Xanthium Orientale subsp. Italicum (Moretti) Greuter: bioassay-guided isolation and its chemical basis of antitumor cytotoxicity.

Inspired by the allelopathetic effects of Xanthium orientale subsp. italicum (Moretti) Greuter, bioassay-guided isolation was employed to identify its antitumor constituents and clarify the chemical basis of its multitarget activity. Among four fractions of X.orientale extraction, TCM-fr and PE-fr were discovered to exhibit significant cytotoxicity aganist HepG two and A549 cells, which were further isolated by chromatographic methods to yield 16 compounds, including six active ones: xanthatin (1), xanthinosin (2), lupeol (6), oleanolic acid (9), betulinic acid (10) and emodin (12) with IC₅₀ of 10 ∼ 120μM. The systematically study of antitumor constituents has firstly provided a chemical basis for the multitarget and synergistic anticancer activity of the genus Xanthium. The method presented could be utilized to guide the exploitation and promising utilization of X. orientale on cancer therapy.