• BMB Reports
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• 제31권5호
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• pp.492-497
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• 1998

Cu,Zn-superoxide dismutase (SOD) was purified from horseradish by using Mono Q and Superose 12 FPLC column chromatography. The native molecular mass of the purified enzyme was approximately 33 kDa, as determined by gel filtration. The subunit molecular weight, as estimated by SDS-PAGE, was 16 kDa. These results indicated that the native enzyme is a homodimer. We investigated the free radical-generating function of horseradish Cu,Zn-SOD by using a chromogen, 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) which reacts with ${\cdot}OH$ radicals to form $ABTS^{+{\cdot}}$ The formation of $ABTS^{+{\cdot}}$ was required for both active Cu, Zn-SOD and $H_2O_2$. The optimal pH for the free radical-generating activity of this enzyme was 6.0-8.0, and it retained about $40^{\circ}C$ of its maximum activity when exposed at $40^{\circ}C$ for 15 min. A neutral scavenger, ethanol, inhibited the $ABTS^{+{\cdot}}$ formation by horseradish Cu, Zn-SOD more effectively than that by the mammalian enzyme. These results suggest that the active channel of horseradish enzyme is slightly larger than that of the mammalian enzyme.

• 농업과학연구
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• 제11권2호
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• pp.315-321
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• 1984

0.1M tetraethylammoniumperchlorate (TEAP)를 지지전해질로 한 acetonitrile속에서 direct current (DC), differential pulse (DP) polarography 및 cyclo voltammetry (CV) 방법에 의한 Sumithion의 전기화학적 환원반응은 -1.0~-2.50volt vs. Ag-AgCl 범위에서, 제1단계로 P-Oph 결합의 분열에 의하여 dimethylthiophosphonyl radical과 p-nitro-m-cresol이 생성되는 1전자 유사가역반응이 일어나고, 제2단계는 전형적인 1전자 비가역 반응으로 dimethylthiophosphonyl radical이 dimethylthiophosphonate가 되며, 제3단계 반응은 2.7volt vs. Ag-AgCl의 높은 음전위에서 p-nitro-m-cresol은 4전자 비가역반응에 의한 nitro group의 환원으로 p-hydroxy-amino-m-cresol이 생성되는 총 3단계의 비가역적인 electron-transfer chemical reaction (EC) 메카니즘으로 전극반응이 진행됨을 알았다.

• 대한한의학회지
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• 제22권3호
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• pp.31-41
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• 2001

Objectives : This study was performed to investigate the effects of Cordyceps Sinensis (CS) and Cordyceps Militaris (CM) on anti oxidation in the livers of ${CCl_4}-treated$ rats. Methods : Hepatotoxicity in rats was induced by carbon tetracWoride. $CCl_4-induced$ rats were administered with the extract of CS and CM. Results : In vitro, CS and CM didn't affect levels of lipid peroxide and the activities and type conversion ratio of xanthine oxidase. However, hydroxyl radicals and DPPHL radicals were decreased. In vivo, in the ${CCl_4}-treated$ rats, lipid peroxide, the activities and type conversion ratio of xanthine oxidase and superoxide radicals were increased but superoxide dismutase was decreased. After CS and CM were administered to ${CCl_4}-treated$ rats, levels of lipid peroxide, the activities and type conversion ratio of xanthine oxidase and superoxide radicals were decreased but superoxide dismutase was increased. Conclusions : These results suggest that CS and CM decrease the activities of free-radical-generating enzymes which form lipid peroxide and increase the activities of oxygen free radical scavenging enzymes.

• 생명과학회지
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• 제11권6호
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• pp.503-508
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• 2001

한방에서는 경련억제의 목적으로 처방되고 있는 석창포의 정유액을 분리하여 활성산소종 생성계 효소인 xanthine oxi-dase와 alehyde osidase에 대한 억제활성을 in vitro에서 측정하고 지질과산화 억제효과를 in vitro 와 in vivo에 각각 조사하였으며 DPPH radical 소거 효과를 검토하여 다음과 같은결과를 얻었다. 석창포 정유는 xanthine oxidase에 대해서는 0.01 mg/ml에서 13.3%, aldehyde oxidase에 대해선.s 0.001mg/ml에 서 5.0% 각각 효소 활성을 억제 하였으나, 괴량에서는 오히려 효소활성을 증가시키는것으로 나타났다. 지질과산화 억제효과는 1.0mg/ml에서 대조군에 비해 49.4% 억제하여 우수한 효과를 보였으며 향기를 7일간 흡입시킨 in vivo test에서는 인위적으로 지질과산화를 유발시킨 대조군에 비해 과산화지질이 16.7% 감소되었다. 그러나 DPPH radical에 대한 소거효과는 2.0 mg/ml에서약 4%의 미미한 효과를 나타내었다.

