scholarly journals Relation between Crystal Structures of Precursors and Final Products: Example of Vitamin D Intermediates

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1802
Author(s):  
Monika Wanat ◽  
Maura Malinska ◽  
Andrzej Kutner ◽  
Krzysztof Woźniak
Keyword(s):  
Vitamin D ◽  
Crystal Structures ◽  
Theoretical Calculations ◽  
Geometrical Parameters ◽  
Space Groups ◽  
Vitamin D Analogues ◽  
Vitamin D Analog ◽  
Exocyclic Methylene ◽  
Solid Form ◽  
Methylene Group

In this paper, we proved that the solid-state structure of vitamin D analog is well represented by the structures of its structural fragments. This is important in predicting the biological activity of vitamin D analogs that are not available in the solid form. The previously published crystal structure of advanced vitamin D intermediate provided additional insights into vitamin D properties. A similar analysis based on simple vitamin D intermediate analogues showed that precursors crystallized in the space groups typical for vitamins D; geometrical parameters were related to the corresponding parameters in the vitamin D analogues; and crystal structures of the basic intermediates and their final products contained similar intermolecular interactions, essential for the infinite hydrogen bond motif observed in the vitamin D analogues. The energy of these interactions is related as shown by theoretical calculations, that is, energy frameworks analysis. Moreover, analysis of the hydrogen bonds motifs revealed a relation between these motifs and the absolute configuration of basic intermediates as well as the space orientation of the exocyclic methylene group in the final structures.

Supramolecular assemblies of organotin(iv)–diphosphoryl adducts: insights from X-rays and DFT

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98610-98617 ◽  
Author(s):  
Khodayar Gholivand ◽  
Akram Gholami ◽  
Kurt J. Schenk ◽  
Mehdi D. Esrafili ◽  
Kaveh Farshadfar
Keyword(s):  
Crystal Structures ◽  
Theoretical Calculations ◽  
Supramolecular Assemblies ◽  
Geometrical Parameters ◽  
X Rays ◽  
Hirshfeld Analysis

The influence of tin-bonded substituents on the organization of the crystal structures and also coordination interactions were discussed using geometrical parameters, Hirshfeld analysis and theoretical calculations.

190: BXL-628, a Vitamin D Analog, Decreases RHOA/ROK Signalling in Rat and Human Bladder

2006 ◽  
Vol 175 (4S) ◽  
pp. 62-62
Author(s):  
Annamaria Morelli ◽  
Sandra Filippi ◽  
Rosa Mancina ◽  
Linda Vignozzi ◽  
Gabriella B. Vannelli ◽  
...  
Keyword(s):  
Vitamin D ◽  
Human Bladder ◽  
Vitamin D Analog

Association between calcitriol and paricalcitol with oxidative stress in patients with hemodialysis

2020 ◽  
pp. 1-8
Author(s):  
Hasan Haci Yeter ◽  
Berfu Korucu ◽  
Elif Burcu Bali ◽  
Ulver Derici
Keyword(s):  
Oxidative Stress ◽  
Vitamin D ◽  
Antioxidant Status ◽  
Total Antioxidant Status ◽  
Stress Index ◽  
Total Oxidant Status ◽  
Vitamin D Analog ◽  
Total Antioxidant ◽  
Oxidant Status ◽  
And Oxidative Stress

