The total tannins of Geum japonicum Thunb. var. chinense extracted by green and natural deep eutectic solvent: Extraction optimization, component identification and hypoglycemic activity

What if the key to unlocking nature's medicine cabinet lies in a green, sugar-based solvent? A new study reveals how a natural deep eutectic solvent, paired with ultrasound, efficiently extracts bioactive compounds from a traditional herb, with rosmarinic acid as the star performer.

Forget harsh chemicals—the future of plant extraction might be as sweet as it sounds. Researchers turned to a natural deep eutectic solvent (NADES), a green alternative, to pull out valuable compounds from Anchusa italica flowers, a traditional remedy for cardiovascular issues. The result? A cleaner, more efficient way to harness nature's chemistry.

Using advanced UPLC-Q-Exactive Orbitrap-MS, the team identified a wealth of bioactive molecules, with rosmarinic acid (RA) dominating at nearly 40% of the methanolic extract. But the real win came when they paired the NADES with ultrasonic assistance, optimizing conditions through response surface methodology. Key factors included a water content of 29.051% and a material-liquid ratio of 20.961 mL/g, with extraction time of 35.725 minutes and ultrasonic power of 240.342 W.

The optimized process yielded a comprehensive evaluation value (CEV) of 222.452, reflecting high total polyphenol content and RA levels. In vitro tests showed RA's impressive antioxidant power, scavenging over 90% of DPPH and ABTS radicals. This sustainable protocol not only boosts extraction efficiency but also underscores the potential of NADES in green chemistry, offering a promising path for natural product research.

Key Points

• NADES + ultrasound boosts extraction yield of polyphenols and rosmarinic acid.
• Rosmarinic acid dominates at 39.85% of methanolic extract.
• Optimized conditions yield CEV 222.45 and >90% radical scavenging.