121986-08-1Relevant academic research and scientific papers
The first encapsulation of hydroxynitrile lyase from Hevea brasiliensis in a sol-gel matrix
Veum, Lars,Hanefeld, Ulf,Pierre, Alain
, p. 10419 - 10425 (2004)
A straightforward process for the encapsulation of HbHNL under low methanol conditions has been developed. By adding a sol, prepared by hydrolysis of TMOS/MTMS at pH 2.8 with continuous removal of methanol, to a stirred solution of the enzyme in a buffer at pH 6.5, at least 65% of the activity of the free enzyme could be recovered after the encapsulation. The aquagels were successfully used in the synthesis of (S)-cyanohydrins. Graphical Abstract.
Large-scale synthesis of (R)-2-amino-1-(2-furyl)ethanol via a chemoenzymatic approach
Purkarthofer, Thomas,Pabst, Thomas,Van Den Broek, Cor,Griengl, Herfried,Maurer, Oliver,Skranc, Wolfgang
, p. 618 - 621 (2006)
A two-step chemoenzymatic synthesis of (R)-2-amino-1-(2-furyl)ethanol for laboratory production was developed followed by successful up-scaling to kilogram scale. The generation of the asymmetric centre was accomplished by a highly enantioselective cyanohydrin reaction of furan-2-carbaldehyde with hydrocyanic acid catalyzed by the hydroxynitrile lyase from Hevea brasiliensis. Subsequent sodium borohydride reduction furnished the desired product with an enantiomeric excess of higher than 99.5%. This procedure can be considered a convenient general route for the stereoselective synthesis of ethanol amine derivatives underlining the role of biocatalysis for the generation of stereogenic centres in the synthesis of chiral intermediates.
Stabilization of Hydroxynitrile Lyases from Two Variants of Passion Fruit, Passiflora edulis Sims and Passiflora edulis Forma flavicarpa, by C-Terminal Truncation
Nuylert, Aem,Motojima, Fumihiro,Khanongnuch, Chartchai,Hongpattarakere, Tipparat,Asano, Yasuhisa
, p. 181 - 189 (2019/12/12)
Because the synthesis of chiral compounds generally requires a broad range of substrate specificity and stable enzymes, screening for better enzymes and/or improvement of enzyme properties through molecular approaches is necessary for sustainable industri
Hydroxynitrile Lyase Isozymes from Prunus communis: Identification, Characterization and Synthetic Applications
Zheng, Yu-Cong,Xu, Jian-He,Wang, Hui,Lin, Guo-Qiang,Hong, Ran,Yu, Hui-Lei
supporting information, p. 1185 - 1193 (2017/04/13)
Biocatalysts originating from Badamu (Prunus communis) have been applied to catalyze the asymmetric synthesis of (R)-4-methylsulfanylmandelonitrile, a key building block of thiamphenicol and florfenicol. Here, four hydroxynitrile lyase (HNL) isozymes from Badamu were cloned and heterologously expressed in Pichia pastoris. The biochemical properties and catalytic performances of these isozymes were comprehensively explored to evaluate their efficiency and selectivity in asymmetric synthesis. Among then, PcHNL5 was identified with outstanding activity and enantioselectivity in asymmetric hydrocyanation. Under the optimized mild biphasic reaction conditions, seventeen prochiral aromatic aldehydes were converted to valuable chiral cyanohydrins with good yields (up to 94%) and excellent optical purities (up to >99.9% ee), which provide a facile access to numerous chiral amino alcohols, hypoglycemic agents, angiotension converting enzyme (ACE) inhibitors and β-blockers. This work therefore underlines the importance of discovering the most potent biocatalyst among a group of isozymes for converting unnatural substrates into value-added products. (Figure presented.).
An orthogonal biocatalytic approach for the safe generation and use of HCN in a multistep continuous preparation of chiral O-acetylcyanohydrins
Brahma, Aischarya,Musio, Biagia,Ismayilova, Uliviya,Nikbin, Nikzad,Kamptmann, Sonja B.,Siegert, Petra,Jeromin, Günter E.,Ley, Steven V.,Pohl, Martina
supporting information, p. 262 - 266 (2016/01/20)
An enantioselective preparation of O-acetylcyanohydrins has been accomplished by a three-step telescoped continuous process. The modular components enabled an accurate control of two sequential biotransformations, safe handling of an in situ generated hazardous gas, and in-line stabilization of products. This method proved to be advantageous over the batch protocols in terms of reaction time (40 min vs 345 min) and ease of operation, opening up access to reactions which have often been neglected due to safety concerns.
