柱前荧光衍生-高效液相色谱法测定尿和血清中的环境雌激素

建立了同时测定人尿和血清中环境雌激素双酚A、4-壬基酚、17α-乙炔基雌二醇及内源性雌激素雌三醇、17α-雌二醇和17β-雌二醇的对硝基苯甲酰氯柱前荧光衍生-高效液相色谱测定方法。尿样经酸水解、固相萃取柱浓缩、净化分离;血清样品经乙腈沉淀蛋白后,用乙醚萃取游离态雌激素,N2气流挥干、在无水条件下,雌激素与对硝基苯甲酰氯反应生成荧光产物,用高效液相色谱法定量。检出限为2．7—8．3μg／L;加标回收率尿样为78．0％-102．5％,血清样为72．6％-98．6％;方法精密度为1．29％-4．52％。应用本法对20份尿样和10份血清样进行了测定,结果满意。     

Determination and removal of sulfonamides and quinolones from environmental water samples using magnetic adsorbents

In this study, the magnetic materials known as polymerized ionic liquid@3‐(trimethoxysilyl)propyl methacrylate@Fe₃O₄ nanoparticles were synthesized and utilized as potential adsorbents. First, these nanoparticles were applied to the analysis of sulfonamides and quinolones present in different water samples using magnetic solid phase extraction and high‐performance liquid chromatography. Under optimized conditions, the developed method showed excellent detection sensitivity, with limits of detection (S/N = 3) and quantification limits (S/N = 10) within 0.2–1.0 and 0.8–3.4 μg/L, respectively. The spiked recoveries of the SAs and QNs in environmental water samples ranged from 83.5 to 103.0%, with RSDs of less than 4.5%. In addition, the adsorbents effectively removed sulfamethoxazole and ofloxacin present in existing aquatic environments. The adsorption kinetics and isotherms of sulfamethoxazole and ofloxacin on the magnetic adsorbents were studied to assess removal performance. The results indicate that the adsorption process follows a pseudo‐second‐order mechanism, which reveals that the sorption mechanism is the rate‐limiting step and produces high q_max values (sulfamethoxazole = 70.35 mg/g and ofloxacin = 48.95 mg/g), thus demonstrating the enormous adsorption capacity of these magnetic adsorbents.     

Chiral,pH responsive hydrogels constructed by N‐Acryloyl‐alanine and PEGDA/α‐CD inclusion complex: preparation and chiral release ability

Chiral, pH‐responsive hydrogels are constructed by poly(ethylene glycol) diacrylate/α‐cyclodextrin (PEGDA/α‐CD) inclusion complex and L‐N‐acryloyl‐alanine or D‐N‐acryloyl‐alanine (L‐NAA or D‐NAA) by an effective free radical polymerization approach. PEGDA containing two C=C end groups was used simultaneously to introduce α‐CD units in the resulting hydrogels and to serve as a cross‐linking agent, by which forming the designed hydrogels in quantitative yield. Hydrophilic α‐CD moieties acted as pore‐forming agent, while the L(D)‐NAA‐based polymer chains bearing –COOH groups enabled the hydrogels to display remarkable swelling–deswelling behavior in response to pH variation. The chiral NAA monomer‐derived polymer chains rendered the hydrogels with intriguing optical activity, according to circular dichroism spectra. Scanning electron microscopy revealed the uniformly porous microstructures of hydrogels. More remarkably, the L‐NAA‐based hydrogels preferentially adsorbed trans‐4‐hydroxy‐d ‐proline and preferentially released trans‐4‐hydroxy‐l ‐proline, while D‐NAA‐based hydrogels provided opposite results. The hydrogels also demonstrated remarkable enantioselective release ability towards chiral drug ibuprofen. Copyright © 2015 John Wiley & Sons, Ltd.     

