Selectivity of New β-Cyclodextrin Derivatives as CGC Stationary Phases and Application for the Analysis of Volatile Compounds in Traditional Chinese Medicines

New cyclodextrin derivatives （CDs）, heptakis（2, 6-di- O-methyl-3- O-methoxymethyl）-β-CD （ Ⅰ ） and heptakis（2, 3, 6-tri-O-methoxymethyl）-β-CD （ Ⅱ ）, were investigated for their chromatographic performance as stationary phases for capillary gas chromatography （CGC）. Both of the CDs exhibited good selectivity and satisfactory separation for test mixtures and aromatic positional isomers, and volatile compounds from Ligusticurn chuanxiong Hort. Additionally, the selectivity and elution orders of major compounds were compared with a well-recognized commercial column on the basis of the results by gas chromatography-mass spectrometry （GC-MS）. The present work demonstrates the good selectivity of the two new CDs and can be used as GC stationary phases for the separation of positional isomers and analytes in complex samples.

Determination Enantiomer Excess(e.e.%)of Chiral Sharpless Epoxides with β-Cyclodextrin Derivatives as Chiral Stationary Phases of Capillary Gas Chromatography

Using four β-cyclodextrin derivatives, 2,6-di-O-benzyl-3-O-heptanonyl-β-CD, 2,6-di- O-benzyl-3-O-octanonyl-β-CD, 2,3-di-O-benzyl-6-O-heptanonyl-β-CD, and 2,3-di-O-benzyl -6-O- octanonyl-β-CD, as chiral stationary phases of capillary gas chromatography （CGC）, the enantiomers of Sharpless epoxides were well separated. The enantiomer excess values （e.e.%） of some chiral Sharpless epoxides were also determined successfully using these CDs.

A Study on the Driving Force for Binding of Benzene Derivatives by α-and β-Cyclodextrin

A three-dimensional diagram shows that the association constants (Ka) for the inclusionof a- and 6-CD with substitUted benzene are mainly correIated with the molar refraction (R.) andhydrophobic constant (%) of the substitUents of guest compounds. It reveals that the inclusion ofcyclodextrin with the substitUted benzene is dondnantly driYen by van der Waals forces andhydrophobic interactions.

The Enantiomer Separations of Allethrone and Propargyllone Using Two Long Chain Acylated b-Cyclodextrin Derivatives as CGC Capillary Stationary Phases

Using two b-cyclodextrin derivatives (CDs) with long chain of acyl groups as chiral stationary phases (CSPs) of capillary gas chromatography (CGC), the enantiomers of racemic allethrone and propargyllone were well resolved after derived with acetyl chloride. The enantiomer excess values (e.e.%) of 1S-allethrone and 1S-propargyllone were also determined successfully using these CDs.

SYNTHESIS AND CHARACTERIZATION OF NOVEL MULTIFUNCTIONAL HOST COMPOUNDS.1.β-CYCLODEXTRIN DERIVATIVE BEARING DIETHANOLAMINE MOIETY

A novel β-cyclodextrin(β-CD)derivative bearing diethanolamine moiety was synthesized by a convenient method with 63% yield,and the new host compound was characterized by (13)~C-NMR,FT-IR spectra etc,

Synthesis of Amino Acid Derived β-Cyclodextrins Used in Chiral Separation by Capillary Electrophoresis

Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis{2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-(hydroxy) propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis{2,6-di-O-[3-L-(1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis{2,6-di-O-[3-(L-1-hydroxymethyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl amino)- 2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetramethylene amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD). Their chemical structures were certified using FTIR and ()~1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD, that are in soluble in water, the other amino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.

Gas Chromatographic Enantiomer Separation of Cyclopropane Derivatives on Three 2, 6-Di-O-allyl-3-O-acylated-β- cyclodextrins Chiral Stationary Phases

Eight pairs of enantiomers of cyclopropane derivatives were resolved on capillary gas chromatographic columns using three new 2, 6-di-O-allyl-3-O-acylated-β-cyclodextrins as chiral stationary phases. It was found that the three β-CDs can separate some of the racemic cyclopropane derivatives well.

Synthesis of Methylated β-Cyclodextrins Derived Optically Active Poly(N-diphenylmethyl maleimide)

The methylated β-cyclodextrins derived optically active polymers are firs synthesized through asymmetric polymerization of N-diphenylmethyl maleimide with lithium salt of heptakis(2,6-O-dimethyl) β-cyclodextrin (DM-β-CD) as an initiator. The resulting polymers show negative specific rotation which is opposite in sign to that of DM-β-CD. The asymmetric induction is further confirmed by circular dichroism. The structure is characterized by IR and NMR spectroscopies

A NOVEL DERIVATIVE OF β-CYCLODEXTRIN AS CHIRAL SIATIONARY PHASE IN CAPILLARY GAS CHROMATOGRAPHY

A novel β-cyclodextrin derivative, 2, 6-di-O-butyl-3-O-acetyl-β-cyclodex- trin, was prepared and used as chiral stationary phase for capillary gas chromato- graphic resolution of enantiomers, lhe glass capillary columns with the derivative having low melting point and high thermal stability could produce more than 3000 plates per column meter and have proven to be good chlral columns to separate the enantiomers of some amino acids, derivatives of epoxy ethane and alkyl halide, etc.

