• Korean Journal of Pharmacognosy
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• v.33 no.3 s.130
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• pp.177-181
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• 2002

This study was carried out to investigate the antioxidative activities of Rosa davurica Pall for the purpose of development of novel antioxidant from natural products. Antioxidant activities of four different parts of Rosa davurica Pall such as fruit, leaf, stem and root were examined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The methanol extract from the root of Rosa davurica Pall showed the highest antioxidative activity among 16 samples tested. And, we also tested radical scavenging effects of 5 different extract compartments(Hexane, $CHCl_3$, EtOAc, BuOH and $H_2O$ fraction). EtOAc and BuOH fractions from the root of Rosa davurica Pall exhibited antioxidative activities higher to those of natural, ${\alpha}-tocopherol$ or synthetic antioxidants, BHT. The antioxidative substance of EtOAc fraction from the root of Rosa davurica Pall was successively purified with silica gel adsorption column chromatography and Sephadex LH-20 column chromatography. The purified active substance was isolated as crystal and identified as (+)-catechin by $^{l}H-NMR$ and $^{13}C-NMR$. This compound exhibited DPPH radical scavenging activity with the $IC_50$ value of $1.7\;{\mu}g/ml$. In the analysis of catechin content, the leaf extracts contained the highest catechin, and fruit extracts contained the lowest catechin. Considering antioxidative activity on DPPH assay, the extracts of Rosa davurica Pall showed a possibility to be used as a new material for natural antioxidant and functional food.

• Journal of Applied Biological Chemistry
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• v.48 no.3
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• pp.138-143
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• 2005

Antibacterial, free radical scavenging, proliferative, and cytotoxicity effects of Doenjang extracts were examined. All samples except water extract showed strong antibacterial activity against oral bacteria, Streptococcus. pyogenes, S. mutants, S. sanguinis, S. sorbrinus, S. criceti, S. antinosus, S. gordonii, and Porphyromonas. gingivalis (MIC and MBC values: 0.08-1.25 and 0.16-2.50 mg/ml, respectively). DPPH method showed ethanol and ethyl acetate extracts are effective inhibitors of oral bacteria. Based on MTT assay, 24 h exposure to 0.31 mg/ml of all extracts, excepted water extract, resulted in strong cytotoxicity on KB cells. All extracts strongly inhibited human gingival fibroblast viability.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.637-638
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• 2006

Bioassay-guided fractionation of an organic extract of the culture broth from an unidentified marine-derived fungus led to the isolation of a new metabolite, N-[2-(4-hydroxyphenyl) acetyl]formamide (1), along with four known polyketides, 4-hydroxyphenyl acetamide (2), 4-hydroxyphenyl acetic acid (3), 3,4-dihydroxyphenyl acetic acid (4), and N-[2-(4-hydroxyphenyl)ethenyl]formamide (5). The structures of 1-5 were elucidated by spectral data analyses. Among them, compounds 1, 4, and 5 exhibited significant radical scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 8.4, 11.9, and $0.2{\mu}M$, respectively.

• Journal of Mushroom
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• v.17 no.3
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• pp.136-143
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• 2019

In this study, we analyze the antioxidant and anti-inflammatory activities of various extracts of Cryptoporus volvatus. Three extracts were prepared using hot-water, 70% ethanol, and 70% methanol. Compared to the hot-water and 70% methanol extracts, the 70% C. volvatus ethanol extracts showed significantly higher DPPH radical scavenging activities (76.1%), nitrite scavenging activities (29.5%), and total polyphenol content (9.17 mg GAE/g). The DPPH radical and nitrite scavenging activities of C. volvatus both correlated significantly with the total polyphenol content. The Pearson's correlation coefficient of DPPH radical and nitrite scavenging activities with total polyphenol content were r = 0.744 (p<0.05) and r = 0.921 (p<0.01), respectively. To test their anti-inflammatory effects, nitric oxide production and cell viability were measured by performing nitric oxide (NO) and MTT assays on lipopolysaccharide-treated RAW 264.7 cells. The NO production levels of the 70% ethanol extract-treated cells were slightly lower than those of the others. In our MTT assay, the hot-water extracts showed higher cell viabilities (81.4%) than those of 70% ethanol and 70% methanol extracts. The ${\beta}$-glucan content of C. volvatus was 37.8%. From the results of this study, it is suggested that C. volvatus, an easily accessible wild mushroom, has potential to be used in the development of medicines, cosmetics, and functional health foods.

• Natural Product Sciences
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• v.14 no.3
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• pp.202-205
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• 2008

The antioxidant activity of Paeonia suffruticosa (Paeoniaceae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of P. suffruticosa showed the strong antioxidant activity. The antioxidant activity of ethyl acetate soluble fraction was stronger than that of the others ($IC_{50}$, $1.2\;{\mu}g/mL$), and the fraction was subjected to purification by repeated silica gel and Sephadex LH-20 column chromatography. Suffruticosol A, suffruticosol B, methyl gallate, and gallic acid, were isolated from the ethyl acetate soluble fraction. Their structures were elucidated by physico-chemical and spectroscopic studies.

