丁苯酞-哒嗪酮衍生物的设计、合成及其抗凝活性研究

为了提高丁苯酞的抗血小板凝集活性,以6-氨基丁苯酞为起始原料,经重氮化/还原、环化、水解、脱氯、醚化和磺酰化反应合成了20个新型的丁苯酞-哒嗪酮衍生物,其结构经1H-NMR、13C-NMR和HRMS确证。体外抗血小板凝集活性测试结果表明:化合物6a、6b和6k对二磷酸腺苷(ADP)诱导的血小板凝集的抑制活性(IC50 = 44.9-180.0 μmol/L)优于先导化合物丁苯酞(IC50 = 1252 μmol/L)和阳性对照阿司匹林(IC50 = 1140 μmol/L);同时化合物 6b(IC50 = 63.6 μmol/L)和6k(IC50 = 191.9 μmol/L)对花生四烯酸(AA)诱导的血小板凝集也表现出显著的抑制活性。本研究为丁苯酞-哒嗪酮骨架在治疗缺血性脑卒中方面的研究提供了理论参考。     

Analysis of nonlinear systems arise in thermoelasticity using fractional natural decomposition scheme

The pivotal aim of the present study is to employ fractional natural decomposition method (FNDM) to find the solution for a nonlinear system arising in thermoelasticity. The considered coupled system is generalised many physical phenomena associated with the material with elastic characters and its temperature and also which is called a Cauchy problem. We consider the coupled system by incorporating the Caputo fractional operator and investigate three distinct cases for different initial values to illustrate the applicability and efficiency of the FNDM. With respect to fractional order, we capture the behaviour of the achieved solution cited in three different cases and exemplified with the aid of 2D and 3D plots for the particular value of the parameters in the model. Moreover, some interesting behaviours of the projected model are confirms the prominence of the employed fractional operator while analysing the nonlinear coupled equations exemplifying real-world problems and also shows the capability of the considered algorithm.     

Speeds of sound and isothermal compressibilities in the water-rich region of aqueous 2-butoxyethanol and 2-butanone at 25°C

Speeds of sound were measured at 25°C in the water-rich region of aqueous 2-butoxyethanol (BE) and 2-butanone (BUT). Density, heat capacity, and thermal expansivity data available in literature were used to calculate isothermal compressibilities, _T . The composition derivative, N ( _T/n_B), a third derivative of Gibbs free energy, showed a peak anomaly atx _BE=0.0175 for BE-H₂O, and a bend atx _BUT=0.033 for BUT-H₂O. n_B (n_BE or n_BUT) is the amount of the solute andx _BE andx _BUT are the respective mole fractions. The location of these anomalies were the same as those of other third derivatives found earlier for the same aqueous solutions. These anomalies were shown earlier to mark the transition point across which the mixing scheme changes in a qualitative fashion.     

A Convenient Synthesis of Novel Meldrum＇s Acid C60 Fullerene Derivatives

A series of novel Meldrum＇s acid C60 derivatives were prepared in moderate yields from a convenient one-pot reaction of C60, the Meldrum＇s acid derivatives, 12 and 1,8-diazabicyclo-[5,4,0]-undec-7-ene （DBU） in toluene at room temperature under nitrogen atmosphere. All the new compounds were fully characterized by the spectral data and elemental analysis. A carbene intermediate mechanism was proposed for this reaction.     

Synthesis and structure of aqua-2′,?-(2,6-pyridindiyldiethylidene) dioxamohydrazide-copper(II) hydrate

In a template synthesis from copper(II) acetate, 2,6-diacetylpyridine, and semioxamazide (NH₂CO CONHNH₂), two copper(II) complexes, [Cu(dapsox)(H₂O)]·H₂O and [Cu(Hdapsox)](H₂O)]ClO₄, (where H₂dapsox = 2′,2?-(2,6-pyridindiyldiethylidene)dioxamohydrazide) were obtained and characterized. The structure of the former complex was determined by a single-crystal X-ray analysis. Cu^II is located in a square pyramidal environment. The polydentate ligand, dapsox²⁻ is coordinated in dianionic form, as an unsymmetrical quadridentate planar system forming one-membered and two-five-membered metal-chelate rings. The fifth coordination site is occupied by a water molecule.     

近红外漫反射一阶导数光谱法作安体舒通质量控制研究

研究了近红外漫反射一阶导数光谱法作安休舒通粉末药品质量控制的可能性，用多变量统计分类技术，从安体舒通粉末药品的近红外漫反射一阶导数光谱，成功地鉴别了真，劣和假药，结果令人满意。     

异色满并吡唑衍生物的合成及其抗炎作用

异色满（isochroman）属于异革并毗哺类杂环化合物，近年来，已经合成出许多具有镇痛、降压、抗组胶和抗肿瘤等药理活性的异色满类化合物，但大都为异色满环上的1，2，4位取代衍生物或者螺环化合物［”’j，关于并杂坏的异色满报道甚少，鉴于许多有生理活性的天然产物中带有咄哩环以及异色满衍生物所表现的药理性质，本文选择异色满酮一4的足二酮衍生物为原料，完成了异色满并毗峻衍生物的合成，并对其抗炎活性进行了研究．合成路线如下：所用仪器有BRUCKER七0型核磁共振仪，TMS为内标；Perkin－Elmer1730型红外分光光度计，KBr压片；…     

Surface segregation of silicon impurities in organic materials

The present revolution in novel organic materials is driven by the synthesis of new materials exhibiting specific functional properties. Traces of silicon compounds are often present in these materials and, although the bulk concentrations of these impurities may be low, segregation can seriously modify the surface composition. Surfaces and interfaces play an important role in many applications, and the intrinsic properties of the materials are thus often obscured by the presence of segregated impurities. By studying silicon impurity segregation in poly‐dialkoxy phenylenevinylene (PPV), polycarbonate and dendrimer macromolecules, we demonstrate how low‐energy ion scattering may be used to determine the surface impurity fraction and to observe which groups at the surface are shielded by the segregated species. We demonstrate that the performance of PPV‐ based light‐emitting diodes is significantly reduced for submonolayer coverages of siloxanes. We find that the kinetics of the segregation process depend strongly on the materials and the sample preparation conditions. We find that the presence of solvents is needed to enable segregation at room temperature. Heating does enable siloxane impurity segregation in polycarbonate in the solid phase, whereas for polydimethylsiloxane in PPV films we find that segregation in the solid phase does not occur up to 200 °C. The siloxane molecules are found to segregate to preferential sites at the surface, shielding the polar groups. Finally, we demonstrate that purification of the surface is often possible through simple procedures that provide an easy way to study the intrinsic properties of the materials. Copyright © 2004 John Wiley & Sons, Ltd.     

Improved Syntheses of Halofuranose Derivatives with the Desired α-Configuration

Chlorination of ribofuranose or 2-deoxyribofuranose derivatives was carried out in a 1,4-dioxane solution of hydrogen chloride. This improved procedure allowed the syntheses of 1-chloro-α-D -ribofuranose and 1-chloro-2-deoxy-α-D -ribofuranose derivatives and offered ease of handling, high yield, and the stereo-controlled α-configuration at C-I.     

三氮唑核苷及衍生物的设计合成与生物活性研究

以四乙酰核糖、1,2,4-三氮唑-3-羧酸甲酯为原料,经过缩合、氨解、保护、亲核取代、水解等五步反应得到4个新的三氮唑核苷衍生物4a～4d,所有目标化合物的化学结构均经核磁共振氢谱、质谱或(和)元素分析所确正.通过体外抗病毒活性测试表明,四个目标化合物中有两个对流感甲型病毒具有一定的抑制作用.