Secondary Metabolites And Their Bioactivity Of Two Endophytic Fungi Isolated From Marine Organisms

Amongst marine microorganisms, marine fungi represent an important resource for the discovery of structurally unique natural products with anticipated biomedical potential. Recently, a lot of biologically active metabolites have been discovered and reported from marine derived endophytic fungi. This dissertation describes the isolation, structure elucidation, and bioactivity evaluation of chemical constituents of two marine endophytic fungi. The two endophytic fungi strains were isolated from a red algal derived endophytic fungus Chaetomium sp (QEn(?)) and an unidentified mangrove derived fungus (Fs).The endophytic fungus Chaetomium sp. was originally separated from the marine red alga Polysiphonia urceolate Grev that was collected from the Qingdao coastline, while the fungus (Fs) was separated from mangrove plant Sonneratia caseolaris collected from south China sea. Two fungi were fermented respectively. The liquid medium was incubated at room temperature for 40 days. The mycelium and filtrate were extracted with methanol and EtOAc, respectively. The extracts was evaporated under reduced pressure at 40℃ and yielded crude extracts from mycelium and filtrate respectively. Since the HPLC profiles of the two extracts were nearly identical, they were combined before further separation.The compounds were isolated by repeated column chromatography (CC) on silica gel, RP-18, and Sephadex LH-20, as well as by preparative thin layer chromatography (PTLC), recrystallization, and semi-preparative HPLC. The structures of these compounds were elucidated by means of spectroscopic methods including IR, UV, EI-MS, FAB-MS, HR-ESI-MS, 1D-NMR ('H-NMR, ¹³C-NMR,...