• 한국한의학연구원논문집
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• 제3권1호
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• pp.229-239
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• 1997

The superoxide anion radical$(O_2)$ poses a threat to macromocules and cell organelles of the living cells. This toxicity damage to all groups of proteins results in loss of enzyme function concerned with metabolism and ion transport, and peroxidation of unsaturated fatty acids and cholesterol results in a change of permeability characteristics of the membrane, and oxidative of nucleic acids results in genomic damage and thereby cause mutation, potential carcinogenesis and somatic damage that produce cellular aging Superoxide dismutase(SOD) has received substantial attention as a potential therapeutic agent. It has been investigated as a possible agent for the prevention of ontogenesis, the reduction of cytotoxic effect of anticancer drugs, and protection against damage in ischemic tissue. It is suggest that $O_2$ is concerned with cellular aging, thereafter we need to investigate herb that activated to SOD.

• 생약학회지
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• 제33권3호통권130호
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• pp.173-176
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• 2002

In search for the plant-derived antioxidant compound, it was found that the EtOAc, BuOH extracts obtained from the leaves parts of Oryza sativa L. which exhibited a significant antioxidant activity from 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical cleavage. Activity-guided fractionation on the basis of the inhibitory activity upon the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical cleavage. and repeated column chromatography afforded several antioxidant compounds from Oryza sativa L. The structures and stereochemistry of these compounds were established on the basis of analysis of spectra and some chemical transformations as follows: 5,7-dihydroxy- 8-methoxyflavone, $acacetin-7-O-{\beta}-rutinoside$, $pectolinarigenin-7-O-{\beta}-rutinoside$. At antioxidant activity test for isolated three compounds, antioxidant activity was showed too.

• Food Science and Biotechnology
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• 제18권1호
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• pp.167-171
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• 2009

This study examined the antioxidative activity of delphinidin, a kind of anthocyanidin from eggplant. Cellular protective potential from oxidative damage by nitric oxide (NO), superoxide anion ($O_2^-$), and peroxynitrite ($ONOO^-$) using epithelial cell line LLC-PK1 cell as well as in vitro radical scavenging effects were investigated. Delphinidin showed strong in vitro radical scavenging effects against NO, $O_2^-$, and hydroxyl radical (${\cdot}OH$) in dose-dependent manners. In addition, delphinidin increased cell viability in LLC-PK1 cells in a concentration-dependent manner when viability was reduced by $ONOO^-$-induced oxidative damage. To elucidate the protective mechanisms of delphinidin from $ONOO^-$, sodium nitroprusside (SNP), and pyrogallol were also employed to generate NO and $O_2^-$, respectively. The treatment of delphinidin recovered reductions in cell viability caused by SNP and pyrogallol, indicating that delphinidin can attenuate oxidative stress induced by NO and $O_2^-$. The present study suggests that delphinidin is a promising anti oxidative agent.

• Archives of Pharmacal Research
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• 제28권5호
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• pp.529-533
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• 2005

In the course of searching for hepatoprotective agents from natural products, six compounds were isolated from the MeOH extract of the leaves of Juglans sinensis, as guid ed by their DPPH free radical scavenging activity. The structures were determined as juglanoside B (1), quercetin 3-O-${\alpha}$-L-arabinofuranoside (avicularin, 2), quercetin 3-O-${\alpha}$-L-arabinopyranoside (guaijaverin,3), quercetin 3-O-${\alpha}$-L-rhamnopyranoside (quercitrin,4), (+)-catechin (5) and quercetin 3-O-${\beta}$- D-galactopyranoside (hyperin,6). Compounds 2-6 showed significant DPPH free radical scavenging effects. An evaluation for the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity was conducted, and compounds 1, 2, and 5 showed protective effects against nitrofurantoin-induced cytotoxicity, and compound 5 also exhibited a moderate protective effect on amiodarone-induced cytotoxicity in Hep G2 cells.

• Archives of Pharmacal Research
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• 제20권2호
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• pp.148-154
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• 1997

The antioxidant activity of Artemisia iwayomogi was determined by measuring the radical scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. The methanol extract of A. iwayomogi showed strong antioxidant activity, and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate > n-butanol > water > chloroform > n-hexane fraction. The ethyl acetate and n-butanol soluble fractions exhibiting strong antioxidant activity were further purified by repeated sitica get and Sephadex LH-20 column chromatography. Antioxidant chlorogenic acid was isolated as one of the active principles from the n-butanol fraction, together with the inactive components, 1octacosanol, scopoletin, scopolin, apigenin $7, 4^{I}$-di-O-methylether, luteolin $6, 3^{I}$-di-O-methylether (jaceosidin), apigenin methylether (genkwanin), 2, 4-dihydroxy-6-methoxyacetophenone $4-O-{\beta}-$D-glucopyranoside and quebrachitol. The antioxidant activity of chlorogenic acid was comparable to that of L-ascorbic acid, which is a well known antioxidant.

