frangulinic acid
Webster's Dictionary (GCIDE)
Frangulic \Fran*gu"lic\, Frangulinic \Fran`gu*lin"ic\, a. (Chem.) Pertaining to, or drived from, frangulin, or a species (Rhamnus Frangula) of the buckthorn. [1913 Webster]
Frangulinic acid (Chem.), a yellow crystalline substance, resembling alizarin, and obtained by the decomposition of frangulin. [1913 Webster]