• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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• pp.258-262
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• 2007

In the present study, we investigated the antioxidant activity of methanol extract and its organic fractions (n-hexane, $CH_2Cl_2$, EtOAc, n-BuOH and $H_2O$) of Capsiccum annuum leaves against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. As results, methanol extract, and its ethyl acetate and n-butanol fractions showed good scavenging effect at 100 ${\mu}g/ml$. Four compounds were isolated from the ethyl acetate fraction through silica gel and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated as apigenin (1), vanillic acid (2), uracil (3) and apigenin $7-O-{\beta}-D-apiofuranosyl(1{\rightarrow}2)-{\beta}-D-glucopyranoside$ (4) by comparison of spectral data with those in reference. $IC_{50}$ value of compound 2 was 14.7 ${\mu}g/ml$, while compounds 1, 3 and 4 had no effect on the DPPH radical.

• Nutrition Research and Practice
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• v.5 no.2
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• pp.93-100
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• 2011

Inhibition of angiotensin I-converting enzyme (ACE) activity is the most common mechanism underlying the lowering of blood pressure. In the present study, five organic extracts of a marine brown seaweed Ecklonia cava were prepared by using ethanol, ethyl acetate, chloroform, hexane, and diethyl ether as solvents, which were then tested for their potential ACE inhibitory activities. Ethanol extract showed the strongest ACE inhibitory activity with an $IC_{50}$ value of 0.96 mg/ml. Five kinds of phlorotannins, phloroglucinol, triphlorethol-A, eckol, dieckol, and eckstolonol, were isolated from ethanol extract of E. cava, which exhibited potential ACE inhibition. Dieckol was the most potent ACE inhibitor and was found to be a non-competitive inhibitor against ACE according to Lineweaver-Burk plots. Dieckol had an inducible effect on the production of NO in EAhy926 cells without having cytotoxic effect. The results of this study indicate that E. cava could be a potential source of phlorotalnnins with ACE inhibitory activity for utilization in production of functional foods.

• Journal of Information Display
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• v.4 no.4
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• pp.4-7
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• 2003

The world largest 21.3" LTPS LCD has been successfully developed using SLS crystallization technology. Integration of gate circuit, transmission gate and level shifter was successfully performed in a large area display. Uniform and high performance of high quality grains of SLS technology make it possible to realize a uniform large size LTPS TFT-LCD with half the number of data driver IC's that is typically used in a-Si LCD. High aperture ratio of 65 % was achieved using an organic inter insulating method which lead to a high brightness of 500 cd/$cm^2$.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.241-244
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• 2003

The world largest 21.3" LTPS LCD has been successfully developed using SLS crystallization technology. Successful integration of gate circuit, transmission gate and level shifter was performed in a large area uniformly. Uniformity and high performance from high quality grains of SLS technology make it possible to come true a uniform large size LTPS TFT-LCD with half number of data driver IC's used in typical a-Si LCD. High aperture ratio of 65% was obtained using an organic inter insulating method, which lead a high brightness of 500cd/cm2.

• Natural Product Sciences
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• v.24 no.2
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• pp.125-131
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• 2018

Berries and branches essential oil of Juniperus phoenicea were obtained by electromagnetic induction heating assisted extraction and by hydrodistillation with a yield varied from ($1.2{\pm}0.3$ to $2.4{\pm}0.7%$) and from ($0.6{\pm}0.1%$ to $1.1{\pm}0.1%$), respectively. forty eight compounds were identified representing (97.2 - 99.7%) of the oil. ${\alpha}$-Pinene (40.3 - 67.8%) and ${\delta}$-3-carene (13.5 - 26.8%) were the main compounds in berries and branches essential oils. Antioxidant activity was evaluated by three means: inhibition of 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical, reducing power and ${\beta}$-Carotene/linoleic acid bleaching. The antioxidant activity of essential oils showed $IC_{50}$ ranging from $67.6{\pm}1.02{\mu}g/mL$ to $131.5{\pm}0.8{\mu}g/mL$ for berries and from $98{\pm}1.25{\mu}g/mL$ to $166.8{\pm}0.29{\mu}g/mL$ for the branches. Berries oil show more potent antioxidant activity compared to branches. This result is supported by the three methods investigated in this work.

• Korean Journal of Pharmacognosy
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• v.44 no.1
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• pp.1-5
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• 2013

Nelnumbo nucifera Gaerth. (Nymphaeaceae) has been used in a korean traditional medicine to treat fever, sunstroke and dizziness. The receptaculums of this plant were refluxed with MeOH, and then fractionated with organic solvents ($CH_2Cl_2$, EtOAc and n-BuOH) to screen whitening activity using tyrosinase inhibitory activity. EtOAc ($IC_{50}$, 45.23 ${\mu}g/ml$) fractions showed a good tyrosinase inhibitory activity. Column chromatographic separation of $CH_2Cl_2$ and EtOAc fractions of Receptaculum nelumbinis led to the isolation 3 compounds. Their chemical structures were characterized as ${\beta}$-sitosterol (1), quercetin 3-O-${\beta}$-D-galactopyranoside (2) and kaempferol 3-O-${\beta}$-D-glucopyranoside (3) by comparison NMR spectral data and with those in references, respectively. Isolated compounds 1 and 3 were firstly isolated from Receptaculums nelumbinis. Compounds 2 and 3 showed potent whitening activities.

