title: Novel DPPH radical scavengers, demethylbisorbibutenolide and trichopyrone, from a fungus.
abstract: In our screening program for antioxidants with 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging activity, two novel compounds, demethylbisorbibutenolide (1) and trichopyrone (2), were isolated from the fermentation broth of the fungus of USF-4860 strain isolated from a soil sample. The structures of these compounds were determined from spectroscopic evidence. The biosynthetic origin of the carbon atoms of 2 was unambiguously determined by feeding experiments using (13)C-labeled precursors and elucidation of the (13)C-NMR spectrum of (13)C-labeled 2. These studies showed that 2 was derived from five acetates and a methyl group of methionine. In the DPPH-radical scavenging assay, 1 and 2 gave ED(50) values of 149 and 167 muM after standing for 2.0 hr. Compound 2 reacted with the DPPH radical to form reaction product 3 which was determined to be 1-[4-(3,4-dihydro-3-methyl-6-{1,3-pentadienyl}-2,4-dioxo-2H-pyran-3-yl)-phenyl]-1-phenyl-2-picrylhydrazine from spectroscopic evidence.
authors.affiliation: School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Washida
authors.forename: Naoki
authors.initials: N
authors.lastname: Abe
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Akira
authors.initials: A
authors.lastname: Hirota
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology; D001713:Biphenyl Compounds; D001643:Bridged Bicyclo Compounds / Q000302:isolation & purification* / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D005285:Fermentation; D016166:Free Radical Scavengers / Q000302:isolation & purification* / Q000494:pharmacology*; D005658:Fungi / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D010851:Picrates / Q000737:chemistry*; D011753:Pyrones / Q000302:isolation & purification* / Q000494:pharmacology*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001713:Biphenyl Compounds; D001643:Bridged Bicyclo Compounds; D016166:Free Radical Scavengers; D007202:Indicators and Reagents; D010851:Picrates; D011753:Pyrones; C521265:demethylbisorbibutenolide; C521266:trichopyrone; C004931:1,1-diphenyl-2-picrylhydrazyl; D015107:4-Butyrolactone