scholarly journals Screening of coformers for quercetin cocrystals through mechanochemical methods

2022 ◽  
Vol 47 (1) ◽  
pp. 64-75
Author(s):  
Fayene Zeferino Ribeiro de Souza ◽  
Amanda Cosmo de Almeida ◽  
Patr�cia Osorio Ferreira ◽  
Richard Perosa Fernandes ◽  
Fl�vio Junior Caires
Keyword(s):  
Fourier Transform ◽  
Powder Diffraction ◽  
Stoichiometric Ratio ◽  
Pharmacological Properties ◽  
X Ray ◽  
Thermoanalytical Techniques ◽  
Thermal Data ◽  
Interesting Approach ◽  
Low Solubility ◽  
Pyrazinoic Acid

Quercetin (QUE) is a nutraceutical compound that exhibits pharmacological properties such as antioxidant, cardioprotective, anti-ulcer, and anti-inflammatory effects. Although QUE is well-known for its benefits, its efficacy is limited due to low solubility. Thus, cocrystallization acts as an interesting approach to improve the solubility�among other properties�of this compound. In this work, cocrystallization screening was applied through neat grinding (NG) and liquid-assisted grinding (LAG), in which QUE and four cocrystal formers (benzamide,�picolinamide, isonicotinamide, and pyrazinoic acid) were tested. The precursors and QUE-coformer systems were characterized using thermoanalytical techniques (TG-DTA), X-ray powder diffraction (XRPD), and Fourier transform infrared (FTIR) spectroscopy. The results showed the formation of QUE cocrystals with picolinamide and isonicotinamide coformers in a 1:1 stoichiometric ratio. Furthermore, although coformers are isomers, spectroscopic and thermal data suggest that the supramolecular synthons involved in cocrystallization are different.

Structural and microstructural characterization of bioapatites and synthetic hydroxyapatite using X-ray powder diffraction and Fourier transform infrared techniques

2006 ◽  
Vol 39 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Santu Chakraborty ◽  
Sandip Bag ◽  
Subrata Pal ◽  
Alok K. Mukherjee
Keyword(s):  
Fourier Transform ◽  
Powder Diffraction ◽  
Microstructural Characterization ◽  
Fourier Transform Infrared ◽  
Calcium Hydroxyapatite ◽  
Partial Replacement ◽  
Human Teeth ◽  
X Ray ◽  
Rabbit Bone ◽  
Synthetic Hydroxyapatite

Bioapatite, the main constituent of mineralized tissue in mammalian bones and teeth, is similar in structure and composition to calcium hydroxyapatite (HAP), Ca10(PO4)6(OH)2. The crystallographic analyses of four bioapatites of human-, goat- and rabbit-bone and human-teeth origin, and one synthetic HAP preparedviamicrowave irradiation, have been carried out using X-ray powder diffraction techniques. Fourier transform infrared spectra and Rietveld analyses indicate partial replacement of PO43−ions by CO32−ions in all bioapatites.

Improved Crystallinity of Zinc Sulfide Nanoparticles in Aqueous Environment

2005 ◽  
Vol 879 ◽  
Author(s):  
Navendu Goswami ◽  
P. Sen
Keyword(s):  
Particle Size ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Zinc Sulfide ◽  
Structural Transformation ◽  
Powder Diffraction ◽  
Aqueous Environment ◽  
X Ray ◽  
Zinc Sulfide Nanoparticles

AbstractZinc sulfide nanoparticles, prepared employing a non-equilibrium route, are investigated for surface related effects. Water has been shown to induce a structural transformation in nanoparticles prepared this way, which is not related to their particle size. Employing Fourier transform infrared spectroscopy and x-ray powder diffraction, we show here the importance of S-H interaction in the buildup to the final ZnS structure of these nanoparticles. These particles hold promise as water sensors.

BaCeN2, ein Bariumnitridocerat(IV) mit einer Struktur vom anti-TiP-Typ / BaCeN2, a Bariumnitridocerate(IV ) with a Structure of the anti-TiP Type

1994 ◽  
Vol 49 (9) ◽  
pp. 1169-1174 ◽  
Author(s):  
Oliver Seeger ◽  
Joachim Strähle
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Neutron Powder Diffraction ◽  
Type Structure ◽  
Stoichiometric Ratio ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Neutron Powder Diffraction Data ◽  
Moisture Sensitive ◽  
Trigonal Prismatic

Reaction of Ba3N2 with CeN in the stoichiometric ratio 1:3 at 850 °C under an atmosphere of N2 followed by quenching yields air and moisture sensitive BaCeN2. The product crystallizes isotypically to β-RbScO2 with the anti-TiP type structure in the hexagonal space group P63/mmc with a = 365.06(2), c = 1266.03(3) pm, Z = 2. The structure was determined using X-ray and neutron powder diffraction data. In the structure the Ba2+ cations occupy trigonal prismatic holes with distances Ba-N = 288(1) pm while the Ce atoms are in octahedral positions with distances C e -N = 242.4(8) pm

scholarly journals Crystal structure of Pigment Red 254 from X-ray powder diffraction data

