About the mutagenicity of chlorine-substituted furanones and halopropenals. A QSAR study using molecular orbital indices.

Electron affinities, frontier molecular orbital energies and electron densities at individual carbon atoms were calculated for 11 chlorofuranones including the strong mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and for 5 halopropenals by semi-empirical AM1 and ab initio STO-3G methods. Significant correlations were found between Ames TA100 mutagenicity and the following AM1 electronic parameters of chlorofuranones: electron affinity (r = 0.9556). LUMO energy (r = 0.9332) and frontier electron density of LUMO at the alpha-carbon (r = 0.8882). In halopropenals only LUMO electron density at the beta-carbon correlates well with mutagenicity. The observed correlations suggest a reaction mechanism in which chlorofuranones and halopropenals act as electron acceptors in the interaction with DNA.