• 한국자동차공학회논문집
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• 제7권8호
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• pp.66-75
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• 1999

In two-stroke engines, methods of evaluating scavenging effciency have been studied in parallel with trials for improvement of scavenging process. But simulating methods have a wide difference with difference with scavenging process in real engines and methods of evaluating scavening efficiency in real engines are very difficult and very expensive. This study shows that there is a possbility of evaluating scavenging efficiency in real engines very easily by analysis of in-cylinder pressure data. And as a characteristics two-stroke engines, the poly tropic indices in the process of compression are varies with degreeof scavenging and good representatives of scavenging efficiency.

• Natural Product Sciences
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• 제13권1호
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• pp.40-45
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• 2007

The methanol extract of Coscinium fenestratum, commonly own as tree turmeric, which is widely used in the indigenous system of medicine was studied for its in vitro scavenging activity in different methods viz DPPH scavenging, nitric oxide scavenging, iron chelation activity, superoxide scavenging, ABTS radical scavenging and lipid peroxidation. The results were analyzed statistically by regression method. Its antioxidant activity was estimated by $IC_{50}$ value and the values are $57.1\;{\mu}g/ml$ for DPPH radical scavenging, $36.5\;{\mu}g/ml$ for iron chelating activity, $51.7\;{\mu}g/ml$ for nitric oxide scavenging, $53.63\;{\mu}g/ml$ for ABTS scavenging, $44.2\;{\mu}g/ml$ for superoxide scavenging, and $40\;{\mu}g/ml$ for lipid peroxidation. In all the methods, the extract showed its ability to scavenge free radicals in a concentration dependent manner. The results indicate that C. fenestratum has potent antiofidant activity.

• 한국식품영양학회지
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• 제35권5호
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• pp.313-323
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• 2022

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

• 생약학회지
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• 제32권3호통권126호
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• pp.253-256
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• 2001

The present study was designed for the improvement of routine measurement of superoxide and hydroxyl radical scavenging activities utilized by a microplate reader. Superoxide radical scavenging activity by the ascorbic acid, which is a well-known superoxide scavenger, was determined in a dose-dependent manner. Hydroxyl radical scavenging activity by the thiourea, which is a well-known hydroxyl radical scavenger, was also well detected in a dose-dependent manner. Our results suggest that the use of microplate reader to assay the superoxide and hydroxyl radical scavenging activities improves the accuracy of data and enables the use of much smaller amounts of samples and/or reagents, with much simpler experimental procedure. Therefore, These methods appear to be suitable for screening of superoxide and hydroxyl radical scavenging activities in both the plant medicinal extracts and the isolated compounds.

• 한국식품과학회지
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• 제51권2호
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• pp.133-140
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• 2019

Antioxidant activities of Ulmus davidiana root and bark extracts were evaluated by various antioxidant tests, including DPPH radical-scavenging, nitric oxide-scavenging, superoxide anion radical-scavenging, and ABTS radical-scavenging assays, and superoxide dismutase (SOD)-like activity and reducing power analysis, along with the determination of total phenolic and flavonoid contents. Both the extracts showed strong antioxidant activities by these testing methods. Ulmus davidiana root extract possessed strong reducing power and nitric oxide-scavenging activity, and high scavenging activities against free radicals including the superoxide anion, and the ABTS and DPPH radicals, but a weaker scavenging activity of SOD. In contrast, the Ulmus davidiana bark extract exhibited a strong SOD-like activity, but all the other activities were weak. It was observed that the total phenolic and flavonoid contents of the Ulmus davidiana root extract were higher than those of the Ulmus davidiana bark extract.

• 동의생리병리학회지
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• 제21권4호
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• pp.934-939
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• 2007

In recent year, We are concerned about anti-aging, disease-prevention, longevity, so many methods are used in solving this problem. And Those are related with antioxidative ability. Recently, We heard that Mori Cortex was known to reduce the hypertension and was helpful in promoting health, and Mori Ramulus was effective against obesity, etc. So, This study was performed to investigate the antioxidative effect of hot-water extracts of Mori Cortex and Mori Ramulus used for 3 methods, those are DPPH radical scavenging activity, Nitric oxide(NO) radical scavenging activity and Bovine serum albumin(BSA). And we compared Mori Cortex and Mori Ramulus on Antioxidative Effects. The results of this study were as follows: We measured levels of DPPH radical scavenging activity and Nitric oxide(NO) radical scavenging activity. And we obtained results that Mori Ramulus was most effective with the concentration of 5 $mg/m{\ell}$, and Mori Cortex was most effective with the concentration of 2.5 $mg/m{\ell}$, And we examined the antioxidative effects of Mori Ramulus and Mori Cortex with $CU^{2+}/H_20_2$-induced Bovine serum albumin(BSA). And we obtained that antioxidative ability was increased after 1.25 $mg/m{\ell}$ and that was most effective with the concentration of 5 $mg/m{\ell}$ on both of them. And antioxidative ability of Mori Cortex was better than Mori Ramulus(p<0.05). So I guess that hot-water extracts of Mori Ramulus and Mori Cortex have effects on antioxidative ability, but Mori Cortex is better than Mori Ramulus on antioxidation. Hereafter we need differential experimental methods of antioxidative effect on both of them.

