Design, Synthesis and Antifungal/Nematicidal Activity of Novel 1,2,4-Oxadiazole Derivatives Containing Amide Fragments

Abstract

Plant diseases that are caused by fungi and nematodes have become increasingly serious in recent years. However, there are few pesticide chemicals that can be used for the joint control of fungi and nematodes on the market. To solve this problem, a series of novel 1,2,4-oxadiazole derivatives containing amide fragments were designed and synthesized. Additionally, the bioassays revealed that the compound F15 demonstrated excellent antifungal activity against Sclerotinia sclerotiorum (S. sclerotiorum) in vitro, and the EC50 value of that was 2.9 μg/mL, which is comparable with commonly used fungicides thifluzamide and fluopyram. Meanwhile, F15 demonstrated excellent curative and protective activity against S. sclerotiorum-infected cole in vivo. The scanning electron microscopy results showed that the hyphae of S. sclerotiorum treated with F15 became abnormally collapsed and shriveled, thereby inhibiting the growth of the hyphae. Furthermore, F15 exhibited favorable inhibition against the succinate dehydrogenase (SDH) of the S. sclerotiorum (IC50 = 12.5 μg/mL), and the combination mode and binding ability between compound F15 and SDH were confirmed by molecular docking. In addition, compound F11 showed excellent nematicidal activity against Meloidogyne incognita at 200 μg/mL, the corrected mortality rate was 93.2%, which is higher than that of tioxazafen.

Design, Synthesis, and Bioactivity of Novel Quinazolinone Scaffolds Containing Pyrazole Carbamide Derivatives as Antifungal Agents

“…It was provided by the Guizhou Institute of Plant Protection. In this study, the in vitro antifungal activity of the target compound 6a 1 -a 32 against R. solani was screened using the mycelial growth rate method [ 27 , 28 ]. The commercial fungicides fluconazole and bixafen were selected as the positive controls.…”

Design, Synthesis, and Biological Activity of Novel Chalcone Derivatives Containing an 1,2,4-Oxadiazole Moiety

“…However, Tioxazafen has not formally been used on a large scale in agricultural production. To enhance the flexibility of the structure of Tioxazafen and discover the high activity 1,2,4-oxadiazole compound, some 1,2,4-oxadiazole derivatives containing 1,3,4oxadiazole/thiadiazole and amide moieties with good nematocidal, antibacterial, and antifungal activities have been synthesized (Zhu, et al, 2020;Liu, et al, 2022).…”

Benzamides Substituted with Quinoline-Linked 1,2,4-Oxadiazole: Synthesis, Biological Activity and Toxicity to Zebrafish Embryo

“…Apart from their applications in medicine [4], quinoline derivatives have shown potential in pesticides, such as insecticidal [5][6][7], herbicidal [8] and fungicidal activities [9][10][11][12]. As the bioisostere of the amide, the 1,2,4-oxadiazole heterocycle has good hydrolytic and metabolic properties [13], and exhibits a wide range of biological activities in the field of pesticides [14][15][16][17][18][19]. In addition, there have already been quite a few products containing quinoline or 1,2,4-oxadiazole scaffold launched successively, including quinoxyfen [20], ipflufenoquin [21], quinmerac, tioxazafen and oxolamine (Figure 1).…”