. Versatile applications of this discovery are currently underway.

Zinc Enolate/Sulfinate Prepared from a Single-Run Reaction Using Zinc Dust with O-Tosylated 4-Hydroxy Coumarin and Pyrone

International Nuclear Information System (INIS)

Shin, Ueon Sang; Joo, Seong-Ryu; Kim, Seung-Hoi

2016-01-01

We demonstrated the preparation of new zinc complexes, 2-oxo-2H-chromen-4-yloxy tosylzinc (I), and 6-methyl-2-oxo-2H-pyran-4-yloxy tosylzinc (II), by the oxidative addition of readily available zinc dust into the corresponding 4-tosylated coumarin (A) and pyrone (B), respectively. Of special interest, the thus-obtained zinc complexes showed an electrophile-dependent reactivity. The subsequent coupling reactions of I and II with a variety of acid chlorides provided the O-acylation product in moderate yields. More interestingly, it should be emphasized that the thus-prepared zinc complexes (I and II) functioned both as zinc enolate and zinc sulfinate, providing C(3)-disubstituted product (b) and sulfone (c), respectively, from a single-run reaction when I or II was treated with benzyl halides. Even though somewhat low yields were achieved under the nonoptimized conditions, the novel zinc complexes present another potential application for zinc reagents. Versatile applications of this discovery are currently underway

Does an allergy to fish pre-empt an adverse protamine reaction? A case report and a literature review.

LENUS (Irish Health Repository)

Collins, C

2008-11-01

The operating theatre exposes patients to myriad potential agents which could result in a life-threatening anaphylactic reaction. Anaesthetic drugs, blood products, and latex are only some of the possible allergens. Reactions are deemed to be anaphylactic when immediate sensitivity is combined with cardiovascular collapse. A patient who had a known allergy to shellfish presented for first time cardiopulmonary bypass. The perfusion team were concerned that there was a realistic possibility that an adverse reaction to protamine could occur. Anaphylactic reactions to protamine in patients allergic to fish have been reported. The anaesthetic team were informed and the necessary precautions taken. We report on the outcome for our patient and also discuss other risk factors and the types of reactions that can result when an adverse reaction to protamine occurs.

Isotope aided micronutrient studies in rice production with special reference to zinc deficiency pt.2

International Nuclear Information System (INIS)

Kim, T.S.; Kim, J.S.; Kim, J.S.

1979-01-01

A field experiment has been carried out to evaluate the residual effect of zinc fertilizers by rice plant grown under flooded conditions in the field. The results obtained are summarized as follows: Residual effect of zinc fertilizers on yields of rough and hulled grains showed slight increases. Effect of zinc application methods on yields of the grains were shown that zinc mixed treatment could be more effectively utilized than treatment of zinc on the soil surface. In case of levels of zinc application, 5kg zinc per hectare represented high yields of the grains than those obtained from 10 kg and 20 kg zinc placement per hectare respectively. Regarding the form of zinc fertilizers, the urea-zinc complex showed less effective on yields of the grains than did the zinc sulfate. This phenomenon was consistent with the previous result. Yields of total zinc in rice plant grown on the rice straw added soils (Treatment No. 2 and 8) and the urea-zinc complex treated soil were increased markedly as compared to those data obtained from the previous year. The percentage of zinc derived from fertilizer decreased largely as compared to that of the first year crop. The yield of fertilizer zinc in rice plant decreased slightly in the most zinc treatments but in the case of treatments of zinc mixed with the straw added soil and the urea-zinc complex increased reversely as compared to the previous results. The mixed application of zinc with soil showed higher yield of fertilizer zinc than the soil surface placement. Approximately from 4.6 to 24.3 per cent of zinc taken up by rice plants were derived from the fertilizer zinc. Zinc fertilizer use efficiency ranged from 0.213 to 0.584 per cent when 5 kg zinc per hectare applied. (author)

Novel Zinc(II Complexes [Zn(atc-Et2] and [Zn(atc-Ph2]: In Vitro and in Vivo Antiproliferative Studies

Directory of Open Access Journals (Sweden)

Erica de O. Lopes

2016-05-01

Full Text Available Cisplatin and its derivatives are the main metallodrugs used in cancer therapy. However, low selectivity, toxicity and drug resistance are associated with their use. The zinc(II (ZnII thiosemicarbazone complexes [Zn(atc-Et2] (1 and [Zn(atc-Ph2] (2 (atc-R: monovalent anion of 2-acetylpyridine N4-R-thiosemicarbazone were synthesized and fully characterized in the solid state and in solution via elemental analysis, Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis and proton nuclear magnetic resonance (1H NMR spectroscopy, conductometry and single-crystal X-ray diffraction. The cytotoxicity of these complexes was evaluated in the HepG2, HeLa, MDA-MB-231, K-562, DU 145 and MRC-5 cancer cell lines. The strongest antiproliferative results were observed in MDA-MB-231 and HepG2 cells, in which these complexes displayed significant selective toxicity (3.1 and 3.6, respectively compared with their effects on normal MRC-5 cells. In vivo studies were performed using an alternative model (Artemia salina L. to assure the safety of these complexes, and the results were confirmed using a conventional model (BALB/c mice. Finally, tests of oral bioavailability showed maximum plasma concentrations of 3029.50 µg/L and 1191.95 µg/L for complexes 1 and 2, respectively. According to all obtained results, both compounds could be considered as prospective antiproliferative agents that warrant further research.

Gastroprotection studies of Schiff base zinc (II) derivative complex against acute superficial hemorrhagic mucosal lesions in rats.

Science.gov (United States)

Golbabapour, Shahram; Gwaram, Nura Suleiman; Hassandarvish, Pouya; Hajrezaie, Maryam; Kamalidehghan, Behnam; Abdulla, Mahmood Ameen; Ali, Hapipah Mohd; Hadi, A Hamid A; Majid, Nazia Abdul

2013-01-01

The study was carried out to assess the gastroprotective effect of the zinc (II) complex against ethanol-induced acute hemorrhagic lesions in rats. The animals received their respective pre-treatments dissolved in tween 20 (5% v/v), orally. Ethanol (95% v/v) was orally administrated to induce superficial hemorrhagic mucosal lesions. Omeprazole (5.790×10(-5) M/kg) was used as a reference medicine. The pre-treatment with the zinc (II) complex (2.181×10(-5) and 4.362×10(-5) M/kg) protected the gastric mucosa similar to the reference control. They significantly increased the activity levels of nitric oxide, catalase, superoxide dismutase, glutathione and prostaglandin E2, and decreased the level of malondialdehyde. The histology assessments confirmed the protection through remarkable reduction of mucosal lesions and increased the production of gastric mucosa. Immunohistochemistry and western blot analysis indicated that the complex might induced Hsp70 up-regulation and Bax down-regulation. The complex moderately increased the gastroprotectiveness in fine fettle. The acute toxicity approved the non-toxic characteristic of the complex (<87.241×10(-5) M/kg). The gastroprotective effect of the zinc (II) complex was mainly through its antioxidant activity, enzymatic stimulation of prostaglandins E2, and up-regulation of Hsp70. The gastric wall mucus was also a remarkable protective mechanism.

Chemical-Biological Properties of Zinc Sensors TSQ and Zinquin: Formation of Sensor-Zn-Protein Adducts versus Zn(Sensor)2 Complexes.

Science.gov (United States)

Nowakowski, Andrew B; Meeusen, Jeffrey W; Menden, Heather; Tomasiewicz, Henry; Petering, David H

2015-12-21

Fluorescent zinc sensors are the most commonly used tool to study the intracellular mobile zinc status within cellular systems. Previously, we have shown that the quinoline-based sensors Zinquin and 6-methoxy-8-p-toluenesulfonamido-quinoline (TSQ) predominantly form ternary adducts with members of the Zn-proteome. Here, the chemistries of these sensors are further characterized, including how Zn(sensor)2 complexes may react in an intracellular environment. We demonstrate that these sensors are typically used in higher concentrations than needed to obtain maximum signal. Exposing cells to either Zn(Zinquin)2 or Zn(TSQ)2 resulted in efficient cellular uptake and the formation of sensor-Zn-protein adducts as evidenced by both a fluorescence spectral shift toward that of ternary adducts and the localization of the fluorescence signal within the proteome after gel filtration of cellular lysates. Likewise, reacting Zn(sensor)2 with the Zn-proteome from LLC-PK1 cells resulted in the formation of sensor-Zn-protein ternary adducts that could be inhibited by first saturating the Zn- proteome with excess sensor. Further, a native SDS-PAGE analysis of the Zn-proteome reacted with either the sensor or the Zn(sensor)2 complex revealed that both reactions result in the formation of a similar set of sensor-Zn-protein fluorescent products. The results of this experiment also demonstrated that TSQ and Zinquin react with different members of the Zn-proteome. Reactions with the model apo-Zn-protein bovine serum albumin showed that both Zn(TSQ)2 and Zn(Zinquin)2 reacted to form ternary adducts with its apo-Zn-binding site. Moreover, incubating Zn(sensor)2 complexes with non-zinc binding proteins failed to elicit a spectral shift in the fluorescence spectrum, supporting the premise that blue-shifted emission spectra are due to sensor-Zn-protein ternary adducts. It was concluded that Zn(sensors)2 species do not play a significant role in the overall reaction between these sensors and

Influence of Exciplex formation on the electroluminescent properties of dimeric Zn (II) bis-2-(2'-hydroxyphenyl) benzoxazole complex and monomeric Zn (II) 2-(1'-hydroxynaphthyl) benzothiazole complex

Science.gov (United States)

Prakash, Sattey; Anand, R. S.; Manoharan, S. Sundar

2011-10-01

In this paper we present the factors affecting electroluminescent properties of Zinc complexes of oxazole & thiazole derivatives. Electroluminescent spectra of the Zinc (II) complex of bis-[2-(2'-hydroxyphenyl) benzoxazole], [Zn (HPBO)2]2 and 2-(1'-hydroxynaphthyl) benzothiazole [Zn (HNBT)2] show unusual broadening and shows structural and photophysical similarity with [Zn (HPBT)2]2, a dimeric complex. The [Zn (HPBO)2]2 complex as an emissive layer in the device structure ITO /PEDOT:PSS /TPD (30nm) /[Zn (HPBO)2]2 (60nm) /BCP (6nm) /Ca (3nm) /Al (200nm) shows a broad bluish green emission, with a full width at half maxima (FWHM1˜70nm). The EL spectra is much broader compared to the PL spectra because of exciplex formation at the interfacial region between the emissive layer (EML) & hole transport layer (HTL). We also show the device performance of Zinc 2-(1'-hydroxynaphthyl) benzothiazole [Zn (HNBT)2] complex as emissive layer. Distinctly this device shows a broad greenish yellow emission with a peak maxima at 535nm and 690nm, owing to the exciplex formation between electron transport layer (ETL) and emissive layer (EML), which is in sharp contrast to the exciplex formation across the HTL-EML interface observed for the [Zn (HPBO)2]2 complex.

Role of zinc-protein complexes in the serum of human beings with reference to health and infectious diseases

International Nuclear Information System (INIS)

Bibi, S.; Sajjad, I.; Akram, W.; Viqar, N.; Iqbal, M.S.; Iqbal, M.Z.

1997-01-01

Serum of one hundred thirty normal subjects and 100 patients of different infections were analysed by electrophoresis and atomic absorption flame spectrophotometric technique. It was found that about sixty percent of zinc is bound to albumin and thirty percent is bound to alpha 2-globulins with a variation of 2-5%, beta-globulins and gamma-globulins with a variation of 2-5% in different normal subjects. While the determination of zinc in patients of different infections shows 20-30% decrease in the concentration of albumin bound zinc. The concentration of zinc in alpha 2-globulins remains the same in normal subjects as well as in patients of different infections. The results indicate that in low nourished normal subjects, there is a low concentration of zinc complexes of albumin and a greater chance of different infectious diseases it was further known that albumin works for the transport of zinc and possibly, alpha 2-globulins plays on intermediate role for the attachment of zinc to different body organs. From the above determinations, it is clear that it is the low concentration of zinc in normal subjects which favours the attack of infectious disease. So higher levels of zinc in serum means more resistance towards the attack of infectious diseases. (author)

Transition metal complexes with pyrazole-based ligands.Part 29. Reactions of zinc(II and mercury(II thiocyanate with 4-acetyl-3-amino-5-methylpyrazole

Directory of Open Access Journals (Sweden)

KATALIN MÉSZÁROS SZÉCSÉNYI

2009-11-01

Full Text Available The work is concerned with the crystal and molecular structures of zinc(II and mercury(II complexes with 4-acetyl-3-amino-5-methyl-pyrazole (aamp of the coordination formulae [Zn(NCS2(aamp2] and (Haamp2[Hg(SCN4]. The zinc(II complex was obtained by the reaction of a warm methanolic solution of aamp with a mixture of zinc(II nitrate and ammonium thiocyanate, whereas the mercury(II complex was prepared by the reaction of a warm ethanolic solution of aamp and a warm, slightly acidified aqueous solution of [Hg(SCN4]2-. Both complexes have a tetrahedral geometry, which in the case of zinc complex is formed by monodentate coordination of two aamp molecules and two isothiocyanate groups. The Zn(II and Hg(II atoms have significantly deformed coordination geometry. In both crystal structures the pyrazole derivative has a planar form, probably stabilized by an intramolecular N–H···O hydrogen bond. Apart from the X-ray structural analysis, the isolated complexes were characterized by elemental analysis, IR spectroscopy, conductometric measurements and thermal analysis.

Improved colorimetric determination of serum zinc.

Science.gov (United States)

Johnson, D J; Djuh, Y Y; Bruton, J; Williams, H L

1977-07-01

We show how zinc may easily be quantified in serum by first using an optimum concentration of guanidine hydrochloride to cause release of zinc from proteins, followed by complexation of released metals with cyanide. The cyanide complex of zinc is preferentially demasked with chloral hydrate, followed by a colorimetric reaction between zinc and 4-(2-pyridylazo)resorcinol. This is a sensitive water-soluble ligand; its complex with zinc has an absorption maximum at 497 nm. Values found by this technique compare favorably with those obtained by atomic absorption spectroscopy.

Structural and antimicrobial properties of irradiated chitosan and its complexes with zinc

International Nuclear Information System (INIS)

Khan, Azam; Mehmood, Shaukat; Shafiq, Muhammad; Yasin, Tariq; Akhter, Zareen; Ahmad, Shabir

2013-01-01

The aim of this research was to evaluate the structural and antimicrobial properties of irradiated chitosan and its complexes with zinc. Chitosan having a molecular weight (M η ) of 220 kDa was exposed to gamma rays in dry, wet and solution forms. The chitosan-zinc complexes were prepared by varying the M η of chitosan and Zn content. Viscometeric analysis revealed a sharp decrease in the M η of chitosan irradiated in solution form even at lower doses compared with the dry and wet forms. X-ray diffraction patterns demonstrated variation in the crystallinity of chitosan upon exposure to gamma rays. The antibacterial response of the irradiated chitosan and its complexes against gram-positive and gram-negative bacteria demonstrated wide spectrum of effective antimicrobial activities, which increased with the dose. Additionally, the complexes exhibited excellent antifungal activity with no growth of Aspergallious fumigatus and Fusarium solani even after two weeks. These results suggested that the irradiated chitosan and its complexes with Zn can be used as antimicrobial additives for various applications. - Highlights: • Gamma radiation is used to lower the molecular weight of chitosan. • The effect of environment on radiation degradation of chitosan is studied. • Its complexes with different amount of zinc are prepared and characterized. • Radiation-degraded chitosan and complexes showed good antibacterial properties

Chitosan–Zinc(II Complexes as a Bio-Sorbent for the Adsorptive Abatement of Phosphate: Mechanism of Complexation and Assessment of Adsorption Performance

Directory of Open Access Journals (Sweden)

Maryam Roza Yazdani

2017-12-01

Full Text Available This study examines zinc(II–chitosan complexes as a bio-sorbent for phosphate removal from aqueous solutions. The bio-sorbent is prepared and is characterized via Fourier Transform Infrared Spectroscopy (FT-IR, Scanning Electron Microscopy (SEM, and Point of Zero Charge (pHPZC–drift method. The adsorption capacity of zinc(II–chitosan bio-sorbent is compared with those of chitosan and ZnO–chitosan and nano-ZnO–chitosan composites. The effect of operational parameters including pH, temperature, and competing ions are explored via adsorption batch mode. A rapid phosphate uptake is observed within the first three hours of contact time. Phosphate removal by zinc(II–chitosan is favored when the surface charge of bio-sorbent is positive/or neutral e.g., within the pH range inferior or around its pHPZC, 7. Phosphate abatement is enhanced with decreasing temperature. The study of background ions indicates a minor effect of chloride, whereas nitrate and sulfate show competing effect with phosphate for the adsorptive sites. The adsorption kinetics is best described with the pseudo-second-order model. Sips (R2 > 0.96 and Freundlich (R2 ≥ 0.95 models suit the adsorption isotherm. The phosphate reaction with zinc(II–chitosan is exothermic, favorable and spontaneous. The complexation of zinc(II and chitosan along with the corresponding mechanisms of phosphate removal are presented. This study indicates the introduction of zinc(II ions into chitosan improves its performance towards phosphate uptake from 1.45 to 6.55 mg/g and provides fundamental information for developing bio-based materials for water remediation.

Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

Science.gov (United States)

Maret, Wolfgang

2017-10-31

In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

Facile Preparation of Hybrid Zinc Porphyrin Dendrimer Using Coordination Complex

Energy Technology Data Exchange (ETDEWEB)

Choi, Go-Eun; Shin, Eun Ju [Sunchon National University, Suncheon (Korea, Republic of)

2016-03-15

Porphyrins and metalloporphyrins have been investigated extensively due to their important role in natural photosynthesis, strong absorption in visible region, good light-harvesting properties, unique photophysical and electrochemical properties, and the development of simple synthetic routes for various derivatives. Dendrimers have globular structure with branches of repeating units and wide diversity of the architecture because their size, shape, and functionalities can be tailored. Numerous dendrimers have been designed and synthesized for various applications ranging from catalyst to drug delivery. Both pyridine dendrons Py-PD and Py-AD were successfully coordinated at axial position on central zinc metal cation in zinc porphyrin dendrimers ZnP-AD, ZnP-AD2, or ZnP-AD4. Therefore, it was proven that the formation of axial coordination complex between metal-centered dendrimer and ligand-containing dendron provides another facile method for the preparation of new hybrid dendrimer.

Characterization and Influence of Green Synthesis of Nano-Sized Zinc Complex with 5-Aminolevulinic Acid on Bioactive Compounds of Aniseed.

Science.gov (United States)

Tavallali, Vahid; Rahmati, Sadegh; Rowshan, Vahid

2017-11-01

A new water soluble zinc-aminolevulinic acid nano complex (n[Zn(ALA) 2 ]), which was characterized by TEM, IR, and EDX spectra, has been prepared via sonochemical method under green conditions in water. In the current study, the effectiveness of foliar Zn amendment using synthetic Zn-ALA nano complex, as a new introduced Zn-fertilizer here, was evaluated. As the model plant, Pimpinella anisum, the most valuable spice and medicinal plant grown in warm regions, was used. By using zinc nano complex, further twenty compounds were obtained in the essential oil of anise plants. Application of 0.2% (w/v) Zn-ALA nano complex increased the levels of (E)-anethole, β-bisabolene, germacrene D, methyl chavicol, and α-zingiberene in the essential oil. Nano Zn complex at the rate of 0.2% induced considerable high phenolic compounds and zinc content of shoots and seeds. Chlorogenic acid had the highest level between four detected phenolic compounds. The maximum antioxidant activity was monitored through the application of Zn nano complex. According to the results, nanoscale nutrients can be provided with further decreased doses for medicinal plants. Using Zn-ALA nano complex is a new and efficient method to improve the pharmaceutical and food properties of anise plants. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

S =1/2 ferromagnetic-antiferromagnetic alternating Heisenberg chain in a zinc-verdazyl complex

Science.gov (United States)

Yamaguchi, Hironori; Shinpuku, Yasuhiro; Shimokawa, Tokuro; Iwase, Kenji; Ono, Toshio; Kono, Yohei; Kittaka, Shunichiro; Sakakibara, Toshiro; Hosokoshi, Yuko

2015-02-01

We successfully synthesized the zinc-verdazyl complex [Zn(hfac)2].(o -Py -V ) [hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate; o -Py-V = 3-(2-pyridyl)-1,5-diphenylverdazyl], which is an ideal model compound with an S = 1/2 ferromagnetic-antiferromagnetic alternating Heisenberg chain (F-AF AHC). Ab initio molecular-orbital (MO) calculations indicate that two dominant interactions JF and JAF form the S = 1/2 F-AF AHC in this compound. The magnetic susceptibility and magnetic specific heat of the compound exhibit thermally activated behavior below approximately 1 K. Furthermore, its magnetization curve is observed up to the saturation field and directly indicates a zero-field excitation gap of 0.5 T. These experimental results provide evidence for the existence of a Haldane gap. We successfully explain the results in terms of the S = 1/2 F-AF AHC through quantum Monte Carlo calculations with | JAF/JF|=0.22 . The ab initio MO calculations also indicate a weak AF interchain interaction J' and that the coupled F-AF AHCs form a honeycomb lattice. The J' dependence of the Haldane gap is calculated, and the actual value of J' is determined to be less than 0.01 | JF| .

Concentration of Reovirus and Adenovirus from Sewage and Effluents by Protamine Sulfate (Salmine) Treatment 1

Science.gov (United States)

England, Beatrice

1972-01-01

Protamine sulfate was employed to recover reoviruses, adenoviruses, and certain enteroviruses from sewage and treated effluents; 50- to 400-fold concentration of viral content was achieved. PMID:4342842

Post-synthetic modification of mesoporous zinc-adeninate framework with tris(2,2′-biprydine) ruthenium(II) complex and its electrochemiluminescence

Energy Technology Data Exchange (ETDEWEB)

Park, Ji Eun; Shin, Ik Soo [Dept. of Chemistry, Soongsil University, Seoul (Korea, Republic of); Oh, Hye Jae; An, Ji Hyun [Dept. of Chemistry Education, Seoul National University, Seoul (Korea, Republic of)

2017-04-15

Herein we report a redox-active metal-organic framework (MOF) via post-synthetic cation exchange with tris(2,2′-biprydine) ruthenium(II) complex (Ru(bpy){sub 3}{sup 2+}). A porous anionic zinc-adeninate framework (bMOF-100) is spacious enough to easily entrap 2.43 of Ru(bpy){sub 3}{sup 2+} cations within the mesopore. The encapsulation supported the framework structure preventing any distortion from a rapid solvent evaporation under SEM observation. Ru(bpy){sub 3}{sup 2+}@bMOF-100 was then immobilized on the surface of glassy carbon electrode, and its electrocatalytic and electrochemiluminescent (ECL) properties were investigated in aqueous and organic solution. Especially, Ru(bpy){sub 3}{sup 2+}@bMOF-100 showed the excellent electrochemical properties of Ru(bpy){sub 3}{sup 2+}, but gradual decomposition of the MOF structure was observed under electrochemical measurements because of the sluggish oxidation of adeninate ligand.

A bipyridine-ligated zinc(II) complex with bridging flavonolate ligation: synthesis, characterization, and visible-light-induced CO release reactivity.

Science.gov (United States)

Sorenson, Shayne; Popova, Marina; Arif, Atta M; Berreau, Lisa M

2017-09-01

Metal-flavonolate compounds are of significant current interest as synthetic models for quercetinase enzymes and as bioactive compounds of importance to human health. Zinc-3-hydroxyflavonolate compounds, including those of quercetin, kampferol, and morin, generally exhibit bidentate coordination to a single Zn II center. The bipyridine-ligated zinc-flavonolate compound reported herein, namely bis(μ-4-oxo-2-phenyl-4H-chromen-3-olato)-κ 3 O 3 :O 3 ,O 4 ;κ 3 O 3 ,O 4 :O 3 -bis[(2,2'-bipyridine-κ 2 N,N')zinc(II)] bis(perchlorate), {[Zn 2 (C 15 H 9 O 3 ) 2 (C 10 H 8 N 2 ) 2 ](ClO 4 ) 2 } n , (1), provides an unusual example of bridging 3-hydroxyflavonolate ligation in a dinuclear metal complex. The symmetry-related Zn II centers of (1) exhibit a distorted octahedral geometry, with weak coordination of a perchlorate anion trans to the bridging deprotonated O atom of the flavonolate ligand. Variable-concentration conductivity measurements provide evidence that, when (1) is dissolved in CH 3 CN, the complex dissociates into monomers. 1 H NMR resonances for (1) dissolved in d 6 -DMSO were assigned via HMQC to the H atoms of the flavonolate and bipyridine ligands. In CH 3 CN, (1) undergoes quantitative visible-light-induced CO release with a quantum yield [0.004 (1)] similar to that exhibited by other mononuclear zinc-3-hydroxyflavonolate complexes. Mass spectroscopic identification of the [(bpy) 2 Zn(O-benzoylsalicylate)] + ion provides evidence of CO release from the flavonol and of ligand exchange at the Zn II center.

Studies on cluster, salt and molecular complex of zinc-quinolinate

Indian Academy of Sciences (India)

Reactions of zinc halides with 8-hydroxyquinoline (hydroxQ) in equimolar ratio were carried out in different solvents. ... determination of surface area. We prepared a ..... resulted in the formation of de-solvated complex, which on standing at ...

A Rac1-GDP Trimer Complex Binds Zinc with Tetrahedral and Octahedral Coordination, Displacing Magnesium

Energy Technology Data Exchange (ETDEWEB)

Prehna,G.; Stebbins, E.

2007-01-01

The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3{sub 2}21 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

Synthesis and crystal structure of a polymeric zinc(II complex derived from 4-nitro- phenylacetic acid and propane-1,3-diamine

Directory of Open Access Journals (Sweden)

G-H. Sheng

2014-05-01

Full Text Available A new polymeric zinc(II complex, [ZnL2(PDA]n, has been prepared by the reaction of zinc sulfate, 4-nitrophenylacetic acid, and propane-1,3-diamine (PDA in water. Structure of the complex has been characterized by single-crystal X-ray diffraction. The complex crystallizes as orthorhombic space group Pnma, with unit cell dimensions a = 15.732(1 Å, b = 23.912(1 Å, c = 5.5565(3 Å, V = 2090.2(2 Å3, Z = 4, R1 = 0.0427, wR2 = 0.0968, S = 1.048. The Zn atom is coordinated in a tetrahedral geometry. Single crystals of the complex are stabilized by hydrogen bonds and p···p interactions. DOI: http://dx.doi.org/10.4314/bcse.v28i2.17

Zinc surface complexes on birnessite: A density functional theory study

Energy Technology Data Exchange (ETDEWEB)

Kwon, Kideok D.; Refson, Keith; Sposito, Garrison

2009-01-05

Biogeochemical cycling of zinc is strongly influenced by sorption on birnessite minerals (layer-type MnO2), which are found in diverse terrestrial and aquatic environments. Zinc has been observed to form both tetrahedral (Zn{sup IV}) and octahedral (Zn{sup VI}) triple-corner-sharing surface complexes (TCS) at Mn(IV) vacancy sites in hexagonal birnessite. The octahedral complex is expected to be similar to that of Zn in the Mn oxide mineral, chalcophanite (ZnMn{sub 3}O{sub 7} {center_dot} 3H{sub 2}O), but the reason for the occurrence of the four-coordinate Zn surface species remains unclear. We address this issue computationally using spin-polarized Density Functional Theory (DFT) to examine the Zn{sub IV}-TCS and Zn{sup VI}-TCS species. Structural parameters obtained by DFT geometry optimization were in excellent agreement with available experimental data on Zn-birnessites. Total energy, magnetic moments, and electron-overlap populations obtained by DFT for isolated Zn{sup IV}-TCS revealed that this species is stable in birnessite without a need for Mn(III) substitution in the octahedral sheet and that it is more effective in reducing undersaturation of surface O at a Mn vacancy than is Zn{sub VI}-TCS. Comparison between geometry-optimized ZnMn{sub 3}O{sub 7} {center_dot} 3H{sub 2}O (chalcophanite) and the hypothetical monohydrate mineral, ZnMn{sub 3}O{sub 7} {center_dot} H{sub 2}O, which contains only tetrahedral Zn, showed that the hydration state of Zn significantly affects birnessite structural stability. Finally, our study also revealed that, relative to their positions in an ideal vacancy-free MnO{sub 2}, Mn nearest to Zn in a TCS surface complex move toward the vacancy by 0.08-0.11 {angstrom}, while surface O bordering the vacancy move away from it by 0.16-0.21 {angstrom}, in agreement with recent X-ray absorption spectroscopic analyses.

Zinc complexed chitosan/TPP nanoparticles: A promising micronutrient nanocarrier suited for foliar application.

Science.gov (United States)

Deshpande, Paresh; Dapkekar, Ashwin; Oak, Manoj D; Paknikar, Kishore M; Rajwade, Jyutika M

2017-06-01

Cultivation of cereals in zinc deficient soils leads to declined nutritional quality of grain. Zinc deficiency in humans is a consequence of consumption of micronutrient deficient cereals as staple food. To achieve an increase in zinc density in grain, we evaluated zinc complexed chitosan nanoparticles (Zn-CNP) as a potential 'nanocarrier' suited for foliar fertilization. Zn-CNP were synthesized using tri-polyphosphate as a cross-linker. Spherical Zn-CNP (diameter 250-300nm) were positively charged (zeta potential, +42.34mV) and contained ∼20mg Zn/g (w/w). Plant growth in zinc deficient sand media, followed by foliar application of Zn-CNP (twice-a-week, for 5 weeks) after anthesis resulted in 27 and 42% increase in grain zinc content of MACS 3125 and UC1114 (durum wheat cultivars) respectively. Translocation of zinc ions from foliar applied Zn-CNP into the leaf and seed tissue was demonstrated using zinquin and dithizone stains, respectively. The study indicates the suitability of chitosan-based nanocarriers in agronomic biofortification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Water soluble {2-[3-(diethylamino)phenoxy]ethoxy} substituted zinc(II) phthalocyanine photosensitizers

Energy Technology Data Exchange (ETDEWEB)

Çakır, Dilek [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Göl, Cem [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze, 41400, Kocaeli (Turkey); Çakır, Volkan [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze, 41400, Kocaeli (Turkey); Bıyıklıoğlu, Zekeriya, E-mail: zekeriya_61@yahoo.com [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Kantekin, Halit [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2015-03-15

The new peripherally and non-peripherally tetra-{2-[3-(diethylamino)phenoxy] ethoxy} substituted zinc phthalocyanines (2a and 3a) were synthesized by cyclotetramerization of phthalonitrile derivatives (2 and 3). 2-[3-(diethylamino)phenoxy] ethoxy group was chosen as substituent because the quaternization of the diethylamino functionality on the structure of this group produced water soluble zinc phthalocyanines (2b and 3b). The water solubility is very important for many different applications such as photosensitizers in the photodynamic therapy of cancer because the water soluble photosensitizers can be injected directly to the body and they can transport to cancer cells through blood stream. The new compounds were characterized by using elemental analysis, UV–vis, IR, {sup 1}H NMR, {sup 13}C NMR and mass spectroscopies. The photophysical and photochemical properties of these novel photosensitizer compounds were examined in DMSO (both non-ionic and ionic complexes) and in PBS (for ionic complexes) solutions. The investigation of these properties is very important for the usage of the compounds as photosensitizers for PDT because determination of these properties is the first stage of potential of the compounds as photosensitizers. The bovine serum albumin (BSA) and DNA binding behaviour of the studied water soluble zinc (II) phthalocyanines were also investigated in PBS solutions for the determination of biological activity of these compounds. - Highlights: • Synthesis of water soluble zinc phthalocyanines. • Photophysical and photochemical properties for phthalocyanines. • Photodynamic therapy studies.

Water soluble {2-[3-(diethylamino)phenoxy]ethoxy} substituted zinc(II) phthalocyanine photosensitizers

International Nuclear Information System (INIS)

Çakır, Dilek; Göl, Cem; Çakır, Volkan; Durmuş, Mahmut; Bıyıklıoğlu, Zekeriya; Kantekin, Halit

2015-01-01

The new peripherally and non-peripherally tetra-{2-[3-(diethylamino)phenoxy] ethoxy} substituted zinc phthalocyanines (2a and 3a) were synthesized by cyclotetramerization of phthalonitrile derivatives (2 and 3). 2-[3-(diethylamino)phenoxy] ethoxy group was chosen as substituent because the quaternization of the diethylamino functionality on the structure of this group produced water soluble zinc phthalocyanines (2b and 3b). The water solubility is very important for many different applications such as photosensitizers in the photodynamic therapy of cancer because the water soluble photosensitizers can be injected directly to the body and they can transport to cancer cells through blood stream. The new compounds were characterized by using elemental analysis, UV–vis, IR, 1 H NMR, 13 C NMR and mass spectroscopies. The photophysical and photochemical properties of these novel photosensitizer compounds were examined in DMSO (both non-ionic and ionic complexes) and in PBS (for ionic complexes) solutions. The investigation of these properties is very important for the usage of the compounds as photosensitizers for PDT because determination of these properties is the first stage of potential of the compounds as photosensitizers. The bovine serum albumin (BSA) and DNA binding behaviour of the studied water soluble zinc (II) phthalocyanines were also investigated in PBS solutions for the determination of biological activity of these compounds. - Highlights: • Synthesis of water soluble zinc phthalocyanines. • Photophysical and photochemical properties for phthalocyanines. • Photodynamic therapy studies

Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems ...

African Journals Online (AJOL)

Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems. ... method has been used to study heavy metal interaction in model lake water in KNO3 ... is of no consequential effect because in its normal state, the [OH-] of the lake water is ...

Synthesis and characterization of iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of salicylidene-N-anilinoacetohydrazone (H2L1) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H2L2).

Science.gov (United States)

AbouEl-Enein, S A; El-Saied, F A; Kasher, T I; El-Wardany, A H

2007-07-01

Salicylidene-N-anilinoacetohydrazone (H(2)L(1)) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H(2)L(2)) and their iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. Mononuclear complexes are formed with molar ratios of 1:1, 1:2 and 1:3 (M:L). The IR studies reveal various modes of chelation. The electronic absorption spectra and magnetic susceptibility measurements show that the iron(III), nickel(II) and cobalt(II) complexes of H(2)L(1) have octahedral geometry. While the cobalt(II) complexes of H(2)L(2) were separated as tetrahedral structure. The copper(II) complexes have square planar stereochemistry. The ESR parameters of the copper(II) complexes at room temperature were calculated. The g values for copper(II) complexes proved that the Cu-O and Cu-N bonds are of high covalency.

Critical current density in MgB2 bulk samples after co-doping with nano-SiC and poly zinc acrylate complexes

International Nuclear Information System (INIS)

Zhang, Z.; Suo, H.; Ma, L.; Zhang, T.; Liu, M.; Zhou, M.

2011-01-01

SiC and poly zinc acrylate complexes co-doped MgB 2 bulk has been synthesized. Co-doping can cause higher carbon substitutions and the second phase particles. Co-doping can further increase the Jc value of MgB 2 bulk on the base of the SiC doping. The co-doped MgB 2 bulk samples have been synthesized using an in situ reaction processing. The additives is 8 wt.% SiC nano powders and 10 wt.% [(CH 2 CHCOO) 2 Zn] n poly zinc acrylate complexes (PZA). A systematic study was performed on samples doped with SiC or PZA and samples co-doped with both of them. The effects of doping and co-doping on phase formation, microstructure, and the variation of lattice parameters were studied. The amount of substituted carbon, the critical temperature (T c ) and the critical current density (J c ) were determined. The calculated lattice parameters show the decrease of the a-axis, while no obvious change was detected for c-axis parameter in co-doped samples. This indicates that the carbon was substituted by boron in MgB 2 . The amount of substituted carbon for the co-doped sample shows an enhancement compared to that of the both single doped samples. The co-doped samples perform the highest J c values, which reaches 3.3 x 10 4 A/cm 2 at 5 K and 7 T. It is shown that co-doping with SiC and organic compound is an effective way to further improve the superconducting properties of MgB 2 .

The Effects of Leucine, Zinc, and Chromium Supplements on Inflammatory Events of the Respiratory System in Type 2 Diabetic Rats.

Directory of Open Access Journals (Sweden)

Saeed Kolahian

Full Text Available Diabetes mellitus is a major cause of serious micro- and macrovascular diseases that affect nearly every system in the body, including the respiratory system. Non-enzymatic protein glycation due to hyperglycaemic stress has fundamental implications due to the large capillary network and amount of connective tissue in the lung. The current study was designed to determine whether leucine, zinc, and chromium supplementations influence the function and histological structure of the respiratory tract in a rat model of type 2 diabetes. Seventy-seven rats were divided into eleven groups, consisting of 7 animals each. One group served as negative control and insulin and glibenclamide were used as positive control drugs. Thus, eight groups received the nutritional supplements alone or in combination with each other. Nutritional supplements and glibenclamide were added to the drinking water and neutral protamine Hagedorn insulin was subcutaneously injected during the 4 weeks of treatment period. The induction of type 2 diabetes in the rats caused an infiltration of mononuclear cells and edema in the submucosa of the trachea and lung, severe fibrosis around the vessels and airways, and perivascular and peribronchial infiltration of inflammatory cells and fibrin. In the diabetic group, the total inflammation score and Reid index significantly increased. Diabetes induction significantly reduced the total antioxidant status and elevated the lipid peroxidation products in the serum, lung lavage and lung tissue of the diabetic animals. Treatment with nutritional supplements significantly decreased the histopathological changes and inflammatory indices in the diabetic animals. Supplementation of diabetic rats with leucine, zinc, and chromium, alone and in combination, significantly increased the total antioxidant status and lipid peroxidation level in the diabetic animals. The nutritional supplements improved the enzymatic antioxidant activity of catalase

The Effects of Leucine, Zinc, and Chromium Supplements on Inflammatory Events of the Respiratory System in Type 2 Diabetic Rats

Science.gov (United States)

Kolahian, Saeed; Sadri, Hassan; Shahbazfar, Amir Ali; Amani, Morvarid; Mazadeh, Anis; Mirani, Mehdi

2015-01-01

Diabetes mellitus is a major cause of serious micro- and macrovascular diseases that affect nearly every system in the body, including the respiratory system. Non-enzymatic protein glycation due to hyperglycaemic stress has fundamental implications due to the large capillary network and amount of connective tissue in the lung. The current study was designed to determine whether leucine, zinc, and chromium supplementations influence the function and histological structure of the respiratory tract in a rat model of type 2 diabetes. Seventy-seven rats were divided into eleven groups, consisting of 7 animals each. One group served as negative control and insulin and glibenclamide were used as positive control drugs. Thus, eight groups received the nutritional supplements alone or in combination with each other. Nutritional supplements and glibenclamide were added to the drinking water and neutral protamine Hagedorn insulin was subcutaneously injected during the 4 weeks of treatment period. The induction of type 2 diabetes in the rats caused an infiltration of mononuclear cells and edema in the submucosa of the trachea and lung, severe fibrosis around the vessels and airways, and perivascular and peribronchial infiltration of inflammatory cells and fibrin. In the diabetic group, the total inflammation score and Reid index significantly increased. Diabetes induction significantly reduced the total antioxidant status and elevated the lipid peroxidation products in the serum, lung lavage and lung tissue of the diabetic animals. Treatment with nutritional supplements significantly decreased the histopathological changes and inflammatory indices in the diabetic animals. Supplementation of diabetic rats with leucine, zinc, and chromium, alone and in combination, significantly increased the total antioxidant status and lipid peroxidation level in the diabetic animals. The nutritional supplements improved the enzymatic antioxidant activity of catalase, glutathione peroxidase

Electroluminescence and photosensitivity spectra of organic diode structures based on zinc complexes

Science.gov (United States)

Kaplunov, M. G.; Krasnikova, S. S.; Nikitenko, S. L.; Yakushchenko, I. K.

