TY  - JOUR
A1  - Rosenkranz, Eva
A1  - Maywald, Martina
A1  - Hilgers, Ralf-Dieter
A1  - Brieger, Anne
A1  - Clarner, Tim
A1  - Kipp, Markus
A1  - Pluemaekers, Birgit
A1  - Meyer, Sören
A1  - Schwerdtle, Tanja
A1  - Rink, Lothar
T1  - Induction of regulatory T cells in Th1-/Th17-driven experimental autoimmune encephalomyelitis by zinc administration
JF  - The journal of nutritional biochemistry
N2  - The essential trace element zinc is indispensable for proper immune function as zinc deficiency accompanies immune defects and dysregulations like allergies, autoimmunity and an increased presence of transplant rejection. This point to the importance of the physiological and dietary control of zinc levels for a functioning immune system. This study investigates the capacity of zinc to induce immune tolerance. The beneficial impact of physiological zinc supplementation of 6 mu g/day (0.3 mg/kg body weight) or 30 mu g/day (1.5 mg/kg body weight) on murine experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis with a Th1/Th17 (Th, T helper) cell-dominated immunopathogenesis, was analyzed. Zinc administration diminished EAE scores in C57BL/6 mice in vivo (P<.05), reduced Th17 ROR gamma T+ cells (P<.05) and significantly increased inducible iTreg cells (P<.05). While Th17 cells decreased systemically, iTreg cells accumulated in the central nervous system. Cumulatively, zinc supplementation seems to be capable to induce tolerance in unwanted immune reactions by increasing iTreg cells. This makes zinc a promising future tool for treating autoimmune diseases without suppressing the immune system. (C) 2015 Elsevier Inc. All rights reserved.
KW  - Zinc
KW  - Regulatory T cells (Treg)
KW  - Foxp3
KW  - Mixed lymphocyte culture (MLC)
KW  - Experimental autoimmune encephalomyelitis (EAE)
KW  - Th17
Y1  - 2016
U6  - https://doi.org/10.1016/j.jnutbio.2015.11.010
SN  - 0955-2863
SN  - 1873-4847
VL  - 29
SP  - 116
EP  - 123
PB  - Elsevier
CY  - New York
ER  - 
TY  - THES
A1  - Mondal, Suvendu Sekhar
T1  - Design of isostructural metal-imidazolate frameworks : application for gas storage
T1  - Synthese isostruktureller Metall-Imidazolat Frameworks : Anwendung für Gasspeicherung
N2  - The sharply rising level of atmospheric carbon dioxide resulting from anthropogenic emissions is one of the greatest environmental concerns facing our civilization today. Metal-organic frameworks (MOFs) are a new class of materials that constructed by metal-containing nodes bonded to organic bridging ligands. MOFs could serve as an ideal platform for the development of next generation CO2 capture materials owing to their large capacity for the adsorption of gases and their structural and chemical tunability. The ability to rationally select the framework components is expected to allow the affinity of the internal pore surface toward CO2 to be precisely controlled, facilitating materials properties that are optimized for the specific type of CO2 capture to be performed (post-combustion capture, precombustion capture, or oxy-fuel combustion) and potentially even for the specific power plant in which the capture system is to be installed. For this reason, significant effort has been made in recent years in improving the gas separation performance of MOFs and some studies evaluating the prospects of deploying these materials in real-world CO2 capture systems have begun to emerge. We have developed six new MOFs, denoted as IFPs (IFP-5, -6, -7, -8, -9, -10, IFP = Imidazolate Framework Potsdam) and two hydrogen-bonded molecular building block (MBB, named as 1 and 2 for Zn and Co based, respectively) have been synthesized, characterized and applied for gas storage. The structure of IFP possesses 1D hexagonal channels. Metal centre and the substituent groups of C2 position of the linker protrude into the open channels and determine their accessible diameter. Interestingly, the channel diameters (range : 0.3 to 5.2 Å) for IFP structures are tuned by the metal centre (Zn, Co and Cd) and substituent of C2 position of the imidazolate linker. Moreover hydrogen