Veronicafolin－β-环糊精的物化表征及Veronicafolin－羟丙基-β-环糊精包合物溶解性的增强

用氢谱、红外光谱、X-射线粉末衍射、热分析、元素分析等测试方法研究了Veronicafolin (3,5,4′-三羟基-6,7,3′-三甲氧基黄酮) 和β-环糊精 (β-CD) 的固体包合物的谱学特征。元素分析结果显示形成Veronicafolin-β-CD·20H2O包合物，其中C：39.58%, H: 5.75%，表明包合物中主客体比为1∶1。该包合类型属于A_L-型。通过紫外-可见分光光度法研究了在羟丙基-β-环糊精（HP-β-CD）的存在下Veronicafolin的相溶解度曲线，测得校正曲线为y = 24148x + 0.0075 (r=0.9999)，相溶解曲线为y=0.4738x-2.0×10^-7 (r=0.9490)，包结平衡常数Ks为4.5×10⁶mol-1。HP-β-CD提高了黄酮醇Veronicafolin的溶解度。     

含萘磺酰基大环多胺与Cu(II)和DNA作用的荧光性能研究

以1,4,7,10-四氮杂环十二烷(Cyclen)为原料,合成了含有萘磺酰基的大环多胺,其结构经1H NMR、MS、元素分析等表征。用荧光光谱法测定了大环多胺与Cu(II)在不同pH下的配位情况,研究了大环多胺激发和发射波长,配体浓度与吸光度的线性关系;Cu(II)、小牛胸腺嘧啶DNA对大环多胺荧光性能的影响。     

Enantiomeric separation of citalopram analogues by HPLC using macrocyclic glycopeptide and cyclodextrin based chiral stationary phases

The enantiomeric separation of a novel series of twenty-eight racemic mixtures of citalopram analogues was performed by high performance liquid chromatography (HPLC). Due to the effectiveness of citalopram as an antidepressant drug, the development of new compounds based on its chemical structure is interesting, and their enantiomeric separation is needed to allow further pharmacokinetic studies. Several bonded cyclodextrin (both native and derivatized) and macrocyclic glycopeptide based chiral stationary phases (CSPs) were evaluated for their ability to separate this set of compounds via HPLC. Polar ionic, polar organic, and reversed phase modes were tested. Twenty-five of the racemic mixtures were separated with resolutions and enantiomeric selectivities up to 2.9 and 1.33, respectively. A total of eighteen baseline separations were achieved, while seven compounds were partially separated. Vancomycin based columns operated in the polar ionic mode resulted in the greatest number of separations. Lastly, the chromatographic behaviors of similar compounds were compared based on their chemical structure and also on the chiral selectors used.     

环糊精与两种有机物的包合物的不同光解特性

The effectiveness of the solubilization and photodegradation of β-cyclodextrin （β-CD） and hydroxypropyl-β- cyclodextrin （HPCD） on two hydrophobic organic compounds （HOC） of methyl parathion and pentachlorophenol was investigated. The results indicate that the solubilization or photodegradation of two HOC were influenced by complexing with β-CD or HPCD. The solubility of pentachlorophenol （PCP） was increased linearly with β-CD concentration. The solubility of methyl parathion （MPT） was increased with the increase of β-CD concentration initially, however, as the β-CD concentration was enhanced above 3 g/L, the solubility was decreased with increase of β-CD concentration. The solubilities of two HOC were increased linearly with the increase of HPCD concentration. Although the photodegradation of MPT was improved, the photodegradation of PCP was restrained by complexation of HOC with β-CD or HPCD. In a word, the effectiveness of photodegradation or solubilization of HPCD was more significant than that of β-CD. One potential application of such a method was the in situ remediation of hydrophobic organic pollutants in contaminated soil and groundwater or industrial waste streams.     

