scholarly journals Theoretical study on pegylation reaction mechanisms of IFN-α-2a, IFN-α-2b and IFN-β-1a

2017 ◽  
Vol 82 (7-8) ◽  
pp. 841-850
Author(s):  
Mohammad Taqavian ◽  
Daryoush Abedi ◽  
Fatemeh Zigheimat ◽  
Leila Zeidabadinejad
Keyword(s):  
Polyethylene Glycol ◽  
Reaction Mechanism ◽  
Dft Calculations ◽  
Transition State ◽  
Reaction Mechanisms ◽  
Theoretical Study ◽  
Computational Study ◽  
Single Transition ◽  
Experimental Works ◽  
Ab Initio And Dft

Ab initio and DFT calculations have been carried out to study the reaction mechanism between interferons (IFNs) ?-2a, ?-2b and ?-1a and polyethylene glycol (PEG) group. The calculations show that the mechanisms are concerted, in agreement with the results of experimental works. However, although it appears that there is one single transition state, the characteristics of its structure reveal a very synchronous reaction mechanism. The reactions are clearly exothermic and as well have feasible activation energies. Our computational study shows that the lowest transition state energies are related to Lys 134, His 34 and Met 1 of IFN-?-2a, IFN-?-2b and IFN-?-1a, respectively.

Theoretical study on reaction mechanism of phosphate-catalysed N–S acyl transfer of N-sulfanylethylanilide (SEAlide)

2020 ◽  
Vol 18 (47) ◽  
pp. 9706-9711
Author(s):  
Akira Shigenaga
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Reaction Mechanisms ◽  
Theoretical Study ◽  
Acyl Transfer

Reaction mechanisms of phosphate-catalyzed N–S acyl transfer of N-sulfanylethylanilide (SEAlide) were elucidated by DFT calculations and NCI analyses.

Reactions of an Aluminium(I) Reagent with 1,2-, 1,3- and 1,5-Dienes: Dearomatisation, Reversibility, and a Pericyclic Mechanism

2019 ◽  
Author(s):  
Clare Bakewell ◽  
Martí Garçon ◽  
Richard Y Kong ◽  
Louisa O'Hare ◽  
Andrew J. P. White ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Transition State ◽  
Reaction Pathways ◽  
Aromatic Rings ◽  
Aromatic Character ◽  
Pericyclic Reaction

The reactions of an aluminium(I) reagent with a series of 1,2-, 1,3- and 1,5-dienes are reported. In the case of 1,3-dienes the reaction occurs by a pericyclic reaction mechanism, specifically a cheletropic cycloaddition, to form aluminocyclopentene containing products. This mechanism has been interrogated by stereochemical experiments and DFT calculations. The stereochemical experiments show that the (4+1) cycloaddition follows a suprafacial topology, while calculations support a concerted albeit asynchronous pathway in which the transition state demonstrates aromatic character. Remarkably, the substrate scope of the (4+1) cycloaddition includes dienes that are either in part, or entirely, contained within aromatic rings. In these cases, reactions occur with dearomatisation of the substrate and can be reversible. In the case of 1,2- or 1,5-dienes complementary reactivity is observed; the orthogonal nature of the C=C π-bonds (1,2-diene) and the homoconjugated system (1,5-diene) both disfavour a (4+1) cycloaddition. Rather, reaction pathways are determined by an initial (2+1) cycloaddition to form an aluminocyclopropane intermediate which can in turn undergo insertion of a further C=C π-bond leading to complex organometallic products that incorporate fused hydrocarbon rings.

Reactions of an Aluminium(I) Reagent with 1,2-, 1,3- and 1,5-Dienes: Dearomatisation, Reversibility, and a Pericyclic Mechanism

2019 ◽  
Author(s):  
Clare Bakewell ◽  
Martí Garçon ◽  
Richard Y Kong ◽  
Louisa O'Hare ◽  
Andrew J. P. White ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Transition State ◽  
Reaction Pathways ◽  
Aromatic Rings ◽  
Aromatic Character ◽  
Pericyclic Reaction

