title: Chlorinated polyketide obtained from a Daldinia sp. treated with the epigenetic modifier suberoylanilide hydroxamic acid.
abstract: A new chlorinated pentacyclic polyketide, daldinone E (1), was purified from a Daldinia sp. fungal isolate treated with the epigenetic modifier suberoylanilide hydroxamic acid (SAHA). A biosynthetically related epoxide-containing daldinone analogue, 2, was also purified from the same fungus. The structures of both compounds were established by spectroscopic methods, and the absolute configurations were assigned by analysis of their NMR data (coupling constants and ROESY correlations) and DFT calculations of specific rotations and ECD spectra. During the course of these studies it was determined that metabolite 2 and the previously reported daldinone B shared the same spectroscopic data, leading to a revision of the reported structure. Both compounds 1 and 2 also exhibited DPPH radical scavenging activities with potency comparable to the positive control ascorbic acid.
authors.affiliation: Institute for Natural Products Applications and Research Technologies, Natural Products Discovery Group, and ‡Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma , 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States.
authors.forename: Lin
authors.initials: L
authors.lastname: Du
authors.forename: Jarrod B
authors.initials: JB
authors.lastname: King
authors.forename: Robert H
authors.initials: RH
authors.lastname: Cichewicz
mesh_terms: D001713:Biphenyl Compounds / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D056572:Histone Deacetylase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006877:Hydroxamic Acids / Q000494:pharmacology; D007711:Klebsiella pneumoniae / Q000187:drug effects; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010851:Picrates / Q000494:pharmacology*; D061065:Polyketides / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D000077337:Vorinostat; D013098:Xylariales / Q000737:chemistry*
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D056572:Histone Deacetylase Inhibitors; D006843:Hydrocarbons, Chlorinated; D006877:Hydroxamic Acids; D010851:Picrates; D061065:Polyketides; C000599235:daldinone E; D000077337:Vorinostat; C004931:1,1-diphenyl-2-picrylhydrazyl