Synthesis of Geranyl-2-Thiouridine-Modified RNA.

This unit describes the chemical synthesis of the S-geranyl-2-thiouridine (ges2 U) phosphoramidite and its incorporation into RNA oligonucleotides through solid-phase synthesis. Starting from the 2-thiouracil nucleobase and the protected ribose, the 2-thiouridine is synthesized and the geranyl functionality is introduced into the 2-thio position by using geranyl bromide as the geranylating reagent before the conversion of this modified nucleoside into a phosphoramidite building block. The modified phosphoramidite is used to make the geranyl-RNA oligonucleotides with a solid-phase DNA synthesizer. These RNA strands are then purified by ion-exchange HPLC before further structural and functional studies, such as base pairing and enzyme recognition, can be done. © 2017 by John Wiley & Sons, Inc.