- METHOD FOR PRODUCING AMIDE COMPOUND
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Provided is a novel method for producing amide compounds at high stereochemical selectivities. The method according to the present invention for producing amide compounds is provided with an amidation step for reacting, in the presence of a catalyst compr
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Paragraph 0094-0095
(2020/05/14)
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- Naphthoquinones as covalent reversible inhibitors of cysteine proteases—studies on inhibition mechanism and kinetics
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The facile synthesis and detailed investigation of a class of highly potent protease inhibitors based on 1,4‐naphthoquinones with a dipeptidic recognition motif (HN‐L‐Phe‐L‐Leu‐OR) in the 2‐position and an electron‐withdrawing group (EWG) in the 3‐positio
- Barthels, Fabian,Distler, Ute,Engel, Volker,Engels, Bernd,Hellmich, Ute A.,Johe, Patrick,Klein, Philipp,Le, Thien Anh,Opatz, Till,Schirmeister, Tanja,Schmid, Paul,Tenzer, Stefan,Wagner, Annika
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supporting information
(2020/05/16)
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- Stereocontrolled [11C]Alkylation of N-Terminal Glycine Schiff Bases To Obtain Dipeptides
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The use of various quaternary ammonium salts as chiral phase-transfer catalysts allowed effective and stereoselective radiochemical [11C]alkylation to obtain functionalized dipeptides. We herein report a broadly applicable procedure for the asymmetric [11C]alkylation of dipeptides to give labeled N-terminal peptides by using different [11C]alkyl halides. Contended stereoselectivities of the reactions were observed by using 11C-labeled alkyl halides, [11C]methyl iodide and [11C]benzyl iodide, and diastereomeric ratios with different specialized catalysts of 95:5 and 90:10 were achieved, respectively. Accordingly, the straightforward synthesis of enantioenriched compounds should play a vital role in peptide-based radiopharmaceutical development and positron emission tomography imaging.
- Filp, Ulrike,Peko?ak, Aleksandra,Poot, Alex J.,Windhorst, Albert D.
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supporting information
p. 5592 - 5596
(2017/10/13)
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- Enzymatic synthesis of activated esters and their subsequent use in enzyme-based peptide synthesis
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Chemoenzymatic peptide synthesis is potentially the most cost-efficient technology for the synthesis of short and medium-sized peptides. However, there are still some limitations when challenging peptides, e.g. containing sterically demanding acyl donors, non-proteinogenic amino acids or proline residues, are to be synthesized. To remedy these limitations, special ester moieties have been used that are specifically recognized by the enzyme, e.g. guanidinophenyl, carboxamidomethyl (Cam) or trifluoroethyl (Tfe) esters, which, unfortunately, are notoriously difficult to synthesize chemically. Herein, we demonstrate that Cam and Tfe esters are very useful for Alcalase-CLEA mediated peptide synthesis using sterically demanding and non-proteinogenic acyl donors as well as poor nucleophiles, and combinations thereof. Furthermore, these esters can be efficiently synthesized by using the lipase Cal-B or Alcalase-CLEA. Finally, it is shown that the ester synthesis by Cal-B and subsequent peptide synthesis by Alcalase-CLEA can be performed simultaneously using a two-enzyme-one-pot approach with glycolamide or 2,2,2-trifluoroethanol as additive.
- Nuijens, Timo,Cusan, Claudia,Schepers, Annette C.H.M.,Kruijtzer, John A.W.,Rijkers, Dirk T.S.,Liskamp, Rob M.J.,Quaedflieg, Peter J.L.M.
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experimental part
p. 79 - 84
(2012/02/03)
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- Fully enzymatic peptide synthesis using C-terminal tert-butyl ester interconversion
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Chemoenzymatic peptide synthesis is potentially the most cost-efficient technology for the synthesis of short and medium-sized peptides with some important advantages. For instance, stoichiometric amounts of expensive coupling reagents are not required an
- Nuijens, Timo,Cusan, Claudia,Van Dooren, Theodorus J. G. M.,Moody, Harold M.,Merkx, Remco,Kruijtzer, John A. W.,Rijkers, Dirk T. S.,Liskamp, Rob M. J.,Quaedflieg, Peter J. L. M.
