@article{AstRutledgeTodd2012, author = {Ast, Sandra and Rutledge, Peter J. and Todd, Matthew H.}, title = {Reversing the triazole topology in a cyclam-triazole-dye ligand gives a 10-fold brighter signal response to Zn2+ in aqueous solution}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, number = {34}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201201072}, pages = {5611 -- 5615}, year = {2012}, abstract = {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 ( = 2.0 ns, Phi(f) = 0.76).}, language = {en} } @article{AwadKochMickleretal.2012, author = {Awad, Duha Jawad and Koch, Andreas and Mickler, Wulfhard and Schilde, Uwe and Strauch, Peter}, title = {EPR spectroscopy of 4, 4 '-Bis(tert-butyl)-2, 2 '-bipyridine-1, 2-dithiolatocuprates(II) in host lattices with different coordination geometries}, series = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie}, volume = {638}, journal = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0044-2313}, doi = {10.1002/zaac.201100517}, pages = {965 -- 975}, year = {2012}, abstract = {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.}, language = {en} } @article{BaeslerKoppPohletal.2019, author = {Baesler, Jessica and Kopp, Johannes F. and Pohl, Gabriele and Aschner, Michael and Haase, Hajo and Schwerdtle, Tanja and Bornhorst, Julia}, title = {Zn homeostasis in genetic models of Parkinson's disease in Caenorhabditis elegans}, series = {Journal of trace elements in medicine and biology}, volume = {55}, journal = {Journal of trace elements in medicine and biology}, publisher = {Elsevier GMBH}, address = {M{\"u}nchen}, issn = {0946-672X}, doi = {10.1016/j.jtemb.2019.05.005}, pages = {44 -- 49}, year = {2019}, language = {en} } @article{BaeslerKoppPohletal.2019, author = {Baesler, Jessica and Kopp, Johannes Florian and Pohl, Gabriele and Aschner, Michael and Haase, Hajo and Schwerdtle, Tanja and Bornhorst, Julia}, title = {Zn homeostasis in genetic models of Parkinson's disease in Caenorhabditis elegans}, series = {Journal of Trace Elements in Medicine and Biology}, volume = {55}, journal = {Journal of Trace Elements in Medicine and Biology}, publisher = {Elsevier}, address = {M{\"u}nchen}, doi = {10.1016/j.jtemb.2019.05.005}, pages = {44 -- 49}, year = {2019}, abstract = {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.}, language = {en} } @misc{BornhorstKippHaaseetal.2018, author = {Bornhorst, Julia and Kipp, Anna P. and Haase, Hajo and Meyer, Soeren and Schwerdtle, Tanja}, title = {The crux of inept biomarkers for risks and benefits of trace elements}, series = {Trends in Analytical Chemistry}, volume = {104}, journal = {Trends in Analytical Chemistry}, publisher = {Elsevier}, address = {Oxford}, issn = {0165-9936}, doi = {10.1016/j.trac.2017.11.007}, pages = {183 -- 190}, year = {2018}, abstract = {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.}, language = {en} } @phdthesis{Mondal2013, author = {Mondal, Suvendu Sekhar}, title = {Design of isostructural metal-imidazolate frameworks : application for gas storage}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69692}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {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 {\AA}) 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 {\AA}) is slightly lower than that of IFP-1 (channel diameter: 4.2 {\AA}); 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 {\AA}, N2 3.6 {\AA} 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.}, language = {en} } @article{RosenkranzMaywaldHilgersetal.2016, author = {Rosenkranz, Eva and Maywald, Martina and Hilgers, Ralf-Dieter and Brieger, Anne and Clarner, Tim and Kipp, Markus and Pluemaekers, Birgit and Meyer, S{\"o}ren and Schwerdtle, Tanja and Rink, Lothar}, title = {Induction of regulatory T cells in Th1-/Th17-driven experimental autoimmune encephalomyelitis by zinc administration}, series = {The journal of nutritional biochemistry}, volume = {29}, journal = {The journal of nutritional biochemistry}, publisher = {Elsevier}, address = {New York}, issn = {0955-2863}, doi = {10.1016/j.jnutbio.2015.11.010}, pages = {116 -- 123}, year = {2016}, abstract = {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.}, language = {en} }