Mononuclear Zn(II)-DPA and Cu(II)-DPA complexes crafted on 2-hydroxy-6-cyanonaphthalene fluorophore selectively recognize PPi over ATP and other anions including inorganic phosphates in aqueous medium, showing turn-on type fluorescence enhancements. Coordination of a hydroxyl group of the fluorophore, directly or in alkoxy form, to the central metal ion is crucial for the sensing processes. Both the complexes elicit a fluorescence increase in a time-dependent fashion.
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http://dx.doi.org/10.1039/c1ob05999h | DOI Listing |
Molecules
November 2024
Instituto de Química-UNAM, Circuito Exterior, C.U. Coyoacán, Mexico City C.P. 04510, Mexico.
Four mononuclear bioefficient zinc coordination complexes [Zn(NN)](ClO) (-) involving chiral bidentate Schiff base ligands have been synthesized and characterized by IR, H, and C NMR spectroscopy and mass spectrometry. X-ray crystal structures of three of the zinc complexes revealed that the zinc metal ion is hexacoordinated, exhibiting a distorted octahedral geometry where both the nitrogen atoms (NN = pyridyl and imine) of imines are coordinated to the central zinc ion. The isolated zinc complexes were evaluated for their antimicrobial activity in vitro against , , and , displaying varying levels of growth inhibition.
View Article and Find Full Text PDFGeneration of -nitrosothiol (RSNO) and nitric oxide (NO) mediated by zinc(ii) coordination motifs is of prime importance for understanding the role of zinc(ii)-based cofactors in redox-signalling pathways. This study uniquely employs a set of mononuclear [LZn] cores (where L = MePzPz/MePzPy/MePzQu) for introducing subtle alterations of the primary coordination sphere and investigates the role of ligand tuning in the transformation of NO in the presence of thiols. Single crystal X-ray diffraction (SCXRD) analyses on [LZn-X](X) (where X = perchlorate/triflate) illustrate consistent changes in the bond distances, thereby showing variations of the metal-ligand interactions depending on the nature of the heterocyclic donor arms (pyrazole/pyridine/quinoline).
View Article and Find Full Text PDFHeliyon
September 2024
Department of Chemistry, College of Science, Tikrit University, Tikrit, Iraq.
In this paper, four new mono-nuclear Ni(II), Pd(II), Pt(II) and Zn(II) complexes were prepared by using a bi-dentate Schiff base ligand, ()-2-(((4-bromo-2,6-dichlorophenyl)imino)methyl)-5-chlorophenol (), with bivalent ions in a methanol and distil water mixture as solvent in presence of NaOH as base. The structures of the prepared compounds were characterized by spectroscopic techniques (IR and H NMR), CHN analysis, and molar conductivity. The M(II) (Ni, Pd and Pt) ions are four-coordinated by a bi-dentate NO donor ligand, forming square planar geometry, whereas the Zn(II) is coordinated as a tetrahedral geometry.
View Article and Find Full Text PDFInt J Mol Sci
July 2024
Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, I-53100 Siena, Italy.
Glutaminyl-peptide cyclotransferases (QCs) convert the N-terminal glutamine or glutamate residues of protein and peptide substrates into pyroglutamate (pE) by releasing ammonia or a water molecule. The N-terminal pE modification protects peptides/proteins against proteolytic degradation by amino- or exopeptidases, increasing their stability. Mammalian QC is abundant in the brain and a large amount of evidence indicates that pE peptides are involved in the onset of neural human pathologies such as Alzheimer's and Huntington's disease and synucleinopathies.
View Article and Find Full Text PDFDalton Trans
August 2024
University of Belgrade - Faculty of Chemistry Studentski trg 12-16, 11000 Belgrade, Serbia.
In this paper, three different Zn(II) complexes with ()-2-(2-(1-(6-bromopyridin-2-yl)ethylidene)hydrazinyl)-,,-trimethyl-2-oxoethan-1-aminium chloride (HLCl) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR and NMR spectroscopy. All complexes are mononuclear, with the ligand (L) coordinated in a deprotonated formally neutral zwitterionic form NNO donor set atoms. Complex 1 forms an octahedral geometry with the composition [ZnL](BF), while complexes 2 [ZnL(NCO)] and 3 [ZnL(N)] form penta-coordinated geometry.
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