Extraction Of Paeonol From Cortex Moutan With Aqueous Two-phase And Preliminary Study On Extraction Of Components From Salvia Miltiorrhiza By Three-liquid-phase

At present,when the traditional organic solvent extraction method is used to extract the active components from natural products in industry,it consumes more organic solvents and energy,therefore,the production cost is higher.The aqueous two-phase consisting of different hydrophilic small molecular organic solvents and inorganic salts and the liquid-liquid-liquid three-phase extraction systems have many advantages such as small organic solvent consumption,moderate price and environmental protection because of high water content.Moreover,the systems have fast phase separation and good selectivity.Compared with the commonly used polymers,the viscosity of the systems was lower,which are more conducive to recovery of organic solvents and separation of the target products.There are many active components in Cortex moutan and salvia miltiorrhiza,which have many pharmacological effects such as anti-inflammatory,anti-biosis,anti-tumor,anti-atherosclerosis,protecting liver and kidney and ischemic tissue.Therefore,extraction and separation of components from aqueous two-phase and liquid-liquid-liquid three-phase systems are of great research and practical significance.In this paper,the effects of pH value,inorganic salt type and concentration,amount of organic solvent,extraction time and temperature on the extraction of paeonol were discussed firstly.And compared with the traditional ethanol extraction method;Then the aqueous two-phase systems were improved with ethyl acetate as cosolvent and the effects of ethyl acetate content,extraction time and temperature on the extraction of paeonol were discussed.Moreover,the re-extraction of paeonol from different systems was studied.The kinetics and thermodynamics of paeonol dissolution in aqueous two-phase and modified systems were discussed as well.Finally,the three-liquid-phase system was constructed on the basis of aqueous two-phase system,and the feasibility of three-liquid-phase system in the extraction of active components from natural products was investigated.The results showed that:（1）Paeonol was mainly distributed in the top phase.The conditions for extraction of paeonol in the optimized aqueous system of THF/NaH₂PO₄ were as follows:pH value of3.00,THF amount of 30.4%（v/v）,concentration of NaH₂PO₄ aqueous solution 0.600g/mL,extraction temperature was 37.0℃and extraction time for 6.00 h.Compared with ethanol/NaH₂PO₄ and CH₃COCH₃/NaH₂PO₄ aqueous two-phase systems,the top phase extraction amount was increased by 14.3%and 4.35%,respectively.However,the top phase extraction amount of paeonol was decreased by 8.33%compared with the traditional 70%ethanol（17.5 mL）extraction method.（2）Ethanol/CH₃COCH₃/THF aqueous two-phase extraction systems were improved with ethyl acetate as cosolvent.It was found that the phase separation rate was faster and the formation time was shorter after adding ethyl acetate.The conditions for the extraction of paeonol were as follows:THF/EA（v:v=7:3）amount of 30.4%（v/v）,concentration of NaH₂PO₄ aqueous solution 0.600 g/mL（pH=3.00）,extraction temperature of 37.0℃ and extraction time for 6.00 h.The top phase extraction amount was increased by 7.69% compared with the traditional 70%ethanol（17.5 mL）extraction method.（3）Through re-extraction of the residue and investigation of the kinetic and thermodynamic behavior,it was found that the extraction effect of paeonol in the THF improved extraction system was better,and the dissolution and desorption reached equilibrium state as soon as possible.The spontaneous distribution from salt-rich phase to organic solvent-rich phase was relatively largest as well.（4）On the basis of ethanol aqueous two-phase extraction system,hexane was added.Thefeasibility of extracting effective components from salvia miltiorrhiza with liquid-liquid-liquid three-phase system constructed by hydrophobic organic solvent（hexane）-hydrophilic small molecule organic solvent（ethanol）-inorganic salt solution（sodium dihydrogen phosphate）was investigated.The extraction solutions of Salvia miltiorrhiza were analyzed by thin-layer chromatography and high performance liquid chromatography（HPLC）.The results showed that the fat-soluble and water-soluble components in Salvia miltiorrhiza were distributed in different liquid phases.The results preliminarily showed that the extraction and separation of different polar components in medicinal materials were realized by using the three-liquid-phase extraction system.