Abstract
Extracts of the aerial parts of Xanthium strumarium and fruit of X. pungens afforded a new Xanthanolide diol derivative, 11α,13-dihydroxyxanthatin and a new dimeric xanthanolide sesquiterpene lactone, pungiolide C, in addition to some known compounds. The structures of the new compounds were determined by spectroscopic methods particularly high resolution 1H-, 13C-NMR and 2D 1H-1H and 1H-13C COSY NMR analysis.
