Geometric Isomerism of an Acetamidino Derivative Determined by NMR Investigations

Amidines, the nitrogen analogues of carboxylic acids, show interesting roles as pharmacophore groups in biologically active agents and in compounds of pharmaceutical interest. In the last years, our research group disclosed inhibitors of inducible and neuronal Nitric Oxide Synthase (iNOS and nNOS, respectively) containing the amidino moiety, with the aim to extend the study of the possible ligand-enzyme interactions. Here we discuss the synthesis and spectral studies of acetamidino derivative N-(2-(pyrrolidin-1-yl)ethyl)acetimidamidinium bromide, and how these studies led us to identification of a E/Z configurational change, which could be helpful in elucidating the ligand-enzyme interactions.