Isoflavan derivatives from Glycyrrhiza glabra (licorice)

A new isoflavan was isolated from the root of Glycyrrhiza glabra (licorice; Fabaceae), and its structure was elucidated as 8-prenyl-phaseollinisoflavan on the basis of spectroscopic evidence. Five known isoflavans have also been isolated, and identified with glabridin, 4'-O-methylglabridin, hispaglabridins A, B and what was previously elucidated as ''3'-methoxyglabridin''. The structure of the latter compound was revised to 3'-hydroxy-4'-O-methylglabridin by an irradiation experiment and long range C-13-H-1 COSY spectral analysis.