The molecular mechanism studies of chirality effect of PHA-739358 on Aurora kinase A by molecular dynamics simulation and free energy calculations

Aurora kinase family is one of the emerging targets in oncology drug discovery and several small molecules targeting aurora kinases have been discovered and evaluated under early phase I/II trials. Among them, PHA-739358 (compound 1r) is a 3-aminopyrazole derivative with strong activity against Aurora A under early phase II trial. Inhibitory potency of compound 1r (the benzylic substituent at the pro-R position) is 30 times over that of compound 1s (the benzylic substituent at the pro-S position). In present study, the mechanism of how different configurations influence the binding affinity was investigated using molecular dynamics (MD) simulations, free energy calculations and free energy decomposition analysis. The predicted binding free energies of these two complexes are consistent with the experimental data. The analysis of the individual energy terms indicates that although the van der Waals contribution is important for distinguishing the binding affinities of these two inhibitors, the electrostatic contribution plays a more crucial role in that. Moreover, it is observed that different configurations of the benzylic substituent could form different binding patterns with protein, thus leading to variant inhibitory potency of compounds 1r and 1s. The combination of different molecular modeling techniques is an efficient way to interpret the chirality effects of inhibitors and our work gives valuable information for the chiral drug design in the near future.     

宜昌茶叶的氟含量及氟浸出率的测定

利用氟离子选择电极,测定了湖北宜昌几种茶叶中的氟含量及氟的浸出率。结果表明,这几种茶叶氟含量在46．8—357．1μg／g之间,茶叶氟的浸出率在72．9％-80．1％之间,宜昌茶叶可作为一种安全的氟来源。     

RuIII@CMC/Fe3O4 hybrid: an efficient,magnetic, retrievable,self-organized nanocatalyst for green synthesis of pyranopyrazole and polyhydroquinoline derivatives

Molecular Diversity - RuIII incorporated with magnetic nanosized CMC/Fe3O4 hybrid (RuIII@CMC/Fe3O4) has readily developed by a very simple self-organized procedure of RuCl3 and Na–CMC/Fe3O4...     

基于离子交换和表面引发接枝聚合制备阴离子表面印迹材料及其识别特性研究

建立了一种新的离子表面印迹(IIP)方法. 使用偶联剂γ-氨丙基三甲氧基硅烷(AMPS)对微米级硅胶微粒进行表面改性, 制得表面含有氨基的改性硅胶AMPS-SiO₂. 凭借离子交换作用, 阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)结合在模板离子磷酸根周围; 改性硅胶AMPS-SiO₂表面的氨基与溶液中的过硫酸盐构成氧化还原引发体系, 使DMC及交联剂N,N'-亚甲基双丙烯酰胺(MBA)在硅胶微粒表面发生接枝交联聚合, 从而实现了磷酸根离子的表面印迹, 制得了阴离子表面印迹材料IIP-PDMC/SiO₂. 采用静态与动态两种方法, 考察研究了IIP-PDMC/SiO₂对PO₄^3-离子的识别特性与结合性能. 研究结果表明, 离子表面印迹材料IIP-PDMC/SiO₂对PO₄^3-离子具有特异的识别选择性与优良的结合亲和性, 相对于对比离子高锰酸根离子, IIP-PDMC/SiO₂对PO₄^3-离子的识别选择性系数为9.58.     

Free-standing crystalline CaCO3 films composed of three-dimensional microstructures with different morphologies

Crystalline vaterite CaCO₃ self-standing films composed of three-dimensional microstructures were synthesized by a simple gas diffuse method with the assistance of poly(vinyl alcohol) (PVA). The microstructures with different morphology (sphere-like, rose-like, and pumpkin-like) were self-assembled by three-dimensional oriented attachment of faceted micro-platelets, and the films were all stable in air for more than one year. The concentrations of Ca²⁺ ions and PVA all played important roles in the formation of vaterite crystal phase. In addition, the introduction of salt (NaCl, NaNO₃) would reduce the size of the micro-platelets significantly. A possible mechanism for the formation of the self-standing films is put forward.     

Fabrication and characterizations of oligopyrrole doped with dodecylbenzenesulfonic acid in reverse microemulsion

The pyrrole-oligomer nanoparticles doped dodecylbenzenesulfonic acid (DBSA) have been fabricated in water-DBSA-isopropyl alcohol-isooctane reverse microemulsion, since DBSA could play the roles of both surfactant and dopant. We have found the optimum synthetic conditions by the analysis of factors affecting the yield and conductivity of oligopyrrole. The effect of solubility on the improved properties of DBSA-oligopyrrole in some organic solvents was studied employing UV-vis-NIR spectroscopy. This indicates that doping and pyrrole-oligomers may improve the poor processibility of PPy. Its environmentally stable properties were characterized by thermogravimetric and differential thermal analysis (TG-DTA). The maximum room temperature conductivity of products is 8.01 S/cm using the four-probe technique. The pyrrole-oligomers have been determined by the analysis of molecular weight measurement, and X-ray photoelectron spectroscopy (XPS) and elemental analysis were employed to investigate the formation of DBSA-oligopyrrole complexes. Correspondingly, the structural properties of DBSA-oligopyrrole were studied by infrared spectroscopy (IR), X-ray diffraction (XRD), transmission electron micrographs (TEM), and scanning electron microscopy (SEM).     

前驱体CeOHCO3的结构对CeO2催化性能的影响（英文）

以尿素替代水为溶剂,采用改良的尿素水解法制备不同结构的CeOHCO3和CeO2,并运用N2吸附-脱附、X射线衍射、H2程序升温还原、O2程序升温脱附、X射线光电子能谱、扫描电镜及甲烷燃烧反应对CeO2催化剂进行表征和催化性能测试.结果表明,CeO2催化性能和前驱体CeOHCO3的晶相结构(六方相或八面体相)存在直接关系.与以八面体为前驱体制得的颗粒状CeO2相比,以六方相为前驱体制得的棒状CeO2具有比表面积大、氧化还原能力强、表面氧空缺浓度高以及催化甲烷燃烧活性高的特点.     

萘甲酸功能化聚砜的制备及其与Eu(Ⅲ)稀土离子配合物的荧光发射特性

以1,4-二氯甲氧基丁烷(BCMB)为氯甲基化试剂,使聚砜(PSF)氯甲基化(CM),形成氯甲基化聚砜(CMPSF),然后用6-羟基-2-萘甲酸(HNA)使CMPSF的氯甲基与HNA的酚羟基之间发生亲核取代反应,将萘甲酸(NA)配基键合在聚砜侧链,制得了功能化改性的聚砜NAPSF。采用红外光谱和核磁共振氢谱对其结构进行了表征。考察了主要因素对CMPSF与HNA之间亲核取代反应的影响规律,分析了反应机理,优化了反应条件。结果表明,CMPSF与HNA之间取代反应的速率与亲核试剂HNA的浓度无关,遵循SN1的反应机理;使用极性较强的溶剂二甲亚砜,有利于亲核取代反应的进行;在适宜条件下,CMPSF的氯甲基转化率可达96%,NA的键合量为1.68 mmol/g。将NAPSF与Eu(Ⅲ)离子配位,制得了聚合物-稀土配合物NAPSF-Eu(Ⅲ),它不仅发射出Eu3+离子的特征荧光,而且对Eu3+离子的荧光发射显示出很强的敏化作用。萘甲酸功能化的大分子配基NAPSF对Eu3+离子的敏化作用,远强于苯甲酸(BA)功能化的大分子配基BAPSF对Eu3+离子的敏化作用。