2-Amino-alpha-2'-deoxyadenosine increased duplex stability of methoxyethylphosphoramidate alpha-oligodeoxynucleotides with RNA target

A new efficient synthesis of 2-amino-alpha-2'-deoxyadenosine and its incorporation into methoxyethylphosphoramidate alpha-oligodeoxynucleotides (ODNs) via H-phosphonate chemistry were reported. Thermal denaturation experiments demonstrated a significant stabilization of the complexes formed between these analogues and their RNA target (+2 degrees C/NH2A) relative to adenosine-containing phosphoramidate alpha-oligonucleotides. Concerning the binding specificity of these modified ODNs, unlike natural ODNs, discrimination against G pairing is higher and against C pairing is lower.