Background: Juvenile hormone (JH) signaling inhibitors may be used as insect growth regulators because of their ability to control metamorphosis and reproduction in insects by regulating the action of JH.
Results: We identified ethyl (E)-3-(4-{[7- (4-methoxycarbonylbenzyloxy)-1,4-benzodioxan-6-yl]methyl}phenyl)prop-2-enoate (EMBP) and observed its strong precocious metamorphosis-inducing activity against silkworm larvae. To further elucidate its mechanism of action, we investigated the effect of EMBP on the JH-mediated signaling pathway in vitro and in vivo. In a reporter assay using a Bombyx mori cell line, EMBP strongly suppressed the induction of reporter gene expression by Juvenile hormone I (JH I) in a concentration-dependent manner. A parallel rightward shift was observed in the dose-response curve of JH I after treatment with EMBP, indicating that EMBP competitively inhibited JH. Moreover, we monitored developmental changes in the JH-responsive gene, Krüppel homolog 1 (Kr-h1), and ecdysone-responsive gene, Broad-Complex (BRC), in EMBP-treated silkworm larvae. EMBP suppressed only the expression of Kr-h1 in third-instar larvae.
Conclusion: Our results demonstrated that EMBP specifically regulates the JH-mediated Kr-h1 signaling pathway. EMBP could be used as a lead compound in the development of new insect growth regulators. © 2023 Society of Chemical Industry.
Keywords: insect growth regulator; juvenile hormone; precocious metamorphosis; structure-activity relationship.
© 2023 Society of Chemical Industry.