Metabolites Of Pestalotiopsis Microspora From Endophytic Fungi Of Taxus Chinensis

Secondary metabolites from endophytic fungi account for an important part of natural products derived from plants. Long-term coevolution between endophytic fungi and their hosts makes it possible for endophytic fungi to produce diverse and complex metabolics with novel structures and distinct activities. Endophytic fungi gradually become an important source of natural medicines. Recently, a lot of biologically active metabolites have been discovered and reported from endophytic fungi, which made the kinds and number of natural products more vast and rich, and it also provided possibility for mining new type pharmaceutical lead compounds with high efficiency and low toxicity. This dissertation describes the isolation, structural elucidation, and bioactivity evaluation of chemical constituents isolated from Pestalotiopsis microspora, an endophytic fungus isolated from Taxus chinensis.Pestalotiopsis microspora was fermented on solid medium at room temperature for 28 days. The mycelium was extracted with EtOAc to give the crude extract. The extract was subjected to repeated column chromatography on normal and reverse phase silica gel, Sephadex LH-20, preparative thin layer chromatography, recrystallization, and semi-preparative HPLC, giving rise to 23 componds. Their structures, including 3 new structures, i e. HDS-5, HDS-36 and HDS-39, were elucidated by means of spectroscopic methods including IR, UV, EI-MS, HR-EI-MS, CD,1D-NMR (1H-NMR,13C-NMR, DEPT) and 2D-NMR (1H-1H COSY, HMBC, HMQC, NOESY).The cytotoxic activity and antimicrobial activity of HDS-5 was observed in vitro. The results showed that HDS-5 displayed no cytotoxic activity against two tumor cell lines (Caski and HeLa) and no antimicrobial activity against six pathogenic bacteria, including Escherichia coli, Pseudomonas aeruginosa, Micrococcus luteus, Xanthomonas campestris pv. Oryzae, Erwinia carotovora subsp. Carotovora and Pseudomnas syringae pv.actinidae. In another experiment, HDS-1 showed significant synergistic activity with gibberellin towards Distylium chinense seeds.