Anti-bacterial, catalytic and docking behaviours of novel di/trimeric imidazolium salts

2-Chloro-3-cyano-4-nitrobenzyl pyridinium bromide as a potent anti-lung cancer molecule prepared using a single-step solvent-free method

Mono-/dimeric-substituted pyridinium and pyrazolium bromides were prepared under conventional and solvent-free silica-supported domestic microwave conditions. The atom economy, environmental product mass intensity and product mass intensity for solvent-free reactions showed significant importance for the synthesis of target molecules. 4-Nitrobenzyl-substituted pyridinium bromide showed potent anticancer properties compared with mono-/dimeric-substituted pyridinium and pyrazolium bromides against a lung cancer cell line (A-549). Molecular simulation studies were carried out for mono-/dimeric-substituted pyridinium and pyrazolium bromide against protein human CDK1/cyclinB1/CKS2 using the AutoDock program.

Synthesis of potent MDA-MB 231 breast cancer drug molecules from single step

We have prepared novel potent breast cancer drug molecules from non-toxic and inexpensive method. Column chromatography is not necessary for purification of target molecules. The value of overall atom economy, environmental factor, environmental catalyst and product mass intensity gives additional merits for this synthetic method. Synthesized flexible dimeric imidazolium bromides showed less toxicity and gives excellent anticancer response against normal mammary epithelial cells. Novel dimeric pyridinium bromides showed excellent anticancer response against tested cancer cell lines. In cell cycle, novel flexible dimeric pyridinium bromides showed significant arrest in the G2/M phase by nearly three folds, when compared with control drug. We have studied the targeting epidermal growth factor receptor for all the synthesized flexible amino substituted and methyl substituted dimeric pyridinium bromides.

Discovery of Novel Dimeric Pyridinium Bromide Analogues Inhibits Cancer Cell Growth by Activating Caspases and Downregulating Bcl-2 Protein

Flexible dimeric substituted pyridinium bromides with primary and tertiary amines are prepared by conventional and solvent-free methods. The formation of compounds 2 and 4 is much easier than that of compounds 1 and 3 because of the benzyl carbon which is more electropositive than the primary alkyl carbon. The newly synthesized dimeric pyridinium compounds are optimized using DFT and B3LYP 6-31 g(d,p). The in vitro antiproliferative activity is studied in lung (A549) and breast cancer cell lines (MDA-MB 231). Among the four compounds, 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4 showed potent anticancer activity when compared to the standard drug 5-fluorouracil. 1,1'-(1,3-Phenylene bis(methylene)bis 2-aminopyridinium bromide 4 is not toxic to normal cell lines 3T3-L1 and MRC-5 cell lines. Also, 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4-induced apoptosis in cancer cell lines is examined using AO/EB and Hoechst staining, which is further supported by cell cycle analysis. Western blot analysis showed that 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4 induces apoptosis through the extrinsic apoptotic pathway by upregulating caspase 3 and caspase 9. This compound also downregulates intrinsic apoptotic proteins, including Bcl-2, Bcl-x, and Bad. From the present study results, it is confirmed that 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4 has potent anticancer activity when compared to other compounds.

Synthesis, Characterization, Pharmacogenomics, and Molecular Simulation of Pyridinium Type of Ionic Liquids and Their Applications

Substituted pyridinium bromides are prepared by conventional and solvent-free greener methods. The solvent-free solid-phase (greener) method is superior to the conventional method because of its nontoxic nature, simple reaction setup procedure, and twenty times less time consumption. Column chromatography and toxic organic solvents are avoided. Substituted pyridinium salts 1-2(a-c) show excellent catalytic response in the preparation of β-amino carbonyl derivatives using the conventional approach. Pharmacokinetics is very important in target validation and in shifting a lead compound into a drug. The physicochemical properties discussed here can be used effectively in the drug designing candidate, which is a cumbersome process in clinical research. In addition, molecular simulations are demonstrated, and compounds 1-2(a-c) possess the most potent VEGFR-2 kinase protein inhibitory activities, and most interestingly, compound 2a strongly binds and regulates the VEGFR-2 kinase activity in therapeutic approaches and cancer prevention.

