328-39-2Relevant articles and documents
Rational engineering ofAcinetobacter tandoiiglutamate dehydrogenase for asymmetric synthesis ofl-homoalanine through biocatalytic cascades
Diao, Shiqing,Jiang, Shuiqin,Liu, Yan,Sun, Yangyang,Wang, Hualei,Wang, Liuzhu,Wei, Dongzhi
, p. 4208 - 4215 (2021/06/30)
l-Homoalanine, a useful building block for the synthesis of several chiral drugs, is generally synthesized through biocascades using natural amino acids as cheap starting reactants. However, the addition of expensive external cofactors and the low efficiency of leucine dehydrogenases towards the intermediate 2-ketobutyric acid are two major challenges in industrial applications. Herein, a dual cofactor-dependent glutamate dehydrogenase fromAcinetobacter tandoii(AtGluDH) was identified to help make full use of the intracellular pool of cofactors when using whole-cell catalysis. Through reconstruction of the hydrophobic network between the enzyme and the terminal methyl group of the substrate 2-ketobutyric acid, the strict substrate specificity ofAtGluDH towards α-ketoglutarate was successfully changed, and the activity obtained by the most effective mutant (K76L/T180C) was 17.2 times higher than that of the wild-type protein. A three-enzyme co-expression system was successfully constructed in order to help release the mass transfer restriction. Using 1 Ml-threonine, which is close to the solubility limit, we obtained a 99.9% yield ofl-homoalanine in only 3.5 h without adding external coenzymes to the cascade, giving 99.9% ee and a 29.2 g L?1h?1space-time yield. Additionally, the activities of the engineeredAtGluDH towards some other hydrophobic amino acids were also improved to 1.1-11.2 fold. Therefore, the engineering design of some dual cofactor-dependent GluDHs could not only eliminate the low catalytic activity of unnatural substrates but also enhance the cofactor utilization efficiency of these enzymes in industrial applications.
Decarboxylative Radical Addition to Methylideneoxazolidinones for Stereocontrolled Synthesis of Selectively Protected Diamino Diacids
Annadate, Ritesh,Beadle, Jonathan,Hsiao, Yu-Ting,Pascoe, Cameron,Vederas, John C.
supporting information, p. 7270 - 7273 (2021/10/01)
Syntheses of stereochemically pure and selectively protected diamino diacids can be achieved by redox decarboxylation of distal N-hydroxyphthalimide esters of protected aspartic, glutamic or α-aminoadipic acids via radical addition to methylideneoxazolidinones. The products are useful for solid-supported syntheses of robust bioactive carbocyclic peptide analogs. Yields of reactive primary radical addition are superior to those of more stabilized radicals, and the reaction fails if the alkylideneoxazolidinone has a methyl substituent on its terminus (i.e., 13a/13b).
Synthesis of Unprotected 2-Arylglycines by Transamination of Arylglyoxylic Acids with 2-(2-Chlorophenyl)glycine
Inada, Haruki,Shibuya, Masatoshi,Yamamoto, Yoshihiko
, p. 11047 - 11059 (2020/10/12)
The transamination of α-keto acids with 2-phenylglycine is an effective methodology for directly synthesizing unprotected α-amino acids. However, the synthesis of 2-arylglycines by transamination is problematic because the corresponding products, 2-arylglycines, transaminate the starting arylglyoxylic acids. Herein, we demonstrate the use of commercially available l-2-(2-chlorophenyl)glycine as the nitrogen source in the transamination of arylglyoxylic acids, producing the corresponding 2-arylglycines without interference from the undesired self-transamination process.
Highly Efficient Synthesis of Amino Acids by Amination of Bio-Derived Hydroxy Acids with Ammonia over Ru Supported on N-Doped Carbon Nanotubes
Xie, Zhenbing,Chen, Bingfeng,Peng, Fangfang,Liu, Mingyang,Liu, Huizhen,Yang, Guanying,Han, Buxing
, p. 5683 - 5689 (2020/09/21)
The amino acids have extensive applications, and their productions from biomass-derived feedstocks are very attractive. In this work, the synthesis of amino acids by amination of bio-derived hydroxy acids with ammonia over different metallic nano-catalysts supported on various supports is studied. It is found that Ru nano-catalysts on the nitrogen-doped carbon nanotubes (Ru/N?CNTs) have an outstanding performance for the reaction. Different hydroxy acids can be catalytically converted into the corresponding amino acids with yields up to 70.0 % under mild conditions, which is higher than those reported. The reasons for the high efficiency of the catalyst are investigated, and the reaction pathway is proposed on the basis of control experiments.
Direct Synthesis of Free α-Amino Acids by Telescoping Three-Step Process from 1,2-Diols
Inada, Haruki,Shibuya, Masatoshi,Yamamoto, Yoshihiko
supporting information, p. 709 - 713 (2019/01/25)
A practical telescoping three-step process for the syntheses of α-amino acids from the corresponding 1,2-diols has been developed. This process enables the direct synthesis of free α-amino acids without any protection/deprotection step. This method was also effective for the preparation of a 15N-labeled α-amino acid. 1,2-Diols bearing α,β-unsaturated ester moieties afforded bicyclic α-amino acids through intramolecular [3 + 2] cycloadditions. A preliminary study suggests that the resultant α-amino acids are resolvable by aminoacylases with almost complete selectivity.
