• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.412-417
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• 2009

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on DPPH (1,1-diphenyl- 2-picrylhydrazyl), a total extract of the twigs of Vitex rotundifolia (Verbenaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of three iridoid compounds, 10-O-vanilloylaucubin (1), 10-O-p-hydroxybenzoylaucubin (2) and aucubin (3), two C-glycoside flavones, vitexin (4) and orientin (5), and a quinic acid derivative, 3,4-di-O-caffeoylquinic acid (6). Their structures were elucidated by spectroscopic studies. Among them, compounds 5 and 6 showed the significant antioxidative effects on DPPH free radical scavenging test. In riboflavin-NBT-light and xanthine-NBT-xanthine oxidase systems, compounds 5 and 6 exhibited the formation of the blue formazan in a dose-dependent manner. Compounds 5 and 6 showed better superoxide quenching activities than vitamin C.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.84-88
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• 2011

Edestin, a major hempseed storage protein from Cheungsam, was isolated to apparent homogeneity by acid precipitation and gel filtration chromatography. The native molecular weight of purified edestin was approximately 300 kDa by Sephacryl S-300 gel filtration. Upon adding 2-mercaptoethanol, the isolated edestin of 56.7 kDa on the non-reduced sodium dodecyl sulfate polyacrylamide gel was converted into subunits, suggesting that the protein might be composed of subunits linked by disulfide bond. Cheungsam edestin was rich in essential amino acids and it has 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity. The results suggest that Cheungsam edestin might be utilized as a superior antioxidative nutrient.

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.289-290
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• 2012

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.388.2-388.2
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• 2002

Quercus species have been used for diarrhea. dysentery, dermatitis. haemoptoe, and haemorrhagia in Korean folk medicine. Specially Quercus salicina have been used for diuretic. anti-inflammatory. antiedemic. and litholytic agent. In order to investigate the efficacy of antioxidative activity the activity guided fraction and isolation of physiologically active substance were performed. (omitted)

• Korean Journal of Plant Resources
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• v.11
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• pp.89-109
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• 1998

Screening of new antioxidants form oriental medicines resulted in the isolation of a new antioxidative compound and eight known compounds from the stem bark of Kalopanax pictus. On the basis of various spectrosopic studies, the structure of the new compound was determined to be 4-rhamnose-3,5-dimethoxybenzoic acid methly ester. Other known compounds were identified as ferulic acid, 4,5,6,-trihydroxyflavanone, 2', 4',4' -trihydroxychalcone, caffeic acid, coniferyl alcohol, syringin, 1,3-di-O-caffeoylquinic acid. These compounds showed lipid peroxidation inhibitory acitivity in rat liver microsomes and free radical scavenging acitivity.

• Journal of the Korean Chemical Society
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• v.57 no.4
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• pp.520-524
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• 2013

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.57-58
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• 2008

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.499-502
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• 2003

The methanol (MeOH) extracts from the fruits of Rubus coreanum showed antioxidative activity. The antioxidative substance in MeOH extracts was successively purified with solvent fractionation, adsorption chromatography, and gel filtration. The purified active substance was isolated by HPLC and identified as quercetin by EI-MS, and $^1H-NMR$ analyses. The amount of quercetin was 0.25 mg per 100 g in fresh fruits of Rubus coreanum Miquel.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.214-219
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• 2006

A bacterial strain, initially identified as B1-3, was isolated from cheonggukjang, a traditional Korean dish made from fermented soybeans. Using the Biolog system and 16S rRNA sequence analysis, we identified B1-3 as Bacillus mojavensis. We manufactured a quickly fermented soybean (QFS) food product using the B. mojavensis, and guided by their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability. We isolated substances with antioxidative activity from it. Using mass spectrometry (MS) and nuclear magnetic resonance (NMR) techniques, we isolated 4 compounds from the ethyl acetate (EtOAc)-soluble neutral fraction of methyl alcohol (MeOH) extracts of the QFS food product (genistein, daidzein, 3R,4R-3-methyl-3,4-dihydroxy-2-pentanone, and 3S,4R-3-methyl-3,4-dihydroxy-2-pentanone) and 3 compounds from its acidic fraction (4-hydroxyphenylacetic acid, genistin, and daidzein). Two compounds from the neutral fraction (3R,4R-3-methyl-3,4-dihydroxy-2-pentanone and 3S,4R-3-methyl-3,4-dihydroxy-2-pentanone) were not detected in nonfermented soybeans (NFS) or in the filtrate of the LB broth used to culture B. mojavensis. However, they were detected in the filtrate of the same broth when it contained 2% glucose. These results suggest that these 2 compounds were derived from glucose (or other saccharides) in the soybean during fermentation. One compound that was found in the acidic fraction (4-hydroxyphenylacetic acid) was readily detected in NFS, but not in the culture broth. This suggests that 4-hydroxyphenylacetic acid was derived from NFS. We concluded that the antioxidative activity of cheonggukjang is a result of the interactions between soybean components and the microorganisms used in the fermentation of cheonggukjang.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.246-255
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• 1996

To develop a natural antioxidative peptide, the gelatin was extracted from fish (Yellowfin sole) skin by hot $water(50^{\circ}C)$ extraction method and hydrolyzed with Alcalase, pronase and collagenase through a continuous 3-step membrane reactor. Each step enzymatic hydrolysates were determined the antioxidative activity and their synergistic effects, compared with $\alpha-tocopherol$ and butylated hydroxytoluene (BHT). Also, we tried to investigate the antioxidative disposition of peptide which was successfully separated by gel filtration, ion-exchange chromatography, and HPIC in cultured rat hepatocytes intoxicated with tert-butyl hydroperoxide (TBHP). Second step enzymatic hydrolysate (SSEH) among all hydrolysates and $\alpha-tocoperol$ was showed the strongest antioxidative activity. The optimum concentration of antioxidative activity for SSEH was $1\%(w/w)$ in linoleic acid. The synergistic effects were increased in using the hydrolysate with tocopherol and BHT. In the presence of the peptide isolated from SSEH, supplemented hepatocytes exposed to TBHP showed that delayed cell killing and decreased significantly the lipid peroxidation, compared with hepatocytes not cultured with isolated peptide.