Extraction And Purification Of Flavonoids From Pine Needles And Antioxidative Activity Of The Extract

Pine is knows as the Pinaceae, Pinus plants.Pine needles is the one of main by-products of pine plants.In recent years,studies have shown that pine needles extract has sedative,anti-inflammatory, antitussive,antioxidant, anti-aging,enhancing immunity,anti-fatigue,anti-mutation,hypolipidemic, hypoglycemic and antibacterial activity. Flavonoids was extracted from pine needles with ethanol, the extraction process was optimized; Then products were separated and purified. And antioxidant activities of the purified products were studied.The main results were as follows:(1) On the base of the single factor experiments of ultrasonic-assisted extraction technique of flavonoids from pine needles,the method of response surface analysis (RSA) with four factors and three levels was adopted and the factors influencing the technological parameters were determined by means of regression analysis. The results showed that the optimum conditions were:55% of the ethanol concentration,310 W of the ultrasonic power,52℃of extraction temperature,l:42 of the ratio of material to solvent,30 min of extraction time,under such condition the extraction rate of flavonoids from pine needles was 3.66%.(2) Four kinds of macro porous resins were selected to compare their performances in absorbing and desorbing flavonoids from pine needles. Experimental results show that AB-8 resin possesses higher absorption and desorption capacity. The optimum parameters for separation were as follows: sample concentration was 0.50 mg/mL; Sample volume was 50mL; Flow rate of the adsorption was 1.0 mL/min; The optimal solution for the desorption was 70% ethanol with 50 mL at the flow rate of 1.0mL/min. The purity of flavonoids was 31.08%.(3) When concentration of antioxidants increased,the scavenging rate of Hydroxyl radical, superoxide anion and DPPH radical also increased. When the antioxidants concentration reached a certain concentration,the scavenging rate increased slowely.(4) Flavonoids from pine needles can inhibit hydroxyl radical.superoxide anion and DPPH radical. Scavenging effect on hydroxyl radical and superoxide anion was lower than the same concentration of Vc. When the antioxidants concentration was lower than 0.01mg/mL,scavenging effect of flavonoids from pine needles on DPPH radical was higher than the same concentration of Vc. And when the antioxidants concentration was higher than 0.01mg/mL,scavenging effect of flavonoids from pine needles on DPPH radical was lower than the same concentration of Vc.