Abstract
Background and Objective: Xanthium strumarium is a widespread medicinal plant species; particularly fruits and roots are known for improving memory, voice, and appetite as well as curing of poisonous bites of insects and epilepsy. Materials and Methods: The aerial parts of X. strumarium were extracted with a combination of organic solvents. The exhaustively dried organic extract was fractionated until obtaining pure individuals by employing the appropriate chromatographic techniques. The spectral information obtained from different nuclear magnetic resonance experiments, mass, infrared, and ultraviolet spectra were the keys to elucidate the chemical structures. Results: Nine compounds (1-9) were obtained: a germacrane sesquiterpene (1), five xanthatin-type sesquiterpenoids (5-9) with a-methylene-.-lactone moiety, including the new one, methoxy xanthanol (9), a benzopyran derivative not previously found in nature 3,4-diepoxy-2,2-dimethyl-2H-1-benzopyran-6-carboxaldehyde (2), and coumarin (3), along with the C-28 steroid campesterol (4). Conclusion: Most of the compounds under the study showed an appreciated cytotoxic activity against HCT116 and HepG2 cancer cell lines.