Design, Synthesis, and Biological Evaluation of Novel Potent and Selective α_vβ₃/α_vβ₅ Integrin Dual Inhibitors with Improved Bioavailability. Selection of the Molecular Core

A novel series of potent and selective α_vβ₃/α_vβ₅ dualinhibitors was designed, synthesized, and evaluated against several integrins. These compounds were synthesized through a Mitsunobu reaction between the guanidinium mimetics and the corresponding central templates. Guanidinium mimetics with enhaced rigidity (i.e., (2-pyridylamino)propoxy versus the 2-(6-methylamino-2-pyridyl)ethoxy) led to improved activity toward α_vβ₃. Exemplary oral bioavailability in mice was achieved using the indole central scaffold. Although, oral bioavailability was maintained when the indole molecular core was replace with the bioisosteric benzofuran or benzothiophene ring systems, it was found to not significantly impact the integrin activity or selectivity. However, the indole series displayed the best in vivo pharmacokinetic properties. Thus, the indole series was selected for further structure−activity relationships to obtain more potent α_vβ₃/α_vβ₅ dual antagonist with improved oral bioavailability.