Study On The Secondary Metabolites Of Three Fungi Associated With Gastrodia Elata

Fungi,widely distributed in nature,could produce a large number of compounds with novel structures which might have extraordinary bioactivities as well.Based on the aim of discovery of novel compounds with bioactivities,three fungal strains Penicillium sp.BT-73,Hypoxylon sp.DQT-88 and Alternaria sp.H-35 associated with Gastrodia elata,were selected as the research objects,and their secondary metabolites were studied.The first chapter is a summary of the research progress about secondary metabolites from fungi with five-membered oxygen-containing heterocyclic ring in recent years.In the second chapter,the secondary metabolites and their bioactivities of Penicillium sp.BT-73 were evaluated.Finally,7 compounds were isolated from the fermentation broth of Penicillium sp.BT-73,including two novel compounds penicbt A(1)and canescone F(2),together with five known compounds(z)-tetradec-7-enoic acid(3),penicilliol A(4),gregatin A(5),methyl curvulinate(6)and 2-(4-hydroxyphenyl)-ethanol(7).Then,the ACh E(acetylcholine lipase)inhibition activities,cytotoxic activities,anti-inflammatory activities through inhibiting nitric oxide production and PTP1B(protein tyrosine phosphatase 1B)inhibition activities of the new compounds were investigated.As the results,compounds 1 and 2 showed moderate inhibition activities to ACh E with the concentration of 50 μM,and the inhibition rates were 34.94% and 40.49%,respectively.In addition,none of these two compounds showed obvious activities in other bioactivity tests.In the third chapter,the secondary metabolites of Hypoxylon sp.DQT-88 were purified and their bioactivities were studied.In this fungus fermentation cultivation,8 compounds were isolated including sporothriolide(1),1,2,3-propanetriyl(7Z,7′Z,7″Z)tris(-7-pentadecenoate)(2),dihydrosporothriolide(3),pogostol(4),xylaguaianol C(5),14(10-1)abeo-eudesmane-11,13-diol(6),1-monolinolein(7)and cerebrosid(8),respectively.Noteworthily,sporothriolide(1)showed an extraordinary quantity with 818.7 mg/g in the ethyl acetate extract of fermentation broth,which indicated that Hypoxylon sp.DQT-88 strain could be the mass production strain of sporothriolide.Based on it,the fermentation condition of Hypoxylon sp.DQT-88 were optimized and the production of compound 1 was improved to 973.5 mg/g in this study.In the fourth chapter,the secondary metabolites and their bioactivities of Alternaria sp.H-35 were investigated.11 compounds,m-cresol(1),α-acetylorcinol(2),alternariol-9-methyl ethe(3),alternariol(4),tricycloalternarene 3b(5),tricycloalternarene 2b(6),actg-toxin E(7),hylodiglyceride(8),thymidine(9),ergosterol(10)and ergosterol endoperoxide(11),were isolated respectively.Subsequently,the antimicrobial activities of compounds 2-5 were evaluated.