RESUMO
Two phenols, bakuchiol (1) and 3-hydroxybakuchiol (2), and two isoflavone glycosides, daidzin (3) and genistin (4) were isolated from Otholobium mexicanum J. W. Grimes (Fabaceae). Moreover, the ability of the raw extract and isolated metabolites to inhibit the enzymes α-amylase and α-glucosidase was evaluated in vitro. In the α-amylase assay, the methanolic extract exhibited a moderate inhibitory activity with an IC50 of 470 µg/mL, while inhibition percentages of bakuchiol (1), 3-hydroxybakuchiol (2), and daidzin (3) were less than 25% at the maximum dose tested (1 µM). Genistin (4) exhibited a poor activity with an IC50 of 805 µM. In the α-glucosidase assay, the methanolic extract exhibited a strong inhibitory activity with an IC50 value of 32 µg/mL, while 3-hydroxybakuchiol (2) exhibited a moderate inhibitory activity with an IC50 of 345 µM. Daidzin (3) and genistin (4) exhibited lower inhibitory activity with IC50 values of 564 µM and 913 µM, respectively. Bakuchiol (1) exhibited a poor inhibitory activity with an inhibition percentage less than 10% at the maximum dose tested (1 mM).
