Synthesis and Properties of Nucleic Acid Methylene Carboxamide Mimics Derived from Morpholine Nucleosides

Uracyl and adenine containing oligomers derived from carboxymethyl derivatives of morpholine nucleoside analogues (MorGly) were synthesized using the methods of peptide chemistry. Capillary electrophoresis conditions were found for the analysis of the homogeneity of the nucleic acid mimics protonated at physiological pH. The thermal stability of complementary complexes formed by the MorGly oligomers was shown to depend dramatically on the heterocyclic base structure (uracil or adenine). Based on the study of tandem complexes it was demonstrated that the impact on the thermal stability of cooperative interactions at oligomer junctions was higher for modified oligomers than for native oligodeoxyriboadenylates. Adenine containing MorGly oligomers formed more stable complexes with poly(U) than native oligodeoxyriboade nylates of the same length. Complexes formed by modified oligomers with polyribonucleotides were more stable if compared with polydeoxyribonucleotides.