Design and synthesis ofN1,N8-diacetylspermidine analogues having a linker with desired functional groups

2019 ◽  
Vol 17 (4) ◽  
pp. 867-875
Author(s):  
Reiya Ohta ◽  
Akihiro Oguro ◽  
Kazuhiro Nishimura ◽  
Kenichi Murai ◽  
Hiromichi Fujioka ◽  
...  
Keyword(s):  
Functional Groups ◽  
Theoretical Calculations ◽  
Design And Synthesis

The synthesis of newN1,N8-diacetylspermidine (DiAcSpd) analogues having a linker with desired functional groups in the methylene skeleton, which have been designed by theoretical calculations, is described.

scholarly journals A Theoretical Study of the Adsorption Process of B-aflatoxins Using Pyracantha koidzumii (Hayata) Rehder Biomasses

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 283
Author(s):  
Abraham Méndez-Albores ◽  
René Escobedo-González ◽  
Juan Manuel Aceves-Hernández ◽  
Perla García-Casillas ◽  
María Inés Nicolás-Vázquez ◽  
...  
Keyword(s):  
Functional Groups ◽  
Electrostatic Interactions ◽  
Density Functional ◽  
Ph Value ◽  
Theoretical Calculations ◽  
Basis Set ◽  
Hydroxyl Group ◽  
Biosorption Process

Employing theoretical calculations with density functional theory (DFT) using the B3LYP/6-311++G(d,p) functional and basis set, the interaction of the aflatoxin B1 (AFB1) molecule and the functional groups present in the Pyracantha koidzumii biosorbent was investigated. Dissociation free energy and acidity equilibrium constant values were obtained theoretically both in solution (water) and gas phases. Additionally, the molecular electrostatic potential for the protonated molecules was calculated to verify the reactivity. Thus, methanol (hydroxyl group), methylammonium ion (amino group), acetate ion (carboxyl group), and acetone (carbonyl group), were used as representatives of the substrates present in the biomass; these references were considered using the corresponding protonated or unprotonated forms at a pH value of 5. The experimental infrared spectrophotometric data suggested the participation of these functional groups in the AFB1 biosorption process, indicating that the mechanism was dominated by electrostatic interactions between the charged functional groups and the positively charged AFB1 molecule. The theoretical determination indicated that the carboxylate ion provided the highest interaction energy with the AFB1 molecule. Consequently, an enriched biosorbent with compounds containing carboxyl groups could improve the yield of the AFB1 adsorption when using in vitro and in vivo trials.

Design and synthesis of new enzymes based on the lactate dehydrogenase framework

1991 ◽  
Vol 332 (1263) ◽  
pp. 177-184 ◽  
Keyword(s):  
Crystal Structure ◽  
Lactate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Functional Groups ◽  
Maximum Rate ◽  
Chemical Probes ◽  
Protein Surface ◽  
Design And Synthesis ◽  
Tryptophan Residues ◽  
Lactate Dehydrogenases

Analysis of the mechanism and structure of lactate dehydrogenases is summarized in a map of the catalytic pathway. Chemical probes, single tryptophan residues inserted at specific sites and a crystal structure reveal slow movements of the protein framework that discriminate between closely related small substrates. Only small and correctly charged substrates allow the protein to engulf the substrate in an internal vacuole that is isolated from solvent protons, in which water is frozen and hydride transfer is rapid. The closed vacuole is very sensitive to the size and charge of the substrate and provides discrimination between small substrates that otherwise have too few functional groups to be distinguished at a solvated protein surface. This model was tested against its ability to successfully predict the design and synthesis of new enzymes such as L-hydroxyisocaproate dehydrogenase and fully active malate dehydrogenase. Solvent friction limits the rate of forming the vacuole and thus the maximum rate of catalysis.

