Simultaneous purification of minor components in natural products using twin-column recycling chromatography with a step solvent gradient

The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds. This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents. By introducing water at a small fiowing rate between the twin columns, a step solvent gradient is created, by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it fiowing from the upstream to downstream column. Hence, the band broadening is counterbalanced, resulting in an enrichment effect for those minor components in separation process. Herein, two target substances, which showed similar peak position in high performance liquid chromatography (HPLC) and did not exceed 1.8% in crude paclitaxel were selected as target compounds for separation. By using the twincolumn recycling chromatography with a step solvent gradient, a successful purification was achieved in getting the two with the purity almost 100%. We suggest this method is suitable for the separation of most components in natural produces, which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products (thin-layer chromatography and prep (c) 2024 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.