• 한국자원식물학회지
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• 제26권3호
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• pp.347-354
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• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• Food Science and Biotechnology
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• 제15권1호
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• pp.39-43
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• 2006

Levels of quercetin in different parts of onion were investigated using high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS) suitable for use with functional food material. Two main peaks were observed on HPLC chromatograms from the extracts of the skin, and the outer, middle, and core parts of onion. Using LC/MS, peak 1 was tentatively identified as quercetin monoglucoside at m/z 466.4, and peak 2 as quercetin with [M]+ at m/z 303.3. The levels of quercetin in the skin, and the outer, middle and core parts of the plant were 16.83,2.67,0.95, and 0.35 mg/g, respectively. In the study of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, skin, the nonedible part, contained the highest amount of quercetin, compared to the other edible parts, and showed the highest DPPH radical scavenging activity. Levels of quercetin and DPPH radical scavenging activity increased from core to skin. All parts of onion exhibited the strongest antibacterial activity only against Staphylococcus aureus and Vibro parahaemolyticus. Antibacterial activities of onion exhibited that S. aureus was more sensitive than V. parahaemolyticus. Among the four onion extracts, the middle part showed the strongest inhibitory activity against S. aureus but all onion extracts showed similar antibacterial activities against V. parahaemolyticus.

• Ocean and Polar Research
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• 제34권4호
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• pp.445-451
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• 2012

The EtOH extracts of red seaweeds (Symphyocladia latiuscula, Chondrus ocellatus and Carpopeltis affinis) and solvent partitioned fractions were investigated for their 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects and the total phenolic contents were correlated with ABTS and DPPH radical scavenging activities. The EtOH extracts and their solvent partitioned fractions exhibited strong ABTS and DPPH radical scavenging activities. Among the solvent partitioned fractions obtained from n-Hexane (HX), methylenchloride (MC), ethylacetate (EA), and buthanol (BuOH), the HX fraction from C. affinis showed higher radical scavenging activities than other fractions. Total phenolic contents showed significant correlation ($r^2$ = 0.709) with ABTS radical scavenging activity. The results of this study suggest that the strong radical scavenging activity of HX fraction from C. affinis is a promising natural antioxidant for healthcare products.

• Advances in Traditional Medicine
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• 제8권1호
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• pp.32-38
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• 2008

Galgeuntang water extract exhibited a strong free radical scavenging activity and reducing power determination. However, a gradual increase in the free radical scavenging activity and reducing power determination was obtained with increasing concentrations. The highest radical scavenging activity was shown by the water extract from Galgeuntang (116.93 ${\mu}g$/mL) and the water extract from Cinnamonum cassia Presl. (95.01 ${\mu}g$/mL). These results of phenolic and flavonoid contents of the extracts indicated that the strong radical scavenging activity of the Cinnamonum cassia Presl. extract might be in part due to the phenolic compounds. The correlation coefficient between TPC and DPPH ($r^2$ = 0.9312), TFC and DPPH ($r^2$ = 0.9677), showed positive correlation among total phenolic/flavonoid contents and antioxidant activity. These results suggest that Galgeuntang has a potential antioxidant activity.

• 한국식품저장유통학회지
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• 제30권6호
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• pp.960-968
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• 2023

The rhizome of Phragmites communis Trin. is used for vomiting and belching by clearing stomach and the sprout is used as tea. Phragmites japonica is similar with P. communis except the color of sheath is purple. This study is aimed to compare the in vitro antioxidant activity, total polyphenol and flavonoids contents of P. communis and P. japonica. The antioxidant activities of fractions from the two Phragmites plants were evaluated by 1,1-diphenyl-2- picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay. The antioxidant activity varied with plant parts and extract solvents. The fractions of leaf extract from the two Phragmites plants (4.06±1.32-16.47±1.28%) showed higher antioxidant activity by DPPH assay compared with rhizome fractions of two Phragmites plants (0.00±0.00-14.15±0.07%), these are lower compared with ascorbic acid and butylhydroxyanisole (BHA). The highest ABTS radical scavenging activity was found for rhizome ether fraction, namely 74.95±0.56% and 73.04±1.85% for P. communis and P. japonica, these are higher than BHA. The total polyphenol and flavonoids contents were different with plant parts and extract solvents, likewise antioxidant activity. A significant correlation was shown between DPPH and ABTS radical scavenging activity. Considering the results of this study, the leaves and stems of P. communis and P. japonica are expected to be used as natural antioxidants.

• Preventive Nutrition and Food Science
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• 제18권3호
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• pp.196-202
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• 2013

Citron seed extracts (CSEs) were made using distilled water (CSEW), ethanol (CSEE), and n-hexane (CSEH), to measure the total polyphenol contents, DPPH and ABTS radical scavenging activities, and anti-complementary activity. The total polyphenol content was observed the highest in CSEE (188.71 ${\mu}g/mL$), and occurred in the following order: CSEE>CSEW (141.11 ${\mu}g/mL$)>CSEH (26.19 ${\mu}g/mL$) at 10 mg/mL. CSEE (63.56%) and CSEW (56.61%) showed significantly higher DPPH radical scavenging activities when compared with CSEH (28.57%). ABTS radical scavenging activities of CSEE (45.53%) and CSEW (40.02%) were also observed to be higher, whereas CSEH did not show ABTS radical scavenging activity. Anti-complementary activity of CSEE (26.85%) showed a greater activity than that of CSEW (7.84%) at 1,000 ${\mu}g/mL$. Limonin and nomilin contents had the highest values (1.882% and 2.089%) in CSEE, and with 0.327% and 0.139% in CSEW; however, CSEH showed relatively very low values at 0.061% and 0.026%, respectively. Among the CSEs tested, CSEE as a by-product from citron may provide an important source of dietary antioxidant compounds with rich polyphenol and limonoid contents, and immunopotentiating activity, including the complement activation factor.

