• Archives of Pharmacal Research
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• v.20 no.2
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• pp.148-154
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• 1997

The antioxidant activity of Artemisia iwayomogi was determined by measuring the radical scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. The methanol extract of A. iwayomogi showed strong antioxidant activity, and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate > n-butanol > water > chloroform > n-hexane fraction. The ethyl acetate and n-butanol soluble fractions exhibiting strong antioxidant activity were further purified by repeated sitica get and Sephadex LH-20 column chromatography. Antioxidant chlorogenic acid was isolated as one of the active principles from the n-butanol fraction, together with the inactive components, 1octacosanol, scopoletin, scopolin, apigenin $7, 4^{I}$-di-O-methylether, luteolin $6, 3^{I}$-di-O-methylether (jaceosidin), apigenin methylether (genkwanin), 2, 4-dihydroxy-6-methoxyacetophenone $4-O-{\beta}-$D-glucopyranoside and quebrachitol. The antioxidant activity of chlorogenic acid was comparable to that of L-ascorbic acid, which is a well known antioxidant.

• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.110-116
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• 2016

As a part of an ongoing search for natural plants with antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a total extract of the aerial parts of Bidens frondosa L. (Compositae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of five compounds, quercetin-3-O-${\beta}$-D-glucopyranoside (1), luteolin-7-O-${\beta}$-D-glucopyranoside (2), 7,8,3',4'-tertrahydroxy-flavanone (3), okanin-4-O-${\beta}$-D-glucopyranoside (4), and okanin (5). Their structures were elucidated by spectroscopic studies. Compounds 3-5 were isolated for the first time from this plant. Among them, compounds 3 and 5 showed the significant radical scavenging effects on DPPH, and compounds 3 and 5 also showed the potent riboflavin and xanthine originated superoxide quenching activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.518-523
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• 2016

This study investigated the nutritional components and antioxidant activity of dry bitter melon (Momordica charantia L.). The moisture, crude protein, crude fat, crude ash, carbohydrate, and ascorbic acid contents of dry bitter melon were 6.10%, 3.31%, 1.08%, 2.31%, 87.20%, and 908.84 mg/100 g, respectively. Potassium was the most abundant mineral, followed by Mg, P, Na, Ca, Zn, Cu, and Mn, which means dry bitter melon was an alkali material. Regarding amino acid contents, dry bitter melon was rich in arginine, urea, asparagine, ${\gamma}-aminobutyric$ acid, and alanine. Total polyphenol and total flavonoid contents of dry bitter melon extract were 36.08 mg gallic acid equivalents/extract g and 15.66 mg tannic acid equivalents/extract g, respectively. The $IC_{50}$ value for 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity was 9.81 mg/mL for dry bitter melon ethanol extracts.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.3
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• pp.327-334
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• 2018

Studies on seaweed-based materials have been progressing steadily day by day. In this experiment, we checked the anti-oxidant, whitening, and moisturizing activities of fermented extract from a mixture of Undariapinnatifida, Saccharina japonica, and Gloiopeltis furcate. Also, Lactobacillus sakei strains of kimchi were used as the lactic acid bacteria. The physiological status of the combined seaweed extracts was also investigated. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging results showed that the inhibitory effects of the combined seaweed extracts were higher than the positive control. Furthermore, 3,4-dihydroxy-L-phenylalanine (L-DOPA) and Mushroom tyrosinase tests were conducted during the whitening efficacy experiment. Hence, it was confirmed that the whitening activity of fermented extracts was greater than the extracts without fermentation. HPLC analysis of fucose (an active ingredient of seaweed) was also performed and a standard method for solvent conditions was newly established. This study suggests that the composite of algae extract has potentials to be used as anti-oxidant and whitening agents in cosmetics.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1378-1380
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• 2005

The efficiency and the optical properties of the yellow organic light-emitting devices (OLEDs) were significantly affected by the existence of the multiple quantum well (MQW) structures consisting of N, N'- bis-(1-naphthyl)-N, N'-diphenyl-1,1-biphenyl-4,4'- diamine(NPB)/5,6,11,12 - tetraphenylnaphthacene (rubrene). The maximum efficiency and the luminance of OLEDs with 3-periods of the NPB/rubrene MQWs at 41.6 $mA/cm^2$ were 3.66 cd/A and 1524 $cd/m^2$, respectively, and their Commission Internationale de l'Eclairage chromaticity coordinates were (0.34, 0.55), which indicates a yellow color. These results indicate that the efficiencies of the OLEDs by using MQW emitting layers can be improved.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.351-358
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• 2016

