In Silico Study of the Resistance to Organophosphorus Pesticides Associated with Point Mutations in Acetylcholinesterase of Lepidoptera: B. mandarina, B. mori, C. auricilius, C. suppressalis, C. pomonella, H. armígera, P. xylostella, S. frugiperda, and S. litura.

An in silico analysis of the interaction between the complex-ligands of nine acetylcholinesterase (AChE) structures of Lepidopteran organisms and 43 organophosphorus (OPs) pesticides with previous resistance reports was carried out. To predict the potential resistance by structural modifications in Lepidoptera insects, due to proposed point mutations in AChE, a broad analysis was performed using computational tools, such as homology modeling and molecular docking. Two relevant findings were revealed: (1) Docking results give a configuration of the most probable spatial orientation of two interacting molecules (AChE enzyme and OP pesticide) and (2) a predicted ΔGb. The mutations evaluated in the form 1 acetylcholinesterase (AChE-1) and form 2 acetylcholinesterase (AChE-2) structures of enzymes do not affect in any way (there is no regularity of change or significant deviations) the values of the binding energy (ΔGb) recorded in the AChE-OPs complexes. However, the mutations analyzed in AChE are associated with a structural modification that causes an inadequate interaction to complete the phosphorylation of the enzyme.

Comparative Analysis of a Secondary Metabolite Profile from Roots and Leaves of Iostephane heterophylla by UPLC-MS and GC-MS.

Iostephane heterophylla is a traditional Mexican medicinal plant and is an important source of secondary metabolites with antimicrobial and cytotoxic activity. The aim of this work was to conduct a comparative analysis of secondary metabolites of different roots and leaf extracts of I. heterophylla from two zones in Mexico using ultraperformance liquid chromatography (UPLC) and gas chromatography (GC) coupled with mass spectrometry (MS). Twelve secondary metabolites from roots were identified in the leaves. Five new molecular weight secondary metabolites not previously reported were found. Six bioactive metabolites were quantified (quercetin ≤0.151 mg/mL in root and ≤0.041 mg/mL in leaf; hesperidin ≤0.66 mg/mL in root and ≤0.173 mg/mL in leaf; epicatechin ≤0. 163 mg/mL in root and ≤0.664 mg/mL in leaf; caffeic acid ≤0.372 mg/mL in root and ≤0.393 mg/mL in leaf; chlorogenic acid ≤0.234 mg/mL in root and ≤0.328 mg/mL in leaf; and xanthorrhizol ≤0.667 mg/mL in root), and a selective extraction method was established: quercetin in root and leaf by reflux; hesperidin in leaf by Soxhlet and in leaf by reflux; chlorogenic acid in root by Soxhlet and in leaf by reflux; chlorogenic acid ≤0.234 mg/mL in root and ≤0.328 mg/mL in leaf by ultrasound-assisted extraction; epicatechin in root by ultrasound-assisted extraction; caffeic acid in root by reflux and in leaf by Soxhlet. The most efficient solvent was methanol. This study provides a new secondary metabolite profile found in the leaves of I. heterophylla, highlighting it is an essential source of three bioactive compounds: epicatechin, hesperidin, and quercetin.