• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.102-107
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• 2002

Cereal grains are rich in phenolic compounds that give beneficial effect in human health. Although several research works have been reported on the effects of phytochemicals of plant origin, such as fruits, vegetables, few studies have examined the antioxidative effects of whole cereal grains. The objective of this study was to determine total antioxidant capacity of 80% ethanolic extracts of cereal grains by testing the ability of the extracts to inhibit UV -induced lipid peroxidation in vitro using linoleic acid in comparison to well-known antioxidant such as ascorbic acid and tannic acid. The total phenolic content of the cereal grain (80% ethanolic extracts) investigated in this study varied from 2.1 mg/g (wheat cv. Olgeurumil) to 10.4 mg/g (barely cv. Seodunchalbori). Highly positive relationship between total phenol compounds and antioxidant activity was found. When the antioxidant activities of all investigated extracts were measured with application of same quantity of phenol compounds, oat grain extracts showed similar antioxidant activity of barely cultivars. However, barely extract appeared as the most potent antioxidant activity of inhibition of UV -induced lipid peroxidation. This indicated that factors such as phenolic compound composition and their individual antioxidant activity could playa crucial role in the total antioxidant activity of cereal grains.

• Natural Product Sciences
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• v.20 no.3
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• pp.176-181
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• 2014

The antioxidant activities of 29 components isolated from the aerial parts of Artemisia iwayomogi were evaluated in vitro and in cell culture. Among the tested compounds, 2, 6, 8, 10, 13, and 14 exhibited the greatest peroxyl radical-scavenging activities in the oxygen radical absorbance capacity (ORAC) assay, and 2, 10, and 14 also showed significant reducing capacities. However, all compounds showed weak metal chelating activities. Their cellular antioxidant activities were evaluated in HepG2 cells. At $10{\mu}M$, compounds 6, 8, and 14 exhibited stronger protection against 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress than compounds 2, 10, and 13. Moreover, Compounds 2 and 8 were more effective in protecting against $Cu^{2+}$-induced oxidative stress than compounds 6, 10, 13, and 14 at $10{\mu}M$. These results suggest that the phenolic compounds in A. iwayomogi have the potential to be developed as natural antioxidants for the treatment of oxidative stress-related diseases.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.336-339
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• 2005

Common thistle contains water-soluble substances that are antioxidative to foods. Antioxidant activities measured by DPPH method for the ground samples were the greatest in leaves, although was less than that of commonly used antioxidants, BHT and ascorbic acid. Methanol extracts and fractions from Xanthium occidentale plants dose-dependently increased DPPH free radical scavenging activity, in vitro test. The extracts from leaves showed the strongest antioxidant activity. DPPH scavenging activity of the individual fraction was in order of n-butanol>water>ethyl acetate>n-hexane fraction. By means of HPLC analysis, leaf samples of Xanthium occidentale had the highest amount of phenolic compounds, related with antioxidant activity, and followed by stems and roots. Total content of these antioxidant phenolic com­pounds for leaves extracts were detected in water fraction (36.7 mg 100 $g^{-1}$) as the greatest amount, especially chlorogenic acid (39.4 mg 100 $g^{-1}$) was the greatest component. These results suggest that Xanthium occidentale plants had potent antioxidant activity, and their activities were differently exhibited depending on plant part and fraction.

• Journal of Applied Biological Chemistry
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• v.51 no.2
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• pp.57-60
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• 2008

Eight compounds, including 2 flavones, luteolin (1) and apigenin (2), 2 flavonols, kaempferol (3) and quercetin (4), and 4 flavonoid glucosides, luteolin-7-O-${\beta}$-D-glucoside (5), apigetrin (6), astragalin (7), and isoquercitrin (8), isolated from the whole herb of Sonchus oleraceus L. were analyzed on the basis of chemical and spectroscopic evidence. This was the first time to report compounds 3, 4, 6, 7 and 8 from the Sonchus oleraceus L. The antioxidant activities of the isolated flavonoids and their glucoside derivatives were evaluated by DPPH free radical-scavenging assay, showing that compounds 1, 3, 4 and 8 exhibited stronger antioxidant activities compared with ${\alpha}$, tocopherol and curcumin. Flavonoids containing more hydroxyl groups exhibited better antioxidant activities. The antioxidant activity of flavonols was superior to their corresponding flavones, and that of aglycone are more potent than their glucoside derivatives.

