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.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.phytochem.2012.01.011 | DOI Listing |
Plant Dis
November 2024
Colorado State University, Department of Agricultural Biology, 1177 Campus Delivery, Fort Collins, Colorado, United States, 80523;
Plant Dis
June 2024
Department of Fruit Science, Mendel University in Brno 691 44, Lednice na Morave, Czech Republic.
Fungal trunk diseases (FTDs) have been a significant threat to the global stone fruit industry. FTDs are caused by a consortium of wood-decaying fungi. These fungi colonize woody tissues, causing cankers, dieback, and other decline-related symptoms in host plants.
View Article and Find Full Text PDFJ Fungi (Basel)
August 2021
Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, 51014 Tartu, Estonia.
is a cosmopolitan endophyte and opportunistic pathogen having occurred on several conifer species in Europe for at least 200 years. In Europe, disease outbreaks have increased on several spp. in the last few decades.
View Article and Find Full Text PDFFungal Biol
February 2014
Department of Plant Sciences, University of the Free State, Bloemfontein, South Africa.
Botryosphaeriaceae represents an important and diverse family of latent fungal pathogens of woody plants. We address the question of host range of these fungi by sampling leaves and branches of four native South African trees, including Acacia karroo (Fabaceae), Celtis africana (Cannabaceae), Searsia lancea (Anacardiaceae), and Gymnosporia buxifolia (Celastraceae). Two new species of the Botryosphaeriaceae, namely Tiarosporella africana sp.
View Article and Find Full Text PDFJ Nat Prod
April 2013
Dipartimento di Scienze, Università della Basilicata, Via dell'Ateneo Lucano, 10, 85100 Potenza, Italy.
The absolute configuration (AC) of the bioactive metabolites phyllostin (1) and scytolide (2), two hexahydro-1,4-benzodioxines produced by Phyllosticta cirsii, and oxysporone (3), a dihydrofuropyranone recently isolated from a strain of Diplodia africana, has been assigned by computational analysis of their optical rotatory dispersion (ORD), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD) spectra. Computational prediction of ORD, ECD, and VCD allowed us to assign (3S,4aR,8S,8aR) AC to naturally occurring (-)-1, while (4aR,8S,8aR) AC was assigned to (-)-2 employing only ECD and VCD, because in this case ORD analysis turned out to be unsuitable for AC assignment. Theoretical prediction of both ORD and ECD spectra of 3 led to assignment of (4S,5R,6R) AC to (+)-3.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!