Study On Secondary Metabolites Produced By Three Strains Of Endophytic Fungi Isolated From Pharmaceutical Plants

Endophytes from pharmaceutical plants not only products sorts of novel bioactive metabolites but also may synthesis the same or similar products by pharmaceutical plants because of their variety in nature and different metabolic pathway.Besides,it can solve the problem of materials and plants protection that metabolites from microbiology can be enlarged by the way of fermentation.Thus, because the resource of pharmaceutical plants decreases quickly,the research in metabolites of endophytes from pharmaceutical plants is a new way for the sustainable development of natural products,ecosystem and environment.Secondary metabolites from three strains of endophytic fungi were observed in this study in which there was a mutant by the genome shuffling for the discovery of new bioactive compounds as leading compounds of new drugs.Secondary metabolites from endophytic fungus TF5(Tubercularia sp.) were observed in this study.Employing different isolation and purification methods,six compounds were obtained from solid-state fermentation with PDA medium.The structures of the compounds were elucidated by spectroscopic methods.TX2 was cytochalasin D,TX3 was (Z)-4,6,9-trihydroxy-10-nonyl-3,4,5,6,9,10-hexahydrooxecin-2-one,which was a new ten-membered lactone,TX0 was 5-methoxycarbonylmellein,and TX6 was ergosterol peroxide.TF5-741 was a mutant of endophytic fungus TF5(Tubercularia sp.) selected by genome shuffling Solid-state fermentation was performed on strain TF5-741 with PDA medium and sabourand medium.Employing different isolation and purification methods,nine compounds were obtained.The structures of the compounds were elucidated by spectroscopic methods.XR2 was 2-(1,8-dimethyl-7,8-dihydronaphthalen-2-yl)propane-1,2,3-triol,XR6 was 3-(3-hydroxyprop-1-en-2-yl)-4a,5-dimethyldecahydronaphthalene-1,2,8a-triol,XR7 was 6-(3-hydroxyprop-1-en-2-yl)-4,5-dimethyl-1,2,3,4-tetrahydronaphthalene-1,2-diol, and XRc was5-hydroxymellein.XR2,XR6 and XR7 belonged to new sesquiterpenes and were named Tuberculariol A,Tuberculariol B and Tuberculariol C。Besides,secondary metabolites from endophytic fungus AF-272,which was isolated from the pharmaceutical plant,Ephedra sp.were observed in this study. Solid-state fermentation was performed on strain AF-272 with 5L PDA medium Employing different isolation and purification methods,two compounds were obtained and elucidated by spectroscopic methods.AX1 was mycophenolate,and AX2 was mycophenolic acid.All new compounds were studied for their bioactivities,including antimicrobial, and anti-tumor.Compound TX3 showed moderate antimicrobial activity against Mycobacterium tuberculosis with the MIC values at 25μg/mL and weak anti-tumor activity against HeLa cell line on MTT and can disrupt the actin filaments of HeLa cell moderately.Our study indicated that endophytic fungus TF5 and its mutant TF5-741 may produce a series of novel compounds and were worth to be researched in-depth. Compound TX3 had the potentiality to be a leading compound of new drug,and Compounds XR2,XR6 and XR7 also were worth to be researched in-depth because of their novel structure.