scholarly journals The Progress of Li-S Batteries-Understanding of the Sulfur Redox Mechanism: Dissolved Polysulfide Ions in the Electrolytes

2018 ◽  
Vol 3 (9) ◽  
pp. 1700233 ◽  
Author(s):  
Dong Zheng ◽  
Gongwei Wang ◽  
Dan Liu ◽  
Jingyu Si ◽  
Tianyao Ding ◽  
...  
Keyword(s):  
Redox Mechanism ◽  
Polysulfide Ions

Repelling Polysulfide Ions by Boron Nitride Nanosheet Coated Separators in Lithium–Sulfur Batteries

2019 ◽  
Vol 2 (4) ◽  
pp. 2620-2628 ◽  
Author(s):  
Ye Fan ◽  
Dan Liu ◽  
Md Mokhlesur Rahman ◽  
Tao Tao ◽  
Weiwei Lei ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Boron Nitride Nanosheet ◽  
Lithium Sulfur Batteries ◽  
Polysulfide Ions ◽  
Lithium Sulfur

scholarly journals Osmium–arene complexes with high potency towards Mycobacterium tuberculosis

Metallomics ◽  
2021 ◽  
Vol 13 (4) ◽  
Author(s):  
James P C Coverdale ◽  
Collette S Guy ◽  
Hannah E Bridgewater ◽  
Russell J Needham ◽  
Elizabeth Fullam ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Global Health ◽  
Mechanism Of Action ◽  
Health Problem ◽  
Normal Lung ◽  
Lung Cells ◽  
Redox Mechanism ◽  
Human Lung Cells ◽  
Half Sandwich ◽  
Global Health Problem

Abstract The treatment of tuberculosis (TB) poses a major challenge as frontline therapeutic agents become increasingly ineffective with the emergence and spread of drug-resistant strains of Mycobacterium tuberculosis (Mtb). To combat this global health problem, new antitubercular agents with novel modes of action are needed. We have screened a close family of 17 organometallic half-sandwich Os(II) complexes [(arene)Os(phenyl-azo/imino-pyridine)(Cl/I)]+Y– containing various arenes (p-cymene, biphenyl, or terphenyl), and NMe2, F, Cl, or Br phenyl or pyridyl substituents, for activity towards Mtb in comparison with normal human lung cells (MRC5). In general, complexes with a monodentate iodido ligand were more potent than chlorido complexes, and the five most potent iodido complexes (MIC 1.25–2.5 µM) have an electron-donating Me2N or OH substituent on the phenyl ring. As expected, the counter anion Y (PF6–, Cl–, I–) had little effect on the activity. The pattern of potency of the complexes towards Mtb is similar to that towards human cells, perhaps because in both cases intracellular thiols are likely to be involved in their activation and their redox mechanism of action. The most active complex against Mtb is the p-cymene Os(II) NMe2-phenyl-azopyridine iodido complex (2), a relatively inert complex that also exhibits potent activity towards cancer cells. The uptake of Os from complex 2 by Mtb is rapid and peaks after 6 h, with temperature-dependence studies suggesting a major role for active transport. Significance to Metallomics Antimicrobial resistance is a global health problem. New advances are urgently needed in the discovery of new antibiotics with novel mechanisms of action. Half-sandwich organometallic complexes offer a versatile platform for drug design. We show that with an appropriate choice of the arene, an N,N-chelated ligand, and monodentate ligand, half-sandwich organo–osmium(II) complexes can exhibit potent activity towards Mycobacterium tuberculosis (Mtb), the leading cause of death from a single infectious agent. The patterns of activity of the 17 azo- and imino-pyridine complexes studied here towards Mtb and normal lung cells suggest a common redox mechanism of action involving intracellular thiols.

scholarly journals Redox Mechanism of Azathioprine and Its Interaction with DNA

2021 ◽  
Vol 22 (13) ◽  
pp. 6805
Author(s):  
Mihaela-Cristina Bunea ◽  
Victor-Constantin Diculescu ◽  
Monica Enculescu ◽  
Horia Iovu ◽  
Teodor Adrian Enache
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Structural Changes ◽  
Differential Pulse ◽  
Immunosuppressive Drug ◽  
Redox Mechanism ◽  
Before And After ◽  
Dna Film ◽  
Scanning Electron

