Interaction of the anti-tumour drug cis-Pt(en)Cl2 with cytidilyl-3′ → 5′-guanosine

Abstract

Chemical shifts occurring in ¹H nuclear magnetic resonance and Sephadex G 25 chromatography are used to follow the reaction of the dinucleotide C3′p5′G (cytidilyl-3′phosphate5′-guanosine) in aqueous solution and to separate its products. Binding of the platinum occurs in first place at the cytosine, then at the guanine base. Two major complexes are produced, Pt:CpG and (Pt:CpG)₂, which account for respectively for an internal and an external cross-linking effect.