Synthesis, antibiotic structure–activity relationships, and cellulose dissolution studies of new room-temperature ionic liquids derived from lignin

Abstract Background Ionic liquids (ILs) are promising pretreatment solvents for lignocellulosic biomass, but largely prepared from petroleum precursors. Benzaldehydes depolymerized lignin, such as vanillin, syringaldehyde, and 4-methoxy benzaldehyde, represent renewable feedstocks the synthesis of ionic liquids. We herein report syntheses novel lignin-derived liquids, with extended N -alkyl chains, examine their melting points, cellulose dissolution capacities, toxicity profiles against Daphnia magna E. coli strain 1A1. The latter organism has been engineered to produce isoprenol, a drop-in biofuel precursor commodity chemicals. Results new N,N -diethyl -dipropyl methyl benzylammonium ILs were at room temperature, showing 75–100 °C decreased points compared N,N,N -trimethyl analog. Extension chains also increased antibacterial activity threefold, while vanillin showed 2- 4-fold lower those syringaldehyde 4-methoxybenzaldehyde. trend anions was found be methanesulfonate < acetate hydroxide. Microcrystalline dissolution, 2 4 wt% after 20 min 100 °C, observed in all using light microscopy IR spectroscopy. Conclusions H-, S- G-lignin oxidation products provided differential cytotoxic D. , suggesting these compounds could tailored application specificity within biorefinery.