The antioxidant and α-glucosidase inhibitory compounds isolated from the roots of <i>Glycyrrhiza uralensis</i> Fisch

As a ‘medicine food homology’ herbal medicine, Glycyrrhiza uralensis Fisch. has been consumed widely in the pharmaceutical and food industries. In this paper, seventeen known compounds (1–17) were isolated from the ethyl acetate fraction of G. uralensis roots. Their structures were elucidated as isoliquiritin (1), liquiritigenin (2), liquiritin (3), ononin (4), quercetin (5), 2,4-dihydroxybenzoic acid (6), isoliquiritigenin (7), kaempferol (8), rutin (9), naringenin (10), isolicoflavonol (11), licoflavonol (12), β-sitosterol (13), p-hydroxyphenethylanisate (14), 6,8-diprenylgenistein (15), luteolin (16) and p-hydroxybenzoic acid (17). Among them, compounds 11 and 12 were verified with significant α-glucosidase inhibitory activity with IC50 of 1.9 and 2.6 μM for the first time, respectively. Compounds 5, 8, 12 and 16 exhibited distinctive antioxidant efficacies. Additionally, the structure–activity relationship analysis has been discussed. Herein, this paper highlights that the ethyl acetate fraction of G. uralensis is a potentially natural source for exploring antioxidant and antidiabetic constituents.