• Title/Summary/Keyword: methanol activation

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

  • Shen, Ting;Kim, Jong-Dai;Cho, Jae-Youl
    • Korean Journal of Medicinal Crop Science
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    • v.17 no.1
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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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    • v.30 no.2
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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.

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

  • Yang, Jin-Seok;Kim, Seong-Il;Kim, Chun-Keun;Park, Jung-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.14 no.1
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    • pp.49-53
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    • 2007
  • The direct methanol fuel cell (DMFC) is a promising power source for portable applications due to many advantages such as simple construction, compact design, high energy density, and relatively high energy-conversion efficiency. In this work, an electrochemical methanol sensor for monitoring the methanol concentration in direct methanol fuel cells was fabricated using a thin composite nafion membrane as the electrolyte. We have analyzed the I-V characteristic of the fabricated methanol sensor as a function of methanol concentration, catalyst electrode and platinum(Pt) thickness. The fabricated sensor was analyzed by I-V measurement with various methanol concentration. When we measured the sensor characteristics with 10nm Pt and at 1V, the current value was $1.30{\times}10^{-6}A,\;1.96{\times}10^{-6}A\;and\;2.80{\times}10^{-6} A$ for three methanol concentration of 1M, 2M and 3M, respectively. When the methanol concentration was fixed at 2M, the current value of the fabricated device with Pt layers of 5, 10 and 15 nm thickness was $3.06{\times}10^{-6}A,\;1.96{\times}10^{-6}A\;and\;1.00{\times}10^{-6}A$, respectively. These results lead us to the conclusion that when the methanol concentration increases, the output current increases and when the catalyst electrode become thinner, the current increase more. It showed that, the thinner the catalyst electrode, the more electrochemistry become activation.

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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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    • v.10 no.3
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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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Effect of Zingiber officinale Roscoe Fractionation of Extracts on Mouse Spleen and Macrophage Cells Activation (생강 분획에 따른 추출물이 마우스 비장세포와 Cytokine (IL-1 ${\beta}$, IL-6, TNF-${\alpha}$)의 생성량에 미치는 영향)

  • Ryu, Hye-Sook
    • The Korean Journal of Food And Nutrition
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    • v.20 no.2
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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.

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

  • Lee, Si-Eun;Lee, Mi-Hwa;Choi, Ho-Young;Sohn, Nak-Won;Kang, Hee
    • The Korea Journal of Herbology
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    • v.27 no.1
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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.

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

  • Jung, Young-Seok;Jung, Hye-Mi;Seo, Un-Kyo
    • The Journal of Internal Korean Medicine
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    • v.30 no.1
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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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    • v.15 no.17
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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.

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

  • Park, Byoung Chun;Park, Soo Hyun;Kyong, Jin Burm;Kim, Chang Bae
    • Journal of the Korean Chemical Society
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    • v.43 no.4
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    • pp.456-460
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    • 1999
  • Rates of 1-adamantyl fluoroformate with substituted pyridines ($3-CH_3,\;4-CH_3,\;H,\;3-Cl,\;3,4-(CH_3)_2,\;3,5-(CH_3)_2$) in methanol have been measured by conductometric method at various temperatures and concentrations. The activation parameters (${\Delta}H^{\neq},\;{\Delta}S^{\neq}$) and Hammett reaction constant (${\rho}$) or Bronsted coefficient (${\beta}$) were evaluated from rate constants. The activation entropies are large and negative, and the activation enthalpies are small and positive. The Hammett reaction constant (${\rho}$) and Bronsted coefficient (${\beta}$) values were -4.15 and 0.63, respectively. From the above results, it may be concluded that this reaction proceeds to a concerted displacement mechanism in methanol.

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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 - (구리 촉매하에서 규소와 메탄올의 반응에 의한 Tetramethyl orthosilicate(TMOS) 합성(제2보) - 구리촉매하에서 규소와 메탄올과의 반응의 반응속도론 -)

  • Soh, Soon-Young;Won, Ho-Youn;Chun, Yong-Jin;Lee, Bum-Jae;Yang, Hyun-Soo
    • Applied Chemistry for Engineering
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    • v.10 no.2
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    • pp.259-262
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    • 1999
  • The copper-catalyzed reaction of silicon with methanol was carried out in a mixed bed reactor to obtain tetramethyl orthosilicate (TMOS). In order to determine the kinetics of the reaction per active site on the silicon surface, a flow rate transition technique was employed. A kinetic study showed the reaction was in Linear relationship with the amount of contact mass and independent on the concentration of methanol. This result indicated that the rate-determining step was not the chemical process involving methanol, but the formation of silicon intermediate on the contact mass. On the basis of optimum experimental conditions, the maximum TMOS formation rate per g-silicon is 0.030 (g/min) at $210^{\circ}C$, in which activation energy was 8.5 kcal/mol and reaction rate equation was $k=4.09{\times}10^4\;exp$ ($-4.73{\times}10^3/T$).

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