新型含N-杂环卡宾二硫化碳配体的锰铼金属双核化合物的合成、表征及电化学性质简

合成了一系列含N-杂环卡宾二硫化碳加合物配体的锰铼金属有机化合物,其中包括3种单核化合物和3种双核化合物,对它们的结构进行了表征,并研究其反应性和电化学性质. 与三烷基膦二硫化碳配体相比,含N-杂环卡宾二硫化碳加合物配体的锰铼金属有机化合物展现出不同的反应特性. 研究结果表明,[MnRe(CO)6(μ-H){μ-CH3SC(S)IMes2}]配合物具有催化质子还原成氢气的能力.     

一种可用于光降解的纳米氧化锌油水分离网

通过低温水热法在钢丝网上生长六棱柱形的氧化锌纳米柱.包覆了氧化锌纳米柱的钢丝网具有水下超疏油的特殊浸润性,并可用于油水分离.滤网在室温常压下可对含有汽油、柴油和原油等油水混合物进行高效快速分离,分离效率可达98%以上.材料可以承受1.4 kPa的油层压力且可反复使用.由于氧化锌的光响应性强,滤网可快速降解水中的亚甲基蓝,2 h的降解率可达80%.包覆了氧化锌纳米柱的钢丝网具备同时进行油水分离和降解环境中污染物的能力,是一种新型多功能水处理材料.     

共存牺牲剂对染料敏化TiO_2纳米晶体系电子传输的影响

采用卟啉染料敏化TiO2纳米晶在可见光条件下(λ390 nm)进行水分解制氢.考察了不同牺牲剂———甲醇(MeOH)、三乙醇胺(TEOA)及其混合物对体系析氢效率的影响.通过荧光猝灭及光电化学性能分析发现,激发态染料与TiO2之间的电子转移极大地受到添加的牺牲剂的影响,而体系的pH值对其影响不大.     

Construction of a portable sample preparation device with a magnetic poly(methacrylic acid‐co‐ethylene dimethacrylate) monolith as the extraction medium and its application in the enrichment of UV filters in water samples

A portable sample preparation device with a magnetic polymer monolith as the extraction medium was constructed. The monolith was synthesized by polymerizing methacrylic acid and ethylene dimethacrylate around a cylindrical magnet. In this way, the monolith with a magnetic core could be readily attached to the extraction device by magnetism. The constructed device was evaluated for the enrichment of UV filters in water samples, followed by high‐performance liquid chromatographic analysis. The extraction efficiency for the targets was satisfactory with no matrix interference. Good linearities were obtained for the UV filters with the correlation coefficients >0.9986. The limits of detection and quantification for the UV filters were 0.3–0.8 and 1.0–2.4 ng/mL, respectively. The recoveries of the UV filters from the spiked water samples at the concentration of 100 ng/mL were 95.3–101.7%, with relative standard deviations <10%. Accordingly, the proposed portable device was demonstrated to be suitable for on‐site simultaneous sampling, purification, and preconcentration within a single step.     

Rapid separation and characterization of diterpenoid alkaloids in processed roots of Aconitum carmichaeli using ultra high performance liquid chromatography coupled with hybrid linear ion trap‐Orbitrap tandem mass spectrometry

The lateral root of Aconitum carmichaeli, a popular traditional Chinese medicine, has been widely used to treat rheumatic diseases. For decades, diterpenoid alkaloids have dominated the phytochemical and biomedical research on this plant. In this study, a rapid and sensitive method based on ultra high performance liquid chromatography coupled with linear ion trap‐Orbitrap tandem mass spectrometry was developed to characterize the diterpenoid alkaloids in Aconitum carmichaeli. Based on an optimized chromatographic condition, more than 120 diterpenoid alkaloids were separated with good resolution. Using a systematic strategy that combines high resolution separation, highly accurate mass measurements and a good understanding of the diagnostic fragment‐based fragmentation patterns, these diterpenoid alkaloids were identified or tentatively identified. The identification of these chemicals provided essential data for further phytochemical studies and toxicity research of Aconitum carmichaeli. Moreover, the ultra high performance liquid chromatography with linear ion trap‐Orbitrap mass spectrometry platform was an effective and accurate tool for rapid qualitative analysis of secondary metabolite productions from natural resources.     

Molecularly imprinted spin column extraction coupled with high‐performance liquid chromatography for the selective and simple determination of trace nitrophenols in water samples

In this study, we developed a simple and selective spin column extraction technology utilizing hydrophilic molecularly imprinted polymers as the sorbents for extracting nitrophenol pollutants in water samples (the East Lake, the Yangtze River, and wastewater). The whole procedure was achieved by centrifugation of the spin column, and multiple samples were simultaneously processed with a low volume of solvent and without evaporation. Under the optimized condition, recoveries of nitrophenol compounds on the spin column packed with hydrophilic molecularly imprinted polymers ranged from 87.3 to 92.9% and an excellent purification effect was obtained. Compared with activated carbon, multi‐walled carbon nanotubes, LC‐C₁₈ sorbents, hydrophilic molecularly imprinted polymers exhibited a highly selective recognition ability for nitrophenol compounds and satisfactory sample extraction efficiency. Subsequently, the spin column extraction coupled with high‐performance liquid chromatography was established, which was found to be linear in the range of 2–1000 ng/mL for 2,4‐dinitropehnol and 2‐nitrophenol, and 6–1000 ng/mL for 4‐nitrophenol with correlation coefficients greater than 0.998. The detection limits ranged from 0.3–0.5 ng/mL. It is shown that the proposed method can be used for the determination of trace nitrophenol pollutants in complex samples, which is not only beneficial for water quality analysis but also for environmental risk assessment.     

