The one-electron reduction of carbonium ions. Part 13. The conformational effects of cyclopropyl, isopropyl, and phenyl substituents flanked with methyl groups on the reduction rate of the tropylium ion with the chromous ion

1979 ◽  
pp. 1005 ◽  
Author(s):  
Ken'ichi Takeuchi ◽  
Koichi Komatsu ◽  
Kenji Yasuda ◽  
Fumihiro Mikuchi ◽  
Kunio Okamoto
Keyword(s):  
Reduction Rate ◽  
Methyl Groups ◽  
Conformational Effects ◽  
Carbonium Ions ◽  
Electron Reduction ◽  
The One

Effects of base pairing on the one-electron reduction rate of cytosine

2003 ◽  
pp. 2840 ◽  
Author(s):  
Kiyohiko Kawai ◽  
Aya Yokoohji ◽  
Sachiko Tojo ◽  
Tetsuro Majima
Keyword(s):  
Reduction Rate ◽  
Base Pairing ◽  
Electron Reduction ◽  
The One

scholarly journals Reduction of ferric haemoproteins by tetrahydropterins: a kinetic study

2005 ◽  
Vol 392 (3) ◽  
pp. 583-587 ◽  
Author(s):  
Chantal Capeillere-Blandin ◽  
Delphine Mathieu ◽  
Daniel Mansuy
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Cytochrome B5 ◽  
Reduction Rate ◽  
Cation Radical ◽  
Order Reduction ◽  
Reduction Potentials ◽  
Electron Reduction ◽  
The One

We previously showed that one-electron transfer from tetrahydropterins to iron porphyrins is a very general reaction, with formation of an intermediate cation radical similar to the one detected in NO synthase. As a model reaction, the rates of reduction of eight haemoproteins by diMePH4 (6,7-dimethyltetrahydropterin) have been studied and correlated with their one-electron reduction potentials, Em (FeIII/FeII). On the basis of kinetic data analyses, a bimolecular collisional mechanism is proposed for the electron transfer from diMePH4 to ferrihaemoproteins. Haemoproteins with reduction potentials below −160 mV were shown not to be reduced by diMePH4 to the corresponding ferrohaemoproteins. For haemoproteins with reduction potentials more positive than −160 mV, such as chloroperoxidase, cytochrome b5, methaemoglobin and cytochrome c, there was a good correlation between the second-order reduction rate constant and the redox potential, Em (FeIII/FeII):The rate of reduction of cytochrome c by BH4 [(6R)-5,6,7,8-tetrahydrobiopterin] was determined to be similar to that of the reduction of cytochrome c by diMePH4. These results confirm the role of tetrahydropterins as one-electron donors to FeIII porphyrins.

Sign in / Sign up

Export Citation Format

Share Document