Design and synthesis of the novel cross-linking reagents triggered by the triple helix formation.

In our attempt to new nucleobase analogs capable of interstrand cross-linking, we developed 2-amino-6-vinyl purine analog (1). The oligonucleotides incorporating 1 showed efficient interstrand cross-linking with selectivity toward cytidine at a target site. In this paper, we describe the design of the new cross-linking reagents (2) bearing 2-amino-6-vinyl purine motif, and triplex-directed alkylation with 2 to double-stranded DNA.