title: Biscopyran, a phytotoxic hexasubstituted pyranopyran produced by Biscogniauxia mediterranea, a fungus pathogen of cork oak.
abstract: A new phytotoxic hexasubstituted pyranopyran, biscopyran (3), was isolated together with phenylacetic acid (2) and previously isolated 5-methylmellein (1) from the liquid culture filtrates of Biscogniauxiamediterranea, a major fungal pathogen involved in oak decline in Sardinia. Biscopyran was characterized by spectroscopic methods as a new (Z)-2-methoxy-1-[7-((Z)-2-methoxybut-2-enoyl)-3,4,5,6-tetramethyl-2H,7H-pyrano[2,3-b]pyran-2-yl]but-2-en-1-one. Biscopyran assayed at 0.26-0.026 mM concentration range caused epinasty on cork oak cuttings. On a nonhost plant, tomato, biscopyran caused wilting. Phenylacetic acid, assayed at the same concentration, was toxic to Q. suber, while on tomato cuttings it induced internal tissue collapse 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: Anna
authors.initials: A
authors.lastname: Andolfi
authors.forename: Lucia
authors.initials: L
authors.lastname: Maddau
authors.forename: Antonio
authors.initials: A
authors.lastname: Franceschini
authors.forename: Francesco
authors.initials: F
authors.lastname: Marras
mesh_terms: D005658:Fungi / Q000737:chemistry*; D007558:Italy; D018551:Solanum lycopersicum / Q000187:drug effects; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011714:Pyrans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology / Q000633:toxicity; D029963:Quercus; D013237:Stereoisomerism
chemical_list: D011714:Pyrans; C500675:biscopyran