Investigation of antisense DNA having C-5 polyamine substituted 2′-deoxyuridine derivative

Phosphorothioate analogs of oligodeoxyribonucleotide (S-ODN) bearing non-branched polyamine molecule at C-5 position of certain pyrimidine base were synthesized. The synthesis of the modified S-ODNs was accomplished via post-synthetic modification method utilizing C-5 methoxycarbonylmethyl substituted deoxyuridine derivative with modest yields. The thermal stability of the dulexes containing modified S-ODNs was assessed through the measurement of the melting points (Tms). Interestingly, the Tms of the modified oligomers were considerably lower than that of the corresponding unmodified oligomer at relatively high concentration range. At lower concentration, on the other hand, the Tms of the modified S-ODNs were higher than that of the unmodified oligomer.