Novel pyridinium based ionic liquids with amide tethers: Microwave assisted synthesis, molecular docking and anticancer studies

The ionic liquids are remarkable molecules with exceptional properties and applications. The microwave assisted green method was used to synthesize (yield, up to 95%) a new series of pyridinium based ionic liquids (ILs); utilizing molecular hybridization of 2- and/or 3-methyl pyridine and several fluorinated phenyls. The characterization of the synthesized ILs was carried out using different spectroscopic techniques (H-1, C-13, F-18, P-31, B-11 NMR and mass). The DNA binding constants (Kb) of the ionic liquids were in the range of 1.3 x 10(3) to 1.52 x 10(8) M-1; indicating good binding tendencies of the ionic liquids with DNA. All the ionic liquids intercalated with DNA through minor grooves via covalent, intercalative and electrostatic bondings. All the reported ionic liquids showed >50% anticancer activities with two lung cancer cell lines i.e. A549 and H-1229. Moreover, the maximum proliferation inhibitions were 99.16 to 91.24% for 4a series and 9923 to 99.69% for 5a series of the ionic liquids. The docking studies indicated quite good binding affinities (-4.6 to -4.9 kcal/mol.) of the reported ionic liquids with DNA. The experimental results of DNA bindings were in good agreement with those of docking ones. The percentage inhibitions were excellent for 4a, 4e and 5n and, hence, these ionic liquids may be the future anticancer agents. (C) 2019 Elsevier B.V. All rights reserved.