Progress in stimuli-responsive molecularly imprinted polymers for enrichment analysis of trace components in traditional Chinese medicine / 中国中药杂志

Molecularly imprinted polymers demonstrate outstanding performance in the research on trace ingredients because of their high selectivity. Stimuli-responsive molecularly imprinted polymers(STR-MIPs) with the introduction of different responsive groups on the basis of traditionally imprinted materials can undergo reversible transformations when exposed to external stimuli such as temperature, magnetism, pH or light. Such responsiveness, combined with the specific recognition, endows STR-MIPs with excellent perfor-mance in trace component studies. Traditional Chinese medicine(TCM) contains complex components with trace content, and thus STR-MIPs have broad application prospects in the enrichment analysis of trace components in TCM. This paper elaborates on the application of STR-MIPs in the enrichment analysis of trace components in TCM from the perspectives of different stimuli, summarized relevant research achievements in the recent five years to broaden the application fields of molecular imprinting, and proposed a few opi-nions about their future development.

Research progress of dummy template molecularly imprinted polymers in separation of natural products / 中国中药杂志

The dummy template molecularly imprinted polymers not only has such characteristics of normal imprinted polymers as rapid identification, easy preparation, stable structure and multiple reuse, but also can imprint the compounds in natural products that are not suitable as direct template. Therefore, it has drawn more and more attention in the field of the study of natural products. This paper summarizes the methods for the selection of dummy template molecules by investigating the relevant literatures in the past ten years, analyzes the advantages and disadvantages of dummy template molecules in the practical application, and based on the types of natural products active ingredients, this paper is the first to review of the latest progress in extraction and separation of dummy template molecularly imprinted polymers. We believed that this paper could provide references for better applications of the dummy template molecularly imprinted polymers to extract and separate natural products.

Efficient discovery and capturing of nNOS-PSD-95 uncouplers from Trifolium pratense / 中国中药杂志

Magnetic molecularly imprinted polymers(MMIPs) were prepared with ZL006 as template, acrylamide(AA) as the functional monomer, and acetonitrile as pore-forming agent; then Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscopy(SEM) were used to characterize their forms and structures. Simultaneously, the MMIPs prepared previously were used as sorbents for dispersive magnetic solid phase extraction(DSPE) to capture and identify potential nNOS-PSD-95 uncouplers from extracts of Trifolium pratense and the the activities of the screened compounds were evaluated by the neuroprotective effect and co-immunoprecipitation test. The experiment revealed that the successfully synthesized MMIPs showed good dispersiveness, suitable particle size and good adsorption properties. Formononetin, prunetin and biochanin A were separated and enriched from Trifolium pratense by using the MMIPs as artificial antibodies and finally biochanin A was found to have higher cytoprotective action and uncoupling action according to the neuroprotective effect and co-immunoprecipitation test.

Determination of 11Kinds of Aminoglycosides in Aquatic Products by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry with Molecularly Imprinted Polymers Solid Phase Extraction / 分析化学

An ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of 11 kinds of aminoglycosides (AGs), including paromomycin, spectinomycin, tobramycin, gentamycin, kanamycin, hygromycin B, apramycin, streptomycin, dihydrostreptomycin,amikacin and neomycin in aquatic products. Samples were extracted by phosphate buffer solution, and purified on molecularly imprinted polymers (MIP) solid phase extraction column. After separated by Obelisc R chromatographic column, AGs were detected by UPLC-MS/MS. It showed a good linearity relationship in the AGs concentration range of 1.0-1000 ng/mL with the correlation coefficient R2>0.994. The limit of detection (LOD,S/N≥3) was ranged from 1.0 μg/kg to 10.0 μg/kg,and the limit of quantitation (LOQ,S/N≥10) was ranged from 2.0 μg/kg to 20.0 μg/kg. Besides, the average recoveries presented 78.4%-109.6% with the relative standard deviation (RSD, n=6) of 2.3%-14.9%. This method was successfully applied to the simultaneous determination of 11 kinds of AGs with high sensitivity in aquatic products.

