ONE-STEP LARGE-SCALE PREPARATIVE ISOLATION OF ISOQUINOLINE ALKALOIDS FROM RHIZOMA COPTIDIS CHINENSIS BY POLYAMIDE COLUMN CHROMATOGRAPHY AND THEIR QUANTITATIVE STRUCTURE-RETENTION RELATIONSHIP ANALYSIS

Isoquinoline alkaloids are a large class of compounds responsible for the activity of many herbal drugs and possess various pharmacological effects. For their importance, in this paper, a simple, economical, and efficient method has been successfully developed for the large-scale separation of isoquinoline alkaloids from the crude extract of Rhizoma Coptidis by polyamide column chromatography in one-step, which can be easily extended to the separation of other quaternary isoquinoline alkaloids from herbal raw materials. One step separation on 1.5 g extract using a mixture of dichloromethane and methanol in a gradient afforded 283.34 mg (RSD 6.83%) berberine, 97.68 mg (RSD 4.32%) palmatine, 30.02 mg (RSD 3.62%) coptisine, 32.54 mg (RSD 2.86%) columbamine, 24.32 mg (RSD 2.14%) jateorrhizine, 8.88 mg (RSD 1.78%) magnoflorin with purity of 90.34% (RSD 0.53%), 92.32% (RSD 0.75%), 87.12% (RSD 0.25%), 90.01% (RSD 0.62%), 95.56% (RSD 0.58%), 82.39% (RSD 0.92%) and 77.50% (RSD 1.23%), yield of 5.44%, 1.87%, 0.58%, 0.62%, 0.47%, 0.17%, 0.24% and the recovery of 65.95%, 73.25%, 33.32%, 91.89%, 89.03%, 40.73% and 70.02%, respectively. The retention behavior of the alkaloids under study was investigated by means of Principal Component Analysis (PCA) and stepwise-multilinear regression (MLR).