Efficient Antibacterial Dimeric Nitro Imidazolium Type of Ionic Liquids from a Simple Synthetic Approach

Synthesis of dimeric nitro-substituted imidazolium salts under the conventional/solvent-free method is reported. The solvent-free method is more important than the conventional one because of its shorter reaction time, higher yield from easily available starting material, environmental safety, and so forth. Counter anion exchange is carried out using inorganic salt, which is dissolved in deionized water at room temperature. In antibacterial studies, dimeric nitro-substituted imidazolium cations with bromide counter anions showed excellent inhibition against E. coli and P. aeruginosa bacteria. These experimental results were further supported by molecular docking studies. All the compounds (3-6) (a-d) showed excellent antibacterial activity than the standard drugs (gentamycin, nalidixic acid, oflaxacin, ciproflaxacin, and amikacin). Molecular docking studies showed strong hydrogen bonding, polar and hydrophobic interactions between the dimeric imidazolium salts, and Escherichia coli/Pseudomonas aeruginosa/Proteus vulgaris/Staphylococcus aureus receptors.

Quaternary Ammonium Compounds (QACs) and Ionic Liquids (ILs) as Biocides: From Simple Antiseptics to Tunable Antimicrobials

Quaternary ammonium compounds (QACs) belong to a well-known class of cationic biocides with a broad spectrum of antimicrobial activity. They are used as essential components in surfactants, personal hygiene products, cosmetics, softeners, dyes, biological dyes, antiseptics, and disinfectants. Simple but varied in their structure, QACs are divided into several subclasses: Mono-, bis-, multi-, and poly-derivatives. Since the beginning of the 20th century, a significant amount of work has been dedicated to the advancement of this class of biocides. Thus, more than 700 articles on QACs were published only in 2020, according to the modern literature. The structural variability and diverse biological activity of ionic liquids (ILs) make them highly prospective for developing new types of biocides. QACs and ILs bear a common key element in the molecular structure-quaternary positively charged nitrogen atoms within a cyclic or acyclic structural framework. The state-of-the-art research level and paramount demand in modern society recall the rapid development of a new generation of tunable antimicrobials. This review focuses on the main QACs exhibiting antimicrobial and antifungal properties, commercial products based on QACs, and the latest discoveries in QACs and ILs connected with biocide development.

Mechanisms of action of ionic liquids on living cells: the state of the art

Ionic liquids (ILs) are a relatively new class of organic electrolytes composed of an organic cation and either an organic or inorganic anion, whose melting temperature falls around room-temperature. In the last 20 years, the toxicity of ILs towards cells and micro-organisms has been heavily investigated with the main aim to assess the risks associated with their potential use in (industrial) applications, and to develop strategies to design greener ILs. Toxicity, however, is synonym with affinity, and this has stimulated, in turn, a series of biophysical and chemical-physical investigations as well as few biochemical studies focused on the mechanisms of action (MoAs) of ILs, key step in the development of applications in bio-nanomedicine and bio-nanotechnology. This review has the intent to present an overview of the state of the art of the MoAs of ILs, which have been the focus of a limited number of studies but still sufficient enough to provide a first glimpse on the subject. The overall picture that emerges is quite intriguing and shows that ILs interact with cells in a variety of different mechanisms, including alteration of lipid distribution and cell membrane viscoelasticity, disruption of cell and nuclear membranes, mitochondrial permeabilization and dysfunction, generation of reactive oxygen species, chloroplast damage (in plants), alteration of transmembrane and cytoplasmatic proteins/enzyme functions, alteration of signaling pathways, and DNA fragmentation. Together with our earlier review work on the biophysics and chemical-physics of IL-cell membrane interactions (Biophys. Rev. 9:309, 2017), we hope that the present review, focused instead on the biochemical aspects, will stimulate a series of new investigations and discoveries in the still new and interdisciplinary field of "ILs, biomolecules, and cells."