Electrosynthesis of amino acids from biomass-derivable acids on titanium dioxide
Fukushima, Takashi,Yamauchi, Miho
supporting information, p. 14721 - 14724 (2019/12/24)
Seven amino acids were electrochemically synthesized from biomass-derivable α-keto acids and NH2OH with faradaic efficiencies (FEs) of 77-99% using an earth-Abundant TiO2 catalyst. Furthermore, we newly constructed a flow-Type electrochemical reactor, named a "polymer electrolyte amino acid electrosynthesis cell", and achieved continuous production of alanine with an FE of 77%.
Catalytic amino acid production from biomass-derived intermediates
Deng, Weiping,Wang, Yunzhu,Zhang, Sui,Gupta, Krishna M.,Hülsey, Max J.,Asakura, Hiroyuki,Liu, Lingmei,Han, Yu,Karp, Eric M.,Beckham, Gregg T.,Dyson, Paul J.,Jiang, Jianwen,Tanaka, Tsunehiro,Wang, Ye,Yan, Ning
, p. 5093 - 5098 (2018/05/23)
Amino acids are the building blocks for protein biosynthesis and find use in myriad industrial applications including in food for humans, in animal feed, and as precursors for bio-based plastics, among others. However, the development of efficient chemical methods to convert abundant and renewable feedstocks into amino acids has been largely unsuccessful to date. To that end, here we report a heterogeneous catalyst that directly transforms lignocellulosic biomass-derived α-hydroxyl acids into α-amino acids, including alanine, leucine, valine, aspartic acid, and phenylalanine in high yields. The reaction follows a dehydrogenation-reductive amination pathway, with dehydrogenation as the rate-determining step. Ruthenium nanoparticles supported on carbon nanotubes (Ru/CNT) exhibit exceptional efficiency compared with catalysts based on other metals, due to the unique, reversible enhancement effect of NH3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing membrane distillation to facilitate product purification is proposed and validated. Overall, this study offers a rapid and potentially more efficient chemical method to produce amino acids from woody biomass components.
Organocatalytic Enantioselective Addition of α-Aminoalkyl Radicals to Isoquinolines
Liu, Xiangyuan,Liu, Yang,Chai, Guobi,Qiao, Baokun,Zhao, Xiaowei,Jiang, Zhiyong
supporting information, p. 6298 - 6301 (2018/10/09)
With a dual organocatalytic system involving a chiral phosphoric acid and a dicyanopyrazine-derived chromophore (DPZ) photosensitizer and under the irradiation with visible light, an enantioselective Minisci-type addition of α-amino acid-derived redox-active esters (RAEs) to isoquinolines has been developed. A variety of prochiral α-aminoalkyl radicals generated from RAEs were successfully introduced on isoquinolines, providing a range of valuable α-isoquinoline-substituted chiral secondary amines in high yields with good to excellent enantioselectivities.
PROCESS FOR THE RACEMIZATION OF ALPHA-AMINO ACIDS
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Paragraph 0086-0087, (2016/08/29)
According to the present invention, a method is provided wherein a basic aqueous phase containing an optically active α-amino acid is brought into contact with an organic phase containing a racemisation catalyst in the form of a copper metal complex of copper ions and an α-amino acid and salicylaldehyde, in the presence of a phase transition catalyst, thereby subjecting the optically active α-amino acid to racemisation. In the α-amino acid racemisation method according to the present invention, the reaction conditions are mild and thus there is little α-amino acid breakdown and the yield is high, the racemisation catalyst can be reused, the α-amino acid resulting from the racemisation can easily be isolated and purified, and the racemisation method can be implemented in volume such that the invention is economic.
A method for preparing DL-leucine (by machine translation)
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Paragraph 0011, (2017/03/14)
The invention discloses a method for preparing DL-leucine. The method of the invention first through ethanol, acetamide, ethanol sodium and isobutyl bromide reaction, reaction solution distillation recovery ethanol, distillation residues hot-melt, filtering, cooling to crystallize, shall be 2-isobutyl-acetamide; and then the 2-isobutyl-acetamide react with sodium hypochlorite, reaction solution distillation recovery chcl, distillation residual the toluene-P-sulfonic acid reaction, the reaction liquid filtering, cooling to crystallize, shall be leucine paratoluene sulfonic acid; leucines toluene-P-sulfonic acid with sodium hydroxide reaction, and the re-adjustment to pH 6-6.5 DL-leucine can be obtained. The invention chemical synthetic mild reaction conditions, the low requirements for the equipment, production cycle is short, with little investment, low cost; relatively high yield, there are few by-products, can be produced in large quantities, which is beneficial for industrial; acetamide can be formed by preparing ketene dimer, easily available raw materials. (by machine translation)