• 한국자동차공학회논문집
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• 제12권5호
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• pp.58-65
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• 2004

A cylindrical constant volume combustion chamber was used to investigate the combustion characteristics of stratified methane-air mixture under several initial charge conditions in the author's previous reports. The results showed that the improvement of thermal efficiency and reduction of heat loss was realized simultaneously by using 2-stage injection method. This paper deals with the reason why the stratified combustion has showed better combustion rate through the measurement and analysis of chemiluminescence of C $H^{*}$ and $C_{2}$$^{*}$ radicals. An optic fiber bundle is used to measure the local emission of C $H^{*}$ and $C_{2}$$^{*}$ radicals to map the relationship between the excess air ratio and local radical intensity ratio in the combustion vessel at 5 mm apart form the geometric center. The results show that there exist a relationship between the intensity ratio and the air-fuel ratio. It is revealed that the improvement of combustion rate in a lean-stratified mixture is realized through the 2-stage injection method. method.

• Food Science and Biotechnology
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• 제18권1호
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• pp.124-129
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• 2009

Antioxidant activities of the extract of red seaweed, Polysiphonia morrowii, were evaluated using several in vitro assay systems. Activity-guided fractionation revealed that the 90% MeOH fraction of the P. morrowii extract exhibited the highest antioxidant activity, and that this fraction had a high total phenolic content ($135.7{\pm}5.0\;mg$ gallic acid/g extract). Therefore, the antioxidant activities of the 90% MeOH fraction against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical, reducing power, ferrous chelating, and hydrogen peroxide were investigated. The results revealed that the antioxidant activities of the 90% MeOH fraction were similar and/or superior to that of commercial antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). In addition, the ability of the 90% MeOH fraction to inhibit oxidative damage to DNA was assessed by measuring the conversion of the supercoiled pBR322 plasmid DNA to the open circular form. The 90% MeOH fraction was found to significantly protect this hydroxyl radical-induced DNA damage in a dose-dependent manner. Taken together, these findings suggest that the 90% MeOH fraction of P. morrowii extract and/or its constituents has the potential for use as a new bioresource of antioxidants.

• 대한한의학회지
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• 제16권2호
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• pp.348-364
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• 1995

Jwagyuyeum and Woogyuyeum, being known to reinforce Kidney-yin and -yang, were tested for the effects of on free radical generating enzyme and lipid peroxidation in senile rat brain. In vitro, levels of lipid peroxide in tissues of brain were proportionally decreased to concentration of extracts prepared from Jwagyuyeum and Woogyuyeum. They were much more decreased, when lipid peroxidation was induced with ferrous iron ($Fe^{-2}$). In vivo, after both berbs were administered to the rat. levels of lipid peroxide in brain were decreased. especially it was much more decreased using Jwagyuyeum. Also, enzyme activities of xanthine oxidase and aldehyde oxidase in brain were decreased. The ratio of type conversion of the brain xanthine oxidase was lowered in both, especially Jwagyuyeum was much more done. These results suggest that Jwagyuyeum and Woogyuyeum decrease the activities of free radical generating enzymes such as xanthine oxidase and aldehyde oxidase which form lipid peroxide, Consequently both herbs might delay aging.

• 대한한의학회지
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• 제17권2호
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• pp.191-202
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• 1996

Cervus elaphus for herb-acupuncture solution(CEHAS) was tested for the effects of free radical generating enzyme and lipid peroxidation in rat's liver. In vitro, levels of lipid peroxide in tissues of liver were proportionally decreased to concentration of CEHAS. They were much more decreased. when lipid peroxidation was induced with ferrous iron $(Fe^{-2})$. Also, enzyme activities of xanthine oxidase were decreased. The ratio of type conversion of xanthine oxidase was lowered, too. But, here was not special changes on enzyme activities of aldehyde oxidase. These results suggest that CEHAS decrease the activities of free radical generating enzymes such as xanthine oxidase which form lipid peroxide.

• 한국한의학연구원논문집
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• 제2권1호
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• pp.192-204
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• 1996

Cervus elaphus for herb-acupuncture solution (CEHAS) was tested for the effects of free radical generating enzyme and lipid peroxidation in rat's kidney. In vitro, levels of lipid peroxide in tissues of kidney were proportionally decreased to concentration of extracts prepared from CEHAS. They were much more decreased, when lipid peroxidation was induced with ferrous iron (FeII). Also, enzyme activities of xinthine oxidase were decreased. The ratio of type conversion of xanthine oxidase was lowered, two. But, it was not seen changes on enzyme activities of aldehyde oxidase. These results suggest that CEHAS decrease the activities of free radical generating enzymes such as xanthine oxidase which form lipid peroxide.

• 대한화학회지
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• 제18권5호
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• pp.341-353
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• 1974

Triphenylphosphine phenylimide의 비수용액에서의 전기화학적인 환원반응을 polarography, cyclic voltammetry, controlled-potential coulometry 및 electron spin resonance 법을 써서 고찰하였다. 이 유기인화합물은 one-electon transfer에 따라서 anion radical이 형성되나 순간일 뿐이고 protonation과 재차 one-electon reduction 결과 인과 질소사이의 이중결합이 끊어진다. 그 결과 아닐린이 주요 반응생성물로서 발견되었다. 또 한편 동반하는 화학반응결과 생긴 주산물의 하나인 triphenylposphine oxide의 환원결과 인과 페닐 사이의 단일결합이 끊어지는 것도 관찰할 수 있었다.