New insecticidal activity found in secondary metabolites of fungi: Expected to be useful for environmentally friendly insect-controlling agricultural chemicals

September 28, 2023

A joint research group of Setsunan University, University of Tsukuba, Tokyo University of Pharmacy and Life Sciences, Kindai University, and RIKEN CSRS has discovered that secondary metabolites produced by fungi (molds) have an inhibitory activity against enzymes essential for insect growth.

By using genetically modified filamentous fungus where decalin synthase genes are deleted or modified, the research group successfully obtained derivatives that differ from the original biosynthetic product in the decalin configuration. Thinking that these compounds would be useful not only for the evaluation of known biological activities, but also for searching for overlooked biological activities, the group started studying inhibitory activities against insect enzymes, which had not been reported in this group of compounds. Based on the structural similarity between the decalin backbone and ecdysteroids, the group focused on the inhibitory activity of glutathione S-transferase Noppera-bo, which is involved in ecdysteroid biosynthesis. As a result, they found that the cis-decalin derivatives have the inhibitory activity.

The findings are expected to be useful for the development of environmentally friendly insect-controlling agrochemicals.

Original article
PLOS ONE doi: 10.1371/journal.pone.0290851
N. Kato, K. Ebihara ,T. Nogawa, Y. Futamura, K. Inaba, A. Okano, H. Aono, Y. Fujikawa, H. Inoue, K. Matsuda, H. Osada, R. Niwa, S. Takahashi,
"cis-Decalin-containing tetramic acids as inhibitors of insect steroidogenic glutathione S-transferase Noppera-bo".
Shunji Takahashi
Unit Leader
Natural Product Biosynthesis Research Unit