Synthesis and Characterization of the Diastereomers Λ‐ and Δ‐[Ru(bpy)₂(m‐bpy‐Gly‐L‐His‐L‐Lys)]Cl₂−¹H NMR Studies on Their Interactions with the Deoxynucleotide Duplex d[(5′‐CGCGAATTCGCG‐3′)₂]

Abstract

The synthesis and characterization of the diastereomeric complexes Λ-and ∆-[Ru(bpy) 2 (m-bpy-GHK)]Cl 2 , (GHK = glycine-L-histidine-L-lysine, m-bpy = 4͉-methyl-2,2͉-bipyridine) as well as their binding properties to the deoxynucleotide duplex d(5Ј-CGCGAATTCGCG-3Ј) 2 studied by means of NMR, ESI-MS and CD spectroscopy, are reported. The ROESY spectrum of Λ-[Ru(bpy) 2 (m-bpy-GHK)]Cl 2 shows intramolecular cross peaks between the bpy H3 or H3Ј protons and the aromatic H2 and H5 of the histidine imidazole ring, indicating that the peptide adopts an orientation with the imidazole ring close to the bpy ligand, possibly interacting by π-stacking. The absence of intramolecular cross peaks between the peptide and the bipyridine ligands in the ROESY

Strategy for the Stereochemical Assignment of Tris-Heteroleptic Ru(II) Complexes by NMR Spectroscopy

“…Inspection of Figure 9a reveals that the degeneracy in chemical shifts due to the C 2V symmetry of ligand B (dppz) remains unchanged in rac–1a (except for a 0.04 ppm difference between positions 2 and 11), which suggests the very similar anisotropic effect of the substituted phenanthrolines in this arrangement. Similar results were observed by Myari et al23 in the bis-heteroleptic complex attached with a short amino acids sequence [Ru(bpy) 2 (m-bpy-GHK)]Cl 2 (GHK = glycine-L-histidine-L-lysine, m-bpy = 4-methyl-2,2′-bipyridine), where the degeneracy in 1 H chemical shifts of the two bpy ligands was detected. The CIS of dppz is 1.38 and 1.42 ppm at positions 2 and 11, respectively, while 0.82 and 0.99 ppm for Me 2 phen at 2 and 11, and 0.76 and 1.07 ppm for A2 and A11, respectively.…”

DNA Intercalators in Cancer Therapy: Organic and Inorganic Drugs and Their Spectroscopic Tools of Analysis

“…A number of groups have attached single amino acids and short peptides to transition metal complexes [73][74][75][76][77][78][79][80][81][82][83]. Recently, Karidi et al reported the first example of an amino acid chain attached to a chloro(polypyridyl) ruthenium(II) complex [84].…”

Synthesis, characterization and DNA binding properties of oligopyridine-ruthenium(II)-amino acid conjugates

“…Among the most studied compounds is the complex [Ru(bpy) 3 ] 2+ , which shows a weak association with DNA, most probably due to the electrostatic interactions with the DNA phosphates [12][13][14]. Attempts to undertake the random binding of ruthenium tris-chelates to DNA have been raised by tethering a DNA-recognition peptide to one of the bipyridine ligands [15][16][17][18][19][20][21][22][23]. It has been suggested that the nature of the peptide affects the DNA binding affinity of the ruthenium complex [15,17,18].…”