Ribooligonucleotides

The issue of silyl migration in ribooligonucleotide synthesis has been reviewed ... 

A polymeric version of this group has been developed for terminal phosphate protection in ribooligonucleotide synthesis. ... 

Ciesiolka, J.M.I.I.M., Nickles, T., Welch, M., Yarus, M., Zinnen, S. Affinity selection-amplification from randomized ribooligonucleotide pools. Meth. Enzymol. 267, 315-335 (1996). 

The issue of silyl migration in ribooligonucleotide synthesis has been reviewed in S. L. Beaucage and R. P. Iyer, Tetrahedron, 48, 2223 (1992). 

All ribooligonucleotides described in the following were chemically synthesized using the H phosphonate method [34, 35]. It was demonstrated that this method allows the preparation of the relatively large amounts (> 10 mg) of RNA being necessary for 2D NMR studies at reasonable costs and with the required purity. In addition, as compared to phosphora-midite chemistry, the H phosphonate chemistry offers the advantage of recovery and reusing of synthons. This is particularly important for expensive modified or isotopically labelled nucleotides. 

Two-dimensional NOESY allows detection of spatial proximity between protons that are separated by less than 4.5 A. By the correlated spectroscopy method (COSY) scalar couplings between protons, which are separated by at most three (in some exceptions four) chemical bonds, are used. In the case of ribooligonucleotides such couplings consequently can only be observed between the protons of the ribose rings and the C5 and C6 protons of the pyrimidine bases of a given nucleotide. The NOESY method, however, permits the detection of contacts between the protons of different nucleotides. 

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