Background: An entomopathogenic fungus, Isaria javanica pf185, causes mortality in nymphs of the green peach aphid and inhibits the growth of fungal plant pathogens. However, the metabolites of pf185 involved in these antifungal and aphicidal activities are unknown. This study was performed to identify the metabolites with these activities.
Results: An antifungal metabolite was purified by repetitive column chromatography and preparative high-performance liquid chromatography. Based on data from mass spectrometry and nuclear magnetic resonance, the active metabolite was identified as dibutyl succinate. The minimum concentration of dibutyl succinate to inhibit germination of conidia of the cause of anthracnose, Colletotrichum acutatum, was 4 mg mL-1 . Dibutyl succinate at 2 µg mL-1 inhibited mycelial growth. It also had strong aphicidal activity against the nymphs of the green peach aphid, Myzus persicae, median lethal concentration (LC50) of 306 mg L-1 at 24 h exposure, and median lethal time (LT50) of 14.5 h at 388 mg L-1 exposure.
Conclusion: This is the first report indicating that a single metabolite, dibutyl succinate, from the beneficial fungus I. javanica, has potential for use in integrated pest management to inhibit both insect and fungal plant pathogens. © 2018 Society of Chemical Industry.
Keywords: Isaria javanica; antifungal activity; aphid; dibutyl succinate; dual biocontrol.
© 2018 Society of Chemical Industry.