• 전기화학회지
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• 제10권4호
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• pp.295-300
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• 2007

A new characterization method using a porous plug model was proposed to determine the degree of sulfonation (DS) of ionomer binder with respect to the membrane used in membrane-electrode assemblies (MEAs) and to analyze the fraction of proton pathways through ionomer-catalyst combined electrodes in MEAs for polymer electrolyte fuel cells (PEFCs). Sulfonated poly(ether ether ketone) was prepared to use a polymeric electrolyte and laboratory-made SPEEK solution (5wt.%, DMAc based) was added to catalyst slurry to form catalyst layers. In case of the SPEEK-based MEAs in this study, DS of ionomer binder for catalyst layers should be the same or higher than that of the SPEEK membrane used in the MEAs. The porous plug model suggested that most of protons were via the ionomer binder (${\sim}92.5%$) bridging the catalyst surface to the polymeric electrolyte, compared with the pathways through the alternative between the interstitial water on the surface of ionomer binder or catalyst and the ionomer binder (${\sim}7.3%$) and through only the interstitial water on the surface of ionomer or catalyst (${\sim}0.2%$) in the electrode of the MEA comprising of the sulfonated poly(ether ether ketone) membrane and the 5wt.% SPEEK ionomer binder. As a result, it was believed that the majority of proton at both electrodeds moves through ionomer binder until reaching to electrolyte membrane. The porous plug model of the electrodes of MEAs reemphasized the importance of well-optimized structure of ionomer binder and catalyst for fuel cells.

• 한국식품영양과학회지
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• 제35권7호
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• pp.823-827
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• 2006

신선한 미더덕을 동결건조하여 분말로 만들어 water, MeOH, EtOH 및 acetone의 용매로 추출하여 항암활성을 조사하였다. 대장암 세포주 HT-29에 대한 미더덕 추출물의 암세포증식 억제효과는 ethanol 추출물이 $500\;{\mu}g/mL$ 농도에서 45.0%로 가장 높은 활성을 보였으며, 대조구와 다른 추출물에 비교하여 크게 세포의 응축과 세포수의 감소를 형태학적으로 관찰할 수 있다. 용매별 추출물 중 가장 강력한 항암활성을 가지는 ethanol 추출물을 이용하여 정제수율을 높여 암세포 성장억제효과를 확인하기 위하여 n-hexane, diethyl ether, ethyl acetate 및 water 순으로 극성을 높여 분획한 결과 diethyl ether 분획물에서 가장 높은 항암활성을 나타내었다. 그리고 diethyl ether 분획물을 인간대장암 유래의 세포주 SW620, 자궁경부암 세포 HeLa 및 유방암 세포 MCF-7에 처리하였을 때 농도 의존적으로 높은 항암활성이 나타났으며, 가장 높은 농도 $500\;{\mu}g/mL$ 처리 시 모두 10%이하의 세포 생존율을 나타내었다. 지금까지는 한약재를 비롯한 농산물 유래의 추출물이 항암효과를 보이는 연구가 보고된바 있으나 해양생물 유래의 추출물에서 항암효과를 보이는 결과에 대하여 구체적으로 보고된 바가 없는 실정이다. 따라서 이번 연구결과는 생리활성 물질을 탐색함에 있어서 해양생물이 중요한 천연자원이 될 수 있다는 가능성을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1143-1148
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• 2010

We investigated the separation of nitrogen heterocyclic compound (NHC) contained in a model coal tar fraction comprising four kinds of NHC [indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)], three kinds of bicyclic aromatic compound (BAC) [1-methylnaphthalene (1MN), 2-methylnaphthalene (2MN), dimethylnaphthalene (DMN) mixture with ten structural isomers (DMNs; regarded as one component)], biphenyl (Bp) and phenyl ether (Pe) by liquid membrane permeation (LMP). A batch-stirred tank was used as the permeation unit. An aqueous solution of saponin and n-hexane were used as the liquid membrane and the outer oil phase, respectively. Yield and selectivity of individual NHC was much larger than that of BAC, Bp and Pe. Increasing the initial mass fraction of the saponin to the membrane solution ($C_{sap,0}$) and the initial volume fraction of O/W emulsion to total liquid in a stirred tank (${\phi}_{OW,0}$) resulted in deteriorating the yield of individual NHC, but increasing the stirring speed (N) resulted in improving the yield of each NHC. With increasing $C_{sap,0}$, the selectivity of each NHC based on DMNs increased. Increasing ${\phi}_{OW,0}$ and N resulted in decreasing the selectivity of individual NHC based on DMNs. At an experimental condition fixed, the sequence of the yield and selectivity in reference to DMNs for each NHC was Q > Qu = iQ > In. Furthermore, we compared LPM method with methanol extraction method in view of the separation efficiency (yield, selectivity) of NHC.

