• Title/Summary/Keyword: Solvent effects.

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A Study on the Anti-microbial Effect on S. mutans and Anti-oxidant Effect of Zanthoxylum pericarpium Extract (산초 추출물의 S. mutans 항균활성 및 항산화 효능 연구)

  • Lee, Sang-Gon;Park, Chan-Ik
    • The Korea Journal of Herbology
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    • v.26 no.4
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    • pp.181-185
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    • 2011
  • Objectives : The Zanthoxylum pericarpium has been used as oriental spicy seasoning and a medicinal plant from old times. This study was performed to determine the anti-oxidant efficacy of Zanthoxylum pericarpium extract and the anti-microbial effects. Methods : We got Zanthoxylum pericarpium extract using PSE (pressurized solvent extraction) method. The anti-microbial effect of Zanthoxylum pericarpium extract was assessed on Streptococcus mutans(S. mutans) and anti-oxidant effect of the extract was assessed by measuring DPPH radical scavenging activity and SOD like activity. Results : 1. Zanthoxylum pericarpium extract had high anti-microbial activity on S. mutans. 2. DPPH radical scavenging activity significantly increased in the Zanthoxylum pericarpium extract. 3. SOD like activity also significantly increased in the Zanthoxylum pericarpium extract. Conclusions : The PSE extract from Zanthoxylum pericarpium has good anti-microbial and anti-oxidant effects in a concentration-dependent manner.

Effects on Suspension Solution for Electrophoretic Superconducting Thick-film Wire (전기영동 초전도 후막선재의 현탁용매 영향)

  • 소대화;박정철;이영매;조용준;코로보바
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.81-84
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    • 1999
  • For the research of the effects on suspension solution with YBCO and BSCCO for elcectrophoretic deposition to prepare superconducting thick-film wire, it was investigated that the preheating technique for the superconducting powders in vacuum system was used with various solvent solutions of acetone, ethanol, toluene and buthanol for electrophoresis. As a result it was useful to remove the influence of remaining and adsorbed solvent solution which was existed between and on the particle surfaces when the specimens of superconducting wire by electrophoresis were treated in vacuum of 10$\^$-3/ Torr and temperature around 200$^{\circ}C$ in bell-jar system. From the prepared superconducting wire samples, the critical current density, Jc was measured by 4-point prove method in liquid N$_2$ at the value of 10$\^$3/ to 10$\^$4/ A/$\textrm{cm}^2$, respectively, for the YBCO and BSCCO superconducting wires.

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Stoichiometric Solvation Effects. Part 4. Product-Rat Correlations for Solvolyses of p-Methoxyphenyl Chloroformate in Alcohol-Water Mixtures

  • 구인선;양기열;구자찰;박종근;이익준
    • Bulletin of the Korean Chemical Society
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    • v.18 no.9
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    • pp.1017-1021
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    • 1997
  • Solvolyses of p-methoxyphenyl chloroformate in water, D2O, CH3OD, 50% D2O-CH3OD, and in aqueous binary mixtures of acetone, ethanol and methanol are investigated at 25.0 ℃. Product selectivities are reported at 25 ℃ for a wide range of ethanol-water and methanol-water solvent compositions. The Grunwald-Winstein plots of first-order rate constants for p-methoxyphenyl chloroformate with YCl (based on 1-adamantyl chloride) show marked dispersions into three separate curves for the three aqueous mixtures with a small m value and a rate maximum for aqueous alcohol solvents. Third-order rate constants, kww, kaw, kwa and kaa were calculated from the observed kww and kaa values together with kaw and kwa calculated from the intercept and slope of the plot of 1/S vs. [alcohol]/[water]. The calculated rate constants, kcalc and mol % of ester agree satisfactorily with those of the observed rate constants, kobs and mol % of ester, supporting the stoichiometric solvation effect analysis. The kinetic solvent isotope effects determined in water and methanol are consistent with the proposed mechanism of the general base catalyzed carbonyl addition-elimination.

