The nutritional value versus toxicity was conducted in muscles, gonads, livers, and skin of Tetraodon lineatus from Lake Nasser, Egypt, during 2018. Its overall moisture was 74.92 ± 2.27 muscles, 72.45 ± 2.887 gonads and 35.49 ± 5.55 % livers. The livers recorded the highest crude protein (23.66 ± 3.48%) and total lipids (36.45 ± 6.32%). The annual total protein in muscles was 16.91 ± 2.54%, while the annual total lipids were 3.39 ± 1.05 %. Leucine was the most abundant (0.548 mg/g) ˃ isoleucine (0.284 mg/g) of the essential amino acids. Sixteen fatty acids were recorded (12: SFAs, 4: MUSFAs), with butyric acid predominating. Assessment of tetrodotoxin (TTX) as mouse per unit (MU/g), gave the highest toxic abundant for skin (53.13%) ˃ gonads (34.6)  ˃ muscles (12.9) and no detection in the livers. The average toxicity in all organs is at a low level and lower than the maximum permissible limits (<100 MU/g) despite strongly toxic samples. The abundance of all toxic samples was in summer (44.8%) and spring (36.8), followed by winter and autumn (9.2 each one). Muscles, gonads, and livers showed no response to toxicity tests during winter. On the contrary, muscles were highly contaminated with TTX in summer (25%) and spring (22.2). The findings confirmed that T. lineatus has a good nutritional value, toxicity restrictions in specific organs and seasons, recommending its better utilization with more studies to confirm its safety for human consumption.

Worldwide, the bird cherry-oat aphid, Rhopalosiphum padi, (R. padi) affects wheat, sorghum, and other grain crops, and conventional pesticides to control this aphid negatively affects the surrounding environment. Therefore, knowing the entomotoxicity of different chemical compounds against R. padi is an important step to control these pests. Thus, we aimed to evaluate the toxicity of different nicotinic acetylcholine receptor modulators (thiamethoxam, imidacloprid, acetamiprid, and sulfoxaflor) and the octopamine receptor agonists’ (ORAs hereon) synergistic effect (chlordimeform and amitraz) on the selected pesticides’ toxicity against R. padi adults. We found that chlordimeform was more effective than amitraz (LC₅₀: 144.01 and 238.33 µg/mL, respectively), after 24-h of exposure. Sulfoxaflor was the most toxic pesticide (LC₅₀ values were 4.61 and 0.44 µg/mL), whereas we identified acetamiprid as the least potent one (LC₅₀ values were 111.82 and 88.69 µg/ mL). Thiamethoxam was the most effective neonicotinoid pesticide among those we used. Chlordimeform and amitraz had synergized effects with the surveyed pesticides, with amitraz showing the highest synergistic ratio. These findings indicate that ORAs are promising tools to increase the selected pesticides’ effectiveness on R. padi control, which may contribute to the decrease in the use of generic pesticides, the emergence of resistant strains, and, consequently, their impacts on the environment

Different methods for the synthesis of pyridine derivatives as well as the chemical reactivity profiles and structures of these substances are reviewed. The utility of these compounds as precursors is emphasized in the synthesis of many heterocycles that are pharmacologically active organic compounds and agrochemicals. This review results from a literature survey containing some synthetic methods and applications of pyridine derivatives.

Starting from 3-cyano-4, 6-distyrylpyridin-2 (1H)-thione (1), the compound N-(4-chlorophenyl)-2-((3-cyano-4, 6-distyrylpyridin-2-yl) thio) acetamide (2) was prepared. Compound (2) underwent cyclization upon heating in ethanolic sodium ethoxide solution to give the corresponding cyclized form 3-amino-N-(4-chlorophenyl)-4, 6-distyrylthieno [2, 3-b] pyridine-2-carboxamide (3). The elemental analyses and spectroscopic data of compounds (2) and (3) are in agreement with their proposed structures. Their insecticidal activity against cowpea aphid, Aphis craccivora Koch, was studied. The results of insecticidal activity for compounds (2) and (3) against the nymphs and the adults of the tested insects exhibited that compounds (2) and (3) have a higher insecticidal activity than that of acetamiprid, a reference insecticide, after 24 h of treatment.

In examining for unique insecticidal agents, two derivatives namely, 2-((3-cyano-4, 6-distyrylpyridin-2-yl) thio)-N-(4-nitrophenyl) acetamide (2) and 3-amino-N-(4-nitrophenyl)-4, 6-distyrylthieno [2, 3-b] pyridine-2-carboxamide (3) were synthesized from distyrylpyridine-2-thione (1). The new compounds were structurally clarified by spectral and elemental analysis data. The insecticidal activity of these compounds were carried out against cowpea aphid, Aphis craccivora Koch. It is demonstrated that the compounds 2 and 3 have noteworthy insecticidal activity against nymphs of cowpea aphid with LC50 values of 0.025-0.027 ppm and 0.005-0.006 ppm after 24 h and 48 h of treatment, respectively. Also, the compounds 2 and 3 have noteworthy insecticidal activity against adults of cowpea aphid with LC50 values of 0.112-0.129 ppm and 0.014-0.015 ppm after 24 h and 48 h of treatment, respectively, that were comparable to that of the control acetamiprid.