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991.
Halogenated BODIPYs are important synthetic precursors and potential sensitizers for photodynamic therapy (PDT). Electrophilic bromination of pyrrolic-unsubstituted BODIPYs using bromine regioselectively generated mono- to heptabromoBODIPYs in a stepwise fashion in good to excellent yields. These resultant bromoBODIPYs were applied for regioselective substitution and Suzuki coupling reaction to generate BODIPYs 4, 5, 6, and 7 in good to excellent yields. According to NMR and X-ray analysis results, the stepwise bromination first takes place at 2,6-, then at 3,5-, and eventually at 1,7-positions, whereas the regioselective substitution occurs first at 3,5- then at 1,7-positions of the chromophore. The spectroscopic properties of these resultant BODIPYs were studied, which shows the potential application of these bromoBODIPYs as sensitizers for PDT. 相似文献
992.
Tang L Pang Y Yan Q Shi L Huang J Du Y Zhao K 《The Journal of organic chemistry》2011,76(8):2744-2752
A concise and efficient approach to the syntheses of coumestan analogues has been developed. The underpinning strategy involves a FeCl(3)-mediated direct intramolecular oxidative annellation of 4-hydroxy-3-phenyl-2H-chromen-2-one derivatives. Utilizing this synthetic protocol, a variety of coumestan derivatives were conveniently obtained from readily available reagents. 相似文献
993.
Min Zhu Hai-Jun Pang Peng-Peng Zhang Yuan Chen Dan-Dan Wang Ming-Guan Liu Yong-Hui Wang 《Journal of solid state chemistry》2011,184(5):1070-1078
Three new high dimensional CuI/Ag-pz porous coordination polymers (PCPs) with different Keggin polyoxometalate templates have been hydrothermally synthesized: [CuI5(pz)6Cl][HPMoVI10MoV2O40] (1) [Ag5(pz)7(BW12O40)] (2) and [CuI5(pz)6H(H2W12O40)]·4H2O (3) (pz=pyrazine). The choice of the particular Keggin POM templates is shown to influence the structural properties of the Cu/Ag PCPs. Compound 1 shows a Cl-bridged Cu-pz-Cl double layer, between which two kinds of [HPMoVI10MoV2O40]4−(PMo12) polyanions are located. Compound 2 presents a 3D Ag-pz framework with parallelogram-like voids, into which BW12O405− (BW12) Keggin ions are incorporated. Compound 3 contains a Cu-pz cationic layer framework, between which are located [H(H2W12O40)]5− (W12) Keggin ions. Primary photocatalytic experiment indicates that compound 1 presents excellent photocatalytic activity. The photoluminescence properties and electrochemistry properties of the compounds are also discussed. 相似文献
994.
A simple and sensitive method was developed for the determination of three carbamate pesticides in water samples. It is based on temperature controlled ionic liquid dispersive liquid phase microextraction combined with high-performance liquid chromatography. The ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate was used as the extractant, and the factors affecting the extraction were investigated in detail. The detection limits obtained for isoprocarb, diethofencarb and fenothiocarb are 0.91, 0.45, and 1.40 μgL-1, respectively, and the precisions are in the range between 1.0 and 1.8% (n?=?6). The method was validated with environmental water samples and the results indicate that it represents a viable alternative to existing methods. Figure
Temperature controlled ionic liquid dispersive liquid phase microextraction was developed for the enriching three carbamate pesticides. 1-Hexyl-3-methylimidazolium hexafluorophosphate was used as the extractant. The detection limits for isoprocarb, diethofencarb, fenothiocarb are 0.91, 0.45, 1.40 μgL-1. Real-world environmental water samples analysis indicated that it was a viable alternative to existing methods. 相似文献
995.
