New water soluble bis-imidazolium salts with a saldach scaffold: Synthesis, characterization and in vitro cytotoxicity/bactericidal studies

•Novel water-soluble saldach scaffold with two dangling imidazolium terminals were developed.•Their Mn(III) and Fe(III) complexes with the [M(N2O2)Cl] core have been synthesized and characterized.•Optimization of X = BF4− (IC50 = 22.17 μM) may offer a candidate for breast cancer chemotherapy.•X = BF4− ((MIC/MBC)S. aureus = 1.33/4.99 mM) may be a S. aureus antibiotic candidate.•X = PF6− ((MIC/MBC)E. coli = 1.39/2.58 mM) could serve as E. coli infection fighter.

A series of water-soluble bis-imidazolium salts of the type H2(iPr)2saldach(1,2-Me2Im+-X−)2 (4) and their mononuclear complexes [M(III)Cl{(iPr)2saldach(1,2-Me2Im+-X−)2}] (M = Mn, 5; Fe, 6), (X = Cl, a; PF6, b; BF4, c), where saldach = N,N′-bis(salicylidene)-(±)-trans-1,2-diaminocyclohexane, have been synthesized and characterized using elemental analysis, electronic, spectral, magnetic as well as conductometric methods and MALDI-TOF-, ESI-MS. All complexes possess a distorted square pyramidal coordination geometry with MN2O2Cl chromophore, as revealed by the elemental, spectral and literature data. These salts have been evaluated for in vitro cytotoxicity against HepG-2 and MCF-7 cell lines. Among them, 4c (IC50 = 22.17 μM) exhibited potency against MCF-7. The bactericidal efficacy of 4a–c was screened against a panel of common pathogenic bacteria. Compound 4a was found to be the most potent antibacterial agent and could inhibit all the bacterial strains more effectively than standard antibiotics.

Graphical abstractA new family of water-soluble bis-imidazolium salts, H2(iPr)2saldach(1,2-Me2Im+-X−)2 (4a–c) and their mononuclear Mn(III)/Fe(III) complexes has been successfully isolated and evaluated for their cytotoxic/bactericidal effects.Figure optionsDownload full-size imageDownload as PowerPoint slide