- Transglycosylation in the Modification and Isotope Labeling of Pyrimidine Nucleosides
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Transglycosylation of pyrimidine nucleosides is demonstrated in a one-pot synthesis of uridine derivatives under microwave irradiation. Inductive activation of 2′,3′,5′-tri-O-acetyl uridine with a 5-nitro group produces a more-reactive glycosyl donor. Under optimized Vorbrüggen conditions, the 5-nitrouridine facilitates a reversible nucleobase exchange with a series of 5-substituted uracils. The protocol is also exemplified in a gram-scale reaction under thermal heating. The strategy provides easy access to isotopically labeled uridine.
- Gong, Yong,Chen, Lu,Zhang, Wei,Salter, Rhys
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supporting information
p. 5577 - 5581
(2020/07/24)
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- A solid-supported acidic oxazolium perchlorate as an easy-handling catalyst for the synthesis of modified pyrimidine nucleosides via Vorbrüggen-type N-glycosylation
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A solid-supported acidic oxazolium perchlorate was investigated as a heterogeneous catalyst in N-glycosylation reactions using silylated modified pyrimidines and an acylated ribose or glucose to afford the corresponding pyrimidine nucleosides. This salt is a nonhygroscopic and stable powder whose activity is comparable to that of 2-methyl-5-phenylbenzoxazolium perchlorate. A reaction with this polymer catalyst can be conducted on a gram scale. Reusability of the solid-supported catalyst was also investigated.
- Basu, Nabamita,Oyama, Kin-ichi,Tsukamoto, Masaki
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supporting information
p. 1921 - 1924
(2017/04/27)
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- Alternative nucleic acid molecules and uses thereof
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The present disclosure provides alternative nucleosides, nucleotides, and nucleic acids, and methods of using them.
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- ALTERNATIVE NUCLEIC ACID MOLECULES AND USES THEREOF
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The present disclosure provides alternative nucleosides, nucleotides, and nucleic acids, and methods of using them.
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- ALTERNATIVE NUCLEIC ACID MOLECULES AND USES THEREOF
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The present disclosure provides alternative nucleosides, nucleotides, and nucleic acids, and methods of using them.
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- MODIFIED NUCLEIC ACID MOLECULES AND USES THEREOF
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The present disclosure provides modified nucleosides, nucleotides, and nucleic acids, and methods of using them.
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- Systematic assignment of NMR spectra of 5-substituted-4-thiopyrimidine nucleosides
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Unambiguous characterization of 5-substituted-4-thiopyrimidine nucleosides (ribonucleosides and 2'-deoxynucleosides) was performed using NMR spectroscopy. Assignments of all proton and carbon signals of 5-bromo-4-thiouridine and related nucleosides were systematically carried out and firmly established by COSY and HMQC techniques. The NMR data of various 4-thiopyrimidine nucleosides are compared, and the key contributing factors discussed. The approach presented here is applicable to other modified nucleosides and nucleotides, as well as nucleobases. Copyright
- Zhang, Xiaohui,Wang, Jian,Xu, Yao-Zhong
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p. 523 - 529
(2013/09/02)
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- Triazole pyrimidine nucleosides as inhibitors of Ribonuclease A. Synthesis, biochemical, and structural evaluation
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Five ribofuranosyl pyrimidine nucleosides and their corresponding 1,2,3-triazole derivatives have been synthesized and characterized. Their inhibitory action to Ribonuclease A has been studied by biochemical analysis and X-ray crystallography. These compounds are potent competitive inhibitors of RNase A with low μM inhibition constant (Ki) values with the ones having a triazolo linker being more potent than the ones without. The most potent of these is 1-[(β-d-ribofuranosyl)-1,2,3-triazol-4-yl]uracil being with Ki = 1.6 μM. The high resolution X-ray crystal structures of the RNase A in complex with three most potent inhibitors of these inhibitors have shown that they bind at the enzyme catalytic cleft with the pyrimidine nucleobase at the B1 subsite while the triazole moiety binds at the main subsite P1, where P-O5′ bond cleavage occurs, and the ribose at the interface between subsites P1 and P0 exploiting interactions with residues from both subsites. The effect of a susbsituent group at the 5-pyrimidine position at the inhibitory potency has been also examined and results show that any addition at this position leads to a less efficient inhibitor. Comparative structural analysis of these RNase A complexes with other similar RNase A - ligand complexes reveals that the triazole moiety interactions with the protein form the structural basis of their increased potency. The insertion of a triazole linker between the pyrimidine base and the ribose forms the starting point for further improvement of these inhibitors in the quest for potent ribonucleolytic inhibitors with pharmaceutical potential.
- Parmenopoulou, Vanessa,Chatzileontiadou, Demetra S.M.,Manta, Stella,Bougiatioti, Stamatina,Maragozidis, Panagiotis,Gkaragkouni, Dimitra-Niki,Kaffesaki, Eleni,Kantsadi, Anastassia L.,Skamnaki, Vassiliki T.,Zographos, Spyridon E.,Zounpoulakis, Panagiotis,Balatsos, Nikolaos A.A.,Komiotis, Dimitris,Leonidas, Demetres D.
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p. 7184 - 7193
(2013/01/15)
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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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- The AlkB domain of mammalian ABH8 catalyzes hydroxylation of 5-methoxycarbonylmethyluridine at the wobble position of tRNA
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Family ties: The AlkB family of nonheme iron, α-ketoglutarate (αKG)-dependent dioxygenases is involved in biological processes such as DNA/RNA repair and obesity. The AlkB domain of ABH8 is shown to catalyze the hydroxylation of a modified uridine (mcmsu
- Fu, Ye,Dai, Qing,Zhang, Wen,Ren, Jin,Pan, Tao,He, Chuan
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supporting information; experimental part
p. 8885 - 8888
(2011/02/23)
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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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- 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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