• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.226-226
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• 2006

Ethylene was polymerized with a catalyst having sterically hindered pentamethylcyclopentadienyl ligand, $Cp^{\ast}_{2}ZrCl_{2}/MAO$, and the polymerization mixture were treated with dry oxygen (oxidative workup) to produce hydroxyl-terminated polyethylenes (PE-OH). Polyethylene-block-Poly (${\Box}-caprolactone$) was synthesized from PE-OH and ${\cdot}\^{A}-caprolactone$A by using stannous octoate as a catalyst for ring opening polymerization of ${\cdot}\^{A}-caprolactone$. Polyethylene-block-Poly(methyl methacrylate) was obtained by transforming the hydroxyl-terminated polyethylenes to macroinitiators for atom transfer radical polymerization (ATRP) and by reacting them with MMA.

• Elastomers and Composites
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• v.43 no.4
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• pp.221-229
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• 2008

Starch as matrix polymer was used to do graft copolymerization with 2-ethylhexylacrylate, methyl methacrylate and acrylic acid. The polymerization was carried out by radical emulsion polymerization with increasing contents of starch. When 0.174% of $\alpha$-amylase as enzyme for starch was added, it was found that it made the best stable emulsion. The glass transion temperature of the polymerized material was increased with starch contents. The particle size and viscosity of the emulsion increased with starch contents due to the increased hydroxy group. Peel strength also increased with contents of starch because the enhanced hydroxy group caused to increase affinity between substrate surface and polymer materials. However, the initial tackiness decreased with starch contents owing to film hardness by higher glass transion temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.270-273
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• 2009

A comb-like copolymer consisting of a poly(vinylidene fluoride-co-chlorotrifluoro-ethylene) backbone and poly(hydroxy ethyl acrylate) side chains, i.e. P(VDF-co-CTFE)-g-PHEA, was synthesized through atom transfer radical polymerization (ATRP) using CTFE units as a macroinitiator. Successful synthesis and a microphase-separated structure of the copolymer were confirmed by proton nuclear magnetic resonance (1H-NMR), FT-IR spectroscopy, and transmission electron microscopy (TEM). This comb-like polymer was crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification of the -OH groups of PHEA and the -COOH groups of IDA. Upon doping with phosphoric acid ($H_3PO_4$) to form imidazole-$H_3PO_4$ complexes, the proton conductivity of the membranes continuously increased with increasing $H_3PO_4$ content. A maximum proton conductivity of 0.015 S/cm was achieved at $120^{\circ}C$ under anhydrous conditions. In addition, these P(VDF-co-CTFE)-g-PHEA/IDA/$H_3PO_4$ membranes exhibited good mechanical properties (765 MPa of Young's modulus), and high thermal stability up to $250^{\circ}C$, as determined by a universal testing machine (UTM) and thermal gravimetric analysis (TGA), respectively.

• Korean Journal of Medicinal Crop Science
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• v.20 no.4
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• pp.259-269
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• 2012

This study was performed to determined the antioxidant activities, anticancer and immuno-activities of anthocyanin fraction from Rubus coreanus Miquel fruits (Bokbunja). Anthocyanin fraction extracted from Bokbunja revealed the presence of three anthocyanin components, which were tentatively identified as cyanidin 3-O-sambubioside, cyanidin 3-O-xylosylrutinoside and cyanidin 3-O-rutinoside using RP-HPLC/DAD/MS. The anthocyanin fraction from Bokbunja always showed reducing power and high scavenging activities against DPPH, hydroxy radical (OH) and superoxide anion radical ($O_2{^-}$) similar to general synthetic antioxidant and polyphenol compounds from plant origin. Anthocyanin fraction from Bokbunja showed high inhibition on proliferation of LNCaP and A549 cells and did not inhibit the proliferation of other cancer cells. Immuno-activities of Anthocyanin fraction from Bokbunja were investigated, it showed high promotion of human B and T cells growth about 50% and secretion of IL-6 and TNF-${\alpha}$ by treatment after 6 days. Over all, the result of the study suggest that anthocyanin fraction from Bokbunja displays antioxidant activity comparable to that general synthetic antioxidant, also, anthocyanin fraction from Bokbunja are expected to be good candidate for development into source of anticaner and immuno-activator agent in food industry.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.133-139
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• 2014

