Discodermolide及其衍生物三维定量构效关系的研究

Discodermolide是一种新颖的作用于微管蛋白的抗肿瘤化合物, 具有良好的药用前景. 为了设计出药效更好的类似物, 我们用比较分子力场分析(CoMFA)和比较分子相似性指数分析(CoMSIA)对discodermolide及其衍生物进行了三维定量构效关系(3D-QSAR)的研究, 并建立了相关的预测模型. 其中, CoMFA模型的交叉验证相关系数(q2)为0.592, 非交叉验证相关系数(r2)为0.982, 标准偏差(SEE)为0.094, F值为119.761; CoMSIA模型的q2为0.544, r2为0.980, SEE为0.098, F值为108.715. 计算结果表明, 获得的CoMFA和CoMSIA模型具有良好的预测能力, 可以应用于指导该类化合物的设计.     

固定Fe 3＋的磁性微球分离富集鼠肝中铁结合蛋白的初步研究

采用键合Fe3＋的纳米材料分离富集了大鼠肝脏中的铁结合蛋白质组, 并进行了质谱分析. 在相同的起始富集蛋白质量以及相同的吸附和洗脱条件下, 键合了Fe3＋的磁性纳米材料比未键合金属离子的空白材料富集了更多的蛋白质, 经质谱鉴定得到42个蛋白质, 主要包括代谢酶类、呼吸链主要成员、氧化还原蛋白、转运蛋白、血红蛋白等.     

Molecular Dynamics Simulation of Glucomannan Solution

1 INTRODUCTION Konjac Glucomanan (KGM), found in konjac plant with molecular weight ranging from 2×105 to 2×106[1], is neutral polyoses with excellent water solubility. The structural studies of KGM have been well presented, but its accurate structure has not been clearly clarified so far, so the investigation is still in progress. According to the previous studies[2～4], the conjectural structure of KGM is as follows: KGM is natural polyoses formed by D-glucose and D-mannose link…     

C8H10+·侧链分解过程反应机理的理论研究

正乙苯正离子自由基C8H10+·的分解可以作为研究烷基苯正离子反应机理的原型。使用Gaussian98程序包、在B3LYP/6-311++G**基组水平上对C8H10+·的分解反应体系进行了充分研究。C8H10+·的分解的链反应是由C-H键断裂开始的。作者用振动模式分析对所有反应通道进行了充分研究,以确定过渡态并阐明了反应机理。研究表明,能量上最有利的通道为C8H10+·→ TS4 → P2 + H·,产生C6H6+·+C2H4的通道也为竞争性反应通道。     

(±)-16-羟基-6,7-脱氢铁锈醇甲醚及其类似物的合成

采用AC→ABC的合成策略,以α-环柠檬醛为A环起始原料,通过与C环化合物8缩合、选择性还原及分子内环合得到关键中间体11,再经过官能团修饰和转换,合成了16-羟基-6,7-脱氢铁锈醇甲醚及其3个类似物.     

Synthesis and Crystal Structure of a Tetranuclear Carboxylate-bridged Lanthanum(III)-Zinc(II) Complex [La_2Zn_2(m-CNC_6H_4COO)_(10)(Py)_2(C_2H_5OH)_2]

1 INTRODUCTION In the past few years, more extensive attention had been paid to the research on the chemistry of the heterometallic complexes containing simultaneously lanthanide (Ln) and transition metal ions[1～9]. Interest has been largely focused on the magnetic properties resulting from the Gd(III)-Cu(II) couple, which has been found to be directly ferromagnetic irrespective of the structural details[1～5]. Recent studies have further revealed that the magnitude of the ferromagnet…     

Crystal Structures and Antimicrobial Activity of Two Phosphorus Compounds

1 INTRODUCTION Both phosphorus and sulfur are the non-metal ele- ments rich in biological bodies. Phosphorus is the core element of nucleic acid, which is the principal ingredient of lives; and sulfur is the important ele- ment in the skeleton of nitrogen-fixing enzyme’s activity center[1]. It has been found that LR, 4-bis(4- methoxyphenyl)-1,3,2,4-dithiadiphosphe-tane-2,4- disulfide (Scheme 1), is an effective thiation reagent for ketones, carboxamides, esters, S-substituted thio- est…     

Synthesis and Crystal Structure of a Dinuclear Cu(II) Complex [Cu(C12H17N2O)(NCS)]2 with Tridentate Schiff Base Ligand N(Salicylidene)-3-dimethylaminopropylamine

1 INTRODUCTION Metal complexes with multidentate Schiff baseligands have been extensively studied because suchligands can bind with one, two or more metal centersinvolving various modes and allow successful synt-hesis of homo and/or heteronuclear metal complexeswith interesting stereochemistry. Researches into thecopper(II) complexes have been stimulated by,amongst other things, biological modeling applica-tions, catalysis, design of molecular ferromagnets andmaterial chemistry[1～4]. I…     

Preparation,Crystal Structure and Thermal Decomposition Process of Dysprosium Benzoate Complex with 1,10.Phenanthroline

A dinuclear dysprosium（III） complex with benzoic acid and 1,10-phenanthroline, [Dy（BA）3phen]2 （BA = benzoate, PHEN = 1,10-phenanthroline） （C66H46Dy2NaO12, Mr = 1412.07） was synthesized and characterized by elemental analysis, UV, IR, X-ray diffraction, molar conductance and TG-DTG techniques. It crystallizes in triclinic, space group P1 with a = 10.773（2）, b = 11.933（3）, c = 12.417（5） A, α= 105.226（3）,β= 93.470（3）, γ= 113.475（2）°, V= 1388.0（7）, Z = 1, Dc = 1.689 g/cm3, μ（MoKa） = 2.742 mm-1 and F（000） = 698. R = 0.0210, wR = 0.0538. In the crystal, each Dy（III） ion is eight-coordinated by one bidentate chelating carboxylate group, four bidentate bridging carboxylate groups and one 1,10-phenanthroline molecule. The thermal decomposition process of [Dy（BA）3phen]2 has been determined by thermal analysis.     

Theoretical Studies on the First Hyperpolarizabilities of One-dimensional Donor-bridge-acceptor Chromophores

The ground-state dipole moments and second-order nonlinear optical （NLO） properties of a series of one-dimensional （1D） chromophores with donor-bridge-acceptor （D-B-A） structures have been investigated by using the second-order MФller-Plesset （MP2） and density functional theory （DFT） methods with the basis set of 6-31＋G（d）. According to the calculated results, the relationship between the molecular static first hyperpolarizability （βμ） and the directions of electron transition has been summarized. In terms of the sign of βμ, these 1D organic chromophores were classified into two categories： type Ⅰ with negative βμ and type Ⅱ bearing positive βμ. The analyses show that the remarkable difference of the first hyperpolarizabilities between Ⅰ and Ⅱ chromophores is associated mainly with the electrostatic interaction between terminal groups and the transport electrons in excited states. Moreover, different from the popular viewpoint, the obtained results also show that most of this series of 1D D-B-A molecules are more charge-separated in the ground states than in the excited states. As a whole, this theoretical investigation, to some extent, can be considered as a useful reference in designing the NLO chromophores with large first hyperpolarizabilities.