• Applied Biological Chemistry
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• v.50 no.4
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• pp.358-361
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• 2007

The heartwoods of Rhus verniciflua was extracted with $H_2O$ and the concentrated extract was partitioned with $CHCl_3$, EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc and n-BuOH fractions, four compounds were isolated through the repeated silica gel, ODS and Sephadex LH-20 column chromatographies. They were determined as sinapyl aldehyde (1), 2,4-dihydroxybenzaldehyde (2), 2,4-dihydroxybenzoic acid (3) and 2,4-dihydroxyphenylglyoxylic acid (4) on the basis of spectroscopic data, respectively. Among the isolated compounds, sinapyl aldehyde $(34.7{\pm}0.6%)$ and 2,4-dihydroxyphenylglyoxylic acid $(43.8{\pm}0.9%)$ showed the strong antioxidative activity than artificial antioxidant BHT $(14.4{\pm}0.3%)$ in DPPH radical scavenging activity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.3
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• pp.124-128
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• 2011

Electrospun webs have been widely investigated for applying to drug delivery system (DDS) because of their high specific surface area and high porosity. In this study, the composite webs of PLA (poly(lactic acid)) and $TiO_2$ were fabricated by melt-electro-spinning method for applying to drug delivery system. The morphologies of PLA/$TiO_2$, webs were observed using scanning electron microscope (SEM) and field emission transmission electron microscope (FE-TEM). The crystal structures of PLA/$TiO_2$ composite webs were confirmed by X-ray diffractometer (XRD).

• Journal of the Korean Electrochemical Society
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• v.18 no.2
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• pp.51-57
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• 2015

We report the effect of the impurities including water and bromide in the propylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PMPyr-TFSI) on the electrochemical performance of lithium ion batteries. The several kinds of PMPyr-TFSI electrolytes with different amount of impurities are applied as the electrolyte to the cell with the high potential electrode, $LiNi_{0.5}Mn_{1.5}O_4$ spinel. It is found that the impurities in the electrolytes cause the detrimental effect on the cell performance by tracing the cycleability, voltage profile and Coulombic efficiency. Especially, the polarization and Coulombic efficiency go to worse by both impurities of water and bromide, but the cycleability was not highly influenced by bromide impurity unlike the water impurity.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.263-266
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• 2005

Cymbidium goeringii REICHB. fil was extracted with 80% MeOH and solvent-fractionated with EtOAc, n-BuOH and $H_2O$, successively. From EtOAc fraction, three sterols were isolated on repeated silica gel and ODS column chromatographies. The chemical structures were determined as ${\beta}-sitosterol$ (1), daucosterol (2) and ergosterol peroxide (3) by NMR, MS and IR, which is the first to be isolated from Cymbidium goeringii REICHB. fil.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.202-205
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• 2001

The root of Zingiber officinale R. was extracted with 80% aqueous MeOH, and the concentrated extract was fractionated with EtOAc, n-BuOH and water phases. The EtOAc fraction exhibited most potent antioxidant activity among them, and two active compounds were isolated by activity-guided separation using repetitive silica gel column chromatography. On the bases of spectral data and the chemical characteristics, the structure of the compounds were determined as 6-shogaol and 12-shogaol, respectively. The $EC_{50}$ values of them were evaluated as 26.4 ${\mu}M$ and 22.5 ${\mu}M$, respectively, where these values were higher than the commercial antioxidants, such as, BHA, BHT and ${\alpha}-tocopherol$.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.421-424
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• 2005

The leaf of Petasites japonicus was extracted with 80% aqueous MeOH and solvent fractionated with EtOAc, n-BuOH and water successively. From the EtOAc fractions, two triterpenoids were isolated through the repeated silica gel and ODS column chromatographies. The chemical structures of the isolated terpenoids were determined as rosamutin (1) and peduncloside (2) through the interpretation of several spectral data including 2D-NMR such as $^1H-{^1H}$ gCOSY, gHSQC and gHMBC.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.82-85
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• 2006

The fruits of Cornus kousa Burg. were extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc fraction, three sterols were isolated through the repeated silica gel and ODS column chromatographies. According to the results of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as ${\beta}-sitosterol$ (1), $stigmast-4-en-6{\beta}-ol-3-one$ (2) and daucosterol (3). They were the first to be isolated from Cornus kousa Burg.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.298-302
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• 2000

In our investigation on chemical constituents of edible mushrooms, seven compounds I-VII have been isolated from the methanolic extract of the fruit body of Sarcodon aspratus. The methanolic extract was separated by solvent partition, silica gel column chromatography and Sephadex LH-20 column chromatography, and compounds I-VII were finally purified by preparative HPLC or TLC. Their structures were assigned as 4-hydroxybenzoic acid methyl ester, 4-hydroxybenzaldehyde, cyclo(Ala-Pro), adenosine, nicotinamide, BL V, linoleic acid, respectively, on the basis of mainly $^1H\;NMR$ spectra.

• Applied Biological Chemistry
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• v.22 no.1
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• pp.10-17
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• 1979

The saponins isolated form the herb of Panax ginseng C.A. Meyer were investigated as compared with ginseng root saponins. By adopting DEAE cellulose ion exchange chromatography the pure saponins were isolated from Korean ginseng roots and leaves. The ginseng root and leaf saponins showed some differences in the pattern of the two-dimensional thin layer chromatogram. The ratio of panaxadiol to panaxatriol in the saponins was 1.7 in the roots and 3.5 in the leaves. Infra-red spectrum of ginseng leaf saponins isolated by liquid chromatography was identical with that of root saponins.

• Polymer(Korea)
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• v.38 no.2
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• pp.138-143
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• 2014

${\alpha},{\omega}$-Hydroxypropyl polydimethylsiloxane (HO-PDMS) was prepared by hydrosilylation of hydrogen terminated polydimethylsiloxane with allyl alcohol. Polydimethylsiloxane modified urethane with isocyanate group (PSU) was prepared from cyclic trimer of hexamethylenediisocyanate with HO-PDMS. PDMS modified urethane base resin with acrylic group (PSUA) was prepared from the urethane reaction of PSU with isocyanate group and 2-hydroxyethylmethacrylate. Their structures were characterized using FTIR and NMR. Coating materials were prepared by mixing PSUA, acrylic hardner, photo-initiator, and solvent and coated on PET film to obtain flexible and hard coating film by UV irradiation. Transparency of coating film was 89.7%, contact angle, $88^{\circ}$, and pencil hardness, 3H.