JOURNAL OF ORGANIC CHEMISTRY
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2022
·
IF 4.198
Jun Ma,Qijie Zou,Chunhua Wang,Guangwei Yin,Fangyi Li
Herein, we report a base promoted dibromination of enamides using CBr4 as a bromine source to provide expedient access to β,β-dibrominated secondary enamides. Preliminary synthetic application study shows that these novel products can be readily transformed to 5-Br oxazoles via Cu(I) catalyzed intramolecular cyclization in good yields.
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CHEMICAL ENGINEERING SCIENCE
·
2026
·
IF 5.1
Shuang Liu,Lei Ye,Shaokai Huang,Peng Zhou,Mingxuan Ma,Miao Hu,Xujin Ren,Xin Pu,Xin Han,Jichang Liu
La/ZSM-5@ASA composites were developed by a stepwise assembly strategy. • La 3+ displaced the acidic protons and generated new BAS [Si-OLa(OH) 2 -Al]. • ASA overcoat passivated external surface acid sites and enabled pre-cracking. • Hierarchical La/ZSM-5@ASA shows high light-olefin selectivity in n -paraffin cracking. Catalytic cracking of surplus automotive fuels, heavy oil and waste plastics into light olefins is an efficient resource-reutilization strategy. Conventional ZSM-5 zeolites, however, suffer from limited light-olefin selectivity and coke-induced deactivation due to strong acidity and microporous constraints. Herein, a stepwise assembly strategy involving La modification and subsequent amorphous silica-alumina (ASA) overcoating was developed to construct core–shell catalysts with optimized acidity and diffusion. La modification modulated acid strength and distribution, and DFT calculations revealed it lowered the energy barrier of the rate-determining protonation step, promoting propylene formation. The ASA overcoat, applied via co-gelation, passivated external strong Brønsted acid sites and introduced open interfacial diffusion channels. This architecture enabled pre-cracking of reactants, promoting efficient C-C bond cleavage and suppressing secondary reactions. The optimized hierarchical La/ZSM-5@ASA(1:1) achieved 63.10% total ethylene and propylene selectivity in n -heptane cracking, outperforming ZSM-5 and 0.50La/ZSM-5 by 5.12% and 1.38%, respectively. This advantage is more pronounced for longer linear hydrocarbons, and the suppression of methane and coke precursors boosts atom utilization efficiency, indicating a carbon-economic cracking pathway.
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ELECTROANALYSIS
·
2023
·Vol. 36
·期 3
·e202300324
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IF 3
Kankan Chen,Jiawei Xu,Jingjing Song,Zhonggang Liu,Zheng Guo
The ratiometric electrochemical sensors have been highly explored to minimize system errors and environmental interference. However, it is extremely desirable on the development of an effective ratiometric electrochemical sensor in a facile approach without the complicated assembly process. In this work, an effective internal reference probe was coupled based on the polymerized thionine (pTh) via a one-step electrodeposition method. The ratiometric electrochemical sensing platform was applied for 5-hydroxytryptamine (5-HT) detection, where the internal reference probe, Th, presented the robust redox signal and can be clearly distinguished from the oxidation signal of 5-HT. The proposed pTh modified GCE presented the outstanding electrochemical performance on sensing 5-HT in a wide concentration range with a detection limit of 8.4 nΜ. Further, the fabricated sensor was efficiently employed for the detection of 5-HT in various human serum samples and the obtained results were consistent with the reported range in serum samples. This work offers the great possibility on the fabrication of efficient ratiometric sensors in a facile approach and presents great application prospects in clinical diagnosis.
