title: Pseudoguanolide sesquiterpene lactones from Vernoniopsis caudata and their in vitro antiplasmodial activities.
abstract: Two new helenanolide sesquiterpene lactones, 1 and 2, as well as one known related structure, 11alpha,13-dihydrohelenalin-[2-(1-hydroxyethyl)acrylate] (3), together with 4'-beta-d-O-glucopyranosyl-luteolin and ethyl 2,5-dihydroxycinnamate were isolated from an ethyl acetate extract of leaves of Vernoniopsis caudatawith potent antiplasmodial activity (IC50 1.6 microg/mL) in a preliminary biological screen. The structures of the new compounds were determined by spectroscopic techniques. The three sesquiterpene lactones 1-3 displayed strong in vitro antiplasmodial activity, with IC50 values of 1, 0.19, and 0.41 microM, respectively. However, these compounds also exhibited considerable cytotoxicity on KB cells (IC50 < 1 microM in each case).
authors.affiliation: Laboratoire de Pharmacognosie Appliquée aux Maladies Infectieuses, Institut Malgache de Recherches Appliquées, BP 3833, 101 Antananarivo, Madagascar.
authors.forename: Voahangy
authors.initials: V
authors.lastname: Ramanandraibe
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Martin
authors.forename: Dina L
authors.initials: DL
authors.lastname: Rakotondramanana
authors.forename: Lengo
authors.initials: L
authors.lastname: Mambu
authors.forename: David
authors.initials: D
authors.lastname: Ramanitrahasimbola
authors.forename: Medhi
authors.initials: M
authors.lastname: Labaïed
authors.forename: Philippe
authors.initials: P
authors.lastname: Grellier
authors.forename: Philippe
authors.initials: P
authors.lastname: Rasoanaivo
authors.forename: François
authors.initials: F
authors.lastname: Frappier
mesh_terms: D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D020128:Inhibitory Concentration 50; D007624:KB Cells; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008270:Madagascar; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045789:Sesquiterpenes, Guaiane; D014407:Tumor Cells, Cultured
chemical_list: D000962:Antimalarials; D000972:Antineoplastic Agents, Phytogenic; D007783:Lactones; D012717:Sesquiterpenes; D045789:Sesquiterpenes, Guaiane; C502245:helenalin-((2-hydroxyethyl-3-methyl)acrylate); C502244:helenalin-(2-(1-hydroxyethyl)acrylate)