• Archives of Pharmacal Research
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• v.25 no.4
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• pp.449-452
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• 2002

The antioxidant activity of Juniperus chinensis (Cupressaceae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of J. chinensis heartwood showed the strong antioxidant activity. The antioxidant activity of n-BuOH soluble fraction was stronger than that of the others, and the fraction was subjected to purification by repeated silica gel and Sephadex LH-20 column chromatography. Quercetin, naringenin, taxifolin, aromadendrin and isoquercitrin were isolated from the n-BuOH fraction. Their structures were elucidated by physico-chemical and spectroscopic studies.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.33-40
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• 2017

Objectives : The objective of this study is to evaluate antioxidant activity of water extracts from steamed Polygonati Rhizoma(PR). Methods : The alcohol steamed PR from Jinju-si, Gyeongsangnam-do and Samcheok-si Gangwon-do are treated for the research into the antioxidant activity of the water extract. The sample was divided into 4 groups that PR without steaming process, PR with once, second and third steaming process. The antioxidant activities of polyphenol, flavonoid, DPPH, SOD, hydroxyl radical and nitrite scavenging activity. Results : The total content of polyphenol was the grow rapidly when the number of steaming adds up. For the third time, both the steamed PR from Jinju-si and the one from Samcheok-si in the water extract indicate the highest content levels measured $50.59\;mg/m{\ell}$ and $37.33\;mg/m{\ell}$ respectively. The more the number of steaming increases, the more rising the content of flavonoid. The steamed PR from Jinju-si and Samcheok-si in the third time are measured $30.03\;mg/m{\ell}$ and $54.9\;mg/m{\ell}$ respectively. DPPH radical scavenging activity of the steamed PR rises high rather than the non-steamed one when the number of steaming increases. As increase steaming time, SOD like activity and hydroxyl radical scavenging ability were increasing too. The steamed PR from Jinju-si in the third time is measured as the highest level 22.4%, 71.90% respectively. As increase steaming time, nitrite scavenging ability was the number was decreased. Conclusions : These results suggest that water extracts from steamed PR, exhibited higher antioxidant activities can be potentially used as proper natural antioxidants.

• Journal of Life Science
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• v.24 no.4
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• pp.386-392
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• 2014

Haw (Crataegus pinnatifida $B_{UNGE}$) is a medicinal plant commonly used in Korea due to its beneficial health effects. This study was performed to investigate the antioxidative activity of bioactive components from haw seed. Freeze-dried seed was processed with various solvents such as 70% methanol, 70% ethanol, a mixture of chloroform and methanol (2:1, v / v), n-butanol and ethyl acetate (EA). DPPH, reducing power, ferric reducing antioxidant power (FRAP), and ABTS radical scavenging activity decreased in this order: 70% methanol, 70% ethanol, EA, CM, n-butanol extracts. NO radical scavenging activity was high in the n-butanol extract (36.73% in 0.8 mg/ml concentration) and low in the 70% ethanol extract (24.96% in 0.8 mg/ml concentration). $OH^-$ radical scavenging activity of n-butanol extract (40.42% in 0.8 mg/ml concentration) was higher than the other extracts, but EA extract was the lowest (13.39%) at the same concentration. The results show that each extract contained various antioxidative substances and it seemed that different influence at each antioxidative activity.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1216-1220
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• 2003

The antioxidative activities of methanol extracts of chestnut flower (Castanea Crenata Flos.) were determinated in vitro using an experimental model system. Solid yield of chestnut flower extracts was 6.26% and total phenolic acid accounted for about 20% of the crude extract. The DPPH radical scavenging activity of methanol extracts prepared from chestnut flower was 17.22%. Although the DPPH radical scavenging activity of chestnut flower extracts was lower than that of other antioxidants, chestnut flower extracts showed continuous activity by time course. The SOD-like activities of methanol extracts prepared from chestnut flower were 65.10%, 95.70% in BHT, 93.29% in quercetin, and 30.30% in ascorbic acid. Chestnut flower extracts showed 51.45% inhibitory effect on peroxidation of egg yolk lecithin.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.1018-1027
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• 2019

Natural-derived protein-derived low molecular weight peptides have been known to have physiological activities such as antioxidant, hypertension relief, immunomodulation, pain relief and antimicrobial activity. In this study, the low-molecular peptides were produced using commercial proteases (alcalase, bromelain, flavourzyme, neutrase, papain, protamex), and the antioxidant activity (DPPH scavenging activity, superoxide radical scavenging activity, hydroxy radical scavenging activity, and metals chelation capacity), constituent amino acid and molecular weight of the peptide were analyzed. Enzyme reaction was performed by adding 50 g of chopped Ogae meat slurry and 2%(w/v) protein enzyme into the enzyme reactor for 2 h at a pH of 6 and a temperature of $60^{\circ}C$. The degree of hydrolysis(%) after the reaction ranged from $36.65{\pm}4.10%$ to $70.75{\pm}5.29%$. The highest degree of hydrolysis of protamex was 46.3%, and the highest value of papain hydrolysate was $70.75{\pm}5.29%$. On the other hand, alcalase hydrolysate showed the lowest value of $36.65{\pm}4.10%$. Bromelain-treated low molecular weight peptides showed the highest DPPH radical scavenging activity and the lowest scavenging activity of alcalase-treated peptides. Superoxide radical scavenging activity showed that bromelain treated low molecular peptide showed the highest radical scavenging activity of 50% or more. Hydroxyl radical scavenging activity ranged from about 16.73 to 69.16%, the highest among bromelain-treated low molecular peptides. $Fe^{2+}$ chelation abilities showed a distribution between about 17.85 to 47.84%. The chelation capacity of the hydrolysates was not significantly different without any difference to the enzymes used. The results of amino acid analysis showed differences between hydrolysates of alcalase, bromelain, flavourzyme, neutrase, papain, and protamex enzymes. The most amino acid was glutamic acid. The molecular weight distribution of the enzyme hydrolyzates was in the range of 300-2,000 Da, although the molecular weight distribution differed according to the treated enzymes.