Synthesis, molecular docking and insecticidal activity evaluation of chromones of date palm pits extract against Culex pipiens (Diptera: Culicidae)

Abstract

Agricultural wastes may provide natural alternative to mosquitoes control because of their bioactive components. The current study involved evaluation of the toxicity of date palm pits extracted in methanol 70% against third larval instar of Culex pipiens. Methanolic extract of date palm pits via HPLC yielded two novel chromone flavonoid compounds; chromone 1 and chromone 2. These chromone derivatives were synthetically prepared under laboratory conditions. Results showed that chromone 1 and chromone 2 exhibited excellent insecticidal activity against third larval instar of Cx. pipiens after 24 hours of treatment at LC50 32.359 and 38.717 ppm, respectively and great inhibition of AChE with value -61.48 and -60.45 %, respectively compared to control. Chromone 1 and chromone 2 were theoretically evaluated for interactions with acetylcholinesterase (AChE) using in silico molecular docking techniques. Both experimental and in silico results showed that chromone 1 exhibited higher activity than chromone 2. These results proved that, the chromone derivatives considered to be inhibitors for AChE enzyme in Cx. pipiens.