Catalysts
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2022
·Vol. 12
·期 9
·997
·
IF 4.501
Xingmiao Zhu,Pengcheng Chen,Pu Zheng
4-Hydroxy benzylideneacetone (4-HBA) is an organic synthesis intermediate and can be used as a precursor for the synthesis of raspberry ketone. Herein, 2-deoxy-D-ribose 5-phosphate aldolase (DERA) was overexpressed inE. coliBL21 (DE3) as an attractive catalyst for enzymatic aldol reactions. The aldol reaction between 4-hydroxybenzaldehyde (4-HBD) and acetone to biosynthesize 4-HBA was catalyzed by whole-cellE. coliBL21 (DE3) (pRSF-Deoc). The yield and 4-HBA concentration were 92.8% and 111.35 mM, respectively, when using 120 mM 4-HBD and acetone as substrates. When the concentration of 4-HBD was increased to 480 mM, 376.4 mM 4-HBA was obtained by a fed-batch strategy with a yield of 78.4%, which was about a 28% improvement compared to the one-time addition strategy.E. coliBL21 (DE3) (pRSF-Deoc) cells were further immobilized withK-carrageenan, and the immobilized cells still maintained a residual activity of above 90% after 10 repeated uses. Our study provides a promising method of biosynthesizing 4-HBA.Keywords:4-hydroxybenzylideneacetone;2-deoxy-D-ribose 5-phosphate aldolases;whole-cell catalysis;fed-batch strategy;immobilized cells
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ENVIRONMENTAL TECHNOLOGY
·
2021
·
IF 3.247
Binchao Lu,Liang Wang,Xin Zheng,Zhongce Hu,Zhiyan Pan
Environmental contamination by 4-chlorophenol (4-CP) is a major concern. Photosynthetic bacteria have the ability to biodegrade 4-CP under dark aerobic conditions. In this study, we found that using different carbon sources (i.e. glucose, sodium acetate, sodium propionate sucrose, and malic acid) as co-metabolic substrates accelerated the biodegradation of 4-CP, and this acceleration was especially pronounced in the glucose treatment. A maximum degradation rate of 96.99% was reached under a concentration of 3.0 g·L−1 after 6 days of culture. The optimum conditions were pH 7.5, a temperature of 30°C, and a rotation speed of 135 rpm. The biodegradation of 4-CP was achieved at a range of salinities (0–3.0% NaCl, w/v). The biodegradation kinetics agreed with the Haldane model, and the kinetic constants were rmax = 0.14 d−1, Km = 33.9 mg·L−1, and Ki = 159.6 mg·L−1. Additionally, the coexistence of phenol or 2,4-dichlorophenol (2, 4-DCP) had a certain impact on the degradation of 4-CP under dark aerobic conditions. When the coexisting phenol concentration reached 100 mg·L−1, the maximum degradation rate of 4-CP reached 90.20%. The degradation rate of 4-CP decreased as the concentration of coexisting 2, 4-DCP increased.
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TRANSITION METAL CHEMISTRY
·
2019
·Vol. 44
·期 7
·655-662
·
IF 1.016
Cui Yanshuai,Liang Bo,Zhang Jin,Wang Ran,Sun Haotian,Wang Longgang,Gao Dawei
Abstract Palladium nanoparticles (Pd NPs) have been drawing great interest as catalysts for water treatment. Herein, high molecular weight polyethyleneimine (PEI) (molecular weight: 70 kDa) was used as template to stabilize Pd NPs. PEI was incubated with disodium tetrachloropalladate, followed by reduction with sodium borohydride. Pd NPs had narrow size distribution with diameter from 3.64 to 6.20 nm. The PEI-stabilized palladium nanoparticles (Pd n -PEI NPs) showed excellent long-term stability and positive zeta potential in phosphate saline buffers with different pH values. In addition, Pd n -PEI NPs exhibited high efficiency for catalysis of 4-nitrophenol (4-NP) in aqueous solution. The catalytic reduction of 4-NP followed the pseudo-first-order behavior, which had the highest catalytic ability ( k nor = 229). The enhanced properties can be attributed to the high stability and smaller size of Pd n -PEI NPs in aqueous solution, resulting from the application of PEI template. This method can be used to prepare highly stable metal nanoparticles with potential applications in catalysis of polluted water in the future. Graphical abstract
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BIOTECHNOLOGY LETTERS
·
2018
·Vol. 40
·期 7
·1049-1055
·
IF 1.846
Zhao Weirui,Ding Huanru,Hu Sheng,Huang Jun,Lv Changjiang,Mei Jiaqi,Jin Zhihua,Yao Shanjing,Mei Lehe
Objective To develop a new and efficient biocatalytic synthesis method of imidazole-4-acetic acid (IAA) from l -histidine ( l -His). Results l -His was converted to imidazole-4-pyruvic acid (IPA) by an Escherichia coli whole-cell biocatalyst expressing membrane-bound l -amino acid deaminase (m l -AAD) from Proteus vulgaris firstly. The obtained IPA was subsequently decarboxylated to IAA under the action of H 2 O 2 . Under optimum conditions, 34.97 mM IAA can be produced from 50 mM l -His, with a yield of 69.9%. Conclusions Compared to the traditional chemical synthesis, this biocatalytic method for IAA production is not only environmentally friendly, but also more cost effective, thus being promising for industrial IAA production.
