A 2′,4′-Bridged Nucleic Acid Containing 2-Pyridone as a Nucleobase: Efficient Recognition of a C⋅G Interruption by Triplex Formation with a Pyrimidine Motif

Significantly enhanced binding affinity to C⋅G base pairs without loss of sequence selectivity is achieved by using a nucleotide containing a 2-pyridone and a 2′-O,4′-C-methylene-bridged nucleic acid analogue (PB, see picture). The degree of stabilization of the triplex formed enables C⋅G interruptions in a homopurine⋅homopyrimidine double-stranded DNA to be detected.