- Thermodynamic Reaction Control of Nucleoside Phosphorolysis
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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.).
- Kaspar, Felix,Giessmann, Robert T.,Neubauer, Peter,Wagner, Anke,Gimpel, Matthias
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supporting information
p. 867 - 876
(2020/01/24)
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- Bio-catalytic synthesis of unnatural nucleosides possessing a large functional group such as a fluorescent molecule by purine nucleoside phosphorylase
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Unnatural nucleosides are attracting interest as potential diagnostic tools, medicines, and functional molecules. However, it is difficult to couple unnatural nucleobases to the 1′-position of ribose in high yield and with β-regioselectivity. Purine nucleoside phosphorylase (PNP, EC2.4.2.1) is a metabolic enzyme that catalyses the conversion of inosine to ribose-1α-phosphate and free hypoxanthine in phosphate buffer with 100% α-selectivity. We explored whether PNP can be used to synthesize unnatural nucleosides. PNP catalysed the reaction of thymidine as a ribose donor with purine to produce 2′-deoxynebularine (3, β form) in high conversion (80%). It also catalysed the phosphorolysis of thymidine and introduced a pyrimidine base with a halogen atom substituted at the 5-position into the 1′-position of ribose in moderate yield (52-73%), suggesting that it exhibits loose selectivity. For a bulky purine substrate [e.g., 6-(N,N-di-propylamino)], the yield was lower, but addition of a polar solvent such as dimethyl sulfoxide (DMSO) increased the yield to 74%. PNP also catalysed the reaction between thymidine and uracil possessing a large functional fluorescent group, 5-(coumarin-7-oxyhex-5-yn) uracil (C4U). Conversion to 2′-deoxy-[5-(coumarin-7-oxyhex-5-yn)] uridine (dRC4U) was drastically enhanced by DMSO addition. Docking simulations between dRC4U and E. coli PNP (PDB 3UT6) showed the uracil moiety in the active-site pocket of PNP with the fluorescent moiety at the entrance of the pocket. Thus, the bulky fluorescent moiety has little influence on the coupling reaction. In summary, we have developed an efficient method for producing unnatural nucleosides, including purine derivatives and modified uracil, using PNP.
- Hatano, Akihiko,Wakana, Hiroyuki,Terado, Nanae,Kojima, Aoi,Nishioka, Chisato,Iizuka, Yu,Imaizumi, Takuya,Uehara, Sanae
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p. 5122 - 5129
(2019/10/05)
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- Biotransformation of halogenated nucleosides by immobilized Lactobacillus animalis 2′-N-deoxyribosyltransferase
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An immobilized biocatalyst with 2′-N-deoxyribosyltransferase (NDT) activity, Lactobacillus animalis NDT (LaNDT), was developed from cell free extracts. LaNDT was purified, characterized and then immobilized by ionic interaction. Different process parameters were optimized, resulting in an active derivative (2.6 U/g) able to obtain 1.75 mg/g of 5-fluorouracil-2′-deoxyriboside, an antimetabolite known as floxuridine, used in gastrointestinal cancer treatment. Furthermore, immobilized LaNDT was satisfactorily used to obtain at short reaction times other halogenated pyrimidine and purine 2′-deoxynucleosides such as 6-chloropurine-2′-deoxyriboside (4.9 U/g), 6-bromopurine-2′-deoxyriboside (4.3 U/g), 6-chloro-2-fluoropurine-2′-deoxyriboside (5.4 U/g), 5-bromo-2′-deoxyuridine (2.8 U/g) and 5-chloro-2′-deoxyuridine (1.8 U/g) compounds of pharmaceutical interest in antiviral or antitumor treatments. Besides, increasing the biocatalyst amount 8 times per volume unit allowed obtaining a 5-fold improvement in floxuridine biotransformation. The developed biocatalyst proved to be effective for the biosynthesis of a wide spectrum of nucleoside analogues by employing an economical, simple and environmentally friendly methodology.
