Noncovalent interactions in polyamine/nucleoside (or diaminocarboxylate) systems studied by potentiometric and NMR techniques

1997 ◽  
pp. 1161-1166 ◽  
Author(s):  
Lechoslaw Lomozik ◽  
Anna Gasowska ◽  
Leszek Bolewski
Keyword(s):  
Noncovalent Interactions ◽  
Nmr Techniques

NMR Techniques for the Investigation of Solvation Phenomena and Noncovalent Interactions

ChemInform ◽  
2006 ◽  
Vol 37 (23) ◽  
Author(s):  
Alessandro Bagno ◽  
Federico Rastrelli ◽  
Giacomo Saielli
Keyword(s):  
Noncovalent Interactions ◽  
Nmr Techniques

Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

1990 ◽  
Vol 48 (2) ◽  
pp. 166-167
Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet
Keyword(s):  
Energy Metabolism ◽  
Calcium Ions ◽  
Energy Production ◽  
Regulation Of Respiration ◽  
Free Calcium ◽  
Mitochondrial Matrix ◽  
Cytochemical Study ◽  
Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

Advancing the use of Voronoi–Dirichlet polyhedra to describe interactions in organic molecular crystal structures by the example of galunisertib polymorphs

CrystEngComm ◽  
2021 ◽  
Author(s):  
Viktor N. Serezhkin ◽  
Anton V. Savchenkov
Keyword(s):  
Crystal Structures ◽  
Molecular Crystal ◽  
Noncovalent Interactions ◽  
Organic Molecular Crystal ◽  
Universal Approach ◽  
Structure Properties

The universal approach for studying structure/properties relationships shows that every polymorph of galunisertib is characterized with unique noncovalent interactions.

Isolation of isoflavonoids from Amphimas pterocarpoides and structure elucidation using LC-HRMSn and NMR techniques

Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
J Tchoumtchoua ◽  
M Halabalaki ◽  
D Njamen ◽  
J Mbanya ◽  
L Skaltsounis
Keyword(s):  
Structure Elucidation ◽  
Nmr Techniques

The intermolecular anthracene-transfer in a regiospecific antipodal C60 difunctionalization

2020 ◽  
Author(s):  
Radu Talmazan ◽  
Klaus R. Liedl ◽  
Bernhard Kräutler ◽  
Maren Podewitz
Keyword(s):  
Noncovalent Interactions ◽  
Interaction Model ◽  
Alder Reaction ◽  
Diels Alder ◽  
Stacking Interactions ◽  
Pi Stacking ◽  
Diels Alder Reaction ◽  
Double Decker ◽  
Anthracene Molecule ◽  
New Strategies

We analyze the mechanism of the topochemically controlled difunctionalization of C60 and anthracene, where an anthracene molecule is transferred from one C60 monoadduct to another one under exclusive formation of equal amounts of C60 and the difficult to make antipodal C60 bisadduct. Our herein disclosed dispersion corrected DFT studies show the anthracene transfer to take place in a synchronous retro Diels-Alder/Diels-Alder reaction: an anthracene molecule dissociates from one fullerene under formation of an intermediate, while already undergoing stabilizing interactions with both neighboring fullerenes, facilitating the reaction kinetically. In the intermediate, a planar anthracene molecule is sandwiched between two neighboring fullerenes and forms equally strong "double-decker" type pi-pi stacking interactions with both of these fullerenes. Analysis with the distorsion interaction model shows that the anthracene unit of the intermediate is almost planar with minimal distorsions. This analysis sheds light on the existence of noncovalent interactions engaging both faces of a planar polyunsaturated ring and two convex fullerene surfaces in an unprecedented 'inverted sandwich' structure. Hence, it sheds light on new strategies to design functional fullerene based materials.<br>

The X40x10 Halogen Bonding Benchmark Revisited: Surprising Importance of (n-1)d Subvalence Correlation

2017 ◽  
Author(s):  
Manoj Kumar Kesharwani ◽  
Nitai Sylvetsky ◽  
Debashree Manna ◽  
Jan M.L. Martin
Keyword(s):  
Dissociation Energy ◽  
Noncovalent Interactions ◽  
Halogen Bonding ◽  
Coupled Cluster ◽  
Dissociation Energies ◽  
Iodine Species ◽  
Explicitly Correlated ◽  
High Level ◽  
Cluster Methods ◽  
Small Separation

