论文部分内容阅读
Chemical examination of an EtOAc extract of cultured Aspergillus versicolor fungus from deep-sea sediments resulted in the isolation of four xanthones,eight anthraquinones and five alkaloids,including a new xanthone,oxisterigmatocystin D (1) and a new alkaloid,aspergillusine A (13).High resolution electron impact mass spectrometry (HR-EI-MS),FT-IR spectroscopy,and NMR techniques were used to elucidate the structures of these compounds,and the absolute configuration of compound 1 was established by its NMR features and coupling constant.Furthermore,the biosynthesis pathway of these xanthones and anthraquinones were deduced,and their antioxidant activity and cytotoxicity in human cancer cell lines (HTC-8,Be1-7420,BGC-823,A549,and A2780) were evaluated.The trolox equivalent antioxidant capacity (TEAC) assay indicated most of the xanthones and anthraquinones possessing moderate antioxidant activities.The Nrf2-dependent luciferase reporter gene assay revealed that compounds 6,7,9,and 12 potentially activated the expression of Nrf2-regulated gene.In addition,compounds 5 and 11 showed weak cytotoxicity on A549 with the IC50 values of 25.97 and 25.60 μmol·L-1,respectively.