Isoliquiritigenin extracted from licorice <Emphasis Type="Italic">Glycyrrhiza uralensis</Emphasis> roots by a facile conversion technique

Isoliquiritigenin (1), one of the major constituents of licorice, is a natural pigment with a simple chalcone structure 4,2',4'-trihydroxychalcone. This study was performed to determine whether liquiritin, isoliquiritin, and liquiritigenin can be converted into isoliquiritigenin using alkaline conversion after acid hydrolysis. An orthogonal L₉ (3)⁴ test design was used in the extraction mode and used for optimization of the extract conditions, and the yield from the conventional procedure and from the optimum procedure to extract 1 was compared. The results demonstrated that the yield of the novel procedure was increased about 27 times compared with the conventional procedure, which indicated that the novel procedure is powerful in separating and purifying isoliquiritigenin.