Synthesis, characterization, and in vitro cytotoxicity of some gold(I) and trans platinum(II) thionate complexes containing water-soluble PTA and DAPTA ligands.: X-ray crystal structures of [Au(SC4H3N2)(PTA)], trans-[Pt(SC4H3N2)2(PTA)2], trans-[Pt(SC5H4N)2(PTA)2], and trans-[Pt(SC5H4N)2(DAPTA)2]

A series of gold(I) and platinum(II) complexes of the type [Au(SR)(P)] and trans-[Pt(SR)(2)(P)(2)] [SR = 2-thiopyridine (SPy), 2-thiopyrimidine (SPyrim); P = 1,3,5-triaza-7-phosphaadamantane (PTA), 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane (DAPTA)] were prepared and characterized, and their in vitro cytotoxicities against a panel of seven human cancer cell lines were evaluated. The highly water soluble gold(l) complexes [Au(SR)(P)] [P = PTA and SR = SPy (1), SPyrim (2); P = DAPTA and SR = SPy (3), SPyrim (4)] showed low cytotoxicity, while the platinum(II) complexes trans- [Pt(S R)2(P)21 [P = PTA and SR = SPyrim (5), SPy (6); P = DAPTA and SR = SPyrim (7), SPy (8)] demonstrated potent cytotoxicity for ovarian, colon, renal, and melanoma cancer cell lines on the basis of a comparison with ID50 values for some established cytotoxic drugs. Single crystals of 2, 5, 6, and 8 suitable for X-ray structural characterization were obtained, and the study revealed the trans configuration for 5, 6, and 8 in their solid states.