Molecular Catalysis最新文献

英文中文

Zr-based MOF as a support for lipase immobilization to enhance enzymatic transesterification for biodiesel production 以 Zr 基 MOF 为支撑固定脂肪酶，增强生物柴油生产中的酶促酯交换反应

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-09 DOI: 10.1016/j.mcat.2024.114603

Xiangsheng Zheng, Xiaohong Hao, Yan Wang, Siyu Gao, Dantong Wen, Jinchuan Wang

The development of novel biocatalysts is essential to promote the commercialization of biodiesel production by transesterification reaction. In this paper, Rhizopus oryzae lipase (ROL) was immobilized on an amino-functionalized zirconium-based metal organoskeleton by interfacial adsorption. The immobilization conditions were optimized and the enzymatic properties were tested, and the resulting novel biocatalysts exhibited higher stability and heat resistance. SEM, XRD and BET analyses were used to characterize the biocatalysts and carrier materials. The catalytic performance of ROL@UiO-66-NH₂ in the production of biodiesel by transesterification reaction was explored, and the production process was optimized by response surface method. The results showed that the conversion rate of FAEE reached 82.05% at molar ratio of ethanol/oil of 15.43:1, reaction temperature of 50.28°C, reaction time of 120.9 min, DES addition of 48.08 wt%, biocatalyst addition of 3 wt%, and ultrasonic power of 90 W. In addition, ROL@UiO-66-NH₂ demonstrated good recyclability, with the catalytic efficiency remaining at 71.87% after five cycles.

开发新型生物催化剂对于促进通过酯交换反应生产生物柴油的商业化至关重要。本文通过界面吸附法将根瘤菌脂肪酶（ROL）固定在氨基功能化的锆基金属有机骨架上。对固定化条件进行了优化，并测试了酶的特性，结果表明新型生物催化剂具有更高的稳定性和耐热性。利用 SEM、XRD 和 BET 分析了生物催化剂和载体材料的特性。探讨了 ROL@UiO-66-NH2 在酯交换反应生产生物柴油过程中的催化性能，并采用响应面法对生产工艺进行了优化。结果表明，在乙醇/油摩尔比为 15.43:1、反应温度为 50.28°C、反应时间为 120.9 分钟、DES 添加量为 48.08 wt%、生物催化剂添加量为 3 wt%、超声功率为 90 W 的条件下，FAEE 的转化率达到 82.05%。

{"title":"Zr-based MOF as a support for lipase immobilization to enhance enzymatic transesterification for biodiesel production","authors":"Xiangsheng Zheng, Xiaohong Hao, Yan Wang, Siyu Gao, Dantong Wen, Jinchuan Wang","doi":"10.1016/j.mcat.2024.114603","DOIUrl":"10.1016/j.mcat.2024.114603","url":null,"abstract":"<div><div>The development of novel biocatalysts is essential to promote the commercialization of biodiesel production by transesterification reaction. In this paper, <em>Rhizopus oryzae</em> lipase (ROL) was immobilized on an amino-functionalized zirconium-based metal organoskeleton by interfacial adsorption. The immobilization conditions were optimized and the enzymatic properties were tested, and the resulting novel biocatalysts exhibited higher stability and heat resistance. SEM, XRD and BET analyses were used to characterize the biocatalysts and carrier materials. The catalytic performance of ROL@UiO-66-NH<sub>2</sub> in the production of biodiesel by transesterification reaction was explored, and the production process was optimized by response surface method. The results showed that the conversion rate of FAEE reached 82.05% at molar ratio of ethanol/oil of 15.43:1, reaction temperature of 50.28°C, reaction time of 120.9 min, DES addition of 48.08 wt%, biocatalyst addition of 3 wt%, and ultrasonic power of 90 W. In addition, ROL@UiO-66-NH<sub>2</sub> demonstrated good recyclability, with the catalytic efficiency remaining at 71.87% after five cycles.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114603"},"PeriodicalIF":3.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis of SCD3-containing bicyclo[1.1.1]pentanes enabled by photocatalyzed difunctionalization of [1.1.1]propellane 通过光催化[1.1.1]丙烷的二官能化合成含 SCD3 的双环[1.1.1]戊烷

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-09 DOI: 10.1016/j.mcat.2024.114592

Yumiao Liu , Qing Pang , Binbin Chen , Zizhen Zhu , Jiabin Shen , Pengfei Zhang

Bicyclo[1.1.1]pentanes (BCPs) have emerged as appealing bioisosteres for para-substituted benzene rings in drug design. In this study, we report an intermolecular photocatalytic addition of [1.1.1]propellane and S-(methyl-d₃) arylsulfonothioates to synthesize novel deuterium-containing BCPs derivatives via energy transfer processes (EnT). This efficient and green protocol provides an access to introduce deuterium into BCP scaffolds and enriches the present library of BCPs compounds for drug design.

