Anion Transport by Bambusuril-Bile Acid Conjugates: Drastic Effect of the Cholesterol Content.

Artificial anion transporters offer a potential way to treat deficiencies in cellular anion transport of genetic origins. In contrast to the large variety of mobile anion carriers and self-assembled anion channels reported, unimolecular anion channels are less investigated. Herein, we present a unique example of a unimolecular anion channel based on a bambusuril (BU) macrocycle, a well-established anion receptor.

Tuning CH Hydrogen Bond-Based Receptors toward Picomolar Anion Affinity via the Inductive Effect of Distant Substituents.

Inspired by nature, artificial hydrogen bond-based anion receptors have been developed to achieve high anion selectivity; however, their binding affinity is usually low. The potency of these receptors is usually increased by the introduction of aryl substituents, which withdraw electrons from their binding site through the resonance effect. Here, we show that the polarization of the C(sp )-H binding site of bambusuril receptors, and thus their potency to bind anions, can be modulated by the inductive effect.

Transmembrane transport of fluoride studied by time-resolved emission spectroscopy.

Here we present a new method to monitor fluoride transmembrane transport into liposomes using a europium(III) complex. We take advantage of the long emission lifetime of this probe to measure the transport activity of a fluorescent transporter. The high sensitivity, selectivity, and versatility of the assay allowed us to study different types of fluoride transporters and unravel their mechanisms of action.

Monofunctionalized Fluorinated Bambusurils and Their Conjugates for Anion Transport and Extraction.

Bambusurils are macrocyclic molecules that are known for their high binding affinity and selectivity toward anions. Here, we present the preparation of two bambusurils bearing fluorinated substituents and one carboxylic function. These monofunctionalized bambusurils were conjugated with crown ether and cholesterol units.

Reductant-Induced Free Radical Fluoroalkylation of Nitrogen Heterocycles and Innate Aromatic Amino Acid Residues in Peptides and Proteins.

A series of fluoroalkylated cyclic λ -iodanes and their hydrochloride salts was prepared and used in a combination with sodium ascorbate in buffer or aqueous methanol mixtures for radical fluoroalkylation of a range of substituted indoles, pyrroles, tryptophan or its derivatives, and Trp residues in peptides. As demonstrated on several peptides, the aromatic amino acid residues of Trp, Tyr, Phe, and His are targeted with high selectivity to Trp. The functionalization method is biocompatible, mild, rapid, and transition-metal-free.