Design,Synthesis And Biological Activity Studies Of Dehydrozingerone,Waltherione A And Benzoylurea Derivatives

Based on the pesticide molecular design strategy,three types of 39 compounds were designed and synthesized,and 30 new compounds were obtained.All the compounds were confirmed by 1H NMR,13C NMR and HRMS.In the first part,a total of 30 dehydrozingerone derivatives were designed and their structure-activity relationship was studied.The bioactivity results showed that the antifungal activity of all compounds was higher than that of the natural product dehydrozingerone at 50 μg mL-1,and compounds 13,16,18,19 and 27 exhbited broad-spectrum antifungal activity.The antifungal activities of these compounds were even higher than that of the commercial pyrimethanil and azoxystrobin,and especially the inhibitory activities of compound 27 against 15 plant pathogenic fungi were above 94%at 50 μg mL-1.In addition,these five compounds also showed good nematicidal activity against the second-instar larvae of Meloidogyne incognita.The nematicidal activity of compounds 16,19 and 27 on the second-instar larvae of Meloidogyne incognita for 72h at 250 μg mL-1 were 74.8%,68.6%and 64.4%respectively,and the nematicidal activity of compounds 13,18 on the second-instar larvae of Meloiclogyne incognita for 24h at 250 μg mL-1 were 100%.The results indicated that these five compounds have potential for further structural optimization,and it is expected that a compound with both fungicidal and nematicidal activity will be found in the future.In the second part,five Waltherione A analogues were designed and synthesized,and the preliminary studies of their structure-activity relationship were completed.Preliminary results indicate that the pyridone structure on the right side of structure of Waltherione A has almost no effect on nematicidal activity,while its seven-membered bridge structure shows certain nematicidal activity,which is worthy of further exploration.In the third part,four benzoylpyrimidineurea compounds were designed and synthesized,and their fungicidal activity and the acute toxicity to zebrafish embryos were studied.The antifungal activity of compounds Ⅱ-2 and Ⅱ-3 against Sclerolinia sclerotiorum was tested at 3 mg mL-1.and the protective activities were 55.7%and 83.0%respectively.In addition,we also tested the acute toxicity of compounds Ⅱ-3 and Ⅱ-4 on zebrafish embryos.The results showed that compounds Ⅱ-3 and Ⅱ-4 were low toxicity compounds for zebrafish embryos with LC50 of 21.668 μg mL-1 and 378.387 μg mL-1.