Artificial allosteric receptors for nucleotide bases and alkali-metal cations

Abstract

New allosteric thymine receptors, 2,6-diamidopyridine derivatives tethered to an anthracene ring by a polyoxyethylene chain, were synthesized. In these receptors, binding of 1-butylthymine was enhanced by a factor of 4-6 by recognition of sodium cations, and the changes in the electron density of the anthracene ring were found to have influence on the allosterism by through-space interaction. The anthracene-linked diamidopyridines represent a rationally designed new class of artificial allosteric receptors.

Podand‐Based Dimeric Chromium(III)–Salen Complex for Asymmetric Henry Reaction: Cooperative Catalysis Promoted by Complexation of Alkali Metal Ions

“…Meanwhile, signals of the aromatic protons on the phenyl groups that are linked to the polyether chain moved downfield, in a manner similar to that reported previously 5d. Furthermore, Nonlinear data fitting14 delivered the association constant K a =79±12 for binding a guest K + . This result is in accordance with the reported value 3a.…”

“…[5d] Furthermore, Nonlinear data fitting [14] delivered the association constant K a = 79 AE 12 for binding a guest K + . This result is in accordance with the reported value.…”

Artificial Allosteric Receptors

“…Compound 49 was introduced by Inouye and co-workers in 1993 and binds to nucleobases via hydrogen-bonding and p-stacking after activation with a sodium ion that coordinates to a podand-like oligoethylenglycol chain (Scheme 36, top). [89] Schneider, García-EspaÇa, and Luis and co-workers reported on negatively cooperative receptor 50 where a copper(II) ion serves as the effector that binds to an oligoethylene diamine chain. [90] Thereby, it orientates two p-conjugated moieties in a way that they cannot intercalate both into double-stranded DNA (Scheme 36, bottom).…”

“…Branda and co-workers then came up with a series of receptors (85-87) that showed negatively cooperative binding of copper(I) ions and organic substrates such as alkylated uracil (88) or barbiturates (89). [127][128][129] In all of these systems coordination of the copper(I) to two 2,2'-bipyridines causes the receptor to adopt a closed conformation in which the hydrogen bonding motifs are not accessible.…”

“…Since then two other receptors (Scheme ) have been developed that can interact with nucleobases or double‐stranded DNA upon activation with a cationic effector. Compound 49 was introduced by Inouye and co‐workers in 1993 and binds to nucleobases via hydrogen‐bonding and π‐stacking after activation with a sodium ion that coordinates to a podand‐like oligoethylenglycol chain (Scheme , top) 89…”