Turning natural products into insecticide candidates: Design and semisynthesis of novel fraxinellone-based N-(1,3-thiazol-2-yl)carboxamides against two crop-threatening insect pests

Bioorg Med Chem Lett. 2019 Jan 15;29(2):179-184. doi: 10.1016/j.bmcl.2018.12.002. Epub 2018 Dec 3.

Abstract

To improve the insecticidal activities of fraxinellone, two series of fraxinellone-based N-(1,3-thiazol-2-yl)carboxamides containing 25 compounds were prepared by structural modification. Their structures were determined by melting point, optical rotation, IR, 1H NMR and ESI-MS. The steric configurations of compounds 6i, 7d and 7i were unambiguously confirmed by X-ray diffraction further. The bioassay showed that compounds 6b and 6i exhibited more potent larvicidal and growth inhibitory activities against Plutella xylostella Linnaeus and Mythimna separata Walker, respectively. Moreover, compounds 6b and 6i also displayed low cytotoxicity to noncancerous mammalian cells. The structure-activity relationships (SARs) of all target compounds were also observed.

Keywords: 1,3-Thiazole; Cytotoxic activity; Fraxinellone; Insecticidal activity; Structural modification; Structure–activity relationship.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzofurans / chemistry
  • Benzofurans / pharmacology*
  • Biological Products / chemical synthesis
  • Biological Products / chemistry
  • Biological Products / pharmacology*
  • Crystallography, X-Ray
  • Dose-Response Relationship, Drug
  • Insecticides / chemical synthesis
  • Insecticides / chemistry
  • Insecticides / pharmacology*
  • Models, Molecular
  • Molecular Structure
  • Moths / drug effects*
  • Moths / growth & development
  • Structure-Activity Relationship

Substances

  • Benzofurans
  • Biological Products
  • Insecticides
  • fraxinellone