Synthesis of a novel macrocyclic ligand containing bipyridine units

The 6-hydroxymethyl-6'-tetrahydropyranyloxymethyl-2, 2'-bipyridine (2) was synthesized by the reaction of 6,6'-dihy-droxymethyl-2, 2'-bipyridine (1) with 3, 4-dihydropyran (DHP). 6-Tetrahydropyranyloxymethyl-6'-iodomethyl-2, 2'-bipyridine (5) was obtained from mesylate and iodizating reaction of compound 2. The coupling of 2 and 5 followed by hydrolysis gave bis(6'-hydroxymethyl-2,2'-bipyridme-6-methyl)ether (7) .The macrocydic ligand 8 was obtained by treating 7 and 6,6'-dibromomethyl-2,2'-bipyridine. The synthetic conditions of the intermediate 2 and macocyclic ligand 8 were discussed.     

Synthesis of aromatic-linked polyamine macrocyclic derivatives as HIV-1 entry inhibitors

A series of novel aromatic-linked polyamine macrocyclic derivatives have been synthesized.Their structures were confirmed by MS and ~1H NMR.These compounds exhibited potent anti-HIV-1 activities.     

新型含噻二唑环的二茂铁衍生物的合成与电化学性质研究

Three novel thiadiazolo-ferrocence derivatives containing long chain alkyl group were synthesized and characterized. The voltammetric behaviour of these thiadaizolo-ferrocene derivatives was studied on gold electrode (diameter 1 mm) in CH2Cl2/0.2 mol/L tetra-n-butylammonium hexafluorophosphate. The influence of β-cyclodextrinon the voltammetric behaviour of the compounds was also studied.     

Highlighting the role of the hydroxyl position on the alkyl spacer of hydroxypropyl-beta-cyclodextrin for enantioseparation in capillary electrophoresis

This work investigates the resolving power of 2,3-dihydroxypropyl-beta-CD (2,3-DHP-beta-CD) and 3-hydroxypropyl-beta-CD (3-HP-beta-CD) as chiral mobile phase additives (CMPAs) using CE. The effects of experimental parameters (CD concentration, buffer pH, and buffer concentration) on enantiorecognition were investigated. More than 20 basic chiral drugs were resolved with satisfactory enantioselectivity. Comparison with 2-hydroxypropyl-beta-CD (2-HP-beta-CD) showed that one or both of the two new chiral selectors show enhanced enantiorecognition for several molecules with bulky substitutes, such as Zopiclone and Mianserin, however, 2-HP-beta-CD has higher enantiorecognition for most of the analytes. Further studies on the structures of analytes and CMPAs showed that the OH moiety on the propyl spacer plays an important role in the separation of some chiral drugs.     

Headspace solid-phase microextraction with novel sol–gel permethylated-β-cyclodextrin/hydroxyl-termination silicone oil fiber for determination of polybrominated diphenyl ethers by gas chromatography–mass spectrometry in soil

A simple, sensitive, and accurate method for determination of polybrominated diphenyl ethers (PBDEs) in soil has been developed based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography–mass spectrometry (GC–MS). Permethylated-β-cyclodextrin/hydroxyl-termination silicone oil (PM-β-CD/OH-TSO) fiber was first prepared by sol–gel technology and employed in SPME procedure. By exploiting the superiorities of sol–gel coating technique and the advantages of the high hydrophobic doughnut-shaped cavity of PM-β-CD, the novel fiber showed desirable operational stability and extraction ability. After optimization on extraction conditions like water addition, extraction temperature, extraction time, salts effect, and solvents addition, the method was validated in soil samples, achieving good linearity (r > 0.999), precision (R.S.D. < 10%), accuracy (recovery > 78%), and detection limits (S/N = 3) raging from 13.0 to 78.3 pg/g.     

