Separation and purification of flavonoids from Artemisia annua L.by polyethylene glycol-ammonium sulfate aqueous two-phase system

An aqueous two- phase system of PEG- ( NH4) 2SO4was used to extract flavonoids from the crude ethanol extract of Artemisia annua L..The effects of average molecular weight of PEG, mass percent of ( NH4) 2SO4, mass percent of PEG, pH and temperature on partition coefficient and extraction rate of flavonoids were explored by single factor experiments, then the extraction condition of flavonoids was further optimized by orthogonal method.Then the optimum conditions were obtained as follows: An aqueous two- phase system of 30% PEG600 and 25% ( NH4) 2SO4, pH of 3 and temperature of 45℃.Under the optimal extraction conditions, flavonoids from Artemisia annua L.was mainly distributed in the upper phase with a partition coefficient of 21.86 and the extraction rate of 96.33%.