Study On The Isolation,Purification,Structure Identification And Biological Activity Of Polysaccharides From Leaves Of Sequoia Sempervirens

Polysaccharide is a biological macromolecule with a variety of biological activities.The biological activity depends on its internal structure to a certain extent.The level of its extraction rate is affected by various factors in the extraction process.Explore its extraction,separation and purification process,can obtain purer polysaccharides more efficiently,and measuring its biological activity can provide reference value for subsequent development.In this paper,the effects of cellulase concentration,ultrasonic pH,ultrasonic temperature and ultrasonic time on the extraction rate of Sequoia sempervirens leaves were studied,and various separation and purification methods were compared.The structure of Sequoia sempervirens leaves was preliminarily explored and its biological activities were determined,so as to explore the action mechanism of polysaccharides from leaves of Sequoia sempervirens,improve the value of Sequoia sempervirens leaves and provide a theoretical basis for subsequent development.The main findings are as follows:1.The optimum extraction conditions were as follows: enzyme concentration2%,ultrasonic pH5.0,ultrasonic time 13 min and ultrasonic temperature 52℃.Under these conditions,the extraction rate of polysaccharide was 4.39%.2.Among various separation and purification methods,enzyme-TCA method has the best effect,with protein removal rate and polysaccharide retention rate of68.48% and 65.76% respectively.3.The monosaccharide composition of Sequoia sequoia leaf refined polysaccharide was separated by DEAE-52 and Sephadex G-100 chromatography is mannose: galacturonic acid: glucose: galactose: fucose = 8.15: 19.62: 33.63: 24.41:14.2,and the main monosaccharides are galacturonic acid,glucose and galactose.4.polysaccharides from leaves of Sequoia sempervirens have certain antioxidant activity.5.polysaccharides from leaves of Sequoia sempervirens promotes the apoptosis of A549 cells by up-regulating the expression level of reactive oxygen species in A549 cells,and inhibits the migration ability of A549 cells.