- A High-Throughput Screening Method for the Directed Evolution of Hydroxynitrile Lyase towards Cyanohydrin Synthesis
-
Chiral cyanohydrins are useful intermediates in the pharmaceutical and agricultural industries. In nature, hydroxynitrile lyases (HNLs) are a kind of elegant tool for enantioselective hydrocyanation of carbonyl compounds. However, currently available methods for demonstrating hydrocyanation are still stalled at precise, but low-throughput, GC or HPLC analyses. Herein, we report a chromogenic high-throughput screening (HTS) method that is feasible for the cyanohydrin synthesis reaction. This method was highly anti-interference and sensitive, and could be used to directly profile the substrate scope of HNLs either in cell-free extract or fermentation clear broth. This HTS method was also validated by generating new variants of PcHNL5 that presented higher catalytic efficiency and stronger acidic tolerance in variant libraries.
- Zheng, Yu-Cong,Ding, Liang-Yi,Jia, Qiao,Lin, Zuming,Hong, Ran,Yu, Hui-Lei,Xu, Jian-He
-
p. 996 - 1000
(2021/01/15)
-
- Structure-Guided Tuning of a Hydroxynitrile Lyase to Accept Rigid Pharmaco Aldehydes
-
The chiral vicinal C-O/C-N bifunctional groups generated from enzymatic hydrocyanation represents a useful methodology. However, construction of the pharmacophore of β2-adrenoreceptor agonists with this method remains a great challenge because of complete racemization of the benzylic alcohol during deprotection of the acetal groups. In this study, structure-guided redesign of a hydroxynitrile lyase originating from Prunus communis (PcHNL5) enables a highly enantioselective hydrocyanation of rigid benzo-ketal aldehyde which was proved to be resistant against racemization during the deprotection step, with dramatically improved productivity (>95% conversion vs 2-adrenoreceptor agonist, in an optically pure form (>99% ee) with an overall yield of 54%, which is the highest value reported.
- Hong, Ran,Li, Fu-Long,Lin, Guo-Qiang,Lin, Zuming,Xu, Jian-He,Yu, Hui-Lei,Zheng, Yu-Cong
-
p. 5757 - 5763
(2020/06/09)
-
- Preparation and reactions of certain racemic and optically active cyanohydrins derived from 2-chlorobenzaldehyde, 4-fluorobenzaldehyde, benzo[d][1,3]-dioxole-5-carbaldehyde and 2,3-dihydrobenzo[b][1,4]dioxine-6-carbaldehyde. Antimicrobial and in vitro antitumor evaluation of the products
-
THE CHEMOENZYMATIC reaction of selected aldehydes, namely 2-chlorobenzaldehyde (1a), 4-fluorobenzaldehyde (1b), benzo[d][1,3]dioxole-5-carbaldehyde (1c) and/or 2,3-dihydrobenzo [b] [1,4] dioxine-6-carbaldehyde (1d) with hydrogen cyanide in presence of (R)-oxynitrilase (R)-Pa HNL [EC 4.1.2.10] from almonds, as a chiral catalyst, gave the optically active cyanohydrin enantiomers ( R)-2a-c, respectively. Acetone cyanohydrin (3), was also used, as a transcyanating agent, to give the same products. The racemic cyanohydrins (R,S)-2a-d have been synthesized, as well, by treating compounds 1a-d with aqueous potassium cyanide solution in presence of a saturated solution of sodium metabisulphite (Na2S2O5). The optical purity of cyanohydrins (R)-2a-c was determined through their derivatization with (S)-naproxen chloride (S)-5 to the respective diastereomers (R,2S)-6a-c which were obtained in diastereomeric excess (de) values up to 93 % (1H NMR). Heating compounds (R)-2a,b and / or their racemic analogues (R,S)-2a-c with concentrated hydrochloric acid gave the respective α-hydroxycarboxylic acids 7a-c. Moreover, reduction of cyanohydrins (R,S)-2b,c under different conditions resulted in a hydrodecyanation giving the respective primary alcohols 8a,b. Structures and configurations of the new compounds were confirmed with compatible elementary microanalyses and spectroscopic (IR, 1H NMR, 13C NMR, MS and single crystal X-ray crystallography) measurements. The antimicrobial activity of derivatives 6a-d against four bacterial species (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and two fungi (Aspergillus flavus and Candida albicans) were undertaken. Moreover, compounds (R,2S)-6b, (R,2S)(S,2S)-6b and (R,2S)-6c were screened for their in virto antitumor activity against three human solid cancer cell lines (HCT 116, HepG2 and MCF-7). In general, the tested compounds were found inactive or showed weak activities in comparison with the standard drugs.
