Synthesis, structure, and antitumor activity of 1,3-dithiol- and 1,3-dithiolan-2-ylidenemalonatoplatinum(II) complexes

Cytotoxicity of two novel cisplatin analogues, (CPA)2Pt[DOLYM] and (DACH)Pt[DOLYM], to human cancer cells in vitro

Despite the impressive antitumor activity of cisplatin, two major limitations of the drug, that is severe side effects and drug-resistance of cancer cells, make its use difficult for cancer therapy. These limitations have resulted in a great deal of effort having been expended into structural modifications of cisplatin. In this study, we tested two novel cisplatin analogues, (CPA)2Pt [DOLYM] (COMP-I) and (DACH)Pt[DOLYM] (COMP-II), for the mode of cytotoxic action against human tumor cells comparing with cisplatin and carboplatin in vitro. These two novel analogues had considerable cytotoxic activities against five kinds of human solid tumor cells, and especially COMP-II was more effective on HCT15 colon cancer cells than other compounds. In addition, COMP-II had cytostatic activity at low concentrations (10-0.3 microgram/ml), but other compounds revealed little effect on tumor growth at the low concentration.

Synthesis and antitumor activity of (diamine)platinum(II) complexes of benzylmalonate derivatives

(Diamine)platinum(II) complexes of benzylmalonate derivatives as a leaving group designed in a wide range of lipophilicity and water-solubility were prepared and their antitumor activities were attempted to correlate to their lipophilicity or solubility. A good relationship was observed between their in vitro toxicity and solubility of the title complexes with the same carrier ligand, DACH (trans-(+/-)-1,2-diaminocyclohexane): The most soluble complexes are most cytotoxic whereas the least soluble complexes are least cytotoxic. However, no relationship could be established between their in vivo activity and their lipophilicity or solubility presumably due to other pharmacokinetic factors involved in vivo. The molecular structure of (IPA)2Pt(DBM).2CH3OH (IPA = isopropylamine; DBM = dibenzylmalonate) was determined by X-ray diffraction: space group P2(1)/n, a = 11.433 (3), b = 14.461 (4), c = 17.478 (4) A, beta = 97.25 (3) degrees, z = 4, R = 0.0437.