scholarly journals Chalcogen–Nitrogen Bond: Insights into a Key Chemical Motif

2020 ◽  
Vol 2 (1) ◽  
pp. 21
Author(s):  
Marco Bortoli ◽  
Andrea Madabeni ◽  
Pablo Andrei Nogara ◽  
Folorunsho B. Omage ◽  
Giovanni Ribaudo ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Glutathione Peroxidase ◽  
Pharmacological Action ◽  
Inorganic Materials ◽  
Molecular Systems ◽  
Cytoprotective Activity ◽  
Nitrogen Bonds ◽  
Valuable Role ◽  
Nitrogen Bond

Chalcogen–nitrogen chemistry deals with systems in which sulfur, selenium or tellurium is linked to a nitrogen nucleus. This chemical motif is a key component of different functional structures, ranging from inorganic materials and polymers to rationally designed catalysts, to bioinspired molecules and enzymes. The formation of a selenium–nitrogen bond, and its disruption, are rather common events in organic Se-catalyzed processes. In nature, along the mechanistic path of glutathione peroxidase, evidence of the formation of a Se–N bond in highly oxidizing conditions has been reported and interpreted as a strategy to protect the selenoenzyme from overoxidation. Selenium is also bonded to nitrogen in the well-known ebselen, a selenenylamide with antioxidant, antimicrobic and cytoprotective activity and its formation/disruption has a crucial role for its pharmacological action. Focusing on examples taken from selenium organic chemistry and biochemistry, the selenium–nitrogen bond is described, and its strength and reactivity are quantified using accurate computational methods applied to model molecular systems. Significant trends show up when comparing to sulfur/tellurium–nitrogen bonds, also reaffirming the peculiar and valuable role of selenium in chemistry and life in this context.

scholarly journals Chalcogen-Nitrogen Bond: Insights into a Key Chemical Motif

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 114
Author(s):  
Marco Bortoli ◽  
Andrea Madabeni ◽  
Pablo Andrei Nogara ◽  
Folorunsho B. Omage ◽  
Giovanni Ribaudo ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Computational Methods ◽  
Inorganic Materials ◽  
Molecular Systems ◽  
Nitrogen Nucleus ◽  
Intramolecular Cyclizations ◽  
Valuable Role ◽  
Nitrogen Bond

Chalcogen-nitrogen chemistry deals with systems in which sulfur, selenium, or tellurium is linked to a nitrogen nucleus. This chemical motif is a key component of different functional structures, ranging from inorganic materials and polymers, to rationally designed catalysts, to bioinspired molecules and enzymes. The formation of a selenium–nitrogen bond, typically occurring upon condensation of an amine and the unstable selenenic acid, often leading to intramolecular cyclizations, and its disruption, mainly promoted by thiols, are rather common events in organic Se-catalyzed processes. In this work, focusing on examples taken from selenium organic chemistry and biochemistry, the selenium–nitrogen bond is described, and its strength and reactivity are quantified using accurate computational methods applied to model molecular systems. The intermediate strength of the Se–N bond, which can be tuned to necessity, gives rise to significant trends when comparing it to the stronger S– and weaker Te–N bonds, reaffirming also in this context the peculiar and valuable role of selenium in chemistry and life.

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

Recent Progress in the Analysis of Captopril Using Electrochemical Methods: A Review

2019 ◽  
Vol 15 (3) ◽  
pp. 198-206 ◽  
Author(s):  
Sarfaraz Ahmed Mahesar ◽  
Saeed Ahmed Lakho ◽  
Syed Tufail Hussain Sherazi ◽  
Hamid Ali Kazi ◽  
Kamran Ahmed Abro ◽  
...  
Keyword(s):  
Enzyme Inhibitor ◽  
Modified Electrodes ◽  
High Sensitivity ◽  
Pharmaceutical Formulations ◽  
Inorganic Materials ◽  
Electrochemical Methods ◽  
Nano Particles ◽  
Moderate Heart Failure ◽  
Analytical Instrumentation

