2 -5’-Linked 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 ... 

The deprotection of crude oligoribonucleotides traditionally requires a basic treatment that concomitantly allows transamination of the exocyclic acyl protecting groups, /8-elimination of the 2-cyanoethyl phosphate protecting group, and cleavage of the succinic ester bond that links the oligoribonucleotide to the solid support. The base deprotection is by far the most rate-... 

Ohtsukaet al. (1972) have synthesized oligoribonucleotides on an insoluble 4 -aminophenoxymethylpolystyrene support. The first nucleotide, 5 -0MMTr-2 -0-acyI protected, was linked to the polymer via a 3 -phosphoramidate linkage. After deblocking at the 5 -0, it was coupled to the second nucleotide, a 5 -OMMTr-2 -0-acyl-protected 3 -phosphate, to form the dinucleotide. 

Figure 2. Photo-cross-linking reaction of psoralen-conjugated oligo(nucleoside phosphoro-thioate) (PS-P-As) with its complementary oligoribonucleotide (sense-RNA). [PS-P-As] = [sense-RNA] = 20pM. UVA-irradiation was carried out in phosphate buffered saline (0.135M NaCl, pH7.0) at 365nm with l.lmJ/cm sec.

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