title: Bioactive Secondary Metabolites Produced by the Oak Pathogen Diplodia corticola.
abstract: Three new lactones and a new fatty acid ester, named sapinofuranones C and D, diplopyrone B, and diplobifuranylone C, respectively, were isolated from Diplodia corticola, together with sphaeropsidins A and C, diplopyrone, diplobifuranylones A and B, diplofuranone A, and the (S,S)-enantiomer of sapinofuranone B. Sapinofuranones C and D, diplopyrone B, and diplobifuranylone C were characterized as (5S)-5-((1,S-1,6-dihydroxyhexa-2,4-dienyl)-dihydrofuran-2-one, 4,5-dihydroxy-deca-6,8-dienoic acid methyl ester, (5S)-5-hydroxy-6-(penta-1,3-dienyl)-5,6-dihydro-pyran-2-one, and 5'-((1R)-1-hydroxyethyl)-2',5'-dihydro-2H-[2,2']bifuranyl-5-one by spectroscopic and chemical methods, respectively. The relative configuration of sapinofuranone C was assigned by X-ray diffraction analysis, whereas its absolute configuration was determined by applying the advanced Mosher's method to its 11-O-p-bromobenzoyl derivative. The same method was used to assign the absolute configuration to C-5 of diplopyrone B and to that of the hydroxyethyl of the side chain of diplobifuranylone C, respectively. The metabolites isolated were tested at 1 mg/mL on leaves of cork oak, grapevine cv. 'Cannonau', and tomato using the leaf puncture assay. They were also tested on tomato cuttings at 0.2, 0.1, and 0.05 mg/mL. Each compound was tested for zootoxic activity on Artemia salina L. larvae. The efficacy of sapinofuranone C and diplopyrone B on three plant pathogens, namely, Athelia rolfsii, Fusarium avenaceum, and Phytophthora nicotianae was also evaluated. In all phytotoxic assays only diplopyrone B was found to be active. It also showed strong inhibition on the vegetative growth of A. rolfsii and P. nicotianae. All metabolites were inactive in the assay performed for the zootoxic activity (A. salina) even at the highest concentration used (200 μg/mL). Diplopyrone B showed a promising antioomycete activity for the control of Phytophthora spp. also taking into account the absence of zootoxic activity.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Napoli Federico II , Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Napoli, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Masi
authors.affiliation: Dipartimento di Agraria, Sezione di Patologia Vegetale ed Entomologia, Università degli Studi di Sassari , Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Maddau
authors.affiliation: Dipartimento di Agraria, Sezione di Patologia Vegetale ed Entomologia, Università degli Studi di Sassari , Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Benedetto Teodoro
authors.initials: BT
authors.lastname: Linaldeddu
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Napoli Federico II , Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Napoli, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Cimmino
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Napoli Federico II , Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Napoli, Italy.
authors.forename: Wanda
authors.initials: W
authors.lastname: D'Amico
authors.affiliation: Dipartimento di Agraria, Sezione di Patologia Vegetale ed Entomologia, Università degli Studi di Sassari , Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Scanu
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Napoli Federico II , Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Napoli, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Evidente
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Napoli Federico II , Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Napoli, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Tuzi
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Napoli Federico II , Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Napoli, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Evidente
mesh_terms: D001203:Ascomycota / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D007783:Lactones / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D010935:Plant Diseases / Q000382:microbiology*; D029963:Quercus / Q000382:microbiology*; D064210:Secondary Metabolism
chemical_list: D007783:Lactones
keywords: Botryosphaeriaceae; diplobifuranylone C; diplopyrone B; furanones; phytotoxins; sapinofuranones C and D; unsaturated carboxylic acids; α-pyrone