The reactions of an aluminium(I) reagent with a series of 1,2-, 1,3- and 1,5-dienes are reported. In the case of 1,3-dienes the reaction occurs by a pericyclic reaction mechanism, specifically a cheletropic cycloaddition, to form aluminocyclopentene containing products. This mechanism has been interrogated by stereochemical experiments and DFT calculations. The stereochemical experiments show that the (4+1) cycloaddition follows a suprafacial topology, while calculations support a concerted albeit asynchronous pathway in which the transition state demonstrates aromatic character. Remarkably, the substrate scope of the (4+1) cycloaddition includes dienes that are either in part, or entirely, contained within aromatic rings. In these cases, reactions occur with dearomatisation of the substrate and can be reversible. In the case of 1,2- or 1,5-dienes complementary reactivity is observed; the orthogonal nature of the C=C π-bonds (1,2-diene) and the homoconjugated system (1,5-diene) both disfavour a (4+1) cycloaddition. Rather, reaction pathways are determined by an initial (2+1) cycloaddition to form an aluminocyclopropane intermediate which can in turn undergo insertion of a further C=C π-bond leading to complex organometallic products that incorporate fused hydrocarbon rings.

Succinylated isoniazid potential prodrug: Design of Experiments (DoE) for synthesis optimization and computational study of the reaction mechanism by DFT calculations

2021 ◽  
pp. 132323
Author(s):  
Diego Campos Prieto ◽  
Renan Vinícius de Araújo ◽  
Sara de Souza Lima ◽  
Felipe Zauith Assad ◽  
Scott M. Grayson ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Design Of Experiments ◽  
Dft Calculations ◽  
Computational Study

Computational study on gold-catalyzed (4 + 3) intramolecular cycloaddition of trienyne: mechanism, reactivity and selectivity

RSC Advances ◽  
2016 ◽  
Vol 6 (77) ◽  
pp. 73454-73468 ◽  
Author(s):  
Meng-Ru Li ◽  
Gui-Chang Wang
Keyword(s):  
Density Functional Theory ◽  
Reaction Mechanism ◽  
Dft Calculations ◽  
Density Functional ◽  
Computational Study ◽  
Functional Theory ◽  
Intramolecular Cycloaddition

The reaction mechanism, reactivity and selectivity of the Au(i)-catalyzed intramolecular (4 + 3) cycloaddition of trienyne have been studied by density functional theory (DFT) calculations.

scholarly journals Ab-Initio Computational Study : The Activation Energy Changes and Steric Effects In Peptide Synthesis Of Ac-AA-NH2 and Ac-AP-NH2

Molekul ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 137
Author(s):  
Indah Pratiwi ◽  
Bambang Cahyono ◽  
Parsaoran Siahaan
Keyword(s):  
Activation Energy ◽  
Reaction Mechanism ◽  
Ab Initio ◽  
Peptide Synthesis ◽  
Reaction Mechanisms ◽  
Steric Effect ◽  
Computational Study ◽  
Computational Method ◽  
Side Chain ◽  
Concerted Reaction

Ab-Initio computational method can be used for simulating reaction mechanisms, such as concerted reaction mechanism on peptide synthesis. The concerted reaction is one of many possible pathways on how peptide can be synthesized. The purpose of this study are probing the concerted reaction mechanism and comparing the steric effect to the reaction, given by different side-chain of alanine (A) and proline (P). Two dipeptides formed from alanine and proline were computed at HF-SCF/6-31G** theory level: Ac-AA-NH2 and Ac-AP-NH2. The res.lts show the activation energy of Ac-AA-NH2  and Ac-AP-NH2 forming via concerted pathway are 167.541 kJ/mol and 161.044 kJ/mol, respectively. The steric difference in side-chain affects the dihedral angle of the structure, and also gives difference to the entropy value of reaction.

Theoretical study of C-arylations with aryl halides to determine the reaction mechanism, the effect of substituents and heteroatoms

2019 ◽  
Vol 21 (19) ◽  
pp. 10163-10170 ◽  
Author(s):  
Rocío Durán ◽  
Nicolás Núñez-Navarro ◽  
Flavia C. Zacconi ◽  
Barbara Herrera
Keyword(s):  
Reaction Mechanism ◽  
Reaction Mechanisms ◽  
Theoretical Study ◽  
Aryl Halides ◽  
Effect Of Substituents

A set of Ullman-like reaction mechanisms are reported using DFT wB97XD/6-311D.

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