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 δTm of +3.0 °C/ base pair with RNA as complement. These oligomers may therefore be of considerable interest as antisense constructs.