Using Both Chemical and Biological Fingerprints for the Quality Study of Estrogenic Licorice ( Glycyrrhiza uralensis )

The quality of phytoestrogenic licorice was studied by using both chemical and biological fingerprints. A recombinant yeast strain that consists of an estrogen responsive element linked with a reporter gene ( ADE2 ) and a transformed human estrogen receptor–containing plasmid was used for screening and evaluation of estrogenic activity in licorice. Several estrogen‐like components in licorice were screened, and licoisoflavone B and formononetin were identified. Licorice extracted with 70% ethanol showed 5 different patterns of chemical fingerprints (LR‐A, LR‐E, LR‐F, LR‐H, LR‐K), as identified by chromatographic analysis. Among these, LR‐E exhibited the strongest estrogenic activity, whereas LR‐A, LR‐F, and LR‐H were in the middle, and LR‐K had the weakest activity.