Study And Application Of Extracting And Separating Rutin From Chinese Medicinal Plants

Traditional Chinese medicine has been widely used for prevention and treatment of human diseases in China for thousands of years. Low toxicity and good therapeutic effect which are common advantages of traditional Chinese medicine make them attract widespread attention in many areas, especially when the concept of human health have been gradually transformed from treatment to precaution. Saururus chinensis is Saururaceae genus of plants, the whole of which can be used as medicine. Saururus chinensis contains so many effective ingredients, one of which is rutin, that it possesses multiple efficacy and pharmacological activity. Moreover, it is easy to get. Thus, it is necessary to research and develop it for future medicine. Flos sophorae is the dry flowers and buds of Sophora japonica L, rutin content of which accounts for 20% or more. Thus, Flos sophorae is the commonly used Chinese medicinal plant to extract rutin in the pharmaceutical industry.In this paper, applied modern sample pretreatment techniques (microwave assisted extraction, molecular imprinting technique, solid phase extraction and magnetic separation technology) as the extraction and separation means to selective extract and separate the target compound of rutin from two medicinal herbs including Saururus chinensis and Flos sophorae. And studied various factors on extracting rutin systematically, and determined the optimal conditions of extraction method for rutin. In addition, synthesized imprinted polymers with good selective effects for rutin, and the adsorption conditions were optimized and successfully applied to separate and analyze rutin in Chinese herbal medicine. At last, combining molecular imprinting technique with magnetic separation technology, polymers which were effective and saving energy and time were synthesized with selective adsorption, easiness to implement solid-liquid separation. This study was carried out mainly as the following three aspects:1、The extraction analysis of rutin from Chinese medicinal plantsIn this work, a new green solvent ionic liquid was used to extract the target ingredient of rutin from Saururus chinensis and Flos sophorae. Four extraction methods including ionic liquid-based microwave-assisted extraction (ILMAE), ionic liquid-based ultrasonic-assisted extraction (ILUAE), ionic liquid-based heating extraction (ILHE) and ionic liquid-based marinated extraction (ILME) for extracting rutin were compared in this work. By single-factor experiments and orthogonal experiments, extraction conditions of four methods were optimized and the optimal extraction method was found out to be ILMAE. The mechanism of extraction methods was also studied. And the extraction conditions of ILMAE including the concentration of ionic liquid aqueous solution, solid-liquid ratio, extracting temperature and microwave irradiation time were mainly investigated for extracting rutin. And the obtained optimal conditions of ionic liquid-based microwave-assisted extraction were as follows: for Saururus chinensis, 2.0 mol/L of [bmim]Br solution concentration, 1:30 of solid-liquid ratio, 12 min of the irradiation time, 60℃of extraction temperature; while for Flos sophorae, 2.0 mol/L of [bmim] Br solution concentration, 1:30 of solid-liquid ratio, 10 min of the irradiation time, 70℃of extraction temperature. Qualitative and quantitative analysis of rutin was determined by HPLC. The linear range from 30 to 300 mg/L of rutin solution was good, and the linear regression equation were Y=17675.87X+190450.40 (Gradient elution, r2 = 0.99917) and Y=330278.32X+38047.71 (Isocratic elution, r2 = 0.99932), respectively, with 5.3μg/L of the detection limit. The average recoveries of real samples were 101.23% (Saururus chinensis) and 99.62% (Flos sophorae) with RSDs <3% (n = 3). The proposed method had good precision and reproducibility and applied to real samples with satisfactory results.2、Extraction and separation of rutin from Chinese medicinal plants using molecular imprinting-solid phase extractionUsing solution polymerization, better molecularly imprinted polymer using rutin as the template molecule was obtained by optimizing the synthetic conditions including the type of functional monomer and crosslinker, and the molar ratio of template, functional monomer and crosslinker. And the optimized synthetic conditions obtained were as follows: bi-functional monomer (AM-2-VP, molar ratio=3:1), bi-crosslinker (EDMA-DVB, molar ratio=3:1), the molar ratio of template, functional monomer and crosslinker was 1:6:20, tetrahydrofuran was used as the solvent and porogen agent. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) were applied to characterize molecularly imprinted polymer (MIPs) and non-molecularly imprinted polymers (NIPs) which were synthesized under the optimal conditions. And they were packed into syringes used as simple solid phase columns, and applied to adsorption of compounds from mixed standard samples (rutin and its analogs quercetin, naringenin and kaempferol) and the extracts of Saururus chinensis and Flos sophorae in order to investigate the adsorption and selectivity properties of MISPE. The average recoveries of rutin from the two herbs were 87.6% (RSD = 3.24%) and 90.8% (RSD = 2.97%), respectively. In addition, in order to study the selectivity properties of MISPE, the commonly used solid phase extraction columns including C18, Silica and PCX were purchased and applied for adsorption of rutin from real samples, the results of which told us that only MISPE had selective adsorption for rutin, and the study results indicated that molecularly imprinted polymers as the adsorbent of solid phase extraction column has good application prospects for active ingredients from complicated samples.3、Synthesis of Magnetic Molecularly Imprinted Polymer and its application in separation and analysis of rutin from Chinese medicinal plants A specific selective adsorption of polymer, which can be separated quickly from liquids only applying external magnetic field was synthesized by combining magnetic separation technology with molecular imprinting technology. Firstly, magnetic Fe3O4 particles were synthesized and coated with tetraethoxy silane, then the surface of them were modified with organic groups in order to make them dispersed in organic solvents. In this study, after coated with silica, the surface of the particles was modified with functional groups (vinyl). Then the functional magetic particles were used to synthesize magnetic molecularly imprinted polymers (MMIPs) with rutin as the template molecule and magnetic non-imprinted polymers (MNIPs). The adsorption properties and selective properties were investigated to evaluate MMIPs, which were then applied to real samples including Saururus chinensis and Flos sophorae. The results showed that MMIPs not only had strong selective adsorption, but were easy to implement solid-liquid separation. When used in the separation and analysis of two herbs, the average recoveries of Saururus chinensis and Flos sophorae obtained were 88.4% and 89.3% with RSDs<5%, respectively. The results of this study indicated that MMIPs provided a new analytical method for synthesizing adsorption materials which could be applied for the separation and enrichment of rutin from Chinese medicinal plants.