THE ISOLATION OF NEW PYRANO-2-ARYLBENZOFURAN DERIVATIVES FROM THE ROOT OF GLYCYRRHIZA-GLABRA

Two new pyrano-2-arylbenzofuran derivatives named glabrocoumarones A a nd B were isolated from commercially available licorice of Glycyrrhiza glabra origin, and their structures were elucidated as 4',6-dihydroxy -[6 '',6 ''-dimethylpyrano(2 '',3 '':2',3')]-2-arylbenzofuran and 2',6 -dihydroxy-[6 '',6 ''-dimethylpyrano(2 '',3 '':4',3')]-2-aryl-benzofur an, respectively, on the basis of spectroscopic evidence. Six known co mpounds were also obtained and identified spectroscopically as glabrol , 3-hydroxyglabrol, shinflavanone, [6 '',6 ''-dimethylpyrano(2 '',3 '' ,6'''-dimethylpyrano(2''',3''':4',3')]-flavanone (xambioona), mma,gamm a-dimethylallyl-2',4,4'-trihydroxychalcone and [6 '',6 ''-dimethylpyra no(2 '',3 ma,gamma-dimethylallyl-2',3,4'-trihydroxychalcone.