Theoretical Studies of Solvent Effects on Gas Phase Reactions of Methoxide Ion with Substituted Ethylenes$^\dag$

  • Lee, Ik-Choon;Lee, Bon-Su;Won Jong-Ok
    • Bulletin of the Korean Chemical Society
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    • v.8 no.6
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    • pp.444-449
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    • 1987
  • Solvent effects on gas phase reactions of methoxide ion with substituted ethylenes, $CH_2$ = CHR where R = CN, CHO and $NO_2$, are investigated theoretically using the AM1 method. Results show that the methoxide approaches in-plane in all reactions, but subsequently rotate out-of-plane to form tetrahedral complexes in additon reactions. All reactions of a bare methoxide are found to be exothermic, the exothermicity being the greatest in the ${\beta}$-addition, in which the excess energy is forced to be contained within the ${\beta}$-adduct rendering extreme instability. However a part of the excess energy can be removed by a solvate molecule giving a stable complex prior to the product formation. The hydride transfer processes were found to be unfavorable due to the high activation barriers. The ${\alpha}-H^+$ abstraction process from acrylonitrile becomes endothermic as a result of monosolvation of the methoxide, in agreement with experimental results.

Volatile Compounds and Antiproliferative Effects of Dendropanax morbifera on HepG2 Cells (황칠나무의 휘발성 화합물 분석 및 HepG2 세포의 증식 억제 효과)

  • Yang, Seun-Ah;Garcia, Coralia V.;Lee, Ji-Won
    • Journal of Life Science
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    • v.27 no.5
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    • pp.561-566
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    • 2017
  • Dendropanax morbifera Lev. is known in Korea for its golden sap and medicinal properties. The many biological activities of the leaf and stem extracts suggest that this tree could be a valuable source of medicinal compounds for the treatment of various ailments such as dermatitis, migraines, dysmenorrhea, muscle pain, and infectious diseases. However, there is little information on the composition and biological activity of the volatile fraction of D. morbifera. Therefore, in this study, the volatile compounds in leaves, stems, and sap of D. morbifera were isolated using solvent and supercritical fluid extraction (SFE), and analyzed by gas chromatography/mass spectrometry to reveal their chemical composition and identify potential compounds of interest. Fifteen compounds were identified in the leaf extracts, whereas 29 and 3 compounds were identified in the stem and sap extracts, respectively. The volatile profiles obtained using solvent and SFE differed. Esters and aromatic hydrocarbons predominated in the solvent extract of leaves and SFE extract of stems, whereas the solvent extract of stems and SFE extract of leaves contained terpenoids. Limonene, ${\alpha}$-pinene, and ${\beta}$-myrcene were identified in the volatile extract of sap, with limonene representing 96.30% of the total peak area. In addition, the antiproliferative effects of the solvent extracts of leaves and stems were evaluated, revealing that these solvent extracts were particularly effective in decreasing the proliferation of HepG2 cells.

Biological Activities of Various Solvent Extracts from Propolis (프로폴리스 용매별 추출물의 생리활성)

  • Lee, Ho-Jae;Bae, Young-Il;Jeong, Chang-Ho;Shim, Ki-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.1
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    • pp.1-7
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    • 2005
  • The scavenging effects of four extracts on the DPPH radical were increased with increasing amount of extract. However, these effects were not statistically significant. The reducing power of the extracts is increased as the amount of extract is increased. To compare reducing powers of various solvent extracts, 50% ethanol extract showed the highest reducing power. The various solvent extracts were also capable of scavenging nitrite in a manner dependent on concentration. They exhibited scavenging effects 90% on nitrite at the dose 500 p.g of water extract from propolis. The propolis extract significantly inhibited all the microorganisms tested, showing the largest inhibitory zone for Bacillus subtilis and Bacillus cereus. The 70% ethanol extract from propolis exhibited the strongest inhibitory effect on A549. The inhibitory effect of four extracts showed in that order 70% ethanol extract>95% ethanol extract>water extract>50% ethanol extract.