以β-环糊精及其衍生物为手性选择剂毛细管电泳拆分几种药物的旋光对映体

在毛细管电泳中，采用β－环糊精（β－ＣＤ）及其衍生物为手性选择剂对扑尔敏、异丙嗪、二氧异丙嗪和氧氟沙星对映体进行了分离。优化了分离条件；讨论了环糊精空腔边缘与溶．质分子作用的基团的种类和分离效果的联系，通过计算手性分离的热力学常数比较了不同手性选择剂对扑尔敏对映体的分离能力。最后，讨论了乙腈在手性分离中的作用。     

N-环丙甲基-7α-[(R)-1-羟基-1-甲基-3-(2-噻吩)丙基]-6,14-内乙基桥四氢去甲基蒂巴因(噻诺啡)合成和晶体结构

N-环丙甲基-7α-[(R)-1-羟基-1-甲基-3-(2-噻吩)丙基]-6,14-内乙基桥四氢去甲基蒂巴因(噻诺啡)是阿片受体部分激动剂.噻诺啡经过一步法合成其结构通过单晶X射线衍射分析确证,其结构保持吗啡"T"型主体结构.     

Differential protonation and dynamic structure of doxylamine succinate in solution using 1H and 13C NMR

A protonation and dynamic structural study of doxylamine succinate, a 1:1 salt of succinic acid with dimethyl-[2-(1-phenyl-1-pyridin-2-yl-ethoxy)ethyl]amine, in solution using one- and two-dimensional 1H and 13C NMR experiments at variable temperature and concentration is presented. The two acidic protons of the salt doxylamine succinate are in 'intermediate' exchange at room temperature, as evidenced by the appearance of a broad signal. This signal evolves into two distinct signals below about -30 degrees C. A two-dimensional 1H-1H double quantum filtered correlation experiment carried out at -55 degrees C shows protonation of one of the acidic protons to the dimethylamine nitrogen. A two-dimensional rotating frame 1H-1H NOE experiment at the same temperature reveals that the other proton remains with the succinate moiety. Comparison of the 1H and 13C chemical shifts and the 13C T1 relaxation times of the salt with those of the free base further substantiate the findings.     

Chiral separation of the four stereoisomers of a novel antianginal agent using a dual cyclodextrin system in capillary electrophoresis

Reported here is an analytical method enabling the stereochemical resolution of a new antianginal compound possessing two stereogenic centers, leading to four stereoisomers. Only one of these isomers is currently under development as a novel antianginal agent and consequently, the other three isomers are considered as unwanted chiral impurities. Therefore, an enantioselective method is required in order to check its enantiomeric purity. This paper presents a method exploiting the high efficiency of capillary electrophoresis and the complexing properties of cyclodextrins to achieve the separation of the four stereoisomers of this weakly basic compound (pKa = 7.4). For this purpose, the combination of a neutral cyclodextrin, hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD), and an anionic cyclodextrin, carboxymethyl-beta-cyclodextrin (CM-beta-CD), was added to the separation buffer running in an uncoated silica capillary. After selection of the suitable cyclodextrin system, satisfactorily separation conditions were as follows: 30 mM phosphate buffer (pH 6.4) containing 10 mM of HP-gamma-CD and 10 mM of CM-beta-CD, running voltage +30 kV. The resulting run time and resolutions were respectively about 17 min and between 1.95 and 2.84. Linearity curves (0.993 < r2 < 0.998) are also shown.     

Protein-ligand binding free energy estimation using molecular mechanics and continuum electrostatics. Application to HIV-1 protease inhibitors

A method is proposed for the estimation of absolute binding free energy of interaction between proteins and ligands. Conformational sampling of the protein-ligand complex is performed by molecular dynamics (MD) in vacuo and the solvent effect is calculated a posteriori by solving the Poisson or the Poisson-Boltzmann equation for selected frames of the trajectory. The binding free energy is written as a linear combination of the buried surface upon complexation, SASbur, the electrostatic interaction energy between the ligand and the protein, Eelec, and the difference of the solvation free energies of the complex and the isolated ligand and protein, deltaGsolv. The method uses the buried surface upon complexation to account for the non-polar contribution to the binding free energy because it is less sensitive to the details of the structure than the van der Waals interaction energy. The parameters of the method are developed for a training set of 16 HIV-1 protease-inhibitor complexes of known 3D structure. A correlation coefficient of 0.91 was obtained with an unsigned mean error of 0.8 kcal/mol. When applied to a set of 25 HIV-1 protease-inhibitor complexes of unknown 3D structures, the method provides a satisfactory correlation between the calculated binding free energy and the experimental pIC5o without reparametrization.     