Simultaneous enantioseparation of four beta2-agonists by capillary electrophoresis with cyclodextrin additives. Study of the enantioselective mechanism

The simultaneous capillary electrophoretic enantioseparation of adrenergic beta(2)-agonists enantiomers (trantinterol, mabuterol, clenbuterol, bambuterol) was studied with beta-cyclodextrin, ethyl-beta-CD, methyl-beta-CD, hydroxypropyl-beta-CD, and hydroxyethyl-beta-CD as chiral selector. The type and concentration of the chiral selector and buffer pH played a very important role in the enantioseparation of the analyzed compounds. Hydroxypropyl-beta-CD was found to be the most effective complexing agent and allowed excellent chiral/achiral resolutions compared to the other CDs. The simultaneous enantioseparation of four beta(2)-agonists was achieved using 100 mM citric acid-10 mM Na(2)HPO(4) buffer at pH 2.5 containing 120 mM hydroxypropyl-beta-CD with an applied voltage of 20 kV. Method validation in terms of repeatability, linearity, and limits of detection and quantification was performed. The effect of structural features of analytes on R(s) and t(m) was studied. Complexation binding constants for the interactions between the four compounds and three different CDs were evaluated for elucidating the enantioseparation mechanism. It was found that very small differences in the chemical structure of the analytes resulted in significant changes in stereoselective recognition.     

Structure and intramolecular flexibility of beta-cyclodextrin complex with (-)-epigallocatechin gallate in aqueous solvent

The probable structure of the inclusion complex of beta-cyclodextrin (beta-CD) and (-)-epigallocatechin gallate (EGCg) in D2O was investigated using several NMR techniques. EGCg formed a 1:1 complex with beta-CD, in which the A ring and a portion of the C ring of EGCg were included at the head of the phenolic hydroxyl group attached to C7 of EGCg in the beta-CD cavity from the wide secondary hydroxyl group side. In the 1:1 complex with beta-CD, EGCg maintained the conformation in which the B and B' rings of EGCg took pseudoequatorial and pseudoaxial positions with respect to the C ring, respectively. The structure of the inclusion complexes of beta-CD and EGCg obtained from NMR experiments supported those determined from AM1 semiempirical SCF MO calculations well.     

Synthesis of a new pyranoanthocyanin dimer linked through a methyl-methine bridge

Two new anthocyanin-derived compounds corresponding to the ethylpyranomalvidin-3-glucoside and the pyranomalvidin-3-glucoside dimer linked through a methyl-methine bridge were synthesized for the first time and their structure characterized by LC-DAD/MS and NMR spectroscopy. The latter was obtained in a hydroalcoholic model solution through the reaction of the carboxypyranomalvidin-3-glucoside with ethylpyranomalvidin-3-glucoside and displays a blue/green color in solution.     

Host-Guest Interactions between N,N＇-Bis（ferrocenylmethyl- ene）-Diaminobutane and Benzenetetracarboxylic Dianhydride Bridged Bis（β-cyclodextrin）s

A novel water soluble ditopic guest, the quaternary ammonium salt of N,N＇-bis（ferrocenylmethylene）-diaminobutane （1）, and a known water soluble ditopic host, benzenetetracarboxylic dianhydride bridged bis（β-cyclodextrin）s （2）, have been synthesized and characterized. ^1H NMR spectra and cyclic voltammogram （CV） studies revealed the host-guest interactions between them in aqueous solution. The supramolecular interaction also exists in solid state as confirmed by the studies of the solid samples, which were obtained by frozen-drying the solution sampies, using FTIR spectroscopy and differential scanning calorimetry （DSC） techniques. TEM measurement demonstrated that wire-shaped supramolecular aggregates exist in the aqueous solution of the two compounds. The lengths of the aggregates could reach micrometers.     