Background: Captopril is the synthetic dipeptide used as an angiotensin converting enzyme inhibitor. Captopril is used to treat hypertension as well as for the treatment of moderate heart failure. Analytical instrumentation and methodology plays an important role in pharmaceutical analysis. Methods: This review presents some important applications of electrochemical modes used for the analysis of captopril. So far captopril has been analyzed by using different bare and modified working electrodes with a variety of modifiers from organic and inorganic materials to various types of nano particles/materials. Results: This paper presents some of the methods which have been published in the last few years i.e. from 2003 to 2016. This review highlights the role of the analytical instrumentation, particularly electrochemical methods in assessing captopril using various working electrodes. Conclusion: A large number of studies on voltammetry noted by means of various bare and modified electrodes. Among all of the published voltammetric methods, DPV, SWV, CV and miscellaneous modes were trendy techniques used to analyze captopril in pharmaceutical formulations as well as biological samples. Electrodes modified with nanomaterials are promising sensing tools as this showed high sensitivity, good accuracy with precision as well as selectivity. In comparison to chromatographic methods, the main advantages of electrochemical methods are its cheaper instrumentation, lower detection limit and minimal or no sample preparation.

scholarly journals ’n Prakties-teologiese ondersoek na die kerklike jaar in die prediking van die Nederduitse Gereformeerde Kerk

2005 ◽  
Vol 61 (4) ◽  
Author(s):  
G. Bothma
Keyword(s):  
Dutch Reformed ◽  
Nederduitse Gereformeerde Kerk ◽  
Christian Worship ◽  
Practical Theological ◽  
The Church ◽  
Valuable Role

A practical-theological investigation into the role of the church year in the liturgy and preaching of the Dutch Reformed ChurchThe aim of this article is to discuss the valuable role the church year can play in liturgy and preaching and the service and activities of the church. The article demonstrates that the rediscovery of the church year is one of the most remarkable aspects of the twentiethcentury reform and renewal of Christian worship. Within a context of poverty and continuing change, the church year – if valued positively and if accentuated in the preaching – could lead to the celebration of God.

Reductant substrate for glutathione peroxidase modulates oxidant inhibition of Ca2+ signaling in endothelial cells

1995 ◽  
Vol 268 (1) ◽  
pp. H278-H287 ◽  
Author(s):  
S. J. Elliott ◽  
T. N. Doan ◽  
P. N. Henschke
Keyword(s):  
Endothelial Cells ◽  
Glutathione Peroxidase ◽  
Oxidant Stress ◽  
Glutathione S Transferase ◽  
Glutathione Redox Cycle ◽  
Tert Butyl Hydroperoxide ◽  
Intracellular Glutathione ◽  
Glutamylcysteine Synthetase ◽  
Dependent Signal

Oxidant stress mediated by tert-butyl hydroperoxide (t-BOOH) inhibits agonist-stimulated Ca2+ entry and internal store Ca2+ release in cultured endothelial cells. The role of intracellular glutathione in modulating the effects of oxidant stress on Ca2+ signaling was determined in cells preincubated with buthionine-[S,R]-sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, or 1-chloro-2,4-dinitrobenzene (CDNB), a cosubstrate for glutathione-S-transferase. BSO and CDNB decreased endothelial cell glutathione content by 85 and 97%, respectively (control glutathione, 21.5 +/- 2.3 nmol/mg protein). Each agent accelerated the time-dependent effects of t-BOOH on Ca2+ signaling in fura 2-loaded cells and potentiated the inhibition of bradykinin-stimulated 45Ca2+ efflux induced by t-BOOH. These results indicate that decreased availability of reduced glutathione, the primary cosubstrate for glutathione peroxidase, potentiates the effect of hydroperoxide oxidant stress on receptor-operated Ca2+ entry across the plasmalemma and Ca2+ release from internal stores. The present findings suggest that intracellular glutathione availability and/or glutathione redox cycle activity are critically important modulators of oxidant inhibition of Ca(2+)-dependent signal transduction.

