New antitumor-active Pt(II) complexes of (1R, 2R)-cyclohexanediamine (=(1R, 2R)-dach) and 2-(aminomethyl)cyclohexylamine (=amcha) isomers containing D-glucuronate, D-gluconate, tetra-O-acetylglucuronate (=Ac4-glucuronate) or tetra-O-acetylgluconate (=Ac4-gluconate) as a leaving group were synthesized. The structures of the Pt(II) complexes were determined by analyzing the infrared and 13C-nuclear magnetic resonance spectra and it was concluded that these leaving groups coordinate to the central Pt(II) ions through the carboxyl groups. Antitumor activities of the Pt(II) complexes were tested against murine leukemia L1210 according to the protocol of the National Cancer Institute (Bethesda, Md.). All the Pt(II) complexes synthesized were antitumor-active. In particular, water-soluble Pt(gluconato)(NO3)(cis-amcha) and lipo-soluble Pt(Ac4-β-glucuronato)2-((1R, 2R)-dach) exhibited excellent antitumor activity, giving T/C% values of 317 and 388, respectively, each with four cured mice out of six at a dose of 50 mg/kg. These two Pt(II) complexes are considered to be worthy of further development.
