• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.600-603
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• 1996

The methanol extract of Aralia elata bark showed antimicrobial activities against bacteria, yeast and fungi. The active components were successively purified with solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, silica gel partition column chromatography and HPLC. The active substances were separated with HPLC where 1% acetic acid-MeOH (60 : 40, v/v) was used as mobile phase. The isolated active substance ($t_r$ 17.1 min) was identified as trans-3,4-dihydroxycinnamic acid by $MS,\;^1H-NMR\;and\;^13C-NMR$.

• Elastomers and Composites
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• v.47 no.3
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• pp.216-222
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• 2012

In this study, p-acryloyloxybenzoic acid(ABA) was synthesized with p-hydroxybenzoic acid(HBA) and acryloyl chloride(AC). The synthesized ABA monomer was grafted onto ethylene-propylene-diene rubber(EPDM) in toluene using benzoyl peroxide(BPO) as an initiator. The structures of ABA and EPDM-g-ABA were characterized by FT-IR, $^1H$-NMR, and $^{13}C$-NMR spectrometer. The graft ratio of EPDM-g-ABA increased with increasing the concentration of the initiator and the monomer. Mechanical properties such as tensile strength and compression set of the EPDM-g-ABA were improved with increasing the graft ratio. The $T_g$ and initial decomposition temperature were also increased with increasing the graft ratio.

• Elastomers and Composites
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• v.47 no.4
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• pp.329-335
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• 2012

In this study, we synthesized poly(ethylene-ter-high ${\alpha}$-olefin-ter-p-methylstyrene) using Zr metallocene catalyst/borate type cocatalyst system. Various effects of the high ${\alpha}$-olefin (1-hexene, 1-octene, 1-decene, and 1-dodecene) were observed. The structure and composition of the terpolymers were characterized using $^{13}C$ NMR and $^1H$ NMR. Catalytic activity, polymer yield, molecular weight and molecular weight distribution were analyzed according to the chain length of high ${\alpha}$-olefin. We determined morphology, crystallinity and thermal properties of the terpolymers.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.680-683
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• 2003

Through the screening of caspase-3 inducing inhibitors in U937 human monocytic leukemia cell from natural sources, Caesalpiniae sappan, which showed a high level of inhibition, was selected. The inhibition compound was purified from methanol extract by silica gel column chromatography and HPLC. The inhibitor was identified as brazilin by spectroscopic methods of ESI-MS, $^1H-NMR$, and $^{13}C-NMR$. Brazilin showed inhibitory activity of caspase-3 induction, a major protease of apoptosis cascade, with $IC_{50}$ value of $4.5\;{\mu}g/mL$ after 7 hr of treatment in U937 cells.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.226-230
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• 2005

Chitosan derivatives, 6-amino-6-deoxychitosan (6A6DC) was successively prepared as a reactive carbohydrate for the stabilization of epidermal growth factor (EGF) by the reactions of chitosan with tosyl chloride, sodium azide, and lithium aluminum tetrahydride. The structure of 6A6DC was confirmed by EA, FT-IR, $^1H-NMR$ and $^{13}C\{^1H\}-NMR$. The degree of substitution (ds) of amino groups in 6A6DC was determined to be 0.7. 6A6DC did not show any cytotoxicity on the normal human dermal fibroblast (NHDF) proliferation at least in the range tested (0.3 g/mL 600 g/mL) and was considered as a suitable material for the stabilization of EGF against proteolytic degradation due to its non-cytotoxicity and high reactivity.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.448-453
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• 2000

During the screening of inhibitors of caspase-3 induction in U937 human monocytic leukemia cells from natural sources, Petasites japonicum, which showed a high level of inhibition was selected. The inhibiting compound was purified from the methanol extract by Sephadex LH-20 column chromatography and HPLC. The inhibitor was identified as [3-(3,4-dihydroxyphenyl)-2-oxopropyl]ester, petasiphenol, by spectroscopic methods of UV, EIMS, $^1H-NMR$, $^{13}C-NMR$ and HMBC. It showed a caspase-3 inducing inhibitory activity at $8\;{\mu}g/ml$ of $IC_{50}$ value with DNA fragmentation inhibition in U937 human leukemia cells. It also showed a free radical scavenging ability of 1,1-diphenyl-2-picrylhydrazyl.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.260-267
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• 2021

