Process For Separating Active Components Of Scutellaria Baicalensis Seorgi By Supercritical Fluid Chromatography Technology

Scutellaria baicalensis Georgi,as a traditional Chinese medicine,is rich in multiple flavonoid active components such as baicalein and wogonin,which own idiographic pharmacological effects in the anti-oxidation,anti-inflammatory,antivirus,anti-cancer,and other aspects.The existing purification process of baicalein and wogonin suffers from low purity,long time consumption,high solvent consumption,and great difficulty in operation.This paper aims to develop a new green high-efficiency purification technology of the active components in scutellaria baicalensis Georgi based on supercritical fluid chromatography（SFC）,and further form industrialized platform technology.Taking the resolution of baicalein and wogonin as the target parameter,the effects of the entrainer flow rate,CO₂ flow rate,temperature,and pressure on the separation process were investigated.The optimal condition of the separation process of baicalein and wogonin in SFC was obtained:entrainer flow rate 5 m L/min,CO₂ flow rate18g/min,pressure 12 MPa,and temperature 318.15 K.Under the optimal condition,the purities of baicalein and wogonin are 95.3wt.%and 85.7wt.%,respectively.Besides,retention factor models of the two components were established based on the average lattice-fluid model.The adsorption data of baicalein and wogonin on the Zor Bax SB-CN column were determined through the elution by characteristic point method.The maximum adsorptive capacity of baicalein and wogonin were 70.10 and 45.25 mg/m L,respectively.The Langmuir adsorption model fitted the adsorption equilibrium data of baicalein and wogonin.The diffusion coefficients of baicalein and wogonin in SC-CO₂/CH₃OH were determined by the Taylor peak expansion method,which were（1.32～3.24）×10^-7 m²/s,（1.45～3.46）×10^-7 m²/s.The correlation models of diffusion coefficient with pressure,temperature,and mobile phase density were established.A SFC model to separate baicalein and wogonin was established by Aspen Chromatography.The relative deviation of the resolution between the simulation and the experimental results is 4.94%,confirming the reliability of the established model.On this basis,a supercritical fluid-simulated moving bed（SF-SMB）model separation process of baicalein and wogonin was established.The eluent flow rate,extract flow rate,raffinate flow rate,and switching time t_s were optimized.The optimal condition was that the feed concentration C_swas 1.0 g/L,the feed flow ratewas1000.0 L/h,was 2677.53 L/h,was 3098.67 L/h,was 578.86 L/h and t_swas 7.4 min.Consequently,the purities of baicalein and wogonin products were 99.1wt.%and 99.3wt.%,and the yields were 99.8%and 83.5%,respectively,meeting the purity requirements of the active components of traditional Chinese medicine with a high yield.