title: Secoemestrin D, a cytotoxic epitetrathiodioxopiperizine, and emericellenes A-E, five sesterterpenoids from Emericella sp. AST0036, a fungal endophyte of Astragalus lentiginosus1.
abstract: A new epitetrathiodioxopiperizine, secoemestrin D (1), and five sesterterpenoids bearing a new carbon skeleton, emericellenes A-E (2-6), together with previously known fungal metabolites, sterigmatocystin (7), arugosin C (8), and epiisoshamixanthone (9), were obtained from the endophytic fungal strain Emericella sp. AST0036 isolated from a healthy leaf tissue of Astragalus lentiginosus. The planar structures and relative configurations of the new metabolites 1-6 were elucidated using MS and 1D and 2D NMR spectroscopic data. All compounds were evaluated for their potential anticancer activity using a panel of six tumor cell lines and normal human fibroblast cells. Only metabolites 1 and 7 showed cytotoxic activity. More importantly, secoemestrin D (1) exhibited significant cytotoxicity with IC50 values ranging from 0.06 to 0.24 μM and moderate selectivity to human glioma (SF-268) and metastatic breast adenocarcinoma (MDA-MB-231) cell lines.
authors.affiliation: Southwest Center for Natural Products Research and Commercialization, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona , 250 E. Valencia Road, Tucson, Arizona 85706, United States.
authors.forename: Ya-Ming
authors.initials: YM
authors.lastname: Xu
authors.forename: Patricia
authors.initials: P
authors.lastname: Espinosa-Artiles
authors.forename: Mangping X
authors.initials: MX
authors.lastname: Liu
authors.forename: A Elizabeth
authors.initials: AE
authors.lastname: Arnold
authors.forename: A A Leslie
authors.initials: AA
authors.lastname: Gunatilaka
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001130:Arizona; D027883:Astragalus Plant / Q000382:microbiology*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D032842:Emericella / Q000737:chemistry*; D005260:Female; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010879:Piperazines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D054830:Sesterterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D010879:Piperazines; D054830:Sesterterpenes; C587214:secoemestrin D