Synthesis, characterisation, and anticancer and antioxidant activities of novel complexes of palladium and an organic Schiff-base ligand

Treatment of the Schiff base 2-N-(salicylidene) benzothiazole (SabtH) with palladium chloride afforded the neutral 2-N-(salicylidene) benzothiazole palladium(II) complex. This was then treated with one molar equivalent of either ethylenediamine or 1,10-phenanthroline, yielding the neutral mixed ligand complexes 1 and 2, respectively. The prepared organic ligand and its mixed ligand complexes were characterised via UV-Vis, FTIR, 1H-NMR, and 13C-NMR spectroscopy. The antiproliferative activities of 1 and 2 were tested against MCF-7 (breast) and HT-29 (colon) cancer cells using an MTT assay. 1 showed strong antiproliferative activity against both MCF-7 and HT-29 cancer cells, with IC50 values of 74.6 ± 8.35 and 174 ± 20.28 µg/mL, respectively. In addition, 2 exhibited the maximum antioxidant activity, with an EC50 value of 1029 ± 196.76 µg/mL. KEY WORDS: 2-N-(Salicylidene) benzothiazole, 1,10-Phenanthroline, Palladium mixed ligand complexes, Anticancer, Antioxidant activity Bull. Chem. Soc. Ethiop. 2024, 38(3), 605-613. DOI: https://dx.doi.org/10.4314/bcse.v38i3.5