betadex and ethylenediamine

Herein, the fabrication of a fascinating multifunctional cyclodextrin (CD) chiral stationary phase and its chiral separation performance in capillary electrochromatography are proposed. A facile interfacial polymerization was used to anchor ethanediamine-β-cyclodextrin (EDA-β-CD) polymerized with trimesoyl chloride (TMC) and to form the chiral stationary phase (CSP) composite onto the surface wall of the capillary. The characters of prepared columns were confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray Photoelectron Spectrometer (XPS), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). This novel CSP offers multi-typical interactions including hydrogen bonding, π-interaction, hydrophobic and electrostatic interaction as well as steric effects which contribute to prominent chiral recognition for Dansyl-DL-amino acids in CEC modes. The EDA-β-CD modified column showed eminent enantioseparation performance towards five Dansyl-DL-amino acids (the DL-forms of valine, threonine, leucine, phenylalanine, serine). Besides, the prepared columns were perfectly reproducible and stable. The relative standard deviations of the enantiomer retention times for intra-day (n = 5), inter-day (n = 3) runs and column-to-columns (n = 3) are below 0.54%, 1.35% and 4.89%, individually. This innovative chiral stationary phase shows a broader application view and scope in chiral recognition domain.

Topics: Amino Acids; beta-Cyclodextrins; Capillary Electrochromatography; Dansyl Compounds; Ethylenediamines; Leucine; Phenylalanine; Reproducibility of Results; Spectroscopy, Fourier Transform Infrared; Stereoisomerism

Curcumin is a powerful scavenger of reactive oxygen species and could prevent the corneal cells from oxidative damage. However, the clinical efficacy of curcumin is limited by its low aqueous solubility and stability, leading to poor bioavailability. β-cyclodextrin, with a hydrophilic surface and a hydrophobic cavity and self-assembling properties, can form inclusion complexes with lipophilic drugs such as curcumin for ocular delivery. We synthesized ethylene diamine (EDA)-modified β-cyclodextrin and prepared the curcumin complexation using the solvent evaporation method. The EDA-β-cyclodextrin provided a better thermodynamic stability and higher complex yield for curcumin complexes, compared to β-cyclodextrin, which were demonstrated on the analysis of their van't Hoff plots and phase solubility diagrams. We characterized EDA-β-cyclodextrin curcumin nanoparticles and determined that the EDA modified β-cyclodextrin is a more suitable carrier than parental β-cyclodextrin, using FT-IR, XRD, TEM, and analyses of solubility and storage stability. In addition, the curcumin-EDA-β-cyclodextrin nanoparticles had better in vitro corneal penetration and 3 -h cumulative flux in a porcine cornea experiment, and displayed an improved biocompatibility, confirmed by the histological examination of porcine corneas and cell viability of bovine corneal epithelial cells. These results together revealed a role of EDA modification in the β-cyclodextrin carrier, including the improvement of curcumin complex formation, thermodynamic properties, cytotoxicity, and the in vitro corneal penetration. The EDA-β-cyclodextrin inclusion can provide curcumin a higher degree of aqueous solubility and corneal permeability.

Topics: Animals; beta-Cyclodextrins; Cornea; Curcumin; Drug Delivery Systems; Ethylenediamines; Nanoparticles; Particle Size; Solubility; Surface Properties; Swine

In order to investigate the effect of the linking spacer on the enantioseparation ability of β-cyclodextrin (β-CD) functionalized polymeric monoliths, three β-CD-functionalized organic polymeric monoliths with different spacer lengths were prepared by using three amino-β-CDs, i.e. mono-6-amino-6-deoxy-β-CD, mono-6-ethylenediamine-6-deoxy-β-CD, mono-6-hexamethylenediamine-6-deoxy-β-CD, as starting materials. These amino-β-CDs reacted with glycidyl methacrylate to produce functional monomers which were then copolymerized with ethylene dimethacrylate. The enantioseparation ability of the three monoliths was evaluated using 14 chiral acidic compounds, including mandelic acid derivatives, nonsteroidal anti-inflammatory drugs, N-derivatized amino acids, and chiral herbicides under optimum chromatographic conditions. Notably, the poly(GMA-NH2-β-CD-co-EDMA) column provides higher enantioresolution and enantioselectivity than the poly(GMA-EDA-β-CD-co-EDMA) and poly(GMA-HDA-β-CD-co-EDMA) columns for most tested chiral analytes. Furthermore, the enantioseparation performance of triazole-linker containing monoliths was compared to that of ethylenediamine-linker containing monoliths. The results indicate that the enantioselectivity of β-CD monolithic columns is strongly related to the length and type of spacer tethering β-CD to the polymeric support.