双环[1.1.1]戊烷（BCPs）已成为药物设计中对位取代苯环的有吸引力的生物寄主。在本研究中，我们报告了[1.1.1]丙烷和 S-（甲基-d3）芳基硫代磺酸酯的分子间光催化加成，通过能量转移过程（EnT）合成新型含氘 BCPs 衍生物。这种高效、绿色的方法为在 BCPs 支架中引入氘提供了途径，并丰富了现有的 BCPs 化合物库，可用于药物设计。

引用次数: 0

Engineering an alcohol dehydrogenase from Gluconobacter oxydans for improved production of a bulky Ezetimibe intermediate 从氧葡萄糖杆菌中改造出一种醇脱氢酶，以改进大体积依折麦布中间体的生产

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-09 DOI: 10.1016/j.mcat.2024.114586

Yuqinxin Xie (谢雨沁欣), Dongzhi Wei (魏东芝), Jinping Lin (林金萍)

(4S)-3-[(5S)-5-(4-fluorophenyl)-5‑hydroxy-valyl]-4-phenyl-1,3-oxazacyclopentane-2-one ((S)-Fop alcohol) is a key chiral intermediate for the synthesis of ezetimibe, and could be synthesized via asymmetric reduction of (S)-4-phenyl-3-[5-(4-fluorophenyl)-5-oxopentanoyl]-2-oxazolidione (Fop dione). However, discovering and engineering of ketoreductases toward bulky-bulky (diaryl) ketones is still challenging. Previously, we identified an alcohol dehydrogenase Gox0525 from Gluconobacter oxydans DSM2343 which possessed strict diastereoselectivity (d.e. value > 99%) but low activity toward Fop dione. In this study, a semi-rational design based on the focused rational iterative site-specific mutagenesis (FRISM) based on site-directed saturation mutagenesis was performed to improve the catalytic efficiency of Gox0525. The variant M4 (Y92G/P93M/Y94P/L151V) shows a 64-fold enhanced catalytic efficiency (K_cat/K_m) and 47-fold in specific activity compared with the wild type Gox0525. Engineered Escherichia coli cells co-expressing the variant M4 and glucose dehydrogenase from Bacillus subtilis (BsGDH) for NADPH regeneration were employed as biocatalysts for gram-scale reaction of Fop dione. As a result,95 mM (33.76 g/L) Fop dione was completely transformed within 4 h, affording (S)-Fop alcohol with > 99% d.e. value, the yield of 96%, and the space-time yield of 195.6 g/L/d.

(4S)-3-[(5S)-5-(4-氟苯基)-5-羟基-缬氨酰]-4-苯基-1,3-恶唑杂环戊烷-2-酮（(S)-Fop 醇）是合成依折麦布的关键手性中间体，可通过 (S)-4-phenyl-3-[5-(4-fluorophenyl)-5-oxopentanoyl]-2-oxazolidione (Fop dione) 的不对称还原合成。然而，发现和工程化酮还原酶来处理笨重的（二芳基）酮类化合物仍然具有挑战性。此前，我们从 Gluconobacter oxydans DSM2343 中发现了一种醇脱氢酶 Gox0525，它具有严格的非对映选择性（d.e. 值为 99%），但对 Fop 二酮的活性较低。为了提高 Gox0525 的催化效率，本研究在定点饱和诱变的基础上进行了基于聚焦理性迭代位点特异性诱变（FRISM）的半理性设计。与野生型 Gox0525 相比，变体 M4（Y92G/P93M/Y94P/L151V）的催化效率（Kcat/Km）提高了 64 倍，比活性提高了 47 倍。将共同表达变体 M4 和用于 NADPH 再生的枯草芽孢杆菌葡萄糖脱氢酶（BsGDH）的工程大肠杆菌细胞用作生物催化剂，进行克级规模的 Fop 二酮反应。结果，95 mM (33.76 g/L) Fop dione 在 4 h 内被完全转化，得到(S)-Fop 醇，d.e. 值为 99%，产率为 96%，时空产率为 195.6 g/L/d。

