New α ‐Glucosidase Inhibitors from the Mongolian Medicinal Plant Ferula mongolica

The four new and four known sesquiterpenoid derivatives 1  –  4 and 5  –  8 , respectively, were isolated from the air‐dried roots of Ferula mongolica . The structures of these compounds were determined by spectroscopic methods and found to be rel ‐(2 R ,3 R )‐2‐[(3 E )‐4,8‐dimethylnona‐3,7‐dienyl]‐3,4‐dihydro‐3,8‐dihydroxy‐2‐methyl‐2 H ,5 H ‐pyrano[2,3‐ b ][1]benzopyran‐5‐one ( 1 ), rel ‐(2 R ,3 R )‐2‐[(3 E )‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐hydroxy‐2,3‐dimethyl‐4 H ‐furo[2,3‐ b ][1]benzopyran‐4‐one ( 2 ), rel‐ (2 R ,3 R )‐2‐[(3 E )‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐hydroxy‐2,3‐dimethyl‐4 H ‐furo[3,2‐ c ][1]benzopyran‐4‐one ( 3 ), rel‐ (2 R ,3 R )‐2‐[(3 E )‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐methoxy‐2,3‐dimethyl‐4 H ‐furo[3,2‐ c ][1]benzopyran‐4‐one ( 4 ), (4 E ,8 E )‐1‐(2‐hydroxy‐4‐methoxyphenyl)‐5,9,13‐trimethyltetradeca‐4,8,12‐trien‐1‐one ( 5 ), the rel‐ (2 R ,3 S ) diastereoisomer 6 of 2 , the rel‐ (2 R ,3 S ) diastereoisomer 7 of 4 , and (4 E ,8 E )‐1‐(2,4‐dihydroxyphenyl)‐5,9,13‐trimethyltetradeca‐4,8,12‐trien‐1‐one ( 8 ). These compounds were tested as inhibitors against the enzyme α ‐glucosidase. The compounds 1  –  6 and 8 exhibited significant inhibitory activity and, therefore, represent a new class of α ‐glucosidase inhibitors.