Topics: Amination; Amino Acids; Anti-Inflammatory Agents, Non-Steroidal; beta-Cyclodextrins; Chromatography, High Pressure Liquid; Epoxy Compounds; Ethylenediamines; Mandelic Acids; Methacrylates; Methylmethacrylates; Polymerization; Stereoisomerism; Triazoles

The peptide sequence PHSRN is the second cell binding site of the human fibronectin protein, a glycoprotein which plays a critical adhesive role during development, tissue repair and angiogenesis. The copper(II) complexes with the peptide fragment PHSRN were characterized by potentiometric and UV-visible, CD, EPR spectroscopic methods. Thermodynamic and spectroscopic evidences indicate that at physiological pH, only one copper(II) complex species, [CuLH(-2)], is present and the metal ion is bound to one imidazole and two amide nitrogen atoms (N(Im), 2N(-)) in a tetrahedral distorted square planar coordination. Two new β-cyclodextrin-ethylendiamino derivatives with the PHSRN covalently attached were synthesized as multitargeting molecules, able to have a site-specific recognition sequence, to interact with copper(II) ions and to be a potential carrier of hydrophobic drugs. Copper(II) complexes with these β-cyclodextrin derivatives were characterized by means of potentiometric and spectroscopic techniques. The comparison of the experimental parameters determined at different pH values with those obtained for the parent peptide complex species, shows that at physiological pH the ethylendiamino-β-CD moiety does not influence the peptide interaction with copper ions and the β-CD hydrophobic cavity is not blocked, being available to host hydrophobic drugs such as naproxen.

Topics: beta-Cyclodextrins; Binding Sites; Cations, Divalent; Circular Dichroism; Coordination Complexes; Copper; Drug Carriers; Electron Spin Resonance Spectroscopy; Ethylenediamines; Fibronectins; Humans; Hydrogen-Ion Concentration; Integrins; Ligands; Magnetic Resonance Spectroscopy; Naproxen; Oligopeptides; Protein Binding; Protein Structure, Tertiary; Spectrophotometry, Ultraviolet; Thermodynamics

A novel beta-cyclodextrin (beta-CD) functionalized organic polymer monolith was prepared by covalently bonding ethylenediamine-beta-CD (EDA-beta-CD) to poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (poly(GMA-co-EGDMA)) monolith via ring opening reaction of epoxy groups. SEM characterization was performed to confirm the homogeneity of the monolithic polymer. The resulting monolith was then characterized by DSC and XPS elemental analysis to study the thermal stability of the monolith, and to prove the successful immobilization of beta-CD on the polymer substrate. The beta-CD ligand density of 0.68 mmol g(-1) was obtained for the modified monolith, indicating the high reactivity and efficiency of the EDA-beta-CD modifier. The ethylenediamine-beta-CD functionalized monoliths were used for the chiral separation of ibuprofen racemic mixture and showed promising results.

Topics: beta-Cyclodextrins; Calorimetry, Differential Scanning; Chromatography, High Pressure Liquid; Ethylamines; Ethylene Glycols; Ethylenediamines; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; Ibuprofen; Methacrylates; Methanol; Microscopy, Electron, Scanning; Photoelectron Spectroscopy; Stereoisomerism

Two kinds of rhodamine modified beta-cyclodextrins (R-1 and R-2), which are coupled up ethylene diamine (EDA) and tetraethylene pentamine (TEPA) between Rh B and beta-cyclodextrin, respectively, have been synthesized. R-1 and 2 work as a new fluorogenic probe for monitoring pH of Hela cells, and MTT of assay R-1, R-2, and rhodamine B indicate that less a cytotoxicity of those R-1 and R-2 than that of rhodamine B, where R-1 has much less one than that of R-2. The fluorogenetic probe capability of R-2 was recognized in an area of acidic area in living cell, which is lysosome.