Preparation and chiral recognitio of a novel chiral stationary phase for HPLC,based on mono(6~A-N-1-(2-hydroxyl)-phenylethylimino-6~A-deoxy)-β-cyclodextrin and covalently bonded silica gel

A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary phase exhibited good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.

Inclusion Complexation of β-CD with Phenothiazine and N-Alkylphenothiazine Derivatives

Inclusion of Acyclodextrin (ACD) with phenothiazine 1 and Nalkylpheno-thiazine derivatives (alkyl = ethyl 2, isobutyl 3 and isopentyl 4) in aqueous solution was studied by means of UV-vis spectroscopy. The association constant Ka values for the inclusion of β-CD with 1, 2, 3 and 4 were determined to be 188, 214, 129 and 80 L/mol, respectively. It indicates that the stability of the inclusion complexes is dependent on the structure and the volume of the substituents in the guest compounds.

Synthesis of Crown Ether-tethered b-Cyclodextrin and Fabrication of Its Self-assembled Monolayer on Gold Surface

A novel b-cyclodextrin derivative 6 bearing a crown ether moiety has been synthesized by a convenient method in 9.4% yield. Its self-assembled monolayer (SAM) was fabricated on the gold surface, which was characterized by using surface-enhanced Raman spectra.

Inclusion behavior of oxybutynin with hydroxypropyl-β-cyclodextrin

Inclusion behavior of oxybutynin (OBN) with hydroxypropyl-β-cyclodextrin (HP-β-CD) was investigated by ultraviolet absorption spectrum and fluorescence spectrum. A reliable determination of the complex stoichiometry was provided by the continuous variation technique. Alcohol was added to further investigate the mechanism of the inclusion behavior. Thermodynamic constants ΔG, ΔH and ΔS for inclusion interaction of OBN and HP-β-CD were determined. The results show that host-guest complex with molar ratio of 1-1 is formed, and inclusion stability constant between OBN and HP-β-CD is 54.9 L/mol determined by ultraviolet spectrum and 11.1 L/mol determined by fluorescence spectrum. OBN has weak binding ability with HP-β-CD in aqueous solution (stability constant <102 L/mol) and addition of alcohol leads to a decrease of stability constant, which indicates that the hydrophobic force contributes to the inclusion process. ΔG, ΔH and ΔS are all less than zero, which indicates that the inclusion process is a spontaneous and exothermic process.

Alkylated and silylated β-cyclodextrin for gas chromatographic chiral stationary phases

Three new chiral stationary phases, 2,6 di O heptyl 3 O trimethylsilyl β cyclodextrin(DHTBCD), 2,6 di O pentyl 3 O trimethylsilyl β cyclodextrin (DPTBCD) and 2,6 di O butyl 3 O trimethylsilyl β cyclodextrin (DBTBCD), were synthesized. Chromatographic properties such as column efficiency, thermal stability and column life span, were studied. The separations of enantiomers, such as ketone, esters, alcohols and olefines, were investigated on the alkylated and silylated β cyclodextrin stationary phases. The influence of diluent on chiral separation was studied. The experimental results indicate that the stationary phases show good chromatographic properties in separating enantiomers. It is observed that inclusion complexation and hydrogen bonding interaction hardly play a role in separating enantiomers.

高效液相色谱法测定α-环糊精的对甲苯磺酰化产物

单对甲苯磺酰-α-环糊精酯(mono-OTs-α-CD)是制备其他α-CD单衍生物的重要中间体。建立了一种测定α-环糊精对甲苯磺酰化反应产物的液相色谱新方法。3种不同碳位上(C3、C2和C6)的(mono-OTs-α-CD)在ODS柱上被完全分离,保留时间依次为7.70、10.08和12.18 min。它们在5~500 mg·L^(-1)范围内的线性回归方程分别为y=89.176 x-559.19(R^(2)=0.9990),y=87.917 x-430.16(R^(2)=0.9996)和y=70.529 x-24.259(R^(2)=0.9992),回收率为92.5%~102.3%,RSDs小于1.8%,检出限(LOD)较低(0.5 mg·L^(-1)),说明该方法的准确性和精密度较好,能满足反应监测要求。初步考察了原料投料比、反应温度、反应时间和反应体系酸碱度对单取代反应的影响,在优化的反应条件(投料比为1:2,反应温度为15℃,反应时间为15 min)下,C3位上的mono-OTs-α-CD产率可达34.84%(n=3)。

Binding properties of amino-modified βb-cyclodextrin derivativeswith 1- and 2-naphthols

