Colorimetric estimation of alfuzosin hydrochloride in pharmaceutical preparation based on computational studies

2016 ◽  
Vol 8 (8) ◽  
pp. 1798-1805 ◽  
Author(s):  
Khalid A. M. Attia ◽  
Nasr M. El-Abasawi ◽  
Ahmed. H. Abdelazim

Computational and theoretical studies were done electronically and geometrically to find a suitable, selective and sensitive coupling agent applicable for diazocoupling estimation of alfuzosin hydrochloride (ALF).

2020 ◽  
Vol 22 (44) ◽  
pp. 25661-25668
Author(s):  
Mauricio Lineros-Rosa ◽  
Antonio Francés-Monerris ◽  
Antonio Monari ◽  
Miguel Angel Miranda ◽  
Virginie Lhiaubet-Vallet

Combined spectroscopic and computational studies reveal that, in spite of their structural similarities, 5-formyluracil and 5-formylcytosine photosensitize cyclobutane thymine dimers through two different types of mechanisms.


Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 811
Author(s):  
Maria Tomé ◽  
Arnald Grabulosa ◽  
Mercè Rocamora ◽  
Gabriel Aullón ◽  
Mercè Font-Bardía ◽  
...  

The study of the reactivity of three 2-phenyl-3H-indole ligands of general formulae C8H3N-2-(C6H4-4-R1)-3-NOMe-5-R2 (1) [with R1 = H, R2 = OMe (a); R1 = R2 = H (b) or R1 = Cl, R2 = H (c)] with [Pd(η3-1-R3C3H4)(μ-Cl)]2 (R3 = H or Ph) has allowed us to isolate two sets of new Pd(II)-allyl complexes of general formulae [Pd(η3-1-R3C3H4)(1)Cl] {R3 = H (2) or Ph (3)}. Compounds 2a–2c and 3a–3c were characterized by elemental analyses, mass spectrometry and IR spectroscopy. The crystal structures of 2a, 3a and 3b were also determined by X-ray diffraction. 1H-NMR studies reveal the coexistence of two (for 2a–2c) or three (for 3a–3c) isomeric forms in CD2Cl2 solutions at 182 K. Additional studies on the catalytic activity of mixtures containing [Pd(η3-C3H5)(μ-Cl)]2 and the parent ligand (1a–1c) in the allylic alkylation of (E)-3-phenyl-2-propenyl (cinnamyl) acetate with sodium diethyl 2-methylmalonate as well as the stoichiometric reaction between compounds 3a and 3c with the nucleophile reveal that in both cases the formation of the linear trans- derivative is strongly preferred over the branched product. Computational studies at a DFT level on compound 3a allowed us to compare the relative stability of their isomeric forms present in solution and to explain the regioselectivity of the catalytic and stoichiometric processes.


2021 ◽  
pp. 59-67
Author(s):  
E. N. BELLENDIR ◽  
◽  
O. D. RUBIN ◽  
S. E. LISICHKIN ◽  
I. V. BAKLYKOV

The development of a methodology for numerical modeling and calculation of reinforced concrete structures of operated hydraulic structures, reinforced with prestressed basalt composite reinforcement, including on the basis of experimental research data carried out in the branch of JSC“Institute Hydroproject”-“NIIES” is presented. Computational studies were carried out on the basis of spatial fi nite element models in the framework of the ANSYS software package. Developing the models, the results of experimental and theoretical studies of hydrotechnical reinforced concrete structures were used in which prestressed basalt composite reinforcement is placed both in the tensioned and compressed zones of the structures.


Science ◽  
2018 ◽  
Vol 361 (6400) ◽  
pp. 381-387 ◽  
Author(s):  
Stasik Popov ◽  
Brian Shao ◽  
Alex L. Bagdasarian ◽  
Tyler R. Benton ◽  
Luyi Zou ◽  
...  

Vinyl carbocations have been the subject of extensive experimental and theoretical studies over the past five decades. Despite this long history in chemistry, the utility of vinyl cations in chemical synthesis has been limited, with most reactivity studies focusing on solvolysis reactions or intramolecular processes. Here we report synthetic and mechanistic studies of vinyl cations generated through silylium–weakly coordinating anion catalysis. We find that these reactive intermediates undergo mild intermolecular carbon-carbon bond–forming reactions, including carbon-hydrogen (C–H) insertion into unactivated sp3 C–H bonds and reductive Friedel-Crafts reactions with arenes. Moreover, we conducted computational studies of these alkane C–H functionalization reactions and discovered that they proceed through nonclassical, ambimodal transition structures. This reaction manifold provides a framework for the catalytic functionalization of hydrocarbons using simple ketone derivatives.


