Effects of Different Extraction Methods on the Molecular Composition and Biological Activities of Polysaccharides from Pleione yunnanensis

In this study, polysaccharides from Pleione yunnanensis (Orchidaceae, abbreviated as P. yunnanensis) were obtained by five methods: hot water extraction, microwave extraction, cold water extraction, enzymatic extraction, and ultrasonic extraction. Their structural characteristics, antioxidant properties, and hypolipidemic activities were explored. The results showed that the five polysaccharides all exhibited typical infrared spectral characteristics of polysaccharides. Their monosaccharide compositions were basically the same, all consisting of glucose and mannose, but their surface morphologies differed significantly. The polysaccharide extracted by the enzymatic method had the lowest molecular weight but showed good antioxidant properties. The polysaccharides extracted by ultrasonic and cold water methods showed great potential for hypolipidemic effects. Different extraction methods had impacts on the physicochemical properties, biological activities, and microstructures of P. yunnanensis polysaccharides. In practical applications, it is necessary to select appropriate extraction methods according to different requirements. The results of this study provide a reference basis for the precise development and utilization of P. yunnanensis polysaccharides.