用去氧胆酸盐和β-环糊精的毛细管胶束电动色谱拆分手性药物

用β－环糊精（β－ＣＤ）和去氧胆酸钠（ＳＤＣ）的环糊精改性毛细管胶束电动色谱，实际拆分了ＥＭＤ－５６４３１和扑尔敏两种手性药物，研究了ＳＤＣ和β－ＣＤ浓度及ｐＨ值对分离的影响。初步讨论了分离的机理。认为ＣＤ－ＳＤＣ体系中胶束单体分子几乎均被ＣＤ包合；ＣＤ可能与部分胶束单体包合而存在于ＳＤＣ的胶束中；该拆分体系中ＳＤＣ与β－ＣＤ的浓度比在４∶１～４∶３时拆分效果最好。并发现ＳＤＣ对β－ＣＤ有显著的增溶作用。     

用去氧胆酸盐和β-环糊精的毛细管胶束电动色谱拆分手性药物

 用β－环糊精（β－ＣＤ）和去氧胆酸钠（ＳＤＣ）的环糊精改性毛细管胶束电动色谱，实际拆分了ＥＭＤ－５６４３１和扑尔敏两种手性药物，研究了ＳＤＣ和β－ＣＤ浓度及ｐＨ值对分离的影响。初步讨论了分离的机理。认为ＣＤ－ＳＤＣ体系中胶束单体分子几乎均被ＣＤ包合；ＣＤ可能与部分胶束单体包合而存在于ＳＤＣ的胶束中；该拆分体系中ＳＤＣ与β－ＣＤ的浓度比在４∶１～４∶３时拆分效果最好。并发现ＳＤＣ对β－ＣＤ有显著的增溶作用。     

相溶解度法研究芦荟大黄素和环糊精及其衍生物的包结作用

本文用相溶解度法研究了芦荟大黄素与β－环糊精（ＣＤ）衍生物的包结作用,测定了包结物的包结常数,表明β－ＣＤ衍生物对芦蔡大黄素有较好的增溶作用,有应用价值。     

环糊精与抗癌药物HMBA相互作用的谱学研究

α－,β－,γ－ＣＤ与抗癌药ＨＭＢＡ相互作用的ＮＭＲ研究表明ＨＭＢＡ分子大小与α－ＣＤ内腔尺寸最为匹配,相互作用力最强。１３Ｃ－ＮＭＲ研究表明α－ＣＤ与ＨＭＢＡ形成了包结物,而且两者之间还有氢键存在。ＨＭＢＡ上的α－Ｃ,在与α－ＣＤ作用后产生的较大低场位移,说明在ＨＭＢＡ·α－ＣＤ体系中包结作用较强,使ＨＭＢＡ上α－Ｃ化学位移变化大。而ＨＭＢＡ上的－Ｃ＝Ｏ,在与α－,β－ＣＤ作用后产生高场位移,位移程度ＨＭ－ＢＡ．β－ＣＤ＞ＨＭＢＡ．α－ＣＤ,则氢键作用在ＨＭＢＡ．β－ＣＤ体系中较强些。     

β环糊精对显色反应作用的研究：Ⅱ.与表现活性剂的协同作用机理探讨

本文从β－环糊精（β－ＣＤ）的包合作用及其对表面活性剂（ＳＦ）包合后引起的包合常数增大等方面，探讨了β－ＣＤ－与离子表面活性剂对显色反应的协同增敏作用机理，研究表明：β－ＣＤ与ＳＦ形成包合物ＳＦ－β－ＣＤ及ＳＦ－β－ＣＤ对显色剂及其显色络合物包合作用的增强，是产生协同增敏作用的主要因素，但还须考虑对空白值的影响以及配合物的稳定性，还提出了对一同显色体系应用不同ＳＦ－β－ＣＤ估计协同增敏趋势的方法。     

