This study optimizes the extraction process and explores the antioxidant activity of Gastrodia elata polysaccharides, aiming to provide theoretical reference for the extraction, development, and application of the polysaccharides. Polysaccharides were extracted from G. elata by an ultrasonic-assisted method with deep eutectic solvents. The extraction process was optimized by single factor and response surface tests. The antioxidant activity of polysaccharides was evaluated by DPPH and ABTS⁺ free radical scavenging rates. The optimal deep eutectic solvents were composed of choline chloride and lactic acid at a molar ratio of 1:2. The optimal extraction conditions were the ultrasonic treatment at 50 ℃ for 48 min, a solid-to-liquid ratio of 1:38, and a water content of 42%. Under these conditions, the polysaccharide yield reached (19.88±0.93)%. The results of antioxidant activity experiment in vitro showed that the scavenging rates of G. elata polysaccharides on DPPH and ABTS⁺ free radicals were up to (26.39±1.47)% and (30.61±0.16)%, respectively, which indicated that the polysaccharides extracted by the deep eutectic solvents had a certain antioxidant ability. The extracted polysaccharides can be further studied and developed as a potential natural antioxidant.
Polysaccharides/pharmacology* ; Gastrodia/chemistry* ; Antioxidants/pharmacology* ; Deep Eutectic Solvents/chemistry* ; Solvents/chemistry*