Determination of a representative formal redox potential of the Fe(II)/Fe(III) redox couple in cyanhaemoglobin, at pH=7 and related to the state in solution, was the objective of this work. It was achieved at low concentrations of the protein (5μM) to circumvent undesired adsorption. Square-wave voltammetry instead of classical cyclic voltammetry was applied because this method is more sensitive and provides information on the formal redox potential and reversibility, even for rapid processes. We obtained E°'=-0.12±0.01V for cyanhaemoglobin and E°'=-0.10±0.01V, vs. SHE, for myoglobin in comparison. These values differ by only 20mV because the two Fe(II)/Fe(III) redox centres are embedded in closely resembling chemical environments. The small difference is probably owed to the additional axially coordinating cyanide ligand in cyanmethaemoglobin which slightly favours the Fe(III) state in the haem macrocycle.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.bioelechem.2017.11.012 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Novel One-Step Total Synthesis of -Dehydroosthol and Citrubuntin.
Molecules
February 2025
College of Pharmacy, Dali University, Dali 671000, China.
Efficient and simple syntheses of -dehydroosthol and citrubuntin were achieved in a single step by implementing a protecting-group-free, redox-neutral strategy that utilized readily available starting materials. In this approach, a practical one-pot (domino) Heck/dehydration reaction was carried out utilizing less reactive bromocoumarin, resulting in excellent stereoselectivity and atomic economy. Through the implementation of this new, efficient, and scalable synthesis method, the formal synthesis of a series of novel meroterpenoid natural products was successfully achieved.
View Article and Find Full Text PDFIodoarene Activation: Take a Leap Forward toward Green and Sustainable Transformations.
Chem Rev
March 2025
Research Organization of Science and Technology, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu Shiga 525-8577, Japan.
Constructing chemical bonds under green sustainable conditions has drawn attention from environmental and economic perspectives. The dissociation of (hetero)aryl-halide bonds is a crucial step of most arylations affording (hetero)arene derivatives. Herein, we summarize the (hetero)aryl halides activation enabling the direct (hetero)arylation of trapping reagents and construction of highly functionalized (hetero)arenes under benign conditions.
View Article and Find Full Text PDFPhotoredox-Catalyzed Nucleophilic Aromatic Substitution of Halophenols with Azoles via Oligomeric Phenylene Oxide Radicals.
J Am Chem Soc
March 2025
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
Nucleophilic aromatic substitution (SAr) reactions are widely employed in organic synthesis yet typically require the use of electron-deficient arenes for efficient reactivity. Herein, we report a photocatalytic protocol for formal SAr of electron-rich 4-halophenols with azole nucleophiles under mild, redox-neutral conditions. The transformation proceeds via a two-stage mechanism consisting of initial halophenol oligomerization to produce a key oligo(phenylene oxide) intermediate and its subsequent breakdown through SAr with the azole enabled by photoredox-catalyzed arene umpolung.
View Article and Find Full Text PDFDeciphering Reaction Mechanisms of Molecular Proton Reduction Catalysts with Cyclic Voltammetry: Kinetic vs Thermodynamic Control.
Acc Chem Res
March 2025
University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
ConspectusThe kinetics and thermodynamics of elementary reaction steps involved in the catalytic reduction of protons to hydrogen define the reaction landscape for catalysis. The mechanisms can differ in the order of the elementary proton transfer, electron transfer, and bond-forming steps and can be further differentiated by the sites at which protons and electrons localize. Access to fully elucidated mechanistic, kinetic, and thermochemical details of molecular catalysts is crucial to facilitate the development of new catalysts that operate with optimal efficiency, selectivity, and durability.
View Article and Find Full Text PDFTotal Synthesis of Anhydroryanodol and Formal Synthesis of Ryanodol and Ryanodine.
Org Lett
February 2025
Key Laboratory of Applied Surface and Colloid Chemistry of MOE & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China.
Building on our prior synthesis of the representative Ryanodane diterpene garajonone, we report here the chemical synthesis of anhydroryanodol, a significant degradation product of Ryanodane diterpenes that features distinct oxidation sites, utilizing the same advanced intermediate. This was accomplished through a series of late-stage regio- and stereoselective redox operations. This study, in conjunction with our earlier synthesis of garajonone, represents the first unified approach to the synthesis of Ryanodane diterpenes with differing oxidation sites based on a single synthetic strategy.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!