查找使用阿拉丁产品的科研文献

Multifunctional β-Cyclodextrin Polymer for Simultaneous and Effective Removal of Organic Micropollutants, Heavy Metals, and Detrimental Microorganisms from Water

Yibie Qin,Zuohua Liu,Changyuan Tao,Jiancheng Shu,Xia Xiong

A new porous β-cyclodextrin-based polymer (PCD-Gs) adsorbent was synthesized by the copolymerization of allyl-β-CD and partially allylated gallic acid under different monomer feeding ratios. With a series of single-factor experiments, it was found that the PCD-Gs not only exhibited ultrarapid and efficient absorption capacity for bisphenol A and Cd(II) but also possessed strong bactericidal ability and good resistance to salt and acid. Multivariate analyses showed that there was no competitive adsorption but a positive effect between Cd(II) and bisphenol A on PCD-Gs in the binary system. Besides, the PCD-Gs had outstanding regeneration ability and removal efficiency even at environmentally relevant concentrations. Combined with 1H NMR analysis, a multimechanism was suggested that the polymer of PCD-Gs possesses multiple action sites and presents great potential for simultaneously and effectively removing organic micropollutants, metal ions, and detrimental microorganisms from contaminated water, which contributes to deep purification of water and simplification of the water treatment process.

Heterometallic PdII–Cl–CuI Catalyst for Efficient Hydrolysis of β-1,4-Glycosidic Bonds in 1-Butyl-3-methylimidazolium Chloride

Yiwen Yang,Haifeng Qi,Huixiang Li,Zhanwei Xu,Xiumei Liu,Shuyin Yu,Zongchao Conrad Zhang

Efficient hydrolysis of β-1,4-glycosidic bonds of cellulose is a pivotal step in biorefineries of cellulosic biomass. In this work, we discovered that paired PdCl2–CuCl exhibited excellent synergetic catalytic activity over the single PdCl2 or CuCl in the hydrolysis of β-1,4-glycosidic bonds in 1-butyl-3-methylimidazolium chloride ([BMim]Cl) and further investigated the catalytic species in this system. The catalytic activity increased and reached a plateau at a CuCl/PdCl2 ratio of 1 with increasing molar ratio of CuCl/PdCl2 while keeping the Pd concentration constant. A combination of experimental evidence based on in situ far-infrared absorption, X-ray absorption, X-ray photoelectron, and electron paramagnetic resonance spectroscopies and DFT calculations demonstrate the coupling reaction between [PdIICl4]2– and [CuICl3]2– via the Cl bridge to form the heterometallic complex anion [Cl2PdII–Cl–CuICl2]2–. The heterometallic species is stable during the reaction and maintains its catalytic performance in the presence of various oxygenate additives. Using paired PdCl2–CuCl as a catalyst, the activation energy of hydrolytic cleavage of β-1,4-glycosidic bonds of cellobiose is determined as low as 95.8 kJ/mol. PdCl2–CuCl/[BMim]Cl combined with CrCl3 can be reused five times in cellobiose conversion to 5-hydroxymethylfurfural (5-HMF) without an apparent decrease of catalytic activity. The performance of this catalytic system is further verified for efficient cellulose conversion. More than 60% product yield is obtained at 100 °C from the cellulose, affording monosaccharides for efficient production of high value-added chemicals, such as 5-HMF, when CrCl3 is present to catalyze the conversion of glucose to 5-HMF.

