Fitzmaurice Richard J, Gaggini Francesca, Srinivasan Natarajan, Kilburn Jeremy D
School of Chemistry, University of Southampton, Southampton, UK SO17 1BJ.
Org Biomol Chem. 2007 Jun 7;5(11):1706-14. doi: 10.1039/b700988g. Epub 2007 Apr 25.
A series of thiourea and guanidinium derivatives have been prepared and their ability to bind a carboxylate group has been investigated. Guanidinium 33, featuring two additional amides and a pyridine moiety, proved to be the most potent carboxylate binding site and was able to bind acetate in aqueous solvent systems (K(ass) = 480 M(-1) in 30% H(2)O-DMSO). The pyridine moiety is critical to obtaining strong binding, and comparison with the binding properties of analogous compounds in which the pyridine is replaced by a benzene ring provides a striking example of enthalpy-entropy compensation.
