eprintid: 11691 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/01/16/91 datestamp: 2023-11-10 03:26:13 lastmod: 2023-11-10 03:26:13 status_changed: 2023-11-10 01:15:52 type: article metadata_visibility: show creators_name: Ahmad, N.A. creators_name: Jumbri, K. creators_name: Ramli, A. creators_name: Ghani, N.A. creators_name: Ahmad, H. creators_name: Kassim, M.A. title: Synthesis, characterisation and antioxidant properties of ferulate-based protic ionic liquids: Experimental and modelling approaches ispublished: pub keywords: Crystalline materials; Density functional theory; Free radicals; Hydrogen bonds; Ionic liquids; Positive ions; Probability density function; Spectrum analysis, Active pharmaceutical ingredients; COSMO-RS; Density function theory calculations; DFT calculation; Dpph radicals; Free radical scavenging; Intermolecular hydrogen bonds; Protic ionic liquids, Antioxidants note: cited By 13 abstract: Active pharmaceutical ingredients (APIs) in the form of crystalline solid are commonly produced in drug manufacturing industries. However, crystalline solid APIs have a low solubility and the ability to cause polymorphism transformation. In order to overcome these problems, a modification of APIs in the form of protic ionic liquids (PILs) has been proposed. In the present study, a series of five ferulate-based PILs were successfully synthesised and characterised by appropriate spectral analysis. The antioxidant activity of synthesised PILs was determined through the 2,2�diphenyl�1�picrylhydrazyl (DPPH) free radical scavenging assays. The spectroscopy analysis confirmed the formation of PILs supported by the Density Function Theory (DFT) calculation. The synthesised ferulate-based PILs exhibited low EC 50 ranging from 12.93 ± 0.05 to 17.40 ± 0.04 μM indicating a strong antioxidant activity compared to parent acid (EC 50 of 21.40 ± 0.05 μM). Prediction of antioxidant activity of the PILs and their ionic interactions at the molecular level were studied by applying DFT calculation at B3-LYP/6-311G*** level and COSMO-RS. Based on the optimised geometry, the ion-pair of PILs formed a strong directional intermolecular hydrogen bond between the �NH group of the cation with the �COOH group of the anion with interaction energy of �111 to �120 kcal mol �1 . Predicted antioxidant activity indicated that the PILs's cation has a weak interaction with an anion as observed from the �-potential analysis. © 2019 Elsevier B.V. date: 2019 publisher: Elsevier B.V. official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060105123&doi=10.1016%2fj.molliq.2019.01.048&partnerID=40&md5=622db65f63683cc4be89bfa0367b1d8c id_number: 10.1016/j.molliq.2019.01.048 full_text_status: none publication: Journal of Molecular Liquids volume: 278 pagerange: 309-319 refereed: TRUE issn: 01677322 citation: Ahmad, N.A. and Jumbri, K. and Ramli, A. and Ghani, N.A. and Ahmad, H. and Kassim, M.A. (2019) Synthesis, characterisation and antioxidant properties of ferulate-based protic ionic liquids: Experimental and modelling approaches. Journal of Molecular Liquids, 278. pp. 309-319. ISSN 01677322