Evaluation Of Antioxidant Activity Of Polysaccharides,Flavonoids And Their Compounds Of Jujube

Jujube is one of the main fruit industry in southern China,especially in Hunan province,the development of resources and the comprehensive utilization of fruit are the important guarantee for the sustainable and efficient development of jujube industry.It has great practical value and economic value to promote the comprehensive utilization of jujube fruit resources and the development and evaluation of related functional components.In this paper,we used several jujube varieties in Hengyang area as the test materials,using the content of flavonoids and polysaccharides as the main indexes,Selected Hunan Hengyang millet dates as experimental materials on the base of the analysis of the content of flavonoids and polysaccharides in different varieties of jujube,studied the extraction,separation and purification of flavonoids and polysaccharides from jujube,and studied the antioxidant activity and antioxidant activity of Hacat cells in vitro,The main results are as follows:（1）This paper determined the content of flavonoids in 7 kinds of jujube fruits in Hunan of Hengyang,selected the best varieties.Taking the egg jujube,millet jujube,sμgar jujube etc as test materials,analyzed the content of flavonoids in jujubes.The results showed that,the average content of flavonoids was 0.493 mg/g in the jujube,the content of flavonoids of millet jujube and medicinal jujube is the highest,which was 0.606 mg/g,0.579 mg/g;the content of flavonoids of Lizao jujube,Sub sμgar jujube,Candied jujube is higher,that is0.522 mg/g,0.495 mg/g,0.466 mg/g respectively;The content of flavonoids of wild jujube and egg jujube was the lowest,only 0.439 mg/g and 0.344 mg/g.There was a difference of1.8 times between the highest and the lowest contents of flavonoids.（2）Studied the extraction technology of flavonoids of millet jujube.The optimum ultrasonic extraction process of flavonoids of millet jujube was obtained by the single factor experiment and orthogonal experiment:material liquid ratio is 1:16,extraction time is 20min,ethanol volume fraction is 60%,ultrasonic power is 700 W;The protein in the mixed solution can be effectively removed by the addition of three chloroacetic acid（TCA）with alcohol precipitation,when the adding amount of TCA was 1%,the removal effect of protein is best,the removal rate of protein reached 74.67%,at the same time,it can ensure the retention of polysaccharide.The purity of Polysaccharides by activated carbon decolorization and AB-8 resin was 76.84%.（3）In the purification of flavonoids from millet jujube,studied the purification effects of five macroporous resins on flavonoids.The results showed that,the static adsorption capacity of different resins to flavonoids was XDA-1>X-5>AB-8>NKA-II>D201,the static analytical ability of 5 resins to flavonoids was X-5>NKA-II>AB-8>XDA-1>D201,and the X-5,NKA-II and XDA-1 resins were screened for further tests.The results showed that,the dynamic adsorption and desorption rates of X-5 resin on the flavonoids of millet jujube were 79.50%and 99.53%.The purification process of flavonoids by X-5 resin were:the concentration of flavonoids in the sample solution was 0.263 mg/m L,the pH value of the sample solution was 5.0,the flow rate was 2 BV/h,the eluent ethanol concentration was about 70%,and the pH value of the eluent was about 6.0.The purity of flavonoids was68.12%under this condition.（4）Compared the contention and antioxidant activity of flavonoids and polysaccharides of three varieties jujube by using reducing power,scavenging capacity of 3 kinds of free radicals as evaluation index,studied the coordination types and the coordination strength of the two kinds of antioxidants with combined the free radical scavenging experiments with the additive and the isobologram.the results showed that,the antioxidant properties of millet jujube in vitro was stronger than the other jujube;there was a positive correlation between the antioxidant activity and the content of flavonoids and polysaccharides in different jujube varieties;the reducing ability and scavenging ability of 3 kinds of free radicals of flavonoids and polysaccharides of the three jujube were positively correlated with the concentration in the experimental concentration range,the antioxidant activity was lower than VC;the antioxidant activity of flavonoids was higher than that of polysaccharides.The IC_50mix values of different combinations were less than IC_50add value after the combination,it confirmed that there was a synergistic antioxidation of them,and the synergistic effect of this compounds on superoxide anion free radical was stronger than that of DPPH free radical,the best ratio of synergistic effects of compounds is 1:1.（5）Studied the effects of compounds and controls（VC）on the level of SOD and ROS after cellular oxidative damage with the HaCat cell as the carrier.The results showed that,the 0.3,0.6 mg/mL compounds of flavonoids and polysaccharide of millet jujube and the0.07 mg/m L VC had significant protective effects on the oxidative damage caused by H₂O₂in the experimental concentration range,Moreover,the antioxidant activity of compounds of flavonoids and polysaccharides in millet jujube was stronger than that of VC,it showed that the compounds of flavonoids and polysaccharides in millet jujube has better antioxidant effect on HaCat cells.