• Korean Chemical Engineering Research
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• 제51권4호
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• pp.523-526
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• 2013

본 연구에서는 수질정화 기술개발을 위하여 수산화라디칼 및 오존 발생기를 이용하여 수중에 존재하는 천연 지방산 분해 제거 연구를 수행하였다. 천연 지방산은 수산화라디칼 및 오존에 의하여 1차 분해반응 형태로 제거되었으며, 천연 지방산의 분해반응에서 수산화라디칼 단독으로 사용하는 것 보다 오존과 함께 사용한 경우 분해 효율을 크게 향상시킬 수 있음을 알 수 있었다. 또한, 천연 지방산이 수산화라디칼과 오존에 의해 분해되는 화학반응 기구를 제안하였다.

• 한국토양비료학회지
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• 제50권5호
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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.

• 한국토양비료학회지
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• 제47권5호
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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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• 제14권1호
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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.

• 한국식품과학회지
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• 제35권5호
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• pp.988-993
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• 2003

대파에 함유된 항산화 물질을 구명하고자 대파를 3가지 다른 방법으로 추출하여 대파 착즙액, 열수추출물, MeOH 추출물을 얻었다. 이들 추출물을 각각 용매분획하여 얻어진 EtOAc 가용 산성획분을 silica gel adsorption column chromatography로 정제하여 얻어진 활성획분을 GC-MS 분석하였다. 그 결과, 대파 착즙액과 열수추출물에서는 succinic acid ,fumaric acid, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxy-benzoic acid, 4-hydroxycinnamic acid 그리고 4-hydroxy-3-methoxycinnamic acid의 6종 화합물이 동정되었으며, MeOH 추출물로부터는 4-hydroxybenzoic acid, 4-hydroxy-3-methoxy-benzoic acid, 4-hydroxycinnamic acid, 4-hydroxy-3-methoxy-cinnamic acid의 4종 화합물이 동정되었다. 동정된 이들 화합물을 대상으로 DPPH radical-scavenging 활성을 검정한 결과, 4-hydroxy-3-methoxycinnamic acid가 가장 강한 항산화 활성을 나타냈다. 또한 각각의 대파추출물에 함유된 항산화 물질의 함량을 GC에 의해 정량분석한 결과, 대파 착즙액과 열수추출물 및 MeOH 추출물 모두 강한 항산화 활성을 나타내는 4-hydroxy-3-methoxycinnamic acid가 가장 많이 함유되어 있었다.

• Journal of the Korean Wood Science and Technology
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• 제37권1호
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• pp.78-86
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• 2009

본 연구에서는 느티나무의 에탄올 추출액에서 7-hydroxy-3-methoxycadalene 외에 3,7-dimethoxycadalene와 7-hydroxycadalene-5,8-quinone (keyakinone A) 등 2종의 카달렌 동족체를 분리하였고, 이 중에서 7-hydroxy-3-methoxycadalene을 대상으로 hydroxyl 라디칼 소거활성과 MTT assay에 의한 세포독성을 평가하였다. 7-Hydroxy-3-methoxycadalene의 hydroxyl 라디칼 소거활성은 농도에 의존적이며, 100 ppm에서는 hydroxy 라디칼이 거의 100% 제거되는 우수한 효과를 나타냈다. 그러나 7-hydroxy-3-methoxycadalene은 낮은 농도(1 ppm 이하)에서는 세포 생존율이 약 90% 가량으로 세포독성이 거의 나타나지 않았지만 농도가 높아질수록 세포 생존율에 크게 영향을 미치는 것으로 나타났다. 이러한 7-hydroxy-3-methoxycadalene은 4종의 느릅나무과 수종(느릅나무(Ulmus davidiana), 참느릅나무(Ulmus parvifolia), 큰잎느릅나무(Ulmus crophylla), 당느릅나무(Ulmus macrocarpa))에서는 전혀 발견되지 않았다. 느릅나무과 수종에서는 공통적으로 7-hydroxycadalene (분자량 214)으로 추정되는 화합물이 발견되었으며, 이는 느티나무에서 단리한 7-hydroxy-3-methoxycadalene에서 3번 위치의 메톡실기($OCH_3$)가 이탈된 구조의 화합물이다.

• Archives of Pharmacal Research
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• 제6권1호
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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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• 제31권3호
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• pp.545-546
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• 2010

• 한국약용작물학회지
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• 제21권4호
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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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• 제6권3호
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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.