Study on the technology of efficient extraction of eleutheroside E from Acanthopanax senticosus by green solvent DES

Objectives: Acanthopanax senticosus (Rupr. & Maxim.) Harms is a medicinal and edible plant which is clinically used for the recovery and treatment of cardiovascular and central diseases. As a characteristic active pharmaceutical ingredient of Acanthopanax senticosus, eleutheroside E is the core of the therapeutic effect. Organic solvent extraction has low selectivity, low extraction rate, difficulty in separation and purification and safety risks. The purpose of this study was to extract the effective component of Acanthopanax senticosus with a new green solvent.

Methods: In this article, two kinds of deep eutectic solvents (DESs) (DES-1 and DES-2) were synthesised by heating and stirring methods. Eleutheroside E was extracted by ultrasonic extraction with two kinds of DES as extractants and quantitatively analysed by Orbitrap-tandem mass spectrometry (MS/MS).

Results: The main results showed that the initial polarity of the DES was similar to that of 60 to 80% ethanol and hydrogen bond donors were the main factors affecting the polarity of DES. In the test, the viscosity of DES was higher than that of ethanol, and even the addition of a small amount of water (10%) caused intermolecular hydrogen bond disruption and redistribution of the solvent, resulting in a significant decrease in solvent viscosity. The solvents in the test group were stable after standing at 5°C in the dark for 100 days. The extraction rate of eleutheroside E by DES solvent was 5-6 times higher than that by ethanol. DES-1 and DES-2 can efficiently extract eleutheroside E.

Conclusion: This study developed a new method for the application of the green extraction of eleutheroside E with certain practical significance.