Synthesis and Characterisation of Novel Palladium(II) Isatin-3-Thiosemicarbazone Complexes with Phosphine and Phenanthroline Ligands: In Vitro Evaluation Against Cancer Cell Lines and Bacterial Strains

Year 2025, Volume: 12 Issue: 3, 181 - 188, 14.09.2025

Ali H. Al-obaidi Luma A Al-doori , Ahmed Irzoqi , Mohanad Yasir

https://doi.org/10.18596/jotcsa.1646336

Abstract

In this study, three new palladium (II) complexes with isatin-3-thiosemicarbazone (ITC) were prepared by reacting Pd(II) with ITC and phosphine or diamine ligands. Characterisation was done using CHN analysis, molar conductivity, FTIR spectroscopy, and ¹H, ¹³C, and ³¹P NMR spectroscopy. All analyses confirmed that the complexes exhibit a square planar structure around the Pd²⁺ ion. The ITC ligand displayed a bidentate coordination mode, binding through nitrogen and sulphur atoms. In vitro biological activity studies revealed excellent anti-ovarian cancer potential. Notably, the complex (Pd(ITC)(Phen))Cl₂ demonstrated only 5% cell survival at a 400 µM concentration, while the other two complexes, (Pd(ITC)₂)Cl₂ and (Pd(ITC)(PPh₃)Cl)Cl, did not exceed 10%. These results illustrate the strong ability of these complexes to inhibit cancer cell growth in vitro. Additionally, the three synthesised complexes demonstrated clear antibacterial activity against four bacterial strains: two Gram-positive (Streptococcus faecalis and Staphylococcus aureus) and two Gram-negative (E. coli and Pseudomonas aeruginosa). The activity was concentration-dependent, decreasing as the concentration lowered. The complex (Pd(ITC)(Phen))Cl₂ exhibited the highest antibacterial activity, particularly against Gram-positive bacteria, followed by (Pd(ITC)(PPh₃)Cl)Cl and (Pd(ITC)₂)Cl₂. These findings indicate the possible development of these complexes as therapeutic agents with anticancer and antibacterial properties, particularly in addressing bacterial resistance to conventional antibiotics.

Keywords

Pd(II) , (ITC) , Cyclic nitrogen , Anti-ovarian cancer activity

Ethical Statement

This study was approved by the ethical committee of Tikrit University

Supporting Institution

NIL

Thanks

The staff of central lab at Tikrit University

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