• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.523-526
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• 2013

In order to purify the waste water containing natural fatty oil, hydroxy radical and/or ozone are used to remove the fatty oil dispersed in the waste water. The fatty oil is decomposed by oxidation reaction through hydroxy radical and ozone, and eliminated as a function of first order reaction. It is clearly confirmed that the fatty oil in waste water can be effectively removed much more in the use of both hydroxy radical and ozone than only hydroxy radical as an oxydant. In addition, the decomposition chemical reaction mechanism of the fatty oil by hydroxy radical and ozone is proposed.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.489-496
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• 2017

This study was conducted to test the applicability of hydroxy radical reactor system, which applied advanced oxidation processes, to sterilize pathogenic bacteria for nutrient solution recycling in closed hydroponics. Removal efficiency was tested on 25 L of nutrient solution maxed with 10 mL culture solution of bacteria, E. coli, and R. solanacearum in a pilot tank. The testing conditions included various levels of hydroxy radicals resulting from air flow rates of 40, 80, and $120L\;min^{-1}$, and 12 hours processing time. The removal of bacteria, E. coli, and R. solanacearum by hydroxy radical in nutrient solution was significantly increased with an increase in the flow rate of the air from $40L\;min^{-1}$ to $120L\;min^{-1}$. The optimum removal efficiency was achieved at an air flow rate of $120L\;min^{-1}$ for 2 hours treatment. There were no significant differences in removal efficiency among bacteria, E. coli, and R. solanacearum for tested level and time of hydroxy radical. These results verified the efficiency of hydroxy radical in removing the pathogenic bacteria and the applicability of hydroxy radical reactor system in the field.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.362-367
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• 2014

This study was performed to test the applicability of the ozone/hydroxy radical reaction system, which applied advanced oxidation processes, to remove total petroleum hydrocarbon (TPH) from the fine soil in washing water of the soil washing process. Removal efficiency was tested on 40 L of washing water in a pilot reaction tank. Fine soil contaminated with $800mg\;kg^{-1}$ TPH was prepared at 5% and 10% suspended solids. Testing conditions included ozone/hydroxy radical flow rates of 40, 80, and $120L\;min^{-1}$, and processing time of 2 to 12 hours. The removal efficiency of petroleum hydrocarbon from water waster by ozone/hydroxy radical was increased with higher flow rates and lower percentages of suspended solids. Optimal efficiency was achieved at $80L\;min^{-1}$ flow rate for 4 hours for the 5% suspended solids, and $120L\;min^{-1}$ for 6 hours for the 10% suspended solids. These results verified the efficiency of hydroxy radical in removing TPH and the applicability of the ozone/hydroxy radical reaction system in the field.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.107-109
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• 1993

Non-enzymatic glycosylation and fragmentation of collagen molecule were investigated by irradiating Ultraviolet A(UV-A) with or without scavengers of reactive oxygen species (ROS) in the presence of glucose. Non-enzymatic glycosylation was increased by UV-A at high concentration of glucose. It was reduced in the presence of the scavengers of superoxide radical and singlet oxygen, but not reduced in the presence of hydroxy radical scavenger. Fragmentation of collagen was increased by UV-A, but it was decreased in the presence of all ROS scavengers tested. Superoxide radical and singlet oxygen produced by autoxidation of glucose without UV-A may encounter the initial phase of glycosylation. Data presented here suggest that UV-A affects only on the fragmentation process, but all ROS except hydroxy radical act on both processes. It appears that hydroxy radical does not act on the glycosylation process.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.988-993
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• 2003

The ethyl acetate-soluble acidic fraction of juice, hot water, and MeOH extract of Allium fistulosum L. showed DPPH radical-scavenging activity. Each fraction was purified through silica gel adsorption column chromatography, and the active substances in the juice and hot water extract were identified as succinic acid, fumaric acid, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 4-hydroxycinnamic acid, and 4-hydroxy-3-methoxycinnamic acid. For the MeOH extract, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 4-hydroxycinnamic acid, and 4-hydroxy-3-methoxycinnmic acid were identified as the active substances by GC-MS. The contents of these compounds were determined by GC analysis, and their anti-oxidative activities were measured using the DPPH radical-scavenging assay. The results obtained showed that 4-hydroxy-3-methoxycinnamic acid was the dominant antioxidant in Allium fistulosum L.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.78-86
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• 2009

