Microwave assisted extraction of polysaccharides from Yupingfeng powder and their antioxidant activity

Background: Microwave assisted reflux extraction of polysaccharides YPF-P from the famous Chinese traditional drug, Yupingfeng powder, optimization of extracting conditions and evaluation of their antioxidant activity were conducted in this study. Results: Single factor effect trends were achieved through yields and contends of YPF P obtained from different extracting conditions. Then through a three level, four variable Box Behnken design of response surface methodology adopting yield as response, the optimal conditions were determined as follows: Material/solvent ratio 1:23.37, microwave power 560 W, Extraction temperature 64°C, and extraction time 9.62 min. Under the optimal conditions, the YPF P extraction yield was 3.23%, and its content was detected as 38.52%. In antioxidant assays, the YPF P was tested to possess 1,1 diphenyl 2 picrylhydrazyl (DPPH) radical scavenging activities with an IC50 value of 0.262 mg/ml. In addition, YPF P was also proved to have relatively low ferric reducing antioxidant power (FRAP), compared to Vc, through FRAP assay. Conclusion: In the microwave assisted reflux extraction research, good YPF P yield was achieved from materials with relatively low YPF P content. And for the first time, both DPPH and FRAP assays were conducted on YPF P, which proved that the antioxidant activity of YPF P contributed to the functions of this medicine.