• Archives of Pharmacal Research
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• v.26 no.6
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• pp.458-462
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• 2003

The antioxidant activity of the stem bark from Albizzia julibrissin was evaluated for its potential to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, to inhibit the generation of the hydroxyl radical ($\cdot OH$), total reactive oxygen species (ROS) and to scavenge authentic peroxynitrites ($ONOO^{-}$). The methanol extract of A. julibrissin exhibited strong antioxidant activity in the tested model systems. Therefore, it was further fractionated using several solvents. The antioxidant activity of the individual fractions were in the order of ethyl acetate (EtOAc) ＞ n-butanol (n-BuOH) ＞ dichloromethane ($CH_2 CI-2$) ＞ and water ($H_2O$). The ethyl acetate soluble fraction, which exhibited strong antioxidant activity, was further purified by repeated silicagel, Sephadex LH-20 and RP-18 gel column chromatography. Sulfuretin (1) and 3 ,4 ,7-trihydroxyflavone (2) were isolated as the active principles. Compounds 1 and 2 exhibited good activity in all tested model systems. Compound 1 exhibited five times more inhibitory activity on the total ROS than Trolox. Compound 2 showed six times stronger DPPH radical scavenging activity than L-ascorbic acid. These results show the possible antioxidant activity of the A. julibrissin crude extract and its major constituents.

• Journal of the Korean Society of Food Culture
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• v.19 no.1
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• pp.52-60
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• 2004

This study was performed to investigate the effect of Lycii fructus beer on serum lipid profiles and antioxidant activity in rat Sprague-Dawley (SD) rats weighting about 190g were divided into the following 5 groups ; distillate water (Control), 5% ethanol in distillate water (Ethanol), commercial beer (CB), Lycii fructus beer (LFB) and 5% alcohol red wine diluted with distillate water (RW). Body weight, total food intake, FER and percent organ (liver, kidney) weight per body weight were not significantly changed by Lycii fructus beer drinking. After 6 weeks, serum total cholesterol, triglyceride and HDL cholesterol level were not significantly different. But, Lycii fructus beer intake tended to decrease serum triglyceride level and atherogenic index. Also, GOT and GPT levels were expressed lower than Ethanol group. There was not significantly different in hepatic glutatiione (GSH) content and glutathione-S-transferase (GST) activities among 5 groups. Lipid peroxidation in the hepatic was decreased by Lycii fructus beer intake. The results demonstrated that Lycii fructus beer was potential and effective antioxidant that can protect the decrease associated with alcohol.

• Journal of the Korean Society of Food Culture
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• v.22 no.3
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• pp.336-341
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• 2007

Antioxidant activity of Astragalus membranaceus, Polygonatum stenophyllum, Angelica gigas, Acanthopanax sessiliflorus and Angelica pubescens extracts cultivated in Jecheon prepared with different solvents were determined by 1,1-diphenyl-2-picrylhydrzyl(DPPH) radical scarvenging ability and thiocyanate method . The highest hydroxy radical scarvenging activity was shown in Acanthopanax sessiliflorus, while the lowest was in Polygonatum stenophyllum. Angelica gigas showed strong antioxidant activity by thiocyanate method. Methanol extracts and water extracts showed higher antioxidant activities than ethanol extracts. Angelica pubescens showed the highest polyphenol contents and Acanthopanax sessiliflorus showed the highest flavonoid contents. Direct correlation between the hydroxy radical scavenging activity and polyphenol contents or flavonoid contents was established by simple regression(r>0.8) in each solvent extracts. Among medicinal plants cultivated in Jecheon, Acanthopanax sessiliflorus and Angelica pubescens showed strong antioxidant activities. These results suggest that methanol or water extracts of several medicinal plant cultivated in Jecheon could be used as natural antioxidants.

• Journal of the Korean Society of Food Culture
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• v.18 no.6
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• pp.569-574
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• 2003

This study was conducted to investigate the effect of physical properties and antioxidant activities of the beer made by Lycii fructus for development of functional beer. Physical properties such as $Brix^{\circ}$, pH and hunter values were determined and compared with commercial beer. L(lightness) value was not significant difference among beer, although a(redness) and b(yellowness) values were higher in Lycii fructus beer than those of the commercial beer. Total phenolic acid contents were 0.790 mg/mL in Lycii fructus beer and 0.603 mg/mL in commercial beer. Electron donatin ability was 93% in Lycii fructus beer and 87% in commercial beer. Lycii fructus beer showed higher SOD-liked activities than in the commercial beer. The relative antioxidant effects of the Lycii fructus beer showed 19% inhibitory effect on the peroxidation of egg yolk lecithin.