The purpose of this research was to examine the effect of the ehanol extracts of Sophora japonica L. (S. japonica). flowers, fruits and branches on skin enhancement with assessing anti-oxidative, whitening, and wrinkle enhancement effects. Results showed that l,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activities were $17.68{\pm}1.59{\sim}51.40{\pm}1.04$, $27.48{\pm}0.22{\sim}50.89{\pm}0.13$ and $30.79{\pm}0.55{\sim}45.17{\pm}0.83%$, respectively, in 50~1,000 mg/L of concentrations. The capacities of inhibiting tyrosinase of ethanol extracts from S. japonica. flowers, fruits and branches were $0.27{\pm}0.12{\sim}11.38{\pm}0.57$, $0.27{\pm}0.02{\sim}0.82{\pm}0.27$ and $0.09{\pm}0.16{\sim}0.55{\pm}0.27%$, respectively. The capacities of preventing porcine pancreatic elastase (PPE) were $3.70{\pm}1.23{\sim}7.28{\pm}1.01$, $3.06{\pm}2.13{\sim}13.03{\pm}2.99$ and $6.00{\pm}0.96{\sim}9.71{\pm}0.44%$, respectively, in the case of 50~1,000 mg/L of concentrations. It is concluded that the effects of S. japonica. flowers, fruits and branches on skin improvement are varied significantly.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.223-231
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• 2021

The antioxidant activity of Chrysanthemum indicum L. extract (CIL) was investigated by fermenting lactic acid bacteria with the CIL from 64% and 80% ethanol extraction and measuring the total phenolic contents (TPC), flavonoid, 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power (RP), and linoleic acid auto-oxidation inhibitory activity. CIL was confirmed to inhibit bacterial auto-oxidation. TPC was increased in strains 3109 and 3237, while flavonoid decreased in all strains. DPPH was increased in strains 3074 and 3109 fermented with 64% CIL and all the strains with 80% CIL. RP was increased and linoleic acid auto-oxidation inhibitory activity decreased in all the strains fermented with 64% or 80% CIL. Among the 4 strains, strain 3109 had the highest DPPH and RP; thus, it was most effective in increasing CIL's antioxidant efficacy through the fermentation process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.533-534
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• 2005

Temperature-dependent current-voltage characteristics of organic light-emitting diodes(OLEDs) were studied in a device structure of ITO/TPD/$Alq_3$/Al. The OLEDs were based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-l,1'-diphenyl-4,4'-diamine(TPD) as a hole transport and tris(8-hydroxyquinoline) aluminum($Alq_3$) as an electron transport and emissive material. The current-voltage characteristics were measured in the temperature range of 10K and 300K. We analyzed an electrical conduction mechanism of the OLEDs using space-charge-limited current(SCLC) and Fowler-Nordheim tunneling.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.1-4
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• 2000

The Bis(8-oxyquinolino) zinc lII (Znq2) were synthesized successfully from zinc chloride $(ZnCl_2)$ as a initial material . The organic electroluminescece devices (ELDs) were fabricated with N-N'-diphenyl-N-N'-bis (3-meth-ylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) which act as a hole transporting layer and the Znq2 act as an EL emitting layer and electron transporting layer. In order to maximize luminance of ELD, TPD/Znq2/Al were deposited onto cleaned indium tin oxide (ITO) by changing thickness of EL emitting layer. The photoluminescence (PL) results show that Znq2 compound emits yellow green from 540nm. electrochemical behavior with V-J and V-L curve of carrier injection was investigated from 6 V. respectively. The maximum luminance were defected about $838 cd/m^2$. From these results, ai synthesized Znq2 material maybe one of the useful material of organic EL display material.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.277-282
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• 2009

The antioxidant potency of methanolic extract of Duchesnea indica (MDI; Indian strawberry) was investigated by employing various established in vitro systems, such as total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power assay, metal chelating assay, superoxide radical scavenging activity and protective ability of DNA damage and protein oxidation. MDI inhibited metal chelating by 75.57% at 2 mg/mL, scavenged 50% DPPH free radical at 29.13 ${\mu}$g/mL, and eliminated approximately 46.21% superoxide radical at the concentration of 1 mg/mL. In addition, MDI showed strong ability on reducing power, DNA damage protection and protein oxidation protection. Overall, results suggested that MDI might be beneficial as a potent antioxidant and effectively employed as an ingredient in food applications.