Purification And Anti-oxidation Activity Of Flavonoids From Hippophae Rhamnoides Linn Leaves

Seabuckthorn( Hippophae rhamnoides Linn) is a flavonoids rich plant of Hippophae. Flavonoids in seabuckthorn fruits and pomace have been researched more during the pass studies. However, few studies focused on the extraction of flavonoid from seabuckthorn leaves. Seabuckthorn leaves have more potential of development with the advantages of wide distribution, abundant resources, long harvest period, and easier extracting technology. Therefore, extraction, purification and antioxidation activity of flavonoids form seabuckthorn leaves were studied for further development and application of seabuckthorn. It has significance in the food, pharmaceutical and health products. The main accomplishment results of this study are listed as follows:Ethanol concentration, extraction time and extraction temperature were investigated to optimize the extraction of total flavonoids in seabuckthorn leaves. And the optimum conditions were: the leaves were extracted twice for 2.0 hours and 1.5 hours with 50%ethanol at 80℃.The total flavonoids was 18.52 mg·g-1 with purity of 12.43%.AB-8 macroporous resin was applied to purify flavonoids extracted from seabuckthorn leaves, and the static and dynamic adsorption and desorption conditions were optimized. The total flavonoids were static adsorption with 0.04 g·L-1 and the raw material liquid concentration at 30 temperature for 2 h and the pH value of sea ℃buckthorn leaves flavonoids was 3. The total flavonoids were best static desorption conditions under 70% ethanol concentrations at 30 ℃temperature for 3 h and desorption solution volume ratio and the quality of the resin is 25:1. Dynamic adsorption and desorption of AB-8 macroporous resin effect was evaluated. And to determine the optimum dynamic adsorption and desorption conditions. The total flavonoids were dynamic adsorption with 5.0 g·L-1 sample concentration at 2.0 mL·min-1 the sample solution flow rate for the original pH. The total flavonoids were best dynamic desorption conditions with 70% ethanol volume at 2.0 mL·min-1 desorption flow rate. The flavonoid in the samples increased from 12.43% to 50.18% by purification. Which means purification flavonoid content is 4.04 times as compare to the pre-purified product.DPPH radicals scavenging ability, ABTS radicals scavenging and recover ability of the total flavonoids from Sea buckthorn leaves were studied with rutin as the control. The total flavonoids did a great job on clearing DPPH radical scavenging and ABTS radical scavenging. The IC50 was 18.5μg·mL-1 and 28.8 μg·mL-1 respectively. The results showed that total flavonoid of Sea buckthorn leaves was a good oxidant.In summary, extraction, purification and antioxidation activity of total flavonoids in sea buckthorn leaves were studied in this paper. The results provided scientific basis for further development and utilization of the total flavonoids in seabuckthorn.