LAUSR

Abstract Herein syntheses and characterization of the complexes [Pt(PG)(PPh3)2] (1) and [Ru(PG)(dppm)2] (2), where PG (propyl gallate) = propyl 3,4,5-trihydroxybenzoate, PPh3 = triphenylphosphine and dppm = 1,1-bis(diphenylphosphino) methane, are described. The structure of the complex [Pt(PG)(PPh3)2] was elucidated by X-ray diffraction. The cytotoxicity of the complexes against four tumor cell lines, lung carcinoma (A549), breast carcinoma (MCF-7), hepatocellular carcinoma (HepG2), glioblastoma (U251MG), and a normal fibroblast (CCD-1059Sk) were evaluated. The selectivity index values showed that complex (2) is more potent and selective than the free propyl gallate molecule and complex (1). Furthermore, complex (2) is a slightly higher active against the tumor cells MCF-7 and HepG2 than the cisplatin. In addition, BSA-binding experiments and antioxidant activity of the complexes were evaluated. The interactions of the complexes with the BSA showed negative ΔH and ΔS values, leading to van der Waals force or hydrogen bond formation between the complexes and the biomolecule. Furthermore, the negative ΔG values reveal that the interaction process of complex/BSA is spontaneous. It was observed that the [Pt(PG)(PPh3)2] complex has an inhibitory effect against free radicals, whereas [Ru(PG)(dppm)2] was not active. Circular dichroism showed that the free ligand and the complexes are unable to modify the DNA secondary structure of this biomolecule.