JOURNAL OF MOLECULAR STRUCTURE
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2023
·
IF 3.8
Xiangrong Li,Ruonan Xu,Tianjun Ni
Flavonols are studied extensively because of their interesting biological activities. Galangin, kaempferol, quercetin, and myricetin are structurally related flavonols that differ only in the number of B-ring hydroxyl substituents. In this work, we have carried out a detailed study on the interaction of these structurally related flavonols and γ-globulin/fibrinogen/trypsin/pepsin by using experimental as well as molecular docking approaches. Studies show that the flavonol-protein complex is formed after the interaction of flavonols with the four proteins, which has moderate quenching and binding ability. The effects of the number and position of the hydroxyl groups in flavonols B-ring on the quenching constant, binding constant, number of binding sites, thermodynamic parameters as well as the changes of the secondary structure of proteins are elucidated. The interaction between flavonols and γ-globulin/fibrinogen/trypsin/pepsin is a spontaneous exothermic process driven by enthalpy and entropy, and the main force types are hydrophobic and hydrogen bonds. For some systems, electrostatic forces are also involved. The interaction of flavonols with the four proteins results in loosening and unfolding of backbone of proteins. Moreover, galangin and quercetin also reduce the hydrophobicity of the tryptophan (Trp) microenvironment. The secondary structure of γ-globulin/fibrinogen/trypsin is affected by the number of hydroxyl groups on the B-ring. Except that myricetin does not bind to the catalytic active center of pepsin and seems to have no inhibitory effect on the activity of pepsin, for other flavonol-fibrinogen/trypsin/pepsin systems, flavonols are bound to the active center of the three proteins, and have certain influence on the activity of them.
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JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
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2023
·
IF 5.6
Changjun Zhang,Yujia Zhang,Yangjing Lv,Jianan Guo,Bianbian Gao,Yi Lu,Anjie Zang,Xi Zhu,Tao Zhou,Yuanyuan Xie
Based on the multitarget-directed ligands (MTDLs) strategy, a series of chromone-hydroxypyridinone hybrids were designed, synthesised, and evaluated as potential multimodal anti-AD ligands. Prospective iron-chelating effects and favourable monoamine oxidase B (MAO-B) inhibitory activities were observed for most of the compounds. Pharmacological assays led to the identification of compound 17d, which exhibited favourable iron-chelating potential (pFe3+ = 18.52) and selective hMAO-B inhibitory activity (IC50 = 67.02 ± 4.3 nM, SI = 11). Docking simulation showed that 17d occupied both the substrate and the entrance cavity of MAO-B, and established several key interactions with the pocket residues. Moreover, 17d was determined to cross the blood–brain barrier (BBB), and can significantly ameliorate scopolamine-induced cognitive impairment in AD mice. Despite its undesired pharmacokinetic property, 17d remains a promising multifaceted agent that is worth further investigation.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
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IF 5.876
Xiaofeng You,Yan Wang,Lin Han,Qing Liu,Zhaoyang Fei,Xian Chen,Zhuxiu Zhang,Jihai Tang,Mifen Cui,Xu Qiao
Hyper-cross-linked resin has enormous potential in the removal of organic dyes from aqueous solutions due to its adjustable porous structure and designable chemical properties, whereas its poor adsorption capacity limits the application. In this study, the co-modified hyper-cross-linked resin (HCP-x) with tunable porosity was synthesized by adjusting the dosages of 4-vinylpyridine (4-VP) and 4-vinylbenzoic acid (4-VA) in the polymerization process. The results indicated that pores in the range of 4–12 nm show up in HCP-x resin with the addition of 4-VP and 4-VA. Particularly, the polymer containing 10% by weight of monomer (HCP-90) had the highest specific surface area, the largest micropore volume and a bigger mesoporous volume in the terpolymer . The adsorption experiment results demonstrated that HCP-90 showed 4 times increased Rhodamine B adsorption than the original resin. This study described a simple method to co-modify the hyper-cross-linked resin by introducing two functional monomers, and the modified material was potential for Rhodamine B adsorption.