Fabrication and cytocompatibility evaluation for blood‐compatible polyethersulfone membrane modified by a synthesized poly (vinyl pyrrolidone)‐block‐poly (acrylate‐graft‐poly(methyl methacrylate))‐block‐poly‐(vinyl pyrrolidone)

Polyethersulfone (PES) membrane, one of the most important polymeric materials because of its good chemical resistance, thermal stability, mechanical, and film‐forming properties, has already been used in hemodialysis, tissue engineering, and artificial organs. In order to improve the blood compatibility of PES membrane, many amphiphilic block copolymers have been synthesized and used as additives for surface modification. The object of this study is to develop a hydrophilic PES membrane by blending a comblike amphiphilic block copolymer poly (vinyl pyrrolidone)‐block‐poly [acrylate‐graft‐poly (methyl methacrylate)]‐block‐poly‐(vinyl pyrrolidone) [PVP‐b‐P (AE‐g‐PMMA)‐b‐PVP] synthesized by RAFT polymerization. The cytocompatibility performance of PVP‐b‐P (AE‐g‐PMMA)‐b‐PVP modified PES membrane was evaluated, which showed better cytocompatibility compared with that of pristine PES membrane. Endothelial cells cultured on the modified membranes present improved growth in terms of scanning electron microscope observation, MTT assay, and confocal laser scanning microscope observation. These results indicate that the modified membrane has great potential application in blood‐contact fields such as hemodialysis and bio‐artificial liver supports. Copyright © 2015 John Wiley & Sons, Ltd.     

Influence of Steric Hindrance of N‐Heterocyclic Ancillary Ligands on the Structure and Magnetic Properties of Manganese(II) Coordination Polymers

Three biphenyl‐3,5‐dicarboxylic acid (H₂ L ) based coordination polymers, namely, [Mn₃( L )₃(2,2′‐bpy)₂]_n ( 1 ), {[Mn( L )(phen)] · (MeOH)}_n ( 2 ), and [Mn( L )(dipt)]_n ( 3 ), (2,2′‐bpy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline, and dipt = 2,9‐dimethyl‐1,10‐phenanthroline) were synthesized and characterized by single‐crystal X‐ray diffraction and analyses of their magnetic properties. 1 is a trinuclear manganese structure with a 2D motifs, which can join by hydrogen bond bridges to give 3D supramolecular architectures. 2 has a dinuclear center forming a 1D supramolecular ladder chain. The mononuclear complex 3 displays 1D metal‐organic chains driven by μ₂‐ L linkers. Their structural differences were investigated, revealing that the influence of steric hindrance on the structures of acid‐based coordination polymers is realized through changing the N‐heterocyclic ancillaries of diverse steric hindrance. Obviously, with decreasing of the steric hindrance of the N‐donor ligand, complexes 1 – 3 show structures from 1D to 2D and mononuclear to multinuclear. Magnetic susceptibility measurements indicate that 1 and 2 have dominating antiferromagnetic couplings between metal ions, whereas compound 3 is paramagnetic.     

Recent Development of Durable and Self‐Healing Surfaces with Special Wettability

Artificial special wetting surfaces have drawn much interest due to their important applications in many fields. Nevertheless, tremendous challenges still remain for the fabrication of wetting surfaces with durable and self‐healing properties. Here, recent progress of durable, self‐healing wetting surfaces is highlighted by discussing the fabrications of several typical wetting surfaces including superhydrophobic surfaces, superamphiphobic surfaces, underwater superoleophobic surfaces, and high hydrophilic antifouling surfaces based on expertise and related research experience. To conclude, some perspectives on the future research and development of these special wetting surfaces are presented.

     

Synthesis and Antiviral Bioactivity of Novel 2‐Substituted Methlthio‐5‐(4‐Amino‐2‐Methylpyrimidin‐5‐yl)‐1,3,4‐Thiadiazole Derivatives

A series of novel 2‐substituted methlthio‐5‐(4‐amino‐2‐methylpyrimidin‐5‐yl‐)‐1,3,4‐thiadiazole derivatives were synthesized, characterized and evaluated for antiviral activities against tobacco mosaic virus (TMV). The preliminary biological results indicated that most compounds exhibit excellent antiviral activity against TMV in vivo. Among these compounds, compounds 9c , 9i , and 9p displayed the similar curative effect against TMV (EC₅₀ = 287.05–322.47 µg/mL) to that of the commercial agent Ningnanmycin (EC₅₀ = 301.83 µg/mL). In particular, compound 9d demonstrated the best curative effect against TMV (EC₅₀ = 266.21 µg/mL), which was better than that of commercial Ningnanmycin.     

