Base-modified phosphoramidite analogs of pyrimidine ribonucleosides for RNA structure-activity studies.

摘要: Publisher Summary This chapter describes the design, synthesis, and utilization of base-modified analogs natural ribonucleosides originally developed for structure–activity studies hammerhead ribozyme. These compounds are also applied to study RNA–ligand interactions in hairpin ribozyme, group II intron, VP vaccinia virus, development a “subtraction mutagenesis” approach with basic modifications system. The most frequently used method incorporation modified nucleosides synthetic RNAs is via solid-phase oligonucleotide synthesis based on phosphoramidite chemistry. utilizes repetitive coupling appropriately protected monomeric nucleotides growing chain 3´ 5 direction. After assembly completed, removal phosphate, base, 2´-OH protecting results target RNA or without incorporated units. To incorporate specifically nucleotide at desired position, it necessary prepare building block groups that compatible general methodology regular unmodified monomers. Thus, monomer includes standard procedure introduction 5´-O-dimethoxytrityl group, 2´-O-tert-butyldimethylsilyl 3´-diisopropylaminocyanoethylphosphoramidite, protection base.