Molecular Recognition of Bridged Bis （β－cyclodextrin） s Linked by Phenylenediseleno Tether on the Primary or Secondary Side with Fluorescent Dyes

A novel β‐cyclodextrin dimer, 2, 2′‐o‐phenylenediseleno‐bridged bis (β‐cyclodextrin) (2), has been synthesized by reaction of mono‐[2‐O‐(p‐tolylsulfonyl)]‐β‐cyclodextrin and poly(o‐phenylenediselenide). The complexation stability constants (K₂) and Gibbs free energy changes (‐ΔG°) of dimer 2 with four fluorescence dyes, that is, ammonium 8‐anilino‐1‐naphthalenesulfonate (ANS), sodium 6‐(p‐toluidino)‐2‐naphthalenesulfonate (TNS), Acridine Red (AR) and Rhodamine B (RhB) have been determined in aqueous phosphate buffer solution (pH = 7.2, 0.1 mol‐L^?1) at 25 °C by means of fluorescence spectroscopy. Using the present results and the previously reported corresponding data of β‐cyclodextrin (1) and 6, 6′‐o‐phenylenediseleno‐bridged bis (β‐cyclodextrin) (3), binding ability and molecular selectivity are compared, indicating that the bis (β‐cyclodextrin)s 2 and 3 possess much higher binding ability toward these dye molecules than parent β‐cyclodextrin 1, but the complex stability constant for 2 linked from the primary side is larger than that of 3 linked from the secondary side, which is attributed to the more effective cooperative binding of two hydrophobic cavities of host 3 and the size/shape‐fit relationship between host and guest. The binding constant (K₂,) upon inclusion complexation of host 3 and AR is enhanced by factor of 27.3 as compared with that of 1. The 2D ¹H NOESY spectrum of host 2 and RhB is performed to confirm the binding mode and explain the relative weak binding ability of 2.     

Development and evaluation of cyclodextrin complexed hydroxyapatite nanoparticles for preferential albumin adsorption

Our study focuses on the incorporation of β-CD into the HA structure, its effects on the phase of HA and the biological responses to proteins and blood cells. Hydroxyapatite (HA) containing levels of β-cyclodextrin (β-CD) of upto 0.9 wt% has been produced by co-precipitation method. The complexes were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TG) and differential scanning analysis (DSC) methods. The size of the complexes as analyzed using DLS (dynamic light scattering) was between 150 nm and 350 nm. The results show that an increase in concentration of β-CD in the prepared samples that leads to an increase in hydrophobicity seems to promote an affinity for albumin adsorption. The PAGE results were substantiated by Lowry measurements and the results reveal that the H2 (containing 0.7 wt% β-CD) sample shows around 40% increase in albumin adsorption when compared to the H1 (containing 0.5 wt% β-CD) sample. The preferential adsorption of albumin has not been demonstrated in vivo. The ability to design particles that can preferentially interact with particular protein can obtain desired targeting effects. So the results indicate that HA/β-CD complexes have immense potential in targeted delivery of drugs. The in vivo potential of the developed samples was further confirmed in vitro by the results of cell aggregation and haemolytic activity.     

Synthesis and characterization of an ultrathin polyion complex membrane containing β-cyclodextrin for separation of organic isomers

An ultrathin polyion complex (PIC) layer containing β-cyclodextrin (β-CD) was formed on the surface of a charged base membrane. Thus, a positively charged copolymer containing β-CD was synthesized by the radical copolymerization of β-CD monomer and allylamine, and was used to modify the surface of a Nafion membrane containing negatively charged fixed ions. Electron spectroscopy for chemical analysis (ESCA) confirmed the presence of the copolymer on the surface of the Nafion membrane due to the formation of a PIC layer. The ability of the membrane to separate organic isomer mixtures was tested by the pervaporation technique, using butanol isomer mixtures as the feed model. The membrane exhibited a good selectivity toward butanol isomers, indicating the effectiveness of β-CD as a selective fixed carrier for the isomers.     

