Enhanced Purification of 7-Xylosyl-10-deacetyl Paclitaxel through Twin-Column Recycling Chromatography with a Step Solvent Gradient

7-Xylosyl-10-deacetyl paclitaxel is a crucial semisynthetic precursor of paclitaxel, which could prevent cancer cells from dividing and growing. In this study, twin-column recycling chromatography with a step solvent gradient was applied to the isolation and purification of 7-xylosyl-10-deacetyl paclitaxel. By introduction of a weak solvent between the two columns, band broadening was counteracted to facilitate the separation process. Also the effects of various variables including the magnitude of solvent gradient, feeding volume, switch number, and interval were comprehensively investigated, and the operating conditions were systematically optimized. In the results, 7-xylosyl-10-deacetyl paclitaxel was successfully refined from 23.90% to almost 100%, with a remarkable yield of over 95%. This study demonstrates the distinct advantage of utilizing a new chromatography system in the separation of natural products.