Passive sampling of chlorophenols in water and soils using diffusive gradients in thin films based on β-cyclodextrin polymers

Yuanting Zhu,Guizhou Xu,Xueyao Wang,Xiaowen Ji,Xun Jia,Lin Sun,Xueyuan Gu,Xianchuan Xie

Chlorophenols (CPs) have been listed as priority control pollutants because of their high toxicity and wide range. An In-situ monitoring technique using diffusive gradients in thin films based on porous β-cyclodextrin polymers as binding materials (CDP-DGT), was established to monitor four typical CPs, namely, 4-Chlorophenol (4-CP), 2,4-Dichlorophenol (2,4-DCP), 2,4,5-Trichlorophenol (2,4,5-TCP), 2,4,6-Trichlorophenol (2,4,6-TCP) in water and soils. The performance of CDP-DGT are stable under the conditions of pH 3.5–9.3, ionic strength 0.001–0.500 mol L −1 and dissolved organic matter concentration 0–20 mol L −1 . The adsorption capacities of CDP-DGT for 4-CP, 2,4-DCP, 2,4,5-TCP, 2,4,6-TCP were 57.80 μg cm −2 , 98.82 μg cm −2 , 95.69 μg cm −2 and 98.91 μg cm −2 , respectively. The time-average weighted concentrations of four CPs determined by CDP-DGT at Sanjiangkou wharf (Yangtze river, China) were consistent with the results of grab sampling, indicating the feasibility of CDP-DGT application in actual water. In addition, the distribution of CPs in the red soil of Kunming and paddy soil of Yixing were also studied by CDP-DGT, and the desorption kinetics in the two soils were analyzed with the DIFS model. The higher the soil organic matter content is, the more CPs are distributed in the soil solid phase. CPs in both soils can be partially resupplied to soil solution from the soil solid phase and the higher the partition coefficient for labile CPs is, the stronger the supplement capacity is.

1-Octyl-3-methylimidazolium hexafluorophosphate-functionalised magnetic poly β-cyclodextrin for magnetic solid-phase extraction ofpyrethroids from tea infusions

Qinqin Xu,Zikai Liu,Chen Yan,Runhua Lu,Wenfeng Zhou

In this study, a novel sorbent, 1-octyl-3-methylimidazolium hexafluorophosphate functionalised magnetic poly β-cyclodextrin, was successfully synthesised and applied to magnetic solid-phase extraction for the determination of pyrethroids in tea infusions. The sorbent was characterised by transmission electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometer and Brunauer–Emmett–Teller measurement. All factors affecting extraction efficiency, such as sorbent amount, extraction time, ionic strength and desorption conditions, were optimised individually. Under the chosen conditions, wide linearity (2.5–500 μg L−1) with determination coefficients ranging from 0.9995 to 0.9999, low limits of detection of 0.32–0.54 μg L−1 and good precision (intra-day: 2.6–7.0%; inter-day: 3.5–7.6%) were achieved for four pyrethroids in tea infusions. The relative recoveries of target analytes in real tea infusion samples were from 70% to 101% with relative standard deviations lower than 9.1%. We conclude that the proposed method is promising in the detection of pyrethroids in tea infusions.

Magnetic poly(β-cyclodextrin) combined with solubilizing agents for the rapid bioaccessibility measurement of polycyclic aromatic hydrocarbons in soils

Shibin Qin,Shihua Qi,Xiaoshui Li,Qiuyun Shi,Huan Li,Xiaoxuan Mou,Yuan Zhang

The rapid determination of the bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in soils is challenging due to their slow desorption rates and the insufficient extraction efficiency of the available methods. Herein, magnetic poly(β-cyclodextrin) microparticles (Fe 3 O 4 @PCD) were combined with hydroxypropyl-β-cyclodextrin (HPCD) or methanol (MeOH) as solubilizing agents to develop a rapid and effective method for the bioaccessibility measurement of PAHs. Fe 3 O 4 @PCD was first validated for the rapid and quantitative adsorption of PAHs from MeOH and HPCD solutions. The solubilizing agents were then coupled with Fe 3 O 4 @PCD to extract PAHs from soil-water slurries, affording higher extractable fractions than the corresponding solution extraction and comparable to or higher than single Fe 3 O 4 @PCD or Tenax extraction. The desorption rates of labile PAHs could be markedly accelerated in this process, which were 1.3–12.0 times faster than those of single Fe 3 O 4 @PCD extraction. Moreover, a low HPCD concentration was sufficient to achieve a strong acceleration of the desorption rate without excessive extraction of the slow desorption fraction. Finally, a comparison with a bioaccumulation assay revealed that the combination of Fe 3 O 4 @PCD with HPCD could accurately predict the PAH concentration accumulated in earthworms in three field soil samples, indicating that the method is a time-saving and efficient procedure to measure the bioaccessibility of PAHs.