{"title":"Engineering an alcohol dehydrogenase from Gluconobacter oxydans for improved production of a bulky Ezetimibe intermediate","authors":"Yuqinxin Xie (谢雨沁欣), Dongzhi Wei (魏东芝), Jinping Lin (林金萍)","doi":"10.1016/j.mcat.2024.114586","DOIUrl":"10.1016/j.mcat.2024.114586","url":null,"abstract":"<div><div>(4<em>S</em>)-3-[(5<em>S</em>)-5-(4-fluorophenyl)-5‑hydroxy-valyl]-4-phenyl-1,3-oxazacyclopentane-2-one ((<em>S</em>)-Fop alcohol) is a key chiral intermediate for the synthesis of ezetimibe, and could be synthesized via asymmetric reduction of (<em>S</em>)-4-phenyl-3-[5-(4-fluorophenyl)-5-oxopentanoyl]-2-oxazolidione (Fop dione). However, discovering and engineering of ketoreductases toward bulky-bulky (diaryl) ketones is still challenging. Previously, we identified an alcohol dehydrogenase Gox0525 from <em>Gluconobacter oxydans</em> DSM2343 which possessed strict diastereoselectivity (<em>d.e.</em> value > 99%) but low activity toward Fop dione. In this study, a semi-rational design based on the focused rational iterative site-specific mutagenesis (FRISM) based on site-directed saturation mutagenesis was performed to improve the catalytic efficiency of Gox0525. The variant M4 (Y92G/P93M/Y94P/L151V) shows a 64-fold enhanced catalytic efficiency (<em>K</em><sub>cat</sub>/<em>K</em><sub>m</sub>) and 47-fold in specific activity compared with the wild type Gox0525. Engineered <em>Escherichia coli</em> cells co-expressing the variant M4 and glucose dehydrogenase from <em>Bacillus subtilis</em> (BsGDH) for NADPH regeneration were employed as biocatalysts for gram-scale reaction of Fop dione. As a result,95 mM (33.76 g/L) Fop dione was completely transformed within 4 h, affording (<em>S</em>)-Fop alcohol with > 99% <em>d.e.</em> value, the yield of 96%, and the space-time yield of 195.6 g/L/d.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114586"},"PeriodicalIF":3.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Illuminating tandem reactions characterized by temporal separation of catalytic activities via DFT calculations: A case study of Ni-catalyzed alkyne semi-hydrogenation 通过 DFT 计算阐明以催化活性的时间分离为特征的串联反应：镍催化炔烃半氢化案例研究

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-08 DOI: 10.1016/j.mcat.2024.114600

Yiying Yang , Xiaotai Wang , Dongju Zhang

The concept of “temporal separation of catalytic activities” outlines a scenario where multiple transformations within a catalytic tandem reaction proceed sequentially over time without mutual interference. After presenting several examples of such reactions, we specifically focus on an example of the Ni-catalyzed alkyne semi-hydrogenation as a significant case study. By performing density functional theory (DFT) calculations, we illuminate the unique dynamic character of the reaction that the intermediate remains dormant until the reactant exhausted. The insights gained from the present calculations have led us to propose a comprehensive energy landscape model for the catalytic tandem reactions with temporal separation of catalytic activities, which offers a logical explanation for the temporal dormancy of the intermediate. This class of reactions is expected to be highly valuable as it presents the opportunity to fine-tune individual reaction steps, thereby introducing fresh concepts for precise control of reactions in one-pot chemistry.

"催化活性的时间分离 "概念概括了一种情况，即催化串联反应中的多种转化随着时间的推移依次进行，互不干扰。在介绍了几个此类反应的实例之后，我们特别将镍催化的炔烃半加氢反应作为一个重要案例进行研究。通过进行密度泛函理论（DFT）计算，我们揭示了该反应的独特动态特性，即中间体在反应物耗尽之前一直处于休眠状态。从目前的计算中获得的洞察力促使我们为催化活性暂时分离的催化串联反应提出了一个全面的能景模型，为中间体的暂时休眠提供了合理的解释。这一类反应具有很高的价值，因为它提供了对单个反应步骤进行微调的机会，从而为一锅化学反应的精确控制引入了新的概念。