增效试剂对过氧化物模拟酶催化显色体系的增效作用——Fe-TPPS_4-4-AAP-苯酚衍生物-H_2O_2体系

本文以β－环糊精（β－ＣＤ）和表面活性剂为增效试剂，分别研究了它们对以Ｆｅ－ｍｅｓｏ－（四（４－磺基苯）卟啉）（Ｆｅ－ＴＰＰＳ４）为催化剂，催化过氧化氢氧化４－氨基安替比林（４－ＡＡＰ）与苯酚衍生物显色反应的速度和灵敏度的影响，发现β－ＣＤ和十二烷基苯磺酸钠（ＳＤＢＳ）对该体系具有明显的增效作用．在３×１０－３ｍｏｌ／Ｌβ－ＣＤ存在下，测定Ｈ２Ｏ２的灵敏度比文献报道的提高了１．５６倍．利用ＳＤＢＳ浓度与催化显色反应初速度的增加值之间的线性关系，建立了测定微量ＳＤＢＳ的方法     

增效试剂对过氧化物模拟酶催化显色体系的增效作用——Fe—TPPS4—4—AAP—苯酚

本以β－环糊精（β－ＣＤ）和表面活性剂为增效剂，分别研究了它们对以Ｆｅ－ｍｅｓｏ－（四（４－磺基苯）卟啉）（Ｆｅ－ＴＰＰＳ４）为催化剂，催化过氧化氢氧化４－氨基安替比林（４－ＡＡＰ）与苯酚衍生物显色反应的速度和灵敏度的影响，发现β－ＣＤ和十二烷基苯磺酸钠（ＳＤＢＳ）对该体系具有明显的增效作用，在３×１０＾－３ｍｏｌ／Ｌβ－ＣＤ存在下，测定Ｈ２Ｏ的灵敏度比献报道的提高了１．５６倍，利用ＳＤＢＳ深     

β—环糊精对D／L—酪氨酸对映体的手性识别及超分子包合物的合成

利用圆二色谱研究了β－环糊精（β－ＣＤ）对Ｄ／Ｌ酪氨酸的手性识别行为，制备出了β－ＣＤ与Ｌ－酪氨酸（Ｌ－Ｔｙｒ）的固体超分子化合物，并用元素分析、薄层分析、Ｘ射线粉末衍射及热分析对包合物进行了表征，用荧光光谱法测定了包合物的形成常数．实验结果表明，β－ＣＤ具有选择包结Ｌ－酪氨酸的特性；主客体形成１１的包合物，其组成为Ｌ－Ｔｙｒ／β－ＣＤ·１２Ｈ２Ｏ；稳定常数为５．１３×１０３Ｌ／ｍｏｌ；包合物的热稳定性比主客体皆有改善     

环糊精流动相添加剂分离色氨酸对映体的薄层色谱法

用β环糊精（β－ＣＤ）作为流动相手性添加剂,在聚酰胺薄膜上分离２,４二硝基苯基色氨酸（ＤＮＰ－Ｔｒｐ）对映体,流动相最佳组成：βＣＤ尿素饱和溶液－甲醇甲酸（９：１：２,Ｖ／Ｖ／Ｖ）,还分离了非对映异构体辛可宁和辛可尼丁以及邻、间、对硝基苯胺。     

β环糊精的双核铜络合物对芳香基氨基酸分子识别的研究

用荧光分光光度法和紫外分光光度法测定了β－环糊精双核铜络合物（Ｃｕ２－β－ＣＤ）在强碱性溶液中与氨基酸的超分子作用，发现Ｃｕ２－β－ＣＤ与芳香基氨基酸的荧光光谱和紫外光谱发生明显变化，Ｃｕ２－β－ＣＤ对于芳香基氨基酸具有分子识别作用，对于酪氨酸和苯丙氨酸，主客体间形成超分子络合物的化学计量比为１：４．有Ｓｃａｔｃｈａｒｄ方程或Ｌｉｎｅｗｅａｖｅｒ－Ｂｕｒｋ曲线分别了它们的物理常数，推测Ｃｕ２－β２     

High-performance liquid chromatography utilization of ionic liquids as mobile phase additives for separation and determination of the isomers of amino benzoic acids

