title: Synthesis of 6-chloroisoquinoline-5,8-diones and pyrido[3,4-b]phenazine-5,12-diones and evaluation of their cytotoxicity and DNA topoisomerase II inhibitory activity.
abstract: The substituted chloroisoquinolinediones and pyrido[3,4-b]phenazinediones were synthesized, and the cytotoxic activity and topoisomerase II inhibitory activity of the prepared compounds were evaluated. Chloroisoquinolinediones have been prepared by the reported method employing 6,7-dichloroisoquinoline-5,8-dione. The cyclization to pyrido[3,4-b]phenazinediones was achieved by adding the aqueous sodium azide solution to the dimethylformamide solution of corresponding chloroisoquinoline-5,8-dione. The cytotoxicity of the synthesized compounds was evaluated by a SRB (Sulforhodamine B) assay against various cancer cell lines such as A549 (human lung cancer cell line), SNU-638 (human stomach cancer cell), Col2 (human colon cancer cell line), HT1080 (human fibrosarcoma cell line), and HL-60 (human leukemia cell line). Almost all the synthesized pyrido[3,4-b]phenazinediones showed greater cytotoxic potential than ellipticine (IC(50)=1.82-5.97 microM). In general, the cytotoxicity of the pyrido[3,4-b]phenazinediones was higher than that of the corresponding chloroisoquinolinediones. The caco-2 cell permeability of selected compounds was 0.62 x 10(-6)-35.3 x 10(-6)cm/s. The difference in cytotoxic activity among tested compounds was correlated with the difference in permeability to some degree. To further investigate the cytotoxic mechanism, the topoisomerase II inhibitory activity of the synthesized compounds was estimated by a plasmid cleavage assay. Most of compounds showed the topoisomerase II inhibitory activity (28-100%) at 200 microM. IC(50) values for the most active compound 6a were 0.082 microM. However, the compounds were inactive for DNA relaxation by topoisomerase I at 200 microM.
authors.affiliation: School of Pharmacy, Ewha Womans University, Seoul 120-750, South Korea.
authors.forename: Jin Sung
authors.initials: JS
authors.lastname: Kim
authors.forename: Hee-Kyung
authors.initials: HK
authors.lastname: Rhee
authors.forename: Hyen Joo
authors.initials: HJ
authors.lastname: Park
authors.forename: In-Kyoung
authors.initials: IK
authors.lastname: Lee
authors.forename: Sang Kook
authors.initials: SK
authors.lastname: Lee
authors.forename: Myung-Eun
authors.initials: ME
authors.lastname: Suh
authors.forename: Hwa Jeong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Chung-Kyu
authors.initials: CK
authors.lastname: Ryu
authors.forename: Hea-Young Park
authors.initials: HY
authors.lastname: Choo
mesh_terms: D018938:Caco-2 Cells; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D004355:Drug Stability; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007546:Isoquinolines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D010539:Permeability; D010619:Phenazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D059005:Topoisomerase II Inhibitors
chemical_list: D004791:Enzyme Inhibitors; D007546:Isoquinolines; D010619:Phenazines; D059005:Topoisomerase II Inhibitors; D004247:DNA