<p>We have re-evaluated the X40x10 benchmark for halogen bonding using conventional and explicitly correlated coupled cluster methods. For the aromatic dimers at small separation, improved CCSD(T)–MP2 “high-level corrections” (HLCs) cause substantial reductions in the dissociation energy. For the bromine and iodine species, (n-1)d subvalence correlation increases dissociation energies, and turns out to be more important for noncovalent interactions than is generally realized. As in previous studies, we find that the most efficient way to obtain HLCs is to combine (T) from conventional CCSD(T) calculations with explicitly correlated CCSD-F12–MP2-F12 differences.</p>

Isolation of New Glycosides from Anemarrhena Asphodeloides Rhizome and Screening of their Anticancer Activity

2019 ◽  
Vol 16 (6) ◽  
pp. 474-477 ◽  
Author(s):  
Pham Van Khang ◽  
Nguyen Thi Hien Lan ◽  
Le Quang Truong ◽  
Mai Thi Minh Chau ◽  
Mai Xuan Truong ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Spectral Data ◽  
Cell Lines ◽  
Cancer Cell ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Ic50 Values ◽  
Nmr Techniques ◽  
Inhibitory Activities ◽  
Anemarrhena Asphodeloides

In this report, two new steroidal glycosides were isolated and determined from n-butanol fraction of A.asphodeloides. The structures were confirmed in comparison with the spectral data of known compounds by using different spectroscopic analysis approaches including 1D & 2D-NMR techniques and HRMS. The anti-proliferation screening against cancer cell lines A549 and HeLa indicated that compound 1 exhibited good inhibitory activities with IC50 values of 0.79 and 0.55 &#181;g/mL, respectively.

Nuclear Magnetic Resonance Spectroscopic Behaviour of Some Selective Natural Flavonoids: A Look Through

2020 ◽  
Vol 17 (2) ◽  
pp. 185-196
Author(s):  
Shyamal K. Jash ◽  
Dilip Gorai ◽  
Lalan C. Mandal ◽  
Rajiv Roy
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Natural Products ◽  
Magnetic Resonance ◽  
Hard Core ◽  
2D Nmr ◽  
Vital Role ◽  
Spectral Technique ◽  
Nmr Techniques ◽  
Significant Class ◽  
Nuclear Magnetic

Flavonoids are considered as a significant class of compounds among the natural products, exhibiting a variety of structural skeletons as well as multidirectional biological potentials. In structural elucidations of natural products, Nuclear Magnetic Resonance (NMR) spectroscopy has been playing a vital role; the technique is one of the sharpest tools in the hands of natural products chemists. The present resume deals with hard-core applications of such spectral technique, particularly in structural elucidation of flavonoids; different NMR techniques including 1H-NMR, 13C-NMR, and 2D-NMR [viz. 1H-1H COSY, COLOC, HMBC, HMQC] are described in detail.

Recent Developments in Azole Compounds as Antitubercular Agent

2019 ◽  
Vol 16 (3) ◽  
pp. 290-306
Author(s):  
Rina Das ◽  
Gyati S. Asthana ◽  
Krishan A. Suri ◽  
Dinesh Mehta ◽  
Abhay Asthana
Keyword(s):  
Therapeutic Agent ◽  
Current Problem ◽  
Noncovalent Interactions ◽  
Drug Resistant ◽  
Antitubercular Drugs ◽  
Chemistry Research ◽  
Improper Use ◽  
Recent Developments ◽  
Important Direction ◽  
Tuberculosis Therapy

Tuberculosis (TB) is a global health disaster and is a wide-reaching hitch. The improper use of antibiotics in chemotherapy of TB patients led to the current problem of tuberculosis therapy which gives rise to Multi-Drug Resistant (MDR) strains. Nitrogen heterocycles including azole compounds are an important class of therapeutic agent with electron-rich property. Azole-based derivatives easily bind with the enzymes and receptors in organisms through noncovalent interactions, thereby possessing various applications in medicinal chemistry. Research on azoles derivatives have been expansively carried out and have become one of the extremely active area in recent years and the progress is quite rapid. A genuine attempt to review chemistry of azoles and to describe various azole-based compounds synthesized in the last two decades having promising antitubercular potential is described in the present article. It is hopeful that azole compounds may continue to serve as an important direction for the exploitation of azole-based antitubercular drugs with better curative effect, lower toxicity, less side effects, especially fewer resistances and so on.

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