Glycyrrhiza glabra L. (licorice) contains not only glycyrrhizin, the s
weet principle of licorice, but also diverse flavonoids in different o
rgans of the intact plants. A large amount of glabridin, a prenylated
flavonoid, was detected exclusively in the cork layer and the decayed
part of the thickening roots. Large amounts of flavonoid glycosides, l
iquiritigenin glycosides and isoliquiritigenin glycosides, were mainly
distributed in the woody part of the thickening roots. On the other h
and, large amounts of flavonoids such as pinocembrin and licoflavanone
were present on the outer surface of the young leaves, whereas isoque
rcitrin, a common flavonoid glycoside, was detected inside the leaves.
Cultured cells of G. glabra produced no detectable amount of glabridi
n, liquiritigenin glycosides, isoliquiritigenin glycosides, pinocembri
n, licoflavanone and isoquercitrin but produced formononetin, an isofl
avonoid, which is commonly distributed in leguminous plants and in the
underground and above-ground parts of G. glabra.