TY - JOUR. T1 - Sieve-based device for MALDI sample preparation. I. Influence of sample deposition conditions in oligonucleotide analysis to achieve significant increases in both sensitivity and resolution. AU - Molin, Laura. AU - Cristoni, Simone. AU - Crotti, Sara. AU - Bernardi, Luigi Rossi. AU - Seraglia, Roberta. AU - Traldi, Pietro. PY - 2008/11. Y1 - 2008/11. N2 - Spraying of oligonucleotide-matrix solutions through a stainless steel (ss) sieve (38 μm, 450 mesh) leads to the formation, on the matrix-assisted laser desorption/ionization (MALDI) sample holder, of uniformly distributed microcrystals, well separated from each other. When the resulting sample holder surface is irradiated by laser, abundant molecular species form, with a clear increase in both intensity and resolution with respect to values obtained by Dried Droplet, Double Layer, and Sandwich deposition methods. In addition, unlike the usual situation, the sample is perfectly homogeneous, and identical spectra are ...
The present invention provides methods for synthesis and therapeutic use of DNA and RNA oligonucleotides and analogs. RNA oligonucleotides are synthesized using a small, circular DNA template which lacks an RNA polymerase promoter sequence. The RNA synthesis is performed by combining a circular single-stranded oligonucleotide template with an effective RNA polymerase and at least two types of ribonucleotide triphosphate to form an RNA oligonucleotide multimer comprising multiple copies of the desired RNA oligonucleotide sequence. Preferably, the RNA oligonucleotide multimer is cleaved to produce RNA oligonucleotides having well-defined ends. Preferred RNA oligonucleotide multimers contain ribozymes capable of both cis (autolytic) and trans cleavage.
Obtain superior separations and LC/MS characterization data for synthetic oligonucleotides, from routine mass and sequence confirmation to a more detailed impurity profile analysis.
Obtain superior separations and LC/MS characterization data for synthetic oligonucleotides, from routine mass and sequence confirmation to a more detailed impurity profile analysis.
These locked nucleic acid (LNA) DNA and RNA oligonucleotides have increased Tm that can be modulated to provide greater sensitivity, SNP detection, and mismatch discrimination.
Oligonucleotides can be synthesized by condensing a protected nucleoside H‐phosphonate monoester with a second nucleoside in the presence of a coupling agent to produce a dinucleoside H‐phosphonate diester
F. Li, P. Pallan, M. Maier, K. Rajeev, S. Mathieu, C. Kreutz, Y. Fan, J. Sanghvi, R. Micura, E. Rozners, M. Manoharan, M. Egli*; Crystal structure, stability and in vitro RNAi activity of oligoribonucleotides containing the ribo-difluorotoluyl nucleotide: insights into substrate requirements by the human RISC Ago2 enzyme; Nucl. Acids Res. 2007, 35, 6424-6438. ...
Tytu : Synthesis, physico-chemical and biological properties of DNA and RNA oligonucleotides containing short alkylamino internucleotide bond. ...
Quantified miR-608-target interactions. (A) Target and miRNA RNA oligonucleotides sequences. Seed regions are colored. (B) Predicted structures and binding en
All Ive done is take the formula for dAGCT (DNA oligonucleotide) and found the letters corresponding to the quotients (the little numbers) in ascending order. I then translated them. The result said to try the RNA oligonucleotide which is AGCU and add "C of" to it. So I did. The translation that came back with the "C of" added to it is scientifically unexplainable. How could the author have known about DNA and RNA, let alone know how we describe it? He couldnt. So just what is the explanation? Surely it cant be divine intervention again ...
BioAssay record AID 197831 submitted by ChEMBL: Perfect off-state by site-specific incorporation of o-nitrobenzyl (o-NB) unit into RNase S was determined before photolysis at 10 x E5 M/min.
Bio-Synthesiss BNA gapmers chimeric antisense RNA oligonucleotide give you the highest knock-down, lowest off-target effect for an efficient inhibition of coding and non coding long RNA (lncRNA) function.
Regulatory and validation aspects of oligonucleotide analysis Ipsita Roymoulik, Ph.D.(Avecia Biotechnology), will describe methodology for robust method transfer into manufacturing. Yansheng Wu, Ph.D. (Archemix), will discuss analysis of oligonucleotide aptamers and PEGylated oligos, both with novel applications compared with RNAi. Martin Gilar, Ph.D. (Waters), will present methods for analyzing single- and double-stranded RNAi therapeutics. A live Q&A session will follow the presentations, offering you a chance to pose questions to our expert panelists.. Register today at www.genengnews.com/oligos. ...