2017-01-01

Devices based on zinc complexes with sulphanylaminosubstituted ligands are characterized by dual function - electroluminescence (EL) and photosensitivity. Both EL and photosensitivity are associated with the formation of exciplexes.

Sulfidation of zinc plating sludge with Na2S for zinc resource recovery

International Nuclear Information System (INIS)

Kuchar, D.; Fukuta, T.; Onyango, M.S.; Matsuda, H.

2006-01-01

A high amount of zinc disposed in the landfill sites as a mixed-metal plating sludge represents a valuable zinc source. To recover zinc from the plating sludge, a sulfidation treatment is proposed in this study, while it is assumed that ZnS formed could be separated by flotation. The sulfidation treatment was conducted by contacting simulated zinc plating sludge with Na 2 S solution at S 2- to Zn 2+ molar ratio of 1.5 for a period of 1-48 h, while changing the solid to liquid (S:L) ratio from 0.25:50 to 1.00:50. The conversion of zinc compounds to ZnS was determined based on the consumption of sulfide ions. The reaction products formed by the sulfidation of zinc were identified by X-ray diffraction (XRD). As a result, it was found that the conversion of zinc compounds to ZnS increased with an increase in S:L ratio. A maximum conversion of 0.809 was obtained at an S:L ratio of 1.00:50 after 48 h. However, when the zinc sludge treated at S:L ratio of 1.00:50 for 48 h was subjected to XRD analyses, only ZnS was identified in the treated zinc sludge. The result suggested that the rest of zinc sludge remained unreacted inside the agglomerates of ZnS. The formation behavior of ZnS was predicted by Elovich equation, which was found to describe the system satisfactorily indicating the heterogeneous nature of the sludge

Electroluminescence and photosensitivity spectra of organic diode structures based on zinc complexes

International Nuclear Information System (INIS)

Kaplunov, M.G.; Krasnikova, S.S.; Nikitenko, S.L.; Yakushchenko, I.K.

2017-01-01

Devices based on zinc complexes with sulphanylaminosubstituted ligands are characterized by dual function – electroluminescence (EL) and photosensitivity. Both EL and photosensitivity are associated with the formation of exciplexes.

Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis

Energy Technology Data Exchange (ETDEWEB)

Plapp, Bryce V.; Savarimuthu, Baskar Raj; Ferraro, Daniel J.; Rubach, Jon K.; Brown, Eric N.; Ramaswamy, S. (Iowa)

2017-07-07

During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a nearby glutamate residue, as suggested by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs. Zinc coordination and participation of water in the enzyme mechanism were investigated by X-ray crystallography. The apoenzyme and its complex with adenosine 5'-diphosphoribose have an open protein conformation with the catalytic zinc in one position, tetracoordinated by Cys-46, His-67, Cys-174, and a water molecule. The bidentate chelators 2,2'-bipyridine and 1,10-phenanthroline displace the water and form a pentacoordinated zinc. The enzyme–NADH complex has a closed conformation similar to that of ternary complexes with coenzyme and substrate analogues; the coordination of the catalytic zinc is similar to that found in the apoenzyme, except that a minor, alternative position for the catalytic zinc is ~1.3 Å from the major position and closer to Glu-68, which could form the alternative coordination to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide or N-benzylformamide (or with NAD+ and fluoro alcohols) have the classical tetracoordinated zinc, and no water is bound to the zinc or the nicotinamide rings. The major forms of the enzyme in the mechanism have a tetracoordinated zinc, where the carboxylate group of Glu-68 could participate in the exchange of water and substrates on the zinc. Hydride transfer in the Michaelis complexes does not involve a nearby water.

Complexes cobalt(II, zinc(II and copper(II with some newly synthesized benzimidazole derivatives and their antibacterial activity

Directory of Open Access Journals (Sweden)

S. O. PODUNAVAC-KUZMANOVIC

1999-05-01

Full Text Available The preparation and properties of some complexes of cobalt(II, zinc(II and copper(II with several newly synthesized benzimidazole derivatives (L are reported. The complexes, of the general formula [MCl2L2] (M=Co(II, Zn(II and [CuCl2L(H2O], have a tetrahedral structure. The complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility measurements, IR and absorption electronic spectra. The antibacterial activitiy of the benzimidazoles and their complexes was evaluated against Erwinia carotovora subsp. carotovora and Erwinia amylovora. The complexes were found to be more toxic than the ligands.

Comparison of Superparamagnetic Iron Oxide Labeling Efficiency between Poly-L-Lysine and Protamine Sulfate for Human Mesenchymal Stem Cells: Quantitative Analysis Using Multi-Echo T2 Magnetic Resonance Imaging

International Nuclear Information System (INIS)

Suh, Ji Yeon; Lee, Jeong Hyun; Lee, Chang Kyung; Shin, Ji Hoon; Choi, Choong Gon; Kim, Jeong Kon

2013-01-01

To quantify in vitro labeling efficiency of protamine sulfate (PS) and poly-L-lysine (PLL) for labeling of human mesenchymal stem cells (hMSCs) with superparamagnetic iron oxide (SPIO) using multi-echo T2 magnetic resonance (MR) imaging at 4.7 T. The hMSCs were incubated with SPIO-PS or SPIO-PLL complexes. Their effects on the cell metabolism and differentiation capability were evaluated, respectively. The decrease of iron concentrations in the labeled cells were assessed immediately, and at 4 d after labeling using multi-echo T2 MR imaging at 4.7 T. The results were compared with those of Prussian blue colorimetry. The hMSCs were labeled more efficiently by SPIO-PLL than SPIO-PS without any significant effect on cell metabolism and differentiation capabilities. It was feasible to quantify the iron concentrations in SPIO-agarose-phantoms and in agarose mixture with the labeled cells from T2 maps obtained from multi-echo T2 MRI. However, the iron concentration of the labeled cells was significantly higher by T2-maps than the results of Prussian blue colorimetry. The hMSCs can be effectively labeled with SPIO-PLL complexes more than with SPIO-PS without significant change in cell metabolism and differentiation. In vitro quantification of the iron concentrations of the labeled is feasible from multi-echo T2 MRI, but needs further investigation.

Comparison of Superparamagnetic Iron Oxide Labeling Efficiency between Poly-L-Lysine and Protamine Sulfate for Human Mesenchymal Stem Cells: Quantitative Analysis Using Multi-Echo T2 Magnetic Resonance Imaging

Energy Technology Data Exchange (ETDEWEB)

Suh, Ji Yeon; Lee, Jeong Hyun; Lee, Chang Kyung; Shin, Ji Hoon; Choi, Choong Gon; Kim, Jeong Kon [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

2013-02-15

To quantify in vitro labeling efficiency of protamine sulfate (PS) and poly-L-lysine (PLL) for labeling of human mesenchymal stem cells (hMSCs) with superparamagnetic iron oxide (SPIO) using multi-echo T2 magnetic resonance (MR) imaging at 4.7 T. The hMSCs were incubated with SPIO-PS or SPIO-PLL complexes. Their effects on the cell metabolism and differentiation capability were evaluated, respectively. The decrease of iron concentrations in the labeled cells were assessed immediately, and at 4 d after labeling using multi-echo T2 MR imaging at 4.7 T. The results were compared with those of Prussian blue colorimetry. The hMSCs were labeled more efficiently by SPIO-PLL than SPIO-PS without any significant effect on cell metabolism and differentiation capabilities. It was feasible to quantify the iron concentrations in SPIO-agarose-phantoms and in agarose mixture with the labeled cells from T2 maps obtained from multi-echo T2 MRI. However, the iron concentration of the labeled cells was significantly higher by T2-maps than the results of Prussian blue colorimetry. The hMSCs can be effectively labeled with SPIO-PLL complexes more than with SPIO-PS without significant change in cell metabolism and differentiation. In vitro quantification of the iron concentrations of the labeled is feasible from multi-echo T2 MRI, but needs further investigation.

Reactions of zinc hydride and magnesium hydride with pyridine; synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes

NARCIS (Netherlands)

Koning, A.J. de; Boersma, J.; Kerk, G.J.M. van der

1980-01-01

The synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes are described. Zinc hydride and magnesium hydride dissolve in and react with pyridine, and the reaction has been studied in detail in the case of zinc hydride. Evaporation of the solvent after 1–2 hours at 0°C

Metal complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid and benzohydroxamic acid. Crystal and molecular structure of [Cu(phen)2(Cl)]Cl x H2Sha, a model for a peroxidase-inhibitor complex.

Science.gov (United States)

O'Brien, E C; Farkas, E; Gil, M J; Fitzgerald, D; Castineras, A; Nolan, K B

2000-04-01

Stability constants of iron(III), copper(II), nickel(II) and zinc(II) complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid (HAha) and benzohydroxamic acid (HBha) have been determined at 25.0 degrees C, I=0.2 mol dm(-3) KCl in aqueous solution. The complex stability order, iron(III) > copper(II) > nickel(II) approximately = zinc(II) was observed whilst complexes of H2Sha were found to be more stable than those of the other two ligands. In the preparation of ternary metal ion complexes of these ligands and 1,10-phenanthroline (phen) the crystalline complex [Cu(phen)2(Cl)]Cl x H2Sha was obtained and its crystal structure determined. This complex is a model for hydroxamate-peroxidase inhibitor interactions.

Chronic zinc exposure decreases the surface expression of NR2A-containing NMDA receptors in cultured hippocampal neurons.

Directory of Open Access Journals (Sweden)

Jia Zhu

Full Text Available Zinc distributes widely in the central nervous system, especially in the hippocampus, amygdala and cortex. The dynamic balance of zinc is critical for neuronal functions. Zinc modulates the activity of N-methyl-D-aspartate receptors (NMDARs through the direct inhibition and various intracellular signaling pathways. Abnormal NMDAR activities have been implicated in the aetiology of many brain diseases. Sustained zinc accumulation in the extracellular fluid is known to link to pathological conditions. However, the mechanism linking this chronic zinc exposure and NMDAR dysfunction is poorly understood.We reported that chronic zinc exposure reduced the numbers of NR1 and NR2A clusters in cultured hippocampal pyramidal neurons. Whole-cell and synaptic NR2A-mediated currents also decreased. By contrast, zinc did not affect NR2B, suggesting that chronic zinc exposure specifically influences NR2A-containg NMDARs. Surface biotinylation indicated that zinc exposure attenuated the membrane expression of NR1 and NR2A, which might arise from to the dissociation of the NR2A-PSD-95-Src complex.Chronic zinc exposure perturbs the interaction of NR2A to PSD-95 and causes the disorder of NMDARs in hippocampal neurons, suggesting a novel action of zinc distinct from its acute effects on NMDAR activity.

A Nonbactericidal Zinc-Complexing Ligand as a Biofilm Inhibitor: Structure-Guided Contrasting Effects on Staphylococcus aureus Biofilm.

Science.gov (United States)

Kapoor, Vidushi; Rai, Rajanikant; Thiyagarajan, Durairaj; Mukherjee, Sandipan; Das, Gopal; Ramesh, Aiyagari

2017-08-04

Zinc-complexing ligands are prospective anti-biofilm agents because of the pivotal role of zinc in the formation of Staphylococcus aureus biofilm. Accordingly, the potential of a thiosemicarbazone (compound C1) and a benzothiazole-based ligand (compound C4) in the prevention of S. aureus biofilm formation was assessed. Compound C1 displayed a bimodal activity, hindering biofilm formation only at low concentrations and promoting biofilm growth at higher concentrations. In the case of C4, a dose-dependent inhibition of S. aureus biofilm growth was observed. Atomic force microscopy analysis suggested that at higher concentrations C1 formed globular aggregates, which perhaps formed a substratum that favored adhesion of cells and biofilm formation. In the case of C4, zinc supplementation experiments validated zinc complexation as a plausible mechanism of inhibition of S. aureus biofilm. Interestingly, C4 was nontoxic to cultured HeLa cells and thus has promise as a therapeutic anti-biofilm agent. The essential understanding of the structure-driven implications of zinc-complexing ligands acquired in this study might assist future screening regimes for identification of potent anti-biofilm agents. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chirality sensing with stereodynamic biphenolate zinc complexes.

Science.gov (United States)

Bentley, Keith W; de Los Santos, Zeus A; Weiss, Mary J; Wolf, Christian

2015-10-01

Two bidentate ligands consisting of a fluxional polyarylacetylene framework with terminal phenol groups were synthesized. Reaction with diethylzinc gives stereodynamic complexes that undergo distinct asymmetric transformation of the first kind upon binding of chiral amines and amino alcohols. The substrate-to-ligand chirality imprinting at the zinc coordination sphere results in characteristic circular dichroism signals that can be used for direct enantiomeric excess (ee) analysis. This chemosensing approach bears potential for high-throughput ee screening with small sample amounts and reduced solvent waste compared to traditional high-performance liquid chromatography methods. © 2015 Wiley Periodicals, Inc.

Lead inhibition of DNA-binding mechanism of Cys(2)His(2) zinc finger proteins.

Science.gov (United States)

Hanas, J S; Rodgers, J S; Bantle, J A; Cheng, Y G

1999-11-01

The association of lead with chromatin in cells suggests that deleterious metal effects may in part be mediated through alterations in gene function. To elucidate if and how lead may alter DNA binding of cysteine-rich zinc finger proteins, lead ions were analyzed for their ability to alter the DNA binding mechanism of the Cys(2)His(2) zinc finger protein transcription factor IIIA (TFIIIA). As assayed by DNase I protection, the interaction of TFIIIA with the 50-bp internal control region of the 5S ribosomal gene was partially inhibited by 5 microM lead ions and completely inhibited by 10 to 20 microM lead ions. Preincubation of free TFIIIA with lead resulted in DNA-binding inhibition, whereas preincubation of a TFIIIA/5S RNA complex with lead did not result in DNA-binding inhibition. Because 5S RNA binds TFIIIA zinc fingers, this result is consistent with an inhibition mechanism via lead binding to zinc fingers. The complete loss of DNase I protection on the 5S gene indicates the mechanism of inhibition minimally involves the N-terminal fingers of TFIIIA. Inhibition was not readily reversible and occurred in the presence of an excess of beta-mercaptoethanol. Inhibition kinetics were fast, progressing to completion in approximately 5 min. Millimolar concentrations of sulfhydryl-specific arsenic ions were not inhibitory for TFIIIA binding. Micromolar concentrations of lead inhibited DNA binding by Sp1, another Cys(2)His(2) finger protein, but not by the nonfinger protein AP2. Inhibition of Cys(2)His(2) zinc finger transcription factors by lead ions at concentrations near those known to have deleterious physiological effects points to new molecular mechanisms for lead toxicity in promoting disease.

Crystal structure of mixed ligand compound [HgPhen{(C2H5)2NCS2}2] and character of intermolecular interaction in the structures of [MPhen{(C2H5)2NCS2}2] (M = Zn, Cd, Hg) complexes

International Nuclear Information System (INIS)

Klevtsova, R.F.; Glinskaya, L.A.; Zemskova, S.M.; Larionov, S.V.

2002-01-01

Monocrystals of mixed ligand complex [HgPhen(Et 2 NCS 2 ) 2 ] (Phen = 1, 10-phenanthroline) have been prepared and by the method of X-ray diffraction its crystal structure has been determined. The structure of mercury complex has been compared with structures of previously studied cadmium and zinc complexes similar in composition. The character of interaction between molecules of cadmium, zinc, mercury mixed ligand complexes and ways of their packing have been considered. It is shown that the structure of the complexes presents a molecular group assembled from two monomeric compounds at the expense of interaction between heterocyclic ligands contained in the mixed ligand complexes [ru

Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N'-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide.

Science.gov (United States)

Emam, Sanaa M; El-Saied, Fathy A; Abou El-Enein, Saeyda A; El-Shater, Heba A

2009-03-01

Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of furan-2-carbaldehyde 4-methoxy-N-anilinoacetohydrazone were synthesized and characterized by elemental and thermal (TG and DTA) analyses, IR, UV-vis and (1)H NMR spectra as well as magnetic moment and molar conductivity. Mononuclear complexes are obtained with 1:1 molar ratio except complexes 3 and 9 which are obtained with 1:2 molar ratios. The IR spectra of ligand and metal complexes reveal various modes of chelation. The ligand behaves as a neutral bidentate one and coordination occurs via the carbonyl oxygen atom and azomethine nitrogen atom. The ligand behaves also as a monobasic tridentate one and coordination occurs through the enolic oxygen atom, azomethine nitrogen atom and the oxygen atom of furan ring. Moreover, the ligand behaves as a neutral tridentate and coordination occurs via the carbonyl oxygen, azomethine nitrogen and furan oxygen atoms as well as a monobasic bidentate and coordination occurs via the enolic oxygen atom and azomethine nitrogen atom. The electronic spectra and magnetic moment measurements reveal that all complexes possess octahedral geometry except the copper complex 10 possesses a square planar geometry. The thermal studies showed the type of water molecules involved in metal complexes as well as the thermal decomposition of some metal complexes.

Steric Effects on the Binding of Phosphate and Polyphosphate Anions by Zinc(II) and Copper(II) Dinuclear Complexes of m-Xylyl-bis-cyclen.

Science.gov (United States)

Esteves, Catarina V; Esteban-Gómez, David; Platas-Iglesias, Carlos; Tripier, Raphaël; Delgado, Rita

2018-05-11

The triethylbenzene-bis-cyclen (cyclen = 1,4,7,10-tetraazacyclododecane) compound (tbmce) was designed with an imposed structural rigidity at the m-xylyl spacer to be compared to a less restrained and known parent compound (bmce). The framework of both compounds differs only in the substituents of the m-xylyl spacer. The study was centered in the differences observed in the acid-base reactions of both compounds, their copper(II) and zinc(II) complexation behaviors, as well as in the uptake of phosphate and polyphosphate anions (HPPi 3- , ATP 4- , ADP 3- , AMP 2- , PhPO 4 2- , and HPO 4 2- ). On the one hand, the acid-base reactions showed lower values for the third and fourth protonation constants of tbmce than for bmce, suggesting that the ethyl groups of the spacer in tbmce force the two cyclen units to more conformational restricted positions. On the other hand, the stability constant values for copper(II) and zinc(II) complexes revealed that bmce is a better chelator than tbmce pointing out to additional conformational restraints imposed by the triethylbenzene spacer. The binding studies of phosphates by the dinuclear copper(II) and zinc(II) complexes showed much smaller effective association constants for the dicopper complexes. Single-crystal X-ray and computational (density functional theory) studies suggest that anion binding promotes the formation of tetranuclear entities in which anions are bridging the metal centers. Our studies also revealed the dinuclear zinc(II) complex of bmce as a promising receptor for phosphate anions, with the largest effective association constant of 5.94 log units being observed for the formation of [Zn 2 bmce(HPPi)] + . Accordingly, a colorimetric study via an indicator displacement assay to detect phosphates in aqueous solution found that the [Zn 2 bmce] 4+ complex acts as the best receptor for pyrophosphate displaying a detection limit of 2.5 nM by changes visible to naked eye.

Availability of native and fertilizer zinc in some Indian soils: studies with 65Zinc

International Nuclear Information System (INIS)

Chaudhury, J.; Deb, D.L.

1979-01-01

Isotopically exchangeable zinc (Et values) was determined by different methods in some soils having pH(H 2 O) varying from 3.05 to 8.40 using 65 Zn. The Et values obtained using different extractants showed significant correlation with available zinc, organic carbon and soil pH. The recovery of applied zinc in the aqueous phase was less than one percent in most of the soils having pH higher than 7.0. Application of zinc with complexing agents like DTPA and EDTA increased the recovery of applied zinc in the solution to about 95 percent. Soil pH, organic C and DTPA extractable zinc showed significant relationship with the recovery of applied zinc under different treatments. Use of EDTA and DTPA extractants reduced the zinc buffering capacity of soil to a value less than one, irrespective of the initial pH of the soil, whereas the values were comparatively higher in presence of different levels of zinc carrier. (auth.)

Zinc removal from wastewater by complexation-microfiltration process

OpenAIRE

Trivunac Katarina; Sekulić Zoran; Stevanović Slavica

2012-01-01

As a result of its wide industrial applications, zinc has become an important contaminant in aquatic environment since it is a toxic heavy metal and some of its compounds such as zinc arsenate and zinc cyanide, may be extremely hazardous. Therefore, there is a growing need for developing simple methods capable of separating and recovering trace zinc from environmental waters. Nowadays, the ultra and microfiltration method for trace metals removal from waters by the addition of water-sol...

Zinc Bioavailability from Phytate-Rich Foods and Zinc Supplements. Modeling the Effects of Food Components with Oxygen, Nitrogen, and Sulfur Donor Ligands.

Science.gov (United States)

Tang, Ning; Skibsted, Leif H

2017-10-04

Aqueous solubility of zinc phytate (K sp = (2.6 ± 0.2) × 10 -47 mol 7 /L 7 ), essential for zinc bioavailability from plant foods, was found to decrease with increasing temperature corresponding to ΔH dis of -301 ± 22 kJ/mol and ΔS dis of -1901 ± 72 J/(mol K). Binding of zinc to phytate was found to be exothermic for the stronger binding site and endothermic for the weaker binding site. The solubility of the slightly soluble zinc citrate and insoluble zinc phytate was found to be considerably enhanced by the food components with oxygen donor, nitrogen donor, and sulfur donor ligands. The driving force for the enhanced solubility is mainly due to the complex formation between zinc and the investigated food components rather than ligand exchange and ternary complex formation as revealed by quantum mechanical calculations and isothermal titration calorimetry. Histidine and citrate are promising ligands for improving zinc absorption from phytate-rich foods.

Thermal decomposition study and biological characterization of zinc(II) 2-chlorobenzoate complexes with bioactive ligands

Czech Academy of Sciences Publication Activity Database

Findoráková, L.; Györyová, K.; Hudecová, D.; Mudroňová, D.; Kovářová, Jana; Homzová, K.; Nour El-Dien, F. A.

2013-01-01

Roč. 111, č. 3 (2013), s. 1771-1781 ISSN 1388-6150. [Central and Eastern European Conference on Thermal Analysis and Calorimetry /1./ - CEEC-TAC1. Craiova, 07.09.2011-10.09.2011] Institutional research plan: CEZ:AV0Z40500505 Keywords : zinc * 2-chlorobenzoate * thermal Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.206, year: 2013

Stimuli-responsive protamine-based biodegradable nanocapsules for enhanced bioavailability and intracellular delivery of anticancer agents

Energy Technology Data Exchange (ETDEWEB)

Radhakrishnan, Krishna; Thomas, Midhun B.; Pulakkat, Sreeranjini [Indian Institute of Science, Department of Materials Engineering (India); Gnanadhas, Divya P.; Chakravortty, Dipshikha [Indian Institute of Science, Department of Microbiology and Cell Biology (India); Raichur, Ashok M., E-mail: amr@materials.iisc.ernet.in [Indian Institute of Science, Department of Materials Engineering (India)

2015-08-15

Enzyme- and pH-responsive polyelectrolyte nanocapsules having diameters in the range of 200 ± 20 nm were fabricated by means of Layer-by-Layer assembly of biopolymers, protamine, and heparin, and then loaded with anticancer drug doxorubicin. The incorporation of the FDA-approved peptide drug protamine as a wall component rendered the capsules responsive to enzyme stimuli. The stimuli-responsive drug release from these nanocapsules was evaluated, and further modulation of capsule permeability to avoid premature release was demonstrated by crosslinking the wall components. The interaction of the nanocapsules with cancer cells was studied using MCF-7 breast cancer cells. These capsules were readily internalized and disintegrated inside the cells, culminating in the release of the loaded doxorubicin and subsequent cell death as observed by confocal microscopy and MTT Assay. The bioavailability studies performed using BALB/c mice revealed that the encapsulated doxorubicin exhibited enhanced bioavailability compared to free doxorubicin. Our results indicate that this stimuli-responsive system fabricated from clinically used FDA-approved molecules and exhibiting minimal premature release has great potential for drug-delivery applications.

A randomized trial comparing perinatal outcomes using insulin detemir or neutral protamine Hagedorn in type 1 diabetes

DEFF Research Database (Denmark)

Hod, Moshe; Mathiesen, Elisabeth R; Jovanovič, Lois

2014-01-01

OBJECTIVE: This randomized controlled trial aimed to compare the efficacy and safety of insulin detemir (IDet) with neutral protamine Hagedorn (NPH), both with insulin aspart, in pregnant women with type 1 diabetes. The perinatal and obstetric pregnancy outcomes are presented. METHODS: Subjects w...

Exciplex electroluminescence and photoluminescence spectra of the new organic materials based on zinc complexes of sulphanylamino-substituted ligands.

Science.gov (United States)

Kaplunov, Mikhail G; Krasnikova, Svetlana S; Nikitenko, Sergey L; Sermakasheva, Natalia L; Yakushchenko, Igor K

2012-04-03

We have investigated the electroluminescence spectra of the electroluminescent devices based on the new zinc complexes of amino-substituted benzothiazoles and quinolines containing the C-N-M-N chains in their chelate cycles. The spectra exhibit strong exciplex bands in the green to yellow region 540 to 590 nm due to interaction of the excited states of zinc complexes and triaryl molecules of the hole-transporting layer. For some devices, the intrinsic luminescence band of 460 nm in the blue region is also observed along with the exciplex band giving rise to an almost white color of the device emission. The exciplex band can be eliminated if the material of the hole-transporting layer is not a triarylamine derivative. We have also found the exciplex emission in the photoluminescence spectra of the films containing blends of zinc complex and triphenylamine material.

Zinc(II) complexes with intramolecular amide oxygen coordination as models of metalloamidases.

Science.gov (United States)

Rivas, Juan C Mareque; Salvagni, Emiliano; Prabaharan, Ravi; de Rosales, Rafael Torres Martin; Parsons, Simon

2004-01-07

Polydentate ligands (6-R1-2-pyridylmethyl)-R2(R1= NHCOtBu, R2= bis(2-pyridylmethyl)amine L1, bis(2-(methylthio)ethyl)amine L2 and N(CH2CH2)2S L3) form mononuclear zinc(II) complexes with intramolecular amide oxygen coordination and a range of coordination environments. Thus, the reaction of Zn(ClO4)2.6H2O with L1-3 in acetonitrile affords [(L)Zn](ClO4)2(L=L1, 1; L2, 2) and [(L3)Zn(H2O)(NCCH3)](ClO4)2 3. The simultaneous amide/water binding in resembles the motif that has been proposed to be involved in the double substrate/nucleophile Lewis acidic activation and positioning mechanism of amide bond hydrolysis in metallopeptidases. X-ray diffraction, 1H and 13C NMR and IR data suggests that the strength of amide oxygen coordination follows the trend 1>2 >3. L1-3 and undergo cleavage of the tert-butylamide upon addition of Me4NOH.5H2O (1 equiv.) in methanol at 50(1)degrees C. The rate of amide cleavage follows the order 1> 2> 3, L1-3. The extent by which the amide cleavage reaction is accelerated in 1-3 relative to the free ligands, L1-3, is correlated with the strength of amide oxygen binding and Lewis acidity of the zinc(II) centre in deduced from the X-ray, NMR and IR studies.

Chemical stability of insulin. 3. Influence of excipients, formulation, and pH.

Science.gov (United States)

Brange, J; Langkjaer, L

1992-01-01

The influence of auxiliary substances and pH on the chemical transformations of insulin in pharmaceutical formulation, including various hydrolytic and intermolecular cross-linking reactions, was studied. Bacteriostatic agents had a profound stabilizing effect--phenol > m-cresol > methylparaben--on deamidation as well as on insulin intermolecular cross-linking reactions. Of the isotonicity substances, NaCl generally had a stabilizing effect whereas glycerol and glucose led to increased chemical deterioration. Phenol and sodium chloride exerted their stabilizing effect through independent mechanisms. Zinc ions, in concentrations that promote association of insulin into hexamers, increase the stability, whereas higher zinc content had no further influence. Protamine gave rise to additional formation of covalent protamine-insulin products which increased with increasing protamine concentration. The impact of excipients on the chemical processes seems to be dictated mainly via an influence on the three-dimensional insulin structure. The effect of the physical state of the insulin on the chemical stability was also complex, suggesting an intricate dependence of intermolecular proximity of involved functional groups. At pH values below five and above eight, insulin degrades relatively fast. At acid pH, deamidation at residue A21 and covalent insulin dimerization dominates, whereas disulfide reactions leading to covalent polymerization and formation of A- and B-chains prevailed in alkaline medium. Structure-reactivity relationship is proposed to be a main determinant for the chemical transformation of insulin.

Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein

International Nuclear Information System (INIS)

Inui, Ken; Sagane, Yoshimasa; Miyata, Keita; Miyashita, Shin-Ichiro; Suzuki, Tomonori; Shikamori, Yasuyuki; Ohyama, Tohru; Niwa, Koichi; Watanabe, Toshihiro

2012-01-01

Highlights: ► BoNT and NTNHA proteins share a similar protein architecture. ► NTNHA and BoNT were both identified as zinc-binding proteins. ► NTNHA does not have a classical HEXXH zinc-coordinating motif similar to that found in all serotypes of BoNT. ► Homology modeling implied probable key residues involved in zinc coordination. -- Abstract: Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X 35 -D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.

Surface complexation modeling of zinc sorption onto ferrihydrite.

Science.gov (United States)

Dyer, James A; Trivedi, Paras; Scrivner, Noel C; Sparks, Donald L

2004-02-01

A previous study involving lead(II) [Pb(II)] sorption onto ferrihydrite over a wide range of conditions highlighted the advantages of combining molecular- and macroscopic-scale investigations with surface complexation modeling to predict Pb(II) speciation and partitioning in aqueous systems. In this work, an extensive collection of new macroscopic and spectroscopic data was used to assess the ability of the modified triple-layer model (TLM) to predict single-solute zinc(II) [Zn(II)] sorption onto 2-line ferrihydrite in NaNO(3) solutions as a function of pH, ionic strength, and concentration. Regression of constant-pH isotherm data, together with potentiometric titration and pH edge data, was a much more rigorous test of the modified TLM than fitting pH edge data alone. When coupled with valuable input from spectroscopic analyses, good fits of the isotherm data were obtained with a one-species, one-Zn-sorption-site model using the bidentate-mononuclear surface complex, (triple bond FeO)(2)Zn; however, surprisingly, both the density of Zn(II) sorption sites and the value of the best-fit equilibrium "constant" for the bidentate-mononuclear complex had to be adjusted with pH to adequately fit the isotherm data. Although spectroscopy provided some evidence for multinuclear surface complex formation at surface loadings approaching site saturation at pH >/=6.5, the assumption of a bidentate-mononuclear surface complex provided acceptable fits of the sorption data over the entire range of conditions studied. Regressing edge data in the absence of isotherm and spectroscopic data resulted in a fair number of surface-species/site-type combinations that provided acceptable fits of the edge data, but unacceptable fits of the isotherm data. A linear relationship between logK((triple bond FeO)2Zn) and pH was found, given by logK((triple bond FeO)2Znat1g/l)=2.058 (pH)-6.131. In addition, a surface activity coefficient term was introduced to the model to reduce the ionic strength

A homologous series of homoleptic zinc bis(1,4-di-tert-butyl-1,4-diaza-1,3-butadiene) complexes: Kx[Zn(t-BuNCHCHN-t-Bu)2], Zn(t-BuNCHCHN-t-Bu)2, and [Zn(t-BuNCHCHN-t-Bu)2](OTf)x)(X=1,2)

NARCIS (Netherlands)

Koten, G. van; Rijnberg, E.; Richter, B.; Thiele, K.-H.; Boersma, J.; Veldman, N.; Spek, A.L.

1998-01-01

A homologous series of mono- and dicationic, neutral, and mono- and dianionic zinc diazabutadiene complexes, Kx[Zn(t-BuNCHCHN-t-Bu)2], Zn(t-BuNCHCHN-t-Bu)2, and [Zn(t-BuNCHCHN-t-Bu)2](OTf)x (x = 1, 2), have been prepared and isolated in pure form. The crystal structures of the mono- and dicationic

Effect of Zinc Oxide Doping on Electroluminescence and Electrical Behavior of Metalloporphyrins-Doped Samarium Complex

Science.gov (United States)

Janghouri, Mohammad; Amini, Mostafa M.

2018-02-01

Samarium complex [(Sm(III)] as a new host material was used for preparation of red organic light-emitting diodes (OLEDs). Devices with configurations of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):(poly(styrenesulfonate) (PEDOT:PSS (50 nm)/polyvinyl carbazole (PVK):[zinc oxide (ZnO)] (50 nm)/[(Sm(III)]:[zinc(II) 2,3-tetrakis(dihydroxyphenyl)-porphyrin and Pt(II) 2,3-dimethoxyporphyrin] (60 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) (15 nm)/Al (150 nm) have been fabricated and investigated. An electroplex occurring at the (PVK/Sm: Pt(II) 2,3-dimethoxyporphyrin) interface has been suggested when ZnO nanoparticles were doped in PVK. OLED studies have revealed that the photophysical characteristics and electrical behavior of devices with ZnO nanoparticles are much better than those of devices with pure PVK. The efficiency of devices based on [(Sm(III)] was superior than that of known aluminum tris(8-hydroxyquinoline) (Alq3) and also our earlier reports on red OLEDs under the same conditions.

A Rac1--GDP trimer complex binds zinc with tetrahedral and octahedral coordination, displacing magnesium

Energy Technology Data Exchange (ETDEWEB)

Prehna, G.; Stebbins, C

2007-01-01

The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3221 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein

Energy Technology Data Exchange (ETDEWEB)

Inui, Ken [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472 (Japan); Sagane, Yoshimasa [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Miyata, Keita [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472 (Japan); Miyashita, Shin-Ichiro [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Suzuki, Tomonori [Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558 (Japan); Shikamori, Yasuyuki [Agilent Technologies International Japan, Ltd. Takaura-cho 9-1, Hachioji-shi, Tokyo 192-0033 (Japan); Ohyama, Tohru; Niwa, Koichi [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Watanabe, Toshihiro, E-mail: t-watana@bioindustry.nodai.ac.jp [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan)

2012-03-16

Highlights: Black-Right-Pointing-Pointer BoNT and NTNHA proteins share a similar protein architecture. Black-Right-Pointing-Pointer NTNHA and BoNT were both identified as zinc-binding proteins. Black-Right-Pointing-Pointer NTNHA does not have a classical HEXXH zinc-coordinating motif similar to that found in all serotypes of BoNT. Black-Right-Pointing-Pointer Homology modeling implied probable key residues involved in zinc coordination. -- Abstract: Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X{sub 35}-D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.

Comparisons of the spectroscopic and microbiological activities among coumarin-3-carboxylate, o-phenanthroline and zinc(II) complexes

Science.gov (United States)

Islas, María S.; Martínez Medina, Juan J.; Piro, Oscar E.; Echeverría, Gustavo A.; Ferrer, Evelina G.; Williams, Patricia A. M.

2018-06-01

Coumarins (2H-chromen-2-one) are oxygen-containing heterocyclic compounds that belong to the benzopyranones family. In this work we have synthesized different coordination complexes with coumarin-3-carboxylic acid (HCCA), o-phenanthroline (phen) and zinc(II). In the reported [Zn(CCA)2(H2O)2] complex, coumarin-3-carboxylate (CCA) is acting as a bidentate ligand while in the two prepared complexes, [Zn(phen)3]CCA(NO3) (obtained as a single crystal) and [Zn(CCA)2phen].4H2O, CCA is acting as a counterion of the complex cation [Zn(phen)3]+2 or coordinated to the metal center along with phen, respectively. These compounds were characterized on the basis of elemental analysis and thermogravimetry. NMR, FTIR and Raman spectroscopies of the compounds and the CCA potassium salt (KCCA) allow to determine several similarities and differences among them. Finally, their behavior against alkaline phosphatase enzyme and their antimicrobial activities were also measured.

Repletion of zinc in zinc-deficient cells strongly up-regulates IL-1β-induced IL-2 production in T-cells.

