Fungicidal Activity Of 2-（5H）-Furanone,Polysubstituted 3-ester Furan And 2-ester Pyrrolidone Derivatives

In recent years,with the rapid development of life science,five-membered heterocyclic compounds are widely valued for their significant biological activities,such as antiviral,antitumor,cytotoxic,insecticidal and herbicidal activities.As an important part of heterocyclic compounds,nitrogen-containing and oxygen-containing five-membered heterocyclic compounds are widely applied in the design and synthesis of new pesticides due to their low toxicity,excellent biological activity and easy modification of structure,and the easy introduction of other functional groups.Thus,they have become one of the research hotspots in the field of green pesticide,medicine and other chemical products.Furans as five-membered heterocyclic compounds containing oxygen,play an important role in many fields.Among them,2-（5H）-furanone,an important furan compound widely existing in natural products,has demonstrated many pharmaceutical and pesticide activities.The derivatives containing this structure often exhibit good biological activity.Therefore,many scholars have designed and synthesized a large number of 2-（5H）-furanone derivatives based on 2-（5H）-furanone natural compounds.Many new compounds with excellent biological activity have been reported,especially in anticancer,plant growth regulation,weed control and some other aspects,but there are few studies on the application of bactericidal activity.Pyrrole is a common and very important five-membered nitrogen-containing heterocyclic compound,which can be found in different structural motifs of different pesticides.The pesticides containing pyrrole ring show not only persist and high efficiency,but also good environmental compatibility.At present,many fungicides containing active pyrrole segments have been put into the pesticide market.Considering the high application value of pyrrole compounds especially polysubstituted pyrrolididone,the exploration on their synthetic method and bactericidal activity is of great significance.In order to obtain compounds with higher fungicidal activity,based on the previous work in our research group,in this paper the fungicidal activity has been investigated for compounds containing 2-5（H）-furanone active structural units which have been patented by our group and the polysubstituted 2-ester pyrrolidone compounds,Pyrrolone-derived ionic liquid,polysubstituted 3-ester furan compounds and cyclohexylbutyrate compounds with high diastereoselectivity which were reported by our group previously.Among these compounds,the derivatives containing 2-5（H）-furanone,with certain inhibitory effect on rice tillering,are novel strigolactone analogues.It has low toxicity,good plant tolerance,environmental compatibility and has been tested in rice growth regulation research.The specific research contents include the following two aspects:（1）According to the synthetic procedures reported by our group,57 compounds were synthesized,including 20 compounds containing 2-5（H）-furanone,12 aldol condensation compounds with diastereoselectivity,14 polysubstituted 3-ester furans,5 polysubstituted 2ester pyrrolidone compounds and 6 Pyrrolone-derived ionic liquid.（2）The mycelial growth rate method was used to determine the fungicidal activity of 57 target compounds on six plant pathogens including Fusarium gramineum,Thanateaphorous cucumeris,Colletotrichum orbiculare,Alternaria leaf spot,Botrytis cinereal and Alternaria Solani.At the concentration of 50 μg/mL,most of the compounds exhibit good biological activity,among which 2-5（H）-furanone compounds showed excellent fungicidal activity.The EC50 of compounds A2,A4,A6,A10 and A17 against Thanateaphorus cucumeris were 5.52μg/mL,1.72μg/mL,4.06μg/mL,10.99μg/mL and 3.04μg/mL;the EC50 of compound A4 against Botrytis cinereal was 5.45;Among the compounds,the EC50 of compounds A36 and A43 against Botrytis cinereal was 19.76 μg/mL and 17.61 μg/mL,respectively.Among the polysubstituted 2-ester pyrrolidone compounds,the EC50 of compound B4 against Thanateaphorus cucumeris was 26.14 μg/mL.The study of fungicidal activity indicates that 2-5（H）-furanone derivatives displayed good fungicidal activity,which provided a reference for the design and synthesis of new fungicides.