Multiscale analysis and engineering of aromatic deep eutectic solvent for bioactive components extraction and lignocellulose fractionation

Abstract

Deep eutectic solvents (DES) are increasingly used in biomass processing, where extraction of bioactive compounds and lignocellulose fractionation often need to be considered together. However, the unclear molecular mechanisms hinder their engineered application. In this work, aromatic DES were synthesized using guaiacol (Gua) or p‐toluenesulfonic acid (PTSA) as a third component. ChCl‐EG‐Gua achieved the highest extraction performance, yielding 105.48 mg RE/g DW flavonoids and 215.91 mg GAE/g DW polyphenols while preserving strong antioxidant activity. ChCl‐EG‐PTSA removed 97.60% hemicellulose and 77.68% lignin. Multiscale modeling combining density functional theory (DFT) and molecular dynamics simulations revealed that the aromatic hydrogen bond donor (HBD) engages with target extracts via ππ stacking and CHπ interactions. This forms a distinct spatial configuration that strengthens van der Waals (vdW) forces, elucidating the underlying interaction mechanism. This work provides molecular guidance for balancing extraction, fractionation, and solvent constraints in integrated biomass utilization.