• 약학회지
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• 제34권6호
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• pp.447-456
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• 1990

Various methods are available for the production of L-threonine. The microbial production of L-threonine has been achieved by breeding L-threonine analog-resistant auxotrophic mutants of various bacteria. The enzymatic production of L-threonine has been demonstrated by use of threonine metabolic enzymes such as threonine deaminase, threonine aldolase, or threonine dehydrogenase complex. Threonine synthesis from glycine and ethanol seems to be catalyzed by the enzymes Methanol dehydrogenase(MDH) and Serine hydroxymethyltransferase(SHMT), which was also found to catalyze the aldol condensation of glycine with acetaldehyde. The improved production of L-threonine has been achieved by amplifying the genes for the L-threonine biosynthetic enzymes using recombinant DNA techniques.

• 한국세라믹학회지
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• 제28권9호
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• pp.739-749
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• 1991

Calcium hydroxide fine powders were synthesized by hydration of calcium oxide, and the shapes of powders obtained were examined for each synthethic condition. When distilled water was used as a solvent, irregular and agglomerated submicron powders were obtained, and it was impossible to control of the shapes. In methanol-added solutions, hexagonal plate-like particles were obtained, but addition of ethanol had no effect. However on the occasion that substituted ethylene glycol for ethanol of 5 vol%, hexagonal plate-like powders were obtained. The shapes of powders synthesized in acetic acid and salicylic acid solutions were hexagonal platelike, and were spherical and very fine in citric acid and oxalic acid solutions, respectively. But in some solutions, calcium salts were precipitated by the reaction between calcium and acid added. And the size of powders were very fine using ultrasonic vibration instead of mechanical agitation.

• 한국세라믹학회지
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• 제33권5호
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• pp.485-494
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• 1996

Silica Aerogels with the density and porosity of 0.1g/cm3 and 96% were synthesized by two different supercri-tical drying processes (i.e additional solvent and intial pressure methods) Isoptopanol was chosen as sol-gel and supercritical drying solvents in order to synthesize aerogels at the lower temperature and pressure because the critical values of isopropanol are lower than those of methanol and ethanol commonly used. The P-V-T relationship of isopropanol was experimentally described for optimizing supercritical drying conditions such as the amount of extra solvent and supercritical drying temperature and pressure. In the addional solvent method monolithic and transparent aerogels were obtained by supercritical drying at 25$0^{\circ}C$ and 900 psing after 40% of the reactor volume was filled with isopropanol. Crack-free aerogels were synthesized at 25$0^{\circ}C$ and 1100~1200 psig by the initial pressure method with an intial nitrogen gas pressure of 400 psig and the isopropanol amount of 5% of the reactor volume.

• Bulletin of the Korean Chemical Society
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• 제26권3호
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• pp.447-450
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• 2005

The crude methanol extract of the fruits of Amomum tsao-ko (Zingiberaceae) showed cytotoxic activity. Bioactivity-guided separation led to the isolation of a diarylheptanoid, tsaokoarylone [7-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)-hepta-4E,6E-dien-3-one] (2). 2 showed cytotoxicity at 4.9 and 11.4 $\mu$g/mL ($IC_{50}$) against human nonsmall cell lung cancer A549 and human melanoma SK-Mel-2, respectively, determined by SRB colorimetric method. During purification-(4-hydroxyphenyl)-4-hydroxyhexan-2-one (4) together with three known diarylheptanoids was also isolated. Their structures were determined from interpretation of spectroscopic data (IR, UV, MS, and NMR) and synthesis confirmed the structure of 2.

• 약학회지
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• 제48권2호
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• pp.135-140
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• 2004

For the development of new COX-2 inhibitors, 1,5-diarylhydantoins 5a∼5c and 1,5-diaryl-2-thiohydantoin 6a∼6c were synthesized from commercially available phenylacetic acids through esterification, bromination, C-N bond formation and cyclization. Esters 2a∼c were efficiently synthesized from the starting materials 1a∼c by refluxing in absolute methanol for 3 hours with catalytic concentrated sulfuric acid. Bromination of 2a∼c was carried out with use of N-bomosuccinimide at rt in dichloromethane. The bromine of 3a∼c was substituted with aniline in ethanol or N,N-dimethylformamide to provide 4a∼c. Hydantoins and 2-thiohydantoins were synthesized from 4a∼c by treatment of potassium isocyanate or potassium thiocyanate in dil-ethanol with triethylamine.

