139-86-6Relevant academic research and scientific papers
Artificial Biocatalytic Cascade with Three Enzymes in One Pot for Asymmetric Synthesis of Chiral Unnatural Amino Acids
Zhou, Haisheng,Meng, Lijun,Yin, Xinjian,Liu, Yayun,Xu, Gang,Wu, Jianping,Wu, Mianbin,Yang, Lirong
, p. 6470 - 6477 (2019)
Two biocatalytic reactions, transamination catalyzed by transaminases and reductive amination catalyzed by amino acid dehydrogenases, can be used for asymmetric synthesis of optically pure unnatural amino acids. However, although transaminases show a great diversity and broad substrate spectrum, most transaminase reactions are reversible, while amino acid dehydrogenases catalyze reductive amination irreversibly but with strict substrate specificity. Accordingly, herein we developed a tri-enzyme one-pot reaction system to exploit the respective advantages of transaminases and amino acid dehydrogenases, while overcoming the disadvantages of each. In this work, representatives of all four subgroups of transaminases coupled with different amino acid dehydrogenases to produce five l- and four d- unnatural amino acid products, using ammonia and the co-enzyme NAD(P)H, which is regenerated by a robust alcohol dehydrogenase with 2-propanol as cheap cosubstrate. The complete conversion and high enantiopurity (ee > 99 %) of the products, demonstrated it as an ideal alternative for asymmetric synthesis of chiral amino acid compounds.
Chemical Dynamic Thermodynamic Resolution and S/R Interconversion of Unprotected Unnatural Tailor-made α-Amino Acids
Wang, Shuni,Zhou, Shengbin,Wang, Jiang,Nian, Yong,Kawashima, Aki,Moriwaki, Hiroki,Ace?a, José L.,Soloshonok, Vadim A.,Liu, Hong
, p. 9817 - 9830 (2015)
Described here is an advanced, general method for purely chemical dynamic thermodynamic resolution and S/R interconversion of unprotected tailor-made α-amino acids (α-AAs) through intermediate formation of the corresponding nickel(II)-chelated Schiff bases. The method features virtually complete stereochemical outcome, broad substrate generality (35 examples), and operationally convenient conditions allowing for large-scale preparation of the target α-AAs in enantiomerically pure form. Furthermore, the new type of nonracemizable axially chiral ligands can be quantitatively recycled and reused, rendering the whole process economically and synthetically attractive.
Method for preparing 3 - (2 - thienyl) - D D-alanine
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, (2021/05/12)
The invention discloses a method for preparing 3-(2-thienyl)-D-alanine, which comprises the following steps: (1) hydantoin and 2-thiophenecarboxaldehyde carry outare subjected to condensation reactionunder the shielding of inert gas and the existence of a catalyst and water, so that 2-thiophenesubhydantoin is obtained; (2) 2-thiophenesubhydantoin carries outis subjected to hydrogenation reductionreaction under the existence of hydrogen and a catalyst, so that 2-thiophenehydantoin and N-formyl-2-thienyl-DL-alanine are obtained; (3) 2-thiophenehydantoin obtained in step (2) carries outis subjected to enzymatic conversion reaction under the effect of D-hydantoinhydrolase and carbamoylase and under the shielding of inert gas, so that 3-(2-thienyl)-D-alanine is obtained. The method is safe tooperate, highly efficient and environmentally -friendly, reaction conditions are mild, the yield of reaction is high, the quality of the product is good, and reaction amplification can also be realized.
METHOD FOR PREPARING THIENYL ALANINE HAVING OPTICAL ACTIVITY
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Paragraph 0073, (2018/10/30)
This invention relates to a method of preparing optically active β-2-thienyl-alanine, and more particularly to a method of preparing optically active β-2-thienyl-L-alanine or optically active β-2-thienyl-D-alanine through an optical resolution reaction using chiral dibenzoyl tartaric acid or a derivative thereof as an optical resolving agent.