{"title":"Illuminating tandem reactions characterized by temporal separation of catalytic activities via DFT calculations: A case study of Ni-catalyzed alkyne semi-hydrogenation","authors":"Yiying Yang , Xiaotai Wang , Dongju Zhang","doi":"10.1016/j.mcat.2024.114600","DOIUrl":"10.1016/j.mcat.2024.114600","url":null,"abstract":"<div><div>The concept of “temporal separation of catalytic activities” outlines a scenario where multiple transformations within a catalytic tandem reaction proceed sequentially over time without mutual interference. After presenting several examples of such reactions, we specifically focus on an example of the Ni-catalyzed alkyne <em>semi-</em>hydrogenation as a significant case study. By performing density functional theory (DFT) calculations, we illuminate the unique dynamic character of the reaction that the intermediate remains dormant until the reactant exhausted. The insights gained from the present calculations have led us to propose a comprehensive energy landscape model for the catalytic tandem reactions with temporal separation of catalytic activities, which offers a logical explanation for the temporal dormancy of the intermediate. This class of reactions is expected to be highly valuable as it presents the opportunity to fine-tune individual reaction steps, thereby introducing fresh concepts for precise control of reactions in one-pot chemistry.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114600"},"PeriodicalIF":3.9,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Catalytic amination of 1,6-hexanediol for synthesis of N, N, N’, N’-tetramethyl-1,6-hexanediamine over Cu/Ni/Zn catalysts 在铜/镍/锌催化剂上催化 1,6-己二醇胺化以合成 N,N,N',N'-四甲基-1,6-己二胺

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-08 DOI: 10.1016/j.mcat.2024.114601

Zhifei Wang , Jun Li , Yakui Wang , Hongbin Ju , Lu Zhang , Yajie Jiang

Synthesis of N, N, N’, N’-tetramethyl-1,6-hexanediamine(TMHDA) by the amination of 1,6-hexanediol(HDO) and dimethylamine(DMA) at normal pressure over an outstanding Cu/Ni/Zn catalyst supported on aluminum oxide(γ-Al₂O₃) was studied in this article. Cu/Ni/Zn/γ-Al₂O₃(Cu: Ni: Zn = 28: 7: 12) exhibited excellent catalytic performance, which HDO was almost completely transformed and TMHDA reached 85 % selectivity at 200 °C. The amination of HDO required two hydrogenations and two dehydrogenations, and the selectivity of the amination catalyst depended on the balance of dehydrogenation and hydrogenation. Various characterization (TEM, BET, XRD, H₂-TPR, XPS) demonstrated that the addition of Zn to the Cu/Ni catalyst could reduce the agglomeration of Cu/Ni particles and change the valence distribution of Cu. The Cu/Ni/Zn/γ-Al₂O₃ catalyst was a very promising and green method for the synthesis of tertiary diamines through amination of diols.

本文研究了在常压下，在以氧化铝（γ-Al2O3）为载体的 Cu/Ni/Zn 催化剂上，通过 1,6-hexanediol (HDO) 与二甲胺 (DMA) 的胺化反应合成 N, N, N', N'-tetramethyl-1,6-hexanediamine (TMHDA)。Cu/Ni/Zn/γ-Al2O3（Cu: Ni: Zn = 28: 7: 12）表现出优异的催化性能，在 200 °C 时，HDO 几乎完全转化，TMHDA 的选择性达到 85%。HDO 的胺化需要两次加氢和两次脱氢，胺化催化剂的选择性取决于脱氢和加氢的平衡。各种表征（TEM、BET、XRD、H2-TPR、XPS）表明，在 Cu/Ni 催化剂中添加 Zn 可减少 Cu/Ni 颗粒的团聚，并改变 Cu 的价态分布。Cu/Ni/Zn/γ-Al2O3 催化剂是通过二元醇胺化合成叔二胺的一种非常有前景的绿色方法。

引用次数: 0

Theoretical insight into the mechanism of Li-mediated nitrogen reduction reaction by density functional theory 通过密度泛函理论深入了解锂介导的氮还原反应机理

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-07 DOI: 10.1016/j.mcat.2024.114593

Ji Zhang , Aimin Yu , Dong-sheng Li , Chenghua Sun

Lithium-mediated electrochemical nitrogen reduction reaction (NRR) as an alternative to the Haber-Bosch process has attracted increasing attention because of its high faradaic efficiency and reproducibility. However, the limited understanding of the mechanism has hampered further improvement of its catalytic performance. This work has endeavored to study the process of Li-mediated NRR and its underlying mechanism using density functional theory. It is founded that the Li₆N₂, Li₇N₂ atom groups, Li₃N (001) and Li₃N (110) layer stably exist on the deposited Li (001) layer. The replacing model has been established to describe the hydrogenation process with ethanol as a proton source, revealing that the replacement between Li and H atom is a spontaneously thermal process. Based on the replacing mechanism, the structure of interface and coverage rate of reactive sites are the two main factors that determine the ammonia formation. These findings further our understanding of Li-mediated NRR mechanism and will be helpful for the rational design of experiments of Li-mediated NRR.

