申请人:Ajinomoto Co., Inc.
公开号:EP0612717A1
公开(公告)日:1994-08-31
The present invention provides crystals of L-phenylalanine monomethyl sulfate which have low solubility compared to L-tyrosine and D-phenylalanine. The L-phenylalanine monomethylsulfate crystals are obtained by subjecting a solution containing monomethyl sulfuric acid and phenylalanine to crystallization.
Further, the present invention also provides a process for recovering L-phenylalanine from a water layer by neutralizing the esterified reaction, extracting an ester of L-phenylalanine therefrom with an organic solvent, and recovering remaining L-phenylalanine in the water layer as L-phenylalanine monomethylsulfate. L-phenylalanine monomethyl sulfate is obtained by esterifying L-phenylalanine and methanol in the presence of sulfuric acid, neutralizing the esterified solution with a base in the presence of water, extracting the produced L-phenylalanine methyl ester from the neutralized solution with an organic solvent, and then crystallized the resultant water layer under acidic condition.
本发明提供了与 L-酪氨酸和 D-苯丙氨酸相比溶解度较低的 L-苯丙氨酸单甲基硫酸盐晶体。L-苯丙氨酸单甲基硫酸盐晶体是通过将含有单甲基硫酸和苯丙氨酸的溶液进行结晶而获得的。
此外,本发明还提供了一种从水层中回收 L-苯丙氨酸的工艺,方法是中和酯化反应,用有机溶剂提取其中的 L-苯丙氨酸酯,并以 L-苯丙氨酸单甲基硫酸盐的形式回收水层中剩余的 L-苯丙氨酸。L-苯丙氨酸单甲酯硫酸盐是通过在硫酸存在下将 L-苯丙氨酸和甲醇酯化,在水存在下用碱中和酯化溶液,用有机溶剂从中和溶液中萃取生成的 L-苯丙氨酸甲酯,然后在酸性条件下将生成的水层结晶而得到的。