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81.
Mono‐ and Dinuclear Phosphorescent Rhenium(I) Complexes: Impact of Subcellular Localization on Anticancer Mechanisms 下载免费PDF全文
Rui‐Rong Ye Dr. Cai‐Ping Tan Mu‐He Chen Liang Hao Prof. Liang‐Nian Ji Prof. Zong‐Wan Mao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7800-7809
Elucidation of relationship among chemical structure, cellular uptake, localization, and biological activity of anticancer metal complexes is important for the understanding of their mechanisms of action. Organometallic rhenium(I) tricarbonyl compounds have emerged as potential multifunctional anticancer drug candidates that can integrate therapeutic and imaging capabilities in a single molecule. Herein, two mononuclear phosphorescent rhenium(I) complexes ( Re1 and Re2 ), along with their corresponding dinuclear complexes ( Re3 and Re4 ), were designed and synthesized as potent anticancer agents. The subcellular accumulation of Re1–Re4 was conveniently analyzed by confocal microscopy in situ in live cells by utilizing their intrinsic phosphorescence. We found that increased lipophilicity of the bidentate ligands could enhance their cellular uptake, leading to improved anticancer efficacy. The dinuclear complexes were more potent than the mononuclear counterparts. The molecular anticancer mechanisms of action evoked by Re3 and Re4 were explored in detail. Re3 with a lower lipophilicity localizes to lysosomes and induces caspase‐independent apoptosis, whereas Re4 with higher lipophilicity specially accumulates in mitochondria and induces caspase‐independent paraptosis in cancer cells. Our study demonstrates that subcellular localization is crucial for the anticancer mechanisms of these phosphorescent rhenium(I) complexes. 相似文献
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Quantitative 31P‐NMR spectroscopy for the determination of fosfomycin and impurity A in pharmaceutical products of fosfomycin sodium or calcium 下载免费PDF全文
Haipeng Jiang Hong Chen Nian Cai Jing Zou Xiulian Ju 《Magnetic resonance in chemistry : MRC》2015,53(6):454-459
A quantitative 31P‐NMR method for the determination of fosfomycin and impurity A in pharmaceutical products of fosfomycin sodium or calcium has been developed. In this method, coaxial inserts containing trimethyl phosphate are used as external standard. The method is convenient and robust, and gives both high accuracy and precision. It is shown that an accurate determination is possible using different probes and coaxial inserts. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Xiao‐Qiao Wang Nian Liu Cai‐Feng Wang Su Chen 《Journal of polymer science. Part A, Polymer chemistry》2016,54(10):1323-1331
Autonomous mechanical mass transportation for cargos on the microscale with no need of continuous external powering is of great scientific and technological interest due to their extensive applications. However, it is still challenging to create a self‐driven system applicable to diverse micromaterial transportation demands. In this work, we developed a novel autonomous conveyer gel driven by frontal polymerization (FP). The chemical wave produced in FP was stable, and self‐propagating with a constant velocity, which can be easily monitored by thermal imaging or fluorescence labeling. We investigated the influence of the initiation temperature, swelling ratio of the gel substrate, and the size of the cargos on the motion of driven behavior. Results showed that the driving velocity can be well controlled by altering the initiation temperatures of FP. The swelling ratio and the size of the cargos had a key impact on the feasibility of self‐driven behavior. In addition, powerful driven capability by FP was demonstrated by successfully transporting cargos in series, and further applied for targeted synthesis of CdS nanocrystals. The methodology developed here provides an effective way to convert chemical energy to mechanical work, and may be useful in energy conversion and utilization, mass transportation and other applications. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1323‐1331 相似文献