Science.gov (United States)

Daaboul, Doha; Rosenkranz, Eva; Uciechowski, Peter; Rink, Lothar

2012-10-01

Mild zinc deficiency in humans negatively affects IL-2 production resulting in declined percentages of cytolytic T cells and decreased NK cell lytic activity, which enhances the susceptibility to infections and malignancies. T-cell activation is critically regulated by zinc and the normal physiological zinc level in T-cells slightly lies below the optimal concentration for T-cell functions. A further reduction in zinc level leads to T-cell dysfunction and autoreactivity, whereas high zinc concentrations (100 μM) were shown to inhibit interleukin-1 (IL-1)-induced IL-1 receptor kinase (IRAK) activation. In this study, we investigated the molecular mechanism by which zinc regulates the IL-1β-induced IL-2 expression in T-cells. Zinc supplementation to zinc-deficient T-cells increased intracellular zinc levels by altering the expression of zinc transporters, particularly Zip10 and Zip12. A zinc signal was observed in the murine T-cell line EL-4 6.1 after 1 h of stimulation with IL-1β, measured by specific zinc sensors FluoZin-3 and ZinPyr-1. This signal is required for the phosphorylation of MAPK p38 and NF-κB subunit p65, which triggers the transcription of IL-2 and strongly increases its production. These results indicate that short-term zinc supplementation to zinc-deficient T-cells leads to a fast rise in zinc levels which subsequently enhance cytokine production. In conclusion, low and excessive zinc levels might be equally problematic for zinc-deficient subjects, and stabilized zinc levels seem to be essential to avoid negative concentration-dependent zinc effects on T-cell activation.

GluR2 ligand-binding core complexes

DEFF Research Database (Denmark)

Kasper, C; Lunn, M-L; Liljefors, T

2002-01-01

X-ray structures of the GluR2 ligand-binding core in complex with (S)-Des-Me-AMPA and in the presence and absence of zinc ions have been determined. (S)-Des-Me-AMPA, which is devoid of a substituent in the 5-position of the isoxazolol ring, only has limited interactions with the partly hydrophobic...

Luminescent zinc(ii) and copper(i) complexes for high-performance solution-processed monochromic and white organic light-emitting devices.

Science.gov (United States)

Cheng, Gang; So, Gary Kwok-Ming; To, Wai-Pong; Chen, Yong; Kwok, Chi-Chung; Ma, Chensheng; Guan, Xiangguo; Chang, Xiaoyong; Kwok, Wai-Ming; Che, Chi-Ming

2015-08-01

The synthesis and spectroscopic properties of luminescent tetranuclear zinc(ii) complexes of substituted 7-azaindoles and a series of luminescent copper(i) complexes containing 7,8-bis(diphenylphosphino)-7,8-dicarba- nido -undecaborate ligand are described. These complexes are stable towards air and moisture. Thin film samples of the luminescent copper(i) complexes in 2,6-dicarbazolo-1,5-pyridine and zinc(ii) complexes in poly(methyl methacrylate) showed emission quantum yields of up to 0.60 (for Cu-3 ) and 0.96 (for Zn-1 ), respectively. Their photophysical properties were examined by ultrafast time-resolved emission spectroscopy, temperature dependent emission lifetime measurements and density functional theory calculations. Monochromic blue and orange solution-processed OLEDs with these Zn(ii) and Cu(i) complexes as light-emitting dopants have been fabricated, respectively. Maximum external quantum efficiency (EQE) of 5.55% and Commission Internationale de l'Eclairage (CIE) coordinates of (0.16, 0.19) were accomplished with the optimized Zn-1 -OLED while these values were, respectively 15.64% and (0.48, 0.51) for the optimized Cu-3 -OLED. Solution-processed white OLEDs having maximum EQE of 6.88%, CIE coordinates of (0.42, 0.44), and colour rendering index of 81 were fabricated by using these luminescent Zn(ii) and Cu(i) complexes as blue and orange light-emitting dopant materials, respectively.

Surface modification of graphene oxide nanosheets by protamine sulfate/sodium alginate for anti-cancer drug delivery application

Science.gov (United States)

Xie, Meng; Zhang, Feng; Liu, Lijiao; Zhang, Yanan; Li, Yeping; Li, Huaming; Xie, Jimin

2018-05-01

In order to improve the efficiency of anticancer drug delivery, a graphene oxide (GO) based drug delivery system modificated by natural peptide protamine sulfate (PRM) and sodium alginate (SA) was established via electrostatic attraction at each step of adsorption based on layer-by-layer self-assembly. The nanocomposites were then loaded with anticancer drug doxorubicin hydrochloride (DOX) to estimate the feasibility as drug carriers. The nanocomposites loaded with DOX revealed a remarkable pH-sensitive drug release property. The modification with protamine sulfate and sodium alginate could not only impart the nanocomposites an improved dispersibility and stability under physiological pH, but also suppress the protein adhesion. Due to the high water dispersibility and the small particle size, GO-PRM/SA nanocomposites were able to be uptaken by MCF-7 cells. It was found that GO-PRM/SA nanocomposites exhibited no obvious cytotoxicity towards MCF-7 cells, while GO-PRM/SA-DOX exhibited better cytotoxicity than GO-DOX. Therefore, the GO-PRM/SA nanocomposites were feasible as drug delivery vehicles.

Preparation, infrared, raman and nmr spectra of N,N'-diethylthiourea complexes with zinc(II), cadmium(II) and mercury(II) halides

Energy Technology Data Exchange (ETDEWEB)

Marcotrigiano, G [Bari Univ. (Italy). Cattedra di Chimica, Facolta di Medicina-Veterinaria

1976-05-01

Several complexes of N,N'-diethylthiourea (Dietu) with zinc(II), cadmium(II) and mercury(II) halides were prepared and characterized by i.r. (4000-60 cm/sup -1/), raman (400-60 cm/sup -1/), in the solid state and n.m.r. and conductometric methods in solution. The complexes Zn(Dietu)/sub 2/X/sub 2/, Cd(Dietu)/sub 2/X/sub 2/ (X=Cl, Br, I) and Hg(Dietu)/sub 2/X/sub 2/ (X=Br, I) are tetrahedral species in which intramolecular -NH...X interactions have been observed. The 1:1 mercury(II) complexes, Hg(Dietu)X/sub 2/ (X=Cl, Br), appear to have a dimeric tetrahedral halide-bridged structure in the solid state. In all these complexes N,N'-diethylthiourea is sulphur-bonded to the metal.

Highly microporous carbons derived from a complex of glutamic acid and zinc chloride for use in supercapacitors

Science.gov (United States)

Dong, Xiao-Ling; Lu, An-Hui; He, Bin; Li, Wen-Cui

2016-09-01

The selection of carbon precursor is an important factor when designing carbon materials. In this study, a complex derived from L-glutamic acid and zinc chloride was used to prepare highly microporous carbons via facile pyrolysis. L-glutamic acid, a new carbon precursor with nitrogen functionality, coordinated with zinc chloride resulted in a homogeneous distribution of Zn2+ on the molecular level. During pyrolysis, the evaporation of the in situ formed zinc species creates an abundance of micropores together with the inert gases. The obtained carbons exhibit high specific surface area (SBET: 1203 m2 g-1) and a rich nitrogen content (4.52 wt%). In excess of 89% of the pore volume consists of micropores with pore size ranging from 0.5 to 1.2 nm. These carbons have been shown to be suitable for use as supercapacitor electrodes, and have been tested in 6 M KOH where a capacitance of 217 F g-1 was achieved at a current density of 0.5 A g-1. A long cycling life of 30 000 cycles was achieved at a current density of 1 A g-1, with only a 9% loss in capacity. The leakage current through a two-electrode device was measured as 2.3 μA per mg of electrode and the self-discharge characteristics were minimal.

Zinc(II) complexes with potent cyclin-dependent kinase inhibitors derived from 6-benzylaminopurine: synthesis, characterization, X-ray structures and biological activity

Czech Academy of Sciences Publication Activity Database

Trávníček, Zdeněk; Kryštof, Vladimír; Šipl, M.

2006-01-01

Roč. 100, č. 2 (2006), s. 214-225 ISSN 0162-0134 R&D Projects: GA ČR GA203/04/1168 Institutional research plan: CEZ:AV0Z50380511 Keywords : Zinc(II) complexes * 6-Benzylaminopurine derivatives * Bohemine * Olomoucine * X-ray structures Subject RIV: CA - Inorganic Chemistry Impact factor: 2.654, year: 2006

Organically complexed copper, zinc, and chelating agents in the rivers of Western Puerto Rico

International Nuclear Information System (INIS)

Montgomery, J.R.; Echevarria, J.E.

1975-01-01

The method for determining soluble chelators gives their concentration in copper-equivalent chelating capacity units in fresh or slightly brackish (less than 3 percent salinity) water. The mean concentration of chelators in the Rio Guanajibo for December 1973 and January 1974 was 0.4 mg of copper per liter of water (N = 21, SD = 0.2) and for February 1974, 0.9 mg/liter (N = 8, SD = 0.4). The combined mean for the Rio Anasco and Culebrinas was 0.5 mg/liter (N = 7, SD = 0.4) in January and February 1974. The mean concentration of ionic copper was 0.5 μg/liter (N = 7, SD = 0.6) and of ionic zinc, 0.2 μg/liter (N = 8, SD = 0.1) in the Rio Guanajibo from November 1972 to February 1973. The concentration of organically bound copper was 0.3 μ/liter (N = 7, SD = 0.2) and that of organically bound zinc was 0.6 μg/liter (N = 8, SD = 0.6); this indicates that there was more than a sufficient quantity of chelator available in the river to complex all the soluble copper. The presence of a high ratio of Ca 2+ to Cu 2+ probably prevents the formation of larger concentrations of organically complexed copper. The mean concentration of chelating agents in the Guanajibo River seems to be directly related to the increased organic input from municipalities and a sugar mill. The concentration of chelators in tropical rivers appears to be higher than that found in Canadian lakes. The mean concentration for particulate organic carbon (POC) was 3653 μg atoms/liter (SD = 3653, N = 29). The dissolved reactive phosphate (DRP) ranged from a mean of 1.1 μg atom/liter. No significant correlation could be found between POC, DRP, and the concentration of chelators

Effects of zinc complexes on the distribution of zinc in calcareous soil and zinc uptake by maize.

Science.gov (United States)

Alvarez, José M; Rico, María I

2003-09-10

The movement and availability of Zn from six organic Zn sources in a Typic Xerorthent (calcareous) soil were compared by incubation, column assay, and in a greenhouse study with maize (Zea mays L.). Zinc soil behavior was studied by sequential, diethylenetriaminepentaacetate, and Mehlich-3 extractions. In the incubation experiment, the differences in Zn concentration observed in the water soluble plus exchangeable fraction strongly correlated with Zn uptake by plants in the greenhouse experiment. Zinc applied to the surface of soil columns scarcely moved into deeper layers except for Zn-ethylenediaminetetraacetate (EDTA) that showed the greatest distribution of labile Zn throughout the soil and the highest proportion of leaching of the applied Zn. In the upper part of the column, changes in the chemical forms of all treatments occurred and an increase in organically complexed and amorphous Fe oxide-bound fractions was detected. However, the water soluble plus exchangeable fraction was not detected. The same results were obtained at the end of the greenhouse experiment. Significant increases were found in plant dry matter yield and Zn concentration as compared with the control treatment without Zn addition. Increasing Zn rate in the soil increased dry matter yield in all cases but Zn concentration in the plant increased only with Zn-EDTA and Zn-ethylenediaminedi-o-hydroxyphenyl-acetate (EDDHA) fertilizers. Higher Zn concentration in plants (50.9 mg kg(-)(1)) occurred when 20 mg Zn kg(-)(1) was added to the soil as Zn-EDTA. The relative effectiveness of the different Zn carriers in increasing Zn uptake was in the order: Zn-EDTA > Zn-EDDHA > Zn-heptagluconate >/= Zn-phenolate approximately Zn-polyflavonoid approximately Zn-lignosulfonate.

Potential interaction between zinc ions and a cyclodextrin-based diclofenac formulation.

Science.gov (United States)

Hamdan, Imad I; El-Sabawi, Dina; Abdel Jalil, Mariam

2016-03-01

Complexes of diclofenac sodium (DF-Na) with hydroxypropyl betacyclodextrin (HPβCD) were prepared by co-evaporation in a 1:1 ratio and characterized in light of previously reported data. Phase solubility diagrams were obtained for DF-Na with HPβCD in the presence and absence of zinc ions. Dissolution profiles were obtained for DF-Na and its HPβCD complex at acidic (pH 1.2) as well as in phosphate buffer (pH 6.8), in the presence and absence of zinc. HPβCD, as expected, was shown to improve the dissolution of DF-Na in acidic medium but not in phosphate buffer (pH 6.8). The presence of zinc ions decreased the in vitro dissolution of DF-HPβCD complex in acidic medium (pH 1.2) but not in phosphate buffer (pH 6.8). It was confirmed that the precipitate that was formed by zinc ions in the presence of HPβCD and DF-Na contained no cyclodextrin and most likely it was a mixture of the complexes: DF 2 -Zn and DF-Zn with some molecules of water. In vivo experiments on rats have shown that HPβCD has no statistically significant effect on absorption or bioavailability of DF-Na in spite of the observed improvement of its in vitro dissolution by HPβCD. Moreover, zinc ions were shown to decrease the absorption rate of DF-Na in rats model but did neither significantly alter the absorption nor bioavailability of DF-HPβCD complex. The zinc induced precipitates of DF were shown to have significantly different crystalline properties when HPβCD was present. Therefore, the pharmaceutical details of a DF-Na preparation should be considered when designing the formulation and predicting possible interaction between DF-Na (or other potential NSAIDs) and zinc metal.

Synthesis, characterization, spectroscopic and theoretical studies of new zinc(II), copper(II) and nickel(II) complexes based on imine ligand containing 2-aminothiophenol moiety

Science.gov (United States)

Shafaatian, Bita; Mousavi, S. Sedighe; Afshari, Sadegh

2016-11-01

New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes.

Impaired protamination and sperm DNA damage in a Nellore bull with high percentages of morphological sperm defects in comparison to normospermic bulls

Directory of Open Access Journals (Sweden)

J.T. Carreira

2015-04-01

Full Text Available The routine semen evaluation assessing sperm concentration, motility and morphology, does not identify subtle defects in sperm chromatin architecture. Bulls appear to have stable chromatin, with low levels of DNA fragmentation. However, the nature of fragmentation and its impact on fertility remain unclear and there are no detailed reports characterizing the DNA organization and damage in this species. The intensive genetic selection, the use of artificial insemination and in vitro embryo production associated to the cryopreservation process can contribute to the chromatin damage and highlights the importance of sperm DNA integrity for the success of these technologies. Frozen-thawed semen samples from three ejaculates from a Nellore bull showed high levels of morphological sperm abnormalities (55.8±5.1%, and were selected for complementary tests. Damage of acrosomal (76.9±8.9% and plasma membranes (75.7±9.3% as well as sperm DNA strand breaks (13.8±9.5% and protamination deficiency (3.7±0.6% were significantly higher compared to the values measured in the semen of five Nellore bulls with normospermia (24.3±3.3%; 24.5±6.1%; 0.6±0.5%; 0.4±0.6% for acrosome, plasma membrane, DNA breaks and protamine deficiency, respectively (P<0.05. Motility and percentage of spermatozoa with low mitochondrial potential showed no differences between groups. This study shows how routine semen analyses (in this case morphology may point to the length and complexity of sperm cell damage emphasizing the importance of sperm function testing.

Zinc chelates as new activators for sulphur vulcanization of acrylonitrile-butadiene elastomer

Directory of Open Access Journals (Sweden)

2009-04-01

Full Text Available The goal of this work was to apply several zinc chelates as activators for sulphur vulcanization of acrylonitrilebutadiene elastomer (NBR, in order to find alternatives for the conventionally used zinc oxide. In this article, we discuss the effects of different zinc complexes on the cure characteristics, crosslinks distribution in the elastomer network and mechanical properties of acrylonitrile-butadiene rubber. Zinc chelates seem to be good substitutes for zinc oxide as activators for sulphur vulcanization of NBR rubber, without detrimental effects on the crosslinking process and physical properties of the obtained vulcanizates. Moreover, application of zinc complexes allows to reduce the amount of zinc ions in rubber compounds by 40% compared to conventionally crosslinked vulcanizates with zinc oxide. It is a very important ecological goal since zinc oxide is classified as toxic to aquatic species and its amount in rubber products must be reduced below 2.5% at least. From a technological point of view it is a very important challenge.

Zinc composite anode for batteries with solid electrolyte

Science.gov (United States)

Tedjar, F.; Melki, T.; Zerroual, L.

A new negative composite anode for batteries with a solid electrolyte is studied. Using a complex of zinc ammonium chloride mixed with zinc metal powder, the advantage of the Zn/Zn 2+ electrode ( e = -760 mV) is kept while the energy density and the shelf-life of the battery are increased.

Mechanical Coating of Zinc Particles with Bi2O3-Li2O-ZnO Glasses as Anode Material for Rechargeable Zinc-Based Batteries

Directory of Open Access Journals (Sweden)

Tobias Michlik

2018-02-01

Full Text Available The electrochemical performance of zinc particles with 250 μm and 30 μm diameters, coated with Bi2O3-Li2O-ZnO glass is investigated and compared with noncoated zinc particles. Galvanostatic investigations were conducted in the form of complete discharge and charging cycles in electrolyte excess. Coated 30 μm zinc particles provide the best rechargeability after complete discharge. The coatings reached an average charge capacity over 20 cycles of 113 mAh/g compared to the known zero rechargeability of uncoated zinc particles. Proposed reasons for the prolonged cycle life are effective immobilization of discharge products in the glass layer and the formation of percolating metallic bismuth and zinc phases, forming a conductive network through the glass matrix. The coating itself is carried out by mechanical ball milling. Different coating parameters and the resulting coating quality as well as their influence on the passivation and on the rechargeability of zinc–glass composites is investigated. Optimized coating qualities with respect to adhesion, homogeneity and compactness of the glass layer are achieved at defined preparation conditions, providing a glass coating content of almost 5 wt % for 250 μm zinc particles and almost 11 wt % for 30 μm zinc particles.

Coordination Behavior of Ni2+, Cu2+, and Zn2+ in Tetrahedral 1-Methylimidazole Complexes: A DFT/CSD Study

OpenAIRE

Tetteh, Samuel

2018-01-01

The interaction between nickel (Ni2+), copper (Cu2+), and zinc (Zn2+) ions and 1-methylimidazole has been studied by exploring the geometries of eleven crystal structures in the Cambridge Structural Database (CSD). The coordination behavior of the respective ions was further investigated by means of density functional theory (DFT) methods. The gas-phase complexes were fully optimized using B3LYP/GENECP functionals with 6-31G∗ and LANL2DZ basis sets. The Ni2+ and Cu2+ complexes show distorted ...

Zinc in the prevention of Fe2initiated lipid and protein oxidation

Directory of Open Access Journals (Sweden)

M. PAOLA ZAGO

2000-01-01

Full Text Available In the present study we characterized the capacity of zinc to protect lipids and proteins from Fe2+-initiated oxidative damage. The effects of zinc on lipid oxidation were investigated in liposomes composed of brain phosphatidylcholine (PC and phosphatidylserine (PS at a molar relationship of 60:40 (PC:PS, 60:40. Lipid oxidation was evaluated as the oxidation of cis-parinaric acid or as the formation of 2-thiobarbituric acid-reactive substances (TBARS. Zinc protected liposomes from Fe2+ (2.5-50 muM-supported lipid oxidation. However, zinc (50 muM did not prevent the oxidative inactivation of glutamine synthelase and glucose 6-phosphate dehydrogenase when rat brain superntants were oxidized in the presence of 5 muM Fe2+ and 0.5 mM H2O2 .We also studied the interactions of zinc with epicatechin in the prevention of liid oxidation in liposomes. The simulaneous addition of 0.5 muM epicatechin (EC and 50 muM zinc or EC separately. Zinc (50 muM also protecte liposomes from the stimulatory effect of aluminum on Fe2+-initiated lipid oxidation. Zinc could play an important role as an antioxidant in biological systems, replacing iron and other metals with pro-oxidant activity from binding sites and interacting with other components of the oxidant defense system.

Phenoxo bridged dinuclear Zn(II) Schiff base complex as new precursor for preparation zinc oxide nanoparticles: Synthesis, characterization, crystal structures and photoluminescence studies

Energy Technology Data Exchange (ETDEWEB)

Saeednia, S., E-mail: sami_saeednia@yahoo.com [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Iranmanesh, P. [Department of physics, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Ardakani, M. Hatefi; Mohammadi, M.; Norouzi, Gh. [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of)

2016-06-15

Highlights: • A novel nano-scale Zn(II) complex was synthesized by solvothermal method. • Chemical structure of the nanostructures was characterized as well as bulk complex. • The photoluminescence property of the complex was investigated at room temperature. • The thermogravimetry and differential thermal analysis were carried out. • Thermal decomposition of the nanostructures was prepared zinc oxide nanoparticles. - Abstract: Nanoparticles of a novel Zn(II) Schiff base complex, [Zn(HL)NO{sub 3}]{sub 2} (1), (H{sub 2}L = 2-[(2-hydroxy-propylimino) methyl] phenol), was synthesized by using solvothermal method. Shape, morphology and chemical structure of the synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier Transform Infrared Spectoscopy (FT-IR) and UV–vis spectroscopy. Structural determination of compound 1 was determined by single-crystal X-ray diffraction. The results were revealed that the zinc complex is a centrosymmetric dimer in which deprotonated phenolates bridge the two five-coordinate metal atoms and link the two halves of the dimer. The thermal stability of compound 1 was analyzed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of the initial substrates concentration and reaction time on size and morphology of compound 1 nanostructure was investigated as well. Furthermore, the luminescent properties of the complex 1 were examined. ZnO nanoparticles with diameter between 15 and 20 nm were simply synthesized by solid-state transformation of compound 1 at 700 °C.

Iron and zinc complexation in wild-type and ferritin-expressing wheat grain: implications for mineral transport into developing grain

DEFF Research Database (Denmark)

Neal, Andrew L; Geraki, Kalotina; Borg, Søren

2013-01-01

of modified complexation of both metals in transgenic grain overexpressing wheat ferritin. For zinc, there is a consistent doubling of the number of complexing phosphorus atoms. Although there is some EXAFS evidence for iron phytate in ferritin-expressing grain, there is also evidence of a structure lacking......We have used synchrotron-based X-ray fluorescence and absorption techniques to establish both metal distribution and complexation in mature wheat grains. In planta, extended X-ray absorption fine structure (EXAFS) spectroscopy reveals iron phytate and zinc phytate structures in aleurone cells...... of ferritin-expressing grains is quite different from that in wild-type grain. This may explain why the raised levels of minerals transported to the developing grain accumulate within the crease region of the transgenic grain....

Zinc composite anode for batteries with solid electrolyte

Energy Technology Data Exchange (ETDEWEB)

Tedjar, F.; Melki, T.; Zerroual, L. (Setif Univ. (Algeria). Unite de Recherche Electrochimie)

1992-05-01

A new negative composite anode for batteries with a solid electrolyte is studied. Using a complex of zinc ammonium chloride mixed with zinc metal powder, the advantage of the Zn/Zn[sup 2+] electrode (e = -760 mV) is kept while the energy density and the shelf-life of the battery are increased. (orig.).

Protection against ionising radiation and synergism with thiols by zinc aspartate

International Nuclear Information System (INIS)

Floersheim, G.L.; Floersheim, P.

1986-01-01

Pre-treatment with zinc aspartate protected mice against the lethal effects of radiation and raised the LD 50 from 8 gy to 12.2 Gy. Zinc chloride and zinc sulphate were clearly less active. The radioprotective effect of zinc aspartate was equivalent to cysteamine and slightly inferior to S,2-aminoethylisothiourea (AET). Zinc aspartate displayed a similar therapeutic index to the thiols but could be applied at an earlier time before irradiation. Synergistic effects occurred with the combined administration of zinc aspartate and thiols. By giving zinc aspartate with cysteamine, the LD 50 was increased to 13.25 Gy and, by combining it in the optimal protocol with AET, to 17.3 Gy. The radioprotection by zinc and its synergism with thiols is explained by the stabilisation of thiols through the formation of zinc complexes. (author)

Radiation induced traps of zinc phosphate and phosphide

International Nuclear Information System (INIS)

Murali, K.R.; Rao, D.R.

1980-01-01

Thermoluminescence (TL) glow curve (TGC) method has been used to study the traps produced by X-irradiation in Zn 3 (PO 4 ) 2 and Zn 3 P 2 . Prominent TL glow peaks were observed at 100 0 and 360 0 C for zinc phosphate while for zinc phosphide only one glow peak at 245 0 C was observed, and in the latter case the TL output was in general quite low compared to zinc phosphate. The TL spectra for both the glow peaks of zinc phosphate indicated emission band in the region around 560 nm, while for zinc phosphide the emission occurred at 575 nm (in the temperature region 200-270 0 C). The low temperature glow peaks below 270 0 C were less stable compared to those above 300 0 C and were completely destroyed when the irradiated samples were stored in darkness for 24 hr at room temperature. Shining by 470 nm light however produced preferential bleaching of the two TL peaks at 100 and 360 0 C with no effect on the 245 0 C glow peak of zinc phosphide. It is concluded that during heat treatment large numbers of Zn-vacancies are formed due to which complexes like Zn-P are produced by irradiation and the TL traps destroyed in a radiative recombination process are related with these complexes. (author)

NMR investigation of dynamic processes in complexes of nickel(II) and zinc(II) with iminodiacetate, n-methyliminodiacetate and n-ethyliminodiacetate

International Nuclear Information System (INIS)

Wagner, M.R.

1985-11-01

Analysis of oxygen-17 bulk water relaxation rates with an aqueous solution of 1:1 Ni(II):ida reveals that two rate-limiting processes are involved with solvent exchange. Analysis of carbon-13 longitudinal relaxation rates of the bis-ligand complexes with zinc(II) are used to determine molecular tumbling rates and methyl rotation rates. The carbon-13 transverse relaxation rates for the carbons in the bis-ligand complex with Ni(II) are adequately fitted to the Solomon-Bloembergen equation. Three carboxylate carbon peaks are seen with the 13 C spectrum of the 1:2 Ni(II):ida complex, which coalesce into a single peak above about 360 K. The mechanism and rate of ligand exchange are determined for the complexes Zn(II)L 2 -2 (L = mida, eida) in aqueous solution by total lineshape analysis of the proton spectrum at 500 MHz

Prediction of Serum Zinc Levels in Mexican Children at 2 Years of Age Using a Food Frequency Questionnaire and Different Zinc Bioavailability Criteria.

Science.gov (United States)

Cantoral, Alejandra; Téllez-Rojo, Martha; Shamah-Levy, Teresa; Schnaas, Lourdes; Hernández-Ávila, Mauricio; Peterson, Karen E; Ettinger, Adrienne S

2015-06-01

The 2006 Mexican National Health and Nutrition Survey documented a prevalence of zinc deficiency of almost 30% in children under 2 years of age. We sought to validate a food frequency questionnaire (FFQ) for quantifying dietary bioavailable zinc intake in 2-year-old Mexican children accounting for phytic acid intake and using serum zinc as a reference. This cross-sectional study was nested within a longitudinal birth cohort of 333 young children in Mexico City. Nonfasting serum zinc concentration was measured and dietary zinc intake was calculated on the basis of a semiquantitative FFQ administered to their mothers. The relationship between dietary zinc intake and serum zinc was assessed using linear regression, adjusting for phytic acid intake, and analyzed according to two distinct international criteria to estimate bioavailable zinc. Models were stratified by zinc deficiency status. Dietary zinc, adjusted for phytic acid intake, explained the greatest proportion of the variance of serum zinc. For each milligram of dietary zinc intake, serum zinc increased on average by 0.95 μg/dL (0.15 μmol/L) (p = .06). When stratified by zinc status, this increase was 0.74 μg/dL (p = .12) for each milligram of zinc consumed among children with adequate serum zinc (n = 276), whereas among those children with zinc deficiency (n = 57), serum zinc increased by only 0.11 μg/dL (p = .82). A semiquantitative FFQ can be used for predicting serum zinc in relation to dietary intake in young children, particularly among those who are zinc-replete, and when phytic acid or phytate intake is considered. Future studies should be conducted accounting for both zinc status and dietary zinc inhibitors to further elucidate and validate these findings. © The Author(s) 2015.

Ultrafast pump-probe spectroscopy of Zinc Phthalocynine (ZnPc) and light harvesting complex II (LHC II)

CSIR Research Space (South Africa)

Ombinda-Lemboumba, Saturnin

2009-07-01

Full Text Available pump-probe spectroscopy of Zinc Phthalocynine (ZnPc) and light harvesting complex II (LHC II) SAIP 7-10 July 2009, University of Kwazulu Natal. S. Ombinda-Lemboumba1, 2 A. du Plessis1, L. Botha1, D.E. Roberts1, P. Molukanele1, 3, R.W. Sparrow3, E... and phtobiology (2008) Page 12 Conclusion SAIP 7-10 July 2009, University of Kwazulu natal Femto group © CSIR 2008 www.csir.co.za • Presented our method of correcting chirp induced by white light generation. • Pump...

Synthesis, characterization and thermal studies of nickel (II), copper (II), zinc (II) and cadmium (II) complexes with some mixed ligands

International Nuclear Information System (INIS)

Mitra, Samiran; Kundu, Parimal; Singh, Rajkumar Bhubon

1998-01-01

Dichloro-(DCA) and trichloroacetate(TCA) -cyclic ligand morpholine (Morph)/thiomorpholine (Tmorph)/methylmorpholine (Mmorph)/dimethyl-piperazine (DMP) complexes of nickel (II), copper (II), zinc (II) and cadmium (II) with the compositions [Ni(tmorph) 2 (DCA) 2 ], [Ni(tmorph) 2 (TCA) 2 ].2H 2 O, [Cu(DMP) 2 (TCA) 2 ],[ML 2 X 2 ].nH 2 O where M=Zn II or Cd II , L=Morph, DMP or tmorph and X=DCA or TCA and n=O except in case of [Cd (Morph) 2 (TCA) 2 ] where n=1 have been synthesised. Some intermediate complexes have been isolated by temperature arrest technique (pyrolysis) and characterised. Configurational and conformational changes have been studied by elemental analyses, IR and electronic spectra, magnetic moment data (in the case of Ni(II) and Cu(II) complexes) and thermal analysis. E a * , ΔH, and ΔS for the decomposition reaction of these complexes are evaluated and the stability of the complexes with respect to activation energy has also been compared. The linear correlation has been found between E a * and ΔS for the decomposition of the complexes. (author)

Zinc-enriched boutons in rat spinal cord

DEFF Research Database (Denmark)

Schrøder, H D; Danscher, G; Jo, S M

2000-01-01

The rat spinal cord reveals a complex pattern of zinc-enriched (ZEN) boutons. As a result of in vivo exposure to selenide ions, nanosized clusters of zinc selenide are created in places where zinc ions are present, including the zinc-containing synaptic vesicles of ZEN boutons. The clusters can...

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

International Nuclear Information System (INIS)

Salehi, E.; Naderi, Reza; Ramezanzadeh, B.

2017-01-01

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn 2+ cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn 2+ and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

Energy Technology Data Exchange (ETDEWEB)

Salehi, E.; Naderi, Reza [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Ramezanzadeh, B., E-mail: ramezanzadeh@aut.ac.ir [Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654, Tehran (Iran, Islamic Republic of)

2017-02-28

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn{sup 2+} cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn{sup 2+} and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Zinc Binding by Lactic Acid Bacteria

Directory of Open Access Journals (Sweden)

Jasna Mrvčić

2009-01-01

Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

A zinc complex of heparan sulfate destabilises lysozyme and alters its conformation

International Nuclear Information System (INIS)

Hughes, Ashley J.; Hussain, Rohanah; Cosentino, Cesare; Guerrini, Marco; Siligardi, Giuliano; Yates, Edwin A.; Rudd, Timothy R.

2012-01-01

Highlights: ► Zinc–heparan sulfate complex destabilises lysozyme, a model amyloid protein. ► Addition of zinc, without heparan sulfate, stabilises lysozyme. ► Heparan sulfate cation complexes provide alternative protein folding routes. -- Abstract: The naturally occurring anionic cell surface polysaccharide heparan sulfate is involved in key biological activities and is implicated in amyloid formation. Following addition of Zn–heparan sulfate, hen lysozyme, a model amyloid forming protein, resembled β-rich amyloid by far UV circular dichroism (increased β-sheet: +25%), with a significantly reduced melting temperature (from 68 to 58 °C) by fluorescence shift assay. Secondary structure stability of the Zn–heparan sulfate complex with lysozyme was also distinct from that with heparan sulfate, under stronger denaturation conditions using synchrotron radiation circular dichroism. Changing the cation associated with heparan sulfate is sufficient to alter the conformation and stability of complexes formed between heparan sulfate and lysozyme, substantially reducing the stability of the protein. Complexes of heparan sulfate and cations, such as Zn, which are abundant in the brain, may provide alternative folding routes for proteins.

The relative efficiency of zinc carriers on growth and zinc nutrition of corn

International Nuclear Information System (INIS)

Prasad, B.; Sinha, K.

1981-01-01

A comparison of different zinc carriers showed that application of Zn-DTPA, Zn-EDTA, Zn-fulvate and ZnSO 4 significantly increased the dry matter yield and zinc uptake by corn over the control treatment where no zinc was applied. The chelates in particular enhanced to a greater extent the uptake of both native and applied sources than that observed with ZnSO 4 as the zinc carrier. Both the dry matter yield and zinc uptake by corn showed a positive and significant relationship with self-diffusion coefficient of zinc showing thereby that diffusion contributed mainly the supply of Zn from the ambient soil matrix to plant roots. The effectiveness of the chelates varied depending on their capacity to retain Zn in a soluble form in the soil solution. It is evident that zinc nutrition of plants in alkaline and calcareous soils can be more effectively regulated by both synthetic and natural chelates or organic manures which contain substantial amount of complexed zinc. (orig.)

A bio-inspired zinc finger analogue anchored in 2D hexagonal meso-porous silica for room temperature CO_2 activation via a hydrogeno-carbonate route

International Nuclear Information System (INIS)

Doghri, Hanene; Baranova, Elena A.; Albela, Belen; Bonneviot, Laurent; Mongia Said-Zina

2017-01-01

Bio-inspired diethylenetriamine-zinc(II) complexes were anchored into the nano-pores of hexagonal meso-porous MCM41-like silicas targeting a carbamate free and low temperature CO_2 recycling process. A step-by-step approach was adopted to perform an in situ synthesis in order to mimic the zinc finger of carbonic anhydrases, the fastest family of enzymes. In the presence of a surface-masking pattern of TMA"+ ions, some silanol groups were capped using grafted trimethylsilyl functions, TMSgr, (gr for grafted). After removing the masking ions, a tridentate diethylenetriamine ligand was anchored using diethylenetriamine propyl-trimethoxysilane. The so-called DETA_a_n ligands (an for anchored) were partially mono-protonated using either cyclohexane or isopropanol as a solvent. Nonetheless, up to two thirds of them were metallated by Zn(II) ions, leading to the targeted anchored zinc finger mimic [Zn(DETAan)L]+(L = Cl or OH). CO_2 is then adsorbed at room temperature and in humid ambient air by the formation of an intermediate hydrogeno-carbonate-zinc complex. Specific IR signatures at 1330 and 1400 cm"-"1 together with characteristic C 1s and Zn 2p3/2 XPS binding energies at 286.4 and 1024.6 eV advocate for a rather symmetrical bidentate [η"2-CO_3] structural unit in the anchored complex [Zn(DETA_a_n)(η"2-HCO_3"*)]"+, where the Zn(II) ion is most likely penta-coordinated. The internal pH value varied by less than 0.5 depending on the metal reacting with the DETA_a_n ligand and its ability to generate HCO_3"-, due to the buffering effect of surface silanol and amino groups according to the level of protonation of the DETA moieties measured from the N 1s XPS spectra. In contrast to nitrate ions, chloride ions were found to inhibit the formation of hydrogeno-carbonate. (authors)

Zinc binding activity of human metapneumovirus M2-1 protein is indispensable for viral replication and pathogenesis in vivo.

Science.gov (United States)

Cai, Hui; Zhang, Yu; Ma, Yuanmei; Sun, Jing; Liang, Xueya; Li, Jianrong

2015-06-01

Human metapneumovirus (hMPV) is a member of the Pneumovirinae subfamily in the Paramyxoviridae family that causes respiratory tract infections in humans. Unlike members of the Paramyxovirinae subfamily, the polymerase complex of pneumoviruses requires an additional cofactor, the M2-1 protein, which functions as a transcriptional antitermination factor. The M2-1 protein was found to incorporate zinc ions, although the specific role(s) of the zinc binding activity in viral replication and pathogenesis remains unknown. In this study, we found that the third cysteine (C21) and the last histidine (H25) in the zinc binding motif (CCCH) of hMPV M2-1 were essential for zinc binding activity, whereas the first two cysteines (C7 and C15) play only minor or redundant roles in zinc binding. In addition, the zinc binding motif is essential for the oligomerization of M2-1. Subsequently, recombinant hMPVs (rhMPVs) carrying mutations in the zinc binding motif were recovered. Interestingly, rhMPV-C21S and -H25L mutants, which lacked zinc binding activity, had delayed replication in cell culture and were highly attenuated in cotton rats. In contrast, rhMPV-C7S and -C15S strains, which retained 60% of the zinc binding activity, replicated as efficiently as rhMPV in cotton rats. Importantly, rhMPVs that lacked zinc binding activity triggered high levels of neutralizing antibody and provided complete protection against challenge with rhMPV. Taken together, these results demonstrate that zinc binding activity is indispensable for viral replication and pathogenesis in vivo. These results also suggest that inhibition of zinc binding activity may serve as a novel approach to rationally attenuate hMPV and perhaps other pneumoviruses for vaccine purposes. The pneumoviruses include many important human and animal pathogens, such as human respiratory syncytial virus (hRSV), hMPV, bovine RSV, and avian metapneumovirus (aMPV). Among these viruses, hRSV and hMPV are the leading causes of acute

40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN P-97-553...

Foliar uptake of zinc by vascular plants. Radiometric study

International Nuclear Information System (INIS)

Maresova, J.; Remenarova, L.; Hornik, M.; Pipiska, M.; Augustin, J.; Lesny, J.

