Extraction, purification, and antioxidant activities of polysaccharides from Tricholoma mongolicum Imai.

Ultrasonic-microwave synergistic extraction (UMSE), purification, and characterization of Tricholoma mongolicum Imai polysaccharides (TMIPs) from fruit bodies were investigated in this study. Response surface methodology (RSM) was employed to optimize the UMSE conditions. The results indicated that the optimal extraction conditions were as follows: extraction time of 24.65 min, microwave power of 109.98 W, and water to raw material ratio of 21.62 ml/g. Under optimized conditions, the yield and purity of TMIPs were 35.41 ± 0.62% and 73.92 ± 0.83%, respectively. Crude TMIPs were purified by DEAE-Cellulose 52 chromatography and Sephadex G-100 chromatography to afford four fractions, namely, TMIP-1, TMIP-2, TMIP-3, and TMIP-4. Preliminary TMIP characterization was conducted by Fourier transform infrared spectroscopy. TMIP antioxidant activities were investigated by measuring its scavenging ability on 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radicals, ferric reducing activity power, and reducing power assay. The results indicated that TMIPs have good antioxidant activity.