Phytochemical investigation and biological activities of Fusarium SP. An entomogenous fungus

Abstract

Entomopathogenic fungi have an incredible capacity to produce biologically active metabolites. The present study was undertaken to evaluate the insecticidal activity of extracts, fractions and pure compounds from Fusarium sp. ARSEF 3300 entomopathogenic fungi against Spodoptera frugiperda Smith (Lepidoptera) and Ceratitis capitata Wiedemann (Diptera). Additionally, antimicrobial activity was determined against Staphylococcus aureus ATCC 6538 and Pseudomonas aeruginosa ATCC 27853. The culture media developed in the absence and presence of remains of the S. frugiperda insect were called fungus (H) and fungus-insect (HI), respectively. Volatile compounds in the extracts obtained with ethyl acetate were identified by GC-MS. Seven compounds of known chemical structure were isolated: cholesterol (1), campesterol (2), palmitic acid (3), cis-Oleic acid (4), stearic acid (5), ester propyl myristate (6) and cis-9, cis-12 Linoleic acid (7). The ethyl acetate extract of the HI supernatant of Fusarium sp., showed the highest ingestion dissuading activity in S. frugiperda (83% at 300 μg/g of diet) and the highest oviposition deterrence in C. capitata (50% at 50 μg/cm 2 ). Extracts of H and HI supernatants from Fusarium sp. inhibited the growth of the P. aeruginosa (53.64% and 45.39%) and S. aureus (76.08% and 79.61%) at 400 μg/mL. Palmitic acid (46.23% and 38.59%), cis-Oleic acid (49.95% and 42.33%) and stearic acid (50.44% and 39.72%) showed the highest inhibition of growth and biofilm production in S. aureus at 100 μg/mL. Our results suggest the possible utilization of entomopathogenic fungal metabolites in the control of insect pests and human health.