Extended quantitative structure-activity relationships for 80 aromatic and heterocyclic amines: structural,...

Area of Science:

• Toxicology
• Medicinal Chemistry
• Computational Chemistry

Background:

• Mutagenic/carcinogenic heterocyclic amines are formed during protein food cooking and are probable/possible human carcinogens.
• These amines require metabolic activation to electrophilic derivatives, potentially nitrenium ions, to exert genotoxic effects.
• Cytochrome P450 enzymes play a crucial role in the bioactivation of these compounds.

Purpose of the Study:

• To elucidate the mechanisms of mutagenesis/carcinogenesis by developing quantitative structure-activity relationships (QSARs) for aromatic and heterocyclic amines.
• To identify key structural factors influencing the mutagenic potency of a diverse range of amines.

Main Methods:

• Development of QSAR models for 80 structurally diverse amines with a 10-order of magnitude range in mutagenic potency.
• Inclusion of novel structural factors and quantum chemical calculations (ab initio and Hückel).
• Application of multiple linear regression analysis to correlate structural features with mutagenic potency.

Main Results:

• The extent of the aromatic pi-electron system was identified as the primary determinant of mutagenic potency.
• Dipole moment and calculated nitrenium ion stability contributed smaller effects to mutagenic potency.
• Multiple linear regression models explained approximately two-thirds of the variance in mutagenic potency.

Conclusions:

• The aromatic pi-electron system is a critical factor in amine mutagenicity.
• Cytochrome P450 1A's role in amine toxification is supported by these findings.
• Further theoretical and experimental research on cytochrome P450 reaction mechanisms and active site modeling is warranted.