Keggin结构钨磷酸稀土镨盐杂多蓝的合成及抗艾滋病病毒（HIV－1）活性的研究

Ｋｅｇｇｉｎ结构钨磷酸稀土镨盐杂多蓝的合成及抗艾滋病病毒（ＨＩＶ－１）活性的研究刘术侠，刘彦勇，王恩波，曾毅，李泽琳（东北师范大学化学系，长春，１３００２４）（中国预防医学科学院，北京）关键词稀土，钨磷杂多蓝，合成，抗艾滋病病毒（ＨＩＶ－１）活性杂多...     

氧氟沙星片剂和滴眼液中氧氟沙星对映体的毛细管电泳拆分及定量分析

采用环糊精及其衍生物为手性选择剂在CE上对氧氟沙星对映体进行了分离，研究了环糊精种类、浓度、分离电压、温度对分离的影响．重点考察了氧氟沙星的定量线性范围、检测限和重现性，在20-200mg／L浓度范围内，迁移时间重现性的相对标准偏差(RSD)控制在1．13％以内，峰面积重现性的RSD控制在4．3％以内，检测限为1mg／L．结果表明用20mmo1／L二甲基-β-环糊精(DM-β-CD)为手性选择剂，背景电解质为50mmo1／L Na2HPO4，pH＝3．0，不加有机添加剂情况下可得到较好的分离效果．同时，对氧氟沙星药品实样进行了分析，建主了一种市售氧氟沙星片剂和滴眼液中氧氟沙星对映体简单、快速的毛细管电泳分离、定量分析方法．     

Pectin in controlled drug delivery – a review

Controlled drug delivery remains a research focus for public health to enhance patient compliance, drug efficiency and reduce the side effects of drugs. Pectin, an edible plant polysaccharide, has been shown to be useful for the construction of drug delivery systems for specific drug delivery. Several pectin derived formulations have been developed in our laboratory and tested in vitro, ex vivo, and in vivo for the ability to deliver bioactive substances for therapeutic purposes in the context of interactions with living tissues. Pectin derivatives carrying primary amine groups were more mucoadhesive and have shown potential in nasal drug delivery and other mucosal drug delivery. Pectin derivatives with highly esterified galacturonic acid residues are more hydrophobic and able to sustain the release of incorporated fragrances for a prolonged duration. Less esterified pectin derivatives are able to penetrate deeper into the skin and may be useful in aromatherapy formulations. Pectin, in combination with zein, a corn protein, forms hydrogel beads. The bound zein restricts bead swelling and retains the porosity of the beads; the pectin networks shield the zein from protease attack. The complex beads are ideal vehicles for colon-specific drug delivery. Studies presented in this paper indicate the flexibility and possibility to tailor pectin macromolecules into a variety of drug delivery systems to meet different clinical requirements. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture.     

Dendrimers as potential drug carriers; encapsulation of acidic hydrophobes within water soluble PAMAM derivatives

This paper describes the synthesis of three neutral water soluble poly(amidoamine) (PAMAM) dendrimer derivatives. The ability of the two larger dendrimers to bind small acidic hydrophobic molecules is reported. Spectroscopic data and pH behaviour suggested that the acidic hydrophobes were forming stable ion pairs with the dendrimer's internal, basic tertiary nitrogens. With respect to forming 1:1 and 2:1 substrate/dendrimer complexes, both of the larger dendrimers were equally efficient at binding. All dendrimer/substrate complexes were completely miscible with water in all proportions (i.e. infinitely water soluble). When the bound substrates are drug moieties, then the resulting complexes could be considered as potential drug delivery systems. Flow calorimetry demonstrated that the dendrimers were able to release their hydrophobic guests when in contact with a biological cell.