scholarly journals Identification, Quantification, and Method Validation of Anthocyanins

2021 ◽  
Vol 5 (1) ◽  
pp. 43
Author(s):  
Paula Garcia-Oliveira ◽  
Antia G. Pereira ◽  
Maria Fraga-Corral ◽  
Catarina Lourenço-Lopes ◽  
Franklin Chamorro ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Biological Activities ◽  
Value Added ◽  
Current Data ◽  
Validation Process ◽  
Validation Parameters ◽  
Analytical Technology ◽  
Positive Results ◽  
Identification And Quantification

Nowadays, anthocyanins have gained scientific and industrial attention due to their biological activities and coloring properties. In this regard, anthocyanins have been proposed for use in the development of new nutraceutical foods to replace synthetic additives as well as to be value-added ingredients. The aim of this study was to evaluate current data on identification and quantification techniques and the validation process of such methods. Our results showed that anthocyanins have been identified by different methods, including nuclear magnetic resonance and chromatography-based techniques. Although problems have been described in this validation, most of the reports showed positive results on the validation parameters, suggesting that the current analytical technology offers a satisfactory identification and quantification of anthocyanins.

An Application of the Polarizable Continnum Model for Obtaining Chalcones Magnetic Properties

2020 ◽  
Vol 12 (7) ◽  
pp. 939-950
Author(s):  
Agnes Jalowitzki Silva ◽  
Thaís F. Giacomello ◽  
Gunar V. da S. Mota ◽  
Antônio M. de J. Chaves ◽  
Fabio L. P. Costa
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Population Distribution ◽  
Chemical Shifts ◽  
Biological Activities ◽  
Geometry Optimization ◽  
Analytical Techniques ◽  
Spectroscopic Techniques ◽  
Nuclear Magnetic

Chalcones exhibit a wide variety of beneficial biological activities. In addition, these compounds include the prevention of diseases related to oxidative stress. The structural characterization of these molecules by means of analytical techniques can become a difficult task due to the complexity of some structures. However, cases of erroneously established natural product structure review are still found in the literature despite recent advances in spectroscopic techniques. Therefore, it is necessary to develop quantum calculation protocols that can aid in the correct structural ascertainment of these compounds. Thus, in this work, we tried to develop a parameterized protocol for calculations of chemical shift of carbon-13 nuclear magnetic resonance, in order to ensure a correct structural determination of polyphenols, with a focus on chalcones. For this, a series of molecules belonging to this class, with complex and varied structural skeletons, reliably elucidated in the literature, was selected and subjected to stochastic conformational searches using the Monte Carlo method and the Merk molecular force filed. The lower energy conformations of each molecule were selected for the geometry optimization step, performed at the mPW1PW91/6-31G(d) level. The chemical shifts of carbon-13 were calculated at the same level of theory, taking into account the population distribution of Boltzmann. The calculations were affected in both liquid phases, using the Polarizable Continuous Model as an implicit solvation model. The results show that the level of theory applied in the liquid phase allows a good reproduction of the experimental data. The application of the scaling factor allows the cancellation of systematic errors, which means that the values of scaled chemical shift are closer to the experimental ones. Thus, the parameterized protocol proved to be an important tool for the structural elucidation of polyphenols by calculations of carbon-13 nuclear magnetic resonance chemical shifts.

Advanced spectroscopic detectors for identification and quantification: Nuclear magnetic resonance

2017 ◽  
pp. 479-514 ◽  
Author(s):  
Nadine Bohni ◽  
Karine Ndjoko-Ioset ◽  
Arthur S. Edison ◽  
Jean-Luc Wolfender
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Identification And Quantification ◽  
Nuclear Magnetic

scholarly journals 3-(Substituted Aryl)-1-benzofuranyl-2-propenones: Antimicrobial Properties of Some Chalcones-Type Compounds and their 2-Pyrazoline Derivatives

2011 ◽  
Vol 8 (4) ◽  
pp. 1574-1581 ◽  
Author(s):  
Demet Coskun ◽  
Misir Ahmedzade ◽  
Sevda Kirbag
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Infrared Spectroscopy ◽  
Melting Point ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Biological Activities ◽  
Antimicrobial Properties ◽  
Resonance Spectroscopy ◽  
Melting Point Determination ◽  
Point Determination

2-Acetylbenzofuran on condensation with furan-2-carboxaldehyde and pyrrole-2-carboxaldehyde in methanolic KOH solution yielded the corresponding benzofuran chalcones. These two compounds and nine benzofuran chalcones were synthesized before, were further reacted with hydrazine hydrate in ethanol which led to the formation of 2-pyrazoline derivatives. All the synthesized compounds were characterized by elemental analysis, melting point determination, infrared spectroscopy and nuclear magnetic resonance spectroscopy. Nine chalcone-type compounds and eleven 2-pyrazolines were evaluated for their biological activities against the six bacteria and the three yeast and it was seen that thirteen compounds showed activity. Four of them are chalcone-type compounds showed more or less activity.

scholarly journals Ferrocenyl imidazolo[2,1-b]-1,3,4-thiadiazoles: A microwave-assisted catalyst-free synthesis, characterization, and biological activities

2020 ◽  
pp. 174751982093990
Author(s):  
Yuting Liu ◽  
Lan Yang ◽  
Dawei Yin
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Biological Activities ◽  
Low Cost ◽  
Microwave Assisted ◽  
Catalyst Free ◽  
Alkyl Groups ◽  
13C Nuclear Magnetic Resonance ◽  
1H Nuclear Magnetic Resonance ◽  
Nuclear Magnetic

Ferrocenyl imidazolo[2,1- b]-1,3,4-thiadiazoles are synthesized using 2-amino-5-substituted-1,3,4-thiadiazole and α-bromoacetyl ferrocene as substrates under microwave-assisted and catalyst-free conditions. The structures are characterized by infrared, 1H nuclear magnetic resonance, 13C nuclear magnetic resonance, mass spectrometry, and elemental analysis. Compared with conventional methods, the present protocol has the advantages of being rapid, efficient, environmentally friendly, and low cost. The results of biological activity studies showed that the products displayed better activities than those of 2-amino-5-substituted-1,3,4-thiadiazole. The biological activities of compounds in which R = phenyl were better than those with alkyl groups. Compounds with electron-withdrawing groups on the aryl moiety showed increased biological activities.

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