Two isoflavans and a 3-arylcoumarin from the roots of lotus lalambensis growing in Saudi Arabia

Phytochemical investigation of Lotus lalambensis roots resulted in the isolation and identification of two isoflavan derivatives; vestitol (1) and lotisoflavan (3). Lotisoflavan (3) is isolated for the first time from plants under normal conditions. In addition a 3-arylcoumarin derivative; 2',7-dihydroxy-4',5-dimethoxy-3-arylcoumarin (2) was also isolated. Structures of the compounds were elucidated utilizing UV, [a], 1D- 2D-NMR spectroscopy as well as MS. The positions of the methyl groups were unequivocally assigned based on combination of HMBC and NOESY experiments.