查找使用阿拉丁产品的科研文献

β-Cyclodextrin dinuclear copper supported on graphene/polypyrrole nanocomposites as an electrochemical sensor for enantioselectivity recognition of tryptophan enantiomers

Zhang Zengdong,Wang Jia,Pei Hebing,Guo Ruibin,Liu Nijuan,Mo Zunli

Electrochemical chiral recognition has gained much of attention as an efficient method for enantiomeric recognition. Herein, a chiral sensing platform via β-cyclodextrin dinuclear copper (Cu-β-CD) as a chiral selector supported on graphene/polypyrrole (RGO/Ppy) nanocomposites were fabricated for recognition of tryptophan (Trp) enantiomers. Cu-β-CD with additional chiral sites improves recognition efficiency, and the addition of the conducting polymer Ppy enhances the electrical conductivity of the nanocomposite and addresses the agglomeration effect of graphene (RGO). In addition, the composition and morphology of the materials were analyzed by transmission electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The mechanism of chiral recognition was evaluated by water contact angle experiments and UV–Vis absorption spectroscopy. And the battery of chiral recognition experiments revealed that the chiral sensing platform RGO/Ppy/Cu-β-CD/GCE provides excellent recognition of the Trp enantiomer with an enantioselectivity coefficient of 3.24. It also exhibits outstanding stability and reproducibility, with a minimum line of detection (LOD) of 0.37 mM and 1.05 mM for L-Trp and D-Trp, respectively. With these results, the RGO/Ppy/Cu-β-CD/GCE chiral sensing platform has provided a feasible approach for the electrochemical chiral recognition of Trp enantiomers.

Histone methyltransferase SETDB1 promotes osteogenic differentiation in osteoporosis by activating OTX2-mediated BMP-Smad and Wnt/β-catenin pathways

Hu Lianying,Cheng Zhen,Wu Lunan,Luo Liangliang,Pan Ping,Li Shujin,Jia Qiyu,Yang Ning,Xu Bin

Osteogenic differentiation plays important roles in the pathogenesis of osteoporosis. In this study, we explored the regulatory mechanism of histone methyltransferase SET domain bifurcated 1 (SETDB1) underlying the osteogenic differentiation in osteoporosis. The common osteoporosis-related genes were retrieved from the GeneCards, CTD, and Phenolyzer databases. The enrichment analysis was conducted on the candidate osteoporosis-related genes using the PANTHER software, and the binding site between transcription factors and target genes predicted by hTFtarget. The bioinformatics analyses suggested 6 osteoporosis-related chromatin/chromatin binding protein or regulatory proteins (HDAC4, SIRT1, SETDB1, MECP2, CHD7, and DKC1). Normal and osteoporosis tissues were collected from osteoporosis patients to examine the expression of SETDB1. It was found that SETDB1 was poorly expressed in osteoporotic femoral tissues, indicating that SETDB1 might be involved in the development of osteoporosis. We induced SETDB1 overexpression/knockdown, orthodenticle homeobox 2 (OTX2) overexpression, activation of Wnt/β-catenin or BMP-Smad pathways alone or in combination in osteoblasts or ovariectomized mice. The data indicated that SETDB1 methylation regulated H3K9me3 in the OTX2 promoter region and inhibited the expression of OTX2. Besides, the BMP-Smad and Wnt/β-catenin pathways were inhibited by OTX2, thereby resulting in inhibited osteogenic differentiation. Animal experiments showed that overexpressed SETDB1 could promote the increase of calcium level and differentiation of femoral tissues. In conclusion, upregulation of SETDB1 promotes osteogenic differentiation by inhibiting OTX2 and activating the BMP-Smad and Wnt/β-catenin pathways in osteoporosis.

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

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

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.

Effective separation of α-asarone and β-asarone in TCM by covalent organic framework modified magnetic solid phase extraction

Wei Wei,Qiang Han,Sheng Tian,Yanping Wang,Huiying Zhang,Haibo Wang,Qionglin Liang

The separation of active ingredients in traditional Chinese medicine (TCM) is of great significance in determining the efficacy of TCM as well as the pharmacological study of active ingredients, improving the scope of application of TCM and the efficiency of disease prevention and treatment. In the current study, we have successfully synthesized a core–shell structure magnetic microsphere Fe 3 O 4 -COF for the separation of α-asarone and β-asarone in the combined decoction of Acorous Tatarinowii Rhizoma (ATR) and Polygalae Radix (PR). The successful synthesis of Fe 3 O 4 -COF was demonstrated chemically and morphologically by using five characterizations such as Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM). Extraction conditions were investigated and optimized, including adsorbent dosage, adsorption time, sample pH value, elution solvent, elution time and volume of elution solution. Under the optimal experimental conditions, we got a low limit of detection (LOD) of α-asarone and β-asarone were 0.0379 μg/mL and 0.0432 μg/mL, and the relative standard deviations (RSD) were less than 2.3%. And the number and intensity of impurity peaks in the chromatogram after extraction of complex samples were significantly reduced and the good recoveries were still maintained after multiple extractions of complex samples, which showed satisfied specific adsorption and excellent resistance to matrix interference. The successful establishment of this method will provide a new direction for the separation and analysis of active ingredients in traditional Chinese medicine.