• Parasites, Hosts and Diseases
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• 제22권1호
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• pp.127-134
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• 1984

As a series of studies to clarify clonorchicidal substances in body surface mucus of some freshwater fishes, the substance in the epidermal mucus of Cyprinus carpio was isolated by silica gel column and thin layer chromatography and analysed for its chemical nature. Wormicidal trial was done in vitro, and the results obtained are summarized as follows: The mucus was extracted by ethyl ether and separated into 4 fractions by column chromatography using benzene as solvent. The second fraction with yellowish red colour among them showed the strongest clonorchicidal effect. The yellowish red fraction obtained by column chromatography was then fractionated into 6 spots by thin layer chromatography with petrol/ etherjchloroform (30/70, v/v), and the Rf. 0.714 spot among the 6 spots showed the strongest effect. The Rf. 0.714 spot was further fractionated into 6 spots by thin layer chromatography with benzene/acetone (90/10, vlv), and the Rf. 0.800 spot among the later 6 spots revealed the strongest effect. The Rf. 0.800 spot was chromatographed on column with benzene and 2 fractions were obtained. The second fraction of light brown colour represented the final purified fraction. By these Purification Procedures, clonorchicidal substance was Purified 15-fold with 0.035 yield from the mucus of C. carpio, and 10mg of the final fraction killed the cercaria in 26 min, the metacercaria in 115 min, and the adult in 443 min. Infra red and nuclear magnetic resonance spectrometric analysis of the purified substance revealed that the substance belongs to an ethyl ester of unsaturated fatty acid with 2 double bonds, 15 methylene groups and 1 methyl group.

• 약학회지
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• 제42권3호
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• pp.330-335
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• 1998

Gastrodia elata (GE) is a oriental medicinal herb which has been used traditionally for the treatment of various brain diseases including convulsion and epilepsy. In orde r to examine the mechanism of anticonvulsive effect, we treated the methanol extract of GE (500mg/kg, P.0) to the pentylenetetrazole (PTZ)-induced convulsive rats. Methanol extracts of GE significantly inhibited (35%) the convulsion state as well as the level of lipid peroxidation (25%) in the brain. The ether fraction of methanol extracts among the others effectively ibhibited in vitro lipid peroxidation dose dependently ($5.O{\times}10^{-6}{\sim}2.O{\times}1O^{-5}g/ml$). The scavenging effect on hydroxy radicals was found in all the fractions of ether, butanol, and dichloromethane. These results suggest that the anticonvulsive effect of GE is possibly due to the antioxidative effects of the active components in GE.

• 한국약용작물학회지
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• 제6권2호
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• pp.91-95
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• 1998

추출조건에 따른 지골피의 몇가지 물리적 성질 및 화학성분조성을 조사하였다. 1. 고형분과 총당함량은 물추출이 에탄올 추출물보다 높았으나 반면에 탄닌산함량은 에탄올 추출물에서 높았다. 2. 지골피 물추출물이 탁도와 갈색도가 에탄올추출물보다 높았으며 색도 중 적도와 황색도는 유사하였다. 3. 용매별 분획추출결과 수율은 물 > n-부탄올 > 에틸에텔 > 초산에 틸 분획순으로 증가하였다.

