The antioxidant and α-glucosidase inhibitory compounds isolated from the roots of Glycyrrhiza uralensis Fisch.

Abstract

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.