| Abstract
| - The cis- and trans-dichloro- and diiodo-platinum(II) complexes containing two acetonimines (cis- and trans-[PtX2{HNC(CH3)2}2], 1 and 2 for X = Cl and 1‘ and 2‘ for X = I, respectively) or one acetonimine andone ammine (cis- and trans-[PtX2(NH3){HNC(CH3)2}], 3 and 4 for X = Cl and 3‘ and 4‘ for X = I,respectively) have been prepared from platinum-ammine precursors by condensation with acetone. Exceptfor the cis-diiodo species, in all other cases the presence of a base was required. A crucial role of the ligandtrans to the ammine undergoing condensation with acetone has been disclosed: the greater the trans effectthe greater the reactivity. In a panel of human tumor cell lines representative of ovarian, colon, lung, andbreast cancers, cis complexes 1 and 3 are less active than cis-DDP (mean IC50 = 20, 12.5, and 2.8 μM,respectively), whereas trans complexes 2 and 4 are more active than trans-DDP (mean IC50 = 10.6, 26, and164 μM, respectively), thus indicating that substitution of acetonimine for one or two ammine ligandsdetermines strikingly different effects depending upon the complex geometry.
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