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EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
·
2021
·
IF 6.514
Dongdong Luo,Zhikun Guo,Xuecui Zhao,Lijuan Wu,Xiaochun Liu,Yingzhi Zhang,Yuhang Zhang,Zirong Deng,Xianjun Qu,Shuxiang Cui,Shengbiao Wan
Sphingosine-1-phosphate receptor 2 (S1PR2) has been identified as a brand-new GPCR target for designing antagonists to reverse 5-FU resistance. We herein report the structural optimization and structure-activity relationship of JTE-013 derivatives as S1PR2 antagonists. Compound 9d was the most potent S1PR2 antagonist (K D = 34.8 nM) among developed compounds. Here, compound 9d could significantly inhibit the expression of dihydropyrimidine dehydrogenase (DPD) to reverse 5-FU-resistance in HCT116 DPD and SW620/5-FU cells. Further mechanism studies demonstrated that compound 9d not only inhibited S1PR2 but also affected the transcription of S1PR2. In addition, compound 9d also showed acceptable selectivity to normal cells (NCM460). Importantly, compound 9d with suitable pharmacokinetic properties could significantly reverse 5-FU-resistance in the HCT116 DPD and SW620/5-FU xenograft models without obvious toxicity, in which the inhibition rates of 5-FU were increased from 23.97% to 65.29% and 27.23% to 60.81%, respectively. Further immunohistochemistry and western blotting analysis also demonstrated that compound 9d significantly decreases the expression of DPD in tumor and liver tissues. These results indicated that compound 9d is a promising lead compound to reverse 5-FU-resistance for colorectal cancer therapy.
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APPLIED ORGANOMETALLIC CHEMISTRY
·
2023
·
IF 3.9
Yongzhao Zhang,Xuzheng Chen,Zhenya Zhu,Luping Lv
5-hydroxymethylfurfural (5-HMF) has been considered as an important biomass-based platform chemical for its wide applications. Currently, the production of 5-HMF from the catalytic dehydration of glucose is preferred, in which the Brønsted and Lewis acids in catalysts play an important role. Here, it was found that MIL-53(Al) modified with tin was an active, selective, and reusable catalyst for the transformation of glucose to 5-HMF in dimethyl sulfoxide (DMSO) solvent. Around 42.3% yield of 5-HMF with 93% glucose conversion was achieved, when the prepared metal-organic frameworks (MOFs) was used as the catalyst, showing superior catalytic performance compared with most of other MOFs. Moreover, the catalyst possessed inert catalytic properties in water with almost no any influence on the conversion of glucose, suggesting a compelling opportunity to act as a support material.
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Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Ruokun Jia,Jiayuan Deng,Xiaohang Yang,Ruisong Xue,Pengpeng Wang,Xingbo Bian,Qiyao Wang
Graphitic carbon nitride (CN) hold great promise as a photocatalyst for generating hydrogen energy via water splitting, owing to its remarkable ability to respond to visible light and its strong reduction capacity. However, the photocatalytic water splitting for H 2 evolution performance of pure CN was impeded by its low surface area, inadequate hydrophilicity, and unsatisfactory photoelectric conversion efficiency. Here we tackled these challenges by synthesizing a series of CN/H-ZSM-5 composites with varying amount of H-ZSM-5 zeolite using a straightforward thermal copolymerization method. The contact angle and N 2 adsorption-desorption measurements confirmed that the incorporated hydrophilic and porous H-ZSM-5 zeolite contribute to increased surface area and improved hydrophilicity of the CN/H-ZSM-5 composites. Meanwhile the resulting CN/H-ZSM-5 composites exhibited significant separation and migration enhancement of photoexcited charge carriers. Consequently, the optimized CN/H-ZSM-5 composite, containing 50 mg of H-ZSM-5 zeolite, demonstrated 13 times increase in photocatalytic H 2 production rate than that of pure CN. This work not only provided a competitively universal approach on the design of high-efficiency CN based photocatalyst, but also clarified the role of H-ZSM-5 zeolite in the H 2 evolution enhancement.
