Patent ID: 8450088

Claim:
A process for purification of CMP-N-acetylneuraminic acid (CMP-NeuAc), comprising the following steps (1) to (5): step (1): a step of adding a calcium ion or a manganese ion to a CMP-NeuAc-containing solution, thereby causing phosphoric acid, pyrophosphoric acid, and a nucleotide which coexist with CMP-NeuAc to precipitate, wherein the CMP-NeuAc-containing solution is a solution obtained by catalytic reaction of cytidine 5′-triphosphate (5′-CTP) and neuraminic acid (NeuAc) by use of CMP-NeuAc synthetase as a catalyst; step (2): a step of adding a phosphatase to the CMP-NeuAc-containing solution, thereby converting the nucleotide which coexists with CMP-NeuAc into a nucleoside; step (3): a step of adding ethanol, thereby precipitating CMP-NeuAc in the form of salt; step (4): a step of collecting the thus-precipitated CMP-NeuAc; and step (5): a step of subjecting the thus-collected CMP-NeuAc to cation exchange reaction by bringing the thus-collected CMP-NeuAc into contact with a cation-exchange resin, and then to a treatment with carbon powder, wherein these steps are performed in a sequence selected from: step (1), step (2), step (3), step (4), and then step (5) or step (1) and step (2) are performed simultaneously and then steps (3), (4), and (5) are performed sequentially, and wherein the thus purified CMP-NeuAc in the form of salt has a purity measured by HPLC of 95% or more.