Novel Method to Produce Beta-Amino Acids

描述(由申请人提供)： 作为一类关键的医药中间体，β-氨基酸作为一类重要的医药中间体，在当前和未来的许多药物中的应用正在迅速增长。在这个项目中，将开发一种生产光学纯β-氨基酸的成本效益高的工艺，以适应对β-氨基酸的商业需求。该方法包括从容易制备的外消旋取代二氢尿嘧啶开始的两个酶反应。5，6-二氢尿嘧啶可以在5或6位被取代，具有不同的官能团，它与二氢尿嘧啶酶接触以催化立体选择性的水解反应，产生对映体富含手性N-氨基甲酰-β-氨基酸和对映体富含未反应的手性5，6-二氢尿嘧啶。然后，手性N-氨基甲酰基-(-氨基酸)被酶解去氨基，得到光学纯的(-氨基酸)。通过使用具有相反立体选择性的酶回收和水解未反应的手性5，6-二氢尿嘧啶，可以得到纯形式的β-氨基酸的对位对映体。该方法的一个重要特点是两个酶反应可以在一锅内进行，不需要分离中间产物N-氨基甲酰-β-氨基酸。在使用5，6-二氢尿嘧啶和5-甲基-5，6-二氢尿嘧啶的第一阶段中，已经证明了这一概念。 在第二阶段，首要任务将是寻找底物范围更广的氨基甲酰基酶，特别是使用定向进化技术寻找芳基取代的N-氨基甲酰-(-氨基酸)。还将发现和产生具有相反对映体选择性的二氢尿嘧啶酶(即对二氢尿嘧啶的R-对映体的对映选择性水解酶)。利用在第二阶段中获得的酶，将进一步开发成本效益高的一锅法将外消旋取代的二氢尿嘧啶转化为相应的对映体纯的β-氨基酸，该过程通过二氢尿嘧啶酶/氨基甲酰酶双酶系统以非固定化和固定化的形式进行。最后，将为重要的商业目标在100克规模上演示生产对映体纯的β-氨基酸。

DESCRIPTION (provided by applicant): Beta-Amino acids are rapidly growing in importance as a key class of pharmaceutical intermediates, with applications in a number of current and future drugs. A cost-effective process for the production of optically pure beta-amino acids will be developed in this project to accommodate the commercial needs for beta-amino acids. The method involves two enzymatic reactions starting from conveniently prepared racemic substituted dihydrouracils. The 5,6-dihydrouracil, which may be substituted at either the 5 or 6 positions with various functional groups, is contacted with a dihydrouracilase enzyme to catalyze a stereoselective hydrolysis reaction, producing an enantiomerically-enriched chiral N-carbamoyl-beta-amino acid and an enantiomerically enriched, unreacted chiral 5,6-dihydrouracil. The chiral N-carbamoyl-(-amino acid was then decarbamoylated enzymatically to produce an optically pure (-amino acid. The opposite enantiomer of the beta-amino acid can be produced in pure form by recovering and hydrolyzing the unreacted chiral 5,6- dihydrouracil using the enzymes with opposite stereoselectivity. An important feature of this method is that the two enzyme reaction can be carried out in one pot and it is not necessary to isolate the intermediate N-carbamoyl-beta-amino acids. This proof of concept has been demonstrated in Phase 1 using 5,6-dihydrouracil and 5-methyl-5,6-dihydrouracil. In Phase II, the top priority will be searching for carbamoylase enzymes with a broader substrate range, particularly including aryl-substituted N-carbamoyl-(-amino acids using directed evolution technology. Dihydrouracilases with opposite enantioselectivity (i.e. enantioselectively hydrolyzing the R-enantiomer of dihydrouracils) will also be found and produced. The cost-effective one-pot process to convert racemic substituted dihydrouracils to the corresponding enantiomerically pure beta-amino acids via the coupled dihydrouracilase/carbamoylase two-enzyme system in the non-immobilized and immobilized forms will be developed further using the enzymes acquired in Phase 2. Finally, the production of enantiomerically-pure beta-amino acids will be demonstrated on the 100 gram scale for important commercial targets.