Isolation of (-)-avenaciolide as the antifungal and antimycobacterial constituent of a Seimatosporium sp. Endophyte from the medicinal plant Hypericum perforatum .

An extract of Seimatosporium sp., an endophyte from the Canadian medicinal plant Hypericum perforatum, exhibited significant antifungal and antimycobacterial activity against Candida albicans and Mycobacterium tuberculosis H37Ra. Bioassay guided fractionation led to the isolation of (-)-avenaciolide as the only bioactive constituent of the extract. This is the first report of both the antimycobacterial activity of avenaciolide and its isolation from a Seimatosporium sp. fungus.