Polyketides and Terpenoids with Potent Antibacterial Activities from the Artemisia argyi‐Derived Fungus Trichoderma koningiopsis QA‐3

The AcOEt extract of Artemisia argyi‐derived fungus Trichoderma koningiopsis QA‐3 showed potent inhibitory activity against pathogenic bacteria. Fractionation of the extract resulted in the isolation of three new polyketides (1–3) and two new terpenoids (4 and 5), together with three known metabolites (6–8). Their chemical structures were analyzed by NMR spectra, ECD, HR‐ESI‐MS or HR‐EI‐MS, optical rotation, and X‐ray crystallographic data, as well as by comparison with literature reports. In the antibacterial assays, 3‐hydroxyharziandione (4) showed potent activity against human pathogen Escherichia coli with an MIC value of 0.5 μg/mL, while 6‐(3‐hydroxypent‐1‐en‐1‐yl)‐2H‐pyran‐2‐one exhibited strong activity against marine‐derived aquatic pathogen Micrococcus luteus with an MIC value of 1.0 μg/mL.