Study On New Disease,Chemical Constituents And Biological Activities Of Sinowilsonia Henryi

Sinowilsonia henryi is a large deciduous arbor which belongs to the genus Sinowilsonia in Hamamelidaceae.It is important of scientific research,ecology and economic value.In this study,the pathogen of leaf spot of S.henryi was identified,and the chemical composition and biological activity of bark and leaves were preliminarily studied.The results are as follows:Diseased leaf tissues of Sinowilsonia henryi were cultured for single spore isolation,and one representive strain was identified by morphology and phylogenetic analysis based on ITS and LSU sequences.Finally,mycelium plugs and spore suspensions of the strain were inoculated on the living leaves of S.henryi to test its pathogenicigy.The results showed that the pathogen of the leaf spot disease of S.henryi was Gonatobotryum apiculatum,which is a new disease of S.henryi.In addition,the specific taxonomic status of G.apiculatum was confirmed,and it was firstly found that the fungus produced two types of conidia on authentic media.Eight compounds were separated from ethyl acetate phase through methanol extraction,liquid-liquid extraction,separation by silica gel and Sephadex LH-20column chromatography.By comparing the nuclear magnetic resonance ~1H-NMR,13C-NMR and other spectral data,the structures of 6 of them were identified,including Methyl gallate,Bergapten,3,5,7-trihydroxy-8,4'-dimethoxyflavone,Gallic acid,Dibutyl phthalate and Vitexin.Preliminary studies indicate that 6 compounds were isolated from Sinowilsonia henryi for the first time.The mycelial growth rate method and the filter paper method were used to determine the biologically activities of the methanol extract,extracts of various solvent phases and compounds of Sinowilsonia henryi.The results showed that,at a mass concentration of 1 mg/m L,the chloroform and ethyl acetate extraction sites had good antifungal activity against five plant pathogenic fungi.At a mass concentration of 5mg/m L,the chloroform and ethyl acetate extraction has antibacterial activity against four plant pathogenic bacteria.The screening results of the compounds showed that at a mass concentration of 100 mg/L,the compounds showed different antifungal activity against five plant pathogenic fungi.Among them,the inhibitory rates of Bergamot lactone and Methyl gallate against Rhizoctonia solani were 48.94%and 69.11%,respectively,and the inhibitory rate of Vitexin against Bipolaris maydis was 34.63%.Under the condition that the test mass concentration of 300 mg/L,the compounds had no bacteriostatic activity against the four plant pathogenic bacteria.