- Yosef, Hisham Abdallah A.,Elmasry,Ibrahim, Nabila M.,Ismael, Eman H. I.,Mahran
-
p. 301 - 328
(2017/06/08)
-
- Chemoenzymatic flow cascade for the synthesis of protected mandelonitrile derivatives
-
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.
- Delville, Marille M. E.,Koch, Kaspar,Van Hest, Jan C. M.,Rutjes, Floris P. J. T.
-
supporting information
p. 1634 - 1638
(2015/03/05)
-
- Purification and characterization of a novel (R)-hydroxynitrile lyase from Eriobotrya japonica (Loquat)
-
A hydroxynitrile lyase was isolated and purified to homogeneity from seeds of Eriobotrya japonica (loquat). The final yield, of 36% with 49-fold purification, was obtained by 30-80% (NH4)2SO4 fractionation and column chromatography on DEAE-Toyopearl and Concanavalin A Sepharose 4B, which suggested the presence of a carbohydrate side chain. The purified enzyme was a monomer with a molecular mass of 72 kDa as determined by gel filtration, and 62.3 kDa as determined by SDS-gel electrophoresis. The N-terminal sequence is reported. The enzyme was a flavoprotein containing FAD as a prosthetic group, and it exhibited a Km of 161 μM and a k cat/Km of 348 s-1 mM-1 for mandelonitrile. The optimum pH and temperature were pH 5.5 and 40°C respectively. The enzyme showed excellent stability with regard to pH and temperature. Metal ions were not required for its activity, while activity was significantly inhibited by CuSO4, HgCl2, AgNO3, FeCl3, β-mercaptoethanol, iodoacetic acid, phenylmethylsulfonylfluoride, and diethylpyrocarbonate. The specificity constant (kcat/Km) of the enzyme was investigated for the first time using various aldehydes as substrates. The enzyme was active toward aromatic and aliphatic aldehydes, and showed a preference for smaller substrates over bulky one.
- Ueatrongchit, Techawaree,Kayo, Ai,Komeda, Hidenobu,Asano, Yasuhisa,H-Kittikun, Aran
-
p. 1513 - 1522
(2008/12/21)
-
- A new (R)-hydroxynitrile lyase from Prunus mume: Asymmetric synthesis of cyanohydrins
-
A new hydroxynitrile lyase (HNL) was isolated from the seed of Japanese apricot (Prunus mume). The enzyme has similar properties with HNL isolated from other Prunus species and is FAD containing enzyme. It accepts a large number of unnatural substrates (benzaldehyde and its variant) for the addition of HCN to produce the corresponding cyanohydrins in excellent optical and chemical yields. A new HPLC based enantioselective assay technique was developed for the enzyme, which promotes the addition of KCN to benzaldehyde in a buffered solution (pH=4.5).
- Nanda, Samik,Kato, Yasuo,Asano, Yasuhisa
-
p. 10908 - 10916
(2007/10/03)
-
- Enantioselective addition of trimethylsilyl cyanide to aldehydes catalysed by bifunctional BINOLAM-AlCl versus monofunctional BINOL-AlCl complexes
-
A highly enantioselective cyanation of aldehydes takes place by using a bifunctional catalyst derived from 3,3′-bis(diethylaminomethyl) substituted binaphthol (BINOLAM) and dimethylaluminium chloride. The addition is of wide scope and runs best in toluene at temperatures ranging from -20 to -40°C, in the presence of 4 A? MS and triphenylphosphine oxide as additives. The (R)- or (S)-cyanohydrins result when using (S)- or (R)-BINOLAM-AlCl complexes, respectively. The valuable ligand can be recovered by simple extractive work-up and recycled without loss of efficiency (both in terms of chemical and stereochemical yields). This methodology is applied to the Shibasaki synthesis of epothilone A. All the evidence available for the BINOLAM-AlCl enantioselective addition of TMSCN to aldehydes call for the intervention of a hydrocyanation reaction, addition of a catalytic amount of hydrogen cyanide, generated in situ, to an aldehyde, followed by O-silylation. In order to determine the role of the basic amino groups of BINOLAM, comparative studies are carried out with the monofunctional 1,1′-binaphthol-derived complex BINOL-AlCl. Graphical Abstract.
- Casas, Jesús,Nájera, Carmen,Sansano, José M.,Saá, José M.
-
p. 10487 - 10496
(2007/10/03)
-
- Ueber die erste rekombinante Hydroxynitril-Lyase und ihre Anwendung in der Synthese von (S)-Cyanhydrinen
-
Keywords: Asymmetrische Synthesen; (S)-Cyanhydrine; Enzymkatalyse; Lyasen
- Foerster, Siegfried,Roos, Juergen,Effenberger, Franz,Wajant, Harald,Sprauer, Achim
-
p. 493 - 494
(2007/10/03)
-
- (R)- and (S)-cyanohydrins using oxynitrilases in whole cells
-
Almond meal and Sorghum bicolor shoots were used as the sources of oxynitrilases for the preparation of a number (R)- and (S)-arylcyanohydrins, respectively, from the corresponding aldehydes in diisopropyl ether. Two different in situ methods were used to introduce hydrogen cyanide into the reaction mixture. In method 1, acetone cyanohydrin decomposes enzymatically and/or chemically to hydrogen cyanide. In method 2, hydrogen cyanide freely evaporates from a solution in diisopropyl ether from one compartment of the reaction vessel and ends up to the other where it dissolves into the reaction mixture.
