QSAR treatment of multiple toxicities: the mutagenicity and cytotoxicity of quinolines.

A series of 15 quinoline congeners were assayed for mutagenicity and cytotoxicity in the Ames test using strain TA100 bacteria. Statistical analysis of the data allowed simultaneous determination of the mutagenicity and cytotoxicity of each quinoline. These data were used to develop three quantitative structure-activity relationships (QSAR). In all three QSAR, the strength of the relationship between hydrophobicity (as measured by log P) and biological activity was similar as h was near 1 in all three cases. For the mutagenicity of these quinolines, both hydrophobic and steric interactions appear to be important. In contrast, the cytotoxicity is mainly affected by increasing hydrophobicity and by the addition of electron withdrawing substituents to the quinoline ring. Comparison to other QSAR from our laboratory and others lends support to these findings. Both simultaneous consideration of different biological activities and the comparison of newly developed QSAR with previous data for the purpose of lateral validation should be encouraged in future QSAR studies.