For the isomers of amino benzoic acid, including o-, m-, p-amino benzoic acid, the beneficial effects of using the ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF₄]), as mobile phase additives on retention behavior and separation were investigated. Chromatographic separation of the o-, m-, p-amino benzoic acid was performed on a reversed-phase C18 column by ultraviolet detection at 245 nm. The effects of several chromatographic parameters, concentrations and pH values of [BMIm][BF₄] solutions, methanol concentration and length of alkyl chain on different ionic liquids, on the separation and determination of the isomers were evaluated. The optimized chromatographic conditions were established using an aqueous 0.5 μmol/L [BMIm][BF₄] solution (pH 3.0)/methanol (40:60, v/v) as mobile phase without need of gradient elution, with separation of three amino benzoic acids achieved within four min. The calibration curve showed good linearity over the tested range of 2 mg/L to 120 mg/L for the three isomers with a correlation coefficients of 0.9999. The recoveries of the three amino benzoic acids of spiked components were between 99.8% and 100%. The method has been successfully applied to the determination of p-amino benzoic acid in the pharmaceutical, Bromine Mitag Procaine Injection.     

Relativistic multireference calculation of photodissociation of o-, m-, and p-bromofluorobenzene

Quantum chemical calculations with relativistic effects were performed on the photodissociation of o-, m-, and p-bromofluorobenzene (o-, m-, and p-BrFPh) at 266 nm. The method of multistate second-order multiconfigurational perturbation theory in conjunction with spin-orbit interaction through complete active space state interaction was employed to calculate the potential energy curves for the ground and low-lying excited states of o-, m-, and p-BrFPh along their photodissociation reaction coordinates. The dissociation mechanisms with products of Br((2)P(3∕2)) and Br(?)((2)P(1∕2)) states were clarified with the computed potential energy curves and the surface crossings. The current calculations augmented previous theoretical investigations by including relativistic effects and resolved some differences of experimental assignment regarding the dissociation channels of o-, m-, and p-BrFPh.     

Distinguishing by principal component analysis of o-xylene, m-xylene, p-xylene and ethylbenzene using electron ionization mass spectrometry

The possibility of distinguishing between o-, m-, p-xylene and ethylbenzene on the basis of only their 70 eV electron ionization (EI) mass spectra has been investigated. These four isomers were distinguished by principal component analysis (PCA) of respective EI mass spectra (recorded under identical conditions). Considered mass spectra contained either eleven or five m/z values, which had intensity greater than 5% or 10% of base peak, respectively.     

乙二胺桥联环糊精二聚体的多重识别研究

本文合成了由两个乙二胺分子桥联的β-环糊精二聚体(1)。在碱性溶液中1与二价铜离子形成稳定的配合物(2), 根据客体分子被包合前后主、客体质子化学位移的变化研究了水溶液中三个主体分子: β-环糊精、1和2分别与对、间和邻氯苯酚及其钠盐的包合反应。通过比较主-客体包合物生成常数的大小可以推断2与有机阴离子客体之间存在多重识别作用。     

Assembly of beta-cyclodextrin with 3S-tetrahydro-beta-carboline-3-carboxylic acid and self-assembly of 6-(3'S-carboline-3'-carboxylaminoethylamino)-6-deoxy-beta-cyclodextrin: approaches to enhance anti-oxidation stability and anti-thrombotic potency

