Dications of Fluorenylidenes. The Relationship between Redox Potentials and Antiaromaticity for Meta- and Para-Substituted Diphenylmethylidenefluorenes

2005 ◽  
Vol 70 (26) ◽  
pp. 10709-10716 ◽  
Author(s):  
Nancy S. Mills ◽  
Cornelia Tirla ◽  
Michele A. Benish ◽  
Amber J. Rakowitz ◽  
Lisa M. Bebell ◽  
...  
Keyword(s):  
Redox Potentials ◽  
The Relationship

LETHAL BIOSYNTHESIS OF A BACTERIOCIN, VIBRIOCIN, BY V. COMMA: I. VIBRIOCIN PRODUCTION AND SENSITIVITY IN RELATION TO REDOX POTENTIALS AND STREPTOMYCIN RESISTANCE

1963 ◽  
Vol 9 (3) ◽  
pp. 339-343 ◽  
Author(s):  
H. Farkas-Himsley ◽  
P. L. Seyfried
Keyword(s):  
Redox Potential ◽  
Streptomycin Resistance ◽  
Mixed Population ◽  
Redox Potentials ◽  
Test Conditions ◽  
Steady Decrease ◽  
The Relationship ◽  
Anaerobic Test

The relationship between vibriocin production by streptomycin-sensitive (SMs) Vibrio comma and a specific redox potential is described. Streptomycin-resistant (SMr) mutants are shown to be predominantly sensitive to vibriocin and thus serve as indicator strains. Vibriocin sensitivity can be demonstrated under aerobic but not anaerobic test conditions. A discussion is given, implicating bacteriocins as a factor contributing to the "Welsch phenomenon" wherein the growth of a mixed population of SMs and SMr bacteria in broth results in a steady decrease of the SMr mutants to the level normally present in a sensitive culture.

scholarly journals Involvements of Hyperhomocysteinemia in Neurological Disorders

Metabolites ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Marika Cordaro ◽  
Rosalba Siracusa ◽  
Roberta Fusco ◽  
Salvatore Cuzzocrea ◽  
Rosanna Di Paola ◽  
...  
Keyword(s):  
Tau Protein ◽  
Neurological Disorders ◽  
Calcium Influx ◽  
Pathological Condition ◽  
Brain Disorders ◽  
Redox Potentials ◽  
Arterial Damage ◽  
The Relationship ◽  
Definite Limit

Homocysteine (HCY), a physiological amino acid formed when proteins break down, leads to a pathological condition called hyperhomocysteinemia (HHCY), when it is over a definite limit. It is well known that an increase in HCY levels in blood, can contribute to arterial damage and several cardiovascular disease, but the knowledge about the relationship between HCY and brain disorders is very poor. Recent studies demonstrated that an alteration in HCY metabolism or a deficiency in folate or vitamin B12 can cause altered methylation and/or redox potentials, that leads to a modification on calcium influx in cells, or into an accumulation in amyloid and/or tau protein involving a cascade of events that culminate in apoptosis, and, in the worst conditions, neuronal death. The present review will thus summarize how much is known about the possible role of HHCY in neurodegenerative disease.

scholarly journals On the relationship between oxidation-reduction potential and biological activity in cytochrome c analogues. Results from four novel two-fragment complexes

1987 ◽  
Vol 245 (3) ◽  
pp. 773-779 ◽  
Author(s):  
C J A Wallace ◽  
A E I Proudfoot
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Biological Activities ◽  
Amino Acid Residues ◽  
Redox Potentials ◽  
Peptide Bonds ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Stable Association ◽  
The Relationship

We have confirmed the propensity of fragments of cytochrome c to form complexes that reproduce the structure and, in part, the functionality, of the native protein by preparing four novel complexes. We have used trypsin under three different sets of conditions in sequence to prepare a contiguous two-fragment complex (1-55).(56-104). One of the intermediates is a stable overlapping complex (1-65).(56-104). Conditions for limited acid hydrolysis of peptide bonds in cytochrome c have been developed that optimize the yield of fragments (1-50) and (51-104). These two fragments also form a stable association, as do (1-50) and (56-104). These complexes are potentially useful for the semisynthesis of analogues modified in the region of the cleavage sites, which include a number of highly conserved amino acid residues, and are being used for studies of protein folding, interactions with oxidase, cytochrome c immunogenicity and of artificially induced spontaneous resyntheses between complexing fragments. Like other known two-fragment complexes of cytochrome c, they exhibit normal visible spectra, including the presence of the 695 nm band, indicative of a functional haem crevice. Studies of their biological activities and redox potentials lead to a number of conclusions on structure-function relationships in cytochrome c. Most significantly there is a linear relationship between the logarithm of electron-transfer rates from cytochrome c reductase and redox potential in this series of analogues, indicating that such transfer is thermodynamically controlled. This discovery contributes to our understanding of the interaction of cytochrome and reductase. Since the relationship is obeyed by other types of analogues, except for those that involve modification of the active site of cytochrome c, we have a useful diagnostic for those residues that participate directly in electron transfer.

Electrochemical studies of biologically active arylazoxy compounds. The relationship between redox potentials and molluscicidal activities

2003 ◽  
Vol 544 ◽  
pp. 25-34 ◽  
Author(s):  
Francine Santos de Paula ◽  
Alessandra G Cioletti ◽  
Jorge F da Silva Filho ◽  
Antônio Euzébio G Santana ◽  
Aldenir F dos Santos ◽  
...  
Keyword(s):  
Biologically Active ◽  
Electrochemical Studies ◽  
Redox Potentials ◽  
The Relationship

The relationship between redox potentials and substituent constants in biologically active arylazoxy compounds

2005 ◽  
Vol 579 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Francine Santos de Paula ◽  
Écio Matias Sales ◽  
Maura Vallaro ◽  
Roberta Fruttero ◽  
Marília O.F. Goulart
Keyword(s):  
Biologically Active ◽  
Redox Potentials ◽  
Substituent Constants ◽  
The Relationship
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