Crystals of N-acetylneuraminic acid alkali metal salt / anhydrate and its production method

摘要

According to the present invention, an aqueous solution of N-acetylneuraminic acid containing an N-acetylneuraminic acid alkali metal salt / anhydride crystal and an alkali metal-containing compound having a pH of 3.0 to 9.0 is provided. Then, an N-acetylneuraminic acid alkali metal salt / anhydride crystal is precipitated by adding or dropping a solvent selected from the group consisting of alcohols and ketones, and alkali metal N-acetylneuraminate from the aqueous solution. It is possible to provide a method for producing a crystal of an alkali metal salt of N-acetylneuraminic acid / anhydrate, which is characterized by collecting a salt / anhydrate crystal.