scholarly journals Electrochemical Study of the Redox Properties of Levulinic Acid in Organic and Aqueous-Organic Solutions

2021 ◽  
Vol 14 (3) ◽  
pp. 388-395
Author(s):  
Galina V. Burmakina ◽  
Keyword(s):  
Dimethyl Sulfoxide ◽  
Levulinic Acid ◽  
Reduction Potential ◽  
Redox Properties ◽  
Electrochemical Methods ◽  
Electrochemical Study ◽  
Electron Reduction ◽  
Organic Solutions

The redox properties of levulinic acid (LA) were studied by electrochemical methods in acetonitrile, a mixture of acetonitrile with water, ethanol, acetone, and dimethyl sulfoxide. It was shown that the irreversible two-electron reduction of LA under the studied conditions leads to the formation of γ-valerolactone. This reduction potential depends on the solvent and shifted anodically by following order: dimethyl sulfoxide

scholarly journals Electrochemical Study of the Reduction of Levulinic Acid in Acetonitrile on Various Electrodes

2021 ◽  
Vol 14 (4) ◽  
pp. 552-560
Author(s):  
Galina V. Burmakina ◽  
◽  
Dmitry V. Zimonin ◽  
Victor V. Verpekin ◽  
Anatoly I. Rubaylo
Keyword(s):  
Glassy Carbon ◽  
Electrode Material ◽  
Levulinic Acid ◽  
Proton Donor ◽  
Electrochemical Methods ◽  
Electrochemical Study ◽  
Iron Copper ◽  
Lead Electrodes

The reduction of levulinic acid by electrochemical methods in acetonitrile with or without proton donor on platinum, rhodium, glassy carbon, dropping mercury, iron, copper and lead electrodes were studied. The reduction of levulinic acid was shown to depend on the nature of electrode material and to proceed according to either electrocatalytic or electrochemical mechanisms

scholarly journals Redox properties and prooxidant cytotoxicity of a neuroleptic agent 6,7-dinitrodihydroquinoxaline-2,3-dione (DNQX).

2013 ◽  
Vol 60 (2) ◽  
Author(s):  
Jonas Šarlauskas ◽  
Aušra Nemeikaitė-Čėnienė ◽  
Lina Misevičienė ◽  
Kastis Krikštopaitis ◽  
Žilvinas Anusevičius ◽  
...  
Keyword(s):  
Electrochemical Reduction ◽  
Bovine Leukemia Virus ◽  
Reduction Potential ◽  
Leukemia Virus ◽  
Redox Properties ◽  
Single Electron ◽  
Reduction Peak ◽  
Neuroleptic Agent ◽  
Electron Reduction ◽  
Dt Diaphorase

In order to characterize the possible mechanism(s) of cytotoxicity of a neuroleptic agent 6,7-dinitrodihydroquinoxaline-2,3-dione (DNQX) we examined the redox properties of DNQX, and its mononitro- (NQX) and denitro- (QX) derivatives. The irreversible electrochemical reduction of the nitro groups of DNQX was characterized by the reduction peak potentials (Ep,7) of -0.43 V and -0.72 V vs. Ag/AgCl at pH 7.0, whereas NQX was reduced at Ep,7 = -0.67 V. The reactivities of DNQX and NQX towards the single-electron transferring enzymes NADPH:cytochrome P-450 reductase and NADPH:adrenodoxin reductase/adrenodoxin complex were similar to those of model nitrobenzenes with the single-electron reduction potential (E¹₇) values of -0.29 V - -0.42 V. DNQX and NQX also acted as substrates for two-electron transferring mammalian NAD(P)H:quinone oxidoreductase (DT-diaphorase). The cytotoxicity of DNQX in bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK) was prevented by antioxidants and an inhibitor of NQO1, dicoumarol, and was enhanced by the prooxidant alkylating agent 1,3-bis(2-chloromethyl)-1-nitrosourea. A comparison with model nitrobenzene compounds shows that the cytotoxicity of DNQX and NQX reasonably agrees with the ease of their electrochemical reduction, and/or their reactivities towards the used enzymatic single-electron reducing systems. Thus, our data imply that the cytotoxicity of DNQX in FLK cells is exerted mainly through oxidative stress.

Redox Properties of CeIVDOTA in Carbonated Aqueous Solutions. A Radiolytic and an Electrochemical Study

2021 ◽  
Vol 125 (7) ◽  
pp. 1436-1446
Author(s):  
Inna Popivker ◽  
Dan Meyerstein ◽  
Dalia Gitin ◽  
Elad N. Avraham ◽  
Eric Maimon ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Redox Properties ◽  
Electrochemical Study

scholarly journals An electrochemical study of pH influences on corrosion and passivation for a Q235 carbon steel in HNO3–NaNO2, HAc–NaNO2 and HCl–NaNO2 solutions

RSC Advances ◽  
2019 ◽  
Vol 9 (67) ◽  
pp. 39055-39063 ◽  
Author(s):  
Xuan Li ◽  
Pei Zhang ◽  
Huiju Huang ◽  
Xiaochen Hu ◽  
Yong Zhou ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Electrochemical Methods ◽  
Electrochemical Study ◽  
Ph Values ◽  
Q235 Carbon Steel

In this study, the influences of different pH values on the corrosion and passivation behaviors of a Q235 carbon steel in HNO3–NaNO2, HAc–NaNO2 and HCl–NaNO2 solutions were studied by electrochemical methods.

