• 한국식품저장유통학회지
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• 제19권2호
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• pp.229-234
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• 2012

양파의 매운 맛과 냄새를 감소시켜 섭취가 용이하도록 제조된 흑양파가 항산화 활성이 있다고 보고되어있어서 흑양파로부터 항산화 활성물질을 구명하고자 하였다. 흑양파 MeOH 추출물을 용매분획하여 얻어진 분획물들 중 EtOAc층이 높은 DPPH와 $ABTS^+$ radical scavenging 활성이 있었다. 그래서 EtOAc층을 silica gel과 Sephadex LH-20 등의 column chromatography를 이용하여 2종의 항산화 활성물질을 분리하였다. 단리한 이들 화합물을 대상으로 ESI-MS 및 NMR 분석을 통하여 3,4-dihydroxybenzoic acid (1)와 quercetin (2)로 각각 동정하였다. 이 화합물들은 $ABTS^+$ 및 DPPH radical scavenging 활성이 있었으며, 화합물 2는 화합물 1에 비해 더 높은 radical scavenging 활성이 있었다.

• Preventive Nutrition and Food Science
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• 제14권3호
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• pp.195-200
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• 2009

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.

• 한국산림과학회지
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• 제102권4호
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• pp.566-570
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• 2013

정금나무의 기능성 품종을 육성하기 위하여 정금나무 선발 5개체의 열매에 대한 항산화 활성을 측정하였으며, 항산화 성분인 총 페놀 함량을 측정하였다. 총 페놀 함량은 gallic acid를 기준물질로 하여 분석한 결과 15.8~19.9 mg/g 범위로 전체 평균 17.9 mg/g을 나타냈으며, DPPH free radical 소거활성은 400 ppm의 농도에서 69.1~91.4% 범위로 전체평균 84.2%를 나타내었다. 환원력은 0.56~0.96 범위로 전체 평균 0.79를 나타내었다. 상관분석 결과 DPPH free radical 소거활성과 환원력에서 상관계수가 0.969로 매우 높은 정의 상관관계를 나타내었다.

• Environmental Analysis Health and Toxicology
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• 제15권4호
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• pp.147-155
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• 2000

In order to evaluate anti -oxidant activities and protective effect against oxidatve damage, DPPH radical scavenging activity and lipid peroxidation inhibitory activity were measured among methanol extracts prepared from natural medicinal plants. Fourteen natural medicinal plants which were reported to have anti -oxidative or anti-inflammatory effects were selected based on our previous report. In addition to the total methanol extracts, n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions were prepared from each total extract. DPPH radical scavenging assay was performed against 14 total extracts and all samples showed dose-dependent activities in various extent. Among those, 6 samples, methanol extracts of Euryale ferox, paeonia suffruticosa, Areca catechu var. dulcissima, Cinnamomun cassia, Alpinia katsumadai and Betula platyphlla var. japonica showed IC$\sub$50/ value lower than 6.0 $\mu\textrm{g}$/ml. The highest DPPH radical scavenging activity was found in ethylacetate fraction of paeonia suffruticosa with IC$\sub$50/ value of 1.1 $\mu\textrm{g}$/ml. Analysis of lipid peroxidation inhibitory activity on hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast (V79-4) cells revealed that the highest inhibitory effect was observed in methanol extract of Betula platyhpylla var. japonica. Lipid peroxidation inhibitory activity was observed as a dose-dependent manner in all samples used in this study. Among fraction samples, ethylacetate fraction of Alpinia katsumadai had the strongest inhibitory activity with IC$\sub$50/ value of 0.9 $\mu\textrm{g}$/ml.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.211.1-211.1
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• 2003

On the purpose of develcpement of antioxidative compound from natural sources, medicinal plants known to have antioxidant actuvity have been examined concening DPPH radical scavenging activity and SOD-liked activities. Among 8 plants exhibiting the activity, Houttuynia cordata THUNB was selected as resources to search for active compounds due to rareness of study. The antioxidative compounds from Houttuynia cordata THUNB,quercitrin was assayed using a DPPH free radical. The DPPH radical scavenging activity of quercitrin was similar to that of BHA and Ascorbic acid

• 한국약용작물학회지
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• 제21권3호
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• pp.197-203
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• 2013

We studied the total polyphenol content, DPPH radical scavenging activity, hydroxyl radical scavenging activity and ${\alpha}$-glucosidase inhibition of water extracts from 17 medicinal plants. Total polyphenol contents ranged from 10.0 (Coix lachryma-jobi L, CL) ~ 279.7 (Perilla sikokiana, PS)mg/g. The water extract from medicinal plants were evaluated for its free radical scavenging activities and compared with a commercial antioxidant, ascorbic acid. DPPH radical scavenging activity of Pyrus pyrifolia (PP), Chamaecyparis obtusa L. (COL), Chamaecyparis obtusa F. (COF), and PS were higher than positive control. Higher hydroxyl radical scavenging activity were shown in Acanthopanax senticosus (AS) and Cordyceps militaris (CM) than the other plants. The highest anti-${\alpha}$-glucosidase activity was observed in Cornus officinalis (CO) and Paeonia suffruticosa Andrews (PSA) water extracts. PSA showed not only the higher DPPH radical scavenging activity but also the anti-${\alpha}$-glucosidase activity. The results of our study that PP, COL, COF, PS, AS, CM, CO and PSA could be potential candidates for natural antioxidants.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1310-1315
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• 2008

