• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.553-556
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• 2004

In this study we have performed ab initio computer simulations to investigate the conformational characteristics of the tetraethyl (1) and triethyl ester (2) of p-tert-butylcalix[4]arene. The structures of different conformational isomers for each compound have been optimized using ab initio RHF/6-31G methods. After optimization, B3LYP/6-31+G(d,p) single point calculations of the final structures are done to include the effect of electron correlation and the basis set with diffuse function and polarization function. Relative stability of tetraethyl ester (1) of p-tert-butylcalix[4]arene is in following order: cone (most stable) > partial cone > 1,3- alternate > 1,2-alternate isomer. Relative stability of triethyl ester (2) of p-tert-butylcalix[4]arene is in following order: cone (most stable) > 2-partial cone > 1-partial cone > 3-partial cone ~ 1,3-alternate ~ 1,2- alternate isomer.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1337-1342
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• 2014

A novel and convenient route for the synthesis of a series of thalidomide derivatives is described. Compound 2 was cyclized with different amines under alkaline condition to obtain 4-nitro substituted phthalimidines 3a-d. Hydroxylactams 4a-d were produced via bromination and hydroxylation. Different acyl chlorides were reacted with hydroxylactams to provide the desired esters 5a-d. All compounds were evaluated by MTT assay for their inhibitory activities against HCT-116, MG-63, MCF-7, HUVEC and HMVEC cell lines in vitro. Most of them showed no obvious cytotoxic effect on normal human cells, compounds 4a-d, $5a_2$, $5a_4$, $5a_5$, $5b_2$, $5c_2$ and $5d_2$ exhibited potent antitumor activities, among which compounds $5a_2$ and $5b_2$ were more effective than 5-FU.

• 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.

• 한국응용과학기술학회지
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• 제15권3호
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• pp.39-45
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• 1998

In recent years, there has been considerable interest in the development of new functional surfactant including new type of anionic surfactants. Anionic surfactants, ${\alpha}-sulfo$ fatty acids that straight long chain alkyl group having from 12 to 18 carbon atoms, were synthesized with sulfur trioxide-dioxane complex to good yield. Xylitol ${\alpha}-sulfo$ fatty acid esters were obtained by reaction that the acetification and esterification of xylitol, by addition reaction with sodium chloride and hydrolysis respectively. These compounds were a new group of destructible surfactants which readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved surface tension, critical micelle concentration(cmc), foaming power, emulsion power, and hydrolysis properties, were measured. The cmc values of the compounds by ring method were assumed to $7.0{\times}10^{-3}{\sim}3.0{\times}10^{-2}mol/{\ell}$ range and surface tensions at cmc were $25{\sim}31dyne/cm$ respectively.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.107-110
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• 2001

Among the tested ten enzymes, Optimase M-440 showed the highest activity in transesterification of N-t-Boc-L-Phe-OTFE with D-glucose. Monosaccharides and their derivatives acted as good acyl acceptors in the Optimase M -440 catalyzed transesterification of N-t-Boc-L-Phe-OTFE. Optimase M-440 showed a preferable catalytic activity on the primary hydroxyl group of saccharides and a good regioselectivity. Optimase M-440 showed the highest activity in pyricline among the tested solvents. As acyl donors, trifluoroethyl esters of amino acids showed a high reactivity in transesterification. Optimase M-440 showed a broad substrate specificity towards amin 。 acid esters and saccharides.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.164-168
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• 2003

유채유를 사용하여 바이오디젤 생산을 위한 1단 전이에스테르화 공정에 있어서 반응온도 $60^{\circ}C$, 유지에 대한 메탄올 몰비 1:10 이상, 1.0 % (w/w) 포타슘 하이드록시드의 조건에서 98.5% 이상의 전화율을 얻을 수 있었다.

• Preventive Nutrition and Food Science
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• 제13권1호
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• pp.12-17
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• 2008

Douchi, a popular seasoning agent in Chinese dishes prepared by the Aspergillus oryzae fermentation of black beans, was subjected to supercritical fluid extraction (SFE) and gas chromatography-mass spectrometry analysis for its volatile components. A total of 73 components were identified in two commercial brands, which were positively confirmed and quantified. Among the common components in the two brands were 18 acids, 12 alcohols, 11 aldehydes, 9 esters, 1 furan, 11 other oxygen-containing compounds, 4 pyrazines, 2 pyridines and 5 miscellaneous compounds. The most abundant components found were acetic acid, benzoic acid, 2,6-dimethylpyrazine, 2-piperidinone, 3-methylbutanoic acid, maltol, 4-ethylphenol, 2-methylpropanoic acid, butanoic acid, 2-pyrrolidinone, all fatty acids and some esters.

• BMB Reports
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• 제28권3호
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• pp.261-264
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• 1995

The lipids of a Korean native blood-sucking leech (Hirudo nipponia) were isolated and analyzed. Cholesterol, fatty acids, triglycerides, glycerylether diester and cholesteryl esters were found from epidennal extracts. The major fatty acids in the leech skin were $C_{16:0}$, $C_{18:0}$, $C_{20:1}$. $C_{20:3}$ components. These components were derived from cholesteryl esters, glycerides, fatty acids and other polar lipids. After 60 days fasting, cholesterol, fatty acids and triglycerides in the skin were reduced in number and the total fatty acid composition was changed slightly. The data of total fatty acids in fasted and fed leech showed that medium-chain fatty acids were more affected than long-chain fatty acids. Other trace fatty acids appeared to be decreased by fasting.

• Applied Biological Chemistry
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• 제31권4호
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• pp.394-399
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• 1988

야생 식용 산채류중 씀바귀와 비름의 휘발성 풍미성분을 수증기 증류법으로 추출해서 GC와 GC-MS 조합에 의하여 분석하였다. 씀바귀에서는 alcohols류 13종, esters류 9종, aldehydes류 12종, ketones류 6종, hydrocarbons류 9종, acids류 6종, phenols류 3종 그리고 기타 3종의 총 61 성분이 확인 되었다. 비름에서는 alcohols류 15종, esters류 5종, aldehydes류 13종, ketones류 8종, hydrocarbons류 3종, acids류 7종, 기타 5종의 총 56 성분이 확인되었다.

• 한국응용과학기술학회지
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• 제20권3호
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• pp.251-258
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• 2003

Biodiesel as methyl esters derived from vegetable oils has considerable advantages in terms of environmental protetion. In the present work, methyl esters were produced from soybean oil by lipase-catalyzed transesterification. To reduce inactivation of commercial immobilized lipases emulsified two-step process was developed using the stepwise addition of methanol with 4:1 molar ratio at 4h intervals. Also with immobilized lipase from Candida antarctica(Novozym 435) high conversion of 98.5 percent was possible at $45^{\circ}C$ of reaction temperature with 4:1 of methanol-to-oil molar ratio and 1%(v/v) methyl glucoside oleic polyester as an emulsifier in the presence of cosolvent.