Extraction,Purification,Structural Characterization And Biological Activity Of Polysaccharides From Perccottus Glenii

The extraction,separation,purification,structure and biological activity of polysaccharide from the head of Perccottus glenii were systematically studied by modern separation and purification technology in this paper.The main contents are as follows:1.Extraction and biological activity of crude polysaccharide(PGP)from the head of Perccottus glenii.PGP was extracted by alkali extraction and alcohol precipitation,and the yield was 8.2%.The contents of total sugar,protein,and fat in PGP were 11.5%,69.9%,and 0.1%,respectively.PGP had in vitro hydroxyl radical scavenging ability,total reduction ability,?-glucosidase,and angiotensin I converting enzyme(ACE)inhibition ability.PGP improved the activity of total superoxide dismutase,reduced glutathione,and total antioxidant capacity in liver tissue and serum of mice,inhibit the production of hydroxyl radicals,and reduce the content of malondialdehyde.This showed that PGP had certain biological activity in vitro and good antioxidant activity in vivo.2.Study on the structure and biological activity of deproteoglycan(PGP-D).PGP-D was obtained by using Seavg reagent,pepsin,papain,and enzyme-Seavg combined method.Pepsin was the best with protein removal rate of 86.0%,polysaccharide loss rate of 3.7%,and hydroxyl radical semi-scavenging rate of 47.6%.PGP-D was mainly composed of arabinose,rhamnose,mannose,galactose,galacturonic acid,and glucuronic acid with relative contents of 8.0%,3.3%,7.3%,3.6%,4.5%,and 45.6%,respectively.PGP-D was an acidic heteropolysaccharide containing ?-glycosidic bond.PGP-D had hydroxyl radical scavenging ability,total reduction ability,and ACE inhibition ability in vitro,which were superior to PGP,but had certain promotion ability to ?-glucosidase.3.Study on the structure and biological activity of purified polysaccharide.PGP-D was chromatographed on DEAE-52 cellulose and Sephadex G-100 gel column to obtain three homogeneous polysaccharides(PGP-0,PGP-1 and PGP-2)with molecular weights of 2.9k D,2.3k D and 3.2k D,respectively.They were all composed of arabinose,rhamnose,galactose,glucose,galacturonic acid,and glucuronic acid,but their relative contents were quite different.Scanning electron microscope images showed that although the surface morphology of each component polysaccharide was different,it was smooth and delicate,presuming that the intermolecular interaction force of the polysaccharide was strong.UV and IR spectra showed that each component polysaccharide shows typical sugar absorption peaks,indicating purified polysaccharide was a pyranose heteropolysaccharide linked by ?-glycosidic bonds.Nuclear magnetic resonance analysis showed that each component polysaccharides contained uronic acid,and the anomeric carbon configuration were ?-type anomeric carbon,which were pyranose.In vitro biological activity studies showed that PGP-0,PGP-1,and PGP-2 were possessed hydroxyl radical scavenging ability,total reduction ability,and ACE inhibition ability.The best one was PGP-1.