title: Rickenyls A-E, antioxidative terphenyls from the fungus Hypoxylon rickii (Xylariaceae, Ascomycota).
abstract: Our screening efforts for new natural products with interesting bioactivity have revealed the neotropical ascomycete Hypoxylon rickii as a prolific source. We isolated five secondary metabolites with a p-terphenyl backbone from the mycelial extract of a fermentation of this fungus in 70 l scale by using RP-HPLC, which were named rickenyls A-E (1-5). Their structures were elucidated by X-ray crystallography and NMR spectroscopy, complemented by HRESIMS. Two of the compounds contained a quinone core structure in ortho (2) and para-position (5), respectively. We obtained 2 spontaneously and by lead tetraacetate oxidation from 1. All compounds were screened for antimicrobial, antioxidative and cytotoxic activities. Rickenyl A (1) exhibited strong antioxidative effects and moderate cytotoxic activity against various cancer cell lines.
authors: Helmholtz Centre for Infection Research GmbH (HZI), Department Microbial Drugs, Inhoffenstraße 7, 38124 Braunschweig, Germany; German Centre for Infection Research Association (DZIF), Partner site Hannover-Braunschweig, Inhoffenstraße 7, 38124 Braunschweig, Germany.
authors: Eric
authors: E
authors: Kuhnert
authors: Helmholtz Centre for Infection Research GmbH (HZI), Department Microbial Drugs, Inhoffenstraße 7, 38124 Braunschweig, Germany; German Centre for Infection Research Association (DZIF), Partner site Hannover-Braunschweig, Inhoffenstraße 7, 38124 Braunschweig, Germany.
authors: Frank
authors: F
authors: Surup
authors: German Centre for Infection Research Association (DZIF), Partner site Hannover-Braunschweig, Inhoffenstraße 7, 38124 Braunschweig, Germany; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Pharmaceutical Biotechnology, Saarland University Campus, Building C2.3, 66123 Saarbrücken, Germany.
authors: Jennifer
authors: J
authors: Herrmann
authors: Universität des Saarlandes, Institut für Anorganische Chemie, 66123 Saarbrücken, Germany.
authors: Volker
authors: V
authors: Huch
authors: German Centre for Infection Research Association (DZIF), Partner site Hannover-Braunschweig, Inhoffenstraße 7, 38124 Braunschweig, Germany; Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Pharmaceutical Biotechnology, Saarland University Campus, Building C2.3, 66123 Saarbrücken, Germany.
authors: Rolf
authors: R
authors: Müller
authors: Helmholtz Centre for Infection Research GmbH (HZI), Department Microbial Drugs, Inhoffenstraße 7, 38124 Braunschweig, Germany; German Centre for Infection Research Association (DZIF), Partner site Hannover-Braunschweig, Inhoffenstraße 7, 38124 Braunschweig, Germany. Electronic address: marc.stadler@helmholtz-hzi.de.
authors: Marc
authors: M
authors: Stadler
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D016227:Benzoquinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D006801:Humans; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013730:Terphenyl Compounds / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D013098:Xylariales / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D016227:Benzoquinones; D013730:Terphenyl Compounds
keywords: Antioxidant; Hypoxylon; Hypoxylon rickii; Secondary metabolites; Structure elucidation; Terphenyl; Terphenylquinone; Xylariaceae; Xylariales