The development of effective insecticides is crucial for sustainable agriculture. This research focuses on a series of pyridine derivatives (3–9) that were prepared and evaluated for their agricultural bioefficacy as potential insecticides against cowpea aphid, Aphis craccivora Koch (Homoptera: Aphididae). The results demonstrate significant variations in bioefficacy among the tested compounds. Toxicity index analysis revealed the following order of insecticidal activity: 8>4>6>3>5>7>9, highlighting compound 8 as the most potent. Furthermore, potential binding interactions were elucidated through molecular docking studies between these compounds and relevant insect target proteins. So, the observed bioactivity trends were rationalized with the use of the docking data, which offered useful information on the binding affinities and molecular interactions. AChE, or acetylcholine esterase (PDB ID: 2ACE), has been docked against the seven synthetic molecules (3–9). Interestingly, compounds (2-(pyridin-2-ylthio)acetonitrile; 8), (2-(pyridin-2-ylthio)acetic acid; 6), and (ethyl 2-(pyridin-2-ylthio)acetate; 4) had the highest binding affinity, with respective docking scores (S) of -7.51, -7.45, and -7.12 kcal/mol, while compounds (thieno[2,3-b]pyridine derivatives; 7 and 9) had the lowest binding affinity (S=-6.52 and -6.73 kcal/mol, respectively). According to protein-ligand docking configurations, these compounds exhibited a range of binding interactions inside the 2ACE active site. Hence, this study contributes to the development of new pyridine-based insecticides for sustainable pest management in agricultural applications.

The white mango scale insect Aulacaspis tubercularis (Newstead) (Hemiptera: Diaspididae), which causes defoliation, drying out of young twigs, dieback, poor flowering, and decreased fruit output, causes serious damage to mango trees in Egypt. Attacks on mango fruits result in pink imperfections that lower their value as a commercial and export item. The current report aims to support the development of integrated management plans to combat A. tuberculosis and to identify more effective, eco-friendly insecticides. The bug may cause a considerable decrease in mango production and jeopardize the sustainability of mango plantation production if no management measures are taken. Currently, the application of a small number of insecticides—the majority of which have poor performance and are disruptive is the primary method used to manage A. tubercularis. In order to suppress this insect, we created novel pesticides called insect growth regulators (N, N′-substituted benzamide derivatives). By using both traditional and elemental spectroscopic investigations (IR, 1HNMR, and 13CNMR), these synthesized compounds which are linked to the most well-known insect growth regulator insecticides had their structures validated. The findings showed that A. tubercularis nymphs were more responsive to the evaluated treatments than adult females. After one day of application, all tested treatments resulted in a sizable proportion of mortality; the percentage of mortality increased with time for both A. tubercularis nymphs and adult females. Furthermore, the treatment with compound 3b was more effective than other synthesized compounds, with a LC50 of 0.318 ppm against nymphs and a LC50 of 0.993 ppm against adult females of A. tubercularis. While the treatment with compound 5 was the least toxic for controlling this pest, many assessments are essential to studying the efficacy of these treatments on advantageous insects.

The following work could bring new insights into the application of heterocyclic N, N′-substituted thiobenzamide derivatives as novel pesticides. Insect growth regulators such as chitin synthesis inhibitors seem promising because of their specific mode of action on insects and their lower toxicity against vertebrates than conventional insecticides. Thus, a novel series of thiobenzamide derivatives have been prepared in a pure state. The structure of these synthesized compounds which related to the most famous insect growth regulator insecticides, were confirmed by elemental and modern spectroscopic analyses (IR, UV, ¹HNMR and ₁₃CNMR). Toxicological and biochemical parameters of the synthesized compounds against the cotton leafworm, Spodoptera littoralis under laboratory conditions were also investigated. Regarding the determined LC₅₀ value for compound 2,4-Dichloro-N-[(2-methoxyphenyl)carbamothioyl]- benzamide 14 showed the most potent toxic effects than the other synthetic target compounds, with LC50 46.84 ppm of 2nd instar larvae and LC50 148.05of the 4th instar larvae.

In our work we study the toxic effects of the prepared pyridine and pyradazine derivatives. Five compounds have been synthesized in pure state as reported procedures, and their toxicity as potential insecticidal agents against adult and nymphs of Aphis nerii were screened. The toxicity data in adults, exhibited that compound 6a is more toxic than other synthesized compounds, which LC50 was1.04 ppm while, in nymph compound 4a is more toxic than other synthesized compounds, which LC₅₀ was 0.02 ppm. The other screened compounds showed weak to strong toxicological activity. The structure-activity relationships (SAR) for these compounds were also discussed.