1′, 5′ ‐Anhydrohexitol Oligonucleotides: Synthesis, Base Pairing and Recognition by Regular Oligodeoxyribonucleotides and Oligoribonucleotides

Oligonucleotides constructed of 1′, 5′‐anhydrohexitol nucleoside building blocks (hexitol nucleic acids, HNA) are completely stable towards 3′‐exonuclease and form very stable self‐complementary duplexes as well as sequence‐selective stable duplexes with the natural DNA and RNA. Triple‐helix formation has also been observed. These hybridisation characteristics are highly dependent on the base sequence and the experimental conditions. When using a phosphate buffer containing 0.1M NaCl, a homopurine HNA dodecamer gives a δ T m of +3.0 °C/ base pair with RNA as complement. These oligomers may therefore be of considerable interest as antisense constructs.