Direct dissolution and NMR analysis of the plant cell walls via perdeuterated pyridinium-based ionic liquid

The utilization of biomass for biofuels does not lead to a net increase in CO₂ emissions, which is recognized as the major factor for climate warming, and thus is considered to be viable alternatives to nonrenewable petroleum resources. A better understanding of plant cell wall structures and their constituents (i.e., polysaccharides and lignin) is considered essential for the efficient and economical transformation of differing sources of biomass into liquid fuels and chemicals via lignin engineering. While dissolving biomass in imidazolium-based ionic liquids was widely reported in the literature, herein, we report the perdeuterated pyridinium-based ionic liquid for direct dissolution and NMR analysis of the biomass to reveal the detailed structure of the plant cell walls. Further applications of this novel ionic liquid-based solvent system include the determination of lignin content, H:S:G ratios and inter-unit lignin bonding arrangements, without the need for lengthy lignin isolation procedures.