- Britos, Claudia N.,Lapponi, María José,Cappa, Valeria A.,Rivero, Cintia W.,Trelles, Jorge A.
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- An efficient and facile methodology for bromination of pyrimidine and purine nucleosides with sodium monobromoisocyanurate (SMBI)
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An efficient and facile strategy has been developed for bromination of nucleosides using sodium monobromoisocyanurate (SMBI). Our methodology demonstrates bromination at the C-5 position of pyrimidine nucleosides and the C-8 position of purine nucleosides. Unprotected and also several protected nucleosides were brominated in moderate to high yields following this procedure.
- Maity, Jyotirmoy,Stromberg, Roger
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p. 12740 - 12750
(2013/11/06)
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- A comparison between immobilized pyrimidine nucleoside phosphorylase from Bacillus subtilis and thymidine phosphorylase from Escherichia coli in the synthesis of 5-substituted pyrimidine 2′-deoxyribonucleosides
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Pyrimidine nucleoside phosphorylase from Bacillus subtilis (BsPyNP, E.C. 2.4.2.3) and thymidine phosphorylase from Escherichia coli (EcTP, E.C. 2.4.2.4) were used, as immobilized enzymes, in the synthesis of 5-halogenated pyrimidine 2′-deoxyribonucleosides (14-18) by transglycosylation in fully aqueous medium. From the comparative study of the two biocatalysts, no remarkable differences emerged about their substrate specificity, bioconversion yield, stability in organic cosolvents (DMF and MeCN). Moreover, both biocatalysts could be recycled for at least 5 times with no loss of the productivity. Both enzymes do not accept arabinonucleosides and 2′,3′- dideoxynucleosides as substrates, whereas they catalyze bioconversions involving 5′-deoxyribonucleosides and 5-halogenated uracils. The synthesis of compounds 14-18 proceeded at a similar conversion (33-68% for BsPyNP and 25-62% for EcTP, respectively). Immobilization was found to exert, for both the biocatalysts, a dramatic enhancement of stability upon incubation in MeCN. Optimization of 5-fluoro-2′-deoxyuridine (14) synthesis (pH 7.5, 10 mM phosphate buffer, nucleoside/nucleobase 3:1 molar ratio) and subsequent scale-up afforded the target compound in 73% (EcTP) or 76% (BsPyNP) conversion (about 9 g/L).
- Serra, Immacolata,Bavaro, Teodora,Cecchini, Davide A.,Daly, Simona,Albertini, Alessandra M.,Terreni, Marco,Ubiali, Daniela
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- Bromination at C-5 of pyrimidine and C-8 of purine nucleosides with 1,3-dibromo-5,5-dimethylhydantoin
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Treatment of the protected and unprotected nucleosides with 1,3-dibromo-5,5-dimethylhydantoin in aprotic solvents such as CH 2Cl2, CH3CN, or DMF effected smooth bromination of uridine and cytidine derivatives at C-5 of pyrimidine rings as well as adenosine and guanosine derivatives at C-8 of purine rings. Addition of Lewis acids such as trimethylsilyl trifluoromethanesulfonate enhanced the efficiency of bromination.
- Rayala, Ramanjaneyulu,Wnuk, Stanislaw F.
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experimental part
p. 3333 - 3336
(2012/07/30)
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- Biotransformation of halogenated 2′-deoxyribosides by immobilized lactic acid bacteria
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An efficient and green bioprocess is herein reported to obtain halogenated nucleosides by transglycosylation using immobilized lactic acid bacteria (LAB). Lactobacillus animalis ATCC 35046 showed a yield of 95% at 0.5 h to synthesize 5-fluorouracil-2′-deoxyriboside (floxuridine). Calcium alginate was the best matrix for whole-cell immobilization by entrapment. Its productivity was 87 mg/L h in a continuous bioprocess. When adsorption techniques were evaluated, DEAE-Sepharose was the support which showed higher microbial load, its productivity being 53 mg/L h. Additionally, this microorganism was able to produce 5-bromouracil-2′-deoxyriboside, 6-chloropurine-2′- deoxyriboside and 6-bromopurine-2′-deoxyriboside.
