title: Phenalenones: insight into the biosynthesis of polyketides from the marine alga-derived fungus Coniothyrium cereale.
abstract: The marine alga-derived fungus Coniothyrium cereale is a prolific producer of phenalenones. These polyketides were shown to possess antimicrobial effects and inhibitory activity towards the protease human leucocyte elastase (HLE). The current study focused on the biosynthesis of eight different structural types of phenalenones, comprising the natural products rousselianone A' (1), coniosclerodin (3), cereolactam (12), cereoaldomine (15), and trypethelone (16). Solid agar cultures of C. cereale were used to follow up the incorporation of [1-(13)C] labeled acetate into these metabolites. Taking the respective mechanisms of polyketide metabolism into account, the labeling pattern was interpreted, thus providing a hypothesis for the biosynthetic formation of the phenalenones. The polyketide skeleton of the phenanthrene-based compound cereolactam is proposed to be formed through degradation of a heptaketide by loss of two carbon atoms.
authors.affiliation: Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, D-53115 Bonn, Germany. g.koenig@uni-bonn.de.
authors.forename: Mamona
authors.initials: M
authors.lastname: Nazir
authors.forename: Fayrouz
authors.initials: F
authors.lastname: El Maddah
authors.forename: Stefan
authors.initials: S
authors.lastname: Kehraus
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Egereva
authors.forename: Jörn
authors.initials: J
authors.lastname: Piel
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Brachmann
authors.forename: Gabriele M
authors.initials: GM
authors.lastname: König
mesh_terms: D059001:Aquatic Organisms / Q000737:chemistry*; D001203:Ascomycota / Q000737:chemistry*; D053898:Biosynthetic Pathways; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D043803:Phenalenes / Q000737:chemistry*; D061065:Polyketides / Q000737:chemistry / Q000378:metabolism*; D013194:Staining and Labeling; D013997:Time Factors
chemical_list: D043803:Phenalenes; D061065:Polyketides; C038036:phenalen-1-one