• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.35-43
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• 2000

Aqueous solutions of chlorobenzene and chlorinated phenols were exposed to 200kHz ultrasound with a power of $6.0W/\textrm{cm}^2$ per unit volume on sonochemical reactor under ambient temperature and pressure conditions. The concentration of chlorobenzene and chlorinated phenols decreased with ultrasound, indicating first-order kinetics. Degradation rate constants are calculated from the slope of plots. The order of the rate constants is as follows : 2-chlorphenol(2-CP)$\leq$ 4-chlorophenol(4-CP)<3-chlorophenol(3-CP)$5.63~9.96({\times}10^{-2})min^{-1}$ under argon. The degradation was suppressed by the addition of t-BuOH and the suppressed yield was agreed with their reactivity for hydroxy radical. The main products of these systems were formic acid, acetic acid, small amount of methane and inorganic carbon forms as carbon dioxide, carbon monoxide in sonolysis of chlorinated phenols, and also these results agreed with change of TOC.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.248-262
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• 2009

This study is on the feasibility of use of glycoprotein in various areas such as cosmetics and food etc. by extracting, isolating and refining glycoprotein from carrots, red ginseng extract residue, sesame and pine needles using protease(pepsin) and by analyzing general characteristics and measuring various bioactivities. The results of analysis of nutritional composition showed protein contents of glycoprotein. In the analysis of constitutive amino acids, the ratio of contents of hydroxy proline and glycine, the characteristics of glycoproteins appeared similar and the contents of glutamic acid and aspartic acid appeared higher. As a result of measurement contents of total polyphenol and flavonoid, it showed that glycoprotein had more contents generally, and the effect of bioactivity of glycoprotein appeared higher although different kinds of glycoprotein showed a little DPPH radical and nitrite scavenging ability, total antioxidant capacity by ABTS, ACE inhibitory.

• Journal of the Korean Society of Fashion and Beauty
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• v.5 no.3
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• pp.99-104
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• 2007

The most extensively used synthetic antioxidants are butylated hydroxyanisole (BHA), butylated hydroxy toluene (BHT) and tert-butylhydroquinone (TBHQ). However BHT and BRA have been suspented of being responsible for liver damage andcar cinogenesis. Therefore, the importance of the search and exploitation of natural antioxidant, especially of plant origin, has greatly increased in recent years. Plant contain a wide variety of chemicals that have potent biological effects. As a result, there has been a growing interest in the use of herbs as a source of therapeutic drugs. The aim of this study was to assess the antioxidant and cosmeceutical of natural materials. The antioxidant and cosmeceutical activity of natural materials were investigated by hydroxyl radical scavenging, superoxide dismutase (SOD) -like, xanthine oxidase inhibition, tyrosinase inhibition, anti-microbial and astringent.

• Journal of the Korean Society of Food Culture
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• v.27 no.5
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• pp.505-511
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• 2012

This study was conducted to investigate the antioxidant activity of Jeolpyeon containing lotus seed powder. Original Jeolpyeon and Jeolpyeon with BHT (butyl hydroxy toluene) werecompared. Antioxidant activities were measured based ontotal polyphenolic contents, total flavonoid contents, DPPH radicalscavenging activity, reducing power, and SOD-like activity. Total polyphenolic and total flavonoid contents of Jeolpyeon containing lotus seed powder were estimated at $37.81{\pm}0.45$ mg GAE/g and $26.35{\pm}0.13$ mg QE/g respectively. DPPH radical scavenging activity increased upon addition of lotus seed powder. Further, reducing power was higher in Jeolpyeon containing lotus seed powder than original Jeolpyeon or Jeolpyeon with BHT. The antioxidative effect of Jeolpyeon significantly increased uponaddition of lotus seed powder.

• YAKHAK HOEJI
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• v.24 no.3_4
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• pp.151-157
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• 1980

Color transition mechanism of shikonin as an acid-alkali indicator was studied. It was confirmed that the presence of phenolic hydroxy radical was essential for the color change of shikonin. But in accordance with shikonin sodium salt (blue color), which was presumed to make chelation as six membered rings. Shikonin in alkaline solution, by dissociated phenolic protons of naphthoquinone nucleous, converted to the corresponding anion and instead of disappearance tautomerization, electron delocalization occurred and an additional pair of nonbonding electrons in the anion was available for interaction with .phi. electron system of the ring with further extension of the conjugation. It was responsible for its blue color(corresponding color: orange) with needs less energy difference (${\phi}{\rarw}{\phi}^{*}$) because of conjugation extension. Shikonin sodium salt seems to have similar nuclear structure as shikonin anion.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.81-85
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• 2002

A marine bacterium producing superoxide dismutase, strain number B446, was screened with nitrite quantitation method using hydroxy amine and photochemically generated superoxide ion, and the superoxide dismutase was purified through 35-75% ammonium sulfate precipitation, DEAE-Sephadex A-25 ion exchange chromatography, Sephadex G-200 gel filtration chromatography, and High-Q anion exchange chromatography to a yield of 6% and purification fold of 32.3.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.619-623
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• 1999

$2^{l},3^{l}$-dideoxyisoguanosine was synthesized from guanosine via intermediate 6-[(4-methyl-phenyl)thio]-2-oxo-9-($2^{l},3^{l},5^{l}$-tri-O-acetyl-$\beta$-D-ribofuranosyl)-2,3-dihydropurine (4). The 2-oxo, 6-amino and $5^{l}$-hydroxy triprotected isoguanosine derivative was utilized to reduce high polarity and promote poor solubility of intermediates. The protecting groups for oxo and 6-amino were easily removed in reduction of olefin in ribose without additional reaction steps.$2^{l},3^{l}$-Vicinal diol in ribose sugar moiety was transformed to olefin with Bu3SnH by radical reaction via bisxanthate. Removing $5^{l}$-O-TBDMS protecting group gave final product, $2^{l},3^{l}$-dideoxyisoguanosine (12) in a 10% overall yield.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.524-532
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• 2016

This study was performed to compare the antioxidative activities of methanol extracts from Asparagus cochinchinensis with whole root (W-AC), flesh (F-AC), and root bark (B-AC). To evaluate the antioxidative properties of their methanol extracts, 1,1-diphenyl-2-picrylhydrazyl radical, nitrite, hydroxyl radical, 2,2'-azino-bis(3-ethylbenz thiazoline-6-sulfonate) radical scavenging activities, and contents of total flavonoid and polyphenol contents were measured. B-AC extract showed the highest antioxidative activity, whereas F-AC extract showed the lowest. For B-AC extract, caffeic acid was isolated by preparative high-performance liquid chromatography and confirmed by liquid chromatography-mass spectrometry and absorption spectroscopy, which showed 1.6% of total polyphenol contents among all methanol extracts.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Polymer(Korea)
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• v.38 no.4
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• pp.491-495
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• 2014

Pressure sensitive adhesive (PSA) based on 2-ethylhexyl acrylate (2-EHA)/acrylic acid (AA) copolymer was synthesized using different photoinitiators. Results showed that PSA with Irgacure$^{(R)}$651 (benzyldimethylketal) and Irgacure$^{(R)}$184(1-hydroxy-cyclohexylphenyl ketone) proved to be good for adhesion properties. This may be attributed to strong absorption near 350 nm wavelength and also high solubility in monomer mixtures. The addition of Irgacure$^{(R)}$819, bisacylphosphine oxides as a photoinitiator caused cohesive failure with high loading in a peel test owing to the additional radical formation. It is assumed that the insoluble photoinitiator reacts with oxygene, which may act as a hydrogen donor.