• Journal of the Korean Society of Food Culture
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• v.33 no.1
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• pp.78-85
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• 2018

This study examined the changes in antioxidant activity and contents of phenolic compounds inblanched, steamed, and autoclaved burdock root (BR). The total polyphenolic and flavonoids contents of raw and cooked BR were determined spectrophotometrically. The antioxidant activity of BR was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and oxygen radical absorbance capacity (ORAC) assays. The main phenolic compounds in BR were quantified by HPLC (high performance liquid chromatography). Both blanching and steaming treatments significantly increased the antioxidant activities of BR in all groups (5 min, 15 min, and 30 min), whereas in autoclaving treatment, the 30 min treatment only showed an increase in the antioxidant activities of BR. The 30 min blanched BR exhibited the strongest DPPH and ABTS radical scavenging activities and possessed the highest total polyphenol and flavonoid phenolic contents. The 15 min-steamed BR showed the highest ORAC value. The main phenolic compound of the 15 min-steamed BR was CGA (chlorogenic acid). These results suggest that heat cooking methods, such as blanching and steaming, improve the antioxidant activity of BR by increasing the concentration of phenolic compounds.

• Natural Product Sciences
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• v.9 no.2
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• pp.80-82
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• 2003

Since reactive oxygen radicals play an important role in carcinogenesis and other human diseases including neurodegenerative states, antioxidants present in natural products have received considerable attention for alleviation of these disease states. Therefore, in order io identify antioxidants in plant extracts, fifty-seven methanolic extracts derided from indigenous Korean plants were primarily assessed for potential to scavenge stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. As a result, nine plant extracts were found to exhibit the DPPH free radical scavenging activity in the criteria of $IC_{50}<40\;{\mu}g/ml$. In particular, the extracts of Melioma oldhami $(IC_{50}=0.1\;{\mu}g/ml)$, Myrica rubra $(IC_{50}=16.2\;{\mu}g/ml)$, Sympolocos paniculata $(IC_{50}=23.0\;{\mu}g/ml)$, Carpinus laxiflora $(IC_{50}=25.1\;{\mu}g/ml)$, and Cleyera japonica $(IC_{50}=26.2\;{\mu}g/ml)$ showed a potent radical scavenging activity. Further study for the identification of active compounds from these lead extracts might be warranted.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.143-147
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• 2019

This study evaluated the anti-oxidant activity of avicularin and isovitexin from Lespedeza cuneata using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH) scavenging assays. The results showed that among the four fractions, the highest OH radical scavenging activity was exhibited by the n-butanol fraction. The DPPH radical scavenging activities of avicularin and isovitexin were higher than 50% at a concentration of $100{\mu}g/mL$. Moreover, one hundred micrograms per liter of avicularin and isovitexin exhibited effective anti-oxidant activity, with the OH radical scavenging rates being 87.54 and 91.48%, respectively. These results suggest that Lespedeza cuneata would be useful anti-oxidant agents from natural sources.

• Food Science and Preservation
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• v.19 no.2
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• pp.229-234
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• 2012

The antioxidant substance in black onion was identified. The assays that used 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazo line-6-sulphonic acid) ($ABTS^+$) radicals showed that the ethyl acetate fraction of black onion methanol extract had a higher level of radical-scavenging activity than the other fractions. Two antioxidative compounds were purified and isolated from the ethyl acetate fraction via column chromatographies of silica gel and Sephadex LH-20 using the guided DPPH radical-scavenging assay. The isolated compounds were identified as 3,4-dihydroxybenzoic acid (1) and quercetin (2) based on mass spectrometry and nuclear magnetic resonance. The isolated compounds showed a high level of DPPH and ABTS+ radical-scavenging activity. Compound 2 had a higher level of radical-scavenging activity than 1.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.927-932
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• 1998

The antioxidant activity of Symphyocladia latiuscula was determined by measuring lipid peroxide produced when a mouse liver homogenate was exposed to the air at $37^{\circ}C$, using 2-thiobarbituric acid (TBA) and radical scavenging effect on 1,1 - diphenyl - 2 - picrylhydrazyl (DPPH) radical, and free radical generation inhibition by $ACF_2$(Hepatocyte). The methanol extract of S. latiuscula showed high antioxidant activity. And the methanol extract was fractionated with several solvents. With regard their fractions, the antioxidant activity were in the order of dichloromethane > hexane > butanol > ethyl acetate > water fraction. The dichloromethane fraction showed the strongest radical scavenging activity ($50\%$ inhibitory concentration[$IC_{50}$]=3,14 $\mu$g/ml), and strong inhibitory effect on the lipid peroxidation of the mouse liver homogenate, which was compared with lascorbic acid, inhibition effect was stronger than Lascorbic acid. The methanol extract of S. latiuscula and its dichlromethane soluble fraction also inhibited over $50\%$ at concentration of 0.2 mg/ml and 0.1 mg/ml on free radical generation of hepatocyte ($AC_2F$). While the water fraction was inactive in all the assay for antioxidant activity.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.376.1-376.1
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• 2002