Protein asunder homolog (Asun) also known as cell cycle regulator Mat89Bb homolog (Mat89Bb) is a protein that in humans is encoded by the Asun gene. GRCh38: Ensembl release 89: ENSG00000064102 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000040250 - Ensembl, May 2017 "Human PubMed Reference:". "Mouse PubMed Reference:". Bourdon V, Naef F, Rao PH, Reuter V, Mok SC, Bosl GJ, Koul S, Murty VV, Kucherlapati RS, Chaganti RS (Nov 2002). "Genomic and expression analysis of the 12p11-p12 amplicon using EST arrays identifies two novel amplified and overexpressed genes". Cancer Res. 62 (21): 6218-23. PMID 12414650. "Entrez Gene: C12orf11 chromosome 12 open reading frame 11". Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1-2): 171-4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298. Bonaldo MF, Lennon G, Soares MB (1997). "Normalization and subtraction: two approaches to facilitate gene ...
The miRIDIAN microRNA Hairpin Inhibitors are single-stranded chemically-modified RNA oligonucleotides designed to inhibit the function of endogenous miRNA. miRIDIAN microRNA Hairpin Inhibitors specifically target each mature microRNA as derived from a unique precursor and exhibit greater potency and longevity than 2 -O- methyl RNA oligos that are antisense to the mature microRNA. For additional information please read the miRIDIAN brochure and flier ...
Specifically hydrolyzes Lys-29-linked and Lys-33-linked diubiquitin. Also cleaves Lys-63-linked chains, but with 40-fold less efficiency compared to Lys-29-linked ones. Positive regulator of the Wnt signaling pathway that deubiquitinates APC protein, a negative regulator of Wnt-mediated transcription. Plays a role in the regulation of cell morphology and cytoskeletal organization. Required in the stress fiber dynamics and cell migration. May also modulate TNF-alpha signaling ...
Our unpurified product contains various organic salts, including benzamide, isobutyramide, and ammonium acetate which are utilized during synthesis to protect both the backbone and the bases. The following procedure utilizes a disposable reverse-phase cartridge to remove these salts.. ULTRAMILD OLIGOS: Before desalting UltraMild oligos that have been cleaved and deprotected using potassium carbonate in MeOH, the MeOH content must be reduced to , 5% through speed-vacing or dilution with "A" Buffer. An organic content , 5% will prevent DNA from binding to the Sep-Pak resin! Adding TE to UltraMild oligos is not required.. The DNA Glen-Pak cartridges can be used for desalting DNA or RNA oligonucleotides directly after deprotection or post purification by HPLC and Polyacrylamide Gel Electrophoresis (PAGE). The cartridges are designed specifically for DMT-ON purification where failure sequences not containing a 5 DMT are eluted with salt washes, but when an oligo is loaded in 0.1M TEAA instead of ...
Analusis, a European journal on Analytical Chemistry, is published under the auspices of the Société Française de Chimie, the Société de Chimie Industrielle and the Gesellschaft Deutscher Chemiker
RNase L and Ire1p are members of a superfamily of regulated endoribonucleases that play essential roles in mediating diverse types of cellular stress responses. 2′-5′ oligoadenylates, produced in response to interferon treatment and viral double-stranded RNA, are necessary to activate RNase L. In contrast, unfolded proteins in the endoplasmic reticulum activate Ire1p, a transmembrane serine/threonine kinase and endoribonuclease. To probe their similarities and differences, molecular properties of wild-type and mutant forms of human RNase L and yeast Ire1p were compared. Surprisingly, RNase L and Ire1p showed mutually exclusive RNA substrate specificity and partially overlapping but not identical requirements for phylogenetically conserved amino acid residues in their nuclease domains. A functional model for RNase L was generated based on the comparative analysis with Ire1p that assigns novel roles for ankyrin repeats and kinase-like domains.. ...
Provide the most valuable information resources about Uridine,5-methyl-2-O-methyl-,CAS 55486-09-4,Molecular Formula C11H16N2O6,structure,manufactures etc. ★Find quality Uridine,5-methyl-2-O-methyl- CAS:55486-09-4 manufacturers, suppliers, exporters, importers, buyers, wholesalers,producers start here!
If you ever need to put a backslash (") or a single quote ("") amongst those values, backslashes it (for example \\xyz or a\b ...
