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1.
Abstract The structure of 2′,3′-didehydro-2′,3′-dideoxyguanosine was determined by X-ray crystallographic analysis of the complex with pyridine. The two independent nucleoside molecules have similar, commonly observed glycosyl link (x = -102.3° and -94.2°) and 5′-hydroxyl (y = 54.0° and 47.6°) conformations. The five-membered rings are very planar with r.m.s. deviations from planarity of less than 0.015 A. 2′,3′-Didehydro-2′,3′-dideoxyadenosine has a similar glycosyl link conformation but a different 5′-hydroxyl group orientation and a slightly less planar 5-membered ring. 相似文献
2.
Allan L. Stuart Sashi V.P. Kumar Sagar V. Gupta Wajdi M. Zoghaib Scott Napper Keith C. Brown 《Nucleosides, nucleotides & nucleic acids》2013,32(12):2219-2231
Abstract 5-Ethyl-2′-deoxyuridine(EtdUrd), though a potent inhibitor of herpes simplex virus (HSV) replication, is rapidly catabolized to produce an inactive pyrimidine base by thymidine and/or uridine phosphorylases. 5-Ethyl-2′-deoxycytidine (EtdCyd) was synthesized to confer metabolic stability and thus improve efficacy against systemic HSV infections. EtdCyd was inactive against HSV in the presence or absence of deaminase inhibitors in VERO cells up to 2 mM. The relationship between molecular conformation and antiherpes activity for EtdUrd and EtdCyd is discussed. 相似文献
3.
4.
Two uridine 2′,3′-cyclic monophosphate (cUMP) derivatives, 5′-deoxy (DcUMP) and 5′-O-methyl (McUMP), were studied by means
of quantum chemical methods. Aqueous solvent effects were estimated based on the isodensity-surface polarized-continuum model
(IPCM). Gas phase calculations revealed only slight energy differences between the syn- and anti-conformers of both compounds: the relative energies of the syn-structure are −0.9 and 0.2 kcal mol-1 for DcUMP and McUMP, respectively. According to the results from the IPCM calculations, however, both syn-conformers become about 14 kcal mol-1 more stable in aqueous solution than their corresponding anti-structures. Additionally, the effects of a countercation and protonation on DcUMP were studied, revealing that the syn-structure is also favored over the anti-one for these systems. 相似文献
5.
The binding of acridine orange to single-stranded polyribonucleic acid at low polymer to dye ratios exhibits cooperative behavior of the kind observed with other simple polyanions. It is thus attributed to electrostatic interaction between polymer and stacked dye molecules. At higher polymer to dye ratios, however, distinct deviations from the predictions of the basic theory occur. These are interpreted by additional non-cooperative binding of acridine orange to the bases of the polymer subunits owing to dye-base stacking. This effect is studied also with 5-AMP monomers where it likewise leads to complex formation. Both systems are investigated experimentally by means of the changes produced in the dye spectrum. Based on quantitative analyses the equilibrium constants of both systems are evaluated and discussed. They indicate a sandwich-type of intercalation of dye between two bases of the single-stranded polymer. 相似文献
6.
P. P. Torrence D. Alster S. Huss G. Gosaelin J.-L. Imbach 《Nucleosides, nucleotides & nucleic acids》2013,32(1-2):521-522
Abstract Sequential substitution of xyloadenosine into the trimeric and tetrameric 2–5A cores1 allows evaluation of the importance of the 3′ hydroxyl groups to 2′5′-phosphodiesterase (PDE) activity. 相似文献
7.
