Six undescribed sesquiterpenoids from the endophytic fungus Irpex lacteus: Their antifungal and inhibitory activities against Setaria viridis.
TL;DR
Twelve sesquiterpenoids, comprising six new compounds and six known compounds, were isolated from the endophytic fungus Irpex lacteus derived from Castanea mollissima Blume and exhibited diverse antifungal activities against Fusarium equiseti.
Abstract
Twelve sesquiterpenoids, comprising six new compounds (1-6) and six known compounds (7-12), were isolated from the endophytic fungus Irpex lacteus derived from Castanea mollissima Blume. Structural elucidation was achieved through a combination of spectroscopy, ECD calculations, and X-ray crystallography. These compounds exhibited diverse antifungal activities against Fusarium equiseti. Compound 7 displayed antifungal activity against F. equiseti with a MIC of 2 μg/mL, which was comparable to the positive control nystatin (1 μg/mL). Compared with all the tested compounds, compound 3 at 60 μg/mL exerted the strongest inhibitory effect on the shoot growth of Setaria viridis seedlings, with an inhibition rate of 82%. For the root growth of S. viridis seedlings, compound 9 at 30 μg/mL showed the highest inhibitory activity, reaching an inhibition rate of 94%. These findings highlight the metabolic diversity of I. lacteus and provide valuable insights into the development of antifungal agents against F. equiseti and herbicides against S. viridis.