Separation of flavonoids in the leaves of Sophora japonica by macroporous adsorption resin mixed-bed technology

Purpose - The purpose of this paper is to separate and purify flavonoids existing in the leaves of Sophora japonica by a novel method, macroporous adsorption resin (MAR) mixed-bed technology, and the optimal MAR mixed bed was screened based on the adsorption experimental result with the order of single, two, three and four MAR mixed bed separately. Design/methodology/approach - The adsorption performance of MAR and MAR mixed bed for flavonoids was studied using ultraviolet - visible (UV-VIS) spectrophotometry. Findings - This research showed that the MAR mixed bed of LZ-54 = LZ-67 with a mass ratio of mLZ-54: mLZ-67 = 1: 1 was the optimized combination with the optimal conditions of adsorption (volume V = 140 mL, pH = 5, T = 35 degrees C) and desorption (liquid ratio R = 50 per cent, T = 30 degrees C, pH = 6) obtained, relatively. Practical implications - This study aims to find an efficient way of separating flavonoids and other components that are useful for human health from Sophora japonica, which is complying with the policy of sustainable development. Originality/value - This contribution provided a novel way to separate flavonoids from Sophora japonica. Under the optimal conditions, the adsorption rate (F) of MAR mixed bed LZ-54 = LZ-67 to the flavonoids was 63.65 per cent, the desorption rate (D) was 87.31 per cent and the purity was dramatically achieved at 58.17 per cent from 17.67 per cent after a round of adsorption/desorption operation.