189440-33-3Relevant academic research and scientific papers
Synthesis and characterization of copper complexes with tripodal ligands bearing amino acid groups
Gawlig, Christopher,Jung, Jannis,Mollenhauer, Doreen,Schindler, Siegfried
, p. 951 - 959 (2021)
The tripodal ligand (2-aminoethyl)bis(2-pyridylmethyl)amine (uns-penp), known for its Cu/O2 intermediates, was modified at one side arm by a selection of amino acids. With L-Tyrosine (Tyr), L-Histidine (His) and L-Lysine (Lys) it was possible to introduce chirality into the tripodal ligand system and to investigate the corresponding copper(I) complexes [Cu{L-His(BPh3)uns-penp}], [Cu(L-Lys)uns-penp]OTf and [Cu(L-Tyr)uns-penp]OTf. [Cu{L-His(BPh3)uns-penp}] could be structurally characterized and represents the first example of a copper(I) complex with a coordinated imidazole ring of the histidine ligand. Furthermore, these complexes demonstrated catalytic activity for the oxygenation of thioanisole with hydrogen peroxide as an oxidant.
Development of a ratiometric fluorescent zinc ion probe in near-infrared region, based on tricarbocyanine chromophore
Kiyose, Kazuki,Kojima, Hirotatsu,Urano, Yasuteru,Nagano, Tetsuo
, p. 6548 - 6549 (2006)
Novel ratiometric fluorescent probes for Zn2+ in the near-infrared region, based on a tricarbocyanine chromophore, have been designed, synthesized, and evaluated. Upon addition of Zn2+, a 44 nm red shift of the absorption maximum was observed, which indicates that this probe could work as a ratiometric probe for Zn2+. This change is due to the difference in the electron-donating ability of the amine substituent before and after reaction with Zn2+. This fluorescence modulation of amine-substituted tricarbocyanines should be applicable to dual-wavelength measurement of various biomolecules or enzyme activities. Copyright
Unusual Recognition and Separation of Hydrated Metal Sulfates [M2(μ-SO4)2(H2O)n, M = ZnII, CdII, CoII, MnII] by a Ditopic Receptor
Ghosh, Tamal Kanti,Dutta, Ranjan,Ghosh, Pradyut
, p. 3640 - 3652 (2016)
A ditopic receptor L1, having metal binding bis(2-picolyl) donor and anion binding urea group, is synthesized and explored toward metal sulfate recognition via formation of dinuclear assembly, (L1)2M2(SO4)2. Mass spectrometric analysis, 1H-DOSY NMR, and crystal structure analysis reveal the existence of a dinuclear assembly of MSO4 with two units of L1. 1H NMR study reveals significant downfield chemical shift of -NH protons of urea moiety of L1 selectively with metal sulfates (e.g., ZnSO4, CdSO4) due to second-sphere interactions of sulfate with the urea moiety. Variable-temperature 1H NMR studies suggest the presence of intramolecular hydrogen bonding interaction toward metal sulfate recognition in solution state, whereas intermolecular H-bonding interactions are observed in solid state. In contrast, anions in their tetrabutylammonium salts fail to interact with the urea -NH probably due to poor acidity of the tertiary butyl urea group of L1. Metal sulfate binding selectivity in solution is further supported by isothermal titration calorimetric studies of L1 with different Zn salts in dimethyl sulfoxide (DMSO), where a binding affinity is observed for ZnSO4 (Ka = 1.23 × 106), which is 30- to 50-fold higher than other Zn salts having other counteranions in DMSO. Sulfate salts of CdII/CoII also exhibit binding constants in the order of ～1 × 106 as in the case of ZnSO4. Positive role of the urea unit in the selectivity is confirmed by studying a model ligand L2, which is devoid of anion recognition urea unit. Structural characterization of four MSO4 [M = ZnII, CdII, CoII, MnII] complexes of L1, that is, complex 1, [(L1)2(Zn)2(μ-SO4)2]; complex 2, [(L1)2(H2O)2(Cd)2(μ-SO4)2]; complex 3, [(L1)2(H2O)2(Co)2(μ-SO4)2]; and complex 4, [(L1)2(H2O)2(Mn)2(μ-SO4)2], reveal the formation of sulfate-bridged eight-membered crownlike binuclear complexes, similar to one of the concentration-dependent dimeric forms of MSO4 as observed in solid state. Finally, L1 is found to be highly efficient in removing ZnSO4 from both aqueous and semiaqueous medium as complex 1 in the presence of other competing ZnII salts via precipitation through crystallization. Powder X-ray diffraction analysis has also confirmed bulk purity of complex 1 obtained from the above competitive crystallization experiment.
