نتایج جستجو برای: radical trapping

تعداد نتایج: 111787  

Journal: :Ultrasonics sonochemistry 2015
Qing-An Zhang Yuan Shen Xue-Hui Fan Juan Francisco García Martín Xi Wang Yun Song

Direct evidence for the formation of 1-hydroxylethyl radicals by ultrasound in red wine and air-saturated model wine is presented in this paper. Free radicals are thought to be the key intermediates in the ultrasound processing of wine, but their nature has not been established yet. Electron paramagnetic resonance (EPR) spin trapping with 5,5-dimethyl-l-pyrrolin N-oxide (DMPO) was used for the ...

2001
Wendy K. M. Chan

The electron paramagnetic resonance technique of spin trapping was employed to study the interaction of hydroxyl radicals with carnosine and related His-containing dipeptides. His and His-containing dipeptides were able to quench 49.1-94.996 of hydroxyl radicals produced by Fez+ and HzOz. The hydroxyl radical scavenging activity of dipeptides was in the order @-Ala < yaminobutyric acid (GABA) <...

2009
Mitsuko Ukai Hiromi Kameya Hideo Nakamura Yuhei Shimoyama

The properties of radicals induced in the gamma ray irradiated pepper were investigated by means of spin trapping method and CW-ESR spectroscopy. Three radicals were found in the specimens irrespective of irradiation. The representative ESR spectrum of pepper is composed of a sextet centered at g = 2.0, a singlet at the same g-value, and a singlet at g = 4.0. The first signal is attributable to...

Journal: :Environmental Health Perspectives 1994
X Shi Y Mao L N Daniel U Saffiotti N S Dalal V Vallyathan

In recent years, more attention has been given to the mechanism of disease induction caused by the surface properties of minerals. In this respect, specific research needs to be focused on the biologic interactions of oxygen radicals generated by mineral particles resulting in cell injury and DNA damage leading to fibrogenesis and carcinogenesis. In this investigation, we used electron spin res...

Journal: :The Journal of biological chemistry 1984
P B McCay E K Lai J L Poyer C M DuBose E G Janzen

Free radical reactions involved in the metabolism of carbon tetrachloride by rat liver have been considered to be a cause of at least part of the injury resulting from exposure to this halocarbon. In an earlier study employing electron spin resonance and spin-trapping techniques, we demonstrated that trichloromethyl (13.CCl3) radicals are readily observed in rat liver microsomes metabolizing 13...

Journal: :Environmental Health Perspectives 1994
X Shi N S Dalal

While Cr(V) species and .OH radicals have been suggested to play significant roles in the mechanism of chromate-related carcinogenesis, controversy still exists regarding the identity of the Cr(V) species and their role in the generation of .OH radicals. Some recent studies have suggested that the primary Cr(V) species involved is the tetraperoxochromate(V) (CrO8(3-)) ion, which produces .OH ra...

Journal: :The Journal of biological chemistry 1999
S Sankarapandi J L Zweier

Prior spin trapping studies reported that H(2)O(2) is metabolized by copper,zinc-superoxide dismutase (SOD) to form (.)OH that is released from the enzyme, serving as a source of oxidative injury. Although this mechanism has been invoked in a number of diseases, controversy remains regarding whether the hydroxylation of spin traps by SOD is truly derived from free (.)OH or (.)OH scavenged off t...

Journal: :Nucleic acids research 1990
W Hiraoka M Kuwabara F Sato A Matsuda T Ueda

Free-radical reactions induced by OH-radical attack on cytosine-related compounds were investigated by a method combining ESR, spin trapping with 2-methyl-2-nitrosopropane and high-performance liquid chromatography (HPLC). Cytidine, 2'-deoxycytidine, cytidine 3'-monophosphate, cytidine 5'-monophosphate, 2'-deoxycytidine 5'-monophosphate and their derivatives, of which 5,6-protons at the base mo...

2015
Zaiwang Zhao Yanjuan Sun Qian Luo Fan Dong Hui Li Wing-Kei Ho

In the present work, it is very surprising to find that the precursors mass, a long overlooked factor for synthesis of 2D g-C3N4, exerts unexpected impact on g-C3N4 fabrication. The nanoarchitecture and photocatalytic capability of g-C3N4 can be well-tailored only by altering the precursors mass. As thiourea mass decreases, thin g-C3N4 nanosheets with higher surface area, elevated conduction ba...

2017
Bachir Raho Ghalem

The in vitro antimicrobial and antioxidant activities of the exopolysaccharide (EPS) extracted from yoghurt starter were investigated. Antimicrobial activity tests were carried out using disc diffusion methods with Escherichia coli, Staphylococcus aureus and Streptococcus D, Proteus spp and the yeast of Candida albicans. The antioxidant properties were evaluated using the test of DPPH free radi...

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