title: Design, synthesis, and biological evaluation of 14-substituted aromathecins as topoisomerase I inhibitors.
abstract: The aromathecin or "rosettacin" class of topoisomerase I (top1) inhibitors is effectively a "composite" of the natural products camptothecin and luotonin A and the synthetic indenoisoquinolines. The aromathecins have aroused considerable interest following the isolation and total synthesis of 22-hydroxyacuminatine, a rare cytotoxic natural product containing the 12 H-5,11a-diazadibenzo[ b, h]fluoren-11-one system. We have developed two novel syntheses of this system and prepared a series of 14-substituted aromathecins as novel antiproliferative topoisomerase I poisons. These inhibitors are proposed to act via an intercalation and "poisoning" mechanism identical to camptothecin and the indenoisoquinolines. Many of these compounds possess greater antiproliferative activity and anti-top1 activity than the parent unsubstituted compound (rosettacin) and previously synthesized aromathecins, as well as greater top1 inhibitory activity than 22-hydroxyacuminatine. In addition to potentially aiding solubility and localization to the DNA-enzyme complex, nitrogenous substituents located at the 14-position of the aromathecin system have been proposed to project into the major groove of the top1-DNA complex and hydrogen-bond to major-groove amino acids, thereby stabilizing the ternary complex.
authors.affiliation: Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue CancerCenter, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Maris A
authors.initials: MA
authors.lastname: Cinelli
authors.forename: Andrew
authors.initials: A
authors.lastname: Morrell
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Dexheimer
authors.forename: Evan S
authors.initials: ES
authors.lastname: Scher
authors.forename: Yves
authors.initials: Y
authors.lastname: Pommier
authors.forename: Mark
authors.initials: M
authors.lastname: Cushman
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D015195:Drug Design; D006801:Humans; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D011485:Protein Binding; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D059004:Topoisomerase I Inhibitors
chemical_list: D000970:Antineoplastic Agents; D007212:Indolizines; D008024:Ligands; D011804:Quinolines; D059004:Topoisomerase I Inhibitors; D004247:DNA; D004264:DNA Topoisomerases, Type I