Study On Chemical Constituents And Antimicrobial Activities Of Polyporus Picipes Leavening

Polyporus pecipes,a wood rooting fungus of Polyporaceace family, is found on the trunks of living or dead trees. Pharmacologically, it is traditionally used to treat cancer such as breast cancer and prostatic cancer, and it can be eaten during the early time of its life. It has functions of enhancing immunity, softening blood vessels, preventing ageing of heart and regulating the nerve of brain. Since the metabolites from fungi have a lot of structure types and antimicrobial activities, in order to develop the fungal resources and look for new active components, this thesis, based on microbial zymology, phytochemistry and theory of modern chemical separation, on the premise of antimicrobial activities of the extracts from fermenting liquor and mycelia, uses modern chromatographic techniques and isolation methods to purify the chemical constituents of ethyl acetate extract from mycelia of Polyporus pecipes systematically. The following are the results of the study:Filter paper method was adopted to test the antimicrobial activities of Polyporus pecipes fermentation metobolites against seven common bacteria. At the concentration of 40mg/mL, ethyl acetate extract from mycelia could significantly inhibit Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Corymebacterium pakinense, ethyl acetate extract from fermentation broth showed notable inhibition to Staphylococcus aureus, Bacillus megaterium , Bacillus subtilis, Escherichia coli and B.mesentericus. Whereas, n-butanol extract revealed inapparent inhibition to bacteria.The minimum inhibitory concentration (MIC) of ethyl acetate extract from mycelia to Staphylococcus aureus and Escherichia coli were 2.50mg/mL,Bacillius cereus 1.25mg/ml and Bacillius subtilis 0.625 mg/mL. MIC of ethyl acetate extract from fermentation broth, to Staphylococcus aureus and Bacillius subtilis,were 2.50 mg/mL and 1.25 mg/mL, respectively. MIC of n-butanol extract from mycelia to Bacillius cereus was 2.50 mg/mL and from fermentation broth to both Staphylococcus aureus and Bacillius cereus were 2.50 mg/mL. Mycelial growth rate method was adopted to test the antimicrobial activities against six common pathogenic fungi. The inhibitory ratio of ethyl acetate extract from mycelia to Alternaria brassicae and Fusarium graminearum was 100% at 4 mg/mL, 83.89% and 76.93% at 0.5 mg/mL, respectively. Ethyl acetate extract from fermentation broth could completely inhibit Phytophthora capsici, Colletotrichum orbiculare, Fusarium graminearum and F.oxysporium fsp. uasinfectum at 4mg/mL and Fusarium graminearum at 0.5 mg/mL.The inhibitory ratio of n-butanol extract from mycelia were higher than 70% to Colletotrichum orbiculare, Fusarium graminearum and F.oxysporium fsp. uasinfectum at 0.5 mg/mL, n-bunatol extract from fermentation broth revealed good inhibitory properties to Alternaria brassicae and F.oxysporium fsp. uasinfectum.The ethyl acetate extract from mycelia was isolated and purified through coloum chromatographys, five compounds were found and three were identified by GC-MS,EI-MS,1H NMR,13C NMR,DEPT,(–)ESI-MS and compared with standard compounds. CompoundⅠwas ergosterol peroxide,Ⅳwas 1-(2,4-dihydroxy-5-methylphenyl)ethanpone,Ⅴwas 4,6,8(14),22(23)-tetraen-3-one-ergostane. These three compounds were isolated the firet time from Polyporus pecipes . And 1-(2,4-dihydroxy-5-methylphenyl)ethanpone was the first reported natural product.