29678-81-7Relevant academic research and scientific papers
Efficient Synthesis of D-Phenylalanine from L-Phenylalanine via a Tri-Enzymatic Cascade Pathway
Lu, Cui,Zhang, Sheng,Song, Wei,Liu, Jia,Chen, Xiulai,Liu, Liming,Wu, Jing
, p. 3165 - 3173 (2021/06/09)
D-phenylalanine is an important intermediate in food and pharmaceutical industries. Here, to enable efficient D-phenylalanine biosynthesis from L-phenylalanine, a tri-enzymatic cascade was designed and reconstructed in vivo. The activity of Proteus vulgaris meso-diaminopimelate dehydrogenase (PvDAPDH) toward phenyl pyruvic acid was identified as the limiting step. To overcome, the tension in the phenyl pyruvic acid side-chain, PvDAPDH was engineered, generating PvDAPDHW121A/R181S/H227I, whose catalytic activity of 6.86 U mg?1 represented an 85-fold increase over PvDAPDH. Introduction of PvDAPDHW121A/R181S/H227I, P. mirabilis L-amino acid deaminase, and Bacillus megaterium glucose dehydrogenase in E. coli enabled the production of 57.8 g L?1 D-phenylalanine in 30 h, the highest titer to date using 60 g L?1 L-phenylalanine as starting substrate, which meant a 96.3 % conversion rate and >99 % enantioselectivity on a 3-L scale. The proposed tri-enzymatic cascade provides a novel potential bio-based approach for industrial production of D-phenylalanine from cheap amino acids.
Chirality switching in the enantioseparation of 2-hydroxy-4-phenylbutyric acid: Role of solvents in selective crystallization of the diastereomeric salt
Hirose, Takuji,Kodama, Koichi,Shitara, Hiroaki,Yi, Meng
, (2020/03/04)
Chirality switching was induced by solvents in the enantioseparation of 2-hydroxy-4-phenylbutyric acid (HPBA) via diastereomeric salt formation with an enantiopure aminoalcohol. The (S)-salt was crystallized from butanol solutions and the (R)-salt was obt
Highly Efficient Deracemization of Racemic 2-Hydroxy Acids in a Three-Enzyme Co-Expression System Using a Novel Ketoacid Reductase
Xue, Ya-Ping,Wang, Chuang,Wang, Di-Chen,Liu, Zhi-Qiang,Zheng, Yu-Guo
, p. 1 - 13 (2018/04/26)
Enantiopure 2-hydroxy acids (2-HAs) are important intermediates for the synthesis of pharmaceuticals and fine chemicals. Deracemization of racemic 2-HAs into the corresponding single enantiomers represents an economical and highly efficient approach for synthesizing chiral 2-HAs in industry. In this work, a novel ketoacid reductase from Leuconostoc lactis (LlKAR) with higher activity and substrate tolerance towards aromatic α-ketoacids was discovered by genome mining, and then its enzymatic properties were characterized. Accordingly, an engineered Escherichia coli (HADH-LlKAR-GDH) co-expressing 2-hydroxyacid dehydrogenase, LlKAR, and glucose dehydrogenase was constructed for efficient deracemization of racemic 2-HAs. Most of the racemic 2-HAs were deracemized to their (R)-isomers at high yields and enantiomeric purity. In the case of racemic 2-chloromandelic acid, as much as 300 mM of substrate was completely transformed into the optically pure (R)-2-chloromandelic acid (> 99% enantiomeric excess) with a high productivity of 83.8 g L?1 day?1 without addition of exogenous cofactor, which make this novel whole-cell biocatalyst more promising and competitive in practical application.
