哒嗪核苷类的研究进展

众所周知,许多嘧啶的核苷类化合物都有较强的生理活性,其中5-氟脲苷是有效的抗癌药。而哒嗪和嘧啶在结构上具有同分异构关系,因此,对于哒嗪核苷类化合物的合成及其生     

4—氟—3,6—二氯哒嗪合成新方法

氟代哒嗪类化合物与有一定生理活性的氟代嘧啶类化合物有着同分异构的关系。而4-氟-3,6-二氯哒嗪又是合成其它药物的重要中间体。1984年田官荣报道了4-氟-3,6-二氯哒嗪的合成及同亲核试剂的反应性能和同类化合物     

嘧啶衍生物对牛蒡子苷元片段修饰的研究

用一系列具有生物活性的嘧啶衍生物修饰牛蒡子苷元,旨在寻找增强牛蒡苷元子抗肿瘤活性的同时又能降低嘧啶抗肿瘤副作用的先导化合物.本研究通过把卤代后的嘧啶衍生物与牛蒡子苷元酚羟基相接,合成得到11个新的化合物,通过1H NMR与LC-MS表征确定其结构.最终,增加了牛蒡子苷元抗肿瘤化合物库中化合物的数量,为接下来的体外活性筛选做准备.     

嘌呤、嘧啶类新手性化合物的合成

把具有生理活性的嘌呤、嘧啶类有机碱基引入不对称合成 ,利用嘌呤、嘧啶类化合物作为Michael加成给体与天然手性助剂 ( - ) 薄荷醇所制得的手性源 5 (R) [( 1R ,2S ,5R) 氧基 ] 2 ( 5H) 呋喃酮 ( 3a)进行不对称Michael加成反应 ,合成了新的光学纯嘌呤、嘧啶类手性化合物 ( 5a～ 5e) .详细地研究了合成方法并测定了它们的[α],IR ,UV ,1HNMR ,13 CNMR ,MS ,元素分析等结构分析数据 .经X 四圆衍射确定了腺嘌呤手性化合物 5a的立体化学结构 .为合成嘌呤、嘧啶类手性化合物提供了有效的途径 ,为深入研究具有生理活性的手性核苷酸类化合物提供了重要的手性源     

一些嘧啶酰胺的合成及其生物活性

嘧啶环是生物活性化合物中具有较好生理活性的基因。本文试图将嘧啶环引入农用药剂,合成系列酰胺类化合物。生物试验结果表明,其中一些化合物具有杀蝇效能,一些化合物对较难防治的寄生疫霉具有良好的抑制效能。     

嘧啶类化合物的合成及抗菌活性研究进展

嘧啶类化合物因其广泛的生物活性在医药、农药等领域备受关注. 将不同基团引入嘧啶结构中, 经过结构修饰能产生一系列具有抗菌活性的嘧啶衍生物, 它在新型农药创制中发挥着越来越重要的作用. 对嘧啶类化合物的合成及杀菌活性的研究进行了分类综述, 并展望了它的发展趋势和应用前景.     

基于氮杂环卡宾的多齿C,N-配体过渡金属化合物的合成与应用

综述了基于氮杂环卡宾的多齿C,N-配体过渡金属化合物的合成与应用研究的最新进展,结合本课题组的工作介绍了含有吡啶、嘧啶、吡唑、萘啶、哒嗪、三唑和邻菲罗啉等氮杂环基团的氮杂环卡宾过渡金属化合物在有机合成中的应用.     