Influence of the aromatic moiety in α- And β-arylalanines on their biotransformation with phenylalanine 2,3-aminomutase from: Pantoea agglomerans
Varga, Andrea,Bánóczi, Gergely,Nagy, Botond,Bencze, László Csaba,To?a, Monica Ioana,Gellért, ákos,Irimie, Florin Dan,Rétey, János,Poppe, László,Paizs, Csaba
, p. 56412 - 56420 (2016/07/06)
In this study enantiomer selective isomerization of various racemic α- and β-arylalanines catalysed by phenylalanine 2,3-aminomutase from Pantoea agglomerans (PaPAM) was investigated. Both α- and β-arylalanines were accepted as substrates when the aryl moiety was relatively small, like phenyl, 2-, 3-, 4-fluorophenyl or thiophen-2-yl. While 2-substituted α-phenylalanines bearing bulky electron withdrawing substituents did not react, the corresponding substituted β-aryl analogues were converted rapidly. Conversion of 3- and 4-substituted α-arylalanines happened smoothly, while conversion of the corresponding β-arylalanines was poor or non-existent. In the range of pH 7-9 there was no significant influence on the conversion of racemic α- or β-(thiophen-2-yl)alanines, whereas increasing the concentration of ammonia (ammonium carbonate from 50 to 1000 mM) inhibited the isomerization progressively and decreased the amount of the by-product (i.e. (E)-3-(thiophen-2-yl)acrylic acid was detected). In all cases, the high ee values of the products indicated excellent enantiomer selectivity and stereospecificity of the isomerization except for (S)-2-nitro-α-phenylalanine (ee 92%) from the β-isomer. Substituent effects were rationalized by computational modelling revealing that one of the main factors controlling biocatalytic activity was the energy difference between the covalent regioisomeric enzyme-substrate complexes.
Bisepoxide cross-linked enzyme aggregates - New immobilized biocatalysts for selective biotransformations
Weiser, Diana,Varga, Andrea,Kovacs, Klaudia,Nagy, Flora,Szilagyi, Andras,Vertessy, Beata G.,Paizs, Csaba,Poppe, Laszlo
, p. 1463 - 1469 (2014/05/20)
Glycerol diglycidyl ether (GDE) is a convenient and inexpensive bisepoxide cross-linker as demonstrated by the preparation of cross-linked enzyme aggregates (CLEAs) from two enzyme classes. The GDE CLEAs of lipase from Pseudomonas fluorescens (AK), lipase from Burkholderia cepacia (PS), and lipase B from Candida antarctica (CaL B) as well as of phenylalanine ammonia-lyase (PAL) from Petroselinum crispum demonstrated improved properties as compared with their glutaraldehyde (GA) cross-linked counterparts. Ultrasonication studies indicated that the GDE CLEAs of lipase PS and PAL were mechanically more stable than the GA CLEAs. In the kinetic resolution of rac-1-phenylethanol, the catalytic activity of the GDE-lipase CLEAs (U=69.6, 134.8, and 127.4 U g -1 for AK, CaL B, and PS prepared at 22 °C, respectively) surpassed that of the corresponding GA-lipase CLEAs (U=24.4, 131.0, and 119.2 U g-1 for AK, CaL B, and PS prepared at 22 °C, respectively). The GDE co-CLEAs from PAL and bovine serum albumin (BSA) could be recycled at least three times if used for the stereoselective ammonia addition in 6 M ammonia to (E)-3-(thiophen-2-yl)acrylic acid, whereas the recycling of the conventional GA-PAL CLEAs from this medium failed. The missing linker: Glycerol diglycidyl ether is applied as a cross-linker for cross-linked enzyme aggregates (CLEAs) of various enzymes such as lipases and phenylalanine ammonia lyases. The bisepoxide CLEAs prove to be efficient and robust biocatalysts surpassing the performance of the glutaraldehyde CLEAs.
Novel preparation of chiral α-amino acids using the Mitsunobu-Tsunoda reaction
Noisier, Anais F. M.,Harris, Craig S.,Brimble, Margaret A.
supporting information, p. 7744 - 7746 (2013/09/02)
An efficient synthesis of racemic or optically active α-amino acids by modified-Mitsunobu alkylation of a racemic or chiral glycine template from alcohols was developed. Libraries of amino acids were prepared in moderate to good yield with good to high enantioselectivity. This simple method widens the scope for preparation of structurally diverse amino acids.