bonded MBB of 1 and 2 is formed an in situ functionalization of a ligand under solvothermal condition. Two different types of channels are observed for 1 and 2. Materials contain solvent accessible void space. Solvent could be easily removed by under high vacuum. The porous framework has maintained the crystalline integrity even without solvent molecules. N2, H2, CO2 and CH4 gas sorption isotherms were performed. Gas uptake capacities are comparable with other frameworks. Gas uptake capacity is reduced when the channel diameter is narrow. For example, the channel diameter of IFP-5 (channel diameter: 3.8 Å) is slightly lower than that of IFP-1 (channel diameter: 4.2 Å); hence, the gas uptake capacity and Brunauer-Emmett-Teller (BET) surface area are slightly lower than IFP-1. The selectivity does not depend only on the size of the gas components (kinetic diameter: CO2 3.3 Å, N2 3.6 Å and CH4 3.8 ) but also on the polarizability of the surface and of the gas components. IFP-5 and-6 have the potential applications for the separation of CO2 and CH4 from N2-containing gas mixtures and CO2 and CH4 containing gas mixtures. Gas sorption isotherms of IFP-7, -8, -9, -10 exhibited hysteretic behavior due to flexible alkoxy (e.g., methoxy and ethoxy) substituents. Such phenomenon is a kind of gate effects which is rarely observed in microporous MOFs. IFP-7 (Zn-centred) has a flexible methoxy substituent. This is the first example where a flexible methoxy substituent shows the gate opening behavior in a MOF. Presence of methoxy functional group at the hexagonal channels, IFP-7 acted as molecular gate for N2 gas. Due to polar methoxy group and channel walls, wide hysteretic isotherm was observed during gas uptake. The N2 The estimated BET surface area for 1 is 471 m2 g-1 and the Langmuir surface area is 570 m2 g-1. However, such surface area is slightly higher than azolate-based hydrogen-bonded supramolecular assemblies and also comparable and higher than some hydrogen-bonded porous organic molecules.
N2  - Metallorganische Gerüstverbindungen (MOFs) sind eine neue Klasse von porösen Koordinationspolymeren, die aus Metall-Knoten und verbrückenden Liganden bestehen. MOFs können Gasgemische trennen und Gase speichern. Aufgrund ihres modularen Aufbaus können die MOF-Eigenschaften systematisch variiert werden. Ein wichtiges Ziel für das Design von MOFs ist die Synthese von Materialien, die eine hohe selektive Aufnahmefähigkeit und -kapazität für Kohlenstoffdioxid besitzen. Im Rahmen der Arbeit ist es gelungen sechs neue MOFs (IFP-5, -6, -7, -8, -9 und -10) zu synthetisieren. Diese MOFs tragen die Kurzbezeichnung IFP. IFP steht als Abkürzung für Imidazolat-Framework-Potsdam (Imidazolat-basierte Gerüstverbindung Potsdam). In diesen IFPs wurde der Metallknoten (Zink, Cobalt, Cadmium) und der Brückenligand, ein 2-substituiertes Imidazolat-amid-imidat, in der Position variiert, um gute und selektive Sorptionseigenschaften für Kohlenstoffdioxid zu erzielen. Von den synthetisierten Verbindungen hat das IFP-5 die besten Sorptionseigenschaften für Kohlenstoffdioxid. Es konnte weiter gezeigt werden, dass sich die IFP-Struktur bei der Wahl von geeigneten Substituenten 2, wie z.B. Methoxy und Ethoxy auch für das Design von gate-opening (Tür-öffnenden) Effekten eignet. Diese Effekte können wiederum genutzt werden, um selektiv Gasmischungen zu trennen. Wenn man das 4,5-Dicyano-2-methoxy-imidazol in Gegenwart von Zink- und Cobalt-Salzen unter solvothermalen Bedingungen zur Reaktion bringt, erhält man beispiellose supramolekulare Wasserstoffbrückenbindungen zu einem dreidimensionalen Netzwerk, die mit Kanälen verknüpft sind. Diese Kanäle können von Lösungsmittelmolekülen (Wasser und Dimethylformamid) befreit werden und Gase aufnehmen. Insgesamt besteht nun die neue MOF-Klasse der Imidazolat-basierten IFPs aus Vertretern. Das Potential der 2-substituierten 4,5-Dicyanoimidazole ist nicht nur auf die Bildung von porösen Koordinationspolymeren beschränkt, sondern kann auch für die Synthese von bisher unbekannten supramolekularen Strukturen genutzt werden.
