Journal of Advanced Research
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2020
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IF 6.992
Yuanze Zhou,Lijing Liao,Xikai Liu,Biao Liu,Xinxin Chen,Yan Guo,Chuanlong Huang,Yucheng Zhao,Zhixiong Zeng
Plant tryptophan decarboxylase (TDC) is a type II Pyridoxal-5′-phosphate-dependent decarboxylase (PLP_DC) that could be used as a target to genetically improve crops. However, lack of accurate structural information on plant TDC hampers the understanding of its decarboxylation mechanisms. In the present study, the crystal structures of Oryza sativa TDC ( O sTDC) in its complexes with pyridoxal-5′-phosphate, tryptamine and serotonin were determined. The structures provide detailed interaction information between TDC and its substrates. The Y359 residue from the loop gate is a proton donor and forms a Lewis acid-base pair with serotonin/tryptamine, which is associated with product release. The H214 residue is responsible for PLP binding and proton transfer, and its proper interaction with Y359 is essential for Os TDC enzyme activity. The extra hydrogen bonds formed between the 5-hydroxyl group of serotonin and the backbone carboxyl groups of F104 and P105 explain the discrepancy between the catalytic activity of TDC in tryptophan and in 5-hydroxytryptophan. In addition, an evolutionary analysis revealed that type II PLP_DC originated from glutamic acid decarboxylase, potentially as an adaptive evolution of mechanism in organisms in extreme environments. This study is, to our knowledge, the first to present a detailed analysis of the crystal structure of Os TDC in these complexes. The information regarding the catalytic mechanism described here could facilitate the development of protocols to regulate melatonin levels and thereby contribute to crop improvement efforts to improve food security worldwide.
研究领域:
植物学
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生物化学
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遗传学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Yaqi Qu,Mengying He,Hualiang An,Xinqiang Zhao,Yanji Wang
Selective hydrogenation of dimethyl toluene-2,4-dicarbamate (TDC) to methyl cyclohexyl-2,4-dicarbamate (HTDC) is an essential intermediate step in the new green route for synthesizing methylcyclohexyl-2,4-diisocyanate (HTDI). Herein, we investigated the synthesis of HTDC from TDC by a solvent-free, mild and safe catalytic transfer hydrogenation (CTH) process using isopropanol as H-donor. Firstly, a bimetallic catalyst In 2 O 3 @RhPt with a high metal dispersion was prepared by one-pot method. The characterization results demonstrated that Rh and Pt atoms formed alloy structure and their interaction led to an electron-rich Pt and an electron-deficient Rh. What’s more, Pt could also stabilize the surface of In 2 O 3 . Then the Rh/Pt ratio was optimized and In 2 O 3 @Rh 49 Pt 51 catalyst was found to show the best catalytic performance: about 99% of TDC conversion and 100% of HTDC selectivity at 80 ℃ and ambient pressure. It was proved by the designed experiments that isopropanol dehydrogenation was the dominant step and the active hydrogen species existed in the form of radicals in the CTH process of TDC to HTDC. Additionally, the synergistic effect in the RhPt alloy boosted the catalytic performance. Finally, the CTH reaction pathway and mechanism was elucidated based on the experimental and DFT calculation results.
