Physico-chemical investigation of asymmetrical peptidolipidyl-cyclodextrins.

A new class of amphiphilic peptidolipidyl-cyclodextrins is reported. The derivatives are chiral due to the presence of an L-leucine in the spacer arm that links a saccharide moiety and a grafted, saturated hydrocarbon chain. Self-assembly properties of the peptidolipidyl-cyclodextrins are characterized by quasi-elastic light scattering, turbidity and UV-visible absorption measurements.

Inclusion complex of n-octyl beta-D-glucopyranoside and alpha-cyclodextrin in aqueous solutions: thermodynamic and structural characterization.

Complex formation between octyl beta-D-glucopyranoside (OG) and alpha-cyclodextrin (alphaCD) was investigated on the basis of three highly accurate and appropriate experimental techniques. First, surface tension measurements showed that alphaCD directly acts on the surfactant monomers in the aqueous phase, leading to progressive depletion of the air-water interface with increasing cyclodextrin contents. Significant shift of OG critical micelle concentration (cmc) was consequently observed: the higher alphaCD concentration, the higher the cmc value.

Self-assemblies of amphiphilic cyclodextrins.

Cyclodextrins are natural cyclic oligosaccharides widely used as "molecular cages" in the pharmaceutical, agrochemical, food and cosmetical industries. The optimization of their pharmacological properties has led to the synthesis of numerous analogues. Amphiphilic derivatives were designed to improve the cell targeting of the drug-containing cyclodextrin cavities through their transportation in the organism, within self-assembling systems.

Lipid lateral segregation driven by diacyl cyclodextrin interactions at the membrane surface.

Cyclodextrins are hydrophilic molecular cages with a hydrophobic interior allowing the inclusion of water-insoluble drugs. Amphiphilic cyclodextrins obtained by appending a hydrophobic anchor were designed to improve the cell targeting of the drug-containing cavities through their liposome transportation in the organism. After insertion in model membranes, they were found to induce a lateral phase separation into a pure lipid phase and a fluid cyclodextrin-rich phase (L(CD)) with reduced acyl chain order parameters, as observed with a derivative containing a cholesterol anchor (M.

The effect of cyclodextrins on the aqueous solubility of a new MMP inhibitor: phase solubility, 1 H-NMR spectroscopy and molecular modeling studies, preparation and stability study of nebulizable solutions.

Purpose: Ro 28-2653 (RO) is a synthetic inhibitor of matrix metalloproteinases (MMPs), which is potentially effective against bronchial remodeling. Given that this molecule has very poor aqueous solubility, different cyclodextrins (CDs) have been tested to increase its solubility. The aim of this study was to prepare and to characterize inclusion complexes between RO and CDs, in order to develop nebulizable solutions.

Hydration of black foam films made of amphiphilic cyclodextrins.

We investigate the interfacial behavior of a new type of amphiphilic cyclic oligosaccharide obtained by grafting a phospholipid onto a methylated cyclodextrin. These compounds are able to form stable black foam films, the structure of which can be determined using X-ray reflectivity. These films consist of a highly hydrated bilayer of modified cyclodextrins which are remarkably thick due to their abundant hydration core.

Ionic complexation properties of per(3,6-anhydro)cyclodextrin derivatives towards lanthanides.

Using per(3,6-anhydro)cyclodextrin derivatives [per(3,6-anhydro)CD], it was possible to produce new lanthanide chelates by careful choice of the size and functional groups. Heptakis(3,6-anhydro-2-O-methyl)cyclomaltoheptaose fulfils the best criteria for complexation of lanthanide ions. Nuclear magnetic resonance was used to derive the association constants and the stoichiometries of these new complexes.

Structural identification of new glycolipids based on cyclodextrin using high-resolution positive and negative electrospray ionization mass spectrometry.

In the continuing challenge to increase the performance of cyclodextrins (CDs) for various applications, new phospholipidyl-cyclodextrin derivatives showing improved self-organization properties in water have been synthesized, as new carriers for drug vectorization, starting from natural beta-cyclodextrin. Due to the important chemical modifications of the original cyclic oligosaccharide molecules, simple nuclear magnetic resonance (NMR) experiments do not easily lead to both an unambiguous assignment of the structures and to a rapid evaluation of the purity of the final products. However, positive and negative ion electrospray ionization (ESI-MS) in combination with accurate mass measurements and tandem mass spectrometry (MS/MS) led to the positive structural identification of the first series of these new amphiphilic compounds.

A sensitive and specific enzyme immunoassay for the detection of methyl ether derivatives of cyclomaltoheptaose.

We have raised antibodies against two methylated derivatives of beta-CD, heptakis(2,6-di-O-methyl)cyclomaltoheptaose (Dimeb) and heptakis(2,3,6-tri-O-methyl)cyclomaltoheptaose (Trimeb). These antibodies were used to develop two specific and sensitive enzyme immunoassays, presenting a detection limit close to 500 and 30 pg/mL for Trimeb and Dimeb, respectively. Cross reactivities of different linear and cyclic maltooligosaccharides were investigated, demonstrating a high specificity against the structural features of the secondary hydroxyls rim.

Direct investigation of the vectorization properties of amphiphilic cyclodextrins in phospholipid films.

Recently, new cyclodextrin derivatives were synthesized and shown to exhibit strong amphiphilic properties. In this paper, we study the action of these new amphiphilic cyclodextrins on phospholipids. Mixed phospholipid/cyclodextrin derivative films were prepared and studied using X-ray reflectivity for various phospholipid/cyclodextrin ratios.

Beta-anomeric selectivity in the glycosidation of D-mannofuranurono-6,3-lactone catalyzed by boron trifluoride diethyl etherate.

The BF3-promoted glycosylation of D-mannofuranurono-6,3-lactone with dodecanol or methanol afforded n-alkyl beta-D-mannofuranosidurono-6,3-lactone. Reduction of n-dodecyl beta-D-mannofuranosidurono-6,3-lactone with sodium borohydride yielded the corresponding alkyl beta-D-mannofuranoside.

Cyclodextrin-induced lipid lateral separation in DMPC membranes: (2)H nuclear magnetic resonance study.

Cholesteryl cyclodextrins, obtained by grafting a cholesterol moiety on the oligosaccharide core, combine the size selectivity of the cyclodextrin cavity with the carrier properties of model membrane systems such as micelles or liposomes. The cholesteryl cyclodextrins were incorporated as guests in chain perdeuterated dimyristoyl phosphatidylcholine (DMPC-d54) membranes. The deuterium nuclear magnetic resonance (NMR) spectra obtained with the A form of cholesteryl-beta-cyclodextrin (beta CC(A)), with a succinyl spacer inserted between the cholesterol moiety and the cyclodextrin headgroup, indicated that this compound induces a lateral phase separation of DMPC-d54, into a pure lipid phase and a cholesteryl cyclodextrin-rich phase.