KW  - Metal-organic framework
KW  - Gas Sorption
KW  - Cobalt
KW  - Zinc
KW  - Ionic Liquid
KW  - metal-organic framework
KW  - gas sorption
KW  - cobalt
KW  - zinc
KW  - ionic liquid
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-69692
ER  - 
TY  - JOUR
A1  - Bornhorst, Julia
A1  - Kipp, Anna P.
A1  - Haase, Hajo
A1  - Meyer, Soeren
A1  - Schwerdtle, Tanja
T1  - The crux of inept biomarkers for risks and benefits of trace elements
JF  - Trends in Analytical Chemistry
N2  - Nowadays, the role of trace elements (TE) is of growing interest because dyshomeostasis of selenium (Se), manganese (Mn), zinc (Zn), and copper (Cu) is supposed to be a risk factor for several diseases. Thereby, research focuses on identifying new biomarkers for the TE status to allow for a more reliable description of the individual TE and health status. This review mirrors a lack of well-defined, sensitive, and selective biomarkers and summarizes technical limitations to measure them. Thus, the capacity to assess the relationship between dietary TE intake, homeostasis, and health is restricted, which would otherwise provide the basis to define adequate intake levels of single TE in both healthy and diseased humans. Besides that, our knowledge is even more limited with respect to the real life situation of combined TE intake and putative interactions between single TE.
KW  - Trace elements
KW  - Copper
KW  - Zinc
KW  - Manganese
KW  - Selenium
KW  - Biomarker
KW  - Inductively coupled plasma mass spectrometry
KW  - Hyphenated techniques
KW  - Isotope ratios
Y1  - 2018
U6  - https://doi.org/10.1016/j.trac.2017.11.007
SN  - 0165-9936
SN  - 1879-3142
VL  - 104
SP  - 183
EP  - 190
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Baesler, Jessica
A1  - Kopp, Johannes Florian
A1  - Pohl, Gabriele
A1  - Aschner, Michael
A1  - Haase, Hajo
A1  - Schwerdtle, Tanja
A1  - Bornhorst, Julia
T1  - Zn homeostasis in genetic models of Parkinson’s disease in Caenorhabditis elegans
JF  - Journal of Trace Elements in Medicine and Biology
N2  - While the underlying mechanisms of Parkinson’s disease (PD) are still insufficiently studied, a complex interaction between genetic and environmental factors is emphasized. Nevertheless, the role of the essential trace element zinc (Zn) in this regard remains controversial. In this study we altered Zn balance within PD models of the versatile model organism Caenorhabditis elegans (C. elegans) in order to examine whether a genetic predisposition in selected genes with relevance for PD affects Zn homeostasis. Protein-bound and labile Zn species act in various areas, such as enzymatic catalysis, protein stabilization pathways and cell signaling. Therefore, total Zn and labile Zn were quantitatively determined in living nematodes as individual biomarkers of Zn uptake and bioavailability with inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) or a multi-well method using the fluorescent probe ZinPyr-1. Young and middle-aged deletion mutants of catp-6 and pdr-1, which are orthologues of mammalian ATP13A2 (PARK9) and parkin (PARK2), showed altered Zn homeostasis following Zn exposure compared to wildtype worms. Furthermore, age-specific differences in Zn uptake were observed in wildtype worms for total as well as labile Zn species. These data emphasize the importance of differentiation between Zn species as meaningful biomarkers of Zn uptake as well as the need for further studies investigating the role of dysregulated Zn homeostasis in the etiology of PD.
KW  - Caenorhabditis elegans
KW  - Zinc
KW  - Zinc homeostasis
KW  - Parkinson disease
KW  - Labile zinc
Y1  - 2019
U6  - https://doi.org/10.1016/j.jtemb.2019.05.005
VL  - 55
SP  - 44
EP  - 49
PB  - Elsevier
CY  - München
ER  - 
TY  - JOUR
A1  - Baesler, Jessica
A1  - Kopp, Johannes F.
