TY - JOUR T1 - Mutagenicity of dimethyl heteroaromatic triazenes in the Ames test: the role of hydrophobicity and electronic effects. JF - Molecular Pharmacology JO - Mol Pharmacol SP - 939 LP - 944 VL - 36 IS - 6 AU - A J Shusterman AU - A K Debnath AU - C Hansch AU - G W Horn AU - F R Fronczek AU - A C Greene AU - S F Watkins Y1 - 1989/12/01 UR - http://molpharm.aspetjournals.org/content/36/6/939.abstract N2 - The mutagenicities of five heterocyclic 3,3-dimethyltriazenes have been evaluated in the Ames test. The octanol-water partition coefficients (P) for these triazenes have been measured, and their electron distributions and molecular orbital energies were calculated using the MNDO semiempirical molecular orbital method. Molecular structures of three triazenes have been determined using X-ray crystallography. The mutagenicities of these five triazenes, which range from nearly inactive to very highly mutagenic, are well predicted by quantitative structure-activity relationships that had been derived previously for the mutagenicity of aryltriazenes. The form of these equations indicates that more hydrophobic and more electron-rich triazenes are more active in the Ames test. This supports the hypothesis that the ease of initial triazene activation by cytochrome P-450 governs the mutagenicity of these compounds. ER -