Synthesis and Characterization of Benzylidene Acetal-Type Bridged Nucleic Acids (BA-BNA).
Benzylidene acetal-type bridged nucleic acids (BA-BNAs) have a bridged structure that cleaves upon exposure to appropriate external stimuli, which induces changes in oligonucleotide properties. In particular, duplex stability and resistance to enzymatic digestion vary depending on the incorporation number and/or position of BA-BNAs. This unit describes the synthesis of some types of BA-BNA thymine nucleosides and the corresponding BA-BNA phosphoramidites, as well as the incorporation of BA-BNA nucleosides into oligonucleotides. Moreover, typical procedures that induce property changes in each BA-BNA are described. 6-Nitroveratrylidene and 2-nitrobenzylidene acetal type BA-BNA respond to photoirradiation and subsequent thiol treatment. Benzylidene and 4-nitrobenzylidene acetal type BA-BNAs respond to acids and reducing agents, respectively. Every BA-BNA is derivatized into 4'-C-hydroxymethyl RNA by hydrolysis of the acetal-bridged structure.
['Kodama|Tetsuya|T|', 'Morihiro|Kunihiko|K|', 'Obika|Satoshi|S|']
D001597:Benzylidene Compounds D001952:Bridged-Ring Compounds D012313:RNA
external stimuli property change acid-trigger bridged nucleic acid (BNA) light-trigger redox-change-trigger sugar-modified nucleoside