Studies On Synthesis And Fungicidal Activity Of Analogues Of Kakuol (Ⅲ)

In the prosess of developping efficient and less residue pesticide, natrual products-based pesticides draw more and more attention for its extensive source, obtainning easily, safty to human and animals , environment friendly ,and other advantages.Kakual and analogues of Kakual was isolated from the methanol extracts of Asarum sieboldii (Miq) Maek rhizomes firstly,they have high level biological activity,but few of information abuot their synthesis and structure-activity relationship.In order to get more active substances and investigate their structure-activity relationship,we synthesized 23 kakuol analogues from Kakual(b) and 2-hydroxy-4,5-methylene-dioxyhypnone(a) by Claisen-Schmidt reaction with many kinds of benzaldehyde analogues, of which 22 derivatives were first studied.All the synthesized compounds were characterized by IR, NMR and MS.Twenty-Three Compounds were tested in vitro against 6 fungi: Cytospora sp , curvularia lunata.boed , Fusarium oxysporum vasinfectum , Fusarium solani , Pyricularia grisea , Fusarium bulbigenum in parison with kakuol analogues at concentration of 100mg/L.The fungicidal activity results showed that the 23 compounds has differerntly inhibition on plant pathogenic funfus mycelial growth at concentration of 100 mg/L. a4 have a higher rate of inhibition in derivatives of a, the rates of which espectively were 69.9%,40.5%,50.2%,41.9%,51.3%and 73.9%. b1 has a higher rate of inhibition in derivatives of b,they were 65.8%,48.6%,48.5%,59.5%,65.7% and 65.9%. And others have lower inhibition rate, which is ranged from 2%-50%.