Frontier orbital energies, hydrophobicity and steric factors as physical QSAR descriptors of molecular mutagenicity. A review with a case study: MX compounds.

A review on QSARs (Quantitative Structure-Activity Relationships) in modelling molecular mutagenicity is given. The importance of hydrophobicity, frontier orbital (HOMO and LUMO) energies and steric factors as physical descriptors of mutagenicity is emphasized. In addition, some possible connections between QSAR models and the general electrophilic theory of genotoxic activity are discussed. As a detailed example, QSARs for the Ames Salmonella typhimurium TA100 mutagenicity of halogenated hydroxyfuranones including MX, one of the most potent bacterial mutagens ever identified, are discussed and a plausible mechanism for their mutagenic activity is proposed.