Synthesis And Biological Activity Of The New Compounds Based On Rotenone

Rotenone is a natural botanical insecticide which had the advantage of higheffectivity, low toxicity and low residue. It can be used as a lead compound for thedesign of new pesticides. Hereon, The structure of rotenone was modified byintroducing the oxime ether and hydrazone groups into its molecule, which still retainits biological activities groups. according to the principle of superposition of activemolecules and hybridization of sub-structures, hoping to get more efficient and widerspectra of compounds.Two types of rotenone derivatives, rotenone oxime ether and cyproteronerotenone hydrazone, were designed and synthesized. The structures of the newcompounds were characterized by1H NMR and MS, and the insecticidal and fungicidalactivities of the new compounds was tested. The results are as follows:1) Kept the mother ring structure of rotenone, introduced oxime ether group withpesticidal activity into its12-carbonyl,9kinds of rotenone oxime ether derivativeswere designed and synthesized, and the oximation and etherification conditions werestudied.Insecticidal activity tests showed that at the concentration of500mg/L, thecompounds show moderate insecticidal activity against Aphis fabae, especially rotenone oxime [(E)-3-chloro-allyl ether](2d), rotenone oxime[3,3-dimethyl-2-one-butyl](2g), rotenone oxime [(Z)-3-chloro-allyl ether(2c) and rotenone oxime propargyl ether(2b), which possessed the insecticidal activity against Aphis fabae with inhibitory rate of61.9%,61.7%,55.4%and55.1%, respectively. The fungicidal activity tests showed that these series of compounds had no antifungal activity.2)By breaking the connected five rings of rotenone and keeping the activebenzopyran and benzofuran groups,4kinds of N-cyclopropyl rotenone-hydrazone and8species of cyclopropyl rotenone double hydrazone derivatives has synthesized viaintroducing the hydrazone groups into the molecule. The mechanism rearrangementreaction of rotenone and the influence of substituents to the hydrazone reaction werealso discussed.The results of antifungal activity showed that most of these compounds possessedgood to excellent fungicidal activities against Sclerotonia sclerotiorum and Erysiphe graminis, with a high selectivity at the concentration of25mg/L. Compound4and6g has a good inibition effect against Sclerotonia sclerotiorum, the inhibition rate is84.1%and87.0%, respectively. compound4,6b,6f,6g and6h show80.0%inhibitionrate against Erysiphe graminis, and6e exhibits excellent fungicidal activity againstErysiphe graminis with inhibition rate of90.0%. Introducing acyl into compound4toget5a~5d, which lost the inhibition activities against Erysiphe graminis. Compound4,6e,6f and6g show a good activity, which was identified as the most promisingfungicide for further study.