The electrochemical behavior and the interaction of the immunosuppressive drug azathioprine (AZA) with deoxyribonucleic acid (DNA) were investigated using voltammetric techniques, mass spectrometry (MS), and scanning electron microscopy (SEM). The redox mechanism of AZA on glassy carbon (GC) was investigated using cyclic and differential pulse (DP) voltammetry. It was proven that the electroactive center of AZA is the nitro group and its reduction mechanism is a diffusion-controlled process, which occurs in consecutive steps with formation of electroactive products and involves the transfer of electrons and protons. A redox mechanism was proposed and the interaction of AZA with DNA was also investigated. Morphological characterization of the DNA film on the electrode surface before and after interaction with AZA was performed using scanning electron microscopy. An electrochemical DNA biosensor was employed to study the interactions between AZA and DNA with different concentrations, incubation times, and applied potential values. It was shown that the reduction of AZA molecules bound to the DNA layer induces structural changes of the DNA double strands and oxidative damage, which were recognized through the occurrence of the 8-oxo-deoxyguanosine oxidation peak. Mass spectrometry investigation of the DNA film before and after interaction with AZA also demonstrated the formation of AZA adducts with purine bases.

Nucleophilic substitution of S-phenyl thiol esters by electrogenerated polysulfide ions in N,N-dimethylacetamide

1998 ◽  
pp. 607-610 ◽  
Author(s):  
Abdelkader Ahrika ◽  
Meriem Anouti ◽  
Julie Robert ◽  
Jacky Paris
Keyword(s):  
Nucleophilic Substitution ◽  
Thiol Esters ◽  
Polysulfide Ions

Kinetics and mechanism of the reduction of CrVI to CrIII by D-ribose and 2-deoxy-D-ribose

1999 ◽  
Vol 77 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Verónica Daier ◽  
Sandra Signorella ◽  
Marcela Rizzotto ◽  
María Inés Frascaroli ◽  
Claudia Palopoli ◽  
...  
Keyword(s):  
Redox Reaction ◽  
Kinetics And Mechanism ◽  
Epr Spectra ◽  
Oxidation Reactions ◽  
Redox Mechanism ◽  
Rate Laws ◽  
Aldonic Acid

The oxidation of D-ribose and 2-deoxy-D-ribose by CrVI yields the aldonic acid and Cr3+ as final products when an excess of sugar over CrVI is used. The redox reaction occurs through CrVI–>CrIII and CrVI–>CrV–>CrIII paths. The complete rate laws for the CrVI oxidation reactions are expressed by -d[CrVI]/dt = kH[H+]2 [ribose][CrVI], where kH = (5.9 ± 0.1) × 10-2 mol-3 dm9 s-1, and -d[CrVI]/dt = (k0 + kH'[H+]2) [2-deoxyribose][CrVI], where k0 = (1.3 ± 0.5) × 10-3 mol-1 dm3 s-1 and kH' = (4.2 ± 0.1) × 10-2 mol-3 dm9 s-1, at 33°C. An intermediate sugar alkoxide radical could be trapped with DMPO and observed by EPR as a multiline signal at g = 2.003. CrV is formed in a rapid step by reaction of the sugar radical with CrVI. CrV reacts with the substrate faster than CrVI does. The EPR spectra show that five- and six-coordinate oxochromate(V) intermediates are formed, and the distribution of these CrV species in the reaction mixture essentially depends on the solution acidity.Key words: ribose, 2-deoxyribose, chromium, redox, mechanism, kinetics.

scholarly journals Study of redox mechanism of poly(o-aminophenol) using in situ techniques: evidence of two redox processes

2005 ◽  
Vol 576 (1) ◽  
pp. 139-145 ◽  
Author(s):  
H.J. Salavagione ◽  
J. Arias-Pardilla ◽  
J.M. Pérez ◽  
J.L. Vázquez ◽  
E. Morallón ◽  
...  
Keyword(s):  
Redox Processes ◽  
Redox Mechanism ◽  
In Situ Techniques

scholarly journals Two Isoforms of Protein Disulfide Isomerase Alter the Dimerization Status of E2A Proteins by a Redox Mechanism

1999 ◽  
Vol 274 (2) ◽  
pp. 1040-1049 ◽  
Author(s):  
Maurice Markus ◽  
Robert Benezra
Keyword(s):  
Protein Disulfide Isomerase ◽  
Disulfide Isomerase ◽  
Redox Mechanism ◽  
Protein Disulfide

Alloxan-dialuric acid cycling: A complex redox mechanism

2009 ◽  
Vol 43 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Janina A. Rosso ◽  
Marcos A. Astorga ◽  
Daniel O. Mártire ◽  
Mónica C. Gonzalez
Keyword(s):  
Redox Mechanism
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