• 제목/요약/키워드: methanol activation

검색결과 227건 처리시간 0.035초

그람음성균 유래 lipopolysaccharide로 활성화된 대식세포의 기능 수행시 갈화 [Pueraria lobata (Willd.) Ohwi]의 조절작용 (Immunomodulatory Effect of Pueraria lobata on the Functional Activation of Macrophages by Lipopolysaccharide Treatment)

  • 센팅;김종대;조재열
    • 한국약용작물학회지
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    • 제17권1호
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    • pp.8-14
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    • 2009
  • Pueraria lobata (Willd.) Ohwi was investigated to check its modulatory effects on the activation of macrophages upon inflammatory conditions treatment. For this purpose, we examined several inflammatory responses such as nitric oxide (NO) production, reactive oxygen species (ROS) generation, cytoprotection and phagocytosis under the treatment of methanol extract from P. lobata (Pl-ME). Pl-ME dose-dependently blocked NO production in lipopolysaccharide (LPS)- stimulated RAW264.7 cells but not sodium prusside (SNP)-generated NO release. The NO inhibition seemed to be due to blocking inducible NO synthase (iNOS), since Pl-ME suppressed its expression in a NF-${\kappa}B$-independent manner. Similarly, this extract also effectively protected RAW264.7 cells from LPS-induced cytotoxicity. However, Pl-ME did not block ROS generation and rather it enhanced. Finally, this extract negatively modulated FITC-dextran uptake. Therefore, our data suggested that Pl-ME may be involved in negatively regulating some macrophage-mediated inflammatory responses such as NO production and phagocytic uptake.

A Kinetic Study on Solvolysis of Diphenyl Thiophosphorochloridate

  • Koh, Han-Joong;Kang, Suk-Jin;Kevill, Dennis N.
    • Bulletin of the Korean Chemical Society
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    • 제30권2호
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    • pp.383-388
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    • 2009
  • Rates of solvolyses of diphenyl thiophosphorochloridate ($(PhO)_2$PSCl, 1) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone and 2,2,2-trifluoroethanol (TFE) are reported. For four representative solvents, studies were made at several temperatures and activation parameters were determined. The 30 solvents gave a reasonably precise extended Grunwald-Winstein plot, correlation coefficient (R) of 0.989. The sensitivity values (l = 1.29 and m = 0.64) of diphenyl thiophosphorochloridate ($(PhO)_2$PSCl, 1) were similar to those obtained for diphenyl phosphorochloridate ($(PhO)_2$POCl, 2), diphenylphosphinyl chloride ($Ph_2$POCl, 3) and diphenylthiophosphinyl chloride ($Ph_2$PSCl, 4). As with the previously studied of 3~4 solvolyses, an $S_N$ pathway is proposed for the solvolyses of diphenyl thiophosphorochloridate (1). The activation parameters, ${\Delta}H^{\neq}\;(=11.6{\sim}13.9\;kcal{\cdot}mol^{-1})\;and\;{\Delta}S^{\neq}\; (=\;-32.1\;{\sim}\;-42.7\;cal{\cdot}mol^{-1}{\cdot}K^{-1})$, were determined, and they were in line with values expected for an $S_N$2 reaction. The large kinetic solvent isotope effects (KSIE, 2.44 in MeOH/MeOD and 3.46 in $H_2O/D_2$O) are also well explained by the proposed $S_N$2 mechanism.

직접 메탄올 연료전지용 메탄올 센서의 백금 두께의 변화에 따른 전류-전압 특성 변화 (I-V Characteristics of a Methanol Sensor for Direct Methanol fUel Cell(DMFC) as a Function of Deposited Platinum(Pt) Thickness)

  • 양진석;김성일;김춘근;박정호
    • 마이크로전자및패키징학회지
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    • 제14권1호
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    • pp.49-53
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    • 2007
  • 직접 메탄올 연료전지는 간단한 구조와 디자인 그리고 높은 에너지 밀도와 에너지 변환 효율등의 장점으로 인하여 휴대용 장치들의 전력원으로 사용된다. 본 논문에서는 직접 메탄올 연료전지의 연료 농도를 감지하기 위한 얇은 나피온 막과 Pt 촉매전극의 합성으로 만들어진 메탄을 센서를 제작하였다. 제작된 메탄을 센서를 사용하여 메탄올 농도와 촉매전극(Pt)의 두께 변화에 따른 전류-전압 특성을 분석하였다. Pt 촉매전극 10nm, 전압이 1V 이고 메탄올 농도 1, 2, 3M일 때 전류 값이 각각 $1.30{\times}10^{-6}A,\;1.96{\times}10^{-6}A,\;2.80{\times}10^{-6} A$ 이었다. 메탄올 농도를 2M로 고정하고 촉매전극의 두께를 5, 10, 15nm로 변화시켰을 때 전류 값은 각각 $3.06{\times}10^{-6}A,\;1.96{\times}10^{-6}A,\;1.00{\times}10^{-6}A$ 이었다. 촉매전극이 얇을수록 전류가 증가하고 전기화학반응이 더 활발히 일어나는 것으로 사료된다.

