Unusual sesquiterpenes from Centaurea athoa DC

Three new elemane-type sesquiterpenes; athoin, 14-O-acetylathoin and methyl 14-O-acetylathoin-12-oate were isolated from the aerial parts of Centaurea athoa DC., accompanying with eight known compounds: a germacrane-type sesquiterpene; 4'-hydroxypecterolide-14-O-acetate, three phenolic compounds; p-hydroxybenzoic acid, protocatechuic acid, vanillic acid-4-O-beta-D-glucopyranoside methyl ester, an acetophenon glucoside; picein, two phenylpropane glucosides; syringin and 9-O-methyl coniferin, and a phytosterol; beta-sitosterol-3-O-beta-D-glucopyranoside. Structural elucidation of the compounds was based on both spectroscopic evidence and reference data comparison. (C) 2016 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.