3 S-1,2,3,4-Tetrahydro-beta-carboline-3-carboxylic acid (THCA) isolated from Bulbus allii macrostemi was identified as the active antiplatelet aggregation ingredient. However, the very poor water solubility and the shortcoming of being oxidized easily in vivo seriously limit the clinical application of THCA. In the present study, two strategies were used to reduce this tendency. First, the inclusion complex of THCA with beta-cyclodextrin (beta-CD) was prepared. Spectral studies identified that the inclusion complex (beta-CD1,2/THCA) was in equilibrium between beta-CD/THCA and beta-CD2/THCA, and the proportion of two isomers was beta-CD concentration dependent; it was 89% vs 11% in our study. The oxidation of both THCA and beta-CD1,2/THCA by H2O2 followed first-order kinetics, and 35% of THCA and 33% of beta-CD1,2/THCA were oxidized during the monitoring period. In vitro antiplatelet aggregation and in vivo oral administration antithrombotic activity of THCA was largely increased via inclusion complexation with beta-CD. Second, a novel conjugate 6-(3' S-carboline-3'-carboxyamino-ethylamino)-6-deoxy-beta-CD (5-monomer) was prepared. Spectral characterizations demonstrated that 5-monomer was able to self-assemble into 5-dimer, which was coexisting with the monomer with a ratio of 79% vs 21% in solution. The in vitro oxidation of 5-monomer/5-dimer by H2O2 did not occur during the monitoring period. The in vitro antiplatelet aggregation and in vivo antithrombotic assays of 5-monomer /5-dimer demonstrated that the bioactivity of THCA was remarkably increased via conjugation with 6-ethylamino-6-deoxy-beta-CD and produced greater in vitro and in vivo effectiveness than that of the inclusion complex beta-CD1,2/THCA at the same dose. The significant improvement of the bioactivity and stability of THCA indicates that inclusion complexation and conjugation with beta-CD provide promising approaches to improve the practical use of THCA in clinical applications.     

Thermodynamic study on the effects of beta-cyclodextrin inclusion with berberine.

The fluorescence enhancement of berberine (Berb) as a result of complex with beta-cyclodextrin (beta-CD) is investigated. The association constants of alpha-CD and beta-CD with Berb are 60 and 137 M(-1) at 20 degrees C in pH 7.20 aqueous solution. Effects of temperature on the forming inclusion complexes of beta-CD with Berb have been examined through using fluorescence titration. Enthalpy and entropy values calculated from fluorescence data are -33.7 kJ mol(-1) and 74.3 J x mol(-1) K(-1) respectively. It was found that the dielectric constant of beta-CD cavity is about 24 in a rough analogy with absolute alcohol. These results suggest that the extrusion of 'high energy water' molecules from the cavity of beta-CD and hydrophobic interaction upon the inclusion complex formation are the main forces of the inclusion reaction. Effect of pH on the association of beta-CD with Berb was also studied. Mechanism of the inclusion of beta-CD with Berb is further studied by absorption and NMR measurements. Results show that beta-CD forms a 1:1 inclusion complex with Berb.     

Site-selective formation of optically active inclusion complexes of alkoxo-subphthalocyanines with beta-cyclodextrin at the toluene/water interface

Several subphthalocyanine derivatives that contain an alkoxo substituent as an axial ligand (RO-Subpc, R = 9-anthracenemethyl, benzyl, phenyl, 3,5-dimethylbenzyl, 3,5-dimethylphenyl, 4-methylbenzyl, and 4-methylphenyl) were synthesized. The formation of inclusion complexes of RO-Subpc with beta-CD in DMSO and at the toluene/water interface was investigated by UV/Vis absorption spectroscopy, induced circular dichroism (ICD), and nuclear magnetic resonance (NMR) measurements. Interfacial tension measurements suggested that beta-CD adsorbed as a monolayer at the toluene/water interface and probably orientated towards the toluene phase with its primary face. The 1:1 composition of beta-CD.RO-Subpc inclusion complexes was confirmed in DMSO and at the toluene/water interface for BzO-Subpc, PhO-Subpc, MeBzO-Subpc, and MePhO-Subpc. A 2:1 inclusion complex of AnO-Subpc formed in DMSO. The observed ICD spectra of beta-CDRO-Subpc inclusion complexes are discussed with respect to molecular modeling and the simulation based on Tinoco-Kirkwood theory. Interestingly, the ICD spectra of beta-CD.BzO-Subpc and beta-CD.MeBzO-Subpc inclusion complexes exhibited a negative sign in DMSO and a positive sign at the toluene/water interface. This reversal of the ICD sign strongly suggests a difference in the structure of the inclusion complexes: beta-CD at the interface formed the inclusion complex with its primary face, whereas the secondary face of beta-CD bound favorably to RO-Subpc in DMSO.     

