• KSBB Journal
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• v.19 no.1
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• pp.57-61
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• 2004

A peroxynitrite is formed when superoxide and nitric oxide exist at near eqimolar ratio in biological systems. Although not a free radical by chemical nature, peroxynitrite is a powerful oxidant having a wide array of tissue damaging effects ranging from lipid oxidation and inactivation of enzymes and ion channels through protein oxidation and nitration to inhibition of mitochondrial respiration. During our search for new antioxidizing components from natural resources, twenty salt marsh plants were screened for their ONOO and DPPH radical scavenging activities. Among them, methanol extract of Rosa rugosa, lxeris tamagawaensis, Erigeron annus, Tetragonia tetragonoides, Imperata cylindrica, and Suaeda japonica inhibited more than 85% of peroxynitrite produced by 3-morpholinsydnonimine (SIN-1) at a concentration of 5 $\mu\textrm{g}$/$m\ell$. In addition, Rosa rugosa, Artemisia capillaris, Erigeron annus and Ixeris tamagawaensis showed significant scavenging effect against DPPH (1,1-diphenyl-2-picrylhydrazyl radical).

• Natural Product Sciences
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• v.10 no.5
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• pp.244-247
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• 2004

The inhibitory effects of the leaves of Eucalyptus darylmpleana (Myrtaceae) on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The scavenging effect of the ethyl acetate fraction of Eucalyptus darylmpleana leaves on DPPH radical was stronger than the other fractions, and further purified by silica gel and Sephadex LH-20 column chromatography. 3,4-Dihydroxybenzoic acid, gallic acid, quercetin, quercetin $3-O-{\alpha}-_L-rhamnoside$, quercetin $3-O-{\beta}-_D-glucoside$ and quercetin 3-O-rutinoside were isolated and elucidated by spectroscopic data. Among these components, gallic acid and quercetin $3-O-{\alpha}-_L-rhamnoside$ exhibited potent scavenging activities on DPPH radical with $IC_{50}$ values of 6.02 and $5.54\;{\mu}M$, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.975-980
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• 2009

In this study we evaluated polyphenol contents, phytate contents, and antioxidant activities (DPPH radical and hydroxyl radical scavenging activity) in several soybean cultivars. The polyphenol contents of the cultivars ranged from 0.0446 mg/g to 0.0652 mg/g, with the highest level found in the WS82 cultivar, whereas and the lowest in Duyukong. The phytate content of the WS2906 cultivar was the highest at 22.28 mg/g whereas Duyukong showed the lowest level. $IC_50$ values (concentration of soybean extract exerting 50% scavenging of radicals) for DPPH radical and hydroxyl radical scavenging activity showed the highest in WS82. A positive correlation between DPPH radical scavenging activity and polyphenol contents was observed in the soybean cultivars, whereas not significant relationship between antioxidant activity and phytate content was found.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.67-72
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• 2003

The leaves of D. racemosum showed strong DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and the order of the radical scavenging activity against DPPH radical is ethyl acetate (EtOAc) fraction>crude extracts>residue fraction>hexane fraction>ether fraction, under the experimental conditions. Since EtOAc fraction has highest antioxidative activity among these fractions, the isolation was performed from the EtOAc fraction of the leaves of D. racemosum and four phenolic compounds were isolated and identified as follows: methyl gallate, kaempferol, quercetin and quercitrin. The free radical scavenging activities of these compounds were 79.9%, 93.1%, 93.6% and 66.7% at 10 ㎍/ml, respectively. The IC₅₀ of compound 1, compound 2, compound 3 and compound 4 were 6.1, 4.1, 3.6 and 6.5 ㎍/ml, respectively. These compounds have higher antioxidative activity compared with reference compounds, ascorbic acid (IC₅₀ = 9.6 ㎍/ml).

