Diaza- and triazachrysenes: Potent topoisomerase-targeting agents with exceptional antitumor activity against the human tumor xenograft, MDA-MB-435

Several 5,12-diazachrysen-6-ones and 5,6,11-triazachrysen-12-ones were synthesized with varied substituents at the 5- or 11-position, respectively. Each compound was evaluated for its potential to stabilize the cleavable complex formed with TOP I and DNA. Two analogues with very potent TOP1-targeting activity, 3a and 4a, exhibited cytotoxic activity with IC50 values at or below 2 nM against RPM18402. Compound 3a was active in vivo by either ip or po administration in the human tumor xenograft athymic nude mice model. (C) 2002 Elsevier Science Ltd. All rights reserved.