Discovery of a Biocontrol Strain : Its Metabolites and Antifungal Activity against Pathogenic Fungus .

Finding safe and environmentally friendly fungicides is one of the important strategies in modern pesticide research and development. In this work, the antipathogenic effects of the fungus against the anthracnose pathogen were studied. The EtOAc extract of showed remarkable antifungal activity against with an inhibition rate of 50% at 256 μg/mL. Bioguided isolation of the cultural broth of produced four new drimane sesquiterpenes, trichalarins A-D (-), and six other metabolites (-). Their structures were established by extensive spectroscopic methods, quantum chemical calculations, and single-crystal X-ray diffraction. All compounds exhibited antifungal activity against with minimum inhibitory concentrations (MICs) of 8-64 μg/mL in vitro. Further in vivo assay suggested that compounds , , and could significantly inhibit growth in avocado fruit with inhibition rates close to 80% at the concentration of 256 μg/mL, while compounds and had an inhibition rate over 90% at the concentration of 512 μg/mL. The EtOAc extract of had no inhibitory effect on seed germination and growth at the concentration of 2 mg/mL, showing good environmental friendliness. Thus, the fungus could be considered as an ideal biocontrol strain, and its metabolites provided a diverse material basis for the antibiotic agents.