2012-01-01

The aim of this paper was to obtain quantitative data of foliar uptake kinetics and long distance transport of zinc in tobacco (Nicotiana tabacum L.) and hop (Humulus lupulus L.) plants. Zinc was used as a model of microelement and toxic metal, tobacco and hop as a representatives of agriculturally important plants. A tip of leaf blade was immersed in the solution spiked with 65 ZnCl 2 and foliar uptake and translocation to other parts of the plant grown in nutrient solution was measured by gamma-spectrometry and autoradiography. We found that foliar zinc uptake by both plants is dependent on the initial metal concentration within the range C 0 = 10-100 μmol dm -3 ZnCl 2 . Zinc is immobilized mainly in immersed part of the contact leaf and only 0 = 0.1 mmol dm -3 ZnCl 2 concentrations >2.5 mg/g Zn and 4.8 mg/g Zn (dry wt.) in immersed part of tobacco and hop leaf plant, respectively were found after 5 days of exposure. Low mobility of zinc entering the plant via the leaf surface can be attributed to the immobilization of zinc into Zn-ligand complexes with high stability constants log K at pH 6.0-8.0, such as the reaction products of Zn 2+ ions with citric acid, histidine or phosphates. Zinc can be extracted from dried leaves by the solutions of inorganic salts, carboxylic acids, amino acids and synthetic complexing ligands such as EDTA. Anionic (SDS) and non-ionic (Tween 40) surfactants causes the decrease of the Zn foliar uptake, but not translocation of Zn from the contact leaf area. Obtained data are discussed from the point of view of possible limited efficiency of liquid formulations designed for practical applications as Zn foliar fertilizers. (author)

Controlled Growth of ZnSe Nanocrystals by Tuning Reactivity and Amount of Zinc Precursor

Directory of Open Access Journals (Sweden)

Lai-Jun Zhang

2013-01-01

Full Text Available Zinc selenide (ZnSe nanocrystals were synthesized via a phosphine-free route using the highly reactive alkylamine-H2Se complex as selenium precursor and zinc precursors with different reactivity. The reactivity of zinc precursor was tuned by using three kinds of zinc carboxylates with different alkyl chain lengths, including zinc acetate, zinc nonanoate, and zinc stearate. The effect of the reactivity and the amount of zinc precursor on nucleation and growth of ZnSe nanocrystals were investigated by ultraviolet-visible absorption and photoluminescence spectra. Result indicates that the growth and optical property of the resulting ZnSe nanocrystals are strongly dependent on the alkyl chain length and the amount of the zinc carboxylates and both shorter alkyl chain length, and more amount of zinc carboxylate will lead to faster growth of ZnSe nanocrystals. This allows that the controlled growth and excellent optical property of high-quality ZnSe nanocrystals can be achieved by combining the different reactivity and the used amount of zinc precursor, such as by using stoichiometric and reactive Zn precursor and Se precursor or by using larger amount of more unreactive Zn precursor relative to the highly reactive alkylamine-H2Se complex precursor.

Adipokine zinc-α2-glycoprotein regulated by growth hormone and linked to insulin sensitivity.

Science.gov (United States)

Balaz, Miroslav; Ukropcova, Barbara; Kurdiova, Timea; Gajdosechova, Lucia; Vlcek, Miroslav; Janakova, Zuzana; Fedeles, Jozef; Pura, Mikulas; Gasperikova, Daniela; Smith, Steven R; Tkacova, Ruzena; Klimes, Iwar; Payer, Juraj; Wolfrum, Christian; Ukropec, Jozef

2015-02-01

Hypertrophic obesity is associated with impaired insulin sensitivity and lipid-mobilizing activity of zinc-α2-glycoprotein. Adipose tissue (AT) of growth hormone (GH) -deficient patients is characterized by extreme adipocyte hypertrophy due to defects in AT lipid metabolism. It was hypothesized that zinc-α2-glycoprotein is regulated by GH and mediates some of its beneficial effects in AT. AT from patients with GH deficiency and individuals with obesity-related GH deficit was obtained before and after 5-year and 24-month GH supplementation therapy. GH action was tested in primary human adipocytes. Relationships of GH and zinc-α2-glycoprotein with adipocyte size and insulin sensitivity were evaluated in nondiabetic patients with noncancerous cachexia and hypertrophic obesity. AT in GH-deficient adults displayed a substantial reduction of zinc-α2-glycoprotein. GH therapy normalized AT zinc-α2-glycoprotein. Obesity-related relative GH deficit was associated with almost 80% reduction of zinc-α2-glycoprotein mRNA in AT. GH increased zinc-α2-glycoprotein mRNA in both AT of obese men and primary human adipocytes. Interdependence of GH and zinc-α2-glycoprotein in regulating AT morphology and metabolic phenotype was evident from their relationship with adipocyte size and AT-specific and whole-body insulin sensitivity. The results demonstrate that GH is involved in regulation of AT zinc-α2-glycoprotein; however, the molecular mechanism linking GH and zinc-α2-glycoprotein in AT is yet unknown. © 2014 The Obesity Society.

Single-crystal structure, photophysical characteristics and electroluminescent properties of bis(2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate)zinc

International Nuclear Information System (INIS)

Xu Huixia; Yue, Yan; Wang Hua; Chen Liuqing; Hao Yuying; Xu Bingshe

2012-01-01

In this paper, a zinc (II) complex of Zn 2 (4-tfmBTZ) 4 (4-tfmBTZ=2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate) was reported. Via combination of experimental and theoretical approaches, its molecular structure, photophysical characteristics, electronic structure and electroluminescent properties were investigated. The results indicate that Zn 2 (4-tfmBTZ) 4 exists as five-coordinate geometric structure and two zinc atoms are bridged by oxygen atoms. The intense absorption band was located at 404 nm, which mainly originate from the transition HOMO−1 to LUMO+2. The blue-light emission was observed in tetrahydrofuran solution and thin film. White-light emission with four emission peaks was observed with CIE coordinate of (0.29, 0.33) and a higher CRI of 85.1 by fabricating bilayer device using Zn 2 (4-tfmBTZ) 4 as electron-transport and NPB as hole-transport material. - Highlights: ► The single-crystal and electronic structures of Zn 2 (4-tfmBTZ) 4 . ► The multicolor emission of Zn 2 (4-tfmBTZ) 4 were realized by the simple devices. ► White OLED is achieved with particularly high color rending index (CRI) by the emission of Zn 2 (4-tfmBTZ) 4 .

Welding zinc coated steel with a CO/sub 2/ laser

International Nuclear Information System (INIS)

Akhter, R.; Steen, W.M.

1993-01-01

Welding of zinc coated steel has been studied using a high power CO/sub 2/ laser. This process is of great interest to the manufactures of car, washing machines and other components made from sheet steel and subject to corrosion. The problem associated with the welding of zinc coated steel is the low boiling point of zinc (906C) relative to the high melting point of steel (1500C). The problem is particularly important in lap welding where the zinc layer is between the lapped sheets. Under these conditions the laser 'keyhole' will generate very high vapour pressure in the zinc layer with a consequent severe risk of vapour eruption destroying the continuity of the weld bead. Several techniques are presented for the removal of zinc vapours from the interface between the two sheets. It is shown that this problem solved by suitable gap between the sheets during lap welding. Hence full penetration welds without deterioration of the weld bead can be obtained. A theory has been presented which predicted an exact gap size needed to exhaust the zinc vapour. The gap depends upon the welding speed, zinc coating thickness and thickness of the sheet. The theory predicts the weld quality satisfactorily. (author)

Biologically-transformed zinc and its availability for bioaccumulation by marine organisms

International Nuclear Information System (INIS)

Fowler, S.W.; Heyraud, M.

1980-01-01

Zinc which occurs in sea water as a trace element exists in several different stable or meta-stable forms in the aquatic environment. One of them is ''complexed'' form which is relatively stable. Radiotracer studies were carried out to investigate the mode of formation of the complexed zinc fraction and to find whether this fraction once formed by biological means is available for accumulation by marine biota. Sea water solutions used in the experiments were filtered through double 0.45 μm Millipore filters. Chelex-100 resin which quantitatively removes zinc from sea water was used to measure the relative degree of binding of different species of 65 Zn formed by association with marine organisms. 65 Zn in exometabolites from living animals represented in this case by shrimp (Lymata seticaudata), influence of organic detritus represented in this case by dead shrimp on the conversion of different forms of zinc and bioavailability of biologically processed 65 Zn were studied. It was observed that: (1) living and dead marine animals can produce a soluble species of complexed, possibly organically bound, zinc, (2) uptake of this species is reduced relative to that of the ionic form indicating that zinc which has passed through biological cycles may be less available for bioaccumulation than zinc which has been directly introduced into the marine environment in inorganic forms. (M.G.B.)

Protamines and spermatogenesis in Drosophila and Homo sapiens : A comparative analysis.

Science.gov (United States)

Kanippayoor, Rachelle L; Alpern, Joshua H M; Moehring, Amanda J

2013-04-01

The production of mature and motile sperm is a detailed process that utilizes many molecular players to ensure the faithful execution of spermatogenesis. In most species that have been examined, spermatogenesis begins with a single cell that undergoes dramatic transformation, culminating with the hypercompaction of DNA into the sperm head by replacing histones with protamines. Precise execution of the stages of spermatogenesis results in the production of motile sperm. While comparative analyses have been used to identify similarities and differences in spermatogenesis between species, the focus has primarily been on vertebrate spermatogenesis, particularly mammals. To understand the evolutionary basis of spermatogenetic variation, however, a more comprehensive comparison is needed. In this review, we examine spermatogenesis and the final packaging of DNA into the sperm head in the insect Drosophila melanogaster and compare it to spermatogenesis in Homo sapiens.

Various ways to reduce zinc oxide levels in S-SBR rubber compounds

NARCIS (Netherlands)

Heideman, G.; Noordermeer, Jacobus W.M.; Datta, Rabin; van Baarle, Ben

2007-01-01

Because of environmental concerns, the zinc content in rubber compounds has come under scrutiny. The research described in this article encompasses zinc-oxide, various zinc-complexes and alternative metal oxides as activators for sulphur vulcanisation. Regarding zinc complexes, it can be concluded

Conservation, diversification and expansion of C2H2 zinc finger proteins in the Arabidopsis thaliana genome

Directory of Open Access Journals (Sweden)

Böhm Siegfried

2004-07-01

Full Text Available Background The classical C2H2 zinc finger domain is involved in a wide range of functions and can bind to DNA, RNA and proteins. The comparison of zinc finger proteins in several eukaryotes has shown that there is a lot of lineage specific diversification and expansion. Although the number of characterized plant proteins that carry the classical C2H2 zinc finger motifs is growing, a systematic classification and analysis of a plant genome zinc finger gene set is lacking. Results We found through in silico analysis 176 zinc finger proteins in Arabidopsis thaliana that hence constitute the most abundant family of putative transcriptional regulators in this plant. Only a minority of 33 A. thaliana zinc finger proteins are conserved in other eukaryotes. In contrast, the majority of these proteins (81% are plant specific. They are derived from extensive duplication events and form expanded families. We assigned the proteins to different subgroups and families and focused specifically on the two largest and evolutionarily youngest families (A1 and C1 that are suggested to be primarily involved in transcriptional regulation. The newly defined family A1 (24 members comprises proteins with tandemly arranged zinc finger domains. Family C1 (64 members, earlier described as the EPF-family in Petunia, comprises proteins with one isolated or two to five dispersed fingers and a mostly invariant QALGGH motif in the zinc finger helices. Based on the amino acid pattern in these helices we could describe five different signature sequences prevalent in C1 zinc finger domains. We also found a number of non-finger domains that are conserved in these families. Conclusions Our analysis of the few evolutionarily conserved zinc finger proteins of A. thaliana suggests that most of them could be involved in ancient biological processes like RNA metabolism and chromatin-remodeling. In contrast, the majority of the unique A. thaliana zinc finger proteins are known or

High-throughput automated parallel evaluation of zinc-based catalysts for the copolymerization of CHO and CO2 to polycarbonates

NARCIS (Netherlands)

Meerendonk, van W.J.; Duchateau, R.; Koning, C.E.; Gruter, G.J.M.

2004-01-01

Copolymn. of CO2 and oxiranes using a high-pressure autoclave typically allows one expt. per reactor per day. A high-throughput parallel setup was developed and validated for the copolymn. of CO2 and cyclohxene oxide (CHO) with two b-diiminato zinc complexes. The catalyst activity is affected by

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

Directory of Open Access Journals (Sweden)

Rafael Simó

Full Text Available Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes and in vivo (C57BL6/mice experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

Science.gov (United States)

Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight

Synthesis, crystal structure and DFT studies of a Zinc(II) complex of 1,3-diaminopropane (Dap), [Zn(Dap)(NCS)2][Zn(Dap)(NCS)2]n. The additional stabilizing role of S⋯π chalcogen bond

Science.gov (United States)

Alotaibi, Mshari A.; Alharthi, Abdulrahman I.; Zierkiewicz, Wiktor; Akhtar, Muhammad; Tahir, Muhammad Nawaz; Mazhar, Muhammad; Isab, Anvarhusein A.; Ahmad, Saeed

2017-04-01

A zinc(II) complex of 1,3-diaminopropane (Dap), [Zn(Dap)(NCS)2][Zn(Dap)(NCS)2]n (1) has been prepared and characterized by elemental analysis, IR, 1H &13C NMR spectroscopy, and its crystal structure was determined by X-ray crystallography. The crystal structure of 1 consists of two types of molecules, a discrete monomer and a polymeric one. In the monomeric unit, the zinc atom is bound to one terminal Dap molecule and to two N-bound thiocyanate ions, while in the polymeric unit, Dap acts as a bridging ligand forming a linear chain. The Zn(II) ions in both assume a slightly distorted tetrahedral geometry. The structures of two systems: the [Zn(Dap)(NCS)2][Zn(Dap)(NCS)2]3 complex as a model of 1 and [Zn(Dap)(NCS)2]4 as a simple polymeric structure were optimized with the B3LYP-D3 method. The DFT results support that the experimentally determined structure (1) is more stable in comparison to a simple polymeric structure, [Zn(Dap)(NCS)2]n (2). The interaction energies (ΔE) for NCS anions obtained by B3LYP-D3 method are about -145 kcal mol-1, while the calculated ΔE values for neutral organic ligands are about twice smaller. The X-ray structure of 1 shows that the complex is stabilized mainly by hydrogen bonds. We also found that weak chalcogen bonds play an additional role in stabilization of compound 1. Some of the intermolecular S⋯N distances are smaller than the sum of the van der Waals radii of the corresponding atoms. To the best of our knowledge, this is the first study that shows the structure where the trivalent sulfur is involved in formation of a S⋯π chalcogen bond. The NBO and NCI analyses confirm the existence of this kind of interactions.

Coprecipitation synthesis of zinc ferrit (FE 2 O 3 /ZNO) nanoparticles ...

African Journals Online (AJOL)

Zinc ferrite (Fe2O3/ZnO) nanocomposites were successfully synthesized by simple co-precipitation method via iron (III) nitrate 9-hydrate (Fe(NO3)3.9H2O) and zinc nitrate hexahydrate (Zn(NO3)2.6H2O) as precursor in the presence of cetyltrimethylammonium bromide (CTAB) surfactant. The samples were characterized by ...

Synthesis, characterization and anticancer activity of kaempferol-zinc(II) complex.

Science.gov (United States)

Tu, Lv-Ying; Pi, Jiang; Jin, Hua; Cai, Ji-Ye; Deng, Sui-Ping

2016-06-01

According to the previous studies, the anticancer activity of flavonoids could be enhanced when they are coordinated with transition metal ions. In this work, kaempferol-zinc(II) complex (kaempferol-Zn) was synthesized and its chemical properties were characterized by UV-VIS, FT-IR, (1)H NMR, elemental analysis, electrospray mass spectrometry (ES-MS) and fluorescence spectroscopy, which showed that the synthesized complex was coordinated with a Zn(II) ion via the 3-OH and 4-oxo groups. The anticancer effects of kaempferol-Zn and free kaempferol on human oesophageal cancer cell line (EC9706) were compared. MTT results demonstrated that the killing effect of kaempferol-Zn was two times higher than that of free kaempferol. Atomic force microscopy (AFM) showed the morphological and ultrastructural changes of cellular membrane induced by kaempferol-Zn at subcellular or nanometer level. Moreover, flow cytometric analysis indicated that kaempferol-Zn could induce apoptosis in EC9706 cells by regulating intracellular calcium ions. Collectively, all the data showed that kaempferol-Zn might be served as a kind of potential anticancer agent. Copyright © 2016 Elsevier Ltd. All rights reserved.

The study and microstructure analysis of zinc and zinc oxide

Directory of Open Access Journals (Sweden)

N. Luptáková

2015-01-01

Full Text Available The given paper is closely connected with the process of the manufacturing of ZnO. The purity of the metal zinc has crucial influence on the quality of ZnO. ZnO can be produced by pyrometallurgical combustion of zinc and hard zinc. But this mentioned method of preparation leads to the creation of the enormous amount of waste including chemical complexes. On the basis of the occurrence of the residual content of other elements, it is possible to make prediction about the material behavior in the metallographic process. The input and finally materials were investigated and this investigation was done from the aspect of structural and chemical composition of the materials.

Cobalt(II), nickel(II), copper(II), and zinc(II) complexes with [3(5)]adamanzane, 1,5,9,13-tetraazabicyclo[7.7.3]nonadecane and [(2.3)(2).2(1)]adamanzane, 1,5,9,12-tetraazabicyclo[7.5.2]hexadecane

DEFF Research Database (Denmark)

Broge, Louise; Pretzmann, Ulla; Jensen, Nicolai

2001-01-01

) and of three cobalt(II), four nickel(II), one copper(II), and two zinc(II) complexes with [3(5)]adamanzane. For nine of these compounds (2-8, 10b, and 12) the single-crystal X-ray structures were determined. The coordination geometry around the metal ion is square pyramidal in [Cu([(2.3)(2).2(1)]adz)Br]ClO4 (2......) and trigonal bipyramidal in the isostructural structures [Cu([3(5)]adz)Br]Br (3), [Ni-([3(5)]adz)Cl]Cl (5), [Ni([3(5)]adz)Br]Br (6), and [Co([3(5)]adz)Cl]Cl (8). In [Ni([3(5)]adz)(NO3)]NO3 (4) and [Ni([3(5)]-adz)(ClO4)]ClO4 (7) the coordination geometry around nickel(II) is a distorted octahedron...... with the inorganic ligands at cis positions. The coordination polyhedron around the metal ion in [Co([3(5)]adz)][ZnCl4] (10b) and [Zn([3(5)]adz)][ZnCl4] (12) is a slightly distorted tetrahedron. Anation equilibrium constants were determined spectrophotometrically for complexes 2-6 at 25 and 40 degreesC and fall...

Synthesis, photophysical and photochemical properties of zinc phthalocyanines bearing fluoro-functionalized substituents

International Nuclear Information System (INIS)

Aktaş, Ayşe; Pişkin, Mehmet; Durmuş, Mahmut; Bıyıklıoğlu, Zekeriya

2014-01-01

In this study, the synthesis of phthalonitrile derivatives bearing fluoro-functionalized groups and their peripherally-tetra substituted zinc phthalocyanine complexes were reported. The phthalonitrile derivatives 2a–5a were prepared by nucleophilic substitution of 4-nitrophthalonitrile with 2-[3-(trifluoromethyl)phenoxy]ethanol, 2-{2-[3-(trifluoromethyl) phenoxy]ethoxy}ethanol, 2-(2,3,5,6-tetrafluorophenoxy)ethanol, 2-[2-(2,3,5,6-tetrafluorophenoxy)ethoxy]ethanol, respectively. Zinc phthalocyanines bearing fluoro-functionalized groups (2b–5b) were obtained from the corresponding phthalonitrile derivatives. The newly synthesized phthalocyanines displayed good solubility in organic solvents such as chloroform (CHCl 3 ), dichloromethane (DCM), tetrahydrofuran (THF), toluene, dimethylformamide (DMF) and dimethylsulfoxide (DMSO). On the other hand, the singlet oxygen, photodegradation, fluorescence quantum yields and fluorescence lifetime of these complexes were determined in DMSO. The effects of the substitution with fluoro-functionalized groups on these parameters were also compared. -- Highlights: • Synthesis of peripherally substituted zinc phthalocyanines. • Photophysical and photochemical properties in DMSO for phthalocyanines. • Photodynamic therapy studies

Synthesis, photophysical and photochemical properties of zinc phthalocyanines bearing fluoro-functionalized substituents

Energy Technology Data Exchange (ETDEWEB)

Aktaş, Ayşe [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Pişkin, Mehmet [Marmara University, Faculty of Art and Science, Department of Chemistry, 34722 Kadikoy-Istanbul (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze 41400, Kocaeli (Turkey); Bıyıklıoğlu, Zekeriya, E-mail: zekeriya_61@yahoo.com [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2014-01-15

In this study, the synthesis of phthalonitrile derivatives bearing fluoro-functionalized groups and their peripherally-tetra substituted zinc phthalocyanine complexes were reported. The phthalonitrile derivatives 2a–5a were prepared by nucleophilic substitution of 4-nitrophthalonitrile with 2-[3-(trifluoromethyl)phenoxy]ethanol, 2-{2-[3-(trifluoromethyl) phenoxy]ethoxy}ethanol, 2-(2,3,5,6-tetrafluorophenoxy)ethanol, 2-[2-(2,3,5,6-tetrafluorophenoxy)ethoxy]ethanol, respectively. Zinc phthalocyanines bearing fluoro-functionalized groups (2b–5b) were obtained from the corresponding phthalonitrile derivatives. The newly synthesized phthalocyanines displayed good solubility in organic solvents such as chloroform (CHCl{sub 3}), dichloromethane (DCM), tetrahydrofuran (THF), toluene, dimethylformamide (DMF) and dimethylsulfoxide (DMSO). On the other hand, the singlet oxygen, photodegradation, fluorescence quantum yields and fluorescence lifetime of these complexes were determined in DMSO. The effects of the substitution with fluoro-functionalized groups on these parameters were also compared. -- Highlights: • Synthesis of peripherally substituted zinc phthalocyanines. • Photophysical and photochemical properties in DMSO for phthalocyanines. • Photodynamic therapy studies.

Effects of zinc supplementation on Shiga toxin 2e-producing Escherichia coli in vitro.

Science.gov (United States)

Uemura, Ryoko; Katsuge, Tomoko; Sasaki, Yosuke; Goto, Shinya; Sueyoshi, Masuo

2017-10-07

Swine edema disease is caused by Shiga toxin (Stx) 2e-producing Escherichia coli (STEC). Addition of highly concentrated zinc formulations to feed has been used to treat and prevent the disease, but the mechanism of the beneficial effect is unknown. The purpose of the present study was to investigate the effects of highly concentrated zinc formulations on bacterial growth, hemolysin production, and an Stx2e release by STEC in vitro. STEC strain MVH269 isolated from a piglet with edema disease was cultured with zinc oxide (ZnO) or with zinc carbonate (ZnCO 3 ), each at up to 3,000 ppm. There was no effect of zinc addition on bacterial growth. Nonetheless, the cytotoxic activity of Stx2e released into the supernatant was significantly attenuated in the zinc-supplemented media compared to that in the control, with the 50% cytotoxic dose values of 163.2 ± 12.7, 211.6 ± 33.1 and 659.9 ± 84.2 after 24 hr of growth in the presence of ZnO, ZnCO 3 , or no supplemental zinc, respectively. The hemolytic zones around colonies grown on sheep blood agar supplemented with zinc were significantly smaller than those of colonies grown on control agar. Similarly, hemoglobin absorbance after exposure to the supernatants of STEC cultures incubated in sheep blood broth supplemented with zinc was significantly lower than that resulting from exposure to the control supernatant. These in vitro findings indicated that zinc formulations directly impair the factors associated with the virulence of STEC, suggesting a mechanism by which zinc supplementation prevents swine edema disease.

Single-crystal structure, photophysical characteristics and electroluminescent properties of bis(2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate)zinc

Energy Technology Data Exchange (ETDEWEB)

Xu Huixia, E-mail: xuhuixia0824@163.com [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Yue, Yan [Department of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Wang Hua [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Chen Liuqing [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Hao Yuying [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Department of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Xu Bingshe [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

2012-04-15

In this paper, a zinc (II) complex of Zn{sub 2}(4-tfmBTZ){sub 4} (4-tfmBTZ=2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate) was reported. Via combination of experimental and theoretical approaches, its molecular structure, photophysical characteristics, electronic structure and electroluminescent properties were investigated. The results indicate that Zn{sub 2}(4-tfmBTZ){sub 4} exists as five-coordinate geometric structure and two zinc atoms are bridged by oxygen atoms. The intense absorption band was located at 404 nm, which mainly originate from the transition HOMO-1 to LUMO+2. The blue-light emission was observed in tetrahydrofuran solution and thin film. White-light emission with four emission peaks was observed with CIE coordinate of (0.29, 0.33) and a higher CRI of 85.1 by fabricating bilayer device using Zn{sub 2}(4-tfmBTZ){sub 4} as electron-transport and NPB as hole-transport material. - Highlights: Black-Right-Pointing-Pointer The single-crystal and electronic structures of Zn{sub 2}(4-tfmBTZ){sub 4}. Black-Right-Pointing-Pointer The multicolor emission of Zn{sub 2}(4-tfmBTZ){sub 4} were realized by the simple devices. Black-Right-Pointing-Pointer White OLED is achieved with particularly high color rending index (CRI) by the emission of Zn{sub 2}(4-tfmBTZ){sub 4}.

The Silver Oxide-Zinc Alkaline Primary Cell. Part 2. Effects of Various Types of Negative Electrodes on Cell Characteristics

National Research Council Canada - National Science Library

Shepherd, C. M

1951-01-01

... (generally a potassium hydroxide solution). During discharge, the silver peroxide in the positive electrode is reduced to metallic silver and the metallic zinc in the negative electrode is oxidized either to zinc oxide or to a complex zincate ion...

Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes

Science.gov (United States)

Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M. Arif

2016-05-01

We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica.

Oxidation and Condensation of Zinc Fume From Zn-CO2-CO-H2O Streams Relevant to Steelmaking Off-Gas Systems

International Nuclear Information System (INIS)

Bronson, Tyler Mark; Ma, Naiyang; Zhu, Liang Zhu; Sohn, Hong Yong

2017-01-01

Here the objective of this research was to study the condensation of zinc vapor to metallic zinc and zinc oxide solid under varying environments to investigate the feasibility of in-process separation of zinc from steelmaking off-gas dusts. Water vapor content, temperature, degree of cooling, gas composition, and initial zinc partial pressure were varied to simulate the possible conditions that can occur within steelmaking off-gas systems, limited to Zn-CO 2 -CO-H 2 O gas compositions. The temperature of deposition and the effect of rapidly quenching the gas were specifically studied. A homogeneous nucleation model for applicable experiments was applied to the analysis of the experimental data. It was determined that under the experimental conditions, oxidation of zinc vapor by H 2 O or CO 2 does not occur above 1108 K (835 °C) even for highly oxidizing streams (CO 2 /CO = 40/7). Rate expressions that correlate CO 2 and H 2 O oxidation rates to gas composition, partial pressure of water vapor, temperature, and zinc partial pressure were determined to be as follows: Rate ((mol)/(m 2 s)) = 406 exp ((−50.2kJ/mol)/(RT)) (pZnpCO 2 − PCO/K eq CO 2 ) ((mol)/(m 2 xs)) Rate (((mol)/(m 2 s))) = 32.9 exp (((−13.7kJ/mol)/(RT))) (pZnPH 2 O − PH 2 /K eq H 2 O) ((mol)/(m 2 xs)). It was proven that a rapid cooling rate (500 K/s) significantly increases the ratio of metallic zinc to zinc oxide as opposed to a slow cooling rate (250 K/s). SEM analysis found evidence of heterogeneous growth of ZnO as well as of homogeneous formation of metallic zinc. The homogeneous nucleation model fit well with experiments where only metallic zinc deposited. An expanded model with rates of oxidation by CO 2 and H 2 O as shown was combined with the homogenous nucleation model and then compared with experimental data. The calculated results based on the model gave a reasonable fit to the measured data. For the conditions used in this study, the rate equations for the oxidation of zinc by

Synthesis, thermal, spectral and biological properties of zinc(II) 4-hydroxybenzoate complexes

Czech Academy of Sciences Publication Activity Database

Homzová, K.; Györyová, K.; Bujdošová, Z.; Hudecová, D.; Ganajová, M.; Vargová, Z.; Kovářová, Jana

2014-01-01

Roč. 116, č. 1 (2014), s. 77-91 ISSN 1388-6150 Institutional support: RVO:61389013 Keywords : zinc * 4-hydroxybenzoate * thermal Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.042, year: 2014

Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

Directory of Open Access Journals (Sweden)

Christopher Kremer

2014-04-01

Full Text Available Herein, we present three new 2,2’-bipyridines that carry two β-cyclodextrin moieties in different substitution patterns. When coordinated by zinc(II or copper(I ions (or their complexes, these compounds undergo conformational changes and switch between “open” and “closed” forms and thereby bringing together or separating the cyclodextrin moieties from each other.

Stability constants of glutarate complexes of copper(II), zinc(II), cobalt(II) and uranyl(II) by paper electrophoresis

International Nuclear Information System (INIS)

Singh, R.K.P.; Yadava, J.R.; Yadava, K.L.

1981-01-01

Stability constants of Copper(II), Zinc(II), Cobalt(II) and Uranyl(II) glutarates have been determined by paper electrophoresis. Glutaric acid (0.005 mol dmsup(-3)) was added to the background electrolyte : 0.1 mol dmsup(-3) HClO 4 . The proportions of (CH 2 ) 3 COOH COO - and (CH 2 ) 3 C 2 O 4 2- were varied by changing the pH of the electrolyte. These anions yielded the complexes Cu(CH 2 ) 3 C 2 O 4 , [Zn(CH 2 ) 3 COOH COO] + [Co(CH 2 ) 3 COOH COO] + and UO 2 (CH 2 ) 3 C 2 O 4 whose stability constants are found to be 10sup(3.9), 10sup(2.9), 10sup(2.7) and 10sup(13.5) respectively. (author)

Adsorption and photocatalytic properties of transition metal Zinc(II) complex based on 5-(4-(tetrazol-5-yl)phenyl)isophthalic acid

Science.gov (United States)

Qiao, Yu; Ren, Shan-Shan; Liu, Li-Hui; Guan, Wei-Sheng; Li, Zhi-Min; Che, Guang-Bo; Liu, Chun-Bo; Wang, Yan-Yan; Wang, Qing-Wei; Li, Xiu-Ying; Zhu, En-Wei

2018-06-01

A new coordination polymeric zinc(II) complex, namely, [Zn2(L)(H2O)3]n·nNO3(1), (H3L = 5-(4-(tetrazol-5-yl)phenyl)isophthalic acid) has been synthesized under solvothermal conditions and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction analysis and powder X-ray diffraction. Complex 1 exhibits a three-dimensional structure with a Schläfli symbol of 44•69•82 topologies, constructed from two crystallographically independent five and six coordinated mode with metal center and connected H3L ligands. The complex has good thermal stability and excellent photoluminescent property. Furthermore, by comparing the photoluminescent and photocatalytic mutation results induced by interconversion of metal ions, we confirm that the properties mutation induced by metal ions is much controllable and obvious. In addition, the complex exhibits significantly enhanced photocatalytic activity for methylene blue (MB) under UV light irradiation (λ < 400 nm), and the degradation rate could reach 75% in 80 min. Meanwhile trapping experiments indicated that the •O2- and h+ are the main activated species.

Single crystal X-ray structure of the artists' pigment zinc yellow

Science.gov (United States)

Simonsen, Kim Pilkjær; Christiansen, Marie Bitsch; Vinum, Morten Gotthold; Sanyova, Jana; Bendix, Jesper

2017-08-01

The artists' pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO4·K2O·3H2O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography determined the structure of zinc yellow as KZn2(CrO4)2(H2O)(OH) or as KZn2(CrO4)2(H3O2) emphasizing the μ-H3O2- moiety. Notably, the zinc yellow is isostructural to the recently structurally characterized cadmium analog and both belong to the natrochalcite structure type.

Dietary phytate, zinc and hidden zinc deficiency.

Science.gov (United States)

Sandstead, Harold H; Freeland-Graves, Jeanne H

2014-10-01

Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

Science.gov (United States)

Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

2016-10-01

With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes.

Science.gov (United States)

Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M Arif

2016-05-15

We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica. Copyright © 2016 Elsevier B.V. All rights reserved.

Beneficiation studies on low-grade complex polymetallic lead-zinc ore of duddar (lasbela) Balochistan, Pakistan

International Nuclear Information System (INIS)

Bhatti, M.R.; Kazim, K.R.; Mehmood, R.; Akram, A.

2016-01-01

A bench-scale beneficiation study was performed on low-grade complex lead-zinc ore of Duddar area, District Lasbela, Balochistan Province, Pakistan. The polymetallic ore under investigation contains galena and sphalerite as valuable minerals of lead and zinc. The low-grade ore was upgraded by selective sequential froth flotation technology to recover both minerals. An effort was made to investigate the effect of important variables on grade and recovery of concentrates and to design the process flow sheet. Different parameters of flotation process such as particle size of the feed, pH and % solids of the pulp, speed of impeller, type of reagents (collectors, frothers, regulators and modifiers) and their quantities, conditioning time and flotation time were optimized to attain maximum grade and recovery of respective concentrates. The rougher concentrates obtained were subjected to one regrinding and two cleaning operations to achieve higher-grade concentrates of both metals. Bench-scale flotation tests show that it is possible to obtain a lead concentrate assaying 65.24% Pb with recovery rate of 81.32% and a zinc concentrate containing 55.63% Zn content with recovery rate of 80.28%. Both the concentrates meet the specifications required for metallurgical and chemical grades. (author)

Excretion of Different Forms of Zinc by the prawn Palaemon serratus (Pennant)

International Nuclear Information System (INIS)

Small, L.F.; Keckes, S.; Fowler, S.W.

1976-01-01

Freshly collected speciments of Palaemon serratus from the upper Adriatic Sea were used to determine excretion rates of zinc in ''zinc-free'' water by anodic stripping polarographic techniques. Weight-specific excretion of total zinc varied reciprocally with body weight apparently in a log-log relationship. Weight-specific excretion of ionic-particulate zinc appeared greatest in short term (1-3 hr) experiments, while weight specific excretion of complexed zinc appeared greatest in longer term (4-5 hr) experiments; however, we cannot exclude the possibility that ionic-particulate zinc and dissolved organic compounds were excreted separately and subsequently combined in the water to yield zinc complex. (author)

Excretion of different forms of zinc by the prawn Palaemon serratus (Pennant)

International Nuclear Information System (INIS)

Small, L.F.; Keckes, S.; Fowler, S.W.

1974-01-01

Freshly collected specimens of Palaemon serratus from the upper Adriatic Sea were used to determine excretion rates of zinc in zinc-free water by anodic stripping polarographic techniques. Weight-specific excretion of total zinc varied reciprocally with body weight, apparently in a log--log relationship. Weight-specific excretion of ionic-particulate zinc appeared greatest in short term (1 to 3 hr) experiments, while weight-specific excretion of complexed zinc appeared greatest in longer term (4 to 5 hr) experiments; however, we cannot exclude the possibility that ionic-particulate zinc and dissolved organic compounds were excreted separately and subsequently combined in the water to yield zinc complex. (auth)

Reactivation in vitro of zinc-requiring apo-enzymes by rat liver zinc-thionein

OpenAIRE

Udom, Albert O.; Brady, Frank O.

1980-01-01

The ability of rat liver zinc-thionein to donate its metal to the apo-enzymes of the zinc enzymes horse liver alcohol dehydrogenase, yeast aldolase, thermolysin, Escherichia coli alkaline phosphatase and bovine erythrocyte carbonic anhydrase was investigated. Zinc-thionein was as good as, or better than, ZnSO4, Zn(CH3CO2)2 or Zn(NO3)2 in donating its zinc to these apo-enzymes. Apo-(alcohol dehydrogenase) could not be reactivated by zinc salts or by zinc-thionein. Incubation of the other apo-e...

Association between zinc nutritional status and glycemic control in individuals with well-controlled type-2 diabetes.

Science.gov (United States)

Perez, Alvaro; Rojas, Pamela; Carrasco, Fernando; Basfi-Fer, Karen; Perez-Bravo, Francisco; Codoceo, Juana; Inostroza, Jorge; Galgani, Jose E; Gilmore, L Anne; Ruz, Manuel

2018-03-26

Interest in healthy properties of food and nutrients as co-adjuvant in type-2 diabetes therapy has increased in recent years. Zinc supplementation trials have shown improvements in glycemic control in these patients, although it seems dependent on zinc status of the individuals. The objective of this study was to evaluate the relationship between zinc nutritional status and glucose homeostasis in patients with type-2 diabetes. Eighty patients with well controlled type-2 diabetes were recruited and clinical, anthropometric and dietary evaluations were performed. One week after, insulin sensitivity and beta cell function were assessed by a modified Frequently Sampled Intravenous Glucose Tolerance Test. Zinc status was assessed by plasma zinc and the size of rapidly Exchangeable Zinc Pool (EZP); zinc intake was also determined. Glucagon concentration was evaluated in a subsample of 36 patients. Patients presented a normal zinc status although zinc intake was lower than recommended. Overall, no associations were observed between zinc status and glycemic control markers. Nevertheless, positive correlations were observed between EZP and fasting insulin concentration (ρ = 0.393, p = 0.021) and HOMA-IR (ρ = 0.386, p = 0.024) in women, and between plasma zinc concentration and HbA1c (ρ = 0.342, p = 0.020) in men. No significant associations were found between zinc status and glycemic control parameters in patients with well-controlled type 2 diabetes and normal zinc status, although low-degree gender-dependent associations were observed. Further research is required to assess the role of zinc status in zinc deficient patients. Copyright © 2018 Elsevier GmbH. All rights reserved.

Evolution of the zinc compound nanostructures in zinc acetate single-source solution

International Nuclear Information System (INIS)

Wang Ying; Li Yinhua; Zhou Zhengzhi; Zu Xihong; Deng Yulin

2011-01-01

A series of nanostructured zinc compounds with different nanostructures such as nanobelts, flake-like, flower-like, and twinning crystals was synthesized using zinc acetate (Zn(Ac) 2 ) as a single-source. The evolution of the zinc compounds from layered basic zinc acetate (LBZA) to bilayered basic zinc acetate (BLBZA) and twinned ZnO nano/microcrystal was studied. The low-angle X-ray diffraction spectra indicate the layered spacing is 1.34 and 2.1 nm for LBZA and BLBZA, respectively. The Fourier transform infrared (FTIR) spectra results confirmed that the bonding force of acetate anion with zinc cations decreases with the phase transformation from Zn(Ac) 2 to BLBZA, and finally to LBZA. The OH − groups gradually replaced the acetate groups coordinated to the matrix zinc cation, and the acetate groups were released completely. Finally, the Zn(OH) 2 and ZnO were formed at high temperature. The conversion process from Zn(Ac) 2 to ZnO with release of acetate anions can be described as Zn(Ac) 2 → BLBZA → LBZA → Zn(OH) 2 → ZnO.

