Synthesis and characterization of Pd(II) and Pt(II) complexes of p-isopropylbenzaldehyde N-protected thiosemicarbazones. Cytotoxic activity against ras-transformed cells.

Abstract Cytotoxicity tests in tumor cells sensitive to cis -DDP (HL-60, JURKAT, Hela and 3T3) and in tumor cells transformed by ras oncogenes and resistant to cis -DDP (Pam 212- ras ) show that cyclometallated complexes 1a [Pd( p -is.TSCN-NHMe)] 4 , 2b [Pt( p -is.TSCN-NMe 2 )] 4 and 4a [Pd( p -is.TSCN-NHex)] 4 may be endowed with specific cytotoxic properties. In fact, these three novel metal-thiosemicarbazone compounds kill Pam 212- ras cells through apoptosis induction. These results, together with others recently published, indicate that the design and synthesis of metallated-thiosemicarbazone compounds may lead to the discovery of novel antitumor agents able to circumvent cis -DDP resistance, in particular tumor cell lines.