The invention provides a method for extracting and purifying
pravastatin sodium from a
fermentation liquor, and belongs to the field of biological
medicine preparation. According to the method for extracting and purifying
pravastatin sodium from the
fermentation liquor, a large amount of impurities and pigments are removed by alkalizing and acidifying the
fermentation liquor, and the effective components in an acidizing liquid are enriched by an adsorbent, so that the purity of an extraction substrate is improved, the quantity of the extraction substrate is greatly reduced, and the quality ofan extraction liquid is further improved; in the whole production process, a single
solvent system is adopted, the process is not complicated, the generated three wastes are low in amount, and the method is suitable for large-scale production. The content of
pravastatin sodium produced by the method is more than 98.8 percent, the content of main
impurity 6-epipravastatin is less than 0.15%, the content of total related substances is less than 0.4%, the product quality accords with the EP9.6 edition
quality standard (the content of the
pravastatin sodium is between 97.0% and 102.0%; a main
impurity A, namely6-epipravastatin, is less than or equal to 0.3%; the content of the total related substances is less than or equal to 0.6%) of qualified
pravastatin sodium, the total yield can reach more than 75%, and the large-scale production prospect is good.