Abstract: In this study,we identified an endophytic fungus FS4 which was isolated from the stem of Huperzia serrate and investigated the inhibitory activity on acetylcholinesterase of its main metabolites.On the basis of morphological character and 18S rRNA gene sequences analysis,strain FS4 was classified as Aspergillus fumigatus and its extract showed significant inhibitory activity of acetylcholinesterase with inhibition rate of 84.6% at the concentration of 2 mg/mL.Furthermore,we isolated and identified five compounds which were Ergosterin (1),dioctyl phthalate (2),1′-9-12 linoleic acid-2′-3′-dihyodr-oxy propyl ester (3),microsphaerone C (4) and helvolic acid (5) respectively by employing silica column chromatography,LC-MS and NMR methods.Compounds 3,4 and 5 showed inhibitory activity of acetylcholinesterase,the inhibition rates were 73.5%,84.1% and 77.6% respectively and the IC₅₀ values were 0.057,0.038 and 0.05 mg/mL correspondently.

Key words: Huperzia serrata, Aspergillus fumigatus, acetylcholinesterase;inhibition