A1  - Pohl, Gabriele
A1  - Aschner, Michael
A1  - Haase, Hajo
A1  - Schwerdtle, Tanja
A1  - Bornhorst, Julia
T1  - Zn homeostasis in genetic models of Parkinson’s disease in Caenorhabditis elegans
JF  - Journal of trace elements in medicine and biology
KW  - Caenorhabditis elegans
KW  - Zinc
KW  - Zinc homeostasis
KW  - Parkinson disease
KW  - Labile zinc
Y1  - 2019
U6  - https://doi.org/10.1016/j.jtemb.2019.05.005
SN  - 0946-672X
VL  - 55
SP  - 44
EP  - 49
PB  - Elsevier GMBH
CY  - München
ER  - 
TY  - JOUR
A1  - Awad, Duha Jawad
A1  - Koch, Andreas
A1  - Mickler, Wulfhard
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - EPR spectroscopy of 4, 4 '-Bis(tert-butyl)-2, 2 '-bipyridine-1, 2-dithiolatocuprates(II) in host lattices with different coordination geometries
JF  - Zeitschrift für anorganische und allgemeine Chemie
N2  - A series of new heteroleptic MN2S2 transition metal complexes with M = Cu2+ for EPR measurements and as diamagnetic hosts Ni2+, Zn2+, and Pd2+ were synthesized and characterized. The ligands are N2 = 4, 4'-bis(tert-butyl)-2, 2'-bipyridine (tBu2bpy) and S2 =1, 2-dithiooxalate, (dto), 1, 2-dithiosquarate, (dtsq), maleonitrile-1, 2-dithiolate, or 1, 2-dicyanoethene-1, 2-dithiolate, (mnt). The CuII complexes were studied by EPR in solution and as powders, diamagnetically diluted in the isostructural planar [NiII(tBu2bpy)(S2)] or[PdII(tBu2bpy)(S2)] as well as in tetrahedrally coordinated[ZnII(tBu2bpy)(S2)] host structures to put steric stress on the coordination geometry of the central CuN2S2 unit. The spin density contributions for different geometries calculated from experimental parameters are compared with the electronic situation in the frontier orbital, namely in the semi-occupied molecular orbital (SOMO) of the copper complex, derived from quantum chemical calculations on different levels (EHT and DFT). One of the hosts, [NiII(tBu2bpy)(mnt)], is characterized by X-ray structure analysis to prove the coordination geometry. The complex crystallizes in a square-planar coordination mode in the monoclinic space group P21/a with Z = 4 and the unit cell parameters a = 10.4508(10) angstrom, b = 18.266(2) angstrom, c = 12.6566(12) angstrom, beta = 112.095(7)degrees. Oxidation and reductions potentials of one of the host complexes, [Ni(tBu2bpy)(mnt)], were obtained by cyclovoltammetric measurements.
KW  - 1
KW  - 2-Dithiosquarate
KW  - 1
KW  - 2-Dithiooxalate
KW  - 1
KW  - 2-Dicyanoethene-1
KW  - 2-dithiolate
KW  - 4
KW  - 4'-Bis(tert-butyl)-2
KW  - 2'-bipyridine
KW  - X-ray structure
KW  - EPR
KW  - Copper
KW  - Nickel
KW  - Zinc
Y1  - 2012
U6  - https://doi.org/10.1002/zaac.201100517
SN  - 0044-2313
VL  - 638
IS  - 6
SP  - 965
EP  - 975
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Ast, Sandra
A1  - Rutledge, Peter J.
A1  - Todd, Matthew H.
T1  - Reversing the triazole topology in a cyclam-triazole-dye ligand gives a 10-fold brighter signal response to Zn2+ in aqueous solution
JF  - European journal of inorganic chemistry : a journal of ChemPubSoc Europe
N2  - The fluorescence response of a set of cyclam-triazole-dye ligands is controlled by the appended dye, but simple reversal of the triazole topology affords a novel probe for Zn2+ with a longer fluorescence lifetime and higher fluorescence quantum yield upon Zn2+ binding (<tau t > = 2.0 ns, Phi(f) = 0.76).
KW  - Sensors
KW  - Zinc
KW  - Click chemistry
KW  - Fluorescence
KW  - Electrochemistry
Y1  - 2012
U6  - https://doi.org/10.1002/ejic.201201072
SN  - 1434-1948
IS  - 34
SP  - 5611
EP  - 5615
PB  - Wiley-VCH
CY  - Weinheim
ER  -