Development and mechanistic insights into a novel deep eutectic solvent-based aqueous two-phase system for sustainable recovery of ginsenosides from Panax quinquefolius L.

Abstract

Ginsenosides, the principal bioactive constituents in American ginseng (Panax quinquefolius L.), have gained significant pharmacological interest due to their cardiovascular protective effects, antitumor activities, and immunomodulatory properties. This study employed an ultrasonic-assisted deep eutectic solvent-based aqueous two-phase system (UAE-DES-ATPS) to accomplish an approach to simultaneous extraction and selective separation of polysaccharides and ginsenosides from the fibrous roots of Panax quinquefolius L. Of the six evaluated choline chloride-based DESs, the combination of choline chloride and N,N-dimethylurea showed exceptional results and enhanced effectiveness. Through comprehensive optimization, the optimal aqueous biphasic system composition was established as 80 % (w/w) choline chloride-N,N-dimethylurea and 60 % (w/w) K₂HPO₄, achieving a remarkable ginsenoside extraction yield of 73.20 mg/g. This represents a 54.6 % enhancement compared to conventional extraction systems (47.36 mg/g). Key operational parameters including solid-liquid ratio (1:25 g/mL), ultrasonic duration (30 min), and temperature (60°C) were systematically optimized. Comparative analysis revealed that this green approach outperforms traditional ultrasonic-assisted extraction methods in both yield and purity. Structural characterization (FT-IR, ¹H NMR) confirmed DES formation, while HPLC quantification validated the high purity of obtained ginsenosides. Mechanistic insights from quantum chemical calculations and molecular dynamics simulations revealed that the superior performance of choline chloride-N,N-dimethylurea originates from its enhanced solvent accessible surface area (SASA), optimized hydrogen-bonding interactions with ginsenosides, and favorable intermolecular interaction energies.