Studying and modeling of the extraction properties of the natural deep eutectic solvent and sorbitol-based solvents in regard to biologically active substances from glycyrrhizae roots

What if the secret to unlocking nature's pharmacy lies not in exotic chemicals, but in a simple sugar alcohol? A new study reveals how sorbitol-based solvents can be fine-tuned to extract bioactive compounds from licorice roots with remarkable precision.

Licorice roots are a treasure trove of bioactive substances, but extracting them efficiently has always been a challenge. Researchers turned to natural deep eutectic solvents (NADES)—eco-friendly alternatives to traditional solvents—and their sorbitol-based cousins. Using a mix of statistical physics, thermodynamics, and physical chemistry, they modeled how these solvents interact with licorice's key compounds, glycyram and licuroside. The experiments were straightforward: macerate the roots in various solvent blends at room temperature for 24 hours, then analyze the results with advanced techniques like HPLC and impedance spectroscopy. The findings were striking. The regression models predicted extraction yields with near-perfect accuracy—R² values of 0.993 for glycyram and 0.976 for licuroside. The dielectric constant (ε) of the solvent emerged as a master variable. A sorbitol-based NADES with ε = 33 ± 2 performed just as well as a conventional sorbitol:ethanol:water mix with ε = 34. But a modified NADES with ε = 41 ± 2 lagged behind, while sorbitol-ethanol-water solvents hit peak performance in the ε = 40–50 range. This work isn't just about licorice—it provides a theoretical framework to predict and optimize solvent performance for any extraction, simply by knowing its dielectric constant.

Key Points

• Sorbitol-based NADES and solvents extract licorice bioactives effectively.
• Theoretical models predict yields with R² up to 0.993.
• Dielectric constant guides optimal solvent selection.