环十二肽溶液构象的二维核磁共振研究

利用二维核磁共振方法及距离几何计算研究了在片段组装法全新蛋白质合成中用作底座分子的环十二肽的溶液构象. 研究结果表明在环十二肽分子主链中包含四个转角结构,四个赖氨酸侧链均位于环的同一侧.环肽的构象为以环肽为模板组装四螺旋束分子提供了有利的条件     

通过基于多肽酰肼的化学连接反应合成高张力环状四肽

刘磊课题组采用其发展的基于多肽酰肼的化学连接反应, 成功合成了一系列高张力环状四肽分子. 多肽酰肼在温和氧化条件下活化为多肽酰基叠氮中间体, 随后与4-巯基苯乙酸形成硫酯, 进而经由分子内天然化学连接反应得到环状四肽. 通过后续的自由基脱硫反应, 可得到连接位点为丙氨酸的产物.     

含四元环的多环芳香化合物的研究进展

含四元环的多环芳香化合物通常能够表现出独特的光物理和化学性质,在很多领域具有潜在应用价值.分别针对线型、角型、螺旋型和环型含四元环多环芳香化合物的合成方法、分子堆积方式、光电性质及载流子迁移率等方面进行归纳总结.研究表明,表面合成法更利于制得规则形貌的多环芳香化合物;线型类分子表现出了较高的载流子迁移率;角型分子通常显...     

5,10,15,20-四(4-(4-吡啶)酮基)苯基卟啉的合成、表征及晶体结构

利用丙酸法合成了一种新的化合物5,10,15,20-四(4-(4-吡啶)酮基)苯基卟啉,并进行了IR,UV-Vis,MS及EA表征,探讨了试剂4-羟基吡啶的异构现象及合成方法。采用溶液结晶法得到了该卟啉分子的晶体,对其进行了X-射线单晶衍射及粉末衍射测定。结果表明:该晶体属于正交晶系,空间群为Fddd。相邻的卟啉分子通过吡啶环之间的π…π作用与其他卟啉分子相连形成二维层状结构。层与层之间进一步通过吡啶环与卟啉环之间的π…π作用而形成三维超分子结构。该化合物可以作为构建金属卟啉框架新材料(MPF)的良好配体。     

以磁纳米粒为核的pH敏感型聚谷氨酸树状分子药物载体

报道了一种新的肽类树枝状分子改性磁性纳米药物载体.以天然氨基酸L-谷氨酸为原料,通过收敛法合成了聚(L-谷氨酸)树状分子,将多巴胺配体键合到聚(L-谷氨酸)树状分子上,用核磁(1H-NMR)、质谱(MS)对合成出的树状分子配体进行了表征,然后通过配体交换对四氧化三铁磁纳米粒表面进行多功能化.以阿霉素为模型药物通过pH敏...     

八元瓜环与二(2-亚甲基-1,2,3,4-四氢异喹啉)的自组装模式

以用1,2,3,4-四氢喹啉和二溴乙烷合成的二(2-亚甲基-1,2,3,4-四氢异喹啉)的溴化氢酸盐为客体, 八元瓜环为主体, 利用1H NMR技术, 单晶X射线衍射方法以及理论计算等方法, 考察了两者的自组装模式. 1H NMR分析结果表明, 在溶液状态条件下, 不仅每一个八元瓜环分子同时与两个客体分子的芳环部分相互作用, 而且每一个客体分子两端的芳环部分同时与两个八元瓜环分子相互作用, 从而形成一维的自组装超分子链; 而在固体状态下, 每一个八元瓜环也可同时包结两个客体的芳环部分而形成三元的自组装结构, 但八元瓜环包结两个客体形成一独立的三元自组装结构. 利用晶体结构建立模型的计算结果说明, 模拟溶液状态比固体状态条件下的主客体包结更有利于体系能量的降低, 与主客体在溶液中1H NMR实验结果相符.     

环稠卟啉合成的研究进展

利用卟啉大环的碳架组成及其连带成分进行各种环合反应是构建环稠卟啉分子的有效方法. 基于这一合成策略, 概述了近年来通过卟啉分子的结构修饰完成环稠卟啉合成的最新研究进展.     

三组分串联反应一锅合成多环稠合的1,5-苯并二氮杂䓬化合物

以取代的邻苯二胺、1,3-环戊二酮或1,3-环己二酮(5,5-二甲基-1,3-环己二酮)、2,3-二羰基化合物为原料,无水乙醇为溶剂,对甲苯磺酸为催化剂,经2~5 h串联反应一锅合成43种新颖的1,5-苯并二氮杂?化合物,产率最高可达95%.该反应序列首先通过两次的亲核加成-脱水反应过程,形成分子内亚胺和烯胺结构的活性中间体,然后再经分子内的碳碳偶联环合-质子转移等过程,生成多环稠合的1,5-苯并二氮杂?目标化合物,实现了在一个反应体系中形成一个二氮杂七元环和四个新化学键(两个C—N,一个C=C,一个C—C).该方法操作简单,反应便捷,对环境友好,产率高,为1,5-苯并二氮杂?化合物的合成提供绿色环保,高效简便的合成思路.     

含长链亚烷基桥的芳炔类共轭大环的合成

采用模板导向法高产率地合成了两个含长链亚烷基桥的芳炔类共轭大环. 通过四碘化合物与单保护双炔化合物的四重Hagiraha偶合反应构建了环化所需要的复杂前体. 通过相应的模板四炔衍生物的分子内Glaser 偶合反应环化得到大环. 大环的结构用NMR, GPC 及UV-Vis表征确证.     

氧杂环丁烷的合成

氧杂环丁烷作为一类饱和四元环醚类化合物,不仅是重要的有机合成中间体,也是天然和合成的具有抗癌、抗HIV、抑制谷氨酰胺合成酶等多种生物或药物活性化合物分子结构中的重要活性单元.因此,发展氧杂环丁烷骨架的有效合成方法非常重要.本文以分子内形成C—C键的环化反应、分子内形成C—O键的Williamson醚化反应、烯烃和醛酮[...     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。