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JOURNAL OF PHYSICAL CHEMISTRY B
·
2025
·
IF 2.9
Qingxue Li,Danqi Li,Bo Zhuang,Wenkai Zhang,Ran-Ran Feng,Feng Gai
It has been shown that 4-cyanoindole-2′-deoxyribonucleoside (4CNI-NS) is a versatile spectroscopic probe of DNA structure and dynamics, as it can pair with all four natural DNA bases. However, its photophysics have not been examined in detail. Herein, we employed multiple techniques, including static fluorescence spectroscopy, time-resolved fluorescence spectroscopy, transient infrared spectroscopy, and theoretical calculations, to assess the photophysical properties of this nucleoside analogue in a series of solvents. We found that (1) its fluorescence has a large quantum yield (0.85 ± 0.10) and a relatively long decay lifetime (10.3 ± 1.0 ns) in H2O, both of which become smaller in other solvents examined, (2) its maximum fluorescence emission frequency exhibits a linear dependence on the relative polarity index of the solvent, (3) the oscillator strength of its C≡N stretching vibration is increased by a factor of >10 upon transition to its excited electronic state (S1), (4) besides solvent relaxation, a rotational motion around the single bond connecting the pentose group and the indole ring is also present in the S1 state, and (5) in aprotic solvents both processes lead the C≡N stretching frequency (νESA) to shift toward higher frequencies, whereas in protic solvents the effects of these processes are more complex. Taken together, these findings provide a molecular basis for interpreting the spectroscopic signals of this nucleoside analogue in practical applications.
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Chinese Physics B
·
2025
·
IF 1.5
Yang-kun Zhang,Yu-chen Wang,Wei Yang,Dong-xia Shi,Luo-jun Du,Guang-yu Zhang
Molybdenum disulfide (MoS2) is an emerging two-dimensional (2D) semiconductor and has great potential for high-end applications beyond the traditional silicon-based electronics. Compared to the monolayers, multilayer MoS2 has improved electron mobility and current density, and therefore provides a more promising platform in terms of thin-film transistors, flexible electronic devices, etc. However, the synthesis of large-area, high-quality multilayer MoS2 films with controlled layer number remains a challenge. Here, we develop a two-step oxygen-assisted chemical vapor deposition (OA-CVD) methodology for the synthesis of 4-inch MoS2 films from monolayer to trilayer on sapphire substrates. The influence of critical growth parameters on the growth of multilayer MoS2 is systematically explored, such as the evaporation temperature of MoO3 and the flow rate of O2. Flexible field-effect transistor (FET) devices fabricated from bilayer/trilayer MoS2 show substantial improvements in mobility compared with flexible FETs based on monolayer films.
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HIGH PERFORMANCE POLYMERS
·
2019
·
IF 1.584
Ziwen Hou,Sizhuo Jin,Xiaowen Wang,Shuai Wang,Junyu Zhao,Zhiming Mi,Shengqi Ma,Daming Wang,Xiaogang Zhao,Hongwei Zhou,Chunhai Chen
In this work, 4,4′-isopropylidenedicyclohexanol (HBPA)-based dinitro isomers mixture (H″BPBN and H′BPBN) was synthesized and separated, and the structures of dinitro isomers were confirmed by differential scanning calorimetry and proton nuclear magnetic resonance spectroscopy. A series of copolyimides were prepared from diamino monomers with different percentages of novel diamine H″BPDA and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride via a conventional two-step procedure. All the copolyimides could afford flexible, tough, and transparent films with transmittance no less than 73% at 450 nm, which was attributed to the fact that nonplanar alicyclic diamine and the bulky and weakly polarizable trifluoromethyl hampered the formation of charge-transfer complex. Moreover, all the copolyimides were soluble not only in polar solvents such as N,N-dimethylformamide but also in low-boiling-point solvents such as dichloromethane, which was related to the fact that the existence of alicyclic diamine and bulky trifluoromethyl decreased the intermolecular force. In addition, the conformation effects of H″BPDA and H′BPDA on the aspects of thermal, mechanical, optical, and soluble performance of copolyimides were investigated and their structure–property relationships were discussed in detail.
