Crystal Structures and Cytotoxicity of Ortho-Xylene Linked Bis-benzimidazolium Salts

Med Chem. 2015;11(5):473-81. doi: 10.2174/1573406411666150101153115.

Abstract

Azolium (imidazolium and benzimidazolium) salts are known as stable precursors for the synthesis of Metal-N-Heterocyclic Carbene (M-NHC) complexes. Recently, some reports have been compiled indicating that benzimidazolium salts have anticarcinogenic properties. The current research is the further investigation of this phenomenon. Three ortho-xylene linked bis-benzimidazolium salts (1-3) with octyl, nonyl and decyl terminal chain lengths have been synthesized. Each of the compounds was characterized using FT-IR and NMR spectroscopic techniques. The molecular geometries of two of the salts (1-2) have been established using X-ray crystallographic technique. The compounds were tested for their cytotoxic properties against three cancerous cell lines namely, human colon cancer (HCT 116), human colorectal adenocarcinoma (HT- 29) and human breast adenocarcinoma (MCF-7). Mouse embryonic fibroblast (3T3-L1) was used as the model cell line of normal cells. The compounds showed selective anti-proliferative activities against the colorectal carcinoma cells. For HCT 116 and HT-29 cells, the IC50 values ranged 0.9-2.6 µM and 4.0-10.0 µM, respectively. The salts 1 and 3 displayed moderate cytotoxicity against the breast cancer (MCF-7) cells with IC50 58.2 and 13.3 µM, respectively. However, the salt 2 produced strong cytotoxicity against MCF-7 cells with IC50 4.4 µM. Interestingly, the compounds demonstrated poor cytotoxic effects towards the normal cells (3T3-L1) as the IC50 was found to be as high as 48.0 µM. Salts 2 and 3 demonstrated more pronounced anti-proliferative effect than the standard drugs used (5-Flourouracil and Tamoxifen).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / toxicity
  • Benzimidazoles / chemical synthesis
  • Benzimidazoles / chemistry*
  • Benzimidazoles / toxicity*
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Crystallography, X-Ray
  • Drug Screening Assays, Antitumor
  • HT29 Cells
  • Humans
  • MCF-7 Cells
  • Magnetic Resonance Spectroscopy
  • Mice
  • Models, Molecular*
  • Molecular Structure
  • Spectroscopy, Fourier Transform Infrared
  • Xylenes / chemical synthesis
  • Xylenes / chemistry*
  • Xylenes / toxicity*

Substances

  • Antineoplastic Agents
  • Benzimidazoles
  • Xylenes
  • 2-xylene