Prenylated Dibenzoylmethane Derivatives from the Root of Glycyrrhiza inflata (Xinjiang Licorice)

Three dibenzoylmethanes were isolated from licorice of Xinjiang origin (botanically assigned to Glycyrrhiza inflata), and their structures were elucidated spectroscopically as 1-(2,4-dihydroxy-5-prenylphenyl)-3-(4-hydroxyphenyl)-1,3-propanedione (I), 1-(2,4-dihydroxy-5-prenylphenyl)-3-(4-hydroxy-3-prenylphenyl)-1,3-propanedione (II) and 1-(2,4-dihydroxy-5-prenylphenyl)-3-(2,2-dimethyl-2H-1-benzopyren-6-yl)-1,3-propanedione (III). The latter two constituents were new natural products, and were named glycyrdiones A and B, respectively.