• 한방비만학회지
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• 제9권2호
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• pp.57-63
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• 2009

In recent year, We are concerned about anti-aging, disease-protection, long-life, many methods are used in solving this problem. And Those are related with antioxidative ability. Recently, We heard that Cucurbita moschata Duch. has anti-hypertensive effect and good for health. So I let made a experiment for this result of the anti-oxidant effect of Cucurbita moschata Duch. used for 3 methods, those are DPPH radical scavenging activity, Nitric oxide(NO) radical scavenging activity and Bovine serum albumin(BSA). The results of this study were as follows: We measured level of DPPH radical scavenging activity. And we obtained results that the ability of DPPH radical's elimination was increased when concentration of Cucurbita moschata Duch. was to $20\;mg/m{\ell}$. We measured level of Nitric oxide(NO) radical scavenging activity. And we founded that the ability of NO radical's elimination was increased when concentration of Cucurbita moschata Duch. was to $10\;mg/m{\ell}$. When we inspected antioxidation with Bovine serum albumin(BSA). And we obtained that antioxidative ability was increased after$2.5\;mg/m{\ell}$ of Cucurbita moschata Duch.. So I guess that Cucurbita moschata Duch. has effect of antioxidative ability. Hereafter we need differential experimental methods for evidence of antioxidative effect on Cucurbita moschata Duch.

• 대한본초학회지
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• 제24권4호
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• pp.95-99
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• 2009

Objectives : This study were carried out to investigate the anti-oxidative activities of $\gamma$-SPE(gamma irradiated shell of Persicae semen extract with ethanol). Methods : Anti-oxidative was measured by DPPH free radical scavenging activities, nitric oxide radical scavenging activities, SOD-like activities, xanthine oxidase radical scavenging activities, nitrite scavenging activities and tyrosinase inhibition activities. Results : Effects of free radial scavenging was increased by irradiation. Tyrosinase inhibition activities was decreased by $\gamma$-SPE. Conclusions : Results suggested that $\gamma$-SPE have a potential as a new anti-oxidative material.

• 동아시아식생활학회지
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• 제19권3호
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• pp.375-383
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• 2009

This study was conducted to measure the total polyphenol contents and DPPH radical scavenging activities of different potato plants parts, varieties, and grades, and by distribution and different cooking conditions. The results were as follows. For the plant parts, total phenolic content and DPPH radical scavenging activity were highest in the flowers followed by leaves and stems, respectively. Among 5 potato varieties, 'Jasim' had the highest DPPH radical scavenging activity and the activity of its pulp was lower than that of its cortex(peel). Regardless of potato grade, the cortexes(peel) of samples had two-fold higher DPPH radical scavenging activity than pulp, and the Grade SS potato had the highest phenolic content. It was also found that the bud ends and stem ends had comparably larger amounts of phenolic compounds in horizontally cut potatoes. Finally, the descending order for DPPH radical scavenging activity, according to different cooking conditions, was as follows: gas oven range-baking, frying, microwave-heating, sauteing, boiling in 1% saline solution, steaming, and boiling in 3% saline solution.

• 한국식품저장유통학회지
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• 제10권3호
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• pp.388-393
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• 2003

가공 과정에서 대량 발생하는 폐기물 중 하나인 귤피를 천연 기능성 소재로 개발하기 위한 기초자료를 마련하고자 추출방법을 달리한 귤피 추출물의 생리활성을 확인하였다. 또한 감마선 조사에 의한 귤피 추출물의 생리활성 변화에 관하여도 관찰하였다. 정치추출의 경우 열수추출에 비해 초기 L$^{*}$ 값이 낮은 반면 a$^{*}$ 값과 b$^{*}$ 값이 높았으나 저장기간 또는 감마선 조사에 의해 차이가 없어졌으며, 감마선 조사선량의 증가에 따라 귤피추출액의 L$^{*}$ 값과 a$^{*}$ 값은 증가하였으며, b$^{*}$ 값은 감소하였다. 전자공여능, tyrosinase 저해효과, nitrite 소거능은 감마선 조사에 의해 영향을 받지 않았으나 저장기간동안 이러한 생리활성이 감소함을 확인하였다. 또한 추출방법(열수 vs 정치)에 따른 귤피 추출물의 생리활성의 차이는 나타나지 않았으며 감마선 조사는 천연물 추출물의 생리활성에 영향을 주지 않음을 확인하였다. 그러므로 경제적인 추출방법을 선택한다면 감귤가공후 폐자원인 귤피를 다양한 용도의 기능성 소재로 활용할 수 있다고 판단된다.