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Fluorescence quenching of 5-methyl-3-phenyl-2-[s-oxadiazol-2'-thione-5'-yl] indole by $CCl_4$ and aniline in different solvents

  • H M, Suresh-Kumar;R S, Kunabenchi;J S, Biradar;N N, Math;J S, Kadadevaramath
    • Journal of Photoscience
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    • 제10권3호
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    • pp.225-229
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    • 2003
  • The fluorescence quenching of 5-methyl-3-phenyl-2-[s-oxadiazol-2'-thionen5'-yl] indole by carbon tetrachloride ($CCl_4$) and aniline in different solvents viz., dioxane, benzene, toluene, methanol, propanol has been carried out at room temperature to understand the role of quenching mechanisms. The Stern-Volmer plots have been found to be linear. As probability of quenching per encounter 'p' is less than unity, and the activation energy for quenching 'E$_{a}$' is greater than the activation energy of diffusion 'E$_{d}$', it is inferred that the fluorescence of quenching mechanism is not due to material diffusion alone.e.e.

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생강 분획에 따른 추출물이 마우스 비장세포와 Cytokine (IL-1 ${\beta}$, IL-6, TNF-${\alpha}$)의 생성량에 미치는 영향 (Effect of Zingiber officinale Roscoe Fractionation of Extracts on Mouse Spleen and Macrophage Cells Activation)

  • 류혜숙
    • 한국식품영양학회지
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    • 제20권2호
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    • pp.125-133
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    • 2007
  • Ginger(Zingiber officinale Roscoe) has long been used as a food source in Korea, and it is widely used as a dietary condiment throughout the world. The present study focused on the immunomodulative effects of ginger extracts via in vitro experiments. To identify the immune-activation fractions of the plant, we performed the systematic fractionation of ginger with methanol, hexane, chloroform, butanol and water for separation and refining. The results showed that the chloroform fraction had the highest immune cell activation properties. In conclusion, this study suggests that ginger extracts may enhance immune function by regulating the splenocyte proliferation as well as the cytokine production capacity of activated macrophages.

하엽(荷葉) 메탄올 추출물의 마우스 대식세포 inducible nitric oxide synthase 합성과 신호전달에 대한 조절 (Nelumbinis Folium Methanol Extract Regulates Inducible Nitric Oxide Synthase Signaling Pathways in Mouse Peritoneal Macrophages)

  • 이시은;이미화;최호영;손낙원;강희
    • 대한본초학회지
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    • 제27권1호
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    • pp.65-71
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    • 2012
  • Objective : Nelumbinis Folium (NF) is used for diarrhea, headache and dizziness in traditional medicine. In this paper, we examined the anti-inflammatory effects of the methanol extract of NF in mouse macrophages. Methods : Peritoneal macrophages from thioglycollate medium-injected mice were cultured and stimulated with lipopolysaccharide(LPS) or LPS/interferon(IFN)-${\gamma}$ for viability assay, cytokine measurement and Western blotting. Results : NF methanol extract suppressed the levels of nitric oxide (NO) through reduction of inducible NO synthase in a concentration-dependent manner. The extract reduced LPS/IFN-${\gamma}$-stimulated STAT1 phosphorylation and LPS-induced $I{\kappa}B{\alpha}$ degradation through inhibition of $I{\kappa}B{\alpha}$ kinase activation. The extract also inhibited p38, JNK/SAPK and ERK1/2 activation. Conclusions : Our findings suggested that NF has anti-inflammatory activity, and have a potential for therapeutic application. Further research is required to investigate its anti-inflammatory active compounds.

1-methyl-4-phenylpyridinium($MPP^+$)로 유도된 파킨슨병의 세포손상에 대한 황백의 신경세포 보호효과 (Neuroprotective Effect of Methanol Extract of Phellodendri Cortex Against 1-methyl-4-Phenylpyridinium-induced Apoptosis in PC-12 Cells)

  • 정영석;정혜미;서운교
    • 대한한방내과학회지
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    • 제30권1호
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    • pp.51-63
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    • 2009
  • Background and Objective : The prospects for developing an anti-apoptotic natural component or a compound that exerts a neuroprotective effect with few or no side effects for the treatment of neurodegenerative disease appear favorable. In the present study, we evaluated the effects of the methanol extract of Phellodendri Cortex (PC extract) on 1-methyl-4-phenyl pyridinium($MPP^+$)-induced apoptosis in PC-12 cells. Materials and Methods : We used the methanol extract of Phellodendri Cortex (PC extract). PC-12 cells were cultured by RPMZ-1640. We found the PC extract's gene expression (Bax, Bcl-2) by using RT-PCR. We examined the PC extract's protein expression (Bcl-2, Bax, cytochrome c, poly (ADP-ribose) polymerase (PARP), caspase-3) by SDS-PAGE and Western blot. Results : Apoptosis in $MPP^+$-induced PC-12 cells was accompanied by an increased Bax/Bcl-2 ratio, release of cytochrome c to the cytosol and the activation of caspase-3. PC extract inhibited the down-regulation of Bcl-2 and the up-regulation of Bax, as well as the release of mitochondrial cytochrome c into the cytosol. In addition, PC extract attenuated caspase-3 activation and cleavage of poly (ADP-ribose) polymerase (PARP). Conclusion : These results suggest that the neuroprotective potentials of PC extract against $MPP^+$-induced apoptosis can be. at least partially, ascribed to its anti-apoptotic effects in PC-12 cells.

