• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1219-1222
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• 2010

A simple and efficient method has been developed for conversion of arenecarbaldehyde-3-methylquinoxalin-2-ylhydrazones to 3-(2-methylquinoxalin-3-yl)-2-(substitutedphenyl)thiazolidin-4-ones in good yields using microwave irradiation technique on silica as solid support under solvent free conditions. The synthesized compounds were characterized by elemental microanalysis, infrared spectroscopy, $^1H$ NMR, and mass spectroscopy. All the synthesized thiazolidinones were investigated for their antimicrobial and antifungal activities. The results of the biological activities revealed that the compounds 3b, 3d, 3f and 3h exhibited excellent antibacterial activities while 3d and 3h exhibited good antifungal activity.

• 한국재료학회지
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• 제26권6호
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• pp.332-336
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• 2016

Three kinds of porous polymer were synthesized using a solvothermal of tri-4,4'-diphenylmethane diisocyanate (MDI-trimer) and different diamino monomers. The effects of the synthesis conditions and the monomer selection on the synthesis of porous polymer properties were studied. The results show that the synthesis of $NH_2$-containing monomer molecules smaller the microporous polymers was easy to implement; the specific surface areas of the polymers are related to the monomer ratio and the reaction time. The results show that the synthesized porous polymer had good hydrogen storage performance; the hydrogen storage ability improved with the addition of heterocyclic nitrogen.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.636-640
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• 2012

We modify ZnO nanorods with Zn-porphyrin to obtain the improved characteristics of energy transfer, which is further investigated for the applicability to photovoltaic devices. A nitrogen heterocyclic ligand containing a thiol group is covalently grafted onto the surface of finely structured ZnO nanorods with a length of 50-250 nm and a diameter of 15-20 nm. Zn-porphyrin is then attached to the ligand molecules by the mechanism of metalligand axial coordination. The resulting energy band diagram suggests that the porphyrin-modified ZnO nanorods might provide an efficient pathway for energy transfer upon being applied to photovoltaic devices.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.1863-1868
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• 2010

A simple and efficient synthesis of various $\alpha$-aminophosphonates (3a-l) by the reaction of substituted aromatic/heterocyclic aldehydes, 2-amino-6-methoxy-benzothiazole and dibutyl/diphenyl phosphites under microwave irradiation without catalyst was accomplished. The phosphonates were characterized by elemental analysis, IR, $^1H$, $^{13}C$- and $^{31}PNMR$ spectra. They showed promising antimicrobial, anti-oxidant activities depending on the nature of bioactive groups at the $\alpha$-carbon.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.207-212
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• 2004

In this study, we attempted to prepare compounds with heterocyclic replacements for metabolically unstable esters of benzopyranyl indole-2-carboxylic esters, which showed good in vitro and in vivo cardioprotective efficacies possibly through the opening of mitochondrial ATP-sensitive potassium channel ($K_{ATP}$). Initially, we tried to construct indolin-2-yl-heterocycles using unprotected indoline-2-carboxylic acid, but the cyclization was proceeded with oxidation of the indoline ring to the indole, which didn't react with benzopyranyl epoxide. Thus we introduced N-Boc group to deplete the electron density of the indoline ring. We successfully prepared various indolin-2-yl-heterocycles by the cyclization of the building blocks including carboxamide, ${\beta}$-hydroxy amide, hydrazide, nitrile starting from N-Boc-indoline-2-carboxylic acid.

• 대한전기학회논문지
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• 제40권1호
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• pp.91-98
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• 1991

Electrical conductivity of poly (3-alkylthiophene) derivatives with substituted long alkyl chain such as poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), and poly (3-docosylthiophene) increases with increasing temperature. However, after attaining a maxiumum value, it decreases with further temperature increase. Hysteresis is also observed in the temperature dependence of conductivity and absorption spectra. The absorption spectra also changes rapidly at the phase transition. These phenomena are discussed in terms of the increase of the energy band gap in the liquid states due to the decrease of co-planarity of thiophene rings accompanied by remarkable conformation changes.

