Purification and Antioxidant Activity of Alpinia officinarum Residue Flavonoid

Capacities of static absorption and desorption of 7 macroporous resins toward Alpinia officinarum flavonoids extracted from the Alpinia officinarum residue after essential oil extraction were investigated to select the fittest one with great result. Then dynamic absorption and desorption were carried out to find the best conditions of galangal flavonoids purification. Comparison of purity and antioxidant activity of the flavonoid before or after purification were used to estimate the effect of purification. Results showed that,XDA-6 was the fittest macroporous resins for Alpinia officinarum flavonoid purification with the best absorption and desorption capacities,and the best condition of purification were as follows:Flow velocity of 2 BV/h,sample concentration of 2 mg/mL,sample volume of 31.6 BV,the eluent was 70%(v/v)ethanol,the eluent flow rate was 2.5 mL/min,and the eluent dosage was 3.1 BV. Under this condition. The purity of the sample increased from 43.55%±0.15% to 85.42%±0.64% with the better scavenging rate of DPPH,scavenging rate of superoxide anion radicals and reducing ability. The IC₅₀ of DPPH and superoxide anion free radicals scavenging decreased from 0.014,0.222 mg/mL to 0.012,0.186 mg/mL.