Results 61 to 70 of about 35,554 (229)

Purine and pyrimidine synthesis differently affect the strength of the inoculum effect for aminoglycoside and β-lactam antibiotics

Microbiology Spectrum
The inoculum effect has been observed for nearly all antibiotics and bacterial species. However, explanations accounting for its occurrence and strength are lacking.
Daniella M. Hernandez, Melissa Marzouk, Madeline Cole, Marla C. Fortoul, Saipranavi Reddy Kethireddy, Rehan Contractor, Habibul Islam, Trent Moulder, Ariane R. Kalifa, Estefania Marin Meneses, Maximiliano Barbosa Mendoza, Ruth Thomas, Saad Masud, Sheena Pubien, Patricia Milanes, Gabriela Diaz-Tang, Allison J. Lopatkin, Robert P. Smith   +17 more
doaj   +1 more source

Acceptor‐Bridged Engineering Enables Highly Efficient Solution‐Processed Pure‐Green MR‐TADF OLEDs With External Quantum Efficiency of 29% and Small Roll‐Off

Advanced Science, EarlyView.
Solution‐processible pure green multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters are developed through a strategic acceptor‐bridging engineering approach that integrates MR‐building blocks with pyrimidine‐derived frameworks.
Xuming Zhuang, Qing Zhang, Jinbei Wei, Zhiqiang Li, Baoyan Liang, Chenguang Wang, Hai Bi, Yue Wang, Geyu Lu   +8 more
wiley   +1 more source

Synthesis and polymerization of 1-(2-diallylaminoethyl)pyrimidines

Designed Monomers and Polymers, 2018
We report the preparation and characterization of three pyrimidine-based monomers, specifically: 1-(2-diallylaminoethyl)uracil, 1-(2-diallylaminoethyl)thymine and 1-(2-diallylaminoethyl)cytosine.
Jomana Elaridi, Alaa Ezzeddine, Lara Abramian, Ali Koubeissi, Nikolay Vladimirov, Kamal H. Bouhadir   +5 more
doaj   +1 more source

Untersuchungen zum Ursprung der Substratspezifität von Enzymen der Amidohydrolase‐Superfamilie

Angewandte Chemie, EarlyView.
Umfassende Analysen zweier Enzymklassen aus der Amidohydrolase‐Superfamilie (AHS) ergaben, dass die Katalyse über eine 1,4‐ bzw. 1,6‐nukleophile konjugierte Addition abläuft und diese Eigenschaft die Substratspezifität bestimmt. Obwohl alle Substrate und Produkte vollständig achiral sind, führt dieser mechanistische Unterschied zu einer invertierten ...
Lukas Drexler, Torben F. Fürtges, Till Rudack, Reinhard Sterner   +3 more
wiley   +1 more source

Pyrimidine Acyclo-C-Nucleosides by Ring Transformations of 2-Formyl-L-arabinal

Molecules, 2005
The protected 2-formyl-L-arabinal 2 reacted with thiourea and cyanamide in the presence of sodium hydride to afford via ring transformations the 5-[1R,2S-1,2- bis(benzyloxy)-3-hydroxypropyl]-1,2-dihydropyrimidines 3 and 4, respectively.
Klaus Peseke, Manfred Michalik, Holger Feist, Ahmed Bari   +3 more
doaj   +1 more source

On the Origin of Substrate Specificity of Enzymes from the Amidohydrolase Superfamily

Angewandte Chemie International Edition, EarlyView.
Comprehensive analyses of two enzyme classes from the amidohydrolase superfamily (AHS) revealed that catalysis proceeds either via 1,4 or 1,6 nucleophilic conjugate addition and that this property defines substrate specificity. Moreover, although all substrates and products are entirely achiral, this mechanistic difference results in an inverted ...
Lukas Drexler, Torben F. Fürtges, Till Rudack, Reinhard Sterner   +3 more
wiley   +1 more source

Diverse Methods with Stereoselective Induction in the Asymmetric Biginelli Reaction

Molecules
The relevance of the asymmetric Biginelli reaction (ABR) has been increased in this century, due to the pharmacological application of its products. This review focuses predominantly on articles published in the period from 2015 to 2024 on asymmetric ...
Marcos Díaz-Fernández, Manuel Algarra, Saturnino Calvo-Losada, José-Joaquín Quirante, Francisco Sarabia, María-Soledad Pino-González   +5 more
doaj   +1 more source

Microwave-Promoted Synthesis of 4-Arylpyrimidines by Pd-Catalysed Suzuki–Miyaura Coupling of 4-Pyrimidyl Tosylates in Water

SynOpen, 2017
The Suzuki–Miyaura coupling reaction of 4-pyrimidyl tosylates was investigated with aryl, heteroaryl and alkyl boronic acids. The reaction provided 4-substituted pyrimidines in good-to-excellent yields after one-hour microwave irradiation in water at 100 
José Rodríguez-Aguilar, Beatriz Ordóñez, Matías Vidal, Marcos Caroli Rezende, Moisés Domínguez   +4 more
doaj   +1 more source

The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

Beilstein Journal of Organic Chemistry, 2014
An extension of the substrate scope of the Flögel-three-component reaction of lithiated alkoxyallenes, nitriles and carboxylic acids is presented. The use of dicarboxylic acids allowed the preparation of symmetrical bis(β-ketoenamides) from simple ...
Mrinal K. Bera, Moisés Domínguez, Paul Hommes, Hans-Ulrich Reissig   +3 more
doaj   +1 more source

Mechanism of Hydrogen Sulfide Generation and Prevention Strategies in Oil and Gas Fields: A Case Study of the Sickle Bay Operation Area

Asia-Pacific Journal of Chemical Engineering, EarlyView.
ABSTRACT To address the persistent exceedance of hydrogen sulfide (H2S) concentrations and the limited effectiveness of existing treatments in the Sickle Bay oil production area, this study deeply analyzes the mechanism of H2S generation in the Sickle Bay oil production area and proposes targeted prevention and control strategies. The results show that
Bo Lei, Yao‐long Li, Bao‐ping Bai, Xiang‐de Zhang, Guan‐tao Shi, Yong‐long Xie, Chen‐xiao Hou, Cong‐Yu Ke   +7 more
wiley   +1 more source