研究领域:
化学工程
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催化科学
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DOI
高影响因子
NANO
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2021
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IF 1.556
Xin Wang,Guo-Dong Han,Juan Wang
Due to the high theoretical capacity of sulfur (1675 mAh g − 1 ) , low cost and environmental friendliness, lithium-sulfur batteries have shown broad prospects in future energy conversion and storage systems. However, the shuttle effect and insulating properties of sulfur restrict its practical application. Herein, we report a facile approach to fabricate Al-TDC@S-PPy composite material as lithium-sulfur battery electrode. In this strategy, a topological porous Al-TDC ( TDC = 2 ,5-thiophenedicarboxylate) with 8-connected clusters is reported, which can provide strong adsorption for dissolved intermediate polysulfides and alleviate volume expansion. Meanwhile, Polypyrrole, (PPy) as a conductive and flexible additive to expedite electron transport, improves electrical conductivity. Consequently, the Al-TDC@S-PPy composite cathode exhibits a higher initial specific capacity (1310.4 mAh g − 1 at 0.2 C). The final reversible capacity is 411.0 mAh g − 1 after 200 cycles at 1 C. We can extend this strategy to other metal-organic frameworks (MOFs) and manufacture MOF/conductive polymer composite electrodes for high-performance lithium-sulfur batteries.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
CELLULAR AND MOLECULAR BIOLOGY
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2022
·Vol. 68
·期 1
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IF 1.206
Yuwei Li,Tingting Yan,Lijun Yin,Yongqiang Cheng,Xin Jia
The Chinese traditional soybean product, sufu, is getting increasingly popular in Asia for its special taste and rich nutrition. In this paper, physicochemical properties of sufu during fermentation, isolation and characterization of BA-producing bacteria, as well as their decarboxylase activities were thoroughly investigated. Tyramine, putrescine, phenylethylamine and cadaverine were the main BA in sufu fermentation. Tyramine level increased drastically to reach 513.72 mg/kg during sufu ripening, posing potential health risks. During sufu fermentation, there was a positive correlation between amino nitrogen and BA, yet no significant correlation was found between BAs with pH and total acidity. Additionally, 23 strains of tyramine- and phenylethylamine-producing bacteria harboring the TDC gene, including Enterococcus faecalis 45, Enterococcus faecium 36, Pediococcus acidilactici 310 and Pediococcus pentosaceus 27 that were responsible for tyramine production in sufu have been characterized. The current study provides insights into understanding the production of tyramine in sufu by microorganisms, which laid the groundwork for controlling biogenic amine production in fermented soybean products.
研究领域:
食品科学
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微生物学
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生物技术
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Qianqian Wang,Xiaoyan Ma,Fengjin Qu,Ran bi,Senyang Song,Pengcheng Ma,Jing Sun,Fang Chen,Qiufan Tang
Precisely regulating the defect degree in metal-organic framework (MOF) crystals and exploring the structure-activity relationship is of great significance for urea-assisted seawater electrolysis to produce green hydrogen. Herein, a series of X-FeNi-TDC nanoarrays with various defects are successfully constructed through the competitive coordination of ligand 2,5-thiophenedicarboxylic acid (H 2 TDC) and fluorinated acetic acid modulators with different pK a and coordination ability of -COO. The 20D-FeNi-TDC nanosheets containing more unsaturated sites and moderate electron delocalization exhibit multifunctional activity with an overpotential of 194 mV in OER, 116 mV in HER and an applied voltage of 1.326 V in UOR at 10 mA cm - 2 . In addition, small angle X-ray scattering (SAXS), small angle neutron scattering (SANS), X-ray absorption near-edge structure (XANES) and density functional theory (DFT) calculation further elucidate alterations in pore structure and electronic arrangement of metal sites. This study provides insight into the mechanism by which modulators regulate defects in MOF-based electrocatalyst.
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2023
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IF 5.5
Lu Ji,Fang Li,Conghui Che,Wei Xue,Qiusheng Yang,Xiaoshu Ding,Dongsheng Zhang,Xinqiang Zhao,Yanji Wang
In the reaction of dimethyl carbonate (DMC) and 2,4-diaminotoluene (TDA), Au/CeO 2 exhibits higher selectivity than CeO 2 for dimethyl toluene-2,4-dicarbamate (TDC). However, its catalytic activity drops after H 2 reduction (denoted as Au/CeO 2 -R). The characterization results illustrate that Au exists as a single atom with the primary species as Au δ+ in Au/CeO 2 , forming Ce x Au 1−x O 2 structure similar to solid solution. Whereas for Au/CeO 2 -R catalyst, Au mainly exists as Au 0 , forming the Au-O-Ce structure on CeO 2 surface. Significantly, the strong interaction between Au and CeO 2 increases Ce 3+ and oxygen vacancies content, as well as modulates their acidic property. However, the catalytic activity of Au/CeO 2 -R is found to be lower than Au/CeO 2 as the species formed by DMC dissociation on its surface are not easily desorbed. Other transition metals supported on CeO 2 are also prepared, wherein Pt/CeO 2 and Pd/CeO 2 exhibit good TDC selectivity. In the end, the electronegativity and catalytic activity of metals are correlated.
研究领域:
催化
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）