In this study, a carboxylate-based anionic surfactant SLEC-3 was prepared from coconut oil and the structure was elucidated by using FT-IR, ¹H-NMR and ¹³C-NMR analysis. Measurements of interfacial properties such as critical micelle concentration, static and dynamic surface tensions, emulsification index, and foam stability have shown that SLEC-3 is better in terms of interfacial activity and more effective in lowering interfacial free energy than those of SLES, which has been widely used as a conventional anionic surfactant in the detergent industry. Biodegradability, acute oral toxicity and dermal irritation tests also revealed that SLEC-3 surfactant possesses excellent mildness and low toxicity, indicating the potential applicability in detergents and cleaner products formulation.

• Journal of the Korean Wood Science and Technology
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• v.30 no.1
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• pp.56-62
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• 2002

The air-dried bark of Salix rorida was extracted with acetone-water(7:3, v/v) and its extractives were concentrated with a vacuum evaporator. The extractives were fractionated with a series of n-hexane, chloroform, ethylacetate(EtOAc) and water on a separatory funnel. Each fraction was freeze-dried to give some dark brown powder. The EtOAc and water soluble fractions were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The isolated compounds were tested with a cellulose TLC developed with TBA and 6% acetic acid and then visualized on UV lamp or sprayed with vanillin-HCl-EtOH. The purified compounds were flavonoids and their glycosides as follows:(+)-catechin, naringenin, salipurposide, aromadendrin, isosalipurposide, aromadendrin-7-O-𝛽-D-glucopy- ranoside and taxifolin-7-O-𝛽-D-glucopyranoside. The structures of each compounds were confirmed by ¹H-NMR, ¹³C-NMR and mass spectra.

• Polymer(Korea)
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• v.27 no.5
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• pp.470-476
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• 2003

In order to obtain high refractive plastic materials, 1,2 -ethylenedisulfanylbis(2-mercaptomethyl-1-ethanthiol) (ESTT) was newly prepared in good yield by the reaction of 1,2-ethylenedisulfanylbis(2-bromomethyl-1-ethanthiol) (ESTB) with thiourea followed by hydrolysis using an aqueous ammonia solution and characterized by $^1$H-NMR (-SH at 1.7 ppm), $\^$13/C-NMR(-CH$_2$SH at 28.4 ppm) and FT-IR (-SH at 2540 cm$\^$-1/) spectroscopy, etc. Polythiourethanes (PTU) were obtained from the combinations of ESTT with each of 4,4＇-methylenebis(phenylisocyanate) (MDI), tolyene 2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), mxylene diisocyanate (XDI), and 1,6-diisocyanatohexane (HMDI) in the presence of dibutyltin dilaurylate as a catalyst, in a casting mold, and characterized by FT-IR (existence of N=C=O) spectroscopy and elemental analyzer (sulfur content). Accordingly, their thermal, mechanical and optical properties were investigated by using DSC, TGA, hardness tester and refractometer: both the melting point on DSC and crystallinity on X -ray diffraction (XRD) for specimens of PTUs were not observed. PTUs with T$\_$g/s above 110 $^{\circ}C$ showed good hardness (Shore D) in the range of 86 to 89. Thermal stabilities of PTUs obtained by using ESTT and each of diisocyanates containing aromatic rings were especially good. Also, the optical transmittances of amorphous PTUs through UV-visible source in the range of 400 to 600 nm were good. PTUs showed refractive indexes above 1.60, and their refractive indexes gradually increased with increase of sulfur contents.

• Journal of Adhesion and Interface
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• v.13 no.3
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• pp.131-136
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• 2012

In this study, commercial poly(vinyl alcohol) (PVA) film was dyed with reactive dichroic dyes under mild conditions using organic solvents in stead of strong basic aqueous solution. After drawing of 500% of this PVA film, the polarizing efficiency and the single piece transmittance were measured. The degree of saponification of the commercialized PVA film was determined by using NMR and FT-IR spectromety. The commercial PVA film, with ca. 100% of the degree of saponification determined by NMR spectrometry, was dyed with the reactive dichroic dyes, which have 3,5-dichloro-2,4,6-triazine moiety. As a result, we found that the PVA film dyed with the reactive congo red showed relatively good polarization efficiency, and the PVA film dyed with the reactive direct black 22 exhibited relatively good single piece transmittance.