• 한국식품영양과학회지
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• 제33권9호
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• pp.1419-1425
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• 2004

본 연구는 이팝나무 잎의 용매분획물을 이용하여 DPPH 소거 작용, 환원력과 같은 항산화 활성과 tyrosinase 저해 활성을 실험한 결과 에틸 아세테이트 분획물에서 높은 항산화 및 tyrosinase 저해 활성을 나타내었다. 따라서 silica gel column chromatography와 MPLC를 이용하여 그 활성물질을 분리하였으며, 분리한 화합물은 $^1H$, $^{13}C$-NMR 및 2DNMR을 이용하여 luteolin-4'-O-glucoside로 구조동정을 하였다. 분리한 luteolin-4'-O-glucoside와 기존 항산화제와의 비교실험에서 DPPH 라디칼 소거 활성과 환원력은 시료의 농도가 증가함에 따라 활성이 증가하였다. 순수하게 분리한 luteolin-4'-O-glucoside를 이용하여 tyrosinase 저해 활성도 농도 의존적이었으며, $IC_{50}$ 값은 23.2 ${\mu}g/mL$로 나타났다. 그러므로 luteolin-4'-O-glucoside는 식품첨가물로 항산화제로서의 활용도 및 미백효과를 지니는 기능성 화장품원료로서 이용가치가 높을 것으로 생각된다.

• 한국정보통신학회논문지
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• 제7권7호
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• pp.1563-1568
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• 2003

국제환경기구(GEF)의 해양환경 위해 지정 대상의 하나인 선박안정수 처리기술로써, 선박 안정수에 포함되어 타 지역으로부터 이동되는 유해성외래침입생물 처리방안을 제안하였다 alpha-AL$_2$O$_3$ 유전장벽층 전극에 의한 강 전리방전 기술을 적용하여 주위 산소와 물분자로부터 고농도 수산자유기(OH : hydroxyl radical) 및 활성입자( OH, $O_2$＋, O (1D), HO$_2$)를 전리, 발생시켜서 이들을 해수에 신속히 용해 확산시켜 비교적 낮은 ∼20mg/L 정도의 수산기농도 하에서 유해성외래침입생물을 소멸 처리하는 환경 친화적 녹색 청정 처리기술이다. 제안된 기술은 대상물의 처리 후 부수적으로 발생할 수 있는 처리잔류물이 전혀 발생하지 않으며, 인공적 화학성분의 약제를 사용하지 않는 저렴한 처리방법으로 대ㆍ소형 원양선박의 안정수에 포함되어 있는 유해성외래침입생물의 타 지역 해양확산을 방지하고 안전하게 처리할 수 있는 자연치유적 신기술이다.

• Macromolecular Research
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• 제17권3호
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• pp.174-180
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• 2009

Chemical modification of titanium/titanium oxide (Ti/$TiO_2$) substrates has recently gained a great deal of attention because of the applications of Ti/$TiO_2$-based materials to biomedical areas. The reported modification methods generally involve passive coating of Ti/$TiO_2$ substrates with protein-resistant materials, and poly(ethylene glycol) (PEG) has proven advantageous for bestowing a nonbiofouling property on the surface of Ti/$TiO_2$. However, the wider applications of Ti/$TiO_2$ based materials to biomedical areas will require the introduction of biologically active moieties onto Ti/$TiO_2$, in addition to nonbiofouling property. In this work, we therefore utilized surface-initiated polymerization to coat the Ti/$TiO_2$ substrates with polymers presenting the nonbiofouling PEG moiety and subsequently conjugated biologically active compounds to the PEG-presenting, polymeric films. Specifically, a Ti/$TiO_2$ surface was chemically modified to present an initiator for atom transfer radical polymerization, and poly(ethylene glycol) methacrylate (pEGMA) was polymerized from the surface. After activation of hydroxyl groups of poly(pEGMA) (pPEGMA) with N,N'-disuccinimidyl carbonate, biotin, a model compound, was conjugated to the pPEGMA films. The reactions were confirmed by infrared spectroscopy, X-ray photoelectron spectroscopy, contact angle goniometry, and ellipsometry. The biospecific binding of target proteins was also utilized to generate micropatterns of proteins on the Ti/$TiO_2$ surface.

• Bulletin of the Korean Chemical Society
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• 제15권5호
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• pp.349-353
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• 1994

The CN radical was generated in a jet with an inert buffer gas, helium from high voltage dc discharge of the precursor $CH_3CN$. The Fourier transform emission spectra of the O-O band of the $(B^2{\Sigma}^+{\to}X^2{\Sigma}^+)$ transition of CN have been obtained with a Bruker IFS-120HR spectrometer. The spectra show an anomalous distribution of rotational intensity which cannot be explained by a simple Boltzmann distribution. The analysis of the transition frequencies provides molecular constants with high accuracy for both the ground and the excited electronic states of the CN radical.

• 상하수도학회지
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• 제12권3호
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• pp.55-64
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• 1998

The degradation efficiency of chlorophenolic compounds in $TiO_2/H_2O_2$ combined system was compared with that of in $TiO_2$ sole system. As a result, the addition of hydrogen peroxide in photocatalytic oxidation reaction greatly enhanced the degradation efficiency of chlorophenolic compounds due to the availability of the hydroxyl radical formed on the $TiO_2$ surface. The hydrogen peroxide under UV illumination produces hydroxyl radicals that appear to be another source of hydroxyl radical formation. These results indicated the $TiO_2/H_2O_2$ combined system shows higher degradation efficiency than the $TiO_2$ sole system. Compared to another oxidation reaction, hydrogen peroxide assisted photocatalytic oxidation is more promising in practical aspect.