• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.86-89
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• 2009

In this study, we investigated the free radical [1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (${\cdot}OH$) and superoxide anion (${O_2}^-$)] scavenging activity of MeOH extract and 3 fractions of Citrus junos. Of the tested fractions, the BuOH fraction showed the strongest DPPH scavenging activity, showing the $IC_{50}$ values of 63.4 mg/mL. Therefore, we continuously carried out DPPH, ${\cdot}OH$ and ${O_2}^-$ scavenging activity tests of BuOH fraction of Citrus junos. The BuOH fraction of Citrus junos inhibited DPPH radical to 97.5% at a concentration of 1000 mg/mL and the scavenging activities were increased concentration-dependently. In addition, BuOH fraction from Citrus junos also scavenged ${\cdot}OH$ in a concentration dependent manner from 5 to 1000 mg/mL. Furthermore, BuOH fraction showed about 56% ${O_2}^-$-scavengimg activity at 25 mg/mL concentration but, the scavenging activities were not enhanced in a dose dependent manner. The present results suggest that BuOH fraction of Citrus junos would have the protective potential from oxidative stress induced by free radicals.

• Archives of Pharmacal Research
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• v.29 no.3
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• pp.199-202
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• 2006

From the leaves of Goniothalamus tenuifolius, a new natural product namely 3'-hydroxy-3,5,7,4'-tetramethoxyflavone (1) was isolated, along with seven other known compounds (2-8). Each of these isolates was evaluated for free radical scavenging activity on the DPPH decoloration test. The data obtained in this study suggested that the ortho 3',4'-diphenolic structure was essential for the activity of these flavonol derivatives.

• Advances in Traditional Medicine
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• v.8 no.4
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• pp.329-338
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• 2008

The aim of the study is to investigate the antioxidant activity through, reducing power, 2, 2-diphenyl-1-picryl hydrazyl radical (DPPH), nitric oxide radical (NO), superoxide radical, hydrogen peroxide radical ($H_2O_2$) scavenging activity and the amount of total phenolic compounds of chloroform, ethyl acetate, methanol and aqueous extracts of the leaves of Talinum portulacifolium. Chloroform extract of leaves of T. portulacifolium showed highest antioxidant activity, with a direct relationship between activity and concentration of extracts ($15-240\;{\mu}g/mL$). Among all the extracts, the highest amount of the total polyphenolic compounds was found in the chloroform extract. Chloroform extract of T. portulacifolium showed an important free radical scavenging activity towards the DPPH, NO, Superoxide and $H_2O_2$ radicals, with $IC_{50}$ values of 133.26, 165.75, 156.34 and $135.29\;{\mu}g/mL$, respectively. In the lipid peroxidation assay, extracts of chloroform and ethyl acetate showed a remarkable inhibitory activity. The extracts showed significant activity in all the experiments but lower than the standard antioxidant, ascorbic acid.

• ALGAE
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• v.18 no.4
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• pp.341-347
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• 2003

The potential antioxidative activity of water-soluble enzymatic hydrolyzates from a kelp, Ecklonia cava was evaluated by free radical scavenging and lipid peroxidation assays. To prepare water-soluble hydrolyzates from E. cava the seaweed was enzymatically hydrolyzed by five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase). Among all the hydrolyzates, Celluclast hydrolyzate effectively scavenged free radicals released from DPPH (1,1-diphenyl-2- pricrylhydrazyl) and recorded around 73% scavenging activity at the concentration of 4 mg ${\cdot}ml^{-1}$. This hydrolyzate was thermally stable and DPPH radical scavenging activity remained 80% or higher at heating temperatures of 40 and 60$^{\circ}C$ up to 12 h and around 80% at 100$^{\circ}C$ up to 8 h. AMG and Ultraflo hydrolyzate inhibited the lipid peroxidation of fish oil as that of $\alpha$-tocopherol. These results suggested that an enzymatic extraction will be an effective way for the production of a potential antioxidant from seaweeds.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.351-356
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• 2006

In this study, we investigated the effect of adding a 1, 3, or 5% solution of germinated brown rice concentrate (GBRC) to fermented kimchi. During fermentation, the concentration of free amino acids and essential amino acids increased with increasing concentrations of GBRC. In particular, higher levels of free amino acids were associated with a sweet taste compared with controls. The ${\gamma}$-aminobutyric acid (GABA) content of kimchi containing the 5% GBRC solution was 3 times higher than that of controls. The total phenolic compound content (130 mg%) did not change significantly in the control group, but increased in 10 mg% increments as the GBRC concentration rose from 1 to 3 to 5%. 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity and superoxide radical scavenging activity also increased with the GBRC concentration, with maximum activity during the ripe stage with GBRC measured at 79 to 82% compared with controls (30 to 71 %). The nitrite scavenging activity was 10% higher with GBRC compared with controls and was highest when the pH was 1.2. These results showed that the addition of GBRC is effective in improving the function of kimchi.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.405-410
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• 2006

