Ribonucleoside diphosphate reductase is an allosteric enzyme consisting of two nonidentical subunits, proteins Bl and B2. Bl contains dithiols which participate in the oxidation-reduction reactions of electron transport, while B2 contains a free radical essential for activity. Ribonucleoside diphosphates are bound to Bl but not to B2. Addition of 2’-deoxy-2’-chloro ribonucleoside diphosphates t...

Pyrrolidine dithiocarbamate (PDTC) is considered an antioxidant and is frequently used to study the role of free radical reactions in various biological processes and against free radical-induced cellular injuries. However, its antioxidant properties are not characterized. In this study, electron spin resonance (ESR) was used to investigate the antioxidant potential of PDTC with hydroxyl radica...

A GROWING NUMBER of articles purport to demonstrate the importance of oxygen free radicals in a variety of pathophysiologic processes, including injury due to radiation, inflammation, and oxygen toxicity. The purpose of this essay is to examine the hypothesis that activated oxygen species may play a role in the extension of myocardial injury due to ischemia followed by reperfusion. Activated ox...

Reactive oxygen species play critical role in kidney damage. Free radical-scavenging activities of Panax ginseng are known to be increased by heat-processing. The structural change of ginsenoside and the generation of Maillard reaction products (MRPs) are closely related to the increased free radical-scavenging activities. In the present study, we have demonstrated the Maillard reaction model e...

Glycation, the nonenzymatic reaction between protein amino groups and reducing sugars, induces protein damage that has been linked to several pathological conditions, especially diabetes, and general aging. Here we describe the direct identification of a protein-bound free radical formed during early glycation of histone H1 in vitro. Earlier EPR analysis of thermal browning reactions between fr...

Photosynthetic oxygen reduction by isolated chloroplast lamellar systems has been studied with the aid of superoxide dismutase. Two mechanisms of oxygen reduction by illuminated chloroplast lamellar systems can be differentiated: 1. In the presence of low potential electron acceptors like AQ or MV the superoxide free radical ion is the product of autooxidation of the reduced acceptor. Addition ...

1,2-Bis-boronic esters are useful synthetic intermediates particularly as the two boronic can be selectively functionalized. Usually, less hindered primary ester reacts, but herein, we report a coupling reaction that enables reversal of this selectivity. This is achieved through formation boronate complex with an electron-rich aryllithium which, in presence electron-deficient aryl nitrile, lead...

background the aim of the present study was to investigate the effect of ginger and glibenclamide on oxidative stress markers. oxidative stress is caused by an unbalance between a relative overload of oxidants and depletion of antioxidants, as implicated in the pathogenesis of several chronic diseases, including atherosclerosis and diabetes mellitus. regarding the role of oxidative stress in th...

background & aim: free radicals play a crucial role in the development of tissue damage in various human diseases such as cancer, aging, neurodegenerative disease, malaria and arteriosclerosis, and pathological events in living organisms. antioxidants may have an important role in the prevention of these diseases. the aim of this study is to evaluate potency of scavenging of dpph free radic...

Multiwalled carbon nanotubes (MWCNTs) have been functionalized with -SO3H groups using new three steps chemical routes. Firstly, OH groups have been attached to CNT surfaces through a radical reaction. The second step involves converting the hydroxyl groups into the oxide one and last step included the attachment of –SO3H groups on the MWCNTs surfaces in the presence of 1-butyl-3-methyl imidazo...