Abstract. Background: The pathophysiological basis of chronic kidney disease and its complications, including cardiovascular disease, are associated with chronic inflammation and oxidative stress. We investigated the effects of active vitamin D (calcitriol) and synthetic vitamin D analog (paricalcitol) on oxidative stress in hemodialysis patients. Methods: This cross-sectional study was composed of 83 patients with a minimum hemodialysis vintage of one year. Patients with a history of any infection, malignancy, and chronic inflammatory disease were excluded. Oxidative markers (total oxidant and antioxidant status) and inflammation markers (C-reactive protein and interleukin-6) were analyzed. Results: A total of 47% (39/83) patients were using active or analog vitamin D. Total antioxidant status was significantly higher in patients with using active or analog vitamin D than those who did not use (p = 0.006). Whereas, total oxidant status and oxidative stress index were significantly higher in patients with not using vitamin D when compared with the patients who were using vitamin D preparation (p = 0.005 and p = 0.004, respectively). On the other hand, total antioxidant status, total oxidant status, and oxidative stress index were similar between patients who used active vitamin D or vitamin D analog (p = 0.6; p = 0.4 and p = 0.7, respectively). Conclusion: The use of active or selective vitamin D analog in these patients decreases total oxidant status and increases total antioxidant status. Also, paricalcitol is as effective as calcitriol in decreasing total oxidant status and increasing total antioxidant status in patients with chronic kidney disease.

scholarly journals Pixeled metasurface for multiwavelength detection of vitamin D

Nanophotonics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 3921-3930
Author(s):  
Valentina Di Meo ◽  
Alessio Crescitelli ◽  
Massimo Moccia ◽  
Annamaria Sandomenico ◽  
Angela M. Cusano ◽  
...  
Keyword(s):  
Vitamin D ◽  
Small Molecules ◽  
Vibrational Excitation ◽  
Localized Surface Plasmon ◽  
Large Field ◽  
Geometrical Parameters ◽  
Single Chip ◽  
Large Area ◽  
Accurate Analysis ◽  
Hydroxyvitamin D

AbstractThe steadily increasing demand for accurate analysis of vitamin D level, via measurement of its best general marker, 25-hydroxyvitamin D (25(OH)D), pushes for the development of novel automated assays capable of working at very low concentrations. Here, we propose a plasmonic biosensor of 25(OH)D3 (calcifediol) based on surface-enhanced infrared absorption spectroscopy, which exploits the resonant coupling between plasmonic nanoantennas and vibrational excitation of small molecules. Specifically, our proposed platform features a large-area (several mm2) metasurface made of gold nanoantennas fabricated on a silicon substrate, comprising different macroregions (“pixels”) of area 500 × 500 µm2. In each pixel, the nanoantenna geometrical parameters are tuned so as to support localized surface plasmon resonances (and hence large field enhancements at the nanoscale) within different regions of the infrared spectrum. As a result, a single chip is capable of performing analysis from the region of functional groups to that of fingerprint. Two different designs are fabricated via electron beam lithography, functionalized with a correlated antibody for the detection of 25(OH)D3, and characterized via Fourier-transform infrared spectroscopy. Our experiments demonstrate the capability to detect a concentration as low as 86 pmol/L, and an amount of immobilized small molecules of 25(OH)D3 monohydrate (molecular weight: 418.65 g/mol) as low as 4.31 amol over an area of 100 × 100 µm2.

MINDO-Forces Study on Substituted Nitromethane ⇋ aci-Nitromethane Tautomerism

2005 ◽  
Vol 60 (1-2) ◽  
pp. 47-53
Author(s):  
Bareehan M. Salim ◽  
Salim M. Khalil
Keyword(s):  
Theoretical Calculations ◽  
Geometry Optimization ◽  
Heats Of Formation ◽  
Geometrical Parameters ◽  
Free Energies ◽  
Electron Densities ◽  
Isodesmic Reactions ◽  
Complete Geometry Optimization

MINDO-Forces calculations with complete geometry optimization have been performed on nitromethane, aci-nitromethane and X-substituted nitromethane and aci-nitromethane (X = F, OH, NH2, CH3, CN, CF3, NO2, CHO). It is found that nitromethane is more stable than aci-nitromethane by 9.337 kcal/mol. This agrees with theoretical calculations. Thermodynamically, substituted aci-nitro tautomers are more stable than the corresponding nitromethane, except in case of the substituent F. Geometrical parameters, heats of formation, electron densities, Gibbs free energies and isodesmic reactions are reported.

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