| 摘要 |
PURPOSE:To readily obtain the titled ester, having excellent stability and useful in the field of medicines and foods, by reacting a phosphoric acid ester compound with L-ascorbic acid in the presence of a phosphatase-containing substance which is a bacterial product. CONSTITUTION:5-50g/l 5,6-Isopropylidene-L-ascorbic acid and a phosphoric acid ester compound (e.g. acetyl phosphate) in an equivalent amount of 6-12 times based on the above-mentioned compound are dissolved in ion exchange water and adjusted to pH3.2-3.8. 5-20g/l phosphatase-containing substance produced by Citrobacter freundii and a phosphoric acid buffer solution are added and reacted at pH3.2-3.8 and 10-45 deg.C for 2-48hr while stirring. The reaction after completing the reaction is then heated in a boiling hot water path to inactivate the enzyme. The reaction solution is subsequently centrifuged to provide a supernatant liquid, which is then passed through an ion exchange column, desalted and neutralized to collect the aimed L-ascorbic acid-2- phosphate. |