If you ever need to put a backslash (") or a single quote ("") amongst those values, backslashes it (for example \\xyz or a\b ...
Abstract A series of 16 yellow fever (YF) viruses isolated from mosquitoes, monkeys and humans in different epidemiological contexts in Senegal and The Gambia between 1976 and 1983, was analyzed by T1 RNase oligonucleotide fingerprints of the genomic 32P-labeled RNA, by SDS-polyacrylamide gel electrophoresis of the intracellular virus-specified polypeptides, by peptide mapping of the envelope E glycoprotein and by immunological reactivities with monoclonal antibody fluids (MAF's) against the E glycoprotein. These strains had not been passed in suckling mice and were isolated in Aedes pseudoscutellaris Mos 61 cultured cells. These strains showed no virulence in three-week-old Swiss mice when injected intraperitoneally. Direct comparison of the large T1 RNase-resistant oligonucleotide maps indicated a relative genetic stability (92%-100%). A greater change was observed when these strains were compared with an epidemic YF strain isolated in 1965 with an oligonucleotide fingerprint map sharing 82%-88%
Antiviral immunity is triggered by immunorecognition of viral nucleic acids. The cytosolic helicase RIG-I is a key sensor of viral infections and is activated by RNA containing a triphosphate at the 5 end. The exact structure of RNA activating RIG-I remains controversial. Here, we established a chemical approach for 5 triphosphate oligoribonucleotide synthesis and found that synthetic single-stranded 5 triphosphate oligoribonucleotides were unable to bind and activate RIG-I. Conversely, the addition of the synthetic complementary strand resulted in optimal binding and activation of RIG-I. Short double-strand conformation with base pairing of the nucleoside carrying the 5 triphosphate was required. RIG-I activation was impaired by a 3 overhang at the 5 triphosphate end. These results define the structure of RNA for full RIG-I activation and explain how RIG-I detects negative-strand RNA viruses that lack long double-stranded RNA but do contain blunt short double-stranded 5 triphosphate RNA in the
We provided in vivo and in vitro data indicating that D5 is a DNA primase. First, a D5 ts mutant complementation assay (13) demonstrated the importance of conserved amino acids in the predicted primase active site for DNA replication. Furthermore, purified recombinant D5 exhibited primase activity that depended on conserved amino acids in the predicted active site.. Primases are DNA-dependent RNA polymerases that synthesize oligoribonucleotides 2-15 nt or longer, usually starting with ATP or GTP (18). Generally, any single-stranded DNA can serve as a template, although there may be preferential usage of some sequences. D5 primase activity was demonstrated by using single-stranded circular φX174 and M13 phage templates. A discrete RNase-sensitive band migrated near the 14-nt marker. We cannot be sure of the actual length of this oligoribonucleotide, because the markers were phosphorylated, and small oligonucleotides migrate anomalously in high percentage polyacrylamide gels (33). However, the ...
RNA and 2 -O-methyl RNA oligonucleotides RNA and 2 -O-methyl RNA oligonucleotide synthesis is performed at Gene Link using the b cyanoethyl chemistry and state of the art synthesizers. These involve proprietary software protocols with long coupling times and specialized cycles to obtain ultra clean oligos.. RNA oligos are susceptible to degradation to the same extent as native RNA extracted from various sources. An attractive alternate to prevent degradation from nucleases is the use of 2 -O- methyl RNA bases, when specific 2 OH is not required. The 2 -O- methyl oligonucleotides confer considerable nuclease resistance and are similar in hydrogen bonding properties to RNA/RNA than the lower RNA/DNA binding property. The coupling efficiency of 2 -O- methyl phosphoramidite is also higher than the RNA monomers resulting in higher yield of full length oligos.. Gene Link also offers custom synthesis of RNA and DNA chimeric oligos with investigator specified ribo or deoxy bases or 2 -O-methyl bases. ...
RNase H is a 18.9 kDa recombinant endoribonuclease purified from an Escherichia coli strain. The enzyme hydrolyses specifically the phosphodiester bonds of RNA hybridized to DNA and produces 5´ phosphate-terminated oligoribonucleotides and single-stranded DNA. The enzymes does not degrade single and double-stranded DNA or unhybridized RNA. It is a key enzyme in the removal of mRNA after first-strand cDNA synthesis. Treating cDNA with RNase H prior to PCR can improve sensitivity as RNA bonded to the cDNA template may prevent binding of the amplification primers in a PCR reaction. RNase treatment is often necessary when amplifying longer, full-length cDNA targets. In addition, this enzymes is useful for the removal of poly(A) tails on mRNAs after hybridization with oligo(dT) and also for the site-specific enzymatic cleavage of RNA. ...
