Ultrasound-assisted extraction of sulfated polysaccharide from Nizamuddinia zanardinii: Process optimization, structural characterization, and biological properties

摘要

Single-factor experiment and Box-Behnken design were used to evaluate and optimize the effect of extraction time (40, 50, and 60 min), ultrasonic power (100, 150, and 200 W), water-solid ratio (60, 70, and 80 mL/g), and extraction temperature (70, 80, and 90 degrees C) on the recovery of fucoidan from Nizamuddinia zanardinii by ultrasound-assisted extraction method (UAE). The optimal extraction conditions were as follows: extraction time of 58 min, ultrasonic power of 196 W, water-to-raw-material ratio of 80 mL/g, and extraction temperature of 70 degrees C. Under these conditions, the polysaccharide yield was 3.51%. Extracted fucoidan was composed of fucose (32.33%), galactose (29.95%), mannose (27.97%), xylose (6.56%), and glucose (3.19%). The UAE-extracted fucoidan had appreciable DPPH radical scavenging and reducing power. The fucoidan exhibited notable cell growth inhibition against HeLa (62.36%) and HepG(2) (56.83%) cancer cell lines, and induced RAW264.7 murine macrophage cells to release considerable amount of nitric oxide (41 mu mol).