New Metabolites from Onopordum illyricum

Abstract
A phytochemical investigation of Onopordum illyricum afforded, in addition to several known compounds, two new eudesmane sesquiterpenes (1 and 2), two new elemane sesquiterpenes (3 and 4), and one new neolignan derivative (5). The structure elucidation of all compounds was based on their H-1 and C-13 NMR spectral data, including those derived from ID TOCSY, 2D NMR, COSY-DQF, HSQC, and HMBC experiments, as well as extensive 1D ROESY studies