An increasing number of small biosamples (e.g. proteins and enzymes) need micropreparation in lab. However, neither large-scale free-flow electrophoresis (LS-FFE) nor chip FFE (C-FFE) could fit the growing demands. Herein, a simple quasi-chip FFE (QC-FFE) was constructed. In contrast to C-FFE, the features of QC-FFE are as follows: (i) its separation chamber is reassemblable and rewashable avoiding discard of C-FFE due to blockage of solute precipitation in chamber; (ii) its chamber size is 45 mm × 30 mm × (80-500) μm (108-654 μL volume) having function of micropreparation; (iii) there are up to 16 outlets in QC-FFE bestowing fine fraction for micropurification. The QC-FFE was used for the micropurification of model enzyme of self-digestible trypsin in crude pancreatin. Under the given conditions, the purification factor of enzyme was 11.7, the specific activity reached 6236 U/mg, the run time for 19 μL sample purification was 45 s and the throughput of trypsin was 3.34 mg/h, and the yield of pure trypsin was 55.2%. All of the results show the feasibility of enzyme micropreparation via QC-FFE. The developed device and procedure have potential use to other micropurification of protein or peptide sample. 相似文献
996.
997.
Lei Y Pang M Fan W Feng J Song S Dang S Zhang H 《Dalton transactions (Cambridge, England : 2003)》2011,40(1):142-145
Hydrophilic Ce, Tb doped BaYF(5) nanocrystals with uniform size were synthesized by a microwave-assisted route. The synthesized nanocrystals can be well dispersed in hydrophilic solutions (DMSO, DMF, EG, H(2)O). This synthesis procedure represents a less time consuming method, with high product yield and without using any assistant or/and template reagents, which may be expected to be a general method for rapid synthesis of other hydrophilic RE doped fluoride fluorescent nanocrystals. The Ce(3+), Tb(3+) codoped BaYF(5) nanocrystals show bright green fluorescence emission. The Ce(3+) acts as an effective energy transfer medium and the emission at the high (5)D(3) energy level of Tb is enhanced in this host material. 相似文献
998.
Near-infrared (NIR) emission can offer distinct advantages for biological applications. A fluorescent sensor, Zinhbo-1, based on bis(benzoxazole) ligand with 2,2'-dipicolylamine (DPA) as receptor, was synthesized. In aqueous solution, Zinhbo-1 demonstrates high sensitivity and selectivity for sensing Zn(2+) with about 10-fold enhancement and nanomolar sensitivity (K(d) = 0.29 nM). Moreover, sensor Zinhbo-1 can detect Zn(2+) in near-infrared region (over 700 nm) with large Stokes shift (ca. 230 nm) attributing to the Zn(2+)-induced excited state intramolecular proton transfer (ESIPT). 相似文献
999.
Lin Z Pang J Yang H Cai Z Zhang L Chen G 《Chemical communications (Cambridge, England)》2011,47(34):9675-9677
An inorganic-organic hybrid affinity monolithic column was synthesized by a novel "one-pot" approach. The resulting hybrid affinity monoliths have potential applications in specific recognition and enrichment of glycoproteins. 相似文献
1000.
Pseudostellaria heterophylla (Miq.) Pax is one of the most widespread herbal and healthcare products in China. Extensive clinical use has shown that it has functions which "strengthens qi and generates saliva, moistens the lung and relieves cough". The ethyl acetate fraction extracted from the roots of the plant Pseudostellaria heterophylla exhibited a dose-dependent antitussive effect between 100 to 500 mg/kg. At a dose of 400 mg/kg, the ethyl acetate fraction treatment markedly prolonged the cough latent period and reduced the number of coughs in a guinea pig model induced by citric acid. Fall lung airway resistance, rise in dynamic lung compliance, decreased serum levels of IL-8, GM-CSF, TNF-α, and ET-1 in rat model of stable phase chronic obstructive pulmonary disease induced by cigarette smoke exposure were also observed. These results suggest that ethyl acetate fraction has antitussive activity related to its improvement in lung function via attenuation of airway inflammation by adjustment of multi-cytokine levels. 相似文献