Optimization of polysaccharides extraction from Tricholoma mongolicum Imai and their antioxidant and antiproliferative activities.

Response surface methodology was used to optimize the enzyme-assisted extraction parameters for polysaccharides from Tricholoma mongolicum Imai (TMIPs). The orthogonal test design was employed to determine the optimal concentration of three kinds of enzyme (trypsin, pectinase and papain) and the optimal concentrations of trypsin, pectinase and papain were 1.5%, 2.5%, and 2.0% (dry weight % of T. mongolicum Imai powder), respectively. In addition, three variables that remarkably affected the yield of polysaccharides such as extraction temperature, pH and extraction time were studied based on a Box-Behnken design. The results demonstrated that extraction time was the most remarkable factor affecting the TMIPs yield, followed by pH and temperature. Optimal extraction was obtained at 48.4°C, pH 5.4, and extraction time of 132min. Under these optimum conditions, the yield was 24.01%, which is consistent with the predicted value. Furthermore, crude polysaccharides were purified to obtain four fractions. In vitro antioxidant and antiproliferative activities results showed that TMIP-4 had stronger antioxidant and antiproliferative capacity than other fractions.