The Structure Characterization And Biological Activity Of The Polysaccharide Of Abacus Serrata

Glochidion eriocarpum Champ.is a Glochidion plant under Euphorbiaceae,also called "Maoqigong" and "Qidabo" in Chinese.According to the records of A Collection of Chinese Herbal Medicines,it boasts effects like dissipating blood stasis,stanching bleeding,alleviating rheumatism,dispersing swelling and relieving pain.The existing studies focus on isolation and identification of small molecules,but polysaccharides which from Glochidion eriocarpum Champ.is rarely studied and reported.Polysaccharides is an ingredient with a variety of biological activities,which may play a certain role in the efficacy of Glochidion eriocarpum Champ.Ultrasound-assisted water-extraction and alcohol-precipitation method is adopted to extract SPZc from the whole plants of Glochidion eriocarpum Champ.The process conditions of extracting SPZc by using optimized ultrasound-assisted water-extraction and alcohol-precipitation method through single factor analysis and response surface analysis are as follows:material-solvent ratio:1:45g/mL;extraction temperature:70?;extraction time:2.5h;ultrasonic power:300W;the best yield rate:3.87%.SPZc contains 83.3%total sugars,67.2%glycuronic acid and 2.43%protein.After decolorization of SPZc with H2O2 method,the yield rate is 75.28%.SPZp is obtained by joint deproteinization through enzymatic method and Sevage method,with a yield rate of 60.48%.SPZp is purified through DEAE-FAST-FLOW anion-exchange columns.SPZ0.1a is thus collected.SPZ0.1a is further purified with Superdex G-75 gel columns to obtain SPZch.After high-performance gel liquid chromatography detection of SPZch,single narrow symmetrical peak is obtained,suggesting that SPZch is a kind of amylose with uniform molecular weight,whose molecular weight is 17,268Da.Gas chromatography-mass spectrometry(GC-MS),infrared spectroscopy,partial acid hydrolysis,periodate oxidation,smith degradation,methylation analysis,nuclear magnetic resonance analysis and other methods are adopted for structural identification of SPZch.The results show that SPZch consists of monosaccharides like Ara,Xyl,Man,Glc and Gal,with a relative molar ratio of 0.257:0.075:0.140:0.071:0.456,which is a heteropolysaccharide composed by 5 monosaccharides;SPZch is ?,?-pyranoid ring amylose.For SPZch,its main chain is connected as follows:?6)-?-D-Galp-(1?3)-?-D-Galp-(1?4)-?-D-Galp(1?glycosidic bond,and its branch chain is connected as follows:?2-?-D-Manp-1?3,6)-?-D-Galp-(1?and?3,5-?-L-Araf-(1?4,6)-?-D-Galp-(1? The end group ?-L-Araf-(1? is connected to the main chain through O-3 Bond.The ends consist of Ara,Xyl and Glc.The activity of polysaccharides which from Glochidion eriocarpum Champ.was studied,such as resistance to oxidation,blood sugar reduction and neuroprotection.The results show that,the polysaccharides has a removal rate of 70.62%and 76.23%for ·OH and DPPH,respectively,presenting excellent removal effects;It also has an inhibition rate of 96.14%for ?-glucosidase,showing good hypoglycemic effects;meanwhile,it also offers significant protection for nerve cells,providing certain theoretical basis for the pharmaceutical development of polysaccharides which from Glochidion eriocarpum Champ..