- Self-Assembly of Functionalized Lipophilic Guanosines into Cation-Free Stacked Guanine-Quartets
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The hierarchical self-assembly of various lipophilic guanosines exposing either a phenyl or a ferrocenyl group in the C(8) position was investigated. In a solution, all the derivatives were found to self-assemble primarily into isolated guanine (G)-quartets. In spite of the apparent similar bulkiness of the two substituents, most of the derivatives form disordered structures in the solid state, whereas a specific 8-phenyl derivative self-assembles into an unprecedented, cation-free stacked G-quartet architecture.
- Campitiello, Marilena,Cremonini, Alessio,Squillaci, Marco A.,Pieraccini, Silvia,Ciesielski, Artur,Samorì, Paolo,Masiero, Stefano
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- Self-Assembly of a Guanosine Derivative To Form Nanostructures and Transmembrane Channels
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We herein report the self-assembly of a lipophilic bromoguanosine derivative (G1) in homogeneous solution, in the solid state and in planar bilayer membranes. The self-assembly of G1, driven by H-bonding and π–π stacking interactions can form different nano-structures depending on incubation time. The G1 nanostructure is able to bind a bioactive dye like Rose Bengal. In crystal state, it shows ribbon type H-bonding pattern and exhibits birefringence in polarized light. And further, the self-assembled nanostructure of G1 can form discrete transmembrane ion channels in lipid bilayer membranes, enabling passage of potassium ions.
- Das, Rabindra Nath,Kumar, Y. Pavan,Kumar, S. Arun,Schütte, Ole Mathis,Steinem, Claudia,Dash, Jyotirmayee
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- Synthesis and in vitro evaluation of antiviral and cytostatic properties of novel 8-triazolyl acyclovir derivatives
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As a part of the research aimed on identification of new nucleobase derivatives with improved biological properties, a series of novel 8-substituted acyclovir derivatives were synthesized. The 8-azidoguanosine 4 and novel 8-azidoacyclovir 9 were synthesized from commercially available guanosine 1 and acyclovir 6 which were transformed into 8-bromopurine derivatives 2 and 7 and hydrazine derivatives 3 and 8, respectively. 8-Triazolylguanosine 5 and 8-triazolylacyclovir analogs 10–12 were successfully synthesized via the Cu(I) catalyzed 1,3-dipolar cycloaddition reaction of azides 4 and 9 with propargyl alcohol, 4-pentyn-1-ol and 5-hexyn-1-ol. The novel 1,4-disubstituted 1,2,3-triazolyl compounds 5, 10–12 were evaluated for antiviral activity against selected DNA and RNA viruses and cytostatic activity against normal Madine Darby canine kidney (MDCK I) cells, and seven tumor cell lines (HeLa, CaCo-2, NCI-H358, Jurkat, K562, Raji and HuT78). While tested compounds exerted no antiviral activity at nontoxic concentrations, the 8-triazolyl acyclovir derivative 10, with the shortest alkyl substituent at the C-4 of triazole ring, was found to be the most active against the CaCo-2 cell line.
- Safti?, Dijana,?ini?, Biserka,Glava?-Obrovac, Ljubica,Studzińska, Miros?awa,Paradowska, Edyta,Le?nikowski, Zbigniew J.
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- Absorption Characteristics and Quantum Yields of Singlet Oxygen Generation of Thioguanosine Derivatives
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6-Thioguanine (1a) is considered to be photochemotherapeutic due to its specific characteristics of photosensitivity to UVA light and singlet molecular oxygen generation. To extend its phototherapeutic ability, two related thioguanines, 8-thioguanine (2a) and 6,8-dithioguanine (3a), have been designed and explored. Since the solubility of these thioguanines in dehydrated organic solvents is too poor to study, their triacetyl-protected ribonucleosides, that is, 2′,3′,5′-tri-O-acetyl-6-thioguanosine (1c), 2′,3′,5′-tri-O-acetyl-8-thioguanosine (2c) and 2′,3′,5′-tri-O-acetyl-6,8-dithioguanosine (3c) were prepared and investigated. The absorption maxima of 1c, 2c and 3c in acetonitrile were found at longer wavelengths than that of unthiolated guanosine (4c). Especially, 3c has the longest wavelength for absorption maximum and the highest value in terms of molar absorption coefficient among all thionucleobases and thionucleosides reported. These absorption properties were also well reproduced by quantum chemical calculations. Quantum yields of singlet oxygen generation of 2c and 3c were determined by near-infrared emission measurements to be as large as that of 1c. These results suggest that the newly synthesized thioguanosines, in particular 3c, can be further developed as a potential photosensitive agent for light-induced therapies.
