title: Structure and Absolute Configuration of Kongiidiazadione, a New Phytotoxic 3-Substituted-5-Diazenylcyclopentendione Produced by Diaporthe Kongii.
abstract: A new 3-substituted-5-diazenylcyclopentendione named kongiidiazadione was isolated from culture filtrates of Diaporthe kongii, associated with stem cankers on sunflower in Australia. Kongiidiazadione was characterized by spectroscopic (essentially nuclear magnetic resonance [NMR] and high-resolution, electrospray ionization, mass spectrometry [HRESIMS]) methods as (-)-5-diazenyl-3-hydroxymethyl-cyclopent-3-en-1,2-dione. The stereochemistry of the diazenyl group was determined by IR spectroscopy, while the (R) absolute configuration at C(5) was assigned by computational analysis of its electronic circular dichroism (ECD) spectrum. When assayed on leaf disks of different plant species at 5 mM, the kongiidiazadione had a differential impact, causing clear necrosis, in particular to Helianthus annuus. Moreover, kongiidiazadione proved to have a weak antibacterial activity against gram-positive Bacillus amyloliquefaciens.
authors.affiliation: Università di Napoli Federico II, Dipartimento di Scienze Chimiche, Complesso Universitario Monte Sant'Angelo, Napoli, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Evidente
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Scienze delle Produzioni Alimentari, Bari, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Boari
authors.affiliation: Università della Basilicata, Dipartimento di Scienze, Potenza, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Vergura
authors.affiliation: Università di Napoli Federico II, Dipartimento di Scienze Chimiche, Complesso Universitario Monte Sant'Angelo, Napoli, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Cimmino
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Scienze delle Produzioni Alimentari, Bari, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Vurro
authors.affiliation: Graham Centre for Agriculture Innovation (an Alliance between Charles Sturt University and NSW DPI), WaggaWagga, New South Wales, Australia.
authors.forename: Gavin
authors.initials: G
authors.lastname: Ash
authors.affiliation: Università della Basilicata, Dipartimento di Scienze, Potenza, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Superchi
authors.affiliation: Università di Napoli Federico II, Dipartimento di Scienze Chimiche, Complesso Universitario Monte Sant'Angelo, Napoli, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Evidente
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D001203:Ascomycota / Q000378:metabolism*; D007659:Ketones / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D000890:Anti-Infective Agents; D007659:Ketones
keywords: Carthamus lanatus; Diaporthe kongii; absolute configuration; electronic circular dichroism; kongiidiazadione; phytotoxin