In this study 2 cadalene homologues - 3,7-dimethoxycadalene and 7-hydroxycadalene-5,8-quinone (keyakinone A)-were further identified from ethanol extracts of Zelkova serrata wood, except 7-hydroxy-3-methoxycadalene. Two biological activities-scavenging activity of hydroxy radical and cell toxicity by MTT assay-were measured with 7-hydroxy-3-methoxycadalene. The scavenging activity of hydroxyl radical of the compound was excellent and increased with its concentration. At 100 ppm hydroxyl radicals were removed completely. However, MTT assay revealed that 7-hydroxy-3-methoxycadalene showed critical toxicity to the cells. When 1 ppm of the compound was treated to the cells, cell viability was reached up to 90%, while it was reduced to 22% after treatment of 9 ppm. In 4 different Ulmaceae species, such as Ulmus davidiana, Ulmus parvifolia, Ulmus macrocarpa, Ulmus macrophylla, 7-hydroxy-3-methoxycadalene was not found at all. Instead, 7-hydroxycadalene (Mw 214), in which methoxyl group is omitted from 7-hydroxy-3-methoxycadalene, was distributed in the heartwood of 4 Ulmaceae species as major cadalene compound.

• Archives of Pharmacal Research
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• v.6 no.1
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• pp.1-6
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• 1983

The reaction of ethylenecarbonate (I) with bromine was carried out in the presence of benzolperoxide as radical initiator. The following several different esters being ring opened were obtained; bromoacetyl-bromoformate, (1-hyroxy, 1, 2-dibromo)-ethyl bromoformate, (1-hydroxy, 1, 2, 2'-tribromo)diethylacarbonate, 2-bromoethyl-tribromoacetate, (1-acetoxy, 1'-bromomethyl)-bromomalo nate, 2-bromoethyl-bromoacetoxy-tribromoacetate.

• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.545-546
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• 2010

• Korean Journal of Medicinal Crop Science
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• v.21 no.4
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• pp.255-261
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• 2013

The purpose of this study was to examined the antioxidant activities by water and 70% ethanol extract from durian (Durio zibethinus.) seed, sarcocarp and peel. Durian extract were studied for reducing sugar content, polyphenol content, superoxide dismutase (SOD) like activity, electron donating ability, nitrite scavenging ability, flavonoid content, hydroxy radical scavenging activity. Reducing sugar content were increased peel > sarcocarp > seed. Total polyphenol, flavonoid content, DPPH radical scavenging ability and SOD like activity were increased seed > peel > sarcocarp. Total polyphenol content was relatively high as $21.90{\pm}0.50mg/g$ in the ethanol extract of the seed. DPPH radical scavenging ability was relatively high as $62.08{\pm}2.63%$ in the water extract of the seed. Nitrite scavenging ability was no significant difference. Hydroxy radical scavenging activity was increased seed > peel > sarcocarp, was relatively high as $58.27{\pm}1.13%$ in the water extract of the seed.

• Natural Product Sciences
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• v.6 no.3
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• pp.135-138
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• 2000

MeOH extract of Cuscuta chinensis seeds was fractionated with n-hexane, EtOAc and BuOH successively, and antioxidant activities were tested for all fractions using DPPH free radical scavenging method. In the tested fractions, EtOAc fraction showed high antioxidant activity$(EC_{50},\;50\;{\mu}g)$ From the EtOAc fraction, five compounds have been isolated. On the basis of spectral data, these compounds were identified as ${\beta}-sitosterol$, methyl 4-hydroxy-3,5-dimethoxycinnamate, ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$, caffeic acid, quercetin, kaempferol and calycopteretin. Among these compounds, ${\beta}-sitosterol$ and ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$ showed no antioxidant activity. $EC_{50}$ values of methyl 4-hydroxy-3,5-dimethoxycinnamate, caffeic acid, quercetin, kaempferol and calycopteretin were 0.6, 8, 19, 17 and $12\;{\mu}g$, respectively.