High-Throughput Preparation of Optically Active Cyanohydrins Mediated by Lipases
Thomas, Juliana Christina,Aggio, Bruno Bernardi,Marques de Oliveira, Alfredo Ricardo,Piovan, Leandro
, p. 5964 - 5970 (2016/12/26)
Cyanohydrins are versatile compounds with high applicability in organic synthesis; they are used as starting materials for the synthesis of other chemical targets with high industrial added value. Lipase-mediated kinetic resolution reactions are a promising route for the synthesis of optically active cyanohydrins. These reactions can be carried out through the acylation of cyanohydrins or the deacylation of cyanohydrin esters, with different biocatalysts and under different reaction conditions. Unfortunately, depending on the substrate structure, long reaction times can be required to achieve suitable enantiomeric excesses. In this context, we present a high-throughput protocol for the production of optically active cyanohydrins in continuous-flow mode. The products were obtained with moderate to good enantioselectivity (E values from 8 up to >200) and with productivity values from 2.4 to 8.7 times higher in continuous-flow mode than in batch mode. Moreover, the reaction times were reduced from hours in batch mode to minutes in continuous-flow mode.
Improving the properties of bacterial r-selective hydroxynitrile lyases for industrial applications
Wiedner, Romana,Kothbauer, Bettina,Pavkov-Keller, Tea,Gruber-Khadjawi, Mandana,Gruber, Karl,Schwab, Helmut,Steiner, Kerstin
, p. 325 - 332 (2015/03/05)
Hydroxynitrile lyases (HNLs) catalyse the reversible cleavage of cyanohydrins to carbonyl compounds and HCN. The recent discovery of bacterial HNLs with a cupin fold gave rise to a new promising class of these enzymes. They are interesting candidates for the synthesis of cyanohydrins on an industrial scale owing to their high expression levels in Escherichia coli. The activity and enantioselectivity of the manganese-dependent HNL from Granulicella tundricola (GtHNL) were significantly improved by site-saturation mutagenesis of active site amino acids. The combination of beneficial mutations resulted in a variant with 490-fold higher specific activity in comparison to the wild-type enzyme. More importantly, GtHNL-A40H/V42T/Q110H is a highly competitive alternative for the synthesis of chiral cyanohydrins, such as 2-chlorobenzaldehyde cyanohydrin, (R)-2-hydroxy-4-phenylbutyronitrile, and (R)-2-hydroxy-4-phenyl-3-butene nitrile, which serve as intermediates for the synthesis of pharmaceuticals.
(R)-selective hydroxynitrile lyase variants with a cupin fold having improved substrate scope and the use thereof
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Paragraph 0082; 0083, (2015/12/31)
The present invention relates to an improved recombinant cupin-hydroxynitrile lyase (HNL), which is capable to catalyze the asymmetric cyanohydrin reaction, wherein the recombinant cupin-HNL comprises at least one amino acid substitution, preferably at le
Chemoenzymatic flow cascade for the synthesis of protected mandelonitrile derivatives
Delville, Marille M. E.,Koch, Kaspar,Van Hest, Jan C. M.,Rutjes, Floris P. J. T.
supporting information, p. 1634 - 1638 (2015/03/05)
A chemoenzymatic two-step cascade process, with both steps having incompatible reaction conditions, was successfully performed in continuous flow. The chemoenzymatic aqueous formation of cyanohydrins was integrated with a subsequent organic phase protection step in a single flow process utilising a membrane-based phase separation module. The wider applicability of our setup was demonstrated with the synthesis of nine protected cyanohydrin derivatives, all obtained in good yields and high to excellent enantioselectivity.
A simple separation method for (S)-hydroxynitrile lyase from cassava and its application in asymmetric cyanohydrination
Zheng, Zubiao,Zi, Yan,Li, Zhongzhou,Zou, Xinzhuo
, p. 434 - 439 (2013/06/27)
Using an acetone precipitation method, crude (S)-hydroxynitrile lyase [(S)-MeHNL] was separated from Munihot esculenta (cassava) leaves, and used directly as biocatalyst to catalyze asymmetric cyanohydrination and produce cyanohydrins with enantiomeric purities (≥90% ee) significantly greater than those previously reported. The use of a water/i-Pr2O system with an enzyme, NaCN, and appropriate amounts of acetic acid is crucial in improving the stereoselectivity of cyanohydrin formation by minimizing the non-enzymatic reaction and the racemization of the chiral products. The proposed isolation method for crude (S)-MeHNL has a high value because of its simplicity, and low cost as well as the high activity of the crude (S)-MeHNL.
