Alpha-glucosidase inhibitory constituents of Linaria kurdica subsp. eriocalyx.

Three known iridoid glycosides, antirrhide (1), antirrhinoside (2), and 5-O-beta-allosylantirrhinoside (3), and two known flavone glycosides, linariin (4"'-O-acetylpectolinarin) (4) and linarin (acacetin-7-O-beta-D-rutinoside) (5) were isolated from Linaria kurdica Boiss & Hohen. subsp. eriocalyx. The structures of the isolated compounds were established from spectroscopic evidence. Compounds 1-3 showed high inhibitory potential against alpha-glucosidase.