Antimicrobial dihydrobenzofurans and xanthenes from a foliar endophyte of Pinus strobus

• DOI: 10.1016/j.phytochem.2015.07.009
• Publication Date: 2015-07-16T21:31:54Z
• Authors: Susan N. Richardson; Tienabe K. Nsiama; Allison K. Walker; David R. McMullin; J. David Miller
• Keywords: Endophyte

Foliar fungal endophytes of Pinus strobus (eastern white pine) were collected from different sites across south-eastern New Brunswick, Canada and screened for the production of bioactive metabolites. From one site, two fungal isolates representing a formerly unknown genus and species within the family Massarinaceae (Pleosporales, Dothideomycetes, Ascomycota) were resolved by phylogenetic analysis. These isolates produced crude organic extracts that were active against Microbotryum violaceum and Saccharomyces cerevisiae. From these strains, DAOM 242779 and 242780, four dihydrobenzofurans (1-4) and two xanthenes (5-6) were characterized. Structures were elucidated by HRMS, interpretation of NMR spectra and other spectroscopic techniques. All isolated metabolites displayed antimicrobial activity against the biotrophic fungal pathogen M. violaceum and Bacillus subtilis.