Ditopic crown ether – guanidinium ion receptors for the molecular recognition of amino acids and small peptides

Abstract

A series of ditopic synthetic receptors based on a crown ether-guanidinium ion recognition motif is reported. The compounds show binding affinity to selected amino acids, including important neuro-transmitters. The effect of the distance of the ammonium and the carboxylate ion, the rigidity of the spacer, and the use of pre-organized pyrrole- and pyrene-guanidinium groups on binding affinity and selectivity are discussed. (C) 2010 Elsevier Ltd. All rights reserved.