Studies On The Secondary Metabolites Of Aspergillus Ustus 3.3904

This thesis is composed of two sections.Section one presents the studies on the chemical constituents of Aspergillus ustus 3.3904.Section two is a review about the main chemical components and pharmacological activities of the secondary metabolites of Aspergillus ustus.In this study,Aspergillus ustus 3.3904 was selected as the experimental object.After30 days cultivation on rice medium,the fermentation was extracted with ethyl acetate.Using a variety of modern chromatographic separation techniques,twenty seven compounds were isolated and purified from the extract.Their structures were determined by detailed analyses of 1D NMR,2D NMR,UV,IR,HRESIMS,CD and X-ray diffraction crystallography,and by comparison with corresponding data in the literature.Among them,1-11 were novel polyketones.Compounds 1a and 1b,2a and2 b,3a and 3b,5a and 5b,8a and 8b,9a and 9b are 6 pairs of enantiomers.And compounds 1a and 1b,2a and 2b feature a novel 6/6/6/6 tetracyclic polyketones skeleton.The types of compounds include alkaloids,polyketones,sesquiterpenoids,steroids,and so on.In the review section,the compounds isolated from Aspergillus ustus were summarized,which included sesterterpenes,sesquiterpenes,meroterpenoid,alkaloids,steroids,and other types of compounds.The main biological activities of those compounds were described in detail in order to provide reference for the further study of secondary metabolites of Aspergillus ustus.