Separation And Purification Of Phenylglycosides From Cistanche Tubulosa (Schenk) Wight

Cistanche tubulosa(Schenk Dwight)is a famous Chinese medicinal herb,which is mainly produced in southern Xinjiang.The main medicinal components of cistanche tubulosa are phenylglycosides(PheGs),which are mainly echinosides(Ech-Gs)and acteoside(Act-Gs),which account for more than 90% of the total content of PheGs and are the index components of PheGs.In order to obtain high-purity PheGs products,the bottleneck problem is how to realize highselectivity separation.Therefore,it is of great significance to design and develop a separation and purification method with good selectivity,high efficiency,energy saving and environmental friendliness for the development and utilization of cistanche tubulosa.In order to obtain high-purity PheGs,this paper first studied the high-efficiency extraction process of PheGs from cistanche tubulosa,followed by the separation and purification of the extract of cistanche tubulosa,and explored the separation and purification process of PheGs by mesoporous carbon adsorption method and molecularly imprinted polymer adsorption method.The research is as follows:PheGs extraction process: first,the effects of different extraction methods,such as high shear homogenization extraction(HSHE),microwave assisted extraction(MAEM)and ultrasonic assisted extraction(UAEM),on PheGs extraction performance were studied.On this basis,the HSHE method to optimize extraction process and the best extraction technology for: extraction temperature is 70?,the ethanol concentration was 50%,high shear homogeneous emulsification machine speed for 16000 rpm,high shear homogeneous emulsification machine work 2 min,cistanche tubulosa power and the ratio of ethanol solution for 1?9,extracted once.Under the above conditions,the yield and purity of Ech-Gs and Act-Gs were 1.37% and 0.52%,respectively,and 6.32% and 1.82%,respectively.Purification of PheGs by mesoporous carbon adsorption: three mesoporous carbon ordered mesoporous carbon(OrMC),disordered mesoporous carbon(DiMC)and 3D mesoporous carbon(3DMC)with different structures were screened to study their adsorption properties for PheGs.The results show that OrMC has the best performance;OrMC PheGs purification process conditions,results show that the optimal purification process is: the temperature was 60?,pH of 6,on the sample concentration is 0.41 mg/mL.Under the optimal extraction conditions,the adsorption amounts of Ech-Gs and Act-Gs reached 218.73 mg/g and 159.80 mg/g,the desorption rates were 97.86% and 90.75%,and the purity was 17.52% and 11.05%,respectively.On this basis,mesoporous carbon adsorption PheGs mechanism was analyzed,and OrMC adsorption PheGs adsorption thermodynamic and kinetic properties were studied,the results show that OrMC adsorption PheGs conform to the Langmuir adsorption isotherm model,and OrMC adsorption PheGs conform to the quasi second order kinetic equation.Molecular imprinting method purify PheGs: choose the Act-Gs as template molecule,4-vinyl pyridine(4-VP)as functional monomer,acetonitrile,N,N-dimethyl formamide(DMF)(1?1.5,v/v)as the hole agents,2 glycol methacrylate(EGDMA)as crosslinking agent,the azodiisobutyronitrile(AIBN),the optimal molecularly imprinted polymer(MIP1).In the static adsorption test of Act-Gs and Ech-Gs competitive adsorption with the same sample concentration,the adsorption amounts of MIP1 on Act-Gs and Ech-Gs were 112.60 mg/g and 40.82 mg/g,respectively,and the desorption rates were above 98%,and the separation factors of Act-Gs and Ech-Gs were 4.68.The adsorption thermodynamics and adsorption kinetics of MIP1 on Act-Gs were further studied.The results showed that MIP1 had high affinity and low affinity for Act-Gs,and the kinetic adsorption of MIP1 on Act-Gs was in line with the quasi-second-order reaction kinetics model.Finally,an adsorption experiment was conducted on the extract of cistanche cistanche with MIP1.The results showed that the adsorption amounts of MIP1 on Act-Gs and Ech-Gs were 36.86 mg/g and 88.67 mg/g,respectively.After desorption,the recovery rates of Act-Gs and Ech-Gs were 90.09% and 92.76%,respectively,and the purity was 27.88% and 32.82%,respectively.