• 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.

• Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.71-75
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• 2008

The shell of Reeve's turtle has been used as a traditional folk medicine in Korea. We produced a hot water extract from Reeve's turtle shell according to the traditional medical practice. To release bioactive peptides, the hot water extract was enzymatically hydrolyzed with various proteases, and the free radical scavenging activity of the hydrolysate was investigated against 1,1-diphenyl-2-picryl-hydrazyl (DPPH), hydroxyl and peroxyl radicals. The free radical scavenging activity of the enzymatic hydrolysates varied from 1 to 79% depending on the enzymes, free radical species, and concentration. The $EC_{50}$ values demonstrated that the enzymatic hydrolysates of hot water extract from the shell of Reeve's turtle are potential antioxidants.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.300-305
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• 2002

The EtOAc and n-BuOH soluble fractions from the aerial part of Setaria viridis showed a strong free radical scavenging activity. Six major compounds were isolated from these fractions. They were identified by spectral data as tricin (1), p-hydroxycinnamic acid (2), vitexin 2"-Ο-xyloside (3), orientin 2"-Ο-xyloside (4), $tricin-7-Ο-{\beta}-D-glucoside$ (5) and vitexin 2"-Ο-glucoside (6). Among these compounds, 4 and 5 exhibited strong free radical scavenging activities on 1, 1-diphenyl-2-picrylhydrazyl (DPPH). We further studied the effects of these isolated compounds on the lipid peroxidation in rat liver microsomes induced by non-enzymatic method. As expected, 4 and 5 exhibited significant inhibition on $ascorbic/Fe^{2-}$ induced lipid peroxidation in rat liver microsomes.ver microsomes.

• ALGAE
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• v.21 no.1
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• pp.149-156
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• 2006

The aim of the present study was to evaluate the antioxidant activity of red algae in Jeju Island. The algal extracts were obtained with MeOH and fresh water at 20 and 70°C, and screened for antioxidant activities using hydroxyl radical (HO·), superoxide anion (O2–), hydrogen peroxide (H2O2) and DPPH free radical scavenging assays. Among them, Gracilaria verrucosa methanolic extract at 20°C (20ME, 96.85%), G. textorii aqueous extract at 20°C (20AE, 88.01%), Grateloupia filicina 20AE (85.35%), and Polysiphonia japonica 20ME (94.92%) exhibited the highest scavenging activities against HO·, O2–, H2O2, and DPPH free radicals, respectively. Moreover, P. japonica (20ME and 70ME) is correlated between DPPH free radical scavenging activity and polyphenolic contents. These results indicate that some red algae in Jeju Island could be potential candidates for development of antioxidants.

• Advances in Traditional Medicine
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• v.4 no.3
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• pp.187-195
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• 2004

A number of plants from different geographical origins have been shown to possess antioxidant activity. Some of them have been developed as natural antioxidant formulations for food, cosmetic and other applications. Bangladeshi flora is a rich source of a range of plant species, many of which are medicinal plants, and have been used in the preparations of the Unani and Ayurvedic traditional medicines. There are no, or just a few, reports on any systematic screening of the extracts of Bangladeshi plants for free radical scavenging activity using DPPH assay available to date. As part of our on-going search for biological activity in Bangladeshi plants, Kadam (Anthocephalus chinensis), Goran (Ceriaps decandra), Swarnalata (Cuscuta reflexa), Gab (Diospyros peregrina), Sundari (Heritiera fomes), Dhundul (Xylocarpus granatum) and Possur (Xylocarpus mekongensis) have been selected for the assessment of their free radical scavenging activity, and studies on the contents of alkaloids, anthraqunones, flavonoids and tannins in these extracts. Most of these species have been used in traditional medicine in Bangladesh and other countries for the treatment of various illnesses ranging from common cold to cancer. All extracts, except the methanol extract of Cuscuta reflexa, displayed significant free radical scavenging activity in the DPPH assay $(RC_{50}$ values within the range of $2.75\;{\times}\;10^{-2}\;to\;4.7\;{\times}\;10^{-3}\;mg/mL)$. Among these extracts, the methanol extract of Xylocarpus granatum exhibited the most potent activity $(4.7\;{\times}\;10^{-3}\;mg/mL)$ and that of Cuscuta reflexa had the least activity $(1.64\;{\times}\;10^{-1}\;mg/mL)$. While none of these plants showed positive tests with Dragendorff's reagent, presence of low to moderate amounts of phenolic compounds, e.g. anthraquinones, flavonoids and tannins was evident in all of these plants, except for the methanolic extracts of C. reflexa and the barks of D. peregrina, which did not display any evidence for the presence of flavonoids and anthraquinones, respectively.