Taurine zinc solid dispersions enhance bile-incubated L02 cell viability and improve liver function by inhibiting ERK2 and JNK phosphorylation during cholestasis

International Nuclear Information System (INIS)

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lai, Xiaofang; Xu, Donghui

2016-01-01

Highlights: • Taurine zinc SDs could prevent the bile-induced reduction in L02 cell viability. • Taurine zinc SDs can prevent cholestatic liver injury. • Taurine zinc SDs can inhibit BDL-induced hepatocyte apoptosis. • Taurine zinc SDs shows the cholesterol-lowering effects on cholestasis. • Taurine zinc SDs may suppress inflammation via dampening JNK phosphorylation. - Abstract: Dietary intakes of taurine and zinc are associated with decreased risk of liver disease. In this study, solid dispersions (SDs) of a taurine zinc complex on hepatic injury were examined in vitro using the immortalized human hepatocyte cell line L02 and in a rat model of bile duct ligation. Sham-operated and bile duct ligated Sprague-Dawley rats were treated with the vehicle alone or taurine zinc (40, 80, 160 mg/kg) for 17 days. Bile duct ligation significantly increased blood lipid levels, and promoted hepatocyte apoptosis, inflammation and compensatory biliary proliferation. In vitro, incubation with bile significantly reduced L02 cell viability; this effect was significantly attenuated by pretreatment with SP600125 (a JNK inhibitor) and enhanced when co-incubated with taurine zinc SDs. In vivo, administration of taurine zinc SDs decreased serum alanine aminotransferase and aspartate aminotransferase activities in a dose-dependent manner and attenuated the increases in serum total bilirubin, total cholesterol and low density lipoprotein cholesterol levels after bile duct ligation. Additionally, taurine zinc SDs downregulated the expression of interleukin-1β and inhibited the phosphorylation of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase2 (ERK2) in the liver after bile duct ligation. Moreover, taurine zinc SDs had more potent blood lipid regulatory and anti-apoptotic effects than the physical mixture of taurine and zinc acetate. Therefore, we speculate that taurine zinc SDs protect liver function at least in part via a mechanism linked to reduce

Synthesis, thermal, spectral, and biological properties of zinc(II) 4-aminobenzoate complexes

Czech Academy of Sciences Publication Activity Database

Homzová, K.; Györyová, K.; Hudecová, D.; Koman, M.; Melník, M.; Kovářová, Jana

2017-01-01

Roč. 129, č. 2 (2017), s. 1065-1082 ISSN 1388-6150 Institutional support: RVO:61389013 Keywords : zinc(II) 4-aminobenzoate * thermal * spectral Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.953, year: 2016

Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

Science.gov (United States)

Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

2016-04-25

Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

Mutations in the putative zinc-binding motif of UL52 demonstrate a complex interdependence between the UL5 and UL52 subunits of the human herpes simplex virus type 1 helicase/primase complex.

Science.gov (United States)

Chen, Yan; Carrington-Lawrence, Stacy D; Bai, Ping; Weller, Sandra K

2005-07-01

Herpes simplex virus type 1 (HSV-1) encodes a heterotrimeric helicase-primase (UL5/8/52) complex. UL5 contains seven motifs found in helicase superfamily 1, and UL52 contains conserved motifs found in primases. The contributions of each subunit to the biochemical activities of the complex, however, remain unclear. We have previously demonstrated that a mutation in the putative zinc finger at UL52 C terminus abrogates not only primase but also ATPase, helicase, and DNA-binding activities of a UL5/UL52 subcomplex, indicating a complex interdependence between the two subunits. To test this hypothesis and to further investigate the role of the zinc finger in the enzymatic activities of the helicase-primase, a series of mutations were constructed in this motif. They differed in their ability to complement a UL52 null virus: totally defective, partial complementation, and potentiating. In this study, four of these mutants were studied biochemically after expression and purification from insect cells infected with recombinant baculoviruses. All mutants show greatly reduced primase activity. Complementation-defective mutants exhibited severe defects in ATPase, helicase, and DNA-binding activities. Partially complementing mutants displayed intermediate levels of these activities, except that one showed a wild-type level of helicase activity. These data suggest that the UL52 zinc finger motif plays an important role in the activities of the helicase-primase complex. The observation that mutations in UL52 affected helicase, ATPase, and DNA-binding activities indicates that UL52 binding to DNA via the zinc finger may be necessary for loading UL5. Alternatively, UL5 and UL52 may share a DNA-binding interface.

Taurine zinc solid dispersions enhance bile-incubated L02 cell viability and improve liver function by inhibiting ERK2 and JNK phosphorylation during cholestasis.

Science.gov (United States)

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lai, Xiaofang; Xu, Donghui

2016-07-29

Dietary intakes of taurine and zinc are associated with decreased risk of liver disease. In this study, solid dispersions (SDs) of a taurine zinc complex on hepatic injury were examined in vitro using the immortalized human hepatocyte cell line L02 and in a rat model of bile duct ligation. Sham-operated and bile duct ligated Sprague-Dawley rats were treated with the vehicle alone or taurine zinc (40, 80, 160mg/kg) for 17days. Bile duct ligation significantly increased blood lipid levels, and promoted hepatocyte apoptosis, inflammation and compensatory biliary proliferation. In vitro, incubation with bile significantly reduced L02 cell viability; this effect was significantly attenuated by pretreatment with SP600125 (a JNK inhibitor) and enhanced when co-incubated with taurine zinc SDs. In vivo, administration of taurine zinc SDs decreased serum alanine aminotransferase and aspartate aminotransferase activities in a dose-dependent manner and attenuated the increases in serum total bilirubin, total cholesterol and low density lipoprotein cholesterol levels after bile duct ligation. Additionally, taurine zinc SDs downregulated the expression of interleukin-1β and inhibited the phosphorylation of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase2 (ERK2) in the liver after bile duct ligation. Moreover, taurine zinc SDs had more potent blood lipid regulatory and anti-apoptotic effects than the physical mixture of taurine and zinc acetate. Therefore, we speculate that taurine zinc SDs protect liver function at least in part via a mechanism linked to reduce phosphorylation of JNK and ERK2, which suppresses inflammation, apoptosis and cholangiocyte proliferation during cholestasis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Zinc content of selected tissues and taste perception in rats fed zinc deficient and zinc adequate rations

International Nuclear Information System (INIS)

Boeckner, L.S.; Kies, C.

1986-01-01

The objective of the study was to determine the effects of feeding zinc sufficient and zinc deficient rations on taste sensitivity and zinc contents of selected organs in rats. The 36 Sprague-Dawley male weanling rats were divided into 2 groups and fed zinc deficient or zinc adequate rations. The animals were subjected to 4 trial periods in which a choice of deionized distilled water or a solution of quinine sulfate at 1.28 x 10 -6 was given. A randomized schedule for rat sacrifice was used. No differences were found between zinc deficient and zinc adequate rats in taste preference aversion scores for quinine sulfate in the first three trial periods; however, in the last trial period rats in the zinc sufficient group drank somewhat less water containing quinine sulfate as a percentage of total water consumption than did rats fed the zinc deficient ration. Significantly higher zinc contents of kidney, brain and parotid salivary glands were seen in zinc adequate rats compared to zinc deficient rats at the end of the study. However, liver and tongue zinc levels were lower for both groups at the close of the study than were those of rats sacrificed at the beginning of the study

Silver-zinc electrodeposition from a thiourea solution with added EDTA or HEDTA

International Nuclear Information System (INIS)

Oliveira, G.M. de; Carlos, I.A.

2009-01-01

This paper shows the study of silver-zinc electrodeposition from a thiourea solution with added (ethylenedinitrilo)tetraacetic acid (EDTA), disodium salt and N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), trisodium salt. Voltammetric results indicated that silver-zinc alloy can be obtained applying overpotential higher than 0.495 V, in Tu solution containing 1.0 x 10 -1 mol L -1 Zn(NO 3 ) 2 + 2.5 x 10 -2 mol L -1 AgNO 3 . This was due to silver(I) ion complexation with thiourea, which shifted the silver deposition potential to more negative value and due to silver-zinc alloy deposition, which occurred at potentials more positive than the potential to zinc deposition alone. EDTA or HEDTA did not significantly affect the silver and zinc deposition potentials, but decreased the current density for silver-zinc deposition. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the silver-zinc deposits showed that the morphology and composition changed as a function of the conditions of deposition, viz, deposition potential (E d ), deposition charge density (q d ) and solution composition (silver, EDTA and HEDTA concentrations). EDS analysis of the deposits showed sulphur (S) incorporated into the silver-zinc deposit, while SEM images showed that this sulphur content seemed to improve the silver-zinc morphology, as did the presence of EDTA and HEDTA in the solution, which enhanced the sulphur incorporation into the silver-zinc deposit. X-ray diffraction (XRD) analysis of the silver-zinc deposit showed that it was amorphous, irrespective of its composition and morphology

Zinc and metalloproteinases 2 and 9: What is their relation with breast cancer?

Directory of Open Access Journals (Sweden)

Aldenora Oliveira do Nascimento Holanda

Full Text Available Summary Zinc is the catalytic component of proteins that regulate responses to DNA damage, intracellular signaling enzymes, and matrix metalloproteinases, which are important proteins in carcinogenesis. The objective of this review is to bring current information on the participation of zinc and matrix metalloproteinases types 2 and 9 in mechanisms involved in the pathogenesis of breast cancer. We conducted a literature review, in consultation with the PubMed, Lilacs, and Scielo databases. The zinc and cysteine residues are structural elements shared by all members of the family of matrix metalloproteinases, and these proteins appear to be involved in the propagation of various types of neoplasms, including breast cancer. Moreover, transported zinc is likely to be used for the metalation of the catalytic domain of the newly synthesized metalloproteinases before the latter are secreted. Accordingly, increase in zinc concentrations in cellular compartments and the reduction of this trace element in the blood of patients with breast cancer appear to alter the activity of metalloproteinases 2 and 9, contributing to the occurrence of malignancy. Thus, it is necessary to carry out further studies with a view to clarify the role of zinc and metalloproteinases 2 and 9 in the pathogenesis of breast cancer.

Water soluble peripheral and non-peripheral tetrasubstituted zinc phthalocyanines: Synthesis, photochemistry and bovine serum albumin binding behavior

Energy Technology Data Exchange (ETDEWEB)

Çakır, Volkan; Çakır, Dilek [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Pişkin, Mehmet [Department of Food Technology, Çanakkale Vocational School of Technical Sciences, Çanakkale Onsekiz Mart University, 17100 Çanakkale (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze 41400, Kocaeli (Turkey); Bıyıklıoğlu, Zekeriya, E-mail: zekeriya_61@yahoo.com [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2014-10-15

The new peripherally and non-peripherally tetra-1,3-bis[3-(diethylamino)phenoxy]propan-2-ol substituted zinc(II) phthalocyanine complexes (2a and 3a) and their quaternized amphiphilic derivatives (2b and 3b) have been synthesized and characterized using UV–vis, FT-IR, {sup 1}H-NMR, {sup 13}C-NMR, MS spectroscopic data and elemental analysis for the first time. The quaternized complexes (2b and 3b) show excellent solubility in water and DMSO which makes them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. The photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of these novel phthalocyanines are investigated in dimethylsulfoxide (DMSO) for non-quaternized complexes and in DMSO, phosphate buffered solution (PBS) or PBS+triton X-100 (TX) solution for quaternized complexes. In this study, the effects of the aggregation of the molecules, quaternization, position of the substituents (peripherally or non-peripherally) and nature of the solvents (DMSO, PBS or PBS+triton X-100) on the photochemical parameters of the zinc (II) phthalocyanines are also reported. In addition, a spectroscopic investigation of the binding behavior of the quaternized zinc(II) phthalocyanine complexes to bovine serum albumin (BSA) is also presented in this work. - Highlights: • Synthesis of zinc phthalocyanines is performed. • Photophysical and photochemical properties of phthalocyanines are studied. • Photodynamic therapy studies are performed.

Water soluble peripheral and non-peripheral tetrasubstituted zinc phthalocyanines: Synthesis, photochemistry and bovine serum albumin binding behavior

International Nuclear Information System (INIS)

Çakır, Volkan; Çakır, Dilek; Pişkin, Mehmet; Durmuş, Mahmut; Bıyıklıoğlu, Zekeriya

2014-01-01

The new peripherally and non-peripherally tetra-1,3-bis[3-(diethylamino)phenoxy]propan-2-ol substituted zinc(II) phthalocyanine complexes (2a and 3a) and their quaternized amphiphilic derivatives (2b and 3b) have been synthesized and characterized using UV–vis, FT-IR, 1 H-NMR, 13 C-NMR, MS spectroscopic data and elemental analysis for the first time. The quaternized complexes (2b and 3b) show excellent solubility in water and DMSO which makes them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. The photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of these novel phthalocyanines are investigated in dimethylsulfoxide (DMSO) for non-quaternized complexes and in DMSO, phosphate buffered solution (PBS) or PBS+triton X-100 (TX) solution for quaternized complexes. In this study, the effects of the aggregation of the molecules, quaternization, position of the substituents (peripherally or non-peripherally) and nature of the solvents (DMSO, PBS or PBS+triton X-100) on the photochemical parameters of the zinc (II) phthalocyanines are also reported. In addition, a spectroscopic investigation of the binding behavior of the quaternized zinc(II) phthalocyanine complexes to bovine serum albumin (BSA) is also presented in this work. - Highlights: • Synthesis of zinc phthalocyanines is performed. • Photophysical and photochemical properties of phthalocyanines are studied. • Photodynamic therapy studies are performed

Prevention of upper aerodigestive tract cancer in zinc-deficient rodents: Inefficacy of genetic or pharmacological disruption of COX-2

Science.gov (United States)

Fong, Louise Y.Y.; Jiang, Yubao; Riley, Maurisa; Liu, Xianglan; Smalley, Karl J.; Guttridge, Denis C.; Farber, John L.

2009-01-01

Zinc deficiency in humans is associated with an increased risk of upper aerodigestive tract (UADT) cancer. In rodents, zinc deficiency predisposes to carcinogenesis by causing proliferation and alterations in gene expression. We examined whether in zinc-deficient rodents, targeted disruption of the cyclooxygenase (COX)-2 pathway by the COX-2 selective inhibitor celecoxib or by genetic deletion prevent UADT carcinogenesis. Tongue cancer prevention studies were conducted in zinc-deficient rats previously exposed to a tongue carcinogen by celecoxib treatment with or without zinc replenishment, or by zinc replenishment alone. The ability of genetic COX-2 deletion to protect against chemically-induced for-estomach tumorigenesis was examined in mice on zinc-deficient versus zinc-sufficient diet. The expression of 3 predictive bio-markers COX-2, nuclear factor (NF)-κ B p65 and leukotriene A4 hydrolase (LTA4H) was examined by immunohistochemistry. In zinc-deficient rats, celecoxib without zinc replenishment reduced lingual tumor multiplicity but not progression to malignancy. Celecoxib with zinc replenishment or zinc replenishment alone significantly lowered lingual squamous cell carcinoma incidence, as well as tumor multiplicity. Celecoxib alone reduced overexpression of the 3 biomarkers in tumors slightly, compared with intervention with zinc replenishment. Instead of being protected, zinc-deficient COX-2 null mice developed significantly greater tumor multiplicity and forestomach carcinoma incidence than wild-type controls. Additionally, zinc-deficient COX-2−/− forestomachs displayed strong LTA4H immunostaining, indicating activation of an alter-native pathway under zinc deficiency when the COX-2 pathway is blocked. Thus, targeting only the COX-2 pathway in zinc-deficient animals did not prevent UADT carcinogenesis. Our data suggest zinc supplementation should be more thoroughly explored in human prevention clinical trials for UADT cancer. PMID:17985342

Long-Term Cost-Effectiveness of Insulin Glargine Versus Neutral Protamine Hagedorn Insulin for Type 2 Diabetes in Thailand.

Science.gov (United States)

Permsuwan, Unchalee; Chaiyakunapruk, Nathorn; Dilokthornsakul, Piyameth; Thavorn, Kednapa; Saokaew, Surasak

2016-06-01

Even though Insulin glargine (IGlar) has been available and used in other countries for more than a decade, it has not been adopted into Thai national formulary. This study aimed to evaluate the long-term cost effectiveness of IGlar versus neutral protamine Hagedorn (NPH) insulin in type 2 diabetes from the perspective of Thai Health Care System. A validated computer simulation model (the IMS CORE Diabetes Model) was used to estimate the long-term projection of costs and clinical outcomes. The model was populated with published characteristics of Thai patients with type 2 diabetes. Baseline risk factors were obtained from Thai cohort studies, while relative risk reduction was derived from a meta-analysis study conducted by the Canadian Agency for Drugs and Technology in Health. Only direct costs were taken into account. Costs of diabetes management and complications were obtained from hospital databases in Thailand. Both costs and outcomes were discounted at 3 % per annum and presented in US dollars in terms of 2014 dollar value. Incremental cost-effectiveness ratio (ICER) was calculated. One-way and probabilistic sensitivity analyses were also performed. IGlar is associated with a slight gain in quality-adjusted life years (0.488 QALYs), an additional life expectancy (0.677 life years), and an incremental cost of THB119,543 (US$3522.19) compared with NPH insulin. The ICERs were THB244,915/QALY (US$7216.12/QALY) and THB176,525/life-year gained (LYG) (US$5201.09/LYG). The ICER was sensitive to discount rates and IGlar cost. At the acceptable willingness to pay of THB160,000/QALY (US$4714.20/QALY), the probability that IGlar was cost effective was less than 20 %. Compared to treatment with NPH insulin, treatment with IGlar in type 2 diabetes patients who had uncontrolled blood glucose with oral anti-diabetic drugs did not represent good value for money at the acceptable threshold in Thailand.

Synthesis and Study of Chemical and Photo-physical Properties of Quinolinate Aluminum and Zinc Complexes in Organic Light Emitting Diodes (OLEDs)

Science.gov (United States)

Rawat, Madhu; Prakash, Sattey; Singh, C.; Anand, R. S.

2011-10-01

Two well known electroluminescent (EL) compounds, aluminum and zinc metallo-8-hydroxyquinolates have been synthesized. Their chemical and physical properties like NMR, FTIR, Cyclic Voltammetry, absorption and EL are studied. Organic LEDs are fabricated using both the material as emissive layers. Electroluminescence spectra of the complexes are measured. 2Alq3 and Znq2 give peak emission in yellow-green region at wavelengths 527nm and 540nm respectively. Znq2 is slightly red shifted compared to Alq3 because metal to ligand charge transfer is more in Znq2. A study of ON voltage, luminance efficiency and stability of OLEDs using both materials is made.

Zinc in human serum

International Nuclear Information System (INIS)

Kiilerich, S.

1987-01-01

The zinc ion is essential for the living organism. Many pathological conditions have been described as a consequence of zinc deficiency. As zinc constitutes less than 0.01 per cent of the body weight, it conventionally belongs to the group of trace elements. The method of atomic absorption spectrophotometry is used to measure the concentration of zinc in serum and urine from healthy persons. The assumptions of the method is discussed. The importance of proteinbinding, diet and the diurnal variation of serum zinc concentration is presented. Serum versus plasma zinc concentration is discussed. Reference serum zinc values from 104 normal subjects are given. Zinc in serum is almost entirely bound to proteins. A preliminary model for the estimation of the distribution of zinc between serum albumin and α 2 -macroglobulin is set up. This estimate has been examined by an ultracentrufugation method. The binding of zinc to a α 2 -macroglobulin in normal persons is appoximately 7 per cent, in patients with cirrhosis of the liver of alcoholic origin approximately 6 per cent, in patients with insulin dependent diabetes mellitus approximately 5 per cent, and in patients with chronic renal failure approximately 2 per cent. It is concluded, therefore, that for clinical purposes it is sufficient to use the concentration of total serum zinc corrected for the concentration of serum albumin. (author)

Zinc fingers, zinc clusters, and zinc twists in DNA-binding protein domains

International Nuclear Information System (INIS)

Vallee, B.L.; Auld, D.S.; Coleman, J.E.

1991-01-01

The authors recognize three distinct motifs of DNA-binding zinc proteins: (i) zinc fingers, (ii) zinc clusters, and (iii) zinc twists. Until very recently, x-ray crystallographic or NMR three-dimensional structure analyses of DNA-binding zinc proteins have not been available to serve as standards of reference for the zinc binding sites of these families of proteins. Those of the DNA-binding domains of the fungal transcription factor GAL4 and the rat glucocorticoid receptor are the first to have been determined. Both proteins contain two zinc binding sites, and in both, cysteine residues are the sole zinc ligands. In GAL4, two zinc atoms are bound to six cysteine residues which form a zinc cluster akin to that of metallothionein; the distance between the two zinc atoms of GAL4 is ∼3.5 angstrom. In the glucocorticoid receptor, each zinc atom is bound to four cysteine residues; the interatomic zinc-zinc distance is ∼13 angstrom, and in this instance, a zinc twist is represented by a helical DNA recognition site located between the two zinc atoms. Zinc clusters and zinc twists are here recognized as two distinctive motifs in DNA-binding proteins containing multiple zinc atoms. For native zinc fingers, structural data do not exist as yet; consequently, the interatomic distances between zinc atoms are not known. As further structural data become available, the structural and functional significance of these different motifs in their binding to DNA and other proteins participating in the transmission of the genetic message will become apparent

Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces.

Science.gov (United States)

Seifert, Susan; Simon, Frank; Baumann, Giesela; Hietschold, Michael; Seifert, Andreas; Spange, Stefan

2011-12-06

The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions. © 2011 American Chemical Society

Mobile trap algorithm for zinc detection using protein sensors

International Nuclear Information System (INIS)

Inamdar, Munish V.; Lastoskie, Christian M.; Fierke, Carol A.; Sastry, Ann Marie

2007-01-01

We present a mobile trap algorithm to sense zinc ions using protein-based sensors such as carbonic anhydrase (CA). Zinc is an essential biometal required for mammalian cellular functions although its intracellular concentration is reported to be very low. Protein-based sensors like CA molecules are employed to sense rare species like zinc ions. In this study, the zinc ions are mobile targets, which are sought by the mobile traps in the form of sensors. Particle motions are modeled using random walk along with the first passage technique for efficient simulations. The association reaction between sensors and ions is incorporated using a probability (p 1 ) upon an ion-sensor collision. The dissociation reaction of an ion-bound CA molecule is modeled using a second, independent probability (p 2 ). The results of the algorithm are verified against the traditional simulation techniques (e.g., Gillespie's algorithm). This study demonstrates that individual sensor molecules can be characterized using the probability pair (p 1 ,p 2 ), which, in turn, is linked to the system level chemical kinetic constants, k on and k off . Further investigations of CA-Zn reaction using the mobile trap algorithm show that when the diffusivity of zinc ions approaches that of sensor molecules, the reaction data obtained using the static trap assumption differ from the reaction data obtained using the mobile trap formulation. This study also reveals similar behavior when the sensor molecule has higher dissociation constant. In both the cases, the reaction data obtained using the static trap formulation reach equilibrium at a higher number of complex molecules (ion-bound sensor molecules) compared to the reaction data from the mobile trap formulation. With practical limitations on the number sensors that can be inserted/expressed in a cell and stochastic nature of the intracellular ionic concentrations, fluorescence from the number of complex sensor molecules at equilibrium will be the measure

Evaluation of zinc toxicity in soils by means of the CaCl/sub 2/ method

Energy Technology Data Exchange (ETDEWEB)

Merkel, D; Koester, W

1976-01-01

Soils in the valleys of the rivers Innerste and Oker, north of the Harz mountains, are seriously contaminated by heavy metals. Above all high zinc contents cause severe plant damages. They are like injuries caused by air pollution in the environment of smelting-houses. Usually the heavy metal content of the soil is estimated by extraction with diluted acids, e.g., 0.43 N HNO/sub 3/. In this way nearly the whole zinc store is recorded. For an evaluation of the plant available zinc content we extracted contaminated soils with 0.025 N CaCl/sub 2/. This procedure records the influence of soil properties on the plant availability of the zinc like pH value and clay content. With 0.43 NHNO/sub 3/ 260-7500 ppM zinc were estimated. The maximum content of the CaCl/sub 2/ solution was 109 ppM. Cereals at stage of shooting contained 68-1210 ppM (DM), sugar beet leaves 72-812 ppM (DM). The CaCl/sub 2/ method brought about a closer relationship between soils and plants compared with the HNO/sub 3/ method. Beyond it these method permits the establishment of a preliminary toxicity limit which is supposed in the range of 1 ppM. The percent quota of Zn-CaCl/sub 2/ on Zn-HNO/sub 3/ as a measure of the zinc availability was closely related to the pH value of the soil. The relationship was closer the more soils with lower pH values were present, but there was an essential relationship even at pH levels above 7.0. In the environment of a smelting-house the zinc content of plants was closer related to Zn-HNO/sub 3/ compared with Zn-CaCl/sub 2/. In this case the zinc content of the plants was partly caused by the zinc pollution. But at increasing pH value of the soil even here the availability of the soil zinc decreased too. 33 references.

Zinc Transporters, Mechanisms of Action and Therapeutic Utility: Implications for Type 2 Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Stephen A. Myers

2012-01-01

Full Text Available Zinc is an essential trace element that plays a vital role in maintaining many biological processes and cellular homeostasis. Dysfunctional zinc signaling is associated with a number of chronic disease states including cancer, cardiovascular disease, Alzheimer’s disease, and diabetes. Cellular homeostasis requires mechanisms that tightly control the uptake, storage, and distribution of zinc. This is achieved through the coordinated actions of zinc transporters and metallothioneins. Evidence on the role of these proteins in type 2 diabetes mellitus (T2DM is now emerging. Zinc plays a key role in the synthesis, secretion and action of insulin in both physiological and pathophysiological states. Moreover, recent studies highlight zinc’s dynamic role as a “cellular second messenger” in the control of insulin signaling and glucose homeostasis. This suggests that zinc plays an unidentified role as a novel second messenger that augments insulin activity. This previously unexplored concept would raise a whole new area of research into the pathophysiology of insulin resistance and introduce a new class of drug target with utility for diabetes pharmacotherapy.

Copper (II) and zinc (II) complexes with flavanone derivatives: Identification of potential cholinesterase inhibitors by on-flow assays.

Science.gov (United States)

Sarria, André Lucio Franceschini; Vilela, Adriana Ferreira Lopes; Frugeri, Bárbara Mammana; Fernandes, João Batista; Carlos, Rose Maria; da Silva, Maria Fátima das Graças Fernandes; Cass, Quezia Bezerra; Cardoso, Carmen Lúcia

2016-11-01

Metal chelates strongly influence the nature and magnitude of pharmacological activities in flavonoids. In recent years, studies have shown that a promising class of flavanone-metal ion complexes can act as selective cholinesterase inhibitors (ChEIs), which has led our group to synthesize a new series of flavanone derivatives (hesperidin, hesperetin, naringin, and naringenin) complexed to either copper (II) or zinc (II) and to evaluate their potential use as selective ChEIs. Most of the synthesized complexes exhibited greater inhibitory activity against acetylcholinesterase (AChE) than against butyrylcholinesterase (BChE). Nine of these complexes constituted potent, reversible, and selective ChEIs with inhibitory potency (IC 50 ) and inhibitory constant (K i ) ranging from 0.02 to 4.5μM. Copper complexes with flavanone-bipyridine derivatives afforded the best inhibitory activity against AChE and BChE. The complex Cu(naringin)(2,2'-bipyridine) (11) gave IC 50 and K i values of 0.012±0.002 and 0.07±0.01μM for huAChE, respectively, which were lower than the inhibitory values obtained for standard galanthamine (IC 50 =206±30.0 and K i =126±18.0μM). Evaluation of the inhibitory activity of this complex against butyrylcholinesterase from human serum (huBChE) gave IC 50 and K i values of 8.0±1.4 and 2.0±0.1μM, respectively. A Liquid Chromatography-Immobilized Capillary Enzyme Reactor by UV detection (LC-ICER-UV) assay allowed us to determine the IC 50 and K i values and the type of mechanism for the best inhibitors. Copyright © 2016 Elsevier Inc. All rights reserved.

Etude multi-échelle des mécanismes d'élaboration de revêtements d'alliage zinc-nickel à base d'électrolytes alcalins : germination, complexation et structures cristallines

OpenAIRE

Fedi , Baptiste

2016-01-01

The present work aims to deepen the understanding of the mechanisms of zinc-nickelelectrodeposition in alkaline baths. Zinc-nickel deposits containing between 12% and 16%nickel known for their anti-corrosion performance. Complexing agents are required toobtain soluble and reactive nickel forms, and to stabilize the electrolytes. A study ofthe complexing mechanisms has improved the understanding of their respective role andbehavior, and their influence on the stability and the morphology and c...

Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats.

Science.gov (United States)

Kuldeep, Anjana; Nair, Neena; Bedwal, Ranveer Singh

2017-06-01

The aim of this study was to trace zinc nanocrystals in the anterior pituitary of zinc-deficient Wistar rats by using autometallographic technique. Male Wistar rats (30-40 days of age, pre-pubertal period) of 40-50 g body weight were divided into the following: the ZC (zinc control) group-fed with 100 ppm zinc in diet, the ZD (zinc-deficient) group-fed with zinc-deficient (1.00 ppm) diet and the PF (pair-fed) group-received 100 ppm zinc in diet. The experiments were set for 2 and 4 weeks. Pituitary was removed and processed for the autometallographic technique. The control and pair-fed groups retained their normal morphological features. However, male Wistar rats fed on zinc-deficient diet for 2 and 4 weeks displayed a wide range of symptoms such as significant (P zinc nanocrystals in the nuclei. The present findings suggest that the dietary zinc deficiency causes decreased intensity of zinc nanocrystals localization and their distribution in the pituitary thereby contributing to the dysfunction of the pituitary of the male Wistar rats. The severity of zinc deficiency symptoms progressed after the second week of the experiment. Decreased intensity of zinc nanocrystals attenuates the pituitary function which would exert its affect on other endocrine organs impairing their functions indicating that the metabolic regulation of pituitary is mediated to a certain extent by zinc and/or hypothalamus-hypophysial system which also reflects its essentiality during the period of growth.

Single crystal X-ray structure of the artists’ pigment zinc yellow

DEFF Research Database (Denmark)

Simonsen, Kim Pilkjær; Christiansen, Marie Bitsch; Vinum, Morten Gotthold

2017-01-01

electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography......The artists’ pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO4·K2O·3H2O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto...... been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning...

Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

Energy Technology Data Exchange (ETDEWEB)

Zheng, Juanjuan; Zhang, Yu [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Xu, Wentao, E-mail: xuwentaoboy@sina.com [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Luo, YunBo [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Hao, Junran [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Shen, Xiao Li [The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Yang, Xuan [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Li, Xiaohong [The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Huang, Kunlun, E-mail: hkl009@163.com [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China)

2013-04-15

Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did not affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ{sub m}). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage induced by

Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

International Nuclear Information System (INIS)

Zheng, Juanjuan; Zhang, Yu; Xu, Wentao; Luo, YunBo; Hao, Junran; Shen, Xiao Li; Yang, Xuan; Li, Xiaohong; Huang, Kunlun

2013-01-01

Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did not affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ m ). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage induced by OTA in

Does the oral zinc tolerance test measure zinc absorption

Energy Technology Data Exchange (ETDEWEB)

Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

1985-01-01

Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi /sup 65/ZnCl/sub 2/ and a non-absorbed marker, /sup 51/CrCl/sub 3/, dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with /sup 65/Zn and /sup 51/Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and /sup 65/Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and /sup 65/Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption.

Does the oral zinc tolerance test measure zinc absorption

International Nuclear Information System (INIS)

Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

1985-01-01

Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi 65 ZnCl 2 and a non-absorbed marker, 51 CrCl 3 , dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with 65 Zn and 51 Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and 65 Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and 65 Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption

A novel zinc finger protein Zfp277 mediates transcriptional repression of the Ink4a/arf locus through polycomb repressive complex 1

DEFF Research Database (Denmark)

Negishi, Masamitsu; Saraya, Atsunori; Mochizuki, Shinobu

2010-01-01

. METHODOLOGY/PRINCIPAL FINDINGS: We examined the function of Zinc finger domain-containing protein 277 (Zfp277), a novel zinc finger protein that interacts with the PcG protein Bmi1. Zfp277 binds to the Ink4a/Arf locus in a Bmi1-independent manner and interacts with polycomb repressor complex (PRC) 1 through...... is essential for the recruitment of PRC1 to the Ink4a/Arf locus. Our findings also highlight dynamic regulation of both Zfp277 and PcG proteins by the oxidative stress pathways....

Espectrofotometria de zinco em fertilizantes em fluxo Flow injection spectrophotometry of zinc in mineral fertilizers

Directory of Open Access Journals (Sweden)

Arnaldo Antonio Rodella

1999-07-01

Full Text Available Um sistema de análise química por injeção em fluxo é proposto para a determinação espectrofotométrica de zinco em amostras de misturas de fertilizantes minerais, empregando-se zincon como reagente cromogênico. O procedimento analítico envolve redução de íons metálicos por ácido ascórbico, complexação com íon cianeto, seguindo-se a descomplexação seletiva do zinco com formaldeído, liberando-o para que reaja com o zincon formando um complexo azul. A aplicação do método proposto à extratos de mistura de fertilizantes indicou que a ação de interferentes pode ser contornada e que resultados comparáveis aos da espectrometria de absorção atômica são obtidos.A flow injection system for zinc analysis in mineral fertilizer mixtures is proposed using zincon as chromogenic reagent. The effect of interfering ions such as Cu2+, Fe3+, Mn2+ was eliminated by reduction (using ascorbic acid and complexation of these metal íons with cyanide, with zinc included. Zinc is allowed to react with zincon only after the destruction of the zinc cyano complex with formaldehyde. Flow injection analysis permitted efficient control of the reaction time so that only the zinc ion is set free to produce a blue complex with zincon. Zinc was determined in 16 fertilizer mixtures (3 replicates with precision and accuracy comparable to atomic absorption spectrometry.

Distribution of zinc-65 in Agrostis tenuis Sibth. and A. stolonifera L. tissues

Energy Technology Data Exchange (ETDEWEB)

Peterson, P J

1969-11-01

The distribution of /sup 65/Zn in zinc-tolerant and copper-tolerant plants of Agrotis spp. from toxic mine-tailings in England and Wales was compared with zinc distribution in non-tolerant plants. Isotope was applied in culture solution in which the plants were growing. No differences could be demonstrated between the plants by whole-plant radioautography, or by zinc analyses of the tops. Root/shoot ratios calculated from specific activity values varied with population, the non-tolerant plants having the lowest and the zinc-tolerant plants the highest ratio. After solvent (80% ethanol and water) extractions, the root residue of zinc-tolerant plants contained a higher percentage of /sup 65/Zn than that of non-tolerant plants. Chemical fractionation of the roots revealed that the main difference was that the amount of /sup 65/Zn in the pectate extract of the cell wall was high in zinc-tolerant plants and low in non-tolerant plants. The /sup 65/Zn distribution in the copper-tolerant plants was similar to that in the non-tolerant plants, indicating that the tolerance mechanisms for the two elements are different. Soluble protein and RNA preparations were made but they contained low levels of /sup 65/Zn. An exception was the relatively high value for RNA from zinc-tolerant A. stolonifera shoots. An anionic complex of /sup 65/Zn in the soluble fraction was investigated. This complex accounted for most of the radioactivity in A. tenuis extracts of shoots but the concentration of the complex was low in A. stolonifera shoots, and in root extracts of all plants examined. 18 references, 2 figures, 4 tables.

Influence of prostaglandins E2 and F/sub 2α/ on the zinc transport across rat mid-intestine in vitro

International Nuclear Information System (INIS)

Song, M.K.; Adham, N.F.; Lee, D.B.N.; Carmack, C.R.

1986-01-01

Effects of physiological (5.0 μM) and pharmacological (50 μM) doses of prostaglandins (PG) E 2 and F/sub 2α/ on the zinc transport rate across rat jejunum mounted on a Ussing Chamber were determined. Zinc transport rate from mucosal to serosal direction was 4.82 +/- 0.81 n moles/hr/cm 2 whereas the opposite direction was 18.71 +/- 0.96 n moles/hr/cm 2 . When 5.0 μM or 50 μM PGE 2 or PGF/sub 2α/ were added into Ringers-Krebs bicarbonate solution containing 3 mM L-histidine and 0.5 mM 65 Zn Cl 2 to the mucosal side of mucosa, no significant difference in 65 Zn transport rate was observed compared to controls. However, 5.0 μM PGF/sub 2α/ and 50 μM PGE 2 significantly inhibited zinc transport from mucosal to serosal direction. When PGs were added to the opposite side of mucosa, only 5.0 μM PGs significantly inhibited zinc transport from serosal to mucosal direction. Results suggest that PGs act on the inhibition of zinc transport across the basolateral membrane of columnar absorbing cells and that 50 μM PGE 2 was the most powerful inhibitor

40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

Science.gov (United States)

2010-07-01

...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc...

Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

Science.gov (United States)

Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

2016-09-01

The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells. Copyright © 2016 Elsevier GmbH. All rights reserved.

