Cobalt(II)–metformin complexes containing α‐diimine/α‐diamine as auxiliary ligand: DNA binding properties

Abstract

The cobalt(II) complexes [Co(Cl)2(met)(o‐phen)] (1), [Co(Cl)2(en)(met)] (2) and [Co(Cl)2(met)(opda)] (3) (met = metformin, o‐phen = ortho‐phenanthroline, en = ethylenediamine, opda = ortho‐phenylenediamine) were synthesized and characterized using liquid chromatography–mass spectrometry, elemental analysis, molar conductance measurements, thermal analysis, infrared spectroscopy, magnetic moment measurements, electronic spectroscopy and X‐ray diffraction. The metal centre was found to be in an octahedral geometry. UV–visible absorption, fluorescence and viscosity measurements were conducted to assess the interaction of the complexes with calf thymus DNA. The complexes showed absorption hyperchromism in UV–visible spectra with DNA. The binding constants from UV–visible absorption studies were 1.38 × 105, 2.1 × 105 and 3.1 × 105 M−1 for 1, 2 and 3, respectively, and Stern–Volmer quenching constants from fluorescence studies were 0.146, 0.176 and 0.475, respectively. Viscosity measurements revealed that the binding of the complexes with DNA could be surface binding, mainly due to groove binding. The activities of the complexes in DNA cleavage decrease in the order 3 > 2 > 1. The complexes were docked into DNA topoisomerase II using Discovery Studio 2.1 software.

Chromium‐metformin ternary complexes: Thermal, DNA interaction and Docking studies

“…The molecules were built with the Perkin Elmer ChemBio Draw and optimized utilizing Perkin Elmer ChemBio3D software . Geometrical structures of the metal complexes 1, 2, 3 were calculated by optimizing their bond lengths, bond angels and torsional angles.…”

“…Metformin and its ternary complexes have received less attention in spite of their potential metal binding properties and promising applications. From our laboratories, we recently reported the synthesis, characterization and DNA binding studies of cobalt (II), copper (II) and oxovanadium (IV) complexes containing metformin as primary ligand and α‐diimine/α‐diamine as auxiliary ligands . In continuation, in this article, we report synthesis, characterization, DNA binding, light switching, photocleavage, B‐DNA docking studies of chromium (III) complexes of metformin with bipy/opda/phen as secondary ligand.…”

Biological Properties of Transition Metal Complexes with Metformin and Its Analogues

“…Co(II) complexes 45-48 (Scheme 18) with metformin and bidentate N-donor ligands demonstrated the ability to bind DNA within the binding pocket of metformin, similar to Cr complexes 24-26 (Scheme 11) [131,132]. It should be noted that both the Cr and Co complexes with metformin and o-phenylenediamine were characterized by the highest DNA docking scores.…”

“…The effects of 110-115 (Figure 5) and their respective free ligands on the photosynthetic activity of photosystem II (PSII) were studied using photochemically active fragments from spinach leaves [131]. Photochemical changes were quantified based on the PSII chlorophyll fluorescence yield.…”

Robust corrosion guard, mechanical and UV aging properties of metal complex/epoxy hybrid composite coating for C-steel applications

“…Modifications of polymeric epoxy coatings were in progress to improve their protective ability [10][11][12] . Metformin (MF) formed Schiff base compounds by the reaction with aldehyde derivatives and offered coordinative and biological characteristics in addition to creating complexes by reacting with some metal ions [13][14][15][16] . Large scale applications used 2,2 \ -Bipyridine (Bipy) hetero ligand in macromolecular and supramolecular reactions 17,18 .…”