Feasibility study on the use of several phytoecdysteroids as biopesticides via evaluation of their interaction models with Ecdysone receptors of Helicoverpa armigera and Chrysoperla carnea

Helicoverpa armigera (Lepidoptera: Noctuidae) is one of the important pests of cotton with wide host range and cause an irrecoverable damage in the agriculture system in Iran. In the last decade, researchers probe a new technology to produce safe pesticides with some properties like selective effect on target pests and fewer environmental risks on non-target organisms. One of the most popular pesticides is disruptive molting (IGRs) which use widespread in farms. The aim of this article is to evaluate the interaction between some phytoecdysteroids which submitted in data base, during 2013-2015, and Ecdysone receptors in order to control of H. armigera with less adverse effect on Chrysoperla carnea as a natural enemy by molecular Docking. Ecdysone receptor models of H. armigera and C. carnea were designed and their efficacies were estimated. According to Z-score index, qualities of EcR receptors made for H. armigera and C. carnea were equivalent to NMR and X-ray Crystallography methods respectively. Result shown that among tested phytoecdysteroids, 11β-Hydroxy-20-Deoxyshidasterone; 2,3,14,20,26-PentaHydroxy-6-OXO-Stigmast-7-ENE-22.26-Lactol; Callecdysterol A,B,C and Glutinosterone, had minimum inhibition constant (Ki), the most negative bonding energy and minimum changes in RMSD in binding to target pest ecdysone receptor .In conclusion, the mentioned phytoecdysteroids, have a potential to control of H. armigera with fewer side effects on C. carnea life cycle.