title: New trichothecenes isolated from Holarrhena floribunda.
abstract: Bioassay-guided fractionation of an extract of Holarrhena floribunda stem, has led to the isolation of the new trichothecenes, 8-dihydrotrichothecinol A (1), loukacinol A (2), and loukacinol B (3), and the known compounds, trichothecolone (4), trichothecin (5), trichothecinol A (6), rosenonolactone (7), 6beta-hydroxyrosenonolactone (8), and rosololactone (9). The structures were determined by spectral and chemical methods, and absolute configurations were established by a modified Horeau's method using HPLC. Compounds 1 and 6 exhibited significant cytotoxicity against several human tumor cell lines, whereas compound 8 showed moderate and weak antileishmanial activity toward extracellular and intracellular Leishmania donovani, respectively.
authors.affiliation: Departamento de Química, Centro de Química Fina e Biotecnologia, FCT-UNL, 2825-114 Caparica, Portugal, Freie Universität Berlin, Königin-Luise Strasse, 2-4, D-14195 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Loukaci
authors.forename: O
authors.initials: O
authors.lastname: Kayser
authors.forename: K
authors.initials: K
authors.lastname: Bindseil
authors.forename: K
authors.initials: K
authors.lastname: Siems
authors.forename: J
authors.initials: J
authors.lastname: Frevert
authors.forename: P M
authors.initials: PM
authors.lastname: Abreu
mesh_terms: D000818:Animals; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D013057:Spectrum Analysis; D014255:Trichothecenes / Q000737:chemistry / Q000302:isolation & purification*; D014407:Tumor Cells, Cultured
chemical_list: D014255:Trichothecenes