Method for extracting high-purity esculine and fraxin from Cortex Fraxini

The invention provides a method for extracting high-purity esculine and fraxin from Cortex Fraxini, which comprises the following steps: pulverizing a Cortex Fraxini raw material and extracting under hot reflux by a conventional process, preparing a dual-water phase, dissolving, extracting, concentrating, desalinizing and crystallizing. The method mainly comprises the following steps: 1) preparing a dual-water phase system, and separating to obtain an upper phase and a lower phase for later use, and dissolving a Cortex Fraxini extract in the upper phase solvent; 2) centrifugating or filtering the solution containing the Cortex Fraxini extract, adding a right amount of lower phase solvent, sufficiently stirring and mixing, standing, separating the upper phase solution, and concentrating, thereby effectively removing inorganic substances, monosaccharides, polysaccharides. vegetable proteins, chlorophyl and other solid impurities in the Cortex Fraxini extract and enhancing the contents of esculine and fraxin; and removing salts and other impurities from the solution by conventional processes, and concentrating to a proper concentration, thereby sequentially obtaining the esculine and fraxin crystals. The method solves the problems of low crystallizing tendency, high production cost, complex operation and the like in the existing process of preparing esculine and fraxin from Cortex Fraxini, and has the characteristics of simple production equipment, environment friendliness and the like.