An intramolecular ortho-assisted activation of the silicon–hydrogen bond in arylsilanes: an experimental and theoretical study

2018 ◽  
Vol 47 (11) ◽  
pp. 3705-3716 ◽  
Author(s):  
Krzysztof Durka ◽  
Mateusz Urban ◽  
Maja Czub ◽  
Marek Dąbrowski ◽  
Patryk Tomaszewski ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Functional Groups ◽  
Theoretical Study ◽  
Theoretical Calculations ◽  
Boron Carbon ◽  
Intramolecular Activation

An intramolecular activation of the Si–H bond in arylsilanes by selected ortho-assisting functional groups based on boron, carbon and phosphorus was investigated experimentally and by means of theoretical calculations.

scholarly journals Molybdenum Trioxide on Anatase TiO2(101) - Formation of Monodispersed (MoO3)1 Monomers from Oligomeric (MoO3)n Clusters

2020 ◽  
Author(s):  
Nassar Doudin ◽  
Gregory Collinge ◽  
Pradeep Kumar Gurunathan ◽  
Mal Soon Lee ◽  
Vassiliki-Alexandra Glezakou ◽  
...  
Keyword(s):  
Molybdenum Trioxide ◽  
Theoretical Calculations ◽  
Complex Oxide ◽  
Oxide Systems ◽  
Design And Synthesis ◽  
Saturation Coverage ◽  
Resolution Imaging ◽  
Complete Layer ◽  
Immense Potential ◽  
Ordered Layers

<p>Complex oxide systems with hierarchical order are of critical importance in material science and catalysis. Despite their immense potential, their design and synthesis are rather difficult. In this study we demonstrate how the deposition of small oligomeric (MoO<sub>3</sub>)<sub>1-6</sub> clusters, which can be formed by the sublimation of MoO<sub>3</sub> powders, leads to the formation of locally ordered layers of (MoO<sub>3</sub>)<sub>1</sub> monomers on anatase TiO<sub>2</sub>(101). Using both high-resolution imaging and theoretical calculations, we show that at room temperature, such oligomers undergo spontaneous dissociation to their monomeric units. In initial stages of the deposition, this is reflected by the observation of one to six neighboring (MoO<sub>3</sub>)<sub>1</sub> monomers that parallel the size distribution of the oligomers. A transient mobility of such oligomers on both bare TiO<sub>2</sub>(101) and (MoO<sub>3</sub>)<sub>1</sub> covered areas is key to the formation of a complete layer with a saturation coverage of one (MoO<sub>3</sub>)<sub>1</sub> per two undercoordinated surface Ti sites. We further show that such layers are stable to 500 K, making them highly suitable for a broad range of applications. </p>

scholarly journals A contorted nanographene shelter

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Huang Wu ◽  
Yu Wang ◽  
Bo Song ◽  
Hui-Juan Wang ◽  
Jiawang Zhou ◽  
...  
Keyword(s):  
Excited States ◽  
Materials Science ◽  
Theoretical Calculations ◽  
Binding Affinities ◽  
Binding Mechanism ◽  
Comprehensive Investigation ◽  
Design And Synthesis ◽  
Self Assembling ◽  
Artificial Receptors ◽  
Trigonal Prismatic

AbstractNanographenes have kindled considerable interest in the fields of materials science and supramolecular chemistry as a result of their unique self-assembling and optoelectronic properties. Encapsulating the contorted nanographenes inside artificial receptors, however, remains challenging. Herein, we report the design and synthesis of a trigonal prismatic hexacationic cage, which has a large cavity and adopts a relatively flexible conformation. It serves as a receptor, not only for planar coronene, but also for contorted nanographene derivatives with diameters of approximately 15 Å and thicknesses of 7 Å. A comprehensive investigation of the host-guest interactions in the solid, solution and gaseous states by experimentation and theoretical calculations reveals collectively an induced-fit binding mechanism with high binding affinities between the cage and the nanographenes. Notably, the photostability of the nanographenes is improved significantly by the ultrafast deactivation of their excited states within the cage. Encapsulating the contorted nanographenes inside the cage provides a noncovalent strategy for regulating their photoreactivity.

Sign in / Sign up

Export Citation Format

Share Document