Research On Antifungal Active Component Of Phyllostachy Pubescens Extract

In this paper,the antifungal activities of extracts from 20 bamboo species against three selected plant pathogen(Phytophthora melonis Katsura,Fusarium graminearum and Colletotrichum gloeosprioides) were studied.Guided with the method of bioactivity tracking,the antifungal active components were isolated,purified and identified.The main results were summarized as following:1.The antifungal activities of extracts from seclected bamboo species were tested. Results indicated that the acetone extracts of selected bamboo species showed fairly antifungal activities to Phytophthora melonis Katsura and Colletotrichum gloeosprioides. The 95%ethanol extracts had strong antifungal activities to Phytophthora melonis Katsura and Colletotrichum gloeosprioides.The inhibition rates were declined as time going on.2.The antifungal activities of Phyllostachy pubescens extracts by acetone,ethyl acetate,the solution of 0.8%acetic acid,chloroform,Ether and 95%ethanol against three species of plant pathogen were examined.The extracts of acetone,ethyl acetate,the solution of 0.8%acetic acid,chloroform,ether and 95%ethanol exhibited better antifungal activities than the extracts of the other solvents.The inhibition rates after 48h of ethyl acetate,Ether and 95%ethanol extracts to Phytophthora melonis Katsura,Fusarium graminearum and Colletotrichum gloeosprioides were 75.2%,73.5%and 81.5%, respectively.The inhibition rate of the extract of Ether to Phytophthora melonis Katsura is 77.9%,which is better than the rates of the other extracts to Fusarium graminearum and Colletotrichum gloeosprioides,which were 58.1%and 67.3%perspectively.The inhibition rate of extracts of 95%ethanol were 70.4%,78%,74.1%.The value of EC₅₀ of ethyl acetate,ether and 95%ethanol to Fusarium graminearum are 0.7421g/L,2.9533g/L, 2.48643g/L,to Phytophthora melonis Katsura were 0.1085g/L,0.2276g/L,0.6669g/L,and to Colletotrichum gloeosprioides are 0.2014g/L,0.4541g/L,0.4407g/L.The results showed that and the antifungal activity of ethyl acetate extract from Phyllostachy pubescens was stronger than the other extracts3.The composition of antifungal activities was isolated and purified by using biological vitality tracing methods.The result shows that,the fraction of ethyl acetate displays strong antifungal activities,which was extracted from extraction of Phyllostaehy pubescens.The inhibition to Colletotrichum gloeosporioides and Phytophthora melonis Katsura is 98.6% and 94.7%after 48h,while the inhibition of Petroleum ether is 60.4%and 28.2%.Therefore the antifungal activity of ethyl acetate extract from Phyllostachy pubescens was stronger than the extract of Petroleum ether.5 fractions were collected from the ethyl acetate extract of Phyllostachy pubescens.The bioassay suggests that the first(I1) and the third(I3) fraction manifest strong antifungal activities,while other fractions show scarcely activities.After 48h,the inhibition rates of the first and the third fraction to Colletotrichum gloeosporioides are 87.8%and 100%.Z3 were collected by repeated Sephadex LH-20 column chromatography and column chromatography and reversed- phase column.The antifungal activities of Z3 to Colletotrichum gloeosporioides and Phytophthora melonis Katsura were tested by means of measuring antifungal diameter. The inhibition rate of Z3 to Colletotrichum gloeosporioides and Phytophthora melonis Katsura were 72.7%and 85.7%,and the inhibition rate of carbendazim was 78.5%and 87.5%,So the author think that Z3 manifested antifungal activities to two species of plant pathogen.4.The component was isolated and purified from Phyllostachy pubescens by using biological vitality tracing methods,which manifests strong antifungal activities to Colletotrichum gloeosporioides and Phytophthora melonis Katsura.On the basis of UV, NMR,MS data and physico-chemical constants,the structure of this compound was indentified.Every sign points to the fact that this compound is 4-hydroxy-Benzaldehyde.