title: Topostin, a novel inhibitor of mammalian DNA topoisomerase I from Flexibacter topostinus sp. nov. II. Purification and some properties of topostin.
abstract: We describe the isolation of inhibitors of mammalian DNA topoisomerase I, named topostins, from a culture broth of Flexibacter topostinus sp. nov. and some properties of the inhibitors. Topostins A1, A2 and B were isolated by differential solubility in solvents, adsorption chromatography on silica gel and gel filtration on a Sephadex LH-20 column. Topostins A1, A2 and B had specific activities of 4,700, 16,000 and 22,000 U/mg, respectively. The most active metabolite topostin B comprised two components with MW of 567 and 553 in an equimolar ratio.
authors.affiliation: Department of Hygienic Chemistry, Meiji College of Pharmacy, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ikegami
authors.forename: N
authors.initials: N
authors.lastname: Takeuchi
authors.forename: M
authors.initials: M
authors.lastname: Hanada
authors.forename: Y
authors.initials: Y
authors.lastname: Hasegawa
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: T
authors.initials: T
authors.lastname: Andoh
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: S
authors.initials: S
authors.lastname: Miyazaki
mesh_terms: D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003470:Culture Media / Q000032:analysis; D003589:Cytophaga / Q000032:analysis*; D004264:DNA Topoisomerases, Type I / Q000302:isolation & purification / Q000494:pharmacology; D004269:DNA, Bacterial / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000302:isolation & purification*; D008970:Molecular Weight; D009930:Organic Chemicals; D059004:Topoisomerase I Inhibitors
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D004791:Enzyme Inhibitors; D009930:Organic Chemicals; D059004:Topoisomerase I Inhibitors; C063442:topostin A1; C063443:topostin A2; C063444:topostin B; D004264:DNA Topoisomerases, Type I