• Molecular & Cellular Toxicology
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• 제4권2호
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• pp.170-176
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• 2008

The quantitative structure-activity relationship (QSAR) of a set of 35 flavonoid compounds presenting antioxidant activity was established by means of Genetic Algorithm-Multiple Linear Regression (GA-MLR) technique. Four-parametric models for two sets of data, the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity $(R^2=0.788,\;Q^2_{cv}=0.699\;and\;Q^2_{ext}=0.577)$ and scavenging activity of reactive oxgen species (ROS) induced by $H_2O_2 (R^=0.829,\;Q^2_{cv}=0.754\;and\;Q^2_{ext}=0.573)$ were obtained with low external predictive ability on a mass basis, respectively. Each model gave some different mechanistic aspects of the flavonoid compounds tested in terms of the radical scavenging activity. Topological charge, H-bonding complex and deprotonation processes were likely to be involved in the radical scavenging activity.

• 한국자원식물학회지
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• 제26권5호
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• pp.548-556
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• 2013

시설오이로 많이 재배되고 있는 4 품종을 선발하여 생육단계별로 DPPH radical 소거활성, 아질산염 소거활성, ABTS 소거활성 그리고 항산화효소 활성에 대하여 비교 분석하였다. 장죽청장 품종이 모든 생육단계에서 DPPH radical 소거활성이 상대적으로 높게 나타났으며, 그 외 품종들 간에는 큰 차이를 보이지는 않았다. 또한 생육단계별로는 수확기에 못 미친 미성숙단계에서 DPPH radical 소거 활성이 높게 나타났다. 아질산염 소거활성은 pH가 1.2일 경우 모든 품종과 생육단계에서 40% 이상 분해시켰으며, 특히 장형낙합과 신조은백다다기 품종이 상대적으로 높은 활성을 보였다. 또한 pH 4.0에서는 추출물 모두에서 30% 이상의 아질산염 소거활성을 나타냈으며, pH 6.0에서는 대부분 활성이 없었다. ABTS 소거활성은 장죽청장과 늘푸른 청장 품종이 다른 품종보다 상대적으로 다소 높은 소거능을 나타냈고, 생육단계별로는 대부분의 품종에서 ABTS 소거능에 큰 차이를 보이지는 않았다. SOD 활성은 모든 품종과 전 생육단계에서 95% 이상의 높은 활성을 보였으며, 품종 간에 거의 유의한 차이를 나타내지 않았다. CAT 활성은 전체적으로 장죽청장과 늘푸른청장 품종이 그리고 APX 활성은 늘푸른청장, 장형낙합 품종에서 상대적으로 높은 활성을 나타냈고, POX 활성은 생육단계별로 뚜렷한 경향을 보여 수확기에 이를수록 활성이 현저히 감소하는 결과를 나타냈다. 본 실험의 결과, 오이의 높은 항산화능을 확인함으로서 향후 향장소재 및 식품소재로서의 이용 가치성을 증대시킬 수 있음을 시사한다.

• Journal of Applied Biological Chemistry
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• 제53권1호
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• pp.8-12
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• 2010

The antioxidant activity of hawthorn fruit (Crataegus pinnatifida Bunge var. typica Schneider) extracts was investigated by several in vitro antioxidants properties, including DPPH free radical scavenging activity, total phenolic and flavonoid contents, hydroxyl radical scavenging activity, reducing power activity, iron-chelating capacity and nitrite scavenging activity. Among the extracts in this study, the 70% EtOH extract showed higher antioxidant activity than the others. The $IC_{50}$ value of DPPH free radical scavenging activity was $99.26\;{\mu}g/mL$. Furthermore, the 70% EtOH extract also showed significantly high total phenolic and flavonoids contents and reducing power activity. However, the MeOH extract exhibited stronger effects on hydroxyl radical scavenging activity, iron-chelating capacity and nitrite scavenging activity. All the results implicated that, the hawthorn fruit may has the available potential to be utilize as a potential source of natural antioxidant.

• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.10-16
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• 2006

Radical scavenging and antioxidant activities of Laminaria japonica and fermented its extracts were evaluated. Freeze-dried L. japonica was fermented by Aspergillus oryzae and extracted with distilled water. The extract solution was mixed with ethanol and centrifuged. The supernatant was ethanol soluble fraction, non-polysaccharide fraction (ESF), and residue was ethanol insoluble precipitation, polysaccharide fraction (EIP). ESF was subjected to sequential fractionation with dichloromethane, ethyl acetate, butanol and water. To determine the radical scavenging and antioxidant activities of these, DPPH radical, hydroxyl radical, superoxide anion radical scavenging activities and linoleic acid oxidation were tested. Among the extracts, ESF of fermented L. japonica showed the highest radical scavenging activity. The ESF showed DPPH radical scavenging activity of 64.33% at concentration of $50{\mu}g/mL$. It was higher than 57.70% of vit. C. Ethyl acetate and butanol fraction had high value of radical scavenging and antioxidant activities, especially butanol fraction of fermented L. japonica was 79.48 % of hydroxyl radical scavenging activity at concentration of $50{\mu}g/mL$. The fermented L japonica had radical scavenging and antioxidant activities higher than L. japonica. These results suggest that fermented L japonica is healthy food having radical scavenging and antioxidant activities.