Secondary Metabolites From Marine Algal/Mangrove-Derived Endophytic Fungi And Their Bioactivities

Due to the unique structures and potent pharmaceutical activities,marine natural products continued to be rich resources of new drugs or lead compounds.In this dissertation,106 marine-derived fungi were screened under different medium,cultivation methods and culture conditions.The fermentation extracts were evaluated on the basis of bioactivities and HPLC analysis.As a result,two algal-derived endophytic fungi,Paecilomyces variotii EN-291 and Aspergillus nidulans EN-330,and two mangrove-derived endophytic fungi,Penicillum brocae MA-192 and Penicillium oxalicum EN-201 were selected for further investigation of chemical constituents.Most of the isolates were preliminarily screened for their bioactivities.The compounds were isolated by repeated column chromatography on silica gel,RP-18,Sephadex LH-20,preparative thin layer chromatography and preparative high liquid chromatography as well as by recrystallization.Their structures were elucidated by means of spectroscopic methods including UV,MS,1 D-NMR and 2D-NMR.A total of 80 including 27 new compounds were isolated and identified.From the cultures of Paecilomyces variotii EN-291,25 compounds were isolated and identified,including three new oxepin-containing alkaloids(PV1-PV3),two new prenylated indole alkaloids(PV4-PV5)and two new butenolide derivatives(PV10,PV16).14 compounds including two new indole-diterpenoids(AN1,AN2)were isolated and identified from the cultures of Aspergillus nidulans EN-330.22 compounds were isolated and identified from the cultures of Penicillium brocae MA-192,including six new resorcylic acid derivatives(PB2,PB5-PB9),three new 4-oxoquinoline and indole alkaloids(PB10-PB12),and three new sulfide diketopiperazine derivatives(PB13-PB15).From the cultures of Penicillium oxalicum EN-201,19 compounds were isolated and identified,including two new decaturin analogues(PO1-PO2)and one new prenylated indole alkaloid(PO13).Most of the isolated compounds were screened for antimicrobial,cytotoxicity,DPPH radical-scavenging activity and brine shrimp lethality activity,and some of which showed significant activities.This study may provide important proof to the utilization of marine microorganisms and marine natural products.