Identification of Insect-Deterrent Metabolites from Acremonium masseei strain CICY026 a Saprophytic Fungus from a Sinkhole in Yucatán

摘要

Micromycetes from unexplored sources represent an opportunity to discover novel natural products to control insect pests. With this aim, a strain of CICY026 isolated from a tropical sinkhole was identified, cultured on fermented rice, and its ethyl acetate extract (EAE) was evaluated against three serious phytophagous insects ( , and ). DNA from CICY026 was used to confirm its identity. EAE caused settling inhibition (SI) of and (67.5% and 75.3%, respectively). Bioassay-guided fractionation of the active EAE led to the isolation of a novel metabolite, named hexahydroacremonintriol ( ), and of acremonin A glucoside ( ). The structures of and were determined using IR, one- and two-dimensional NMR, HRMS, and confirmed by theoretical data. The aphid was noticeably sensitive to and (SI: 55.6% and 67.2%, respectively), whereas was only slightly affected by (SI: 59%). This new knowledge about mycobiota from these special sinkhole ecosystems will inform the development of new biorational pesticides.