Synthesis and Antibacterial Activity of Novel Substituted Purine Derivatives

A series of novel N‐substituted‐2‐(6‐morpholino‐9H‐purin‐9‐yl)acetamide and 4‐(9‐((5‐substituted‐1,3,4‐oxadiazole/thiadiazole‐2‐yl)methyl)‐9H‐purin‐6‐yl)‐morpholine derivatives were synthesized and evaluated their antibacterial activities against rice bacterial leaf blight and tobacco bacterial wilt caused by Xanthomonas oryzae pv. oryzae (Xoo) and Ralstonia solanacearum (R. solanacearum) via the turbidimeter test in vitro. Antibacterial bioassay indicated that most compounds demonstrated good inhibitory effect against Xoo and R. solanacearum. Especially, compound 6a demonstrated the best inhibitory effect against Xoo with half‐maximal effective concentration (EC₅₀) value of 8.39 μg/mL, which was even better than those of commercial agents Bismerthiazol and Thiodiazole copper. The synthesized purine derivatives containing amide and 1,3,4‐oxadiazole/thiadiazole moieties exhibited excellent antibacterial activities against Xanthomonas oryzae pv. oryzae and R. solanacearum in vitro.     

Pipette vial dispersive liquid–liquid microextraction combined with high‐performance liquid chromatography for the determination of benzoylurea insecticide in fruit juice

A simple, sensitive, and efficient method of using a pipette vial to perform dispersive liquid–liquid microextraction based on the solidification of floating organic droplets was coupled with high‐performance liquid chromatography (HPLC) and a diode array detector for the preconcentration and analysis of four benzoylurea insecticides in fruit juice. In this method, 1‐dodecanol was used as an extractant, and a snipped pipette was used as an experimental vial to simplify the procedure of collecting and separating solidified extractant. The experimental parameters were optimized using a Plackett–Burman design and one‐factor‐at‐a‐time method. Under the optimal conditions in the water model, the limits of detection for analytes varied from 0.03 to 0.28 μg/L, and the enrichment factors ranged from 147 to 206. Linearity was achieved for diflubenzuron and flufenoxuron in a range of 0.5–500 μg/L, for hexaflumuron in a range of 1–500 μg/L, and for triflumuron in a range of 5–500 μg/L. The correlation coefficients for the analytes ranged from 0.9986 to 0.9994 with recoveries of 91.4–110.9%. Finally, the developed technique was successfully applied to fruit juice samples with acceptable results. The relative standard deviations of the analytes at two spiking levels (50 and 200 μg/L) varied between 0.2 and 4.5%.     

Simultaneous determination and pharmacokinetics of five alkaloids in rat plasma by ultra high performance liquid chromatography with tandem mass spectrometry after the oral administration of Corydalis bungeana Turcz extract

Pharmacokinetic studies were conducted on rats for protopine, corynoline, 7′‐(3′,4′‐dihydroxyphenyl)‐N‐[(4‐methoxyphenyl)‐ethyl]propenamide, acetylcorynoline, and 8‐oxocorynoline, five main active components from Corydalis bungeana Turcz (C. bungeana Turcz). An ultra high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the simultaneous determination of the pharmacokinetic characteristics of these components in rat plasma. Chromatographic separation was achieved on an Agilent SB‐C₁₈ column (1.8 μm, 150 × 2.1 mm) using a gradient elution program with a mobile phase consisting of acetonitrile and water containing 0.1% acetic acid at a flow rate of 0.3 mL/min. The analytes were detected in the multiple reaction monitoring mode with positive electrospray ionization. Lower limits of quantification were >0.680 ng/mL and matrix effects ranged from 91.26 to 100.38%. The mean extraction recoveries of quality control samples were less than 79.32%, and the precision and accuracy were within the acceptable limits. All analytes were proven to be stable during sample storage and analysis procedures. The validated method was successfully applied to the pharmacokinetic study of five alkaloid components after oral administration of C. bungeana Turcz extract to rats. The obtained results may be helpful to reveal the mechanism of action and to guide the clinical application of C. bungeana Turcz.