• Journal of the Korean Ceramic Society
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• v.48 no.6
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• pp.510-515
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• 2011

In this study, as a material used to replace silica fumes for high strength concrete, nano-silica compound with organic functional group for dispersion and with inorganic silica group that can cause a pozzolan reaction is synthesized, These nano silica compound is divided into IC, which is nano size $SiO_2$ with irregularly combined hydroxyl group and carboxyl group, and RC, which is nano size $SiO_2$ with regularly combined hydroxyl group and carboxyl group. The effects of these nano silica compound on the hydration of cement are reviewed. As a result, all of synthesized nano-silica compounds have excellent dispersion on the cement flow, we think that dispersion property is the effect of air entraining by synthesized nano-silica compounds. The result of the microstructure observation showed that the particle size of the synthesized nano-silica is smaller than silica fume and spread evenly among the cement particles. In initial The phenomenon of strength decreasing occurred due to delayed hydration reaction by the synthesized nano-silica with carboxyl(-COOH) and hydroxyl(-OH) functional group.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.135-136
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• 2013

본 연구에서는 ripple 구조의 ZnO 박막을 역 구조 태양전지 내에서의 전자 수집층 으로 사용하였으며, $P3HT/IC_{60}BA$와 PEDOT을 각각 active layer와 정공 수집층 으로 사용하였다. zinc acetate의 농도 조절을 통해 다양한 두께와 roughness를 갖는 ripple 구조의 ZnO를 합성할 수 있었으며, hot plate위에서의 온도 조절을 통해 저온에서의 ZnO ripple를 합성할 수 있었다. 다른 농도를 사용해 합성한 ZnO ripple들 보다 0.6M의 zinc acetate를 사용하였을 때 가장 높은 power conversion efficiency (PCE) 와 external quantum efficiency (EQE)를 보여주었다. AFM과 SEM 분석을 통해 0.6M의 zinc acetate조건에서는 표면적이 가장 넓으면서도 다른 농도를 사용 하였을 때에 비해 상대적으로 ripple의 깊이가 더 깊은 표면을 갖는 ZnO가 생성됨을 알 수 있었다. 이는 상대적으로 넓은 surface area를 갖는 ZnO ripple과 active layer 계면사이에서 보다 용이한 charge transfer가 이루어 질수 있기 때문이다.

• YAKHAK HOEJI
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• v.47 no.4
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• pp.224-229
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• 2003

We have investigated the transport characteristics of synthetic antioxidant and free radical scavenger, $\alpha$-phenyl-n-tert-butyl nitrone (PBN) at the blood-brain barrier (BBB) by in vitro uptake study in conditionally immortalized rat brain capillary endothelial cell line (TR-BBB). Also, the efflux of PBN from brain to blood is estimated using the brain efflux index (BEI) method. Choline is a charged organic cation, including nitrogen-methyl group and shows the carrier-mediated distribution to the brain. [$^3$H]Choline uptake by TR-BBB cells was significantly inhibited by PBN with $IC_{50}$/ of 1.2 mM, which appears to be due to similar structures between choline and PBN. And, PBN was microinjected into Par2 of the rat brain by BEI method, and was eliminated from the brain with an apparent elimination half-life of about 2 min. Also, [$^3$H]choline efflux was significantly inhibited by PBN using BEI method. In conclusion, the efflux transport of PBN takes place across the BBB and PBN may be transported into the brain and eliminated from the brain by BBB choline transporter.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.5
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• pp.751-758
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• 2010

Prunus mume is well known contain many functional materials that play beneficial roles in the human body. Studies have found that many organic acids and polyphenol compounds exist in Prunus mume. In this study, content of total polyphenols and flavonoids, antioxidative activity and cytotoxicity of ethanol extract from Prunus mume were measured Contents of total polyphenolic and total flavonoid compounds in ethanol extract from Prunus mume were 16.92 mg/g and 59.95 mg/g, respectively. The $IC_{50}$ of ethanol extract from Prunus mume were $237.72 {\mu}g$/assay and $239.58 {\mu}g$/assay by DPPH and ABTS radical cation scavenging test, respectively. Additionally, ferric ion reducing antioxidant power (FRAP) value of ethanol extract from Prunus mume was 0.94 mM ($FeSO_4$ eq.) by $800 {\mu}g$/assay. Cytotoxicity of Prunus mume against five kinds of cancer cell lines increased as the extract concentration increased Especially, cytotoxicity of the ethanol extract against A-549 (lung cancer line) was higher than that against any other cancer cell line by both MTT and SRB assay. These results show that ethanol extract of Prunus mume has considerably high antioxidative and cytotoxic activities.