Centers for Disease Control (CDC): "Visual OMP (version 4.2) software (DNA Software, Inc., Ann Arbor, MI) was used to design and simulate the performance of the O-group PCR primers and capture probes." - Fitzgerald,C., Collins,M., van Duyne,S., Mikoleit,M., Brown,T., Fields,P. (2007) "Multiplex, Bead-Based Suspension Array for Molecular Determination of Common Salmonella Serogroups", Journal of Clinical Microbiology, 45, 3323-3334.. U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) / Boston University: "The microarray DNA probe design from candidate sequences was carried out using the commercial software oligonucleotide modeling platform (OMP) (available at ), which implements a state-of-the-art hybridization model (SantaLucia and Hicks, 2004)." - Tembe, W., Zavaljevski, N., Bode, E., Chase, C., Geyer, J., Wasieloski, L., Benson, G., Reifman, J. (2007) "Oligonucleotide fingerprint identification for microarray-based pathogen diagnostic assays", Bioinformatics, 23, ...
Recent studies have demonstrated that TLR3 forms dimeric complexes with 45-bp segments of dsRNA, and that single TLR3 dimers formed with a 48-bp dsRNA ON are capable of activating transfected cells expressing high amounts of TLR3 (27). A goal of this study was to determine how TLR3/dsRNA complexes, formed with dsRNA ONs of varying lengths, function in primary cells, and to translate these findings into the development of well-defined, TLR3-dependent adjuvants. In this study, we examined the activation of DC by dsRNA ONs because this response is key for inducing acquired antiviral immunity. We have previously shown that the interaction of TLR3-ECD protein with dsRNA is highly dependent on dsRNA length and TLR3-ECD concentration (27), which implies that the ability of a specifically sized dsRNA ON to bind TLR3 and activate a cell is governed, in part, by the membrane density of TLR3 in the endosomes. Thus, the large differences in TLR3 expression levels that we observed between DC subsets are ...
Protocols for postsynthetic modification of 2‐amino‐containing oligoribonucleotides with either an alkyl‐phenyl disulfide or an alkyl thiol group are described
Adenosine, Adenine, Exhibits, Fluorescence, Oligoribonucleotides, PH, Purines, Rat, Research, Ribosomes, Ricin, Devices, Nanoribbon, Nanoribbons, Nanowire, Semiconductors
OAS1 Human Recombinant fused with 20 amino acid His tag at N-terminus produced in E.Coli is a single, non-glycosylated, polypeptide chain containing 384 amino acids (1-364 a.a.) and having a molecular mass of 43.9kDa. The OAS1 is purified by proprietary c
Ubiquitin-binding protein that specifically recognizes and binds Lys-63-linked ubiquitin. Does not bind Lys-48-linked ubiquitin. Positively regulates the internalization of ligand-activated EGFR by binding to the Ub moiety of ubiquitinated EGFR at the cell membrane ...
Powles, Nicholas and Mistry, Dharmit (2013) The Relative Hydrolytic Reactivities of Pyrophosphites and Pyrophosphates. Organic & Biomolecular Chemistry. ISSN 1477-0520 Powles, Nicholas, Atherton, John H. and Page, Michael I. (2012) Reactive intermediates in the H-phosphonate synthesis of oligonucleotides. Organic and Biomolecular Chemistry, 10 (30). pp. 5940-5947. ISSN 1477-0539 ...
A Serious Man ****A Serious Man is a tart, brilliantly acted fable of lifes little cosmic difficulties, a Coen brothers comedy with a darker philosophical outlook than No Country for Old Men
The latest issue of Analyst is now available for you to browse, and we head east for all three covers.. Theres nanoparticle-assisted laser desorption/ionisation MS from Japan, electrochemical biosensing from Korea, and microextraction from Taiwan.. On the front cover is work from Shu Taira of the School of Material Science at the Japan Advanced Institute of Science and Technology (JAIST), Ishikawa, Japan, and colleagues.. They analysed oligonucleotides by nanoparticle-assisted laser desorption/ionization (nano-PALDI) mass spectrometry, and demonstrated that iron-based nanoparticles may serve as the assisting material of ionization for genes and other biomolecules.. Communication: Oligonucleotide analysis by nanoparticle-assisted laser desorption/ionization mass spectrometry ...
