• Preventive Nutrition and Food Science
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• v.10 no.1
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• pp.92-94
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• 2005

The flavonoids kaempherol and epicatechin, and a proanthocyanidin fraction were isolated from the seed of allspice (Pimenta dioica). Their structures were determined by chemical and spectral analyses. Antioxidant activities of kaempherol, epicatechin and the proanthocyanidin fraction were tested using the reaction with the stable radical diphenyl-p-picrylhydrazyl (DPPH) and exhibited IC/sub 50/ values of 7.83, 4.27 and 2.92 g/mL, respectively. These results demonstrate that allspice proanthocyanidins and flavonoids might act as effective antioxidants.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.903-906
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• 2008

Woodfordia fruticosa Kurz (Lythraceae) is used in the treatment of various ailments in traditional medicines. DPPH activity guided fractionation and purification process was used to identify the free radical-scavenging components from the flowers of this plant. The methanolic extract of the plant was first fractionated into four extracts; namely, n-hexane, chloroform, ethyl acetate and water fractions. Among them, the ethyl acetate fraction was found to be the most effective and was further subjected to activity guided-fractionation and isolation procedures. After successive column chromatography on silica gel and Sephadex LH-20, gallic acid, which is responsible for the radical scavenging activity, was isolated and its structure was elucidated by spectral methods ($^1H$ NMR, $^{13}C$ NMR) and by comparison with literature.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.8-12
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• 2010

The antioxidant activity of hawthorn fruit (Crataegus pinnatifida Bunge var. typica Schneider) extracts was investigated by several in vitro antioxidants properties, including DPPH free radical scavenging activity, total phenolic and flavonoid contents, hydroxyl radical scavenging activity, reducing power activity, iron-chelating capacity and nitrite scavenging activity. Among the extracts in this study, the 70% EtOH extract showed higher antioxidant activity than the others. The $IC_{50}$ value of DPPH free radical scavenging activity was $99.26\;{\mu}g/mL$. Furthermore, the 70% EtOH extract also showed significantly high total phenolic and flavonoids contents and reducing power activity. However, the MeOH extract exhibited stronger effects on hydroxyl radical scavenging activity, iron-chelating capacity and nitrite scavenging activity. All the results implicated that, the hawthorn fruit may has the available potential to be utilize as a potential source of natural antioxidant.

• Natural Product Sciences
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• v.17 no.1
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• pp.14-18
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• 2011

A chemical investigation of the marine-derived fungi Aspergillus versicolor led to the isolation of a new aromatic polyketide (1), The structure was elucidated by spectroscopic analysis, and its radical-scavenging activity, reducing power, and inhibitory activity to lipid oxidation were investigated. Those activities of compound 1 were compared with standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiarybutylhydroquinone (TBHQ), and ascorbic acid ($V_C$). Compound 1 showed antioxidant activity comparable to that of BHA, and siginificantly higher than that of BHT.

• Journal of Applied Biological Chemistry
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• v.48 no.3
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• pp.144-147
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• 2005

DPPH and ABTS radical scavenging, and tyrosinase inhibitory activities of bioactive compounds 1-4 isolated from Cedrela sinensis leaf were assessed. Structures of isolated compounds were established by UV, one- and two-dimensional NMRs, and mass spectroscopic methods.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.363-371
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• 2015

n-Butanol and ethyl acetate extracts of thermal treatment yam (Dioscorea batatas $D_{ECNE.}$) belonging to the family Dioscoreaceae were measured for their radical scavenging activity and lipid peroxidation inhibition ability. In this study, ethyl acetate extract showed the most potent antioxidant activity evaluated by ferrous ion chelating activity and NO radical scavenging activity. Nevertheless, n-butanol extract was more effective in inhibiting linoleic acid peroxidation. A significant difference between n-butanol extract and ethyl acetate extract in nitrite scavenging activity ${\beta}$-carotene bleaching assays could not be found. Also, the results of this study showed that thermal treatment yam could be used as easily accessible source of natural antioxidants and as a possible food supplement.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.328-332
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• 2011

After preparation of acetone, ethanol, methanol, and water extracts (10 g/300 mL) of dried persimmon (Diospyros kaki cv. Fuyu) flower-buds, total phenolic contents (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) RSA, reducing power (RP), and tyrosinase inhibitory activity of the extracts were evaluated. The methanol extracts produced the highest TPC (113.39 mg gallic acid equivalents/g), DPPH RSA ($IC_{50}=40.25\;{\mu}g/mL$), ABTS RSA ($IC_{50}=58.17\;{\mu}g/mL$) and RP ($IC_{50}=69.43\;{\mu}g/mL$) activities while the water extracts generated the lowest values. The ethanol extract showed the highest tyrosinase inhibitor activity (88.90%) at a concentration of 1 mg/mL. These results indicated that persimmon flower-buds may be a useful source of natural antioxidants.

• Natural Product Sciences
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• v.6 no.3
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• pp.135-138
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• 2000

MeOH extract of Cuscuta chinensis seeds was fractionated with n-hexane, EtOAc and BuOH successively, and antioxidant activities were tested for all fractions using DPPH free radical scavenging method. In the tested fractions, EtOAc fraction showed high antioxidant activity$(EC_{50},\;50\;{\mu}g)$ From the EtOAc fraction, five compounds have been isolated. On the basis of spectral data, these compounds were identified as ${\beta}-sitosterol$, methyl 4-hydroxy-3,5-dimethoxycinnamate, ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$, caffeic acid, quercetin, kaempferol and calycopteretin. Among these compounds, ${\beta}-sitosterol$ and ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$ showed no antioxidant activity. $EC_{50}$ values of methyl 4-hydroxy-3,5-dimethoxycinnamate, caffeic acid, quercetin, kaempferol and calycopteretin were 0.6, 8, 19, 17 and $12\;{\mu}g$, respectively.

• Natural Product Sciences
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• v.13 no.1
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• pp.11-16
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• 2007

Alcoholic extract of Spathodea campanulata P. aerial parts, and two of the isolated fractions from celite column showed strong antioxidant activity (92, 94 & 89% RSA, Radical Scavenging Activity). Phytochemical investigation of chloroform/EtOAc faction of this column led to the isolation of phenolic acids, caffiec acid (1), and ferulic acid (2), fraction EtOAc/MeOH on further fractionation afforded 3 Flavonoids, kampferol 3-O-glucoside (3), quercetin 3-methyl ether (4) and 8-methoxy kampferol 3-O-glucoside (5). The isolated constituents were identified by co chromatography with authentic samples, TLC, PC., UV, MS and $^1H-NMR$. Also the lipoidal matter of the plant was studied. The unsaponifiable matter was found to be mixture of hydrocarbons from $(C_{14}-C_{28})$, cholesterol, campasterol, stigmasterol, and ${\alpha}-amyrin$. Fatty acid methyl esters were found to contain 12 fatty acids. The fatty acids containing $C_{18}$ farmed ca.65% of the total mixture.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.299-308
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• 2017

Oxidative stress suppresses animal health, performance, and production, subsequently impacting economic feasibility; hence, maintaining and improving oxidative status especially through natural nutrition strategy are essential for normal physiological process in animals. Phytochemicals are naturally occurring antioxidants that could be considered as one of the most promising materials used in animal diets in various forms. In this review, their antioxidant effects on animals are discussed as reflected by improved apparent performance, productivity, and the internal physiological changes. Moreover, the antioxidant actions toward animals further describe a molecular basis to elucidate their underlying mechanisms targeting signal transduction pathways, especially through the antioxidant response element/nuclear factor (erythroid-derived 2)-like 2 transcription system.