Metal‐Ion‐Binding Analogs of Ribonucleosides: Preparation and Formation of Ternary Pd²⁺ and Hg²⁺ Complexes with Natural Pyrimidine Nucleosides

Abstract

Four metal‐ion‐binding nucleosides, viz. 2,6‐bis(1‐methylhydrazinyl)‐9‐(β‐D‐ribofuranosyl)‐9H‐purine (2a) and its N‐acetylated derivative, 2b, 2,4‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐5‐(β‐D‐ribofuranosyl)pyrimidine (3), and 2,4‐bis(1‐methylhydrazinyl)‐5‐(β‐D‐ribofuranosyl)pyrimidine (4) have been synthesized. The ability of these nucleosides and the previously prepared 2,6‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐9‐(β‐D‐ribofuranosyl)‐9H‐purine to form Pd2+‐ and Hg2+‐mediated complexes with uridine has been studied by 1H‐NMR spectroscopy. To obtain additional support for the interpretation of the NMR data, comparative measurements on the ternary‐complex formation between pyridine‐2,6‐dicarboxamide (5), pyrimidine nucleosides, and K2PdCl4 were carried out.

Metal complexes of 6-pyrazolylpurine derivatives as models for metal-mediated base pairs

“…Most recently, Lönnberg et al have introduced a family of artificial purine-derived nucleosides that were designed with the aim of discriminating a natural nucleobase located opposite the artificial nucleoside [32][33][34][35]. Oligonucleotides capable of specifically recognizing short nucleic acid sequences are relevant in RNA interference and other therapeutic applications for the treatment of genetic disorders [36,37].…”

6-Pyrazolylpurine as an Artificial Nucleobase for Metal-Mediated Base Pairing in DNA Duplexes

“…In the latter context, a series of purine derivatives with appended donor moieties have recently been proposed as artificial nucleobases for the specific recognition of a complementary canonical nucleobase via the formation of a metal-mediated base pair [ 18 , 19 , 20 , 21 ]. For one of these derivatives, i.e.…”

Formation of Mixed-Ligand Complexes of Pd2+ with Nucleoside 5'-Monophosphates and Some Metal-Ion-Binding Nucleoside Surrogates

“…The preparation of metal-ion-binding nucleosides 1 – 5 has been described previously [9,10]. Among the NMPs employed, UMP, CMP, AMP, GMP and IMP were commercial products and the preparation of the 5'-monophosphate of nebularine (NeMP), i.e.…”

“…Only some indications of recognition of thymine within an oligodeoxyribonucleotide by 2,6-bis(3,5-dimethylpyrazol-1-yl)purine in the presence of Pd 2+ have been observed [8]. We have previously tried to evaluate the formation of mixed-ligand Pd 2+ complexes between some metal ion binding nucleoside analogs and pyrimidine nucleosides [9]. Owing to severe solubility problems, the results obtained remain scanty.…”