Hydrolyzes RNA 2,3-cyclic phosphodiester to an RNA 2-phosphomonoester (PubMed:25239919). In vitro, can also ligate 5 and 3 half-tRNA molecules with 2,3-cyclic phosphate and 5-hydroxyl termini, respectively, to the product containing the 2-5 phosphodiester linkage. This reaction does not require ATP and is reversible (PubMed:6347395 and PubMed:8940112).
3.0.CO;2-X. PMID 10741407. Berditchevski F (2002). "Complexes of tetraspanins with integrins: more than meets the eye". J. Cell Sci. 114 (Pt 23): 4143-51. PMID 11739647. Ashman LK (2003). "CD151". J. Biol. Regul. Homeost. Agents. 16 (3): 223-6. PMID 12456024. Ashman LK, Aylett GW, Mehrabani PA, Bendall LJ, Niutta S, Cambareri AC, Cole SR, Berndt MC (1992). "The murine monoclonal antibody, 14A2.H1, identifies a novel platelet surface antigen". Br. J. Haematol. 79 (2): 263-70. doi:10.1111/j.1365-2141.1991.tb04531.x. PMID 1958484. Fitter S, Tetaz TJ, Berndt MC, Ashman LK (1995). "Molecular cloning of cDNA encoding a novel platelet-endothelial cell tetra-span antigen, PETA-3". Blood. 86 (4): 1348-55. PMID 7632941. Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1-2): 171-4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298. Hasegawa H, Utsunomiya Y, Kishimoto K, Yanagisawa K, Fujita S (1996). "SFA-1, a ...
Principal Investigator:SEKINE Mitsuo, Project Period (FY):1993 - 1994, Research Category:Grant-in-Aid for Developmental Scientific Research (B), Research Field:Molecular biology
2002 - Spanish sisterly trio Las Ketchup adds the U.K. to its list of European conquests as its novelty hit The Ketchup Song (Asereje) goes straight to No. 1 on the U.K. singles chart.
Sõna "geneetika" on ingliskeelse sõna genetics eestikeelne vaste. Ingliskeelse sõna võttis tarvitusele 1872. aastal inglise bioloog William Bateson päritolu seaduste tähenduses. Ta tuletas selle sõnast genetic (päritoluga seonduv) järelliitega -ics. Pärilikkust uuriva teadusharu tähenduses võeti see sõna kasutusele 1891.[1]. ...
An elaborate, goodie-filled breakdown of all the things you may have missed on first watch of Arrested Development S4s GOB Bluth-centric episode 11.
H-phosphonate chemistry is of value when the internucleotide linakge required is other than the standard phosphodiester linkage. The H-phosphonate monomers shown below are used instead of the phosphoramidite bases. Using this method, the monomer that is able to be activated is a 5-DMT-base-protected, nucleoside 3-hydrogen phosphonate. The presence of the H- phosphonate moiety on these monomers renders phosphate protection unnecessary. The same base protecting groups are used in phosphite triester chemistry. The H-phosphate synthesis cycle is very similar to that of the phosphoramidite method. Slight differences result from the properties of the monomers utilized. For instance, a different activating agent is used. In addition, the H-phosphonate diesteres generated by the coupling reactions are stable to the normal reaction conditions, so oxidation at every step is unnecessary. Instead, a single oxidation step can be performed at the end of the chain elongation. This single oxidation step makes ...
381160DNAArtificialSynthesized Oligonucleotide Sequence 1catccgtcac acctgctctg ctatcacatg cctgctgaag tggtgttggc tcccgtatca 60260DNAArtificialSynthesized Oligonucleotide Sequence 2catccgtcac acctgctctg atcagggaag acgccaacac tggtgttggc tcccgtatca 60362DNAArtificialSynthesized Oligonucleotide Sequence 3catccgtcac acctgctctg gggagggtgg cgcccgtctc ggtggtgttg gctcccgtat 60ca 62462DNAArtificialSynthesized Oligonucleotide Sequence 4catccgtcac acctgctctg ggatagggtc tcgtgctaga tgtggtgttg gctcccgtat 60ca 62562DNAArtificialSynthesized Oligonucleotide Sequence 5catccgtcac acctgctctg gaccggcgct tattcctgct tgtggtgttg gctcccgtat 60ca 62662DNAArtificialSynthesized Oligonucleotide Sequence 6catccgtcac acctgcyctg gagctgatat tggatggtcc ggtggtgttg gctcccgtat 60ca 62762DNAArtificialSynthesized Oligonucleotide Sequence 7catccgtcac acctgcycyg cccagagcag gtgtgacgga tgtggtgttg gctcccgtat 60ca 62862DNAArtificialSynthesized Oligonucleotide Sequence 8catccgtcac acctgcycyg ccggaccatc caatatcagc tgtggtgttg gctcccgtat 60ca ...