锂介导的电化学氮还原反应（NRR）作为哈伯-博什过程的替代方法，因其高远达效率和可重复性而受到越来越多的关注。然而，对其机理的有限了解阻碍了其催化性能的进一步提高。本研究致力于利用密度泛函理论研究锂介导的无还原反应过程及其内在机理。研究发现，Li6N2、Li7N2 原子团、Li3N (001) 和 Li3N (110) 层稳定地存在于沉积的 Li (001) 层上。建立了置换模型来描述以乙醇为质子源的氢化过程，揭示了 Li 原子与 H 原子间的置换是一个自发的热过程。基于置换机制，界面结构和反应位点的覆盖率是决定氨形成的两个主要因素。这些发现进一步加深了我们对锂介导 NRR 机理的理解，有助于合理设计锂介导 NRR 的实验。

{"title":"Theoretical insight into the mechanism of Li-mediated nitrogen reduction reaction by density functional theory","authors":"Ji Zhang , Aimin Yu , Dong-sheng Li , Chenghua Sun","doi":"10.1016/j.mcat.2024.114593","DOIUrl":"10.1016/j.mcat.2024.114593","url":null,"abstract":"<div><div>Lithium-mediated electrochemical nitrogen reduction reaction (NRR) as an alternative to the Haber-Bosch process has attracted increasing attention because of its high faradaic efficiency and reproducibility. However, the limited understanding of the mechanism has hampered further improvement of its catalytic performance. This work has endeavored to study the process of Li-mediated NRR and its underlying mechanism using density functional theory. It is founded that the Li<sub>6</sub>N<sub>2</sub>, Li<sub>7</sub>N<sub>2</sub> atom groups, Li<sub>3</sub>N (001) and Li<sub>3</sub>N (110) layer stably exist on the deposited Li (001) layer. The replacing model has been established to describe the hydrogenation process with ethanol as a proton source, revealing that the replacement between Li and H atom is a spontaneously thermal process. Based on the replacing mechanism, the structure of interface and coverage rate of reactive sites are the two main factors that determine the ammonia formation. These findings further our understanding of Li-mediated NRR mechanism and will be helpful for the rational design of experiments of Li-mediated NRR.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114593"},"PeriodicalIF":3.9,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring the factors influencing the ketoenamine-enolimine tautomeric equilibrium of pyridoxal 5′-phosphate in branched-chain aminotransferases 支链氨基转移酶中影响 5′-磷酸吡哆醛酮胺-烯醇亚胺同分异构平衡的因素探究

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-07 DOI: 10.1016/j.mcat.2024.114581

Xue Li , He Yu , Jiaqi Sun , Xiaoli Sun

Pyridoxal 5′-phosphate (PLP), the active form of vitamin B6, is a critical coenzyme for various enzymes. It generates a Schiff base with the substrate and exhibits ketoenamine and enolimine tautomeric forms due to intramolecular proton transfer. This study aims to ascertain the predominant tautomeric form of the PLP Schiff base in MtIlvE and analyze its influencing factors. Molecular dynamics simulations indicate that the ketoenamine tautomer has higher binding free energy than the enolimine tautomer. Density functional theory calculations suggest that, despite their ability to interconvert at a relatively low energy barrier, the ketoenamine tautomer is thermodynamically more stable. Factors affecting the keto-enol tautomeric equilibrium were investigated by constructing various QM-cluster models. Our results demonstrate that both the protonation of the pyridine nitrogen and the presence of Tyr209, which stabilizes the O3 anion, shift the tautomeric equilibrium toward the ketoenamine configuration. These findings provide a theoretical basis for investigating enzyme catalytic mechanisms.