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JOURNAL OF SEPARATION SCIENCE
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2019
·Vol. 42
·期 6
·1289-1298
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IF 2.516
Gui-Fang Wu,Xiao-Lan Jiang,Yu-Zhou Gong,Ya-Dong Hu,Xiao-Lin Bai,Xun Liao
In this work, monoamine oxidase B was immobilised onto magnetic nanoparticles to prepare a new type of affinity solid-phase extraction adsorbent, which was used to extract the possible anti-neurodegenerative components from the Lonicera japonica flower extracts. Coupled with high-performance liquid chromatography with mass spectrometry, two monoamine oxidase B ligands were fished-out and identified as isochlorogenic acid A and isochlorogenic acid C, which were found to be inhibitors of the enzyme for the first time, with similar half maximal inhibitory concentration values of 29.05 ± 0.49 and 29.77 ± 1.03 μM, respectively. Furthermore, equilibrium-dialysis dissociation assay of enzyme-inhibitor complex showed that both compounds have reversible binding patterns to monoamine oxidase B, and kinetic analysis demonstrated that they were mixed-type inhibitors for monoamine oxidase B, with K i and K is values of 9.55 and 37.24 μM for isochlorogenic acid A, 9.53 and 35.50 μM for isochlorogenic acid C, respectively. The results indicated that isochlorogenic acid A and isochlorogenic acid C were the major active components responsible for the anti-degenerative activity of the flowers of L. japonica , while magnetic nanoparticles immobilised monoamine oxidase B could serve as an efficient solid-phase extraction adsorbent to specifically extract monoamine oxidase B inhibitors from complex herbal extracts.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2019
·
IF 2.298
Guohong Yao,Sisi Li,Jun Xu,Hui Liu
A dual-responsive hydrogel based on graphene oxide (GO) was prepared by in situ radical copolymerization of N-isopropyl acrylamide (NIPAM) as a temperature-sensitive component and acrylic acid (AA) as a pH-sensitive unit. The resulting hydrogels (GO/poly(NIPAM-co-AA) (PNA) were systematically characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. With the change of AA content, the lower critical solution temperature of hydrogels changed from 26.91 to 24.38 °C. The swelling ratio under alkaline condition was higher than that under acidic condition. The adsorption of rhodamine B (RB) followed Langmuir isotherm model and pseudo-second-order model, and nearly 93% of RB could be released within 10 h at pH 4.01 and 60 °C. With imidacloprid as the model drug, the higher cumulative release rate of the GO/PNA hydrogel was obviously observed at pH = 4.01 than at pH = 9.18. On the basis of their good adsorption–desorption, loading-releasing, and regeneration ability, the GO/PNA hydrogel as a multifunctional adsorbent might have broad application prospects in environmental protection and biomedical engineering.
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RSC Advances
·
2019
·Vol. 9
·期 27
·15196-15204
·
IF 3.049
Yun Hong,Dongsen Mao,Rui Wu,Zhe Gao,Tingting Meng,Rongrong Wang,Lin Liu,Jing Miao
DNAzymes have the potential to suppress gene expression through sequence-specific mRNA cleavage and can therefore play an important role in various gene therapies. Hepatitis B virus (HBV) is still one of the most serious liver infections in people around the world and is difficult to treat. We previously designed a 10-23 DNAzyme called DrzBS, which targets HBV S gene expression, but this enzyme depends on exogenous delivery, and so its application has been limited. To overcome this limitation, we have now developed a chitosan-based nanocarrier (chitosan-g-stearic acid, CSO–SA) for intracellular delivery of DrzBS, then compared the inhibition effect of our CSO–SA/DrzBS complex to a common transfection reagent, Lipofectamine™ 2000/DrzBS, on hepatitis B surface antigen expression. The synthesized CSO–SA assembles into micelles in an aqueous solution and exhibits excellent cytoplasmic targeting, and could protect DrzBS from degradation by ribonuclease. CSO–SA/DrzBS showed a higher inhibition rate (IR) than Lipofectamine™ 2000/DrzBS. Moreover, at the same DrzBS concentration (1.2 μmol L−1), the maximum IR of CSO–SA/DrzBS micelles was 2.4-fold that of the Lipofectamine™ 2000/DrzBS complex, and held on for 96 hours. Compared with Lipofectamine™ 2000/DrzBS, CSO–SA/DrzBS achieved a higher HBV inhibition effect. This study demonstrates that CSO–SA micelles can serve as a potential vector for DrzBS and that CSO–SA/DrzBS micelles are a promising application for anti-HBV gene therapy.
