The antifungal properties of terpenoids from the endophytic fungus Bipolaris eleusines

Abstract

Abstract A series of terpenoids (1–17), comprising six new compounds designated bipolariterpenes A-F (1–6) and eleven recognized compounds (7–17), were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleusines. Their structures and stereochemistry were clarified by HRESIMS, NMR, DP4 + probability analyses, and computations for electronic circular dichroism (ECD). All compounds are made up of six meroterpenoids, four sesterterpenes and seven sesquiterpenes. Among them, four sesterterpenes (4, 5, 10, 11) were investigated for their antifungal, antibacterial and cytotoxic properties, and six meroterpenoids (1–3, 7–9) were evaluated for their antifungal properties. The compounds 7, 9, and 10 had substantial antifungal activity against Epidermophyton floccosum at a concentration of 100 µM. No antibacterial and cytotoxic activities were observed. Graphical Abstract

Keywords

• Endophytic fungus
• Bipolaris eleusines
• Terpenoids
• Isolation and structure elucidation
• Antifungal activity