A facile electrochemical chiral sensor for tryptophan enantiomers based on multiwalled carbon nanotube/hydroxypropyl-β-cyclodextrin functionalized carboxymethyl cellulose

Jie Ji,Lihang Qu,Zhongrui Wang,Guangyao Li,Wei Feng,Guang Yang

The development of facile and convenient sensors for the chiral recognition of enantiomers is of great significance for medical and life science. Herein, a sensitive electrochemical sensor for the chiral recognition of tryptophan (Trp) enantiomers was developed based on the assembly of cellulose grafted with hydroxypropyl-β-cyclodextrins (CMC-CD), multi-walled carbon nanotubes (MWCNTs) and copper ions on the surface of a GCE. The morphologies and electrochemical behaviors of the prepared electrode (GCE/MWCNTs/CMC-CD-Cu) were characterized by differential pulse voltammetry (DPV), FT-IR, XPS, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The oxidation peak current ratio (I L /I D ) of DPV could be reached at 2.2 under the optimal experimental conditions. Compared with D-Trp, the higher electrochemical signal of L-Trp was ascribed to the stronger affinity for L-type tryptophan. Additionally, the as-prepared chiral sensor was successfully utilized to analyze the amount of D-Trp in the racemic mixture.

Cherry Polyphenol Extract Ameliorated Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice by Suppressing Wnt/β-Catenin Signaling Pathway

Fuhua Li,Huiming Yan,Ling Jiang,Jichun Zhao,Xiaojuan Lei,Jian Ming

Ulcerative colitis (UC) is a chronic and nonspecific inflammatory disease of the colon and rectum, and its etiology remains obscure. Cherry polyphenols showed potential health-promoting effects. However, both the protective effect and mechanism of cherry polyphenols on UC are still unclear. This study aimed to investigate the potential role of the free polyphenol extract of cherry in alleviating UC and its possible mechanism of action. Our study revealed that the free polyphenol extract of cherry management significantly alleviated UC symptoms, such as weight loss, colon shortening, the thickening of colonic mucous layer, etc. The free polyphenol extract of cherry treatment also introduced a significant reduction in levels of malondialdehyde (MDA), myeloperoxidase (MPO) and nitric oxide (NO), while causing a significant elevation in levels of catalase (CAT), glutathione (GSH-Px), superoxide dismutase (SOD), as well as the downregulation of pro-inflammatory cytokines. This indicated that such positive effects were performed through reducing oxidative damage or in a cytokine-specific manner. The immunofluorescence analysis of ZO-1 and occludin proteins declared that the free polyphenol extract of cherry had the potential to prompt intestinal barrier function. The reduced expression levels of β-catenin, c-myc, cyclin D1 and GSK-3β suggested that the cherry extract performed its positive effect on UC by suppressing the Wnt/β-ctenin pathway. This finding may pave the way into further understanding the mechanism of cherry polyphenols ameliorating ulcerative colitis.Keywords:ulcerative colitis;cherry polyphenol;anti-inflammatory;antioxidant;Wnt/β-catenin signaling pathway

Monolithic Gold Nanoparticles/Thiol-β-cyclodextrin-Functionalized TiO2 Nanowires for Enhanced SALDI MS Detection and Imaging of Natural Products

