Synthesis, insecticidal activity, and mode of action of novel imidazopyridine mesoionic derivatives containing an amido group

Abstract

BACKGROUND In our previous work, we applied a new synthetic strategy to design and synthesize a series of imidazopyridine mesoionic derivatives with an ester group. The newly synthesized compounds had excellent insecticidal activity against aphids; however, insecticidal activity against planthoppers was less than satisfactory. In the present study, we designed and synthesized a series of novel imidazopyridine mesoionic compounds, containing an amido group, and these compounds were found to have improved insecticidal activity against planthoppers. RESULTS The bioassay results demonstrated that most of the target compounds had moderate‐to‐good insecticidal activity against Sogatella furcifera, and some exhibited good‐to‐excellent insecticidal activity against Aphis craccivora. Among them, compound C6 had the highest insecticidal activity against S. furcifera and A. craccivora, with LC50 values of 10.5 and 2.09 μg mL−1, respectively. Proteomic results suggested that the differentially expressed proteins mainly were enriched in the nervous system‐related pathways after compound C6 treatment. Enzymatic assay results showed that compound C6 and triflumezopyrim had a certain inhibitory effect on acetylcholinesterase. Molecular docking and real‐time quantitative PCR results indicated that compound C6 not only may act on the nicotinic acetylcholine receptor, but also may interact with the α4 and β1 subunits of this receptor. CONCLUSION The results reported here contribute to the development of new mesoionic insecticides and further our understanding of the mode‐of‐action of imidazopyridine mesoionic derivatives. © 2022 Society of Chemical Industry.

Imidazopyridine Family: Versatile and Promising Heterocyclic Skeletons for Different Applications

“…The main condensations involve: Substituted pyridyl-2-ketones with aromatic aldehydes and ammonium acetate (see Figure 9 ) [ 103 , 126 , 193 , 212 , 213 , 214 ]; Substituted picolylamines (2-(Aminomethyl)pyridin) with carboxylic acids in strongly acidic and dehydrating conditions [ 9 ]; Other couplings involve cyano-pyridines with aromatic aldehydes, picolylamines with thioesters, and cyclizations of 2-picolylamides [ 2 , 46 , 215 , 216 ]. …”

“…Other couplings involve cyano-pyridines with aromatic aldehydes, picolylamines with thioesters, and cyclizations of 2-picolylamides [ 2 , 46 , 215 , 216 ].…”

“…According to current nomenclature, imidazopyridines are generally categorized into various groups based on the position of the nitrogen atoms and the distinct connections between the imidazole and pyridine rings (refer to Figure 1 ). Despite potential variations in composition or nitrogen atom count across individual structures (e.g., imidazo[1,2- a ]pyridine and imidazo[4,5- c ]pyridine), they all fall under the classification of imidazopyridines [ 1 , 2 , 3 , 4 ]. Each imidazopyridine nucleus differs in its peculiar biological, physical, and chemical properties, and these diverse behaviors imply various fields of application [ 5 , 6 , 7 ].…”

Design, Synthesis and Bioactivities of Novel Pyridyl Containing Pyrazole Oxime Ether Derivatives

“…For example, Chlorfluazuron, Pyridalyl, Chlorantraniliprole, and Cyantraniliprole ( Figure 1 ), commercial insecticides with a substituted pyridyl framework, demonstrated wonderful insecticidal properties against some important lepidopterous pests such as Plutella xylostella , Mythimna separata (Walker), and so on [ 14 , 15 ]. More recently, agrochemical scientists are focusing on the research of the structural modification of pyridine-based pesticides, and a number of bioactive compounds containing a pyridyl ring were reported [ 16 , 17 , 18 , 19 ], among which Tetrachloraniliprole and Cyclaniliprole were the typical commercial pesticides [ 20 ]. Therefore, the wide spread use of pyridine compounds as a skeleton in the field of crop protection establishes the pyridyl unit as a vital structural class.…”