Theoretical interpretation of the standard redox potential of benzene-1,2-diol and its derivatives

1981 ◽  
Vol 85 (23) ◽  
pp. 3510-3513 ◽  
Author(s):  
Shinichi Yamabe ◽  
Tsutomu Minato ◽  
Masaru Kimura
Electrochem ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 20-31
Author(s):  
Thi Huong Le ◽  
Van Quyen Nguyen ◽  
Gaelle Trippe-Allard ◽  
Jean-Christophe Lacroix ◽  
Pascal Martin

The control of the interface and the adhesion process are key issues for the development of new application based on electrochromic materials. In this work the functionalization of an electrode’s surface through electroreduction of diazonium generated in situ from 4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenylamine (SNS-An) has been proposed. The synthesis of the aniline derivative SNS-An was performed and the electrografting was investigated by cyclic voltammetry on various electrodes. Then the organic thin film was fully characterized by several techniques and XPS analysis confirms the presence of an organic film based on the chemical composition of the starting monomer and allows an estimation of its thickness confirmed by AFM scratching measurements. Depending on the number of electrodeposition cycles, the thickness varies from 2 nm to 10 nm, which corresponds to a few grafted oligomers. In addition, the grafted film showed a good electrochemical stability depending on the scan rates up to 400 V/s and the electrochemical response of the modified electrode towards several redox probes showed that the attached layer acts as a conductive switch. Therefore, the electrode behaves as a barrier to electron transfer when the standard redox potential of the probe is below the layer switching potential, whereas the layer can be considered as transparent towards the electron transfer for redox probes with a redox potential above it.


Chemija ◽  
2020 ◽  
Vol 31 (3) ◽  
Author(s):  
Benjaminas Valiauga ◽  
Nicolas Rouhier ◽  
Jean-Pierre Jacquot ◽  
Narimantas Čėnas

The fluorescence properties of FAD of Thermotoga maritima thioredoxin reductase (TmTR), taken together with the amino acid sequences and structures of similar TRs, are consistent with the interdomain rotation in the catalysis of TmTR. The standard redox potential of FAD of TmTR, –0.230 V, determined by the reactions with 3-acetylpyridine adenine dinucleotide (APAD+/APADH) redox couple, is close to that of E. coli TR. During the reduction of duroquinone with TmTR, the transient formation of neutral FAD semiquinone, and, possibly, FADH2–NAD+ complex was observed. This shows that in spite of obligatory twoelectron (hydride)-transfer between NADH and physiological disulfide oxidants, the FAD cofactor of TmTR may exist under a stable semiquinone form.


2007 ◽  
Vol 3 (3) ◽  
pp. 789-795 ◽  
Author(s):  
Yoshiki Shimodaira ◽  
Toshiko Miura ◽  
Akihiko Kudo ◽  
Hisayoshi Kobayashi

2011 ◽  
Vol 437 (3) ◽  
pp. 455-460 ◽  
Author(s):  
Hai Po Helena Liang ◽  
Teresa M. Brophy ◽  
Philip J. Hogg

TF (tissue factor) is a transmembrane cofactor that initiates blood coagulation in mammals by binding Factor VIIa to activate Factors X and IX. The cofactor can reside in a cryptic configuration on primary cells and de-encryption may involve a redox change in the C-terminal domain Cys186–Cys209 disulfide bond. The redox potential of the bond, the spacing of the reduced cysteine thiols and their oxidation by TF activators was investigated to test the involvement of the dithiol/disulfide in TF activation. A standard redox potential of −278 mV was determined for the Cys186–Cys209 disulfide of recombinant soluble TF. Notably, ablating the N-terminal domain Cys49–Cys57 disulfide markedly increased the redox potential of the Cys186–Cys209 bond, suggesting that the N-terminal bond may be involved in the regulation of redox activity at the C-terminal bond. Using As(III) and dibromobimane as molecular rulers for closely spaced sulfur atoms, the reduced Cys186 and Cys209 sulfurs were found to be within 3–6 Å (1 Å=0.1 nm) of each other, which is close enough to reform the disulfide bond. HgCl2 is a very efficient activator of cellular TF and activating concentrations of HgCl2-mediated oxidation of the reduced Cys186 and Cys209 thiols of soluble TF. Moreover, PAO (phenylarsonous acid), which cross-links two cysteine thiols that are in close proximity, and MMTS (methyl methanethiolsulfonate), at concentrations where it oxidizes closely spaced cysteine residues to a cystine residue, were efficient activators of cellular TF. These findings further support a role for Cys186 and Cys209 in TF activation.


2004 ◽  
Vol 33 (9) ◽  
pp. 1176-1177 ◽  
Author(s):  
Hisayoshi Kobayashi ◽  
Toshiko Miura ◽  
Yoshiki Shimodaira ◽  
Akihiko Kudo

1989 ◽  
Vol 155 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Renato Seeber ◽  
Paola Piu ◽  
Pasquale Piraino ◽  
Piero Zanello

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