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POLYMERS FOR ADVANCED TECHNOLOGIES
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2019
·Vol. 30
·期 4
·963-972
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IF 2.162
Sheng Xiang,Lidong Feng,Xinchao Bian,Bao Zhang,Bin Sun,Yanlong Liu,Gao Li,Xuesi Chen
To obtain an effective compatibilizer for the blends of poly(L-lactide) (PLLA) and poly(ε-caprolactone) (PCL), the diblock copolymers PCL- b -PLLA with different ratios of PCL/PLLA (CL/LA) and different molecular weights ( M n ) were synthesized by ring-opening polymerization (ROP) of L-lactide with monohydric poly(ε-caprolactone) (PCL-OH) as a macro-initiator. These copolymers were melt blended with PLLA/PCL (80/20) blend at contents between 3.0 and 20 phr (parts per hundred resin), and the effects of added PCL- b -PLLA on the mechanical, morphological, rheological, and thermodynamic properties of the PLLA/PCL/PCL- b -PLLA blends were investigated. The compatibility between PLLA matrix and PCL phase was enhanced with decreasing in CL/LA ratios or increasing in M n for the added PCL- b -PLLA. Moreover, the crystallinity of PLLA matrix increased because of the added compatibilizers. The PCL- b -PLLA with the ratio of CL/LA (50/50) and M n ≥ 39.0 kg/mol were effective compatibilizers for PLLA/PCL blends. When the content of PCL- b -PLLA is greater than or equal to 5 phr, the elongations at break of the PLLA/PCL/PCL- b -PLLA blends all reached approximately 180%, about 25 times more than the pristine PLLA/PCL(80/20) blend.
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Nanomaterials
·
2018
·Vol. 8
·期 4
·248
·
IF 3.504
Fuhua Wei,Ding Chen,Zhao Liang,Shuaiqi Zhao
Using a microwave-assisted ball-milling approach, Fe-based metal-organic frameworks (Fe-MOFs) were prepared from FeSO4·7H2O and trimesic acid. Scanning electron microscopy, Fourier-transform infrared spectrometry, X-ray, and thermogravimetric analysis were utilized to characterize the thermal stability and structure of the prepared Fe-MOFs. These Fe-MOFs were used to remove organic dyes from aqueous solutions. Specifically, they removed 96.97% of 23.3592 mg/L of Congo red in a 200 mL solution within 300 min of treatment with natural light at 15 °C. Likewise, 88.21 and 70.90% of 22.7527 mg/L of Orange II and 17.8326 mg/L of Rhodamine B, respectively, were removed from 200 mL solutions within 300 min of treatment at 15 °C. At 35 °C, 99.57, 95.98, and 99.38% of 23.3855 mg/L of Congo Red, 22.7365 mg/L of Orange II, and 17.9973 mg/L of Rhodamine B, respectively, were removed from 200 mL solutions within 300 min of treatment. The adsorption kinetics were investigated and the pseudo-first-order kinetic model was found to be superior to the pseudo-second-order kinetic model. Overall, using metal-organic frameworks to treat dye wastewater was found to be inexpensive, feasible, and efficient. Therefore, this material has future prospects in research and applications in the purification of wastewater.Keywords:wastewater treatment;metal-organic frameworks;dye removal;microwave-assisted ball milling
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RSC Advances
·
2019
·Vol. 9
·期 26
·15033-15041
·
IF 3.049
Ya Gao,Yongjie Zheng,Jixing Chai,Jingzhi Tian,Tao Jing,Deqing Zhang,Junye Cheng,Huiqing Peng,Bin Liu,Guangping Zheng
Effective separation and rapid transfer of photogenerated electron–hole pairs are key features of photocatalytic materials with high catalytic activity, which could be achieved in co-catalysts. It is reported that the two-dimensional (2D) MoS2 is a promising co-catalyst due to its unique semi-conductive properties and graphene-like layered structure. However, the application of MoS2 as a co-catalyst is limited by its poor electrical conductivity. On the other hand, it is worth noting that TiO2 possesses reactive crystal facets, which is one of the dominant mechanisms for the separation of photogenerated electron–hole pairs. In this work, we prepared MoS2/RGO hybrids as co-catalysts which were doped to TiO2 with highly reactive {001} planes via the hydrothermal method. It was found that the {001}-TiO2/MoS2/RGO photocatalysts with 7 wt% MoS2/RGO co-catalyst show the highest photodegradation activity for the degradation of Rh B under visible light irradiation (λ > 400 nm), which could result from the synergy of the effective separation of electron–hole pairs by the {001} facets in TiO2 and the rapid transfer of electron–hole pairs in MoS2/RGO. The results show that the {001}-TiO2/MoS2/RGO hybrid is a low-cost and stable photocatalyst for the effective degradation of Rh B under visible light.