Xian-Na Wang,Bin Li

Surface-assisted laser desorption/ionization mass spectrometry (SALDI MS) has been successfully applied in the analysis of various small molecules. In this work, gold nanoparticles/thiol-β-cyclodextrin-functionalized TiO2 nanowires (AuNPs/SH-β-CD-TiO2 NWs) were prepared to enhance the performance of SALDI MS and mass spectrometry imaging (MSI). A monolithic TiO2 film was first grown on an indium tin oxide (ITO) glass slide via a modified sol–gel method and treated in an alkaline environment to form nanowires. TiO2 NWs were chemically modified by SH-β-CD for immobilizing AuNPs densely and strongly. Compared with the conventional organic matrix 2,5-dihydroxybenzoic acid (DHB), the prepared AuNPs/SH-β-CD-TiO2 NWs showed superior performances on detection sensitivity, repeatability, and analyte coverage. Analytes typically detectable with negative-ion matrix-assisted laser desorption/ionization (MALDI) MS could also be observed using AuNPs/SH-β-CD-TiO2 NWs in the positive ion mode. Its successful usage efficiently enhanced the SALDI MS detection of various small molecules such as carbohydrates, fatty acids, and bile acids in the positive ion mode. The developed SALDI substrate was further used to characterize and discriminate the natural and in vitro cultured Calculus Bovis, as well as natural and artificial Moschus. Furthermore, the spatial distribution of several natural products in spearmint leaves and potato tubers was explored by tissue imprinting and deposition on the AuNPs/SH-β-CD-TiO2 NW surface for SALDI MSI in dual-polarity mode, respectively. The wide application and satisfied detection sensitivity make AuNPs/SH-β-CD-TiO2 NWs ideal for SALDI MS and MSI of various natural products.

Simultaneous Quantification of Propylthiouracil and Its N-β-d Glucuronide by HPLC-MS/MS: Application to a Metabolic Study

Min Li,Qingfeng He,Li Yao,Xiaofeng Wang,Zhijia Tang,Xiao Zhu,Hai-Shu Lin,Xiaoqiang Xiang

Propylthiouracil (PTU) is commonly prescribed for the management of hyperthyroidism and thyrotoxicosis. Although the exact mechanism of action is not fully understood, PTU is associated with hepatoxicity in pediatric population. Glucuronidation mediated by uridine 5′-diphospho-glucuronosyltransferases (UGTs), which possess age-dependent expression, has been proposed as an important metabolic pathway of PTU. To further examine the metabolism of PTU, a reliable HPLC-MS/MS method for the simultaneous quantification of PTU and its N-β-D glucuronide (PTU-GLU) was developed and validated. The chromatographic separation was achieved on a ZORBAX Extend-C18 column (2.1 × 50 mm, 1.8 μm) through gradient delivery of a mixture of formic acid, methanol and acetonitrile. The electrospray ionization (ESI) was operated in its negative ion mode while PTU and PTU-GLU were detected by multiple reaction monitoring (MRM). This analytical method displayed excellent linearity, sensitivity, accuracy, precision, recovery and stability while its matrix effect and carry-over were insignificant. Subsequently, the in vitro metabolism of PTU was assessed and UGT1A9 was identified as an important UGT isoform responsible for the glucuronidation of PTU. The information obtained from this study will facilitate future mechanistic investigation on the hepatoxicity of PTU and may optimize its clinical application.Keywords:propylthiouracil;propylthiouracil glucuronide;in vitro;human liver microsomes;UGT1A9;HPLC-MS/MS

Anti-inflammatory Activity of a Polypeptide Fraction From Achyranthes bidentate in Amyloid β Oligomers Induced Model of Alzheimer’s Disease