2017 ◽  
Vol 73 (4) ◽  
pp. 507-510 ◽  
Author(s):  
Svetlana N. Ivashevskaya
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Pyrrole Ring ◽  
Inversion Center ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Unique Part ◽  
Low Solubility ◽  
Annealing Method

The crystal structure of Pigment Red 254 [P.R. 254, C18H10Cl2N2O2; systematic name: 3,6-bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione] was solved from laboratory X-ray powder diffraction data using the simulated annealing method followed by Rietveld refinement because the very low solubility of the pigment in all solvents impedes the growth of single crystals suitable for X-ray analysis. The molecule lies across an inversion center. The dihedral angle between the benzene ring and the pyrrole ring in the unique part of the molecule is 11.1 (2)°. In the crystal, molecules are linkedviaN—H...O hydrogen bonds, forming chains along [110] incorporatingR22(8) rings.

A study of the reaction of copper(II) ions in hydrated y zeolite with sodium 8-mercaptoquinolinate and 8-hydroxyquinolinate

1985 ◽  
Vol 50 (8) ◽  
pp. 1828-1833
Author(s):  
Gustáv Plesch
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Powder Diffraction ◽  
Electronic Absorption ◽  
Support Surface ◽  
Y Zeolite ◽  
X Ray ◽  
Complex Crystals ◽  
Low Solubility ◽  
Scanning Electron

The reaction of Cu2+ ions from Y zeolite cavities with sodium 8-mercaptoquinolinate (tox) or 8-hydroxyquinolinate (ox) was studied in aqueous solutions by EPR and electronic absorption spectroscopy, X-ray powder diffraction measurements, and scanning electron microscopy. The Cu2+ ions migrate towards the support surface to form [Cu(tox)2] or [Cu(ox)2(H2O)2] complex crystals. Owing to the low solubility of the complex, grains of the [Cu(tox)2] crystallites gradually grow over the support surface. Better soluble than [Cu(tox)2], the [Cu(ox)2(H2O)2] complex crystallizes separately from the carrier in the form of long needles.

Crystal structure determination from powder diffraction data of the coumarin vanillin chalcone

2014 ◽  
Vol 29 (4) ◽  
pp. 361-365 ◽  
Author(s):  
Afef Ghouili ◽  
Jan Rohlicek ◽  
Taïcir Ben Ayed ◽  
Rached Ben Hassen
Keyword(s):  
Crystal Structure ◽  
Fourier Transform ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Schmidt Reaction ◽  
X Ray ◽  
Cell Parameters ◽  
C Nmr

4-hydroxy-3-methoxyphenyl-4-hydroxycoumarin chalcone (C19H14O6) was synthesized by the Claisen–Schmidt reaction with the condensation of 3-acetyl-4-hydroxycoumarin with 4-hydroxy-3-methoxybenzaldehyde (vanillin). The new compound was characterized by Fourier transform infrared microscopy, UV–vis 1H, and 13C NMR spectroscopy and its crystal structure was ab initio determined from laboratory X-ray powder diffraction data. The crystal structure is monoclinic with unit-cell parameters a = 14.3181(4), b = 8.040 71(9), c = 13.5524(3), β = 100.3559(13)°, V = 1534.84(6) Å3, and space group P21/c.

Study of Preprocessing Methods for the Determination of Crystalline Phases in Binary Mixtures of Drug Substances by X-ray Powder Diffraction and Multivariate Calibration

2000 ◽  
Vol 54 (8) ◽  
pp. 1222-1230 ◽  
Author(s):  
Tom Artursson ◽  
Anders Hagman ◽  
Seth Björk ◽  
Johan Trygg ◽  
Svante Wold ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Wavelet Transform ◽  
Powder Diffraction ◽  
Wavelet Transforms ◽  
Multivariate Calibration ◽  
Discrete Wavelet ◽  
Data Set ◽  
X Ray ◽  
Drug Substances ◽  
Orthogonal Signal Correction

In this paper, various preprocessing methods were tested on data generated by X-ray powder diffraction (XRPD) in order to enhance the partial least-squares (PLS) regression modeling performance. The preprocessing methods examined were 22 different discrete wavelet transforms, Fourier transform, Savitzky–Golay, orthogonal signal correction (OSC), and combinations of wavelet transform and OSC, and Fourier transform and OSC. Root mean square error of prediction (RMSEP) of an independent test set was used to measure the performance of the various preprocessing methods. The best PLS model was obtained with a wavelet transform (Symmlet 8), which at the same time compressed the data set by a factor of 9.5. With the use of wavelet and X-ray powder diffraction, concentrations of less than 10% of one crystal from could be detected in a binary mixture. The linear range was found to be in the range 10–70% of the crystalline form of phenacetin, although semiquantitative work could be carried out down to a level of approximately 2%. Furthermore, the wavelet-pretreated models were able to handle admixtures and deliberately added noise.

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