Synthesis and antiviral activity of novel imidazo[2,1-b]thiazoles coupled with morpholine and thiomorpholines

Herein described the synthesis and antiviral evaluation of a novel series of morpholine and thio-morpholine coupled imidazo[2,1-b]thiazoles. The three-step reaction sequence involving the condensation of 1,3-dichloroacetone with thiourea followed by coupling with morpholine and thiomorpholine and finally cyclization with substituted α-bromoacetophenones yielded the desired imidazothiazoles 7(a–l) . Screening of all the new compounds for their in vitro antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells, resulted in two potent analogs, 7d (IC₅₀: 1.1 μM, C₅₀: >300 μM, SI = 273) and 7e (IC₅₀: 2.0 μM, C₅₀: >300 μM, SI = 150), with a favorable toxicity profile and are the best anti-influenza hit analogs for further structural optimization.     

Leveraging Electron Transfer Dissociation for Site Selective Radical Generation: Applications for Peptide Epimer Analysis

Traditional electron-transfer dissociation (ETD) experiments operate through a complex combination of hydrogen abundant and hydrogen deficient fragmentation pathways, yielding c and z ions, side-chain losses, and disulfide bond scission. Herein, a novel dissociation pathway is reported, yielding homolytic cleavage of carbon–iodine bonds via electronic excitation. This observation is very similar to photodissociation experiments where homolytic cleavage of carbon–iodine bonds has been utilized previously, but ETD activation can be performed without addition of a laser to the mass spectrometer. Both loss of iodine and loss of hydrogen iodide are observed, with the abundance of the latter product being greatly enhanced for some peptides after additional collisional activation. These observations suggest a novel ETD fragmentation pathway involving temporary storage of the electron in a charge-reduced arginine side chain. Subsequent collisional activation of the peptide radical produced by loss of HI yields spectra dominated by radical-directed dissociation, which can be usefully employed for identification of peptide isomers, including epimers.

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方向导数的计算公式的注记

方向导数本质上也是函数的一种变化率.利用向量的Schmidt正交化方法进行坐标变换,将方向导数转换为对新变量的偏导数,再结合多元复合函数的求导法则,给出方向导数计算公式的一种新的证明.     

Construction of a 3/4-Ideal Hyperbolic Tetrahedron out of Ideal Tetrahedra

We show how to construct an arbitrary 3/4-ideal hyperbolic tetrahedron out of 10 ideal tetrahedra.     

Modeling Chemical Composition for an Atmospheric Pressure DC Discharge in Air with Water Cathode by 0-D model

This paper reports the results of the chemical composition modeling for an atmospheric pressure DC air discharge with water cathode. The modeling was based on the combined solution of Boltzmann equation for electrons, equations of vibrational kinetics for ground states of N₂, O₂, H₂O and NO molecules, equations of chemical kinetics and plasma conductivity equation. Calculations were carried out using experimental values of E/N and gas temperatures for the discharge currents range of 20–50 mA. The effect of H₂O concentration on the plasma composition was studied. The main particles of plasma were shown to be O₂(a¹Δ, b¹Σ), O(³P), NO, NO₂, HNO₃, H₂O₂ and OH. Effective vibrational temperatures of molecules were higher than gas temperature and they did not depend on the discharge current. Distribution functions on vibrational levels for N₂, O₂, H₂O and NO ground states were non-equilibrium ones.     

Synthesis of derivatives of 1, 2, 4-triazole-3, 5-dicarboxylic acid

By oxidation of 3,5-dimethyl-1,2,4-triazole the monopotassium salt of 1,2,4-triazole-3,5-dicarboxylic acid was obtained. The mononitryl of 1,2,4-triazole-3,5-dicarboxylic acid was isolated during the reaction between 3-diazo-1,2,4-triazole-5-carboxylic acid and potassium cyanide in the presence of copper cyanide. Acid hydrolysis of 3-cyano-1,2,4-triazole-5-carboxylic acid leads to the formation of 3-carbamido-5-carboxy-1,2,4-trlazole, which on esterification with methanol gives rise to 3-carbamido-5-carbomethoxy-1,2,4-triazole.     

木犀草素与胞嘧啶相互作用的理论研究

采用密度泛函理论中的B3LYP方法,在6-31＋G＊基组水平上对木犀草素、胞嘧啶、木犀草素-胞嘧啶复合物进行结构优化和振动频率分析,得到了12种稳定复合物.并应用分子中的原子理论（AIM）分析、自然键轨道（NBO）理论分析得到复合物氢键性质和特征.通过基组重叠误差（BSSE）校正后的相互作用能、成键临界点电荷密度、二阶...     

Crystal structure of binary molybdate Pr2Hf3(MoO4)9

Crystals of binary praseodymium and hafnium molybdate of Pr₂Hf₃(MoO₄)₉ composition are grown by solution-melt crystallization under spontaneous nucleation conditions. By the X-ray diffraction data (X8 Apex automated diffractometer, MoK _α radiation, 2262 F(hkl), R = 0.0170) its composition and crystal structure are determined. Parameters of the trigonal unit cell are: a = b = 9.8001(1) ? c = 58.7095(8) ?, V = 4883.15(10) ?³, Z = 6, space group R c. The crystal structure is composed of three types of polyhedra: MoO₄ tetrahedra, HfO₆ octahedra, and nine-vertex PrO₉. All three types of polyhedra are bonded among themselves by common oxygen vertices of bridging MoO₄ tetrahedra forming an openwork three-dimensional structure. Original Russian Text Copyright ? 2009 by B. G. Bazarov, V. G. Grossman, R. F. Klevtsova, A. G. Anshits, T. A. Vereshchagina, L. A. Glinskaya, Yu. L. Tushinova, K. N. Fedorov, and Zh. G. Bazarova __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 3, pp. 587–590, May–June, 2009.     

Synthesis and fluorescence properties of cerium-KMgF_3 through a solvothermal process

Phosphor of KMgF_3:Ce~(3+)is synthesized through solvothermal method at 180℃and characterized by means of X-ray powder diffraction(XRD)and environment scanning electron microscopy(ESEM).X-ray photoelectron spectroscopy(XPS)is applied to the study of the energy band structure of KMgF_3:Ce~(3+)and confirms the oxygen content of the product is very low.The fluorescence spectra of the rare-earth ion-doped KMgF_3 is investigated by the fluorescence spectrophotometer.In the emission spectra,there is a broadban...