- Britos, Claudia N.,Cappa, Valeria A.,Rivero, Cintia W.,Sambeth, Jorge E.,Lozano, Mario E.,Trelles, Jorge A.
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experimental part
p. 49 - 53
(2012/07/27)
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- Highly efficient method for C-5 halogenation of pyrimidine-based nucleosides in ionic liquids
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A novel, highly efficient, convenient, and benign methodology for C-5 halogenation of pyrimidine-based nucleosides has been developed using N-halosuccinimides as halogenating reagents without using any catalyst in ionic liquid medium. The ionic liquids were successfully recovered and reused for all the reactions. Georg Thieme Verlag Stuttgart.
- Kumar, Vineet,Yap, Jeremy,Muroyama, Andrew,Malhotra, Sanjay V.
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experimental part
p. 3957 - 3962
(2010/03/26)
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- Ionic liquid mediated synthesis of 5-halouracil nucleosides: Key precursors for potential antiviral drugs
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Synthesis of antiviral 5-halouracil nucleosides, also used as key precursors for the synthesis of other potential antiviral drugs, has been demonstrated using ionic liquids as convenient and efficient reaction medium.
- Kumar, Vineet,Malhotra, Sanjay V.
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experimental part
p. 821 - 834
(2010/08/20)
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- Chemoenzymatic preparation of nucleosides from furanoses
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Chemoenzymatic preparation of ribose, deoxyribose and arabinose 5-phosphates was accomplished. These compounds were tested as starting materials in the enzymatic preparation of natural and modified purine and pyrimidine nucleosides, using an overexpressed Escherichia coli phosphopentomutase.
- Taverna-Porro, Marisa,Bouvier, Leon A.,Pereira, Claudio A.,Montserrat, Javier M.,Iribarren, Adolfo M.
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p. 2642 - 2645
(2008/09/19)
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- Importance of 3′-hydroxyl group of the nucleosides for the reactivity of thymidine phosphorylase from Escherichia coli
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Thymidine phosphorylase in phosphate buffer catalyzed the conversion of thymidine to unnatural nucleosides. The 3′-OH, but not the 5′-OH of ribosyl moiety is necessary to be recognized as a substrate. Thus 3′-deoxythymidine could not convert to 5-fluorouracil-2′,3′- dideoxyribose. However, 5′-deoxythymidine was converted to 5-fluorouracil-2′,5′-dideoxyribose. Copyright
- Hatano, Akihiko,Harano, Aiko,Kirihara, Masayuki
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p. 232 - 233
(2007/10/03)
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- Photochemical halogen-exchange reaction of 5-iodouracil-containing oligonucleotides
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Photoreactions of 5-iododeoxyuridine (d(I)U) and d(I)U-containing oligonucleotides in aqueous solutions in the presence of various inorganic salts have been investigated. In the presence of NaCl and NaBr, d(I)U and d(I)U-containing oligonucleotides undergo an efficient photochemical halogen-exchange reaction to give d(Cl)U and d(Br)U, respectively.
- Kawai, Kiyohiko,Saito, Isao,Sugiyama, Hiroshi
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p. 5721 - 5724
(2007/10/03)
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- Antiviral agents
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Nucleoside compounds of the formula STR1 wherein: B is a purine or a pyrimidine; X and X' are H, OH or F, provided that at least one is H; Y and Y' are H, OH, OCH3 or F, provided that at least one is H; Y' and Z together form a cyclic phosphate ester, provided that Y is H; or Z is STR2 where n is zero, one, two or three; and Z' is N3 or OCH3 ; provided that when X' and Y' are OH and Z' is N3, B is not cytosine, and when X' and Y' are OH and Z' is OCH3, B is not uracil, adenine or cytosine; and the pharmaceutically acceptable esters, ethers and salts thereof, have been found to have potent antiviral activity with a high therapeutic ratio.