• 통합자연과학논문집
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• 제1권3호
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• pp.247-249
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• 2008

자성 결정체인 $Fe_3O_4$ 나노 입자를 합성하기위하여 강한 극성 용매인 2-pyrrolidone을 연전도 반응매개체로 하여 용액 내에 $FeCl_3{\cdot}6H_2O$을 용해시켜 2-pyrrolidone의 비등점까지 나노 결정체 고온 열분해 방법을 이용하여 제조되었다. 고온 열분해 후, $Fe_3O_4$ 나노 입자는 methanol/diethyl ether (1:3)에 의해서 침전되어졌다. 합성된 $Fe_3O_4$ 나노 입자는 고결정도, 고자기성을 가지고 있으며, 수용성의 자성 나노 결정체이다. 합성된 $Fe_3O_4$ 나노 입자의 크기와 결정도는 transmission electron microscope (TEM, Tecnai F20)를 이용하여 특성 분석하였으며, area electron diffraction (SAED) pattern과 HRTEM을 이용하여 나노입자의 격자 패턴 (lattice fringes)을 확인하였다.

• 생약학회지
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• 제17권2호
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• pp.107-112
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• 1986

The investigation aimed to study the effects of methanol fraction of licorice (FM 100) and glycyrrhizin on prostaglandin synthetase activity, in relation to their analgesic effects. Effects of FM 100 and glycyrrhizin on the activity of prostaglandin synthetase extracted from bull seminal vesicles were examined by the modified method of Takeguchi et al. The analgesic effect of FM 100 was tested in mice by the acetic acid writhing method. FM 100 was administered orally to mice. BSV prostaglandin synthetase activity was inhibited significantly by FM 100 in a dose-dependent manner, whereas the activity was slightly inhibited by glycyrrhizin. Statistically significant analgesic effects were also observed with FM 100. The results suggest that analgesic effect of licorice may be due to the inhibition of prostaglandin synthesis.

• 한국응용과학기술학회지
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• 제14권2호
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• pp.57-64
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• 1997

The symmetric naphthothiazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. In this study, green-sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-5-phenyl-benzoxazolium(inner salt) with triethyl orthoacetate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, $^1H$-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 502nm. Therefore, it was concluded that benzoxazolo carbocyanine dye can be used as green-sensitizing dye for the spectral sensitization of photographic emulsion.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.223-226
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• 2012

Biomass to Liquid (BTL) is an attractive option for using biomass as an renewable energy. A syngas supplying system has been designed for BTL system, based on the Fischer-Tropsche (FT) process, and long-term operation test was conducted. The syngas supplying system is composed of a fluidized bed gasifier, gas cleaning and compression system, and methanol absorption system. Stable operation of more than hundred hours was achieved with several champaigns. In addition, a pilot scale biomass gasifier has been developed for 1 bbl/day BTL system and its performance was evaluated. Some preliminary results and current status of the development of BTL system will be presented.

• Biomolecules & Therapeutics
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• 제6권3호
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• pp.256-260
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• 1998

-7-o-p-Fluorobenzoylchrysin was synthesized by condensing p-flouorbenzoic acid with chrysin in organic solvent, and its structure was identified by NMR, MS, UV, and IR. We also investigated the physicochemical properties, hypoglycemic effect, and the quantitative analysis method of this compound. The correlation coefficient of calibration curve on this compound was approximately 0.9945 by absorption spectrophotometry and 0.9989 by high perfornance liqid chromatography 7-o-p-Fluorobenzoylchrysin was resolved in 6.014 min by reversed-phase HPLC column with solvents consisting of methanol (80%) and 10mM phosphoric acd. Its blood glucose inhibition rate is 20.7%.