• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.341-353
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• 1974

The electrochemical reduction of triphenylphosphine penylimide in nonaqueous media has been examined by polarography, cyclic voltammetry, controlled-potential coulometry and electron spin resonance spectroscopy. The reduction of triphenylphosphine phenylimide proceeds by a one-electron transfer to form anion radical which undergoes both protonation and a second one-electron reduction followed by cleavage of the phosphorus-nitrogen double bond. Aniline is a major product. The cleavage of a phosphorus-phenyl bond was also observed after reduction of triphenylphosphine oxide which is one of the major products of the chemical reaction which follow the primary process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.142-145
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• 1999

We confirm that when A-type zeolite supporting silver lone is placed in ion-exchanged distilled water, silver ions is eluted and eluted silver ions generates hydroxyl-radical (.OH) and hydro-radical (.H) continuously, the amount of those is proportion to the silver-ion concentration. Hydroxyl-radical is not generated by super-oxide anion-radical (.O2) but by directly dissolved water. To know such a above discussed mechanism, we prepare A-type zeolite supporting silver ions, and measure the amount of the eluted silver tons by atomic absorption spectroscopy and the generated radical by ESR The radical generated by A-type zeolite supporting silver ions is discussed in the application of elecrical and electronic materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.316-319
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• 2000

In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidase (GOx) forms a coordinate bond with the polymer's backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized the enzyme electrode by electropolymerization added some organic solvent, A formative seeds of film growth is delayed by adding the solvent. The delay is induced by radical transfer between the solvent and pyrrole monomer. In the case of adding ethanol, the radical transfer shares the contribution of dopant between electrolyte anion and GOx polyanion. This may lead to increase amount of immobilized the enzyme in ppy. However, adding tetrahydrofuran (THF), the radical transfer is more brisk, resulting in short chained polymer. Therefore, the doping level is lowered and then amount of immobilized of enzyme is decreased. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased. We established qualitatively that amount of immobilization can be improved by adding a little ethanol in the synthetic solution. It is due to radical transfer reaction. The radical transfer shares the contribution of dopant between small and fast electrolyte anion and big and slow GOx polyanion.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.283-286
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• 2004

In the course of screening for reactive oxygen species scavengers from natural products, two antioxidants were isolated from the edible mushroom Polyozellus multiflex and identified as polyozellin and thelephoric acid. Thelephoric acid inhibited 45.7% of the super oxide anion radical, 74.6% of the hydroxyl radical, and 44.0% of the DPPH radical at 0.1 mM, while the positive control ${\alpha}-tocopherol$ did 22.1%, 75.6%, and 26.5% of each radical, respectively. Polyozellin, the reductive acetylated form of thelephoric acid, showed almost same scavenging activity against above mentioned radicals. The isolated compounds showed scavenging activity on the superoxide anion radical in the ESR method ($IC_{50}$ of polyozellin and thelephoric acid were $218.0\;{\mu}M$ and $21.1\;{\mu}M$, respenctively). However, they showed no significant activity on the hydrogen peroxide radical.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.04a
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• pp.79.1-79
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• 2002

• Bulletin of the Korean Chemical Society
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• v.29 no.12
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• pp.2419-2422
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• 2008

• Bulletin of the Korean Chemical Society
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• v.11 no.1
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• pp.74-75
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• 1990

• Advances in Traditional Medicine
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• v.8 no.2
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• pp.135-145
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• 2008

The study was aimed at evaluating the antioxidant and free radical scavenging activities of ethanolic extract and its fractions of Cleome rutidosperma. The antioxidant activity, reducing power, total phenolic content, total flavonoid content, superoxide anion scavenging activity, nitric oxide anion scavenging activity, in vitro antilipid peroxidation activity and in vitro non-enzymatic hemoglobin glycosylation were studied. The results obtained in the study indicate that Cleome rutidosperma is a potential source of natural antioxidant. All the parameters were found to be concentration dependent and increased with increasing amounts of sample. Flavonoids, phenolic compound like tannins, terpenoids may be responsible for the antioxidant activity of the plant. Variation of solubility parameters in various models may be attributed to non-linearity of activity of ethanol extract fractions models. Further investigation on the isolation and identification of antioxidant component(s) in the plant may lead to chemical entities with potential for clinical use.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.151-158
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• 2009

The objective of this study was to determine on optimum ratio of oxidant and catalyst and to evaluate affecting factors such as anions and cations on persulfate oxidation of organic pollutant. Fe(II) activated the persulfate anion to produce a sulfate free radicals and thus effectively used to degrade the target organic pollutant in aqueous system. The chloride ions reacted with sulfate radical produced the $Cl^{\cdot}$ atom and had positive effects on the oxidation of organic pollutant at the initial stage. However, it was observed that chloride ions had the scavenging effects on the rate of oxidation of organic pollutant. Cations and some heavy metals were partly able to activate the persulfate anion to generate a sulfate free radical. However, high levels of cations inhibited the oxidation of organic pollutant.

• Advances in Traditional Medicine
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• v.7 no.3
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• pp.290-296
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• 2007

Glinus oppositifolius and Trianthema decandra belonging to the Ficoidaceae family were commonly used by tribal peoples for the treatment of liver disorders and cancer. The preliminary phytochemical screening of those plants showed the presence of flavonoids, terpenoids, tannins and saponins. The aim of this study was to evaluate the in vitro antioxidant activities of the methanol extracts of Glinus oppositifolius (MEGO) and Trianthema decandra (METD). The antioxidative capacities of MEGO and METD were determined by the following four complementary assay; DPPH radical scavenging assay, superoxide anion generation by xanthine-xanthine Oxidase assay, hydroxyl radical scavenging assay and $Fe^{2+}$-ascorbate induced by lipid peroxidation assay. The $IC_{50}$ values of the both extracts were calculated from the inhibition curve. The $IC_{50}$ MEGO and METD in DPPH, superoxide anion, hydroxyl radical scavenging and lipid peroxidation assay are 1.85, 7.31, 13.95, 22.82 and 2.21, 9.78, 14.87, 19.76 ${\mu}g/ml$ respectively. Both the extracts exhibited a significant antioxidant effects.