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experimental part
p. 2399 - 2404
(2011/02/21)
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- Versatile selective α-carboxylic acid esterification of N-protected amino acids and peptides by alcalase
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Under continuous removal of water, the industrial protease Alcalase allows selective synthesis of α-carboxylic acid methyl, ethyl, benzyl, allyl, 2-(trimethylsilyl)ethyl, and tert-butyl esters of amino acids and peptides under mild conditions in very high
- Nuijens, Timo,Cusan, Claudia,Kruijtzer, John A. W.,Rijkers, Dirk T. S.,Liskamp, Rob M. J.,Quaedflieg, Peter J. L. M.
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experimental part
p. 809 - 814
(2009/07/11)
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- Enzymatic synthesis of C-terminal arylamides of amino acids and peptides
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(Chemical Equation Presented) A mild and cost-efficient chemo-enzymatic method for the synthesis of C-terminal arylamides of amino acid and peptides is described. Using the industrial serine protease Alcalase under near-anhydrous conditions, C-terminal arylamides of N-Cbz-protected amino acids and peptides could be obtained from the corresponding C-terminal carboxylic acids, methyl (Me) or benzyl (Bn) esters, in high chemical and enantio- and diastereomeric purities. Yields ranged between 50% and 95% depending on the size of the aryl substituents and the presence of electron-withdrawing substituents. Complete α-C-terminal selectivity could be obtained even in the presence of various unprotected side-chain functionalities such as β/γ-carboxyl, hydroxyl, and guanidino groups. In addition, the use of the cysteine protease papain and the lipase Cal-B gave anilides in high yields. The chemo-enzymatic synthesis of arylamides proved to be completely free of racemization, in contrast to the state-of-the-art chemical methods.
- Nuijens, Timo,Cusan, Claudia,Kruijtzer, John A. W.,Rijkers, Dirk T. S.,Liskamp, Rob M. J.,Quaedflieg, Peter J. L. M.
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supporting information; experimental part
p. 5145 - 5150
(2009/12/06)
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- Highly stereoselective peptide modifications through Pd-catalyzed allylic alkylations of chelated peptide enolates
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Deprotonation of peptides in the presence of zinc chloride gives rise to highly reactive nucleophiles that can be subjected to palladium-catalyzed allylic alkylation reactions. Excellent diastereoselectivities are obtained that are nearly independent of the allylic substrate used. By using this protocol, highly functionalized side chains can also be incorporated in excellent yields and selectivities. The stereochemicaloutcome of the reaction is exclusively controlled by the peptide chain as long as terminal π-allyl-palladium complexes are involved. Probably, there is a threefold coordination, at least, ofthe deprotonated peptide chain to the chelating zinc ion. In such metal peptide complexes, one face of the generated enolate is shielded by the side chain of the adjacent amino acid, thus directing the electrophilic attack onto the opposite face. This behavior explains why an S amino acid always generates an R amino acid (and the other way round).
- Deska, Jan,Kazmaier, Uli
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p. 6204 - 6211
(2008/02/13)
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- Cross-linked crystals of subtilisin: Versatile catalyst for organic synthesis
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Cross-linked enzyme crystals (CLECs) of subtilisin exhibit excellent activity in aqueous and various organic solvents. This catalyst is more stable than the native enzyme in both aqueous and mixed aqueous/organic solutions. Subtilisin-CLEC was shown to be a versatile catalyst. It was used for the syntheses of peptides and peptidomimetics, mild hydrolysis of amino acid and peptide amides, enantio- and regioselective reactions, and transesterifications.
- Wang, Yi-Fong,Yakovlevsky, Kirill,Zhang, Bailing,Margolin, Alexey L.
