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Peng L You M Yuan Q Wu C Han D Chen Y Zhong Z Xue J Tan W 《Journal of the American Chemical Society》2012,134(29):12302-12307
Molecular recognition is fundamental to the specific interactions between molecules, of which the best known examples are antibody-antigen binding and cDNA hybridization. Reversible manipulation of the molecular recognition events is still a very challenging topic, and such studies are often performed at the molecular level. An important consideration is the collection of changes at the molecular level to provide macroscopic observables. This research makes use of photoresponsive molecular recognition for the fabrication of novel photoregulated dynamic materials. Specifically, a dynamic hydrogel was prepared by grafting azobenzene-tethered ssDNA and its cDNA to the hydrogel network. The macroscopic volume of the hydrogel can be manipulated through the photoreversible DNA hybridization controlled by alternate irradiation of UV and visible light. The effects of synthetic parameters including the concentration of DNA, polymer monomer, and permanent cross-linker are also discussed. 相似文献
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Dinesh G. Dan
Patel Yu‐ya Ohnishi Yixing Yang Sang‐Hyun Eom Richard T. Farley Kenneth R. Graham Jiangeng Xue So Hirata Kirk S. Schanze John R. Reynolds 《Journal of Polymer Science.Polymer Physics》2011,49(8):557-565
We report the synthesis of a 3‐ethylhexyloxy substituted poly(meta‐phenylene), EHO‐PMP that shows absorption and solid state photoluminescence exclusively in the UV region of the electromagnetic spectrum with an emission maximum of 345 nm. Computational analysis of model oligomers by DFT methods indicates that EHO‐PMP is a wide bandgap polymer with the HOMO being localized on a dimeric (biphenyl) unit and with the LUMO being more delocalized. The energy of the LUMO, however, suggests that inefficient electron injection would occur from currently available cathode materials in standard light‐emitting device architectures, and this was observed experimentally. The computational results, coupled with experimental observation, lead us to believe that efficient electroluminescence from organic polymer UV emitters requires advances in electron transport layers and cathode materials. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
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Development and validation of an LC‐MS/MS method for simultaneous quantification of levodopa and MD01 in rat plasma and its application to a pharmacokinetic study of mucuna pruriens extract
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Guangjie Yang Fangrong Zhang Linfang Deng Chang Chen Zhongzhe Cheng Jiangeng Huang Jiangyun Liu Hongliang Jiang 《Biomedical chromatography : BMC》2016,30(9):1506-1514
Mucuna pruriens, an ancient Indian herbal medicine containing levodopa, is widely used for Parkinson's disease. In order to simultaneously determine levodopa and 1,1‐dimethyl‐3‐carboxy‐6,7‐dihydroxy‐1,2,3,4‐tetrahydroisoquinoline (MD01) in rat plasma, an improved LC‐MS/MS method was developed and validated for a pharmacokinetic study in rats orally administered levodopa or Mucuna pruriens extract (MPE). Elimination of matrix effect and improvement of extraction recovery were achieved through systematic optimization of reversed‐phase and hydrophilic interaction chromatographic conditions together with sample clean‐up procedures. A satisfactory chromatographic performance was obtained with a Thermo Aquasil C18 column (50 × 2.1 mm, 3 µm) using acetonitrile and water containing 0.2% formic acid as mobile phases. Futhermore, sodium metabisulfite and formic acid were used as stabilizers in neat solutions as well as rat plasma. The method was validated in a dynamic range of 20.0–10,000 ng/mL for levodopa and MD01; the intra‐ and inter‐day precision and accuracy were acceptable. The method was successfully utilized to determine the levodopa level in plasma samples of rats administered levodopa or MPE. Pharmacokinetic results showed that an increase in the AUC of levodopa was observed in rats following oral administration of multiple doses of MPE. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Study of the in vitro metabolism of TJ0711 using ultra high performance liquid chromatography with quadrupole time‐of‐flight and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry
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Lei Hu Zhenhua Lv Gao Li Xiaolong Xu Chenghao Zhang Peng Cao Jiangeng Huang Luqin Si 《Journal of separation science》2015,38(11):1837-1849
TJ0711 (1‐[4‐(2‐methoxyethyl)phenoxy]‐3‐[2‐(2‐methoxyphenoxy)ethylamino]‐2‐propanol) is a novel β‐adrenoreceptor blocker with vasodilating activity. The aim of this study was to investigate the in vitro metabolic properties of TJ0711 from both qualitative and quantitative aspects using mouse, rat, dog, and human liver microsomes as well as rat hepatocytes. Two modern liquid chromatography with tandem mass spectrometry systems, ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry, were utilized for the analysis. To better characterize the metabolic pathways of TJ0711, two major metabolites were incubated under the same conditions as that for TJ0711. TJ0711 was extensively metabolized in vitro, and a total of 34 metabolites, including 19 phase I and 15 phase II metabolites, were identified. Similar metabolite profiles were observed among species, and demethylation, hydroxylation, carboxylic acid formation, and glucuronidation were proposed as the major metabolic routes. Significant interspecies differences were observed in the metabolic stability studies of TJ0711. Furthermore, gender differences were significant in mice, rats, and dogs, but were negligible in humans. The valuable information provided in this work will be useful in planning and interpreting further pharmacokinetic, in vivo metabolism and toxicological studies of this novel β‐blocker. 相似文献
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Jiangeng Huang Juanjuan Liu Cong Zhang Jiaojiao Wei Li Mei Shan Yu Gao Li Li Xu 《Journal of chromatography. A》2012
In the present study, a simple and sensitive extraction method based on polypropylene membrane-protected micro-solid phase extraction (MP-μ-SPE) has been developed for analysis of sulfonamides in food samples. Poly (methacrylic acid-ethylene glycol dimethacrylate) (p-MAA-EDMA) was synthesized using orthogonal array experimental design, optimized with three factors at four levels and evaluated on yield, hydrophobic and cation-exchange properties. The optimized p-MAA-EDMA was then employed as the sorbent in the MP-μ-SPE for extraction of sulfonamides from milk and chicken muscle samples, followed by high performance liquid chromatographic analysis with ultraviolet detection. Under optimized extraction conditions, good linearities (0.010–1.0 μg mL?1 with r2 > 0.9900), low limits of detection (0.38–0.62 ng mL?1), and acceptable intra-day (2.7–13.7%) and inter-day (6.7–15.2%) relative standard deviations were obtained. It was demonstrated to be an effective approach to handle semi-solid/solid samples with good resistance to interference from “dirty” samples. 相似文献
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