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- Radiolabeling kit/generator for 5-radiohalogenated uridines
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A rapid, simple and inexpensive synthesis of 5-radiohalogenated-2'- deoxyuridine from 5-trimethylstannyl-2'-deoxyuridine is described. The total reaction and purification time including thin layer chromatography (tlc) for quality control is less than 30 min. This method produces excellent yields (>95%) of 123I-, 125I-, 131I-UdR. The radiochemical purity of all tested preparations (>20) was determined to be greater than 99%. This new method is the basis of a radiolabeling kit/generator for preparation of radiohalogenated nucleosides. 2'-Deoxyuridine (UdR) halogenated with a stable isotope of bromine was also synthesized indicating that the method can be applied to the preparation of 5-radiobromo-2'-deoxyuridine (BUdR).
- Baranowska-Kortylewicz,Helseth,Lai,Schneiderman,Schneiderman,Dalrymple
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p. 513 - 522
(2007/10/02)
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- A mild and efficient methodology for the synthesis of 5-halogeno uracil nucleosides that occurs via a 5-halogeno-6-azido-5,6-dihydro intermediate
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A mild and efficient methodology for the synthesis of 5-halogeno (iodo, bromo, or chloro) uracil nucleosides has been developed. 5-Halo-2'-deoxyuridines 4a-c (84-95%), 5-halouridines 7a-c (45-95%), and 5-haloarabinouridines 8a-c (65-95%) were synthesized in good to excellent yields by the reaction of 2'-deoxyuridine (2), uridine (5) and arabinouridine (6), respectively with iodine monochloride, or N-bromo (or chloro)succinimide, and sodium azide at 25-45°C. These C-5 halogenation reactions proceed via a 5-halo-6-azido-5,6-dihydro intermediate (3), from which HN3 is eliminated, to yield the 5-halogeno uracil nucleoside. The 5-halo-6-azido-5,6-dihydro intermediate products (10a, 10b) could be isolated from the reaction of 3',5'-di-O-acetyl-2'-deoxyuridine (9) with iodine monochloride or N-bromosuccinimide and sodium azide at 0°C. The isolation of 10a, 10b indicates that the C-5 halogenation reaction proceeds via a 5-halo-6-azido-5,6-dihydro intermediate.
- Kumar,Wiebe,Knaus
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p. 2005 - 2010
(2007/10/02)
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- In-cell Indirect Electrochemical Halogenation of Pyrimidine Bases and their Nucleosides to 5-Haloderivatives
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Reaction of anodically generated "halonium" species (LiX or Bu4NX, LiClO4, MeCN, Pt/Pt; I2, LiClO4, MeCN) with pyrimidine bases and their nucleosides leads to 5-halo compounds in good yields.
- Palmisano, G.,Danieli, B.,Santagostino, M.,Vodopivec, B.,Fiori, G.
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p. 7779 - 7782
(2007/10/02)
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- Cerium(IV)-Mediated Halogenation at C-5 of Uracil Derivatives
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Treatment of protected uracil nucleosides 1 or 2 with elemental iodine or metal halogenides and ceric ammonium nitrate (CAN) at 80 deg C gave the corresponding protected 5-halouracil nucleosides 3a-f in excellent yields.Treatment of the resulting crude 3a-f with 0.1 M NaOMe/MeOH at ambient temperature gave the corresponding 5-halouridines 4a-f in high overall yields from 1 or 2.Further, 5-halouraciles 9a-f were prepared in good yields by treatment of 1,3-dimethyluracil (7) or uracil (8) with elemental iodine, metal halogenides, or hydrochloric acid and CAN.Halouridines 4a-e also were obtained in good yields by treatment of unprotected uracil nucleosides 5 or 6 with halogen sources as above and CAN.
- Asakura, Jun-ichi,Robins, Morris J.
