Ultrasound-Assisted Enzymatic Extraction of Polysaccharides from Tricholoma matsutake: Optimization, Structural Characterization, and Inhibition of α-Synuclein Aggregation

This study optimized ultrasound-assisted enzymatic (UAE) extraction of TMP (Tricholoma matsutake polysaccharide) through response surface methodology. The optimal conditions included complex enzyme comprising 1.15% cellulase, 0.60% pectinase, and 0.95% dispase, with ultrasound for 24 min at 84.5 degrees C and enzyme hydrolysis at pH 5.0. This process yielded 19.74 +/- 0.51% TMP, exceeding traditional hot water extraction by over four times. Fourier transform infrared spectroscopy (FT-IR) confirmed that UAE did not alter the structure of TMP. In vitro experiments indicated that TMP-UAE demonstrated enhanced antioxidant properties. Further purification through DEAE-52 and Sephadex G-100 chromatography resulted in a homogenous polysaccharide fraction (TMP). Characterization indicated that TMP has an average molecular weight of 2.79 x 104 Da, composed of fucose, galactose, glucose and mannose in a 2.00:9.44:86.29:2.28 molar ratio. FT-IR indicated the presence of C-O-C glycosidic bonds and pyranyl-type sugar rings. Scanning electron microscopy displayed loose lamellar structures with small pores. Finally, TMP exhibited therapeutic potential against C. elegans in Parkinson's disease, including reducing alpha-synuclein aggregation, protecting dopaminergic neurons, and prolonging lifespan. This study provides an efficient extraction method for TMP and an insight into its neuroprotective effect in PD C.elegans.