• Elastomers and Composites
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• v.17 no.1
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• pp.13-21
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• 1982

The purpose of this dissertation is to compare bound andtioxidant, MHPPD with the ordinary one, IPPD, when high polymers are used like NR and SBR. The effect of rubber bound antioxidant and ordinary antioxidant on the Mooney scorch time has been studied by means of the Mooney viscometer. The ageing properties of vulcanizates containing rubber-bound antioxidant and ordinary antioxidant have been studied in terms of hardness, tensile strength and elongation. The results of the Mooney scorch time and ageing properties are as follows: When MHPPD was mixed with NR or SBR compounds, the Mooney scorch time was faster than the IPPD compounds. Also the ageing properties of the vulcanizates containing MHPPD were much superior to the IPPD compounds. Furthermore, the vulcanizates comporised of MHPPD have taken andvantage of and resistance in the ozone test.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.264-267
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• 2005

The purpose of this study was to investigate the ultra sonic extraction method of phenolic compounds and antioxidant activity from Rumex crispus. Rumex crispus was fractionated with hexane, ethyl acetate, butanol and water. The amount of phenol compounds and antioxidant activity was presented higher content in ethyl acetate fraction then others.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.496-500
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• 1997

A strong antioxidant activity, which was measured by the radical scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl(DPPH) radical, was detected in the methanol extract of Salvia miltiorrhiza Bunge (Labiatae). By activity-directed fractionation, compounds 1 and 2 were isolated as antioxidant principles of S. miltiorrhiza. Compounds 1 and 2 were identified as dimethyl lithospermate and 3-(3, 4-dihydroxyphenyl)lactamide, respectively, on the basis of spectral data. The radical scavenging effect of compounds 1 and 2 on DPPH radical exceeded that of L-ascorbic acid which is a well known antioxidant. These two compounds also showed prominent inhibitory activity against free radical generation in dichlorofluorescein (DCF) method and cytoprotective effect against t-BHP in cultured liver cell.

• Natural Product Sciences
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• v.8 no.1
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• pp.26-29
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• 2002

The MeOH extract of Sorbus commixta (Rosaceae) exhibited strong DPPH radical scavenging activity, and through activity-guided fractionation two antioxidant compounds were isolated and identified as $catechin-7-O-{\beta}-D-xylopyranoside$ (1) and $catechin-7-O-\;{\beta}-D-apiofuranoside$ (2) by physicochemical and spectrometric methods. To evaluate the antioxidant effect of these compounds, some in vitro tests, such as the DPPH radical scavenging activity test, the superoxide radical scavenging activity test and the lipid peroxidation inhibitory activity test, were performed. Compounds 1 and 2 showed stronger activities than both a-tocopherol and butylated hydroxy anisole (BHA) in each assay.

• Natural Product Sciences
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• v.11 no.2
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• pp.97-102
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• 2005

From the n-BuOH soluble traction of the 70% aqueous acetone extract of Rhododendron mucronulatum stem, twelve compounds were isolated. On the basis of spectral data, they were identified as scopoletin (1), (+)-taxifolin (2), quercetin (3), (-)-catechin (4), (+)-epicatechin (5), scopolin (6), lyoniside (7), ssioriside (8), fraxin (9), $(+)-lyoniresinol-3{\alpha}-O-{\beta}-D-glucopyranoside$ (10), $(+)-taxifolin-3-O-{\alpha}-L-arabinopyranoside$ (11), and astragalin (12), respectively. All isolated compounds were tested antioxidant activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. Compounds 2 and 3 showed the potent antioxidant activity, and compounds 5, 8, and 11 showed moderate activity.

• YAKHAK HOEJI
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• v.44 no.2
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• pp.119-127
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• 2000

This paper describes isolation and elucidation structure of the components from leaves and evaluate the radical scavenging activity on DPPH radical for antioxidant effect. Bioassay guided fractionation of MeOH extract afforded active EtOAc and BuOH factions. The most active EtOAc fraction was repeatedly chrormatographed over silica and Sephadex LH-20 to afford six flavonoid compounds. Studies on the antioxidant activity of these constituents showed that quercetin was the most active of these compounds. Luteolin and kaempherol are also active, These results suggested that the antioxidant activity of leaves of Angelica gigas may be due to flavonoid components. All the compounds were identified by spectroscopic methods and are the first report from leaves of Angelica gigas.