Application progress of molecularly imprinted polymers in separation of active ingredients from Chinese materia medica / 中草药

Separation of active ingredients from Chinese materia medica (CMM) by molecularly imprinted polymers has such advantages as high speed, low cost, being reusable, low pollution, and so on. Because of this reason, the synthesis of molecularly imprinted polymers and its application in separation have drawn more and more attention of researchers in the field of CMM all over the world. Obviously, the core of this research is to explore the relationship between the polymer-structure and separation efficiency. Based on the types of active ingredients of CMM (flavone, alkaloids, phenylpropanoids, terpenoids, etc.), the design principle of molecularly imprinted polymer, its preparation methods and latest application in separation of active ingredients from CMM were introduced. Therefore, this paper can provide a reference for designing new materials with higher selectivity in separation of active ingredients from CMM.

A novel surface molecularly imprinted polymer as the solid-phase extraction adsorbent for the selective determination of ampicillin sodium in milk and blood samples$ / 药物分析学报

Surface molecularly imprinted polymers (SMIPs) for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support. The physical and morphological characteristics of the polymers were investigated by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), elemental analysis and nitrogen adsorption–desorption test. The obtained results showed that the SMIPs displayed great adsorption capacity (13.5μg/mg), high recognition ability (the imprinted factor is 3.2) and good binding kinetics for ampicillin sodium. Finally, as solid phase extraction adsorbents, the SMIPs coupled with HPLC method were validated and applied for the enrichment, purification and determination of ampicillin sodium in real milk and blood samples. The averages of spiked accuracy ranged from 92.1%to 107.6%. The relative standard deviations of intra-and inter-day precisions were less than 4.6%. This study provides a new and promising method for enriching, extracting and determining ampicillin sodium in complex biological samples.

Application of computational simulation and spectral analysis in preparation of Tanshinone IIA imprinted polymer / 中草药

To prepare Tanshinone IIA (TSIIA) molecularly imprinted polymers (MIPs) with affinity and high selectivity to TSIIA and study its mechanism. Taking TSIIA as the template molecular, synthesizing the MIPs at the surface of silica nanoparticles by grafting copolymerization in the toluene solution. A molecular modeling approach was used to elucidate template-monomer interaction. The interaction between template molecule and functional monomer was studied by UV spectrometry. The theoretical molar ratio of template-monomer was 1∶3 and methyl acrylic acid (MAA) was a better functional monomer than acrylamide (AAM) for MIPs synthesis. The MIPs can be used for the extraction and separation of TSIIA.

Determination of berberine hydrochloride in Zhibai Dihuang Pills with ion selective electrode based on molecularly imprinted polymers / 中草药

Objective: To develop a method for the determination of berberine hydrochloride (BH) in Zhibai Dihuang Pills. Methods: The BH ion selective electrode was fabricated with a molecularly imprinted polymer (MIP). The process is based on the synthesis of polymers with BH as template, methacrylic acid (MAA) as functional monomer, and ethylene glycol dimethacrylate (EGDMA) as a crosslinker. An ion selective electrode was prepared with this MIP as electric active substance. The content of BH was calculated with working curve. Results: The electromotive force (E) exhibited a good Nernst response to BH concentration over a range of 1-100 μmol/L with a slop of 55.48 mV per decade, and recovery rate was 94.5%-105.1%. Conclusion: The method is rapid, precise, and accurate, and the result is satisfaction.

Preparation of Cyproheptadine Imprinted Polymers and Its Application to Solid Phase Extraction / 分析化学

