Afritoxinones A and B, dihydrofuropyran-2-ones produced by Diplodia africana the causal agent of branch dieback on Juniperus phoenicea.
Two phytotoxic dihydrofuropyran-2-ones, named afritoxinones A and B, were isolated from liquid culture of Diplodia africana, a fungal pathogen responsible for branch dieback of Phoenicean juniper in Italy. Additionally, six others known metabolites were isolated and characterized: oxysporone, sphaeropsidin A, epi-sphaeropsidone, R-(-)-mellein, (3R,4R)-4-hydroxymellein and (3R,4S)-4-hydroxymellein. The structures of afritoxinones A and B were established by spectroscopic and optical methods and determined to be as (3aS(*),6R(*),7aS)-6-methoxy-3a,7a-dihydro-3H,6H-furo[2,3-b]pyran-2-one and (3aR(*),6R(*),7aS)-6-methoxy-3a,7a-dihydro-3H,6H-furo[2,3-b]pyran-2-one, respectively. The phytotoxic activity of afritoxinones A and B and oxysporone was evaluated on host (Phoenicean juniper) and non-host plant (holm oak, cork oak and tomato) by cutting and leaf puncture assay. Oxysporone proved to be the most phytotoxic compound. This study represents the first report of secondary metabolites produced by D. africana. In addition, the taxonomic implications of secondary metabolites in Botryosphaeriaceae family studies are discussed.
Dipartimento di Scienze del Suolo, della Pianta, dell'Ambiente e delle Produzioni Animali, Università di Napoli Federico II, 80055 Portici, Italy. evidente@unina.it
Antonio
A
Evidente
Marco
M
Masi
Benedetto T
BT
Linaldeddu
Antonio
A
Franceschini
Bruno
B
Scanu
Alessio
A
Cimmino
Anna
A
Andolfi
Andrea
A
Motta
Lucia
L
Maddau
D001203:Ascomycota / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018653:Juniperus / Q000187:drug effects* / Q000382:microbiology; D018551:Solanum lycopersicum / Q000187:drug effects; D008969:Molecular Sequence Data; D009183:Mycotoxins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000187:drug effects; D011753:Pyrones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D029963:Quercus / Q000187:drug effects
D009183:Mycotoxins; D011753:Pyrones; C577252:afritoxinone A; C577253:afritoxinone B