The reaction of the hydroxyl radical, generated by a Fenton system, with pyrimidine deoxyribonucleotides was investigated by using the e.s.r. technique of spin trapping. The spin trap t-nitrosobutane was employed to trap secondary radicals formed by the reaction of the hydroxyl radical with these nucleotides. The results presented here show that hydroxyl-radical attack on thymidine, 2-deoxycyti...

Oxidation of oxyhemoglobin by nitrite is characterized by the presence of a lag phase followed by the autocatalysis. In phosphate buffer, an asymmetric ESR signal is detected at g = 2.005 (hereafter referred to as the g = 2 radical) during the oxidation which is similar to that of the methemoglobin free radical generated from methemoglobin and H2O2. Catalase and KCN prolong the oxidation, indic...

In the past few years, the cellular effects of ultraviolet (UV) irradiation induced in skin have become increasingly recognized. Indeed, it is now well known that UV irradiation induces structural and cellular changes in all the compartments of skin tissue. The generation of reactive oxygen species (ROS) is the first and immediate consequence of UV exposure and therefore the quantitative determ...

objective(s):astrodaucus persicus, apiaceae, is used as vegetable or food additive in some parts of iran. the essential oils of different parts of astrodaucus persicus from kordestan province were analyzed for the first time and compared with other regions. in this study, antioxidant activities and total phenols determination of aerial parts essential oils and root fractions of a. persicus were...

the side effects of synthetic antioxidants have been considered in different studies. accordingly, there is an increasing interest toward the use of natural substances instead of the synthetic ones. in this study, the aqueous and ethanolic extracts of pistacia vera leaves and fruits as well as hydroalcoholic extract of gum were tested for a possible antioxidant activity using in vitro methods. ...

A vast majority of the studies addressing the free radicals including hydroxyl radical is a damage compound of biochemical molecules such as DNA, proteins and lipids. When free radicals specially hydroxyl radical are not adequately removed from the body, it may damage biological macromolecules, leading to a variety of disease occurs. Therefore, the body should be protected by an enzymatic or no...

Nuclei isolated from rat liver, heart, and kidney catalyze oxygen consumption in the presence of reduced pyridine nucleotide (NADPH) and quinone or quinone-imine antibiotics such as Adriamycin, daunorubicin, actinomycin D, mitomycin C, and streptonigrin. The Km and Vmax values for NADPH were 2.4 x 10(-3) M and 3 x 10(-8) mol O2 per min per mg protein and Km values for the antibiotics ranged fro...

The direct replacement of aromatic fluorine in hexafluorobenzene has hitherto been possible only by the use of nucleophilic reagents. In this investigation, the replacement of nuclear fluorine by nonnucleophilic, or weakly nucleophilic, reagents was achieved by reaction at relatively high temperatures, 300 to 850 °C. For example, the reaction of hexafluorobenzene with such reagents as bromine, ...

RATIONALE Sepsis produces significant mitochondrial and contractile dysfunction in the heart, but the role of superoxide-derived free radicals in the genesis of these abnormalities is not completely understood. OBJECTIVES The study was designed to test the hypothesis that superoxide scavenger administration prevents endotoxin-induced cardiac mitochondrial and contractile dysfunction. METHOD...

the antioxidant potential of crude methanol extract (ce) as well as chloroform (cf), ethyl acetate (ef) and n-butanol (nf) soluble fractions of enhydra fluctuans lour, which is widely used in indigenous system of medicine for different purposes, were studied. the antioxidant potential of extract/different fractions were evaluated using different in vitro antioxidant models. in addition, total a...