The DNA intercalating compounds derived from 6H-pyridocarbazole (ellipticines, olivacines) elicit high antitumor properties. In order to get information about the mechanism of action of these agents it is necessary to study structurally related analogues. For this purpose, various derivatives of the four isomeric 7"-pyridocarbazoles were synthesized by a single photochemical process on indolylpyridylethylenes. These derivatives are able to ...