Pyridoxal water-soluble cobalt(II) helicates: Synthesis, structural analysis, and interactions with biomacromolecules

Vanadium(v) complexes derived from triphenylphosphonium and hydrazides: cytotoxicity evaluation and interaction with biomolecules

“…The hyperchromicity ( H %), bathochromic shift (Δ λ ), binding constant ( K b ), and Gibbs’ free-energy (Δ G ) values of the vanadium complexes were calculated through Benesi–Hildebrand and Gibbs’ free-energy equations according to literature. 44,45…”

“…The Stern–Volmer quenching constant ( K SV ), bimolecular quenching rate constant ( k q ), modified Stern–Volmer binding constant ( K a ), and Gibbs’ free-energy (Δ G ) values for the competitive assays were calculated according to literature. 31,44…”

“…The hyperchromicity (H%), bathochromic shift (Δλ), binding constant (K b ), and Gibbs' free-energy (ΔG) values of the vanadium complexes were calculated through Benesi-Hildebrand and Gibbs' freeenergy equations according to literature. 44,45 Competitive binding assays using CT-DNA:dye adduct were performed by steady-state fluorescence emission analysis through the successive additions of the inorganic compounds (0 to 100 μM) to a quartz cuvette (1.0 cm path length) containing CT-DNA (10 µM) pretreated with ethidium bromide dye (EB, 5.0 µM; intercalator) or 4′,6-diamidine-2-phenylindole dye (DAPI, 5.0 µM; minor groove binder), in a DMF(5%)/Tris-HCl buffer ( pH 7.4) mixture solution. The Stern-Volmer quenching constant (K SV ), bimolecular quenching rate constant (k q ), modified Stern-Volmer binding constant (K a ), and Gibbs' freeenergy (ΔG) values for the competitive assays were calculated according to literature.…”

“…The Stern-Volmer quenching constant (K SV ), bimolecular quenching rate constant (k q ), modified Stern-Volmer binding constant (K a ), and Gibbs' freeenergy (ΔG) values for the competitive assays were calculated according to literature. 31,44 CT-DNA intercalative viscosity analysis were carried out using an Ostwald viscometer immersed in a water bath maintained at 298.15 K, according to literature. 46 The CT-DNA concentration was kept constant in all experiments, while the concentration of the inorganic complexes was increased from 0 to 100 μM in a DMF(5%)/Tris-HCl ( pH 7.4) buffer mixture solution.…”

“…This is indicated by the 380-410 nm hyperchromic effect, signifying non-covalent interactions with the biomolecules akin to what has been reported for other inorganic complexes. 31,44,49 The binding constant (K b ) values were calculated and are summarized in Table 1, showing that C1-C5 exhibit moderate binding capacity (K b ≈ 10 4 M −1 ) for CT-DNA and HSA. Additionally, negative Gibb's free energy (ΔG) values suggest that these complexes interact spontaneously with biomolecules (Table 1).…”