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ENERGY & FUELS
·
2023
·
IF 5.3
Haifeng Tian,Zhiyu Chen,Xing Yang,Peng Gao,Chunxue Jiao,Fei Zha,Yue Chang,Hongshan Chen
A method for the direct synthesis of hierarchical zeolites was developed by converting precursors of zeolites and mesoporous copolymers into homogeneous gels using conventional block copolymers as scaffolds. In this method, hydrothermal synthesis is accomplished on a steam-assisted basis, and the dry gel leaves the system free of the liquid water phase, which successfully avoids phase separation between the soft stencil and the solid silica phase. The catalytic performance of hierarchical zeolites was evaluated on a fixed-bed reactor for the methanol-to-aromatics reaction. The hierarchical structure greatly enhances the catalytic activity of the probe reaction due to the increased outer surface, decreased coke formation, and diffusion resistance in the microporous network. The selectivity of BTX reached 65.8%, and there was no significant deactivation after a reaction of 107 h. The transition state and energy barrier for methanol to aromatics were obtained by the minimum energy search of the LST/QST transition state.
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Advanced Composites and Hybrid Materials
·
2023
·Vol. 6
·期 5
·1-10
·
IF 20.1
Guo Sijia,Ma Min,Ge Ruixiang,Algadi Hassan,Shao Qian
Developing efficient electrocatalysts for biomass electro-oxidation in alkaline seawater is of great significance but remains less explored. Herein, we reported a hierarchical structure consisting of nickel-cobalt layered double hydroxide nanosheets and copper oxide nanowires (CuO@NiCo-LDH), which was favorable for increasing active sites and facilitating electron transfer during 5-hydroxymethylfurfural oxidation (HMFOR). As-designed CuO@NiCo-LDH catalyst achieved a high yield of 2,5-furandicarboxylic acid (FDCA, 89%) and 82% faradaic efficiency (F.E.). It also showed a large current density of 133.4 mA cm −2 at 1.4 V vs. RHE, outperforming most of the previously reported Ni/Co-based HMFOR electrocatalysts. More importantly, it also showed an outstanding HMFOR performance in alkaline seawater, suggesting great promise in practical electrolysis.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Siyu Ma,Zhihao Wang,Bowen Liu,Xiaolei Wang,Shichao Du,Zichen Song,Xinxin Bian,Manchen Hao,Ju Huang,Zhimin Chen,Zhiyu Ren
Pairing the hydrogen evolution reaction (HER) with the thermodynamics-friendly electrooxidation reaction (EOR) is a powerful way to maximize the energy/economic effectiveness, but still a challenge. Herein, the symbiotic Ni/MoN heterojunction arrays were constructed on foam (Ni/MoN/NF) by the nitridation-induced in situ reduction/conversion strategy. The fascinating interfacial electronic structure and surface reconstruction of Ni/MoN/NF heterojunction are responsible for the enhanced HMF-H 2 O paired electrolysis. Ni/MoN/NF only requires a low overpotential of 53 mV to reach the HER current density of 10 mA cm −2 , as well as the good durability; and NiOOH derived on the anode are electronically activated by MoN to achieving high-efficiency conversion from HMF to FDCA (∼100 % conversion, 97.5 % yield and 97.4 % Faradaic efficiency). For the HMF-H 2 O paired electrolysis, the assembled Ni/MoN/NF||Ni/MoN/NF electrolyzer only requires a low potential of 1.391 V to yield the current density of 10 mA cm −2 , ranking at the forefront in the reported coupling catalysts. Theoretical calculations manifest that the upshift of d -band center of the NiOOH/MoN heterojunction contributes to HMF chemisorption and activation, thereby enhancing its catalytic activity towards HMFEOR. Our study sheds light on the significance of designing the paired electrolysis with low voltage input for renewable energy applications.
