• Molecules and Cells
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• 제27권2호
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• pp.211-215
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• 2009

Toll-like receptors (TLRs) play a critical role in sensing microbial components and inducing innate immune and inflammatory responses by recognizing invading microbial pathogens. Lipopolysaccharide-induced dimerization of TLR4 is required for the activation of downstream signaling pathways including nuclear factor-kappa B ($NF-{\kappa}B$). Therefore, TLR4 dimerization may be an early regulatory event in activating ligand-induced signaling pathways and induction of subsequent immune responses. Here, we report biochemical evidence that 6-shogaol, the most bioactive component of ginger, inhibits lipopolysaccharide-induced dimerization of TLR4 resulting in the inhibition of $NF-{\kappa}B$ activation and the expression of cyclooxygenase-2. Furthermore, we demonstrate that 6-shogaol can directly inhibit TLR-mediated signaling pathways at the receptor level. These results suggest that 6-shogaol can modulate TLR-mediated inflammatory responses, which may influence the risk of chronic inflammatory diseases.

• Bulletin of the Korean Chemical Society
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• 제22권12호
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• pp.1303-1308
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• 2001

A series of catalysts, NiSO4/TiO2, for ethylene dimerization was prepared by the impregnation method using aqueous solution of nickel sulfate. On the basis of the results obtained from X-ray diffraction, the addition of NiSO4 shifted the transition of TiO2 from the anatase to the rutile phase toward higher temperatures due to the interaction between NiSO4 and TiO2. Nickel sulfate supported on titania was found to be very active even at room temperature. The high catalytic activity of NiSO4/TiO2 closely correlated with the increase of acidity and acid strength due to the addition of NiSO4. It is suggested that the active sites responsible for ethylene dimerization consist of low valent nickel, Ni+, with an acid.

• Bulletin of the Korean Chemical Society
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• 제22권12호
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• pp.1297-1298
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• 2001

• Bulletin of the Korean Chemical Society
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• 제26권7호
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• pp.1029-1030
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• 2005

• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.735-738
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• 2009

• BMB Reports
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• 제53권3호
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• pp.133-141
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• 2020

The epidermal growth factor receptor (EGFR), a member of the ErbB family (EGFR, ErbB2, ErbB3 and ErbB4), plays a crucial role in regulating various cellular responses such as proliferation, differentiation, and survival. As a result, aberrant activation of EGFR, mostly mediated through different classes of genomic alterations occurring within EGFR, is closely associated with the pathogenesis of numerous human cancers including lung adenocarcinoma, glioblastoma, and colorectal cancer. Thus, specific suppression of oncogenic activity of mutant EGFR with its targeted drugs has been routinely used in the clinic as a very effective anti-cancer strategy in treating a subset of tumors driven by such oncogenic EGFR mutants. However, the clinical efficacy of EGFR-targeted therapy does not last long due to several resistance mechanisms that emerge in the patients following the drug treatment. Thus, there is an urgent need for the development of novel therapeutic tactics specifically targeting mutant EGFR with the focus on the unique biological features of various mutant EGFR. Regarding this point, our review specifically emphasizes the recent findings about distinct requirements of receptor dimerization and autophosphorylation, which are critical steps for enzymatic activation of EGFR and signaling cascades, respectively, among wildtype and mutant EGFR and further discuss their clinical significance. In addition, the molecular mechanisms regulating EGFR dimerization and enzymatic activity by a key negative feedback inhibitor Mig6 as well as the clinical use for developing potential novel drugs targeting it are described in this review.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1273-1279
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• 2007

The NiSO4 supported on Fe2O3 catalysts were prepared by the impregnation method. No diffraction line of nickel sulfate was observed up to 30 wt %, indicating good dispersion of nickel sulfate on the surface of Fe2O3. The addition of nickel sulfate to Fe2O3 shifted the phase transition of Fe2O3 (from amorphous to hematite) to higher temperatures because of the interaction between nickel sulfate and Fe2O3. 20-NiSO4/Fe2O3 containing 20 wt % of NiSO4 and calcined at 500 oC exhibited a maximum catalytic activity for ethylene dimerization. The initial product of ethylene dimerization was found to be 1-butene and the initially produced 1-butene was also isomerized to 2-butene during the reaction. The catalytic activities were correlated with the acidity of catalysts measured by the ammonia chemisorption method.

• 분석과학
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• 제12권3호
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• pp.209-217
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• 1999

Rose bengal과 thiourea로 각각 감응 및 초감응된 광전류의 감소 원인을 규명하기 위하여 염료용액을 분광학적인 방법으로 분석하였다. 광조사 전후 감응용액의 흡수 및 형광 스펙트럼을 분석하므로서 RB와 TU사이에 일어나는 광촉매 이합체화 반응 기구를 확인할 수 있었다. 또 두 염료분자가 이루는 쌍극자 모멘트의 기하학적 배열은 사각이었으며, 이들 사이의 각도는 $124^{\circ}$임을 알 수 있었다.

• 분석과학
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• 제11권1호
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• pp.20-28
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• 1998

감응제인 rose bengal과 초감응제인 allylthiourea를 포함하고 있는 광전기화학 전지를 이용하여 태양에너지를 전기에너지로 변환시킬 때, 광전류가 지속성이 없는 원인을 규명하기 위하여, 광조사 전후의 염료 용액을 형광 및 흡수 분광법으로 분석하였다. 그 결과, 감응제와 초감응제 사이에 광촉매 이합체화 반응이 일어나는 것을 확인하였다. 또한 이합체를 구성하는 각 분자의 기하학적 쌍극자 배열은 사각임을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.541-544
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• 1999

We synthesised a novel photo-alignment material of PCEMA (poly(cinnamolyethyl methacrylate)) on photo-dimerization reaction. Next we investigated the electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-liquid crystal display (LCD) with linearly polarized ultraviolet (UV) light irradiation on PCEHA surface. The excellent voltage-transmittance characteristics of photo-aligned TN-LCD on PCEMA surface were obtained. The threshold voltage of photo-aligned TN-LCD decreases with increasing the UV light irradiation time on PCEMA surface. Also, the response time of photo-aligned TN-LCD on PCEMA surface is almost the same as rubbing-aligned TN-LCD.