- Kiljunen, Eero,Kanerva, Liisa T.
-
p. 1105 - 1116
(2007/10/03)
-
- Preparation of Chiral Cyanohydrins by an Oxynitrilase-Mediated Transcyanation
-
The transcyanation of aromatic and aliphatic aldehydes 1 (RCHO) with acetone cyanohydrin is catalyzed by the enzyme D-oxynitrilase to afford (R)-cyanohydrins 2 (RCH(OH)CN).The biocatalytic method using acetone cyanohydrin gives products of high enantiomeric purity with better consistency than similar conditions using hydrogen cyanide as the cyanide source.The use of an ether-buffer biphasic solvent system is essential for producing products of optimum optical purity, but the solubility properties of the substrate have a pronounced effect on the enantiomeric purity of the final product.A discussion relating the solubility partition coefficient (log P) of a substrate to the enantiomeric purity of the product as a guide for predicting the outcome with new substrates is presented.Application of the method to the preparation of the following cyanohydrins is reported (R, ee): a, C6H5, 92percent ee; b, 3,4-(CH2O2)C6H3, 90percent ee; c, 2-(CH3O)C6H4, 96percent ee; d, C6H5CH2, 88percent ee; e, CH3SCH2CH2, 92percent ee; f, CH3(CH2)5CH2, 92percent ee; g, (CH3)3C, 92percent ee; h, c-C6H11, 96percent ee; i, CH3O2C(CH2)6CH2, 97percent ee; j, (E,E)-CH3CH=CHCH=CH, 96percent ee; k, (CH3)2C=CHCH2CH2C(CH3)=CH, 99percent ee.
- Ognyanov, Vassil I.,Datcheva, Violeta K.,Kyler, Keith S.
-
p. 6992 - 6996
(2007/10/02)
-
- Enzyme-Catalyzed Reactions, 7. - Enantioselective Esterification of Racemic Cyanohydrins and Enantioselective Hydrolysis or Transesterification of Cyanohydrin Esters by Lipases
-
Pure cyanohydrin enantiomers (S)-1/(R)-1 and their O-acyl derivatives (R)-3/(S)-3 are obtained from three different lipase-catalyzed reactions: (i) enantioselective hydrolysis of aliphatic and aromatic racemic cyanohydrin esters 3, ii) enantioselective ac
- Effenberger, Franz,Gutterer, Beate,Ziegler, Thomas,Eckhardt, Elisabeth,Aichholz, Reiner
-
-
- A Convenient Route to (R)-α-Hydroxy Carboxylic Acids and (2R)-1-Amino-2-alkanols from (R)-Cyanohydrins
-
(R)-Cyanohydrins, prepared in good to excellent yields with high optical purity by enzyme-catalyzed addition of hydrogen cyanide to aldehydes in organic solvents, are hydrolyzed with concentrated hydrochloric acid at ambient temperature, usually in very high yield, without any trace of racemization to give (R)-α-hydroxy carboxylic acids.Likewise, no racemization is observed by direct reduction of the (R)-cyanohydrins with lithium aluminium hydride to give (2R)-1-amino-2-alkanols.
- Ziegler, Thomas,Hoersch, Brigitte,Effenberger, Franz
-
p. 575 - 578
(2007/10/02)
-
- Asymmetric Hydrocyanation of a Range of Aromatic and Aliphatic Aldehydes
-
A range of aryl, alkyl and heterocyclic aldehydes have been treated with hydrogen cyanide in the presence of the 'Inoue' catalyst, (R,R)- or (S,S)-cyclo.Most aryl aldehydes with electron-donating substituents in the m-or p-positions give high enantiomeric excess (e.e) values (>=80percent) but aryl aldehydes with strong electron-withdrawing substituents gave moderate e.e. values (=50percent).These moderate values are believed to be due to partial racemization of the product cyanohydrins in the presence of the mildly basic catalyst.In contrast to the reactions of aryl aldehydes, reactions of alkyl aldehydes and of ketones gave low e.e. values (=30percent) and an explanation is proposed.
- Matthews, Barry R.,Jackson, W. Roy,Jayatilake, Gamini S.,Wilshire, Colin,Jacobs, Howard A.
-
p. 1697 - 1710
(2007/10/02)
-