Antimicrobial dihydrobenzofurans and xanthenes from a foliar endophyte of Pinus strobus

The screening of foliar endophytes of Pinus strobus led to the identification of fungus representing a previously unknown genus and species within the family Massarinaceae. From one isolate, four dihydrobenzofurans (1-4) and two xanthenes (5-6) were discovered and characterized. All of these elicited antifungal activity against the fungus Microbotryum violaceum and the Gram-positive bacterium Bacillus subtilis.