The potency of active compound from mangrove fungal endophyte Emericella nidulans BPPTCC 6038 as bioinsecticide

Mangrove fungi are known as the sources of secondary metabolites of active compounds. In the search for novel, potent, fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extract from Emericella nidulans BPPTCC 6038 was tested for toxic activity using brine shrimp lethality bioassay against Artemia salina larvae; insecticidal activity using indirect contact bioassay against neonate of Spodotera litura larvae; and acetylcholinesterase (AChE) inhibition activity by acethylcholinesterase inhibition assay. The results showed that the extract exhibited toxic activity against A. salina larvae, rated as highly toxic at 80 ppm; exhibited insecticidal activity against S. litura larvae, causing mortality by 66.67% at 5 mg; and acetylcholinesterase inhibition activity by 47.60% at 100 ppm. The fractionation on the E. nidulans BPPTCC 6038 extract produced seven fractions, and the best insecticidal activity against S. litura neonate larvae using feeding dietary bioassay was exhibited by the fraction no. 6, causing 98.33% larval mortality at 2500 ppm. The chemical characterization of the E. nidulans BPPTCC 6038 extracts using thin layer chromatography combined with several reagents showed that the extract contained triterpenoid, saponin and phenolic compounds, and the active fraction (fraction no. 6) from E. nidulans BPPTCC 6038 contained triterpenoid and saponin compounds. Thus, the extract of the E. nidulans BPPTCC 6038 might provide new bioactive compounds to be applied as potential bioinsecticides.