title: Cytotoxic sesquiterpene lactones from Vernonia pachyclada from the Madagascar rainforest.
abstract: Bioassay-guided fractionation of the cytotoxic leaf extract of Vernonia pachyclada Baker led to the isolation of three new sesquiterpene lactones, designated glaucolides K-M (1-3). The structures of the new compounds were determined using 1D and 2D NMR spectroscopy, and the structure and stereochemistry of 1 were confirmed by single-crystal X-ray diffraction. Compound 3 showed moderate activity in the A2780 human ovarian cancer cell line, with an IC50 of 3.3 microM.
authors.affiliation: Department of Chemistry, M/C 0212, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212, USA.
authors.forename: Russell B
authors.initials: RB
authors.lastname: Williams
authors.forename: Andrew
authors.initials: A
authors.lastname: Norris
authors.forename: Carla
authors.initials: C
authors.lastname: Slebodnick
authors.forename: Joseph
authors.initials: J
authors.lastname: Merola
authors.forename: James S
authors.initials: JS
authors.lastname: Miller
authors.forename: Rabodo
authors.initials: R
authors.lastname: Andriantsiferana
authors.forename: Vincent E
authors.initials: VE
authors.lastname: Rasamison
authors.forename: David G I
authors.initials: DG
authors.lastname: Kingston
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D020128:Inhibitory Concentration 50; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008270:Madagascar; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D035741:Vernonia / Q000737:chemistry*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D007783:Lactones; D012717:Sesquiterpenes; C505304:glaucolide K; C505305:glaucolide L; C505306:glaucolide M