Self-complementary oligodeoxyribonucleotides incorporating L-related isodeoxynucleosides: synthesis, physical characterization, enzymology, and CD studies.

The synthesis of self-complementary oligodeoxyribonucleotides (14-16, 18) incorporating the L-related isodeoxynucleotides, isodA (1) and/or isodT (2), is described. For this purpose, the fully protected phosphoramidite building blocks 10 and 12 were synthesized. The conceptually new oligomers exhibit high resistance towards exonucleases. Temperature- and concentration-dependent CD spectral data and accompanying thermodynamic parameters of the oligomers show that isodA-isodT or mixed dA-isodT/isodA-dT base pairs participate in duplex stabilization.