An Endophytic Fungus from Hypericum perforatumthat Produces Hypericin

For the first time, an endophytic fungus has been isolated from the stems of the medicinal herb Hypericum perforatum(St. John’s Wort). The fungus produced the napthodianthrone derivative hypericin ( 1) in rich mycological medium (potato dextrose broth) under shake flask and bench scale fermentation conditions. Emodin ( 2) was also produced simultaneously by the fungus under the same culture conditions. We propose 2as the main precursor in the microbial metabolic pathway to 1. The fungus was identified by morphology and authenticated by 28S (LSU) rDNA sequencing. Compounds 1and 2were identified by LC-HRMS, LC-MS/MS, and LC-HRMS/MS and confirmed by comparison with authentic standards. In bioassays with a panel of laboratory standard pathogenic control strains, including fungi and bacteria, both fungal 1and 2possessed antimicrobial activity comparable to authentic standards. This endophytic fungus has significant scientific and industrial potential to meet the pharmaceutical demands for 1in a cost-effective, easily accessible, and reproducible way.