ABSTRACT
Objective: To investigate the chemical constituents from the stem and leaves of Rubus caesius and the inhibitory activities on PTP 1B. Methods: Compounds were separated and purified by silica gel column chromatography, Sephadex LH-20 column chromatography, and preparative liquid chromatography. Their structures were identified by spectral methods. The PTP1B inhibitory activities were screened by microplate reader. Results: Five compounds were obtained from the stems of R. caesius respectively, elucidated as naringin (1), apigenin-7-O-β-D-glucopyranoside (2), isoquercitrin (3), hyperoside (4), and (-)-epicatechin 3-O-gallate (ECG) (5), and two compounds were obtained from the leaves respectively, elucidated as acteoside (6) and ellagic acid (7) respectively. Conclusion: Compounds 1-7 are isolated from this plant for the first time. Different fractions and compounds showed different PTP1B inhibitory activities and acteoside showed high PTP1B inhibitory activity with the IC50 value of (27.41 ± 0.61) μg/mL. This compound may be the main active composition of leaves ethyl acetate fraction.