吡哆醛 5′-磷酸（PLP）是维生素 B6 的活性形式，是各种酶的重要辅酶。它与底物生成希夫碱，并由于分子内质子转移而呈现酮烯胺和烯醇亚胺同分异构体形式。本研究旨在确定 MtIlvE 中 PLP 席夫碱的主要同分异构体形式，并分析其影响因素。分子动力学模拟表明，酮烯胺同分异构体的结合自由能高于烯丙基亚胺同分异构体。密度泛函理论计算表明，尽管酮烯胺同系物能够在相对较低的能障下相互转化，但其热力学稳定性更高。通过构建各种 QM-簇模型，研究了影响酮烯醇同分异构体平衡的因素。我们的研究结果表明，吡啶氮的质子化和 Tyr209 的存在都会使同分异构体的平衡向酮烯胺构型移动，而 Tyr209 能稳定 O3 阴离子。这些发现为研究酶催化机理提供了理论基础。

{"title":"Exploring the factors influencing the ketoenamine-enolimine tautomeric equilibrium of pyridoxal 5′-phosphate in branched-chain aminotransferases","authors":"Xue Li , He Yu , Jiaqi Sun , Xiaoli Sun","doi":"10.1016/j.mcat.2024.114581","DOIUrl":"10.1016/j.mcat.2024.114581","url":null,"abstract":"<div><div>Pyridoxal 5′-phosphate (PLP), the active form of vitamin B6, is a critical coenzyme for various enzymes. It generates a Schiff base with the substrate and exhibits ketoenamine and enolimine tautomeric forms due to intramolecular proton transfer. This study aims to ascertain the predominant tautomeric form of the PLP Schiff base in <em>Mt</em>IlvE and analyze its influencing factors. Molecular dynamics simulations indicate that the ketoenamine tautomer has higher binding free energy than the enolimine tautomer. Density functional theory calculations suggest that, despite their ability to interconvert at a relatively low energy barrier, the ketoenamine tautomer is thermodynamically more stable. Factors affecting the keto-enol tautomeric equilibrium were investigated by constructing various QM-cluster models. Our results demonstrate that both the protonation of the pyridine nitrogen and the presence of Tyr209, which stabilizes the O3 anion, shift the tautomeric equilibrium toward the ketoenamine configuration. These findings provide a theoretical basis for investigating enzyme catalytic mechanisms.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114581"},"PeriodicalIF":3.9,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

One–pot A3–coupling solvent–free synthesis of propargylamines by Pd–impregnated Al–based LDHs synthesized from aluminum salt slag 用铝盐渣合成的钯浸渍铝基 LDH 单锅 A3 偶联无溶剂合成丙炔胺

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-05 DOI: 10.1016/j.mcat.2024.114594

Raihamol Erattammottil Thampikannu , Alejandro Jiménez , Vicente Rives , Miguel Ángel Vicente , Kannan Vellayan

Several Al³⁺–based LDHs with different divalent cations have been synthesized by coprecipitation from aluminum salt slag and have been impregnated with Pd. After their characterization by PXRD, FT–IR, thermal analysis, N₂ adsorption–desorption isotherms at –196 °C and electron microscopy (SEM and TEM), they were used as heterogeneous catalysts in the A³–coupling reaction (benzaldehyde + morpholine + phenylacetylene) to produce propargylamines. The catalyst that showed the best results was NiAl–Pd and the optimal reaction conditions were: catalyst dose 30 mg, temperature 80 °C and reaction time 6 h. In addition, this catalyst showed a good cyclic behavior, retaining a catalytic activity higher than 80 % after 4 cycles.

通过铝盐渣共沉淀法合成了几种含有不同二价阳离子的 Al3+ 基 LDHs，并在其中浸渍了钯。通过 PXRD、傅立叶变换红外光谱、热分析、-196 °C 下的 N2 吸附-解吸等温线和电子显微镜（SEM 和 TEM）对它们进行表征后，将它们用作 A3 偶联反应（苯甲醛 + 吗啉 + 苯乙炔）中的异相催化剂，以生成丙炔胺。NiAl-Pd 催化剂的效果最好，最佳反应条件为：催化剂剂量 30 毫克，温度 80 °C，反应时间 6 小时。

引用次数: 0

Selective oxidation of styrene to valuable C7 or C8 aromatics via green photocatalysis with TiO2-based catalysts 利用基于 TiO2 的催化剂通过绿色光催化将苯乙烯选择性氧化为有价值的 C7 或 C8 芳烃

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-04 DOI: 10.1016/j.mcat.2024.114585

