• Journal of Adhesion and Interface
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• v.2 no.3
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• pp.25-32
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• 2001

Ethyl cyanoacrylate (ECA) is used as an instant adhesive, and it can be readily polymerized by moisture in air without any initiator and applied for industrial products and ohome use. However, pure ECA monomer is low-viscosity liquid at room temperature that flows into substrate surface. To thicken the instant adhesive, poly(methyl methacylate)(PMMA) is often added in it commercially. Another disadvantage of instant adhesive polymer is its brittleness In this study, functional polymers including PMMA for an additive of ECA were prepared to increase viscosity of the monomer and flexibility of the adhesive atthe same time The additives, P(MMA-VAc-EVE), were synthesized by radical copolymerization of MMA with VAc and EVE having low glass transition temperature (Tg). The additives were added to ECA to get functional instant adhesives. The chemical structures of the additives and ECA polymers were confirmed by $^1H$ NMR and FTIR, and their physical and mechanical properites were also evaluated. The Tg of the obtained additives decreased with increasing the content of VAc or VAc-EVE, indicating more improved flexibility. In addition, functional instant adhesive containing the additives showed higher bonding strength than that of the existing one.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.265-269
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• 2004

This study was conducted to develop physiologically active plant materials from medicinal plants. Crude extracts and solvent fractions prepared from Lysimachia cletroides Duby were tested for their antioxidant and antihypertensive activities. For ellucidating antioxidant potential, inhibition rate on linoleic acid peroxidation, as well as scavenging activities on superoxide anion and 1,1-dipicrylphenylhydrazyl (DPPH) radical were evaluated. For analyzing antihypertensive effect, inhibitory activity on angiotensin converting enzyme (ACE) was done. Methanol extract of L. cletroides showed potent inhibition activity of 83% on linoleic acid peroxidation, which was more effective than -2% of ${\alpha}-tocopherol$ at $25\;{\mu}g/ml$. Methanol and water extracts exhibited strong scavenging activities of $86{\sim}109%$ and $96{\sim}122%$ on superoxide anion radical which was higher than $-4{\sim}69%$ of ascorbic acid at $5{\sim}200\;{\mu}g/ml$. Hexane, ether and ethylacetate fractions possessed 133, 100 and 88% inhibitory activities on ACE at $4,000\;{\mu}g/ml$, respectively. From the results, it was expected that Lysimachia cletroides could be a new antioxidant and antihypertensive resource.

• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.32-41
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• 2000

Antimicrobial and antioxidative activities on heartwood extractives from Zelkova serrata were investigated to develop a natural fungicide or preservative. The ethanol extract from Z. serrata was fractionated in the order of petroleum ether, diethylether and ethylacetate to determine antimicrobial activity. The highest antimicrobial activity against the tested microorganisms was found in the petroleum ether soluble fraction. An active antimicrobial compound was isolated from petroleum ether soluble fraction, and identified as 7-hydroxy-3-methoxycadalene by $^1H$-, $^{13}C$-NMR and EI-MS spectrometry. This compound showed higher antifungal activity, but lower antibacterial activity than hinokitiol(${\beta}$-thujaplicin), strong antimicrobial compound isolated from Thujopsis dolabrata. Antioxidative activity was also higher than ${\alpha}$-tocopherol and similar to BHT(butylated hydroxytoluene), one of the strongest synthetic antioxidant. As a result, it was concluded that 7-hydroxy-3-methoxycadalene isolated from Z. serrata had strong antifungal and antioxidative activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1099-1105
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• 2007