A pyrophosphate-responsive gadolinium(III) MRI contrast agent
Surman, Andrew J.,Bonnet, Celia S.,Lowe, Mark P.,Kenny, Gavin D.,Bell, Jimmy D.,Toth, Eva,Vilar, Ramon
, p. 223 - 230 (2011)
This study shows that the relaxivity and optical properties of functionalised lanthanide-DTPA-bis-amide complexes (lanthanide=Gd3+ and Eu3+, DTPA=diethylene triamine pentaacetic acid) can be successfully modulated by addition of specific anions, without direct Ln 3+/anion coordination. Zinc(II)-dipicolylamine moieties, which are known to bind strongly to phosphates, were introduced in the amide "arms" of these ligands, and the interaction of the resulting Gd-Zn2 complexes with a range of anions was screened by using indicator displacement assays (IDAs). Considerable selectivity for polyphosphorylated species (such as pyrophosphate and adenosine-5′- triphosphate (ATP)) over a range of other anions (including monophosphorylated anions) was apparent. In addition, we show that pyrophosphate modulates the relaxivity of the gadolinium(III) complex, this modulation being sufficiently large to be observed in imaging experiments. To establish the binding mode of the pyrophosphate and gain insight into the origin of the relaxometric modulation, a series of studies including UV/Vis and emission spectroscopy, luminescence lifetime measurements in H2O and D2O, 17O and 31P NMR spectroscopy and nuclear magnetic resonance dispersion (NMRD) studies were carried out. Pick an anion: The anion-binding properties of functionalised Ln-DTPA-bis-amide complexes (Ln=Gd3+, Eu3+, DTPA=diethylene triamine pentaacetic acid) were investigated by using indicator displacement assays (IDAs) (see picture). A remarkable selectivity for polyphosphorylated species was observed. This has been successfully used to modulate the relaxivity of the Gd3+ complex with pyrophosphate.
A family of structural and functional models for the active site of a unique dioxygenase: Acireductone dioxygenase (ARD)
Blade, Glenn A.,Parveen, Riffat,Jaimes, Jennifer L.,Ilustre, Wrenell,Salda?a, Diego,Ivan, Denisa A.,Lynch, Vincent M.,Cundari, Thomas R.,Toledo, Santiago
, (2020)
We report the synthesis and biomimetic activity of a family of model complexes with relevance to acireductone dioxygenase (ARD), an enzyme that displays dual function based on metal identity found in the methionine salvage pathway (MSP). Three complexes with related structural motifs were synthesized and characterized derived from phenolate, and pyridine N4O Schiff-base ligands. They display pseudo-octahedral Ni(II)-N4O ligand coordination with water at the sixth site, in close alignment to the structure in the resting state of ARD. The three featured complexes exhibit carbon?carbon bond cleavage activation of lithium acetylacetonate, which was used as a model enzyme substrate. Computationally derived mechanistic routes for the observed reactivity consistent with experimental conditions are herein proposed. The mechanism suggests the possibility of Ni(II)-substrate interactions, followed by oxygen insertion. These results constitute only the third functional model system of ARD, in an attempt to further advance biomimetic contributions to the ongoing debate of ARD's unique metal mediated, regioselective oxidative cleavage.