• Journal of the Korean Society of Food Culture
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• v.35 no.5
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• pp.459-466
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• 2020

The physicochemical and antioxidant properties of cookies prepared using powders of barley sprout (BS), lemon balm (LB), and green tea (GT) were studied. The same dough density was maintained in all the sample groups. The experimental group to which the natural ingredients containing antioxidants were added did not show any significant change in the appearance of cookies compared to the control. LB and GT cookies showed significantly lower hardness compared to the control (p<0.05). Control showed the lowest antioxidant effect when assessed with 2,2-diphenyl-1-picrylhydrazyl. (DPPH) and this gradually increased in the order of BS, LB, and GT. The antioxidant activity of GT was 7 times higher as compared to the control (p<0.05). The antioxidant activity assessed using 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) also showed results similar to that seen with DPPH. GT showed a significantly higher total phenol content, about 2-3 times higher compared to the control (p<0.05). GT had significantly higher total flavonoid content than that of the control (p<0.05). Thus, the addition of natural antioxidant ingredients such as sprout barley, lemon balm and specifically green tea, in the preparation of cookies, resulted in excellent antioxidant activity with similar physicochemical quality characteristics. The study suggests that it is possible to develop cookies that are competitive in terms of nutritional and physiologically active functions.

• 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.

• The Korean Journal of Food And Nutrition
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• v.24 no.1
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• pp.94-100
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• 2011

This study identified the formula of the antioxidant substance separated from the ethyl acetate and the butanol extract and tested the antioxidant properties with the electron donating ability(EDA). Each phase with the fractionated methanol extract from mulberry leaf was screened in advance for the antioxidant substance with EDA. As the result, activity appeared in the ethyl acetate and butanol phase and the antioxidant component was separated. As the consequence, 2 components from the ethyl acetate phase and 1 from the butanol phase were separated, among which the structures of the components from ethyl acetate were determined by wogonin and linarin, whereas the structure of the component from the butanol phase was determined by pectolinarin. In the screening of antioxidant activity by the scavenging effect of the DPPH radical, the wogonin and linarin components from ethyl acetate phase showed more powerful antioxidant property than the component from butanol. The results from this study indicate that the chemical compound separated from the ethyl acetate extract has more powerful antioxidant property than the one separated from the butanol extract. The components separated from the ethyl acetate extract were wogonin and linarin, which are flavonoids, whereas the component from butanol was pectolinarin. Therefore, this study suggested that the feasibility of mulberry leaf as a functional food additive and its value as a natural antioxidant is very high.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2557-2560
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• 2010

To assay for antioxidant capacity of natural products considered important in producing human health benefits, a practical and economical method using pellet techniques was developed. A standard visualizing reagent, 1,1diphenyl-2-picryl-hydrazyl (DPPH), was mixed with a water-miscible polyvinyl alcohol (PVA), serving as a solid phase support for the DPPH reagent. A DPPH pellet was prepared by dropping a small volume of the DPPH solution onto PET film, and drying in an oven. The PVA-based DPPH pellet was dissolved into water, in which the water-miscible PVA plays as a non-ionic surfactant to help the DPPH reagent to be dissolved into the solvent. Using the DPPH assay, the antioxidant capacity of water-soluble extracts of black soybean, barley, green tea, and green gram was examined. Among the natural products tested, green tea showed the highest antioxidant capacity. This PVA-based DPPH antioxidant assay can be further applied in the natural food, raw plant material, and health product inspection field.

• The Korean Journal of Food And Nutrition
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• v.35 no.4
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• pp.268-275
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• 2022

The purpose of this study was to confirm the possibility of using Korean purple yam (Dioscorea alata) as proximate composition, material, and antioxidant activity. In the proximate composition of the freeze-dried purple yam powder, the carbohydrate content was the highest at 86.67%, and in minerals, potassium showed the highest content at 1,765.69 mg/100 g. To study the antioxidant activity of purple yam, distilled water and 70% ethanol were used as extraction solvents. The total polyphenol, total flavonoid, and total anthocyanin contents were 1.3~1.6 times higher in 70% ethanol extract, than in the distilled water extract. As a result of ORAC, DPPH and ABTS radical scavenging activity, SOD activity, and reducing power, the 70% ethanol extract showed higher antioxidant activity than the distilled water extract in all results. As a result of freeze-drying purple yam and measuring antioxidant activity by extraction solvents, it is concluded that purple yam can contribute to the food industry as a natural antioxidant and health functional material.

• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.697-705
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• 2015

This study investigates antimicrobial effects of food-borne pathogens and the antioxidant activity of Torreya nucifera extract. The growth of food-borne pathogens including Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans was inhibited by the extract. The antimicrobial activity of the extract was highest for Staphylococcus aureus among seven gram-positive bacteria and for Pseudomonas aeruginosa among six gram-negative bacteria. The extract exhibited slightly lower DPPH radical-scavenging activity, but its ABTS radical-scavenging activity was higher than that of ${\alpha}$-tocopherol. The results demonstrate the extract's antimicrobial effects on food-borne pathogens as well as potent antioxidant capacity and suggest that Torreya nucifera may be used as a natural antibacterial agent and an effective antioxidant in food.