[Synthesis and binding characteristics of an artificial receptor for biogenic amines]

The synthesis of a ditopic linear receptor 3 consisting of an azacrown ether moiety for binding prim. ammonium functions and a macrotricyclic tetrahedral moiety for binding hydrophobic guest species is described. The covalent interconnection of these subunits was supposed to constitute a receptor with enhanced specificity towards dopamine-type biogenic amines. Host-guest complexation was studied in a competition method with potassium ion using ion selective electrodes. The binding features of 3 with a series of biogenic amines reveal that neither the absolute binding strength nor the selectivity is enhanced in relation to the monotopic receptor 4. It is concluded that 3 does not simultaneously utilize both receptor subunits in binding the biogenic amine substrates.