scholarly journals Unexpected Reaction Pathway for butyrylcholinesterase-catalyzed inactivation of “hunger hormone” ghrelin

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jianzhuang Yao ◽  
Yaxia Yuan ◽  
Fang Zheng ◽  
Chang-Guo Zhan
Keyword(s):  
Reaction Pathway ◽  
Unexpected Reaction

Reaction Pathways to 2-Aminothiophenes and Thiophene-3-carbonitriles

2009 ◽  
Vol 62 (5) ◽  
pp. 402 ◽  
Author(s):  
Luigi Aurelio ◽  
Bernard L. Flynn ◽  
Peter J. Scammells
Keyword(s):  
Comparative Studies ◽  
Reaction Pathway ◽  
Reaction Pathways ◽  
Synthesis And Characterization ◽  
The Past ◽  
Adenosine A1 ◽  
Unexpected Reaction ◽  
Potential Applications ◽  
A1 Receptor

Over the past two decades 2-amino-3-benzoylthiophenes have been found to act as allosteric enhancers of the adenosine A1 receptor (A1AR). As such, compounds of this type have potential applications in the therapy of a variety of disorders by enhancing A1AR activation. Initial studies in this field identified various 2-amino-3-benzoylthiophenes as potential leads and of these PD 81723 1a has become the benchmark for comparative studies due to its favourable ratio of allosteric enhancement to antagonism. Surprisingly the synthesis and characterization of PD 81723 1a has not been previously reported. Herein we report the synthesis and characterization of this important A1AR allosteric enhancer. As part of this study we also found an unexpected reaction pathway to 2-phenylthiophene-3-carbonitriles.

Development of an unexpected reaction pathway for the synthesis of 1,2,4-trisubstituted pyrrolo[1,2-a]quinoxalines through palladium-catalyzed cascade reactions

Tetrahedron ◽  
2017 ◽  
Vol 73 (12) ◽  
pp. 1633-1639 ◽  
Author(s):  
Ali Keivanloo ◽  
Atena Soozani ◽  
Mohammad Bakherad ◽  
Mahdi Mirzaee ◽  
Hadi Amiri Rudbari ◽  
...  
Keyword(s):  
Reaction Pathway ◽  
Cascade Reactions ◽  
Unexpected Reaction ◽  
Palladium Catalyzed

An unexpected reaction pathway in the synthesis of the ABCE framework of strychnine-type alkaloids – A multidisciplinary study

2017 ◽  
Vol 1128 ◽  
pp. 230-238 ◽  
Author(s):  
Michal Šoral ◽  
Jozef Markus ◽  
Jana Doháňošová ◽  
Stanislava Šoralová ◽  
Dana Dvoranová ◽  
...  
Keyword(s):  
Reaction Pathway ◽  
Multidisciplinary Study ◽  
Unexpected Reaction

Unexpected reaction pathway during the palladation of 2,5-diphenylphosphacymantrene

2009 ◽  
Vol 694 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Аllan G. Ginzburg ◽  
Vasily V. Bashilov ◽  
Fedor M. Dolgushin ◽  
Alexander F. Smol’yakov ◽  
Аlexander S. Peregudov ◽  
...  
Keyword(s):  
Reaction Pathway ◽  
Unexpected Reaction

scholarly journals Unexpected Reaction Pathway of the Alpha-Aminoalkyl Radical Derived from One-Electron Oxidation of S-Alkylglutathiones

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 877
Author(s):  
Tomasz Pedzinski ◽  
Krzysztof Bobrowski ◽  
Bronislaw Marciniak ◽  
Piotr Filipiak
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
High Resolution Mass Spectrometry ◽  
Reaction Pathway ◽  
Laser Flash ◽  
Ring Closure ◽  
Unexpected Reaction ◽  
Sulfur Containing ◽  
Resolution Mass ◽  
Intramolecular Ring

Laser flash photolysis and high-resolution mass spectrometry were used to investigate the mechanism of one-electron oxidation of two S-alkylglutathiones using 3-carboxybenzophenone (3CB) as a photosensitizer. This report indicates an unexpected reaction pathway of the α-aminoalkyl radical cation (αN+) derived from the oxidation of S-alkylglutathiones. Instead of a common hydrolysis reaction of αN+ reported earlier for methionine and other sulfur-containing aminoacids and peptides, an intramolecular ring-closure reaction was found for S-alkylglutathiones.

Catalytic Resonance Theory: Parallel Reaction Pathway Control

2019 ◽  
Author(s):  
M. Alexander Ardagh ◽  
Manish Shetty ◽  
Anatoliy Kuznetsov ◽  
Qi Zhang ◽  
Phillip Christopher ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Active Site ◽  
Active Sites ◽  
Reaction Pathway ◽  
Control Strategies ◽  
Oscillation Amplitude ◽  
Catalytic Performance ◽  
Parallel Reaction ◽  
Resonance Theory ◽  
Static Conditions

Catalytic enhancement of chemical reactions via heterogeneous materials occurs through stabilization of transition states at designed active sites, but dramatically greater rate acceleration on that same active site is achieved when the surface intermediates oscillate in binding energy. The applied oscillation amplitude and frequency can accelerate reactions orders of magnitude above the catalytic rates of static systems, provided the active site dynamics are tuned to the natural frequencies of the surface chemistry. In this work, differences in the characteristics of parallel reactions are exploited via selective application of active site dynamics (0 < ΔU < 1.0 eV amplitude, 10<sup>-6</sup> < f < 10<sup>4</sup> Hz frequency) to control the extent of competing reactions occurring on the shared catalytic surface. Simulation of multiple parallel reaction systems with broad range of variation in chemical parameters revealed that parallel chemistries are highly tunable in selectivity between either pure product, even when specific products are not selectively produced under static conditions. Two mechanisms leading to dynamic selectivity control were identified: (i) surface thermodynamic control of one product species under strong binding conditions, or (ii) catalytic resonance of the kinetics of one reaction over the other. These dynamic parallel pathway control strategies applied to a host of chemical conditions indicate significant potential for improving the catalytic performance of many important industrial chemical reactions beyond their existing static performance.

A Paramedic Treatment for Modeling Explicitly Solvated Chemical Reaction Mechanisms

2018 ◽  
Author(s):  
Yasemin Basdogan ◽  
John Keith
Keyword(s):  
Reaction Mechanism ◽  
Chemical Reaction ◽  
Reaction Mechanisms ◽  
Reaction Pathway ◽  
Optimization Procedure ◽  
Cost Effective ◽  
Chemical Reaction Mechanisms ◽  
Solvent Molecules ◽  
Dynamics Simulations ◽  
Mbh Reaction

<div> <div> <div> <p>We report a static quantum chemistry modeling treatment to study how solvent molecules affect chemical reaction mechanisms without dynamics simulations. This modeling scheme uses a global optimization procedure to identify low energy intermediate states with different numbers of explicit solvent molecules and then the growing string method to locate sequential transition states along a reaction pathway. Testing this approach on the acid-catalyzed Morita-Baylis-Hillman (MBH) reaction in methanol, we found a reaction mechanism that is consistent with both recent experiments and computationally intensive dynamics simulations with explicit solvation. In doing so, we explain unphysical pitfalls that obfuscate computational modeling that uses microsolvated reaction intermediates. This new paramedic approach can promisingly capture essential physical chemistry of the complicated and multistep MBH reaction mechanism, and the energy profiles found with this model appear reasonably insensitive to the level of theory used for energy calculations. Thus, it should be a useful and computationally cost-effective approach for modeling solvent mediated reaction mechanisms when dynamics simulations are not possible. </p> </div> </div> </div>

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