OBJECTIVE  To prepare polysaccharides from two sources of Polygonatum cyrtonema Hua. and Polygonatum filipes Merr., and to optimize the extraction process, so as to analyze the physical and chemical properties and evaluate the activity of delaying skin aging.

METHODS  The water extraction and alcohol precipitation method was used to optimize the extraction conditions of polysaccharides by single factor and orthogonal test with extraction temperature, solid-liquid ratio and extraction time as the investigation factors. The polysaccharides were purified by protein removal and dialysis. The monosaccharide composition and structure were analyzed by HPLC and FT-IR. The antioxidant and delay skin aging activities were evaluated by in vitro free radical scavenging test and H₂O₂-induced human skin fibroblast (HFF-1) senescence test.

RESULTS  The optimum extraction conditions were as follows: extraction temperature 80 ℃, solid-liquid ratio 1∶25, extraction time 1.0 h. Polygonatum cyrtonema Hua. polysaccharide(PCP) and Polygonatum filipes Merr. polysaccharide(PFP) both contained D-mannose, D-galacturonic acid monohydrate, D-(+)-glucose, D-galactose and DL-arabinose, while PFP contained characteristic monosaccharide Rhamnose. The molar percentages of D-mannose and D-(+)-glucose in PCP were higher, while the molar percentages of D-mannose, D-galactose and D-galacturonic acid monohydrate in PFP were higher than those in PCP. PCP contained two kinds of glycosidic bonds of α and β configurations, and the characteristics of uronic acid in PFP was significant. PCP and PFP showed good free radical scavenging ability and delay aging of skin cells, and the activity of PFP was stronger.

CONCLUSION  In this experiment, PCP and PFP with different monosaccharide composition and content are obtained by process optimization. Both of them have good delay skin aging activity. The results of this study could provide a scientific basis for the development and application of Polygonatum polysaccharide in anti-aging cosmetics.