• Korean Journal of Medicinal Crop Science
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• v.8 no.4
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• pp.373-377
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• 2000

Two antioxidative compounds in leaves of Castanea crenata were isolated by a bioassay using a DPPH free radical. They were identified as quercitrin, isoquercitrin on the basis of $^1H$ and $^{13}C-NMR$ and MS data. The DPPH radical scavenging activity $(RC_{50}\;:\;12\;{\mu}g)$ of two compounds was similar to that of ${\alpha}-tocopherol\;(12{\mu}g)$ and BHA $(14{\mu}g)$.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.854-858
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• 2005

Methanol and water crude extracts, crude polysaccharides and crude polysaccharides-free of water crude extracts from Shiitake mush-room (Lentinus edodes) were investigated for their antioxidant capacity in total polyphenolics and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Total polyphenolics in the crude polysaccharides-free of water crude extracts were higher than that of the other ones. And crude polysaccharides-free of water crude extracts and water crude extracts show high on DPPH free radical scavenging activity. Positive correlations were found between total polyphenolics and their antioxidant activity.

• Ocean and Polar Research
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• v.34 no.3
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• pp.297-304
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• 2012

Pylaiella littoralis was collected in the Chuuk lagoon of the Federated States of Micronesia (FSM). The FSM has a variety of coral reef ecosystems, which provide essential materials, such as minerals, vitamins, essential amino acids, for marine organisms. In this study, the antioxidant activities of ethanol and enzymatic extracts of P. littoralis were evaluated by measuring their scavenging activities on DPPH free radical, Alkyl radical, hydroxyl radical and cell viability. The enzymatic extracts were hydrolyzed to prepare water soluble extracts by using five carbohydrate degrading enzymes (AMG, Celluclast, Termamyl, Ultraflo, and Viscozyme) and five proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase, and Protamex). As a result, the enzymatic extracts prepared by Flavourzyme, Ultraflo, and Kojizyme exhibited the greatest effects in DPPH free radical, alkyl radical scavenging activity and cell viability. Also, these enzymatic extracts had a higher antioxidant effect then commercial antioxidants in DPPH free radical and Alkyl radical scavenging activity. This study suggests that P. littoralis might be a useful source of natural antioxidants for the development of dietary supplements.

• Korean Journal of Pharmacognosy
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• v.33 no.1 s.128
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• pp.18-20
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• 2002

Assay-guided fractionation of the methanol extract of the leaves of Albizzia julibrissin has furnished quercitrin (1) and afzelin (2) as the scavengers of DPPH radical. Quercitrin and afzelin showed scavenging activity of DPPH free radical with the $IC_{50}$ values of 17.3 and 71.5 ${\mu}M$, respectively.

• Preventive Nutrition and Food Science
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• v.15 no.1
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• pp.44-50
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• 2010

Hawthorn fruit is a conventional medicine used in treating cardiovascular diseases. Its therapeutic effects may relate to its antioxidant compounds. In this study, we evaluated the antioxidant activity of $CH_2Cl_2$, EtOAc, n-butanol and water fractions from 70% methanolic hawthorn fruit extract by total phenolic and flavonoid contents, total antioxidant activity, DPPH free radical scavenging activity, superoxide radical scavenging activity, reducing power assay, lipid peroxidation inhibitory activity and protective effect against hydroxyl-radical-induced DNA damage. Results showed that the EtOAc fraction contained significantly greater antioxidant activities than other fractions, which suggests that the potent EtOAc fraction should be used for further studies to identify the antioxidant compounds.