Design,Synthesis And Bioactivity Studies Of Novel Avermectin Bla Derivatives

Avermectin B1 is safe and highly effective bio-pesticide with special modes of action.The structural modifications of avermectin B1 were successful in technique and commerce since several derivatives of it had higher bioactivities or extended insecticidal spectrum.Therefore,avermectin B1 was used as lead compounds for the discovery of new pesticides in this thesis,we taking in full account of its mechanism,physical and chemical characteristics and structure-activity relationship for structural modification,hoping to improve the activity and reduce toxicity.1.Design,synthesis and biological activity studies of avermectin Bla sulfonation derivatives Sulfonylation derivatives have a wide range of biological and physiological activities which are widely applied in agriculture and medicine.For example,sulfonylurea derivatives are mainly used as herbicide and anti-type ? diabetes drugs;sulfonamide derivatives have a variety of biological activities of antibacterial,antiviral and other activities.Three types of avermectin B1a sulfonation derivatives,sulfonyl amidine,sulfonylurea,sulfonamide,were designed and synthesized by introducing sulfonyl groups into the active position of avermectin C-4",C-4',C-13 postions respectively.All derivatives' structure were characterized by 1H NMR,13C NMR,MS,elemental analysis.Bioassay results showed that all the compounds had possessed certain degree of acaricidal,aphicidal,nematicidal activities,and some were better than that of avermectin B1a.2.Design,synthesis and biological activity studies of avermectin B1a urea derivativesUrea(or Thiourea)derivatives refer to compounds containing with urea group collectively.Various substituted peptide bond in urea group had made the urea derivatives having broad biological activities,and thus had been used in the fields of chemistry,agriculture and medicine.Thus,the urea groups was introduced in avermectin C-4" postion,designed and synthesized three types of avermectin B1a urea derivatives,all derivatives' structure were characterized by 1H NMR,MS,elemental analysis.Bioassay results showed that all the cmpounds had possessed certain degree of aphicidal and acaricidal activities and the former was better than the later one.3.Design,synthesis and biological activity studies of avermectin B1a ?-amino phosphonate derivativesThe a-amino phosphonate,as one of the natural a-amino acid analogs with phosphorus,possessed similar structures with phosphoryl amino acids and hydrolysis peptide intermediates,especially the phosphorus atom owned tetrahedral structure,which was similar with hydrolysis intermediates of carboxylic acid derivatives.Therefore,it played significant role in the mimic enzyme and antibody enzyme research.The studies found that ?-amino phosphonates had possessed importment anti-virus,anti-tumor,weeding and bactericidal activities.By using active structural stitching principle,a-amino phosphonate was introduced in the avermectin B1 a C-4"position through FeCl3 catalyzed three-component reaction to explore extended insecticidal spectrum insecticide derivatives with high efficiency,low toxicity.