Using cyproheptadine ( CYP) as template molecule, methacrylic acid ( MAA) as monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker, molecularly imprinted polymers (MIP) with high selectivity to cyproheptadine (CYP) were prepared by the optimization of porogen, monomer, and the mole ratio of monomer to template. The specific surface area of the prepared polymers was 24. 9 m2 / g. The recovery of CYP was above 94. 0% when the following procedure was applied to the cartridge of MIP as adsorptive material: conditioning with methanol and water, loading with water, washing with water and methanol, and eluting with methanol-ammonia (95: 5, V/ V). As a control, the recovery of CYP on non-imprinted polymers cartridge (NISPE) was only 38. 9% . The binding capacity of the molecularly imprinted solid phase extraction (MISPE) towards CYP found to be about 8. 8 mg of CYP/ g polymers and the imprinting factor (IF) was about 2. 32. Under optimal conditions, a mixed standard solution of CYP, amitriptyline, sulfadiazine and trimethoprim (10 mg / L each) was uploaded on the MISPE and NISPE for selectivity experiment. The gradient elution was used by using 0. 05% sodium pentanesulfonate solution (A)-acetintrile (B) as a mobile phase. The recoveries on the MISPE for sulfadiazine and trimethoprim (different structure with CYP) were less than 10% , however, the recovery for the similar structural amitriptyline was more than 70% , and the recovery more than 90% for CYP. All the recoveries on the NISPE for four analytes were less than 30% . This new MISPE cartridge was applied to extract and enrich CYP in livestock drinking water sample, and the recoveries of CYP ranged from 80. 5% -97. 7% , and the limit of detection (LOD) was 0. 01 mg / L.

Determination of Three Neonicotinoid Pesticides Residues by High Performence Liquid Chromatography with Molecularly Imprinting Solid Phase Extraction / 分析化学

A molecularly imprinted polymer (MIP) for the selective solid phase extraction of imidacloprid, imidaclothiz, thiacloprid was synthesized by polymerization for 24 h using thiacloprid as template. Dynamic adsorption and selective adsorption test showed that the MIP could quickly adsorb the imidacloprid, imidaclothiz, thiacloprid, with good selectivity for targets. The maximum static adsorption capacity of MIP was 31. 7, 36. 7 and 45. 3 mg / g, respectively. A molecularly imprinted solid phase extraction (MIP-SPE) was developed to separate, clean up and enrich the thiacloprid, imidacloprid and imidaclothiz residue in paddy water, soil, rice, tomato, cucumber. The average recoveries were 80. 2% -98. 8% , with relative standard deviation of 1. 4% -4. 5% . The MIP-SPE was used to analyses the real samples, the result was satisfied.

Study on targeted separation of atractylenolide IQ from traditional Chinese herbs by molecularly imprinted solid phase extraction / 中国药学杂志

OBJECTIVE: To establish a novel and efficient method for enriching low content active components from traditional Chinese herbs. METHODS: The enrichment of atractylenolide III was taken as an example. First, molecular imprinting polymers (MIPs) of atractylenolide III were prepared by precipitation polymerization using 1-Vinylimidazole as functional monomer. Second, the atractylenolide III MIPs were packed into solid-phase column to separate atractylenolide III and its analogues from the exracts of Herba Atractylodes Macrocephaia and Codonopsis pilosula. Moreover, the adsorption performance of MIPs for the target components was also investigated. RESULTS: Enrichment factor (EF) of MIP-SPE and C18-SPE column were 78.90 and 51.56 μg · g-1 respectively, suggesting that MIPs had better adsorption property than C18; the precision and accuracy of the developed method were satisfactory with recoveries of 102.2% and LOD of 0.36 μg · mL-1. CONCLUSION These results demonstrate the feasibility of molecularly imprinted solid phase extraction for enriching low content active components in traditional Chinese herbs.

Preparation of Tilmicosin Imprinted Polymers and Its Application to Solid Phase Extraction / 分析化学

Molecularly imprinted polymers (MIPs) with high selectivity to tilmicosin (TIM) were prepared using tylosin(TYL) as dummy template, methacrylic acid(MAA) as monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker.The effects of 4 porogens including dimethyl formamide, methanol, acetone, and chloroform on the recognition capability of MIPs were investigated.Orthogonal test was used to optimize the preparation of MIPs, and the optimal composition was as follows; 1.0 mmol TYL, 8.0 mmol MAA, 20.0 mmol EGDMA, 6.0 mL chloroform, 20.0 mg azobisisobutyronitrile.The solid phase extraction condi tions and characteristics of MIPs as adsorptive material for the selective extraction and enrichment of TIM were also studied.The recovery of TIM was above 90% when the following procedure was applied to MIPs cartridge: conditioning with methanol and water(pH 9.0), loading with acetonitrile, cleaning with methanol and chloroform respectively, and eluting with 3 mL methanol-ammonia(95:5, V/V).The recovery of TIM on non-imprinted polymers cartridge was only 32%.