• 한국자원식물학회지
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• 제28권3호
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• pp.305-311
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• 2015

This study investigated in vitro antioxidant, anti-inflammatory and cytotoxicity on human lung epithelial A549 cells of different solvent extracts from Jerusalem artichoke (Helianthus tuberosus L.) tuber. The EtOH extract contained amounts of phenolics (22.20 tannic acid equivalent ㎎/ɡ) and exhibited the highest antioxidant activity and anti-inflammatory activity. Several methods were employed for measure the antioxidant activity: 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (IC₅₀ = 206.79 ㎍/㎖), reducing power activity (21.26 ascorbic acid equivalent ㎎/ɡ) and total antioxidant activity (19.05 ascorbic acid equivalent ㎎/ɡ). Meantime, the EtOH extract inhibited the NO production completely with a concentration of 800 ㎍/㎖. Besides, the H₂O extract exhibited more potent effect on human lung epithelial A549 cells. This study suggested that Jerusalem artichoke tuber had antioxidant, anti-inflammatory and cytotoxicity on human lung epithelial A549 cells.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1809-1813
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• 2003

Monomeric antioxidant 1 was prepared by the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with N-[4-(chlorocarbonyl)phenyl]maleimide in the presence of imidazole. Monomeric antioxidant 2, bearing carbamate group, was synthesized from the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and azidomaleimide. Antioxidant 3 was prepared by the reaction of N-(4-hydroxyphenyl)maleimide and 3-(3,5-ditert-butyl-4-hydroxyphenyl) propionic chloride in the presence of triethylamine. These reactive antioxidants were grafted onto polypropylene (PP) by melt-processing with free radical initiators in a mini-max moulder. From the infrared spectra of the grafted PP, it was found that the monomeric antioxidants were grafted onto PP. IR spectroscopic methods were used for the quantitative determination of the extent of grafting of monomeric antioxidant. To optimize the reaction conditions, the influences of the concentration of DCP, monomeric antioxidant, reaction time and temperature on the extent of grafting were studied.

• Archives of Pharmacal Research
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• 제19권3호
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• pp.223-227
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• 1996

The antioxidant activity of Ecklonia stolonifera 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 the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The methanol extract of Ecklonia stolonifera showed strong antioxidant activity. And the methanol extract was fractionated with several solvents. With regard their fractions, the antioxidative activity were in the order of ethyl acetate>dichloromethane insoluble intermediated phase>dichloromethane>n-butanol>water fraction. The ethyl acetate soluble fraction exhibiting the strongest antioxidant activity was further purified by repeated silica gel and Sephadex LH-20 column chromatography. Antioxidant phloroglucinol was isolated and identified by$ ^1H-NMR\; and\; ^{13}C-NMR$. Its antioxidant activity was simlilar to that of L-ascorbic acid.

• 대한한의진단학회지
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• 제17권3호
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• pp.275-286
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• 2013

In the present study, antioxidant activity and protective effect of extracts from Sambucus williamsii var. coreana stems (SWC) were evaluated on tert-butyl hydroperoxide (t-BHP) induced oxidative stress in human liver (Chang) cells. Antioxidant activities of the SWC extracts were determined by various radical scavenging activities, such as DPPH, ferric reducing antioxidant power (FRAP), 2,2'-azinobis-(3-ethybenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and oxygen radical absorbance capacity (ORAC) assay. SWC extracts showed strong antioxidant effect on various assay. To determine the hepatoprotective effects of SWC on t-BHP induced oxidative damage, cell viability was measured using MTT assay. Pretreatment of SWC extracts showed increasing cell viability, decreasing ROS and restoring mitochondria membrane potential on t-BHP induced oxidative stress in Chang cells. Our findings suggest that SWC extracts may be considered a potential agent for therapeutic protective effect from oxidative stress through its antioxidant activity.

• Archives of Pharmacal Research
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• 제29권7호
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• pp.577-581
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• 2006

Oxidative mechanisms are thought to have a major role in cataract formation and diabetic complications. Antioxidant enzymes play an essential role in the antioxidant system of the cells that work to maintain low steady-state concentrations of the reactive oxygen species. When HLE-B3 cells, a human lens cell line were exposed to 50-100 mM glucose for 3 days, decrease of viability, inactivation of antioxidant enzymes, and modulation of cellular redox status were observed. Significant increase of cellular oxidative damage reflected by lipid peroxidation and DNA damage were also found. The glycation-mediated inactivation of antioxidant enzymes may result in the perturbation of cellular antioxidant defense mechanisms and subsequently lead to a pro-oxidant condition and may contribute to various pathologies associated with the long term complications of diabetes.

