Preliminary study on the α-glucosidase inhibitors from the roots of Rumex crispus

Objective In order to investigate the α-glucosidase inhibitory activity of the roots of Rumex.cripus Linn,and to find the active components of it.Methods The total extracts of the roots of Rumex.cripusLinn.and those extracts including chloroform,ethyl acetate and n-BuOH were screened by α-glucosidase inhibitory model in vitro.The relationship between the inhibitory ratio and the extract concentration was assayed.Furthermore,the active components of the roots of Rumex.crispas Linn.were investigated.Results The total extracts of the roots of Rumex.cripus Linn.showed a potent α-glucosidase inhibitory activity(IC50 = 1.1 μg/ml),and the ethyl acetate extract(IC50 = 0.22 μg/ml) also showed strong inhibitory activity,which is higher than that of Acarbose(IC50 = 175.97 μg/ml).Furthermore,the ethyl acetate extract of the roots of Rumex.cripusLinn were subjected to column chromatography,and two compound were isolated.Compound 1 were identified as chrysophanol(TDH-1),compound 2 were identified as rhaponticin(TDH-2).Compounds 1 showed weak inhibitory activity,and compound 2 showed some inhibitory activity.Active component TDH-3 showed strong inhibitory activity(IC50 = 1.15 μg/ml,which is higher than that of acarbose.Conclusion The active component(TDH-3) isolated from the roots of Rumex cripus Linn.showed a potent α-glucosidase inhibitory activity.They can be further used as α-glucosidase inhibitor for the treatment of the increased postprandial blood glucose in vivo.