Shouquan Wu Yu Wang Guo Chen Miaomiao Zhang Minggui Wang Jian-Qing He 《BMC pulmonary medicine》2018,18(1):180
Background
2′-5′-Oligoadenylate synthetase 1 (OAS1) plays an important role in inflammatory immune reactions. OAS1 polymorphisms have been associated with increased susceptibility to various diseases. We investigated the association of polymorphisms in OAS1 with tuberculosis (TB).Methods
A total of 1215?TB cases and 1114 healthy controls were enrolled from two independent studies. Genotyping was conducted using the improved multiplex ligase detection reaction (iMLDR) method. Associations between OAS1 polymorphisms (rs2240190, rs1131454, 10,774,671 and 11,066,453) and TB risk were established based on distributions of allelic frequencies using different genetic models.Results
Significant association was observed between rs10774671, rs1131454 and TB. In the initial study, the G allele of rs10774671 was a significantly protective factor against TB (P?=?0.006) and the genotype of GG differed significantly between TB patients and controls under the codominant model (P?=?0.008) after Bonferroni correction. In the validation study, we also observed that the rs10774671 G allele (P?=?0.001) and GG genotype (P?=?0.001) were associated with TB. In addition, we found that the rs1131454 G allele (P?=?0.004) and GG genotype (P?=?0.001) were protective against TB in the Chinese Han population.Conclusions
We report novel associations of polymorphisms in OAS1 with TB in the Chinese Tibetan and Han populations. Similar studies in different populations and functional studies are warranted to confirm our results.8.
9.
Yann Thillier Sarah K. Stevens Christabel Moy Joshua Taylor Jean-Jacques Vasseur Leonid Beigelman Françoise Debart 《Bioorganic & medicinal chemistry》2013,21(17):5461-5469
5′-Triphosphate 2′-5′-oligoadenylate (2–5A) is the central player in the 2–5A system that is an innate immunity pathway in response to the presence of infectious agents. Intracellular endoribonuclease RNase L activated by 2–5A cleaves viral and cellular RNA resulting in apoptosis. The major limitations of 2–5A for therapeutic applications is the short biological half-life and poor cellular uptake. Modification of 2–5A with biolabile and lipophilic groups that facilitate its uptake, increase its in vivo stability and release the parent 2–5A drug in an intact form offer an alternative approach to therapeutic use of 2–5A. Here we have synthesized the trimeric and tetrameric 2–5A species bearing hydrophobic and enzymolabile pivaloyloxymethyl groups at 3′-positions and a triphosphate at the 5′-end. Both analogs were able to activate RNase L and the production of the trimer 2–5A (the most active) was scaled up to the milligram scale for antiviral evaluation in cells infected by influenza virus or respiratory syncytial virus. The trimer analog demonstrated some significant antiviral activity. 相似文献
10.
M. Berger A. Shaw J. Cadet J. R. Jones 《Nucleosides, nucleotides & nucleic acids》2013,32(1-2):395-396
Abstract The deuterations of 2′-deoxyguanosine in the 4′ and 5′ positions have been described elsewhere (1). The starting material is the 5′-aldehyde formed by mild oxidation with N,N-dicyclohexyl carbodiimide in dimethyl sulphoxide of the fully protected nucleoside with free 5′-alcoholic function. The 5′4euteration was achieved by reduction with deuterated sodium borohydride. Incorporation of deuterium in the 4′-position was achieved v i a an enhanced keto-enol tautomerim by heating the aldehyde in 50/50 D20/pyridine, with subsequent reduction of the aldehyde with NaBH4. The 6-furanoid form was isolated from the I-lyxo by-product by reverse phase HPLC. Applied to pyrimidine 2′-deoxyribonucleosides, this method was shown to give deuterated 2′-deoxycytidine and thymidine in good yield. 相似文献
11.
Jasenka Matulic-Adamic Peter Haeberli Anthony B. DiRenzo Victor R. Mokler Lara Maloney Leonid Beigelman 《Nucleosides, nucleotides & nucleic acids》2013,32(10-11):1933-1950
Abstract Novel 5′-amino-5′-deoxy-2′-O-methyl uridine, guanosine and adenosine 3′-O-phosphoramidites 5, 11, and 20, as well as protected 5′-mercapto-5′-deoxy-2′-O-methyl uridine 3′-O-phosphoramidite 23 were synthesized from 2′-O-methyl nucleosides. These analogs were incorporated at the 5′-ends of hammerhead ribozymes to evaluate achiral bridging 5′-N- phosphoramidates and 5′-S-phosphorothioates as alternatives for non- bridging phosphorothioates commonly used for end stabilization against nucleases. Oligonucleotide synthesis and deprotection conditions were optimized for better yields of these modified ribozymes. 相似文献
12.
