New Terpenoids from Viguiera dentata: In Silico Pesticide-Likeness Properties, Acetylcholinesterase Inhibition, Molecular Docking, and Evaluation against Spodoptera frugiperda.

The chemical analysis of the melliferous plant Viguiera dentata (Asteraceae) yielded cycloartanes 1-9 (including the new compounds 7-9), ent-kaurenes (10-15), diversifolin (16) and other constituents. The structure of 9 was confirmed by X-ray analysis. To evaluate the insecticidal potential of its constituents, in silico pesticide-likeness calculations for structures 1-16 were performed indicating no violations of the Tice rules. Tests for activity against acetylcholinesterase revealed that only cycloartanes 1 (78.85 µM) and 6 (53.54 µM) inhibited the enzyme. Molecular docking analysis showed interactions between compounds 1, 10, and 13, with Y337, a key amino acid in the catalytic site. A bioassay against Spodoptera frugiperda revealed that compounds 1, 2, 9, 10, and 13 displayed activity (50% lethal concentration for larval mortality [LC] 51.61, 84.56, 99.66, 24.69, and 62.40 ppm, respectively; reference: betulinic acid LC 94.25 ppm). Thus, specific cycloartanes and ent-kaurenes were identified as insecticidal compounds of V. dentata against S. frugiperda.