Separation of sanguinarine and chelerythrine in Macleaya cordata (Willd) R. Br. based on methyl acrylate-co-divinylbenzene macroporous adsorbents

Sanguinarine (SAN) and chelerythrine (CHE) are known as major effective components in the quaternary benzo[c]phenanthridine isoquinoline alkaloids (QBA) fraction of Macleaya cordata (Willd) R. Br. but possess different biological activities. In this study, a method for the separation of SAN and CHE based on methyl acrylate-co-divinylbenzene (MA-co-DVB) macroporous adsorbents was established. The relationship between the polarities of the adsorbents and their adsorption–desorption behaviors towards SAN and CHE was investigated. The results showed that, among three selected commercial adsorbents and seven synthesized macroporous polymeric adsorbents with different MA content, the adsorbent No. 5 with 50% MA content provided the best separation power, and the two alkaloids were separated successfully in a gradient eluent process with 60% (v/v) ethanol aqueous and 80% ethanol aqueous contained 8% acetic acid. Dynamic adsorption and desorption tests had been performed in the column packed with the adsorbent No. 5 for optimizing the process parameters. Under the optimized conditions, the ratio of SAN and CHE transformed from 2:1 in the QBA fraction of M. cordata to 1:13 and 25:1 in the products obtained from the two-step gradient elution, and the recoveries of both SAN and CHE were nearly 90%.