Preparation Of Phosphorylated Polysaccharides Derived From Bletilla Striata And The Application In Cosmetics

Bletilla striata(Thunb)Reichb.F)is a high medicinal value of Chinese herbal medicine,which contains high levels of hypoglycemic,anti-tumor and other effects of polysaccharides.The polysaccharide phosphate esterification reaction is primarily a covalent modification,and generally it is possible to synthesize low-substituted soluble and highly substituted insoluble phosphorylated polysaccharides.In this paper,water extraction of the polysaccharide was used as experimental raw materials.The characteristics,the physical and chemical properties,the biological activity of the soluble phosphate polysaccharide and the related cosmetics were studied.1.Investigate the optimum conditions for the synthesis of phosphate polysaccharide.The effects of time,temperature,pH,ratio of esterification reagents and polysaccharides on the degree of substitution were investigated by response surface analysis.The optimal conditions were temperature 90.26℃,the reaction time 5 hours,pH=5.21,the ratio of reagent to polysaccharide 0.6 and the optimal degree of substitution was 1.44%.2.The physico-chemical properties of the phosphated polysaccharides with high and low degree of substitution were investigated.The results showed that the phosphate polysaccharides synthesized under acidic conditions are water-soluble and white spongy lumps,but the polysaccharides synthesized under alkaline conditions are white powder;The water content of phosphoric polysaccharide synthesized under acidic and alkaline conditions was 12.15%and 18.23%,the crosslinking degree was 2.12%and 13.72%respectively.Infrared detection can find two kinds of phosphorus ester bond in the phosphate polysaccharide obviously.There were significant differences in the number average molecular weight(Mn)and the computed average molecular weight(Mw).The Mn and Mw of phosphate polysaccharide on acid condition were 4.71×10~4 g/mol and 9.77×10~4g/mol respectively,whereas the Mn and Mw of original polysaccharide were 6.03×10~4 g/mol and9.66×10~4g/mol respectively.3.To investigate the antioxidant capacity,hygroscopicity and moisturizing ability of soluble phosphate polysaccharides,the results indicated that when the concentration of the phosphate polysaccharide reached 4mg/mL,the scavenging rate on·OH was 80%almost,however other aspects of the antioxidant capacity were weak even none.Phosphate polysaccharides moisturizing capacity can be seen that it is in the high humidity and low humidity environment,moisture absorption capacity was between hyaluronic acid and glycerol.Phosphate polysaccharide added in cosmetics found that the capacity of clearing melanin capacity was zero,however,the skin moisture content increased significantly,and the water content decreased slowly.Adding 10%~15%of the product can get high moisturizing cosmetics.