Design,Synthesis And Insecticidal Activity Of Betulinic Acid Derivatives

Betulinic acid is a pentacyclic triterpenoid compound that widely exists in nature and has many biological activities such as anti-tumor,anti-viral and anti-parasite.In recent years,along with in-depth studying of the prevention and the control of agricultural pests from pentacyclic triterpenes,design and synthesis of betulinic acid derivatives as novel botanical insecticides has important research value.This paper aims at preventing agricultural pests,using betulinic acid as a lead compound to design and synthesize four series of betulinic acid derivatives.Further test their biological activity against rice planthoppers,Mythimna separata,Spodoptera litura and Aphis fabae were carried out.Several betulinic derivatives with potential insecticidal activity have been obtained.The full text is mainly composed of four parts:Part 1.The distribution,extraction,design,biological activity of betulinic acid inclulding its analogues and the application of pentacyclic triterpenoids in insecticidal applications are discussed.Part 2.Design,synthesis and insecticidal activity of betulinic acid derivatives in A-ring and E-ring.Using betulinic acid and betulin as a lead compound,a substituent such as anthraquinone,amine,and heterocyclic ring was introduced into the A ring of betulinic acid,at the same time,substituents such as amide and ester were introduced at the C-28 of E ring.the target compounds were tested for insecticidal activity against agricultural pests.Including planthoppers,Mythimna separata and Spodoptera litura.The activity test showed that the insecticidal activity of the target compound was significantly increased.For example,the half mortality rate of BHZ-2 to the rice planthopper was 54.71 μg/ml.Part 3.Design,synthesis and insecticidal activity of 3-amide betulinic acid derivatives.Betulinic acid was used as a lead compound to design and synthesize the betulinic acid derivatives with C-3 amino substituted structure,and their activity against Aphis fabae were tested.Results showed that the lethal rate of BHZXA-1was 41.67% at 50 μg/ml,and better than the control drug.Part 4.Design,synthesis and insecticidal activity of 30-tertiary amine modified betulinic acid derivatives.Betulinic acid was used as a lead compound to design and synthesize the betulinic acid derivatives with C-30 tert-amine substituted structure.Their activity against Aphis fabae were tested,and the activities of some compounds were comparable to the control drug.