Study On Extraction Of Flavonoids From Trollius Ledebouri Reichb.with Natural Deep Eutectic Solvents And Molecularly Imprinted Technology

As a traditional Mongolian medicine with a long history,Trollius ledebouri Reichb.has many biological activities,such as antioxidation,anti-inflammation,antibacterial,anti-virus,anti-tumor and so on.It is rich in flavonoids,polyphenols,alkaloids and other bioactive constituents.Efficient enrichment,separation and purification of active components from Trollius ledebouri Reichb.is the most basic research for its development and utilization.Natural deep eutectic solvents overcome the shortcomings of traditional organic reagents,such as high volatility and toxicity,and has the advantages of easy preparation,easy storage,sustainability and biodegradation.Molecularly imprinted technology simulates the function of biological specific recognition to selectively extract specified components from complex systems.Natural deep eutectic solvents and molecularly imprintedtechnology have been widely used in the field of extraction of natural active products.In this paper,Trollius ledebouri Reichb.was taken as the research object,and the flavonoids in Trollius ledebouri Reichb.were enriched and separated by natural eutectic solvent and molecularly imprinted technology.The main research contents are as follows:(1)The process optimization of extracting flavonoids from Trollius ledebouri Reichb.by natural eutectic solvent.The extraction yields of orientin and vitexin were used as evaluation indexes.NADESs ultrasound-assisted extraction was used to extract flavonoids from Trollius ledebouri Reichb..L-proline:levulinic acid(1:2,n/n)was determined as the best solvent for extracting Trollius ledebouri Reichb..Furthermore,through the response surface method,taking the extraction temperature,extraction time,water content and liquid-solid ratio as investigation factors,the optimum extraction conditions of flavonoids from Trollius ledebouri Reichb.were determined as follows:extraction temperature 60?,extraction time18min,water content 14%(v/v),liquid-solid ratio 48 m Lg^-1.(2)Preparation and characterization of green magnetic double molecularly imprinted polymers(MDMIP).In order to further isolate and purify the bioactive constituents of orientin and vitexin,MDMIP was prepared by using orientin and vitexin as template,Fe₃O₄as magnetic source,attapulgite(ATP)as carrier,choline chloride:caffeic acid:formic acid(3:1:1.5,n/n/n)as functional monomer,ethylene glycol dimethacrylate(EGDMA)as cross-linking agent and2,2-azobisisobutyronitrile(AIBN)as initiator.The optimum preparation conditions of MDMIP were determined by single factor experiment:the ratio of Fe₃O₄:ATP(1:3,w/w),the solvent was ethanol-acetonitrile,and the dosage of p H=9,NADES was 6mmol.The structure and functional groups of the materials were characterized by Zeta potential,FT-IR and XRD,and the morphology and size were determined by SEM,TEM,EDX and DLS,which verified the successful preparation of the materials.The magnetic recovery ability and solution stability of the prepared MDMIP were investigated by magnetic hysteresis loop and sample leaching.(3)Investigation on the adsorption properties and mechanism of green magnetic double molecularly imprinted polymers.Single factor test,Plackett-Burman Design(PBD)and Central Composite Design(CCD)tests were used to determine that the main factors affecting the adsorption capacity of MDMIP were solution volume and adsorption temperature.the best adsorption conditions were solution p H=9,salt content 3wt%,volume 10m L,temperature 60?,vibration speed 200r min^-1.The study of adsorption kinetics and adsorption isotherm showed that the adsorption process of MDMIP conformed to the pseudo-second-order kinetic model and Temkin model,indicating that the adsorption of orientin and vitexin by MDMIP was an inhomogeneous surface chemical adsorption process.In addition,it is proved that MDMIP has excellent selectivity and reusability,and can be successfully applied to the complex system of Trollius ledebouri Reichb.