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Methanol Extract of Flacourtia indica Aerial Parts Induces Apoptosis via Generation of ROS and Activation of Caspases in Human Colon Cancer HCT116 Cells

  • Park, Ki-Woong;Kundu, Juthika;Chae, In Gyeong;Bachar, Sitesh Chandra;Bae, Jung-Woo;Chun, Kyung-Soo
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권17호
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    • pp.7291-7296
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    • 2014
  • Different plant parts of Flacourtia indica have long been used in Ayurvedic medicine. Previous studies have demonstrated that the methanolic extract of F. indica possess anti-inflammatory properties. The present study was aimed at investigating the anticancer effects of methanol extract of Flacourtia indica (FIM) aerial parts in human colon cancer (HCT116) cells. Treatment of cells with FIM at a concentration of $500{\mu}g/ml$ for 24 hours significantly reduced cell viability and induced apoptosis, which was associated with the increased cytoplasmic expression of cytochrome c, activation of caspase-3, and the cleavage of poly-(ADP-ribose) polymerase. Incubation with FIM also inhibited the levels of Bcl-2, Bcl-xl and survivin, which are the markers of cell proliferation, whereas the expression of Bax remained unchanged. Treatment with FIM led to the generation of reactive oxygen species (ROS) in a concentration-dependent manner. Pharmacological inhibition of ROS generation by pretreatment of cells with N-acetyl cysteine abrogated FIM-induced apoptosis in HCT116 cells. Thus, these results demonstrate that FIM has anti-proliferative and pro-apoptotic effects in HCT116 cells and the effects are, at least in part, due to the ROS dependent activation of caspases.

치환 피리딘류와 1-Adamantyl Fluoroformate의 반응에 대한 속도론적 연구 (Kinetics on the Reaction of 1-Adamantyl Fluoroformate with Substituted Pyridines)

  • 박병춘;박수현;경진범;김창배
    • 대한화학회지
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    • 제43권4호
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    • pp.456-460
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    • 1999
  • 메탄올 용매내에서 치환 피리딘류($3-CH_3,\;4-CH_3,\;H,\;3-Cl,\;3,4-(CH_3)_2,\;3,5-(CH_3)_2$)와 1-adamantyl fluoroformate의 반응속도를 여러 온도와 농도 조건에서 전도도 방법으로 측정하였다. 이들 반응속도상수로부터 활성화 파라미터(${\Delta}H^{\neq},\;{\Delta}S^{\neq}$)와 Hammett 반응상수(${\rho}$) 및 Bronsted 상관 계수(${\beta}$)를 구하였다. 이 때 ${\Delta}S^{\neq}$는 큰 음의 값을, ${\Delta}H^{\neq}$는 작은 양의 값을 얻었으며, 반응상수 ${\rho}$값과 상관 계수 ${\beta}$값은 각각 -4.15와 0.63이었다. 이러한 결과로부터 본 반응은 협동 치환 메카니즘으로 진행됨을 알 수 있었다.

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구리 촉매하에서 규소와 메탄올의 반응에 의한 Tetramethyl orthosilicate(TMOS) 합성(제2보) - 구리촉매하에서 규소와 메탄올과의 반응의 반응속도론 - (Tetramethyl orthosilicate(TMOS) Synthesis by the Copper-Catalyzed Reaction of the Metallic Silicon with Methanol (II) - The Kinetics of the Copper-Catalyzed Reaction of Silicon with Methanol -)

  • 소순영;원호연;전용진;이범재;양현수
    • 공업화학
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    • 제10권2호
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    • pp.259-262
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    • 1999
  • 금속 규소와 구리 촉매가 함유된 접촉물과 메탄올의 반응에 의한 메톡시실란의 합성에서의 TMOS 반응 생성속도를 산출하였다. 활성 자리 수의 변화에 따른 영향을 제거하기 위해서 유속 전이 기술을 사용하여 주입되는 메탄올의 유속을 반응도중 급격히 변화시켰다. 실험 결과 TMOS 생성속도에 영향을 미치는 인자는 반응에 참여하는 메탄올 농도가 아닌 접촉물질의 사용량임을 확인하였으며, 이를 바탕으로 TMOS 생성 메카니즘에서 접촉 물질의 표면에서 중간생성물이 형성되는 반응 단계가 반응 율속단계라고 추정되었다. 최적 공정조건에서 규소 1 g당 최대 TMOS 생성속도는 $210^{\circ}C$에서 0.030 (g/min)이었으며, 이때의 활성화 에너지는 값은 8.5 kcal/mol, 반응 생성속도 상수의 온도 의존성은 식 $k=4.09{\times}10^4\;exp$ ($-4.73{\times}10^3/T$)로 나타났다.

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