A general synthetic method to conjugate cysteine-containing peptides to nuc
leosides via a disulfide link has been developed, using the heterobifunctio
nal reagent N-succinimidyl-3-(2-pyridylthio)propionate(SPDP) and amino-modi
fied nucleosides. Representative compounds based on C-6 modified adenosine,
C-5 modified uridine and 2'-deoxyuridine are reported, along with extensiv
e NMR characterizations of these novel nucleosides.