alpha-Amylase and alpha-glucosidase inhibitory activities of the extracts and constituents of Ferulago blancheana, F. pachyloba and F. trachycarpa roots

Eleven coumarins named osthole (1), imperatorin (2), bergapten (3), prants-chimgin (4), grandivitinol (5), suberosin (6), xanthotoxin (7), felamidin (8), marmesin (9), umbelliferone (10), ulopterol (11), and a sterol mixture consisted of stigmasterol (12), beta-sitosterol (13) were isolated from the roots of Ferulago blancheana, F. pachyloba and F. trachycarpa through in vitro bioassay-guided fractionation processes. The extracts and bioactive compounds were evaluated for their alpha-amylase and alpha-glucosidase activities. Among the tested compounds, felamidin and suberosin showed significant alpha-glucosidase inhibitory activity with IC50 values of 0.4 and 0.9 mg/mL, respectively, when compared to the reference standard acarbose (IC50 = 4.9 mg/mL). Grandivitinol (IC50 = 20.0 mg/mL) had the lowest inhibitory effect. On the other hand, none of the tested extracts were found to be active on alpha-amylase inhibition. This is the first report on isolation, characterization of the bioactive compounds and evaluation the alpha-amylase and alpha-glucosidase inhibitory activities of these species.