66-22-8Relevant articles and documents
Two-dimensional 17O multiple quantum magic-angle spinning NMR of organic solids
Wu,Dong
, p. 9119 - 9125 (2001)
We report two-dimensional (2D) 17O multiple-quantum magic-angle spinning (MQMAS) NMR spectra for four 17O-labeled organic compounds: [17O2]-D-alanine (1), potassium hydrogen [17O4]dibenzoat
The Peculiar Case of the Hyper-thermostable Pyrimidine Nucleoside Phosphorylase from Thermus thermophilus**
Kaspar, Felix,Neubauer, Peter,Kurreck, Anke
, p. 1385 - 1390 (2021/01/29)
The poor solubility of many nucleosides and nucleobases in aqueous solution demands harsh reaction conditions (base, heat, cosolvent) in nucleoside phosphorylase-catalyzed processes to facilitate substrate loading beyond the low millimolar range. This, in turn, requires enzymes that can withstand these conditions. Herein, we report that the pyrimidine nucleoside phosphorylase from Thermus thermophilus is active over an exceptionally broad pH (4–10), temperature (up to 100 °C) and cosolvent space (up to 80 % (v/v) nonaqueous medium), and displays tremendous stability under harsh reaction conditions with predicted total turnover numbers of more than 106 for various pyrimidine nucleosides. However, its use as a biocatalyst for preparative applications is critically limited due to its inhibition by nucleobases at low concentrations, which is unprecedented among nonspecific pyrimidine nucleoside phosphorylases.
Structural Evidence for a [4Fe-5S] Intermediate in the Non-Redox Desulfuration of Thiouracil
Au?ynait?, Agota,Boll, Matthias,Fontecave, Marc,Fuchs, Jonathan,Golinelli-Pimpaneau, Béatrice,Me?kys, Rolandas,Pecqueur, Ludovic,Rutkien?, Rasa,Urbonavi?ius, Jaunius,Vaitekūnas, Justas,Zhou, Jingjing
supporting information, p. 424 - 431 (2020/11/30)
We recently discovered a [Fe-S]-containing protein with in vivo thiouracil desulfidase activity, dubbed TudS. The crystal structure of TudS refined at 1.5 ? resolution is reported; it harbors a [4Fe-4S] cluster bound by three cysteines only. Incubation of TudS crystals with 4-thiouracil trapped the cluster with a hydrosulfide ligand bound to the fourth non-protein-bonded iron, as established by the sulfur anomalous signal. This indicates that a [4Fe-5S] state of the cluster is a catalytic intermediate in the desulfuration reaction. Structural data and site-directed mutagenesis indicate that a water molecule is located next to the hydrosulfide ligand and to two catalytically important residues, Ser101 and Glu45. This information, together with modeling studies allow us to propose a mechanism for the unprecedented non-redox enzymatic desulfuration of thiouracil, in which a [4Fe-4S] cluster binds and activates the sulfur atom of the substrate.
Green preparation method of uracil
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Paragraph 0024-0026, (2021/01/25)
The invention relates to a green preparation method of uracil, which comprises the following steps: proportionally mixing acetate, alkali and a benzene solvent in a reaction bottle to obtain a mixed solution, introducing carbon monoxide, pressurizing to generate aldehyde, adding a hydrogen chloride alcohol solution into the reaction bottle, and carrying out condensation reaction on aldehyde and the hydrogen chloride alcohol solution to obtain acetal, and adding urea into the reaction bottle, reacting acetal with urea to obtain a condensate, adding alkali into the reaction bottle, reacting alkali with the condensate to generate uracil sodium salt, adding acidic water into the reaction bottle, crystallizing, cooling, and filtering to obtain uracil. Carbon monoxide and acetate are innovatively used as raw materials, alkali such as sodium methoxide is used for one-pot catalytic synthesis of uracil, the synthesis method in the whole process is mild in condition, simple in process and high in yield and purity, the purposes of few three wastes and environmental protection are achieved, and the method has a good large-scale application prospect.
Green production process of uracil
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Paragraph 0046-0048; 0049-0052; 0053-0055; 0056-0086, (2021/04/14)
The invention relates to the field of chemistry, and particularly provides a green production process of uracil, which comprises the following steps: cyclizing 3-alkoxy (amino) acrylate (amide) and urea alkali metal salt, acidifying, and converting into uracil with the yield of more than 95%.
Anion exchange resins in phosphate form as versatile carriers for the reactions catalyzed by nucleoside phosphorylases
Artsemyeva, Julia N.,Buravskaya, Tatiana N.,Esipov, Roman S.,Konstantinova, Irina D.,Litvinko, Natalia M.,Mikhailopulo, Igor A.,Miroshnikov, Anatoly I.,Remeeva, Ekaterina A.
, p. 2607 - 2622 (2020/11/26)
In the present work, we suggested anion exchange resins in the phosphate form as a source of phosphate, one of the substrates of the phosphorolysis of uridine, thymidine, and 1-(β-D-arabinofuranosyl)uracil (Ara-U) catalyzed by recombinant E. coli uridine (UP) and thymidine (TP) phosphorylases. α-D-Pentofuranose-1-phosphates (PF-1Pis) obtained by phosphorolysis were used in the enzymatic synthesis of nucleosides. It was found that phosphorolysis of uridine, thymidine, and Ara-U in the presence of Dowex 1X8 (phosphate; Dowex-nPi) proceeded smoothly in the presence of magnesium cations in water at 20-50 °C for 54-96 h giving rise to quantitative formation of the corresponding pyrimidine bases and PF-1Pis. The resulting PF-1Pis can be used in three routes: (1) preparation of barium salts of PF-1Pis, (2) synthesis of nucleosides by reacting the crude PF-1Pi with an heterocyclic base, and (3) synthesis of nucleosides by reacting the ionically bound PF-1Pi to the resin with an heterocyclic base. These three approaches were tested in the synthesis of nelarabine, kinetin riboside, and cladribine with good to excellent yields (52-93%).
