Of oligoribonucleotides

Such compounds have been used in the solid-phase synthesis of oligoribonucleotides. In the synthesis of (Up)8U, for example, the coupling reaction gave a yield of 96%.[105]... 

Oligoribonucleotides are more difficult to handle than oligodeoxyribonucleotides, mainly because of their sensitivity towards nucleases. For the synthesis of oligoribonucleotides on insoluble supports, protection of the 2 -hydroxyl group is required, which must be stable towards oxidation with iodine and the acidic conditions of DMT depro-... 

Bain, J. D., and Switzer, C. (1992). Regioselective ligation of oligoribonucleotides using DNA splints. Nucleic Acids Res. 20, 4372. 

Welz et al. developed a procedure for synthesis of oligoribonucleotides based on application of tetrazole for activation of RNA phosphoramidites in automated solid-phase synthesis <2000MB934>. Ar-Benzoyl tetrazole has been developed as a mild and selective reagent for monobenzoylation of the exocyclic amino group in nucleic acid bases <1997TL8811>. An improved procedure is described for the efficient and high yield (76-91%) synthesis of... 

Protection of primary alcohols. This trityl bromide in the presence of AgNO, m DMF reacts selectively with the primary hydroxyl group of carbohydrates and nucleosides. The CPTr ether group is stable to aqueous pyridine and 80% acetic acid, but is selectively cleaved by hydrazine in pyridine-acetic acid. This protecting group is useful in the synthesis of oligoribonucleotides. 

The reversed-phase analysis of oligoribonucleotides has be reported by McFarland and Borer (M6). Employing linear gradient elution techniques, they have separated many dinucleotide monophosphates, homooligonucleotide mixtures, and block co-polymers. Crowther and... 

Lagokvist and Berg (1962) also use the isobutyric acid 0.5 M ammonia (5 3, v/v) paper chromatography solvent. They describe a number of other solvents isopropanol water ammonia (85 15 1.3, v/v/v) isopropanol aceticacid water(6 3 l, v/v/v) and isopropanol n-butanol 12 N HCl water (114 56 49 39) which they used in purification of oligoribonucleotides. 

The chemical synthesis of oligoribonucleotides containing vicinal 2, 5 - and 3, 5 -phosphodiester links, which are found at the branching site of lariat mRNA during mRNA splicing, has been reviewed.267 The synthesis of a substantial number of triribonucleoside diphosphates (184) has been reported analogues of (184 ... 

Another modification in which form thin sheet electrophoresis is employed is known as ionophoresis. In this method, devised by Sanger and his co-workers, high voltage electrophoresis is carried out on ion-exchange paper. It is a rapid method of great resolution and sensitivity and is used in Biochemistry for the separation of constituents of a highly complex mixture e.g. a mixture of oligoribonucleotides produced by partial enzymic hydrolysis of RNA. For separation of the constituents of this hydrolysate mixture, a two-dimensional technique is used in which the mixture is subjected to electrophoresis on cellulose acetate and then the partially separated mixture is transferred to a DEAE-cellulose... 

Enzymic synthesis of oligoribonucleotides, simple large scale methods... 

The structural basis of phosphoramide mustard crosslinking to guanosines in an oligonucleotide has been studied both in vitro and by computer simulation. The effects of 5-fluorouridine and 5-fluoro-2 -deoxyuridine substitution into synthetic RNA and DNA have been studied. Destabilisation of duplex oligo-deoxynucleotides but stabilisation of oligoribonucleotides was found upon the analogue substitution for uridine in the parent duplexes. ... 

Currently, the 5 -DMT/2 -TBDMS combination constitutes the benchmark for the synthesis of oligoribonucleotides. Although many other methods for the synthesis of RNA have been developed, none have gained the popularity of the TBDMS chemistry. Advances in the use of this silyl chemistry in both synthesis [7,8] and deprotection [7,8,61] strategies have made it an even more viable approach to the production of oligoribonucleotides. 

Figure 8 Activators commonly used for the synthesis of oligoribonucleotides according to phosphoramidite chemistry.

This protocol describes automated chemical synthesis of oligoribonucleotides by the phosphoramidite method. The following procedure was developed for the ABI 394 DNA-RNA synthesizer at the 0.2-/Ltmol scale, although it can be modified to utilize any standard synthesizer. 

Deprotection of oligoribonucleotides according to the three protocols presented in Sections V.D.1-3 is quite straightforward. However, the one-pot... 

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