Studies On The Isolation,Purification,Structure And Antioxidant Activity Of Glycoprotein From Coix Seed

Coix seed is the dry and ripe seeds of gramineous plants Coix L.,and as Chinese traditional food with medicinal and edible.It contains abundant protein, lipids, carbohydrates. B vitamins and calcium, phosphorus, iron potassium, etc., the main pharmacological active ingredients is the lipid.Modem pharmacology study shows that Coix seed has the function of anti-ancer,immunonogical, anti-hypertensive, anti-hypoglycemie, anti-oxidation, anti-inflammatory and so on.This article choose coix seed as raw material. Study on the isolation,purification,structure analysis and antioxidant activity in vitro of the Coix seed glycoprotein, the main conclusions are as follows:1.Use hot water extraction to extract glycoprotein from coix seed, on the basis of single factor experiments,using quadratic regression rotary combination test statistical method to optimize the extraction process, quadratic multinomial regression equation is as followsY=3.00750+0.24342X1+0.10863X2+0.12223X3-0.04849X12-0.07819X22-0.17029X32+0.08738X1X2+0.09287X1X3-0.03038X2X3The optimum conditions as follows:the ratio of sample to water is1:25. extraction temperature56C, and extraction time5h, in this condition, the theory extraction ratio of the semen coicis glycoprotein is3.73%.validation test yield is3.6%.2. Two components named respectively TDBP-1,TDBP-2was isolated and purified from the semen coicis glycoprotein by cellulose DEAE-52,Purity of glycoprotein used the SephadexG-100gel column chromatography, indicating two purity fractions after gel filtration,named TDBP-a,TDBP-b, in combination with high performance liquid chromatography showed that two components are all homogeneous. 3. Using phenol-sulfuric acid method and kjeldahl determination to determine sugar content and protein content of semen coicis glycoprotein. Coix seed glycoprotein TDBP and TDBP-a,TDBP-b of sugar content was63.14%,46.12%and63.14%respectively; protein content was28.27%30.32%and28.27%, respectively.4. UV spectrum analysis showed that TDBP-a and TDBP-b are glycoprotein containing O-sugar peptide bond. Infrared spectroseopic analysis showed that TDBP-a and TDBP-b have absorption peak in the3400cm-1,2900cm-1,1640cm-1,1400cm-1,1020cm-1, polysaccharide and protein are all charateristic absorption band in these regions. The absorption peak in the1020cm-1of C-O showed that TDBP-a and TDBP-b contain pyran ring.5.The results of antioxidant activity showed that glycoprotein Coix seed has high reducing capacities, It can effectively scavenge the DPPH-, peroxide anion,and hydroxyl radicals remarkably free radical,glyeoprotein from coix seed has also showed powerful inhibitory effects on peroxidation of polyunsaturated fatty acid from yolk lipoprotein induced by Fe2+.And as the increased of giycoprtein concentration,the total reducing power and the hydroxyl radical,superoxide,and organic free radical scavenging ability have inereased.