Ti4O7 Used as Electrode in Biomedicine and for Electrochemical Study of Scavenging Mechanism

2011 ◽  
Vol 493-494 ◽  
pp. 896-901
Author(s):  
María Canillas ◽  
Ann Rajnicek ◽  
C. Rosero ◽  
Eva Chinarro ◽  
Berta Moreno
Keyword(s):  
Oxidation State ◽  
Reactive Species ◽  
Electrochemical Methods ◽  
Electrochemical Study ◽  
Scavenging Activity ◽  
Reduction Reactions ◽  
Oxidation Reduction ◽  
Nitrogen Reactive Species

The biocompatibility of TiO2 is due to the activity that it shown in front of oxygen and nitrogen reactive species. Some authors suggest that the mechanism go through oxidation reduction reactions where changes of oxidation state in the Titanium and phases are involve. For this reason, Anderson-Magnelli phases could present scavenging activity. Moreover, these materials are use as electrodes and in that way are proposed as electrodes for study their scavenging mechanism by electrochemical methods.

One-electron reduction of tris(2,2'-bipyrimidine)ruthenium(2+) ion in aqueous solution: a photochemical, radiation chemical, and electrochemical study

1989 ◽  
Vol 93 (16) ◽  
pp. 6080-6088 ◽  
Author(s):  
Gilda Neshvad ◽  
Morton Z. Hoffman ◽  
Quinto G. Mulazzani ◽  
Margherita Venturi ◽  
Mauro Ciano ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Study ◽  
Radiation Chemical ◽  
Electron Reduction

scholarly journals One-Electron Reduction Potentials: Calibration of Theoretical Protocols for Morita–Baylis–Hillman Nitroaromatic Compounds in Aprotic Media

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2129 ◽  
Author(s):  
Amauri Francisco da Silva ◽  
Antonio João da Silva Filho ◽  
Mário Vasconcellos ◽  
Otávio Luís de Santana
Keyword(s):  
Cyclic Voltammetry ◽  
Biological Activity ◽  
Chemical Structure ◽  
Reduction Potential ◽  
Chemical Reactivity ◽  
Nitroaromatic Compounds ◽  
Reduction Potentials ◽  
Electron Reduction ◽  
The One ◽  
Antileishmanial Activities

Nitroaromatic compounds—adducts of Morita–Baylis–Hillman (MBHA) reaction—have been applied in the treatment of malaria, leishmaniasis, and Chagas disease. The biological activity of these compounds is directly related to chemical reactivity in the environment, chemical structure of the compound, and reduction of the nitro group. Because of the last aspect, electrochemical methods are used to simulate the pharmacological activity of nitroaromatic compounds. In particular, previous studies have shown a correlation between the one-electron reduction potentials in aprotic medium (estimated by cyclic voltammetry) and antileishmanial activities (measured by the IC50) for a series of twelve MBHA. In the present work, two different computational protocols were calibrated to simulate the reduction potentials for this series of molecules with the aim of supporting the molecular modeling of new pharmacological compounds from the prediction of their reduction potentials. The results showed that it was possible to predict the experimental reduction potential for the calibration set with mean absolute errors of less than 25 mV (about 0.6 kcal·mol−1).

scholarly journals Mutually Isomeric 2- and 4-(3-Nitro-1,2,4-triazol-1-yl)pyrimidines Inspired by an Antimycobacterial Screening Hit: Synthesis and Biological Activity against the ESKAPE Panel of Pathogens

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Sergey Chuprun ◽  
Dmitry Dar’in ◽  
Elizaveta Rogacheva ◽  
Liudmila Kraeva ◽  
Oleg Levin ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Antibacterial Activity ◽  
Reduction Potential ◽  
Gram Negative ◽  
Reduction Potentials ◽  
Apparent Correlation ◽  
Electron Reduction ◽  
Activity Loss ◽  
Eskape Pathogens ◽  
Bioactivity Profile

Starting from the structure of antimycobacterial screening hit OTB-021 which was devoid of activity against ESKAPE pathogens, we designed, synthesized and tested two mutually isomeric series of novel simplified analogs, 2- and 4-(3-nitro-1,2,4-triazol-1-yl)pyrimidines, bearing various amino side chains. These compounds demonstrated a reverse bioactivity profile being inactive against M. tuberculosis while inhibiting the growth of all ESKAPE pathogens (with variable potency patterns) except for Gram-negative P. aeruginosa. Reduction potentials (E1/2, V) measured for selected compounds by cyclic voltammetry were tightly grouped in the −1.3–−1.1 V range for a reversible single-electron reduction. No apparent correlation between the E1/2 values and the ESKAPE minimum inhibitory concentrations was established, suggesting possible significance of other factors, besides the compounds’ reduction potential, which determine the observed antibacterial activity. Generally, more negative E1/2 values were displayed by 2-(3-nitro-1,2,4-triazol-1-yl)pyrimidines, which is in line with the frequently observed activity loss on moving the 3-nitro-1,2,4-triazol-1-yl moiety from position 4 to position 2 of the pyrimidine nucleus.

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