Yuzhen Hu , Zhenlong Song , Peng Zheng , Qi Zhang , Jianguo Liu

The selective oxidation of styrene at its side chains to yield value-added C₇ or C₈ aromatic compounds represents a crucial reaction within the chemical industry. However, achieving precise control over product formation selectivity poses a significant challenge. In this study, we demonstrate the effectiveness of ultra-small nanosized TiO₂-based catalysts in facilitating the selective oxidation of styrene through a mild, eco-friendly photocatalytic approach. Following modification with 0.4% NiO, a notable transformation in product selectivity is observed. The primary products shift from C₈ with 96% selectivity to C₇ with 92% selectivity under UV, and even sunlight-type excitation. Detailed structural and electronic analyses reveal that the incorporation of NiO onto the TiO₂ surface induces the formation of a P-N heterojunction and additional active sites, crucial for promoting C-C cleavage, leading to a selectivity shift from C₈ to C₇ products. This research provides valuable insights into the design of simple TiO₂-based catalysts capable of achieving high selectivity in the oxidation of styrene, highlighting the potential of green photocatalysis in industrial applications.

选择性氧化苯乙烯侧链以生成高附加值的 C7 或 C8 芳香族化合物是化学工业中的一个重要反应。然而，实现对产品形成选择性的精确控制是一项重大挑战。在本研究中，我们通过一种温和、环保的光催化方法，展示了超小型纳米二氧化钛催化剂在促进苯乙烯选择性氧化方面的有效性。用 0.4% 的氧化镍改性后，产品选择性发生了显著变化。在紫外线甚至阳光型激发下，主要产物从选择性为 96% 的 C8 转变为选择性为 92% 的 C7。详细的结构和电子分析表明，在二氧化钛表面掺入氧化镍会诱导形成 P-N 异质结和额外的活性位点，这对促进 C-C 裂解至关重要，从而导致产物选择性从 C8 转变为 C7。这项研究为设计能够在苯乙烯氧化过程中实现高选择性的基于二氧化钛的简单催化剂提供了宝贵的见解，凸显了绿色光催化在工业应用中的潜力。

{"title":"Selective oxidation of styrene to valuable C7 or C8 aromatics via green photocatalysis with TiO2-based catalysts","authors":"Yuzhen Hu , Zhenlong Song , Peng Zheng , Qi Zhang , Jianguo Liu","doi":"10.1016/j.mcat.2024.114585","DOIUrl":"10.1016/j.mcat.2024.114585","url":null,"abstract":"<div><div>The selective oxidation of styrene at its side chains to yield value-added C<sub>7</sub> or C<sub>8</sub> aromatic compounds represents a crucial reaction within the chemical industry. However, achieving precise control over product formation selectivity poses a significant challenge. In this study, we demonstrate the effectiveness of ultra-small nanosized TiO<sub>2</sub>-based catalysts in facilitating the selective oxidation of styrene through a mild, eco-friendly photocatalytic approach. Following modification with 0.4% NiO, a notable transformation in product selectivity is observed. The primary products shift from C<sub>8</sub> with 96% selectivity to C<sub>7</sub> with 92% selectivity under UV, and even sunlight-type excitation. Detailed structural and electronic analyses reveal that the incorporation of NiO onto the TiO<sub>2</sub> surface induces the formation of a P-N heterojunction and additional active sites, crucial for promoting C-C cleavage, leading to a selectivity shift from C<sub>8</sub> to C<sub>7</sub> products. This research provides valuable insights into the design of simple TiO<sub>2</sub>-based catalysts capable of achieving high selectivity in the oxidation of styrene, highlighting the potential of green photocatalysis in industrial applications.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114585"},"PeriodicalIF":3.9,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oxygen evolution over Fe1/NiSe2 single-atom electrocatalyst: The role of thermal-electrical cascade and surface reconstruing Fe1/NiSe2单原子电催化剂上的氧进化：热电级联和表面重构的作用

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-10-04 DOI: 10.1016/j.mcat.2024.114596

Ju Wang , Yusheng Liu , Zhaoxu Wang , Jia Wang , Wenyou Zhu , Wenchang Zhuang , Lin Tian

