5-Substituted 2-Aminopyridine C-Nucleosides as Protonated Cytidine Equivalents: Increasing Efficiency and Selectivity in DNA Triple-Helix Formation

摘要

The easily accessible C-nucleoside 2-amino-5-(2'-deoxy-β-D-ribofuranosyl)pyridine (P) and its 3-methyl (~MeP) and 2'-O-methyl (P_OMe) derivatives were synthesized and invorporated as protonated cytidine equivalents in homopyrimidine oligodeoxynucleotides. Tm measurements indicate that oligonucleotides containing P or ~MeP have a higher affinity to double-stranded DNA over the pH range of 6-8 than 5-methylcytidine (~MeC) containing oligonucleotides.