Synthesis And Fungicidal Activity Of 3,5-diaryl Sclerotiorin Derivatives

Discovery of lead compounds plays an important role in development of green pesticides,and natural products are valuable sources for obtaining lead structures.Accually,natural products have been widely found in pesticide development,since they could provide new types of structural frameworks and novel modes of action,which could be an effective solution to deal with pesticide resistance.Sclerotiorin is a natural product which showed extensive biological activities.Herein,using sclerotiorin as a lead compound,we synthesized a series of sclerotiorin derivatives and tested their fungicidal activities and inhibitory activities against Complex ?.The specific research work is as follows:1?This thesis has briefly summarized synthetic approaches and biological activities of sclerotiorin and its derivatives.2?Based on sclerotiorin,we designed and synthesized 43 new sclerotiorin derivatives.All the compounds have been characterized by 1H NMR,13C NMR,ESI-MS and elemental analysis.3?We tested fungicidal activities of these compounds.Some compounds showed good inhibitory effect against Pythium dissimile,Alternaria solani,Botryotinia fuckeliana,Gibberella zeae under the concentration of 20 ppm.A few compounds show moderate inhibition against Phytophthora infestans,Septoria tritici,Uromyces viciae-fabae under the concentration of 100?200 ppm.Compound ?-6,which showed inhibitory activities against all the seven fungi tested above,demonstrated excellent and broad fungicidal activities.However,these compounds didn't show in vivo fungicidal activities against Sphaerotheca fuliginea,Botrytis cinerea,Rhizoctonia solani under the concentration of 200 ppm.4?We also tested inhibitory activities of these compounds against Complex?.These series of compounds showed excellent inhibitory effect against Complex ?,with IC50 values of most compounds under 100 ?M.Therein sixteen compounds' IC50 values are under 10 ?M and the best one is compound ?-35 whose IC50 is 1.03 ?M.We preliminarily summarized the structure-activity relationship of these compounds and provided a reference guide for further structural modifications.