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Isolation And Identification Of Endophytic Fungi From Scylla Serrata And The Chemical Constituents Of The Strain Cercospora Lagenariae

Posted on:2019-04-27Degree:MasterType:Thesis
Country:ChinaCandidate:X ZhangFull Text:PDF
GTID:2354330545496142Subject:Microbial and Biochemical Pharmacy
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Plant endophytes are defined as a microbial group which live in the plant body among their whole life or a part of life,endophytes could produce novel and diverse metabolic products,they are important resources found in active natural products.In addition,genetic information exchange occurs due to endophytes in the process of mutual benefit and symbiosis with plants for a long time,endophytes may produce the same or similar metabolites as host plants.Huperzine A isolated from Chinese herbal Huperzia serrata has strong acetylcholinesterase inhibitory activity and it is effective in treating Alzheimer's disease.Huperzine A is rarely found in the plant of H.serrate which is slowly growthing moss,the wild resources of H.serrate are facing exhaustion.In recent years,a large number of different types of endophytic fungi have been discovered in Huperzia serrata plants,the endophytic metabolites are rich and varied,a part of endophytic fungi can also produce huperzine A,therefore,the endophytic fungi of H.serrata attracts attention.Therefore we studied the endophytic fungi of H.serrataand their metabolites,the following progress has been made:1.Separation and purification of 101 endophytic fungi from H.serrate,46 strains were combined by morphological screening,identification of purified endophytic fungi using ITS sequencing,37 of these strains were identified,these endophytic fungi belong to 10 fungal species.Including 20 strains of Colletotrichtum sp.,5 strains of Arthrinium sp.,3 strains of ladosporium sp.,2 strains of Penicillium sp.,2 strains of Glomerella sp.,one strain of Malassezia sp.,one strain of Podospora sp.,one strain of Mycosphaerella sp.,one strain of Cercospora sp.,one strain of Sphaerulina sp..And using the MAGA 6.0 software to construct a system relation tree among 37 endophytic fungies.2.Screening of acetylcholinesterase inhibitory activity of ethyl acetate sites and methanol sites of 46 strains of fermented extracts and screening of LPS-induced Nitric Oxide generation in RAW 264.7 cells of ethyl acetate sites and mkethanol sites of 46 strains of fermented extracts.As a result,it was found that four strains(Hupa-ZX-3,Hupa-ZX-7,Hupa-ZX-13,Hupa-ZX-45)exhibited acetylcholinesterase inhibitory activity,and there were a total of 25 strains of fermented extracts.NO inhibition ability was detected.3.Separation and structure identification of a strain of brown rice fermentation product of Cercospora lagenariae with 1H NMR as the guide was performed using silica gel,gel column chromatography and semi-preparative liquid chromatography.A total of nine compounds were obtained:(12R)-pencimycosphaerella-A(1),altemariol(2),alternariol 9-methyl ether(3),nigrosporaol-A(4),alternarienonic acid B(5),2-methyl-5-carboxymethy 1-7-hydroxyc hormone(6),2,5-dimethyl-7-hydroxychromone(7),1-deoxyrubralactone(8),(-)-Alternarlactam(9),(compound 1 is the new compound).Pharmacological activity screening shows compound 6 has NO inhibitrory activity,IC50 = 57.5 ± 1.2 ?M.
Keywords/Search Tags:Huperzia serrate, Endophytic fungi, Isolation and identification, Acetylcholinesterase inhibitory activity, Anti-inflammatory(NO inhibitory)activity, Metabolites, Chemical constituents
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