Search results for "Inclusion compound"
showing 10 items of 45 documents
Binding properties of mono-(6-deoxy-6-amino)-β-cyclodextrin towards p-nitroaniline derivatives: a polarimetric study
2009
Abstract Polarimetry was used in order to investigate the formation of supramolecular complexes between mono-6-amino-β-cyclodextrin and various p-nitroaniline derivatives at two different pH values. Comparison with the behaviour of native β-cyclodextrin gave us the opportunity to consider the effect exerted by the presence of charged groups, having different solvation requirements, on the binding equilibrium. Data offer some support to the hypothesis of ‘dynamic co-inclusion’ of solvent molecules within the host–guest complex.
Synthesis of a Fullerene Derivative of Benzo[18]crown-6 byDiels-Alder Reaction: Complexation Ability, Amphiphilic Properties, and X-Ray Crystal Struc…
1993
A fullerene derivative 1 of benzo[18]crown-6 was obtained by Diels-Alder addition of fullerene[60](C60) to the ortho-quinodimethane prepared in situ from 4,5-bis(bromomethyl)benzo[18]crown-6 (3) with Bu4NI in toluene. Extraction experiments show that the complexation of K+ ions strongly increases the solubility of 1 in protic solvents like MeOH. Using Langmuir-Blodgett techniques, monolayers of the highly amphiphilic fullerene-derived crown ether 1 and its K+ ion complex were prepared. An X-ray crystal structure was obtained from a benzene clathrate of comparison compound 2, synthesized by Diels-Alder reaction of C60 with the ortho-quinodimethane derived from 1,2-bis(bromomethyl)-4,5-dimeth…
A Hybrid Cavitand Made by Capping Permethylated α-Cyclodextrin with Cyclotriveratrylene
2012
A hybrid C 3 -symmetric cavitand 1, in which permethylated α-cyclodextrin (PM α-CDX) is capped with cyclotriveratrylene (CTV), has been prepared in 8 % yield by intramolecular cyclization of a vanillyl alcohol derivative attached to the primary rim of the CDX platform. The reaction proceeds diastereoselectively (dr ≈ 6:1), the chirality of the α-glucopyranosyl units controlling the chirality of the CTV component. Interestingly, in polar solvents, 1 shows self-complexation properties as the primary methoxy groups of the CDX component are directed towards the CTV cavity.
Kinetics of Molecule Transfer between Lipid Vesicles and β-Cyclodextrins
1996
Abstract We propose a calorimetric method based on the van't Hoff model of depression of the freezing temperature to investigate slow kinetics involving lipid vesicles (liposomes) and drug–β-cyclodextrin (Cyd) complexes. Some nonsteroidal antiinflammatory drugs (NSAIDs) were examined and standard phospholipid liposomes were used in our experiments. Three different kinetic processes were investigated: (a)9Transfer of drugs from water-soluble Cyd-complexes to void liposomes. (b)9Uptake of drugs from the surface of liposomes by free Cyd dissolved in the aqueous phase. (c)9Exchange of drugs from loaded to void vesicles, and the effect of free Cyd in enhancing such a transfer. Most experiments w…
Aggregation in aqueous media of tri-block copolymers tuned by the molecular selectivity of cyclodextrins
2009
The water + cyclodextrin + poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) mixtures have been investigated to explore the temperature effect on the aggregation of the copolymer in the presence of cyclodextrins (CDs). The CDs with different cavity sizes were chosen because they may include either the hydrophilic poly(ethylene oxides) block or both kinds of blocks. The differential scanning calorimetry and viscosity experiments straightforwardly evidenced that the critical micellar temperature is shifted to larger values by adding a CD which is able to include the middle poly(propylene oxide) block while it is not influenced by the presence of CD which is selective to the poly…
