Tetra-azolium salts induce significant cytotoxicity in human colon cancer cells, in vitro

Curr Org Synth. 2023 Aug 24. doi: 10.2174/1570179421666230824151219. Online ahead of print.

Abstract

Background: Azolium salts are the organic salts used as stable precursors for generating N-Heterocyclic Carbenes and their metal complexes. Azolium salts have also been reported to have significant biological potential. Hence, in the current study, four tetra-dentate azolium salts were derived from bis-azolium salts by a new synthetic strategy.

Methods: The tetra azolium salts have been synthesized by reacting the imidazole or methyl imidazole with dibromo xylene (meta, para)/ 1-bromo methyl imidazole or dibromo ethane resulting in the mono or bis azolium salts namely I-IV. V-VII have been obtained by reacting I with II-IV, resulting in the tetra azolium salts. Each product was analyzed by various analytical techniques, i.e., microanalysis, FT-IR, and NMR (1H & 13C). Salts V-VII were evaluated for their antiproliferative effect against human colon cancer cells (HCT-116) using MTT assay.

Results: Four chemical shifts for acidic protons between 8.5-9.5 δ ppm in 1H NMR and resonance of respective carbons around 136-146 δ ppm in 13C NMR indicated the successful synthesis of tetra azolium salts. Salt V showed the highest IC50 value, 24.8 µM among all synthesized compounds.

Conclusion: Tetra-azolium salts may play a better cytotoxicity effect compared to mono-, bi-& tri-azolium salts.

Keywords: Anti-cancer; Azolium salts; HCT-116; NHC; Tetra-nuclear; cytotoxicity.