Arctiin is a lignan found in many plants of the Asteraceae family, particularly the greater burdock (Arctium lappa) and Centaurea imperialis, and in Trachelospermum asiaticum, Saussurea heteromalla, and Forsythia viridissima. It is the glucoside of arctigenin. This article incorporates public domain material from the U.S. National Cancer Institute document 'Dictionary of Cancer Terms'.