O-Alkylated Derivatives of 1,3,5-Triamino-1,3,5-trideoxy-cis-inositol:  Triamine Ligands with Unexpectedly High Affinity toward Divalent Transition- and d10-Metal Ions

1999 ◽  
Vol 38 (5) ◽  
pp. 859-868 ◽  
Author(s):  
Michael Weber ◽  
Dirk Kuppert ◽  
Kaspar Hegetschweiler ◽  
Volker Gramlich
Keyword(s):  
Metal Ions ◽  
High Affinity ◽  
D10 Metal ◽  
Derivatives Of

Metal Derivatives of 1,3-Imidazolidine-2-thione with Divalent d10 Metal Ions (Zn–Hg) : Synthesis and Structures

2008 ◽  
Vol 634 (4) ◽  
pp. 718-723 ◽  
Author(s):  
Tarlok S. Lobana ◽  
Renu Sharma ◽  
Rekha Sharma ◽  
Razia Sultana ◽  
R. J. Butcher
Keyword(s):  
Metal Ions ◽  
D10 Metal ◽  
Metal Derivatives ◽  
Derivatives Of

1, 9-Dihydro-purine-6-thione Derivatives of the d8-d10 Metal Ions (PdII, PtII, and CuI): Synthesis, Spectroscopy, and Structures

2012 ◽  
pp. n/a-n/a
Author(s):  
Tarlok S. Lobana ◽  
Parminderjit Kaur ◽  
Geeta Hundal ◽  
Ray J. Butcher ◽  
Chen W. Liu
Keyword(s):  
Metal Ions ◽  
D10 Metal ◽  
Derivatives Of

Metal derivatives of N-substituted imidazolidine-2-thiones with d10 metal ions (Zn–Hg): Synthesis, spectroscopy, ESI-mass and structures

Polyhedron ◽  
2015 ◽  
Vol 87 ◽  
pp. 17-27 ◽  
Author(s):  
Tarlok S. Lobana ◽  
Amanpreet K. Sandhu ◽  
Amanpreet K. Jassal ◽  
Geeta Hundal ◽  
R.K. Mahajan ◽  
...  
Keyword(s):  
Metal Ions ◽  
D10 Metal ◽  
Metal Derivatives ◽  
Derivatives Of

Amentoflavone: A Bifunctional Metal Chelator that Controls the Formation of Neurotoxic Soluble Aβ42 Oligomers

2020 ◽  
Author(s):  
Liang Sun ◽  
Anuj K. Sharma ◽  
Byung-Hee Han ◽  
Liviu M. Mirica
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Amyloid Plaques ◽  
Transition Metal Ions ◽  
Oxygen Species ◽  
High Affinity ◽  
Amyloid Aβ ◽  
Β Amyloid

<p>Alzheimer's disease (AD) is the most common neurodegenerative disorder, yet the cause and progression of this disorder are not completely understood. While the main hallmark of AD is the deposition of amyloid plaques consisting of the β-amyloid (Aβ) peptide, transition metal ions are also known to play a significant role in disease pathology by expediting the formation of neurotoxic soluble β-amyloid (Aβ) oligomers, reactive oxygen species (ROS), and oxidative stress. Thus, bifunctional metal chelators that can control these deleterious properties are highly desirable. Herein, we show that amentoflavone (AMF) – a natural biflavonoid compound, exhibits good metal-chelating properties, especially for chelating Cu<sup>2+</sup> with very high affinity (pCu<sub>7.4</sub> = 10.44). In addition, AMF binds to Aβ fibrils with a high affinity (<i>K<sub>i</sub></i> = 287 ± 20 nM) – as revealed by a competition thioflavin T (ThT) assay, and specifically labels the amyloid plaques <i>ex vivo</i> in the brain sections of transgenic AD mice – as confirmed via immunostaining with an Ab antibody. The effect of AMF on Aβ<sub>42</sub> aggregation and disaggregation of Aβ<sub>42</sub> fibrils was also investigated, to reveal that AMF can control the formation of neurotoxic soluble Aβ<sub>42</sub> oligomers, both in absence and presence of metal ions, and as confirmed via cell toxicity studies. Furthermore, an ascorbate consumption assay shows that AMF exhibits potent antioxidant properties and can chelate Cu<sup>2+</sup> and significantly diminish the Cu<sup>2+</sup>-ascorbate redox cycling and reactive oxygen species (ROS) formation. Overall, these studies strongly suggest that AMF acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity, can also bind Cu<sup>2+</sup> and mediate its deleterious redox properties, and thus AMF has the potential to be a lead compound for further therapeutic agent development for AD. </p>

scholarly journals Functional characterization of the dimerization domain of the ferric uptake regulator (Fur) of Pseudomonas aeruginosa