(Acetonitrile{2-[bis(pyridin-2-ylmethyl-κ2Namino-κN]-N-(2,6-dimethylphenylacetamide-κO}(perchlorato-κOzinc (acetonitrile{2-[bis(pyridin-2-ylmethyl-κ2Namino-κN]-N-(2,6-dimethylphenylacetamide-κO}zinc tris(perchlorate

Directory of Open Access Journals (Sweden)

Ove Alexander Høgmoen Åstrand

2013-02-01

Full Text Available In the title salt, [Zn(C22H24N4O(CH3CN][Zn(ClO4(C22H24N4O(CH3CN](ClO43, two differently coordinated zinc cations occur. In the first complex, the metal ion is coordinated by the N,N′,N′′,O-tetradentate acetamide ligand and an acetonitrile N atom, generating an approximate trigonal–bipyramidal coordination geometry, with the O atom in an equatorial site and the acetonitrile N atom in an axial site. In the second complex ion, a perchlorate ion is also bonded to the zinc ion, generating a distorted trans-ZnO2N4 octahedron. Of the uncoordinating perchlorate ions, one lies on a crystallographic twofold axis and one lies close to a twofold axis and has a site occupancy of 0.5. N—H...O and N—H...(O,O hydrogen bonds are observed in the crystal. Disordered solvent molecules occupy about 11% of the unit-cell volume; their contribution to the scattering was removed with the SQUEEZE routine of the PLATON program [Spek (2009. Acta Cryst. D65, 148–155.].

hZip2 and hZip3 zinc transporters are down regulated in human prostate adenocarcinomatous glands

Directory of Open Access Journals (Sweden)

Franklin Renty B

2007-06-01

Full Text Available Abstract Background The normal human prostate glandular epithelium has the unique function of accumulating high levels of zinc. In prostate cancer this capability is lost as an early event in the development of the malignant cells. The mechanism and factors responsible for the ability of the normal epithelial cells to accumulate zinc and the loss of this capability in the malignant cells need to be identified. We previously reported that Zip1 is an important zinc uptake transporter in prostate cells and is down regulated in the malignant cells in situ along with the depletion of zinc levels. In this report we investigated the expression of two other Zip family zinc transporters, Zip2 and Zip3 in malignant versus nonmalignant (normal and BPH glands. Zip2 and Zip3 relative protein levels were determined by immunohistochemistry analysis of human prostate tissue sections. Results Normal and BPH glandular epithelium consistently exhibited the strong presence of both Zip 2 and Zip3; whereas both transporters consistently were essentially non-detectable in the malignant glands. This represents the first report of the expression of Zip3 in human prostate tissue; and more importantly, reveals that ZiP2 and Zip3 are down regulated in malignant cells in situ as we also had demonstrated for Zip1. Zip2 and Zip3 transporter proteins were localized predominantly at the apical cell membrane, which is in contrast to the Zip1 localization at the basolateral membrane. Zip2 and Zip3 seemingly are associated with the re-uptake of zinc from prostatic fluid. Conclusion These results coupled with previous reports implicate Zip2 and Zip3 along with Zip1 as important zinc uptake transporters involved in the unique ability of prostate cells to accumulate high cellular zinc levels. Zip1 is important for the extraction of zinc from circulation as the primary source of cellular zinc. Zip 2 and Zip3 appear to be important for retention of the zinc in the cellular compartment

Resistance of extremely halophilic archaea to zinc and zinc oxide nanoparticles

Science.gov (United States)

Salgaonkar, Bhakti B.; Das, Deepthi; Bragança, Judith Maria

2016-02-01

Industrialization as well as other anthropogenic activities have resulted in addition of high loads of metal and/or metal nanoparticles to the environment. In this study, the effect of one of the widely used heavy metal, zinc (Zn) and zinc oxide nanoparticles (ZnO NPs) on extremely halophilic archaea was evaluated. One representative member from four genera namely Halococcus, Haloferax, Halorubrum and Haloarcula of the family Halobacteriaceae was taken as the model organism. All the haloarchaeal genera investigated were resistant to both ZnCl2 and ZnO NPs at varying concentrations. Halococcus strain BK6 and Haloferax strain BBK2 showed the highest resistance in complex/minimal medium of up to 2.0/1.0 mM ZnCl2 and 2.0/1.0-0.5 mM ZnO NP. Accumulation of ZnCl2/ZnO NPs was seen as Haloferax strain BBK2 (287.2/549.6 mg g-1) > Halococcus strain BK6 (165.9/388.5 mg g-1) > Haloarcula strain BS2 (93.2/28.5 mg g-1) > Halorubrum strain BS17 (29.9/16.2 mg g-1). Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX) analysis revealed that bulk ZnCl2 was sorbed at a higher concentration (21.77 %) on the cell surface of Haloferax strain BBK2 as compared to the ZnO NPs (14.89 %).

Synthesis, Characterization and Antimicrobial Activities of Transition Metal Complexes of methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate

International Nuclear Information System (INIS)

Ikram, M.; Rehman, S.

2016-01-01

New metal complexes with Schiff base ligand methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate, were synthesized and characterized. Elemental analyses, EI-MS, 1H and 13C(1H)-NMR were used for ligand characterization whereas elemental analyses, EI-MS, IR and UV-Visible spectroscopic techniques were used for the transition metal compounds. All these analyses reveal the bis arrangement of the ligand around the metal centres. The compounds were studied for their antimicrobial activities against different pathogenic microbial species. It was found that the Schiff base ligand was completely inactive in comparison to the transition metal compounds. It was also observed that nickel based metal complex shown good results against Candida albican (25 mm) and zinc based metal complex against Agrobacterium tumefaciens (16 mm). (author)

Theoretical investigation, biological evaluation and VEGFR2 kinase studies of metal(II) complexes derived from hydrotris(methimazolyl)borate.

Science.gov (United States)

Jayakumar, S; Mahendiran, D; Srinivasan, T; Mohanraj, G; Kalilur Rahiman, A

2016-02-01

The reaction of soft tripodal scorpionate ligand, sodium hydrotris(methimazolyl)borate with M(ClO4)2·6H2O [MMn(II), Ni(II), Cu(II) or Zn(II)] in methanol leads to the cleavage of B-N bond followed by the formation of complexes of the type [M(MeimzH)4](ClO4)2·H2O (1-4), where MeimzH=methimazole. All the complexes were fully characterized by spectro-analytical techniques. The molecular structure of the zinc(II) complex (4) was determined by X-ray crystallography, which supports the observed deboronation reaction in the scorpionate ligand with tetrahedral geometry around zinc(II) ion. The electronic spectra of complexes suggested tetrahedral geometry for manganese(II) and nickel(II) complexes, and square-planar geometry for copper(II) complex. Frontier molecular orbital analysis (HOMO-LUMO) was carried out by B3LYP/6-31G(d) to understand the charge transfer occurring in the molecules. All the complexes exhibit significant antimicrobial activity against Gram (-ve) and Gram (+ve) bacterial as well as fungal strains, which are quite comparable to standard drugs streptomycin and clotrimazole. The copper(II) complex (3) showed excellent free radical scavenging activity against DPPH in all concentration with IC50 value of 30μg/mL, when compared to the other complexes. In the molecular docking studies, all the complexes showed hydrophobic, π-π and hydrogen bonding interactions with BSA. The cytotoxic activity of the complexes against human hepatocellular liver carcinoma (HepG2) cells was assessed by MTT assay, which showed exponential responses toward increasing concentration of complexes. Copyright © 2015 Elsevier B.V. All rights reserved.

Zinc-Laccase Biofuel Cell

Directory of Open Access Journals (Sweden)

Abdul Aziz Ahmad

2011-12-01

Full Text Available A zinc-laccase biofuel cell adapting the zinc-air cell design features is investigated. A simple cell design configuration is employed: a membraneless single chamber and a freely suspended laccase in a quasi-neutral buffer electrolyte. The cell is characterised according to its open-circuit voltage, polarization profile, power density plot and discharge capacity at constant current. The biocatalytic role of laccase is evident from the polarization profile and power output plot. Performance comparison between a single chamber and dual chamber cell design is also presented. The biofuel cell possessed an open-circuit voltage of 1.2 V and delivered a maximum power density of 0.9 mW/cm2 at current density of 2.5 mA/cm2. These characteristics are comparable to biofuel cell utilising a much more complex system design.KEY WORDS (keyword:  Biofuel cell, Bioelectrochemical cell, Zinc anode, Laccase and Oxidoreductase.ABSTRAK: Sel bio-bahan api zink-laccase dengan adaptasi daripada ciri-ciri rekabentuk sel zink-udara telah dikaji. Sel dengan konfigurasi rekabentuk yang mudah digunapakai: ruangan tunggal tanpa membran dan laccase diampaikan secara bebas di dalam elektrolit pemampan quasi-neutral. Sel dicirikan berdasarkan voltan litar terbuka, profil polarisasi, plot ketumpatan kuasa dan kapasiti discas pada arus malar. Peranan laccase sebagai bio-pemangkin adalah amat ketara daripada profil polarisasi dan plot ketumpatan kuasa. Perbandingan prestasi di antara sel dengan rekabentuk ruangan tunggal and dwi-ruangan turut diketengahkan. Seperti dijangkakan, sel dengan rekabentuk ruangan tunggal menunjukkan kuasa keluaran yang lebih rendah jika dibandingkan dengan rekabentuk dwi-ruangan kemungkinan disebabkan fenomena cas bocor. Sel bio-bahan api ini mempunyai voltan litar terbuka 1.2 V dan memberikan ketumpatan kuasa maksima 0.9 mW/cm2 pada ketumpatan arus 2.5 mA/cm2. Ciri-ciri ini adalah sebanding dengan sel bio-bahan api yang menggunapakai rekabentuk sel

Sonochemical synthesis and characterization of nano-sized zinc(II coordination complex as a precursor for the preparation of pure-phase zinc(II oxide nanoparticles

Directory of Open Access Journals (Sweden)

Maryam Ranjbar

2017-01-01

Full Text Available In current study, nanoparticles and single crystals of a Zn(II coordination complex, [Zn(dmphI2](1, {dmph=2,9-dimethyl-1,10-phenanthroline(neocuproine}, have been synthesized by the reaction of zinc(II acetate, KI and neocuproine as ligand in methanol using sonochemical and heat gradient methods, respectively. The nanostructure of 1 was characterized by scanning electron microscopy (SEM, X-ray powder diffraction (XRD, FT-IR spectroscopy and elemental analyses, and the structure of compound 1 was determined by single-crystal X-ray diffraction. The thermal stability of nano-sized 1 has been studied by thermogravimetric (TG and differential thermal analyses (DTA. Structural determination of compound 1 reveals the Zn(II ion is four-coordinated in a distorted tetrahedral configuration by two N atoms from a 2,9-dimethyl-1,10-Phenanthroline ligand and two terminal I atoms. The effect of supercritical condition on stability, size and morphology of nano-structured compound 1 has also been studied. The XRD pattern of the residue obtained from thermal decomposition of nano-sized compound 1 at 600 °C under air atmosphere provided pure phase of ZnO with the average particles size of about 31 nm.

[Molecular structure and luminescent property of bis(2-(4-methyl-2-hydroxyphenyl)benzothiazolate) zinc].

Science.gov (United States)

Xu, Hui-Xia; Chen, Liu-Qing; Wang, Hua; Hao, Yu-Ying; Xu, Bing-She

2011-02-01

Bis(2-(4-methyl-2-hydroxyphenyl)benzothiazolate) zinc(Zn(4-MeBTZ)2) was synthesized. Its molecular structure was confirmed by single-crystal x-ray diffraction. Single-crystal data are as follows: space group triclinic, P-1; a = 8.989 9(11) angstroms, b =12.161 7 (15) angstroms, c = 12.871 9 (16) angstroms, alpha = 63.492 (2) degrees, beta = 84.825 (2) degrees, gamma =71.187 (2) degrees. The steric hindrance provided by introduction methyl groups on phenoxide ring prohibited effectively the formation of pentacoordinate complex. There is distinct intermolecular pi-pi interaction between molecules. The dihedral angle between the phenol and benzothiazolate rings of Zn(4-MeBTZ)2 is 2.166 degrees. The HOMO energy, LUMO energy and optical gap are -5.84, -3.46 and 2.37 eV, respectively. The maximum wavelength peak of PL spectra located at 470 nm. The double-layer devices were employed using Zn(4-MeBTZ)2 as emitter and NPB as hole-transport material. The EL spectra split into two peaks located at 501 and 544 nm respectively. The broadened EL spectra were demonstrated to be originated from the exciplexes formed at the interface between NPB and Zn(4-MeBTZ)2.

Zinc deficiency promotes cystitis-related bladder pain by enhancing function and expression of Cav3.2 in mice.

Science.gov (United States)

Ozaki, Tomoka; Matsuoka, Junki; Tsubota, Maho; Tomita, Shiori; Sekiguchi, Fumiko; Minami, Takeshi; Kawabata, Atsufumi

2018-01-15

Ca v 3.2 T-type Ca 2+ channel activity is suppressed by zinc that binds to the extracellular histidine-191 of Ca v 3.2, and enhanced by H 2 S that interacts with zinc. Ca v 3.2 in nociceptors is upregulated in an activity-dependent manner. The enhanced Ca v 3.2 activity by H 2 S formed by the upregulated cystathionine-γ-lyase (CSE) is involved in the cyclophosphamide (CPA)-induced cystitis-related bladder pain in mice. We thus asked if zinc deficiency affects the cystitis-related bladder pain in mice by altering Ca v 3.2 function and/or expression. Dietary zinc deficiency for 2 weeks greatly decreased zinc concentrations in the plasma but not bladder tissue, and enhanced the bladder pain/referred hyperalgesia (BP/RH) following CPA at 200mg/kg, a subeffective dose, but not 400mg/kg, a maximal dose, an effect abolished by pharmacological blockade or gene silencing of Ca v 3.2. Acute zinc deficiency caused by systemic N,N,N',N'-tetrakis-(2-pyridylmethyl)-ethylendiamine (TPEN), a zinc chelator, mimicked the dietary zinc deficiency-induced Ca v 3.2-dependent promotion of BP/RH following CPA at 200mg/kg. CPA at 400mg/kg alone or TPEN plus CPA at 200mg/kg caused Ca v 3.2 overexpression accompanied by upregulation of Egr-1 and USP5, known to promote transcriptional expression and reduce proteasomal degradation of Ca v 3.2, respectively, in the dorsal root ganglia (DRG). The CSE inhibitor, β-cyano-l-alanine, prevented the BP/RH and upregulation of Ca v 3.2, Egr-1 and USP5 in DRG following TPEN plus CPA at 200mg/kg. Together, zinc deficiency promotes bladder pain accompanying CPA-induced cystitis by enhancing function and expression of Ca v 3.2 in nociceptors, suggesting a novel therapeutic avenue for treatment of bladder pain, such as zinc supplementation. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison and analysis of zinc and cobalt-based systems as catalytic entities for the hydration of carbon dioxide.

Directory of Open Access Journals (Sweden)

Edmond Y Lau

Full Text Available In nature, the zinc metalloenzyme carbonic anhydrase II (CAII efficiently catalyzes the conversion of carbon dioxide (CO2 to bicarbonate under physiological conditions. Many research efforts have been directed towards the development of small molecule mimetics that can facilitate this process and thus have a beneficial environmental impact, but these efforts have met very limited success. Herein, we undertook quantum mechanical calculations of four mimetics, 1,5,9-triazacyclododedacane, 1,4,7,10-tetraazacyclododedacane, tris(4,5-dimethyl-2-imidazolylphosphine, and tris(2-benzimidazolylmethylamine, in their complexed form either with the Zn(2+ or the Co(2+ ion and studied their reaction coordinate for CO2 hydration. These calculations demonstrated that the ability of the complex to maintain a tetrahedral geometry and bind bicarbonate in a unidentate manner were vital for the hydration reaction to proceed favorably. Furthermore, these calculations show that the catalytic activity of the examined zinc complexes was insensitive to coordination states for zinc, while coordination states above four were found to have an unfavorable effect on product release for the cobalt counterparts.

Effects of Foliar Application of Nano Zinc Chelate and Zinc Sulfate on Zinc Content, Pigments and Photosynthetic Indices of Holy Basil (Ocimum sanctum(

Directory of Open Access Journals (Sweden)

Zohreh Moghimi pour

2017-02-01

Full Text Available Introduction: Holy basil is a perennial plant belongs to Lamiaceae family. The plant is a perennial and thrives well in the hot and humid climate. Its aerial parts have been in use for food, pharmaceuticals, cosmetics and perfumery industries. Leaves contain 0.5-1.5% essential oil and main oil components are eugenol, methyl eugenol, carvacrol, methyl chavicol and1,8-cineole. A balanced fertilization program with macro and micronutrients is very important in producing high quality yield. Zinc is involved in IAA production, chlorophyll biosynthesis, carbon assimilation, saccharids accumulation, reactive oxygen radicals scavenging and finally carbon utilization in volatile oil biosynthesis. Material and methods: In order to evaluate the effect on zinc foliar application on zinc content of leaves, photosynthetic indices and pigments of holy basil, an experiment was carried out in 2013 at a research farm of Horticultural Science, Shahid Chamran University (31°20'N latitude and 48°40'E longitude and 22.5 m mean sea level, Ahvaz (Iran, a region characterized by semi-dry climate. The experiment was arranged based on Randomized Complete Block Design (RCBD with six treatments and three replications. The treatments were nano zinc chelate (0, 0.5, 1 and 1.5 g.l-1 and zinc sulfate (1 and 1.5 g.l-1 fertilizers. Land preparation includes disking and the formation of raising beds (15cm high and 45cm wide across the top using a press-pan-type bed shaper. Holy basil seeds were sown on two rows on each bed, with 15 cm in-row and 40 cm between-row spacing. The plants were irrigated weekly as needed. Foliar application of zinc fertilizers was done at six-eight leaf stage and were repeated with interval 15 days until full bloom stage. Zinc content, stomata conductance (gs, CO2 under stomata (Ci, transpiration rate (E, net photosynthesis (Pn, light use efficiency (LUE, water use efficiency (WUE and also chlorophyll a, chlorophyll b, chlorophyll a+b and carotenoid

Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

Science.gov (United States)

To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

catena-Poly[zinc-tris(μ-dimethylcarbamato-κ2O:O′-zinc-μ-(2-phenylbenzimidazolido-κ2N:N′

Directory of Open Access Journals (Sweden)

Mark A. Rodriguez

2012-01-01

Full Text Available The crystal structure of the title compound, [Zn2(C13H9N2(C3H6NO23]n, displays a long chiral chain. This is composed of zinc-dimer clusters capped by dimethylcarbamate ligands, which lie on crystallographic twofold rotation axes and are polymerically linked in one dimension by 2-phenylbenzimidadole (2–PBImi organic ligands. The two Zn2+ ions defining the dimetal cluster are crystallographically independent, but display very similar coordination modes and tetrahedral geometry. As such, each Zn2+ ion is coordinated on one side by the N-donor imidazole linker, while the other three available coordination sites are fully occupied by the O atoms from the capping dimethylcarbamates. The chirality of the chain extends along the c axis, generating a rather long 52.470 (11 Å cell axis. Interestingly, the chiral material crystallizes from completely achiral precursors. A twofold axis and 31 screw axis serve to generate the long asymmetric unit.

Zinc and zinc transporters in macrophages and their roles in efferocytosis in COPD.

Directory of Open Access Journals (Sweden)

Rhys Hamon

Full Text Available Our previous studies have shown that nutritional zinc restriction exacerbates airway inflammation accompanied by an increase in caspase-3 activation and an accumulation of apoptotic epithelial cells in the bronchioles of the mice. Normally, apoptotic cells are rapidly cleared by macrophage efferocytosis, limiting any secondary necrosis and inflammation. We therefore hypothesized that zinc deficiency is not only pro-apoptotic but also impairs macrophage efferocytosis. Impaired efferocytic clearance of apoptotic epithelial cells by alveolar macrophages occurs in chronic obstructive pulmonary disease (COPD, cigarette-smoking and other lung inflammatory diseases. We now show that zinc is a factor in impaired macrophage efferocytosis in COPD. Concentrations of zinc were significantly reduced in the supernatant of bronchoalveolar lavage fluid of patients with COPD who were current smokers, compared to healthy controls, smokers or COPD patients not actively smoking. Lavage zinc was positively correlated with AM efferocytosis and there was decreased efferocytosis in macrophages depleted of Zn in vitro by treatment with the membrane-permeable zinc chelator TPEN. Organ and cell Zn homeostasis are mediated by two families of membrane ZIP and ZnT proteins. Macrophages of mice null for ZIP1 had significantly lower intracellular zinc and efferocytosis capability, suggesting ZIP1 may play an important role. We investigated further using the human THP-1 derived macrophage cell line, with and without zinc chelation by TPEN to mimic zinc deficiency. There was no change in ZIP1 mRNA levels by TPEN but a significant 3-fold increase in expression of another influx transporter ZIP2, consistent with a role for ZIP2 in maintaining macrophage Zn levels. Both ZIP1 and ZIP2 proteins were localized to the plasma membrane and cytoplasm in normal human lung alveolar macrophages. We propose that zinc homeostasis in macrophages involves the coordinated action of ZIP1 and ZIP2

Zinc blotting assay for detection of zinc binding prolamin in barley (Hordeum vulgare) grain

DEFF Research Database (Denmark)

Uddin, Mohammad Nasir; Nielsen, Ane Langkilde-Lauesen; Vincze, Eva

2014-01-01

In plants, zinc is commonly found bound to proteins. In barley (Hordeum vulgare), major storage proteins are alcohol-soluble prolamins known as hordeins, and some of them have the potential to bind or store zinc. 65Zn overlay and blotting techniques have been widely used for detecting zinc......-binding protein. However, to our knowledge so far this zinc blotting assay has never been applied to detect a prolamin fraction in barley grains. A radioactive zinc (65ZnCl2) blotting technique was optimized to detect zinc-binding prolamins, followed by development of an easy-to-follow nonradioactive colorimetric...... zinc blotting method with a zinc-sensing dye, dithizone. Hordeins were extracted from mature barley grain, separated by SDS-PAGE, blotted on a membrane, renatured, overlaid, and probed with zinc; subsequently, zinc-binding specificity of certain proteins was detected either by autoradiography or color...

Symptomatic zinc deficiency in experimental zinc deprivation.

OpenAIRE

Taylor, C M; Goode, H F; Aggett, P J; Bremner, I; Walker, B E; Kelleher, J

1992-01-01

An evaluation of indices of poor zinc status was undertaken in five male subjects in whom dietary zinc intake was reduced from 85 mumol d-1 in an initial phase of the study to 14 mumol d-1. One of the subjects developed features consistent with zinc deficiency after receiving the low zinc diet for 12 days. These features included retroauricular acneform macullo-papular lesions on the face, neck, and shoulders and reductions in plasma zinc, red blood cell zinc, neutrophil zinc and plasma alkal...

Effect of consuming zinc-fortified bread on serum zinc and iron status of zinc-deficient women: A double blind, randomized clinical trial

Directory of Open Access Journals (Sweden)

Akbar Badii

2012-01-01

Full Text Available After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1 a non-fortified bread, (2 a high-zinc bread, and (3 a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05. Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p < 0.01. It was concluded that fortification of flour with 50-100 ppm zinc was an effective way to achieve adequate zinc intake and absorption in zinc-deficient people. It also appeared that consuming zinc-fortified bread improved iron absorption.

Effect of Consuming Zinc-fortified Bread on Serum Zinc and Iron Status of Zinc-deficient Women: A Double Blind, Randomized Clinical Trial.

Science.gov (United States)

Badii, Akbar; Nekouei, Niloufar; Fazilati, Mohammad; Shahedi, Mohammad; Badiei, Sajad

2012-03-01

After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1) a non-fortified bread, (2) a high-zinc bread, and (3) a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05). Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p bread improved iron absorption.

C2H2 type of zinc finger transcription factors in foxtail millet define response to abiotic stresses.

Science.gov (United States)

Muthamilarasan, Mehanathan; Bonthala, Venkata Suresh; Mishra, Awdhesh Kumar; Khandelwal, Rohit; Khan, Yusuf; Roy, Riti; Prasad, Manoj

2014-09-01

C2H2 type of zinc finger transcription factors (TFs) play crucial roles in plant stress response and hormone signal transduction. Hence considering its importance, genome-wide investigation and characterization of C2H2 zinc finger proteins were performed in Arabidopsis, rice and poplar but no such study was conducted in foxtail millet which is a C4 Panicoid model crop well known for its abiotic stress tolerance. The present study identified 124 C2H2-type zinc finger TFs in foxtail millet (SiC2H2) and physically mapped them onto the genome. The gene duplication analysis revealed that SiC2H2s primarily expanded in the genome through tandem duplication. The phylogenetic tree classified these TFs into five groups (I-V). Further, miRNAs targeting SiC2H2 transcripts in foxtail millet were identified. Heat map demonstrated differential and tissue-specific expression patterns of these SiC2H2 genes. Comparative physical mapping between foxtail millet SiC2H2 genes and its orthologs of sorghum, maize and rice revealed the evolutionary relationships of C2H2 type of zinc finger TFs. The duplication and divergence data provided novel insight into the evolutionary aspects of these TFs in foxtail millet and related grass species. Expression profiling of candidate SiC2H2 genes in response to salinity, dehydration and cold stress showed differential expression pattern of these genes at different time points of stresses.

PREPARATION OF ZINC ENRICHED YEAST (SACCHAROMYCES CEREVISIAE BY CULTIVATION WITH DIFFERENT ZINC SALTS

Directory of Open Access Journals (Sweden)

Ľuboš Harangozo

2012-02-01

Full Text Available The yeast Saccharomyces cerevisiae is the best known microorganism and therefore widely used in many branches of industry. This study aims to investigate the accumulation of three inorganic zinc salts. Our research presents the ability of this yeast to absorb zinc from liquid medium and such enriched biomass use as a potential source of microelements in animal and/or human nutrition. It was found that the addition of different zinc forms, i.e. zinc nitrate, zinc sulphate and zinc chloride in fixed concentrations of 0, 25, 50 and 100 mg.100 ml-1 did not affect the amount of dry yeast biomass yielded, i.e. 1.0 – 1.2 g of yeast cells from 100 ml of cultivation medium, while higher presence of zinc solutions caused significantly lower yield of yeast biomass. The highest amount of zinc in yeast cells was achieved when added in the form of zinc nitrate in concentration of 200 mg.100 ml-1 YPD medium. The increment of intracellular zinc was up to 18.5 mg.g-1 of yeast biomass.

Zinc at glutamatergic synapses.

Science.gov (United States)

Paoletti, P; Vergnano, A M; Barbour, B; Casado, M

2009-01-12

It has long been known that the mammalian forebrain contains a subset of glutamatergic neurons that sequester zinc in their synaptic vesicles. This zinc may be released into the synaptic cleft upon neuronal activity. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate receptors and transporters. Among these targets, NMDA receptors appear particularly interesting because certain NMDA receptor subtypes (those containing the NR2A subunit) contain allosteric sites exquisitely sensitive to extracellular zinc. The existence of these high-affinity zinc binding sites raises the possibility that zinc may act both in a phasic and tonic mode. Changes in zinc concentration and subcellular zinc distribution have also been described in several pathological conditions linked to glutamatergic transmission dysfunctions. However, despite intense investigation, the functional significance of vesicular zinc remains largely a mystery. In this review, we present the anatomy and the physiology of the glutamatergic zinc-containing synapse. Particular emphasis is put on the molecular and cellular mechanisms underlying the putative roles of zinc as a messenger involved in excitatory synaptic transmission and plasticity. We also highlight the many controversial issues and unanswered questions. Finally, we present and compare two widely used zinc chelators, CaEDTA and tricine, and show why tricine should be preferred to CaEDTA when studying fast transient zinc elevations as may occur during synaptic activity.

Synthesis and characterization of near-IR absorbing metal-free and zinc(II phthalocyanines modified with aromatic azo groups

Directory of Open Access Journals (Sweden)

Mukaddes Özçeşmeci

2015-05-01

Full Text Available Metal-free and zinc(II phthalocyanine complexes bearing peripheral (E-4-((2-hydroxynaphthalen-1-yldiazenyl units have been synthesized. Novel phthalonitrile derivative required for the preparation of phthalocyanine complexes was prepared by coupling 4-aminophthalonitrile and 2-naphthol. The structures of these new compounds were characterized by using elemental analyses, proton nuclear magnetic resonance, fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, fluorescence spectroscopy and mass spectrometry. In the UV-Vis spectra a broad absorption band appears for phthalocyanine complexes at around 450–500 nm resulting from azo-group introduced onto the phthalocyanine ring. The photophysical properties of metal-free and zinc(II phthalocyanines were studied in tetrahydrofuran.

Synthesis, Structural Characterization, Antimicrobial Activity, and In Vitro Biocompatibility of New Unsaturated Carboxylate Complexes with 2,2'-Bipyridine.

Science.gov (United States)

Vasile Scăețeanu, Gina; Chifiriuc, Mariana Carmen; Bleotu, Coralia; Kamerzan, Crina; Măruţescu, Luminiţa; Daniliuc, Constantin G; Maxim, Cătălin; Calu, Larisa; Olar, Rodica; Badea, Mihaela

2018-01-12

The synthesis, structural characterization, cytotoxicity, and antimicrobial properties of four new complexes formed by employing acrylate anion and 2,2'-bipyridine are reported herein. X-ray crystallography revealed the trinuclear nature of [Mn₃(2,2'-bipy)₂(C₃H₃O₂)₆] ( 1 ), meanwhile complexes with general formula [M(2,2'-bipy)(C₃H₃O₂)₂(H₂O) x ]∙ y H₂O (( 2 ) M: Ni, x = 1, y = 0; ( 3 ) M: Cu, x = 1, y = 0; ( 4 ) M: Zn, x = 0, y = 1; 2,2'-bipy: 2,2'-bipyridine; C₃H₃O₂: acrylate anion) were shown to be mononuclear. The lowest minimum inhibitory concentration (MIC) of 128 μg mL -1 was recorded for all four tested complexes against Candida albicans , for complex ( 3 ) against Escherichia coli , and for complex ( 4 ) against Staphylocococcus aureus . Compounds ( 3 ) and ( 4 ) were also potent efflux pumps activity inhibitors (EPI), proving their potential for use in synergistic combinations with antibiotics. Complexes ( 1 )-( 4 ) revealed that they were not cytotoxic to HCT-8 cells. They also proved to interfere with the cellular cycle of tumour HCT-8 cells by increasing the number of cells found in the S and G2/M phases. Taken together, these results demonstrate the potential of zinc and copper complexes for use in the development of novel antimicrobial and anti-proliferative agents.

Leptin and zinc relation : In regulation of food intake and immunity

Directory of Open Access Journals (Sweden)

Abdulkerim Kasim Baltaci

2012-01-01

Full Text Available Leptin is synthesized and released by the adipose tissue. Leptin, which carries the information about energy reserves of the body to the brain, controls food intake by acting on neuropeptide Y (NPY, which exercises a food-intake-increasing effect through relevant receptors in the hypothalamus. Zinc deficiency is claimed to result in anorexia, weight loss, poor food efficiency, and growth impairment. The fact that obese individuals have low zinc and high leptin levels suggests that there is a relation between zinc and nutrition, and consequently also between zinc and leptin. Leptin deficiency increases the predisposition to infections and this increase is associated with the impairments in the production of cytokines. Zinc has a key role in the sustenance of immune resistance against infections. Dietary zinc deficiency negatively affects CD +4 cells, Th functions, and consequently, cell-mediated immunity by causing a decrease in the production of IL-2, IF-γ, and TNF-α, which are Th1 products. The relation between zinc and the concerned cytokines in particular, and the fact that leptin has a part in the immune responses mediated by these cytokines demonstrate that an interaction among cellular immunity, leptin and zinc is inevitable. An overall evaluation of the information presented above suggests that there are complex relations among food intake, leptin and zinc on one hand and among cellular immunity, leptin and zinc on the other. The aim of the present review was to draw attention to the possible relation between zinc and leptin in dietary regulation and cellular immunity.

Zinc

Science.gov (United States)

... Consumer Datos en español Health Professional Other Resources Zinc Fact Sheet for Consumers Have a question? Ask ... find out more about zinc? Disclaimer What is zinc and what does it do? Zinc is a ...

Physicochemical characterization of mineral (iron/zinc) bound caseinate and their mineral uptake in Caco-2 cells.

Science.gov (United States)

Shilpashree, B G; Arora, Sumit; Kapila, Suman; Sharma, Vivek

2018-08-15

Milk proteins (especially caseins) are widely accepted as good vehicle for the delivery of various bioactive compounds including minerals. Succinylation is one of the most acceptable chemical modification techniques to enhance the mineral binding ability of caseins. Addition of minerals to succinylated proteins may alter their physicochemical and biochemical properties. Physicochemical characteristics of succinylated sodium caseinate (S.NaCN)-mineral (iron/zinc) complexes were elucidated. Chromatographic behaviour and fluorescence intensity confirmed the structural modification of S.NaCN upon binding with minerals. The bound mineral from protein complexes showed significantly higher (P < 0.05) in vitro bioavailability (mineral uptake) than mineral salts in Caco-2 cells. Also, iron bound S.NaCN showed higher cellular ferritin formation than iron in its free form. These mineral bound protein complexes with improved bioavailability could safely replace inorganic fortificants in various functional food formulations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Endogenous zinc excretion in relation to various levels of dietary zinc intake in the mink (Mustela vison)

International Nuclear Information System (INIS)

Mejborn, H.

1990-01-01

Endogenous zinc excretion was studied in adult male mink fed experimental diets for 73 d, including a collection period from d 69 to 73. Dietary zinc levels were 2.8, 26 or 121 mg/kg wet weight. In accordance with the results of a methodological study, also reported here, the animals had an intramuscular injection of 65ZnCl2 12 d before the start of the collection period. Total fecal (endogenous + unabsorbed) zinc excretion for d 69-73 in the three groups was 2.3, 20.4 and 91.0 mg. The endogenous zinc excretion was 1.3, 2.0 and 6.4 mg, corresponding to 80.8, 10.6 and 6.4% of the zinc intake. Thus, the endogenous excretion was mainly important for the zinc homeostasis at low zinc intake, whereas at high intake the homeostasis was regulated via absorption from the digestive tract. The overall conclusion of the experiment was that mink are comparable to other species (including man) in regard to mechanisms controlling zinc homeostasis

Neodymium conversion layers formed on zinc powder for improving electrochemical properties of zinc electrodes

International Nuclear Information System (INIS)

Zhu Liqun; Zhang Hui; Li Weiping; Liu Huicong

2008-01-01

Zinc powder, as active material of secondary alkaline zinc electrode, can greatly limit the performance of zinc electrode due to corrosion and dendritic growth of zinc resulting in great capacity-loss and short cycle life of the electrode. This work is devoted to modification study of zinc powder with neodymium conversion films coated directly onto it using ultrasonic immersion method for properties improvement of zinc electrodes. Scanning electron microscopy and other characterization techniques are applied to prove that neodymium conversion layers are distributing on the surface of modified zinc powder. The electrochemical performance of zinc electrodes made of such modified zinc powder is investigated through potentiodynamic polarization, potentiostatic polarization and cyclic voltammetry. The neodymium conversion films are found to have a significant effect on inhibition corrosion capability of zinc electrode in a beneficial way. It is also confirmed that the neodymium conversion coatings can obviously suppress dendritic growth of zinc electrode, which is attributed to the amelioration of deposition state of zinc. Moreover, the results of cyclic voltammetry reveal that surface modification of zinc powder enhances the cycle performance of the electrode mainly because the neodymium conversion films decrease the amounts of ZnO or Zn(OH) 2 dissolved in the electrolyte

Electroplated zinc-cobalt alloy

International Nuclear Information System (INIS)

Carpenter, D.E.O.S.; Farr, J.P.G.

2005-01-01

Recent work on the deposition and use of ectrodeposited zinc-cobalt alloys is surveyed. Alloys containing lower of Nuclear quantities of cobalt are potentially more useful. The structures of the deposits is related to their chemical and mechanical properties. The inclusion of oxide and its role in the deposition mechanism may be significant. Chemical and engineering properties relate to the metallurgical structure of the alloys, which derives from the mechanism of deposition. The inclusion of oxides and hydroxides in the electroplate may provide evidence for this mechanism. Electrochemical impedance measurements have been made at significant deposition potentials, in alkaline electrolytes. These reveal a complex electrode behaviour which depends not only on the electrode potential but on the Co content of the electrolyte. For the relevant range of cathodic potential zinc-cobalt alloy electrodeposition occurs through a stratified interface. The formation of an absorbed layer ZnOH/sup +/ is the initial step, this inhibits the deposition of cobalt at low cathodic potentials, so explaining its 'anomalous deposition'. A porous layer of zinc forms on the adsorbed ZnOH/sup +/ at underpotential. As the potential becomes more cathodic, cobalt co- deposits from its electrolytic complex forming a metallic solid solution of Co in Zn. In electrolytes containing a high concentration of cobalt a mixed entity (ZnCo)/sub +/ is assumed to adsorb at the cathode from which a CoZn intermetallic deposits. (author)

Effects of dietary supplementation with tribasic zinc sulfate or zinc sulfate on growth performance, zinc content and expression of zinc transporters in young pigs.

Science.gov (United States)

Deng, Bo; Zhou, Xihong; Wu, Jie; Long, Ciming; Yao, Yajun; Peng, Hongxing; Wan, Dan; Wu, Xin

2017-10-01

An experiment was conducted to compare the effects of zinc sulfate (ZS) and tribasic zinc sulfate (TBZ) as sources of supplemental zinc on growth performance, serum zinc (Zn) content and messenger RNA (mRNA) expression of Zn transporters (ZnT1/ZnT2/ZnT5/ZIP4/DMT1) of young growing pigs. A total of 96 Duroc × Landrace × Yorkshire pigs were randomly allotted to two treatments and were fed a basal diet supplemented with 100 mg/kg Zn from either ZS or TBZ for 28 days. Feed : gain ratio in pigs fed TBZ were lower (P zinc transporter in either duodenum or jejunum of pigs fed TBZ were higher (P < 0.05) than pigs fed ZS. These results indicate that TBZ is more effective in serum Zn accumulation and intestinal Zn absorption, and might be a potential substitute for ZS in young growing pigs. © 2017 Japanese Society of Animal Science.

Synthesis, physico-chemical characterization and biological activity of 2-aminobenzimidazole complexes with different metal ions

Directory of Open Access Journals (Sweden)

Podunavac-Kuzmanović Sanja O.

