title: Four new steroids from the endophytic fungus Chaetomium sp. M453 derived of Chinese herbal medicine Huperzia serrata.
abstract: An endophytic fungus, Chaetomium sp. M453, was isolated from Huperzia serrata (Thunb. ex Murray) Trev. and subjected to phytochemical investigation. Three unusual C25 steroids, neocyclocitrinols E-G (1-3), and 3β-hydroxy-5,9-epoxy-(22E,24R)-ergosta-7,22-dien-6-one (4) together with three known steroids were isolated from solid fermentation products of the fungus, which were elucidated by extensive spectroscopic analyses, including 1D-, 2D-NMR, and HR-ESI-MS experiments. The absolute configuration of 1 was determined by X-ray crystallographic analysis and CD analyses. The acetylcholinesterase inhibitory activities of compounds 1-4 were tested in vitro. Compound 4 showed weak acetylcholinesterase inhibitory activity.
authors.affiliation: State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming 650091, China; Faculty of medicine, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Fei-Xue
authors.initials: FX
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Li
authors.affiliation: Faculty of medicine, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
authors.forename: Yin-He
authors.initials: YH
authors.lastname: Yang
authors.affiliation: State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming 650091, China.
authors.forename: Guo-Hong
authors.initials: GH
authors.lastname: Li
authors.affiliation: State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming 650091, China; State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China. Electronic address: pjzhao@ynu.edu.cn.
authors.forename: Pei-Ji
authors.initials: PJ
authors.lastname: Zhao
mesh_terms: D045744:Cell Line, Tumor; D002597:Chaetomium / Q000737:chemistry*; D002800:Cholinesterase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D032501:Huperzia / Q000382:microbiology*; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000382:microbiology; D013256:Steroids / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D002800:Cholinesterase Inhibitors; D013256:Steroids
keywords: C25 steroids; Chaetomium sp. M453; Endophytic fungus; Huperzia serrata; Structure identification; X-ray