Natural deep eutectic solvents for the extraction of bioactive steroidal saponins from dioscoreae nipponicae rhizoma

Can a designer liquid concocted from simple natural ingredients replace harsh chemicals in modern drug extraction? Researchers have turned to custom green solvents to unlock valuable compounds from medicinal plants cleanly and efficiently.

Traditional extraction methods often rely on harsh organic solvents, but science is finding greener ways forward. Researchers recently established a simple and eco-friendly technique using natural deep eutectic solvents, or NADESs, to extract four valuable bioactive steroidal saponins from Dioscoreae Nipponicae Rhizoma. Out of twenty-one tailored variants based on choline chloride, betaine, and L-proline, a precise one-to-one mixture of choline chloride and malonic acid outperformed the rest.

Fine-tuning the process through response surface methodology revealed the sweet spot for extraction: a 23.5-minute extraction time, a 57.5 mL/g liquid-solid ratio, and a water content of 54 percent. Microscopic views using a field emission scanning electron microscope captured the physical changes in the plant powder before and after ultrasonic treatment with conventional solvents versus the winning NADES.

Finally, recovery of the extracted compounds proved successful. Using D101 macroporous resin, the team harvested the four steroidal saponins with a satisfying recovery yield ranging from 67.27 to 79.90 percent. This proves that tailored green media hold immense potential to step in as sustainable alternatives to traditional organic solvents.

Key Points

• Tailored choline chloride and malonic acid NADES showed highest extraction efficiency
• Optimized extraction conditions required 23.5 minutes and 54 percent water content
• Macroporous resin achieved satisfactory steroidal saponin recovery between 67.27 and 79.90 percent