2004-01-01

Full Text Available Complexes of 2-aminobenzimidazole (L with nitrates of cobalt(II nickel(II, copper (II, zinc(II and silver(I were synthesized. The molar ratio metal:ligand in the reaction of the complex formation was 1:2. It should be noticed, that the reaction of all the metal salts yielded bis(ligand complexes of the general formula M(L2(NO32 × nH2O (M=Co, Ni Cu, Zn or Ag; n=0, 1, 2 or 6. The complexes were characterized by elemental analysis of the metal, molar conductivity, magnetic susceptibility measurements and IR spectra. Co(II, Ni(II and Cu(II complexes behave as non-electrolytes, whilst Zn(II and Ag(I are 1:1 electrolytes. Cu(II complex has a square-planar stereochemistry, Ag(I complex is linear, whilst the Co(II, Ni(II and Zn(II complexes have a tetrahedral configuration. In all the complexes ligand is coordinated by participation of the pyridine nitrogen of the benzimidazole ring. The antimicrobial activity of the ligand and its complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus and Saccharomyces cerevisiae was investigated. The effect of metal on the ligand antimicrobial activity is discussed.

Copper(II) and zinc(II) as metal-carboxylate coordination complexes based on (1-methyl-1H-benzo[d]imidazol-2-yl) methanol derivative: Synthesis, crystal structure, spectroscopy, DFT calculations and antioxidant activity

Science.gov (United States)

Benhassine, Anfel; Boulebd, Houssem; Anak, Barkahem; Bouraiou, Abdelmalek; Bouacida, Sofiane; Bencharif, Mustapha; Belfaitah, Ali

2018-05-01

This work presents a combined experimental and theoretical study of two new metal-carboxylate coordination compounds. These complexes were prepared from (1-methyl-1H-benzimidazol-2-yl)methanol under mild conditions. The structures of the prepared compounds were characterized by single-crystal X-ray analysis, FTIR and UV-Vis spectroscopy. In the Cupper complex, the Cu(II) ion is coordinated by two ligands, which act as bidentate chelator through the non-substituted N and O atoms, and two carboxylicg oxygen atoms, displaying a hexa-coordinated compound in a distorted octahedral geometry, while in the Zinc complex the ligand is ligated to the Zn(II) ion in monodentate fashion through the N atom, and the metal ion is also bonded to carboxylic oxygen atoms. The tetra-coordinated compound displays a distorted tetrahedral shape. The density functional theory calculations are carried out for the determination of the optimized structures. The electronic transitions and fundamental vibrational wave numbers are calculated and are in good agreement with experimental. In addition, the ligand and its Cu(II) and Zn(II) complexes were screened and evaluated for their potential as DPPH radical scavenger.

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

Science.gov (United States)

Salehi, E.; Naderi, Reza; Ramezanzadeh, B.

2017-02-01

This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn2+ and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Zinc species distribution in EDTA-extract residues of zinc-contaminated soil

International Nuclear Information System (INIS)

Chang, S.-H.; Wei, Y.-L.; Wang, H. Paul

2007-01-01

Soil sample from a site heavily contaminated with >10 wt.% zinc is sampled and extracted with aqueous solutions of ethylene diamine tetra-acetic acid (EDTA) that is a reagent frequently used to extract heavy metals in soil remediation. Three liquid/soil ratios (5/1, 20/1, and 100/1) were used in the extracting experiment. The molecular environment of the residual Zn in the EDTA-extract residues of zinc-contaminated soil is investigated with XANES technique. The results indicate that EDTA does not show considerable preference of chelating for any particular Zn species during the extraction. Zn species distribution in the sampled soil is found to resemble that in all EDTA-extract residues; Zn(OH) 2 is determined as the major zinc species (60-70%), seconded by organic zinc (21-26%) and zinc oxide (9-14%)

A review of zinc oxide mineral beneficiation using flotation method.

Science.gov (United States)

Ejtemaei, Majid; Gharabaghi, Mahdi; Irannajad, Mehdi

2014-04-01

In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy. Copyright © 2013 Elsevier B.V. All rights reserved.

Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis

Science.gov (United States)

Brahma, Sanjaya; Shivashankar, S. A.

2015-12-01

We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 °C), decomposition temperature (202 °C) as that with zinc acetylacetonate (136 °C, 220 °C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process.

Dietary Zinc Intake and Plasma Zinc Concentrations in Children with Short Stature and Failure to Thrive.

Science.gov (United States)

Yazbeck, Nadine; Hanna-Wakim, Rima; El Rafei, Rym; Barhoumi, Abir; Farra, Chantal; Daher, Rose T; Majdalani, Marianne

2016-01-01

The burden of zinc deficiency on children includes an increased incidence of diarrhea, failure to thrive (FTT) and short stature. The aim of this study was to assess whether children with FTT and/or short stature have lower dietary zinc intake and plasma zinc concentrations compared to controls. A case-control study conducted at the American University of Beirut Medical Center included 161 subjects from 1 to 10 years of age. Cases had a statistically significant lower energy intake (960.9 vs. 1,135.2 kcal for controls, p = 0.010), lower level of fat (30.3 vs. 36.5 g/day, p = 0.0043) and iron intake (7.4 vs. 9.1 mg/day, p = 0.034). There was no difference in zinc, copper, carbohydrate and protein intake between the 2 groups. The plasma zinc concentration did not differ between the cases and controls (97.4 vs. 98.2 μg/dl, p = 0.882). More cases had mild-to-moderate zinc deficiency when compared to controls with 10.3 vs. 3.6%, p = 0.095. Our study did not show statistically significant difference in dietary zinc intake and plasma zinc concentrations between children with FTT and/or short stature compared to healthy controls. A prospective study is planned to assess the effect of zinc supplementation on growth parameters in FTT children. © 2016 S. Karger AG, Basel.

Single-layer ZnMN2 (M = Si, Ge, Sn) zinc nitrides as promising photocatalysts.

Science.gov (United States)

Bai, Yujie; Luo, Gaixia; Meng, Lijuan; Zhang, Qinfang; Xu, Ning; Zhang, Haiyang; Wu, Xiuqiang; Kong, Fanjie; Wang, Baolin

2018-05-30

Searching for two-dimensional semiconductor materials that are suitable for visible-light photocatalytic water splitting provides a sustainable solution to deal with the future energy crisis and environmental problems. Herein, based on first-principles calculations, single-layer ZnMN2 (M = Si, Ge, Sn) zinc nitrides are proposed as efficient photocatalysts for water splitting. Stability analyses show that the single-layer ZnMN2 zinc nitrides exhibit energetic and dynamical stability. The electronic properties reveal that all of the single-layer ZnMN2 zinc nitrides are semiconductors. Interestingly, single-layer ZnSnN2 is a direct band gap semiconductor with a desirable band gap (1.74 eV), and the optical adsorption spectrum confirms its optical absorption in the visible light region. The hydrogen evolution reaction (HER) calculations show that the catalytic activity for single-layer ZnMN2 (M = Ge, Sn) is better than that of single-layer ZnSiN2. Furthermore, the band gaps and band edge positions for the single-layer ZnMN2 zinc nitrides can be effectively tuned by biaxial strain. Especially, single-layer ZnGeN2 can be effectively tuned to match better with the redox potentials of water and enhance the light absorption in the visible light region at a tensile strain of 5%, which is confirmed by the corresponding optical absorption spectrum. Our results provide guidance for experimental synthesis efforts and future searches for single-layer materials suitable for photocatalytic water splitting.

Two different zinc sites in bovine 5-aminolevulinate dehydratase distinguished by extended x-ray absorption fine structure

International Nuclear Information System (INIS)

Dent, A.J.; Hasnain, S.S.; Beyersmann, D.; Block, C.

1990-01-01

The zinc coordination in 5-aminolevulinate dehydratase was investigated by extended x-ray absorption fine structure (EXAFS) associated with the zinc K-edge. The enzyme binds 8 mol of zinc/mol of octameric protein, but only four zinc ions seem sufficient for full activity. The authors have undertaken a study on four forms of the enzyme: (a) the eight-zinc native enzyme; (b) the enzyme with only the four zinc sites necessary for full activation occupied; (c) the enzyme with the vacant sites of (b) occupied by four lead ions; (d) the product complex between (b) and porphobilinogen. They have shown that two structurally distinct types of zinc sites are available in the enzyme. The site necessary for activity has an average zinc environment best described by two/three histidines and one/zero oxygen from a group such as tyrosine or a solvent molecule at 2.06 ± 0.02 angstrom, one tyrosine or aspartate at 1.91 ± 0.03 angstrom, and one cysteine sulfur at 2.32 ± 0.03 angstrom with a total coordination of five ligands. The unoccupied site in (b) is dominated by a single contribution of four cysteinyl sulfur atoms at 2.28 ± 0.02 angstrom. Spectra from samples (c) and (d) show only small changes from that of (b), reflecting a slight rearrangement of the ligands around the zinc atom

Fluorescent zinc–terpyridine complex containing coordinated ...

Indian Academy of Sciences (India)

Unknown

Keywords. Zinc peroxo complex; terpyridine complexes; fluorescence ... structure determination 3. Zinc is an essential element for normal function of most .... 63 179; (d) De Silva A P, Gunaratna H Q N, Gunnlaugsson T, Huxley A J M, Mcloy C.

Polymorphic one-dimensional (N2H4)2ZnTe: soluble precursors for the formation of hexagonal or cubic zinc telluride.

Science.gov (United States)

Mitzi, David B

2005-10-03

Two hydrazine zinc(II) telluride polymorphs, (N2H4)2ZnTe, have been isolated, using ambient-temperature solution-based techniques, and the crystal structures determined: alpha-(N2H4)2ZnTe (1) [P21, a = 7.2157(4) Angstroms, b = 11.5439(6) Angstroms, c = 7.3909(4) Angstroms, beta = 101.296(1) degrees, Z = 4] and beta-(N2H4)2ZnTe (2) [Pn, a = 8.1301(5) Angstroms, b = 6.9580(5) Angstroms, c = 10.7380(7) Angstroms, beta = 91.703(1) degrees, Z = 4]. The zinc atoms in 1 and 2 are tetrahedrally bonded to two terminal hydrazine molecules and two bridging tellurium atoms, leading to the formation of extended one-dimensional (1-D) zinc telluride chains, with different chain conformations and packings distinguishing the two polymorphs. Thermal decomposition of (N2H4)2ZnTe first yields crystalline wurtzite (hexagonal) ZnTe at temperatures as low as 200 degrees C, followed by the more stable zinc blende (cubic) form at temperatures above 350 degrees C. The 1-D polymorphs are soluble in hydrazine and can be used as convenient precursors for the low-temperature solution processing of p-type ZnTe semiconducting films.

Synthesis, Structural Characterization, Antimicrobial Activity, and In Vitro Biocompatibility of New Unsaturated Carboxylate Complexes with 2,2′-Bipyridine

Directory of Open Access Journals (Sweden)

Gina Vasile Scăețeanu

2018-01-01

Full Text Available The synthesis, structural characterization, cytotoxicity, and antimicrobial properties of four new complexes formed by employing acrylate anion and 2,2′-bipyridine are reported herein. X-ray crystallography revealed the trinuclear nature of [Mn3(2,2′-bipy2(C3H3O26] (1, meanwhile complexes with general formula [M(2,2′-bipy(C3H3O22(H2Ox]∙yH2O ((2 M: Ni, x = 1, y = 0; (3 M: Cu, x = 1, y = 0; (4 M: Zn, x = 0, y = 1; 2,2′-bipy: 2,2′-bipyridine; C3H3O2: acrylate anion were shown to be mononuclear. The lowest minimum inhibitory concentration (MIC of 128 μg mL−1 was recorded for all four tested complexes against Candida albicans, for complex (3 against Escherichia coli, and for complex (4 against Staphylocococcus aureus. Compounds (3 and (4 were also potent efflux pumps activity inhibitors (EPI, proving their potential for use in synergistic combinations with antibiotics. Complexes (1–(4 revealed that they were not cytotoxic to HCT-8 cells. They also proved to interfere with the cellular cycle of tumour HCT-8 cells by increasing the number of cells found in the S and G2/M phases. Taken together, these results demonstrate the potential of zinc and copper complexes for use in the development of novel antimicrobial and anti-proliferative agents.

Synthesis of triazole-based and imidazole-based zinc catalysts

Energy Technology Data Exchange (ETDEWEB)

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

2013-03-12

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

Status of zinc injection in PWRs

Energy Technology Data Exchange (ETDEWEB)

Bergmann, C.A. [Westinghouse Electric Co., Pittsburgh, PA (United States)

1995-03-01

Based on laboratory and other studies, it was concluded that zinc addition in a PWR primary coolant should result in reduced Alloy 600 PWSCC and general corrosion rates of the materials of construction. Because of these positive results, a Westinghouse Owner`s Subgroup, EPRI, and Westinghouse provided funds to continue the development and application of zinc in an operating plant. As part of the program, Southern Operating Nuclear Company agreed to operate the Farley 2 plant with zinc addition as a demonstration test of the effectiveness of zinc. Since zinc is incorporated in the corrosion oxide film on the primary system surfaces and Farley 2 is a mature plant, it was estimated that about 10 kgs of zinc would be needed to condition the plant before an equilibrium value in the coolant would be reached. The engineered aspects of a Zinc Addition and Monitoring System (ZAMS) considered such items as the constitutents, location, sizing and water supply of the ZAMS. Baseline data such as the PWSCC history of the Alloy 600 steam generator tubing, fuel oxide thickness, fuel crud deposits, radiation levels, and RCP seal leak-off rates were obtained before zinc addition is initiated. This presentation summarizes some of the work performed under the program, and the status of zinc injection in the Farley 2 plant.

Associations between Dietary Iron and Zinc Intakes, and between Biochemical Iron and Zinc Status in Women

Directory of Open Access Journals (Sweden)

Karen Lim

2015-04-01

Full Text Available Iron and zinc are found in similar foods and absorption of both may be affected by food compounds, thus biochemical iron and zinc status may be related. This cross-sectional study aimed to: (1 describe dietary intakes and biochemical status of iron and zinc; (2 investigate associations between dietary iron and zinc intakes; and (3 investigate associations between biochemical iron and zinc status in a sample of premenopausal women aged 18–50 years who were recruited in Melbourne and Sydney, Australia. Usual dietary intakes were assessed using a 154-item food frequency questionnaire (n = 379. Iron status was assessed using serum ferritin and hemoglobin, zinc status using serum zinc (standardized to 08:00 collection, and presence of infection/inflammation using C-reactive protein (n = 326. Associations were explored using multiple regression and logistic regression. Mean (SD iron and zinc intakes were 10.5 (3.5 mg/day and 9.3 (3.8 mg/day, respectively. Median (interquartile range serum ferritin was 22 (12–38 μg/L and mean serum zinc concentrations (SD were 12.6 (1.7 μmol/L in fasting samples and 11.8 (2.0 μmol/L in nonfasting samples. For each 1 mg/day increase in dietary iron intake, zinc intake increased by 0.4 mg/day. Each 1 μmol/L increase in serum zinc corresponded to a 6% increase in serum ferritin, however women with low serum zinc concentration (AM fasting < 10.7 μmol/L; AM nonfasting < 10.1 μmol/L were not at increased risk of depleted iron stores (serum ferritin <15 μg/L; p = 0.340. Positive associations were observed between dietary iron and zinc intakes, and between iron and zinc status, however interpreting serum ferritin concentrations was not a useful proxy for estimating the likelihood of low serum zinc concentrations and women with depleted iron stores were not at increased risk of impaired zinc status in this cohort.

Highly Durable Na2V6O16·1.63H2O Nanowire Cathode for Aqueous Zinc-Ion Battery.

Science.gov (United States)

Hu, Ping; Zhu, Ting; Wang, Xuanpeng; Wei, Xiujuan; Yan, Mengyu; Li, Jiantao; Luo, Wen; Yang, Wei; Zhang, Wencui; Zhou, Liang; Zhou, Zhiqiang; Mai, Liqiang

2018-03-14

Rechargeable aqueous zinc-ion batteries are highly desirable for grid-scale applications due to their low cost and high safety; however, the poor cycling stability hinders their widespread application. Herein, a highly durable zinc-ion battery system with a Na 2 V 6 O 16 ·1.63H 2 O nanowire cathode and an aqueous Zn(CF 3 SO 3 ) 2 electrolyte has been developed. The Na 2 V 6 O 16 ·1.63H 2 O nanowires deliver a high specific capacity of 352 mAh g -1 at 50 mA g -1 and exhibit a capacity retention of 90% over 6000 cycles at 5000 mA g -1 , which represents the best cycling performance compared with all previous reports. In contrast, the NaV 3 O 8 nanowires maintain only 17% of the initial capacity after 4000 cycles at 5000 mA g -1 . A single-nanowire-based zinc-ion battery is assembled, which reveals the intrinsic Zn 2+ storage mechanism at nanoscale. The remarkable electrochemical performance especially the long-term cycling stability makes Na 2 V 6 O 16 ·1.63H 2 O a promising cathode for a low-cost and safe aqueous zinc-ion battery.

Effects of zinc supplementation and zinc chelation on in vitro β-cell function in INS-1E cells

DEFF Research Database (Denmark)

Nygaard, Sanne Bjørn; Larsen, Agnete; Knuhtsen, Astrid

2014-01-01

BACKGROUND: Zinc is essential for the activities of pancreatic β-cells, especially insulin storage and secretion. Insulin secretion leads to co-release of zinc which contributes to the paracrine communication in the pancreatic islets. Zinc-transporting proteins (zinc-regulated transporter, iron......-regulated transporter-like proteins [ZIPs] and zinc transporters [ZnTs]) and metal-buffering proteins (metallothioneins, MTs) tightly regulate intracellular zinc homeostasis. The present study investigated how modulation of cellular zinc availability affects β-cell function using INS-1E cells. RESULTS: Using INS-1E...... cells, we found that zinc supplementation and zinc chelation had significant effects on insulin content and insulin secretion. Supplemental zinc within the physiological concentration range induced insulin secretion. Insulin content was reduced by zinc chelation with N,N,N',N-tektrakis(2-pyridylmethyl...

Association of reduced zinc status with poor glycemic control in individuals with type 2 diabetes mellitus.

Science.gov (United States)

Bandeira, Verônica da Silva; Pires, Liliane Viana; Hashimoto, Leila Leiko; Alencar, Luciane Luca de; Almondes, Kaluce Gonçalves Sousa; Lottenberg, Simão Augusto; Cozzolino, Silvia Maria Franciscato

2017-12-01

This study evaluated the relationship between the zinc-related nutritional status and glycemic and insulinemic markers in individuals with type 2 diabetes mellitus (T2DM). A total of 82 individuals with T2DM aged between 29 and 59 years were evaluated. The concentration of zinc in the plasma, erythrocytes, and urine was determined by the flame atomic absorption spectrometry method. Dietary intake was assessed using a 3-day 24-h recall. In addition, concentrations of serum glucose, glycated hemoglobin percentage, total cholesterol and fractions, triglycerides, and serum insulin were determined. The insulin resistance index (HOMA-IR) and β-cell function (HOMA- β) were calculated. The markers of zinc status (plasma: 83.3±11.9μg/dL, erythrocytes: 30.1±4.6μg/g Hb, urine: 899.1±622.4μg Zn/24h, and dietary: 9.9±0.8mg/day) were classified in tertiles and compared to insulinemic and glycemic markers. The results showed that lower zinc concentrations in plasma and erythrocytes, as well as its high urinary excretion, were associated with higher percentages of glycated hemoglobin, reflecting a worse glycemic control in individuals with T2DM (pzinc levels and glycated hemoglobin percentage (r=-0.325, p=0.003), and a positive correlation between urinary zinc excretion and glycemia (r=0.269, p=0.016), glycated hemoglobin percentage (r=0.318, p=0.004) and HOMA-IR (r=0.289, p=0.009). According to our study results, conclude that T2DM individuals with reduced zinc status exhibited poor glycemic control. Copyright © 2017 Elsevier GmbH. All rights reserved.

Organically pillared layered zinc hydroxides

International Nuclear Information System (INIS)

Kongshaug, K.O.; Fjellvaag, Helmer

2004-01-01

The two organically pillared layered zinc hydroxides [Zn 2 (OH) 2 (ndc)], CPO-6, and [Zn 3 (OH) 4 (bpdc)], CPO-7, were obtained in hydrothermal reactions between 2,6-naphthalenedicarboxylic acid (ndc) and zinc nitrate (CPO-6) and 4,4'biphenyldicarboxylate (bpdc) and zinc nitrate (CPO-7), respectively. In CPO-6, the tetrahedral zinc atoms are connected by two μ 2 -OH groups and two carboxylate oxygen atoms, forming infinite layers extending parallel to the bc-plane. These layers are pillared by ndc to form a three-dimensional structure. In CPO-7, the zinc hydroxide layers are containing four-, five- and six coordinated zinc atoms, and the layers are built like stairways running along the [001] direction. Each step is composed of three infinite chains running in the [010] direction. Both crystal structures were solved from conventional single crystal data. Crystal data for CPO-6: Monoclinic space group P2 1 /c (No. 14), a=11.9703(7), b=7.8154(5), c=6.2428(4) A, β=90.816(2) deg., V=583.97(6) A 3 and Z=4. Crystal data for CPO-7: Monoclinic space group C2/c (No. 15), a=35.220(4), b=6.2658(8), c=14.8888(17) A, β=112.580(4) deg., V=3033.8(6) A 3 and Z=8. The compounds were further characterized by thermogravimetric- and chemical analysis

Zinc-induced Self-association of Complement C3b and Factor H

Science.gov (United States)

Nan, Ruodan; Tetchner, Stuart; Rodriguez, Elizabeth; Pao, Po-Jung; Gor, Jayesh; Lengyel, Imre; Perkins, Stephen J.

2013-01-01

The sub-retinal pigment epithelial deposits that are a hallmark of age-related macular degeneration contain both C3b and millimolar levels of zinc. C3 is the central protein of complement, whereas C3u is formed by the spontaneous hydrolysis of the thioester bridge in C3. During activation, C3 is cleaved to form active C3b, then C3b is inactivated by Factor I and Factor H to form the C3c and C3d fragments. The interaction of zinc with C3 was quantified using analytical ultracentrifugation and x-ray scattering. C3, C3u, and C3b associated strongly in >100 μm zinc, whereas C3c and C3d showed weak association. With zinc, C3 forms soluble oligomers, whereas C3u and C3b precipitate. We conclude that the C3, C3u, and C3b association with zinc depended on the relative positions of C3d and C3c in each protein. Computational predictions showed that putative weak zinc binding sites with different capacities exist in all five proteins, in agreement with experiments. Factor H forms large oligomers in >10 μm zinc. In contrast to C3b or Factor H alone, the solubility of the central C3b-Factor H complex was much reduced at 60 μm zinc and even more so at >100 μm zinc. The removal of the C3b-Factor H complex by zinc explains the reduced C3u/C3b inactivation rates by zinc. Zinc-induced precipitation may contribute to the initial development of sub-retinal pigment epithelial deposits in the retina as well as reducing the progression to advanced age-related macular degeneration in higher risk patients. PMID:23661701

Studies on coordination chemistry and bioactivity of metal complexes of some nitrogen-sulfur donor ligands: Section A: hydraziniumdithiocarbazate and its complexes. Section B: complexes of Ni2+ and Cu2+ ions with s-picolyldithiocarbazate

International Nuclear Information System (INIS)

Tarafder, M.T.H.; Liza bt Abdullah; Crouse, Karen A.; Ali, A.M.

2003-08-01

Two new nitrogen - sulphur donor ligands, hydraziniumdithiocarbazate(HzDTC) and S-picolyldithiocarbazate(SPDTC), along with three novel Schiff bases were prepared. Complexes of some of HzDTC with nickel(II), zinc(II), and those of SPDTC with nickel(II) and copper(II) were prepared and characterized by a variety of physico- chemical techniques. The ligand, HzDTC, was a potential bidentate and uninegatively charged providing terminal amino and thiolate bindings with the metal ions, while SPDTC coordinates via the pyridine nitrogen and the thiolate anion. All of the compounds were tested against four pathogenic bacteria and fungi. HzDTC was found to be very effective antimicrobial than its complexes. The complexes of SPDTC and the Schiff bases of HzDTC were more antifungal. None of the compounds were effective anti- cancer agents except for [Ni(HzDTCA)Cl.H 2 O], which was moderately active against CEM- SS (Human cell T- lymphoblastic) leukemic cells. (author)

Hydrogen-related complexes in Li-diffused ZnO single crystals

Science.gov (United States)

Corolewski, Caleb D.; Parmar, Narendra S.; Lynn, Kelvin G.; McCluskey, Matthew D.

2016-07-01

Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li2O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>1019 cm-3). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm-1, attributed to surface O-H species. When Li2CO3 is used, a structured blue luminescence band and O-H mode at 3327 cm-1 are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy-hydrogen complex, with an acceptor level ˜0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

Hydrogen-related complexes in Li-diffused ZnO single crystals

International Nuclear Information System (INIS)

Corolewski, Caleb D.; Parmar, Narendra S.; Lynn, Kelvin G.; McCluskey, Matthew D.

2016-01-01

Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li_2O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>10"1"9" cm"−"3). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm"−"1, attributed to surface O-H species. When Li_2CO_3 is used, a structured blue luminescence band and O-H mode at 3327 cm"−"1 are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy–hydrogen complex, with an acceptor level ∼0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

Seeking for Non-Zinc-Binding MMP-2 Inhibitors: Synthesis, Biological Evaluation and Molecular Modelling Studies

Directory of Open Access Journals (Sweden)

Alessandra Ammazzalorso

2016-10-01

Full Text Available Matrix metalloproteinases (MMPs are an important family of zinc-containing enzymes with a central role in many physiological and pathological processes. Although several MMP inhibitors have been synthesized over the years, none reached the market because of off-target effects, due to the presence of a zinc binding group in the inhibitor structure. To overcome this problem non-zinc-binding inhibitors (NZIs have been recently designed. In a previous article, a virtual screening campaign identified some hydroxynaphtyridine and hydroxyquinoline as MMP-2 non-zinc-binding inhibitors. In the present work, simplified analogues of previously-identified hits have been synthesized and tested in enzyme inhibition assays. Docking and molecular dynamics studies were carried out to rationalize the activity data.

Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

International Nuclear Information System (INIS)

Lehr, I.L.; Saidman, S.B.

2012-01-01

This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

Science.gov (United States)

Lehr, I. L.; Saidman, S. B.

2012-03-01

This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

Compartmentation of metals in foliage of Populus tremula grown on soils with mixed contamination. II. Zinc binding inside leaf cell organelles

Energy Technology Data Exchange (ETDEWEB)

Vollenweider, Pierre, E-mail: pierre.vollenweider@wsl.c [Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Bernasconi, Petra [Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Environmental Protection Office (AfU), Aabachstrasse 5, 6300 Zug (Switzerland); Gautschi, Hans-Peter [Centre for Microscopy and Image Analysis (CMI), University of Zurich, Gloriastrasse 30, 8006 Zuerich (Switzerland); Menard, Terry; Frey, Beat; Guenthardt-Goerg, Madeleine S. [Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zuercherstrasse 111, 8903 Birmensdorf (Switzerland)

2011-01-15

The phytoextraction potential of plants for removing heavy metals from polluted soils is determined by their capacity to store contaminants in aboveground organs and complex them safely. In this study, the metal compartmentation, elemental composition of zinc deposits and zinc complexation within leaves from poplars grown on soil with mixed metal contamination was analysed combining several histochemical and microanalytical approaches. Zinc was the only heavy metal detected and was stored in several organelles in the form of globoid deposits showing {beta}-metachromasy. It was associated to oxygen anions and different cations, noteworthy phosphorous. The deposit structure, elemental composition and element ratios indicated that zinc was chelated by phytic acid ligands. Maturation processes in vacuolar vs. cytoplasmic deposits were suggested by differences in size and amounts of complexed zinc. Hence, zinc complexation by phytate contributed to metal detoxification and accumulation in foliage but could not prevent toxicity reactions therein. - Zinc contaminants translocated to symplast of aged leaves were detoxified by phytic acid ligands.

Compartmentation of metals in foliage of Populus tremula grown on soils with mixed contamination. II. Zinc binding inside leaf cell organelles

International Nuclear Information System (INIS)

Vollenweider, Pierre; Bernasconi, Petra; Gautschi, Hans-Peter; Menard, Terry; Frey, Beat; Guenthardt-Goerg, Madeleine S.

2011-01-01

The phytoextraction potential of plants for removing heavy metals from polluted soils is determined by their capacity to store contaminants in aboveground organs and complex them safely. In this study, the metal compartmentation, elemental composition of zinc deposits and zinc complexation within leaves from poplars grown on soil with mixed metal contamination was analysed combining several histochemical and microanalytical approaches. Zinc was the only heavy metal detected and was stored in several organelles in the form of globoid deposits showing β-metachromasy. It was associated to oxygen anions and different cations, noteworthy phosphorous. The deposit structure, elemental composition and element ratios indicated that zinc was chelated by phytic acid ligands. Maturation processes in vacuolar vs. cytoplasmic deposits were suggested by differences in size and amounts of complexed zinc. Hence, zinc complexation by phytate contributed to metal detoxification and accumulation in foliage but could not prevent toxicity reactions therein. - Zinc contaminants translocated to symplast of aged leaves were detoxified by phytic acid ligands.

The solvent extraction of zinc, iron, and indium from chloride solutions by neutral organophosphorus compounds

International Nuclear Information System (INIS)

Preston, J.S.; Du Preez, A.C.

1985-01-01

The preparation of several neutral organophosphorus compounds and their evaluation as selective extractants for zinc in chloride media are described. The compounds belong to the series trialkyl phosphates (RO) 3 PO, dialkyl alkylphosphonates R'PO(OR) 2 , alkyl dialkylphosphinates R 2 'PO(OR), and trialkyl-phosphine oxides R 3 'PO. They were characterized by measurement of their physical properties (melting and boiling points, refractive indices, and densities), and their purities were confirmed by osmometric determination of their molecular masses; by carbon and hydrogen microanalysis; by the titrimetric determination of acidic impurities; and, for liquid products, by comparison of their experimental molar refractivities with empirical values. Metal-distribution equilibria were determined for solutions of the extractants in xylene and aqueous phase containing 0,5 to 5,0 M sodium chloride. Moderately good selectivities were shown for zinc(II) over iron(III), and excellent selectivities were shown for zinc(II) over iron(II), copper(II), lead(II), and cadmium(II). The extraction of indium(III) was similar to that of zinc(II). The extraction of zinc(III), iron(III), and indium(III) increased markedly through the series. (RO) 3 PO 2 2 'PO(OR) 3 'PO. The incorporation of phenyl groups into the compounds led to weaker extraction. The extracted complexes of zinc(II), iron(III), and indium(III) have the stoichiometries ZnCl 2 L 2 ,FeCl 3 L 2 (H 2 O), and InCl 3 L 2 (H 2 O) respectively, where L represents the neutral organophosphorus compound

Factors influencing zinc status of apparently healthy indians.

Science.gov (United States)

Agte, Vaishali V; Chiplonkar, Shashi A; Tarwadi, Kirtan V

2005-10-01

To identify dietary, environmental and socio-economic factors associated with mild zinc deficiency, three zinc status indices; erythrocyte membrane zinc (RBCMZn), plasma zinc and super oxide dismutase (SOD) were assessed in free living and apparently healthy Indian population. Dietary patterns of 232 men and 223 women (20-65 yr) from rural, industrial and urban regions of Western India were evaluated by food frequency questionnaire. RBCMZn was estimated using atomic absorption spectrometry, hemoglobin and serum ceruloplasmin by spectrophotometer. On a sub sample (48 men and 51 women) plasma zinc and SOD were also assessed. Mean RBCMZn was 0.5 +/- 0.1 micromols/g protein with 46% individuals showing zinc deficiency. Mean plasma zinc was 0.98 +/- 0.12 microg/mL with 25% men and 2.5% women having values below normal range. Mean SOD was 0.97 +/- 0.1 (u/mL cells). A significant positive correlation was observed between intakes of green leafy vegetables, other vegetables and milk products with RBCMZn status (p plasma zinc (p > 0.2). Cereal and legume intakes were negatively correlated with RBCMZn (p plasma zinc (p 0.2). Fruit and other vegetable intake were positively correlated with SOD (p Plasma zinc indicated positive association with zinc, thiamin and riboflavin intakes (p plasma zinc and SOD. Prominent determinants of zinc status were intakes of beta-carotene and zinc along with environmental conditions and family size.

Zinc Status Affects Glucose Homeostasis and Insulin Secretion in Patients with Thalassemia

Directory of Open Access Journals (Sweden)

Ellen B. Fung

2015-06-01

Full Text Available Up to 20% of adult patients with Thalassemia major (Thal live with diabetes, while 30% may be zinc deficient. The objective of this study was to explore the relationship between zinc status, impaired glucose tolerance and insulin sensitivity in Thal patients. Charts from thirty subjects (16 male, 27.8 ± 9.1 years with Thal were reviewed. Patients with low serum zinc had significantly lower fasting insulin, insulinogenic and oral disposition indexes (all p < 0.05 and elevated glucose response curve, following a standard 75 g oral load of glucose compared to those with normal serum zinc after controlling for baseline (group × time interaction p = 0.048. Longitudinal data in five patients with a decline in serum zinc over a two year follow up period (−19.0 ± 9.6 μg/dL, showed consistent increases in fasting glucose (3.6 ± 3.2 mg/dL and insulin to glucose ratios at 120 min post glucose dose (p = 0.05. Taken together, these data suggest that the frequently present zinc deficiency in Thal patients is associated with decreased insulin secretion and reduced glucose disposal. Future zinc trials will require modeling of oral glucose tolerance test data and not simply measurement of static indices in order to understand the complexities of pancreatic function in the Thal patient.

[Improvement in zinc nutrition due to zinc transporter-targeting strategy].

Science.gov (United States)

Kambe, Taiho

2016-07-01

Adequate intake of zinc from the daily diet is indispensable to maintain health. However, the dietary zinc content often fails to fulfill the recommended daily intake, leading to zinc deficiency and also increases the risk of developing chronic diseases, particularly in elderly individuals. Therefore, increased attention is required to overcome zinc deficiency and it is important to improve zinc nutrition in daily life. In the small intestine, the zinc transporter, ZIP4, functions as a component that is essential for zinc absorption. In this manuscript, we present a brief overview regarding zinc deficiency. Moreover, we review a novel strategy, called "ZIP4-targeting", which has the potential to enable efficient zinc absorption from the diet. ZIP4-targeting strategy is possibly a major step in preventing zinc deficiency and improving human health.

Zinc absorption in inflammatory bowel disease

International Nuclear Information System (INIS)

Valberg, L.S.; Flanagan, P.R.; Kertesz, A.; Bondy, D.C.

1986-01-01

Zinc absorption was measured in 29 patients with inflammatory bowel disease and a wide spectrum of disease activity to determine its relationship to disease activity, general nutritional state, and zinc status. Patients with severe disease requiring either supplementary oral or parenteral nutrition were excluded. The mean 65ZnCl2 absorption, in the patients, determined using a 65Zn and 51Cr stool-counting test, 45 +/- 17% (SD), was significantly lower than the values, 54 +/- 16%, in 30 healthy controls, P less than 0.05. Low 65ZnCl2 absorption was related to undernutrition, but not to disease activity in the absence of undernutrition or to zinc status estimated by leukocyte zinc measurements. Mean plasma zinc or leukocyte zinc concentrations in patients did not differ significantly from controls, and only two patients with moderate disease had leukocyte zinc values below the 5th percentile of normal. In another group of nine patients with inflammatory bowel disease of mild-to-moderate severity and minimal nutritional impairment, 65Zn absorption from an extrinsically labeled turkey test meal was 31 +/- 10% compared to 33 +/- 7% in 17 healthy controls, P greater than 0.1. Thus, impairment in 65ZnCl2 absorption in the patients selected for this study was only evident in undernourished persons with moderate or severe disease activity, but biochemical evidence of zinc deficiency was uncommon, and clinical features of zinc depletion were not encountered

TNFα Post-Translationally Targets ZnT2 to Accumulate Zinc in Lysosomes.

Science.gov (United States)

Hennigar, Stephen R; Kelleher, Shannon L

2015-10-01

Mammary epithelial cells undergo widespread lysosomal-mediated cell death (LCD) during early mammary gland involution. Recently, we demonstrated that tumor necrosis factor-α (TNFα), a cytokine released during early involution, redistributes the zinc (Zn) transporter ZnT2 to accumulate Zn in lysosomes and activate LCD and involution. The objective of this study is to determine how TNFα retargets ZnT2 to lysosomes. We tested the hypothesis that TNFα signaling dephosphorylates ZnT2 to uncover a highly conserved dileucine motif (L294L) in the C-terminus of ZnT2, allowing adaptor protein complex-3 (AP-3) to bind and traffic ZnT2 to lysosomes. Confocal micrographs showed that TNFα redistributed wild-type (WT) ZnT2 from late endosomes (Pearson's coefficient = 0.202 ± 0.05 and 0.097 ± 0.03; Plysosomes (0.292 ± 0.03 and 0.649 ± 0.03; Plysosomal Zn (Plysosomes, increase lysosomal Zn, or activate LCD. Moreover, TNFα increased (Plysosomes and activate LCD. Our findings suggest that women with variation in the C-terminus of ZnT2 may be at risk for inadequate involution and breast disease due the inability to traffic ZnT2 to lysosomes. © 2015 Wiley Periodicals, Inc.

Synthesis of silylated pyrimidines nucleosides. Catalytic condensations with organo-zinc, organo-zirconium, and organo-borane compounds

International Nuclear Information System (INIS)

Vincent, Patrice

1982-01-01

This research thesis addressed the synthesis of new desoxy-2' uridines substituted in C-5. The starting compound was the iodo-5 0-3',5' bis(trimethylsilyl) dUrd. It has been coupled with acetylenic organo-zinc in presence of organo-palladium and nickel compounds to obtain alkynyl-5 dUrd, with ethylenic organo-zirconium compounds in presence of organo-palladium complexes to obtain (E)-alkenyl-5 dUrd, with ethylenic organo-boranes in presence of organo-palladium complexes to obtain (E) and (Z) alkenyl-5 uRd, and with cyclic or heterocyclic organo-zinc compounds in presence of organo-palladium complexes. Thirty new pyrimidine nucleosides have thus been obtained, and some of them have been used for biological tests [fr

Pan-Domain Analysis of ZIP Zinc Transporters

Directory of Open Access Journals (Sweden)

Laura E. Lehtovirta-Morley

2017-12-01

Full Text Available The ZIP (Zrt/Irt-like protein family of zinc transporters is found in all three domains of life. However, little is known about the phylogenetic relationship amongst ZIP transporters, their distribution, or their origin. Here we employed phylogenetic analysis to explore the evolution of ZIP transporters, with a focus on the major human fungal pathogen, Candida albicans. Pan-domain analysis of bacterial, archaeal, fungal, and human proteins revealed a complex relationship amongst the ZIP family members. Here we report (i a eukaryote-wide group of cellular zinc importers, (ii a fungal-specific group of zinc importers having genetic association with the fungal zincophore, and, (iii a pan-kingdom supercluster made up of two distinct subgroups with orthologues in bacterial, archaeal, and eukaryotic phyla.

