Bionactive Secondary Metabolites Of Two Endophytic Fungi From Edgeworthia Chrysantha Lindl.

This paper mainly focused on bioactive secondary metabolites from two endophytic strains?D and 5-19?firstly isolated from the healthy leaves of Edgeworthia chrysantha Lindl..Main contents include the screening of endophytic fungi from medicinal plants,the identification and cultivation of active strains,tracking and separation of active ingredients,identification the compound structure and bioactivity preliminary evaluation.Summarized as follows:Firstly,ten endophytic fungi isolated from E.chrysantha Lindl.was screened by antimicrobial assay to obtain two strains,which showed strong antimicrobial activities.The phylogenetic trees of D,5-19 were generated by 18S rDNA sequences analyses using Clustal X and MEGA.D was showed to be 99%in the homology and clustered in the same branch of the strain Aspergillus fumigatus?HM590663.1?.And 5-19 was clustered in the same branch of the strain Fusarium.oxysporum?JF807401.1?.Secondly,using Czapek medium,the yields of crude extract of fermentation broth?30,50 L?of strains D,5-19 were respectively 0.339g/L,0.133 g/L after scale-up fermentation and extraction.7 metabolites were isolated by p-HPLC and UV-LC,a yield of 2.55,0.13,0.82,0.03,0.02,1.1,2.5%.Seven compounds had been identified by spectroscopic techniques?HR-ESI-MS,ESI-MS,1H-NMR,13C-NMR,DEPT-135,HSQC,HMBC,NOESY,COSY,etc.?.Five alkaloids,bisdethiobis?methylthio?gliotoxin?1?,gliotoxin?2?,pseurotin A?3?,spirotryprostatin A?4?,spirotryprostatin G?5?,were mainly isolated by strain D.Strain 5-19 was producted dibutyl phthalate?6?and beauvericin?7?.Thirdly,seven compounds were evaluated for their antimicrobial activities against three human pathogenic strains?Escherichia coli AB94012,Staphyloccocus aureus AB 2010021 and Candida albicans AY204006?by microbroth dilution method in 96-well culture plates.The results indicated that compounds 4 and 5 were shown to strong antimicrobial against the three strains with the MIC of 3.31,1.56,6.25?M and 1.56,1.56,3.13?M respectively.Compound 1 exhibited the strongest inhibitory effect on S.aureus?MIC 1.56?M?and C.albicans?1.56?M?.Compound 2?5 and 7 also had the best antimicrobial activities against E.coli,S.aureus and C.albicans the MIC values of 3.13,1.56 and 3.91?M respectively.Five isolated alkaloids were evaluated for their antitumor activities against four cancer cell lines MCF-7,A549,HepG2,Hela by MTT method.The results indicated that compound 1 showed cytotoxicity against HepG22(IC₅₀0 32.1?M).Compound 2 displayed cytotoxic activity against MCF-7(IC₅₀0 20.2?M)and A549(IC₅₀0 26.3?M).Compound 4showed the general antitumor activity against A549 and Hela with the IC₅₀value of 23.5,29.1?M.Compound 3 and 5 had the weak inhibitory effect on the four tumor cell.These findings were the experimental basis for systematic investigation on bio-and chemo-diversity of endophytic microbes from E.Chrysantha.The results also provided a good reference to discover new antimicrobial agents from endophytes.