2019 ◽  
Vol 20 (7) ◽  
pp. 1621 ◽  
Author(s):  
Pedada Srinivasa Rao ◽  
Avinash L. Puyad ◽  
Sidhanath V. Bhosale ◽  
Sheshanath V. Bhosale

donor–acceptorDonor–acceptor–π–acceptor–donor (D1-A1-π-A2/A3-D2)-type small molecules, such TPA-MC-2 and TPA-MC-3, were designed and synthesized starting from donor-substituted alkynes (TPA-MC-1) via [2 + 2] cycloaddition−retroelectrocyclization reaction with tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) units, respectively. TPA-MC-2 and TPA-MC-3 chromophores differ on the A2/A3 acceptor subunit, which is 1,1,4,4-tetracyanobutadiene (TCBD) and a dicyanoquinodicyanomethane (DCQDCM), respectively. Both the derivative bearing same donors D1 (triphenylamine) and D2 (trimethylindolinm) and also same A1 (monocyano) as an acceptor, tetracyano with an aryl rings as the π-bridging moiety. The incorporation of TCNE and TCNQ as strong electron withdrawing units led to strong intramolecular charge-transfer (ICT) interactions, resulting in lower LUMO energy levels. Comparative UV–Vis absorption, fluorescence emission, and electrochemical and computational studies were performed to understand the effects of the TCNE and TCNQ subunits incorporated on TPA-MC-2 and TPA-MC-3, respectively.


RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58854-58864 ◽  
Author(s):  
Saad Makhseed ◽  
Basma Ghazal ◽  
Amr Mohamed Abdelmoniem ◽  
Veronika Novakova ◽  
Petr Zimcik

Computational studies validated the experimental results and revealing details about the electronic structures of novel halogenated phthalocyanines. Fluorescence and singlet oxygen quantum yields analysis revealed two-dimensional heavy atom effect.


Author(s):  
О. М. Іванов ◽  
В. М. Арендаренко

Наведено результати теоретичних досліджень зіскладання розрахункової моделі гідрообприскувальноїустановки тунельного типу, призначеної для обприс-кування під високим тиском рослин у тунельній каме-рі. Дослідження проводились із залученням теоріїгідродинаміки та гідростатики для розрахунку скла-дних трубопроводів і багатокомпонентних гідравліч-них систем. За результатами розрахункових дослі-джень було складено аналітичні рівняння, що визна-чають величини гідравлічних параметрів у вузловихточках і встановлюють взаємозв’язок між основни-ми компонентами гідравлічної установки. The results of theoretical studies on the preparation of the computational model hydro spray tunnel designed for spraying high-pressure plants in the tunnel chamber. Studies were carried out using the theory of hydrodynamic and hydrostatic calculations for complex pipelines and multi-hydraulic systems. To achieve the objectives of the study were divided into components of hydraulic systems, each of which is a more simplified version of a complex pipeline. According to the results of computational studies were compiled analytical equations that determine the magnitude of hydraulic parameters at nodes and establish the relationship between the main components of the hydraulic system, and outlines the framework for the selection of a pressure pump for the amount of required pressure and flow.


2017 ◽  
Vol 19 (17) ◽  
pp. 4176-4185 ◽  
Author(s):  
A. Leal-Duaso ◽  
M. Caballero ◽  
A. Urriolabeitia ◽  
J. A. Mayoral ◽  
J. I. García ◽  
...  

Optimized green synthesis of glyceryl monoethers from alcohols and glycidol through experimental and computational studies.


Author(s):  
Natália Ferreira de Sousa ◽  
Luciana Scotti ◽  
Eugene N. Muratov ◽  
Marcus Tullius Scotti

: Background: Organocalcogens are a class of organic compounds obtained by synthesis experiments to include S, Se, or Te. Among the elements that comprise this class, Se is characterized as an essential mineral and nutrient for humans. Se has been widely studied in many aspects. Organic synthesis of organoselenides is used for obtaining new potential drug candidates and may highly benefit from use of computational approaches to reduce time and cost of the experiments. Thus, the goal of our study is to evaluate the computational approaches used in the organoselenides research from 1999 to 2019. Methods: A literature review was performed by searching the database “Web of Sciences”. Results: Most of the theoretical studies include structural elucidation or structure-property analysis. We also found research regarding molecular docking approaches and Quantitative Structure-Activity Relationship (QSAR) studies. Conclusions: Computational studies has been widely applied to organoselenides. They demonstrated promising results and resulted in reduced the cost of research, increased efficacy, and, ultimately, novel organoselenides with desired properties.


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