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

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.

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.

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.