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Frontiers in Bioscience-Landmark
·
2023
·Vol. 28
·期 7
·139
·
IF 3.1
Yanan Zhang,Junjun Huang,Lingyan Yan,Rong Jia,Jihua Guo
Background: RUNX2 (Runt-related transcription factor 2) acts as a key regulator in the odontogenic differentiation of human dental pulp stem cells (hDPSCs). Moreover, the inclusion of exon 5 is important for RUNX2 function. Our previous study showed that Y-Box Binding Protein 1 (YBX1) promoted RUNX2 exon 5 inclusion and mineralization of hDPSCs. However, the regulatory mechanism of RUNX2 exon 5 alternative splicing needed further exploration. Methods: The expression level of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) during the odontogenic differentiation of hDPSCs was analyzed by RT-PCR and Western blot. The roles of hnRNP A1 in the alternative splicing of RUNX2 exon 5 and the odontogenic differentiation of dental mesenchymal cells were analyzed by gain- and loss-of-function experiments. Results: Surprisingly, we found an alternative splicing factor, hnRNP A1, which had an opposite role to YBX1 in regulating RUNX2 exon 5 inclusion and odontogenic differentiation of hDPSCs. Through gain- and loss-of-function assay, we found that hnRNP A1 suppressed the inclusion of RUNX2 exon 5, resulting in the inhibition of odontoblastic differentiation. The overexpression of hnRNP A1 can inhibit the expression of ALP (alkaline phosphatase) and OCN (osteocalcin), and the formation of mineralized nodules during the odontogenic differentiation of both hDPSCs and mouse dental papilla cells (mDPCs), whereas the opposite results were obtained with an hnRNP A1 knockdown preparation. Conclusions: The present study indicated that hnRNP A1 suppressed RUNX2 exon 5 inclusion and reduced the odontogenic differentiation ability of hDPSCs and mDPCs.
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Molecular Catalysis
·
2023
·
IF 4.6
Congcong Zhao,Niuniu Zhu,Guo Qiu,Manyu Zhang,Hongyu Tian
5-Hydroxymethylfurfural (5-HMF) is considered as a bridge connecting biomass and petrochemical products with excellent application potential and market prospects. In this work, a series of hafnium-aluminum bimetallic oxide (Al-HfO x ) catalysts were synthesized with the coprecipitation method, possessing outstanding catalytic effect in the conversion of glucose or fructose to 5-HMF. 5-HMF yield of 49.31% was acquired from glucose in a methyl isobutyl ketone (MIBK)/saturated salt water (SSW) biphasic solvent at 170 ℃ after 2 h. When fructose was the substrate, 5-HMF yield was 74.85% in DMSO at 150 ℃ after 75 min. In addition, the reaction mechanism was speculated that the isomerization process could be promoted by the synergistic effects of aluminum and hafnium species, in which Hf-OH and Al-OH groups, and Hf active sites served as Brønsted and Lewis acidic sites, respectively. After at least four cycles, there was no remarkable wastage in the catalytic activity of Al-HfO x . This paper offers a prospective catalytic strategy for heterogeneous bimetallic oxide catalysts used in the effective conversion of carbohydrates to 5-HMF.
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FOOD SCIENCE AND BIOTECHNOLOGY
·
2023
·
IF 2.9
Zheng Qian,Long Si,Chen Zhi,Fu Jiaolong,Ju Xin,Li Liangzhi
Enzymatic preparation of rare sugars as an alternative to traditional sweeteners is an effective strategy to achieve a low-calorie healthy diet. Ribose-5-phosphate isomerase B (RpiB) is a key enzyme in the non-oxidative branch of the catalytic pentose phosphate pathway. Here, we investigated the potential of Curtobacterium flaccumfaciens ZXL1 ( C. flaccumfaciens ZXL1) derived RpiB (CfRpiB) in D-allose preparation. The optimal reaction conditions for recombinant CfRpiB were found experimentally to be pH 7.0, 55 °C, and no metal ions. The kinetic parameters K m , k cat , and catalytic efficiency k ca t / K m were 320 mM, 4769 s −1 , and 14.9 mM −1 s −1 respectively. The conversion of D-allulose by purified enzyme (1 g L −1 ) to D-allose was 13% within 1 h. In addition, homology modeling and molecular docking were used to predict the active site residues: Asp13, Asp14, Cys72, Gly73, Thr74, Gly77, Asn106, and Lys144.
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