Preparation Of Flavonoids And Matrine Molecularly Imprinted Polymers And Their Application In High Efficiency Recognition And Separation Of Tibetan Medicines

Molecularly imprinted polymer solid materials have many advantages,such as strong recognition,rapid preparation,simple process,low solvent consumption and so on.They have attracted extensive attention in the fields of bioactive substances separation,identification and artificial bionic enzymes.In recent years,molecular imprinting technology has been rapidly developed in the extraction,separation and purification of the active components from traditional Chinese medicine.At present,it is mainly focused on the specific recognition and application of molecularly imprinted polymers to the single compound of traditional Chinese medicine.As an important part of traditional Chinese medicine,Tibetan medicine has many active components with similar structures and functions.It is of great significance to develop a class specific molecular imprinting technique with synchronous and high efficiency extraction,enrichment and separation of structural analogues.In this paper,molecularly imprinted polymers with class specificity and high efficiency recognition for flavonoids and matrine were synthesized by means of UV spectrum and molecular design software prediction technique.The adsorption dynamics and recognition mechanism of the imprinted polymers were studied.The molecularly imprinted solid-phase extraction column and magnetic separation and recognition materials were developed.The rapid extraction,separation and determination of flavonoids and matrine from Rhododendron and Sophora moorcroftiana were established,and the method was successfully applied to the analysis of real samples.Double-templated molecularly imprinted polymers with specific recognition of three matrine-type alkaloids were prepared using matrine and oxymatrine as the template molecules.An approach based on double-templated molecularly imprinted solid-phase extraction coupled with high performance liquid chromatography tandem mass spectrometry was then developed to extract and purify matrine,oxymatrine,and sophocarpine from Sophora moorcroftiana in the Tibetan plateau herbs.The polymers were characterized by Fourier-transform infrared spectroscopy and Scanning electron microscopy.Their adsorption characteristics were evaluated using adsorption kinetics,isotherms,selectivity,and recycling experiments.The mechanism of recognition of three matrine alkaloids by the polymer was studied.The maximum adsorption capacity of the polymer to the martrine was 27.33?g mg^-11 by scatchard plots,to the oxymatrine was51.18?g mg^-1,the binding site was highly selective to the target.A molecularly imprinted solid-phase extraction column was prepared with D-MIPs as adsorbent.The specific enrichment,separation and purification of crude extract from Sophora japonica were screened and optimized.The obtained polymers as adsorbent was further used for the determination of three matrine-type alkaloids coupled with high performance liquid chromatography-tandem mass spectrometry?HPLC-MS/MS?,the recoveries of three matrines spiked at three concentration levels in samples were 73.25%-98.42%?n=5?with relative standard deviation less than 6.82%.The limits of detection for the method were9.23-15.42?g kg^-1?S/N=3?.The method evaluation of the real samples shown that the developed solid-phase extraction column and the established D-MIPs LC-MS\MS method can be successfully applied to the simultaneous extraction,separation and detection of matrine,oxymatrine and sophoricine in Tibetan medicine of Sophora moorcroftiana.A molecularly imprinted solid phase based as dummy template was developed for extraction and clean-up of farrerol from Rhododendron aganniphum.The dummy molecularly imprinted polymer?d-MIP?was prepared by precipitation polymerization,using quercetin as the dummy template,4-vinylpyridine as the functional monomer,ethylene glycol dimethacrylate as the cross-linker,and acetonitrile as the porogen.The d-MIP was characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy.Dynamic curves,adsorption isotherms,and Scatchard plots showed the d-MIP had good affinity,capacity,and selectivity.The specific recognition ability of the polymer was analyzed by Scatchard analysis.The maximum adsorption capacity of the polymer for farrrerol was 20.67 mg g^-1,It has good affinity,adsorption capacity and selectivity to Rhododendron.The prepared d-MIP was used as a sorbent in solid-phase extraction cartridges and successfully applied to specific extraction and purification of farrerol from real samples.High recoveries were obtained for three spiked levels of farrerol in Rhododendron aganniphum using dummy molecularly imprinted solid phase extraction coupled with high-performance liquid chromatography.The linear range was10–100?g mL^-1,the limit of detection was 5.65 mg kg^-1,the recoveries of farrerol were between 78.30%and 86.66%,and the relative standard deviations?n=3?were all less than 1.2%for real samples.The proposed method provides a simple,rapid,and environmentally friendly approach to the analysis of farrerol in complex herbal products.Based on nano-material surface imprinting technology,using functionalized Fe₃O₄-SiO₂-GO as carrier,farrerol as template molecule,ethylene glycol dimethacrylate as crosslinking agent,2,2-azobisisobutyronitril as initiator,the property of good magnetic response was prepared by high class specific adsorption ability as Fe₃O₄-SiO₂-GO@MIPs recognition materials.The structure and morphology of MIPs were characterized by FT-IR,SEM,TEM,XRD and VSM,and the recognition mechanism was studied by dynamic adsorption curve,adsorption isotherm and Scatchard analysis.The results show that Fe₃O₄-SiO₂-GO@MIPs has a good selectivity for the recognition of farrerol and other four structural analogues.Its adsorption capacity is up to 15.05 mg g^-1,among the polymer has two kinds of adsorption sites,the maximum adsorption capacity at low point was 20.66 mg g^-1,the maximum adsorption capacity at high point was 10.04 mg g^-1.The LC-MS/MS method based on magnetic solid phase extraction?SPE?was established by screening and optimizing extraction and separation conditions.The recovery range,LOD and LOQ for four Rhododendrons by Fe3O4-SiO2-GO@MIPs coupling LC-MS/MS of farerol was 80.12-105.46?RSD,1.36-3.45%?,3.00 and 10.00?g L^-1.Texifolin was 82.02-95.41%?RSD,1.09-3.41%?,4.44 and 14.80?g L^-1.Kaempferol was 75.08-89.05%?RSD,1.05-2.37%?,2.31 and 7.76?g L^-1.Hyperoside was 64.04-78.03%?RSD,1.07-3.67%?,2.49 and 8.32?g L^-1,respectively.It is also suitable for the extraction and separation of flavonoids from Rhododendron aganniphum Balf.F.et K.Ward,Rhododendron niveum Hook.F,Rhododendron seinghkuense K.Ward and Rhododendron arboreum Smith,and other natural medicinal plants.