• Preventive Nutrition and Food Science
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• v.16 no.2
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• pp.127-134
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• 2011

The purpose of this study was to purify antioxidant substances from steamed squid extract (SSE). The yield of SSE was 8% by dry weight. The approximate compositions of SSE proteins, lipids, moisture, carbohydrate and ash were 64.95%, 1.69%, 7.23%, 4.44% and 21.69%, respectively. The major amino acids in SSE were taurine (29.17%), glycine (20.33%), alanine (12.51%), and glutamic acid (9.83%). Antioxidant activities were evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, which was measured as 24.7% at 1.0 mg/mL. Four SSE fractions were isolated by Sephadex G-25 gel chromatography; the F2 fraction showed the highest DPPH radical scavenging activity. The F2 fraction was separated by reverse-phase high performance liquid chromatography (HPLC) using an octadecylsilane (ODS) column, yielding a purified antioxidant substance with a DPPH radical scavenging activity of 64.41% at 1.0 mg/mL, representing a 2.64-fold increase in the scavenging activity of SSE purified by the 3-step procedure. The amino acid compositions showed that purified SSE was rich in taurine, glycine, glutamic acid and alanine. The purified SSE significantly elevated 2',7'-dichlorodihydrofluororescein diacetate (DCFH-DA) fluorescence probe, which confirms its effective radical scavenging potential in cellular ROS. In addition, the SSE significantly inhibited oxidative damage of purified genomic DNA. These results suggest that a purified antioxidant substance from SSE can be used as a potential natural compound-based antioxidant in the functional food and pharmaceutical industries.

• 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.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.95-100
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• 2018

Objectives : Ligustri Fructus has been used since ancient times as a medicinal usages in folk medicines against antitumor purpose. Many biological active constituents have been identified from this biomass such as several terpenoids and lignans. In current study, the properties of antioxidant and anti-diabetic complications using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)($ABTS^+$) radicals scavenging, and advanced glycation end products (AGEs) inhibition assays were evaluated by different extraction methods of Ligustri Fructus. Methods : In present continuing research for development of bioactive natural ingredients, antioxidant and AGEs formation inhibitory capacities of Ligustri Fructus extracts using different organic solvents were prepared and the biological potentials were investigated using in vitro bioassays. Antioxidant properties were evaluated employing radical scavenging assays using DPPH and $ABTS^+$ radicals. In addition, the anti-diabetic complications effects of Ligustri Fructus extracts were tested via AGEs formation inhibitory assay. The total phenolic contents were determined using a spectrophotometric method. Results : All the tested extracts exhibited dose-dependent radical scavenging and AGEs formation inhibitory activities. Among the tested samples, hot water extract of Ligustri Fructus was showed the most potent activity with $IC_{50}$ value of $494.8{\pm}6.7{\mu}g/m{\ell}$ against DPPH radical scavenging assay. Also, $ABTS^+$ radical scavenging activity of hot water extract was higher than those of other extracts. In addition, AGEs formation inhibitory effects of each extacts and total phenolic contents were evaluated. Conclusions : These results suggested that Ligustri Fructus can be considered as a new effective source of natural antioxidant and anti-diabetic complications resources.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5343-5350
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• 2015

This study aims to compare and analyze the antioxidant effect of Cheonggukjang's traditional fermentation strain, Bacillus subtilis NG24 which was a control of the study, in order to see the biological activity effect of the new strain, Bacillus amyloliquefaciens NBF11-1 that was first found in the surface of the bamboo stem, but hasn't been insufficiently researched. In the antioxidant activity experiment of the Cheonggukjang extract, the B.amyloliquefaciens NBF11-1 sample showed a significant increase in the total polyphenol extract content, compared to B.subtilis NG24(p=0.032). Also, compared to B.subtilis NG24, the sample containing B.amyloliquefaciens NBF11-1 showed a significant increase in SOD-like Activity, DPPH radical scavenging, and NO radical scavenging, as the concentration rose(p<.05). Additionally, $IC_{50}$ in each antioxidant activity experiment significantly decreased in the B.amyloliquefaciens NBF11-1 sample like SOD-like Activity(p=0.045), DPPH radical scavenging(p=0.041), and NO radical scavenging(p=0.019), compared to B.subtilis NG24.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1793-1798
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• 2015

Antioxidant activities of various solvent extracts from Coriolus versicolor were investigated for their total polyphenol content, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity. C. versicolor extracts were produced by organic solvents such as ethanol, ethyl acetate, and methanol. Total polyphenol and flavonoid contents in the ethanol and ethyl acetate extracts were higher than those in the methanol extract. DPPH radical scavenging activity of methanol extract showed the highest value of 80.3%, which was similar to that of ascorbic acid (85.5%). All extracts showed good (>90.0%) ABTS cation radical scavenging activity. The antimicrobial activities of these extracts from C. versicolor were evaluated against six strains of bacteria using the disc diffusion method. All extracts showed antimicrobial activities against all tested bacteria except Staphylococcus aureus. These results indicate that various extracts from C. versicolor could be useful as natural antioxidant and antimicrobial agents.