Robert Van Ostrand Casey Jacobsen Alicia Delahunty Carley Stringer Ryan Noorbehesht Haidi Ahmed 《Nucleosides, nucleotides & nucleic acids》2017,36(3):181-197
Reported is an efficient synthesis of adenyl and uridyl 5′-tetrachlorophthalimido-5′-deoxyribonucleosides, and guanylyl 5′-azido-5′-deoxyribonucleosides, which are useful in solid-phase synthesis of phosphoramidate and ribonucleic guanidine oligonucleotides. Replacement of 5′-hydroxyl with tetrachlorophthalimido group was performed via Mitsunobu reaction for adenosine and uridine. An alternative method was applied for guanosine which replaced the 5′-hydroxyl with an azido group. The resulting compounds were converted to 5′-amino-5′-deoxyribonucleosides for oligonucleotide synthesis. Synthetic intermediates were tested as antimicrobials against six bacterial strains. All analogs containing the 2′,3′-O-isopropylidine protecting group demonstrated antibacterial activity against Neisseria meningitidis, and among those analogs with 5′-tetrachlorophthalimido and 5′-azido demonstrated increased antibacterial effect. 相似文献
13.
Guy Tourigny Allan L. Stuart Irena Ekiel Philip J. Aduma Sagar V. Gupta 《Nucleosides, nucleotides & nucleic acids》2013,32(7):1189-1200
Abstract The molecular conformations of 3′- and 5′-azido and amino derivatives of 5-methoxymethyl-2′-deoxyuridine, 1, were investigated by nmr. The glycosidic conformation of 5-methoxymethyl-5′-amino-2′,5′-dideoxy-uridine, 5 had a considerable population of the syn form. The 5′-derivatives show a preference for the S conformation of the furanose ring as in 1. In contrast, the 3′-derivatives show preference for the N conformation. For 5-methoxymethyl-3′-amino-2′,3′-dideoxyuridine, 3, the shift towards the N state is pH dependent. The preferred conformation for the exocyclic (C4′,C5′) side chain is g+ for all compounds except 5 which has a strong preference for the t rotamer (79%). Compounds 1, 3 and 5 inhibited growth of HSV-1 by 50% at 2, 18 and 70 μg/ml respectively, whereas 2 and 4 were not active up to 256 μg/ml (highest concentration tested). The compounds were not cytotoxic up to 3,000 μM. 相似文献
14.
Dna2 is a nuclease/helicase with proposed roles in DNA replication, double-strand break repair and telomere maintenance. For each role Dna2 is proposed to process DNA substrates with a 5′-flap. To date, however, Dna2 has not revealed a preference for binding or cleavage of flaps over single-stranded DNA. Using DNA binding competition assays we found that Dna2 has substrate structure specificity. The nuclease displayed a strong preference for binding substrates with a 5′-flap or some variations of flap structure. Further analysis revealed that Dna2 recognized and bound both the single-stranded flap and portions of the duplex region immediately downstream of the flap. A model is proposed in which Dna2 first binds to a flap base, and then the flap threads through the protein with periodic cleavage, to a terminal flap length of ∼5 nt. This resembles the mechanism of flap endonuclease 1, consistent with cooperation of these two proteins in flap processing. 相似文献
15.
Masako Muraoka Akiko Iida Seizo Takahashi Tomohiko Ebata Seiichi Uesugi 《Nucleosides, nucleotides & nucleic acids》2013,32(6):1317-1332
Abstract Self complementary diribonucleoside monophosphates containing 2-aminoadenosine (n2A) and uridine (U) residues, (2′-5′) n2ApU (1), (3′-5′) n2ApU (2), (2′-5′) Upn2A (3) and (3′-5′) Upn2A (4), were synthesized by condensation of suitably protected nucleoside and nucleotide units using dicyclohexylcarbodiimide (DCC). The dimers, (3) and (41, were also obtained from uridine 2′,3′-cyclic phosphate and unprotected 2-aminoadenosine using 2,4,6-triisopropylbenzenesulfonyl chloride (TPS-Cl) as the condensing agent. The conformational properties of these dimers were examined by UV, CD and NMR spectroscopy. The results reveal that the 2′-5′ isomers take a stacked conformation, which contains a larger base-base overlap and is more stable against thermal perturbation with respect to the 3′-5′ isomers. The n2ApU isomers have more stacked structure than the Upn2A isomers. 相似文献
16.
