Mutagenicity of substituted (o-phenylenediamine)platinum dichloride in the Ames test. A quantitative structure-activity analysis.

A set of 13 substituted (o-phenylenediamine)platinum dichlorides has been studied in the Ames test using Salmonella typhimurium (TA-92). These cis-platinum compounds are mutagenic without activation by microsomes. The following correlation equation shows that the most important determinant of mutagenicity by substituents (X) is electron withdrawal via through resonance: log 1/C = 2.23 sigma sigma minus + 5.78. C in this expression is the molar concentration of compound producing 30 mutations/10(8) bacteria initially delivered above background mutation, and sigma minus is the Hammett constant obtained from substituted anilines.