• Toxicological Research
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• 제32권2호
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• pp.89-93
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• 2016

Human cytochrome P450 enzymes (P450s, CYPs) are major oxidative catalysts that metabolize various xenobiotic and endogenous compounds. Many carcinogens induce cancer only after metabolic activation and P450 enzymes play an important role in this phenomenon. P450 1B1 mediates bioactivation of many procarcinogenic chemicals and carcinogenic estrogen. It catalyzes the oxidation reaction of polycyclic aromatic carbons, heterocyclic and aromatic amines, and the 4-hydroxylation reaction of $17{\beta}$-estradiol. Enhanced expression of P450 1B1 promotes cancer cell proliferation and metastasis. There are at least 25 polymorphic variants of P450 1B1 and some of these have been reported to be associated with eye diseases. In addition, P450 1B1 polymorphisms can greatly affect the metabolic activation of many procarcinogenic compounds. It is necessary to understand the relationship between metabolic activation of such substances and P450 1B1 polymorphisms in order to develop rational strategies for the prevention of its toxic effect on human health.

• Natural Product Sciences
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• 제12권1호
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• pp.19-23
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• 2006

Berberis chitria (family Berberidaceae) has a close affinity with B. aristata, used in traditional systems of medicine as a drug 'Daruharidra' for skin disease, jaundice, affection of eyes, and rheumatism. Keeping this in view, in the present study attempts have been made to identify marker characters of B. chitria in order to differentiate the two species. Some of the diagnostic features of the root are patches of pericyclic fibre, pitted sclerieds and berberine containing cells and heterocyclic medullary rays. Besides, the physicochemical characters such as total ash; acid insoluble ash; alcohol and water soluble extractive; tannins; sugar and starch percentages has shown variations. The percentage of berberine as berberine hydrochloride was also calculated through HPTLC densitometric method and it was found little higher than B. aristata and B. asiatica i.e. 3.16%. Thus, this species can be utilized as a possible substitute to Daruharidra.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1997년도 춘계학술대회
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• pp.70-70
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• 1997

$\beta$-Lactamase 억제제로 6-Substituted exomethylene기를 갖는 penam계 화합물이 강력한 활성을 보여주고 있어서, $\beta$-lactamase억제제의 중간체 합성으로 6-exomethylene기에 도입 할 1-substituted thioalkyl-1,2,3-triazole-4-carboxaldehyde를 합성하였다. 2-Bromoethanol에 NaN$_3$를 반응시켜서 2-Azidoethanol을 합성하였고, 이것을 propargyl aldehyde와 반응시켜서 1-(2-hydroxyethyl)-1,2,3-triazole-4-carboxaldehyde를 합성하였다. 이것을 trifluoromethanesulfonic anhydride와 triethylamine존재 하에 heterocyclic mercapto화합물과 반응시켜서 hetorocyclic ring을 함유한 1-substituted thioalkyl-1,2,3-triazole-4-carboxaldehyde를 합성하였다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1997년도 춘계학술대회
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• pp.71-71
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• 1997

$\beta$-lactamase를 생성하는 균들이 $\beta$-lactam계 항생제를 분해하여 불활성화 시키므로 이를 해결하기 위하여 그 효소에 대하여 억제활성을 나타내는 새로운 6-exomethylenepenamsulfone화합물들을 합성하였다. Dibromopenamsulfone과 heterocyclic ring을 함유한 thioethyl triazole-4-carboxaldehyde를 반응시키고, acetic anhydride와 Zn으로 처리하여 E-form과 Z-form의 6-exomethylene penmsulfones을 합성하였다. 이것을 AlCl$_3$로 처리하여 deprotection시킨 후, NaHCO$_3$로 처리하여 6-exomethylene penam sulfones의 Na-salt의 형태로 목적물질을 합성하였다.