- Miyata, Shoma,Yamada, Takeshi,Isozaki, Tasuku,Sugimura, Hideyuki,Xu, Yao–Zhong,Suzuki, Tadashi
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p. 677 - 684
(2018/04/05)
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- Selective C8-Metalation of Purine Nucleosides via Oxidative Addition
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8-Bromo-2′-deoxy-3′,5′-di-O-acetylguanosine (1), 8-bromo-2′,3′,5′-tri-O-acetylguanosine (2), 8-bromo-2′-deoxy-3′,5′-di-O-acetyladenosine (3), and 8-bromo-2′,3′,5′-tri-O-acetyladenosine (4) react with [Pd(PPh3)4] via a C8-Br oxidative addition to give the C8-palladated azolato complexes [5]-[8] featuring an unprotonated N7 ring nitrogen atom. The complexes feature diastereotopic trans-disposed triphenylphosphine ligands, which allowed the determination of 2JPP for complexes of the type trans-[PdL2(PPh3)2] (2JPP = 442 Hz for [7]). In addition, two complex molecules of [7] form a trans-Watson-Crick/Hoogsteen AA base pair in the solid state. N7-protonation of the guanosine-derived complexes [5] and [6] with HBF4·Et2O and of adenosine-derived complexes [7] and [8] using lutidinium triflate yields complexes [9]BF4 and [10]BF4 and complexes [11]OTf and [12]OTf bearing protic NH,NR-NHC ligands derived from guanosine and adenosine, respectively.
- Kampert, Florian,Brackemeyer, Dirk,Tan, Tristan Tsai Yuan,Ekkehardt Hahn
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p. 4181 - 4185
(2018/11/23)
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- Synthesis of 8-alkoxy-6-alkylamino-2-alkylthiopurine nucleosides with a straightforward multiple-functionalization strategy
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A straight forward strategy to synthesize purine nucleosides with multiple functionalization on 2-, 6-, and 8-positions has been developed successfully, which provides a series of 8-alkoxy-6-alkylamino-2-alkylthiopurine nucleosides in moderate to good yields for further biological and medical activity screening.
- Du, Hongguang,Sun, Xiaoyang,Yu, Mingwu,Tian, Miao,Li, Shunlai,Wang, Zhiqian
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supporting information
p. 2949 - 2953
(2016/07/06)
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- Synthesis and fluorescence properties of a full set of extended RNA base analogues
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The synthesis and photophysical characterization of a complete set of fluorescent RNA base analogues derived by conjugating benzofuran moiety at the 5- and 8-positions of pyrimidine and purine bases, respectively, are described. Benzofuran-modified pyrimidine and purine ribonucleoside analogues exhibit contrasting fluorescence properties. Pyrimidine analogues are moderately emissive with emission maximum in the visible region, and importantly, are highly sensitive to solvent polarity and viscosity changes. On the other hand, purine analogues are highly emissive and are minimally affected by solvation and viscosity effects. Thorough photophysical analysis reveals that the pyrimidine and purine ribonucleosides displaying distinct and probe-like fluorescence properties could be useful in designing nucleic acid based biophysical tools to study nucleic acid structure and function.
- Sabale, Pramod M,Nuthanakanti, Ashok,Srivatsan, Seergazhi G
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p. 1004 - 1013
(2013/09/12)
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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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- RNA INCLUDING NUCLEOSIDE COMPOUND, METHOD FOR REGULATING AMOUNT OF PROTEIN PRODUCED FROM THE RNA, AND NUCLEOSIDE COMPOUND
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An RNA of the present invention is an RNA containing a 5′ cap structure and a coding region having a 5′ initiation codon and a 3′ stop codon on both ends of the coding region, the RNA having a nucleoside compound introduced at a site selected from among the 5′ cap structure and 10 bases from a 5′ end of the RNA, wherein the nucleoside compound is such that a group is attached to (i) a carbon atom at position 8 of a purine nucleus or (ii) a carbon atom at position 5 or 6 of a pyrimidine nucleus, the group being represented by formula (I): [in-line-formulae]A-X═X-#??(I)[/in-line-formulae] where A represents an aryl group or a heteroaryl group, # represents a site where the group represented by the formula (I) is attached to the carbon atom at the position 8 of the purine nucleus or the carbon atom at the position 5 or 6 of the pyrimidine nucleus, and two Xs, which are identical to or different from each other, each represents a nitrogen atom or CH whose H may be substituted by alkyl.
