Preparative separation and purification of flavonoids from Lamiophlomis rotata (Benth.) Kudo.

Purpose The purpose of the paper is to separate and purify flavonoids existed in Lamiophlomis rotata (Benth.) Kudo. by macroporous adsorption resin (MAR) mixed-bed technology. Design/methodology/approach The adsorption and desorption parameters were characterized by UV-VIS spectrophotometry. The optimal MAR mixed bed was screened based on the adsorption experiments; the experiment process was investigated by the order of single, two and three MAR mixed bed separately; and the adsorption performance, which was composed by the authority of 80 per cent adsorption ratios and 20 per cent desorption ratios, was adopted to screen MAR mixed bed for flavonoids. The adsorption dynamic investigated the order of reaction first, and then the adsorption mechanism was researched further. The adsorption thermodynamic investigated the adsorption isotherm first, and then the adsorption feature was analyzed. Findings This research found that MAR mixed bed of LS-840 + LSD301 with mass ratio of m LS840 : m LSD301 = 3:2 was the optimized combination, and the optimal conditions of the adsorption were volume V = 50 mL, time t = 6.5 h, T = 40°C. The desorption conditions were ethanol content = 70 per cent, desorption time t = 3.0 h, T = 40°C. The adsorption dynamic experimental data fitted better to the pseudo-second-order, and the intra-particle-diffusion model was more suitable for expression of the adsorption mechanism in mesopores process, whereas the homogeneous particle-diffusion model was more suitable in microspores. The adsorption was a physical and multilayer adsorption, and the adsorption driving force was disappeared as it transferred to the fourth layer. Practical implications Find an efficient way to separate flavonoids that useful for human’s health, which can not only utilize of plant resources effectively, but also make outstanding contributions to medical industry. It has very high economic and social value. Originality/value This contribution provided a new way to separate flavonoids from Lamiophlomis rotata (Benth.) Kudo. Under the optimal conditions, the adsorption rate (F) of MAR mixed bed LS-840 + LSD301 to the flavonoids was 97.81 per cent, the desorption rate (D) was 90.02 per cent and the purity of flavonoids was dramatically increased about 2.08 fold of the crude extract from 28 to 58.4 per cent, and the recovery yield of flavonoids arrived at 91.6 per cent after a circle of adsorption/desorption operation.