研究领域:
材料科学
·
化学工程
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JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Liyan Wei,Biao Zhou,Ke Xiao,Bo Yang,Gang Yu,Juying Li,Caizhen Zhu,Junmin Zhang,Huabo Duan
2,2′,4,4′-tetrabromodiphenyl ether (BDE47) was difficult to be rapidly degraded by common reductive debromination or oxidative decomposition. In this study, the debromination via surfactant-assisted zero valent zinc (Zn 0 ) reduction and subsequent Fenton oxidation was combined to completely degrade BDE47. Firstly, Zn 0 integrated with surfactants including cetyltrimethylammonium chloride (CTAC), polyethylene glycol dodecyl ether (Brij35), or 1-dodecanesulfonic acid sodium salt (SDS) were evaluated for their reactivity to debrominate BDE47. CTAC-assisted Zn 0 system presented the highest removal efficiency of 98.6% for BDE47 ( C 0 = 5 mg/L) under the optimized conditions including 0.3 g/L of Zn 0 particles and 0.05 g/L of CTAC at 25 °C and pH 4.0 during 1-h reaction. Subsequently, the debromination products as low-brominated BDEs were attacked by hydroxyl radicals (•OH) from Fenton reagent, which were decomposed into short-chain carboxylic acids and even mineralized within 2-h oxidation. In addition, HPLC, GC–MS, LC–MS/MS, and IC were employed to detect intermediates during this reaction/oxidation process and the pathways of debromination and oxidation were proposed according to carbon and bromine balance. The above combination achieved the complete degradation of BDE47 via a relative low-cost method to rapidly remove PBDEs, which provide a new approach for the effective treatment of halogenated organic pollutants.
研究领域:
环境科学
·
化学工程
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Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 20
·5377-5385
·
IF 7.779
Ru-Ling Tang,Gang-Xiang Liu,Wen-Dong Yao,Li-Nan Zhang,Wenlong Liu,Sheng-Ping Guo
Phosphite materials have aroused wide attention due to their diverse open frameworks and promising magnetic and optical performances. Here, the first barium scandium phosphite, BaSc2(HPO3)4(H2O)2, was obtained via a facile hydrothermal route. BaSc2(HPO3)4(H2O)2 crystallizes in the polar space group Pn and exhibits a 3D {[Sc2(HPO3)4]2−}∞ anion framework constructed by distorted ScO6 octahedra and HPO32− anion groups. BaSc2(HPO3)4(H2O)2 can exhibit a phase-matchable SHG response of about 0.94 × KH2PO4 at 1064 nm, and a moderate birefringence (0.036@1064 nm) to satisfy the phase-matchable behavior requirement. Deep investigation of its structure–property relationship based on theoretical calculations has also been presented in this work.
研究领域:
材料科学
·
晶体学
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INTERNATIONAL IMMUNOPHARMACOLOGY
·
2013
·
IF 2.417
Jian Xu,Yan-Yan Jia,Shao-Rui Chen,Jian-Tao Ye,Xian-Zhang Bu,Yun Hu,Yun-Zi Ma,Jin-Lei Guo,Pei-Qing Liu
Flavonoids are a class of compounds that exist in nature with the structure of 2-phenyl-chromone. In Chinese traditional medicine , herbal drugs containing flavonoids are widely used for the treatment of inflammation, cardiovascular disease, tumor and so on. In this study, we investigated the anti-inflammatory effect and related mechanisms of a novel synthetic flavonoid, (E)-1-(4-ethoxyphenyl)-3-(4-nitrophenyl)-prop-2-en-1-one (ETH) in lipopolysaccharide (LPS) stimulated macrophages. Our results showed that ETH inhibited LPS-induced TNF-α and IL-6 release in a dose-dependent manner, and decreased TNF-α, IL-1β, IL-6 and iNOS mRNA production. LPS-induced expression of cyclooxygenase-2 (COX-2) was also significantly attenuated by ETH. Pretreatment with ETH reduced the I-κBα phosphorylation, p65 nuclear translocation as well as NF-κB-dependent transcriptional activity. In addition, ETH exhibited a significant protection against LPS-induced inflammatory mortality in mice. Taken together, these findings suggest that ETH can inhibit LPS-induced inflammation via suppressing NF-κB signaling pathway , indicating that ETH may be a potential anti-inflammatory agent.