• KSBB Journal
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• 제29권2호
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• pp.92-97
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• 2014

In this study, we investigate the antimicrobial and antioxidant activities of extracts of Enteromorpha intestinalis. To evaluate the antimicrobial and antioxidant activities, three solvents (hexane, chloroform and methanol) were applied to obtain extracts. The extraction yields are hexane (A) 1.11%, chloroform (B) 0.94%, and methanol (C) 8.2%. Also, the contents of total phenolic compounds of extract A, B, C are 4.03%, 8.15%, and 2.33%, respectively. In the results of antimicrobial activity, extract A and B have higher activity than that of extract C. Especially, Vibrio vulificus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli are more sensitive than others. In antioxidant activity, extract A and B present the higher DPPH activity than that of control (BHA and ascorbic acid). The DPPH radical scavenging activity and SOD-like activity are ordered as B>C>A. However, extract C show high value in ferric reducing antioxidant power assay. In nitrite scavenging activity, extract A is relatively higher than others. However, the antioxidant activities are lower than that of controls (ascorbic acid and BHA). The antioxidant activities are presented the increasing pattern of increasing by the increasing of extract concentration.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.289-293
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• 2003

Antioxidant activity and nicotine degradation activity (NDA) of 21 medicinal herbs were determined by using a 1,1-diphenol-2-picrylhydrazyl (DPPH) method and a PLC/PRF5 human liver cell line method, respectively, to develop an anti-smoking aid. The highest and lowest antioxidant activities represented by $IC_{50}$/ value were 30 $\mu$g/mL of Eugenia caryophyllus and 3,270 $\mu$g/mL of Panax ginseng C. A. Meyer, respectively. Antioxidant activity of Eugenia caryophyllus was equal to 38.0$\pm$1.2 mg VCEAC(vitamin C equivalent antioxidant capacity)/ g herb. The highest and lowest NDA values were 1.81 of Astrgalus membranaceus Bunge and 1.01 of Raphani seed and Lespedeza tomentosa Sieb, respectively. Eleven medicinal herbs with high antioxidant activity and/or NDA were selected to make an herbal tea. The herbal tea had high antioxidant activity (50 $\mu$g/mL $IC_{50}$/ and 22.4$\pm$1.4 mgVCEAC/g) and NDA (1.243). The medicinal herb tea could help smokers quitting smoking by degrading and exhausting nicotine accumulated in body and removing reactive oxygen species.

• 한국자원식물학회지
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• 제29권6호
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• pp.642-649
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• 2016

This study was conducted to investigate the antioxidant activity in the leaves and stems of 50 tomato accessions, in order to examine the possibility of using tomato by-products as a functional material. The extracts of the leaves (LE) and stems (SE) were analyzed for DPPH, ABTS, and total polyphenol content (TPC). Antioxidant activities and TPC differed significantly between the LE and SE of the 50 tomato accessions. TPC in LE and SE showed wide variation, ranging from 24.4 to 60.6 and 12.5 to 18.8 mg GAE/g, respectively. The DPPH and ABTS antioxidant activities of LE ranged from 10.0 to 38.2% (scavenging effect) and 20.8 to 59.0 mg ASC/g, respectively, while the DPPH and ABTS measurements of SE were 1.4 to 8.8% and 2.2 to 22.5 mg ASC/g, respectively. As assessed by the relative antioxidant capacity index (RACI), IT033117 and IT203466 had the highest antioxidant activity in LE and SE, respectively. These results will expand the knowledge of antioxidant activity and provide information on tomato accessions valuable for the development of functional foods and food additives.

• 한국조리학회지
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• 제24권2호
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• pp.103-111
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• 2018

The objectives of the present study were to examine the antioxidant activity of autofocusing fractions from egg white protein hydrolysates and obtain higher antioxidant peptide fraction, which could be applied to the food model system. Alkaline protease hydrolysate of egg white protein exerted higher antioxidant activities than other protein hydrolysates and were fractionated on the basis of the amphoteric nature of sample peptides by preparative isoelectric focusing without toxic solvents and reagents, which is termed autofocusing. Neutral and basic fractions showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the acidic fractions. The acidic and neutral fractions showed higher hydroxyl (OH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) values than the basic fractions. The acidic fractions showed higher metal chelating activity than basic fractions. Antioxidant activities of some autofocusing fractions except for ORAC showed higher compared to the crude hydrolysate. These results suggest that peptides fractions from egg white protein are effective antioxidant, and that autofocusing could be useful to increase antioxidant activity for application to food system.

• 전기의세계
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• 제22권4호
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• pp.30-34
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• 1973

The main purporse of this paper is to study on the influence of temperature effect on electrical-properties, i.e., dielectric breakdown voltage, dielectric constant and resitivity of homemade insulating oil containing antioxidant. Transformer oil manufactured in Korea is taken for a sample, and this sample is classified into seven samples in which antioxidant is contained and not contained, and antioxidant is divided into three kinds of amount: 0.3%, 0.5%, 0.8%. Changing the tempe5rature of the samples by oil bath, the electric properties measured from the samples are as follows: (1) the variation of either the dielectric breakdown voltage or the resistivity are considerably large, but the dielectric constants are almost unchanging. (2) In view of electrical characteristic, the deterioration rate of the samples containing antioxidant is somewhat lower than that of other samples. (3) Nearly the same value is shown in the dielectric-breakdown voltage of the samples, in which contained the different amount of antioxidant: 0.3%, 0.5%, 0.8%, but the decrease rate of resitivity is lowest, 0.3%, of all. As the result of the experiment, This study can suggest that 0.3% be the optimum amount of antioxidant which will be added transformer oil manufactured in Korea and is useful for the understanding about the electrical properties of transformer oil containing antioxidant.