Preparation of enantiomerically pure 1,1′-bi-2-naphthols from 85% cinchonine and 1,1′-bi-2-naphtholboric anhydride

A possibility of preparation of enantiomerically pure 1,1′-bi-2-naphthols using an impure cinchonine has been examined. The solid and the mother liquor formed from the reaction of 1,1′-bi-2-naphtholboric anhydride and 85% cinchonine in toluene could give optically pure (S)-(−)- and (R)-(+)-1,1′-bi-2-naphthol after acidification and kinetic crystallization, the overall yields were 40% and 28%, respectively. Supported by the National Natural Science Foundation of China (2937206) and the Natural Science Foundation of Hubei Province (93J27) Xiong Ying, born in 1971, Graduate student     

分子对接研究手性共价有机框架材料的对映体识别能力

基于分子对接方法,使用AutoDock软件计算手性共价有机框架材料CCOF5与手性对映体相互作用的结合能.计算结果表明:CCOF5与对映体的结合能差大小与对映体分离度大小相一致;CCOF5与对映体的结合能大小与对映体出峰时间顺序基本一致.采用Avogadro软件对AutoDock分子对接构象进行分析,并对手性识别机理进...     

氨基酸对映体拆分的研究进展

本文综述色谱法，毛细管电泳法和萃取法在分离氨基酸对映体方面的有关最新研究成果，讨论各种拆分方法的原理和影响因素。     

苯丙氨酸分子的手性对映体转变机理及水分子（簇）的催化作用

在MP2/6 311++G(3-df,2pd-)//WB97X-D/6-311++G(-d,p-)双水平研究苯丙氨酸(Phe)分子的手性对映体转变机理, 并用分子中的原子理论(AIM)分析驻点的成键特征. 结果表明： 经过羧羟基旋转、 质子迁移、 碳 碳键旋转和氨基翻转的一系列过渡态, Phe分子在质子以氨基氮为桥梁迁移的通道a和以羰基氧与氨基氮顺次为桥梁迁移的通道b内, 实现了手性对映体转变; 当2个水分子簇作为质子迁移媒介时, 在通道b中增加了质子仅以羰基氧为桥梁迁移的反应路径； 通道a具有优势, 速控步骤的内禀能垒为25971 kJ/mol, 反应的表观能垒为27026 kJ/mol； 2个水分子簇催化使速控步骤的内禀能垒降至126.47 kJ/mol, 反应的表观能垒降至80.80 kJ/mol; 考虑零点振动能后, 质子从氨基氮向羰基氧迁移的能垒消失. 即水分子（簇）催化可使Phe分子实现手性对映体转变.     

基于半刚性对映配体的螺旋单一手性配位聚合物

在辅助配体3-(2-甲基-1H-咪唑-1-基)-5-(5-甲基-1H-咪唑-1-基)吡啶(MIMIP)的辅助下, 乳酸衍生物(R)-4-(1-羧基乙氧基)苯甲酸((R)-H₂CBA)和(S)-4-(1-羧基乙氧基)苯甲酸((S)-H₂CBA)分别与Cd(Ⅱ)通过溶剂热反应得到一对结构新颖的单一手性配位聚合物-[Cd((R)-CBA)(MIMIP)\]·H₂O (1-R)和[Cd((S)-CBA)(MIMIP)]·H₂O (1-S), 并测试两个配合物的粉末衍射光谱、 热稳定性、 紫外-可见吸收光谱和荧光性质.  结果表明： 1-R和1-S均结晶于单斜的P2₁2₁2₁空间群, 具有三维超分子框架的对映体; 在1-R中, (R)-CBA^2-和MIMIP分别与Cd(Ⅱ)沿b轴形成两种右手螺旋链, 在1-S中, (S)-CBA^2-和MIMIP与Cd(Ⅱ)形成对映的左手螺旋链;  (R)-CBA^2-和MIMIP与Cd(Ⅱ)在1-R中形成左手螺旋链,(R)-CBA^2-和MIMIP与Cd(Ⅱ)在1-S中形成对映的右手螺旋链.     

Biological activity of enantiomerically pure forms of insect juvenile hormone I and III inBombyx mori

Summary Biological activity of enantiomerically pure juvenile hormones was assayed by topical application on allatectomizedBombyx fourth instar larvae. JHs tested were (10R)-JH I [methyl (2E,6E,10R,11S)-10,11-epoxy-3,11-dimethyl-7-ethyl-2,6-tridecadienoate], (10S)-JH I [methyl (2E, 6E, 10S, 11R)-10,11-epoxy-3,11-dimethyl-7-ethyl-2,6-tridecadienoate], (10R)-JH III [methyl (2E,6E,10R)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate] and (10S)-JH III [methyl (2E,6E,10S)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate]. Among these compounds, natural (10R)-JH I was most active and the dose needed to induce 50% larval molting was 0.04 g/larva; it was approximately 12,000 times more active than unnatural (10S)-JH I. Though natural (10R)-JH III showed slight biological activity, it was only one three-thousandth of that of (10R)-JH I. Unnatural (10S)-JH III exhibited no biological activity at the levels assayed.     

美托洛尔光学异构体在药动学和药效学上的差异

综述美托洛尔和β受体阻断剂所存在的光学异构现象．美托洛尔具两种光学异构体：（一）－美托洛尔和（＋）－美托洛尔．（一）－美托洛尔对家兔离体和在体心脏的心率抑制效应、心肌收缩力抑制效应以及降低山羊血压的效应皆远大于（十）－美托洛尔．（一）－美托洛尔与β受体的亲和力远大于（十）－美托洛尔．人体的氧化代谢表现出对（＋）－美托洛尔略具选择性；而狗的氧化代谢表现为对（一）－美托洛尔略具选择性，这种光学选择性存在着种属和个体差异．药物代谢的立体选择性是由肝药酶的立体结构所决定的．美托洛尔在与其他药物合用时往往表现出药物相互作用的选择性．包括美托洛尔在内的β受体阻断剂的蛋白结合率以及在肾上腺素能神经末梢的贮存和分泌皆具立体选择性．这对于临床给药具有实际意义．     

分子印迹聚合物研究进展

评述了近两年来分子印迹聚合物在制备、应用及其识别机理方面的最新进展。     

芳香醇胺类药物对映体的TLC法拆分

研究了芳香醇胺类药物对映体的分离方法 .用D 10 樟脑磺酸铵作为手性离子对试剂添加到流动相中 ,采用薄层色谱法 ,在普通的硅胶HF2 54薄层板上 ( 2 .5cm× 10cm) ,以不同配比的二氯甲烷———甲醇混合液为流动相 ,通过降低温度的方法 ( 0℃ ,冰箱内 ) ,分离了两种芳香醇胺类药物的对映体———舒喘灵和噻吗心安 .实验证明 ,两种药物的对映体得到了完全分离 ,且该方法简单易行、经济     

A Convenient Preparation of Enantiopure 1, l'-bi-2-naphthols via an Inclusion Complexation in the Solid State

Inclusion reaction of racemic 1, l'-bi-2-naphthol and (S)-proline was examined under the solid state and the solid-liquid conditions. The results indicated that a solid mixture of racemic 1, l'-bi-2-naphthol and (S)-proline in a 1 :1 molar ratio was kept at 50-80 C for 3-4 h, followed by treatment with benzene to give an insoluble solid and a benzene solution, from which (S)-(-)- and (R)-(+)-1, l'-bi-2-naphthols of a modest level of optical purity were obtained. After "kinetic" crystallization, both essentially enantiopure iso-mers were provided in 15%-35 % overall yields, respectively.