In 1977, Gale and associates reported the synthesis and antitumor activity of a series of Pt(II) complexes containing
1,2-diaminocyclohexane as the
ligand. Certain of these complexes showed superior activity and greater water solubility compared to cis-Pt(NH3)2Cl2 complexes ("Neoplatin"). In this paper we report the synthesis and antitumor activity of some 40 new water soluble
platinum(II) and
platinum(IV) complexes. The following classes of the cis-Pt(L)Cl2 complexes were obtained, where L = 1,2-diaminocyclohexane: (a) cis-Pt(L)(X), where X is a derivative of
homophthalic acid or a derivative of 1,3-benzendicarboxylic
acid, (b) cis-Pt(L)(X)(OH)2 and cis-Pt(L)(X)(Cl)2 complexes, where L and X are the above-mentioned
ligands, (c) cis-Pt(L)(X)2 complexes where X is the monoanion of an organic xanthate or dithiocarbamate and L =
1,2-diaminocyclohexane, (d) their corresponding Pt(IV) analogues, Pt(L)(X)2(
OH)2 and Pt(L)(X)2(Cl)2. All complexes were assayed against P388
tumors and/or KB cell-bearing mice. The observed antitumor activities were correlated with the structures and spectra of the complexes as well as with the results of EHMO calculations performed on the leaving
ligand molecules. A number of the most active complexes were also tested for activity against ADJ/
PC6 Yoshida and S-180
tumors in vivo.