A New Family of Potent Carcinogens : Benzopyridocarbazoles

Abstract

ALTHOUGH the introduction of heterocyclic nitrogen atoms in the molecules of polycyclic compounds sometimes decreases carcinogenic activity (for example, the inactive pyrenoline as compared with 3,4-dibenzopyrene¹), there are many instances in which the carcinogenic potency is thereby maintained or even enhanced. Such is the case with the angular benzacridines², some of which are more active than the corresponding 1,2-benzanthracenes in respect of induction of skin epitheliomas and sarcomas, and with the inactive pentacene, in the molecule of which the introduction of two nuclear nitrogen atoms leads to the sarcoma-producing dinaphthazine³. In view of the already established carcinogenic activity of the angular dibenzocarbazoles⁴, it was interesting to examine the biological properties of the recently synthesized aza derivatives⁵.