Moheshwar Sharma Yi X. Li Miroslav Ledvina Miroslav Bobek 《Nucleosides, nucleotides & nucleic acids》2013,32(9-10):1831-1852
Abstract A series of 5′-substituted analogs of toyocamycin were prepared by condensation of silylated 4-amino-6-bromo-5-cyanopyrrolo[2,3-d]pyrimidine with protected 5-azido-5-deoxy- or 5-fluoro-5-deoxyribofuranose followed by debromination and deblocking. Alternatively, 5′-azido-5′-deoxytoyocamycin was prepared by azidation of toyocamycin. Conversion of the 5-nitrile function of the toyocamycin derivatives into a carboxamide or a thiocarboxamide gave the corresponding analogs of sangivamycin or thiosangivamycin while reduction of the 5′-azido-5′-deoxy nucleosides provided 5′-amino-5′-deoxy derivatives. 相似文献
17.
《Nucleosides, nucleotides & nucleic acids》2013,32(5-8):1657-1659
Abstract 2′-2H- and 3′-2H-CDP were synthesized from 5′-MMT-3′-O-TBDMS and 2′,5′- O-diTBDMS cytidine derivatives, respectively, by oxidation followed by acidic removal of 5′-protection, reduction with [NaBD(OAc)3] and finally displacement of a tosyl group by pyrophosphate. 相似文献
18.
Ahmed A. El-Barbary Ahmed I. Khodair Erik B. Pedersen Claus Nielsen 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):707-717
Abstract 3′-Amino and 5′-amino derivatives of hydantoin 2′-deoxynucleosides have been prepared from the corresponding 3′-phthalimido and 5′-azido nucleosides, respectively, which in turn were prepared by condensation of appropriate sugars with 5-benzylidenehydantoin. The amino nucleosides were tested for their potential activity against HIV and HSV. 相似文献
19.
Abstract The advantages of different methods for obtaining a reliable assignment of the vibrational spectra of the antitumoral and antiviral nucleoside analogue, 5-fluoro-2′-deoxyuridine. FdU, are evaluated as a basis for the study of FdU-containing polymers and drug-target interactions. The experimental FT-IR and FT-Raman spectra, are compared with theoretical frequencies obtained by a classical mechanics method and a semiempirical molecular orbital (MO) method, PM3. 相似文献
20.
Interaction of (2′ -5′) and (3′ -5′) Linked 2-Aminoadenylyl-3-aminoadenosines with Polyuridylic Acid
Masako Muraoka Seizo Takahashi Seiichi Uesugi 《Nucleosides, nucleotides & nucleic acids》2013,32(7):1503-1518
Abstract 2′-5′ and 3′-5′ linked 2-aminoadenylyl-2-aminoadenosines [(2′-5′)n2Apn2A (1) and (3′-5′)n2Apn2A (2)] were synthesized by condensation of 5′-O-monomethoxytrityl-N 2 N 6-dibenzoyl-2-aminoadenosine and N 2,N 6,2′,3′-O-tetrabenzoyl-2-aminoadenosine 5′-phosphate using dicyclohexylcarbodiimide (DCC). The conformational properties of these dimers 1 and 2 were examined by UV, NMR and CD spectroscopy. The results reveal that the 2′-5′-isomer 1 takes a stacked conformation, which contains a larger base-base overlap and is more stable against thermal perturbation with respect to the 3′-5′-isomer 2. Interactions of 1 and 2 with polyuridylic acid (Poly (U)) were also examined by Tm, mixing curves, UV and CD spectra. Both the dinucleoside isomers 1 and 2 formed a complex of 1 : 2 stoichiometry with poly(U), which was much more stable than that of the corresponding ApA isomer 相似文献