Synthesis, biological evaluation, substitution behaviour and DFT study of Pd(ii) complexes incorporating benzimidazole derivative

Abstract

Pd(ii) complexes with good DNA/BSA binding ability exhibit cytotoxicity comparable to cisplatin on different cancer cells along with reduced toxicity towards normal cells.

Palladium(II) complexes of tridentate bis(benzazole) ligands: Structural, substitution kinetics, DNA interactions and cytotoxicity studies

“…The values of bimolecular quenching rate constant, kq, were also computed using the KSV = kqτ0 and recorded in the order of ~ 10 12 M -1 s -1 and followed the trend of PdL1 > PdL2 > PdL3 > PdL4 (Table 2). These values are higher than the known strong biopolymer fluorescence quenchers (10 10 M -1 s -1 ), and thus it can be deduced that the complexes quench EB fluorescence statically rather than dynamically [66].…”

Seven membered chelate Pt(ii) complexes with 2,3-di(2-pyridyl)quinoxaline ligands: studies of substitution kinetics by sulfur donor nucleophiles, interactions with CT-DNA, BSA and in vitro cytotoxicity activities

“…It can be deduced also that EtBr is exchanged or displaced from the CT-DNA statically rather than dynamically. 34 As shown for the trend in the magnitude of the binding and quenching values presented in Table 3 , bbqPtCl 2 had the highest affinities for CT-DNA, and the decreasing order of their binding ability is bbqPtCl 2 > dmbpqPtCl 2 > bpqPtCl 2 . Also, the results are in excellent agreement with data obtained from the UV-Vis spectral studies, signifying that the Pt(II) complexes show favorable non-covalent groove binding interactions with CT-DNA.…”

Anticancer activity and biomolecular interaction of Pt(II) complexes: Their synthesis, characterisation and DFT study

“…Protein-free DNA was used for the DNA binding experiment, which was confirmed by formerly reported methods. [22,23] The EtBr (3,8-diamino-5-ethyl-6-phenylphenanthridinium bromide) molecular fluorophore emits intense fluorescence in the presence of CT-DNA owing to its strong intercalation property between the adjacent DNA base pairs. If any drug molecule binds to DNA and replaces EtBr from the EtBr-DNA adduct, it can cause quenching of fluorescence intensity of EtBr.…”

“…This pH dependency on reaction rate is due to the acid dissociation equilibria of the ligands and Complex 2. Below the first pKa (4.66), Complex 2 is present as diaqua species, and beyond that pKa value, it forms bridge dimer [15,22,59,60] through dissociation of aqua molecules. This dimerisation decreases the reactivity of Complex 2, which is also reflected in the observed rate at a higher pH range.…”