The antitumor activity of some palladium(II) complexes with chelating ligands.

A range of palladium(II) complexes with chelating ligands were assayed for their antitumor activity against the tumors P388 and S180 in female mice. The complexes tested were [Pd(L)(ONO2)2] (L = 2,2'-bipyridyl,2-(aminoethyl)pyridine (aep), 2-(aminomethyl)pyridine (amp], [Pd(eth)Cl2] (eth = ethionine) and [Pd(dach)(Meorot)] (dach = trans-1,2-diaminocyclohexane, Meorot = dianion of 3-methylorotic acid). The complexes were administered in water except [Pd(dach)(Meorot)] which was a suspension in klucel. The LD0 values were greater than or equal to 100 mg/kg. None of the complexes were active against the P388 tumor. [Pd(L)ONO2)2] (L = aep, amp) showed marginal activity against S180, while [Pd(dach-)(Meorot)] had an optimal T/C of 267% at dose of 150 mg/kg with 2/10 survivors on day 60.