Molecular recognition thermodynamics and structural elucidation of interactions between steroids and bridged bis(beta-cyclodextrin)s

A series of bridged bis(beta-cyclodextrin(CD))s (2-7) were synthesized, i.e., bridged bis(beta-CD)s 2 and 3 bearing binaphthyl or biquinoline tethers and bridged bis(beta-CD)s 4-7 possessing dithiobis(benzoyl) tether, and their complex stability constants (KS), enthalpy (DeltaH degrees), and entropy changes (DeltaS degrees) for the 1:2 inclusion complexation with representative steroids, deoxycholate, cholate, glycocholate, and taurocholate, have been determined in an aqueous phosphate buffer solution of pH 7.20 at 298.15 K by means of titration microcalorimetry. The original conformations of bridged bis(beta-cyclodextrin)s were investigated by circular dichroism and 1H ROESY spectroscopy. Structures of the inclusion complexes between steroids and bridged bis(beta-CD)s in solution were elucidated by 2D NMR experiments, indicating that anionic groups of two steroid molecules penetrate, respectively, into the two hydrophobic CD cavities in one 6,6'-bridged bis(beta-CD) molecule from the secondary rim to give a 1:2 binding mode upon inclusion complexation. The results obtained from titration microcalorimetry and 2D NMR experiments jointly demonstrate that bridged bis(beta-CD)s 2, 3 and 5-7 tethered by protonated amino group possessing different substituted groups can enhance not only the molecular binding ability toward steroids by electrostatic interaction but also molecular selectivity. Thermodynamically, the resulting 1:2 bis(beta-CD)-steroid complexes are formed by an enthalpy-driven process, accompanied by smaller entropy loss. The increased complex stability mainly results from enthalpy gain, accompanied by large conformational change and extensive desolvation effects for the 1:2 inclusion complexation between bis(beta-CD)s and steroids.     

Simultaneous determination of positional isomers of benzenediols by capillary zone electrophoresis with square wave amperometric detection

A capillary zone electrophoresis method coupling square wave amperometric detection (SWAD) for the simultaneous determination of positional isomers of benzendiols (i.e. o-, m-, p-benzenediols) has been developed. Effects of several factors, such as the composition of the running buffer, the pH value, separation voltage, injection time and the potential applied to the working electrode, were investigated to acquire the optimum conditions. The efficacy of the boric acid and ascorbic acid in the running buffer were discussed. o-, m-, p-Benzendiols can be well separated within 8 min in a 50 cm length of 50 microm diameter fused-silica capillary at a separation voltage of +15 kV. Operated in a wall-jet configuration, a 100 microm Pt-disk electrode used as the working electrode exhibits good response for the analytes. The relation between peak current and analyte concentration was linear over two orders of magnitude with detection limits (S/N = 3) ranging from 0.5 to 1.5 microM for all analytes. The proposed method has been successfully applied to monitor the o-, m-, p-benzendiols contents in the environmental wastewater samples with satisfactory assay results.     

Host-guest interaction of L-tyrosine with beta-cyclodextrin

The inclusion complexes of beta-cyclodextrin (beta-CD) with l-tyrosine (l-TYN) were investigated by using spectrophotometers. The absorption and fluorescence enhancement occurs with beta-CD and l-TYN forms 1:1 inclusion complex. The unusual blue shift of hydroxyl ion in the beta-CD medium confirms OH groups present in the interior part of the beta-CD cavity and -COOH group present in the upper part of the beta-CD cavity. A mechanism is proposed to explain inclusion process. The inclusion interaction was examined and the thermodynamic parameters of inclusion process DeltaG, DeltaH and DeltaS were determined. The results indicated that the inclusion process was an exergonic and spontaneous process. Stable solid inclusion complexes were established and characterized by FT-IR, scanning electron microscope (SEM) methods.