Commercial Preparation of Unnatural Amino Acids by Deracemization

描述（由申请人提供）：非天然氨基酸是制药、农业化学品和精细化学品工业使用的最大类别的中间体之一。由于这些化合物在单一对映异构体药物中的应用，特别是在病毒学和肿瘤学领域，对这些化合物的大规模和高光学纯度的需求现在非常显著.然而，没有合成或生物合成方法已被证明具有足够的通用性来大规模制备这些化合物。里士满化学公司最近开发了一种有效的和通用的化学-酶促方法，通过外消旋原料的去外消旋化以高产率制备对映体纯的L-和D-氨基酸。该方法涉及对映体选择性氨基酸氧化酶生物催化剂和非选择性化学还原催化剂的协同作用，以实现一种对映体的立体转化，并且可以从起始外消旋体得到> 99%的对映体过量，产物收率超过90%。完全在水中进行的这种方法（从而使废物流最小化）与具有50%的最大单程产率的拆分方法相比非常有利。我们已经成功开发出优化工艺效率的方法，并在规模上建立了具有竞争力的经济性。然而，目前该方法的应用范围受到氧化酶生物催化剂的底物范围的限制。我们现在建议应用强大的体外酶进化方法来证明生物催化剂的适应性，从而证明制备药物开发所需的许多非天然氨基酸的一般过程。这些氨基酸由于其有利的药代动力学性质而具有高度相关性，但难以通过传统方法制备。因此，我们的方法通过降低成本、加工要求和废物处理，为精细化工和生命科学行业提供了显著优势。在第一阶段，氨基酸氧化酶具有高活性和对映体选择性对空间庞大的氨基酸将通过我们目前的工艺生物催化剂的体外进化分离。在第二阶段，我们将开发可扩展的化学酶去消旋化工艺，以制备这些非天然氨基酸，并优化关键反应参数，包括底物负荷，生物催化剂生产，配制和重复使用，以及产品分离和回收。实验室进化工作的结果将使我们能够使氧化酶生物催化剂适应许多进一步的目标。在第III阶段，将在大规模非天然氨基酸的商业生产中实施优化的去外消旋化工艺。该工作计划将为精细化工行业带来新的通用生物工艺技术，以商业规模生产手性合成中间体，农用化学品和药物。该项目旨在开发一种经济的酶促方法，用于合成光学纯的非天然氨基酸。这些氨基酸在合成多种重要的药物化合物如HIV蛋白酶抑制剂、抗癌剂和抗糖尿病药物方面有很大的需求。

DESCRIPTION (provided by applicant): Unnatural amino acids represent one of the largest classes of intermediates used by the pharmaceutical, agrochemical and fine chemical industries. Demand for these compounds at large- scale and high optical purity is now very significant, due to their application in single enantiomer pharmaceuticals, particularly for the areas of virology and oncology. No synthetic or biosynthetic method however, has proven sufficiently versatile to prepare these compounds broadly at scale. Richmond Chemical Corporation has recently developed an efficient and general chemo-enzymatic process to prepare enantiomerically pure L- and D- amino acids in high yield by deracemization of racemic starting materials. This method involves the concerted action of an enantioselective amino acid oxidase biocatalyst and a non-selective chemical reducing catalyst to effect the stereo-inversion of one enantiomer and can result in an enantiomeric excess of > 99 % from the starting racemate, with product yields of over 90 %. This approach, conducted entirely in water, (thereby minimizing waste streams) compares very favorably to resolution processes which have a maximum single pass yield of 50 %. We have successfully developed methods to optimize the efficiency of the process and establish competitive economics at scale. However, the current breadth of application of this process is limited by the substrate range of the oxidase biocatalysts. We now propose to apply powerful methods of in vitro enzyme evolution to demonstrate the adaptability of the biocatalysts, and therefore the general process, to prepare many unnatural amino acids required for pharmaceutical development. These amino acids are of high relevance due to their favorable pharmacokinetic properties but are difficult to prepare by traditional methods. As a result, our approach offers significant advantages to the fine chemical and life sciences industries by reducing costs, processing requirements and waste disposal. In Phase I, amino acid oxidases with high activity and enantioselectivity towards sterically bulky amino acids will be isolated through in vitro evolution of our current process biocatalysts. In Phase II we will develop the scalable chemo-enzymatic deracemization processes to prepare these unnatural amino acids and optimize critical reaction parameters including substrate load, biocatalyst production, formulation and re-use, as well as product isolation and recovery. The results of the laboratory evolution work will enable us to adapt the oxidase biocatalysts to many further targets. In Phase III the optimized deracemization processes will be implemented in the commercial manufacture of unnatural amino acids at large-scale. This work plan will result in new general bioprocess technology for the fine chemical industry, to produce chiral synthetic intermediates, agrochemicals and pharmaceuticals at commercial scale. This project is aimed towards the development of an economical enzymatic process for the synthesis of optically pure unnatural amino acids. These amino acids are in great demand for the synthesis of a wide range of important pharmaceutical compounds such HIV protease inhibitors, anti-cancer agents and anti-diabetic drugs.