In this study, 22 novel formononetin derivatives bearing benzothiazole were designed and synthesized, and their antifungal activities against nine plant pathogens were evaluated. H2 exhibited promising activity against Phomopsis sp. (P. sp.) (EC50 = 9.85 μg/mL), superior to azoxystrobin (Az, EC50 = 41.1 μg/mL). At 200 μg/mL, H2 showed curative and protective efficacies of 58.4 and 64.5% against kiwifruit soft rot, outperforming Az (41.6 and 48.2%). Preliminary phenotypic investigations suggested that H2 might disrupt cell wall and membrane integrity, causing electrolyte leakage and malondialdehyde (MDA) accumulation, while mitochondrial membrane potential dissipation further hinted at impaired mitochondrial function. Although the precise molecular target remains unknown, H2 shows promise as a lead candidate, and the benzothiazole moiety appears critical for enhancing activity. This study provides a preliminary basis for developing eco-friendly fungicides.
Dan Shen, Xiaoyan Pan, Han Yang et al.· Journal of Agricultural and...· 0 citations
Twenty-three novel flavonol derivatives bearing a 1,2,3,4-tetrahydroquinoline (THQ) scaffold were designed and synthesized, and their antifungal activities against eight plant pathogenic fungi were evaluated. Several compounds exhibited 100% inhibition against Sclerotinia sclerotiorum and Phytophthora capsici (Pc). Among them, Q8 showed the most potent activity against Pc with an EC50 value of 4.1 μg mL–1, superior to azoxystrobin (69.0 μg mL–1) and fluopyram (123.2 μg mL–1). In vivo tests on chili fruits demonstrated that Q8 at 200 μg mL–1 provided superior curative and protective effects (73.7 and 80.8%) compared to azoxystrobin (53.0 and 54.4%). Mechanistic studies revealed that Q8 disrupted cell membrane integrity and inhibited succinate dehydrogenase (SDH) activity, with computational simulations suggesting a higher binding affinity for SDH than fluopyram. Safety evaluation showed no obvious adverse effects on seed germination or earthworm survival. Collectively, these results indicate that Q8 represents a promising lead compound for fungicide development.
Qingxue Hu, Xiaoting Geng, Fang Tian et al.· Journal of Agricultural and...· 0 citations
