71-00-1Relevant articles and documents
An unprecedented trans-oriented product from the cleavage of a dipeptide.
Saha, Manas K,Bernal, Ivan
, p. 612 - 613 (2003)
An unusual trans cleavage reaction was observed when trans-[Co(3,2,3-tet)Cl2]Cl (3,2,3-tet = N,N'-bis(3-aminopropyl)ethylenediamine), was allowed to react with beta-alanyl-L-histidine (a bioactive dipeptide) in an aqueous medium at pH approximately 7.5 and 45 degrees C for 6 h.
High-throughput screening for the asymmetric transformation reaction of L-histidine to D-histidine by capillary array electrophoresis
Wang, Jun,Liu, Kaiying,Sun, Guangming,Bai, Jiling,Wang, Li
, p. 901 - 904 (2006)
Asymmetric transformation reaction of L-histidine to D-histidine was studied by homemade capillary array electrophoresis for the first time. The enantiomeric excess value of asymmetric histidine products can be directly determined from the electrophoretogram of capillary array electrophoresis. The experiment results showed that the optimized asymmetric transformation reaction condition was in the presence of salicylaldehyde as catalyst and acetic acid as solvent.
Fluorinated S-Adenosylmethionine as a Reagent for Enzyme-Catalyzed Fluoromethylation
Bauer, Carsten,Liao, Cangsong,Peng, Jiaming,Seebeck, Florian P.
, p. 27178 - 27183 (2021/11/16)
Strategic replacement of protons with fluorine atoms or functional groups with fluorine-containing fragments has proven a powerful strategy to optimize the activity of therapeutic compounds. For this reason, the synthetic chemistry of organofluorides has been the subject of intense development and innovation for many years. By comparison, the literature on fluorine biocatalysis still makes for a slim chapter. Herein we introduce S-adenosylmethionine (SAM) dependent methyltransferases as a new tool for the production of fluorinated compounds. We demonstrate the ability of halide methyltransferases to form fluorinated SAM (S-adenosyl-S-(fluoromethyl)-L-homocysteine) from S-adenosylhomocysteine and fluoromethyliodide. Fluorinated SAM (F-SAM) is too unstable for isolation, but is accepted as a substrate by C-, N- and O-specific methyltransferases for enzyme-catalyzed fluoromethylation of small molecules.
Direct monitoring of biocatalytic deacetylation of amino acid substrates by1H NMR reveals fine details of substrate specificity
De Cesare, Silvia,McKenna, Catherine A.,Mulholland, Nicholas,Murray, Lorna,Bella, Juraj,Campopiano, Dominic J.
supporting information, p. 4904 - 4909 (2021/06/16)
Amino acids are key synthetic building blocks that can be prepared in an enantiopure form by biocatalytic methods. We show that thel-selective ornithine deacetylase ArgE catalyses hydrolysis of a wide-range ofN-acyl-amino acid substrates. This activity was revealed by1H NMR spectroscopy that monitored the appearance of the well resolved signal of the acetate product. Furthermore, the assay was used to probe the subtle structural selectivity of the biocatalyst using a substrate that could adopt different rotameric conformations.
Safe and Effective Method of Treating Ulcerative Colitis with Anti-IL12/IL23 Antibody
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, (2020/04/10)
Described are methods and compositions for clinical proven safe and effective treatment of ulcerative colitis, particularly moderately to severely active ulcerative colitis in patients who have had an inadequate response to or are intolerant of a conventional or existing therapy by intravenous and/or subcutaneous administration of an anti-IL-12/IL-23p40 antibody.
Preparation and characterization of a new open-tubular capillary column for enantioseparation by capillary electrochromatography
Li, Yingjie,Tang, Yimin,Qin, Shili,Li, Xue,Dai, Qiang,Gao, Lidi
, p. 283 - 292 (2019/02/05)
In order to use the enantioseparation capability of cationic cyclodextrin and to combine the advantages of capillary electrochromatography (CEC) with open-tubular (OT) column, in this study, a new OT-CEC, coated with cationic cyclodextrin (1-allylimidazolium-β-cyclodextrin [AI-β-CD]) as chiral stationary phase (CSP), was prepared and applied for enantioseparation. Synthesized AI-β-CD was characterized by infrared (IR) spectrometry and mass spectrometry (MS). The preparation conditions for the AI-β-CD-coated column were optimized with the orthogonal experiment design L9(34). The column prepared was characterized by scanning electron microscopy (SEM) and elemental analysis (EA). The results showed that the thickness of stationary phase in the inner surface of the AI-β-CD-coated columns was about 0.2 to 0.5?μm. The AI-β-CD content in stationary phase based on the EA was approximately 2.77?mmol·m?2. The AI-β-CD-coated columns could separate all 14 chiral compounds (histidine, lysine, arginine, glutamate, aspartic acid, cysteine, serine, valine, isoleucine, phenylalanine, salbutamol, atenolol, ibuprofen, and napropamide) successfully in the study and exhibit excellent reproducibility and stability. We propose that the column, coated with AI-β-CD, has a great potential for enantioseparation in OT-CEC.
