The Research On Anti-fungi Active Compounds From Inula Britannica

To discover anti-fungi active compounds from plants is an important way to develop newReduced- Risk Pesticides. The former research discovered that the acetone extract of InulaBritannica L.showed strong inhibition to mycelia growth of Fusarium graminearum andBotrytis cirerea Pers in vitro, and showed potent protective effect against Erysiphe graminison wheat in vivo. In order to find anti-fungi active compounds from Inula Britannica L., thefurther research were carried out. The results are as following: 1 Under the tracing of anti-fungi activity, four compounds were isolated from the flowersof Inula Britannica. The structures were established by MS, H-NRM, C-NRM and DEPT. 1 13They are Taraxasteryl palmitate, Taraxasteryl acetate, 1-O-Acetylbritannilactone anddioctyl(o-)phthalate respectively. 2 Anti-fungi activities of four compounds were tested with Fusarium graminearum invivtro and Erysiphe graminis in vivo. The results showed Taraxasteryl palmitate ,Taraxasterylacetate and dioctyl(o-)phthalate had strong inhibition to the germination of spores ofFusarium graminearum. The inhibition rate are more than 75% in the concentration of0.1mg/mL. Taraxasteryl palmitate and dioctyl(o-)phthalate had potent protective effect againstErysiphe graminis on wheat in vivo and the effects were 56.4% and 73.1% in theconcencetion of 1mg/mL. 3 The miniature potted method againt Erysiphe graminis on wheat in vivo was built. Themethod can reduce greatly the cost of compounds. The difference was compared between themethod and conventional potted method. The results showed that two methods had no markdifference. So the miniature potted method can be used to test micro-compound activitiesagainst Erysiphe graminis on wheat in vivo. 4 The anti-fungi activities of 1-O-Acetylbritannilactone were tested. The results showedthat the compound had potent inhibition against Fusarium graminearum, Phytophthoracapsici, Botrytis cirerea and Sclerotinia sclerotiorum in vivtro, in especially, had stronginhibition to mycelia growth of Sclerotinia sclerotiorum. The EC50 is 71.8μg/mL. Theeffects of 1-O-Acetylbritannilactone on morphology and structure of Sclerotinia sclerotiorumwere examined by means of scanning and transmission electron microscopy techniques. Theresults showed that the compound caused series of marked morphological and structuralchanges .These changes included malformation of mycelia, the separation of cell wall and cellmembrane, and the abnormity of mitochondria.