Optimisation of high-pressure ultrasonic-assisted extraction and antioxidant capacity of polysaccharides from the rhizome of Ligusticum chuanxiong

High-pressure ultrasound-assisted extraction was used to extract polysaccharides from the Ligusticum chuanxiong rhizomes. Three independent variables, namely, extraction temperature (X-1), ultrasonic power (X-2) and extraction time (X-3) were investigated. Response surface methodology was performed based on the results of single-factor tests. Experimental data were fitted to a second-order polynomial equation using multiple regression analysis, and results were examined using appropriate statistical methods. The optimal conditions were as follows: extraction temperature of 85 degrees C, ultrasonic power of 187W and extraction time of 29 min. Under these conditions, the experimental yield of polysaccharides was 5.33%, which is close to the predicted yield of 5.41%. The extracted and purified polysaccharides showed excellent antioxidative effects on 2,2-diphenyl-1-picryl-hydrazy, hydroxyl and superoxide radicals in vitro. (C) 2015 Elsevier B.V. All rights reserved.