Phytochemical examination of Barks of Ulmus macrocarpa isolated two flavanone, three flavanonol, three flavan 3-ol and one procyanidin compounds. We also determinated the antioxidative activity of these compounds by measuring the radical scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Three flavan 3-ol (catechin, epicatechin and catechin-7-O-$\beta$-O-xylopyranoside) and procyanidin B1 showed significant antioxidative activity. (omitted)

• Journal of the Korean institute of surface engineering
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• v.53 no.5
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• pp.265-270
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• 2020

We investigated mechanochemical radical, which is concomitant with chemical lift-off lithography(CLL), on the self-assembled monolayer(SAM)/electrodes and a polydimethylsiloxane(PDMS) using a colorimetric and a spectroscopic method. The 11-mercaptoundecanol(MUO)/Au or the 11-hydroxyundecylphosphonic acid (HUPA)/ITO were contacted with bare or activated PDMS. After contact, the each of SAM/substrates and the PDMS were immersed in a 2,2 Diphenyl-1-picrylhydrazyl(DPPH) radical scavenger. The color of the DPPH exposed to the PDMS was changed from purple to yellow and the absorbance decreased definitely at 515 nm wavelength. The SAM/substrates, however, have caused small changes in spectroscopic property, indicating no existence of radical species. We concluded that mechanochemical radicals were formed by homolytic cleavage of PDMS molecules upon external force and hardly transferred on the SAM/substrates.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.503-511
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• 2023

The aim of this study was to investigate in vitro antioxidant activities of defatted Camellia japonica L. seeds (DCJS). The DCJS were extracted using ethanol and then fractionated with butanol (BuOH), ethyl acetate (EtOAc), chloroform, and hexane. To evaluate antioxidant activity of extract and fractions from DCJS, we investigated free radical scavenging activities such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺), hydroxyl radical (^•OH), and superoxide anion (O₂^-) radicals. The five extract and fractions of DCJS dose-dependently increased DPPH, ABTS⁺ and O₂^- radical scavenging activities. The BuOH fraction of DCJS showed the highest free radical scavenging activities among other extract and fractions. The contents of total polyphenol and flavonoid in BuOH fraction of DCJS were 23.26 mg GAE/g and 32.39 mg QE/g, respectively. The polyphenol and flavonoids contents of BuOH fraction has highest than other extract and fractions. In addition, BuOH and EtOAc fraction of DCJS contained 102.37 and 165.05 ㎍/g of camelliaside B, respectively. Therefore, DCJS has higher antioxidant activity and may be useful as a natural antioxidant material.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.300-306
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• 2003

Rhizoma of Smilax china has been used as anti-inflammatory and analgesic, antiedemic agent in Korean folk medicine. In order to investigate the efficacy of anti-oxidative activity, the activity-guided fractionation and the isolation were performed. Each fractions ($H_2O$ fraction, 20％, 40％, 60％, 100％ MeOH fractions and CHCl$_3$ fraction) was examined antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging potential. It was revealed that 40％, 20％ MeOH fractions and $H_2O$ fractions have significant anti-oxidative activity. From 40％ and 20％ MeOH fractions two flavonoid glycosides and one procyanidin were isolated and elucidated apigenin-7-Ο-$\alpha$-L-rhamnopyranosyl(1\longrightarrow2)-$\beta$-D-glucopyranoside, apigenin-7-Ο-$\alpha$-L-rhamnopyranosyl(1\longrightarrow6)-$\beta$-D-glucopyranoside and catechin(4$\alpha$\longrightarrow6)epicatechin through their physicochemical data and IR, FAB-MS, $^{13}$ C-NMR, and $^1$H-NMR analysis with authentics, respectively. The isolated compounds were examined by DPPH method. Apigenin-7-Ο-$\alpha$-L-rhamnopyranosyl(1\longrightarrow2)-$\beta$-D-glucopyranoside and catechin (4$\alpha$\longrightarrow6) epicatechin showed powerful radical scavenging activities on DPPH radical among three compounds.

• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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• pp.258-262
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• 2007

In the present study, we investigated the antioxidant activity of methanol extract and its organic fractions (n-hexane, $CH_2Cl_2$, EtOAc, n-BuOH and $H_2O$) of Capsiccum annuum leaves against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. As results, methanol extract, and its ethyl acetate and n-butanol fractions showed good scavenging effect at 100 ${\mu}g/ml$. Four compounds were isolated from the ethyl acetate fraction through silica gel and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated as apigenin (1), vanillic acid (2), uracil (3) and apigenin $7-O-{\beta}-D-apiofuranosyl(1{\rightarrow}2)-{\beta}-D-glucopyranoside$ (4) by comparison of spectral data with those in reference. $IC_{50}$ value of compound 2 was 14.7 ${\mu}g/ml$, while compounds 1, 3 and 4 had no effect on the DPPH radical.