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近年来, 以生物质为基础的生物柴油得到了迅速发展, 导致了粗甘油过剩. 通过甘油选择性氢解制1,3-丙二醇, 进而被用于合成高价值的聚对苯二甲酸丙二醇酯被认为是最具工业应用潜力的反应之一, 对于提高生物柴油的利用效率有着极其重要的意义. 但由于反应空间位阻和热力学上的限制给甘油氢解制1,3-丙二醇带来了很大的挑战, 因此需要设计高活性的金属-酸双功能催化剂以降低甘油第二个C-O键断裂的活化能和减少其他副反应的发生. 目前Pt-W和Ir-Re双功能催化剂可高选择性制得1,3-丙二醇, 但仍需较严苛的反应条件实现对氢气的活化和解离. 本课题组曾将准单原子/单原子Pt高度分散于具有大量氧空位和酸位点的WOx载体上, 十分有利于甘油选择性氢解制1,3-丙二醇反应; 在Au-Pt/WOx催化剂中添加Au可促进B酸产生, 进而提高了甘油转化率和1,3-丙二醇的选择性.为了进一步研究Au对Pt/WOx催化剂结构和催化性能的影响, 本文利用CTAB辅助吸附法制备了Au/WO3, 再浸渍Pt制得Pt/Au/WO3双金属催化剂. 在甘油选择性氢解制1,3-丙二醇反应中, 所制催化剂表现出比Au-Pt/WOx更好的催化活性, 1,3-丙二醇时空收率为0.078 g1,3-PDO/(gcat·h), 是后者的1.95倍. 值得一提的是, Au-Pt/WOx催化剂在低压时活性较高, 而Pt/Au/WO3催化剂活性则在压力的升高而提高; 另外反应温度的升高导致副产物正丙醇的选择性上升, 1,3-丙二醇的选择性降低. 因此, 适宜的反应条件为155℃和5 MPa. 与Pt/WO3和Pt/WOx相比, Pt/Au/WO3表现出了更优异的催化性能, 其1,3-丙二醇的时空收率是Pt/WO3的2.36倍和Pt/WOx的4倍.为了探究Au的掺入对Pt/WOx催化剂性能的影响, 通过XRD, TEM, H2-TPR和XPS等技术对催化剂进行了深入表征. 结果表明, 与Pt/WO3相比, Pt/Au/WO3-600催化剂的XRD衍射峰向小角度偏移, 其原因是Au3+离子半径(0.85 ?)比W6+的(0.60 ?)大, Au3+以取代晶格W6+形式进入WO3晶格中; 对H2-TPR前300 ℃耗氢量的计算可知:Pt/WO3可被还原至Pt/WO2.96, 而Pt/Au/WO3可被还原至Pt/Au/WO2.91. 因此与Pt/WO3相比, Pt/Au/WO3表面氧空位更加丰富. TEM和XPS表征可知, 添加0.1 wt%Au后, 促进了更低价态的Pt均匀分散在WO3载体上, 其平均粒径为2.36 nm.综上所述, Au的掺杂改变了Pt/Au/WO3双金属催化剂的结构, 不仅降低了Pt和W的还原温度, 削弱了Pt和W之间的相互作用, 也促进了更低价态的Pt均匀分散于WO3载体上, 使得Pt/Au/WO3双金属催化剂在甘油氢解制1,3-丙二醇反应中具有更为优异的活性和产物选择性. 该催化剂有望被广泛运用于其他生物质平台化合物加氢脱氧的反应中. 相似文献
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Nian Hua Huang~ 《中国化学快报》2008,19(3):350-354
The flame retardant mechanism of the copolyester phosphorus containing linked pendant groups was investigated by thermogravimetric (TG), X-ray photoelectron spectroscopy (XPS) and direct insertion probe pyrolysis mass spectrometry (DP-MS) technique. TG results show that the incorporation of phosphorus containing unit linked pendant groups can destabilize the copolyester due to the cleavage of P-CH2 bond, and phosphorus containing units cannot promote the char-formation of the copolyester during the thermal degradation of the copolyester. XPS spectra indicate that with the increase of the temperature, the P-CH2 bonds of the copolyester break down gradually, the concentration of phosphorus in the condensed phase products decrease gradually and the chemical state of phosphorus does not change in the temperature of 250-380 ℃. Direct pyrolysis MS suggests that the P-CH2 bonds cleavage occurs at pendant groups and species containing phosphorus can volatilize into the gas phase. A flame retardant mechanism is proposed for the gas phase mode of action of the halogen-free copolyester phosphorus containing linked pendant groups. 相似文献
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Catalytic direct dehydrogenation of methanol to formaldehyde was carried out over Ag‐SiO2‐MgO‐Al2O3 catalysts prepared by sol‐gel method. The optimal preparation mass fractions were determined as 8.3% MgO, 16.5% Al2O3 and 20% silver loading. Using this optimum catalyst, excellent activity and selectivity were obtained. The conversion of methanol and the selectivity to formaldehyde both reached 100%, which were much higher than other previously reported silver supported catalysts. Based on combined characterizations, such as X‐ray diffraction (XRD), scanning electronic microscopy (SEM), diffuse reflectance ultraviolet‐visible spectroscopy (UV‐Vis, DRS), nitrogen adsorption at low temperature, temperature programmed desorption of ammonia (NH3‐TPD), desorption of CO2 (CO2‐TPD), etc., the correlation of the catalytic performance to the structural properties of the Ag‐SiO2‐ MgO‐Al2O3 catalyst was discussed in detail. This perfect catalytic performance in the direct dehydrogenation of methanol to formaldehyde without any side‐products is attributed to its unique flower‐like structure with a surface area less than 1 m2/g, and the strong interactions between neutralized support and the nano‐sized Ag particles as active centers. 相似文献