Selective sensing of zinc ions with a novel magnetic resonance imaging contrast agent
Hanaoka, Kenjiro,Kikuchi, Kazuya,Urano, Yasuteru,Nagano, Tetsuo
, p. 1840 - 1843 (2001)
Light-based microscope imaging techniques using fluorescence sensor molecules suffer from photobleaching and light scattering, but magnetic resonance imaging (MRI) can provide three-dimensional imaging without these problems. Recently, "smart" MRI contras
Real-time Tracking and Sensing of Cu+ and Cu2+ with a Single SERS Probe in the Live Brain: Toward Understanding Why Copper Ions Were Increased upon Ischemia
Liu, Jiaqi,Liu, Zhichao,Wang, Weikang,Tian, Yang
, p. 21351 - 21359 (2021)
The imbalance of Cu+ and Cu2+ in the brain is closely related to neurodegenerative diseases. However, it still lacks of effective analytical methods for simultaneously determining the concentrations of Cu+ and Cu2+. Herein, we created a novel SERS probe (CuSP) to real-time track and accurately quantify extracellular concentrations of Cu+ and Cu2+ in the live brain. The present CuSP probe demonstrated specific ability for recognition of Cu+ and Cu2+ in a dual-recognition mode. Then, a microarray consisting of 8 CuSP probes with high tempo-spatial resolution and good accuracy was constructed for tracking and simultaneously biosensing of Cu+ and Cu2+ in the cerebral cortex of living brain. Using our powerful tool, it was found that that the concentrations of Cu2+ and Cu+ were increased by ≈4.26 and ≈1.80 times upon ischemia, respectively. Three routes were first discovered for understanding the mechanisms of the increased concentrations of Cu+ and Cu2+ during ischemia.
A zinc-dipicolylethylenediamine modified near infrared fluorophore for sensing of ATP
Schaeferling, Michael,Lang, Thomas,Schnettelker, Annette
, p. 251 - 256 (2014)
The development of fluorescent probes for sensing of anions in biological environments is still a demanding task. Due to the structural versatility of biological active anions there are many challenges to cope with compared to fluoroionophores for the determination of metal cations. This concerns particularly the design of the recognition element, which has to provide a selective response, preferably unaffected by alterations of pH and ionic strength. Polyphosphate anions such as ATP are interesting targets in bioanalysis because they are involved in many enzymatic reactions and bear versatile biological functions. Zinc dipicolylamine complexes attached to fluorophores have been turned out to be promising candidates for ATP sensing with sufficient sensitivity and selectivity. We now report the first NIR probe that responds to ATP based on a zinc dipicolylethylenediamine receptor. It shows a "turn-on" fluorescence behavior which is selective to other polyphosphate species even at high ionic strength of the sample solution.
MITOCHONDRIAL COPPER DEPLETION REPROGRAMS THE METABOLISM OF TRIPLE NEGATIVE BREAST CANCER
-
, (2021/07/24)
Provided is a mitochondrial copper depleting strategy that exploits the potential vulnerability for this metabolic by cancer cells such as Triple Negative Breast Cancer cells. A nanoparticle is provided that comprises a self-reporting copper-depleting moiety (CDM) embedded in or on the matrix comprising a semi-conducting polymer and a phospholipid-polyethylene glycol (PEG). The positively charged copper-depleting complex targets mitochondria and deprives cytochrome c oxidase of its necessary copper co-factor. Inhibition of the electron transport chain complex IV compromises oxygen consumption and abrogates fatty acid oxidation, resulting in energy deficiency induced apoptosis of the targeted cancer cells. The copper-depleting nanoparticle can report the copper depleting status through multimodal optical signal changes while decreasing the copper level in tumors to inhibit tumor growth with low toxicity and significantly prolonged survival.
Metal beta-lactamase inhibitor as well as preparation method and application thereof
-
Paragraph 0058; 0061, (2020/10/14)
The invention discloses a metal beta-lactamase inhibitor as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving a pyridylamine compound in a solvent 1, adding an ester compound and carbonate, stirring at 80-100 DEG C for 11-13 hours, cooling the reaction product to room temperature, extracting, carrying out vacuum drying, and purifying to obtain a product 1; dissolving the product 1 in a solvent 2, adding ester-based hydrolysate, stirring for 1.5-2.5 hours at room temperature, and extracting, vacuum-drying and purifying a reaction product to obtain a Zn chelating agent; dissolving a beta-lactamase compound in a solvent 3, adding a Zn chelating agent and an alkali, stirring for 11-13 hours at room temperature, and extracting, vacuum-drying and purifying a reaction product to obtain the metal beta-lactamase inhibitor which can be used as a combined agent of antibiotics for inhibiting bacterial proliferation. The inhibitor is simpler to prepare and low in material cost, reduces the biotoxicity of molecules, and has higher antibacterial efficiency.