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p. 4928 - 4933
(2007/10/02)
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- Cyclization-Activated Prodrugs. Basic Esters of 5-Bromo-2'-deoxyuridine
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Some 3'- and 5'-glycyl> esters of 5-bromo-2'-deoxyuridine were prepared and evaluated in vitro as progenitors of the parent alcohol.The sters proved to be relatively stable at low pH but released 5-bromo-2'-deoxyuridine cleanly at rates which were pH and structure dependent.These basic esters are examples of cyclization-activated prodrugs in which generation of active drug is not linked to enzymatic cleavage but rather results from an intramolecular cyclization-elimination reaction.
- Saari, Walfred S.,Schwering, John E.,Lyle, Paulette A.,Smith, Steven J.,Engelhardt, Edward L.
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p. 2590 - 2595
(2007/10/02)
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- REGIOSELECTIVE DEPROTECTION OF 3',5'-O-ACYLATED PYRIMIDINE NUCLEOSIDES BY LIPASE AND ESTERASE
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A lipase was found to catalyze the regioselective hydrolysis at the secondary hydroxyl group of 2'-deoxy 3',5'-di O-hexanoyl pyrimidine nuclosides, whereas a protease catalyzes that at the primary hydroxyl group.
- Uemura, Atsuhiko,Nozaki, Kenji,Yamashita, Jun-ichi,Yasumoto, Mitsugi
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p. 3819 - 3820
(2007/10/02)
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- Synthesis and Antiviral Properties of SOme 2'-Deoxy-5-(fluoroalkenyl)uridines
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The following 5-substituted 2,4-dimethoxypyrimidines were synthesized: 5-(2,2,2-trichloro-1-hydroxyethyl), 5-(2,2,2-trichloro-1-fluoroethyl), 5-(2,2-dichloro-1-fluorovinyl) (5), and 5-(perfluoropropen-1-yl) (a mixture of E and Z isomers, 6 and 7).Demethylation of 5 gave 5-(2,2-dichloro-1-fluorovinyl)uracil, and demethylation of the mixture of 6 and 7 gave some pure (E)-5-(perfluoropropen-1-yl)uracil.Compound 5 was converted into its 2'-deoxyribonucleoside (12) and its α-anomer by standard procedures. 2'-Deoxy-3,5-dilithio-3',5'-O-bis(trimethylsilyl)uridine was reacted with the appropriate fluoroalkene to give the following 5-substituted 2'-(deoxyuridines in low yield (6-24percent): 5-(2-chloro-1,2-difluorovinyl) (a mixture of E and Z isomers, 15 and 16, which were separated on a small scale), 5-(perfluoropropen-1-yl), 5-(perfluorocyclohexen-1-yl), and 5-(perfluorocyclopenten-1-yl).In these reactions, 2'-deoxy-5-(trimethylsilyl)uridine and 2'-deoxyuridine were also formed.The 5-substituted 2'-deoxyuridines were tested for activity against herpes simplex virus type 1.Compound 12 and the mixture of 15 and 16 had an ID50 of 20-26 μg/mL in Vero cells.The activity of the mixture resided in one isomer, which by analogy with the corresponding (Z)- and (E)-5-(2-bromovinyl)-2'-deoxyuridines was concluded to be the Z isomer (16).
- Coe, Paul L.,Harnden, Michael R.,Jones, A. Stanley,Noble, Stewart A.,Walker, Richard T.
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p. 1329 - 1334
(2007/10/02)
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- The bromination and iodination of N1-substituted uracils
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Reaction of N1-substituted uracils with bromine in water at pH=7 leads to 5-bromo-6-hydroxy-5,6-hydrouracils.For different N1-substituents these products were isolated and the relatively stable derivatives were characterized by 1H NMR and mass spectroscopy.On electrophilic iodination with iodide and chloramine-T in water no indications were obtained for the formation of such dihydrouracils except for uridine and deoxyuridine.However, on reaction of N1-substituted uracils with N-iodosuccinimide in CHCl3 containing ethanol, or in ethanol, 5-iodo-6-ethoxy-5,6-dihydrouracils could be isolated as reaction products.
- Bakker, Cees N. M.,Kaspersen, Frans M.
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p. 267 - 271
(2007/10/02)
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