Design, synthesis and acaricidal/insecticidal activities of etoxazole analogues

On the basis of etoxazole, a series of novel 2-(2,6-difluorophenyl)-4-(4-substituted phenyl)-1,3-oxazolines containing a sulfur ether moiety were designed and synthesized via the key intermediate N-(1-(4-(bromomethyl)phenyl)-2-chloroethyl)-2,6-difluorobenzamide. The bioassay results showed that most of these designed target compounds exhibited excellent acaricidal activity against both the eggs and larvae of Tetranychus cinnabarinus, especially the eggs. Among compounds with high activity against the eggs of mites, the LC50 values of 2, 11, 17, and 19 were 0.0003, 0.0002, 0.0005, and 0.0008 mg L(-1), respectively, much lower than that of etoxazole (0.0089 mg L(-1)). Compound 2 was chosen to evaluate the acaricidal activity in the field, and the results displayed that at a concentration of 22 mg kg(-1), 2 had a much better control effect than etoxazole against both T. cinnabarinus and P. latus on eggplant. Some compounds also showed good insecticidal activities against oriental armyworm and mosquito. On the basis of our research, the newly found structure-activity relationship may guide the development of new acaricides/pesticides that are required in the agriculture market.

Section: Resultsmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 88%

Section: ■ Introductionmentioning

confidence: 99%

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Design, Synthesis, and Acaricidal/Insecticidal Activities of Oxazoline Derivatives Containing a Sulfur Ether Moiety

Liu

et al. 2015

“…Except for the fungicidal and herbicidal activities mentioned above, DE-based derivatives have been shown to exert important insecticidal and acaricidal potency as well. In 2012 and 2013, et al designed two series of novel oxazoline-DE hybrids bearing pyrazole (see formula 174, Figure 28) 231 and 2,6-difluorophenyl (see formula 175, Figure 28) 232 groups at the 2position, respectively. The former series compounds exhibited broad-spectrum insecticidal activities against bean aphid, cotton bollworm, mite spider, and mosquito.…”

Section: ■ Introductionmentioning

confidence: 99%

Diaryl Ether: A Privileged Scaffold for Drug and Agrochemical Discovery

Chen

Xiong

Yang

et al. 2020

100

Diaryl ether (DE) is a functional scaffold existing widely both in natural products (NPs) and synthetic organic compounds. Statistically, DE is the second most popular and enduring scaffold within the numerous medicinal chemistry and agrochemical reports. Given its unique physicochemical properties and potential biological activities, DE nucleus is recognized as a fundamental element of medicinal and agrochemical agents aimed at different biological targets. Its drug-like derivatives have been extensively synthesized with interesting biological features including anticancer, anti-inflammatory, antiviral, antibacterial, antimalarial, herbicidal, fungicidal, insecticidal, and so on. In this review, we highlight the medicinal and agrochemical versatility of the DE motif according to the published information in the past decade and comprehensively give a summary of the target recognition, structure–activity relationship (SAR), and mechanism of action of its analogues. It is expected that this profile may provide valuable guidance for the discovery of new active ingredients both in drug and pesticide research.

“… In 2004, Matsumura and co-workers by isotope-labeling experiments found that the benzoylurea insecticide diflubenzuron and antidiabetic glibenclamide both targeted the SUR protein in Drosophila melanogaster and Blattella germanica; such binding made chitin not be biosynthesized normally. , In 2012, Van Leeuwen et al also used the technology of calcofluor white (CFW) staining to demonstrate that etoxazole indeed inhibited chitin biosynthesis in Tetranychus urticae . According to the similarity in the action mechanism of the 2,4-diphenyl-1,3-oxazolines and benzoylureas, both belonging to chitin synthesis inhibitors (CSIs), , our research group preliminarily determined the binding affinity of etoxazole and oxazoline derivatives to SUR in vitro by the fluorescence polarization method and found that the trend of their binding affinity was almost consistent with their acaricidal activities against Tetranychus cinnabarinus in vivo . Therefore, it was verified that oxazoline derivatives, including etoxazole, could bind with SUR, resulting in the inhibition of chitin biosynthesis in the mite body .…”

Section: Introductionmentioning

confidence: 99%

Design, Synthesis, Acaricidal/Insecticidal Activity, and Structure–Activity Relationship Studies of Novel Oxazolines Containing Sulfone/Sulfoxide Groups Based on the Sulfonylurea Receptor Protein-Binding Site

Liu

et al. 2016

Enormous compounds containing sulfone/sulfoxide groups have been used in a variety of fields, especially in drug and pesticide design. To search for novel environmentally benign and ecologically safe pesticides with unique modes of action, a series of 2,4-diphenyl-1,3-oxazolines containing sulfone/sulfoxide groups as chitin synthesis inhibitors (CSIs) were designed and synthesized on the basis of the sulfonylurea receptor protein-binding site for CSIs. Their structures were characterized by (1)H and (13)C nuclear magnetic resonance and high-resolution mass spectrometry. The acaricidal and insecticidal activities of the new compounds were evaluated. It was found that most of the target compounds displayed wonderful acaricidal activities against spider mite (Tetranychus cinnabarinus) larvae and eggs. Especially compounds I-4, II-3, and II-4 displayed higher activities than commercial etoxazole at a concentration of 2.5 mg L(-1). Some target compounds exhibited insecticidal activities against lepidopteran pests. The present work demonstrated that these compounds containing sulfone/sulfoxide groups could be considered as potential candidates for the development of novel acaricides in the future.