嘧啶酮衍生物的微波合成

在微波辅助下,Baylis-Hillman加成物与4-氨基-6-氯嘧啶或2-氨基-噻唑反应,快速合成了两类嘧啶酮衍生物——3-取代-7-氯-4H-嘧啶[1,2-b]哒嗪-4-酮和6-取代-5H-噻唑[3,2-a]嘧啶-5-酮,收率81%～98%,其结构经1H NMR,13C NMR,IR和MS确证。     

取代基对腺嘌呤与胸腺嘧啶氢键复合物体系结合能的影响

优化得到了17个取代胸腺嘧啶与腺嘌呤形成的氢键复合物的结构, 并计算了这些复合物的结合能, 探讨了胸腺嘧啶上不同取代基对结合能的影响. 结果表明, CF₃取代的胸腺嘧啶与腺嘌呤间的结合能大于胸腺嘧啶与腺嘌呤间的结合能, 这可能是屈氟尿苷具有阻止病毒及肿瘤扩散功能的原因所在. SO₃H, CN和NO₂取代的胸腺嘧啶与腺嘌呤间具有更大的结合能, 表明这3个基团取代的胸腺嘧啶也可能具有潜在的抗肿瘤作用. 分子中原子理论与自然键轨道分析表明, 在所有体系中, 氢键N—H…N最强, N—H…O=C次之, C—H…O=C最弱, 轨道作用在氢键作用中占有重要地位.     

乙酰化呋喃型糖基三唑羧酸酯及硫苷的立体选择性合成

自从发现糖酯及硫苷类化合物具有抗菌、抗肿瘤等广泛的生理活性以来,有关这两类化合物的合成及其性质研究已成为人们极为关注的课题。但具有某些生理活性的三唑羧酸类和巯基嘧啶类化合物与糖基形成糖酯和硫苷的有关合成尚未见文献报道。为了寻找高效低毒的化合物,本文通过相转移催化法,在温和的反应条件下,立体专一性地合成了吡喃型     

DSC研制及KNO3、Sn、Bi、Zn相变温度和相变焓测定

According to Watson′s DSC principle, a new design of electric circuit of DSC was proposed, Referring to the instrument constraction of DSC of Perkin-Elmer corporation, a new instrument construction of DSC was designed.This new electric circuit and this new instrument construction can overcome the shortcomings in de- sign of DSC of Perkin-Elmer corporation, Figure 1 is a schematic diagram of the new electric circuit. The temperatures and enthalpies of phase transitions of stan- dard materials were measured by using the new DSC. The experimental results are shown in table 1.     

LEARNING FROM THE PAST：LOOKING TOWARDS THE FUTURE FOR TERTIARY CHEMISTRY IN AUSTRALIA

ＳｕｍｍａｒｙＴｈｅｔｈｅｍｅｏｆ 17ＩＣＣＥｉｓｔｈａｔｔｈｅｎｅｗｃｅｎｔｕｒｙｏｆｆｅｒｓｎｅｗｃｈａｌｌｅｎｇｅｓ,ｎｅｗｏｐｐｏｒｔｕｎｉｔｉｅｓａｎｄｎｅｗｈｏｐｅｓｆｏｒｃｈｅｍｉｃａｌｅｄｕ ｃａｔｉｏｎ .Ｔｈｅｓｅａｓｐｉｒａｔｉｏｎｓａｒｅｃｅｒｔａｉｎｌｙｃｒｉｔｉｃａｌｆｏｒｃｈｅｍｉｃａｌｅｄｕ ｃａｔｉｏｎｉｎＡｕｓｔｒａｌｉａ ,ｐａｒｔｉｃｕｌａｒｌｙａｔｔｈｅｔｅｒｔｉａｒｙｌｅｖｅｌ.Ｉｔｈａｓｂｅｅｎｒｅｃｏｇｎｉｚｅｄｆｏｒａｔｌｅａｓｔｔｈｅｐａｓｔｔｗｏｄｅ…     

中国番荔枝科植物抗癌有效成分研究

介绍了近年来我们实验室中国番荔枝科植物抗癌有效成分研究工作。从番荔枝科5种紫玉盘属植物,5种哥纳香属植物,1种番荔枝属植物,1种囊瓣木属植物中分离得到59种新的番荔枝内酯,32种新的多氧取代环己烯,12种新的苯乙烯吡喃酮和3种新的生物碱,并通过化学和光谱方法鉴定了它们的结构。大部分化合物显示了较强的抗癌活性。并对抗癌活性成分海南哥纳香醇甲进行了全合成。     

