Allosteric Binding of Capsaicin by a Bis(β‐cyclodextrin)‐2,2′‐bipyridine Receptor

Abstract

A new β-cyclodextrin-based receptor that showed allosteric binding behavior towards capsaicin in aqueous solution was prepared. By NMR titration and nonlinear regression, we obtained binding constants, which increased more than fivefold when an effector (Zn(2+)) was bound to a central 2,2'-bipyridine that acts as the allosteric center.

(Nano)mechanical Motion Triggered by Metal Coordination: from Functional Devices to Networked Multicomponent Catalytic Machinery

“…4,4′-Disubstituted 2,2′-bipyridines are among the most common switchable motifs for allosteric receptors due to their ability to toggle between anti - and syn -conformations upon metal-ion binding . This conception has been widely popularized ever since Rebek and co-workers demonstrated its usefulness in impressive allosteric systems in 1979. − Later, many other research groups have further refined this approach. − …”

“…Lützen has highlighted the potential of coordination-induced conformational switching , for the allosteric encapsulation of nonpolar guests. For instance (Figure ), the two β-cyclodextrin units in anti - 159 , attached to the 4,4′-positions of the 2,2′-bipyridine subunit, adopted spatially separated positions in the open form but moved into close proximity through nanomechanical anti – syn rotation upon HETPHEN complexation with added [Zn­( 160 )] 2+ (closed form) . As a result, a preorganized environment was created for the effective encapsulation of capsaicin ( 161 ).…”

“…As a result, a preorganized environment was created for the effective encapsulation of capsaicin ( 161 ). The closed form had five times higher binding affinity toward capsaicin than the open form, and thus release was possible by removing zinc­(II) with EDTA …”

Efficient resolution of racemic crown-shaped cyclotriveratrylene derivatives and isolation and characterization of the intermediate saddle isomer

“…Due to our interest in dissymmetric [29–36] and concave molecular building blocks [37] and their implementation in supramolecular architectures like (allosteric) receptors [38–44] or metallosupramolecular helicates and cages [45–57] we were intrigued by the class of chiral CTVs. This is especially true for derivative 1 (Scheme 2) due to its interesting trifold substitution pattern with an almost orthogonal orientation of the functional groups which make it an ideal precursor for the synthesis of other elaborated derivatives [58–59] and the ease of a recently established large-scale synthesis reported by Rousseau and co-workers [60].…”

Synthesis of ethylamine-bridged β-cyclodextrins and adsorption properties of thorium

“…It is well-grounded that linking two cyclodextrin moieties with a short linker group greatly enhances the molecular binding ability of the original cyclodextrin through the cooperative binding of one guest molecule in the closely located two cyclodextrin cavities [9][10][11][12][13]. Hence, numerous bridged cyclodextrins with different structural materials have been synthesized, and applied to a variety of areas of science and technology such as molecular receptors [14,15], electrochemical sensors [16], drug carriers [17] and monomer of polymer [18] in the last years.…”