Isolation of phomopsolide A as the antimycobacterial constituent of an unidentified endophyte of the Canadian medicinal plant Geum macrophyllum

An extract of an unidentified green filamentous fungus isolated as an endophyte of the Canadian medicinal plant Geum macrophyllum exhibited significant antimycobacterial activity and a distinct 1H NMR profile. Bioassay guided fractionation indicated that the natural product phomopsolide A (1) was responsible for the distinguishing characteristics of the extract.