¹³C cell wall enrichment and ionic liquid NMR analysis: Progress towards a high-throughput detailed chemical analysis of the whole plant cell wall

The ability to accurately and rapidly measure plant cell wall composition, relative monolignol content and lignin-hemicellulose inter-unit linkage distributions has become essential to efforts centered on reducing the recalcitrance of biomass by genetic engineering. Growing ¹³C enriched transgenic plants is a viable route to achieve the high-throughput, detailed chemical analysis of whole plant cell wall before and after pretreatment and microbial or enzymatic utilization by ¹³C nuclear magnetic resonance (NMR) in a perdeuterated ionic liquid solvent system not requiring component isolation. 1D ¹³C whole cell wall ionic liquid NMR of natural abundant and ¹³C enriched corn stover stem samples suggest that a high level of uniform labeling (>97%) can significantly reduce the total NMR experiment times up to ∼220 times. Similarly, significant reduction in total NMR experiment time (∼39 times) of the ¹³C enriched corn stover stem samples for 2D ¹³C-¹H heteronuclear single quantum coherence NMR was found.