Study On Extraction, Isolation, Structure Analysis And Radiation Protection Activity Of Polysaccharides From Parmelia Tinctorium

Objective:Polysaccharide is composed of a number of monosaccharides,which is one of the three basic materials of life.With the development ofbiotechnology and chemical purification technology,chemical structure and pharmacological effect of polysaccharides were gradually identified and applied.Up to now,it was reported that polysaccharides could be used to anti-tumor,anti-oxidant,anti-virus,anti-inflammation, anti-radiation,regulate blood-fat and so on.Lichens are slow-growing symbiotic organisms consisting of a fungus and an algae.They have been used for medicinal purposes throughout the ages,and beneficial claims have to some extent been correlated with their polysaccharide content.To explore the relation between structure and bioactivity,this paper presents extraction,isolation,identification of polysaccharides from Parmelia tinctourium,a kind of lichen,investigates its protective effect in radiation-injured mice.Methods:DEAE-32-Cellulose and Sephadex G-150 were adopted to separate and purify the water solution poiysaccharides from Parmelia tinctourium,two homogeneous polysaccharides named WPT-A and WPT-B have been obtained and identified.The structure feature of WPT-A,WPT-B were characterized by chemical and spectroscopic methods.The effects of WPT-A protection on hematopoietic function,DNA demage repair were performed.Results:WPT-A is composed of galactose,marmose,glucose,and one heptoses.Its main chain is comprised of 1,6 linked galactose,1,3 linked galactose,1,3,4 linked mannose. Side chain are comprised of 1,4 linked glucose,1,2,3,6 linked mannose,2,6 linked 3,4-di-O-methyl-D-mannonitrile,1,2,3,4,6 linked glucose and terminal linked 1-glycero-d-mannoheptitol.WPT-B is composed of glucose,mannose and galactose.Its main chain is comprised of 1,2,3,4,6 linked glucose.Side chain are comprised of 1,6 linked galactose, 1,2,3,6 linked marmose,1,3,4 linked mannose,1,3 linked galactose and terminal linked glucose.The assay of WPT-A protective effects on hematopoietic function and DNA repair in radiation-injured mice indicates that On the 7th day after irradiation compared with the negative control group number of nucleated cells in bone marrow, colony-forming unit of spleen and spleen index of mice have treated with polysaccharides from lichen intraperitoneally for three days prior to irradiation increased markedly.Statistically significant dose-effect relationships were observed in all the indexes of comet assay,the DNA repair of medicine group increased significantly and the residual damage decreased gradually.Conclusion:WPT-A,WPT-B are new heteropolysaccharides from Parmelia tinctourium,their structures were characterized for the first time.WPT-A have protective effect on radiation-injured mice.