• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.97-98
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• 2000

• Geotechnical Engineering
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• v.21 no.12
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• pp.45-56
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• 2005

• Bulletin of the Korean Chemical Society
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• v.21 no.6
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• pp.613-617
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• 2000

p-(2-Vinyloxyethoxy)benzylidenemalononitrile (4a), methyl p-(2-vinyloxyethoxy)benzylidenecyanoacetate (4b), 3,5-dimethoxy-4-(2'-vinyloxyethoxy)benzylidenemalononitrile (5a), methyl 3,5-dimethoxy-4-(2'-vinyloxy-ethoxy) benzylidenecyanoacetate (5 b), o-(2 -vinyloxyethoxy)benzylidenemalononitrile (6a), methyl o-(2-viny-Ioxyethoxy) benzylidenecyanoacetate (6b), 1,3-di-(2',2'-dicyanovinyl)-5-methyl-2-(2'-vinyloxyetioxy)benzene (7a), l,3-di-(2'-carbomethoxy-2'-cyanovinyl)-5-methyl-2-(2'-vinyloxyethoxy)benzene (7b), 2,3,4-tri-(2'-viny-Ioxyethoxy) benzylidenemalononitrile (8a), methyl 2,3,4-tri-(2'-vinyloxyethoxy)benzylidenecyanoacetate (8b), 2,4,6-tri-(2'-vinyloxyethoxy)benzylidenemalononitrile (9a), and methyl 2,4,6-tri-(2'-vinyloxyethoxy)benzyl-idenecyanoacetate(9b) were prepared by the condensation of the corresponding benzaldehyde 1-3 with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 4, 6, and 8 polymerized readily with radical initiators to yield crosslinked polymers 10, 12, and 14. However, compounds 5, 7, and 9 were inert to radical initiators due to the steric hindrance. The resulting polymers 10, 12, and 14 were not soluble in common solvents showing a thermal stability up to $300^{\circ}C$.

• Archives of Pharmacal Research
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• v.11 no.1
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• pp.52-55
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• 1988

From the ether soluble alkaloidal fraction of Panax ginseng, 4-methyl-5-thiazoleethanol, norharman and barman were isolated. 4-Methyl-5-thiazoleethanol was isolated for the first time from natural resources.

• Natural Product Sciences
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• v.4 no.4
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• pp.215-220
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• 1998

A new flavonol $3,5-di-O-KSO_3$:kaempferol 7,4'-dimethyl ether $3,5-O-KSO_3$, was isolated and identified from the flowers of Tamarix amplexicaulis. The known compounds quercetin $3-mono-O-KSO_3$, kaempferol 4'-methyl ether $3-mono-O-KSO_3$, kaempferol 7,4'-dimethyl ether $3-O-KSO_3$, quercetin 7,4'-dimethyl ether $3-mono-O-KSO_3$, kaempferol 3-O-glucuronide and quercetin 3-O-glucuronide were also separated and identified. Structures were established by conventional methods, including electrophoretic analysis, and confirmed by negative FAB-MS, $^1H-\;and\;^{13}C-NMR$.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.657-663
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• 1998

New asymmetric dimer, 7,7'-substituted (or H)-4-oxo-2,2'- dialkyl-l,l',2,2'-dibenzothiazine-3,3'dicarboxylic acid methyl ester-1,1,1',1'-tetraoxide 3,4'-yl ethers 2a-d were synthesized through the oxidative dimerization of 7-substituted (or H)-4-hydroxy-2-alkyl-1,2-benzothiazine-3-carboxylic acid methyl ester 1,1-dioxides la-d using silver oxide($Ag_2O$). 4-Oxo-2,2'-dialkyl-1,1'2,2'-dibenzothiazine-3,3'-dicarboxylic acid methyl ester-1,1,1',l'-tetraoxide 3,4'-yl ether 2c was identified by X-ray crystal structure determination.

