• Korean Journal of Plant Resources
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• v.10 no.3
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• pp.227-230
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• 1997

The authors isolated four olefinic catechols, commonly referred to as urushiol, from the sap of Korean lacquer tree(Rhus vernicifera STOKES) with stronger antioxidative activities than $\alpha-tocopherol$. The hexane extract with a free radical scavenging activity was purified by silica and ODS gel column chromatography. The active compounds were identified by MS and $^1H-NMR$ as 3-[8'(Z),11'(Z),14'-pentadecatrienyl]catechol, 3-[8'(Z),11'(Z)-pentadecadienyl]catechol, 3-[8'(Z)-pentadecenyl] catechol, and 3-pentadecylcatechol. All of these compounds showed strong free radical scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, in which 3-pentadecylacatechol exhibited the highest activity ($IC_{50}$: $1.2{\mu}g/ml$). They also showed a significant inhibitory activity on lipid peroxidation ($IC_{50}$: 2.1 - 3.5 ${\mu}g/ml$). The antioxidative activity of 3-pentadecylcatechol on DPPH radical and lipid peroxidation is approximately two times greater than that of $\alpha$-tocopherol. The results suggest that the urushiol derivatices may contribute to the preservative characteristics effective against oxidative stress and could be a good source for industrial applications including a coating material.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.402-407
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• 2018

In this study, we investigated the antioxidative effects of AY by measuring 1.1-Diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\cdot}OH$), and superoxide radical ($O_2{^-}$) scavenging activities in vitro. AY was extracted with ethanol and then partitioned with n-hexane, methylene chloride ($CH_2Cl_2$), ethylacetate (EtOAc) and n-butanol (n-BuOH). In the DPPH radical scavenging assay, AY at concentrations of 10 to $100{\mu}g/mL$ dose-dependently increased inhibition of DPPH oxidation, with the EtOAc fraction of AY showing the highest DPPH radical scavenging activity fractions. The $^{\cdot}OH$ radical scavenging activities of the extract and four fractions of AY increased by over 80% at a concentration of $50{\mu}g/mL$. In particular, the IC50 value of the EtOAc fraction was $0.03{\mu}g/mL$, which was the lowest value among all fractions. We also found that the EtOAc fraction of AY was better at $O_2{^-}$ radical scavenging than other fractions. Taken together, these results suggest that AY, especially the EtOAc fraction, can be used as a natural antioxidant against free radicals.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.1
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• pp.95-108
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• 2021

Objectives This study was conducted to investigate the beta-glucan, ginsenoside content, antioxidant activity and safety of modified Kyungohkgo added to Sparassis crispa and Hericium erinaceum. Methods The marker compounds contents, antioxidant activity and safety of modified Kyungohkgo were tested. The contents of beta-glucan and ginsenoside Rb1, Rg1, and Rg3 marker compounds were measured, the antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and a safety test was conducted via single dose toxicity assessment. Results Analyzing the contents of marker compounds showed 351.75 mg/g of beta-glucan, 0.0327 mg/g of ginsenoside Rb1 and 0.0802 mg/g of ginsenosai Rg3. In the DPPH free radical scavenging activity, the inhibition concentration 50% of modified Kyungohkgo was 0.2880%. The scavenging activity of modified Kyungohkgo was 5.49% activity at 0.05% concentration, 89.66% activity at 0.5% concentration, 94.68% activity at 1% concentration, and 96.06% activity at 5% concentration. In the single dose toxicity test of modified Kyungohkgo, a dose of 2,000 mg/kg B.W. was set at its highest capacity and observed after oral administration to female and male rats. No toxicological findings were recognized. It was observed that the resulting lethal dose can be set to 2,000 mg/kg B.W. or higher for both females and males. Conclusions The results of the experiment on modified Kyungohkgo showed that the marker compounds contents were beta-glucan and ginsenoside Rb1 and Rg3, that antioxidant activity was observed through the DPPH free radical scavenging activity, and safety was confirmed through the single dose toxicity assessment.

• The Korean Journal of Community Living Science
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• v.19 no.3
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• pp.365-371
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• 2008

This study was conducted to determine the potent physiological activity of traditional wild tea ("Don tea"; coin-shaped tea) as affected by different harvesting times, aging periods and extracting temperatures, No difference in anti-oxidative activities in the harvesting time and extracting temperature of tea leaves was observed. However, short aging periods of Don tea showed high ABTS {2-2-azonobis (3-ethylbenzothiazolin-6-sulphonic acid)} activity, ranging from 71.52 to 79.96%. DPPH (${\alpha},\;{\alpha}-diphenyl-{\beta}-picryl-hydrazyl$) radical scavenging activity of Don tea was 71.10 to 91.40%. Especially, longer aging period and an extracting temperature of $100^{\circ}C$ showed higher DPPH radical scavenging activity. With longer aging periods and an extraction at $90^{\circ}C$, nitrite radical scavenging activity of Don tea ranged from 74.04 to 94.92%. On the other hand, angiotensin 1-converting enzyme (ACE) inhibition activity of Don tea was 59.77-81.97%. It showed higher activity when harvested in June and August, aged for longer periods, and extracted at $100^{\circ}C$. These results suggested Korean traditional Don tea exhibited the highest physiological activity when aged over 8 months.

