Salicylate-Based Protic Ionic Liquids as a Potential Antioxidant

Salicylate-based protic ionic liquids (PILs) were synthesised, characterised and assessed in this study for potential antioxidant in drug design. The synthesised PILs were known as 3-dimethylamino-1-propanol salicylate (3DMAPS) and 3-diethylamino-1propanol salicylate (3DEAPS). Proton nuclear magnetic resonance ( 1 HNMR), Fourier transformation infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to characterise the synthesised PILs. Furthermore, the antioxidant activity of the synthesised PILs was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Both 3DMAPS and 3DEAPS showed a good antioxidant activity compared to parent acid (salicylic acid) as these two compounds could scavenge 20% of DPPH free radical at a concentration of 66.76 0.09 M and 27.27 0.10 M, respectively.