Synthesis, spectral, structural characterization and biological activity of new palladium(II) complexes containing 3‐acetyl‐8‐methoxy‐2H‐chromen‐2‐one derived Schiff bases

Abstract

Four different mononuclear palladium(II) complexes of 3‐acetyl‐8‐methoxycoumarin Schiff bases were synthesized and characterized by spectrochemical techniques. Further analysis through X‐ray crystallography confirmed the structures of the complexes. Their interactive ability with Calf Thymus DNA and protein (Bovine Serum Albumin and Human Serum Albumin) were investigated by means of absorption and emission methods. The intercalative mode of binding with DNA was supported by EB displacement studies and viscosity measurements. Configurational changes that occurred in the proteins have been analysed with the help of 3D fluorescence studies. The complexes were shown to have good antimicrobial activity against the tested bacterial and fungal pathogens. In addition, antiproliferative activity of the complexes was evaluated on A549 and MCF‐7 cell lines and the complexes were comparatively more active than the standard drug cisplatin. Among the compounds, complex 3 was the most effective against MCF‐7 (IC50 value of 5.20 ± 0.15 μM) and A549 (5.09 ± 0.13 μM) compared with the other complexes 1 (6.48 ± 0.17 μM; 5.98 ± 0.09 μM), 2 (5.53 ± 0.12 μM; 5.85 ± 0.11 μM), 4 (6.73 ± 0.19 μM; 6.63 ± 0.16 μM) and cisplatin (16.79 ± 0.08 μM; 15.10 ± 0.05 μM) respectively. LDH and NO release assays confirmed the cytotoxic potential of the synthesized complexes.

Theoretical calculations for new coumarin Schiff base complexes as candidates for in vitro and in silico biological applications

“…(Pd 2 ‐Sb) shows promising cytotoxic activity against MCF‐7 when compared with other Pd(II) complexes of coumarin Schiff base derivatives. [ 56 ]…”

“…(Pd 2 -Sb) shows promising cytotoxic activity against MCF-7 when compared with other Pd(II) complexes of coumarin Schiff base derivatives. [56] (Sb), (Pd 2 -Sb), and (Sb-Zn-Cipro) have IC 50 values of 74, 85.5, and 56 μg ml À1 , respectively, against HCT-116. Zinc complex is more efficient than palladium complex and Schiff base, according to the findings.…”

Recent Progress in Metal‐Incorporated Acyclic Schiff‐Base Derivatives: Biological Aspects

“…[108] Pd II complex 96 synthesized by the Prabhakaran group from 3-acetyl-8-methoxycoumarin Schiff-base ligand L65 (Figure 36) provided high anti-cancer activity against MCF-7 and A549 cancer cell lines with IC 50 values of 5.20 � 0.15 μM and 5.09 � 0.13 μM respectively, which were higher than cis-platin (corresponding IC 50 values of 16.79 � 0.08 μM and 15.10 � 0.05 μM). [109] The cytotoxicity of Pd complex 97 and Pt complex 98 (Figure 37) were studied by Onani's group against the human cell lines Caco-2 (colon), HeLa (Cervical), Hep-G2 (Hepatocellular Carcinoma/liver cancer), MCF-7 (breast cancer), PC-3 (prostate), and MCF-12 A (non-cancer breast). [110] The complexes were highly toxic to the cancer cells.…”

“…Structures of Schiff-base ligand L65 and its Pd II complex 96. [109] Figure 37. Structures of Pd II complex 97 and Pt II complex 98.…”

Anomalous coordination behaviour of 6‐methyl‐2‐oxo‐1,2‐dihydroquinoline‐3‐carboxaldehyde‐4(N)‐substituted Schiff bases in Cu(II) complexes: Studies of structure, biomolecular interactions and cytotoxicity

“…Also, the literature shows that nitrogen heterocyclic thiosemicarbazone‐based compounds exhibit a variety of medicinal properties such as anticancer, antitumour, antifungal, antibacterial, antiviral, antimalarial, antifilarial and anti‐HIV activities . In the recent past, our group has been keenly engaged in the study of the variable coordination behaviours of heterocyclic (both N and O) thiosemicarbazones and semicarbazones with diverse transition metals and biological properties of the resulting complexes. However, the structural and biological properties of 6‐methyl‐2‐oxo‐1,2‐dihydroquinoline‐3‐carbaldehyde‐4( N )‐substituted thiosemicarbazones have not been explored.…”