A green-by-design bioprocess for l-carnosine production integrating enzymatic synthesis with membrane separation
Yin, Dong-Ya,Pan, Jiang,Zhu, Jie,Liu, You-Yan,Xu, Jian-He
, p. 5971 - 5978 (2019/11/14)
l-Carnosine (l-Car, β-alanyl-l-histidine) is a bioactive dipeptide with important physiological functions. Direct coupling of unprotected β-Ala (β-alanine) with l-His (l-histidine) mediated by an enzyme is a promising method for l-Car synthesis. In this study, a new recombinant dipeptidase (SmPepD) from Serratia marcescens with a high synthetic activity toward l-Car was identified by a genome mining approach and successfully expressed in Escherichia coli. Divalent metal ions strongly promoted the synthetic activity of SmPepD, with up to 21.7-fold increase of activity in the presence of 0.1 mM MnCl2. Higher temperature, lower pH and increasing substrate loadings facilitated the l-Car synthesis. Pilot biocatalytic syntheses of l-Car were performed comparatively in batch and continuous modes. In the continuous process, an ultra-filtration membrane reactor with a working volume of 5 L was employed for catalyst retention. The dipeptidase, SmPepD, showed excellent operational stability without a significant decrease in space-time yield after 4 days. The specific yield of l-Car achieved was 105 gCar gcatalyst-1 by the continuous process and 30.1 gCar gcatalyst-1 by the batch process. A nanofiltration membrane was used to isolate the desired product l-Car from the reaction mixture by selectively removing the excess substrates, β-Ala and l-His. As a result, the final l-Car content was effectively enriched from 2.3% to above 95%, which gave l-Car in 99% purity after ethanol precipitation with a total yield of 60.2%. The recovered substrate mixture of β-Ala and l-His can be easily reused, which will enable the economically attractive and environmentally benign production of the dipeptide l-Car.
Preparation and purification method of amino acid compound
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Paragraph 0068; 0069; 0076; 0077, (2018/06/21)
The invention relates to the field of industrial organic synthesis, in particular to a preparation and purification method of an amino acid compound. The method comprises the following steps that (1)alpha-amino nitrile compounds or hydantoin compounds or mixtures thereof are heated to react to obtain alpha-amino acid salt under the condition that volatile alkali and a suitable solvent exist; (2)after the alpha-amino acid salt obtained in step (1) is distilled, the alpha-amino acid salt is recrystallized in an organic solvent to obtain the alpha-amino acid compound. According to the method, reaction conditions are mild, materials can be recycled, and introduction of metal ions and use of ammonium carbonate salt are avoided, so that post-treatment is simple and no waste salt is generated.
A α - amino acid compound synthesis and purification method
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Paragraph 0056; 0064-0066; 0068, (2018/05/16)
The invention relates to a synthesis and purification method for an alpha-amino acid compound. The synthesis and purification method is characterized by comprising the following steps: (1) adding substituted alpha-amino nitrile or a substituted hydantoin-based compound into alkali M(OH)x or metal oxide MxO, adding water or an alcohol and water mixed solvent, and heating for reaction to obtain alpha-amino acid salt; (2) adding ammonium carbonate or ammonium bicarbonate or introducing carbon dioxide into the solution in the step (1), separating to obtain filter liquor and precipitates MxHyCO3, performing reduced pressure concentration on the filter liquor, and recrystallizing in an alcohol solvent to obtain the alpha-amino acid compound (I). The synthesis and purification method for the alpha-amino acid compound is simple, the yield and purity of the obtained alpha-amino acid compound are high; furthermore, recycling utilization and cleaning production of materials can be realized; the synthesis and purification method is especially suitable for synthesis of the alpha-amino acid compound with high water solubility.
Chromatographic Resolution of α-Amino Acids by (R)-(3,3'-Halogen Substituted-1,1'-binaphthyl)-20-crown-6 Stationary Phase in HPLC
Wu, Peng,Wu, Yuping,Zhang, Junhui,Lu, Zhenyu,Zhang, Mei,Chen, Xuexian,Yuan, Liming
supporting information, p. 1037 - 1042 (2017/07/25)
Three new chiral stationary phases (CSPs) for high-performance liquid chromatography were prepared from R-(3,3'-halogen substituted-1,1'-binaphthyl)-20-crown-6 (halogen = Cl, Br and I). The experimental results showed that R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 (CSP-1) possesses more prominent enantioselectivity than the two other halogen-substituted crown ether derivatives. All twenty-one α-amino acids have different degrees of separation on R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6-based CSP-1 at room temperature. The enantioselectivity of CSP-1 is also better than those of some commercial R-(1,1'-binaphthyl)-20-crown-6 derivatives. Both the separation factors (α) and the resolution (Rs) are better than those of commercial crown ether-based CSPs [CROWNPAK CR(+) from Daicel] under the same conditions for asparagine, threonine, proline, arginine, serine, histidine and valine, which cannot be separated by commercial CR(+). This study proves the commercial usefulness of the R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 chiral stationary phase.
