Antiplasmid and carcinogenic molecular orbitals of benz[c]acridine and related compounds.

Effect of K- and L- molecular orbital regions on expression of antiplasmid and carcinogenic activity was studied with various benz[c]acridine derivatives, tricyclic compounds (acridine orange, phenothiazines) and dibenzoazepine (imipramine). Antiplasmid compounds showed the out-of-phase of molecular orbital in the L-region. On the other hand, mutagenic and carcinogenic compounds showed the out-of-phase in the L-region, and their energy was accumulated in the K-region of the molecular orbitals. The present study suggests that the molecular orbitals responsible for the expression of antiplasmid and carcinogenic effects might be basically different.