- Observation of two N2-isobutyrylguanine tautomers by NMR spectroscopy
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N2-Isobutyrylguanine was prepared by treatment of guanine with isobutyryl chloride. Two tautomers, 1,7-dihydro-2-(isobutyroyl)amino-6H-purin-6- one and 1,9-dihydro-2-(isobutyroyl)amino-6H-purin-6-one, were identified in almost 1: 1 ratio in dichloromethane-dimethyl sulfoxide (1: 1 v/v) by NMR spectroscopy. By using the selective-inversion experiments, enthalpy, entropy, and free energy for activation were determined. This work represents the first report of guanine tautomers observed directly by NMR spectroscopy. Copyright
- Yang, Lijing,Li, Jia,Simionescu, Razvan,Yan, Hongbin
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Read Online
- CYCLOPENTYL NUCLEOSIDE ANALOGS AS ANTI-VIRALS
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Described herein are cyclopentyl nucleoside analogs, pharmaceutical compositions that include one or more cyclopentyl nucleoside analogs and methods of using the same to treat HBV, HDV and/or HIV.
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Paragraph 0294
(2020/07/07)
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- A convenient route to synthesize N2-(isobutyryl)-9-(carboxymethyl)guanine for aeg-PNA backbone
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Synthesis of exclusive N2-(isobutyryl)-9-(carboxymethyl)guanine, an important moiety for peptide nucleic acid synthesis has been reported through a high-yielding reaction scheme starting from 6-chloro-2-amino purine. Crystal structures of two intermediates confirmed the formation of N9-regioisomer. This new synthetic route can potentially replace the conventional tedious method with moderate overall yield.
- Datta, Dhrubajyoti
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p. 530 - 541
(2019/11/03)
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- Chirality Dependent Potency Enhancement and Structural Impact of Glycol Nucleic Acid Modification on siRNA
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Here we report the investigation of glycol nucleic acid (GNA), an acyclic nucleic acid analogue, as a modification of siRNA duplexes. We evaluated the impact of (S)- or (R)-GNA nucleotide incorporation on RNA duplex structure by determining three individu
- Schlegel, Mark K.,Foster, Donald J.,Kel'In, Alexander V.,Zlatev, Ivan,Bisbe, Anna,Jayaraman, Muthusamy,Lackey, Jeremy G.,Rajeev, Kallanthottathil G.,Charissé, Klaus,Harp, Joel,Pallan, Pradeep S.,Maier, Martin A.,Egli, Martin,Manoharan, Muthiah
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supporting information
p. 8537 - 8546
(2017/07/06)
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- Synthesis of 3-guaninyl- and 3-adeninyl-5-hydroxymethyl-2-pyrrolidinone nucleosides
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l- And d-glutamic acids, as well as trans-4-hydroxy-l-proline, are converted to the corresponding 3-guaninyl-5-hydroxymethyl-2-pyrrolidinone (4) or 3-adeninyl-5-hydroxymethyl-2-pyrrolidinone (5) nucleoside analog. The protecting group used to block the lactam nitrogen in key intermediates has a significant effect on the diastereoselectivity of the coupling reaction with adenine or guanine.
- Saleh, Abdullah,D'Angelo, John G.,Morton, Martha D.,Quinn, Jesse,Redden, Kendra,Mielguz, Rafal W.,Pavlik, Christopher,Smith, Michael B.
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scheme or table
p. 5574 - 5583
(2011/10/02)
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- Biocatalytic separation of N -7/ N -9 guanine nucleosides
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Vorbrueggen coupling of trimethylsilylated 2-N-isobutanoylguanine with peracetylated pentofuranose derivatives generally gives inseparable N-7/N-9 glycosyl mixtures. We have shown that the two isomers can be separated biocatalytically by Novozyme-435-mediated selective deacetylation of the 5′-O-acetyl group of peracetylated N-9 guanine nucleosides.
- Singh, Sunil K.,Sharma, Vivek K.,Olsen, Carl E.,Wengel, Jesper,Parmar, Virinder S.,Prasad, Ashok K.
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scheme or table
p. 7932 - 7935
(2011/03/17)
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- Synthesis of 1'-phenyl substituted nucleoside analogs
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l'-Phenyl substituted ribonucleoside analogs with all four nucleobases have been synthesized by the conventional N-glycosidation method.