Ethylene Oligomerization by 8—Aminoquinoline Nickel Dichloride Complex Supported on β—Cyclodextrin

IntroductionSincetheexcellentcapabilityoflatetransitionmetalcomplexesforolefinpolymerization ,wasdiscoveredbyBrookhart1andGibson2 ,theinterestinthesecatalystshasgreatlyincreasedinbothacademicandindustrialresearches.3Unfortunately,intheolefinpolymerizationprocessinitiatedbylatetransitionmetalcomplexes,thepolyolefinsproducedoftendepositatthereactorwallsandstirringdevice ,whichwillbedisadvantageoustothefurtherapplicationofthesecat alysts.Inordertoovercometheseproblems,theheteroge nizationoftheho…     

Synthesis and characterization of macrocyclic vinyl aromatic polymers

The synthesis and characterization by size exclusion chromatography, liquid chromatography, NMR, matrix‐assisted laser desorption/ionization, thermal analysis, and other techniques of well‐defined and narrow molecular weight distribution macrocyclic polystyrene (PS), poly(2‐vinylpyridine), poly(α‐methylstyrene), poly (2‐vinyl‐naphthalene) (P2VN), and poly(9,9‐dimethyl‐2‐vinylfluorene) (PDMVF) containing a single 1,4‐benzylidene, methylidene, or 9,10‐anthracenylidene unit are reviewed. The absorption and emission spectroscopy of PS, P2VN, and PDMVF is also discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2139–2155, 2006     

Study on the Supramolecular Interaction of β-Cyclodextrin with Gemfibrozil by Spectrofluorimetry and Its Analytical Application

The supramolecular interaction of gemfibrozil with β-cyclodextrin （β-CD） was studied by spectrofluorimetry. The mechanism of the inclusion was discussed by spectrofluoremetry, infrared spectrum and ^1H NMR spectrum. The results showed that a 1 ： 1 （β-CD ： gemfibrozil） complex was formed with an apparent association constant of 3.844 × 10^3 L·mol^-1. Based on the enhancement of the fluorescent intensity of gemfibrozil, a spectrofluorimetric method for the determination of gemfibrozil in bulk aqueous solution in the presence of β-CD was developed. The linear range was 3.30 ng·mL^- 1 -6.00 ug·mL^-1 with the detection limit of 0.980 ng·mL^-1. There was no interference from the excipients normally used in tablet composition and the serum main compositions. The proposed method was then successfully applied to the determination of gemfibrozil in capsules and serum.     

Chiral separation of cathinone derivatives using β‐cyclodextrin‐assisted capillary electrophoresis–Comparison of four different β‐cyclodextrin derivatives used as chiral selectors

In the past decade, more than 100 different cathinone derivatives slopped over entire Europe due to their enormous popularity. Generally, these novel psychoactive substances are easily available via the internet. This fact leads to various social problems, since cathinones are substances with consciousness‐changing effects and are mainly misused for recreational matters by their consumers. Cathinones possess a chiral center including two enantiomeric forms with potentially different pharmacological behavior. This fact makes analytical method development regarding their chiral separation indispensable. In this study, a chiral capillary zone electrophoresis method for the enantioseparation of 61 cathinone and pyrovalerone derivatives was developed by means of four different β‐cyclodextrin derivatives. As chiral selectors, native β‐cyclodextrin as well as three of its derivatives namely acetyl‐β‐cyclodextrin, 2‐hydroxypropyl‐β‐cyclodextrin, and carboxymethyl‐β‐cyclodextrin were used. The cathinone and pyrovalerone derivatives were either purchased in internet stores or seized by police. As a result, overall 58 of 61 studied substances were partially or baseline separated by at least one of the four chiral selectors using 10 mM of β‐cyclodextrin derivative in a 10 mM sodium phosphate buffer (pH 2.5). Furthermore, the method was found to be suitable for simultaneous enantioseparations, for enantiomeric purity checks and to differentiate between positional isomers. Moreover, an intra‐ and an interday validation was performed successfully for each chiral selector to prove the robustness of the method.