A series of aqueous or methanol extracts from four different Korean salad plants were assayed to determine their allelopathy and antioxidant activity. The extracts applied on filter paper in a Petri-dish bioassay significantly inhibited root growth of against alfalfa (Medicago sativa) seedlings. Leaf extracts from 40 g dry tissue $L^{-1}$ of Aster yomena was most phytotoxic to alfalfa root growth, and followed by that of Cirsium japonicum, Taraxacum officinale, and Ixeris dentate. Methanol extracts of plants dose-dependently increased DPPH free radical scavenging activity in vitro. Antioxidant activity of methanol extracts from the same plant species was investigated, and the result showed high DPPH free radical scavenging activity in Cirsium japonicum, Aster yomena, and Ixeris dentate, however, in Taraxacum officinale was least activity. By means of HPLC analysis, chlorogenic acid, p-coumaric acid, and total phenolics with 7.68, 17.47 and 18.64 mg, $100g^{-1}$, respectively, showed the highest amounts in methanol extracts from Cirsium japonicum leaves. These results suggest that Compositae salad plants contain water-soluble substances with allelopathic potential as well as antioxidant activity.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.511-514
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• 2012

In this study, the comparison of antioxidative effect of the methanol (MeOH) extracts from grains were investigated in vitro radical scavenging system. Ten grains (black rice, rice, barley, wheat, millet, sorghum, glutinous millet, buckwheat, phellines linteus rice and brown rice) were extracted with MeOH. Among the MeOH extracts of grains, sorghum and black rice showed effective scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The $IC_{50}$ values of sorghum and black rice were $47.4{\mu}g/mL$ and $50.6{\mu}g/mL$, respectively. In addition, black rice also exerted the strongest activities on hydroxyl radical (${\cdot}OH$) scavenging activity. Furthermore, the MeOH extracts of black rice showed effective and dose dependant scavenging activities of DPPH radical and ${\cdot}OH$. These results indicated that black rice showed strong free radical scavenging activity. It suggested that black rice could be a promising natural antioxidant against free radical-induced oxidative damage.

• Korean Journal of Medicinal Crop Science
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• v.21 no.3
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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.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.548-556
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• 2013

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of cucumber grown greenhouse. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging, nitrite scavenging ability activity and ABTS radical scavenging ability. The DPPH free radical scavenging activity of Jangjukcheongjang was the highest in most of the growth stage. The Nitrite scavenging ability at pH 1.2 was more than 40% in all cultivars and growth stages. The ABTS radical scavenging ability of Jangjukcheongjang and Nulpureuncheongjang showed relatively little higher than Janghyeongnakhap and Sinjoeunbaekdadagi. The SOD activity showed higher activity than 95% in all cultivars and growth stages. The activity of CAT was highest in the Nulpureuncheongjang of 2 (12~16cm) growth stage, and the APX activity of Nulpureuncheongjang and Janghyeongnakhap showed a relatively high activity. The POX activity showed distinctly different trends depending on the growth stage, and that is, the activity at harvest stage was significantly reduced. These results suggest that the cucumber had the potent biological activities, and that in the future, the availability of cucumber will be increase in the field of high-value cosmetic and food products.

• KSBB Journal
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• v.25 no.1
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• pp.55-61
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• 2010

To investigate antioxidant activity of the culture broth from submerged culture of Tremella fuciformis, we preferentially analyzed the chemical composition of culture broth, which was mainly composed of carbohydrate (296.39 mg/g) and protein (9.24 mg/g), respectively. Also, contents of polyphenols, flavonoids and flavonols were 16.63 mg/g, 9.19 mg/g and 83.74 ${\mu}/g$, respectively. Next, we examined the scavenging abilities on DPPH (1,1-diphenyl-2-picrylhydrazyl) radical, ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) radical, the reducing power, and chelating ability on ferrous ions. All antioxidant activities of the culture broth were increased in proportion to its concentrations. The $IC_{50}$ values were in order as follows ABTS radical scavenging activity < OPPH radical scavenging activity < chelating power. Accordingly, these results suggest that pharmacological function of T. fuciformis might be due to, at least partially, their protective effects against oxidation and the culture broth of T. fuciformis was free radical inhibitors or scavengers at low concentration, involving possibly in termination of free radical reaction as primary antioxidants.