Synthesis And Application Of Urosolic Acid-imprinting Polymer Based On The Silica Surface

A new molecular imprinting technique using ursolic acid (UA )as template molecular , 4-VP as functional monomer,EGDMA as the crossing-linking agent was described for creating UA-specific recognition cavities on silica. The polymer was loaded into the self-made solid-phase extraction(SPE)cartridge. It was found that the UA can be separated and riched effectively with OA. The details are summarized as follows:1. With the "green food" demanding ,it is very necessary to extract ursolic acid from the dogwood acid as active ingredients. In china dogwood research is focusing on the chemical composition and the role of pharmacology now .therefore, this paper seeks to Cornel ursolic acid in the extraction process, laying the foundations for the next step. By orthogonal design experiments,we found that the concentration of ethanol, alcohol consumption, extraction frequency and extraction times influenced the optimal screening. The optimum conditions are: 10g dry meat, dogwood, with 95% ethanol as the extraction solvent, the ratio of liquid material 1:12,a total of two from the first 60 minutes, the second 30 minutes. In this conditions the content of the ursolic acid is 30.42mg. We applied poor analysis of the factors on the extraction effect of the comparison. According to the R-value from the poor analysis, the relative importance of the factors are as follows :ethanol concentrations> extraction time> ethanol consumption > extraction frequency.2. A new molecular imprinting technique using ursolic acid (UA )as template molecular ,4-VP as functional monomer,EGDMA as the crossing-linking agent was described for creating UA-specific recognition cavities on silica. The polymer was loaded into the self-made solid-phase extraction(SPE)cartridge. Using ultraviolet spectrometer analysis ,we studyed the interaction between the template molecule and functional monomer molecular and found that the best functional monomer molar ratio was 1:4; The UA-imprinted silica sorbent was characterized by FT-IR,SEM and the static adsorption experiments.. The results showed that the surface prepared by blotting ursolic acid molecules can be imprinted with polymer molecules with the goal of mutual recognition ursolic acid in the "hole"; While static adsorption and Scatchard analysis it showed that ursolic acid polymers had two binding sites. We compared the selective adsorption properties between ursolic acid and oleanolic acid,ursolic acid is 4.3 times that of oleanolic acid. ursolic acid MIPs have a higher degree of recognition performance and it is good for effective concentration and purification of herb medicine. So the active ingredients in traditional Chinese medicine has broad prospects.3. Imprinted Polymer for SPE research is developed in recent years. With its high-affinity and high selectivity to the templates or template similarities the samples can be concentrated , isolated from other substances to reduce the interference, thereby improving the accuracy of the analysis, lowering detection limits . compared to ordinary filler ,imprinted polymer used as SPE filler has better selectivity,longer-life. In this chapter we discussed the process of SPE cleansing, elution discussio and comparied the ursolic acid and oleanolic acid accumulation on C8 SPE columns and MIPs SPE column . It showed MIPs SPE column had better result and for real samples it had fairly good results too.