Mutagenic activity of platinum and ruthenium complexes.

cis-Dichlorodiammineplatinum(II) [cis-PtCl2(NH3)2] and dichlorotetrakis (dis-methylsulfoxide) ruthenium(II) [RuCl2(DMSO)4] have been tested as mutagens for strains of Salmonella typhimurium carrying the hisG46 missense mutation. Their activity, which has been compared with the activity of mitomycin C, depends on the presence in the test bacteria of the pKM101 plasmid and is affected in various ways by the function of the excision repair system. More precisely, mitomycin C is mutagenic only for strains with an intact uvr system. cis-PtCl2(NH3)2 and RuCl2(DMSO)4 are mutagens both for uvrB and uvr+ strains, but cis-PtCl2(NH3)2 is more active on the latter, while the converse is true for RuCl2(DMSO)4. It seems, therefore, that each drug interacts with DNA by a different mechanism.