Characterization and bioactive potentials of secondary metabolites from Fusarium chlamydosporum
A search for bioactive secondary metabolites from the endophytic fungus Fusarium chlamydosporum, isolated from the root of Suaeda glauca, led to the isolation of three indole derivatives (1–3), three cyclohexadepsipeptides (4–6), and four pyrones (7–10). The structures of new (1) and known compounds (2–10) were elucidated on the basis of extensive spectroscopic analysis. All these compounds were evaluated for phytotoxic, antimicrobial activities, and brine shrimp lethality. Compound 1 showed significant phytotoxic activity against the radicle growth of Echinochloa crusgalli, even better than the positive control of 2,4-D. Cyclohexadepsipeptides (4–6) and pyrones (7–10) exhibited brine shrimp lethality, especially 4 and 7 with the LD50 values of 2.78 and 7.40 μg mL−1, respectively, better than the positive control.