The present study describes the preliminary evaluation of the anticancer activity of Styela plicata. Freeze-dried S. plicata was extracted with methanol, ethanol, acetone, and water, and then anticancer effect of the extracts was measured by the MTT reduction assay and phase-contrast microscopy on the HT-29 human colon carcinoma cells. Among the extracts, acetone extract showed the highest anticancer activity. The cell proliferation rates markedly decreased by 94.0% at the concentration of 500 ${\mu}g/mL$ of acetone extract compared with control cells. The acetone extract was further fractionated with hexane, diethyl ether, ethyl acetate, and water layer according to the degree of polarity. The HT-29 cells with hexane layer extract (250 ${\mu}g/mL$) decreased the cell viability to 5.1% of untreated control. The growth of SW620, HeLa, and MCF-7 cells was decreased to about 10%, by the treatment of hexane layer extract 250 ${\mu}g/mL$. Theses results suggest extracts from S. plicata as possible natural cancer therapeutic material.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.749-757
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• 2019

Methyltrimethoxysilane (MTMS) and trimethylethoxysilane (TMES) as starting materials were dissolved in various types of solvents, and hydrolysis with water and polycondensation reaction were carried out using various types of catalysts to prepare non-fluorinated water-repellent coating solutions. The coating solutions were spin-coated on cold-rolled steel sheets, and thermally cured to prepare water-repellent coating films. The effect of types of catalysts and solvents on the water repellency of the resulting coating films was investigated during this process. When hydrochloric acid and nitric acid, which are strong acids, were used as catalysts, the solutions showed a white opaque state due to the aggregation of siloxane polymers. On the other hand, when acetic acid, phosphoric acid, and oxalic acid, which are weak acids, were used, they were in a stable and transparent state without precipitation. As a result, the contact angles of the coated films, prepared from hydrochloric acid and nitric acid, were $58^{\circ}$ and $92^{\circ}$, respectively, showing low water repellency. On the other hand, when acetic acid, phosphoric acid, and oxalic acid were used, the contact angles of the coated films were $101^{\circ}$, $103^{\circ}$ and $116^{\circ}$, respectively, showing high water repellency. In addition, when isopropanol and ethanol were used as solvents, phase separation occurred in the solutions due to the aggregation of siloxane polymers. On the other hand, when methanol, ethyl acetate, and methyl ethyl ketone were used as solvents, the solutions were transparent and showed a stable state without sedimentation.

• Analytical Science and Technology
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• v.19 no.3
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• pp.194-202
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• 2006

In this work, extraction and purification of the possible whitening agents from the Chinese plants; Chrysanthemum morifolium Ramat (xizang cai ju hua), Rhodiola sachalinensis, and Terminalia chebula Retzius have been described. The chopped leaves of Chrysanthemum morifolium Ramat and Terminalia chebula Retzius were added to water and ethyl ether, respectively. Components were separated on a GS310 column ($21.5{\times}500mm$ i.d., $10-15{\mu}m$) and concentrated into four or three portions. The chopped leaves of Rhodiola salientness were added to methanol and separated and concentrated on a column ($C_{18}$ column, $3.9^{\circ}$�F8;300 mm i.d., $15{\mu}m$) into two parts. The whitening effects of extracts were examined by in-vitro melanin production assay, in melana and B16 cells at a concentration of $10{\mu}g/ml$. The ethyl acetate layer of Chrysanthemum morifolium Ramat showed 92% melanin inhibitory at $200{\mu}g/ml$, the extract of Rhodiola sachalinensis showed a whitening effect of about 60% melanin inhibitory, which was more efficient than the whitening effect of arbutin (45.6%). The methanol extract of Terminalia chebula Retzius inhibited melanin expression by 90% at $100{\mu}g/ml$; however, it was toxic to B16 melanoma cells.