Enhanced conversion of racemic α-arylalanines to (R)-β- arylalanines by coupled racemase/aminomutase catalysis
Cox, Brad M.,Bilsborrow, Joshua B.,Walker, Kevin D.
experimental part, p. 6953 - 6959 (2009/12/25)
(Graph Presented) The Taxus phenylalanine aminomutase (PAM) enzyme converts several (S)-α-arylalanines to their corresponding (R)-β- arylalanines. After incubating various racemic substrateswith 100 μg of PAM for 20 h at 31°C, each (S)-α-arylalanine was enantioselectively isomerized to its corresponding (R)-β-product. With racemic starting materials, the ratio of (R)-β-arylalanine product to the (S)-α-substrate ranged between 0.4 and 1.8, and the remaining nonproductive (R)-α-arylalanine became enriched. To utilize the (R)-α-isomer, the catalysis of a promiscuous alanine racemase from Pseudomonas putida (KT2440) was coupled with that of PAM to increase the production of enantiopure (R)-β-arylalanines from racemic α-arylalanine substrates. The inclusion of a biocatalytic racemization along with the PAM-catalyzed reactionmoderately increased the overall reaction yield of enantiopure β-arylalanines between 4% and 19% (depending on the arylalanine), which corresponded to as much as a 63% increase compared to the turnover with the aminomutase reaction alone. The use of these biocatalysts, in tandem, could potentially find application in the production of chiral β-arylalanine building blocks, particularly, as refinements to the process are made that increase reaction flux, such as by selectively removing the desired (R)-β-arylalanine product from the reaction mixture. 2009 American Chemical Society.
The interaction of heteroaryl-acrylates and alanines with phenylalanine ammonia-lyase from parsley
Paizs, Csaba,Katona, Adrian,Retey, Janos
, p. 2739 - 2744 (2008/02/03)
Acrylic acids and alanines substituted with heteroaryl groups at the β-position were synthesized and spectroscopically characterized (UV, HRMS, 1H NMR, and 13C NMR spectroscopy). The heteroaryl groups were furanyl, thiophenyl, benzofuranyl, and benzothiophenyl and contained the alanyl side chains either at the 2- or 3-positions. While the former are good substrates for phenylalanine ammonia lyase (PAL), the latter compounds are inhibitors. Exceptions are thiophen-3-yl-alanine, a moderate substrate and furan-3-yl-alanine, which is inert. Possible reasons for these exceptions are discussed. Starting from racemic het eroaryl-2-alanines their D-enantiomers were prepared by using a stereodestructive procedure. From the heteroaryl-2- acrylates, the L-enantiomers of the heteroaryl-2-alanines were prepared at high ammonia concentration. These results can be best explained by a Friedel - Crafts-type electrophilic attack at the aromatic part of the substrates as the initial step of the PAL reaction.
Improved preparation of racemic 2-amino-3-(heteroaryl)propanoic acids and related compounds containing a furan or thiophene nucleus
Kitagawa, Tokujiro,Khandmaa, Dashrenchin,Fukumoto, Ayumi,Asada, Makoto
, p. 1137 - 1139 (2007/10/03)
Racemic 2-amino-3-(heteroaryl)propanoic acids (1), mostly with a furan or thiophene nucleus as a heteroaryl group, were synthesized in 48-94% yield by the reduction of 3-(heteroaryl)-2-(hydroxyimino)propanoic acids (5) with zinc dust and formic acid in the presence of a catalytic amount of iron dust at 60°C for 2 h. Under these conditions, unfavorable hydrogenolysis of bromine on the thiophene nucleus does not occur. Traditional Nformylation of the prepared 3-(heteroaryl)alanine (1) with a mixture of formic acid and acetic anhydride afforded 2-(formylamino)-3-(heteroaryl)propanoic acids (6) in 51-95% yield.
