title: Synthesis and antitumour activities of tetracyclic quinolone antineoplastic agents.
abstract: DNA topoisomerases, found in all prokaryotic and eukaryotic cells, play a key role in controlling the topological state of DNA. They are involved in DNA replication, RNA transcription and recombination affecting cell proliferation. Quinolone antibacterial agents have been shown to be inhibitors of DNA gyrase, a bacterial topoisomerase II enzyme. The eukaryotic topoisomerase II is the target of various cytotoxic agents such as adriamycin and etoposide. Due to the mechanistic similarities and sequence homologies shared by both bacterial and mammalian DNA topoisomerase II, we initiated a screening programme to search for quinolones as antitumour agents and reported the identification of a new class of quinolone, quinobenoxazines, having excellent in vitro cytotoxic activity comparable to adriamycin. In the continuation of this research work, we synthesized a series of amino-substituted quinobenoxazines and found that some of them possess more potent in vitro cytotoxicity than the parent unsubstituted quinobenoxazines. The chemical synthesis as well as biological properties of these tetracyclic quinolones are described.
authors.affiliation: Antiinfective Research Division, Abbott Laboratories, Abbott Park, Illinois 60064-3500.
authors.forename: D T
authors.initials: DT
authors.lastname: Chu
authors.forename: R
authors.initials: R
authors.lastname: Hallas
authors.forename: S K
authors.initials: SK
authors.lastname: Tanaka
authors.forename: J
authors.initials: J
authors.lastname: Alder
authors.forename: D
authors.initials: D
authors.lastname: Balli
authors.forename: J J
authors.initials: JJ
authors.lastname: Plattner
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D010078:Oxazines / Q000138:chemical synthesis / Q000494:pharmacology; D015363:Quinolones / Q000138:chemical synthesis* / Q000494:pharmacology; D059005:Topoisomerase II Inhibitors; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D010078:Oxazines; D015363:Quinolones; D059005:Topoisomerase II Inhibitors; C080342:A 74932