• Journal of the Korean Society of Food Culture
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• v.22 no.4
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• pp.454-461
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• 2007

Antioxidative and antimicrobial activities were carried out on the Citrus Unshju peel solvent extracts in order to discover new functional activities. The amounts of polyphenol in 70% metanol extract (MtEx) was measured as 836.8 mg% in Citrus Unshju peel. The EDA (electron donating ability) of 0.01, 0.02 and 0.1% MtEx in Citrus Unshju peel were measured as levels of 81.3, 86.0 and 89.6%. The nitrite scavenging effects of Citrus peel were also determined as the levels of 34.4% (pH 1.2) and 19.5% (pH 7.0). The pH of react solution was more acidic, the nitrite scavenging effect was more increased. The order of antioxidatives was shown as TBHQ > BHT > TOC > ChEx > EaEx > EtEx > WaEx > Control in corn germ oil and TBHQ > ChEx > EaEx > BHT > EtEx > WaEx > TOC > Control in canola oil. A number of the extracts were certified to have antimicrobial activities for a small number of micro-organisms, similar gram negative and positive micro-organisms. According to the results above, it was summerized that Citrus Unshju peel had the higher total polyphenol, EDA, nitrite scavenging effects and antimicrobial activities. Also isolated extract from ChEx and EaEx had high antioxidative, these effects were very similar to that of ${alpha}$-tocopherol and BHT. It would be proposed that Citrus peel can become a new natural source for antioxidative agents in future food industry.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.893-899
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• 2004

To test the cytoprotective effect of sophorae radix (SR) against hydrogen peroxide (H₂O₂)-induced cytotoxicity, we investigated the cell viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay in the presence of ethyl acetate subfractions of SR water extracts In H9c2 cells. And to clarify the cytoprotective mechanism of SR extracts, we evaluated the cellular glutathione (GSH) contents in the presence of subfraction 1, 2, 3, and 4 of SR ethyl acetate soluble fractions. Among 1 -12 subfractions of SR ethyl acetate soluble fractions, 1, 2, 3 and 4 subfractions have an efficacy inhibiting the cytotoxicity induced by H₂O₂ in H9c2 cells. Also, the protective effects of 1, 2, 3 and 4 subfractions of SR ethyl acetate soluble fractions resulted from the anti-oxidant effects. These results suggest that ethyl acetate soluble fractions of SR water extracts is effective in the prevention of H₂O₂-induced cytotoxicity and 1, 2, 3 and 4 subfraction of ethyl acetate soluble fractions possess the anti-oxidant component.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1241-1247
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• 2015

The objective of this study was to determine antioxidant properties of polyphenol fractions of cranberry powder employing lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage cells. Ethyl acetate fraction (EF) and methanol fraction (MF) of cranberry powder were prepared using a C18 Sep-Pak cartridge. When cells were treated with LPS for 20 h, intracellular reactive oxygen species (ROS) and DNA damage significantly increased. In cells pre-treated with EF, MF, and total fraction (TF: combining EF and MF), significant reductions of intracellular ROS were observed. The tested fractions reduced LPS-induced DNA damage measured by Hoechst staining. In addition, LPS-induced DNA oxidation was attenuated when cells were pre-treated with TF and MF. However, there was no significant difference in LPS-induced superoxide dismutase activity.

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.124-130
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• 2020

The present study investigated the anti-proliferate and anti-invasive of Phorbol 12-myristate 13-acetate (PMA)-induced matrix metalloproteinase (MMP-2) and MMP-9 activities of combined treatment with cisplatin and ethyl acetate fractions of Paeonia japonica. Cell Proliferation was detected by the MTS assay and the activity and mRNA expression of MMP-2/-9 were examined by zymography and RT-PCR. As results, cisplatin or p. japonica treatment of YD-10B cells resulted in a dose-dependent inhibition of cell growth. Also, the viability of YD-10B cells treated with combination of 200 μM cisplatin and 50 ㎍/ml p. japonica was inhibited to 50% in compared with the cisplatin alone. In PMA-treated YD-10B cells, co-treatment of 200 μM cisplatin with 50 ㎍/ml p. japonica significantly inhibited mRNA expression and protein activation of MMP-2/-9. Therefore, This study suggest that the combination treatment of cisplatin and p. japonica potentiates a promising anti-invasive agent and has more potential anti-cancer drug for oral cancer therapy than cisplatin alone.