Asymmetric synthesis of (S)-dihydrokavain from l-malic acid
Eskici, Mustafa,Karanfil, Abdullah,?zer, M. Sabih,Kabak, Yal??n,Durucasu, ?nci
, p. 2382 - 2390 (2018/10/20)
A practical and efficient asymmetric synthesis of (S)-dihydrokavain from known ethyl (S)-2-hydroxy-4-phenylbutanoate which is, in turn, readily available from l-malic acid as a cheap chiral pool material is described using regioselective ring-opening of the 1,2-cyclic sulfate with lithium-3,3,3-triethoxypropiolate and subsequent HgO/H2SO4-mediated lactonization as the key steps. Its opposite enantiomer (R)-dihydrokavain was also synthesized from d-malic acid using the same sequences of reactions for the purpose of optical purity determination.
Preparation method of (R)-2-hydroxyl-4-phenyl butyric acid
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Paragraph 0023, (2017/07/21)
The invention discloses a preparation method of (R)-2-hydroxyl-4-phenyl butyric acid. The method comprises the following steps: carrying out catalytic reduction on 2-oxo-4-phenyl butyric acid-L-menthyl ester in an alcohol system to obtain (R)-2-hydroxyl-4
Chloramphenicol base chemistry. Part 10: Asymmetric synthesis of α-hydroxy chiral alcohols via intramolecular Michael additions of γ-hydroxy-α, β-unsaturated enones with chloramphenicol base derived bifunctional urea organocatalysts
Wang, Haifeng,Yan, Linjie,Wu, Yan,Chen, Fener
, p. 2793 - 2800 (2017/04/14)
We have developed the chloramphenicol base urea-catalyzed intramolecular Michael addition of γ-hydroxy-α, β-unsaturated enones. The oxidation of the resulting products provided facile access to the corresponding α-hydroxy chiral alcohols with good efficiency and enantioselectivity, with the reaction displaying broad substrate scope. The utility of this methodology was further demonstrated by the synthesis of (R)-2-hydroxy-4-phenylbutanoate, which is a key building block for the construction of the ACE inhibitor benazepril hydrochloride.
Method for preparing lisinopril intermediate
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Paragraph 0047; 0051, (2017/04/03)
The invention provides a method for preparing a lisinopril intermediate. The lisinopril intermediate is (R)-2-hydroxyl-4-phenylbutyrate. The method has the advantages that the lisinopril intermediate is made of inexpensive and easily available raw materials which are benzaldehyde and pyruvic acid, four-step efficient reaction including condensation, biological enzyme catalytic asymmetric reduction, double-bond hydrogenation and esterification is carried out on the benzaldehyde and the pyruvic acid, and accordingly an optically pure target product (R)-HPBE [(R)-2-hydroxyl-4-phenylbutyrate] can be ultimately obtained at the overall yield of 83%.
Asymmetric hydrogenation reaction of alpha-ketoacids compound
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Paragraph 0037; 0045, (2016/10/10)
The invention relates to the technical field of organic chemistry, especially to an asymmetric hydrogenation reaction of an alpha-ketoacids compound. The asymmetric hydrogenation reaction comprises a scheme shown in the description. In the scheme, R1 is phenyl, substituted phenyl, naphthyl, substituted naphthyl, C1-C6 alkyl, or aralkyl; a substituent group is C1-C6 alkyl, C1-C6 alkoxy, or halogen; and the number of the substituent group is 1-3. In the scheme, M is a chiral spiro-pyridylamino phosphine ligand iridium complex having a structure shown in the description. In the structure, R is hydrogen, 3-methyl, 4-tBu, or 6-methyl.
Direct asymmetric hydrogenation of α-keto acids by using the highly efficient chiral spiro iridium catalysts
Yan, Pu-Cha,Xie, Jian-Hua,Zhang, Xiang-Dong,Chen, Kang,Li, Yuan-Qiang,Zhou, Qi-Lin,Che, Da-Qing
supporting information, p. 15987 - 15990 (2015/02/19)
A new efficient and highly enantioselective direct asymmetric hydrogenation of α-keto acids employing the Ir/SpiroPAP catalyst under mild reaction conditions has been developed. This method might be feasible for the preparation of a series of chiral α-hydroxy acids on a large scale.