研究领域:
药理学
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免疫学
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医学
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生物化学
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JOURNAL OF CHEMICAL THERMODYNAMICS
·
2022
·
IF 3.269
Pengshuai Zhang,Ruping Ge,Chunxia Jin,Jixiu Deng,Feiyang Dai,Yameng Wan,Beibei Zhang,Shuwei Yu,Xing Li,En Zhang,Lan Zhang,Lu Zhang
The mole fraction solubility of 1-[4-(4-hydroxyphenyl)piperazin-1-yl]ethenone (1-HPE) in twelve mono-solvent systems namely “2-methoxyethanol (2-ME), methanol (MeOH), ethanol (EtOH), butan-1-ol ( n -BuOH), 2-propoxyethanol (2-PE), propan-2-ol ( i -PrOH), 2-methylpropan-1-ol ( i -BuOH), Acetonitrile (MeCN), ethane-1,2-diol (EG), 2-ethoxyethanol (2-EE), propan-1-ol ( n -PrOH), 2-butoxyethanol (2-BE)” were determined from 283.15 K to 323.15 K under 0.1 MPa. The experimental solubility order follows: 2-ME > 2-EE > 2-PE > 2-BE > MeOH > EtOH > n -PrOH > i -PrOH ≈ n -BuOH > i -BuOH ≈ MeCN > EG. The UNIQUAC model, modified Apelblat model, NRTL model, Wilson model, Jouyban model and NRTL-SAC model equation were used to correlate of 1-HPE solubility, and the average 10 4 RMSD of them was 0.89, 1.21, 0.94, 4.72, 0.60 and 1.25, respectively. Furthermore, Hansen solubility parameters analysis (HSP) was used to evaluate the miscibility of 1-HPE in the selected solvents. Hirshfeld surface (HS) analysis was performed to discuss the electrostatic features and the patterns of intermolecular interactions of 1-HPE. Thermodynamic properties (Δ mix G , Δ mix S , Δ mix H , Δ dis G , Δ dis S , Δ dis H ) were calculated by the UNIQUAC model. The calculated results indicated that the dissolution and mixing process of 1-HPE in the mono-solvents selected in this work was spontaneous and entropy increment.
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Materials
·
2022
·Vol. 15
·期 17
·5962
·
IF 3.748
Bo Chen,Yu Liang,Yunjia Song,Yunkai Liang,Jian Jiao,Hong Bai,Ying Li
Host immune response has gradually been accepted as a critical factor in achieving successful implant osseointegration. The aim of this study is to create a favorable immune microenvironment by the dominant release of IL-4 during the initial few days after implant insertion to mitigate early inflammatory reactions and facilitate osseointegration. Herein, the B-TNT/PDA/IL-4 substrate was established by immobilizing an interleukin-4 (IL-4)/polydopamine (PDA) coating on a black TiO2nanotube (B-TNT) surface, achieving on-demand IL-4 release under near infrared (NIR) irradiation. Gene Ontology (GO) enrichment analyses based on high-throughput DNA microarray data revealed that IL-4 addition inhibited osteoclast differentiation and function. Animal experiment results suggested that the B-TNT/PDA/IL-4+Laser substrate induced the least inflammatory, tartrate-resistant acid phosphatase, inducible nitric oxide synthase and the most CD163 positive cells, compared to the Ti group at 7 days post-implantation. In addition, 28 days post-implantation, micro-computed tomography results showed the highest bone volume/total volume, trabecular thickness, trabecular number and the lowest trabecular separation, while Hematoxylin-eosin and Masson-trichrome staining revealed the largest amount of new bone formation for the B-TNT/PDA/IL-4+Laser group. This study revealed the osteoimmunoregulatory function of the novel B-TNT/PDA/IL-4 surface by photothermal release of IL-4 at an early period post-implantation, thus paving a new way for dental implant surface modification.Keywords:photothermal;controlled release;IL-4;PDA;TiO2nanotubes;osseointegration;near-infrared laser;titanium
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