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MEASUREMENT
·
2019
·
IF 2.791
Yi Xing,Guanlan Wu,Ying Ma,Yangyang Yu,Xing Yuan,Xiaolin Zhu
A simple and highly sensitive electrochemical sensor for the determination of bisphenol B (BPB) based on a glassy carbon electrode (GCE) modified with Prussian blue (PB) and carboxylated multi-walled carbon nanotubes (MWNTs-COOH) was constructed. The PB/MWCNTs-COOH/GCE was characterized by emission scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, and cyclic voltammetry. Due to the synergistic effect, the PB/MWCNTs-COOH/GCE remarkably enhanced the oxidation of BPB, which improved the anodic peak current of BPB significantly. Under the optimum conditions, the linear response range of BPB was between 5 × 10 −8 and 1.75 × 10 −4 M with the detection limit (S/N = 3) of 5 × 10 −10 M. Additionally, the PB/MWCNTs-COOH/GCE revealed excellent stability, repeatability and reproducibility. Moreover, it was successfully applied in the determination of BPB in real samples. This study provided a sensitive and simple sensor for the quantitative detection of BPB in the environment.
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ENZYME AND MICROBIAL TECHNOLOGY
·
2017
·
IF 2.502
Kun Zhang,Zhiyou Pan,Zhoujian Diao,Shuli Liang,Shuangyan Han,Suiping Zheng,Ying Lin
Kinetic resolution of sec -alcohols is a green process with biocatalyst. Candida antarctica lipase B (CALB) displayed on Pichia pastoris cell-surface (Pp-CALB) was characterized in kinetic resolution of sec -alcohols with different structures. The reaction parameters including acyl donors, molar ratio of substrates, solvents and temperatures were examined with 2-octanol as model substrate. 47.4% molar conversion of 2-octanol and 99.7% ee p were obtained after a 5 h reaction with Pp-CALB, and 90% of its original activity still remained after being reused for 10 cycles. Pp-CALB was then used to several sec -alcohols and it showed great enzymatic activity and enantioselectivity to all tested sec -alcohols, more than 93.1% of ee p . The enantioselective characteristics of Pp-CALB catalysed sec -alcohols with different structures were compared with Novozyme 435 which was almost the same. Solvent free system as one way of green chemistry was applied to Pp-CALB and Pp-CALB showed great catalytic activity and enantioselectivity. Pp-CALB was potential biocatalyst of high enzymatic activity and enantioselectivity using in resolution of sec -alcohols.
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ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Huayu Chen,Shuxin Ouyang,Ming Zhao,Yunxiang Li,Jinhua Ye
Water splitting has been greatly limited by the sluggish kinetics of the oxygen evolution reaction (OER). High-oxidation-state metal species are required as the favorable active sites in OER. Here, amorphous Cox–Fe–B (x is the molar ratio of Co/Fe), Co–B, and Fe–B compounds were successfully synthesized as the oxygen evolution electrocatalysts. The calculation of turnover frequency (TOF) indicates that both the Co and Fe sites are active for OER. Cyclic voltammetry, X-ray photoelectron spectroscopy, and long-term stability curves were used to demonstrate that Fe can stabilize Co in a higher oxidation level and meanwhile promote the generation of OOH-like species (the key intermediates for OER). The reduced impedance for Co2–Fe–B (compared with that for Fe–B and Co–B) obtained from the electrochemical impedance spectra confirms the enhanced conductivity for the Co2–Fe–B. This optimal sample on Cu substrate shows a low overpotential of 0.298 V at the current density of 10 mA cm–2 with a decreased overpotential of 42 mV compared to that of Co–B. The Co2–Fe–B catalyst also exhibits a small Tafel slope of 62.6 mV/dec and good stability. The enhanced performance could be attributed to the synergistic effect of the increased population of high-oxidation-state metal–OOH species and the promoted conductivity of the catalyst. A solar-to-hydrogen energy conversion efficiency of 4.2% and a Faradaic efficiency of 97.2% can be achieved by connecting the HER and as-prepared OER electrodes to a crystalline silicon solar cell.
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危险品化学品经营许可证（带存储）