• 한국연초학회지
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• 제16권2호
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• pp.172-180
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• 1994

This study was carried out to separate and identify the acidic compounds in tobacco leaves. Izmir tobacco leaves was extracted with isopropyl ether and the extract was concentrated. The concentrate was extracted with 6% NaHCO3 aqueous solution. The aqueous extract was acidified with sulfuric acid, and extracted with diethyl ether. The acidic material was fractionated on silicic acid column using a benzene-methanol mixture with a stepwise increasing methanol concentration. The resulting fractions were esterified with diazomethane, and then identified by GC, GC/MS using SPB -5 fused silica capillary column. Most of acidic compounds in Izmir tobacco leaves were elected from fraction B which was benzene-methanol(98 : 2) mixture on silicic acid column chromatography. The identified acidic compounds of Izmir tobacco leaves were 18 saturated acids, 8 unsaturated acids, 5 dicarboxylic acids, 13 aromatic acids and 7 terpenoid acids. The major acidic compounds of lzmir tobacco leaves were 2- methylbutanoic, 3-methyl butanoic, 3- methylpentanoic, hexanoic, nonanedioic, phenylacetic, benzoic, 4- methoxybenzoic, 3, 5- dimethoxybenzoic, methoxycinnamic and 3, 4- dimethoxycinnamic acid. Key Words : Izmir tobacco, Acidic compounds, GC/MS.

• Archives of Pharmacal Research
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• 제17권5호
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• pp.331-336
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• 1994

The ether extract from the roots of angelica clahurica was found to inhibit bovine lens aldose reductase (BLAR0 activity in vitro by 100% at 100.mu.g/ml. Systematic fractionation of the ether soluble fraction and subsequent active frctions monitorede by bioassy led to isolation of four furanocoumarins, isoimperatorin (I0, imperatorin (II), ter-O-methyl byakangelicin (III) and byakangelicin (IV), among which compound III and IV were identified as potential AR inhibitors, their $IC_{50}$ values being $2.8{\mu}M{\;}and{\;}6.2{\mu}M$, respectively. Galactosemic cataract formation tors, in rats treated with 40 g/kg/day of galactose was blocked almost completely throughout the exeprimental periods up to 44 days by i.p. administrations of byakangelicin (IV) at 50 mg/kg/day. In coincidence with the inhibitory action on cataract formation, the galactitol accumulation in rats treated with byakangelicin (IV) was found to be markedly prevented by approximately 80.5% compared to those of the contro. These results indicate that byakangelicin (IV), as a main principle of this plant, possesses high potential for a clinically useful drug of the future which prevents and/or improves sugar cataract as well as diabetic complications.

• Biomolecules & Therapeutics
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• 제6권3호
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• pp.261-268
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• 1998

Propolis is a lipophilic, natural product prepared by mixing the exudates collected from various plants by honeybees with beeswax for the purpose of using to seal hive walls and to strengthen the borders of combs. Because of its versatile bioactivities, propolis has been attracting many investigators'interest. But the pharmacological studies on propolis has, to date, been exclusively performed for an alcohol extract, there is few information of water extract. Therefore, in this study, we investigated the various effects of water extract of Chinese propolis. The water extract of propolis and its fractions of organic solvents showed strong antioxidative activities, especially ether and ethylacetate fractions, and reduced the lipid peroxidation of rat liver in viro. Additionally the ether fraction of propolis (10 mg/ml) inhibited the activity of hyaluronidase by 50%. In vivo, the water extract of propolis considerably decreased s-GOT, s-GPT and s-LDH activities which represent for the hepatotoxicity induced by $CCl_4$ in rats, and prolonged the MST (Medium revival tinge) and ILS (Increasing in MST over control) by 18% in mice which inoculated with sarcoma 180 ascites cells. These results suggest that the water extract of propolis has various bioactivities as well as the alcohol extract.

• 임산에너지
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• 제22권1호
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• pp.30-36
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• 2003

화분을 98%의 EtOH로 추출하고 hexane, CH₂Cl₂, EtOAc, 그리고 H₂O용성으로 분획하여 동결건조 시켰다. 그 중에서 EtOAc 분획을 Sephadex LH-20으로 충진한 칼럼에서 MeOH와 EtOH-hexane혼합액을 용리용매로 사용하여 칼럼크로마토그래피를 실시하였다. 단리된 화합물들은 TLC로 확인한 후 NMR스펙트럼을 사용하여 정확한 구조규명을 하였고 FAB-MS로써 분자량을 측정하였다. 주로 quercetin-3-O-β-D-glucopyranoside와 kaempferol-3-O-β-D-rutinoside같은 flavonol 유도체들과 flavanonol계 화합물인 aromadendrin-5-methyl ether, 그리고 acid 화합물인 p-methoxybenzoic acid가 적은 양으로 단리 되었다.