Studies On Secondary Metabolites And Antitumor Activites Of Two Plant Endophytic Fungus

Endophytic fungi is a class of fungi which spent all or almost all of the life cycle in theplant host and do not show any symptoms to the host. It is a class of micro-organisms livingin plant tissue and the components of plants ecosystem. Endophytic fungi can produce thesame or similar active metabolites compare to the host plants. Thus, Endophytic fungi hasbeen become an important source to natural medicine research and development. In1993,Stierle found a endophytic fungi named Taxomyces andreanae which can producepaclitaxel from Taxus breviflia. This discovery brought a boom about its Pharmacologicalactivity and mechanism. In a later study, we found that endophytic fungi secondarymetabolites have anti-tumor, anti-bacterial, antioxidant, hypoglycemic, immunesuppression, anti-viral activity and so on. Therefore, the activity metabolites fromendophytic fungi has played a significant role in replacing medicinal wild medicinal plantsas alternative sources and new drug development. In this thesis, two fungal strainsincluding Guignardia mangiferae isolated from Smilax glabra and Endomelanconiopsisisolated from Radix Fici are canton features herbs, collected in Luofu Mountain NaturalReservation. It has deep significance for research and development of endophytic fungifrom medicinal plants in southern China. The two fungal strains were selected as aimedstrains to be fermented for further investigation of chemical constituents. All of the isolatedcompounds were preliminary screened on their antitumor activities.The compounds were isolated from the fermentation extracts by repeated columnchromatography (CC) on silica gel, Sephadex LH-20, RP-18, preparative thin layerchromatography (PTLC), as well as by recrystallization. On the basis of means ofspectroscopic methods including UV, IR, EI-MS, HR-ESI-MS,1D-NMR (1H-NMR,13C-NMR, DEPT) and2D-NMR (HSQC,1H-1H COSY, HMBC) as well as by single crystal diffraction, the structures of these compounds were elucidated. Totally,43compoundsincluding14new compounds were isolated and elucidated. From the extracts ofGuignardia mangiferae,30compounds were isolated and elucidated. Among them, tenmixed terpenoids were found to be new compounds (Guignardones D~M). From theextracts of Endomelanconiopsis,13compounds including4new compounds were isolatedand structurally elucidated.Compounds GY16, GY17, GY18, EY1*, EY5, EY12and EY13show obviousinhibition about the three tumor cell.