Secondary Metabolites Analysis And Their Bioactivities Of The Endophytes Fungus Penicillium Polonicum TY12 Associated With A Conitum Vilmorinianum Kom Based On OSMAC Strategy

The secondary metabolites of microorganisms have been recognized as the main source of drug lead compounds as their novel chemical structure and rich biological activities.Modern genome sequencing tools have shown that some microbial gene clusters remain silent under traditional fermentation conditions,with little or no expression,making it difficult to find many active compounds.The One Strain Many Compounds(OSMAC)strategy changes the culture environment of strains to activate silent biosynthetic gene clusters,which is currently an effective means to discover new active compounds.In this paper,Penicillium polonicum TY12,an endophytic fungus of the medicinal plant Aconitum vilmorinianum Kom,was regarded as the research object.The OSMAC strategy is used to determine the type of medium,and the products of potato solid fermentation and PDB liquid fermentation were isolated,identified,and related biological activities were studied.In the first chapter,the research progress of OSMAC strategy in the discovery of microbial active substances is reviewed,and the application of six typical OSMAC methods in the exploration of new microbial secondary metabolites with biological activity is highlighted.The second chapter mainly described the endophytic fungi from the medicinal plant A.vilmorinianum Kom.A total of twenty-two endophytic fungi were isolated from the root of Aconitum vilmorinianum Kom.Through morphological and molecular biology identification,the genus name of each strain was determined,and the dominant flora was analyzed and discussed.In chapter 3,the secondary metabolites of Penicillium polonicum TY12 by potato solid fermentation were studied based on the OSMAC strategy,and ten compounds were isolated and identified,including the new compound polonidine A(1)and nine known compounds: cyclo[Trp-Phe](2),fructigenine A(3),verrucosidin(4),normethylverrucosidin(5),cyclopenol(6),4-(3-hydroxyphenyl)-3-methoxyquinolin-2(1H)-one(7),3-O-methylviridicatin(8),aurantiomides C(9),aspterric acid(10).The results of antibacterial and cytotoxic experiments showed that the new compound 1 had good activity against six kinds of human tumor cells,and showed moderate inhibitory activity against Staphylococcus aureus.Compounds 3,5 and 10 exhibited certain antiinflammatory activities in vitro,which were weaker than that of the positive control dexamethasone.Compounds 2-8 and 10 had no obvious inhibitory effect on acetylcholinesterase.In chapter 4,the secondary metabolites of P.polonicum TY12 by PDB liquid fermentation were studied,from which thirteen known compounds were isolated and identified as: 3-(dimethylaminomethyl)-1-(1,1-dimethyl-2-propenyl)indole(1),5-hydroxy-8-methoxy-4-pheny lisoquinolin-1(2H)-one(2),strychnuxal(3),(E)-pcoumaryl alcohol(4),caryophyllene oxide(5),dehydrogriseofulvin(6),cyclopenol(7),4-(3-Hydroxyphenyl)-3-methoxyquinolin-2(1H)-one(8),penipratynolene(9),methyl succinyl sumiki's acid(10),(E)-heptadec-4-enoic acid(11),ergosterol(12),cyclo[TrpPhe](13).The results of antibacterial assay and anti-acetylcholinesterase assay showed that compound 3 possessed weak inhibitory activity against S.aureus,compound 5 also showed weak inhibitory activity against Candida albicans,and the MIC values of both compounds were 32 ?g/m L.Compounds 3-9,11 and 13 showed no significant antiacetylcholinesterase activity.In this paper,the solid and liquid fermentation products were compared,and the chemical transformation relationship between the liquid fermentation product 3-(dimethylaminomethyl)-1-(1,1-dimethyl-2-propenyl)indole and the new compound polonidine A was studied.