Studies On The Chemical Constituents And Bioactivities Of Endophytic Fungus Boeremia Exigua From Fritillaria Hupehensis

This dissertation is composed of three chapters.Chapter one discusses the chemical composition of Boeremia exigua isolated from Fritillaria hupehensis.Chapter two reviews their biological activity.Chapter three gives a comprehensive review of the eremophilane-type sesquiterpenes with bioactivities from fungi reported in the past six years.In our current investigation,a total of 38 compounds have been isolated from the rice fermentation of Boeremia exigua according to various column chromatography（CC）over silica gel column chromatography（CC）,RP-18,Sephadex LH-20 gel filtration CC.The structures of the isolated compounds were established on the basis of extensive specteoscopic analysis including NMR,HR-ESI-MS,IR,UV,ECD calculations,and other spectroscopic methods.As a result,a total of 38 compounds including 18 new ones were obtained.The new compounds were cytochalasins and eremophilane-type sesquiterpenes.Fortunately,one compound possessed a new structure with ring-rearrangement.Some compounds could significantly inhibit the proliferation of human breast cancer cells（MCF-7）which were tested by MTT method,with IC₅₀ranging from 3.70–22.46μM.Western blotting was used to comfirm the effect of compound 1（exiguachalasin A）on the expression of different proteins.The anti-inflammatory activities of some compounds were tested by Griess method.The results indicated that compounds 4(IC₅₀=6.40μM),15(IC₅₀=8.62μM)and 19(IC₅₀=8.42μM)showed significant anti-inflammatory potential.In recent years,about 210 kinds of eremophilane type sesquiterpenes have been isolated from fungi and activity studies showed that they have various biological activity.The third chapter mainly discussed the bioactivity of eremophilane sesquiterpenes which isolated from fungi reported in the past six years.