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Investigation On The Secondary Metabolites And Their Bioactivities Of Two Fungi Associated With Panax Notoginseng

Posted on:2016-02-26Degree:MasterType:Thesis
Country:ChinaCandidate:K LiuFull Text:PDF
GTID:2180330470953986Subject:Microbiology
Abstract/Summary:PDF Full Text Request
Fungi are considered to be prolific sources of secondary metabolites with diversity of bioactivites and chemical structures. In this dissertation, two fungi strains were selected from the microbial resources associated with Panax notoginseng, by combing antimicrobial assay with chemical diversity screening using TLC-HPLC methods. The phylogenetic analysis and secondary metabolites for the two fungi were identified. In addition, the biological activities of chemical entities have been tested.On the basis of morphological characteristics and molecular studies, YIM PH30001and YIM PH30002were identified as Aspergillus versicolor and Trichoderma koningiopsis, respectively.Total of46compounds were isolated from the two fungi by the chromatography over silica gel, RP-18, MCI, Sephadex LH-20and HPLC. The structures of41compounds, including13new compounds, were elucidated by extensive spectroscopic analysis, including NMR, MS, UV, IR, CD and ORD. The chemical structure types classify as anthraquinones, xanthones, phenols, steroids, polyketides. The in vitro antimicrobial, anticoagulant, anti-inflammatory and enzyme inhibitor activity assays were valued for the new compounds and some known compounds.From the culture broth of YIM PH30001,16compounds were isolated and identified as eight anthraquinones, three xanthones, two phenols and three steroids, compounds averythrin (3), versicolorin B (6) and averantin (7) exhibited favorable antifungal activity against Fusarium solani with MIC of16μg/mL.30compounds were isolated from the fermentation broth of YIM PH30002. Only25compounds including13new compounds (koningiopisin A-H, koninginin Q-R) were elucidated as24polyketides and1anthraquinones. Koningiopsin A (1) and B (2) bear with a substituted butoxyl at C-7, C-8respectively, and their structures are rare in these types of natural products, koningiopsin C (3) showed comprehensive spectrum antimicrobial activities, and exhibited appreciable antifungal activity against Plectosphaerella cucumerina with MIC of16μg/mL. Moreover, some compounds showed well synergistic antifungal activity. The present results illustrated the prospect of novel bioactive secondary metabolites with diversity of structures, from the fungi resource associated with P. notoginseng. Further development and application of these fungi can enrich the library of microbial natural products, and provide material basis for variety of drugs originated from microbial.
Keywords/Search Tags:Panax notoginseng, Trichoderma, biocontrol strain, secondarymetabolites, polyketides, antimicrobial activites
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