L-酪氨酸的消旋研究  

Study on the Racemization of L-Tyrosine

作　　者：王家荣[1] 何佺[1] 彭阳峰[2] 

机构地区：[1]宁波工程学院化工系,浙江宁波315016 [2]华东理工大学化工学院,上海200237

出　　处：《高校化学工程学报》2007年第1期141-145,共5页Journal of Chemical Engineering of Chinese Universities

基　　金：宁波市青年科学基金(2003A62006)

摘　　要：L-酪氨酸的消旋是提高DL-酪氨酸拆分过程收率的重要手段。研究发现，L-酪氨酸在乙酸酐的作用下，分别在碱性水溶液和纯乙酸溶剂中都可实现100％消旋过程。今讨论了在碱性水溶液中，L-酪氨酸、乙酸酐和NaOH三者摩尔比例对消旋过程的影响和在纯乙酸溶剂中，乙酸用量和L-酪氨酸与乙酸酐的摩尔比例与消旋温度对消旋过程的影响。结果表明在乙酸酐的作用下，L-酪氨酸在纯乙酸溶剂中的消旋具有消旋速度快，DL-酪氨酸收率高的优点。合适的消旋条件为：消旋温度80-90℃，乙酸酐和L-酪氨酸的摩尔比为2：1，溶剂醋酸的用量为5mL·g^-1（L-酪氨酸），在此条件下经4h即可实现L-酪氨酸100％的消旋，产品收率90％。In order to improve the availability of DL-tyrosine, the unwanted L-tyrosine in the L-tyrosine-rich by-product of DL-tyrosine optic resolution process for getting D-tyrosine had better be converted into DL-tyrosine again by racemization process. The experimental results show that in the presence of acetic anhydride, the L-tyrosine can be completely racemized and converted into DL-tyrosine both in NaOH aqueous solution and in acetic acid solvent, and moreover, in the presence of acetic anhydride, the L-tyrosine is racemized more rapidly in acetic acid solvent and a higher yield of DL-tyrosine can be achieved. The influences of the factors, such as the molar ratio of L-tyrosine to acetic anhydride and sodium hydroxide in NaOH aqueous solution, the molar ratio of L-tyrosine to acetic anhydride in the acetic acid solvent and the racemizing temperature, on the racemization process were studied. The appropriate racemizing conditions for racemization in acetic acid solvent were found to be： temperature 80-90℃, molar ratio of L-tyrosine to acetic anhydride 2：1 and amount of acetic acid 5 mL for each gram of L-tyrosine. Under above racemization conditions, the L-tyrosine was racemized into DL-tyrosine within 4 h, the rate of racemization is 100% and the yield of the DL-tyrosine product is 90%.

关 键 词：酪氨酸 消旋 乙酸酐 羧酸 

分 类 号：O621.22[理学—有机化学] TQ464.7[理学—化学]