title: Cytotoxicity of an unprecedented brominated oleanolide and a new furoceramide from the Cameroonian spice, Echinops giganteus.
abstract: A preliminary study on Echinops giganteus (Asteraceae) showed that the methanolic extract has interesting cytotoxicities against a panel of cancer cell lines. From this extract, a lignan, a flavonoid and a polyacetylenic thiophene identified were three times less cytotoxic than the extract. In the search of the metabolites responsible for the bioactivity, a new harvested E. giganteus was subjected to a phytochemical study using chromatographic methods. In the course of the work, two new compounds: a brominated oleanolide (1) and a tetrahydrofurano-ceramide (2) were obtained along with β-amyrin acetate (3), 2-(penta-1,3-diynyl)-5-(4-hydroxybut-1-ynyl)-thiophene (4), 2-(penta-1,3-diynyl)-5-(3,4-dihydroxybut-1-ynyl)-thiophene (5) and 4-hydroxy-2,6-di-(3',4'-dimethoxyphenyl)-3,7-dioxabicyclo-(3.3.0)octane (6). Their structures were determined on the basis of NMR spectroscopy and mass spectrometry data in conjunction with those reported in the literature. The cytotoxicity of 1, 2 and 5 was evaluated by employing resazurin assay against a panel of cancer cell lines with IC50values in range 6.12 ± 0.46-46.96 ± 3.61 μM.
authors.affiliation: a Department of Pharmaceutical Sciences , CCS - Universidade Federal de Santa Catarina , Trindade , Brazil.
authors.forename: Louis P
authors.initials: LP
authors.lastname: Sandjo
authors.affiliation: b Department of Biochemistry , University of Dschang , Dschang , Cameroon.|c Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry , University of Mainz , Mainz , Germany.
authors.forename: Victor
authors.initials: V
authors.lastname: Kuete
authors.affiliation: d Department of Chemical Technology , University of Johannesburg , Johannesburg , South Africa.
authors.forename: Xavier N
authors.initials: XN
authors.lastname: Siwe
authors.affiliation: a Department of Pharmaceutical Sciences , CCS - Universidade Federal de Santa Catarina , Trindade , Brazil.
authors.forename: Herve M P
authors.initials: HMP
authors.lastname: Poumale
authors.affiliation: c Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry , University of Mainz , Mainz , Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Efferth
keywords: Asteraceae; Echinops giganteus; brominated triterpene; cytotoxicity; furoceramide