New 3D and 2D supramolecular heteroleptic palladium(II) dithiocarbamates as potent anticancer agents

Abstract

Three new heteroleptic palladium(II) dithiocarbamates with better in vitro anticancer activity than cisplatin were synthesized and characterized by different analytical techniques, elemental analysis, FTIR, NMR, and single crystal X-ray diffraction analysis. The Pd center is chelated by dithiocarbamate ligand {4-benzylpiperazine-1-carbodithioate (1) and (3) or (4-(2-methoxyphenyl)piperazine-1-carbodithioate (2)}, triorganophosphine {tris-(4-flourophenyl)-phosphine (1) and (2) or tris-(4-chlorophenyl)phosphine (3)}, and a chloro-group, resulting in a square planar geometry. The packing diagram reveals a 3D network (1 and 2) and a 2D network (3) composed of various 1D chains in which the molecules are linked via hydrogen bonds (1–3) and halide⋯π (1, 3) interactions. The anticancer activities of complexes against HeLa cell line varies in the sequence 2 (23.438 μM) > 1 (38.293 μM) > 3 (47.554 μM) > cisplatin (78.075 μM). The cytotoxicity of these complexes is due to their strong induction of oxidative stress and DNA-damage ability leading to apoptosis.

Keywords:

• Mixed-ligand palladium complexes
• supramolecular
• anticancer
• oxidative stress
• DNA-ladder analysis

Acknowledgements

We acknowledge the financial support from TWAS (The World Academy of Sciences) project no. 11-143 RG/PHA/AS_C-UNESCO FR: 3240262658, and Higher education Commission of Pakistan.