Isolation, purification, and structural elucidation of Stropharia rugosoannulata polysaccharides with hypolipidemic effect
Yinlu Gao, Gulijiannaiti Abuduaini, Chenhe Yang, Shanshan Zhang, Yanrong Zhang, Hongxiu Fan, Teng Xu, Chenligen Bao, Hongcheng Liu, Dawei Wang, Tingting Liu
Abstract
Stropharia rugosoannulata is a widely grown edible mushroom with a high nutritional value. S. rugosoannulata polysaccharides is one of the most important bioactive components of S. rugosoannulata and has a wide range of activities. A S. rugosoannulata polysaccharides, named SRF-3, was derived from the S. rugosoannulata extraction by freeze-thaw combine with hot water extraction method, then prepareed with DEAE-cellulose column and Sephacryl S-200 HR gel column, and its hypolipidemic activity was determined. The structural characteristics of SRF-3 were analyzed by infrared spectral scanning (FT-IR), ultra-high performance liquid chromatography (UHPLC), acid hydrolysis, methylation analysis, nuclear magnetic resonance (NMR), and Gas Chromatography-Mass Spectrometer (GC-MS). SRF-3 is composed of mannose, galactose, methyl galactose and fructose with ratios of 16, 12, 58 and 12, respectively. In addition, the average relative molecular mass of SRF-3 is approximately 24 kDa. The main chain of SRF-3 is mainly composed of repeating α-D-1,6-Gal p and α-D-1,6-Me-Gal p units, with branches in the O-2 position of Gal. The structure is presumed to be a mannogalactan, with a small amount of t-β-D-Man p present as a side chain. Hypolipidemic activity assay showed that SRF-3 had good antioxidant and hypolipidemic effects in vitro , suggesting that SRF-3 have potential application in reducing liver fat accumulation.