• Food Science and Preservation
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• v.18 no.1
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• pp.59-64
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• 2011

This study was performed to investigate antioxidant activity of various solvent extracts (methanol, ethanol, acetone and water) from canola meal. As the concentration of all extracts increased, antioxidant activities increased gradually. Among solvent extracts from canola meal, methanol extract showed the highest antioxidant activities with $EC_{50}$ values of 0.9, 3.5, 1.3, and 8.5 mg/mL for DPPH radical scavenging ability, ABTS radical scavenging ability, reducing power, and chelating ability, respectively, and it had the highest total phenolics and total flavonoids contents. Furthermore, methanol extract was fractionated into three fractions (MF 1, MF 2, and MF 3) using Sephadex LH-20 column. The highest antioxidant activity was found on MF 2 for DPPH radical scavenging ability, on MF 3 for ABTS radical scavenging ability and reducing power, and on MF 1 for chelating ability at the same concentration of 1.5 mg/mL. The results indicated that each fraction containing various antioxidant materials seemed to have different influence at each antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.997-1002
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• 2013

This study investigated the physicochemical properties (pH, Brix), total phenol content, antioxidant activities (DPPH radical scavenging activity and oxygen radical absorbance capacity (ORAC)), and nitrite scavenging activity of beverage concentrates and purees. All concentrates and purees were produced from natural materials and have been used as the main ingredients in health-related beverages. Our results show that the pH values and Brix of all concentrates and purees ranged from 2.81 to 5.12 and 1.70 to 70.30 Brix, respectively. The highest total phenol content (182.71 mg GAE/mL), DPPH radical scavenging activity (69.88%) and nitrite scavenging activity (28.19%) were obtained from acai berry puree. The concentrate from wild blueberry had the highest ORAC value ($27,514{\mu}M$ TE/mL). Among the correlation coefficient data, the total phenol content exhibited a high correlation coefficient (r=0.9099) and DPPH radical scavenging activity. These results suggest that concentrates and purees from natural materials contribute to antioxidant activities in healthy beverages.

• Biomedical Science Letters
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• v.14 no.1
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• pp.33-38
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• 2008

In order to examine oxidative stress of reactive oxygen species and the antioxidant effect of Citri Reticulatae Pericarpium (CRP) extract, human skin melanoma cells were treated with various concentrations of hydrogen peroxide ($H_2O_2$). Antioxidant effect of CRP extract on $H_2O_2$-induced cytotoxicity, cell viability, DPPH-radical scavenging activity and superoxide dismutase (SOD)-like activity. In this study, $H_2O_2$ decreased cell viability of cultured human skin melanoma cells in dose- and time-dependent manners, and then, midcytotoxicity value (MCV) was determined at $60\;{\mu}M$ after human skin melanoma cells were cultured for 5 hours in the media containing $20{\sim}60\;{\mu}M$ of $H_2O_2$, respectively. The $H_2O_2$ was on cultured human skin melanoma cells because MCV of $H_2O_2$ was lower than $100\;{\mu}M$. In the antioxidant effect of CRP extract, CRP extract increased cell viability DPPH-radical scavenging activity and SOD-like activity. From these results, it is suggested that $H_2O_2$ was very toxic on cultured human skin melanoma cells. And also, CRP extract has the antioxidant effect on $H_2O_2$-induced cytotoxicity.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.237-240
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• 2008

The antioxidant activities of aroma extracts from commercially available red wines in Korea were evaluated. The aroma extracts of the red wines were extracted by simultaneous steam distillation. Antioxidant activity was measured by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid) radical cation scavenging activity. DPPH radical scavenging activity of the aroma extracts in the red wines increased with increases in the amount of wine used for aroma extraction. Antioxidant activities of domestic wine 1, imported wine 7, and imported wine 12 were 97.16, 96.72 and 94.52%/20 mL wine by DPPH assay and 7.09, 8.07 and 7.28 mg ascorbic acid equivalents per mL wine by ABTS assay, respectively. This study demonstrates potent antioxidant activities of the aroma extracts of commercially available red wines in Korea.

• Journal of Applied Biological Chemistry
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• v.48 no.3
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• pp.144-147
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• 2005

DPPH and ABTS radical scavenging, and tyrosinase inhibitory activities of bioactive compounds 1-4 isolated from Cedrela sinensis leaf were assessed. Structures of isolated compounds were established by UV, one- and two-dimensional NMRs, and mass spectroscopic methods.

• KSBB Journal
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• v.29 no.4
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• pp.271-277
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• 2014

In this study, crude extract of the seagrass Zostera japonica, and its solvent-partitioned fractions were evaluated for their antioxidant activity. The crude extract was successively fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions by liquid-liquid partition. These include DPPH radical scavenging, hydroxyl radical scavenging in HT-1080 cells, peroxynitrite scavenging, and protective effect on DNA damage caused by hydroxyl radicals generated. In all assays, except for DPPH radical, 85% aq.MeOH and n-BuOH fraction showed the strong antioxidant activity. These results suggest that Z. japonica may be used as a potential source of natural antioxidants for the development of cosmetic product or functional food in the future.