title: Diplopyrone, a new phytotoxic tetrahydropyranpyran-2-one produced by Diplodia mutila, a fungus pathogen of cork oak.
abstract: A new phytotoxic monosubstituted tetrahydropyranpyran-2-one, named diplopyrone (1), was isolated from the liquid culture filtrates of Diplodia mutila, a plant pathogenic fungus causing a form of canker disease of cork oak (Quercus suber). Diplopyrone was characterized, using spectroscopic and chemical methods, as 6-[(1S)-1-hydroxyethyl]-2,4a,6,8a-tetrahydropyran[3,2-b]pyran-2-one. The absolute stereochemistry of the chiral secondary hydroxylated carbon (C-9), determined by application of Mosher's method, proved to be S. Diplopyrone assayed at a 0.01-0.1 mg/mL concentration range caused necrosis and wilting on cork oak cuttings. On a nonhost plant, tomato, diplopyrone caused brown discoloration or stewing on the stem.
authors.affiliation: Dipartimento di Scienze del Suolo, della Pianta e dell'Ambiente, Università di Napoli Federico II, 80055 Portici, Italy. evidente@unina.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Evidente
authors.forename: Lucia
authors.initials: L
authors.lastname: Maddau
authors.forename: Emanuela
authors.initials: E
authors.lastname: Spanu
authors.forename: Antonio
authors.initials: A
authors.lastname: Franceschini
authors.forename: Silvia
authors.initials: S
authors.lastname: Lazzaroni
authors.forename: Andrea
authors.initials: A
authors.lastname: Motta
mesh_terms: D007558:Italy; D018551:Solanum lycopersicum / Q000187:drug effects; D003904:Mitosporic Fungi / Q000472:pathogenicity*; D015394:Molecular Structure; D009183:Mycotoxins / Q000633:toxicity*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000737:chemistry; D011753:Pyrones / Q000737:chemistry* / Q000633:toxicity*; D029963:Quercus / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D009183:Mycotoxins; D011753:Pyrones; C475235:diplopyrone