现代有机合成的新概念及研究进展

概念是有机合成化学发展的基础之一,新概念的产生和发展可为有机合成开拓新的研究领域和发展方向。此文介绍现代有机合成中的一些新概念和新方法,结合具体的有机合成反应实例展示有机合成在这些概念的基础上取得的新成果和新进展,并综合归纳了现代有机合成的发展方向和应重视的研究领域。     

Water-soluble constituents of Glehnia littoralis fruit

From the water-soluble portion of the methanol extract of the fruit of Glehnia littoralis Fr. SCHMIDT ex MIQ. (Umbelliferae; "hamabofu" in Japanese), thirty compounds, including three new monoterpenoids and a new monoterpenoid glucoside, a new benzofuran glucoside, a new alkyl glucoside, and a new glucide, were obtained. Their structures were clarified by spectral investigation.     

New open modified trigonometrically-fitted Newton-Cotes type multilayer symplectic integrators for the numerical solution of the Schrödinger equation

In this paper we present new modified open Newton Cotes integrators and we develop a new modified trigonometrically-fitted open Newton-Cotes method. We study the connection between the new proposed schemes, the differential methods and the symplectic integrators. although The research on multistep symplectic integrators is very poor, although, much research has been done on one step symplectic integrators and several of then have obtained based on symplectic geometry. In this paper a new open modified numerical algorithm of Newton-Cotes type is produced. We present the new obtained method as symplectic multilayer integrator. The new obtained symplectic schemes are applied for the solution of the resonance problem of the radial Schrödinger Equation. The results show the efficiency of the new proposed algorithm.     

Epoxy resins. New results and developments

In a survey the development of epoxy resin systems is described. During the past years countless formulations based on known structures were used, but only a relative small number of new epoxies and curing agents were investigated and only very few new compounds came on the market. A choice of these products will be discussed, also new latent accelerators and curing agents. By improvement of technical processes purer epoxies can be offered and toxicological risks could be strongly reduced. Especially new results in the fast growing field of photocrosslinking will be described. Besides iodonium, sulfonium and phosphonium compounds new arene iron salts and their behaviour will be presented. Generally, the trend in the epoxy field is to better heat resistant structures for new formulations in the field of adhesives and fibre-reinforced materials, and to new photocrosslinking systems.     

A new three-parameter cubic equation of state for calculation physical properties and vapor–liquid equilibria

A new three-parameter cubic equation of state is presented by combination of a modified attractive term and van der Waals repulsive expression. Also a new alpha function for the attractive parameter of the new EOS is proposed. The new coefficients of alpha function and the other parameters of the attractive term are adjusted using the data of the saturated vapor pressure and liquid density of almost 60 pure compounds including heavy hydrocarbons. The new EOS is adopted for prediction of the various thermophysical properties of pure compounds such as saturated and supercritical volume, enthalpy of vaporization, compressibility factor, heat capacity and sound velocity. Following successful application of the new EOS for the pure components, using vdW one-fluid mixing rules, the new EOSs are applied to prediction of the bubble pressure and vapor mole fraction of the several binary and ternary mixtures. The accuracy of the new EOS for phase equilibrium calculation is demonstrated by comparison of the results of the present EOSs with the PT, PR, GPR and SRK cubic EOSs.     

Toward new camptothecins. Part 4: On the reactivity of nitro and amino precursors of aza analogs of 5-methoxycarbonyl camptothecin

In the context of formation of new aza analogs of camptothecin, nitration then reduction of condensed pyridones was realized, leading to new derivatives of pyrrolo-aza-indoles. Treatment of these compounds with hydrobromic acid led to new structure rearrangements while oxidation of the α-position was unsuccessful. Mechanisms of formation of the new products are discussed.     

Water-soluble constituents of ajowan.

From the water-soluble portion of the methanol extract of the fruit of Carum ajowan (ajowan), which has been used as a spice and medicine, 25 compounds, including five new monoterpenoid glucosides, a new monoterpenoid, two new aromatic compound glucosides, and two new glucides, were obtained. Their structures were clarified by spectral investigation.