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

Role of Ovalbumin/β-Cyclodextrin in Improving Structural and Gelling Properties of Culter alburnus Myofibrillar Proteins during Frozen Storage

Meiwen Lv,Xiukang Wang,Noman Walayat,Zhongli Zhang,Muhammad Hamzah Saleem,Asad Nawaz,Rana Muhammad Aadil,Shakeel Ahmed,Mario J. Simirgiotis,José M. Lorenzo,Basit Latief Jan

This study aimed to analyze the cryoprotective effect of a ovalbumin (OVA) and β-cyclodextrin (βCD) mixture (3:1, OVA/βCD) on the structure, rheology and gelling properties of myofibrillar proteins (MPs) during 90 days of frozen storage. A mixture of OVA/βCD at different concentrations (0, 2, 4, and 6%) was added to MPs and stored at −18 °C for 90 days. The addition of OVA/βCD significantly decreased the sulfhydryl contents while it increased the surface hydrophobicity, which was closely connected with tertiary structural changes. Circular dichroism analysis showed that the addition of OVA/βCD enhanced the stability of the secondary structure by inhibiting the decline in the α-helix. Rheological properties analysis indicated that 6% OVA/βCD treatment showed better storage modulus (G’) and loss modulus (G”). In addition, treatment of OVA/βCD showed better gel forming properties than the control group (0%), helping to form a homogeneous and denser gel network. The results proved that 6% OVA/βCD could be act as a promising cryoprotectant, which can improve the structure and gel behavior ofCulter alburnusMPs during frozen storage. Moreover, OVA/βCD could be a potential alternative to conventional cryoprotectants at the industrial level to increase the economic and commercial values of seafood products.Keywords:myofibrillar proteins;ovalbumin;β-cyclodextrin;cryoprotectant;frozen storage

Photostimulation of lymphatic clearance of β-amyloid from mouse brain: a new strategy for the therapy of Alzheimer’s disease

Li Dongyu,Lin Hao,Sun Silin,Liu Shaojun,Liu Zhang,He Yuening,Zhu Jingtan,Xu Jianyi,Semyachkina-Glushkovskaya Oxana,Yu Tingting,Zhu Dan

Alzheimer’s disease (AD) is an age-related neurodegenerative disorder that poses a significant burden on socio-economic and healthcare systems worldwide. However, the currently available therapy of AD is limited, and new strategies are needed to enhance the clearance of β-amyloid (Aβ) protein and improve cognitive function. Photobiomodulation (PBM) is a non-invasive and effective therapeutic method that has shown promise in treating various brain diseases. Here, we demonstrate that 1267-nm PBM significantly alleviates cognitive decline in the 5xFAD mouse model of AD and is safe as it does not induce a significant increase in cortical temperature. Moreover, with the combination of 3D tissue optical clearing imaging and automatic brain region segmentation, we show that PBM-mediated reductions of Aβ plaques in different subregions of prefrontal cortex and the hippocampus are different. The PBM-induced lymphatic clearance of Aβ from the brain is associated with improvement of memory and cognitive functions in 5xFAD mice. Our results suggest that the modulation of meningeal lymphatic vessels (MLVs) should play an important role in promoting Aβ clearance. Collectively, this pilot study demonstrates that PBM can safely accelerate lymphatic clearance of Aβ from the brain of 5xFAD mice, promoting improvement of neurocognitive status of AD animals suggesting that PBM can be an effective and bedside therapy for AD. Graphical Abstract

TMEM97 is transcriptionally activated by YY1 and promotes colorectal cancer progression via the GSK-3β/β-catenin signaling pathway

