Gold(I/III)-Phosphine Complexes as Potent Antiproliferative Agents

Sci Rep. 2019 Aug 26;9(1):12335. doi: 10.1038/s41598-019-48584-5.

Abstract

The reaction of gold reagents [HAuCl4•3H2O], [AuCl(tht)], or cyclometalated gold(III) precursor, [C^NAuCl2] with chiral ((R,R)-(-)-2,3-bis(t-butylmethylphosphino) quinoxaline) and non-chiral phosphine (1,2-Bis(diphenylphosphino)ethane, dppe) ligands lead to distorted Au(I), (1, 2, 4, 5) and novel cyclometalated Au(III) complexes (3, 6). These gold compounds were characterized by multinuclear NMR, microanalysis, mass spectrometry, and X-ray crystallography. The inherent electrochemical properties of the gold complexes were also studied by cyclic voltammetry and theoretical insight of the complexes was gained by density functional theory and TD-DFT calculations. The complexes effectively kill cancer cells with IC50 in the range of ~0.10-2.53 μΜ across K562, H460, and OVCAR8 cell lines. In addition, the retinal pigment epithelial cell line, RPE-Neo was used as a healthy cell line for comparison. Differential cellular uptake in cancer cells was observed for the compounds by measuring the intracellular accumulation of gold using ICP-OES. Furthermore, the compounds trigger early - late stage apoptosis through potential disruption of redox homeostasis. Complexes 1 and 3 induce predominant G1 cell cycle arrest. Results presented in this report suggest that stable gold-phosphine complexes with variable oxidation states hold promise in anticancer drug discovery and need further development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Cattle
  • Cell Cycle / drug effects
  • Cell Death / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Crystallography, X-Ray
  • Density Functional Theory
  • Electrochemistry
  • Electrodes
  • Endocytosis / drug effects
  • Gold / chemistry
  • Gold / pharmacology*
  • Humans
  • Inhibitory Concentration 50
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Phosphines / chemistry
  • Phosphines / pharmacology*
  • Serum Albumin, Bovine / chemistry
  • Serum Albumin, Human / chemistry
  • Spectrophotometry, Ultraviolet
  • Temperature

Substances

  • Phosphines
  • Serum Albumin, Bovine
  • Gold
  • phosphine
  • Serum Albumin, Human