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p. 3488 - 3495
(2007/10/03)
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- Carbohydrate Protease Conjugates: Stabilized Proteases for Peptide Synthesis
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The synthesis of oligopeptides using stable carbohydrate protease conjugates (CPCs) was examined in acetonitrile solvent systems.CPC was used for the preparation of peptides containing histidine, phenylalanine, tyrosine, and tryptophan in the P1 position in 60-93percent yield.The CPC was used to synthesize peptides containing both hydrophilic and hydrophobic amino acids.The P2 specificity of papain for aromatic residues was utilized for the 2 + 3 coupling of Z-Tyr-Gly-OMe to H2N-Gly-Phe-Leu-OH to generate the leucine enkephalin derivative in 79percent yield.Although papain is nonspecific for the hydrolysis of N-benzyloxycarbonyl amino acid methyl esters in aqueous solution, the rates of synthesis for these derivatives with nucleophile leucine tert-butyl ester differed by nearly 2 orders of magnitude.CPC was used to prepare the aspartame precursor Z-Asp-Phe-OMe in 90percent yield.The increased stability of CPCs prepared from periodate-modified poly(2-methacrylamido-2-deoxy-D-glucose), poly(2-methacrylamido-2-deoxy-D-galactose), and poly(5-methacrylamido-5-deoxy-D-ribose), carbohydrate materials designed to increase the aldehyde concentration in aqueous solution, suggests that the stability of CPCs is directly related to the aldehyde concentration of the carbohydrate material.Periodate oxidation of poly(2-methacrylamido-2-deoxy-D-glucose) followed by covalent attachment to α-chymotrypsin gave a CPC with catalytic activity in potassium phosphate buffer at 90 deg C for 2 h.
- Wartchow, Charles A.,Wang, Peng,Bednarski, Mark D.,Callstrom, Matthew R.
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p. 2216 - 2226
(2007/10/02)
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- The catalytic formation of peptide bonds with carbohydrate protein conjugates of proteases [CPC (proteases)]
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This paper describes the use of carbohydrate protein conjugates of proteases [CPC(proteases)] for the catalytic formation of peptide bonds. We have found that CPC(proteases) are stable in organic solvents and perform at truly catalytic levels and have dem
- Wang, Peng,Hill, Tara G.,Bednarski, Mark D.,Callstrom, Matthew R.
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p. 6827 - 6830
(2007/10/02)
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- ENZYMATIC PEPTIDE SYNTHESIS IN ORGANIC SOLVENT MEDIATED BY MODIFIED α-CHYMOTRYPSIN
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Peptide couplings have been catalyzed in organic medium containing a slight amount of water (0.5percent) by PEG modified α-Chymotrypsin.
- Babonneau, Marie-Therese,Jacquier, Robert,Lazaro, Rene,Viallefont, Philippe
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p. 2787 - 2790
(2007/10/02)
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- 1-ISOPROPYLALLYLOXYCARBONYL (IPAoc) AS A PROTECTIVE GROUP OF AMINES AND ITS DEPROTECTION CATALYSED BY PALLADIUM-PHOSPHINE COMPLEX
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As a new protective group of amines, 1-isopropylallyloxycarbonyl (IPAoc) group was developed.IPAoc group can be removed by treatment with a palladium-phosphine catalyst forming carbon dioxide and 4-methyl-1,3-pentadiene by the decarboxylation and β-hydrogen elimination of (?-1-isopropylallyl)-palladium intermediate under neutral condititons.The present protection-deprotection was applied to a one-pot peptide synthesis.
- Minami, Ichiro,Yuhara, Masami,Tsuji, Jiro
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p. 2737 - 2740
(2007/10/02)
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- On the Use of Carboxamidomethyl Esters in the Protease-Catalyzed Peptide Synthesis
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Carboxyamidomethyl esters (CAM esters) of Z-and Boc-protected alanine and phenylalanine were prepared in order to investigate their usefulness as substrates for α-chymotrypsin- and papain-catalyzed hydrolysis and peptide synthesis reactions.The easy removal of the CAM-C-protecting group under mild conditions and dependent on the enzyme specificity was demonstrated.Examples are given for the protease-catalyzed synthesis of various peptide derivatives using CAM esters as C- and N-components in aqueous-organic media.Comparatively short reaction times were observed. - Key words: Carboxyamidomethyl ester as C-protecting group; Enzymatic deprotection; Peptide synthesis; α-Chymotrypsin- and Papain-catalyzed peptide bond formation
- Kuhl, Peter,Zacharias, Ute,Burckhardt, Helmut,Jakubke, Hans-Dieter
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p. 1195 - 1204
(2007/10/02)
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