• Polymer(Korea)
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• v.30 no.5
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• pp.426-431
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• 2006

Novel azacrown ether containing blue -light emitting anthracene fluorophore, 9,10-bis [p-(1-aza-18-crown-6)methylphenyl] anthracene (3) and N,N-bis [9-(p-methylphenyl) anthracenyl-methyl] -1,6-diaza-18-crown-6 (4) were prepared by reacting anthracene derivatives 1 and 2 with mono- and diaza-18-crown-6, respectively Also, crown ether containing fluorophore copolymer (5) were prepared by reacting 1,6-diaza-18-crown-6 with 1. Their fluorescence emission spectral studies were investigated by binding group I, group II and various metal cations. The fluorophores showed an absorption at ${\lambda}_{max}$= 372 nm and an emission at ${\lambda}_{max}$= 430 nm. pH Dependency of fluorescence emission intensity were examined to determine the optimum pH for the fluorophores.

• Journal of the Korean Institute of Gas
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• v.8 no.4 s.25
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• pp.42-49
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• 2004

We study on and simulate the behavior of one-step fixed bed reactor which synthesize DiMethylEther(DME) from Methane. At last, we know that reaction is decreased in case of excess and no cooling because the temperature of reactor is decreased or increased seriously. Also, we study on optimizing the reactor so that we know the optimized operation condition according to cooling effect, space velocity of reactant and temperature of reactant, etc.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.31-37
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• 1996

This study was conducted to know the odor characteristics and compounds in neutral, acidic and basic fraction from the essential oil of Valerliana fauriei root. Among the fraction from the essential oil of V. fauriei root, the content of neutral fraction was 92%, that of the acidic fraction, 6%, and that of basic and phenolic fractions, less than 1%, respectively. The neutral fraction was characterized by sweet-balsamic, woody, musky and medicinal odor. The acidic fraction had sweat-socks, valeric-like and cheese-like odor characters. The netural fraction of essential oil was fractionated by solvents with different polarities, resulting in 44% of ethyl ether fraction, 34% of pentane-ethyl ether fraction, 11% of pentane fraction and 11% of methanol fraction. The ethyl ether fraction was characterized by woody and medicinal odor and the pentane-ethyl ether fraction, by sweet-balsamic, woody and herb-like odor. The fractions were fractionated again by different solvents, and 12 chemical components including valeranone, 26 components including bornyl acetate, and 43 components including camphene were identified in the ethyl ether fraction, the pentane - ethyl ether fraction, and pentane fraction, respectively. In the acidic fraction, n-butanoic acid and other 44 components were identified, among which the most abundant ones were 3-methyl butanoic acid(42.1%), dimethoxy-2-propanoic acid(11.5%), and 5-­ethyldihydro-2H-furanone(5.7%).

• Microbiology and Biotechnology Letters
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• v.24 no.5
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• pp.624-629
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• 1996

The ethanol extracts from Angelica gigas Nakai and Angelica acutiloba Kitagawa were fractionated to diethyl ether and aqueous partitions. Both partitions had strong antimutagenic effect on the MNNG (N-methyl-N-nitro-N-nitrosoguanidine) by Ames mutagenicity test. Diethyl ether fractions exhibited the greatest antimutagenic effect suppressing the mutagenicity of MNNG with inhibition of 78-80%. The ethanol extracts from both species showed the inhibitory effect on the growth of several human cancer cell lines. Especially, the diethyl ether fraction from ethanol extracts was most effective on human hepatocellular carcinoma cells, inhibiting 90-95% of cell growth. However, the aqueous fractions had least inhibition activity on many cancer cells. There was little cytotoxicity on human normal liver cell by ethanol extracts. Diethyl ether fraction from Angelica gigas Nakai ethanol extract had cytotoxicity less than 20% on human normal liver cells, compared with that from Angelica acutiloba Kitagawa ethanol exract. The adding of 0.5 (g/l) of diethyl ether fractions of Angelica gigas Nakai or Angelica acutiloba Kitagawa increased immune activity by enhacing human B and T cells up to three to four times. It was proven that diethyl ether fraction (0.7 g/1) from Angelica gigas Nakai could control blood pressure by suppressing angiotensin converting enzyme activity up to 98%. From TLC, it was appeared that both of diethyl ether partitions had umbelliferon, known to one of active substances from Angelica gigas Nakai and Angelica acutiloba Kitagawa.