Recent developments of amidine-like compounds as selective NOS inhibitors

The first generation of Nitric Oxide Synthases inhibitors was synthesized in the late 1980’s and early 1990’s; they were mainly amino acid derivatives, binding to the same residues within the enzyme heme-active site with respect to the natural substrate L-Arg, and showed no or scarce selectivity. In 1994, the N-(3-(aminomethyl)-benzyl) acetamidine (1400W), a highly selective compound for human iNOS versus both human eNOS and nNOS, was discovered. Following this landmark discover several other amidine-based iNOS and nNOS selective inhibitors have been disclosed. In this review we will focus on the recent progress and perspectives in the development of amidine-based selective iNOS and nNOS, including close analogues, with particular attention to acetamidine and aminopyridine derivatives.