title: Induced production of 6,9-dibromoflavasperone, a new radical scavenging naphthopyranone in the marine-mudflat-derived fungus Aspergillus niger.
abstract: The addition of metal bromides (NaBr and CaBr2) during fermentation of the marine-mudflat-derived fungus Aspergillus niger induced production of a new radical scavenging brominated naphthopyranone, 6,9-dibromoflavasperone (1); and three known naphtho-γ-pyranone monomers, flavasperone (2), TMC-256A1 (3), and fonsecin (4); and one naphtho-γ-pyranone dimer, aurasperone B (5). The structure of 6,9-dibromoflavasperone (1) was assigned through the combination of spectroscopic data analyses and comparison with the spectral data of flavasperone (2). Compounds 1-5 displayed potent radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl, with IC50 values of 21, 25, 0.3, 0.02, and 0.01 μM, respectively, and 3-5 were more potent than the positive control, ascorbic acid (IC50, 20.0 μM).
authors.affiliation: Department of Chemistry, Pukyong National University, Busan, 608-737, Korea.
authors.forename: Alain Simplice
authors.initials: AS
authors.lastname: Leutou
authors.affiliation: Department of Chemistry, Pukyong National University, Busan, 608-737, Korea.
authors.forename: Keumja
authors.initials: K
authors.lastname: Yun
authors.affiliation: Department of Chemistry, Pukyong National University, Busan, 608-737, Korea. sonbw@pknu.ac.kr.
authors.forename: Byeng Wha
authors.initials: BW
authors.lastname: Son
mesh_terms: D001234:Aspergillus niger / Q000378:metabolism*; D001713:Biphenyl Compounds / Q000737:chemistry; D001965:Bromides / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D002867:Chromones / Q000302:isolation & purification* / Q000494:pharmacology; D055808:Drug Discovery / Q000379:methods*; D005285:Fermentation; D016166:Free Radical Scavengers / Q000302:isolation & purification* / Q000494:pharmacology; D005609:Free Radicals / Q000737:chemistry; D019015:Geologic Sediments / Q000382:microbiology*; D010851:Picrates / Q000737:chemistry; D017670:Sodium Compounds / Q000737:chemistry
chemical_list: C000613906:6,9-dibromoflavasperone; D001713:Biphenyl Compounds; D001965:Bromides; D017610:Calcium Compounds; D002867:Chromones; D016166:Free Radical Scavengers; D005609:Free Radicals; D010851:Picrates; D017670:Sodium Compounds; C113019:calcium bromide; C000613907:aurasperone B; C004931:1,1-diphenyl-2-picrylhydrazyl; C027938:sodium bromide
keywords: 6,9-Dibromoflavasperone; Aurasperone B; Flavasperone; Fonsecin; Radical scavenging activity; TMC-256A1