Study On Purification Technology Of Active Components In Radix Paeoniae Rubra Based On Supercritical Fluid Chromatography

Radix Paeoniae Rubra is one kind of Chinese traditional medicine,in which the main active components of paeoniflorin and albiflorin have different pharmacological effects.However,to data,the traditional purification process of paeoniflorin and albiflorin has some shortcomings,such as complex procedure and solvent residual.As a solution scheme,the purification technology of active components of paeoniflorin and albiflorin based on the preparative supercritical fluid chromatography?Prep-SFC?was first introduced in this paper.Firstly,the optimal operating conditions were determined by the purification technological experiment:SC-CO₂/C₂H₅OH system was used as the mobile phase and the content of ethanol as modifier was 13.64wt.%,the flow rate of CO₂ was 20g·min^-1,the temperature was 313.15K,the pressure was 12MPa,the overloading concentration was 10.00g/L and the overloading volume was 30?L.Under these conditions,the paeoniflorin with purity of 94.11%and the albiflorin with purity of85.65%were obtained by SFC from the crude extract,thus the desired effect was reached.Meanwhile,SFC retention equation was used to correlate the experimental data.The model fitting results were rather good,and the average relative deviation of paeoniflorin and albiflorin were 1.20%and 0.72%,respectively.The adsorption equilibrium data of paeoniflorin and albiflorin were determined at the temperature from 308.15 K to 323.15K and the pressure from 10 MPa to 17MPa by the method of elution by characteristic points.In the experimental concentration range,the maximum adsorption capacity of paeoniflorin and albiflorin was15.24mg/m L and 31.14mg/mL,respectively.Adsorption equilibrium data were fitted well by Langmuir and Freundlich adsorption isotherm model,which indicated that the adsorption process was the monolayer adsorption process.The diffusion coefficients of paeoniflorin and albiflorin in the SC-CO₂/CH₃CH₂OH system were measured at the temperature from 308.15 K to328.15K and the pressure from 10 MPa to 18MPa by Taylor capillary peak broadening method.The diffusion coefficients of paeoniflorin and albiflorin were in the range of?2.97-6.55?×10^-4cm²·s^-1 and?2.73-6.23?×10^-4cm²·s^-1,respectively.The continuous purification technology based on the SFC-SMB was proposed to separate paeoniflorin and albiflorin.The optimal feed flow rate of 23.98 mL/min was obtained through triangle theory.Simulation of separation of paeoniflorin and albiflorin by SFC-SMB was first carried out within the module of Aspen Chromatography.The results showed that,the purity of albiflorin in extract was53.51%,and the purity of paeoniflorin in raffinate was 94.40%at the optimal switching time of 24 min.The results in the present study could provide technical guidance for the design of industrial SFC-SMB separation device of paeoniflorin and albiflorin.It also provides a new idea for the development of purification technology of the active components in natural products.