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

Abstract

AbstractSingle‐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 °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 °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 HepG2 (56.83%) cancer cell lines, and induced RAW264.7 murine macrophage cells to release considerable amount of nitric oxide (41 μmol).Practical applicationsSeaweeds are rich sources of diverse bioactive compounds with valuable nutraceutical, pharmaceutical and cosmeceutical potentials. Nizamuddinia zanardinii is a marine brown seaweed and belong to Sargassaceae family. Iranian South Coasts have abundant supply of N. zanardinii which has a great potential for mariculture and can be utilized as a source of natural compounds. Fucoidan, which is a sulfated polysaccharide found in brown seaweeds, have shown promising health benefits for humans. In this study, the effects of extraction time, ultrasonic power, water–solid ratio, and extraction temperature were investigated on yield, structural, molecular, and biological properties of ultrasound extracted fucoidan. This study provides a practical and effective instruction into the application of ultrasound in the extraction of fucoidan. Additionally, the ultrasound extracted fucoidan exhibited appreciable antioxidant, anticancer, and macrophage‐stimulating capacity indicating its potential value for health and food industry.