Antiproliferative Homoleptic and Heteroleptic Phosphino Silver(I) Complexes: Effect of Ligand Combination on Their Biological Mechanism of Action.

A series of neutral mixed-ligand [HB(pz)]Ag(PR) silver(I) complexes (PR = tertiary phosphine, [HB(pz)] = tris(pyrazolyl)borate anion), and the corresponding homoleptic [Ag(PR)]BF compounds have been synthesized and fully characterized. Silver compounds were screened for their antiproliferative activities against a wide panel of human cancer cells derived from solid tumors and endowed with different platinum drug sensitivity. Mixed-ligand complexes were generally more effective than the corresponding homoleptic derivatives, but the most active compounds were [HB(pz)]Ag(PPh) () and [Ag(PPh)]BF (), both comprising the lipophilic PPh phosphine ligand.