Sodium-dependent glucose cotransporter 2 (SGLT2)inhibitors from Sophora flavescens
To discover new bioactive Sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors from the traditional Chinese medicine:" Kushen" (roots of Sophoraflavescens),the bioassay-guided purification of an active methanolic fraction was performed.Seven known flavonoid glycosides were isolated and determined.Their structures were elucidated as formononetin 7-O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (1),formononetin 7-O-β-D-apiofuranosyl-(1 →6)-β-D-glucopyranoside (2),trifolirhizin (3),(-)-maackiain 3-O-β-D-galactopyranoside (4),trifolirhizin 6'-monoacetate (5),rothindin (6) and ononin (7).All compounds were isolated from this plant for the first time except compound 3.All seven compounds exhibited inhibitory activity against SGLT2.Among them,compounds 3-5 with the maackiain skeleton showed the most potential inhibitory activity against SGLT2 with the IC50 value ranging between 2.61 and 4.47μmol/L.