Optimization of Ultrasonic Assisted Extraction and Bioactivity of Ophiopogon japonicus Polysaccharides by Response Surface Methodology

Abstract A Box–Behnken design (BBD) of response surface methodology (RSM) is employed to further optimize ultrasonic‐assisted extraction conditions for Ophiopogon japonicus polysaccharides. The results show that optimized extraction conditions are liquid–solid ratio of 22:1 mL g −1 , ultrasonic time of 27 min, and ultrasonic power of 200 W. Under these conditions, the mean experimental value of extraction yield (39.49%) is achieved, which is 1.33 times that of distilled water leaching extraction (29.68%). In addition, one of the eluting fractions, SPs‐1 , has high α ‐glucosidase and α ‐amylase inhibitory activities as well as 1,1‐Diphenyl‐2‐picrylhdrazyl radical and α‐glucosidase, 2,2’‐Azino‐bis (3‐ethylbenzthiazoline‐6‐sulfonic acid) cation scavenging activities with an IC 50 value of 0.060, 0.021, 0.50, and 0.10 mg mL −1 . Therefore, SPs‐1 from O. japonicus can be considered as multifunctional biological ingredients to be used in anti‐hyperglycemic pharmaceutical formulation and antioxidant in functional foods.