Ge Xiangyu,Wang Yitong,Yu Shu,Cao Xuemin,Chen Yicong,Cheng Qiong,Ding Fei

Neuroinflammation plays a crucial role in neurodegenerative diseases such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), and anti-inflammation has been considered as a potential therapeutic strategy. Achyranthes bidentate polypeptide fraction k (ABPPk) was shown to protect neurons from death and suppress microglia and astrocyte activation in PD model mice. However, how ABPPk regulates neuroinflammation to exert a neuroprotective role remains unclear. Toxic Aβ oligomers (AβOs) can trigger inflammatory response and play an important role in the pathogenesis of AD. In the present study, for the first time, we investigated the effects and underlying mechanisms of ABPPk on neuroinflammation in AβOs-induced models of AD. In vitro, ABPPk pretreatment dose-dependently inhibited AβOs-induced pro-inflammatory cytokines mRNA levels in BV2 and primary microglia. ABPPk pretreatment also reduced the neurotoxicity of BV2 microglia-conditioned media on primary hippocampal neurons. Furthermore, ABPPk down-regulated the AβOs-induced phosphorylation of IκBα and NF-κB p65 as well as the expression of NLRP3 in BV2 microglia. In vivo, ABPPk pre-administration significantly improved locomotor activity, alleviated memory deficits, and rescued neuronal degeneration and loss in the hippocampus of AβOs-injected mice. ABPPk inhibited the activation of microglia in hippocampal CA3 region and suppressed the activation of NF-κB as well as the expression of NLRP3, cleaved caspase-1, and ASC in the brain after AβOs injection. ABPPk hindered the release of pro-inflammatory cytokines and promoted the release of anti-inflammatory cytokines in the brain. Notably, the polarization experiment on BV2 microglia demonstrated that ABPPk inhibited M1-phenotype polarization and promoted M2-phenotype polarization by activating the LPS- or AβOs-impaired autophagy in microglia. Taken together, our observations indicate that ABPPk can restore the autophagy of microglia damaged by AβOs, thereby promoting M2-phenotype polarization and inhibiting M1-phenotype polarization, thus playing a role in regulating neuroinflammation and alleviating neurotoxicity.

Purification Effects on β-HCH Removal and Bacterial Community Differences of Vertical-Flow Constructed Wetlands with Different Vegetation Plantations

Qing Chen,Honghu Zeng,Yanpeng Liang,Litang Qin,Guangsheng Peng,Liangliang Huang,Xiaohong Song

This study aimed to investigate the removal of β-hexachlorocyclohexane (β-HCH) at realistic concentration levels (10 µg/L) in different plant species in constructed wetlands (Acorus calamus,Canna indica,Thalia dealbata, andPontederia cordata) and the structure of the rhizosphere microbial community response of each group during summer and winter. Results showed that all groups of constructed wetlands had very good decontamination efficiency against β-HCH in water (90.86–98.17%). The species that most efficiently purified β-HCH in water wasA. calamusin summer (98.17%) andC. indicain winter (96.64%). Substrate sorption was found to be the major pathway for β-HCH removal from water in the constructed wetlands. The ability of the wetland plants to absorb and purify β-HCH was limited, andC. indicahad the strongest absorptive capacity among the four plant species. The mean β-HCH removal from the matrix of the planted plants increased by 5.8% compared with that of the control treatment (unplanted plants). The average β-HCH content in the plant rhizosphere substrate was 4.15 µg/kg lower than that in the non-rhizosphere substrate. High-throughput sequencing analysis revealed significant differences (P< 0.05) in the Chao1 and ACE indices of microbes in the substrate of four wetlands during summer and winter. At the genus level, the constructed wetlands with vegetation plantations showed higher microbial abundance than the constructed wetlands without vegetation plantations. In winter, the bacterial community structure of each constructed wetland was quite different, but no dominant flora in the bacterial community structure obviously changed. In summer, the bacterial community structure at the same stage was relatively small. The abundance ofActinobacteriaandSphingomonasremarkably increased over time in summer.Keywords:β-HCH;purification effects;vertical-flow constructed wetlands;bacterial community

Simultaneous Electrochemical Detection of Co-Existing Dihydroxybenzene Isomers Using Porphyrin Zr Metal-Organic Frameworks/β-cyclodextrin/Pencil Graphite Electrode

Siyi Yang,Shangming Wu,Juan Liu,Huanbao Fa,Mei Yang,Changjun Hou