Synthesis, characterization, and in vitro anticancer studies of chlorido(triphenylphosphine)ruthenium(II) dithiocarbamate complexes

Abstract

Three chlorido(triphenylphosphine)ruthenium(II) dithiocarbamate complexes - [RuCl(PPh₃)₃(Mbzdtc)] 1, [RuCl(PPh₃)₃(Ppipdtc)] 2, and [RuCl(Ph₃)₃(Mordtc)] 3 with Mbzdtc = N-methylphenyldithiocarbamate, Ppipdtc = phenylpiperazyldithiocarbamate and (Mordtc) = morpholinyldithiocarbamate were synthesized and characterized by elemental analysis and spectroscopic techniques. The Ru(II) atom is six coordinate and displays an octahedral coordination geometry, in which it is bonded to one dithiocarbamato anion acting as bidentate ligand. Electrochemical studies indicate for complexes 1 and 2 a quasi-reversible one electron redox couple due to Ru(III)/Ru(II), whereas complex 3 showed two redox couples due to Ru(III)/Ru(II) and Ru(II)/Ru(I). The E_1/2 values observed toward the cathodic region are consequence of the presence of S-S donor atom of the dithiocarbamate ligand. The anticancer potential of the complexes was assessed using sulforhodamine B (SRB) assay against renal (TK10) melanoma (UACC62) and breast (MCF7) human cancer cell lines. Complex 1 exhibits the highest cytotoxic activity against MCF7 with an IC₅₀ value of 33.36 μM, whereas complex 3 exhibits the lowest activity against TK10 with an IC₅₀ value of 91.95 μM.

Graphical Abstract

Keywords:

• Ruthenium(II)
• dithiocarbamate
• triphenylphosphine
• anticancer
• electrochemical study

Disclosure statement

No potential conflict of interest was reported by the authors.

Scheme 1. Synthesis of complexes 1–3.

Additional information

Funding

The authors acknowledge the financial support of Sasol and of National Research Foundation, South Africa.