Synthesis and fungicidal activity of phenoxybenzamides containing phenylpyrazole
[Aims]Phenoxybenzamides containing phenylpyrazole were designed and synthesized in order to obtain lead compounds with good fungicidal activities.[Methods]The target compounds were synthesized by connecting diphenyl ether and phenylpyrazole fragments through amide bond.The structures of all target compounds were confirmed by 1H NMR and 13C NMR.The fungistatic activities were determined using the mycelial growth rate method,the in vivo protective activity of compound 8f was tested through pot test,and the molecular docking study and scanning electron microscopy preliminary clarified the possible fungistatic mechanism of compound 8f.[Results]At a concentration of 50 mg/L,the target compounds exhibited good fungistatic activities,with compound 8f exhibiting inhibition rates of 87.03％,70.53％and 82.28％against Sclerotinia sclerotiorum,Valsa mali and Gaeumannomyces graminis,respectively.Additionally,the EC50 value of compound 8f against SS.sclerotiorum was 0.76 mg/L,lower than fluxapyroxad(EC50=0.23 mg/L).In pot test,compound 8f possessed effective protective activities against S.sclerotiorum at a concentration of 100 mg/L,with inhibition rates of 77.8％,albeit lower than fluxapyroxad(93.3％).Scanning electron microscope showed that after treated with compound 8f,the mycelium of S.sclerotiorum contracted,protruded and ruptured,thereby inhibiting the normal growth of the mycelium.Molecular docking analysis showed that compound 8f interacted with succinate dehydrogenase(SDH)through hydrogen bonding,p-π and π-π conjugation,and its target may be SDH.[Conclusions]The phenoxybenzamides containing phenylpyrazole exhibit good fungicidal activities,while compound 8f could be a promising fungicide candidate for further investigation.
万方数据
维普
