New alpha-glucosidase inhibitors from the Mongolian medicinal plant Ferulamongolica

The four new and four known sesquiterpenoid derivatives 1-4 and 5-8, respec tively, were isolated from the air-dried roots of Ferula mongolica. The str uctures of these compounds were determined by spectroscopic methods and fou nd to be rel-(2R,3R)-2-[(3E)-4,8-dimethylnona-3,7-dienyl]-3,4-dihydro-3,8-d ihydroxy-2-methyl-2H,5H-pyrano[2,3-b][1]benzopyran-5-one (1), rel-(2R,3R)-2 -[(3E)-4,8-dimethylnona-3,7-dienyl]-2,3-dihydro-7-hydroxy-2,3 -dimethyl-4H- furo[2,3 -b][1]benzopyran-4- one (2), rel-(2R,3R)-2-[(3E)-4,8-dimethylnona- 3,7-dienyl]-2,3-dihydro-7-hydroxy-2,3-dimethyl-4H-furo[3,2-c][1]benzopyran- 4-one (3), rel-(2R,3R)-2-[(3E)4,8-dimethylnona-3,7-dienyl)-2,3-dihydro-7-me thoxy-2,3-dimethyl-4H-furo[3,2-c][1]benzopyran-4-one (4), (4E,8E)-1-(2-hydr oxy-4-methoxyphenyl)-5,9,13-trimethyltetradeca-4,8,12-trien-1-one (5), the rel-(2R,3S) diastereoisomer 6 of 2, the rel-(2R,3S) diastereoisomer 7 of 4, and (4E,8E)-1-(2,4-dihydroxyphenyl)-5,9,13-trimethyltetradeca-4,8,12-trien -1-one (8). These compounds were tested as inhibitors against the enzyme al pha -glucosidase. The compounds 1-6 and 8 exhibited significant inhibitory activity and, therefore, represent a new class of alpha -glucosidase inhibi tors.