A spectrofluorimetric study of binary fluorophore–cyclodextrin complexes used as chiral selectors

Chiral recognition and kinetic resolution of aromatic amines via supramolecular chiral nanocapsules in nonpolar solvents

Herein we report the first example of chiral recognition and kinetic resolution of aromatic amine guests using supramolecular nanocapsules assembled from cyclodextrin derivatives in nonpolar media. With these nanocapsules, an extremely high chiral recognition of 1-(1-naphthyl)ethylamine (1) in cyclohexane was achieved, with a binding selectivity of up to 41 for (S)-1 over (R)-1. In addition, kinetic resolution of 1 through enantioselective N-acylation was accomplished with an enantiomeric excess of up to 91%.

Self-assembled vesicles prepared from amphiphilic cyclodextrins as drug carriers

Controlled self-assembly of amphiphilic cyclodextrin is always a challenging topic in the field of supramolecular chemistry, since it provides the spontaneous generation of well-defined aggregation with functional host sites with great potential applications in drug-carrier systems. β-Cyclodextrin modified with an anthraquinone moiety (1) was successfully synthesized. In the aqueous solution, 1 was found able to self-assemble into vesicles, which was characterized in detail by TEM, SEM, EFM, and DLS. The formation mechanism of the vesicles was suggested based on the 2D ROESY and UV-vis results, and further verified by the MD simulation. Subsequently, the stimuli response property of the vesicles, including to Cu(2+) and H(+), was also studied. The vesicles can efficiently load Paclitaxel inside the membrane with functional macrocyclic cavities available, which can further carry small molecules, such as ferrocene. The vesicles loading with Paclitaxel have remarkable anticancer effects. This work will provide new strategy in drug-carrier systems and tumor treatment methods.

Enhanced chiral recognition by cyclodextrin dimers

In this article we investigate the effect of multivalency in chiral recognition. To this end, we measured the host-guest interaction of a β-cyclodextrin dimer with divalent chiral guests. We report the synthesis of carbohydrate-based water soluble chiral guests functionalized with two borneol, menthol, or isopinocampheol units in either (+) or (−) configuration. We determined the interaction of these divalent guests with a β-cyclodextrin dimer using isothermal titration calorimetry. It was found that—in spite of a highly unfavorable conformation—the cyclodextrin dimer binds to guest dimers with an increased enantioselectivity, which clearly reflects the effect of multivalency.