The ability to accurately repair DNA damaged by spontaneous errors, oxidation or mutagens is crucial to the survival of cells. This repair is normally accomplished by using an identical or homologous intact sequence of DNA, but scientists have now shown that RNA produced within cells of a common budding yeast can serve as a template for repairing the most devastating DNA damage - a break in both strands of a DNA helix.. Earlier research had shown that synthetic RNA oligonucleotides introduced into cells could help repair DNA breaks, but the new study is believed to be the first to show that a cells own RNA could be used for DNA recombination and repair. The finding provides a better understanding of how cells maintain genomic stability, and if the phenomenon extends to human cells, could potentially lead to new therapeutic or prevention strategies for genetic-based disease.. The research was supported by the National Science Foundation, the National Institutes of Health and the Georgia Research ...
Previous studies from our laboratory have shown that deletion of residues 321 to 344 of the 9-2 isozyme of 2-5-oligoadenylate (2-5(A)) synthetase causes a loss of its enzyme activity (Ghosh, S. K., Kusari, J., Bandyopadhyay, S. K., Samanta, H., Kumar, R., and Sen, G. C. (1991) J. Biol. Chem. 266, 15293-15299). Sequence comparison of this region among the different isozymes of 2-5(A) synthetases revealed that the residues at positions 330 to 333 are highly conserved. Alanine-scanning mutagenesis of these residues demonstrated that the residues present at 331, 332, and 333 are important for activity but the proline at position 330 was dispensable. The triple mutant containing Ala residues at 331, 332, and 333 was completely inactive. Different double mutants were slightly active, and the three single mutants were partially active. The triple mutant was further characterized for delineating the nature of its defect. The mutant protein was enzymatically inactive irrespective of whether it was synthesized
All of the custom DNA and RNA oligonucleotides that IDT offers are synthesized chemically, not enzymatically. As a result, there should not be DNase or RNase present in our samples. It is worth noting that there are abundant nucleases present in most environments, so good laboratory practice is very important to minimize potential exposure ...
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Synthesis of 5-phosphate 2-O-ribosylribonucleosides [Nr(p)] of four common ribonucleosides, and 3-phosphoramidites of 5-phosphate 2-O-ribosyladenosine and 2-O-ribosylguanosine using the H-phosphonate chemistry is described. An additional ring protected by benzoyl groups was incorporated into the main ribosyl ring in the reaction with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-d-ribofuranose in the presence of SnCl4. The obtained 2-O-ribosylribonucleosides (Nr) were applied in the subsequent transformations with selective deprotection. Ethanolamine was applied as a very convenient reagent for selective removal of benzoyl groups. Additionally, the tetraisopropyldisiloxane-1,3-diyl (TIPDSi) group was found to be stable under these deprotection conditions. Thus, the selectively deprotected 5-hydroxyl group of Nr was transformed into an H-phosphonate monoester which was found to be stable under the following conditions: the removal of the TIPDSi group with triethylammonium fluoride and the
We present here a set of 13C-direct detected NMR experiments to facilitate the resonance assignment of RNA oligonucleotides. Three experiments have been developed: (1) the (H)CC-TOCSY-experiment utilizing a virtual decoupling scheme to assign the intraresidual ribose 13C-spins, (2) the (H)CPC-experiment that correlates each phosphorus with the C40 nuclei of adjacent nucleotides via J(C,P) couplings and (3) the (H)CPC-CCH-TOCSY-experiment that correlates the phosphorus nuclei with the respective C10,H10 ribose signals. The experiments were applied to two RNA hairpin structures. The current set of 13C-direct detected experiments allows direct and unambiguous assignment of the majority of the hetero nuclei and the identification of the individual ribose moieties following their sequential assignment. Thus, 13C-direct detected NMR methods constitute useful complements to the conventional 1H-detected approach for the resonance assignment of oligonucleotides that is often hindered by the limited ...