Structure Andanticoagulant Activity Of Polysaccharide From The Mycelium Of Polyporus Albicans (Imaz.) Teng

Polyporus albicans (Imaz.) Teng is a traditional Chinese medicine and edible fungus distributed in Jilin Province of China, which is a Polyporaceae fungus belonging to the Basidiomycetes. There are a few studies of the structure and immunobiological activity of Polyporus albicans (Imaz.) Teng have been reported, but its anti-coagulation activities after sulfate modification are still unknown. Our study is on Polyporus albicans (Imaz.) Teng purification, structural analysis and the anti-coagulation activity after sulfate modification. These findings indicate a huge potential clinical use of Polyporus albicans (Imaz.) Teng.PTPI, one of the most proportional Polyporus albicans(Imaz.) Teng polysaccharide, was obtained by graded freezing, alcohol- precipitation, enzymatic and Sevage deproteinization and HPLC purification. The HPLC data indicated that PTPI was composed of glucose, galactose and seminose residues in the ratio of 15.7:4.2:1, with molecular weight of 3.3×10~4 Da,.PTPI was analyzed by acid hydrolysis, periodate oxidation, Smith degradation, methylation, GC-MS, IR, NMR to identify the structure. The results showed that the main chain of PTPI is composed of (1→2)-β-D-Man residues and a few (1→3)α-Glc, Man residues. PTPI is branched at the (1→2, 6)-β-Glc every two hexose residues along the main chain. The following structure indicates the repeated units of PTPI:Next, we modified the Polyporus albicans (Imaz.) Teng polyose by the method of chlorosulfonic acid-pyridine. The IR spectra of sulfate modified polysaccharides present a S=O characteristic absorption at 1250 cm–1. The data of the Sepharose CL-6B column chromatography showed a unique and high molecular weight shifted elution peak, which caused by the addition of sulfate into polysaccharide. It suggested that partial hydroxyl groups of polysaccharide were substituted with sulfate. The content of sulfur in polysaccharide was 14.7%, and degree of substitution of sulfate was 1.41.The anti-coagulant assay of Polyporus albicans (Imaz.) Teng sulfate (PATS) indicates its remarkable anticoagulant activity in vitro. The study on anticoagulation mechanism suggests that PATS got involved in the intrinsic pathway. The anti-coagulation activity of PATS was due to the inhibition of the coagulation factors IIa and Xa activities ediated by antithrombin III(ATIII). The anti-coagulation mechanism of PATS is absolutely identical to that of heparin. In vivo assay suggests that there is no adverse effect on animal blood, liver and kidney after taking PATS for 12 hrs.Heparin is the most popular anticoagulant used in clinic, however, its side effects have also caused highly concern. It is still under intensive investigation to synthesize effective heparin substitute. In this study, PATS has the similar anti-coagulation characteristic to heparin, but with a better anti-coagulation effect. PATS has more bio-safety advantage because of deriving from edible fungus-polysaccharide. Therefore, PATS has promising future to be developed and used as an ideal substitute for heparin in clinic.