Synthesis and antitumor properties of new platinum(IV) complexes with aminonitroxyl radicals (original) (raw)

Acylation of cis,trans,cis Pt IV (RNH 2)(NH 3)(OH) 2 Cl 2 with acetic anhydride afforded com plexes cis,trans,cis Pt IV (RNH 2)(NH 3)(OAc) 2 Cl 2 , where R is 2,2,6,6 tetramethyl 1 oxyl piperidin 4 yl (1b) or 2,2,5,5 tetramethyl 1 oxylpyrrolidin 3 yl (2b). The complexes were characterized by elemental analysis, HPLC, and IR, UV, and ESR spectra. Complex 1b exhibits high antitumor activity comparable with that of Cisplatin against leukemia P388 used as the experimental tumor. Simultaneous administration of low doses of 1b and Cisplatin (1/20 of LD 50 each) results in synergism of the antitumor activity and 100% cure of animals.