This study was to investigate the influence of pH on the antioxidant activity of melanoidins formed from glucose (Glc) and fructose (Fru) with lysine enantiomers in the Maillard reaction. Melanoidins formed from D-isomers were found to be effective antioxidants in different in vitro assays with regard to the ferrous ion chelating activity, 1, l-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activities, ferric reducing/antioxidant power (FRAP), and 2,2'-azinobis(3-ethylbenothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity. In particular, the chelating activity of these melanoidins at a pH of 7.0 was greater than those with pH of 4.0 and 10.0. The chelating activity and DPPH radical scavenging activity of the melanoidins formed from the Glc systems were higher than those of the melanoidins formed from the Fru systems. However, the FRAP and ABTS radical scavenging activity of these melanoidins were not different according to pH level, with exceptions being the Fru systems.

• KSBB Journal
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• 제19권1호
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• pp.67-71
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• 2004

본 연구에서는 염생식물의 하나인 해당화의 항산화효과를 탐색하기 위해 해당화의 dichloromethane과 methanol의 조추출물을 합하여 n-hexane, 15% aq. MeOH, n-BuOH, $H_2O$로써 순차적으로 용매 분획하여 DPPH 라디칼, peroxynitrite의 소거 활성과 지질 과산화 저해 활성을 측정하였다. 그 결과 각각의 실험에서 해당화의 유의적인 항산화 효과가 확인되었으며, 특히, 4개의 분획물들 중 n-BuOH 획분이 가장 뛰어난 항산화 효과가 있는 것으로 나타났다. 따라서 해당화의 항산화 효과는 비교적 극성이 큰 2차 대사산물에 의한 것임을 추측할 수 있으며, 해당화의 많은 생물학적인 활성들 중 peroxynitrite 소거 효과와 마우스 간 균질물을 이용한 지질 과산화물 생성 억제 활성에 관한 보고는 이것이 처음이다.

• Advances in Traditional Medicine
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• 제4권3호
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• pp.197-209
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• 2004

The study was aimed at evaluating the antioxidant and antimicrobial activities of methanol extract of Caesalpinia bonducella leaves (MECB) (Family: Caesalpiniaceae). The effect of MECB on antioxidant activity, reducing power, free radical scavenging (DPPH radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide radical scavenging), total phenolic content and antimicrobial activities were studied. The antioxidant activity of MECB increased in a dose dependent manner. About 50, 100, 250 and 500 g of MECB showed 53.4, 61.2, 69.1 and 76.2 % inhibition respectively on peroxidation of linoleic acid emulsion. Like antioxidant activity, the effect of MECB on reducing power increased in a dose dependent manner. The free radical scavenging activity of MECB was determined by DPPH radical scavenging method. The potency of this activity was increased with increased amount of extract. MECB was found to inhibit the nitric oxide radicals generated from sodium nitroprusside $(IC_{50}\;=\;102.8\;g/ml)$ whereas the $IC_{50}$ value of curcumin was 20.4 g/ml. Moreover, the MECB was found to scavenge the superoxide generated by photoreduction of Riboflavin. MECB was also found to inhibit the hydroxyl radical generated by Fenton reaction, where the $IC_{50}$ value is 104.17 g/ml compared with catechin 5 g/ml, which indicates the antioxidant activity of MECB. The MECB capable of scavenging hydrogen peroxide in a concentration-dependent manner. The amounts of total phenolic compounds were also determined. Antimicrobial activities of MECB were carried out using disc diffusion methods with five Gram positive, four Gram negative and four fungal species. The results obtained in the present study indicate that MECB leaves are potential source of natural antioxidant and antimicrobial agents.

• Journal of Applied Biological Chemistry
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• 제62권2호
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• pp.143-147
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• 2019

This study evaluated the anti-oxidant activity of avicularin and isovitexin from Lespedeza cuneata using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH) scavenging assays. The results showed that among the four fractions, the highest OH radical scavenging activity was exhibited by the n-butanol fraction. The DPPH radical scavenging activities of avicularin and isovitexin were higher than 50% at a concentration of $100{\mu}g/mL$. Moreover, one hundred micrograms per liter of avicularin and isovitexin exhibited effective anti-oxidant activity, with the OH radical scavenging rates being 87.54 and 91.48%, respectively. These results suggest that Lespedeza cuneata would be useful anti-oxidant agents from natural sources.