• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.555-556
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• 2010

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.1929-1930
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• 2009

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.535-536
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• 2008

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1671-1672
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• 2008

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2573-2576
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• 2014

• Analytical Science and Technology
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• v.10 no.5
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• pp.343-349
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• 1997

Analytical method using the reversed phase ion-pair chromatography (RP-IPC) for the determination of kasugamycin(5-amino-2-methyl-6-(2,3,4,5,6-pentahydroxy cyclohexyloxy)tetrahydropyran-3-yl-amino-${\alpha}$-imino acetic acid), pesticide as fungicide bactercide has been established. The retention behavior of kasugamycin in the RP-IPC was examined with respect to the effect of concentrations of organic modifiers, pH of eluent and types and concentrations of the counter ions as ion-pair reagent. This method developed by the optimum factors, can be used for the application of the quality control in the crude product and its formulation.

• Polymer(Korea)
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• v.26 no.1
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• pp.18-27
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• 2002

Poly(ο-hydroxyamide)s as polybenzoxazoles precursors were synthesized by polycondensation from 2,2'-bis(3-amino-4-hydroxyphenyl) hexafluoropropane and various bis-acids. And the polymers were modified to acid-sensitive polyamides by introducing tetrahydropyran in order to impart photosensitivity. A study of optical transmittance at 365 nm, according to the chemical structure of bis-acid, revealed that the polymer derived from 4,4'-oxydibenzoic acid showed better optical transparency than those from other bis-acids. This tendency of optical transmittance could be explained by formation of charge transfer complex. In case of the polymer derived from 4,4'-oxydibenzoic acid, the electron accepting characteristic of bis-acid is reduced by introduction of electron donating group, -O-. Thus, optical transmittance increased due to the diminished formation of intramolecular charge transfer complex. In addition, the optical transmittance increased with increasing the THP content in the polymer. This is attributed to the reduced intermolecular interaction by the loosening of the packing density of the polymer chain.

• Journal of the Korean Magnetic Resonance Society
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• v.15 no.1
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• pp.14-24
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• 2011

We have performed Liquid Chromatography-Solid Phase Extraction-NMR (LC-SPE-NMR) analysis for liquid crystalline mixture and elucidated the structures of selected components by NMR spectra. Combining the results of one-dimensional 1H experiments as well as homonuclear and heteronuclear two-dimensional experiments, we could analyze the molecular structure of the liquid crystal singles whose structure had not been interpretable by mass spectrometry alone.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.909-918
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• 1996

Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).

• Journal of the Korean Society of Food Culture
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• v.11 no.3
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• pp.403-408
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• 1996

This study was carried out to investigate the volatile flavor compounds of Pinus densiflora Sieb & Zucc according to extraction solvents and steam distillation method. The research results are as follows: 29 kinds of components were extracted by extraction solvents. Hydrocarbon was the major flavor components of the Pinus densiflora Sieb & Zucc. When the flavor components were extracted by solvents and analyzed by GC-Mass, in the hexane, ${\alpha}$-pinene was the highest and the contents ${\beta}$-thujene, trans-caryophyllene, ${\beta}$-mercene, ${\beta}$-cubebene were higher; in the ethyl acetate, the ${\alpha}$-cubebene content was the highest and the contents ${\alpha}$-cubebene, 3,6,9,12,15-pentaoxanonadecan-1-ol, camphene were higher; in the ethanol, the ${\beta}$-D4-tetrahydropyran was the highest and the contents ${\gamma}$-cadinene, 3-ethyl-1,4-hexadiene, ${\alpha}$-cubebene were higher. When the volatile constituents were extracted by steam distillation method, 44 kinds of components were extracted. Hydrocarbon was the major flavor components of the Pinus densiflora Sieb & Zucc. The ${\beta}$-cubebene content was the highest and the contents trans-caryophyllene, 2-hexenal, T-muurolol, ${\delta}$-cadinene were higher. This fact indicated that volatile constituents differ depending upon the extracting solvents and method.