Green synthesis, characterization, and biochemical impacts of new bioactive isoxazoline‐sulfonamides as potential insecticidal agents against the Sphodroxia maroccana Ley

Abstract

BACKGROUNDSphodroxia maroccana Ley is a pest of cork oak crops that damages the roots of seedlings and can severely impair cork oak regeneration. Since the banning of carbosulfan and chlorpyriphos, which were widely used against the larvae of Sphodroxia maroccana because of their harmful impact on the environment, until now there has been no pesticide against these pests. Therefore, it is particularly urgent to develop highly effective insecticidal molecules with novel scaffolds. Isoxazolines are a class of insecticides that act on γ‐aminobutyric acid (GABA)‐gated chloride channel allosteric modulators. In this work, a green synthesis of novel 3,5‐disubstituted isoxazoline‐sulfonamide derivatives was achieved in water via ultrasound‐assisted four‐component reactions, and their insecticidal activities against fourth‐instar larvae of S. maroccana were evaluated.RESULTSMost of the tested compounds showed insecticidal activity compared to fluralaner as positive control and commercially available insecticide. Especially, the isoxazoline‐secondary sulfonamides containing halogens (Br and Cl) on the phenyl group attached to the isoxazoline, 6g (LC50 = 0.31 mg/mL), 6j (LC50 = 0.38 mg/mL), 6k (LC50 = 0.18 mg/mL), 6L (LC50 = 0.49 mg/mL), 6m (LC50 = 0.24 mg/mL), 6q (LC50 = 0.46 mg/mL), exhibited much higher larvicidal activity than fluralaner (LC50 = 0.99 mg/mL).CONCLUSIONNovel isoxazolines containing sulfonamide moieties were designed, synthesized and confirmed by two single‐crystal structures of 4e and 6q. Their bioassay results showed significant larvicidal activity with significant morphological changes in vivo. These results will lay the foundation for the further discovery and development of isoxazoline‐sulfonamide derivatives as novel crop protection larvicides of cork oak. © 2023 Society of Chemical Industry.

Lethal, Sublethal, and Offspring Effects of Fluralaner and Dinotefuran on Three Species of Bactrocera Fruit Flies

“…This phenomenon was also observed in Plutella xylostella (L.) larvae, with the LC 50 of fluralaner being 0.02 mg/L, and that of dinotefuran exceeding 100 mg/L (feeding on a dipped leaf) [ 14 , 38 ]. The high toxicity of fluralaner has also been reported in Sphodroxia maroccana Ley [ 39 ] and Spodoptera frugiperda (J.E. Smith) [ 14 ], suggesting that fluralaner holds promise for diverse applications.…”

Design, synthesis and insecticidal activity of novel Isoxazoline Acylhydrazone compounds

“…9 Recently, isoxazoline insecticide have attracted the attention of scientists, due to their unique structure and different target points with GABA gated chloride channel (GABACl). [10][11][12][13][14][15][16][17][18][19][20][21] Using this skeleton as a starting point for further modification is highly desirable in the quest to develop new insecticides.…”

(3-(4-Chlorophenyl)-4,5-dihydroisoxazol-5-yl)methyl Benzenesulfonate

“…Compounds bearing an isoxazoline moiety are considered a significant class of nitrogen and oxygen atom-containing heterocyclic products, attracting attention from organic and medicinal chemists due to their large spectrum of biological properties such as antibacterial [1,2], antimicrobial [3], anti-inflammatory [4], anticancer [5,6], antidiabetic [7] and anti-Alzheimer effects [8]. Moreover, isoxazoline derivatives are also known by their agrochemical properties as herbicidal [9], insecticidal [10][11][12] and acaricidal agents [13]. On the other hand, sulfonic esters are clearly identified for their crucial role in the synthesis of organic compounds and have shown interesting pharmacological properties in the past decade [14][15][16].…”