Antioxidant and α-glucosidase inhibitiory activity of Cercis chinensis flowers

Antioxidant and α-glucosidase inhibitiory active compounds of Cercis chinensis flowers were investigated with bio-assay guiding method. Ethyl acetate fraction (CLEa) and n-butanol fraction (CLBu) exhibited antioxidant and α-glucosidase inhibitiory activity in vitro, and the corresponding active fractions, EaFr.3, EaFr.5 and BuFr.1, exhibited higher antioxidant and α-glucosidase inhibitiory activity than those of other fractions. Eight compounds, ethyl gallate (1), stearic acid (2), docosanoic acid (3), 5α-stigmast-9(11)-en-3β-ol (4), kaempferol-3-O-α-rhamnopyranoside (5), vanillic acid (6), fisetin (7), and β-sitosterol (8), were isolated and identified from CLEa and CLBu. Ethyl gallate shown the highest antioxidant activity by scavenging DPPH radical and reducing ferric compared. Docosanoic acid and vanillic acid shown stronger α-glucosidase inhibitory activity than that of acarbose.