Multifunctional dinucleotide analogs for the generation of complex RNA conjugates

Oligonucleotide conjugates are needed for in vitro selection schemes aiming at reactions between small, organic reactants. A general strategy is provided for the generation of the required RNA reactant conjugates based on multifunctional dinucleotide analogs. These modified dinucleotides allow for enzymatic ligation to native or enzymatically transcribed RNAs. They further contain a flexible polyethylene glycol spacer for correct spatial positioning and a photolabile cleavage site for selective release. The dinucleotides can be derivatized with the desired organic compounds by activated ester chemistry as was demonstrated by coupling to several nucleobases and nucleotides.