Sesquiterpene Lactones with the 12,8-Guaianolide Skeleton from Algerian <i>Centaurea omphalotricha</i>
Sara Kebbi,
Maria Letizia Ciavatta,
Ali Mokhtar Mahmoud,
Marianna Carbone,
Alessia Ligresti,
Ramdane Seghiri,
Margherita Gavagnin
Affiliations
Sara Kebbi
Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica Biomolecolare (ICB), Via Campi Flegrei, 34-80078 Pozzuoli, Italy
Maria Letizia Ciavatta
Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica Biomolecolare (ICB), Via Campi Flegrei, 34-80078 Pozzuoli, Italy
Ali Mokhtar Mahmoud
Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica Biomolecolare (ICB), Via Campi Flegrei, 34-80078 Pozzuoli, Italy
Marianna Carbone
Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica Biomolecolare (ICB), Via Campi Flegrei, 34-80078 Pozzuoli, Italy
Alessia Ligresti
Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica Biomolecolare (ICB), Via Campi Flegrei, 34-80078 Pozzuoli, Italy
Ramdane Seghiri
Unit of Valorization of Natural Resources, Bioactive Molecules and Physicochemical and Biological Analyzes (VARENBIOMOL), Department of Chemistry, Faculty of Exact Sciences, University of Mentouri Brothers Constantine 1, Constantine 25000, Algeria
Margherita Gavagnin
Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica Biomolecolare (ICB), Via Campi Flegrei, 34-80078 Pozzuoli, Italy
In continuing our investigation on the chemical diversity of Algerian plants, we examined Centaurea omphalotricha, whose chemical composition has been poorly studied. The present work was aimed at characterizing the secondary metabolite pattern of the CHCl3 extract of the aerial parts of this plant that displayed antiproliferative properties in a preliminary screening on HeLa cell line. The chemical analysis led us to characterize the bioactive oxygenated terpenoid fraction which includes, within major known metabolites, two new minor sesquiterpene lactones, centaurolide-A (1) and centaurolide-B (2). The structures of two compounds exhibiting the 12,8-guaianolide skeleton were determined by spectroscopic methods as well as by chemical correlation with inuviscolide (3), a well-known bioactive guaianolide isolated from Dittrichia (=Inula) viscosa. Centaurolides A and B represent the first report of 8,12-guaianolide skeleton in Centaurea genus. The effect of new compounds 1 and 2 and inuviscolide (3) on HeLa cell has also been evaluated.