Biomass-Derived Ionic Liquids Based on a 5-HMF Platform Chemical: Synthesis, Characterization, Biological Activity, and Tunable Interactions at the Molecular Level

A new family of protic ammonium ionic liquids (ILs) with various inorganic anions was synthesized from bio-derived 5-HMF. Starting with cellulose biomass, a complete preservation of the C-6 unit was achieved throughout the synthetic sequence (no carbon loss). Evaluation of green metrics showed a significant advantage of the developed bio-derived pathway to access ILs from a natural renewable source, depending on feasible routes to 5-HMF manufacturing. The reduced number of synthetic steps and availability of the starting materials were the key advantages. Experimental physicochemical and biological studies, as well as computational modeling revealed a unique multifunctional intrinsic organization of these bio-derived ILs. The nature of interactions between the cations and anions of the novel ILs was mapped at the molecular level. The substituents in the cationic core and the nature of the original building blocks had a prominent impact on cytotoxicity of the novel ILs. The obtained results suggest possible sustainable applications of the least toxic ILs, while the regulation of biological activity of the ILs via the corresponding structural adjustments can find biological and medicinal applications. The 5-HMF-derived IL with a sulfate anion demonstrated potentially useful properties in dissolution of microcrystalline cellulose.

Automated summary

A new family of protic ammonium ionic liquids (ILs) with various inorganic anions was synthesized from bio-derived 5-HMF, showing potential sustainable applications and unique multifunctional intrinsic organization. The interaction nature between the cations and anions of the ILs was mapped at the molecular level, impacting cytotoxicity and potential dissolution properties. The results suggest the potential for biological and medicinal applications with structural adjustments for regulation of ILs' biological activity.