Study of molecular recognition has been playing an important role in biomimeticchemistry. β-cyclodextrin (β-CD), the cyclic heptamer of glucopyranose, can form inclusioncomplexes with various types of organic compounds (substrates) through its

β-Cyclodextrin and Its Derivatives Functionalized Magnetic Nanoparticles for Targeting Delivery of Curcumin and Cell Imaging

β-Cyclodextrin （β-CD） and its derivatives functionalized magnetic nanoparticles （MNPs） with high saturated magnetism were fabricated successfully by an effective grafting method. The resultant carboxymethyl/hydroxy- propyl/sulfobutyl ether-β-CD-MNPs （CM/HP/SBE-β-CD-MNPs） nanocomposites were characterized by the TEM, FTIR, DLS, Zeta potential, XRD and VSM. In addition, the loading and release performance of the as-prepared nanocarriers for the hydrophobic anti-cancer drug curcumin was also investigated. The results revealed that the SBE-fl-CD-MNPs possessed the highest loading and release capacity in comparison with other two nanosystems. Cellular uptake and imaging suggested that the SBE-β-CD-MNPs entered into the cell, and curcumin could be suc-cessfully delivered into the cell by SBE-β-CD-MNPs nanocarrier. Moreover, cell toxicity experiments demonstrated the SBE-β-CD-MNPs were non-toxic, while curcumin loaded SBE-β-CD-MNPs showed high potential to kill the HepG2 cells. The as-prepared magnetic composites were expected to expand their potential applications in bio- medical field.

Selective binding of bile salts by β-cyclodextrin derivatives with appended quinolyl arms

Two β-cyclodextrin derivatives bearing appended quinolyl and isoquinolyl arms,i.e.mono-（6-quinolyl- 6-deoxy）-β-cyclodextrin（1） and mono-（6-isoquinolyl-6-deoxy）-β-cyclodextrin（2） were synthesized in satisfactory yields and fully characterized.Their original conformations and binding behaviors toward four bile salt guests,that is,sodium cholate（CA）,sodium deoxycholate（DCA）,sodium glycocholate （GCA）,and sodium taurocholate（TCA）,were investigated by means of fluorescence,circular dichroism and 2D NMR spectroscopy.The study of solution structures revealed that both quinolyl and isoquinolyl arms were located outside the cyclodextrin cavity.The results obtained from the fluorescence titrations showed that the binding abilities of hosts 1 and 2 with selected bile salts varied in an order of DCA 〉 CA 〉 GCA.The selective binding of hosts toward bile salt guests was discussed from the viewpoints of induced-fit and multiple binding.

Novel nanoparticles composed of chitosan and β-cyclodextrin derivatives as potential insoluble drug carrier

This research was aim to develop novel cyclodextrin/chitosan （CD/CS） nanocarriers for insoluble drug delivery through the mild ionic gelation method previously developed by our lab. A series of different β- cyclodextrin （β-CD） derivatives were incorporated into CS nanoparticles including hydroxypropyl-β- cyclodextrin （HP-β-CD）, sulphobutylether-β-cyclodextrin （SB-β-CD）, and 2,6-di-O-methy-βcyclodex- trin （DM-β-CD）. Various process parameters for nanoparticle preparation and their effects on physicochemical properties of CD/CS nanoparticles were investigated, such as the type of CD derivatives, CD and CS concentrations, the mass ratio of CS to TPP （CS/TRP）, and pH values. In the optimal condition, CDICS nanoparticles were obtained in the size range of 215-276 nm and with the zeta potential from 30.22 mV to 35.79 mY. Moreover, the stability study showed that the incorporation of CD rendered the CD/CS nanocarriers more stable than CS nanoparticles in PBS buffer at pH 6.8. For their easy preparation and adjustable parameters in nanoparticle formation as well as the diversified hydrophobic core of CD derivatives, the novel CD/CS nanoparticles developed herein might represent an interesting and versatile drug delivery platform for a variety of poorly water-soluble drugs with different physicochemical properties.

Sulfoalkyl ether β-cyclodextrin derivatives synthesized by a single step method as pharmaceutical biomaterials

We report a simple "one pot" single step method to synthesize sulfoalkyl ether β-cyclodextrin (β-CD) derivatives in aqueous solution, which avoids the limitations associated with commonly used organic synthesis of such derivatives including multi-step reactions, use of expensive, toxic, and often environmentally hazardous organic solvents and/or reagents. Using this method, we obtained sulfopropyl and sulfobutyl ethyl β-CDs. We characterized these two derivatives and evaluated their ability to enhance solubility of fluconazole, a commonly used antifungal drug with poor water solubility. Experimental results indicate that these derivatives are structurally analogous to some of the commercially available β-CD derivatives. More importantly, when they formed supramolecular inclusion complexes with fluconazole, they demonstrated similar, if not better, capacity to enhance fluconazole solubility compared with commercially available β-CD derivatives, suggesting that the simple "one pot" single step synthesis may provide an effective alternative approach to produce large quantity of β-CD derivatives as pharmaceutical biomaterials for medicinal applications.