title: Cytotoxic clerodane diterpenoids and their hydrolysis products from Casearia nigrescens from the rainforest of Madagascar.
abstract: Bioassay-guided fractionation of the cytotoxic leaf and flower extract of Casearia nigrescens led to the isolation of four new clerodane diterpenoids, designated caseanigrescens A-D (1-4). These compounds were subject to hydrolysis to dialdehydes when stored in CDCl3. The structures of compounds 1-4 were determined using 1D and 2D NMR spectroscopy. All four compounds showed moderate cytotoxicity to the A2780 human ovarian cancer cell line, with an IC50 range of 0.83-1.4 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: James S
authors.initials: JS
authors.lastname: Miller
authors.forename: Chris
authors.initials: C
authors.lastname: Birkinshaw
authors.forename: Fidy
authors.initials: F
authors.lastname: Ratovoson
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; D037821:Casearia / Q000737:chemistry*; D045785:Diterpenes, Clerodane / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D005260:Female; D035264:Flowers / Q000737:chemistry; D006801:Humans; D020128:Inhibitory Concentration 50; D008270:Madagascar; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D045785:Diterpenes, Clerodane