Discovery of rosin‐based acylhydrazone derivatives as potential antifungal agents against rice Rhizoctonia solani for sustainable crop protection

Abstract

BACKGROUND The use of fungicides to protect crops from diseases is an effective method, and novel environmentally friendly plant‐derived fungicides with enhanced performance and low toxicity are urgent requirements for sustainable agriculture. RESULTS Two kinds of rosin‐based acylhydrazone compounds were designed and prepared. Based on the antifungal activity assessment against Rhizoctonia solani, Fusarium oxysporum, Phytophthora capsici, Sclerotinia sclerotiorum, and Botrytis cinerea, acylhydrazone derivatives containing a thiophene ring were screened and showed an inhibitory effect on rice R. solani. Among them, Compound 4n, with an electron‐withdrawing group on the benzene ring structure attached to the thiophene ring, showed optimal activity, and the EC50 value was 0.981 mg L−1, which was lower than that of carbendazim. Furthermore, it was indicated that 4n could affect the mycelial morphology, cell membrane permeability and microstructure, cause the generation of reactive oxygen species in fungal cells, and damage the nucleus and mitochondrial physiological function, resulting in the cell death of R. solani. Meanwhile, Compound 4n exhibited a better therapeutic effect on in vivo rice plants. However, the induction activity of 4n on the defense enzyme in rice leaf sheaths showed that 4n stimulates the initial resistance of rice plants by removing active oxygen, thereby protecting the cell membrane or enhancing the strength of the cell wall. Through the quantitative structure–activity relationship study, the quantitative chemical and electrostatic descriptors significantly affect the binding of 4n with the receptor, which improves its antifungal activity. CONCLUSION This study provides a basis for exploiting potential rosin‐based fungicides in promoting sustainable crop protection. © 2022 Society of Chemical Industry.

Functionalized boron nitride nanosheets conjugated with plant micronutrients as seed dressing agents towards control of bacterial wilt disease

“…8 Therefore, it is critical to develop sustainable management strategies for the control of bacterial wilt diseases, which can be strategically approached by screening resistant seeds, soil fumigation treatment with natural essential oils, chemical control, and microbial control. [9][10][11][12][13][14] Currently, the major strategy is still chemical control, involving applying agricultural bactericides (such as Thiessen copper, Zn thiazole, etc.) or essential oils with antibacterial active ingredients (such as phenols, terpenes, etc.)…”

Design and Synthesis of Antifungal Candidates Containing Triazole Scaffold from Natural Rosin against Valsa mali for Crop Protection

“…For the curative effect (CE), first, the V. mali were inoculated and incubated for 48 h. Then, the prepared drug was evenly sprayed on the apple branches, and equal concentration of acetone was set as blank control. The PE and CE of compound 3f and fluconazole against V. mali were measured on apple tree branches with different concentrations (25,50, and 100 μg/mL). The PE and CE were calculated using formula 2.…”

“…Effect of Compound 3f on Mycelial Morphology and Ultrastructure. According to the previous method, 25 the mycelium were treated with acetone and compound 3f (EC 50 value) as blank and treatment groups, respectively. Then, the mycelium was cultured at 25 °C on PDA medium for approximately 3 days, and the samples were prepared according to scanning and transmission EM.…”

A Comprehensive Investigation of Hydrazide and Its Derived Structures in the Agricultural Fungicidal Field

“…In order to explore the fungicidal mechanism of compound 76n , SEM and TEM observations and plasma membrane permeability were performed by Xu et al The results suggested that the R. solani hyphae treated with 76n were shriveled and folded and the organelles were partially blurred. Furthermore, compound 76n could apparently increase the cell membrane permeability.…”

“…Using rosin as a precursor, Xu et al 80 designed and synthesized two series of rosin-based acylhydrazone compounds 75 and 76 and determined their antifungal activity. The bioassays indicated that all compounds 75a−75p showed weak antifungal activity, with inhibition rates between 1.4% and 34.9%.…”