Extraction Of Flavonoids From Bamboo Shell And Effect On Tyrosinase Activity

Bamboo shoot is the new bud of Poaceae Bambusoideae plants. Among 500 kinds of plants in our country, most are edible. Bamboo shoot has rich nutrition, a good taste, which is Chinese traditional cusion Recently, the canned bamboo industry has developted fast. There are more than 500 companies which manufactured canned boom. With the process of canned bamboo shoot,bamboo shell could be left after streaming.Bamboo shell has rich Flavonoids are compounded in plants and animals, and it has scavenging radical, anti-aging, anti-bacterial, anti-virus, anti-cancer and other biological activity. Nowadays, bamboo leaves extracts are being applied in Chemitry, Food and cosmetics industries. This reserch is study on the flavonoids extracted from bamboo shell Then products were separated and purified with many methods. Its antioxidant activity and effect on tyrosinase activity has been sudied. The main results are as follows:(1) On the base of the single factor experiments of ultrasonic-assisted extraction technique of flavonoids from bamboo shell, the method of response surface analysis (RSA) with three 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:60% of the ethanol concentration,70℃of the extraction temperature, the ratio of material to solvent of 1:25, 30min of extraction time, under such condition the extraction rate of flavonoids from bamboo leaves was 0.80%.(2) Four kinds of macro porous resins were selected to compare their performances in absorbing and desorbing flavonoids in Bamboo shell. The optimal absorbent material for flavonoids in Bamboo shell was decided. Experimental results show that AB-8 resin possesses higher absorption and desorption capacity. The optimum parameters for separation were as follows:extract sample concentration of 2.0mg/ml, the range of the sample pH was 5; flow rate 2BV/h, the optimal solution for the adsorption was 70% ethanol with3.5BV at the flow rate ofl 1.0 BV/h. The purity of flavonoids was 33.06%.(3) The inhibitory effects of bamboo shell flavonoid extract on the monophenolase and diphenolase activities of tyrosinase were studied by an enzyme kinetic method. The results indicate that the bamboo shell flavonoid extract could inhibit the monophenolase and diphenolase activities of tyrosinase. Bamboo shell flavonoid extract could delay the time in monophenolase An analysis of inhibition kinetics suggested that bamboo shell flavonoid extract was a reversible mixed inhibitor, and the inhibition equilibrium constants for inhibitor binding with free enzyme Ki and with enzyme-substrate complex Kis were 3.1 mmol/L and 5.7 mmol/L, respectively.(4) The invitro anti-oxidative effect of bamboo shell flavonoids was also analyzed. The results indicate that the flavonoids had better antioxidant ability The flavonoids could cavenge the hydroxyl radical, superoxide radical and DPPH free radical. Chelating properties of pine needle flavonoids was stronger than that of ascorbie acid.