A potential insect growth regulator: synthesis and bioactivity of an allatostatin mimic

Insect growth regulators play an important role in Integrated Pest Management systems. Cockroach-type allatostatins (FGLamides) (ASTs), which are a family of basic peptides first isolated from brains of Diploptera punctata were originally discovered on the basis of their ability to inhibit the production of juvenile hormone by the corpora allata. For this reason, the ASTs can be regarded as possible IGR candidates for pest control although the absence of effect in vivo, rapid degradation and high production costs of the natural peptides preclude their use in pest management. However, we have synthesized a new AST mimic, H17, from the pentapeptide C-terminal active core of the AST. This mimic is able to significantly inhibit the biosynthesis of JH by cockroach CA in vitro (IC(50) value: 12 nM) and in vivo following injection (IC(50) value: 33 nM). H17 also shows a highly significant inhibition of JH production in topical cuticular assays in vivo. Our results suggest that H17 has potential as an IGR for cockroach control.