Novel C8-linked pyrrolobenzodiazepine (PBD)-heterocycle conjugates that recognize DNA sequences containing an inverted CCAAT box

A series of novel DNA-interactive C8-linked pyrrolobenzodiazepine (PBD)–heterocycle polyamide conjugates has been synthesised to explore structure/sequence-selectivity relationships. One conjugate (2d) has a greater selectivity and DNA binding affinity for inverted CCAAT sequences within the Topoisomerase IIa promoter than the known C8-bis-pyrrole PBD conjugate GWL-78 (1b).