From zinc selenate to zinc selenide nano structures synthesized by reduction process

International Nuclear Information System (INIS)

Hutagalung, S.D.; Eng, S.T.; Ahmad, Z.A.; Ishak Mat; Yussof Wahab

2009-01-01

One-dimensional nano structure materials are very attractive because of their electronic and optical properties depending on their size. It is well known that properties of material can be tuned by reducing size to nano scale because at the small sizes, that they behave differently with its bulk materials and the band gap will control by the size. The tunability of the band gap makes nano structured materials useful for many applications. As one of the wide band gaps semiconductor compounds, zinc selenide (ZnSe) nano structures (nanoparticles, nano wires, nano rods) have received much attention for the application in optoelectronic devices, such as blue laser diode, light emitting diodes, solar cells and IR optical windows. In this study, ZnSe nano structures have been synthesized by reduction process of zinc selenate using hydrazine hydrate (N 2 H 4 .2H 2 O). The reductive agent of hydrazine hydrate was added to the starting materials of zinc selenate were heat treated at 500 degree Celsius for 1 hour under argon flow to form one-dimensional nano structures. The SEM and TEM images show the formation of nano composite-like structure, which some small nano bar and nano pellets stick to the rod. The x-ray diffraction and elemental composition analysis confirm the formation of mixture zinc oxide and zinc selenide phases. (author)

Development of nano SiO2 incorporated nano zinc phosphate coatings on mild steel

International Nuclear Information System (INIS)

Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.; Selvi, J. Arockia

2015-01-01

Highlights: • Nano SiO 2 incorporated nano zinc phosphate coating on mild steel was developed. • Coatings showed enhanced corrosion resistance. • The nano SiO 2 is adsorbed on mild steel surface and become nucleation sites. • The nano SiO 2 accelerates the phosphating process. - Abstract: This paper reports the development of nano SiO 2 incorporated nano zinc phosphate coatings on mild steel at low temperature for achieving better corrosion protection. A new formulation of phosphating bath at low temperature with nano SiO 2 was attempted to explore the possibilities of development of nano zinc phosphate coatings on mild steel with improved corrosion resistance. The coatings developed were studied by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Electrochemical measurements. Significant variation in the coating weight, morphology and corrosion resistance was observed as nano SiO 2 concentrations varied from 0.5–4 g/L. The results showed that, the nano SiO 2 in the phosphating solution changed the initial potential of the interface between mild steel substrate and phosphating solution and reduce the activation energy of the phosphating process, increase the nucleation sites and yielded zinc phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance. Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano SiO 2 . The new formulation reported in the present study was free from Ni or Mn salts and had very low concentration of sodium nitrite (0.4 g/L) as accelerator

The effects of Zinc supplementation on serum zinc, alkaline phosphatase activity and fracture healing of bones

International Nuclear Information System (INIS)

Sadighi, A.; Moradi, A.; Roshan, Marjan M.; Ostadrahimi, A.

2009-01-01

Objective was to determine the effect of zinc supplementation on callus information, serum zinc and alkaline phosphatase activity in humans. This randomized, double-blind, placebo controlled clinical trial was conducted on 60 patients with traumatic bone fracture referred to Shohada Hospital of Tabriz, Iran from August to December 2007. Subjects were randomly divided into 2 groups: cases (n=30), receiving one capsule of zinc sulfate consists of 50 mg zinc each day and the controls (n=30), receiving placebo for 60 days. Individual and clinical information was determined by a questionnaire: nutritional intake by 3 days food records at the beginning and the end of trial. Serum zinc and alkaline phosphatase was measured by atomic absorption spectroscopy and by enzymatic method. Callus information during fracture healing was evaluated by radiography of the bone. There was no significant difference in physical activity, gender, age, type of fractures and nutrient intake, between the 2 groups. The administration of zinc caused a significant elevation of serum zinc and alkaline phosphatase activity. Assessment of bone x-rays showed a significant progress in callus formation in cases compared to the controls. This study shows that zinc supplementation can stimulate fracture healing, however, it needs further study. (author)

Study of iron-zinc catalysts by Moessbauer spectroscopy

International Nuclear Information System (INIS)

Arriola, S.H.

1990-01-01

The Moessbauer parameters were determined on a series of catalyst mixtures of iron and zinc oxides with variable quantities of zinc. A change in the crystal structure of the iron oxide when introducing zinc into the samples was observed. The corundum structure of the α-Fe 2 O 3 phase was transformed into the spinel type of zinc ferrite when zinc oxide was present in any quantity. A strong electronic interaction between the zinc ferrite and the zinc oxide present in excess was evident. The catalysts were analyzed using x-ray fluorescence and x-ray diffraction methods. (author) 10 refs.; 4 figs.; 2 tabs

A DFT study on the structures and electronic states of zinc cluster Znn (n = 2-32)

International Nuclear Information System (INIS)

Iokibe, Kei; Tachikawa, Hiroto; Azumi, Kazuhisa

2007-01-01

Ab-initio and density functional theory (DFT) calculations have been carried out for zinc clusters Zn n (n = 2-32, n is the number of atoms to form a cluster) to elucidate the structure and electronic charge states of the clusters and the mechanism of clustering. The binding energies of Zn atoms were negligibly small at n = 2-3, whereas the energy increased significantly at n = 4 (the first transition). The second transition occurred at n = 8-16. In the larger clusters (n = 16-32), the binding energy increased slightly with increasing cluster size (n). The cluster size dependence of the binding energy and bond length between zinc atoms agreed well with that of the natural population of electrons in the 4p orbital of the zinc atom. In the larger clusters (n > 20), it was found that the zinc atoms in the surface region of the cluster have a positive charge, whereas those in the interior region have a negative charge with a large population in the 4p orbital. The formation mechanism of zinc clusters was discussed on the basis of the theoretical results

Improved electrolyte for zinc-bromine flow batteries

Science.gov (United States)

Wu, M. C.; Zhao, T. S.; Wei, L.; Jiang, H. R.; Zhang, R. H.

2018-04-01

Conventional zinc bromide electrolytes offer low ionic conductivity and often trigger severe zinc dendrite growth in zinc-bromine flow batteries. Here we report an improved electrolyte modified with methanesulfonic acid, which not only improves the electrolyte conductivity but also ameliorates zinc dendrite. Experimental results also reveal that the kinetics and reversibility of Zn2+/Zn and Br2/Br- are improved in this modified electrolyte. Moreover, the battery's internal resistance is significantly reduced from 4.9 to 2.0 Ω cm2 after adding 1 M methanesulfonic acid, thus leading to an improved energy efficiency from 64% to 75% at a current density of 40 mA cm-2. More impressively, the battery is capable of delivering an energy efficiency of about 78% at a current density of as high as 80 mA cm-2 when the electrode is replaced by a thermally treated one. Additionally, zinc dendrite growth is found to be effectively suppressed in methanesulfonic acid supported media, which, as a result, enables the battery to be operated for 50 cycles without degradation, whereas the one without methanesulfonic acid suffers from significant decay after only 40 cycles, primarily due to severe zinc dendrite growth. These superior results indicate methanesulfonic acid is a promising supporting electrolyte for zinc-bromine flow batteries.

A Lewis acid β-diiminato-zinc-complex as all-rounder for co- and terpolymerisation of various epoxides with carbon dioxide.

Science.gov (United States)

Reiter, M; Vagin, S; Kronast, A; Jandl, C; Rieger, B

2017-03-01

A β-diiminato-zinc-N(SiMe 3 ) 2 complex ( 1 ) was synthesised and fully characterised, including an X-ray diffraction study. The activity of catalyst 1 towards the coupling reaction of CO 2 and various epoxides, including propylene oxide (PO), cyclohexene oxide (CHO), styrene oxide (SO), limonene oxide (LO), octene oxide (OO) and epichlorohydrin (ECH), was investigated. Terpolymerisation of CO 2 , PO and LO, as well as CO 2 , CHO and PO, was successfully realised, resulting in polymers with adjustable glass transition temperatures and transparencies. Reaction conditions such as temperature, pressure and catalyst concentration were varied to find the optimal reaction values, especially regarding LO/CO 2 . In situ IR experiments hinted that at 60 °C and a critical LO concentration, polymerisation and depolymerisation are in an equilibrium (ceiling effect). Pressurising catalyst 1 with carbon dioxide resulted in a dimeric catalyst ( 2 ) with a OSiMe 3 group as a new initiator. Homopolymerisation of different epoxides was carried out in order to explain the reactivity concerning copolymerisation reaction of CO 2 and epoxides.

Uptake and loss of dissolved zinc by the stickleback gasterosteus Aculeatus l. [Zinc 65

Energy Technology Data Exchange (ETDEWEB)

Matthiessen, P.; Brafield, A.E.

1977-01-01

Uptake and loss by sticklebacks of both stable zinc and /sup 65/Zn in hard and soft water were studied for periods up to 400 h. In calcium-free water, the zinc uptake curve is approximately asymptotic over a period of 24 h, while in hard water internal Zn levels dropped at 24 h. Over 5 h, fish in hard tapwater absorb about 3 to 5 times more Zn than those in calcium-free water. There is positive linear correlation between log Zn uptake and log wet weight of fish. Whole-body concentration factors (c.f.) at 16 h reach a maximum of 12.2 (mean = 2.9), highest concentrations of Zn being found in the gills (mean c.f. = 5.1), and lowest concentrations in the gonads (mean c.f. = 0.8). Over longer periods (400 h), internal stable zinc levels of fish exposed to 1 and 4 ppM Zn/sup +2/ remain little higher than controls (max. 28%) /sup 65/Zn efflux in zinc-free water falls to zero after 5 h, more zinc (78%) being lost after uptake in tapwater than in calcium-free water (56%).

Fortification of staple foods with zinc for improving zinc status and other health outcomes in the general population.

Science.gov (United States)

Shah, Dheeraj; Sachdev, Harshpal S; Gera, Tarun; De-Regil, Luz Maria; Peña-Rosas, Juan Pablo

2016-06-09

, extracted data from included studies, and assessed the risk of bias of the included studies. We included eight trials (709 participants); seven were from middle-income countries of Asia, Africa, Europe, and Latin America where zinc deficiency is likely to be a public health problem. Four trials compared the effect of zinc-fortified staple foods with unfortified foods (comparison 1), and four compared zinc-fortified staple foods in combination with other nutrients/factors with the same foods containing other nutrients or factors without zinc (comparison 2). The interventions lasted between one and nine months. We categorised most trials as having unclear or high risk of bias for randomisation, but low risk of bias for blinding and attrition. None of the studies in comparison 1 reported data on zinc deficiency.Foods fortified with zinc increased the serum or plasma zinc levels in comparison to foods without added zinc (mean difference (MD) 2.12 µmol/L, 95% confidence interval (CI) 1.25 to 3.00 µmol/L; 3 studies; 158 participants; low-quality evidence). Participants consuming foods fortified with zinc versus participants consuming the same food without zinc had similar risk of underweight (average risk ratio 3.10, 95% CI 0.52 to 18.38; 2 studies; 397 participants; low-quality evidence) and stunting (risk ratio (RR) 0.88, 95% CI 0.36 to 2.13; 2 studies; 397 participants; low-quality evidence). A single trial of addition of zinc to iron in wheat flour did not find a reduction in proportion of zinc deficiency (RR 0.17, 95% CI 0.01 to 3.94; very low-quality evidence). We did not find a difference in serum or plasma zinc levels in participants consuming foods fortified with zinc plus other micronutrients when compared with participants consuming the same foods with micronutrients but no added zinc (MD 0.03 µmol/L, 95% CI -0.67 to 0.72 µmol/L; 4 studies; 250 participants; low-quality evidence). No trial in comparison 2 provided information about underweight or stunting.There was

Environmental significance of copper, lead, manganese, uranium and zinc speciation in the event of contaminated waters release from the Ranger Uranium Mining Complex

International Nuclear Information System (INIS)

Noller, B.N.; Currey, N.A.

1983-01-01

The likely impact of the accidental release of tailings dam water during the dry season at the Ranger Uranium Mining Complex was examined. A speciation scheme utilising sizing by filtration and ion-exchange with Chelex 100 has given an insight into the likely partitioning of zinc, copper, lead, manganese and uranium following the addition of tailings dam water to samples from waterbodies in the vicinity of the uranium mining/milling complex. The speciation findings are discussed in terms of likely toxic effects on fish

Synthesis, crystal structure and computational chemistry research of a Zinc(II complex: [Zn(Pt(Biim2

Directory of Open Access Journals (Sweden)

Teng Fei

2012-01-01

Full Text Available The title metal-organic coordination complex [Zn(pt(Biim2] (pt=phthalic acid, benzene-1,2-dicarboxylate, Biim=2,2'-biimidazole 1 has been obtained by using hydrothermal synthesis and characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/n with a = 8.5466(15 Å, b = 11.760(2 Å, c = 20.829(4 Å, β = 95.56(2º, V = 2083.5(6 Å3, Mr =497.78, Dc = 1.587 g/cm3, μ(MoKα = 1.226 mm−1, F(000 = 1016, Z = 4, the final R = 0.0564 and wR = 0.1851 for 3656 observed reflections (I > 2σ(I. The elemental analysis, IR, TG and the theoretical calculation were also investigated.

Taurine zinc solid dispersions attenuate doxorubicin-induced hepatotoxicity and cardiotoxicity in rats

International Nuclear Information System (INIS)

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lu, Wenping; Li, Binglong; Xu, Donghui

2015-01-01

The clinical efficacy of anthracycline anti-neoplastic agents is limited by cardiac and hepatic toxicities. The aim of this study was to assess the hepatoprotective and cardioprotective effects of taurine zinc solid dispersions, which is a newly-synthesized taurine zinc compound, against doxorubicin-induced toxicity in Sprague–Dawley rats intraperitoneally injected with doxorubicin hydrochloride (3 mg/kg) three times a week (seven injections) over 28 days. Hemodynamic parameters, levels of liver toxicity markers and oxidative stress were assessed. Taurine zinc significantly attenuated the reductions in blood pressure, left ventricular pressure and ± dp/dtmax, increases in serum alanine aminotransferase and aspartate aminotransferase activities, and reductions in serum Zn 2+ and albumin levels (P < 0.05 or 0.01) induced by doxorubicin. In rats treated with doxorubicin, taurine zinc dose-dependently increased liver superoxide dismutase activity and glutathione concentration, and decreased malondialdehyde level (P < 0.01). qBase + was used to evaluate the stability of eight candidate reference genes for real-time quantitative reverse-transcription PCR. Taurine zinc dose-dependently increased liver heme oxygenase-1 and UDP-glucuronyl transferase mRNA and protein expression (P < 0.01). Western blotting demonstrated that taurine zinc inhibited c-Jun N-terminal kinase phosphorylation by upregulating dual-specificity phosphoprotein phosphatase-1. Additionally, taurine zinc inhibited cardiomyocyte apoptosis as there was decreased TUNEL/DAPI positivity and protein expression of caspase-3. These results indicate that taurine zinc solid dispersions prevent the side-effects of anthracycline-based anticancer therapy. The mechanisms might be associated with the enhancement of antioxidant defense system partly through activating transcription to synthesize endogenous phase II medicine enzymes and anti-apoptosis through inhibiting JNK phosphorylation. - Highlights: �

Taurine zinc solid dispersions attenuate doxorubicin-induced hepatotoxicity and cardiotoxicity in rats

Energy Technology Data Exchange (ETDEWEB)

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lu, Wenping; Li, Binglong; Xu, Donghui, E-mail: Donghuixu007@163.com

2015-11-15

The clinical efficacy of anthracycline anti-neoplastic agents is limited by cardiac and hepatic toxicities. The aim of this study was to assess the hepatoprotective and cardioprotective effects of taurine zinc solid dispersions, which is a newly-synthesized taurine zinc compound, against doxorubicin-induced toxicity in Sprague–Dawley rats intraperitoneally injected with doxorubicin hydrochloride (3 mg/kg) three times a week (seven injections) over 28 days. Hemodynamic parameters, levels of liver toxicity markers and oxidative stress were assessed. Taurine zinc significantly attenuated the reductions in blood pressure, left ventricular pressure and ± dp/dtmax, increases in serum alanine aminotransferase and aspartate aminotransferase activities, and reductions in serum Zn{sup 2+} and albumin levels (P < 0.05 or 0.01) induced by doxorubicin. In rats treated with doxorubicin, taurine zinc dose-dependently increased liver superoxide dismutase activity and glutathione concentration, and decreased malondialdehyde level (P < 0.01). qBase{sup +} was used to evaluate the stability of eight candidate reference genes for real-time quantitative reverse-transcription PCR. Taurine zinc dose-dependently increased liver heme oxygenase-1 and UDP-glucuronyl transferase mRNA and protein expression (P < 0.01). Western blotting demonstrated that taurine zinc inhibited c-Jun N-terminal kinase phosphorylation by upregulating dual-specificity phosphoprotein phosphatase-1. Additionally, taurine zinc inhibited cardiomyocyte apoptosis as there was decreased TUNEL/DAPI positivity and protein expression of caspase-3. These results indicate that taurine zinc solid dispersions prevent the side-effects of anthracycline-based anticancer therapy. The mechanisms might be associated with the enhancement of antioxidant defense system partly through activating transcription to synthesize endogenous phase II medicine enzymes and anti-apoptosis through inhibiting JNK phosphorylation. - Highlights: �

potentiometric studies of the complexes formed by copper (ii) and zinc

African Journals Online (AJOL)

MBI

, P. M. B. 3011, Kano, Nigeria e-mail: jnaaliya@yahoo.com. ABSTRACT. The overall stability constants of copper (II) and zinc (II) ions with some polar uncharged amino acids including proline, threonine and asparagines were determined by ...

Compartmentation of metals in foliage of Populus tremula grown on soils with mixed contamination. II. Zinc binding inside leaf cell organelles.

Science.gov (United States)

Vollenweider, Pierre; Bernasconi, Petra; Gautschi, Hans-Peter; Menard, Terry; Frey, Beat; Günthardt-Goerg, Madeleine S

2011-01-01

The phytoextraction potential of plants for removing heavy metals from polluted soils is determined by their capacity to store contaminants in aboveground organs and complex them safely. In this study, the metal compartmentation, elemental composition of zinc deposits and zinc complexation within leaves from poplars grown on soil with mixed metal contamination was analysed combining several histochemical and microanalytical approaches. Zinc was the only heavy metal detected and was stored in several organelles in the form of globoid deposits showing β-metachromasy. It was associated to oxygen anions and different cations, noteworthy phosphorous. The deposit structure, elemental composition and element ratios indicated that zinc was chelated by phytic acid ligands. Maturation processes in vacuolar vs. cytoplasmic deposits were suggested by differences in size and amounts of complexed zinc. Hence, zinc complexation by phytate contributed to metal detoxification and accumulation in foliage but could not prevent toxicity reactions therein. Copyright © 2010 Elsevier Ltd. All rights reserved.

Nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children

Directory of Open Access Journals (Sweden)

Márcia Marília Gomes Dantas Lopes

2015-10-01

Full Text Available Background: Zinc is an essential nutrient that is required for numerous metabolic functions, and zinc deficiency results in growth retardation, cell-mediated immune dysfunction, and cognitive impairment. Objective: This study evaluated nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children. Design: We performed a randomised, controlled, triple-blind study. The children were divided into a control group (10% sorbitol, n=31 and an experimental group (10 mg Zn/day, n=31 for 3 months. Anthropometric and dietary assessments as well as bioelectrical measurements were performed in all children. Results: Our study showed (1 an increased body mass index for age and an increased phase angle in the experimental group; (2 a positive correlation between nutritional assessment parameters in both groups; (3 increased soft tissue, and mainly fat-free mass, in the body composition of the experimental group, as determined using bioelectrical impedance vector analysis; (4 increased consumption of all nutrients, including zinc, in the experimental group; and (5 an increased serum zinc concentration in both groups (p<0.0001. Conclusions: Given that a reference for body composition analysis does not exist for intervention studies, longitudinal studies are needed to investigate vector migration during zinc supplementation. These results reinforce the importance of employing multiple techniques to assess the nutritional status of populations.

Coating compositions comprising bismuth-alloyed zinc

DEFF Research Database (Denmark)

2008-01-01

The present application discloses (i) a coating composition comprising a particulate zinc-based alloyed material, said material comprising 0.05-0.7% by weight of bismuth (Bi), the D50 of the particulate material being in the range of 2.5-30 µm; (ii) a coated structure comprising a metal structure...... having a first coating of the zinc-containing coating composition applied onto at least a part of the metal structure in a dry film thickness of 5-100 µm; and an outer coating applied onto said zinc-containing coating in a dry film thickness of 30-200 µm; (iii) a particulate zinc-based alloyed material......, wherein the material comprises 0.05-0.7%(w/w) of bismuth (Bi), and wherein the D50 of the particulate material is in the range of 2.5-30 µm; (iv) a composite powder consisting of at least 25%(w/w) of the particulate zinc-based alloyed material, the rest being a particulate material consisting of zinc...

From Lipid Homeostasis to Differentiation: Old and New Functions of the Zinc Cluster Proteins Ecm22, Upc2, Sut1 and Sut2

Directory of Open Access Journals (Sweden)

Ifeoluwapo Matthew Joshua

2017-04-01

Full Text Available Zinc cluster proteins are a large family of transcriptional regulators with a wide range of biological functions. The zinc cluster proteins Ecm22, Upc2, Sut1 and Sut2 have initially been identified as regulators of sterol import in the budding yeast Saccharomyces cerevisiae. These proteins also control adaptations to anaerobic growth, sterol biosynthesis as well as filamentation and mating. Orthologs of these zinc cluster proteins have been identified in several species of Candida. Upc2 plays a critical role in antifungal resistance in these important human fungal pathogens. Upc2 is therefore an interesting potential target for novel antifungals. In this review we discuss the functions, mode of actions and regulation of Ecm22, Upc2, Sut1 and Sut2 in budding yeast and Candida.

The mechanism of zinc uptake in excised roots and leaf discs of Phaseolus vulgaris L

International Nuclear Information System (INIS)

Van As, J.A.

1991-03-01

The mechanism and nature of zinc uptake was studied with the aid of 65 Zn. Uptake of zinc was also compared to that of potassium and phosphate, which are known to be ATP-dependent. Zinc uptake was characterized by a rapid initial uptake, followed by a slower linear phase. Decreasing the temperature from 25 to 2 deg C resulted in a decrease of only 30% in the rate of zinc uptake. Uptake of zinc was insensitive to DNP - possibly indicating the non-metabolic nature of the uptake process. A possible role for zinc in protein synthesis could not be demonstrated as CHI did not inhibit zinc uptake. Cyanide reduced zinc uptake to almost zero, possibly due to complexation of zinc by cyanide. Light had no effect on the accumulation of Zn, whereas dark incubation reduced potassium uptake substantially. The relative high rate of zinc uptake and the passive nature of the uptake process might be due to the high binding capacity of the free space for zinc ions. Transport of the zinc in the xylem and phloem of intact bean plants, as well as the metabolic dependence of the latter, was also investigated. The bulk of the zinc absorbed by bean plants remained in the roots and stems with only a very small fraction being translocated to shoots. Adsorption was the major uptake mechanism in roots and stems. In contrast to transport in the xylem, zinc was readily transported in the phloem. Loading and unloading of zinc in the phloem was not influenced by low temperature or DNP. Opposed to this, loading of potassium and phosphate was inhibited by DNP, while unloading was inhibited by low temperature. It can therefore be concluded that the uptake and transport of zinc is probably a passive process. 33 figs., 282 refs

The degradation of lining of rotary furnaces in the production of zinc oxide

OpenAIRE

Natália Luptáková; Evgeniy Anisimov; Františka Pešlová

2014-01-01

This paper is closely connected with the complex problem of degradation relating to the refractories of rotary furnace linings in the production of zinc oxide. Zinc oxide can be produced by variety of ways, but the most common method of production which is used in Europe is indirect, i.e. pyrolytic combustion of zinc. This method is also called "French process" of manufacturing ZnO. But this mentioned method of preparation leads to the creation of the enormous amount of zinc slag including ch...

Different roles of glutathione in copper and zinc chelation in Brassica napus roots.

Science.gov (United States)

Zlobin, Ilya E; Kartashov, Alexander V; Shpakovski, George V

2017-09-01

We investigated the specific features of copper and zinc excess action on the roots of canola (Brassica napus L.) plants. Copper rapidly accumulated in canola root cells and reached saturation during several hours of treatment, whereas the root zinc content increased relatively slowly. Excessive copper and zinc entry inside the cell resulted in significant cell damage, as evidenced by alterations in plasmalemma permeability and decreases in cellular enzymatic activity. Zinc excess specifically damaged root hair cells, which correlated with a pronounced elevation of their labile zinc level. In vitro, we showed that reduced glutathione (GSH) readily reacted with copper ions to form complexes with blocked sulfhydryl groups. In contrast, zinc ions were ineffective as glutathione blockers, and glutathione molecules did not lose their specific chemical activity in the presence of Zn 2+ ions. The effect of copper and zinc excess on the glutathione pool in canola root cells was analysed by a combination of biochemical determination of total and oxidized glutathione contents and fluorescent staining of free reduced glutathione with monochlorobimane dye. Excess copper led to dose-dependent diminution of free reduced glutathione contents in the root cells, which could not be explained by the loss of total cellular glutathione or its oxidation. In contrast, we observed little effect of much higher intracellular zinc concentrations on the free reduced glutathione content. We concluded that GSH plays an important role in copper excess, but not zinc excess chelation, in canola root cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Solubilization of insoluble zinc compounds by Gluconacetobacter diazotrophicus and the detrimental action of zinc ion (Zn2+) and zinc chelates on root knot nematode Meloidogyne incognita.

Science.gov (United States)

Saravanan, V S; Kalaiarasan, P; Madhaiyan, M; Thangaraju, M

2007-03-01

To examine the zinc (Zn) solubilization potential and nematicidal properties of Gluconacetobacter diazotrophicus. Atomic Absorption Spectrophotometer, Differential Pulse Polarography and Gas Chromatography Coupled Mass Spectrometry were used to estimate the total Zn and Zn(2+) ions and identify the organic acids present in the culture supernatants. The effect of culture filtrate of Zn-amended G. diazotrophicus PAl5 on Meloidogyne incognita in tomato was examined under gnotobiotic conditions. Gluconacetobacter diazotrophicus PAl5 effectively solubilized the Zn compounds tested and 5-ketogluconic acid was identified as the major organic acid aiding the solubilization of zinc oxide. The presence of Zn compounds in the culture filtrates of G. diazotrophicus enhanced the mortality and reduced the root penetration of M. incognita under in vitro conditions. 5-ketogluconic acid produced by G. diazotrophicus mediated the solubilization process and the available Zn(2+) ions enhanced the nematicidal activity of G. diazotrophicus against M. incognita. Zn solubilization and enhanced nematicidal activity of Zn-amended G. diazotrophicus provides the possibility of exploiting it as a plant growth promoting bacteria.

Hydrogen-related complexes in Li-diffused ZnO single crystals

Energy Technology Data Exchange (ETDEWEB)

Corolewski, Caleb D. [Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164-2814 (United States); Parmar, Narendra S.; Lynn, Kelvin G. [Center for Materials Research, Washington State University, Pullman, Washington 99164-2814 (United States); McCluskey, Matthew D., E-mail: mattmcc@wsu.edu [Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164-2814 (United States); Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States)

2016-07-21

Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li{sub 2}O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>10{sup 19 }cm{sup −3}). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm{sup −1}, attributed to surface O-H species. When Li{sub 2}CO{sub 3} is used, a structured blue luminescence band and O-H mode at 3327 cm{sup −1} are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy–hydrogen complex, with an acceptor level ∼0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

The ecotoxicity of zinc and zinc-containing substances in soil with consideration of metal-moiety approaches and organometal complexes.

Science.gov (United States)

Ritchie, Ellyn; Boyd, Patrick; Lawson-Halasz, Annamaria; Hawari, Jalal; Saucier, Stacey; Scroggins, Richard; Princz, Juliska

2017-12-01

Within Canada, screening-level assessments for chemical substances are required to determine whether the substances pose a risk to human health and/or the environment, and as appropriate, risk management strategies. In response to the volume of metal and metal-containing substances, process efficiencies were introduced using a metal-moiety approach, whereby substances that contain a common metal moiety are assessed simultaneously as a group, with the moiety of concern consisting of the metal ion. However, for certain subgroups, such as organometals or organic metal salts, the organic moiety or parent substance may be of concern, rather than simply the metal ion. To further investigate the need for such additional consideration, certain substances were evaluated: zinc (Zn)-containing inorganic (Zn chloride [ZnCl2] and Zn oxide) and organic (organometal: Zn diethyldithiocarbamate [Zn(DDC) 2 ] and organic metal salts (Zn stearate [ZnSt] and 4-chloro-2-nitrobenzenediazonium tetrachlorozincate [BCNZ]). The toxicity of the substances were assessed using plant (Trifolium pratense and Elymus lanceolatus) and soil invertebrate (Folsomia candida and Eisenia andrei) tests in a sandy soil. Effect measures were determined based on total metal and total parent analyses (for organic substances). In general, the inorganic Zn substances were less toxic than the organometals and organic metal salts, with 50% effective concentrations ranging from 11 to >5194 mg Zn kg -1 dry soil. The data demonstrate the necessity for alternate approaches in the assessment of organo-metal complexes, with the organic moieties or parent substances warranting consideration rather than the metal ion alone. In this instance, the organometals and organic metal salts were significantly more toxic than other test substances despite their low total Zn content. Environ Toxicol Chem 2017;36:3324-3332. © 2017 Crown in the Right of Canada. Published by Wiley Periodicals Inc. on behalf of SETAC. © 2017 Crown

Method of capturing or trapping zinc using zinc getter materials

Science.gov (United States)

Hunyadi Murph, Simona E.; Korinko, Paul S.

2017-07-11

A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

Zinc in an ultraoligotrophic lake food web.

Science.gov (United States)

Montañez, Juan Cruz; Arribére, María A; Rizzo, Andrea; Arcagni, Marina; Campbell, Linda; Ribeiro Guevara, Sergio

2018-03-21

Zinc (Zn) bioaccumulation and trophic transfer were analyzed in the food web of Lake Nahuel Huapi, a deep, unpolluted ultraoligotrophic system in North Patagonia. Benthic macroinvertebrates, plankton, and native and introduced fish were collected at three sites. The effect of pyroclastic inputs on Zn levels in lacustrine food webs was assessed by studying the impact of the eruption of Puyehue-Cordón Caulle volcanic complex (PCCVC) in 2011, by performing three sampling campaigns immediately before and after the PCCVC eruption, and after 2 years of recovery of the ecosystem. Zinc trophodynamics in L. Nahuel Huapi food web was assessed using nitrogen stable isotopes (δ 15 N). There was no significant increase of Zn concentrations ([Zn]) in L. Nahuel Huapi biota after the PCCVC eruption, despite the evidence of [Zn] increase in lake water that could be associated with volcanic ash leaching. The organisms studied exhibited [Zn] above the threshold level considered for dietary deficiency, regulating Zn adequately even under a catastrophic situations like PCCVC 2011 eruption. Zinc concentrations exhibited a biodilution pattern in the lake's food web. To the best of our knowledge, present research is the first report of Zn biodilution in lacustrine systems, and the first to study Zn transfer in a freshwater food web including both pelagic and benthic compartments.

Studies of zinc(II in pharmaceutical and biological samples by extractive spectrophotometry: using pyridoxal-4-phenyl-3-thiosemicarbazone as chelating reagent

Directory of Open Access Journals (Sweden)

Sarma L. Subramanyam

2006-01-01

Full Text Available Pyridoxal-4-phenyl-3-thiosemicarbazone (PPT is proposed as a new sensitive reagent for the sensitive extractive spectrophotometric determination of zinc(II. PPT reacts with zinc(II in the pH range 5.0-6.0 to form a yellow colored complex, which was well extracted into n-butanol. The absorbance value of Zn(II-PPT complex was measured at different intervals of time at 430 nm, to ascertain the stability of the complex. It was observed that the color development was instantaneous and stable for more than 48 h. The system obeyed Beer's law up to 6.0 µg mL-1 of zinc(II, with an excellent linearity in terms of correlation coefficient value of 0.999. The molar absorptivity and Sandell's sensitivity of the extracted species is 1.6 X 10(4 L mol-1 cm-1 and 4.085 X 10-3 µg cm-2 at 430 nm. The detection limit of the method is 0.04 µg mL-1. To assess precision of the method, determinations were carried out at different concentrations; the relative standard deviation does not exceed 3.1%. The composition of the zinc(II complex with PPT was studied by the method of Job's continuous variation, molar ratio method, Asmus' method and slope ratio method. It has been satisfactorily applied for the determination of zinc(II, when present alone or in presence of diverse ions, which are usually associated with zinc(II in pharmaceutical and biological samples. Various certified reference materials (NIST 1573, NBS 1572 and NIST SRM 8435 have been tested for the determination of zinc for evaluating the accuracy of the developed method. The results of the proposed method are in agreement with flame atomic absorption spectometry.

Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

International Nuclear Information System (INIS)

Lee, Jiyoun

2012-01-01

We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry

Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

Energy Technology Data Exchange (ETDEWEB)

Lee, Jiyoun [Sungshin Women' s Univ., Seoul (Korea, Republic of)

2012-04-15

We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry.

The degradation of lining of rotary furnaces in the production of zinc oxide

Directory of Open Access Journals (Sweden)

Natália Luptáková

2014-06-01

Full Text Available This paper is closely connected with the complex problem of degradation relating to the refractories of rotary furnace linings in the production of zinc oxide. Zinc oxide can be produced by variety of ways, but the most common method of production which is used in Europe is indirect, i.e. pyrolytic combustion of zinc. This method is also called "French process" of manufacturing ZnO. But this mentioned method of preparation leads to the creation of the enormous amount of zinc slag including chemical complexes of elements Fe, Zn and Al. The mechanism of degradation of the lining leads to slag rests and it is closely connected with the mutual interaction of the aggressive agents with the components of the lining. This process creates a new undesired surface layer which increased the overall thickness of zinc slag. Stuck slag has the influence on rapid degradation of the linings and moreover it also decreases the production quality of ZnO. Analysis results introduced in this paper are significant information for minimizing of degradation of rotary furnaces.  

Zinc in soybeans. Chemical nature and bioavilability

International Nuclear Information System (INIS)

Khan, A.

1987-01-01

Soybeans were grown hydroponically and intrinsically labeled with 65 Zn through root absorption, stem injection and foliar application. Stem injection resulted in the greatest accumulation of 65 Zn. Regardless of the labeling technique, approximately 40-45% of the seed 65 Zn was associated with the subcellular organelles. The pattern of 65 Zn incorporation into soybeans did not change appreciably as a result of the labelling technique. The major portion of the soluble 65 Zn was either free or associated with very low molecular weight proteins, peptides, or their complexes with phytic acid rather than the major proteins of soybeans. Zinc in soybeans is ionically bound to proteins, peptides and phytic acid. Autoclaving did not affect the chemical association of zinc with soy proteins. Solubility of protein, zinc and phytic acid was studied over the pH range of 3.5-12.0. Bioavailability of zinc to rats from soybeans was lower than from casein and rats adapted to a casein basal diet absorbed more 65 Zn from both casein and soy than rats adapted to a soy basal diet

Analysis of reaction and transport processes in zinc air batteries

CERN Document Server

Schröder, Daniel

2016-01-01

This book contains a novel combination of experimental and model-based investigations, elucidating the complex processes inside zinc air batteries. The work presented helps to answer which battery composition and which air-composition should be adjusted to maintain stable and efficient charge/discharge cycling. In detail, electrochemical investigations and X-ray transmission tomography are applied on button cell zinc air batteries and in-house set-ups. Moreover, model-based investigations of the battery anode and the impact of relative humidity, active operation, carbon dioxide and oxygen on zinc air battery operation are presented. The techniques used in this work complement each other well and yield an unprecedented understanding of zinc air batteries. The methods applied are adaptable and can potentially be applied to gain further understanding of other metal air batteries. Contents Introduction on Zinc Air Batteries Characterizing Reaction and Transport Processes Identifying Factors for Long-Term Stable O...

Release of zinc from the brain of El (epilepsy) mice during seizure induction.

Science.gov (United States)

Takeda, A; Hanajima, T; Ijiro, H; Ishige, A; Iizuka, S; Okada, S; Oku, N

1999-05-15

Brain distribution after i.v. injection of 65ZnCl2 into El mice, an animal model of genetically determined epilepsy, was studied by autoradiography to study the utilization of zinc in the brain. The distribution of 65Zn in the brain of El mice 6 days after injection was almost the same as that of ddY (normal) mice, suggesting that the uptake of zinc by the brain of El mice is normal. To study the movement of zinc in the brain in the course of seizure induction, the concentrations of 65Zn in the brain of seizure-afflicted and untreated control El mice were compared 20 days after 65Zn injection. The concentration of 65Zn in the brain of seized El mice was overall lower than that of control El mice; the concentration of 65Zn was decreased notably in the piriform cortex and amygdaloid nuclei complex during convulsion. These results suggest that the release of zinc from the El mouse brain is enhanced during convulsion. The decrease in actively functioning zinc in the brain may be associated with the increase in susceptibility to seizure in the El mouse. Copyright 1999 Elsevier Science B.V.

Zinc-chelation contributes to the anti-angiogenic effect of ellagic acid on inhibiting MMP-2 activity, cell migration and tube formation.