betadex and tetrahydrofuran

An efficient artificial light-harvesting system is fabricated from a cyclic polysaccharide, sulfato-β-cyclodextrin (SCD); an aggregation-induced emission molecule, an oligo(phenylenevinylene) derivative (OPV-I); and a fluorescent dye, nile red (NiR), via noncovalent interactions in an aqueous solution. In this system, the OPV-I/SCD supramolecular assembly acts as a donor, and NiR that is loaded into the OPV-I/SCD assembly acts as an acceptor. Significantly, an efficient energy-transfer process occurs between the OPV-I/SCD assembly and the loaded NiR, leading to an extremely high antenna effect.

Topics: beta-Cyclodextrins; Biocompatible Materials; Fluorescence Resonance Energy Transfer; Fluorescent Dyes; Furans; Light; Oxazines; Polymers; Water

In this study, a label-free graphene-based fluorescence probe used for detection of volatile organic liquids was fabricated by a simple, efficient and low-cost method. To fabricate the probe, a bio-based β-cyclodextrin (β-CD) was firstly grafted on reduced graphene surfaces effectively and uniformly, as evidenced by various characterization techniques such as Ultraviolet/Visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The subsequent inclusion of Rhodamine B (RhB) into the inner cavities of the β-CD grafted on the graphene surfaces was achieved easily by a solution mixing method, which yielded the graphene-based fluorescent switch-on probe. In addition, the gradual and controllable quenching of RhB by Fluorescence Resonance Energy Transfer from RhB to graphene during the process of stepwise accommodation of the RhB molecules into the β-CD-functionalized graphene was investigated in depth. A wide range of organic solvents was examined using the as-fabricated fluorescence probe, which revealed the highest sensitivity to tetrahydrofuran with the detection limit of about 1.7 μg/mL. Some insight into the mechanism of the different responsive behaviors of the fluorescence sensor to the examined targets was also described.

Topics: beta-Cyclodextrins; Fluorescence; Fluorescence Resonance Energy Transfer; Furans; Graphite; Rhodamines; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction

Tetrahydrofuran (THF) has commonly been used to deliver carotenoids to cells but the use of THF is associated with cytotoxicity and low uptake efficiency of carotenoids. Here, we used fetal bovine serum (FBS) as the delivery vehicle for lycopene in comparison with THF, THF containing 0.0025 % butylated hydroxytoluene (THF/BHT), methyl-beta-cyclodextrin (M-beta-CD) and micelles in two human prostate cancer cell lines, DU145 and PC-3. Lycopene (10 mM) solubilized in THF/BHT and then diluted in FBS at ratios of 5 and 10 gave the highest lycopene uptake in DU145 cells. Using a dilution factor of 10, we found that lycopene (10 microm) carried in FBS in a cell-free system led to significantly less loss of lycopene than in THF, THF/BHT and M-beta-CD within 24 h of incubation. Lycopene solubilized in micelles was more stable than that in FBS within 24 h, but the micelle itself led to marked cytotoxicity to DU145 cells. Lycopene at 10 microm in FBS led to significantly higher uptake of lycopene in both cell lines than that in THF, THF/BHT or M-beta-CD within 24 h of incubation. When FBS was replaced with lipoprotein-deficient serum, the uptake of lycopene by DU145 cells was markedly decreased and was not significantly different from that of THF or THF/BHT. These results demonstrate that FBS is superior to THF, THF/BHT, M-beta-CD and micelles as a delivery vehicle for lycopene in prostate cell lines and that the lipoprotein of FBS is likely responsible for the improved stability and cellular uptake of lycopene.

Topics: Animals; Antioxidants; beta-Cyclodextrins; Butylated Hydroxytoluene; Carotenoids; Cattle; Cell Line, Tumor; Cell Survival; Cell-Free System; Cells, Cultured; Culture Media; Drug Stability; Fetal Blood; Furans; Humans; Lipoproteins; Lycopene; Micelles; Pharmaceutical Vehicles; Solvents

Enantiomers of (+/-) 5-[2 (R,S)-{[2-(o-ethoxyphenoxy) ethyl] amino} propyl]-2-methoxy-benzenesulfonamide (tamsulosin, drug frequently used in the treatment of prostate diseases) were separated by capillary electrophoresis (CE). An acidic background electrolyte (BGE) with sulfated-beta-cyclodextrin (S-beta-CD) was used to create a chiral separation environment. Baseline separation of the isomers was achieved during 5 min using cathodic electro-osmotic flow (EOF) (countercurrent mode). The quantification limits were 5.3 x 10(-6) moll(-1) for R-isomer and 5.7 x 10(-6) moll(-1) for S-isomer. The R.S.D. values of peak area were 0.54% for R-isomer and 0.75% for S-isomer. The results achieved enable determination of 0.5% of optical impurity.

