Insecticidal bioactive compounds derived from Cladosporium cladosporioides (Fresen.) G.A. de Vries and Acremonium zeylanicum (Petch) W. Gams & H.C. Evans

Entomopathogenic fungi (EPF) are the main microbiological control agents of insect pests. One of the key factors in the pathogenicity of EPF is the production of insecticidal bioactive compounds. Therefore, the metabolites of two isolates of EPF, Cladosporium cladosporioides (Fresen.) G.A. de Vries (AF98) and Acremonium zeylanicum (Petch) W. Gams & H.C. Evans (IR87), were analyzed. The presence of insecticidal toxic cyclic peptides such as Bassianolide in C. cladosporioides AF98 metabolites was detected by HPLC. Moreover, GC–MS analysis showed some toxic compounds, including 3,4-Dihydro-7,12-Dihydroxy-7,12-Imethylbenz[A]Anthracene, 1,2,3,4-Tetrahydro-1,1,4,4,6-Pentamethyl-5,7-Dinitronaphthalene, and 1,2,3,4-Tetrahydro-1,1,4,4,6-Pentamethyl-5,7-Dinitronaphthalene in the metabolites purified from A. zeylanicum IR87. Also, a few hazardous compounds, including 3,5-di-tert-butyl-4-trimethylsiloxytoluene, bis(2-Ethylhexyl) phthalate, di-n-octyl phthalate, 1-pentadecene, and 1-eicosene were found which might be toxic against insects. This is the first report on the detection of toxic peptides from C. cladosporioides. These results showed that multiple compounds are likely contributed to the insecticidal effects of the EPF.