Cyclodextrins in polymer synthesis: free radical polymerization of cyclodextrin complexes with oxazoline-functionalized vinyl monomers as guest molec…
2000
The synthesis of five new oxazoline functionalized vinyl monomers N-[4-(4′,5′-dihydrooxazol-2-yl)phenyl]acrylamide (3 a), N-[4-(4′,5′-dihydrooxazol-2-yl)phenyl]-2-methylacrylamide (3 b), N-{10-[4-(4′,5′-dihydrooxazol-2-yl)phenylcarbamoyl]decyl}-2-acrylamide (5 a), N-{10-[4-(4′,5′-dihydrooxazol-2-yl)phenylcarbamoyl]decyl}-2-methylacrylamide (5 b) and N-[4-(4′,5′-dihydrooxazol-2-yl)-phenyl]-4-vinylbenzamide (7) is described. With an equimolar amount of 2,6-dimethyl-β-cyclodextrin (DMCD) these monomers formed hydrophilic inclusion complexes 3 a,b-DMCD, 5 a,b-DMCD and 7-DMCD. These complexes were polymerized radically in an aqueous medium. Resulting polymers P-(3 a, b), P-(5 a, b) and P-(7) pre…
Cyclodextrins in Polymer Synthesis: Free Radical Copolymerization of Methylated β-Cyclodextrin Complexes of Hydrophobic Monomers with N-Isopropylacr…
2000
Methylated β-cyclodextrin (me-β-CD) was used to form water-soluble host/guest complexes with the hydrophobic monomers n-butyl methacrylate (1), cyclohexyl methacrylate (2), isobornyl acrylate (3), isobornyl methacrylate (4), and styrene (5), respectively. The free-radical copolymerizations of the water-soluble N-isopropylacrylamide (NIPAAm) with these complexed monomers were carried out in water at different molar ratios.
Cyclodextrins in polymer synthesis: Free radical polymerization of methylated β-cyclodextrin complexes of methyl methacrylate and styrene, controlled…
2000
Methylated β-cyclodextrin (me-β-CD) was used to complex the hydrophobic monomers methyl methacrylate (1) or styrene (2) yielding the water-soluble 1 : 1-host/guest complexes methyl methacrylate/me-β-CD (1 a) and styrene/me-β-CD (2 a), respectively. In addition, the hydrophobic chain-transfer agent dodecanethiol (3) was complexed by two equivalents of me-β-CD yielding the water-soluble dodecanethiol/me-β-CD (3 a). The included monomers were polymerized in water by a free-radical mechanism in the presence of 3 a as the chain-transfer agent. The chain-transfer constants were determined. In order to evaluate these results, the chain-transfer constants of 3 were also determined in the case of th…
Supramolecular Nanocycles Comprisingβ-Cyclodextrin-click-Ferrocene Units: Rings of Rings of Rings
2010
We applied 1,3-dipolar cycloaddition to bind ethynylferrocene onto 6I-azido-6I-deoxycyclomaltoheptaose under microwave assisted conditions. The process was investigated by (1) H NMR, FT-IR spectroscopy, and MALDI-TOF mass spectrometry. The ability of the synthesized compound to self-organize to cyclic supramolecular structures was investigated by dynamic light scattering measurements and cryo-transmission electron microscopy.
Synthesis and characterisation of novel chemical conjugates based on alpha, beta-polyaspartylhydrazide and beta-cyclodextrins
2006
A new family of supramolecular systems based on a synthetic polyaminoacid and cyclic oligosaccharides such as beta-cyclodextrins (beta-CDs) was synthesised. The pharmaceutical potential of these systems arises from the proper combination between the complexing properties of cyclodextrins and the particular pharmacokinetic profile that can be obtained by using macromolecular conjugates with a biocompatible backbone. Five supramolecular conjugates were synthesised by using alpha,beta-polyaspartylhydrazide (PAHy) as a polymeric component and various amounts of two P-CD derivatives. In particular, by reaction of PAHy with beta-CD monoaldehyde, samples named as A(1), A(2) and A(3), bearing, resp…