Mao Dong,Zhang Xiaowei,Wang Zhaoping,Xu Guannan,Zhang Yun

Transmembrane protein 97 (TMEM97) is a conserved integral membrane protein highly expressed in various human cancers, including colorectal cancer (CRC), and it exhibits pro-tumor roles in breast cancer, gastric cancer, and glioma. However, whether TMEM97 participates in CRC progression is not fully understood. The expression of mRNA and protein was evaluated by real-time qPCR, western blotting, immunofluorescent, and immunohistochemical staining. TMEM97 functions in cell proliferation, apoptosis, migration, and invasion were assessed by CCK-8, flow cytometry, and transwell assays. The roles of TMEM97 in CRC cells in vivo was investigated using a subcutaneous xenograft model. The transcriptional regulation of TMEM97 was explored by luciferase reporter and ChIP assays. The silencing of TMEM97 inhibited migration and invasion of CRC cells in vitro and led to suppressed growth and enhanced apoptosis in CRC cells and xenografts, whereas overexpression of TMEM97 displayed opposite effects. Mechanistically, TMEM97 knockdown caused a reduction of the proliferating marker PCNA and an increase of pro-apoptotic proteins (cleaved caspase 8/3/7 and cleaved PARP) in CRC cells. TMEM97 also positively regulated the β-catenin signaling pathway in CRC cells and xenografts by modulating the phosphorylated-GSK-3β and active (non-phospho) β-catenin levels. Interestingly, YY1, a well-recognized oncogenic transcription factor, was identified to bind to the TMEM97 promoter and enhance its transcriptional activity, and silencing of TMEM97 abolished YY1-mediated pro-tumor effects on CRC cells. Our results suggest that TMEM97 is transcriptionally activated by YY1 and promotes CRC progression via the GSK-3β/β-catenin signaling pathway, providing that TMEM97 might be a novel therapeutic target for preventing CRC development.

Whey protein isolate/flavor cinnamaldehyde conjugates prepared by different methods and the stabilization effects on β-carotene-loaded emulsions

Runan Zhao,Junjie Hu,Tianyi Yan,Haocheng Guo,Yong Deng,Yan Li,Zhengcang Yang,Haitian Fang,Wenjun Wang,Donghong Liu

Whey protein isolate (WPI) interacts with cinnamaldehyde (CA) to form conjugates with superior functional properties, which are affected by the conjugate structures formed by different food processing techniques, especially heating treatment. Initially, we compared three preparation methods of conjugates, including heating WPI before interacting with CA [(HWPI)/CA)], heating the resulting conjugates without heating WPI initially [H-(WPI/CA)], and the normal conjugates without any heating process (WPI/CA). Subsequently, these conjugates were used to stabilize emulsions for the encapsulation and delivery of β-carotene. Both the aforementioned heating methods increased the interaction and enhanced the conjugates' surface hydrophobicity. Synchronous fluorescence suggested that heating expanded the protein structure and exposed hydrophobic groups, while higher CA concentration had a shielding effect on this process. Moreover, H-(WPI/CA) conjugates reduced the interfacial tension to 4.38 mN/m, resulting in the best emulsification, which effectively stabilized emulsions and protected β-carotene from the influence of temperature. H-(WPI/CA) conjugates helped to maintain the retention rate at more than 70% within 28 days and improved β-carotene bioaccessibility during digestion. This knowledge provides insights into investigating the relationship between conjugates preparation methods and their properties, and is of great significance for developing a novel multifunctional food ingredient system based on protein modification.

Supramolecular Fe3O4-gluconic acid@β-cyclodextrin magnetic composite: green synthesis using sucrose and application in removal of p-nitrophenol

Songtao Cai,Jinman Wu,Yaokun Mo,Yuxuan Dai,Peng Liu,Jianxin Luo,Chunyan Zhang,Yifei Liu,Jianjun Liu,Qingwen Zhang,Fuming Du,Yi Wang,Hu Chen

A two-pot method is reported for the synthesis of ferric oxide-gluconic acid/β-cyclodextrin (Fe 3 O 4 -GA@β-CD). The proposed approach is a green one as the raw material is a natural product (sucrose) and no organic solvent is involved. Meanwhile, this novel composite was demonstrated for catalytic degradation of p-nitrophenol (PNP), a prototype toxic with high toxicity and low degradability. This is realized by H 2 O 2 activation induced by the heterogeneous Fenton-like catalysis of the as-prepared Fe 3 O 4 -GA@β-CD nano-microspheres. The results showed that the reaction rate constants of PNP degradation catalyzed by Fe 3 O 4 -GA@β-CD and Fe 3 O 4 -GA were 0.0879 and 0.0514 min −1 , respectively, suggesting improved catalytic performance of Fe 3 O 4 -GA@β-CD compared with Fe 3 O 4 -GA. This can be attributed to the cavity of β-CD, which can capture and include PNP molecules. The effects of pH value, H 2 O 2 concentration, catalyst load and hydroxyl radical quenching on the Fenton-like catalysis were explored and the optimized conditions (pH value = 2.0, H 2 O 2 concentration = 50 mM, and catalyst load = 1.0 g/L) were determined. Additionally, Fe 3 O 4 -GA@β-CD exhibited excellent reusability (catalytic degradation rate = 95.1% after five recycling times) as it can be recycled under external magnetic field owing to its good magnetic response (up to 18.41 emu/g).