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(2013/03/26)
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- 2-Methylwyosine, a nucleoside with restricted anti conformation in the East region enforced by nucleobase moiety modification: Synthesis and conformational analysis by NMR and molecular dynamics
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We synthesized a new 2-methyl derivative of wyosine using a multistep procedure starting from guanosine. We examined different synthetic paths and optimized the conditions for each step. Based on MD calculations and analysis of the 3 J HH and J C1′H1′ of the ribose moiety, we discovered that the sugar part adopted conformation specific for the East region rarely occurring in solution. This unusual conformational preference is probably due to steric repulsions between the methyl group at position 2 and the 5′-CH2OH group. We observed that N-glycosidic bond stability weakened 14-fold upon the introduction of the methyl group in position 2 compared with wyosine.
- Baranowski, Daniel,Golankiewicz, Bozenna,Folkman, Wojciech,Popenda, Mariusz
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p. 707 - 719
(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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- Oxidation of 9-β-d-ribofuranosyl uric acid by one-electron oxidants versus singlet oxygen and its implications for the oxidation of 8-oxo-7,8-dihydroguanosine
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Uric acid, a cellular antioxidant, undergoes oxidation in the presence of one-electron oxidants as well as singlet oxygen. In the present work, the oxidation pathways and products formed from oxidation of the uric acid nucleoside are compared to the more commonly studied uric acid free base. A wider distribution of products, including allantoin, urea, caffolide, and 5-carboxamido-5-hydroxyhydantoin nucleosides, are formed when the N9 position of uric acid is glycosylated. The oxidation pathways share some features in common with the oxidation of 8-oxo-7,8-dihydroguanosine, but the additional spectrum of products implies that the combination of oxidative and deaminative damage to guanosine may lead to a more complex set of DNA lesions than originally described.
- Nguyen, Khiem V.,Muller, James G.,Burrows, Cynthia J.
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supporting information; scheme or table
p. 2176 - 2180
(2011/05/05)
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- Simple method for fast deprotection of nucleosides by triethylamine- catalyzed methanolysis of acetates in aqueous medium
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A straightforward methodology for deacetylation of protected ribonucleosides was developed based on triethylamine-catalyzed solvolysis in aqueous methanol. Reactions are completed in a few minutes under microwave irradiation and the free nucleosides are obtained in high yield after simple evaporation of volatiles. Other important features include the involvement of readily available reagents and the compatibility with diverse functional groups, which make this process very attractive for broad application.
- Meier, Lidiane,Monteiro, Gustavo C.,Baldissera, Rodrigo A.M.,Sa?, Marcus Mandolesi
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experimental part
p. 859 - 866
(2010/09/11)
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- X-ray crystal structures of halogen containing nucleobase derivatives in unsolvated and DMSO solvated forms
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A series of halogenated nucleobase derivatives 1-4 is reported to yield solvent-free (2) and DMSO solvated crystals (1, 3, 4) on the crystallization from DMSO with one of them (4) containing an additional molecule of water. The molecular and crystal structures are described and comparatively discussed with reference to previous results on related compounds. The molecule of 1 is planar, molecules of 2 and 3 show syn alignment with reference to the heterocyclic ring and common C2′-endo conformation of the ribose residue, while 4 is also syn aligned but C4′-exo in the sugar conformation. The packing structures reveal typical aggregations created via networks of hydrogen bonds. These involve conventional N-H···N, N-H···O and O-H···O interactions between nucleobase and ribose units as well as solvent molecules, additionally supported by weak C-H···O contacts but excluding the participation of halogen···halogen interactions as well as halogen···heteroatom contacts in the supramolecular structure formation. Springer Science+Business Media, LLC 2009.