2006 ◽  
Vol 400 (3) ◽  
pp. 385-392 ◽  
Author(s):  
Erdeni Bai ◽  
Federico I. Rosell ◽  
Bao Lige ◽  
Marcia R. Mauk ◽  
Barbara Lelj-Garolla ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Metal Ions ◽  
Binding Site ◽  
Metal Ion ◽  
Association Constants ◽  
Ion Binding ◽  
Ferric Uptake Regulator ◽  
Metal Ion Binding ◽  
Dimerization Domain ◽  
High Affinity

The functional properties of the recombinant C-terminal dimerization domain of the Pseudomonas aeruginosa Fur (ferric uptake regulator) protein expressed in and purified from Escherichia coli have been evaluated. Sedimentation velocity measurements demonstrate that this domain is dimeric, and the UV CD spectrum is consistent with a secondary structure similar to that observed for the corresponding region of the crystallographically characterized wild-type protein. The thermal stability of the domain as determined by CD spectroscopy decreases significantly as pH is increased and increases significantly as metal ions are added. Potentiometric titrations (pH 6.5) establish that the domain possesses a high-affinity and a low-affinity binding site for metal ions. The high-affinity (sensory) binding site demonstrates association constants (KA) of 10(±7)×106, 5.7(±3)×106, 2.0(±2)×106 and 2.0(±3)×104 M−1 for Ni2+, Zn2+, Co2+ and Mn2+ respectively, while the low-affinity (structural) site exhibits association constants of 1.3(±2)×106, 3.2(±2)×104, 1.76(±1)×105 and 1.5(±2)×103 M−1 respectively for the same metal ions (pH 6.5, 300 mM NaCl, 25 °C). The stability of metal ion binding to the sensory site follows the Irving–Williams order, while metal ion binding to the partial sensory site present in the domain does not. Fluorescence experiments indicate that the quenching resulting from binding of Co2+ is reversed by subsequent titration with Zn2+. We conclude that the domain is a reasonable model for many properties of the full-length protein and is amenable to some analyses that the limited solubility of the full-length protein prevents.

Fluorescence Enhancement of Polyamine Derivatives of 1,8-Naphthalimide with Transition Metal Ions

2006 ◽  
Vol 19 (6) ◽  
pp. 506-510 ◽  
Author(s):  
Guo-tao Wen ◽  
Man-zhou Zhu ◽  
Zhuo Wang ◽  
Xiang-ming Meng ◽  
Hui-yuan Hu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Fluorescence Enhancement ◽  
Transition Metal Ions ◽  
Derivatives Of ◽  
Polyamine Derivatives

scholarly journals Removal of Pb(II) Metal Ions from Aqueous Solutions Using Chitosan-Vanillin Derivatives of Chelating Polymers

2019 ◽  
Vol 28 (3) ◽  
pp. 1523-1534 ◽  
Author(s):  
Fadi Alakhras ◽  
Hanin Al-Shahrani ◽  
Eman Al-Abbad ◽  
Fuad Al-Rimawi ◽  
Noureddine Ouerfelli
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Vanillin Derivatives ◽  
Derivatives Of ◽  
Chelating Polymers

scholarly journals Trends and Exceptions in the Interaction of Hydroxamic Acid Derivatives of Common Di- and Tripeptides with Some 3d and 4d Metal Ions in Aqueous Solution

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3941 ◽  
Author(s):  
Ozsváth ◽  
Bíró ◽  
Nagy ◽  
Buglyó ◽  
Sanna ◽  
...  
Keyword(s):  
Metal Ions ◽  
Hydroxamic Acid ◽  
Hydroxamic Acids ◽  
17O Nmr ◽  
Equilibrium Study ◽  
Sandwich Type ◽  
Uv Visible ◽  
First Time ◽  
Derivatives Of ◽  
Half Sandwich

By using various techniques (pH-potentiometry, UV-Visible spectrophotometry, 1H and 17O-NMR, EPR, ESI-MS), first time in the literature, solution equilibrium study has been performed on complexes of dipeptide and tripeptide hydroxamic acids—AlaAlaNHOH, AlaAlaN(Me)OH, AlaGlyGlyNHOH, and AlaGlyGlyN(Me)OH—with 4d metals: the essential Mo(VI) and two half-sandwich type cations, [(η6-p-cym)Ru(H2O)3]2+ as well as [(η5-Cp*)Rh(H2O)3]2+, the latter two having potential importance in cancer therapy. The tripeptide derivatives have also been studied with some biologically important 3d metals, such as Fe(III), Ni(II), Cu(II), and Zn(II), in order to compare these new results with the corresponding previously obtained ones on dipeptide hydroxamic acids. Based on the outcomes, the effects of the type of metal ions, the coordination number, the number and types of donor atoms, and their relative positions to each other on the complexation have been evaluated in the present work. We hope that these collected results might be used when a new peptide-based hydroxamic acid molecule is planned with some purpose, e.g. to develop a potential metalloenzyme inhibitor.

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