Molecular electrostatic potential energies and methylation of DNA bases: a molecular orbital-generated quantitative structure-activity relationship.

1. The results of molecular orbital (MO) calculations, by the MINDO/3 method, on DNA bases, are reported; which point to a radical mechanism of alkylation. 2. Molecular electrostatic potential energy maps indicate propensity for alkylation by N-methyl-N-nitrosourea at key atoms on DNA bases. 3. A correlation between the MO-derived parameters net atomic charges on heteroatoms and superdelocalizability with percentage alkylation by N-methyl-N-nitrosourea is shown.