Separation of honokiol and magnolol by intermittent counter-current extraction

Recently, intermittent counter-current extraction (ICcE) has been developed and shown its advantage in improving resolution between targeted compounds. However, how to choose suitable parameters to increase the throughput has not been systematically studied yet. In present work, we first calculated theoretically the conditions to carry out ICcE elution mode. Then, honokiol and magnolol were separated as model compounds using ICcE elution mode to confirm our conclusion. After parameters like sample concentration and sample feed were optimized in analytical high-performance counter-current chromatography (HPCCC), the separation process was scaled up to preparative HPCCC successfully. 12.8 g honokiol and 16.1 g magnolol were separated from 30 g mixture with purities of 98.6% and 93.7%. And the throughput of target isolation of ICcE elution mode was at least 3.75× higher than isocratic elution mode with the same HPCCC instruments. Our results confirmed our theory calculation and demonstrated the enormous potential of ICcE on preparative separation of binary mixture.