scholarly journals Free Radicals: How Do We Stand Them? Anaerobic and Aerobic Free Radical (Chain) Reactions Involved in the Use of Fluorogenic Probes and in Biological Systems

2014 ◽  
Vol 23 (3) ◽  
pp. 195-203 ◽  
Author(s):  
Stefan I. Liochev
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Biological Systems ◽  
Radical Chain ◽  
Chain Reactions ◽  
Fluorogenic Probes

scholarly journals The detection and inhibition of free radical chain reactions

1942 ◽  
Vol 180 (982) ◽  
pp. 237-256 ◽  
Keyword(s):  
Nitric Oxide ◽  
Free Radical ◽  
Chemical Analysis ◽  
Diethyl Ether ◽  
Pressure Increase ◽  
Stationary States ◽  
Decomposition Rates ◽  
Radical Chain ◽  
Chain Reactions ◽  
Limiting Values

Part I. Comparison of nitric oxide and propylene as inhibitors The reduction by propylene of the rate of pressure increase in the decomposition of propaldehyde at 550° has been shown by chemical analysis to represent a true inhibition of the reaction, and not to be due n an important degree to an induced polymerization of the propylene. With propaldehyde and with diethyl ether the limiting values to which the decomposition rates are reduced by nitric oxide and by propylene respectively are the same, although much more propylene is required to produce a given degree of inhibition. From this it is concluded that the limiting rates are more probably those of independent non-chain processes, than those characteristic of stationary states where the inhibitor starts and stops chains with equal efficiency.

scholarly journals Evidence that Criegee intermediates drive autoxidation in unsaturated lipids

2020 ◽  
Vol 117 (9) ◽  
pp. 4486-4490 ◽  
Author(s):  
Meirong Zeng ◽  
Nadja Heine ◽  
Kevin R. Wilson
Keyword(s):  
Free Radical ◽  
Radical Chain ◽  
Chain Reactions ◽  
Unsaturated Lipids ◽  
Criegee Intermediates ◽  
Age Related ◽  
Lipid Autoxidation ◽  
Free Radical Chain Reaction ◽  
Cyclic Network ◽  
Radical Chain Reaction

Autoxidation is an autocatalytic free-radical chain reaction responsible for the oxidative destruction of organic molecules in biological cells, foods, plastics, petrochemicals, fuels, and the environment. In cellular membranes, lipid autoxidation (peroxidation) is linked with oxidative stress, age-related diseases, and cancers. The established mechanism of autoxidation proceeds via H-atom abstraction through a cyclic network of peroxy–hydroperoxide-mediated free-radical chain reactions. For a series of model unsaturated lipids, we present evidence for an autoxidation mechanism, initiated by hydroxyl radical (OH) addition to C=C bonds and propagated by chain reactions involving Criegee intermediates (CIs). This mechanism leads to unexpectedly rapid autoxidation even in the presence of water, implying that as reactive intermediates, CI could play a much more prominent role in chemistries beyond the atmosphere.

Combustion of Hydrocarbons - Free Radical Chain Reactions

1949 ◽  
Vol 41 (5) ◽  
pp. 893-897 ◽  
Author(s):  
P. L. Cramer ◽  
J. M. Campbell
Keyword(s):  
Free Radical ◽  
Radical Chain ◽  
Chain Reactions

Free radical chain reactions of 3-fluoro-3-iodo-β-lactams

1993 ◽  
Vol 34 (19) ◽  
pp. 3087-3090 ◽  
Author(s):  
Robert Kawecki ◽  
John T. Welch
Keyword(s):  
Free Radical ◽  
Radical Chain ◽  
Chain Reactions

Kinetics of Ionic and Free Radical Chain Reactions in Radiation Chemistry

1969 ◽  
Vol 6 (5) ◽  
pp. 466-473
Author(s):  
Donald H. Martin ◽  
Robert B. Taylor ◽  
Ffrancon Williams
Keyword(s):  
Free Radical ◽  
Radiation Chemistry ◽  
Radical Chain ◽  
Chain Reactions ◽  
Kinetics Of

scholarly journals Protein hydroperoxides can give rise to reactive free radicals

1995 ◽  
Vol 305 (2) ◽  
pp. 643-649 ◽  
Author(s):  
M J Davies ◽  
S Fu ◽  
R T Dean
Keyword(s):  
Free Radicals ◽  
Amino Acid ◽  
Radical Anion ◽  
Similar Process ◽  
Side Chain ◽  
Radical Species ◽  
Radical Chain ◽  
Chain Reactions ◽  
Oxygen Yield ◽  
Rearrangement Processes

Proteins damaged by free-radical-generating systems in the presence of oxygen yield relatively long-lived protein hydroperoxides. These hydroperoxides have been shown by e.p.r. spectroscopy to be readily degraded to reactive free radicals on reaction with iron(II) complexes. Comparison of the observed spectra with those obtained with free amino acid hydroperoxides had allowed identification of some of the protein-derived radical species (including a number of carbon-centred radicals, alkoxyl radicals and a species believed to be the CO2 radical anion) and the elucidation of novel fragmentation and rearrangement processes involving amino acid side chains. In particular, degradation of hydroperoxide functions on the side chain of glutamic acid is shown to result in decarboxylation at the side-chain carboxy group via the formation of the CO2 radical anion; the generation of an identical radical from hydroperoxide groups on proteins suggests that a similar process occurs with these molecules. In a number of cases these fragmentation and rearrangement reactions give rise to further reactive free radicals (R., O2-./HO2., CO2-.) which may act as chain-carrying species in protein oxidations. These studies suggest that protein hydroperoxides are capable of initiating further radical chain reactions both intra- and inter-molecularly, and provide information on some of the fundamental mechanisms of protein alteration and side-chain fragmentation.

Free-Radical Chain Reactions Involving Hydrogen and Bromine Atom Transfer Induced by TiO2-Mediated Photocatalysis

Langmuir ◽  
1999 ◽  
Vol 15 (4) ◽  
pp. 1141-1146 ◽  
Author(s):  
Shlomo Gershuni ◽  
Norbert Itzhak ◽  
Joseph Rabani
Keyword(s):  
Free Radical ◽  
Bromine Atom ◽  
Atom Transfer ◽  
Radical Chain ◽  
Chain Reactions
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