Topics: beta-Cyclodextrins; Cell Line, Tumor; Ethylenediamines; Fluorescent Dyes; HeLa Cells; Humans; Hydrogen-Ion Concentration; Microscopy, Fluorescence; Rhodamines

The goal of this study was to evaluate alternative salt forms of (SBE)7M-beta-CD (currently the sodium salt). The potential salt form would ideally decrease the rate of (SBE)7M-beta-CD release from osmotic pump formulations and result in an increase in the rate and extent of drug release in osmotic pump tablet and pellet dosage forms. Several (SBE)7M-beta-CD salt forms (potassium, calcium, and two ethylene diamine salt forms) were prepared by either titration or ultrafiltration and characterized by elemental analysis and capillary electrophoresis, CE. The physical properties (water uptake behavior, osmolality, complexation characteristics, etc.) were then compared to the sodium salt form. Although the water isotherm and the binding characteristics using various model drugs were similar among all the salt forms, the calcium salt form appeared to be the best alternative candidate due to its lower osmolality and slower intrinsic dissolution rate.

Topics: beta-Cyclodextrins; Calcium; Delayed-Action Preparations; Diffusion; Drug Delivery Systems; Ethylenediamines; Osmolar Concentration; Papaverine; Potassium; Prazosin; Prednisolone; Sodium; Solubility; Testosterone; Viscosity

The supramolecular interaction of beta-cyclodextrin dimer with berberine hydrochloride was studied in aqueous KH2PO4-H3PO4 buffer solution of pH 2.00 at room temperature by spectrofluorimetry. The apparent association constant of the complex was 1.53 x 10(4) L mol(-1). Based on the significant enhancement of fluorescence intensity of supramolecular sandwich complexes, a spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of berberine hydrochloride in aqueous solution in presence of ethylenediamine linked beta-CD dimer. The linear range of the method was 12.8-1.00 x 10(4 )ng mL(-1) with the detection limit 3.6 ng mL(-1). There was no interference from the normally used in tablets and serum constituents. The proposed method was successfully applied to the determination of berberine hydrochloride in tablets and serum. And then it has a promising potential in therapeutic drug monitoring, pharmacokinetics and clinical application.

Topics: Adult; Berberine; beta-Cyclodextrins; Ethylenediamines; Humans; Hydrogen-Ion Concentration; Male; Spectrometry, Fluorescence; Tablets; Temperature

A synthesis of beta-cyclodextrin (beta-CD) dimer, containing two beta-CD moieties that are linked through their sides by ethylenediamine, was presented. The dimer was characterized by means of IR, (1)H NMR, (13)C NMR, and elemental analysis. The inclusion complexation behavior of beta-cyclodextrin dimer with tranilast was studied in an aqueous KH(2)PO(4)-citric acid buffer solution of pH 2.00 at room temperature by spectrofluorimetry. Based on the significant enhancement of fluorescence intensity of tranilast, a spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of tranilast in bulk aqueous solution in the presence of ethylenediamine beta-CD dimer. The apparent association constant of the complex was 8.39 x 10(3) L mol(-1), and the linear range was 10.8-1.40 x 10(4) ng mL(-1) with the detection limit 3.2 ng mL(-1). There was no interference from the excipients normally used in tablets and serum constituents. The proposed method was successfully applied to the determination of tranilast in serum.

Topics: beta-Cyclodextrins; Carbon Isotopes; Cross-Linking Reagents; Dimerization; Ethylenediamines; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Molecular Structure; ortho-Aminobenzoates; Protons; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Fluorescence; Spectrophotometry, Infrared

The multivalent binding of a supramolecular complex at a multivalent host surface by combining the orthogonal beta-cyclodextrin (CD) host-guest and metal ion-ethylenediamine coordination motifs is described. As a heterotropic, divalent linker, an adamantyl-functionalized ethylenediamine derivative was used. This was complexed with Cu(II) or Ni(II). The binding of the complexes to a CD self-assembled monolayer (SAM) was studied as a function of pH by means of surface plasmon resonance (SPR) spectroscopy. A heterotropic, multivalent binding model at interfaces was used to quantify the multivalent enhancement at the surface. The Cu(II) complex showed divalent binding to the CD surface with an enhancement factor higher than 100 relative to the formation of the corresponding divalent complex in solution. Similar behavior was observed for the Ni(II) system. Although the Ni(II) system could potentially be trivalent, only divalent binding was observed at the CD SAMs, which was confirmed by desorption experiments.

Topics: beta-Cyclodextrins; Copper; Ethylenediamines; Hydrogen-Ion Concentration; Ligands; Macromolecular Substances; Models, Molecular; Nickel; Organometallic Compounds; Sensitivity and Specificity; Surface Plasmon Resonance; Surface Properties