Abstract: The aim of this study was to analyze and identify the chemical compositions from Rhizoma Coptidis crude extracts by ultrafiltration HPLC-DAD-MS combined with high-speed countercurrent chromatography,and to screen the α-glucosidase inhibitors from R.Coptidis. Chromatographic separation was carried out on a reversed phase C₁₈ column and a binary mobile phase system consisting of 0.02% acetic acid aqueous(A)and methanol(B)under a gradient condition;Electrospray ionization mass spectrometry(ESI-MS)with positive ion mode was used to detect the chemical constituents.α-Glucosidase were employed as the targeted enzyme,and the ultrafiltration MS technique was employed to screening the inhibitors;HSCCC purification with a binary phase system was made up of ethyl acetate/n-butanol/ethanol/water(3.0:1.7:0.5:6.0,v/v/v/v).Finally,five chemical compounds from R.Coptidis including jaterorhizine,epibererine,coptisine,palmatine and berberine respectively were separated and detected.Palmatine and berberine were found to have αglucosidase inhibition effect.

Key words: Rhizoma Coptidis, ultrafiltration, liquid chromatography/mass spectrometry, high-speed countercurrent chromatography, &alpha, -glucosidase