A Constrained Tricyclic Nucleic Acid Analogue of α‑l‑LNA: Investigating the Effects of Dual Conformational Restriction on Duplex Thermal Stability

A constrained tricyclic analogue
of α-l-LNA (2), which contains dual modes
of conformational restriction
about the ribose sugar moiety, has been synthesized and characterized
by X-ray crystallography. Thermal denaturation experiments of oligonucleotide
sequences containing this tricyclic α-l-LNA analogue
(α-l-TriNA 2, 5) indicate that this modification
is moderately stabilizing when paired with complementary DNA and RNA,
but less stabilizing than both α-l-LNA (2) and α-l-TriNA 1 (4).