Highly efficient N-glycoproteomic sample preparation by combining C18 and graphitized carbon adsorbents

Conventional N-glycoproteome analysis usually applies C₁₈ reversed-phase (RP) adsorbent for sample purification, which will lead to unavoidable sample loss due to the high hydrophilicity of N-glycopeptides. In this study, a porous graphitized carbon (PGC) absorbent was combined with a C₁₈ adsorbent for N-glycopeptide purification in comprehensive N-glycoproteome analysis based on the hydrophobic and polar interactions between carbon and N-glycans. It was observed that the small hydrophilic N-glycopeptides that cannot retain onto C₁₈ adsorbent can be captured by the graphitized carbon, while the large hydrophobic N-glycopeptides that cannot retain onto the graphitized carbon can be feasibly captured by the C₁₈ adsorbent. Comparing with sample purification by using C₁₈ adsorbent only, 28.5 % more N-glycopeptides were identified by combining both C₁₈ and PGC adsorbents. The C₁₈-PGC strategy was further applied for both sample purification and pre-fractionation of a complex protein sample from HeLa cell. After hydrophilic interaction chromatography enrichment, 1,484 unique N-glycopeptides with 1,759 unique N-glycosylation sites were finally identified.

Site-specific qualitative and quantitative analysis of the N- and O-glycoforms in recombinant human erythropoietin

Recombinant human erythropoietin (rhEPO) has been extensively used as a pharmaceutical product for treating anemia. Glycosylation of rhEPO affects the biological activity, immunogenicity, pharmacokinetics, and in-vivo clearance rate of rhEPO. Characterization of the glycosylation status of rhEPO is of great importance for quality control. In this study, we established a fast and comprehensive approach for reliable characterization and relative quantitation of rhEPO glycosylation, which combines multiple-enzyme digestion, hydrophilic-interaction chromatography (HILIC) enrichment of glycopeptides, and tandem mass spectrometry (MS) analysis. The N-linked and O-linked intact glycopeptides were analyzed with high-resolution and high-accuracy (HR–AM) mass spectrometry using an Orbitrap. In total, 74 intact glycopeptides from four glycosylation sites at N₂₄, N₃₈, N₈₃, and O₁₂₆ were identified, with the simultaneous determination of peptide sequences and glycoform compositions. The extracted ion chromatograms based on the HR–AM data enabled relative quantification of glycoforms. Our results could be extended to quality control of rhEPO or could help establish detection approaches for glycosylation of other proteins. Graphical Abstract

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聚乙烯醇/壳聚糖复合水凝胶的物理化学性质

测定了聚乙烯醇(PVA)和壳聚糖(CS)复合水凝胶的平衡含水量、熔融焓、等温溶胀动力学和非等温失水动力学等性质,讨论了水凝胶的组成和制备参数对这些性质的影响.结果显示:PVA/CS复合水凝胶具有适宜于软骨修复替代材料的网络结构和平衡含水量.CS与PVA复合减弱了凝胶的结晶度,但却增强了水与凝胶支架的相互作用.尽管水凝胶力学拉伸强度有所降低,但却优化了凝胶的生物相容性和降解能力.PVA/CS复合水凝胶是一种潜在的软骨修复材料,作为一种理论研究的模型体系,它将促进热力学在复杂医用材料方面的应用.     

模拟体内微环境筛选与肿瘤细胞作用的中药活性成分

利用三维(3D)细胞反应器模拟体内微环境,建立了一种与肿瘤细胞作用的活性分子的筛选和分析方法.利用药物与三维细胞反应器中活肿瘤细胞和固化肿瘤细胞分别作用后的HPLC生物指纹谱峰面积之间有无显著性差异,建立了与细胞结合的活性成分的筛选识别模型.已知抗肿瘤药物紫杉醇和白藜声醇的谱峰均具有显著性差异,而非抗肿瘤药物酮洛芬和青霉素G的谱峰均没有显著性差异,证明利用该模型筛选识别与细胞结合的活性成分是可行的.此外,应用该模型从中草药桃儿七提取物中筛选出了7种可作用于Lovo细胞的活性成分.此研究提供了一种模拟体内微环境下与肿瘤细胞作用的活性成分的筛选和分析方法,在药物发现环节,特别是中草药活性成分研究中具有潜在的应用价值.