In this research, the photocatalytic degradation of benzothiophene in $TiO_2$ aqueous suspension has been studied. $TiO_2$ photocatalysts are prepared by a sol-gel method. The dominant anatase-structure on $TiO_2$ particles is observed after calcining the $TiO_2$ gel at $500^{\circ}C$ for 1hr. Photocatalysts with various transition metals (Nd, Pd and Pt) loading are tested to evaluate the effect of transition metal impurities on photodegradation. The photocatalytic degradation in most cases follows first-order kinetics. The maximum photodegradation efficiency is obtained with $TiO_2$ dosage of 0.4g/L. The photodegradation efficiency with Pt-$TiO_2$ is higher than pure $TiO_2$ powder. The optimal content value of Pt is 0.5wt.%. Also we investigate the applicability of $H_2O_2$ to increase the efficiency of the $TiO_2$ photocatalytic degradation of benzothiophene. The optimal concentration of $H_2O_2$ is 0.05. The effect of pH is investigated; we obtain the maximum photodegradation efficiency at pH 9. Hydroxy-benzothiophenes and dihydroxy-benzothiophenes are identified as reaction intermediates. It is proposed that benzothiophene is oxidized by OH radical to sequentially form hydroxyl-benzothiophenes, dihydroxybenzothiophenes, and benzothiophenedione.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.849-858
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• 2006

Previous screening of the pharmacological action of Gastrodia elata (GE) root (Orchidaceae) showed that methanol (MeOH) extracts have significant anti-inflammatory properties. The antiinflammatory agents of GE, however, remain unclear. In this experiment, MeOH extracts of GE were fractionated with organic solvents for the anti-inflammatory activity-guided separation of GE. Eight phenolic compounds from the ether (EtOEt) and ethyl acetate (EtOAc) fractions were isolated by column chromatography: 4-hydroxybenzaldehyde (I), 4-hydroxybenzyl alcohol (II), benzyl alcohol (III), bis-(4-hydroxyphenyl) methane (IV), 4(4'-hydroxybenzyloxy)benzyl-methylether (V), 4-hydroxy-3-methoxybenzyl alcohol (VI), 4-hydroxy-3-methoxybenzaldehyde (VII), and 4-hydroxy-3-methoxybenzoic acid (VIII). To investigate the anti-inflammatory and anti-oxidant activity of these compounds, their effects on carrageenan-induced paw edema, arachidonic acid (AA)-induced ear edema and analgesic activity in acetic acid (HAc)-induced writhing response were carried out in vivo; cyclooxygenase (COX) activity, reactive oxygen species (ROS) generation in rat basophilic leukemia (RBL 2H3) cells and 1,1-diphenyl-2-picryl-hydroazyl (DPPH) scavenging activity were determined in vitro. These phenolic compounds not only had anti-inflammatory and analgesic properties in vivo, but also inhibited COX activity and silica-induced ROS generation in a dose-dependent manner. Among these phenolic compounds, compound VII was the most potent anti-inflammatory and analgesic. Compound VII significantly inhibited silica-induced ROS generation and compound VI significantly increased DPPH radical scavenging activity. Compounds I, II and III significantly inhibited the activity of COX-I and II. These results indicate that phenolic compounds of GE are anti-inflammatory, which may be related to inhibition of COX activity and to anti-oxidant activity. Consideration of the structure-activity relationship of the phenolic derivatives from GE on the anti-inflammatory action revealed that both C-4 hydroxy and C-3 methoxy radicals of benzyl aldehyde play an important role in anti-inflammatory activities.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.35-43
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• 2000

