A new integrated method of magnetic separation for isoquinoline alkaloids from Coptis chinensis based on their magnetized derivates and key physical properties

For the first time, a new magnetic separation strategy for the alkaloid products in Coptis chinensis was developed in this study. For its basic research, physical properties including thermal properties, solubility and magnetic properties of six Fe-containing magnetic compounds based on isoquinoline alkaloids (including isoquinoline, berberine, palmatine, tetrahydropalmatine, tetrahydropapaverine and berbamine) were characterized firstly, which showed good thermal stability (Tstart>190oC) and expected magnetic susceptibility (>1.35×10-5 emu/g). The measurement results of Gouy method was in agreement with the order determined by vibrating sample magnetometer. Then the new integrated method of extraction-derivatization-magnetic separation was successfully applied for target isoquinoline compounds from Coptis chinensis for the first time on the basis of above studies, and all the recovery of various samples was in the range of 96.85%~101.4%. As the key operation in the whole process, derivatization/magnetization not only makes these alkaloids have good magnetic response in various status but also provides them a new strategy of magnetic separation after their extraction. As a result, the effects of different extraction and derivatization conditions were investigated for target compounds from Coptis chinensis in detail.