- Nasr, Tamer,Taniguchi, Yosuke,Sasaki, Shigeki
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p. 2659 - 2668
(2008/09/18)
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- CYCLOPENTENOL NUCLEOSIDE COMPOUNDS, INTERMEDIATES FOR THEIR SYNTHESIS AND METHODS OF TREATING VIRAL INFECTIONS
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The present invention relates to compounds according to the structure (I), Where B is formula (Ia), formula (Ib) or formula (Ic); A is H, OR2 or halogen (F, Cl, Br, I, preferably F or Br, more preferably F); A' is H, OR2 or halogen (F, Cl, Br, I, preferably F or Br, more preferably F); A" is H or OR1, with the proviso that when A' is OR , A is H; and when A is OR2 , A' is H; X is C-R3 or N; Y is C-R3 or N; preferably X or Y is N and X and Y are not both simultaneously N; R3 is H or C1-C3 alkyl; D is H or NHR2; E is absent or H; G is O or NHR2; J is N or C-R4; K is N or C-H; R4 is H, halogen (F, Cl, Br, I), CN, -C(=O)NH2, NH2, NO2, -C=C-H (cis or trans) or -C≡C-H; Ra is H or CH3; Each R1 is independently H, an acyl group, a C1 - C20 alkyl or ether group, a phosphate, diphosphate, triphosphate, phosphodiester group; Each R2 is independently H, an acyl group, a C1 - C20 alkyl or ether group; and Pharmaceutically acceptable salts, solvates or polymorphs thereof.
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Page/Page column 93
(2008/06/13)
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- PNA-directed triple-helix formation by N7-xanthine
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We report the first example of alkylation of underivatized xanthine with chloroacetic acid to yield a separable mixture of N7- and N 9-(methylenecarboxyl)xanthine and its conversion to a peptide nucleic acid monomer compatible with Fmoc-based oligomerization chemistry. Additionally, we have simultaneously prepared the N7- and N 9-PNA monomers of guanine by alkylation of 2-N-isobutyrylguanine which were subsequently separated. Molecular modeling of the nucleobase base triplets indicates that N7-xanthine and N7-guanine form isomorphous triplets with adenine and guanine, respectively. We also show that polyamides containing N7-xanthine are compatible with triple-helix formation. Georg Thieme Verlag Stuttgart.
- Hudson, Robert H. E.,Goncharenko, Mykhaylo,Wallman, Andrew P.,Wojciechowski, Filip
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p. 1442 - 1446
(2007/10/03)
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- Fmoc/Acyl protecting groups in the synthesis of polyamide (peptide) nucleic acid monomers
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The chemical synthesis of polyamide (peptide) nucleic acid (PNA) monomers 22-25 has been accomplished using Fmoc [N-(2-aminoethyl)glycine backbone], anisoyl (adenine), 4-tert-butylbenzoyl (cytosine) and isobutyryl/ diphenylcarbamoyl (guanine) protecting-group combinations, thus allowing oligomer synthesis on both peptide and oligonucleotide synthesizers. An alternative method for the preparation of (N6-anisoyladenin-9-yl)acetic acid 7 is described using partial hydrolysis of a dianisoylated derivative. Different methods were studied for guanine alkylation including (a) Mitsunobu reaction; (b) low-temperature, sodium hydride- and (c) N, N-diisopropylethylaminemediated alkylation reactions to give preferentially N9-substituted derivatives. Empirical rules are proposed for differentiating N9/N7-substituted guanines based on their 13C NMR chemical-shift differences. The Royal Society of Chemistry 2000.
- Timar, Zoltan,Kovacs, Lajos,Kovacs, Gyoergyi,Schmel, Zoltan
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- Substituted N-ethylglycine derivatives for preparing PNA and PNA/DNA hybrids
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There are described N-ethylglycine derivatives of the formula I in which PG is a urethane-type or trityl-type amino protective group which is labile to weak acids, X is NH, O or S, Y is CH2, NH or O, and B' are bases customary in nucleotide chemistry, the exocyclic amino or hydroxyl groups of which being protected by suitable, known protective groups, or are base substitute compounds, and their salts with tert-organic bases, as well as a process for their preparation. The N-ethylglycine derivatives of the formula I are used in the preparation of PNA and PNA/DNA hybrids.
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- The synthesis of polyamide nucleic acids using a novel monomethoxytrityl protecting-group strategy
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The preparation of novel monomethoxytrityl (Mmt) protected monomers for the synthesis of polyamide nucleic acids (PNAs) is described. The use of base-labile acyl-type nucleobase protecting groups and of a succinyl-linked solid-support offers a synthetic strategy to standard oligonucleotide synthesis conditions. This strategy has been successfully applied for the synthesis of PNAs of mixed base sequence.
- Will, David W.,Breipohl, Gerhard,Langner, Dietrich,Knolle, Jochen,Uhlmann, Eugen
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p. 12069 - 12082
(2007/10/02)
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