Thermodynamic Reaction Control of Nucleoside Phosphorolysis
Kaspar, Felix,Giessmann, Robert T.,Neubauer, Peter,Wagner, Anke,Gimpel, Matthias
supporting information, p. 867 - 876 (2020/01/24)
Nucleoside analogs represent a class of important drugs for cancer and antiviral treatments. Nucleoside phosphorylases (NPases) catalyze the phosphorolysis of nucleosides and are widely employed for the synthesis of pentose-1-phosphates and nucleoside analogs, which are difficult to access via conventional synthetic methods. However, for the vast majority of nucleosides, it has been observed that either no or incomplete conversion of the starting materials is achieved in NPase-catalyzed reactions. For some substrates, it has been shown that these reactions are reversible equilibrium reactions that adhere to the law of mass action. In this contribution, we broadly demonstrate that nucleoside phosphorolysis is a thermodynamically controlled endothermic reaction that proceeds to a reaction equilibrium dictated by the substrate-specific equilibrium constant of phosphorolysis, irrespective of the type or amount of NPase used, as shown by several examples. Furthermore, we explored the temperature-dependency of nucleoside phosphorolysis equilibrium states and provide the apparent transformed reaction enthalpy and apparent transformed reaction entropy for 24 nucleosides, confirming that these conversions are thermodynamically controlled endothermic reactions. This data allows calculation of the Gibbs free energy and, consequently, the equilibrium constant of phosphorolysis at any given reaction temperature. Overall, our investigations revealed that pyrimidine nucleosides are generally more susceptible to phosphorolysis than purine nucleosides. The data disclosed in this work allow the accurate prediction of phosphorolysis or transglycosylation yields for a range of pyrimidine and purine nucleosides and thus serve to empower further research in the field of nucleoside biocatalysis. (Figure presented.).
Preparation method of uracil
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Paragraph 0016-0039, (2020/03/02)
The invention relates to the technical field of biological medicines, in particular to a preparation method for uracil. The preparation method comprises the following concrete steps: step 1, mixing cytosine, sodium nitrite and deionized water in a container under stirring, dropwise adding acid and/or anhydride, and continuing to perform a reaction for 0-6 hours after dropwise adding is finished soas to obtain a reaction solution A; 2, when the residual amount of cytosine is lower than 1%, adjusting the pH value of the reaction solution A to 6.5-7.5 to obtain a reaction solution B; 3, mixing the reaction solution B with 95% ethyl alcohol, and carrying out crystallizing and filtering to obtain a crude uracil product; 4, mixing the crude uracil product with water, and carrying out heating for dissolving to obtain a solution; and step 5, cooling the solution to room temperature, and performing filtering and drying to obtain a uracil product. The preparation method for uracil is simple inprocess, convenient to operate and low in production cost, and has high yield and high purity.
Efficient biocatalytic synthesis of dihalogenated purine nucleoside analogues applying thermodynamic calculations
Giessmann, Robert T.,Kaspar, Felix,Klare, Hendrik F. T.,Kurreck, Jens,Neubauer, Peter,Paulick, Katharina,R?hrs, Viola,Wagner, Anke,Westarp, Sarah,Yehia, Heba
, (2020/02/28)
The enzymatic synthesis of nucleoside analogues has been shown to be a sustainable and efficient alternative to chemical synthesis routes. In this study, dihalogenated nucleoside analogues were produced by thermostable nucleoside phosphorylases in transglycosylation reactions using uridine or thymidine as sugar donors. Prior to the enzymatic process, ideal maximum product yields were calculated after the determination of equilibrium constants through monitoring the equilibrium conversion in analytical-scale reactions. Equilibrium constants for dihalogenated nucleosides were comparable to known purine nucleosides, ranging between 0.071 and 0.081. To achieve 90% product yield in the enzymatic process, an approximately five-fold excess of sugar donor was needed. Nucleoside analogues were purified by semi-preparative HPLC, and yields of purified product were approximately 50% for all target compounds. To evaluate the impact of halogen atoms in positions 2 and 6 on the antiproliferative activity in leukemic cell lines, the cytotoxic potential of dihalogenated nucleoside analogues was studied in the leukemic cell line HL-60. Interestingly, the inhibition of HL-60 cells with dihalogenated nucleoside analogues was substantially lower than with monohalogenated cladribine, which is known to show high antiproliferative activity. Taken together, we demonstrate that thermodynamic calculations and small-scale experiments can be used to produce nucleoside analogues with high yields and purity on larger scales. The procedure can be used for the generation of new libraries of nucleoside analogues for screening experiments or to replace the chemical synthesis routes of marketed nucleoside drugs by enzymatic processes.
Preparation method of uracil
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Paragraph 0041-0052, (2019/11/20)
The invention belongs to the technical field of organic synthesis, and concretely relates to a preparation method of uracil. The preparation method of uracil is characterized in that the uracil is obtained by condensing and cyclizing a compound represented by formula (I) with urea in the presence of an alkali; the formula (I) is shown in the description, and in the formula (I), R is a C1-3 alkyl group, and R1 is a methyl group or an ethyl group; and the compound of formula (I) is prepared from orthoformate and acetate under the action of the alkali. The method for synthesizing uracil from theorthoformate and acetate in a one-pot manner is reported for the first time; and the method has the advantages of cheap and easily available raw materials, simple process, convenience in operation, simplification of the post-treatment process due to the same alkali in the two steps, mild and easily controlled reaction product, no special devices, meeting of industrial mass production requirements,and good industrial application values.
