光学纯的α-羟基酸及其衍生物是制药工业中通用的手性结构单元。在这项研究中,生物催化剂和底物的组合工程显着提高了重组恶臭假单胞菌酯酶(rPPE01)对α-乙酰氧基酸进行酶促拆分的潜力。基于同源建模和分子对接的半理性设计提供了单点变体W187H,其对2-乙酰氧基-2-(2'-氯苯基)乙酸钠(Ac-CPA-Na)的k cat / K M增加了100-倍,从0.0611到6.20 mM –1 s –1,同时保留其出色的对映选择性和广泛的底物谱。通过使用Ac-CPA的钾盐代替Ac-CPA-Na可以减少操作条件下的生物催化剂失活。用0.5 g L –1的含有rPPE01-W187H的冻干细胞,在15 h内将500 mM(R,S)-Ac-CPA-K选择性脱酰基,转化率为49.9%,这两个S产物均得到令人满意的对映体过量(ee)(> 99%ee)和剩余的R底物(98.7%ee)。因此,(S与野生型酯酶的原
光学纯的α-羟基酸及其衍生物是制药工业中通用的手性结构单元。在这项研究中,生物催化剂和底物的组合工程显着提高了重组恶臭假单胞菌酯酶(rPPE01)对α-乙酰氧基酸进行酶促拆分的潜力。基于同源建模和分子对接的半理性设计提供了单点变体W187H,其对2-乙酰氧基-2-(2'-氯苯基)乙酸钠(Ac-CPA-Na)的k cat / K M增加了100-倍,从0.0611到6.20 mM –1 s –1,同时保留其出色的对映选择性和广泛的底物谱。通过使用Ac-CPA的钾盐代替Ac-CPA-Na可以减少操作条件下的生物催化剂失活。用0.5 g L –1的含有rPPE01-W187H的冻干细胞,在15 h内将500 mM(R,S)-Ac-CPA-K选择性脱酰基,转化率为49.9%,这两个S产物均得到令人满意的对映体过量(ee)(> 99%ee)和剩余的R底物(98.7%ee)。因此,(S与野生型酯酶的原
Enantioselective C−H Olefination of α-Hydroxy and α-Amino Phenylacetic Acids by Kinetic Resolution
作者:Kai-Jiong Xiao、Ling Chu、Jin-Quan Yu
DOI:10.1002/anie.201510808
日期:2016.2.18
development of enantioselective C−H activation reactions by desymmetrization. However, the requirement for the presence of two chemically identical prochiral C−H bonds represents an inherent limitation in scope. Reported is the first example of kinetic resolution by a palladium(II)‐catalyzed enantioselective C−H activation and C−C bond formation, thus significantly expanding the scope of enantioselective C−H
A bacterial strain (No. ECU0015), which catalyzes the hydrolysis of phenyl-1,2-ethanediol cyclic carbonates (4-phenyl-1,3-dioxolan-2-one, 1) to (S)-1-phenyl-1,2-ethanediol (2) with high enantioselectivity, was newly isolated from soil samples utilizing the cyclic carbonate as sole carbon and energy source. The bacterium was later identified as Bacillus species by its 16S rDNA sequence and phylogenetic analysis. The optimal reaction temperature and pH for the asymmetric hydrolysis of 1 using whole cells were 35 degrees C and pH 7.3, respectively. Partial bio-oxidation of the produced (R)-diol was observed, resulting in an increase in the ee(p) (enantiomeric excess of product) of the main product (S)-diol. Under the improved reaction condition, the target product (S)-diol was prepared in gram scale, affording an excellent eep (>99%) with a moderate yield (27.8%) as compared to the maximum theoretical yield of 50% for kinetic resolution. This strain of Bacillus sp. also displayed fairly good activity and enantioselectivity towards some other compounds tested, such as 2-acetoxy-2-phenylacetic acid (3) and its derivatives. (C) 2010 Elsevier B.V. All rights reserved.