Influence of co‐ligand on the biological properties of Schiff base metal complexes: Synthesis, characterization, cytotoxicity, and antimicrobial studies

Abstract

In this work, six new mixed ligand Schiff base metal complexes of [M2(L1)(X)2Cl4] type, (where, M = CoII, NiII, CuII, L1 = Schiff base ligand derived from 1‐pyrenecarboxaldehyde and 1,4‐bis[3‐aminopropyl]piperazine and X = pyrazine‐2‐carboxylic acid or 2,2′‐biimidazole) were synthesized and studied their biological activity and cytotoxicity. The synthesized Schiff base ligands, their metal complexes were characterized by Infrared, UV‐Visible spectroscopy, and elemental analysis. Density functional theory calculations were performed to examine the molecular geometry and frontier molecular orbital properties of complexes (1–6). The DNA binding ability of these complexes (1–6) was evaluated by in vitro spectroscopic (absorption and fluorescence) titrations, viscosity measurements, and in silica by molecular docking measurements. The results showed a good binding propensity with the binding constant from 2.65 × 104 to 3.38 × 105 M−1 in the order 6 > 5 > 4 > 3 > 2 > 1, respectively. All complexes exhibited a good binding affinity to BSA proteins with relatively higher binding constant values similar to the trend of DNA binding studies and where Cu (II) complexes have greater efficiency than Co (II) and Ni (II) complexes. The in vitro cytotoxic study of all the complexes was investigated in the cervical cancer (HeLa) cell line, which displayed IC50 values of 1.36–24.2 μM, signifying the potential of complexes for an operative anticancer drug. Metal complexes were also screened for antimicrobial properties, which showed virtuous inhibition than the free ligands.

Synthesis of a new Cd (II) complex as ionophores and its application in construction of a highly selective and sensitive cadmium (II) sensor in petroleum water samples

“…The antifungal activity was evaluated against Candida albicans . The antimicrobial applications were employed applying the agar‐well diffusion method 25–27 …”

“…The plot of E cell against (t-25) yielded a straight line. The standard electrode potential at 25 C is E (25). The slope is calculated to be 0.000163 mV/ C for sensor III and represents the electrode isothermal coefficient.…”

Mixed ligand octahedral Zn(II) complex of N^N^O donor tridentate Schiff base ligand and N^N donor bidentate bipyridine ligand: Synthesis, characterization, biological activity and cytotoxicity

“…The tridentate Schiff base ligand and its zinc complex were tested in vitro for antimicrobial screening on certain bacterial and fungal species by a well‐diffusion technique. Gram‐positive (G+) ( Bacillus subtilis and Staphylococcus aureus ), Gram‐negative (G−) ( Escherichia coli and Pneumocystis pneumoniae ) bacterial species grown in nutrient‐agar medium was incubated (37°C) for 2 days after which subculture were prepared in fresh medium and used as bactericidal studies 23 . The fungal species, Candida albicans was cultured in savored dextrose‐agar medium, incubated (27°C) for 3 days and subcultures in fresh medium after it was used to test antifungal fungal property.…”

“…Gram-positive (G+) (Bacillus subtilis and Staphylococcus aureus), Gram-negative (GÀ) (Escherichia coli and Pneumocystis pneumoniae) bacterial species grown in nutrientagar medium was incubated (37 C) for 2 days after which subculture were prepared in fresh medium and used as bactericidal studies. 23 The fungal species, Candida albicans was cultured in savored dextrose-agar medium, incubated (27 C) for 3 days and subcultures in fresh medium after it was used to test antifungal fungal property. The bacterial and fungal cultures are inoculated in Petri plates using loop and uniformly spread on it with sterile glass spreader.…”

Thiophene-Derived Schiff Base Complexes: Synthesis, Characterization, Antimicrobial Properties, and Molecular Docking

“…In particular, Schiff bases exhibit efficient bioactivity in a wide range of biological applications . Much attention has been given to ligands derived from Schiff base owing to their exceptional structural and synthetic flexibility, fine tunability, and selectivity toward the transition metal atom ,, to form N , N ′-bidentate, N , N ′,X-tridentate, and N , N ′, N ″,X-tetradentate geometries. Schiff bases regulate the performance of metals in a wide array of useful catalytic transformations, such as catalytic activity in the hydrogenation of olefins, ring-opening polymerization (ROP) of cyclic olefins, and pharmacological and biological applications .…”