THE ROLE OF GLUTATHIONE PEROXIDASE 1 CODON 198 (GPX1 Pro198Leu) POLYMORPHISM IN PATIENTS WITH PROSTATE CANCER

2008 ◽  
Vol 179 (4S) ◽  
pp. 459-459
Author(s):  
Canan Kucukgergin ◽  
Oner Sanli ◽  
Tzevat Tefik ◽  
Ismet Nane ◽  
Sule Seckin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Glutathione Peroxidase ◽  
Glutathione Peroxidase 1

scholarly journals Environmental Surveillance through Next-Generation Sequencing to Unveil the Diversity of Human Enteroviruses beyond the Reported Clinical Cases

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 120
Author(s):  
Andrés Lizasoain ◽  
Daiana Mir ◽  
Gisella Masachessi ◽  
Adrián Farías ◽  
Nélida Rodríguez-Osorio ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Next Generation ◽  
Echovirus 30 ◽  
Coxsackievirus B4 ◽  
Important Region ◽  
Enterovirus A71 ◽  
Wastewater Samples ◽  
Valuable Role ◽  
Generation Sequencing

The knowledge about circulation of Human Enteroviruses (EVs) obtained through medical diagnosis in Argentina is scarce. Wastewater samples monthly collected in Córdoba, Argentina during 2011–2012, and then in 2017–2018 were retrospectively studied to assess the diversity of EVs in the community. Partial VP1 gene was amplified by PCR from wastewater concentrates, and amplicons were subject of next-generation sequencing and genetic analyses. There were 41 EVs detected, from which ~50% had not been previously reported in Argentina. Most of the characterized EVs (60%) were detected at both sampling periods, with similar values of intratype nucleotide diversity. Exceptions were enterovirus A71, coxsackievirus B4, echovirus 14, and echovirus 30, which diversified in 2017–2018. There was a predominance of types from EV-C in 2017–2018, evidencing a common circulation of these types throughout the year in the community. Interestingly, high genetic similarity was evidenced among environmental strains of echovirus 30 circulating in 2011–2012 and co-temporal isolates obtained from patients suffering aseptic meningitis in different locations of Argentina. This study provides an updated insight about EVs circulating in an important region of South America, and suggests a valuable role of wastewater-based epidemiology in predicting outbreaks before the onset of cases in the community.

scholarly journals Increasing Referral and Participation Rates to Outpatient Cardiac Rehabilitation: The Valuable Role of Healthcare Professionals in the Inpatient and Home Health Settings

Circulation ◽  
2012 ◽  
Vol 125 (10) ◽  
pp. 1321-1329 ◽  
Author(s):  
Ross Arena ◽  
Mark Williams ◽  
Daniel E. Forman ◽  
Lawrence P. Cahalin ◽  
Lola Coke ◽  
...  
Keyword(s):  
Cardiac Rehabilitation ◽  
Healthcare Professionals ◽  
Home Health ◽  
Participation Rates ◽  
Valuable Role

The Molecular Diversity Scope of Oxindole derivatives in Organic Synthesis.

2021 ◽  
Vol 25 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Fatemeh Javadi ◽  
Fatemeh Mohajer
Keyword(s):  
Organic Chemistry ◽  
Organic Synthesis ◽  
Molecular Diversity ◽  
Biological Properties ◽  
Organic Reactions ◽  
Microbial Properties ◽  
Anti Cancer

: The role of oxindole derivatives is discussed as starting materials in diverse organic reactions including two and more components between the years 2014 until 2020. Oxindoles are famous because of their biological properties for instance chromanone-fused polycyclic pyrrolidinyl-dispirooxindoles, functionalized polycyclic spiro-fused carbocyclicoxindole, and 3,3-disubstituted oxindoles have anti-cancer, anti-tumor, and anti-microbial properties, respectively. Therefore, various methods for synthesizing the oxindole structures have received more attention in organic chemistry.

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