Secondary Metabolites Of Endophytic Fungi Chaetomium Sp.Eef-S10 And Their Biological Activities

Chaetomium sp.Eef-S10,an endophytic fungus from the fruit of Eucalyptus exserta,was used as the research object to isolate and identify the secondary metabolites in the endophytic fungi Chaetomium sp.Eef-S10 and evaluate their biological activities.The main results are as follows:?1?14 compounds were obtained from the ethyl acetate layer of the endophytic fungus Chaetomium sp.Eef-S10,by means of silica gel column chromatography,dextran gel column chromatography,semi-preparative HPLC and recrystallization purification method.The structures of the compounds were analyzed and elucidated by UV,HR-ESI-MS,1D and 2D NMR,and comparative references.Finally 8 compounds were successfully identified,including 3 Depsidones.In the 8 compounds,compound Oy-15 suspected is a new compound,named Mollicellins O?Oy-15?,and the other 7 known compounds were identified as Mollicellins H?Oy-2?,Mollicellins G?Oy-9?and Dibutyl phthalate?Oy-7?,4-Methyl-5,6-dihydro-2H-pyran-2-one?Oy-8?,2,6-Dihydroxy-3,4-dimethylbenzoicacid methylester?Oy-11?and2,4-Dihydroxy-3,6-dimethylbenzoate?Oy-12?.The2,6-Dihydroxy-3,4-dimethylbenzoicacidmethylester?Oy-11?,2,4-Dihydroxy-3,6-dimethylbenzoate?Oy-12?and Mollicellins O?Oy-15?were the first time isolated from Chaetomium.sp..?2?The inhibitory activities of the secondary metabolites of Chaetomium sp.Eef-S10on the growth of 7 test bacteria were determined by Multi-well plate-MTT-chromogenic assay screening.Only Mollicellin G?Oy-9?showed certain antibacterial activity.In the concentration of 200?g/mL,the growth inhibition rate against Bacillus subtilis,Staphylococcus aureus,Agrobacterium tumefaciens and Ralstonia solanacearum were100%.This is the first report on the antibacterial activities of Mollicellin H?Oy-2??Mollicellin G?Oy-9??2,6-Dihydroxy-3,4-dimethylbenzoic acid methyl ester?Oy-11??2,4-Dihydroxy-3,6-dimethylbenzoate?Oy-12?and Mollicellins O?Oy-15?.?3?The inhibitory activities of the secondary metabolites of Chaetomium sp.Eef-S10on the growth of two tested fungI of Colletotrichum gloeosporioides of Dalbergia odorifera and Camellia anthracnose were determined by mycelial growth rate method.At the concentration of 200?g/mL,the inhibitory activities of all monomeric compounds isolated from the endophytic fungus Chaetomium sp.Eef-S10 didn't reach 50%,indicating indirectly that the tested compounds do not have resistance to Colletotrichum gloeosporioides of Dalbergia odorifera and Camellia anthracnose potential.?4?The antioxidative activities of secondary metabolites of endophytic fungi Chaetomium sp.Eef-S10 were determined by the porous plate-DPPH removal method.Among them,only Mollicellins O?Oy-15?showed antioxidant activity,the scavenging capacity of DPPH IC₅₀0 was 71.92?g/mL.The DPPH-scavenging capacity of other compounds did not yet reached 50%at the concentration of 200?g/mL.This thesis is the first time foe the antioxidant activities reports on the Depsidone compounds.