Topics: Acetic Acid; Acetonitriles; Adrenergic alpha-Antagonists; beta-Cyclodextrins; Calibration; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Electrolytes; Electrophoresis; Electrophoresis, Capillary; Furans; Models, Chemical; Osmosis; Reproducibility of Results; Stereoisomerism; Sulfonamides; Sulfur; Tamsulosin; Time Factors

Simple co-lyophilization of serine protease subtilisin Carlsberg with [12]-crown ether-4 (12-crown-4) or methyl-beta-cyclodextrin (MbetaCD) drastically increases its catalytic activity in organic solvents. We investigated whether the improved activity would cause substrate diffusional limitations. To experimentally assess the issue, the enzyme was inactivated with PMSF. Different amounts of active and inactive subtilisin were codissolved in 10 mM phosphate buffer (pH 7.8) followed by lyophilization with or without 12-crown-4 or MbetaCD. Initial rates for the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester and 1-propanol in anhydrous THF were plotted vs. the amount of active enzyme present in the formulations. For all three enzyme formulations a linear relationship was observed and the results clearly show that activation of subtilisin Carlsberg by crown ethers and MbetaCD did not cause diffusional limitations. This was somewhat surprising because theoretical models predicted such diffusional limitations for the activated formulations. However, investigation of the protein powder particles obtained after co-lyophilization with 12-crown-4 and MbetaCD revealed a drastically reduced particle size for these formulations when suspended in THF. The particle micronization afforded by the excipients prevented substrate diffusional limitations, a factor that should be taken into account when designing improved enzyme formulations for synthetic applications in organic solvents.

Topics: beta-Cyclodextrins; Coenzymes; Computer Simulation; Crown Ethers; Cyclodextrins; Enzyme Activation; Enzyme Stability; Furans; Microscopy, Electron, Scanning; Models, Chemical; Particle Size; Serine Endopeptidases; Solutions; Solvents; Substrate Specificity; Subtilisins

The temperature influence on creation of a supramolecular complex in which beta-cyclodextrin (beta-CD) is the host molecule and phenolphtalein (PP) is the guest has been studied in aqueous solution by UV-visible absorption spectroscopy. The decrease of temperature of beta-cyclodextrin-phenolphtalein system resulted in a decrease in absorbance of the UV-vis spectrum. Under favourable conditions (0.1 mM beta-CD, 30 microM PP) the termochromic effect is very significant (approximately =0.1 U of absorbance/10 degrees C). The formation constant of inclusion complex was determined at various temperatures (from 10 to 70 degrees C) using Scott's equation. The association constants (K11) for the binding in 0.02 M sodium carbonate (pH 10.5) at 10 and 70 degrees C are 7.44 and 0.26 x 10(4) M(-1) respectively. The stoichiometric ratio of investigated complex was found to be 1:1 on wide range of beta-cyclodextrin:phenolphtalein concentration ratio (from 0.8:1 to 427:1). Additionally, strong interaction between cyclodextrin and tetrahydrofuran (THF) was observed and the inhibitory effect of tetrahydrofurane on the association of beta-CD PP complex was studied. From linear Van't Hoff plots thermodynamic parameters such as: the change of enthalpy (deltaH(o)) and change of entropy (deltaS(o)) were estimated and interpreted.

Topics: beta-Cyclodextrins; Cyclodextrins; Drug Interactions; Entropy; Furans; Phenolphthalein; Spectrum Analysis; Temperature; Thermodynamics

The retention of 17 propargylamine derivatives was determined on a beta-cyclodextrin polymer (beta-CDP)-coated silica column using tetrahydrofuran-0.05 M K2HPO4 (6:4, v/v) as eluent. The inclusion complex formation between the propargylamine derivatives and a water-soluble beta-CDP was studied by charge-transfer chromatography carried out on reversed-phase TLC layers. The capacity factors were correlated with the various measured and calculated physicochemical parameters of the solutes using principal component analysis followed by non-linear mapping, varimax rotation and cluster analysis. Calculations proved that the hydrophobicity and steric parameters have the highest influence on the retention of propargylamine derivatives. It has been established that each statistical method can be used for the evaluation of similar retention data matrices, however, the results can be slightly different according to the method applied.

Topics: beta-Cyclodextrins; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Cluster Analysis; Cyclodextrins; Furans; Molecular Structure; Monoamine Oxidase Inhibitors; Multivariate Analysis; Pargyline; Propylamines; Regression Analysis