d‐2‐Aminobutyric acid is an unnatural amino acid serving as an important intermediate in pharmaceutical production. Developing a synthetic method that uses cheaper starting materials and produces less by‐product is a pressing demand. A tri‐enzymatic catalytic system, which is composed of l‐threonine ammonia lyase (l‐TAL), d‐amino acid dehydrogenase (d‐AADH), and formate dehydrogenase (FDH), has thus been developed for the synthesis of d‐2‐aminobutyric acid with high optical purity. In this cascade reaction, the readily available l‐threonine serves as the starting material, carbon dioxide and water are the by‐products. d‐2‐Aminobutyric acid was obtained with >90 % yield and >99 % enantioselective excess, even without adding external ammonia, demonstrating that the ammonia from the first reaction can serve as the amino donor for the reductive amination step. This multi‐enzymatic system provides an attractive method with high atomic economy for the synthesis of d‐α‐amino acids from the corresponding l‐α‐amino acids, which are readily produced by fermentation.

中文翻译：

---

通过体外三酶催化体系高度原子经济地合成d-2-氨基丁酸。

d -2-氨基丁酸是一种非天然氨基酸，在药物生产中起重要作用。迫切需要开发一种使用较便宜的起始原料并产生较少副产物的合成方法。一种三酶催化体系，它是由升-苏氨酸脱氨酶（升-TAL），d -氨基酸脱氢酶（d -AADH），和甲酸脱氢酶（FDH），因此已经开发了用于合成d -具有高光学纯度的2-氨基丁酸。在该级联反应中，容易获得的升-苏氨酸作为起始原料，二氧化碳和水是副产品。d-2-氨基丁酸的收率> 90％，对映选择性过量> 99％，即使不添加外部氨，也表明第一反应中的氨可作为还原胺化步骤的氨基供体。这种多酶系统为从相应的l -α-氨基酸合成d -α-氨基酸提供了一种极具吸引力的方法，该方法具有很高的原子经济性，而这些l -α-氨基酸很容易通过发酵产生。