Oxygen evolution reaction (OER) in water electrolysis is a tough challenge. Here we report the thermally activated on-surface oxygen evolution at nickel diselenide under alkaline conditions, specifically focusing on the (101) and (100) facets supported with Fe single-atom electrocatalysts. Assisted by heat, the Fe₁/NiSe₂(101) and (100) facets demonstrate highly efficient activity for oxygen evolution at pH = 14. First-principles calculations and AIMD simulations illustrate excellent electrical conductivity and thermal stability of the Fe₁/NiSe₂(101) and (100) facets, as well as provide a promising understanding of electron transports among the oxygen-containing active species and the electrocatalysts during thermal-electrical cascade of OER under alkaline conditions. The enhanced OER performance depends on the co-adsorbate combinations: *O_(Fe-Se^Ⅰ₎-*OH_(Se^Ⅱ₎ and *O_(Fe-Se^Ⅰ₎-*OH_(Ni) at the Fe₁/NiSe₂(101) facet, whose adsorption behaviors lead to self-activated surface reconstruing. Impressively, the affinity of the key intermediates at the potential-determining steps of OER: *O_(Fe-Se^Ⅰ₎ at the Fe₁/NiSe₂(101) facet, *O_(Fe) and *OOH_(Fe) at the Fe₁/NiSe₂(100) facet, is optimized by such self-activated surface reconstruing.

水电解中的氧进化反应（OER）是一项艰巨的挑战。在此，我们报告了二硒化镍在碱性条件下的热激活表面氧演化，特别关注了由铁单原子电催化剂支撑的 (101) 和 (100) 面。在热的辅助下，Fe1/NiSe2（101）和（100）面在 pH = 14 时表现出高效的氧进化活性。第一性原理计算和 AIMD 模拟表明，Fe1/NiSe2(101) 和 (100) 面具有出色的导电性和热稳定性，并为理解碱性条件下热-电级联 OER 过程中含氧活性物种和电催化剂之间的电子传输提供了前景广阔的思路。增强的 OER 性能取决于共吸附剂组合：Fe1/NiSe2(101)面上的*O(Fe-SeⅠ)-*OH(SeⅡ)和*O(Fe-SeⅠ)-*OH(Ni)的吸附行为导致了自激活表面重构。令人印象深刻的是，在 OER 的电位决定步骤中，关键中间产物的亲和性：Fe1/NiSe2(101)面上的*O(Fe-SeⅠ)、Fe1/NiSe2(100)面上的*O(Fe)和*OOH(Fe)通过这种自激活表面重构得到了优化。

{"title":"Oxygen evolution over Fe1/NiSe2 single-atom electrocatalyst: The role of thermal-electrical cascade and surface reconstruing","authors":"Ju Wang , Yusheng Liu , Zhaoxu Wang , Jia Wang , Wenyou Zhu , Wenchang Zhuang , Lin Tian","doi":"10.1016/j.mcat.2024.114596","DOIUrl":"10.1016/j.mcat.2024.114596","url":null,"abstract":"<div><div>Oxygen evolution reaction (OER) in water electrolysis is a tough challenge. Here we report the thermally activated on-surface oxygen evolution at nickel diselenide under alkaline conditions, specifically focusing on the (101) and (100) facets supported with Fe single-atom electrocatalysts. Assisted by heat, the Fe<sub>1</sub>/NiSe<sub>2</sub>(101) and (100) facets demonstrate highly efficient activity for oxygen evolution at pH = 14. First-principles calculations and AIMD simulations illustrate excellent electrical conductivity and thermal stability of the Fe<sub>1</sub>/NiSe<sub>2</sub>(101) and (100) facets, as well as provide a promising understanding of electron transports among the oxygen-containing active species and the electrocatalysts during thermal-electrical cascade of OER under alkaline conditions. The enhanced OER performance depends on the co-adsorbate combinations: *O<sub>(Fe-Se</sub><sup>Ⅰ</sup><sub>)</sub>-*OH<sub>(Se</sub><sup>Ⅱ</sup><sub>)</sub> and *O<sub>(Fe-Se</sub><sup>Ⅰ</sup><sub>)</sub>-*OH<sub>(Ni)</sub> at the Fe<sub>1</sub>/NiSe<sub>2</sub>(101) facet, whose adsorption behaviors lead to self-activated surface reconstruing. Impressively, the affinity of the key intermediates at the potential-determining steps of OER: *O<sub>(Fe-Se</sub><sup>Ⅰ</sup><sub>)</sub> at the Fe<sub>1</sub>/NiSe<sub>2</sub>(101) facet, *O<sub>(Fe)</sub> and *OOH<sub>(Fe)</sub> at the Fe<sub>1</sub>/NiSe<sub>2</sub>(100) facet, is optimized by such self-activated surface reconstruing.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"569 ","pages":"Article 114596"},"PeriodicalIF":3.9,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

首页上一页

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

Molecular Catalysis

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