N-Aryl-N'-ethyleneaminothioureas effectively inhibit acetylcholinesterase 1 from disease-transmitting mosquitoes

Eur J Med Chem. 2017 Jul 7:134:415-427. doi: 10.1016/j.ejmech.2017.03.050. Epub 2017 Mar 27.

Abstract

Vector control of disease-transmitting mosquitoes by insecticides has a central role in reducing the number of parasitic- and viral infection cases. The currently used insecticides are efficient, but safety concerns and the development of insecticide-resistant mosquito strains warrant the search for alternative compound classes for vector control. Here, we have designed and synthesized thiourea-based compounds as non-covalent inhibitors of acetylcholinesterase 1 (AChE1) from the mosquitoes Anopheles gambiae (An. gambiae) and Aedes aegypti (Ae. aegypti), as well as a naturally occurring resistant-conferring mutant. The N-aryl-N'-ethyleneaminothioureas proved to be inhibitors of AChE1; the most efficient one showed submicromolar potency. Importantly, the inhibitors exhibited selectivity over the human AChE (hAChE), which is desirable for new insecticides. The structure-activity relationship (SAR) analysis of the thioureas revealed that small changes in the chemical structure had a large effect on inhibition capacity. The thioureas showed to have different SAR when inhibiting AChE1 and hAChE, respectively, enabling an investigation of structure-selectivity relationships. Furthermore, insecticidal activity was demonstrated using adult and larvae An. gambiae and Ae. aegypti mosquitoes.

Keywords: Acetylcholinesterase 1; Aedes aegypti; Anopheles gambiae; Insecticides; Thiourea; Vector control.

MeSH terms

  • Acetylcholinesterase / metabolism
  • Aedes / drug effects*
  • Aedes / enzymology
  • Animals
  • Anopheles / drug effects*
  • Anopheles / enzymology
  • Cholinesterase Inhibitors / chemistry
  • Cholinesterase Inhibitors / toxicity*
  • Female
  • Humans
  • Insect Proteins / antagonists & inhibitors
  • Insect Proteins / metabolism
  • Insect Vectors / drug effects*
  • Insect Vectors / enzymology
  • Insecticides / chemistry
  • Insecticides / toxicity*
  • Larva / drug effects
  • Larva / enzymology
  • Thiourea / analogs & derivatives
  • Thiourea / toxicity*

Substances

  • Cholinesterase Inhibitors
  • Insect Proteins
  • Insecticides
  • Acetylcholinesterase
  • Thiourea