- Eissmann, Frank,Schindler, Diana,Weber, Edwin
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experimental part
p. 245 - 254
(2011/01/03)
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- Bicyclic Compounds and Their Use
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The present invention provides fluorescent bicyclic compounds of the formula (I); wherein ring A, the broken lines -----, C1----C2, R4 and R1 are as defined herein. The invention also relates to nucleoside and nucleotide analogues of said compounds, and their use as biological markers.
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Page/Page column 20
(2009/12/23)
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- A fast synthetic route to GDP-sugars modified at the nucleobase
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The direct structural modification of GDP-mannose via the bromination and Suzuki-Miyaura cross-coupling of the unprotected sugar-nucleotide, to produce 8-substituted fluorescent analogues of GDP-mannose. The Royal Society of Chemistry.
- Collier, Alice,Wagner, Gerd K.
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p. 178 - 180
(2008/03/12)
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- Anti-HCV nucleoside derivatives
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The present invention comprises novel and known purine and pyrimidine nucleoside derivatives which have been discovered to be active against hepatitis C virus (HCV). The use of these derivatives for the treatment of HCV infection is claimed as are the novel nucleoside derivatives disclosed herein.
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- Synthesis of some modified guanosine derivatives
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Synthesis of some modified guanosine derivatives having substitution at 8-position by some amino compounds such as diphenylamine, ethylhydrazinoformate, serine, proline and glycine have been described. Furthermore, 2,3-O-isopropylidene-8-bromoguanosine reacts with dimethylamine to give 2,3-O-isopropylidene-8-(N, N-dimethyl)aminoguanosine. The later compound is used for the synthesis of 2,5-anhydronucleoside. The cyclonucleoside is treated with H2S in dry pyridine to give 5-thioguanosine derivative 11. The biological activity of the synthesized compounds have also been measured.
- Amer,Amer,Ahmed, A. F. Sayed,Farouk
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p. 379 - 383
(2007/10/03)
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- Nucleoside derivatives as inhibitors of RNA-dependent RNA viral polymerase
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The present invention provides nucleoside compounds and certain derivatives thereof which are inhibitors of RNA-dependent RNA viral polymerase. These compounds are inhibitors of RNA-dependent RNA viral replication and are useful for the treatment of RNA-dependent RNA viral infection. They are particularly useful as inhibitors of hepatitis C virus (HCV) NS5B polymerase, as inhibitors of HCV replication, and/or for the treatment of hepatitis C infection. The invention also describes pharmaceutical compositions containing such nucleoside compounds alone or in combination with other agents active against RNA-dependent RNA viral infection, in particular HCV infection. Also disclosed are methods of inhibiting RNA-dependent RNA polymerase, inhibiting RNA-dependent RNA viral replication, and/or treating RNA-dependent RNA viral infection with the nucleoside compounds of the present invention.
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- Synthesis of some modified guanosine derivatives
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Synthesis of some modified guanosine derivatives having substitution at 8-position by some amino compounds such as diphenylamine, ethyl hydrazinoformate, serine, proline and glycine have been described. Furthermore, 2′,3′-O-isopopylidene-8-bromoguanosine reacts with dimethylamine to give 2′,3′-O-isopopylidene-8-(N,N-dimethyl)aminoguanosine. The later compound is used for the synthesis of 2,5′-anhydronucleoside. The cyclonucleoside is treated with H2s in dry pyridine to give 5′-thioguanosine derivative 11. The biological activity of the synthesized compounds has also been measured.
- Amer,Amer,Sayed Ahmed,Farouk
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p. 382 - 385
(2007/10/03)
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- Reactivity toward singlet oxygen of a 7,8-dihydro-8-oxoguanosine ('8-hydroxyguanosine') formed by photooxidation of a guanosine derivative
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Total quenching (k(r) ± k(q)) and chemical reaction rates (k(r)) for the removal of singlet oxygen by 2',3',5'-tris((tert-butyldimethylsilyl)oxy)guanosine (1) and its oxidation product, 2',3',5'-tris((tert-butyldimethylsilyl)oxy)-7,8-dihydro-8-oxoguanosine (2), were determined by the time-resolved infrared luminescence technique and competition experiments, respectively. Compound 2 is two orders of magnitude more reactive with singlet oxygen than 1. A mechanism for the formation of 2 from 1 with singlet oxygen is proposed.
- Sheu,Foote
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p. 6439 - 6442
(2007/10/02)
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