Deracemization of Amino Acids

氨基酸的去消旋作用

• 批准号: 6641951
• 负责人: SCOTT J NOVICK
• 金额: $ 45.23万
• 依托单位: BIOCATALYTICS, INC.
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6641951
• 关键词: aminoacid; aminoacid oxidase; chemical synthesis; directed evolution; enzyme activity; enzyme substrate; immobilized enzymes; ketoacid; method development; racemization; stereoisomer; transaminases

DESCRIPTION (provided by applicant): Unnatural amino acids (UAAs) are increasingly becoming important pharmaceutical intermediates, with applications in a number of current and future drugs. Since UAAs are almost always required as pure stereoisomers, a chiral synthesis is preferred over the resolution methods that are most commonly employed. In Phase I the single-pot deracemization process to make the L-enantiomer was demonstrated. In this method the D-enantiomer of a D,L-amino acid mixture is selectively oxidized to the corresponding 2- ketoacid using a D-amino acid oxidase. The 2-ketoacid is then stereoselectively aminated to the L-amino acid by an L-amino acid transaminase or an L-amino acid dehydrogenase. This is accomplished in a reaction single step, intermediates need not be isolated nor is it necessary for protecting groups or derivatization. Yields and enantiomeric excess values approach 100 percent. This method has a broad scope and will be applicable to a wide range of UAA products. Directed evolution was used on a number of the enzymes investigated to create more active enzyme mutants. In Phase II the deracemization process will be further characterized and optimized. Directed evolution will be performed on a number of the enzymes to create mutants with enhanced activity and broader substrate specificity. In addition, the deracemization of amino acids to make the pure D-enantiomer will be investigated. Both methods, for making the pure L- or D-enantiomer will be demonstrated on the 100 gram scale for important commercial targets.

描述（由申请人提供）：非天然氨基酸（UAAs）日益成为重要的医药中间体，在许多当前和未来的药物中得到应用。由于uaa几乎总是需要纯立体异构体，因此手性合成优于最常用的拆分方法。在第一阶段，展示了单锅脱离工艺制备l -对映体。该方法使用D-氨基酸氧化酶选择性地将D、l -氨基酸混合物的D-对映体氧化为相应的2-酮酸。然后通过l -氨基酸转氨酶或l -氨基酸脱氢酶将2-酮酸立体选择性地胺化成l -氨基酸。这是在一个反应步骤中完成的，中间产物不需要分离，也不需要保护基团或衍生化。产率和对映体过剩值接近100%。该方法适用范围广，将适用于各种UAA产品。定向进化被用于许多酶的研究，以创造更活跃的酶突变体。在第二阶段，将进一步表征和优化脱羧过程。定向进化将在一些酶上进行，以创造具有增强活性和更广泛底物特异性的突变体。此外，还将研究氨基酸的去外消旋反应以制备纯d -对映体。这两种制备纯L-或d -对映体的方法都将在100克规模上用于重要的商业目标。