Ultrasonic Assisted Extraction of Flavonoids from Lotus Leaf and Sophora japonica

Flavonoids is a class of compounds with high economic value,which is abundant in various types of agricultural processing waste.Flavonoids from Lotus leaf and Sophora japonica were extracted by ethanol hot-dip and ultrasonic assisted method.The extraction conditions were optimized according to the orthogonal experiment.Then the composition and purity of the extractions were determined by high performance liquid chromatography.Results showed that ultrasonic assisted extraction method was superior to ethanol hot-dip method.The optimum extracted conditions from Lotus leaf were as follows: ethanol concentration70%,temperature 35 ℃,extraction time 40 min,the ratio of material to solvent 1:40(m:v).For the flavoids from Sophora japonica,the best extraction conditions were: the ethanol concentration70%,temperature 25 ℃,ultrasonic extraction time 35 min,and the ratio of material to solvent 1:40(m:V).At the optimum conditions,the main component of the extractions was rutin and extraction yield reached 11.64% from the Lotus leaf and 15.47% from Sophora japonica.The research provided a basis to improve the value-added of agricultural processing waste.