title: Isoaurostatin, a novel topoisomerase inhibitor produced by Thermomonospora alba.
abstract: A novel inhibitor of topoisomerase I designated as isoaurostatin (1) was isolated from the culture filtrate of Thermomonospora alba strain No. 1520. The structure of 1 was determined to be 6,4'-dihydroxyisoaurone on the basis of spectroscopic (NMR and MS) methods. Compound 1 inhibited the relaxation activity of calf thymus topoisomerase I in a noncompetitive manner and did not inhibit the relaxation and decatenation of human placenta topoisomerase II. Compound 1 is an inhibitor belonging to cleavable complex-nonforming type without DNA intercalation.
authors: Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-Honmachi, Kumamoto 862-0973, Japan.
authors: K
authors: K
authors: Suzuki
authors: S
authors: S
authors: Yahara
authors: K
authors: K
authors: Maehata
authors: M
authors: M
authors: Uyeda
mesh_terms: D000192:Actinomycetales / Q000737:chemistry*; D000818:Animals; D001572:Benzofurans / Q000302:isolation & purification* / Q000494:pharmacology; D002417:Cattle; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008956:Models, Chemical; D010920:Placenta / Q000201:enzymology; D011487:Protein Conformation; D013950:Thymus Gland / Q000201:enzymology; D059004:Topoisomerase I Inhibitors
chemical_list: D001572:Benzofurans; D004791:Enzyme Inhibitors; D059004:Topoisomerase I Inhibitors; C433579:isoaurostatin; D004250:DNA Topoisomerases, Type II