Aqueous solutions of chlorobenzene and chlorinated phenols were exposed to 200kHz ultrasound with a power of $6.0W/\textrm{cm}^2$ per unit volume on sonochemical reactor under ambient temperature and pressure conditions. The concentration of chlorobenzene and chlorinated phenols decreased with ultrasound, indicating first-order kinetics. Degradation rate constants are calculated from the slope of plots. The order of the rate constants is as follows : 2-chlorphenol(2-CP)$\leq$ 4-chlorophenol(4-CP)<3-chlorophenol(3-CP)$5.63~9.96({\times}10^{-2})min^{-1}$ under argon. The degradation was suppressed by the addition of t-BuOH and the suppressed yield was agreed with their reactivity for hydroxy radical. The main products of these systems were formic acid, acetic acid, small amount of methane and inorganic carbon forms as carbon dioxide, carbon monoxide in sonolysis of chlorinated phenols, and also these results agreed with change of TOC.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.619-623
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• 1999

$2^{l},3^{l}$-dideoxyisoguanosine was synthesized from guanosine via intermediate 6-[(4-methyl-phenyl)thio]-2-oxo-9-($2^{l},3^{l},5^{l}$-tri-O-acetyl-$\beta$-D-ribofuranosyl)-2,3-dihydropurine (4). The 2-oxo, 6-amino and $5^{l}$-hydroxy triprotected isoguanosine derivative was utilized to reduce high polarity and promote poor solubility of intermediates. The protecting groups for oxo and 6-amino were easily removed in reduction of olefin in ribose without additional reaction steps.$2^{l},3^{l}$-Vicinal diol in ribose sugar moiety was transformed to olefin with Bu3SnH by radical reaction via bisxanthate. Removing $5^{l}$-O-TBDMS protecting group gave final product, $2^{l},3^{l}$-dideoxyisoguanosine (12) in a 10% overall yield.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.725-741
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• 2019

In the current study, we first investigated a method for directly transforming lactose into galacto-oligosaccharides (GOS) for manufacturing low-lactose and GOS-enriched skim milk (GSM) and then evaluated its prebiotic potential by inoculating five strains of Bifidobacterium spp. In addition, fermented GSM (FGSM) was prepared using a potentially probiotic Lactobacillus strain and its fermentation characteristics and antioxidant capacities were determined. We found that GOS in GSM were metabolized by all five Bifidobacterium strains after incubation and promoted their growth. The levels of antioxidant activities including radical scavenging activities and 3-hydroxy-3-methylglutaryl-CoA reductase inhibition rate in GSM were significantly increased by fermentation with the probiotic Lactobacillus strain. Moreover, thirty-nine featured peptides in FGSM was detected. In particular, six peptides derived from ${\beta}$-casein, two peptides originated from ${\alpha}s_1$-casein and ${\kappa}$-casein were newly identified, respectively. Our findings indicate that GSM can potentially be used as a prebiotic substrate and FGSM can potentially prevent oxidative stress during the production of synbiotic fermented milk in the food industry.

• Korean Journal of Pharmacognosy
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• v.37 no.4 s.147
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• pp.235-240
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• 2006

We investigated the antioxidant activities such as DPPH radical scavenging capacity, xanthine oxidase inhibitory activity, and superoxide radical scavenging capacity of the aqueous EtOH extract and its solvent fractions of Artemisia scoparia. The ethyl acetate fraction showed high antioxidant activity, compared to positive controls such as ascorbic acid, butylated hydroxy anisole (BHA), trolox, and allopurinol in these assay systems. Moreover, we examined the inhibitory effect of solvent fractions of A. scoparia on the production of pro-inflammatory factors that the nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and prostaglandin E2 $(PGE_2)$ production activated with LPS $(1{\mu}g/ml)$ in murine macrophage cell line RAW264.7. The amounts of protein levels were determined by immunoblottting. Tn the sequential fractions of hexane and dichloromethane inhibited the NO and $PGE_2$ production and the protein level of iNOS and COX-2. These results suggest that A. scoparia may have anti-inflammatory activity through the antioxidant activity and inhibition of pro-inflammatory factors.