Cytotoxicity of 2,2 ': 6 ',2 ''-terpyridineplatinum(II) complexes against human ovarian carcinoma

2,2':6',2"-Terpyridineplatinum(II) complexes are shown to possess cytotoxic ity against a number of human ovarian tumor cell lines. Many of the complex es show similar activity against cisplatin- and doxormbicin-resistant cell lines as the parental cells suggesting that there is little or no cross-res istance with cisplatin or doxorubicin. The cytotoxicity of bis[2,2':6',2"-t erpyridineplatinum(II)] complexes is strongly dependent on the nature of th e linker. Bis[2,2':6',2"-terpyridineplatinum(II)] complexes with a flexible linker at the 4'-position show poor cytotoxicity; by contrast bis[2,2':6', 2"-terpyridineplatinum(II)] complexes with rigid and short linkers at plati num(II) are strikingly effective. Several of the compounds show greater cyt otoxicity against human ovarian cell lines than carboplatin, the therapeuti c agent currently advocated for the treatment of human ovarian cancers.